diff --git a/.dart_tool/package_config.json b/.dart_tool/package_config.json
index 429b915..70cfbb2 100644
--- a/.dart_tool/package_config.json
+++ b/.dart_tool/package_config.json
@@ -56,6 +56,11 @@
       "packageUri": ".nonexisting/"
     },
     {
+      "name": "_fe_analyzer_shared_why_not_promoted",
+      "rootUri": "../pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted",
+      "packageUri": ".nonexisting/"
+    },
+    {
       "name": "_js_interop_checks",
       "rootUri": "../pkg/_js_interop_checks",
       "packageUri": "lib/",
diff --git a/DEPS b/DEPS
index 6ba4e67..d1a47cc 100644
--- a/DEPS
+++ b/DEPS
@@ -39,7 +39,7 @@
 
   # Checked-in SDK version. The checked-in SDK is a Dart SDK distribution in a
   # cipd package used to run Dart scripts in the build and test infrastructure.
-  "sdk_tag": "version:2.12.0-133.2.beta",
+  "sdk_tag": "version:2.12.0-259.8.beta",
 
   # co19 is a cipd package. Use update.sh in tests/co19[_2] to update these
   # hashes. It requires access to the dart-build-access group, which EngProd
diff --git a/pkg/_fe_analyzer_shared/analysis_options_no_lints.yaml b/pkg/_fe_analyzer_shared/analysis_options_no_lints.yaml
index bba3f74..467f323 100644
--- a/pkg/_fe_analyzer_shared/analysis_options_no_lints.yaml
+++ b/pkg/_fe_analyzer_shared/analysis_options_no_lints.yaml
@@ -15,4 +15,5 @@
     - test/flow_analysis/nullability/data/**
     - test/flow_analysis/reachability/data/**
     - test/flow_analysis/type_promotion/data/**
+    - test/flow_analysis/why_not_promoted/data/**
     - test/inheritance/data/**
diff --git a/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart b/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart
index 6809bbc..327b003 100644
--- a/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/flow_analysis/flow_analysis.dart
@@ -307,6 +307,61 @@
       '_declared=$_declared)';
 }
 
+/// Non-promotion reason describing the situation where a variable was not
+/// promoted due to an explicit write to the variable appearing somewhere in the
+/// source code.
+class DemoteViaExplicitWrite<Variable extends Object, Expression extends Object>
+    extends NonPromotionReason {
+  /// The local variable that was not promoted.
+  final Variable variable;
+
+  /// The expression that wrote to the variable; this corresponds to an
+  /// expression that was passed to [FlowAnalysis.write].
+  final Expression writeExpression;
+
+  DemoteViaExplicitWrite(this.variable, this.writeExpression);
+
+  @override
+  String get shortName => 'explicitWrite';
+
+  @override
+  R accept<R, Node extends Object, Expression extends Object,
+              Variable extends Object>(
+          NonPromotionReasonVisitor<R, Node, Expression, Variable> visitor) =>
+      visitor.visitDemoteViaExplicitWrite(
+          this as DemoteViaExplicitWrite<Variable, Expression>);
+
+  @override
+  String toString() => 'DemoteViaExplicitWrite($writeExpression)';
+}
+
+/// Non-promotion reason describing the situation where a variable was not
+/// promoted due to the variable appearing before the word `in` in a "for each"
+/// statement or a "for each" collection element.
+class DemoteViaForEachVariableWrite<Variable extends Object,
+    Node extends Object> extends NonPromotionReason {
+  /// The local variable that was not promoted.
+  final Variable variable;
+
+  /// The "for each" statement or collection element that wrote to the variable.
+  final Node node;
+
+  DemoteViaForEachVariableWrite(this.variable, this.node);
+
+  @override
+  String get shortName => 'explicitWrite';
+
+  @override
+  R accept<R, Node extends Object, Expression extends Object,
+              Variable extends Object>(
+          NonPromotionReasonVisitor<R, Node, Expression, Variable> visitor) =>
+      visitor.visitDemoteViaForEachVariableWrite(
+          this as DemoteViaForEachVariableWrite<Variable, Node>);
+
+  @override
+  String toString() => 'DemoteViaForEachVariableWrite($node)';
+}
+
 /// A collection of flow models representing the possible outcomes of evaluating
 /// an expression that are relevant to flow analysis.
 class ExpressionInfo<Variable extends Object, Type extends Object> {
@@ -338,6 +393,24 @@
       'ExpressionInfo(after: $after, _ifTrue: $ifTrue, ifFalse: $ifFalse)';
 }
 
+/// Non-promotion reason describing the situation where an expression was not
+/// promoted due to the fact that it's a field (technically, a property get).
+class FieldNotPromoted extends NonPromotionReason {
+  /// The name of the property.
+  final String propertyName;
+
+  FieldNotPromoted(this.propertyName);
+
+  @override
+  String get shortName => 'fieldNotPromoted($propertyName)';
+
+  @override
+  R accept<R, Node extends Object, Expression extends Object,
+              Variable extends Object>(
+          NonPromotionReasonVisitor<R, Node, Expression, Variable> visitor) =>
+      visitor.visitFieldNotPromoted(this);
+}
+
 /// Implementation of flow analysis to be shared between the analyzer and the
 /// front end.
 ///
@@ -715,6 +788,13 @@
   /// is currently promoted.  Otherwise returns `null`.
   Type? promotedType(Variable variable);
 
+  /// Call this method just after visiting a property get expression.
+  /// [wholeExpression] should be the whole property get, [target] should be the
+  /// expression to the left hand side of the `.`, and [propertyName] should be
+  /// the identifier to the right hand side of the `.`.
+  void propertyGet(
+      Expression wholeExpression, Expression target, String propertyName);
+
   /// Retrieves the SSA node associated with [variable], or `null` if [variable]
   /// is not associated with an SSA node because it is write captured.  For
   /// testing only.
@@ -750,6 +830,20 @@
   /// - Call [switchStatement_end].
   void switchStatement_expressionEnd(Statement switchStatement);
 
+  /// Call this method just after visiting the expression `this` (or the
+  /// pseudo-expression `super`, in the case of the analyzer, which represents
+  /// `super.x` as a property get whose target is `super`).  [expression] should
+  /// be the `this` or `super` expression.
+  void thisOrSuper(Expression expression);
+
+  /// Call this method just after visiting an expression that represents a
+  /// property get on `this` or `super`.  This handles situations where there is
+  /// an implicit reference to `this`, or the case of the front end, where
+  /// `super.x` is represented by a single expression.  [expression] should be
+  /// the whole property get, and [propertyName] should be the name of the
+  /// property being read.
+  void thisOrSuperPropertyGet(Expression expression, String propertyName);
+
   /// Call this method just before visiting the body of a "try/catch" statement.
   ///
   /// The order of visiting a "try/catch" statement should be:
@@ -855,8 +949,23 @@
   /// Call this method after visiting a "while" statement.
   void whileStatement_end();
 
+  /// Call this method when an error occurs that may be due to a lack of type
+  /// promotion, to retrieve information about why [target] was not promoted.
+  /// This call must be made right after visiting [target].
+  ///
+  /// The returned value is a map whose keys are types that the user might have
+  /// been expecting the target to be promoted to, and whose values are reasons
+  /// why the corresponding promotion did not occur.  The caller is expected to
+  /// select which non-promotion reason to report to the user by seeing which
+  /// promotion would have prevented the error.  (For example, if an error
+  /// occurs due to the target having a nullable type, the caller should report
+  /// a non-promotion reason associated with non-promotion to a non-nullable
+  /// type).
+  Map<Type, NonPromotionReason> whyNotPromoted(Expression target);
+
   /// Register write of the given [variable] in the current state.
   /// [writtenType] should be the type of the value that was written.
+  /// [expression] should be the whole expression performing the write.
   /// [writtenExpression] should be the expression that was written, or `null`
   /// if the expression that was written is not directly represented in the
   /// source code (this happens, for example, with compound assignments and with
@@ -865,8 +974,8 @@
   /// This should also be used for the implicit write to a non-final variable in
   /// its initializer, to ensure that the type is promoted to non-nullable if
   /// necessary; in this case, [viaInitializer] should be `true`.
-  void write(
-      Variable variable, Type writtenType, Expression? writtenExpression);
+  void write(Expression expression, Variable variable, Type writtenType,
+      Expression? writtenExpression);
 
   /// Prints out a summary of the current state of flow analysis, intended for
   /// debugging use only.
@@ -1249,6 +1358,13 @@
   }
 
   @override
+  void propertyGet(
+      Expression wholeExpression, Expression target, String propertyName) {
+    _wrap('propertyGet($wholeExpression, $target, $propertyName)',
+        () => _wrapped.propertyGet(wholeExpression, target, propertyName));
+  }
+
+  @override
   SsaNode<Variable, Type>? ssaNodeForTesting(Variable variable) {
     return _wrap('ssaNodeForTesting($variable)',
         () => _wrapped.ssaNodeForTesting(variable),
@@ -1274,6 +1390,18 @@
   }
 
   @override
+  void thisOrSuper(Expression expression) {
+    return _wrap(
+        'thisOrSuper($expression)', () => _wrapped.thisOrSuper(expression));
+  }
+
+  @override
+  void thisOrSuperPropertyGet(Expression expression, String propertyName) {
+    _wrap('thisOrSuperPropertyGet($expression, $propertyName)',
+        () => _wrapped.thisOrSuperPropertyGet(expression, propertyName));
+  }
+
+  @override
   void tryCatchStatement_bodyBegin() {
     return _wrap('tryCatchStatement_bodyBegin()',
         () => _wrapped.tryCatchStatement_bodyBegin());
@@ -1350,10 +1478,19 @@
   }
 
   @override
-  void write(
-      Variable variable, Type writtenType, Expression? writtenExpression) {
-    _wrap('write($variable, $writtenType, $writtenExpression)',
-        () => _wrapped.write(variable, writtenType, writtenExpression));
+  Map<Type, NonPromotionReason> whyNotPromoted(Expression target) {
+    return _wrap(
+        'whyNotPromoted($target)', () => _wrapped.whyNotPromoted(target),
+        isQuery: true);
+  }
+
+  @override
+  void write(Expression expression, Variable variable, Type writtenType,
+      Expression? writtenExpression) {
+    _wrap(
+        'write($expression, $variable, $writtenType, $writtenExpression)',
+        () => _wrapped.write(
+            expression, variable, writtenType, writtenExpression));
   }
 
   @override
@@ -1403,10 +1540,14 @@
   /// variable is not in scope anymore.  This should not have any effect on
   /// analysis results for error-free code, because it is an error to refer to a
   /// variable that is no longer in scope.
-  final Map<Variable, VariableModel<Variable, Type> /*!*/ > variableInfo;
+  ///
+  /// `null` is allowed as a special key; it represents the pseudo-variable
+  /// `this`.  (This is needed so that we can explain why `this` is not
+  /// promoted, and why properties of `this` are not promoted).
+  final Map<Variable?, VariableModel<Variable, Type> /*!*/ > variableInfo;
 
   /// The empty map, used to [join] variables.
-  final Map<Variable, VariableModel<Variable, Type>> _emptyVariableMap = {};
+  final Map<Variable?, VariableModel<Variable, Type>> _emptyVariableMap = {};
 
   /// Creates a state object with the given [reachable] status.  All variables
   /// are assumed to be unpromoted and already assigned, so joining another
@@ -1455,13 +1596,13 @@
     Reachability newReachable = afterFinally.reachable.rebaseForward(reachable);
 
     // Consider each variable that is common to all three models.
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
-        <Variable, VariableModel<Variable, Type>>{};
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
+        <Variable?, VariableModel<Variable, Type>>{};
     bool variableInfoMatchesThis = true;
     bool variableInfoMatchesAfterFinally = true;
-    for (MapEntry<Variable, VariableModel<Variable, Type>> entry
+    for (MapEntry<Variable?, VariableModel<Variable, Type>> entry
         in variableInfo.entries) {
-      Variable variable = entry.key;
+      Variable? variable = entry.key;
       VariableModel<Variable, Type> thisModel = entry.value;
       VariableModel<Variable, Type>? beforeFinallyModel =
           beforeFinally.variableInfo[variable];
@@ -1524,7 +1665,7 @@
     // erroneously think that `newVariableInfo` matches `afterFinally`.  If so,
     // correct that.
     if (variableInfoMatchesAfterFinally) {
-      for (Variable variable in afterFinally.variableInfo.keys) {
+      for (Variable? variable in afterFinally.variableInfo.keys) {
         if (!variableInfo.containsKey(variable)) {
           variableInfoMatchesAfterFinally = false;
           break;
@@ -1567,7 +1708,7 @@
   FlowModel<Variable, Type> conservativeJoin(
       Iterable<Variable> writtenVariables,
       Iterable<Variable> capturedVariables) {
-    Map<Variable, VariableModel<Variable, Type>>? newVariableInfo;
+    Map<Variable?, VariableModel<Variable, Type>>? newVariableInfo;
 
     for (Variable variable in writtenVariables) {
       VariableModel<Variable, Type> info = infoFor(variable);
@@ -1575,7 +1716,7 @@
           info.discardPromotionsAndMarkNotUnassigned();
       if (!identical(info, newInfo)) {
         (newVariableInfo ??=
-            new Map<Variable, VariableModel<Variable, Type>>.from(
+            new Map<Variable?, VariableModel<Variable, Type>>.from(
                 variableInfo))[variable] = newInfo;
       }
     }
@@ -1630,14 +1771,14 @@
   FlowModel<Variable, Type> inheritTested(
       TypeOperations<Variable, Type> typeOperations,
       FlowModel<Variable, Type> other) {
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
-        <Variable, VariableModel<Variable, Type>>{};
-    Map<Variable, VariableModel<Variable, Type>> otherVariableInfo =
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
+        <Variable?, VariableModel<Variable, Type>>{};
+    Map<Variable?, VariableModel<Variable, Type>> otherVariableInfo =
         other.variableInfo;
     bool changed = false;
-    for (MapEntry<Variable, VariableModel<Variable, Type>> entry
+    for (MapEntry<Variable?, VariableModel<Variable, Type>> entry
         in variableInfo.entries) {
-      Variable variable = entry.key;
+      Variable? variable = entry.key;
       VariableModel<Variable, Type> variableModel = entry.value;
       VariableModel<Variable, Type>? otherVariableModel =
           otherVariableInfo[variable];
@@ -1674,13 +1815,13 @@
     Reachability newReachable = reachable.rebaseForward(base.reachable);
 
     // Consider each variable in the new base model.
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
-        <Variable, VariableModel<Variable, Type>>{};
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
+        <Variable?, VariableModel<Variable, Type>>{};
     bool variableInfoMatchesThis = true;
     bool variableInfoMatchesBase = true;
-    for (MapEntry<Variable, VariableModel<Variable, Type>> entry
+    for (MapEntry<Variable?, VariableModel<Variable, Type>> entry
         in base.variableInfo.entries) {
-      Variable variable = entry.key;
+      Variable? variable = entry.key;
       VariableModel<Variable, Type> baseModel = entry.value;
       VariableModel<Variable, Type>? thisModel = variableInfo[variable];
       if (thisModel == null) {
@@ -1736,7 +1877,7 @@
     // present in `this` that aren't present in `base`, we may erroneously think
     // that `newVariableInfo` matches `this`.  If so, correct that.
     if (variableInfoMatchesThis) {
-      for (Variable variable in variableInfo.keys) {
+      for (Variable? variable in variableInfo.keys) {
         if (!base.variableInfo.containsKey(variable)) {
           variableInfoMatchesThis = false;
           break;
@@ -1789,13 +1930,13 @@
     Reachability newReachable =
         Reachability.restrict(reachable, other.reachable);
 
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
-        <Variable, VariableModel<Variable, Type>>{};
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
+        <Variable?, VariableModel<Variable, Type>>{};
     bool variableInfoMatchesThis = true;
     bool variableInfoMatchesOther = true;
-    for (MapEntry<Variable, VariableModel<Variable, Type>> entry
+    for (MapEntry<Variable?, VariableModel<Variable, Type>> entry
         in variableInfo.entries) {
-      Variable variable = entry.key;
+      Variable? variable = entry.key;
       VariableModel<Variable, Type> thisModel = entry.value;
       VariableModel<Variable, Type>? otherModel = other.variableInfo[variable];
       if (otherModel == null) {
@@ -1809,7 +1950,7 @@
       if (!identical(restricted, otherModel)) variableInfoMatchesOther = false;
     }
     if (variableInfoMatchesOther) {
-      for (Variable variable in other.variableInfo.keys) {
+      for (Variable? variable in other.variableInfo.keys) {
         if (!variableInfo.containsKey(variable)) {
           variableInfoMatchesOther = false;
           break;
@@ -1975,7 +2116,12 @@
   /// Updates the state to indicate that an assignment was made to the given
   /// [variable].  The variable is marked as definitely assigned, and any
   /// previous type promotion is removed.
+  ///
+  /// If there is any chance that the write will cause a demotion, the caller
+  /// must pass in a non-null value for [nonPromotionReason] describing the
+  /// reason for any potential demotion.
   FlowModel<Variable, Type> write(
+      NonPromotionReason? nonPromotionReason,
       Variable variable,
       Type writtenType,
       SsaNode<Variable, Type> newSsaNode,
@@ -1983,8 +2129,8 @@
     VariableModel<Variable, Type>? infoForVar = variableInfo[variable];
     if (infoForVar == null) return this;
 
-    VariableModel<Variable, Type> newInfoForVar =
-        infoForVar.write(variable, writtenType, typeOperations, newSsaNode);
+    VariableModel<Variable, Type> newInfoForVar = infoForVar.write(
+        nonPromotionReason, variable, writtenType, typeOperations, newSsaNode);
     if (identical(newInfoForVar, infoForVar)) return this;
 
     return _updateVariableInfo(new VariableReference(variable), newInfoForVar);
@@ -2019,7 +2165,8 @@
     if (promotedType != null) {
       newPromotedTypes =
           VariableModel._addToPromotedTypes(info.promotedTypes, promotedType);
-      if (typeOperations.isNever(promotedType)) {
+      if (reference is VariableReference<Object, Object> &&
+          typeOperations.isNever(promotedType)) {
         newReachable = reachable.setUnreachable();
       }
     }
@@ -2035,7 +2182,8 @@
                 tested: newTested,
                 assigned: info.assigned,
                 unassigned: info.unassigned,
-                ssaNode: info.ssaNode),
+                ssaNode: info.ssaNode,
+                nonPromotionHistory: info.nonPromotionHistory),
             reachable: newReachable);
   }
 
@@ -2045,8 +2193,8 @@
       Reference<Variable, Type> reference, VariableModel<Variable, Type> model,
       {Reachability? reachable}) {
     reachable ??= this.reachable;
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
-        new Map<Variable, VariableModel<Variable, Type>>.from(variableInfo);
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
+        new Map<Variable?, VariableModel<Variable, Type>>.from(variableInfo);
     reference.storeInfo(newVariableInfo, model);
     return new FlowModel<Variable, Type>.withInfo(reachable, newVariableInfo);
   }
@@ -2065,7 +2213,7 @@
     TypeOperations<Variable, Type> typeOperations,
     FlowModel<Variable, Type>? first,
     FlowModel<Variable, Type>? second,
-    Map<Variable, VariableModel<Variable, Type>> emptyVariableMap,
+    Map<Variable?, VariableModel<Variable, Type>> emptyVariableMap,
   ) {
     if (first == null) return second!;
     if (second == null) return first;
@@ -2082,7 +2230,7 @@
 
     Reachability newReachable =
         Reachability.join(first.reachable, second.reachable);
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
         FlowModel.joinVariableInfo(typeOperations, first.variableInfo,
             second.variableInfo, emptyVariableMap);
 
@@ -2092,25 +2240,25 @@
 
   /// Joins two "variable info" maps.  See [join] for details.
   @visibleForTesting
-  static Map<Variable, VariableModel<Variable, Type>>
+  static Map<Variable?, VariableModel<Variable, Type>>
       joinVariableInfo<Variable extends Object, Type extends Object>(
     TypeOperations<Variable, Type> typeOperations,
-    Map<Variable, VariableModel<Variable, Type>> first,
-    Map<Variable, VariableModel<Variable, Type>> second,
-    Map<Variable, VariableModel<Variable, Type>> emptyMap,
+    Map<Variable?, VariableModel<Variable, Type>> first,
+    Map<Variable?, VariableModel<Variable, Type>> second,
+    Map<Variable?, VariableModel<Variable, Type>> emptyMap,
   ) {
     if (identical(first, second)) return first;
     if (first.isEmpty || second.isEmpty) {
       return emptyMap;
     }
 
-    Map<Variable, VariableModel<Variable, Type>> result =
-        <Variable, VariableModel<Variable, Type>>{};
+    Map<Variable?, VariableModel<Variable, Type>> result =
+        <Variable?, VariableModel<Variable, Type>>{};
     bool alwaysFirst = true;
     bool alwaysSecond = true;
-    for (MapEntry<Variable, VariableModel<Variable, Type>> entry
+    for (MapEntry<Variable?, VariableModel<Variable, Type>> entry
         in first.entries) {
-      Variable variable = entry.key;
+      Variable? variable = entry.key;
       VariableModel<Variable, Type>? secondModel = second[variable];
       if (secondModel == null) {
         alwaysFirst = false;
@@ -2137,7 +2285,7 @@
     TypeOperations<Variable, Type> typeOperations,
     FlowModel<Variable, Type>? first,
     FlowModel<Variable, Type>? second,
-    Map<Variable, VariableModel<Variable, Type>> emptyVariableMap,
+    Map<Variable?, VariableModel<Variable, Type>> emptyVariableMap,
   ) {
     if (first == null) return second!.unsplit();
     if (second == null) return first.unsplit();
@@ -2154,7 +2302,7 @@
 
     Reachability newReachable =
         Reachability.join(first.reachable, second.reachable).unsplit();
-    Map<Variable, VariableModel<Variable, Type>> newVariableInfo =
+    Map<Variable?, VariableModel<Variable, Type>> newVariableInfo =
         FlowModel.joinVariableInfo(typeOperations, first.variableInfo,
             second.variableInfo, emptyVariableMap);
 
@@ -2169,7 +2317,7 @@
           FlowModel<Variable, Type> first,
           FlowModel<Variable, Type> second,
           Reachability newReachable,
-          Map<Variable, VariableModel<Variable, Type>> newVariableInfo) {
+          Map<Variable?, VariableModel<Variable, Type>> newVariableInfo) {
     if (first.reachable == newReachable &&
         identical(first.variableInfo, newVariableInfo)) {
       return first;
@@ -2188,11 +2336,11 @@
   /// The equivalence check is shallow; if two variables' models are not
   /// identical, we return `false`.
   static bool _variableInfosEqual<Variable extends Object, Type extends Object>(
-      Map<Variable, VariableModel<Variable, Type>> p1,
-      Map<Variable, VariableModel<Variable, Type>> p2) {
+      Map<Variable?, VariableModel<Variable, Type>> p1,
+      Map<Variable?, VariableModel<Variable, Type>> p2) {
     if (p1.length != p2.length) return false;
     if (!p1.keys.toSet().containsAll(p2.keys)) return false;
-    for (MapEntry<Variable, VariableModel<Variable, Type>> entry
+    for (MapEntry<Variable?, VariableModel<Variable, Type>> entry
         in p1.entries) {
       VariableModel<Variable, Type> p1Value = entry.value;
       VariableModel<Variable, Type>? p2Value = p2[entry.key];
@@ -2204,6 +2352,62 @@
   }
 }
 
+/// Linked list node representing a set of reasons why a given expression was
+/// not promoted.
+///
+/// We use a linked list representation because it is very efficient to build;
+/// this means that in the "happy path" where no error occurs (so non-promotion
+/// history is not needed) we do a minimal amount of work.
+class NonPromotionHistory<Type> {
+  /// The type that was not promoted to.
+  final Type type;
+
+  /// The reason why the promotion didn't occur.
+  final NonPromotionReason nonPromotionReason;
+
+  /// The previous link in the list.
+  final NonPromotionHistory<Type>? previous;
+
+  NonPromotionHistory(this.type, this.nonPromotionReason, this.previous);
+
+  @override
+  String toString() {
+    List<String> items = <String>[];
+    for (NonPromotionHistory<Type>? link = this;
+        link != null;
+        link = link.previous) {
+      items.add('${link.type}: ${link.nonPromotionReason}');
+    }
+    return items.toString();
+  }
+}
+
+/// Abstract class representing a reason why something was not promoted.
+abstract class NonPromotionReason {
+  /// Short text description of this non-promotion reason; intended for ID
+  /// testing.
+  String get shortName;
+
+  /// Implementation of the visitor pattern for non-promotion reasons.
+  R accept<R, Node extends Object, Expression extends Object,
+          Variable extends Object>(
+      NonPromotionReasonVisitor<R, Node, Expression, Variable> visitor);
+}
+
+/// Implementation of the visitor pattern for non-promotion reasons.
+abstract class NonPromotionReasonVisitor<R, Node extends Object,
+    Expression extends Object, Variable extends Object> {
+  NonPromotionReasonVisitor._() : assert(false, 'Do not extend this class');
+
+  R visitDemoteViaExplicitWrite(
+      DemoteViaExplicitWrite<Variable, Expression> reason);
+
+  R visitDemoteViaForEachVariableWrite(
+      DemoteViaForEachVariableWrite<Variable, Node> reason);
+
+  R visitFieldNotPromoted(FieldNotPromoted reason);
+}
+
 /// Immutable data structure modeling the reachability of the given point in the
 /// source code.  Reachability is tracked relative to checkpoints occurring
 /// previously along the control flow path leading up to the current point in
@@ -2359,16 +2563,27 @@
 
   /// Gets the info for this reference, creating it if it doesn't exist.
   VariableModel<Variable, Type> getInfo(
-          Map<Variable, VariableModel<Variable, Type>> variableInfo) =>
+          Map<Variable?, VariableModel<Variable, Type>> variableInfo) =>
       _getInfo(variableInfo) ?? new VariableModel<Variable, Type>.fresh();
 
+  /// Gets a map of non-promotion reasons associated with this reference.  This
+  /// is the map that will be returned from [FlowAnalysis.whyNotPromoted].
+  Map<Type, NonPromotionReason> getNonPromotionReasons(
+      Map<Variable?, VariableModel<Variable, Type>> variableInfo,
+      TypeOperations<Variable, Type> typeOperations);
+
+  /// Creates a reference representing a get of a property called [propertyName]
+  /// on the reference represented by `this`.
+  Reference<Variable, Type> propertyGet(String propertyName) =>
+      new _PropertyGetReference<Variable, Type>(this, propertyName);
+
   /// Stores info for this reference in [variableInfo].
-  void storeInfo(Map<Variable, VariableModel<Variable, Type>> variableInfo,
+  void storeInfo(Map<Variable?, VariableModel<Variable, Type>> variableInfo,
       VariableModel<Variable, Type> variableModel);
 
   /// Gets the info for this reference, or `null` if it doesn't exist.
   VariableModel<Variable, Type>? _getInfo(
-      Map<Variable, VariableModel<Variable, Type>> variableInfo);
+      Map<Variable?, VariableModel<Variable, Type>> variableInfo);
 }
 
 /// Data structure representing a unique value that a variable might take on
@@ -2423,6 +2638,9 @@
 
 /// Operations on types, abstracted from concrete type interfaces.
 abstract class TypeOperations<Variable extends Object, Type extends Object> {
+  /// Gets the representation of the top type (`Object?`) in the type system.
+  Type get topType;
+
   /// Classifies the given type into one of the three categories defined by
   /// the [TypeClassification] enum.
   TypeClassification classifyType(Type type);
@@ -2510,12 +2728,22 @@
   /// `null` if the variable has been write captured.
   final SsaNode<Variable, Type>? ssaNode;
 
+  /// Non-promotion history of this variable.
+  final NonPromotionHistory<Type>? nonPromotionHistory;
+
+  /// Promotion information for properties of this variable.  We don't actually
+  /// promote properties, but we track the promotions that would occur if we
+  /// did, so that we can report those as non-promotion reasons.
+  final Map<String, VariableModel<Variable, Type>> properties;
+
   VariableModel(
       {required this.promotedTypes,
       required this.tested,
       required this.assigned,
       required this.unassigned,
-      required this.ssaNode}) {
+      required this.ssaNode,
+      this.nonPromotionHistory,
+      this.properties = const {}}) {
     assert(!(assigned && unassigned),
         "Can't be both definitely assigned and unassigned");
     assert(promotedTypes == null || promotedTypes!.isNotEmpty);
@@ -2533,7 +2761,9 @@
       : promotedTypes = null,
         tested = const [],
         unassigned = !assigned,
-        ssaNode = new SsaNode<Variable, Type>(null);
+        ssaNode = new SsaNode<Variable, Type>(null),
+        nonPromotionHistory = null,
+        properties = const {};
 
   /// Indicates whether the variable has been write captured.
   bool get writeCaptured => ssaNode == null;
@@ -2605,6 +2835,18 @@
         newAssigned, newUnassigned, newWriteCaptured ? null : ssaNode);
   }
 
+  /// Updates `this` with a new set of properties.
+  VariableModel<Variable, Type> setProperties(
+          Map<String, VariableModel<Variable, Type>> newProperties) =>
+      new VariableModel<Variable, Type>(
+          promotedTypes: promotedTypes,
+          tested: tested,
+          unassigned: unassigned,
+          assigned: assigned,
+          ssaNode: ssaNode,
+          nonPromotionHistory: nonPromotionHistory,
+          properties: newProperties);
+
   @override
   String toString() {
     List<String> parts = [ssaNode.toString()];
@@ -2623,12 +2865,20 @@
     if (writeCaptured) {
       parts.add('writeCaptured: true');
     }
+    if (nonPromotionHistory != null) {
+      parts.add('nonPromotionHistory: $nonPromotionHistory');
+    }
     return 'VariableModel(${parts.join(', ')})';
   }
 
   /// Returns a new [VariableModel] reflecting the fact that the variable was
   /// just written to.
+  ///
+  /// If there is any chance that the write will cause a demotion, the caller
+  /// must pass in a non-null value for [nonPromotionReason] describing the
+  /// reason for any potential demotion.
   VariableModel<Variable, Type> write(
+      NonPromotionReason? nonPromotionReason,
       Variable variable,
       Type writtenType,
       TypeOperations<Variable, Type> typeOperations,
@@ -2642,14 +2892,15 @@
           ssaNode: null);
     }
 
-    List<Type>? newPromotedTypes = _demoteViaAssignment(
-      writtenType,
-      typeOperations,
-    );
+    _DemotionResult<Type> demotionResult =
+        _demoteViaAssignment(writtenType, typeOperations, nonPromotionReason);
+    List<Type>? newPromotedTypes = demotionResult.promotedTypes;
 
     Type declaredType = typeOperations.variableType(variable);
     newPromotedTypes = _tryPromoteToTypeOfInterest(
         typeOperations, declaredType, newPromotedTypes, writtenType);
+    // TODO(paulberry): remove demotions from demotionResult.nonPromotionHistory
+    // that are no longer in effect due to re-promotion.
     if (identical(promotedTypes, newPromotedTypes) && assigned) {
       return new VariableModel<Variable, Type>(
           promotedTypes: promotedTypes,
@@ -2671,7 +2922,8 @@
         tested: newTested,
         assigned: true,
         unassigned: false,
-        ssaNode: newSsaNode);
+        ssaNode: newSsaNode,
+        nonPromotionHistory: demotionResult.nonPromotionHistory);
   }
 
   /// Returns a new [VariableModel] reflecting the fact that the variable has
@@ -2685,28 +2937,45 @@
         ssaNode: null);
   }
 
-  List<Type>? _demoteViaAssignment(
-    Type writtenType,
-    TypeOperations<Variable, Type> typeOperations,
-  ) {
+  /// Computes the result of demoting this variable due to writing a value of
+  /// type [writtenType].
+  ///
+  /// If there is any chance that the write will cause an actual demotion to
+  /// occur, the caller must pass in a non-null value for [nonPromotionReason]
+  /// describing the reason for the potential demotion.
+  _DemotionResult<Type> _demoteViaAssignment(
+      Type writtenType,
+      TypeOperations<Variable, Type> typeOperations,
+      NonPromotionReason? nonPromotionReason) {
     List<Type>? promotedTypes = this.promotedTypes;
     if (promotedTypes == null) {
-      return null;
+      return new _DemotionResult<Type>(null, nonPromotionHistory);
     }
 
     int numElementsToKeep = promotedTypes.length;
+    NonPromotionHistory<Type>? newNonPromotionHistory = nonPromotionHistory;
+    List<Type>? newPromotedTypes;
     for (;; numElementsToKeep--) {
       if (numElementsToKeep == 0) {
-        return null;
+        break;
       }
       Type promoted = promotedTypes[numElementsToKeep - 1];
       if (typeOperations.isSubtypeOf(writtenType, promoted)) {
         if (numElementsToKeep == promotedTypes.length) {
-          return promotedTypes;
+          newPromotedTypes = promotedTypes;
+          break;
         }
-        return promotedTypes.sublist(0, numElementsToKeep);
+        newPromotedTypes = promotedTypes.sublist(0, numElementsToKeep);
+        break;
+      }
+      if (nonPromotionReason == null) {
+        assert(false, 'Demotion occurred but nonPromotionReason is null');
+      } else {
+        newNonPromotionHistory = new NonPromotionHistory<Type>(
+            promoted, nonPromotionReason, newNonPromotionHistory);
       }
     }
+    return new _DemotionResult<Type>(newPromotedTypes, newNonPromotionHistory);
   }
 
   /// Determines whether a variable with the given [promotedTypes] should be
@@ -3067,14 +3336,36 @@
       typeOperations.variableType(variable);
 
   @override
-  void storeInfo(Map<Variable, VariableModel<Variable, Type>> variableInfo,
+  Map<Type, NonPromotionReason> getNonPromotionReasons(
+      Map<Variable?, VariableModel<Variable, Type>> variableInfo,
+      TypeOperations<Variable, Type> typeOperations) {
+    Map<Type, NonPromotionReason> result = <Type, NonPromotionReason>{};
+    VariableModel<Variable, Type>? currentVariableInfo = variableInfo[variable];
+    if (currentVariableInfo != null) {
+      Type currentType = currentVariableInfo.promotedTypes?.last ??
+          typeOperations.variableType(variable);
+      NonPromotionHistory? nonPromotionHistory =
+          currentVariableInfo.nonPromotionHistory;
+      while (nonPromotionHistory != null) {
+        Type nonPromotedType = nonPromotionHistory.type;
+        if (!typeOperations.isSubtypeOf(currentType, nonPromotedType)) {
+          result[nonPromotedType] ??= nonPromotionHistory.nonPromotionReason;
+        }
+        nonPromotionHistory = nonPromotionHistory.previous;
+      }
+    }
+    return result;
+  }
+
+  @override
+  void storeInfo(Map<Variable?, VariableModel<Variable, Type>> variableInfo,
       VariableModel<Variable, Type> variableModel) {
     variableInfo[variable] = variableModel;
   }
 
   @override
   VariableModel<Variable, Type>? _getInfo(
-          Map<Variable, VariableModel<Variable, Type>> variableInfo) =>
+          Map<Variable?, VariableModel<Variable, Type>> variableInfo) =>
       variableInfo[variable];
 }
 
@@ -3145,6 +3436,19 @@
       'thenInfo: $_thenInfo)';
 }
 
+/// Data structure representing the result of demoting a variable from one type
+/// to another.
+class _DemotionResult<Type extends Object> {
+  /// The new set of promoted types.
+  final List<Type>? promotedTypes;
+
+  /// The new non-promotion history (including the types that the variable is
+  /// no longer promoted to).
+  final NonPromotionHistory<Type>? nonPromotionHistory;
+
+  _DemotionResult(this.promotedTypes, this.nonPromotionHistory);
+}
+
 /// [_FlowContext] representing an equality comparison using `==` or `!=`.
 class _EqualityOpContext<Variable extends Object, Type extends Object>
     extends _BranchContext<Variable, Type> {
@@ -3437,8 +3741,12 @@
             _current.reachable.parent!, _current);
     _stack.add(context);
     if (loopVariable != null) {
-      _current = _current.write(loopVariable, writtenType,
-          new SsaNode<Variable, Type>(null), typeOperations);
+      _current = _current.write(
+          new DemoteViaForEachVariableWrite<Variable, Node>(loopVariable, node),
+          loopVariable,
+          writtenType,
+          new SsaNode<Variable, Type>(null),
+          typeOperations);
     }
   }
 
@@ -3581,8 +3889,8 @@
       // written type is the variable's declared type.
       initializerType = typeOperations.variableType(variable);
     }
-    _current =
-        _current.write(variable, initializerType, newSsaNode, typeOperations);
+    _current = _current.write(
+        null, variable, initializerType, newSsaNode, typeOperations);
   }
 
   @override
@@ -3741,6 +4049,16 @@
   }
 
   @override
+  void propertyGet(
+      Expression wholeExpression, Expression target, String propertyName) {
+    Reference<Variable, Type>? reference = _getExpressionReference(target);
+    if (reference != null) {
+      _storeExpressionReference(
+          wholeExpression, reference.propertyGet(propertyName));
+    }
+  }
+
+  @override
   SsaNode<Variable, Type>? ssaNodeForTesting(Variable variable) =>
       _current.variableInfo[variable]?.ssaNode;
 
@@ -3785,6 +4103,17 @@
   }
 
   @override
+  void thisOrSuper(Expression expression) {
+    _storeExpressionReference(expression, new _ThisReference<Variable, Type>());
+  }
+
+  @override
+  void thisOrSuperPropertyGet(Expression expression, String propertyName) {
+    _storeExpressionReference(expression,
+        new _ThisReference<Variable, Type>().propertyGet(propertyName));
+  }
+
+  @override
   void tryCatchStatement_bodyBegin() {
     _current = _current.split();
     _stack.add(new _TryContext<Variable, Type>(_current));
@@ -3914,15 +4243,31 @@
   }
 
   @override
-  void write(
-      Variable variable, Type writtenType, Expression? writtenExpression) {
+  Map<Type, NonPromotionReason> whyNotPromoted(Expression target) {
+    if (identical(target, _expressionWithReference)) {
+      Reference<Variable, Type>? reference = _expressionReference;
+      if (reference != null) {
+        return reference.getNonPromotionReasons(
+            _current.variableInfo, typeOperations);
+      }
+    }
+    return {};
+  }
+
+  @override
+  void write(Expression expression, Variable variable, Type writtenType,
+      Expression? writtenExpression) {
     ExpressionInfo<Variable, Type>? expressionInfo = writtenExpression == null
         ? null
         : _getExpressionInfo(writtenExpression);
     SsaNode<Variable, Type> newSsaNode = new SsaNode<Variable, Type>(
         expressionInfo is _TrivialExpressionInfo ? null : expressionInfo);
-    _current =
-        _current.write(variable, writtenType, newSsaNode, typeOperations);
+    _current = _current.write(
+        new DemoteViaExplicitWrite<Variable, Expression>(variable, expression),
+        variable,
+        writtenType,
+        newSsaNode,
+        typeOperations);
   }
 
   @override
@@ -4425,6 +4770,10 @@
   }
 
   @override
+  void propertyGet(
+      Expression wholeExpression, Expression target, String propertyName) {}
+
+  @override
   SsaNode<Variable, Type>? ssaNodeForTesting(Variable variable) {
     throw new StateError('ssaNodeForTesting requires null-aware flow analysis');
   }
@@ -4439,6 +4788,12 @@
   void switchStatement_expressionEnd(Statement switchStatement) {}
 
   @override
+  void thisOrSuper(Expression expression) {}
+
+  @override
+  void thisOrSuperPropertyGet(Expression expression, String propertyName) {}
+
+  @override
   void tryCatchStatement_bodyBegin() {}
 
   @override
@@ -4481,8 +4836,13 @@
   void whileStatement_end() {}
 
   @override
-  void write(
-      Variable variable, Type writtenType, Expression? writtenExpression) {
+  Map<Type, NonPromotionReason> whyNotPromoted(Expression target) {
+    return {};
+  }
+
+  @override
+  void write(Expression expression, Variable variable, Type writtenType,
+      Expression? writtenExpression) {
     assert(
         _assignedVariables._anywhere._written.contains(variable),
         "Variable is written to, but was not included in "
@@ -4615,6 +4975,57 @@
       null;
 }
 
+/// [Reference] object representing a property get applied to another reference.
+class _PropertyGetReference<Variable extends Object, Type extends Object>
+    extends Reference<Variable, Type> {
+  /// The target of the property get.  For example a property get of the form
+  /// `a.b`, where `a` is a local variable, has a target which is a reference to
+  /// `a`.
+  final Reference<Variable, Type> target;
+
+  /// The name of the property.
+  final String propertyName;
+
+  _PropertyGetReference(this.target, this.propertyName);
+
+  @override
+  Type getDeclaredType(TypeOperations<Variable, Type> typeOperations) {
+    return typeOperations.topType;
+  }
+
+  @override
+  Map<Type, NonPromotionReason> getNonPromotionReasons(
+      Map<Variable?, VariableModel<Variable, Type>> variableInfo,
+      TypeOperations<Variable, Type> typeOperations) {
+    Map<Type, NonPromotionReason> result = <Type, NonPromotionReason>{};
+    List<Type>? promotedTypes = _getInfo(variableInfo)?.promotedTypes;
+    if (promotedTypes != null) {
+      for (Type type in promotedTypes) {
+        result[type] = new FieldNotPromoted(propertyName);
+      }
+    }
+    return result;
+  }
+
+  @override
+  void storeInfo(Map<Variable?, VariableModel<Variable, Type>> variableInfo,
+      VariableModel<Variable, Type> variableModel) {
+    VariableModel<Variable, Type> targetInfo = target.getInfo(variableInfo);
+    Map<String, VariableModel<Variable, Type>> newProperties =
+        new Map<String, VariableModel<Variable, Type>>.from(
+            targetInfo.properties);
+    newProperties[propertyName] = variableModel;
+    target.storeInfo(variableInfo, targetInfo.setProperties(newProperties));
+  }
+
+  @override
+  VariableModel<Variable, Type>? _getInfo(
+      Map<Variable?, VariableModel<Variable, Type>> variableInfo) {
+    VariableModel<Variable, Type> targetInfo = target.getInfo(variableInfo);
+    return targetInfo.properties[propertyName];
+  }
+}
+
 /// [_FlowContext] representing a language construct for which flow analysis
 /// must store a flow model state to be retrieved later, such as a `try`
 /// statement, function expression, or "if-null" (`??`) expression.
@@ -4650,6 +5061,36 @@
       'checkpoint: $_checkpoint)';
 }
 
+/// [Reference] object representing an implicit or explicit reference to `this`.
+class _ThisReference<Variable extends Object, Type extends Object>
+    extends Reference<Variable, Type> {
+  @override
+  Type getDeclaredType(TypeOperations<Variable, Type> typeOperations) {
+    // TODO(paulberry): can we return the actual type?  Would that have a
+    // user-visible effect?
+    return typeOperations.topType;
+  }
+
+  @override
+  Map<Type, NonPromotionReason> getNonPromotionReasons(
+      Map<Variable?, VariableModel<Variable, Type>> variableInfo,
+      TypeOperations<Variable, Type> typeOperations) {
+    // TODO(paulberry): implement.
+    return {};
+  }
+
+  @override
+  void storeInfo(Map<Variable?, VariableModel<Variable, Type>> variableInfo,
+      VariableModel<Variable, Type> variableModel) {
+    variableInfo[null] = variableModel;
+  }
+
+  @override
+  VariableModel<Variable, Type>? _getInfo(
+          Map<Variable?, VariableModel<Variable, Type>> variableInfo) =>
+      variableInfo[null];
+}
+
 /// Specialization of [ExpressionInfo] for the case where the information we
 /// have about the expression is trivial (meaning we know by construction that
 /// the expression's [after], [ifTrue], and [ifFalse] models are all the same).
diff --git a/pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart b/pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart
index ba1e3a6..8a3aef0 100644
--- a/pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart
+++ b/pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart
@@ -4033,6 +4033,29 @@
     tip: r"""Try removing 'this.'.""");
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Template<Message Function(String name)> templateFieldNotPromoted =
+    const Template<Message Function(String name)>(
+        messageTemplate:
+            r"""'#name' refers to a property so it could not be promoted.""",
+        withArguments: _withArgumentsFieldNotPromoted);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Message Function(String name)> codeFieldNotPromoted =
+    const Code<Message Function(String name)>(
+  "FieldNotPromoted",
+);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+Message _withArgumentsFieldNotPromoted(String name) {
+  if (name.isEmpty) throw 'No name provided';
+  name = demangleMixinApplicationName(name);
+  return new Message(codeFieldNotPromoted,
+      message:
+          """'${name}' refers to a property so it could not be promoted.""",
+      arguments: {'name': name});
+}
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeFinalAndCovariant = messageFinalAndCovariant;
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
@@ -5927,6 +5950,17 @@
         message: r"""This is the enclosing class.""");
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Null> codeJsInteropExternalMemberNotJSAnnotated =
+    messageJsInteropExternalMemberNotJSAnnotated;
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const MessageCode messageJsInteropExternalMemberNotJSAnnotated = const MessageCode(
+    "JsInteropExternalMemberNotJSAnnotated",
+    message: r"""Only JS interop members may be 'external'.""",
+    tip:
+        r"""Try removing the 'external' keyword or adding a JS interop annotation.""");
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeJsInteropIndexNotSupported =
     messageJsInteropIndexNotSupported;
 
@@ -9621,6 +9655,34 @@
         r"""Try removing the keyword 'var', or replacing it with the name of the return type.""");
 
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Template<
+    Message Function(
+        String
+            name)> templateVariableCouldBeNullDueToWrite = const Template<
+        Message Function(String name)>(
+    messageTemplate:
+        r"""Variable '#name' could be null due to a write occurring here.""",
+    tipTemplate: r"""Try null checking the variable after the write.""",
+    withArguments: _withArgumentsVariableCouldBeNullDueToWrite);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Message Function(String name)> codeVariableCouldBeNullDueToWrite =
+    const Code<Message Function(String name)>(
+  "VariableCouldBeNullDueToWrite",
+);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+Message _withArgumentsVariableCouldBeNullDueToWrite(String name) {
+  if (name.isEmpty) throw 'No name provided';
+  name = demangleMixinApplicationName(name);
+  return new Message(codeVariableCouldBeNullDueToWrite,
+      message:
+          """Variable '${name}' could be null due to a write occurring here.""",
+      tip: """Try null checking the variable after the write.""",
+      arguments: {'name': name});
+}
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeVerificationErrorOriginContext =
     messageVerificationErrorOriginContext;
 
diff --git a/pkg/_fe_analyzer_shared/test/annotated_code_helper_test.dart b/pkg/_fe_analyzer_shared/test/annotated_code_helper_test.dart
index 9fb1558..755d20c 100644
--- a/pkg/_fe_analyzer_shared/test/annotated_code_helper_test.dart
+++ b/pkg/_fe_analyzer_shared/test/annotated_code_helper_test.dart
@@ -16,6 +16,7 @@
   testDir('pkg/_fe_analyzer_shared/test/flow_analysis/nullability/data');
   testDir('pkg/_fe_analyzer_shared/test/flow_analysis/reachability/data');
   testDir('pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/data');
+  testDir('pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data');
   testDir('pkg/_fe_analyzer_shared/test/inheritance/data');
 }
 
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_mini_ast.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_mini_ast.dart
index 9838684..0c02855 100644
--- a/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_mini_ast.dart
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_mini_ast.dart
@@ -154,6 +154,11 @@
         {required bool isExhaustive}) =>
     new _Switch(expression, cases, isExhaustive);
 
+Expression this_(String type) => new _This(Type(type));
+
+Expression thisOrSuperPropertyGet(String name, {String type = 'Object?'}) =>
+    new _ThisOrSuperPropertyGet(name, type);
+
 Expression throw_(Expression operand) => new _Throw(operand);
 
 Statement tryCatch(List<Statement> body, List<CatchClause> catches) =>
@@ -273,12 +278,24 @@
   /// If `this` is an expression `x`, creates the expression `x || other`.
   Expression or(Expression other) => new _Logical(this, other, isAnd: false);
 
+  /// If `this` is an expression `x`, creates the expression `x.name`.
+  Expression propertyGet(String name, {String type = 'Object?'}) =>
+      new _PropertyGet(this, name, type);
+
   /// If `this` is an expression `x`, creates a pseudo-expression that models
   /// evaluation of `x` followed by execution of [stmt].  This can be used to
   /// test that flow analysis is in the correct state after an expression is
   /// visited.
   Expression thenStmt(Statement stmt) =>
       new _WrappedExpression(null, this, stmt);
+
+  /// Creates an [Expression] that, when analyzed, will behave the same as
+  /// `this`, but after visiting it, will cause [callback] to be passed the
+  /// non-promotion info associated with it.  If the expression has no
+  /// non-promotion info, an empty map will be passed to [callback].
+  Expression whyNotPromoted(
+          void Function(Map<Type, NonPromotionReason>) callback) =>
+      new _WhyNotPromoted(this, callback);
 }
 
 /// Test harness for creating flow analysis tests.  This class implements all
@@ -311,8 +328,10 @@
     'int? <: num?': true,
     'int? <: Object': false,
     'int? <: Object?': true,
+    'Never <: Object?': true,
     'Null <: int': false,
     'Null <: Object': false,
+    'Null <: Object?': true,
     'num <: int': false,
     'num <: Iterable': false,
     'num <: List': false,
@@ -347,6 +366,7 @@
     'Object <: int': false,
     'Object <: int?': false,
     'Object <: List': false,
+    'Object <: Null': false,
     'Object <: num': false,
     'Object <: num?': false,
     'Object <: Object?': true,
@@ -354,6 +374,7 @@
     'Object? <: Object': false,
     'Object? <: int': false,
     'Object? <: int?': false,
+    'Object? <: Null': false,
     'String <: int': false,
     'String <: int?': false,
     'String <: num?': false,
@@ -364,6 +385,8 @@
   static final Map<String, Type> _coreFactors = {
     'Object? - int': Type('Object?'),
     'Object? - int?': Type('Object'),
+    'Object? - Never': Type('Object?'),
+    'Object? - Null': Type('Object'),
     'Object? - num?': Type('Object'),
     'Object? - Object?': Type('Never?'),
     'Object? - String': Type('Object?'),
@@ -410,6 +433,9 @@
 
   Harness({this.allowLocalBooleanVarsToPromote = false, this.legacy = false});
 
+  @override
+  Type get topType => Type('Object?');
+
   /// Updates the harness so that when a [factor] query is invoked on types
   /// [from] and [what], [result] will be returned.
   void addFactor(String from, String what, String result) {
@@ -597,15 +623,30 @@
 /// testing.  This is essentially a thin wrapper around a string representation
 /// of the type.
 class Type {
+  static bool _allowComparisons = false;
+
   final String type;
 
   Type(this.type);
 
   @override
+  int get hashCode {
+    if (!_allowComparisons) {
+      // The flow analysis engine should not hash types using hashCode.  It
+      // should compare them using TypeOperations.
+      fail('Unexpected use of operator== on types');
+    }
+    return type.hashCode;
+  }
+
+  @override
   bool operator ==(Object other) {
-    // The flow analysis engine should not compare types using operator==.  It
-    // should compare them using TypeOperations.
-    fail('Unexpected use of operator== on types');
+    if (!_allowComparisons) {
+      // The flow analysis engine should not compare types using operator==.  It
+      // should compare them using TypeOperations.
+      fail('Unexpected use of operator== on types');
+    }
+    return other is Type && this.type == other.type;
   }
 
   @override
@@ -1424,6 +1465,29 @@
       type;
 }
 
+class _PropertyGet extends Expression {
+  final Expression target;
+
+  final String propertyName;
+
+  final String type;
+
+  _PropertyGet(this.target, this.propertyName, this.type);
+
+  @override
+  void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
+    target._preVisit(assignedVariables);
+  }
+
+  @override
+  Type _visit(
+      Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
+    target._visit(h, flow);
+    flow.propertyGet(this, target, propertyName);
+    return Type(type);
+  }
+}
+
 class _Return extends Statement {
   _Return() : super._();
 
@@ -1481,6 +1545,43 @@
   }
 }
 
+class _This extends Expression {
+  final Type type;
+
+  _This(this.type);
+
+  @override
+  String toString() => 'this';
+
+  @override
+  void _preVisit(AssignedVariables<Node, Var> assignedVariables) {}
+
+  @override
+  Type _visit(
+      Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
+    flow.thisOrSuper(this);
+    return type;
+  }
+}
+
+class _ThisOrSuperPropertyGet extends Expression {
+  final String propertyName;
+
+  final String type;
+
+  _ThisOrSuperPropertyGet(this.propertyName, this.type);
+
+  @override
+  void _preVisit(AssignedVariables<Node, Var> assignedVariables) {}
+
+  @override
+  Type _visit(
+      Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
+    flow.thisOrSuperPropertyGet(this, propertyName);
+    return Type(type);
+  }
+}
+
 class _Throw extends Expression {
   final Expression operand;
 
@@ -1622,6 +1723,37 @@
   }
 }
 
+class _WhyNotPromoted extends Expression {
+  final Expression target;
+
+  final void Function(Map<Type, NonPromotionReason>) callback;
+
+  _WhyNotPromoted(this.target, this.callback);
+
+  @override
+  String toString() => '$target (whyNotPromoted)';
+
+  @override
+  void _preVisit(AssignedVariables<Node, Var> assignedVariables) {
+    target._preVisit(assignedVariables);
+  }
+
+  @override
+  Type _visit(
+      Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
+    var type = target._visit(h, flow);
+    flow.forwardExpression(this, target);
+    assert(!Type._allowComparisons);
+    Type._allowComparisons = true;
+    try {
+      callback(flow.whyNotPromoted(this));
+    } finally {
+      Type._allowComparisons = false;
+    }
+    return type;
+  }
+}
+
 class _WrappedExpression extends Expression {
   final Statement? before;
   final Expression expr;
@@ -1681,7 +1813,7 @@
       Harness h, FlowAnalysis<Node, Statement, Expression, Var, Type> flow) {
     var rhs = this.rhs;
     var type = rhs == null ? variable.type : rhs._visit(h, flow);
-    flow.write(variable, type, rhs);
+    flow.write(this, variable, type, rhs);
     return type;
   }
 }
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_test.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_test.dart
index 9621ff7..1657689 100644
--- a/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_test.dart
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/flow_analysis_test.dart
@@ -499,6 +499,94 @@
       ]);
     });
 
+    test('equalityOp_end on property get preserves target variable', () {
+      // This is a regression test for a mistake made during the implementation
+      // of "why not promoted" functionality: when storing information about an
+      // attempt to promote a field (e.g. `x.y != null`) we need to make sure we
+      // don't wipe out information about the target variable (`x`).
+      var h = Harness();
+      var x = Var('x', 'C');
+      h.run([
+        declare(x, initialized: true),
+        checkAssigned(x, true),
+        if_(x.read.propertyGet('y').notEq(nullLiteral), [
+          checkAssigned(x, true),
+        ], [
+          checkAssigned(x, true),
+        ]),
+      ]);
+    });
+
+    test('equalityOp_end does not set reachability for `this`', () {
+      var h = Harness();
+      h.addSubtype('C', 'Object', true);
+      h.run([
+        if_(this_('C').is_('Null'), [
+          if_(this_('C').eq(nullLiteral), [
+            checkReachable(true),
+          ], [
+            checkReachable(true),
+          ]),
+        ]),
+      ]);
+    });
+
+    group('equalityOp_end does not set reachability for property gets', () {
+      test('on a variable', () {
+        var h = Harness();
+        var x = Var('x', 'C');
+        h.run([
+          declare(x, initialized: true),
+          if_(x.read.propertyGet('f').is_('Null'), [
+            if_(x.read.propertyGet('f').eq(nullLiteral), [
+              checkReachable(true),
+            ], [
+              checkReachable(true),
+            ]),
+          ]),
+        ]);
+      });
+
+      test('on an arbitrary expression', () {
+        var h = Harness();
+        h.run([
+          if_(expr('C').propertyGet('f').is_('Null'), [
+            if_(expr('C').propertyGet('f').eq(nullLiteral), [
+              checkReachable(true),
+            ], [
+              checkReachable(true),
+            ]),
+          ]),
+        ]);
+      });
+
+      test('on explicit this', () {
+        var h = Harness();
+        h.run([
+          if_(this_('C').propertyGet('f').is_('Null'), [
+            if_(this_('C').propertyGet('f').eq(nullLiteral), [
+              checkReachable(true),
+            ], [
+              checkReachable(true),
+            ]),
+          ]),
+        ]);
+      });
+
+      test('on implicit this/super', () {
+        var h = Harness();
+        h.run([
+          if_(thisOrSuperPropertyGet('f').is_('Null'), [
+            if_(thisOrSuperPropertyGet('f').eq(nullLiteral), [
+              checkReachable(true),
+            ], [
+              checkReachable(true),
+            ]),
+          ]),
+        ]);
+      });
+    });
+
     test('finish checks proper nesting', () {
       var h = Harness();
       var e = expr('Null');
@@ -1372,6 +1460,65 @@
       ]);
     });
 
+    test('isExpression_end() does not set reachability for `this`', () {
+      var h = Harness();
+      h.run([
+        if_(this_('C').is_('Never'), [
+          checkReachable(true),
+        ], [
+          checkReachable(true),
+        ]),
+      ]);
+    });
+
+    group('isExpression_end() does not set reachability for property gets', () {
+      test('on a variable', () {
+        var h = Harness();
+        var x = Var('x', 'C');
+        h.run([
+          declare(x, initialized: true),
+          if_(x.read.propertyGet('f').is_('Never'), [
+            checkReachable(true),
+          ], [
+            checkReachable(true),
+          ]),
+        ]);
+      });
+
+      test('on an arbitrary expression', () {
+        var h = Harness();
+        h.run([
+          if_(expr('C').propertyGet('f').is_('Never'), [
+            checkReachable(true),
+          ], [
+            checkReachable(true),
+          ]),
+        ]);
+      });
+
+      test('on explicit this', () {
+        var h = Harness();
+        h.run([
+          if_(this_('C').propertyGet('f').is_('Never'), [
+            checkReachable(true),
+          ], [
+            checkReachable(true),
+          ]),
+        ]);
+      });
+
+      test('on implicit this/super', () {
+        var h = Harness();
+        h.run([
+          if_(thisOrSuperPropertyGet('f').is_('Never'), [
+            checkReachable(true),
+          ], [
+            checkReachable(true),
+          ]),
+        ]);
+      });
+    });
+
     test('labeledBlock without break', () {
       var h = Harness();
       var x = Var('x', 'int?');
@@ -3262,7 +3409,7 @@
         // This should not happen in valid code, but test that we don't crash.
         var h = Harness();
         var s = FlowModel<Var, Type>(Reachability.initial).write(
-            objectQVar, Type('Object?'), new SsaNode<Var, Type>(null), h);
+            null, objectQVar, Type('Object?'), new SsaNode<Var, Type>(null), h);
         expect(s.variableInfo[objectQVar], isNull);
       });
 
@@ -3271,7 +3418,7 @@
         var s1 = FlowModel<Var, Type>(Reachability.initial)
             .declare(objectQVar, true);
         var s2 = s1.write(
-            objectQVar, Type('Object?'), new SsaNode<Var, Type>(null), h);
+            null, objectQVar, Type('Object?'), new SsaNode<Var, Type>(null), h);
         expect(s2, isNot(same(s1)));
         expect(s2.reachable, same(s1.reachable));
         expect(
@@ -3287,8 +3434,8 @@
         var h = Harness();
         var s1 = FlowModel<Var, Type>(Reachability.initial)
             .declare(objectQVar, false);
-        var s2 =
-            s1.write(objectQVar, Type('int?'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(
+            null, objectQVar, Type('int?'), new SsaNode<Var, Type>(null), h);
         expect(s2.reachable.overallReachable, true);
         expect(
             s2.infoFor(objectQVar),
@@ -3306,8 +3453,8 @@
             .tryPromoteForTypeCheck(h, _varRef(objectQVar), Type('int'))
             .ifTrue;
         expect(s1.variableInfo, contains(objectQVar));
-        var s2 =
-            s1.write(objectQVar, Type('int?'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(_MockNonPromotionReason(), objectQVar, Type('int?'),
+            new SsaNode<Var, Type>(null), h);
         expect(s2.reachable.overallReachable, true);
         expect(s2.variableInfo, {
           objectQVar: _matchVariableModel(
@@ -3333,8 +3480,8 @@
               assigned: true,
               unassigned: false)
         });
-        var s2 =
-            s1.write(objectQVar, Type('num'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(_MockNonPromotionReason(), objectQVar, Type('num'),
+            new SsaNode<Var, Type>(null), h);
         expect(s2.reachable.overallReachable, true);
         expect(s2.variableInfo, {
           objectQVar: _matchVariableModel(
@@ -3362,8 +3509,8 @@
               assigned: true,
               unassigned: false)
         });
-        var s2 =
-            s1.write(objectQVar, Type('num'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(_MockNonPromotionReason(), objectQVar, Type('num'),
+            new SsaNode<Var, Type>(null), h);
         expect(s2.reachable.overallReachable, true);
         expect(s2.variableInfo, {
           objectQVar: _matchVariableModel(
@@ -3389,8 +3536,8 @@
               assigned: true,
               unassigned: false)
         });
-        var s2 =
-            s1.write(objectQVar, Type('num'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(
+            null, objectQVar, Type('num'), new SsaNode<Var, Type>(null), h);
         expect(s2.reachable.overallReachable, true);
         expect(s2.variableInfo, isNot(same(s1.variableInfo)));
         expect(s2.variableInfo, {
@@ -3417,8 +3564,8 @@
               assigned: true,
               unassigned: false)
         });
-        var s2 =
-            s1.write(objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(
+            null, objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
         expect(s2.reachable.overallReachable, true);
         expect(s2.variableInfo, isNot(same(s1.variableInfo)));
         expect(s2.variableInfo, {
@@ -3440,7 +3587,8 @@
             x: _matchVariableModel(chain: null),
           });
 
-          var s2 = s1.write(x, Type('int'), new SsaNode<Var, Type>(null), h);
+          var s2 =
+              s1.write(null, x, Type('int'), new SsaNode<Var, Type>(null), h);
           expect(s2.variableInfo, {
             x: _matchVariableModel(chain: ['int']),
           });
@@ -3461,7 +3609,8 @@
           });
 
           // 'x' is write-captured, so not promoted
-          var s3 = s2.write(x, Type('int'), new SsaNode<Var, Type>(null), h);
+          var s3 =
+              s2.write(null, x, Type('int'), new SsaNode<Var, Type>(null), h);
           expect(s3.variableInfo, {
             x: _matchVariableModel(chain: null, writeCaptured: true),
           });
@@ -3480,7 +3629,7 @@
             ),
           });
           var s2 = s1.write(
-              objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
+              null, objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
           expect(s2.variableInfo, {
             objectQVar: _matchVariableModel(
               chain: ['int?', 'int'],
@@ -3502,7 +3651,7 @@
             ),
           });
           var s2 = s1.write(
-              objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
+              null, objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
           expect(s2.variableInfo, {
             objectQVar: _matchVariableModel(
               chain: ['Object', 'int'],
@@ -3524,8 +3673,8 @@
             ofInterest: ['num?'],
           ),
         });
-        var s2 =
-            s1.write(objectQVar, Type('num?'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(_MockNonPromotionReason(), objectQVar, Type('num?'),
+            new SsaNode<Var, Type>(null), h);
         expect(s2.variableInfo, {
           objectQVar: _matchVariableModel(
             chain: ['num?'],
@@ -3548,8 +3697,8 @@
             ofInterest: ['num?', 'int?'],
           ),
         });
-        var s2 =
-            s1.write(objectQVar, Type('int?'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(_MockNonPromotionReason(), objectQVar, Type('int?'),
+            new SsaNode<Var, Type>(null), h);
         expect(s2.variableInfo, {
           objectQVar: _matchVariableModel(
             chain: ['num?', 'int?'],
@@ -3618,7 +3767,8 @@
               ),
             });
 
-            var s2 = s1.write(x, Type('C'), new SsaNode<Var, Type>(null), h);
+            var s2 =
+                s1.write(null, x, Type('C'), new SsaNode<Var, Type>(null), h);
             expect(s2.variableInfo, {
               x: _matchVariableModel(
                 chain: ['Object', 'B'],
@@ -3643,7 +3793,8 @@
               ),
             });
 
-            var s2 = s1.write(x, Type('C'), new SsaNode<Var, Type>(null), h);
+            var s2 =
+                s1.write(null, x, Type('C'), new SsaNode<Var, Type>(null), h);
             expect(s2.variableInfo, {
               x: _matchVariableModel(
                 chain: ['Object', 'B'],
@@ -3668,7 +3819,8 @@
               ),
             });
 
-            var s2 = s1.write(x, Type('B'), new SsaNode<Var, Type>(null), h);
+            var s2 =
+                s1.write(null, x, Type('B'), new SsaNode<Var, Type>(null), h);
             expect(s2.variableInfo, {
               x: _matchVariableModel(
                 chain: ['Object', 'A'],
@@ -3694,7 +3846,7 @@
               ),
             });
             var s2 = s1.write(
-                objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
+                null, objectQVar, Type('int'), new SsaNode<Var, Type>(null), h);
             // It's ambiguous whether to promote to num? or num*, so we don't
             // promote.
             expect(s2, isNot(same(s1)));
@@ -3721,8 +3873,8 @@
               ofInterest: ['num?', 'num*'],
             ),
           });
-          var s2 = s1.write(
-              objectQVar, Type('num?'), new SsaNode<Var, Type>(null), h);
+          var s2 = s1.write(_MockNonPromotionReason(), objectQVar, Type('num?'),
+              new SsaNode<Var, Type>(null), h);
           // It's ambiguous whether to promote to num? or num*, but since the
           // written type is exactly num?, we use that.
           expect(s2.variableInfo, {
@@ -3754,7 +3906,8 @@
           ),
         });
 
-        var s2 = s1.write(x, Type('double'), new SsaNode<Var, Type>(null), h);
+        var s2 = s1.write(_MockNonPromotionReason(), x, Type('double'),
+            new SsaNode<Var, Type>(null), h);
         expect(s2.variableInfo, {
           x: _matchVariableModel(
             chain: ['num?', 'num'],
@@ -3908,11 +4061,11 @@
             .declare(c, false)
             .declare(d, false);
         var s1 = s0
-            .write(a, Type('int'), new SsaNode<Var, Type>(null), h)
-            .write(b, Type('int'), new SsaNode<Var, Type>(null), h);
+            .write(null, a, Type('int'), new SsaNode<Var, Type>(null), h)
+            .write(null, b, Type('int'), new SsaNode<Var, Type>(null), h);
         var s2 = s0
-            .write(a, Type('int'), new SsaNode<Var, Type>(null), h)
-            .write(c, Type('int'), new SsaNode<Var, Type>(null), h);
+            .write(null, a, Type('int'), new SsaNode<Var, Type>(null), h)
+            .write(null, c, Type('int'), new SsaNode<Var, Type>(null), h);
         var result = s1.rebaseForward(h, s2);
         expect(result.infoFor(a).assigned, true);
         expect(result.infoFor(b).assigned, true);
@@ -3978,7 +4131,8 @@
           var s0 = FlowModel<Var, Type>(Reachability.initial).declare(x, true);
           var s1 = s0;
           if (unsafe) {
-            s1 = s1.write(x, Type('Object?'), new SsaNode<Var, Type>(null), h);
+            s1 = s1.write(
+                null, x, Type('Object?'), new SsaNode<Var, Type>(null), h);
           }
           if (thisType != null) {
             s1 =
@@ -5363,6 +5517,173 @@
       ]);
     });
   });
+
+  group('why not promoted', () {
+    test('due to assignment', () {
+      var h = Harness();
+      var x = Var('x', 'int?');
+      late Expression writeExpression;
+      h.run([
+        declare(x, initialized: true),
+        if_(x.read.eq(nullLiteral), [
+          return_(),
+        ]),
+        checkPromoted(x, 'int'),
+        (writeExpression = x.write(expr('int?'))).stmt,
+        checkNotPromoted(x),
+        x.read.whyNotPromoted((reasons) {
+          expect(reasons.keys, unorderedEquals([Type('int')]));
+          var nonPromotionReason =
+              reasons.values.single as DemoteViaExplicitWrite<Var, Expression>;
+          expect(nonPromotionReason.writeExpression, same(writeExpression));
+        }).stmt,
+      ]);
+    });
+
+    test('due to assignment, multiple demotions', () {
+      var h = Harness();
+      var x = Var('x', 'Object?');
+      late Expression writeExpression;
+      h.run([
+        declare(x, initialized: true),
+        if_(x.read.isNot('int?'), [
+          return_(),
+        ]),
+        if_(x.read.eq(nullLiteral), [
+          return_(),
+        ]),
+        checkPromoted(x, 'int'),
+        (writeExpression = x.write(expr('Object?'))).stmt,
+        checkNotPromoted(x),
+        x.read.whyNotPromoted((reasons) {
+          expect(reasons.keys, unorderedEquals([Type('int'), Type('int?')]));
+          expect(
+              (reasons[Type('int')] as DemoteViaExplicitWrite<Var, Expression>)
+                  .writeExpression,
+              same(writeExpression));
+          expect(
+              (reasons[Type('int?')] as DemoteViaExplicitWrite<Var, Expression>)
+                  .writeExpression,
+              same(writeExpression));
+        }).stmt,
+      ]);
+    });
+
+    test('preserved in join when one branch unreachable', () {
+      var h = Harness();
+      var x = Var('x', 'int?');
+      late Expression writeExpression;
+      h.run([
+        declare(x, initialized: true),
+        if_(x.read.eq(nullLiteral), [
+          return_(),
+        ]),
+        checkPromoted(x, 'int'),
+        (writeExpression = x.write(expr('int?'))).stmt,
+        checkNotPromoted(x),
+        if_(expr('bool'), [
+          return_(),
+        ]),
+        x.read.whyNotPromoted((reasons) {
+          expect(reasons.keys, unorderedEquals([Type('int')]));
+          var nonPromotionReason =
+              reasons.values.single as DemoteViaExplicitWrite<Var, Expression>;
+          expect(nonPromotionReason.writeExpression, same(writeExpression));
+        }).stmt,
+      ]);
+    });
+
+    test('preserved in later promotions', () {
+      var h = Harness();
+      var x = Var('x', 'Object');
+      late Expression writeExpression;
+      h.run([
+        declare(x, initialized: true),
+        if_(x.read.is_('int', isInverted: true), [
+          return_(),
+        ]),
+        checkPromoted(x, 'int'),
+        (writeExpression = x.write(expr('Object'))).stmt,
+        checkNotPromoted(x),
+        if_(x.read.is_('num', isInverted: true), [
+          return_(),
+        ]),
+        checkPromoted(x, 'num'),
+        x.read.whyNotPromoted((reasons) {
+          var nonPromotionReason =
+              reasons[Type('int')] as DemoteViaExplicitWrite;
+          expect(nonPromotionReason.writeExpression, same(writeExpression));
+        }).stmt,
+      ]);
+    });
+
+    test('re-promotion', () {
+      var h = Harness();
+      var x = Var('x', 'int?');
+      h.run([
+        declare(x, initialized: true),
+        if_(x.read.eq(nullLiteral), [
+          return_(),
+        ]),
+        checkPromoted(x, 'int'),
+        x.write(expr('int?')).stmt,
+        checkNotPromoted(x),
+        if_(x.read.eq(nullLiteral), [
+          return_(),
+        ]),
+        checkPromoted(x, 'int'),
+        x.read.whyNotPromoted((reasons) {
+          expect(reasons, isEmpty);
+        }).stmt,
+      ]);
+    });
+
+    group('because field', () {
+      test('via explicit this', () {
+        var h = Harness();
+        h.run([
+          if_(this_('C').propertyGet('field').eq(nullLiteral), [
+            return_(),
+          ]),
+          this_('C').propertyGet('field').whyNotPromoted((reasons) {
+            expect(reasons.keys, unorderedEquals([Type('Object')]));
+            var nonPromotionReason = reasons.values.single;
+            expect(nonPromotionReason, TypeMatcher<FieldNotPromoted>());
+          }).stmt,
+        ]);
+      });
+
+      test('via implicit this/super', () {
+        var h = Harness();
+        h.run([
+          if_(thisOrSuperPropertyGet('field').eq(nullLiteral), [
+            return_(),
+          ]),
+          thisOrSuperPropertyGet('field').whyNotPromoted((reasons) {
+            expect(reasons.keys, unorderedEquals([Type('Object')]));
+            var nonPromotionReason = reasons.values.single;
+            expect(nonPromotionReason, TypeMatcher<FieldNotPromoted>());
+          }).stmt,
+        ]);
+      });
+
+      test('via variable', () {
+        var h = Harness();
+        var x = Var('x', 'C');
+        h.run([
+          declare(x, initialized: true),
+          if_(x.read.propertyGet('field').eq(nullLiteral), [
+            return_(),
+          ]),
+          x.read.propertyGet('field').whyNotPromoted((reasons) {
+            expect(reasons.keys, unorderedEquals([Type('Object')]));
+            var nonPromotionReason = reasons.values.single;
+            expect(nonPromotionReason, TypeMatcher<FieldNotPromoted>());
+          }).stmt,
+        ]);
+      });
+    });
+  });
 }
 
 /// Returns the appropriate matcher for expecting an assertion error to be
@@ -5434,3 +5755,12 @@
 
 Reference<Var, Type> _varRef(Var variable) =>
     new VariableReference<Var, Type>(variable);
+
+class _MockNonPromotionReason extends NonPromotionReason {
+  String get shortName => fail('Unexpected call to shortName');
+
+  R accept<R, Node extends Object, Expression extends Object,
+              Variable extends Object>(
+          NonPromotionReasonVisitor<R, Node, Expression, Variable> visitor) =>
+      fail('Unexpected call to accept');
+}
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/assignment.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/assignment.dart
new file mode 100644
index 0000000..f867664
--- /dev/null
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/assignment.dart
@@ -0,0 +1,71 @@
+// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+abstract class C {
+  C? operator +(int i);
+  int get cProperty => 0;
+}
+
+direct_assignment(int? i, int? j) {
+  if (i == null) return;
+  /*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ i = j;
+  i. /*notPromoted(explicitWrite)*/ isEven;
+}
+
+compound_assignment(C? c, int i) {
+  if (c == null) return;
+  /*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ c += i;
+  c. /*notPromoted(explicitWrite)*/ cProperty;
+}
+
+via_postfix_op(C? c) {
+  if (c == null) return;
+  /*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ c++;
+  c. /*notPromoted(explicitWrite)*/ cProperty;
+}
+
+via_prefix_op(C? c) {
+  if (c == null) return;
+  /*analyzer.explicitWrite*/ ++ /*cfe.update: explicitWrite*/ c;
+  c. /*notPromoted(explicitWrite)*/ cProperty;
+}
+
+via_for_each_statement(int? i, List<int?> list) {
+  if (i == null) return;
+  for (/*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ i in list) {
+    i. /*notPromoted(explicitWrite)*/ isEven;
+  }
+}
+
+via_for_each_list_element(int? i, List<int?> list) {
+  if (i == null) return;
+  [
+    for (/*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ i in list)
+      i. /*notPromoted(explicitWrite)*/ isEven
+  ];
+}
+
+via_for_each_set_element(int? i, List<int?> list) {
+  if (i == null) return;
+  ({
+    for (/*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ i in list)
+      i. /*notPromoted(explicitWrite)*/ isEven
+  });
+}
+
+via_for_each_map_key(int? i, List<int?> list) {
+  if (i == null) return;
+  ({
+    for (/*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ i in list)
+      i. /*notPromoted(explicitWrite)*/ isEven: null
+  });
+}
+
+via_for_each_map_value(int? i, List<int?> list) {
+  if (i == null) return;
+  ({
+    for (/*cfe.update: explicitWrite*/ /*analyzer.explicitWrite*/ i in list)
+      null: i. /*notPromoted(explicitWrite)*/ isEven
+  });
+}
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/field.dart b/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/field.dart
new file mode 100644
index 0000000..0bbec4e
--- /dev/null
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/field.dart
@@ -0,0 +1,50 @@
+// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class C {
+  int? i;
+  int? j;
+
+  get_field_via_explicit_this() {
+    if (this.i == null) return;
+    this.i. /*notPromoted(fieldNotPromoted(i))*/ isEven;
+  }
+
+  get_field_via_explicit_this_parenthesized() {
+    if ((this).i == null) return;
+    (this).i. /*notPromoted(fieldNotPromoted(i))*/ isEven;
+  }
+
+  get_field_by_implicit_this() {
+    if (i == null) return;
+    i. /*notPromoted(fieldNotPromoted(i))*/ isEven;
+  }
+}
+
+class D extends C {
+  get_field_via_explicit_super() {
+    if (super.i == null) return;
+    super.i. /*notPromoted(fieldNotPromoted(i))*/ isEven;
+  }
+
+  get_field_by_implicit_super() {
+    if (i == null) return;
+    i. /*notPromoted(fieldNotPromoted(i))*/ isEven;
+  }
+}
+
+get_field_via_prefixed_identifier(C c) {
+  if (c.i == null) return;
+  c.i. /*notPromoted(fieldNotPromoted(i))*/ isEven;
+}
+
+get_field_via_prefixed_identifier_mismatched_target(C c1, C c2) {
+  if (c1.i == null) return;
+  c2.i.isEven;
+}
+
+get_field_via_prefixed_identifier_mismatched_property(C c) {
+  if (c.i == null) return;
+  c.j.isEven;
+}
diff --git a/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/marker.options b/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/marker.options
new file mode 100644
index 0000000..1ebb2bc
--- /dev/null
+++ b/pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted/data/marker.options
@@ -0,0 +1,2 @@
+cfe=pkg/front_end/test/id_tests/why_not_promoted_test.dart
+analyzer=pkg/analyzer/test/id_tests/why_not_promoted_test.dart
\ No newline at end of file
diff --git a/pkg/_js_interop_checks/lib/js_interop_checks.dart b/pkg/_js_interop_checks/lib/js_interop_checks.dart
index b936c44..7639e85 100644
--- a/pkg/_js_interop_checks/lib/js_interop_checks.dart
+++ b/pkg/_js_interop_checks/lib/js_interop_checks.dart
@@ -12,6 +12,7 @@
         messageJsInteropAnonymousFactoryPositionalParameters,
         messageJsInteropEnclosingClassJSAnnotation,
         messageJsInteropEnclosingClassJSAnnotationContext,
+        messageJsInteropExternalMemberNotJSAnnotated,
         messageJsInteropIndexNotSupported,
         messageJsInteropNamedParameters,
         messageJsInteropNonExternalConstructor,
@@ -29,6 +30,37 @@
   bool _classHasJSAnnotation = false;
   bool _classHasAnonymousAnnotation = false;
   bool _libraryHasJSAnnotation = false;
+
+  /// Libraries that use `external` to exclude from checks on external.
+  static final Iterable<String> _pathsWithAllowedDartExternalUsage = <String>[
+    '_foreign_helper', // for foreign helpers
+    '_interceptors', // for ddc JS string
+    '_native_typed_data',
+    '_runtime', // for ddc types at runtime
+    'async',
+    'core', // for environment constructors
+    'html',
+    'html_common',
+    'indexed_db',
+    'js',
+    'js_util',
+    'svg',
+    'web_audio',
+    'web_gl',
+    'web_sql'
+  ];
+
+  /// Native tests to exclude from checks on external.
+  // TODO(rileyporter): Use ExternalName from CFE to exclude native tests.
+  List<Pattern> _allowedNativeTestPatterns = [
+    RegExp(r'(?<!generated_)tests/dart2js/native'),
+    RegExp(r'(?<!generated_)tests/dart2js/internal'),
+    'generated_tests/dart2js/native/native_test',
+    RegExp(r'(?<!generated_)tests/dart2js_2/native'),
+    RegExp(r'(?<!generated_)tests/dart2js_2/internal'),
+    'generated_tests/dart2js_2/native/native_test',
+  ];
+
   bool _libraryIsGlobalNamespace = false;
   // TODO(srujzs): This currently disables this check always. This check should
   // instead only be disabled up until a given language version.
@@ -233,6 +265,30 @@
                 enclosingClass.name.length)
           ]);
     }
+
+    // Check for correct `external` usage.
+    if (member.isExternal &&
+        !_isAllowedExternalUsage(member) &&
+        !hasJSInteropAnnotation(member)) {
+      if (member.enclosingClass != null && !_classHasJSAnnotation ||
+          member.enclosingClass == null && !_libraryHasJSAnnotation) {
+        _diagnosticsReporter.report(
+            messageJsInteropExternalMemberNotJSAnnotated,
+            member.fileOffset,
+            member.name.text.length,
+            member.location.file);
+      }
+    }
+  }
+
+  /// Verifies given member is one of the allowed usages of external:
+  /// a dart low level library, a foreign helper, a native test,
+  /// or a from environment constructor.
+  bool _isAllowedExternalUsage(Member member) {
+    Uri uri = member.enclosingLibrary.importUri;
+    return uri.scheme == 'dart' &&
+            _pathsWithAllowedDartExternalUsage.contains(uri.path) ||
+        _allowedNativeTestPatterns.any((pattern) => uri.path.contains(pattern));
   }
 
   /// Returns whether [member] is considered to be a JS interop member.
diff --git a/pkg/analysis_server/benchmark/benchmarks.dart b/pkg/analysis_server/benchmark/benchmarks.dart
index 20ad9aa..1dd12cb 100644
--- a/pkg/analysis_server/benchmark/benchmarks.dart
+++ b/pkg/analysis_server/benchmark/benchmarks.dart
@@ -17,8 +17,10 @@
 
 Future main(List<String> args) async {
   var benchmarks = <Benchmark>[
-    ColdAnalysisBenchmark(),
-    AnalysisBenchmark(),
+    ColdAnalysisBenchmark(ServerBenchmark.das),
+    ColdAnalysisBenchmark(ServerBenchmark.lsp),
+    AnalysisBenchmark(ServerBenchmark.das),
+    AnalysisBenchmark(ServerBenchmark.lsp),
     FlutterAnalyzeBenchmark(),
   ];
 
diff --git a/pkg/analysis_server/benchmark/perf/benchmarks_impl.dart b/pkg/analysis_server/benchmark/perf/benchmarks_impl.dart
index 0d0893f..c9b438c 100644
--- a/pkg/analysis_server/benchmark/perf/benchmarks_impl.dart
+++ b/pkg/analysis_server/benchmark/perf/benchmarks_impl.dart
@@ -5,10 +5,8 @@
 import 'dart:async';
 import 'dart:io';
 
-import 'package:analysis_server/src/protocol_server.dart';
 import 'package:path/path.dart' as path;
 
-import '../../test/integration/support/integration_tests.dart';
 import '../benchmarks.dart';
 import 'memory_tests.dart';
 
@@ -18,11 +16,13 @@
 ///   - analysis-server-edit
 ///   - analysis-server-completion
 class AnalysisBenchmark extends Benchmark {
-  AnalysisBenchmark()
-      : super(
-            'analysis-server',
-            'Analysis server benchmarks of a large project, with an existing '
-                'driver cache.',
+  final AbstractBenchmarkTest Function() testConstructor;
+  AnalysisBenchmark(ServerBenchmark benchmarkTest)
+      : testConstructor = benchmarkTest.testConstructor,
+        super(
+            benchmarkTest.id,
+            '${benchmarkTest.name} benchmarks of a large project, with an existing '
+            'driver cache.',
             kind: 'group');
 
   @override
@@ -32,13 +32,11 @@
   }) async {
     var stopwatch = Stopwatch()..start();
 
-    var test = AnalysisServerMemoryUsageTest();
+    var test = testConstructor();
     if (verbose) {
       test.debugStdio();
     }
-    await test.setUp();
-    await test.subscribeToStatusNotifications();
-    await test.sendAnalysisSetAnalysisRoots(getProjectRoots(quick: quick), []);
+    await test.setUp(getProjectRoots(quick: quick));
     await test.analysisFinished;
 
     stopwatch.stop();
@@ -64,37 +62,20 @@
     return result;
   }
 
-  Future<int> _calcCompletionTiming(
-      AbstractAnalysisServerIntegrationTest test) async {
+  Future<int> _calcCompletionTiming(AbstractBenchmarkTest test) async {
     const kGroupCount = 10;
 
     var filePath =
         path.join(analysisServerSrcPath, 'lib/src/analysis_server.dart');
     var contents = File(filePath).readAsStringSync();
 
-    await test
-        .sendAnalysisUpdateContent({filePath: AddContentOverlay(contents)});
+    await test.openFile(filePath, contents);
 
     var completionCount = 0;
     var stopwatch = Stopwatch()..start();
 
     Future _complete(int offset) async {
-      // Create a new non-broadcast stream and subscribe to
-      // test.onCompletionResults before sending a request.
-      // Otherwise we could skip results which where posted to
-      // test.onCompletionResults after request is sent but
-      // before subscribing to test.onCompletionResults.
-      final completionResults = StreamController<CompletionResultsParams>();
-      completionResults.sink.addStream(test.onCompletionResults);
-
-      var result = await test.sendCompletionGetSuggestions(filePath, offset);
-
-      var future = completionResults.stream
-          .where((CompletionResultsParams params) =>
-              params.id == result.id && params.isLast)
-          .first;
-      await future;
-
+      await test.complete(filePath, offset);
       completionCount++;
     }
 
@@ -116,26 +97,25 @@
         contents = contents.substring(0, index + 1) +
             ' ' +
             contents.substring(index + 1);
-        await test
-            .sendAnalysisUpdateContent({filePath: AddContentOverlay(contents)});
+        await test.updateFile(filePath, contents);
       }
     }
 
     stopwatch.stop();
 
+    await test.closeFile(filePath);
+
     return stopwatch.elapsedMicroseconds ~/ completionCount;
   }
 
-  Future<int> _calcEditTiming(
-      AbstractAnalysisServerIntegrationTest test) async {
+  Future<int> _calcEditTiming(AbstractBenchmarkTest test) async {
     const kGroupCount = 5;
 
     var filePath =
         path.join(analysisServerSrcPath, 'lib/src/analysis_server.dart');
     var contents = File(filePath).readAsStringSync();
 
-    await test
-        .sendAnalysisUpdateContent({filePath: AddContentOverlay(contents)});
+    await test.openFile(filePath, contents);
 
     var stopwatch = Stopwatch()..start();
 
@@ -145,13 +125,14 @@
       contents = contents.substring(0, index + 1) +
           ' ' +
           contents.substring(index + 1);
-      await test
-          .sendAnalysisUpdateContent({filePath: AddContentOverlay(contents)});
+      await test.updateFile(filePath, contents);
       await test.analysisFinished;
     }
 
     stopwatch.stop();
 
+    await test.closeFile(filePath);
+
     return stopwatch.elapsedMicroseconds ~/ kGroupCount;
   }
 }
@@ -160,10 +141,12 @@
 ///   - analysis-server-cold-analysis
 ///   - analysis-server-cold-memory
 class ColdAnalysisBenchmark extends Benchmark {
-  ColdAnalysisBenchmark()
-      : super(
-            'analysis-server-cold',
-            'Analysis server benchmarks of a large project on start-up, no '
+  final AbstractBenchmarkTest Function() testConstructor;
+  ColdAnalysisBenchmark(ServerBenchmark benchmarkTest)
+      : testConstructor = benchmarkTest.testConstructor,
+        super(
+            '${benchmarkTest.id}-cold',
+            '${benchmarkTest.name} benchmarks of a large project on start-up, no '
                 'existing driver cache.',
             kind: 'group');
 
@@ -181,10 +164,8 @@
 
     var stopwatch = Stopwatch()..start();
 
-    var test = AnalysisServerMemoryUsageTest();
-    await test.setUp();
-    await test.subscribeToStatusNotifications();
-    await test.sendAnalysisSetAnalysisRoots(getProjectRoots(quick: quick), []);
+    var test = testConstructor();
+    await test.setUp(getProjectRoots(quick: quick));
     await test.analysisFinished;
 
     stopwatch.stop();
@@ -200,3 +181,16 @@
     return result;
   }
 }
+
+class ServerBenchmark {
+  static final das = ServerBenchmark('analysis-server', 'Analysis Server',
+      () => AnalysisServerBenchmarkTest());
+  static final lsp = ServerBenchmark('lsp-analysis-server',
+      'LSP Analysis Server', () => LspAnalysisServerBenchmarkTest());
+  final String id;
+
+  final String name;
+  final AbstractBenchmarkTest Function() testConstructor;
+
+  ServerBenchmark(this.id, this.name, this.testConstructor);
+}
diff --git a/pkg/analysis_server/benchmark/perf/memory_tests.dart b/pkg/analysis_server/benchmark/perf/memory_tests.dart
index 5f242cd..651763f 100644
--- a/pkg/analysis_server/benchmark/perf/memory_tests.dart
+++ b/pkg/analysis_server/benchmark/perf/memory_tests.dart
@@ -6,38 +6,90 @@
 import 'dart:convert' show jsonDecode, jsonEncode;
 import 'dart:io';
 
+import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
+import 'package:analysis_server/src/lsp/handlers/handler_completion.dart';
+import 'package:analysis_server/src/protocol_server.dart';
 import 'package:test/test.dart';
 
+import '../../test/integration/lsp_server/integration_tests.dart';
 import '../../test/integration/support/integration_tests.dart';
+import '../../test/lsp/server_abstract.dart' show ClientCapabilitiesHelperMixin;
+
+/// A server protocol-agnostic interface to the memory test, allowing the same
+/// benchmarks to run for both the original protocol and LSP.
+abstract class AbstractBenchmarkTest {
+  Future<void> get analysisFinished;
+  Future<void> closeFile(String filePath);
+  Future<void> complete(String filePath, int offset);
+  void debugStdio();
+  Future<int> getMemoryUsage();
+  Future<void> openFile(String filePath, String contents);
+  Future<void> setUp(List<String> roots);
+  Future<void> shutdown();
+
+  Future<void> updateFile(String filePath, String contents);
+}
+
+/// An implementation of [AbstractBenchmarkTest] for a original protocol memory
+/// test.
+class AnalysisServerBenchmarkTest extends AbstractBenchmarkTest {
+  final _test = AnalysisServerMemoryUsageTest();
+
+  @override
+  Future<void> get analysisFinished => _test.analysisFinished;
+
+  @override
+  Future<void> closeFile(String filePath) =>
+      _test.sendAnalysisUpdateContent({filePath: RemoveContentOverlay()});
+
+  @override
+  Future<void> complete(String filePath, int offset) async {
+    // Create a new non-broadcast stream and subscribe to
+    // test.onCompletionResults before sending a request.
+    // Otherwise we could skip results which where posted to
+    // test.onCompletionResults after request is sent but
+    // before subscribing to test.onCompletionResults.
+    final completionResults = StreamController<CompletionResultsParams>();
+    completionResults.sink.addStream(_test.onCompletionResults);
+
+    var result = await _test.sendCompletionGetSuggestions(filePath, offset);
+
+    var future = completionResults.stream
+        .where((CompletionResultsParams params) =>
+            params.id == result.id && params.isLast)
+        .first;
+    await future;
+  }
+
+  @override
+  void debugStdio() => _test.debugStdio();
+
+  @override
+  Future<int> getMemoryUsage() => _test.getMemoryUsage();
+
+  @override
+  Future<void> openFile(String filePath, String contents) =>
+      _test.sendAnalysisUpdateContent({filePath: AddContentOverlay(contents)});
+
+  @override
+  Future<void> setUp(List<String> roots) async {
+    await _test.setUp();
+    await _test.subscribeToStatusNotifications();
+    await _test.sendAnalysisSetAnalysisRoots(roots, []);
+  }
+
+  @override
+  Future<void> shutdown() => _test.shutdown();
+
+  @override
+  Future<void> updateFile(String filePath, String contents) =>
+      _test.sendAnalysisUpdateContent({filePath: AddContentOverlay(contents)});
+}
 
 /// Base class for analysis server memory usage tests.
 class AnalysisServerMemoryUsageTest
-    extends AbstractAnalysisServerIntegrationTest {
-  int _vmServicePort;
-
-  Future<int> getMemoryUsage() async {
-    var uri = Uri.parse('ws://127.0.0.1:$_vmServicePort/ws');
-    var service = await ServiceProtocol.connect(uri);
-    var vm = await service.call('getVM');
-
-    var total = 0;
-
-    List isolateRefs = vm['isolates'];
-    for (Map isolateRef in isolateRefs) {
-      var isolate =
-          await service.call('getIsolate', {'isolateId': isolateRef['id']});
-
-      Map _heaps = isolate['_heaps'];
-      total += _heaps['new']['used'] + _heaps['new']['external'];
-      total += _heaps['old']['used'] + _heaps['old']['external'];
-    }
-
-    service.dispose();
-
-    return total;
-  }
-
+    extends AbstractAnalysisServerIntegrationTest with ServerMemoryUsageMixin {
   /// Send the server an 'analysis.setAnalysisRoots' command directing it to
   /// analyze [sourceDirectory].
   Future setAnalysisRoot() =>
@@ -46,7 +98,7 @@
   /// The server is automatically started before every test.
   @override
   Future setUp() async {
-    _vmServicePort = await _findAvailableSocketPort();
+    _vmServicePort = await ServiceProtocol._findAvailableSocketPort();
 
     onAnalysisErrors.listen((AnalysisErrorsParams params) {
       currentAnalysisErrors[params.file] = params.errors;
@@ -77,14 +129,135 @@
   Future subscribeToStatusNotifications() async {
     await sendServerSetSubscriptions([ServerService.STATUS]);
   }
+}
 
-  static Future<int> _findAvailableSocketPort() async {
-    var socket = await ServerSocket.bind(InternetAddress.loopbackIPv4, 0);
-    try {
-      return socket.port;
-    } finally {
-      await socket.close();
+/// An implementation of [AbstractBenchmarkTest] for an LSP memory test.
+class LspAnalysisServerBenchmarkTest extends AbstractBenchmarkTest
+    with ClientCapabilitiesHelperMixin {
+  final _test = LspAnalysisServerMemoryUsageTest();
+
+  /// Track the file contents so we can easily convert offsets (used in
+  /// the interface) to Positions required by LSP without having to keep
+  /// passing in the contents.
+  final Map<String, String> _fileContents = {};
+  int _fileVersion = 1;
+
+  @override
+  Future<void> get analysisFinished => _test.waitForAnalysisComplete();
+
+  @override
+  Future<void> closeFile(String filePath) {
+    _fileContents.remove(filePath);
+    return _test.closeFile(Uri.file(filePath));
+  }
+
+  @override
+  Future<void> complete(String filePath, int offset) {
+    final contents = _fileContents[filePath];
+    final position = _test.positionFromOffset(offset, contents);
+    return _test.getCompletion(Uri.file(filePath), position);
+  }
+
+  @override
+  void debugStdio() {}
+
+  @override
+  Future<int> getMemoryUsage() => _test.getMemoryUsage();
+
+  @override
+  Future<void> openFile(String filePath, String contents) {
+    _fileContents[filePath] = contents;
+    return _test.openFile(Uri.file(filePath), contents);
+  }
+
+  @override
+  Future<void> setUp(List<String> roots) async {
+    await _test.setUp();
+    _test.projectFolderPath = roots.single;
+    _test.projectFolderUri = Uri.file(_test.projectFolderPath);
+    // Use some reasonable default client capabilities that will activate
+    // features that will excercise more code that benchmarks should measure
+    // (such as applyEdit to allow suggestion sets results to be merged in).
+    await _test.initialize(
+      textDocumentCapabilities: withCompletionItemSnippetSupport(
+        withCompletionItemKinds(
+          emptyTextDocumentClientCapabilities,
+          defaultSupportedCompletionKinds.toList(),
+        ),
+      ),
+      workspaceCapabilities: withDocumentChangesSupport(
+        withApplyEditSupport(emptyWorkspaceClientCapabilities),
+      ),
+      windowCapabilities:
+          withWorkDoneProgressSupport(emptyWindowClientCapabilities),
+    );
+  }
+
+  @override
+  Future<void> shutdown() async => _test.tearDown();
+
+  @override
+  Future<void> updateFile(String filePath, String contents) {
+    _fileContents[filePath] = contents;
+    return _test.replaceFile(_fileVersion++, Uri.file(filePath), contents);
+  }
+}
+
+/// Base class for LSP analysis server memory usage tests.
+class LspAnalysisServerMemoryUsageTest
+    extends AbstractLspAnalysisServerIntegrationTest
+    with ServerMemoryUsageMixin {
+  Map<String, List<Diagnostic>> currentAnalysisErrors = {};
+
+  @override
+  void expect(actual, matcher, {String reason}) =>
+      outOfTestExpect(actual, matcher, reason: reason);
+
+  /// The server is automatically started before every test.
+  @override
+  Future<void> setUp() async {
+    _vmServicePort = await ServiceProtocol._findAvailableSocketPort();
+    vmArgs.addAll([
+      '--enable-vm-service=$_vmServicePort',
+      '-DSILENT_OBSERVATORY=true',
+      '--disable-service-auth-codes',
+      '--disable-dart-dev'
+    ]);
+    await super.setUp();
+
+    errorNotificationsFromServer.listen((NotificationMessage error) {
+      // A server error should never happen during an integration test.
+      fail('${error.toJson()}');
+    });
+  }
+
+  /// After every test, the server is stopped.
+  Future shutdown() async => this.tearDown();
+}
+
+mixin ServerMemoryUsageMixin {
+  int _vmServicePort;
+
+  Future<int> getMemoryUsage() async {
+    var uri = Uri.parse('ws://127.0.0.1:$_vmServicePort/ws');
+    var service = await ServiceProtocol.connect(uri);
+    var vm = await service.call('getVM');
+
+    var total = 0;
+
+    List isolateRefs = vm['isolates'];
+    for (Map isolateRef in isolateRefs) {
+      var isolate =
+          await service.call('getIsolate', {'isolateId': isolateRef['id']});
+
+      Map _heaps = isolate['_heaps'];
+      total += _heaps['new']['used'] + _heaps['new']['external'];
+      total += _heaps['old']['used'] + _heaps['old']['external'];
     }
+
+    service.dispose();
+
+    return total;
   }
 }
 
@@ -137,4 +310,13 @@
     var socket = await WebSocket.connect(uri.toString());
     return ServiceProtocol._(socket);
   }
+
+  static Future<int> _findAvailableSocketPort() async {
+    var socket = await ServerSocket.bind(InternetAddress.loopbackIPv4, 0);
+    try {
+      return socket.port;
+    } finally {
+      await socket.close();
+    }
+  }
 }
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index 95b2236..bb921ee 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -810,6 +810,7 @@
     builder.performanceLog = analysisServer.analysisPerformanceLogger;
     builder.byteStore = analysisServer.byteStore;
     builder.enableIndex = true;
+    builder.lookForBazelBuildFileSubstitutes = false;
     return builder;
   }
 
diff --git a/pkg/analysis_server/lib/src/lsp/lsp_analysis_server.dart b/pkg/analysis_server/lib/src/lsp/lsp_analysis_server.dart
index 106cd91..1165746 100644
--- a/pkg/analysis_server/lib/src/lsp/lsp_analysis_server.dart
+++ b/pkg/analysis_server/lib/src/lsp/lsp_analysis_server.dart
@@ -867,6 +867,7 @@
     builder.performanceLog = analysisServer.analysisPerformanceLogger;
     builder.byteStore = analysisServer.byteStore;
     builder.enableIndex = true;
+    builder.lookForBazelBuildFileSubstitutes = false;
     return builder;
   }
 
diff --git a/pkg/analysis_server/lib/src/lsp/mapping.dart b/pkg/analysis_server/lib/src/lsp/mapping.dart
index d2fad8a..02af79d 100644
--- a/pkg/analysis_server/lib/src/lsp/mapping.dart
+++ b/pkg/analysis_server/lib/src/lsp/mapping.dart
@@ -11,7 +11,6 @@
 import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/lsp_protocol/protocol_special.dart';
 import 'package:analysis_server/lsp_protocol/protocol_special.dart' as lsp;
-import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/lsp/constants.dart' as lsp;
 import 'package:analysis_server/src/lsp/constants.dart';
 import 'package:analysis_server/src/lsp/dartdoc.dart';
@@ -212,7 +211,7 @@
   HashSet<lsp.CompletionItemKind> supportedCompletionItemKinds,
   String file,
   int offset,
-  IncludedSuggestionSet includedSuggestionSet,
+  server.IncludedSuggestionSet includedSuggestionSet,
   Library library,
   Map<String, int> tagBoosts,
   server.LineInfo lineInfo,
@@ -667,7 +666,7 @@
   server.LineInfo Function(String) getLineInfo,
   plugin.AnalysisError error,
 ) {
-  List<DiagnosticRelatedInformation> relatedInformation;
+  List<lsp.DiagnosticRelatedInformation> relatedInformation;
   if (error.contextMessages != null && error.contextMessages.isNotEmpty) {
     relatedInformation = error.contextMessages
         .map((message) =>
@@ -792,18 +791,20 @@
         range: toRange(lineInfo, label.offset, label.length),
         label: label.label);
 
-CodeActionKind toCodeActionKind(String id, lsp.CodeActionKind fallback) {
+lsp.CodeActionKind toCodeActionKind(String id, lsp.CodeActionKind fallback) {
   if (id == null) {
     return fallback;
   }
   // Dart fixes and assists start with "dart.assist." and "dart.fix." but in LSP
   // we want to use the predefined prefixes for CodeActions.
   final newId = id
-      .replaceAll('dart.assist', CodeActionKind.Refactor.toString())
-      .replaceAll('dart.fix', CodeActionKind.QuickFix.toString())
-      .replaceAll('analysisOptions.assist', CodeActionKind.Refactor.toString())
-      .replaceAll('analysisOptions.fix', CodeActionKind.QuickFix.toString());
-  return CodeActionKind(newId);
+      .replaceAll('dart.assist', lsp.CodeActionKind.Refactor.toString())
+      .replaceAll('dart.fix', lsp.CodeActionKind.QuickFix.toString())
+      .replaceAll(
+          'analysisOptions.assist', lsp.CodeActionKind.Refactor.toString())
+      .replaceAll(
+          'analysisOptions.fix', lsp.CodeActionKind.QuickFix.toString());
+  return lsp.CodeActionKind(newId);
 }
 
 lsp.CompletionItem toCompletionItem(
@@ -931,7 +932,7 @@
   // Default to the error's severity if none is specified.
   errorSeverity ??= errorCode.errorSeverity;
 
-  List<DiagnosticRelatedInformation> relatedInformation;
+  List<lsp.DiagnosticRelatedInformation> relatedInformation;
   if (error.contextMessages.isNotEmpty) {
     relatedInformation = error.contextMessages
         .map((message) => toDiagnosticRelatedInformation(result, message))
@@ -1232,7 +1233,7 @@
   return lsp.TextDocumentEdit(
     textDocument: edit.doc,
     edits: edit.edits
-        .map((e) => Either2<TextEdit, AnnotatedTextEdit>.t1(
+        .map((e) => Either2<lsp.TextEdit, lsp.AnnotatedTextEdit>.t1(
             toTextEdit(edit.lineInfo, e)))
         .toList(),
   );
diff --git a/pkg/analysis_server/lib/src/services/completion/dart/feature_computer.dart b/pkg/analysis_server/lib/src/services/completion/dart/feature_computer.dart
index 6461fbf..f205135 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart/feature_computer.dart
+++ b/pkg/analysis_server/lib/src/services/completion/dart/feature_computer.dart
@@ -80,6 +80,7 @@
     double hasDeprecated = 0.0,
     double inheritanceDistance = 0.0,
     double isConstant = 0.0,
+    double isNoSuchMethod = 0.0,
     double localVariableDistance = 0.0,
     double startsWithDollar = 0.0,
     double superMatches = 0.0}) {
@@ -97,6 +98,7 @@
     hasDeprecated,
     inheritanceDistance,
     isConstant,
+    isNoSuchMethod,
     localVariableDistance,
     startsWithDollar,
     superMatches,
@@ -106,6 +108,7 @@
     0.50, // hasDeprecated
     1.00, // inheritanceDistance
     1.00, // isConstant
+    1.00, // isNoSuchMethod
     1.00, // localVariableDistance
     0.50, // startsWithDollar
     1.00, // superMatches
@@ -289,6 +292,17 @@
     return 0.0;
   }
 
+  /// Return the value of the _is noSuchMethod_ feature.
+  double isNoSuchMethodFeature(
+      String containingMethodName, String proposedMemberName) {
+    if (proposedMemberName == containingMethodName) {
+      // Don't penalize `noSuchMethod` when completing after `super` in an
+      // override of `noSuchMethod`.
+      return 0.0;
+    }
+    return proposedMemberName == 'noSuchMethod' ? -1.0 : 0.0;
+  }
+
   /// Return the value of the _keyword_ feature for the [keyword] when
   /// completing at the given [completionLocation].
   double keywordFeature(String keyword, String completionLocation) {
diff --git a/pkg/analysis_server/lib/src/services/completion/dart/suggestion_builder.dart b/pkg/analysis_server/lib/src/services/completion/dart/suggestion_builder.dart
index edc41bb..47d35a8b 100644
--- a/pkg/analysis_server/lib/src/services/completion/dart/suggestion_builder.dart
+++ b/pkg/analysis_server/lib/src/services/completion/dart/suggestion_builder.dart
@@ -575,6 +575,8 @@
     var isConstant = request.inConstantContext
         ? featureComputer.isConstantFeature(method)
         : 0.0;
+    var isNoSuchMethod = featureComputer.isNoSuchMethodFeature(
+        _containingMemberName, method.name);
     var startsWithDollar = featureComputer.startsWithDollarFeature(method.name);
     var superMatches =
         featureComputer.superMatchesFeature(_containingMemberName, method.name);
@@ -584,6 +586,7 @@
         hasDeprecated: hasDeprecated,
         inheritanceDistance: inheritanceDistance,
         isConstant: isConstant,
+        isNoSuchMethod: isNoSuchMethod,
         startsWithDollar: startsWithDollar,
         superMatches: superMatches);
     listener?.computedFeatures(
@@ -592,6 +595,7 @@
         hasDeprecated: hasDeprecated,
         inheritanceDistance: inheritanceDistance,
         isConstant: isConstant,
+        isNoSuchMethod: isNoSuchMethod,
         startsWithDollar: startsWithDollar,
         superMatches: superMatches);
 
@@ -944,22 +948,14 @@
     return elementKind;
   }
 
-  /// Compute a relevance value from the given feature scores:
-  /// - [contextType] is higher if the type of the element matches the context
-  ///   type,
-  /// - [hasDeprecated] is higher if the element is not deprecated,
-  /// - [inheritanceDistance] is higher if the element is defined closer to the
-  ///   target type,
-  /// - [startsWithDollar] is higher if the element's name doe _not_ start with
-  ///   a dollar sign, and
-  /// - [superMatches] is higher if the element is being invoked through `super`
-  ///   and the element's name matches the name of the enclosing method.
+  /// Compute a relevance value from the given feature scores.
   int _computeMemberRelevance(
       {@required double contextType,
       @required double elementKind,
       @required double hasDeprecated,
       @required double inheritanceDistance,
       @required double isConstant,
+      double isNoSuchMethod = 0.0,
       @required double startsWithDollar,
       @required double superMatches}) {
     var score = weightedAverage(
@@ -968,6 +964,7 @@
         hasDeprecated: hasDeprecated,
         inheritanceDistance: inheritanceDistance,
         isConstant: isConstant,
+        isNoSuchMethod: isNoSuchMethod,
         startsWithDollar: startsWithDollar,
         superMatches: superMatches);
     return toRelevance(score);
@@ -1145,6 +1142,7 @@
       double hasDeprecated,
       double inheritanceDistance,
       double isConstant,
+      double isNoSuchMethod,
       double keyword,
       double localVariableDistance,
       double startsWithDollar,
diff --git a/pkg/analysis_server/lib/src/services/correction/executable_parameters.dart b/pkg/analysis_server/lib/src/services/correction/executable_parameters.dart
index 5c93ac9..6f66ef2 100644
--- a/pkg/analysis_server/lib/src/services/correction/executable_parameters.dart
+++ b/pkg/analysis_server/lib/src/services/correction/executable_parameters.dart
@@ -61,7 +61,7 @@
   /// can't be found.
   Future<FormalParameterList> getParameterList() async {
     var result = await sessionHelper.getElementDeclaration(executable);
-    var targetDeclaration = result.node;
+    var targetDeclaration = result?.node;
     if (targetDeclaration is ConstructorDeclaration) {
       return targetDeclaration.parameters;
     } else if (targetDeclaration is FunctionDeclaration) {
@@ -77,7 +77,7 @@
   /// or `null` if it can't be found.
   Future<FormalParameter> getParameterNode(ParameterElement element) async {
     var result = await sessionHelper.getElementDeclaration(element);
-    var declaration = result.node;
+    var declaration = result?.node;
     for (var node = declaration; node != null; node = node.parent) {
       if (node is FormalParameter && node.parent is FormalParameterList) {
         return node;
diff --git a/pkg/analysis_server/test/analysis/update_content_test.dart b/pkg/analysis_server/test/analysis/update_content_test.dart
index f000bb7..d8ee8ac 100644
--- a/pkg/analysis_server/test/analysis/update_content_test.dart
+++ b/pkg/analysis_server/test/analysis/update_content_test.dart
@@ -6,7 +6,6 @@
 import 'package:analysis_server/protocol/protocol_constants.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
-import 'package:analyzer_plugin/protocol/protocol_common.dart' as plugin;
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -235,8 +234,8 @@
     var files = params.files;
     expect(files, hasLength(1));
     Object overlay = files[filePath];
-    expect(overlay, const TypeMatcher<plugin.AddContentOverlay>());
-    plugin.AddContentOverlay addOverlay = overlay;
+    expect(overlay, const TypeMatcher<AddContentOverlay>());
+    AddContentOverlay addOverlay = overlay;
     expect(addOverlay.content, fileContent);
     //
     // Change
@@ -251,8 +250,8 @@
     files = params.files;
     expect(files, hasLength(1));
     overlay = files[filePath];
-    expect(overlay, const TypeMatcher<plugin.ChangeContentOverlay>());
-    plugin.ChangeContentOverlay changeOverlay = overlay;
+    expect(overlay, const TypeMatcher<ChangeContentOverlay>());
+    ChangeContentOverlay changeOverlay = overlay;
     expect(changeOverlay.edits, hasLength(2));
     //
     // Remove
@@ -265,7 +264,7 @@
     files = params.files;
     expect(files, hasLength(1));
     overlay = files[filePath];
-    expect(overlay, const TypeMatcher<plugin.RemoveContentOverlay>());
+    expect(overlay, const TypeMatcher<RemoveContentOverlay>());
   }
 
 //  CompilationUnit _getTestUnit() {
diff --git a/pkg/analysis_server/test/integration/lsp_server/integration_tests.dart b/pkg/analysis_server/test/integration/lsp_server/integration_tests.dart
index e69a2bc..c07285d 100644
--- a/pkg/analysis_server/test/integration/lsp_server/integration_tests.dart
+++ b/pkg/analysis_server/test/integration/lsp_server/integration_tests.dart
@@ -8,12 +8,14 @@
 import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/src/lsp/channel/lsp_byte_stream_channel.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
+import 'package:meta/meta.dart';
 import 'package:path/path.dart';
 
 import '../../lsp/server_abstract.dart';
 
-class AbstractLspAnalysisServerIntegrationTest
+abstract class AbstractLspAnalysisServerIntegrationTest
     with ClientCapabilitiesHelperMixin, LspAnalysisServerTestMixin {
+  final List<String> vmArgs = [];
   LspServerClient client;
 
   final Map<int, Completer<ResponseMessage>> _completers = {};
@@ -63,7 +65,8 @@
   void sendResponseToServer(ResponseMessage response) =>
       client.channel.sendResponse(response);
 
-  Future setUp() async {
+  @mustCallSuper
+  Future<void> setUp() async {
     // Set up temporary folder for the test.
     projectFolderPath = Directory.systemTemp
         .createTempSync('analysisServer')
@@ -77,7 +80,7 @@
     analysisOptionsUri = Uri.file(analysisOptionsPath);
 
     client = LspServerClient();
-    await client.start();
+    await client.start(vmArgs: vmArgs);
     client.serverToClient.listen((message) {
       if (message is ResponseMessage) {
         final id = message.id.map((number) => number,
@@ -128,7 +131,7 @@
     return dirname(pathname);
   }
 
-  Future start() async {
+  Future start({List<String> vmArgs}) async {
     if (_process != null) {
       throw Exception('Process already started');
     }
@@ -154,7 +157,7 @@
       serverPath = normalize(join(rootDir, 'bin', 'server.dart'));
     }
 
-    final arguments = [serverPath, '--lsp', '--suppress-analytics'];
+    final arguments = [...?vmArgs, serverPath, '--lsp', '--suppress-analytics'];
     _process = await Process.start(dartBinary, arguments);
     _process.exitCode.then((int code) {
       if (code != 0) {
diff --git a/pkg/analysis_server/test/lsp/server_abstract.dart b/pkg/analysis_server/test/lsp/server_abstract.dart
index 74726a9..fead448 100644
--- a/pkg/analysis_server/test/lsp/server_abstract.dart
+++ b/pkg/analysis_server/test/lsp/server_abstract.dart
@@ -26,7 +26,8 @@
 import 'package:analyzer_plugin/src/protocol/protocol_internal.dart' as plugin;
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as path;
-import 'package:test/test.dart';
+import 'package:test/test.dart' hide expect;
+import 'package:test/test.dart' as test show expect;
 
 import '../mocks.dart';
 import '../src/utilities/mock_packages.dart';
@@ -724,6 +725,9 @@
     return expectSuccessfulResponseTo(request, (result) => result);
   }
 
+  void expect(actual, matcher, {String reason}) =>
+      test.expect(actual, matcher, reason: reason);
+
   void expectDocumentVersion(
     TextDocumentEdit edit,
     Map<String, int> expectedVersions,
diff --git a/pkg/analysis_server/test/src/cider/completion_test.dart b/pkg/analysis_server/test/src/cider/completion_test.dart
index 86bd6a5..e272ab9 100644
--- a/pkg/analysis_server/test/src/cider/completion_test.dart
+++ b/pkg/analysis_server/test/src/cider/completion_test.dart
@@ -488,7 +488,24 @@
     _assertHasClass(text: 'A');
   }
 
-  Future<void> test_limitedResolution_inPart() async {
+  Future<void> test_limitedResolution_inPart_partOfName() async {
+    newFile('/workspace/dart/test/lib/a.dart', content: r'''
+library my_lib;
+part 'test.dart';
+class A {}
+''');
+
+    await _compute(r'''
+part of my_lib;
+^
+''');
+
+    _assertHasClass(text: 'int');
+    // TODO(scheglov) would be nice to have it
+    _assertNoClass(text: 'A');
+  }
+
+  Future<void> test_limitedResolution_inPart_partOfUri() async {
     newFile('/workspace/dart/test/lib/a.dart', content: r'''
 part 'test.dart';
 class A {}
@@ -503,6 +520,17 @@
     _assertHasClass(text: 'A');
   }
 
+  Future<void> test_limitedResolution_inPart_partOfUri_doesNotExist() async {
+    await _compute(r'''
+part of 'a.dart';
+class A {}
+^
+''');
+
+    _assertHasClass(text: 'int');
+    _assertHasClass(text: 'A');
+  }
+
   Future<void> test_limitedResolution_mixin_method_body() async {
     _configureToCheckNotResolved(
       identifiers: {'print'},
diff --git a/pkg/analysis_server/test/src/services/correction/fix/add_missing_parameter_required_test.dart b/pkg/analysis_server/test/src/services/correction/fix/add_missing_parameter_required_test.dart
index 0f5c502..b073812 100644
--- a/pkg/analysis_server/test/src/services/correction/fix/add_missing_parameter_required_test.dart
+++ b/pkg/analysis_server/test/src/services/correction/fix/add_missing_parameter_required_test.dart
@@ -105,6 +105,17 @@
 ''');
   }
 
+  Future<void> test_function_hasZero_partOfName_noLibrary() async {
+    await resolveTestCode('''
+part of my_lib;
+test() {}
+main() {
+  test(1);
+}
+''');
+    await assertNoFix();
+  }
+
   Future<void> test_method_hasOne() async {
     await resolveTestCode('''
 class A {
diff --git a/pkg/analysis_server/tool/code_completion/completion_metrics.dart b/pkg/analysis_server/tool/code_completion/completion_metrics.dart
index 3cffbee..b9c2038 100644
--- a/pkg/analysis_server/tool/code_completion/completion_metrics.dart
+++ b/pkg/analysis_server/tool/code_completion/completion_metrics.dart
@@ -1121,6 +1121,7 @@
           'hasDeprecated',
           'inheritanceDistance',
           'isConstant',
+          'isNoSuchMethod',
           'keyword',
           'localVariableDistance',
           'startsWithDollar',
@@ -1464,7 +1465,7 @@
   @override
   void builtSuggestion(protocol.CompletionSuggestion suggestion) {
     featureMap[suggestion] = cachedFeatures;
-    cachedFeatures = const [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0];
+    cachedFeatures = const [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0];
   }
 
   @override
@@ -1474,6 +1475,7 @@
       double hasDeprecated = 0.0,
       double inheritanceDistance = 0.0,
       double isConstant = 0.0,
+      double isNoSuchMethod = 0.0,
       double keyword = 0.0,
       double localVariableDistance = 0.0,
       double startsWithDollar = 0.0,
@@ -1484,6 +1486,7 @@
       hasDeprecated,
       inheritanceDistance,
       isConstant,
+      isNoSuchMethod,
       keyword,
       localVariableDistance,
       startsWithDollar,
diff --git a/pkg/analyzer/CHANGELOG.md b/pkg/analyzer/CHANGELOG.md
index ac3f422..51bfd9e 100644
--- a/pkg/analyzer/CHANGELOG.md
+++ b/pkg/analyzer/CHANGELOG.md
@@ -6,6 +6,7 @@
 * Deprecated `CompilationUnitElement.functionTypeAliases`.
   Use `CompilationUnitElement.typeAliases` instead.
 * Added `AnalysisContext.sdkRoot`.
+* Removed `NullSafetyUnderstandingFlag`.
 
 ## 0.41.1
 * Updated `PackageBuildWorkspace` that supports `package:build` to stop
diff --git a/pkg/analyzer/lib/dart/element/null_safety_understanding_flag.dart b/pkg/analyzer/lib/dart/element/null_safety_understanding_flag.dart
deleted file mode 100644
index 5406994..0000000
--- a/pkg/analyzer/lib/dart/element/null_safety_understanding_flag.dart
+++ /dev/null
@@ -1,44 +0,0 @@
-// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'dart:async';
-
-import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/type.dart';
-
-/// Every [DartType] has the nullability suffix, elements declared in legacy
-/// libraries have types with star suffixes, and types in migrated libraries
-/// have none, question mark, or star suffixes.  Analyzer itself can handle
-/// mixtures of nullabilities with legacy and migrated libraries.
-///
-/// However analyzer clients saw only star suffixes so far.  Exposing other
-/// nullabilities is a breaking change, because types types with different
-/// nullabilities are not equal, `null` cannot be used where a non-nullable
-/// type is expected, etc.  When accessing elements and types that come from
-/// migrated libraries, while analyzing a legacy library, nullabilities must
-/// be erased, using [LibraryElement.toLegacyElementIfOptOut] and
-/// [LibraryElement.toLegacyTypeIfOptOut].  The client must explicitly do
-/// this, and explicitly specify that it knows how to handle nullabilities
-/// by setting this flag to `true`.
-///
-/// When this flag is `false` (by default), all types will return their
-/// nullability as star.  So, type equality and subtype checks will work
-/// as they worked before some libraries migrated.  Note, that during
-/// analysis (building element models, and resolving ASTs), analyzer will use
-/// actual nullabilities, according to the language specification, so report
-/// all corresponding errors, and perform necessary type operations.  It is
-/// only when the client later views on the types, they will look as legacy.
-class NullSafetyUnderstandingFlag {
-  static final _zoneKey = Object();
-
-  static bool get isEnabled {
-    return Zone.current[_zoneKey] ?? false;
-  }
-
-  /// Code that understands nullability should be run using this method,
-  /// otherwise all type operations will treat all nullabilities as star.
-  static R enableNullSafetyTypes<R>(R Function() body) {
-    return runZoned<R>(body, zoneValues: {_zoneKey: true});
-  }
-}
diff --git a/pkg/analyzer/lib/error/listener.dart b/pkg/analyzer/lib/error/listener.dart
index 7de0ed7..e89e8b6 100644
--- a/pkg/analyzer/lib/error/listener.dart
+++ b/pkg/analyzer/lib/error/listener.dart
@@ -94,16 +94,18 @@
   /// Report an error with the given [errorCode] and [arguments].
   /// The [node] is used to compute the location of the error.
   void reportErrorForNode(ErrorCode errorCode, AstNode node,
-      [List<Object?>? arguments]) {
-    reportErrorForOffset(errorCode, node.offset, node.length, arguments);
+      [List<Object?>? arguments, List<DiagnosticMessage>? messages]) {
+    reportErrorForOffset(
+        errorCode, node.offset, node.length, arguments, messages);
   }
 
   /// Report an error with the given [errorCode] and [arguments]. The location
   /// of the error is specified by the given [offset] and [length].
   void reportErrorForOffset(ErrorCode errorCode, int offset, int length,
-      [List<Object?>? arguments]) {
+      [List<Object?>? arguments, List<DiagnosticMessage>? messages]) {
     _convertElements(arguments);
-    var messages = _convertTypeNames(arguments);
+    messages ??= [];
+    messages.addAll(_convertTypeNames(arguments));
     _errorListener.onError(
         AnalysisError(_source, offset, length, errorCode, arguments, messages));
   }
diff --git a/pkg/analyzer/lib/src/context/builder.dart b/pkg/analyzer/lib/src/context/builder.dart
index 9280477..e8a31f4 100644
--- a/pkg/analyzer/lib/src/context/builder.dart
+++ b/pkg/analyzer/lib/src/context/builder.dart
@@ -97,6 +97,11 @@
   /// indexing and search.
   bool enableIndex = false;
 
+  /// Sometimes `BUILD` files are not preserved, and other files are created
+  /// instead. But looking for them is expensive, so we want to avoid this
+  /// in cases when `BUILD` files are always available.
+  bool lookForBazelBuildFileSubstitutes = true;
+
   /// Initialize a newly created builder to be ready to build a context rooted in
   /// the directory with the given [rootDirectoryPath].
   ContextBuilder(this.resourceProvider, this.sdkManager, this.contentCache,
@@ -113,8 +118,9 @@
     if (builderOptions.librarySummaryPaths != null) {
       summaryData = SummaryDataStore(builderOptions.librarySummaryPaths!);
     }
-    Workspace workspace =
-        ContextBuilder.createWorkspace(resourceProvider, path, this);
+    Workspace workspace = ContextBuilder.createWorkspace(
+        resourceProvider, path, this,
+        lookForBazelBuildFileSubstitutes: lookForBazelBuildFileSubstitutes);
     final sf =
         createSourceFactoryFromWorkspace(workspace, summaryData: summaryData);
 
@@ -397,7 +403,8 @@
   }
 
   static Workspace createWorkspace(ResourceProvider resourceProvider,
-      String rootPath, ContextBuilder contextBuilder) {
+      String rootPath, ContextBuilder contextBuilder,
+      {bool lookForBazelBuildFileSubstitutes = true}) {
     var packages = contextBuilder.createPackageMap(rootPath);
     var packageMap = <String, List<Folder>>{};
     for (var package in packages.packages) {
@@ -413,7 +420,8 @@
           PubWorkspace.find(resourceProvider, packageMap, rootPath) ??
           BasicWorkspace.find(resourceProvider, packageMap, rootPath);
     }
-    Workspace? workspace = BazelWorkspace.find(resourceProvider, rootPath);
+    Workspace? workspace = BazelWorkspace.find(resourceProvider, rootPath,
+        lookForBuildFileSubstitutes: lookForBazelBuildFileSubstitutes);
     workspace ??= GnWorkspace.find(resourceProvider, rootPath);
     workspace ??=
         PackageBuildWorkspace.find(resourceProvider, packageMap, rootPath);
diff --git a/pkg/analyzer/lib/src/dart/analysis/driver.dart b/pkg/analyzer/lib/src/dart/analysis/driver.dart
index 7c67e46..614d996 100644
--- a/pkg/analyzer/lib/src/dart/analysis/driver.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/driver.dart
@@ -11,7 +11,6 @@
 import 'package:analyzer/dart/analysis/session.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart' show LibraryElement;
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/exception/exception.dart';
@@ -247,6 +246,8 @@
   /// Whether resolved units should be indexed.
   final bool enableIndex;
 
+  late final DriverAnalyzedFiles analyzedFiles = DriverAnalyzedFiles(this);
+
   /// The current analysis session.
   late AnalysisSessionImpl _currentSession;
 
@@ -445,6 +446,7 @@
     if (!_fsState.hasUri(path)) {
       return;
     }
+    analyzedFiles.reset();
     if (AnalysisEngine.isDartFileName(path)) {
       _fileTracker.addFile(path);
       // If the file is known, it has already been read, even if it did not
@@ -1198,6 +1200,7 @@
   /// but does not guarantee this.
   void removeFile(String path) {
     _throwIfNotAbsolutePath(path);
+    analyzedFiles.reset();
     _fileTracker.removeFile(path);
     clearLibraryContext();
     _priorityResults.clear();
@@ -1252,21 +1255,6 @@
       {bool withUnit = false,
       bool asIsIfPartWithoutLibrary = false,
       bool skipIfSameSignature = false}) {
-    return NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-      return _computeAnalysisResult2(
-        path,
-        withUnit: withUnit,
-        asIsIfPartWithoutLibrary: asIsIfPartWithoutLibrary,
-        skipIfSameSignature: skipIfSameSignature,
-      );
-    });
-  }
-
-  /// Unwrapped implementation of [_computeAnalysisResult].
-  AnalysisResult? _computeAnalysisResult2(String path,
-      {bool withUnit = false,
-      bool asIsIfPartWithoutLibrary = false,
-      bool skipIfSameSignature = false}) {
     FileState file = _fsState.getFileForPath(path);
 
     // Prepare the library - the file itself, or the known library.
@@ -1403,12 +1391,6 @@
   /// Return the newly computed resolution result of the library with the
   /// given [path].
   ResolvedLibraryResultImpl _computeResolvedLibrary(String path) {
-    return NullSafetyUnderstandingFlag.enableNullSafetyTypes(
-        () => _computeResolvedLibrary2(path));
-  }
-
-  /// Unwrapped implementation of [_computeResolvedLibrary].
-  ResolvedLibraryResultImpl _computeResolvedLibrary2(String path) {
     FileState library = _fsState.getFileForPath(path);
 
     return _logger.run('Compute resolved library $path', () {
@@ -1545,23 +1527,21 @@
       }
     }
 
-    NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-      if (_libraryContext == null) {
-        _libraryContext = LibraryContext(
-          testView: _testView.libraryContext,
-          session: currentSession,
-          logger: _logger,
-          byteStore: _byteStore,
-          analysisOptions: _analysisOptions,
-          declaredVariables: declaredVariables,
-          sourceFactory: _sourceFactory,
-          externalSummaries: _externalSummaries,
-          targetLibrary: library,
-        );
-      } else {
-        _libraryContext!.load2(library);
-      }
-    });
+    if (_libraryContext == null) {
+      _libraryContext = LibraryContext(
+        testView: _testView.libraryContext,
+        session: currentSession,
+        logger: _logger,
+        byteStore: _byteStore,
+        analysisOptions: _analysisOptions,
+        declaredVariables: declaredVariables,
+        sourceFactory: _sourceFactory,
+        externalSummaries: _externalSummaries,
+        targetLibrary: library,
+      );
+    } else {
+      _libraryContext!.load2(library);
+    }
 
     return _libraryContext!;
   }
@@ -2103,6 +2083,29 @@
             errors);
 }
 
+/// The cache of files analyzed in the driver.
+class DriverAnalyzedFiles {
+  final AnalysisDriver _driver;
+  List<String>? _files;
+
+  DriverAnalyzedFiles(this._driver);
+
+  List<String> get files {
+    var files = _files;
+
+    if (files == null) {
+      var contextRoot = _driver.analysisContext!.contextRoot;
+      _files = files = contextRoot.analyzedFiles().toList();
+    }
+
+    return files;
+  }
+
+  void reset() {
+    _files = null;
+  }
+}
+
 /// An object that watches for the creation and removal of analysis drivers.
 ///
 /// Clients may not extend, implement or mix-in this class.
diff --git a/pkg/analyzer/lib/src/dart/analysis/file_state.dart b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
index 923e178..dc2c87a 100644
--- a/pkg/analyzer/lib/src/dart/analysis/file_state.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
@@ -628,22 +628,9 @@
     );
     parser.enableOptionalNewAndConst = true;
 
-    // TODO(scheglov) https://github.com/dart-lang/sdk/issues/41023
-    CompilationUnit unit;
-    try {
-      unit = parser.parseCompilationUnit(token);
-      unit.lineInfo = lineInfo;
-    } catch (e) {
-      throw StateError('''
-Parser error.
-path: $path
-${'-' * 40}
-$content
-''');
-    }
-
-    var unitImpl = unit as CompilationUnitImpl;
-    unitImpl.languageVersion = LibraryLanguageVersion(
+    var unit = parser.parseCompilationUnit(token) as CompilationUnitImpl;
+    unit.lineInfo = lineInfo;
+    unit.languageVersion = LibraryLanguageVersion(
       package: packageLanguageVersion!,
       override: scanner.overrideVersion,
     );
diff --git a/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart b/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
index 1f449ba..c3b00d8 100644
--- a/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
@@ -6,7 +6,6 @@
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/src/context/source.dart';
@@ -109,10 +108,6 @@
 
   /// Compute analysis results for all units of the library.
   Map<FileState, UnitAnalysisResult> analyzeSync() {
-    // Analyzer understands null safety, so it should set
-    // NullSafetyUnderstandingFlag.
-    assert(NullSafetyUnderstandingFlag.isEnabled);
-
     timerLibraryAnalyzer.start();
     Map<FileState, CompilationUnit> units = {};
 
diff --git a/pkg/analyzer/lib/src/dart/analysis/search.dart b/pkg/analyzer/lib/src/dart/analysis/search.dart
index fa87c88..03439d6 100644
--- a/pkg/analyzer/lib/src/dart/analysis/search.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/search.dart
@@ -503,8 +503,7 @@
   }
 
   void ownAnalyzed(Search search) {
-    var contextRoot = search._driver.analysisContext!.contextRoot;
-    for (var path in contextRoot.analyzedFiles()) {
+    for (var path in search._driver.analyzedFiles.files) {
       if (path.endsWith('.dart')) {
         add(path, search);
       }
diff --git a/pkg/analyzer/lib/src/dart/ast/to_source_visitor.dart b/pkg/analyzer/lib/src/dart/ast/to_source_visitor.dart
index 2758b97..24c111f 100644
--- a/pkg/analyzer/lib/src/dart/ast/to_source_visitor.dart
+++ b/pkg/analyzer/lib/src/dart/ast/to_source_visitor.dart
@@ -891,6 +891,7 @@
     safelyVisitNodeListWithSeparatorAndSuffix(node.metadata, " ", " ");
     sink.write("part of ");
     safelyVisitNode(node.libraryName);
+    safelyVisitNode(node.uri);
     sink.write(';');
   }
 
diff --git a/pkg/analyzer/lib/src/dart/constant/evaluation.dart b/pkg/analyzer/lib/src/dart/constant/evaluation.dart
index 4f7bd29..73b1748 100644
--- a/pkg/analyzer/lib/src/dart/constant/evaluation.dart
+++ b/pkg/analyzer/lib/src/dart/constant/evaluation.dart
@@ -815,7 +815,7 @@
       return true;
     }
     var objType = obj.type;
-    return library.typeSystem.isSubtypeOf2(objType, type);
+    return library.typeSystem.isSubtypeOf(objType, type);
   }
 
   DartObjectImpl _nullObject(LibraryElementImpl library) {
@@ -1538,7 +1538,7 @@
         // TODO(brianwilkerson) Figure out why the static type is sometimes null.
         var staticType = condition.staticType;
         if (staticType == null ||
-            typeSystem.isAssignableTo2(staticType, _typeProvider.boolType)) {
+            typeSystem.isAssignableTo(staticType, _typeProvider.boolType)) {
           // If the static type is not assignable, then we will have already
           // reported this error.
           // TODO(mfairhurst) get the FeatureSet to suppress this for nnbd too.
diff --git a/pkg/analyzer/lib/src/dart/constant/value.dart b/pkg/analyzer/lib/src/dart/constant/value.dart
index 19cc0a5..0730163 100644
--- a/pkg/analyzer/lib/src/dart/constant/value.dart
+++ b/pkg/analyzer/lib/src/dart/constant/value.dart
@@ -277,7 +277,7 @@
       return this;
     }
 
-    if (!typeSystem.isSubtypeOf2(type, resultType)) {
+    if (!typeSystem.isSubtypeOf(type, resultType)) {
       throw EvaluationException(
           CompileTimeErrorCode.CONST_EVAL_THROWS_EXCEPTION);
     }
@@ -495,7 +495,7 @@
     } else if (typeType == null) {
       state = BoolState.TRUE_STATE;
     } else {
-      state = BoolState.from(typeSystem.isSubtypeOf2(type, typeType));
+      state = BoolState.from(typeSystem.isSubtypeOf(type, typeType));
     }
     return DartObjectImpl(typeSystem, typeSystem.typeProvider.boolType, state);
   }
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 17860e4..e3d4d8d4 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -2323,142 +2323,90 @@
   AnalysisContext get context => compilationUnit.library.context;
 
   @override
-  bool get isAlwaysThrows =>
-      element is PropertyAccessorElement &&
-      element!.name == _ALWAYS_THROWS_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isAlwaysThrows => _isPackageMetaGetter(_ALWAYS_THROWS_VARIABLE_NAME);
 
   @override
   bool get isConstantEvaluated => evaluationResult != null;
 
   @override
   bool get isDeprecated {
-    if (element?.library!.isDartCore == true) {
-      if (element is ConstructorElement) {
-        return element!.enclosingElement!.name == _DEPRECATED_CLASS_NAME;
-      } else if (element is PropertyAccessorElement) {
-        return element!.name == _DEPRECATED_VARIABLE_NAME;
-      }
+    var element = this.element;
+    if (element is ConstructorElement) {
+      return element.library.isDartCore &&
+          element.enclosingElement.name == _DEPRECATED_CLASS_NAME;
+    } else if (element is PropertyAccessorElement) {
+      return element.library.isDartCore &&
+          element.name == _DEPRECATED_VARIABLE_NAME;
     }
     return false;
   }
 
   @override
-  bool get isDoNotStore =>
-      element is PropertyAccessorElement &&
-      element!.name == _DO_NOT_STORE_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isDoNotStore => _isPackageMetaGetter(_DO_NOT_STORE_VARIABLE_NAME);
 
   @override
-  bool get isFactory =>
-      element is PropertyAccessorElement &&
-      element!.name == _FACTORY_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isFactory => _isPackageMetaGetter(_FACTORY_VARIABLE_NAME);
 
   @override
-  bool get isImmutable =>
-      element is PropertyAccessorElement &&
-      element!.name == _IMMUTABLE_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isImmutable => _isPackageMetaGetter(_IMMUTABLE_VARIABLE_NAME);
 
   @override
-  bool get isInternal =>
-      element is PropertyAccessorElement &&
-      element!.name == _INTERNAL_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isInternal => _isPackageMetaGetter(_INTERNAL_VARIABLE_NAME);
 
   @override
-  bool get isIsTest =>
-      element is PropertyAccessorElement &&
-      element!.name == _IS_TEST_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isIsTest => _isPackageMetaGetter(_IS_TEST_VARIABLE_NAME);
 
   @override
-  bool get isIsTestGroup =>
-      element is PropertyAccessorElement &&
-      element!.name == _IS_TEST_GROUP_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isIsTestGroup => _isPackageMetaGetter(_IS_TEST_GROUP_VARIABLE_NAME);
 
   @override
   bool get isJS =>
-      element is ConstructorElement &&
-      element!.enclosingElement!.name == _JS_CLASS_NAME &&
-      element!.library!.name == _JS_LIB_NAME;
+      _isConstructor(libraryName: _JS_LIB_NAME, className: _JS_CLASS_NAME);
 
   @override
-  bool get isLiteral =>
-      element is PropertyAccessorElement &&
-      element!.name == _LITERAL_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isLiteral => _isPackageMetaGetter(_LITERAL_VARIABLE_NAME);
 
   @override
   bool get isMustCallSuper =>
-      element is PropertyAccessorElement &&
-      element!.name == _MUST_CALL_SUPER_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+      _isPackageMetaGetter(_MUST_CALL_SUPER_VARIABLE_NAME);
 
   @override
-  bool get isNonVirtual =>
-      element is PropertyAccessorElement &&
-      element!.name == _NON_VIRTUAL_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isNonVirtual => _isPackageMetaGetter(_NON_VIRTUAL_VARIABLE_NAME);
 
   @override
   bool get isOptionalTypeArgs =>
-      element is PropertyAccessorElement &&
-      element!.name == _OPTIONAL_TYPE_ARGS_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+      _isPackageMetaGetter(_OPTIONAL_TYPE_ARGS_VARIABLE_NAME);
 
   @override
-  bool get isOverride =>
-      element is PropertyAccessorElement &&
-      element!.name == _OVERRIDE_VARIABLE_NAME &&
-      element!.library!.isDartCore == true;
+  bool get isOverride => _isDartCoreGetter(_OVERRIDE_VARIABLE_NAME);
 
   @override
-  bool get isProtected =>
-      element is PropertyAccessorElement &&
-      element!.name == _PROTECTED_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isProtected => _isPackageMetaGetter(_PROTECTED_VARIABLE_NAME);
 
   @override
-  bool get isProxy =>
-      element is PropertyAccessorElement &&
-      element!.name == PROXY_VARIABLE_NAME &&
-      element!.library!.isDartCore == true;
+  bool get isProxy => _isDartCoreGetter(PROXY_VARIABLE_NAME);
 
   @override
   bool get isRequired =>
-      element is ConstructorElement &&
-          element!.enclosingElement!.name == _REQUIRED_CLASS_NAME &&
-          element!.library!.name == _META_LIB_NAME ||
-      element is PropertyAccessorElement &&
-          element!.name == _REQUIRED_VARIABLE_NAME &&
-          element!.library!.name == _META_LIB_NAME;
+      _isConstructor(
+          libraryName: _META_LIB_NAME, className: _REQUIRED_CLASS_NAME) ||
+      _isPackageMetaGetter(_REQUIRED_VARIABLE_NAME);
 
   @override
-  bool get isSealed =>
-      element is PropertyAccessorElement &&
-      element!.name == _SEALED_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+  bool get isSealed => _isPackageMetaGetter(_SEALED_VARIABLE_NAME);
 
   @override
-  bool get isTarget =>
-      element is ConstructorElement &&
-      element!.enclosingElement!.name == _TARGET_CLASS_NAME &&
-      element!.library!.name == _META_META_LIB_NAME;
+  bool get isTarget => _isConstructor(
+      libraryName: _META_META_LIB_NAME, className: _TARGET_CLASS_NAME);
 
   @override
-  bool get isVisibleForTemplate =>
-      element is PropertyAccessorElement &&
-      element!.name == _VISIBLE_FOR_TEMPLATE_VARIABLE_NAME &&
-      element!.library!.name == _NG_META_LIB_NAME;
+  bool get isVisibleForTemplate => _isTopGetter(
+      libraryName: _NG_META_LIB_NAME,
+      name: _VISIBLE_FOR_TEMPLATE_VARIABLE_NAME);
 
   @override
   bool get isVisibleForTesting =>
-      element is PropertyAccessorElement &&
-      element!.name == _VISIBLE_FOR_TESTING_VARIABLE_NAME &&
-      element!.library!.name == _META_LIB_NAME;
+      _isPackageMetaGetter(_VISIBLE_FOR_TESTING_VARIABLE_NAME);
 
   @override
   LibraryElement get library => compilationUnit.library;
@@ -2486,6 +2434,40 @@
 
   @override
   String toString() => '@$element';
+
+  bool _isConstructor({
+    required String libraryName,
+    required String className,
+  }) {
+    var element = this.element;
+    return element is ConstructorElement &&
+        element.enclosingElement.name == className &&
+        element.library.name == libraryName;
+  }
+
+  bool _isDartCoreGetter(String name) {
+    return _isTopGetter(
+      libraryName: 'dart.core',
+      name: name,
+    );
+  }
+
+  bool _isPackageMetaGetter(String name) {
+    return _isTopGetter(
+      libraryName: _META_LIB_NAME,
+      name: name,
+    );
+  }
+
+  bool _isTopGetter({
+    required String libraryName,
+    required String name,
+  }) {
+    var element = this.element;
+    return element is PropertyAccessorElement &&
+        element.name == name &&
+        element.library.name == libraryName;
+  }
 }
 
 /// A base class for concrete implementations of an [Element].
@@ -2907,7 +2889,7 @@
 
   @override
   AnalysisSession get session {
-    return _enclosingElement!.session;
+    return enclosingElement!.session;
   }
 
   @override
diff --git a/pkg/analyzer/lib/src/dart/element/generic_inferrer.dart b/pkg/analyzer/lib/src/dart/element/generic_inferrer.dart
index 56c791f..d7da75d 100644
--- a/pkg/analyzer/lib/src/dart/element/generic_inferrer.dart
+++ b/pkg/analyzer/lib/src/dart/element/generic_inferrer.dart
@@ -552,8 +552,7 @@
   bool get isDownwards => origin is! _TypeConstraintFromArgument;
 
   bool isSatisfiedBy(TypeSystemImpl ts, DartType type) {
-    return ts.isSubtypeOf2(lowerBound, type) &&
-        ts.isSubtypeOf2(type, upperBound);
+    return ts.isSubtypeOf(lowerBound, type) && ts.isSubtypeOf(type, upperBound);
   }
 
   /// Converts this constraint to a message suitable for a type inference error.
diff --git a/pkg/analyzer/lib/src/dart/element/greatest_lower_bound.dart b/pkg/analyzer/lib/src/dart/element/greatest_lower_bound.dart
index 1e9aebf..86df48a 100644
--- a/pkg/analyzer/lib/src/dart/element/greatest_lower_bound.dart
+++ b/pkg/analyzer/lib/src/dart/element/greatest_lower_bound.dart
@@ -111,7 +111,7 @@
     if (T1_nullability == NullabilitySuffix.none && T1.isDartCoreNull) {
       // * Null if Null <: T2
       // * Never otherwise
-      if (_typeSystem.isSubtypeOf2(_nullNone, T2)) {
+      if (_typeSystem.isSubtypeOf(_nullNone, T2)) {
         return _nullNone;
       } else {
         return NeverTypeImpl.instance;
@@ -122,7 +122,7 @@
     if (T2_nullability == NullabilitySuffix.none && T2.isDartCoreNull) {
       // * Null if Null <: T1
       // * Never otherwise
-      if (_typeSystem.isSubtypeOf2(_nullNone, T1)) {
+      if (_typeSystem.isSubtypeOf(_nullNone, T1)) {
         return _nullNone;
       } else {
         return NeverTypeImpl.instance;
@@ -209,12 +209,12 @@
     }
 
     // DOWN(T1, T2) = T1 if T1 <: T2
-    if (_typeSystem.isSubtypeOf2(T1, T2)) {
+    if (_typeSystem.isSubtypeOf(T1, T2)) {
       return T1;
     }
 
     // DOWN(T1, T2) = T2 if T2 <: T1
-    if (_typeSystem.isSubtypeOf2(T2, T1)) {
+    if (_typeSystem.isSubtypeOf(T2, T1)) {
       return T2;
     }
 
diff --git a/pkg/analyzer/lib/src/dart/element/least_upper_bound.dart b/pkg/analyzer/lib/src/dart/element/least_upper_bound.dart
index 325bdc0..764d9ef 100644
--- a/pkg/analyzer/lib/src/dart/element/least_upper_bound.dart
+++ b/pkg/analyzer/lib/src/dart/element/least_upper_bound.dart
@@ -183,10 +183,10 @@
     type1 = type1.withNullability(NullabilitySuffix.none);
     type2 = type2.withNullability(NullabilitySuffix.none);
 
-    if (typeSystem.isSubtypeOf2(type1, type2)) {
+    if (typeSystem.isSubtypeOf(type1, type2)) {
       return type2.withNullability(nullability);
     }
-    if (typeSystem.isSubtypeOf2(type2, type1)) {
+    if (typeSystem.isSubtypeOf(type2, type1)) {
       return type1.withNullability(nullability);
     }
 
@@ -212,8 +212,8 @@
             args.add(typeSystem.getLeastUpperBound(args1[i], args2[i]));
           }
         } else if (parameterVariance.isInvariant) {
-          if (!typeSystem.isSubtypeOf2(args1[i], args2[i]) ||
-              !typeSystem.isSubtypeOf2(args2[i], args1[i])) {
+          if (!typeSystem.isSubtypeOf(args1[i], args2[i]) ||
+              !typeSystem.isSubtypeOf(args2[i], args1[i])) {
             // No bound will be valid, find bound at the interface level.
             return _computeLeastUpperBound(
               InstantiatedClass.of(type1),
@@ -637,11 +637,11 @@
     // UP(X1 & B1, T2)
     if (T1 is TypeParameterTypeImpl) {
       // T2 if X1 <: T2
-      if (_typeSystem.isSubtypeOf2(T1, T2)) {
+      if (_typeSystem.isSubtypeOf(T1, T2)) {
         return T2;
       }
       // otherwise X1 if T2 <: X1
-      if (_typeSystem.isSubtypeOf2(T2, T1)) {
+      if (_typeSystem.isSubtypeOf(T2, T1)) {
         return T1;
       }
       // otherwise UP(B1a, T2)
@@ -655,12 +655,12 @@
     // UP(T1, X2 & B2)
     if (T2 is TypeParameterTypeImpl) {
       // X2 if T1 <: X2
-      if (_typeSystem.isSubtypeOf2(T1, T2)) {
+      if (_typeSystem.isSubtypeOf(T1, T2)) {
         // TODO(scheglov) How to get here?
         return T2;
       }
       // otherwise T1 if X2 <: T1
-      if (_typeSystem.isSubtypeOf2(T2, T1)) {
+      if (_typeSystem.isSubtypeOf(T2, T1)) {
         return T1;
       }
       // otherwise UP(T1, B2a)
diff --git a/pkg/analyzer/lib/src/dart/element/replace_top_bottom_visitor.dart b/pkg/analyzer/lib/src/dart/element/replace_top_bottom_visitor.dart
index 1d9c2ca..5709733 100644
--- a/pkg/analyzer/lib/src/dart/element/replace_top_bottom_visitor.dart
+++ b/pkg/analyzer/lib/src/dart/element/replace_top_bottom_visitor.dart
@@ -27,7 +27,7 @@
       if (variance.isContravariant) {
         // ...replacing every occurrence in `T` of a type `S` in a contravariant
         // position where `S <: Never` by `Object?`
-        if (_typeSystem.isSubtypeOf2(type, NeverTypeImpl.instance)) {
+        if (_typeSystem.isSubtypeOf(type, NeverTypeImpl.instance)) {
           return _topType;
         }
       } else {
diff --git a/pkg/analyzer/lib/src/dart/element/top_merge.dart b/pkg/analyzer/lib/src/dart/element/top_merge.dart
index c79f91b..b60f3b1 100644
--- a/pkg/analyzer/lib/src/dart/element/top_merge.dart
+++ b/pkg/analyzer/lib/src/dart/element/top_merge.dart
@@ -236,8 +236,8 @@
       if (R_isCovariant) {
         var T1 = T_parameter.type;
         var T2 = S_parameter.type;
-        var T1_isSubtype = typeSystem.isSubtypeOf2(T1, T2);
-        var T2_isSubtype = typeSystem.isSubtypeOf2(T2, T1);
+        var T1_isSubtype = typeSystem.isSubtypeOf(T1, T2);
+        var T2_isSubtype = typeSystem.isSubtypeOf(T2, T1);
         if (T1_isSubtype && T2_isSubtype) {
           // if `T1 <: T2` and `T2 <: T1`, then the result is
           // `NNBD_TOP_MERGE(T1, T2)`, and it is covariant.
diff --git a/pkg/analyzer/lib/src/dart/element/type.dart b/pkg/analyzer/lib/src/dart/element/type.dart
index 8cf0fb0..c092d6e 100644
--- a/pkg/analyzer/lib/src/dart/element/type.dart
+++ b/pkg/analyzer/lib/src/dart/element/type.dart
@@ -6,7 +6,6 @@
 
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_visitor.dart';
@@ -222,10 +221,8 @@
     }
 
     if (other is FunctionTypeImpl) {
-      if (NullSafetyUnderstandingFlag.isEnabled) {
-        if (other.nullabilitySuffix != nullabilitySuffix) {
-          return false;
-        }
+      if (other.nullabilitySuffix != nullabilitySuffix) {
+        return false;
       }
 
       if (other.typeFormals.length != typeFormals.length) {
@@ -841,10 +838,8 @@
       return true;
     }
     if (other is InterfaceTypeImpl) {
-      if (NullSafetyUnderstandingFlag.isEnabled) {
-        if (other.nullabilitySuffix != nullabilitySuffix) {
-          return false;
-        }
+      if (other.nullabilitySuffix != nullabilitySuffix) {
+        return false;
       }
       return other.element == element &&
           TypeImpl.equalArrays(other.typeArguments, typeArguments);
@@ -1386,7 +1381,7 @@
     for (DartType type in types) {
       // If any existing type in the bucket is more specific than this type,
       // then we can ignore this type.
-      if (bucket.any((DartType t) => typeSystem.isSubtypeOf2(t, type))) {
+      if (bucket.any((DartType t) => typeSystem.isSubtypeOf(t, type))) {
         continue;
       }
       // Otherwise, we need to add this type to the bucket and remove any types
@@ -1394,7 +1389,7 @@
       bool added = false;
       int i = 0;
       while (i < bucket.length) {
-        if (typeSystem.isSubtypeOf2(type, bucket[i])) {
+        if (typeSystem.isSubtypeOf(type, bucket[i])) {
           if (added) {
             if (i < bucket.length - 1) {
               bucket[i] = bucket.removeLast();
@@ -1852,10 +1847,8 @@
     }
 
     if (other is TypeParameterTypeImpl && other.element == element) {
-      if (NullSafetyUnderstandingFlag.isEnabled) {
-        if (other.nullabilitySuffix != nullabilitySuffix) {
-          return false;
-        }
+      if (other.nullabilitySuffix != nullabilitySuffix) {
+        return false;
       }
       return other.promotedBound == promotedBound;
     }
diff --git a/pkg/analyzer/lib/src/dart/element/type_system.dart b/pkg/analyzer/lib/src/dart/element/type_system.dart
index 51ceee2..beb67a5 100644
--- a/pkg/analyzer/lib/src/dart/element/type_system.dart
+++ b/pkg/analyzer/lib/src/dart/element/type_system.dart
@@ -7,7 +7,6 @@
 import 'package:analyzer/dart/ast/ast.dart' show AstNode;
 import 'package:analyzer/dart/ast/token.dart' show TokenType;
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_provider.dart';
@@ -169,7 +168,7 @@
   /// promotion during flow analysis.
   DartType factor(DartType T, DartType S) {
     // * If T <: S then Never
-    if (isSubtypeOf2(T, S)) {
+    if (isSubtypeOf(T, S)) {
       return NeverTypeImpl.instance;
     }
 
@@ -180,7 +179,7 @@
     if (T_nullability == NullabilitySuffix.question) {
       var R = (T as TypeImpl).withNullability(NullabilitySuffix.none);
       var factor_RS = factor(R, S) as TypeImpl;
-      if (isSubtypeOf2(nullNone, S)) {
+      if (isSubtypeOf(nullNone, S)) {
         return factor_RS;
       } else {
         return factor_RS.withNullability(NullabilitySuffix.question);
@@ -192,7 +191,7 @@
     if (T_nullability == NullabilitySuffix.star) {
       var R = (T as TypeImpl).withNullability(NullabilitySuffix.none);
       var factor_RS = factor(R, S) as TypeImpl;
-      if (isSubtypeOf2(nullNone, S)) {
+      if (isSubtypeOf(nullNone, S)) {
         return factor_RS;
       } else {
         return factor_RS.withNullability(NullabilitySuffix.star);
@@ -204,10 +203,10 @@
     if (T is InterfaceType && T.isDartAsyncFutureOr) {
       var R = T.typeArguments[0];
       var future_R = typeProvider.futureType2(R);
-      if (isSubtypeOf2(future_R, S)) {
+      if (isSubtypeOf(future_R, S)) {
         return factor(R, S);
       }
-      if (isSubtypeOf2(R, S)) {
+      if (isSubtypeOf(R, S)) {
         return factor(future_R, S);
       }
     }
@@ -688,16 +687,8 @@
 
   @override
   bool isAssignableTo(DartType fromType, DartType toType) {
-    if (!NullSafetyUnderstandingFlag.isEnabled) {
-      fromType = NullabilityEliminator.perform(typeProvider, fromType);
-      toType = NullabilityEliminator.perform(typeProvider, toType);
-    }
-    return isAssignableTo2(fromType, toType);
-  }
-
-  bool isAssignableTo2(DartType fromType, DartType toType) {
     // An actual subtype
-    if (isSubtypeOf2(fromType, toType)) {
+    if (isSubtypeOf(fromType, toType)) {
       return true;
     }
 
@@ -706,7 +697,7 @@
         !isNullable(fromType) &&
         acceptsFunctionType(toType)) {
       var callMethodType = getCallMethodType(fromType);
-      if (callMethodType != null && isAssignableTo2(callMethodType, toType)) {
+      if (callMethodType != null && isAssignableTo(callMethodType, toType)) {
         return true;
       }
     }
@@ -741,7 +732,7 @@
     }
 
     // If the subtype relation goes the other way, allow the implicit downcast.
-    if (isSubtypeOf2(toType, fromType)) {
+    if (isSubtypeOf(toType, fromType)) {
       // TODO(leafp,jmesserly): we emit warnings/hints for these in
       // src/task/strong/checker.dart, which is a bit inconsistent. That
       // code should be handled into places that use isAssignableTo, such as
@@ -945,7 +936,7 @@
   /// In strong mode, this is equivalent to [isSubtypeOf].
   @Deprecated('Use isSubtypeOf() instead.')
   bool isMoreSpecificThan(DartType leftType, DartType rightType) {
-    return isSubtypeOf2(leftType, rightType);
+    return isSubtypeOf(leftType, rightType);
   }
 
   /// Defines a total order on top and Object types.
@@ -1141,14 +1132,6 @@
   /// See `resources/type-system/subtyping.md`
   @override
   bool isSubtypeOf(DartType leftType, DartType rightType) {
-    if (!NullSafetyUnderstandingFlag.isEnabled) {
-      leftType = NullabilityEliminator.perform(typeProvider, leftType);
-      rightType = NullabilityEliminator.perform(typeProvider, rightType);
-    }
-    return isSubtypeOf2(leftType, rightType);
-  }
-
-  bool isSubtypeOf2(DartType leftType, DartType rightType) {
     return _subtypeHelper.isSubtypeOf(leftType, rightType);
   }
 
@@ -1254,10 +1237,6 @@
 
   @override
   DartType leastUpperBound(DartType leftType, DartType rightType) {
-    if (!NullSafetyUnderstandingFlag.isEnabled) {
-      leftType = NullabilityEliminator.perform(typeProvider, leftType);
-      rightType = NullabilityEliminator.perform(typeProvider, rightType);
-    }
     return getLeastUpperBound(leftType, rightType);
   }
 
@@ -1511,13 +1490,13 @@
     //
     // This allows the variable to be used wherever the supertype (here `Base`)
     // is expected, while gaining a more precise type.
-    if (isSubtypeOf2(to, from)) {
+    if (isSubtypeOf(to, from)) {
       return to;
     }
     // For a type parameter `T extends U`, allow promoting the upper bound
     // `U` to `S` where `S <: U`, yielding a type parameter `T extends S`.
     if (from is TypeParameterType) {
-      if (isSubtypeOf2(to, from.bound)) {
+      if (isSubtypeOf(to, from.bound)) {
         var declaration = from.element.declaration;
         return TypeParameterTypeImpl(
           element: declaration,
diff --git a/pkg/analyzer/lib/src/dart/micro/library_analyzer.dart b/pkg/analyzer/lib/src/dart/micro/library_analyzer.dart
index f5686bf..a4e2455 100644
--- a/pkg/analyzer/lib/src/dart/micro/library_analyzer.dart
+++ b/pkg/analyzer/lib/src/dart/micro/library_analyzer.dart
@@ -509,7 +509,33 @@
   ) {
     if (completionPath != null) {
       var completionUnit = units.values.first;
-      completionUnit.element = _unitElementWithPath(completionPath);
+      var unitElement = _unitElementWithPath(completionPath);
+      // TODO(scheglov) https://github.com/dart-lang/sdk/issues/44840
+      if (unitElement == null) {
+        String shortString(String s) {
+          const maxLength = 1000;
+          if (s.length > maxLength) {
+            return s.substring(0, maxLength);
+          }
+          return s;
+        }
+
+        var libraryContent = '<unknown>';
+        try {
+          libraryContent = _library.getContent();
+          libraryContent = shortString(libraryContent);
+        } catch (_) {}
+
+        var libraryUnitPaths =
+            _libraryElement.units.map((e) => e.source.fullName).toList();
+        throw '[completionPath: $completionPath]'
+            '[library.path: ${_library.path}]'
+            '[library.uri: ${_library.uri}]'
+            '[libraryUnitPaths: $libraryUnitPaths]'
+            '[libraryContent: $libraryContent]'
+            '[unitStr: ${shortString('$completionUnit')}]';
+      }
+      completionUnit.element = unitElement;
       return;
     }
 
diff --git a/pkg/analyzer/lib/src/dart/micro/resolve_file.dart b/pkg/analyzer/lib/src/dart/micro/resolve_file.dart
index c58fb75..48bf382 100644
--- a/pkg/analyzer/lib/src/dart/micro/resolve_file.dart
+++ b/pkg/analyzer/lib/src/dart/micro/resolve_file.dart
@@ -5,7 +5,6 @@
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/analysis/results.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/file_system/file_system.dart';
@@ -336,7 +335,16 @@
         performance: performance!,
       );
       var file = fileContext.file;
-      var libraryFile = file.partOfLibrary ?? file;
+
+      // If we have a `part of` directive, we want to analyze this library.
+      // But the library must include the file, so have its element.
+      var libraryFile = file;
+      var partOfLibrary = file.partOfLibrary;
+      if (partOfLibrary != null) {
+        if (partOfLibrary.libraryFiles.contains(file)) {
+          libraryFile = partOfLibrary;
+        }
+      }
 
       int? completionOffset;
       if (completionLine != null && completionColumn != null) {
@@ -374,13 +382,11 @@
 
         try {
           results = performance!.run('analyze', (performance) {
-            return NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-              return libraryAnalyzer.analyzeSync(
-                completionPath: completionOffset != null ? path : null,
-                completionOffset: completionOffset,
-                performance: performance,
-              );
-            });
+            return libraryAnalyzer.analyzeSync(
+              completionPath: completionOffset != null ? path : null,
+              completionOffset: completionOffset,
+              performance: performance,
+            );
           });
         } catch (exception, stackTrace) {
           var fileContentMap = <String, String>{};
diff --git a/pkg/analyzer/lib/src/dart/resolver/assignment_expression_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/assignment_expression_resolver.dart
index a767e17..88b4fd2 100644
--- a/pkg/analyzer/lib/src/dart/resolver/assignment_expression_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/assignment_expression_resolver.dart
@@ -26,7 +26,7 @@
 
   AssignmentExpressionResolver({
     required ResolverVisitor resolver,
-  })  : _resolver = resolver,
+  })   : _resolver = resolver,
         _typePropertyResolver = resolver.typePropertyResolver,
         _inferenceHelper = resolver.inferenceHelper,
         _assignmentShared = AssignmentExpressionShared(
@@ -88,7 +88,8 @@
 
     if (flow != null) {
       if (writeElement is PromotableElement) {
-        flow.write(writeElement, node.staticType!, hasRead ? null : right);
+        flow.write(
+            node, writeElement, node.staticType!, hasRead ? null : right);
       }
       if (isIfNull) {
         flow.ifNullExpression_end();
@@ -107,7 +108,7 @@
       return;
     }
 
-    if (_typeSystem.isAssignableTo2(rightType, writeType)) {
+    if (_typeSystem.isAssignableTo(rightType, writeType)) {
       return;
     }
 
diff --git a/pkg/analyzer/lib/src/dart/resolver/binary_expression_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/binary_expression_resolver.dart
index 1c8de42..38fcc61 100644
--- a/pkg/analyzer/lib/src/dart/resolver/binary_expression_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/binary_expression_resolver.dart
@@ -28,7 +28,7 @@
   BinaryExpressionResolver({
     required ResolverVisitor resolver,
     required TypePromotionManager promoteManager,
-  })  : _resolver = resolver,
+  })   : _resolver = resolver,
         _promoteManager = promoteManager,
         _typePropertyResolver = resolver.typePropertyResolver,
         _inferenceHelper = resolver.inferenceHelper;
diff --git a/pkg/analyzer/lib/src/dart/resolver/body_inference_context.dart b/pkg/analyzer/lib/src/dart/resolver/body_inference_context.dart
index ed9a552..05991d0 100644
--- a/pkg/analyzer/lib/src/dart/resolver/body_inference_context.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/body_inference_context.dart
@@ -130,7 +130,7 @@
     }
 
     // Otherwise, if `T <: R` then let `S` be `T`.
-    if (_typeSystem.isSubtypeOf2(T, R)) {
+    if (_typeSystem.isSubtypeOf(T, R)) {
       return T;
     }
 
diff --git a/pkg/analyzer/lib/src/dart/resolver/extension_member_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/extension_member_resolver.dart
index 1765615..126a6d7 100644
--- a/pkg/analyzer/lib/src/dart/resolver/extension_member_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/extension_member_resolver.dart
@@ -167,7 +167,7 @@
     if (receiverType.isVoid) {
       _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.USE_OF_VOID_RESULT, receiverExpression);
-    } else if (!_typeSystem.isAssignableTo2(receiverType, node.extendedType!)) {
+    } else if (!_typeSystem.isAssignableTo(receiverType, node.extendedType!)) {
       _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.EXTENSION_OVERRIDE_ARGUMENT_NOT_ASSIGNABLE,
         receiverExpression,
@@ -226,7 +226,7 @@
         var boundType = typeParameters[i].bound;
         if (boundType != null) {
           boundType = substitution.substituteType(boundType);
-          if (!_typeSystem.isSubtypeOf2(argType, boundType)) {
+          if (!_typeSystem.isSubtypeOf(argType, boundType)) {
             _errorReporter.reportErrorForNode(
               CompileTimeErrorCode.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS,
               typeArgumentList.arguments[i],
@@ -459,7 +459,7 @@
 
   /// Ask the type system for a subtype check.
   bool _isSubtypeOf(DartType type1, DartType type2) =>
-      _typeSystem.isSubtypeOf2(type1, type2);
+      _typeSystem.isSubtypeOf(type1, type2);
 
   List<DartType> _listOfDynamic(List<TypeParameterElement> parameters) {
     return List<DartType>.filled(parameters.length, _dynamicType);
diff --git a/pkg/analyzer/lib/src/dart/resolver/flow_analysis_visitor.dart b/pkg/analyzer/lib/src/dart/resolver/flow_analysis_visitor.dart
index 4a01f6e..1f89eb6 100644
--- a/pkg/analyzer/lib/src/dart/resolver/flow_analysis_visitor.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/flow_analysis_visitor.dart
@@ -4,6 +4,7 @@
 
 import 'package:_fe_analyzer_shared/src/flow_analysis/flow_analysis.dart';
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/syntactic_entity.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ -40,6 +41,14 @@
   final Map<Declaration,
           AssignedVariablesForTesting<AstNode, PromotableElement>>
       assignedVariables = {};
+
+  /// For each expression that led to an error because it was not promoted, a
+  /// string describing the reason it was not promoted.
+  Map<SyntacticEntity, String> nonPromotionReasons = {};
+
+  /// For each auxiliary AST node pointed to by a non-promotion reason, a string
+  /// describing the non-promotion reason pointing to it.
+  Map<AstNode, String> nonPromotionReasonTargets = {};
 }
 
 /// The helper for performing flow analysis during resolution.
@@ -333,6 +342,9 @@
   TypeSystemTypeOperations(this.typeSystem);
 
   @override
+  DartType get topType => typeSystem.objectQuestion;
+
+  @override
   TypeClassification classifyType(DartType type) {
     if (isSubtypeOf(type, typeSystem.typeProvider.objectType)) {
       return TypeClassification.nonNullable;
@@ -360,7 +372,7 @@
 
   @override
   bool isSubtypeOf(DartType leftType, DartType rightType) {
-    return typeSystem.isSubtypeOf2(leftType, rightType);
+    return typeSystem.isSubtypeOf(leftType, rightType);
   }
 
   @override
diff --git a/pkg/analyzer/lib/src/dart/resolver/function_expression_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/function_expression_resolver.dart
index 830360d..f60d683 100644
--- a/pkg/analyzer/lib/src/dart/resolver/function_expression_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/function_expression_resolver.dart
@@ -25,7 +25,7 @@
     required ResolverVisitor resolver,
     required MigrationResolutionHooks? migrationResolutionHooks,
     required TypePromotionManager promoteManager,
-  })  : _resolver = resolver,
+  })   : _resolver = resolver,
         _migrationResolutionHooks = migrationResolutionHooks,
         _inferenceHelper = resolver.inferenceHelper,
         _promoteManager = promoteManager;
@@ -99,7 +99,7 @@
 
         // If the greatest closure of `K` is `S` and `S` is a subtype of
         // `Null`, then `T` is `Object?`. Otherwise, `T` is `S`.
-        if (_typeSystem.isSubtypeOf2(inferredType, _typeSystem.nullNone)) {
+        if (_typeSystem.isSubtypeOf(inferredType, _typeSystem.nullNone)) {
           inferredType = _isNonNullableByDefault
               ? _typeSystem.objectQuestion
               : _typeSystem.objectStar;
diff --git a/pkg/analyzer/lib/src/dart/resolver/postfix_expression_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/postfix_expression_resolver.dart
index 08ebc32..bfac763 100644
--- a/pkg/analyzer/lib/src/dart/resolver/postfix_expression_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/postfix_expression_resolver.dart
@@ -26,7 +26,7 @@
 
   PostfixExpressionResolver({
     required ResolverVisitor resolver,
-  })  : _resolver = resolver,
+  })   : _resolver = resolver,
         _typePropertyResolver = resolver.typePropertyResolver,
         _inferenceHelper = resolver.inferenceHelper,
         _assignmentShared = AssignmentExpressionShared(
@@ -74,7 +74,7 @@
   void _checkForInvalidAssignmentIncDec(
       PostfixExpression node, Expression operand, DartType type) {
     var operandWriteType = node.writeType!;
-    if (!_typeSystem.isAssignableTo2(type, operandWriteType)) {
+    if (!_typeSystem.isAssignableTo(type, operandWriteType)) {
       _resolver.errorReporter.reportErrorForNode(
         CompileTimeErrorCode.INVALID_ASSIGNMENT,
         node,
@@ -173,7 +173,7 @@
         var element = operand.staticElement;
         if (element is PromotableElement) {
           _resolver.flowAnalysis?.flow
-              ?.write(element, operatorReturnType, null);
+              ?.write(node, element, operatorReturnType, null);
         }
       }
     }
diff --git a/pkg/analyzer/lib/src/dart/resolver/prefix_expression_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/prefix_expression_resolver.dart
index 6901f05..82f712c 100644
--- a/pkg/analyzer/lib/src/dart/resolver/prefix_expression_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/prefix_expression_resolver.dart
@@ -26,7 +26,7 @@
 
   PrefixExpressionResolver({
     required ResolverVisitor resolver,
-  })  : _resolver = resolver,
+  })   : _resolver = resolver,
         _typePropertyResolver = resolver.typePropertyResolver,
         _inferenceHelper = resolver.inferenceHelper,
         _assignmentShared = AssignmentExpressionShared(
@@ -78,7 +78,7 @@
   void _checkForInvalidAssignmentIncDec(
       PrefixExpressionImpl node, DartType type) {
     var operandWriteType = node.writeType!;
-    if (!_typeSystem.isAssignableTo2(type, operandWriteType)) {
+    if (!_typeSystem.isAssignableTo(type, operandWriteType)) {
       _resolver.errorReporter.reportErrorForNode(
         CompileTimeErrorCode.INVALID_ASSIGNMENT,
         node,
@@ -209,7 +209,8 @@
         if (operand is SimpleIdentifier) {
           var element = operand.staticElement;
           if (element is PromotableElement) {
-            _resolver.flowAnalysis?.flow?.write(element, staticType, null);
+            _resolver.flowAnalysis?.flow
+                ?.write(node, element, staticType, null);
           }
         }
       }
diff --git a/pkg/analyzer/lib/src/dart/resolver/property_element_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/property_element_resolver.dart
index 9a7c23b..00317e0 100644
--- a/pkg/analyzer/lib/src/dart/resolver/property_element_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/property_element_resolver.dart
@@ -143,6 +143,7 @@
     }
 
     return _resolve(
+      node: node,
       target: prefix,
       isCascaded: false,
       isNullAware: false,
@@ -171,6 +172,7 @@
 
     if (target is SuperExpression) {
       return _resolveTargetSuperExpression(
+        node: node,
         target: target,
         propertyName: propertyName,
         hasRead: hasRead,
@@ -179,6 +181,7 @@
     }
 
     return _resolve(
+      node: node,
       target: target,
       isCascaded: node.target == null,
       isNullAware: node.isNullAware,
@@ -198,6 +201,9 @@
     if (hasRead) {
       var readLookup = _resolver.lexicalLookup(node: node, setter: false);
       readElementRequested = readLookup.requested;
+      if (readElementRequested is PropertyAccessorElement) {
+        _resolver.flowAnalysis?.flow?.thisOrSuperPropertyGet(node, node.name);
+      }
       _resolver.checkReadOfNotAssignedLocalVariable(node, readElementRequested);
     }
 
@@ -282,6 +288,7 @@
   }
 
   PropertyElementResolverResult _resolve({
+    required Expression node,
     required Expression target,
     required bool isCascaded,
     required bool isNullAware,
@@ -364,6 +371,8 @@
       nameErrorEntity: propertyName,
     );
 
+    _resolver.flowAnalysis?.flow?.propertyGet(node, target, propertyName.name);
+
     if (hasRead && result.needsGetterError) {
       _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.UNDEFINED_GETTER,
@@ -595,6 +604,7 @@
   }
 
   PropertyElementResolverResult _resolveTargetSuperExpression({
+    required Expression node,
     required SuperExpression target,
     required SimpleIdentifier propertyName,
     required bool hasRead,
@@ -610,6 +620,8 @@
 
     if (targetType is InterfaceTypeImpl) {
       if (hasRead) {
+        _resolver.flowAnalysis?.flow
+            ?.propertyGet(node, target, propertyName.name);
         var name = Name(_definingLibrary.source.uri, propertyName.name);
         readElement = _resolver.inheritance
             .getMember2(targetType.element, name, forSuper: true);
diff --git a/pkg/analyzer/lib/src/dart/resolver/type_property_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/type_property_resolver.dart
index fc603c5..15898fa 100644
--- a/pkg/analyzer/lib/src/dart/resolver/type_property_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/type_property_resolver.dart
@@ -2,18 +2,23 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:_fe_analyzer_shared/src/flow_analysis/flow_analysis.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/syntactic_entity.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:analyzer/diagnostic/diagnostic.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/inheritance_manager3.dart';
 import 'package:analyzer/src/dart/element/type_provider.dart';
 import 'package:analyzer/src/dart/element/type_system.dart';
 import 'package:analyzer/src/dart/resolver/extension_member_resolver.dart';
+import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
 import 'package:analyzer/src/dart/resolver/resolution_result.dart';
+import 'package:analyzer/src/diagnostic/diagnostic.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/resolver.dart';
+import 'package:analyzer/src/generated/source.dart';
 
 /// Helper for resolving properties (getters, setters, or methods).
 class TypePropertyResolver {
@@ -114,9 +119,30 @@
         }
       }
 
+      var whyNotPromoted = receiver == null
+          ? null
+          : _resolver.flowAnalysis?.flow?.whyNotPromoted(receiver);
+      List<DiagnosticMessage> messages = [];
+      if (whyNotPromoted != null) {
+        for (var entry in whyNotPromoted.entries) {
+          var whyNotPromotedVisitor = _WhyNotPromotedVisitor(
+              _resolver.source, _resolver.flowAnalysis!.dataForTesting);
+          if (_typeSystem.isPotentiallyNullable(entry.key)) continue;
+          if (_resolver.flowAnalysis!.dataForTesting != null) {
+            _resolver.flowAnalysis!.dataForTesting!
+                .nonPromotionReasons[nameErrorEntity] = entry.value.shortName;
+          }
+          var message = entry.value.accept(whyNotPromotedVisitor);
+          if (message != null) {
+            messages = [message];
+          }
+          break;
+        }
+      }
+
       _resolver.nullableDereferenceVerifier.report(
           receiverErrorNode, receiverType,
-          errorCode: errorCode, arguments: [name]);
+          errorCode: errorCode, arguments: [name], messages: messages);
       _reportedGetterError = true;
       _reportedSetterError = true;
 
@@ -264,3 +290,71 @@
     );
   }
 }
+
+class _WhyNotPromotedVisitor
+    implements
+        NonPromotionReasonVisitor<DiagnosticMessage?, AstNode, Expression,
+            PromotableElement> {
+  final Source source;
+
+  final FlowAnalysisDataForTesting? _dataForTesting;
+
+  _WhyNotPromotedVisitor(this.source, this._dataForTesting);
+
+  @override
+  DiagnosticMessage? visitDemoteViaExplicitWrite(
+      DemoteViaExplicitWrite<PromotableElement, Expression> reason) {
+    var writeExpression = reason.writeExpression;
+    if (_dataForTesting != null) {
+      _dataForTesting!.nonPromotionReasonTargets[writeExpression] =
+          reason.shortName;
+    }
+    var variableName = reason.variable.name;
+    if (variableName == null) return null;
+    return _contextMessageForWrite(variableName, writeExpression);
+  }
+
+  @override
+  DiagnosticMessage? visitDemoteViaForEachVariableWrite(
+      DemoteViaForEachVariableWrite<PromotableElement, AstNode> reason) {
+    var node = reason.node;
+    var variableName = reason.variable.name;
+    if (variableName == null) return null;
+    ForLoopParts parts;
+    if (node is ForStatement) {
+      parts = node.forLoopParts;
+    } else if (node is ForElement) {
+      parts = node.forLoopParts;
+    } else {
+      assert(false, 'Unexpected node type');
+      return null;
+    }
+    if (parts is ForEachPartsWithIdentifier) {
+      var identifier = parts.identifier;
+      if (_dataForTesting != null) {
+        _dataForTesting!.nonPromotionReasonTargets[identifier] =
+            reason.shortName;
+      }
+      return _contextMessageForWrite(variableName, identifier);
+    } else {
+      assert(false, 'Unexpected parts type');
+      return null;
+    }
+  }
+
+  @override
+  DiagnosticMessage? visitFieldNotPromoted(FieldNotPromoted reason) {
+    // TODO(paulberry): how to report this?
+    return null;
+  }
+
+  DiagnosticMessageImpl _contextMessageForWrite(
+      String variableName, Expression writeExpression) {
+    return DiagnosticMessageImpl(
+        filePath: source.fullName,
+        message:
+            "Variable '$variableName' could be null due to a write occurring here.",
+        offset: writeExpression.offset,
+        length: writeExpression.length);
+  }
+}
diff --git a/pkg/analyzer/lib/src/dart/resolver/typed_literal_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/typed_literal_resolver.dart
index d6c2dfc..6cf4eb2 100644
--- a/pkg/analyzer/lib/src/dart/resolver/typed_literal_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/typed_literal_resolver.dart
@@ -187,10 +187,10 @@
       }
 
       if (_typeSystem.isNonNullableByDefault) {
-        if (_typeSystem.isSubtypeOf2(expressionType, NeverTypeImpl.instance)) {
+        if (_typeSystem.isSubtypeOf(expressionType, NeverTypeImpl.instance)) {
           return NeverTypeImpl.instance;
         }
-        if (_typeSystem.isSubtypeOf2(expressionType, _typeSystem.nullNone)) {
+        if (_typeSystem.isSubtypeOf(expressionType, _typeSystem.nullNone)) {
           if (element.isNullAware) {
             return NeverTypeImpl.instance;
           }
@@ -380,14 +380,14 @@
       }
 
       if (_typeSystem.isNonNullableByDefault) {
-        if (_typeSystem.isSubtypeOf2(expressionType, NeverTypeImpl.instance)) {
+        if (_typeSystem.isSubtypeOf(expressionType, NeverTypeImpl.instance)) {
           return _InferredCollectionElementTypeInformation(
             elementType: NeverTypeImpl.instance,
             keyType: NeverTypeImpl.instance,
             valueType: NeverTypeImpl.instance,
           );
         }
-        if (_typeSystem.isSubtypeOf2(expressionType, _typeSystem.nullNone)) {
+        if (_typeSystem.isSubtypeOf(expressionType, _typeSystem.nullNone)) {
           if (element.isNullAware) {
             return _InferredCollectionElementTypeInformation(
               elementType: NeverTypeImpl.instance,
diff --git a/pkg/analyzer/lib/src/dart/resolver/variable_declaration_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/variable_declaration_resolver.dart
index 68efd6c..d0829f0 100644
--- a/pkg/analyzer/lib/src/dart/resolver/variable_declaration_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/variable_declaration_resolver.dart
@@ -20,7 +20,7 @@
   VariableDeclarationResolver({
     required ResolverVisitor resolver,
     required bool strictInference,
-  })  : _resolver = resolver,
+  })   : _resolver = resolver,
         _strictInference = strictInference;
 
   void resolve(VariableDeclarationImpl node) {
diff --git a/pkg/analyzer/lib/src/dart/resolver/yield_statement_resolver.dart b/pkg/analyzer/lib/src/dart/resolver/yield_statement_resolver.dart
index 41678af..103119a 100644
--- a/pkg/analyzer/lib/src/dart/resolver/yield_statement_resolver.dart
+++ b/pkg/analyzer/lib/src/dart/resolver/yield_statement_resolver.dart
@@ -83,7 +83,7 @@
       impliedReturnType = _typeProvider.streamType2(expressionType);
     }
 
-    if (!_typeSystem.isAssignableTo2(impliedReturnType, declaredReturnType)) {
+    if (!_typeSystem.isAssignableTo(impliedReturnType, declaredReturnType)) {
       _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.YIELD_OF_INVALID_TYPE,
         expression,
@@ -103,7 +103,7 @@
         requiredReturnType = _typeProvider.streamDynamicType;
       }
 
-      if (!_typeSystem.isAssignableTo2(impliedReturnType, requiredReturnType)) {
+      if (!_typeSystem.isAssignableTo(impliedReturnType, requiredReturnType)) {
         _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.YIELD_OF_INVALID_TYPE,
           expression,
diff --git a/pkg/analyzer/lib/src/error/best_practices_verifier.dart b/pkg/analyzer/lib/src/error/best_practices_verifier.dart
index 3c842d0..9f75b54 100644
--- a/pkg/analyzer/lib/src/error/best_practices_verifier.dart
+++ b/pkg/analyzer/lib/src/error/best_practices_verifier.dart
@@ -1611,7 +1611,7 @@
     }
 
     // The cast is necessary.
-    if (!typeSystem.isSubtypeOf2(leftType, rightType)) {
+    if (!typeSystem.isSubtypeOf(leftType, rightType)) {
       return false;
     }
 
diff --git a/pkg/analyzer/lib/src/error/bool_expression_verifier.dart b/pkg/analyzer/lib/src/error/bool_expression_verifier.dart
index 3fa1459..3324386 100644
--- a/pkg/analyzer/lib/src/error/bool_expression_verifier.dart
+++ b/pkg/analyzer/lib/src/error/bool_expression_verifier.dart
@@ -48,7 +48,7 @@
       {required ErrorCode errorCode, List<Object>? arguments}) {
     var type = expression.staticType!;
     if (!_checkForUseOfVoidResult(expression) &&
-        !_typeSystem.isAssignableTo2(type, _boolType)) {
+        !_typeSystem.isAssignableTo(type, _boolType)) {
       if (type.element == _boolElement) {
         _nullableDereferenceVerifier.report(expression, type,
             errorCode: CompileTimeErrorCode
diff --git a/pkg/analyzer/lib/src/error/correct_override.dart b/pkg/analyzer/lib/src/error/correct_override.dart
index db8a2ee..7970e6f 100644
--- a/pkg/analyzer/lib/src/error/correct_override.dart
+++ b/pkg/analyzer/lib/src/error/correct_override.dart
@@ -39,7 +39,7 @@
     superMember = _library.toLegacyElementIfOptOut(superMember);
 
     var superType = superMember.type;
-    return _typeSystem.isSubtypeOf2(_thisTypeForSubtype!, superType);
+    return _typeSystem.isSubtypeOf(_thisTypeForSubtype!, superType);
   }
 
   /// If [_thisMember] is not a correct override of [superMember], report the
@@ -120,8 +120,8 @@
       for (var superParameter in entry.value) {
         var thisType = parameter.type;
         var superType = superParameter.type;
-        if (!_typeSystem.isSubtypeOf2(superType, thisType) &&
-            !_typeSystem.isSubtypeOf2(thisType, superType)) {
+        if (!_typeSystem.isSubtypeOf(superType, thisType) &&
+            !_typeSystem.isSubtypeOf(thisType, superType)) {
           var superMember = superParameter.member;
           errorReporter.reportErrorForNode(
             CompileTimeErrorCode.INVALID_OVERRIDE,
diff --git a/pkg/analyzer/lib/src/error/dead_code_verifier.dart b/pkg/analyzer/lib/src/error/dead_code_verifier.dart
index 6425888..bce84b9 100644
--- a/pkg/analyzer/lib/src/error/dead_code_verifier.dart
+++ b/pkg/analyzer/lib/src/error/dead_code_verifier.dart
@@ -633,7 +633,7 @@
     // An on-catch clause was found; verify that the exception type is not a
     // subtype of a previous on-catch exception type.
     for (var type in _visitedTypes) {
-      if (_typeSystem.isSubtypeOf2(currentType, type)) {
+      if (_typeSystem.isSubtypeOf(currentType, type)) {
         _errorReporter(
           catchClause,
           catchClauses.last,
diff --git a/pkg/analyzer/lib/src/error/getter_setter_types_verifier.dart b/pkg/analyzer/lib/src/error/getter_setter_types_verifier.dart
index 5c5e045..933fe37 100644
--- a/pkg/analyzer/lib/src/error/getter_setter_types_verifier.dart
+++ b/pkg/analyzer/lib/src/error/getter_setter_types_verifier.dart
@@ -115,8 +115,8 @@
 
   bool _match(DartType getterType, DartType setterType) {
     return _isNonNullableByDefault
-        ? _typeSystem.isSubtypeOf2(getterType, setterType)
-        : _typeSystem.isAssignableTo2(getterType, setterType);
+        ? _typeSystem.isSubtypeOf(getterType, setterType)
+        : _typeSystem.isAssignableTo(getterType, setterType);
   }
 
   /// Return the return type of the [getter].
diff --git a/pkg/analyzer/lib/src/error/literal_element_verifier.dart b/pkg/analyzer/lib/src/error/literal_element_verifier.dart
index 36b4318..d62271b 100644
--- a/pkg/analyzer/lib/src/error/literal_element_verifier.dart
+++ b/pkg/analyzer/lib/src/error/literal_element_verifier.dart
@@ -48,7 +48,7 @@
   /// Check that the given [type] is assignable to the [elementType], otherwise
   /// report the list or set error on the [errorNode].
   void _checkAssignableToElementType(DartType type, AstNode errorNode) {
-    if (!typeSystem.isAssignableTo2(type, elementType!)) {
+    if (!typeSystem.isAssignableTo(type, elementType!)) {
       var errorCode = forList
           ? CompileTimeErrorCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE
           : CompileTimeErrorCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE;
@@ -108,7 +108,7 @@
     }
 
     var keyType = entry.key.staticType!;
-    if (!typeSystem.isAssignableTo2(keyType, mapKeyType!)) {
+    if (!typeSystem.isAssignableTo(keyType, mapKeyType!)) {
       errorReporter.reportErrorForNode(
         CompileTimeErrorCode.MAP_KEY_TYPE_NOT_ASSIGNABLE,
         entry.key,
@@ -117,7 +117,7 @@
     }
 
     var valueType = entry.value.staticType!;
-    if (!typeSystem.isAssignableTo2(valueType, mapValueType!)) {
+    if (!typeSystem.isAssignableTo(valueType, mapValueType!)) {
       errorReporter.reportErrorForNode(
         CompileTimeErrorCode.MAP_VALUE_TYPE_NOT_ASSIGNABLE,
         entry.value,
@@ -133,10 +133,10 @@
     if (expressionType.isDynamic) return;
 
     if (typeSystem.isNonNullableByDefault) {
-      if (typeSystem.isSubtypeOf2(expressionType, NeverTypeImpl.instance)) {
+      if (typeSystem.isSubtypeOf(expressionType, NeverTypeImpl.instance)) {
         return;
       }
-      if (typeSystem.isSubtypeOf2(expressionType, typeSystem.nullNone)) {
+      if (typeSystem.isSubtypeOf(expressionType, typeSystem.nullNone)) {
         if (isNullAware) {
           return;
         }
@@ -171,7 +171,7 @@
     }
 
     var iterableElementType = iterableType.typeArguments[0];
-    if (!typeSystem.isAssignableTo2(iterableElementType, elementType!)) {
+    if (!typeSystem.isAssignableTo(iterableElementType, elementType!)) {
       var errorCode = forList
           ? CompileTimeErrorCode.LIST_ELEMENT_TYPE_NOT_ASSIGNABLE
           : CompileTimeErrorCode.SET_ELEMENT_TYPE_NOT_ASSIGNABLE;
@@ -190,10 +190,10 @@
     if (expressionType.isDynamic) return;
 
     if (typeSystem.isNonNullableByDefault) {
-      if (typeSystem.isSubtypeOf2(expressionType, NeverTypeImpl.instance)) {
+      if (typeSystem.isSubtypeOf(expressionType, NeverTypeImpl.instance)) {
         return;
       }
-      if (typeSystem.isSubtypeOf2(expressionType, typeSystem.nullNone)) {
+      if (typeSystem.isSubtypeOf(expressionType, typeSystem.nullNone)) {
         if (isNullAware) {
           return;
         }
@@ -228,7 +228,7 @@
     }
 
     var keyType = mapType.typeArguments[0];
-    if (!typeSystem.isAssignableTo2(keyType, mapKeyType!)) {
+    if (!typeSystem.isAssignableTo(keyType, mapKeyType!)) {
       errorReporter.reportErrorForNode(
         CompileTimeErrorCode.MAP_KEY_TYPE_NOT_ASSIGNABLE,
         expression,
@@ -237,7 +237,7 @@
     }
 
     var valueType = mapType.typeArguments[1];
-    if (!typeSystem.isAssignableTo2(valueType, mapValueType!)) {
+    if (!typeSystem.isAssignableTo(valueType, mapValueType!)) {
       errorReporter.reportErrorForNode(
         CompileTimeErrorCode.MAP_VALUE_TYPE_NOT_ASSIGNABLE,
         expression,
diff --git a/pkg/analyzer/lib/src/error/nullable_dereference_verifier.dart b/pkg/analyzer/lib/src/error/nullable_dereference_verifier.dart
index e1dd812..1b5f219 100644
--- a/pkg/analyzer/lib/src/error/nullable_dereference_verifier.dart
+++ b/pkg/analyzer/lib/src/error/nullable_dereference_verifier.dart
@@ -4,6 +4,7 @@
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:analyzer/diagnostic/diagnostic.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/src/dart/element/type.dart';
@@ -32,13 +33,16 @@
   }
 
   void report(AstNode errorNode, DartType receiverType,
-      {ErrorCode? errorCode, List<String> arguments = const <String>[]}) {
+      {ErrorCode? errorCode,
+      List<String> arguments = const <String>[],
+      List<DiagnosticMessage>? messages}) {
     if (receiverType == _typeSystem.typeProvider.nullType) {
       errorCode = CompileTimeErrorCode.INVALID_USE_OF_NULL_VALUE;
     } else {
       errorCode ??= CompileTimeErrorCode.UNCHECKED_USE_OF_NULLABLE_VALUE;
     }
-    _errorReporter.reportErrorForNode(errorCode, errorNode, arguments);
+    _errorReporter.reportErrorForNode(
+        errorCode, errorNode, arguments, messages);
   }
 
   /// If the [receiverType] is potentially nullable, report it.
diff --git a/pkg/analyzer/lib/src/error/return_type_verifier.dart b/pkg/analyzer/lib/src/error/return_type_verifier.dart
index c59865c..38aad2a 100644
--- a/pkg/analyzer/lib/src/error/return_type_verifier.dart
+++ b/pkg/analyzer/lib/src/error/return_type_verifier.dart
@@ -207,7 +207,7 @@
       // It is a compile-time error if `S` is not `void`,
       // and `S` is not assignable to `T`.
       if (!S.isVoid) {
-        if (!_typeSystem.isAssignableTo2(S, T)) {
+        if (!_typeSystem.isAssignableTo(S, T)) {
           reportTypeError();
           return;
         }
@@ -244,7 +244,7 @@
       // and `Future<flatten(S)>` is not assignable to `T`.
       if (!flatten_S.isVoid) {
         var future_flatten_S = _typeProvider.futureType2(flatten_S);
-        if (!_typeSystem.isAssignableTo2(future_flatten_S, T)) {
+        if (!_typeSystem.isAssignableTo(future_flatten_S, T)) {
           reportTypeError();
           return;
         }
@@ -314,7 +314,7 @@
       // It is a compile-time error if `S` is not `void`,
       // and `S` is not assignable to `T`.
       if (!S.isVoid) {
-        if (!_typeSystem.isAssignableTo2(S, T)) {
+        if (!_typeSystem.isAssignableTo(S, T)) {
           reportTypeError();
           return;
         }
@@ -345,8 +345,8 @@
       // It is a compile-time error if `flatten(S)` is not `void`,
       // and `Future<flatten(S)>` is not assignable to `T`.
       if (!flatten_S.isVoid) {
-        if (!_typeSystem.isAssignableTo2(S, T_v) &&
-            !_typeSystem.isSubtypeOf2(flatten_S, T_v)) {
+        if (!_typeSystem.isAssignableTo(S, T_v) &&
+            !_typeSystem.isSubtypeOf(flatten_S, T_v)) {
           reportTypeError();
           return;
         }
@@ -406,7 +406,7 @@
       typeArguments: [NeverTypeImpl.instance],
       nullabilitySuffix: NullabilitySuffix.star,
     );
-    return _typeSystem.isSubtypeOf2(lowerBound, returnType);
+    return _typeSystem.isSubtypeOf(lowerBound, returnType);
   }
 
   static bool _isVoidDynamic(DartType type) {
diff --git a/pkg/analyzer/lib/src/error/type_arguments_verifier.dart b/pkg/analyzer/lib/src/error/type_arguments_verifier.dart
index 7af6125..642a37f 100644
--- a/pkg/analyzer/lib/src/error/type_arguments_verifier.dart
+++ b/pkg/analyzer/lib/src/error/type_arguments_verifier.dart
@@ -230,7 +230,7 @@
       bound = _libraryElement.toLegacyTypeIfOptOut(bound);
       bound = substitution.substituteType(bound);
 
-      if (!_typeSystem.isSubtypeOf2(typeArgument, bound)) {
+      if (!_typeSystem.isSubtypeOf(typeArgument, bound)) {
         issues ??= <_TypeArgumentIssue>[];
         issues.add(
           _TypeArgumentIssue(i, typeParameter, typeArgument),
@@ -279,7 +279,7 @@
       bound = _libraryElement.toLegacyTypeIfOptOut(bound);
       bound = substitution.substituteType(bound);
 
-      if (!_typeSystem.isSubtypeOf2(typeArgument, bound)) {
+      if (!_typeSystem.isSubtypeOf(typeArgument, bound)) {
         _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS,
           _typeArgumentErrorNode(typeName, i),
@@ -367,7 +367,7 @@
 
         var substitution = Substitution.fromPairs(fnTypeParams, typeArgs);
         var bound = substitution.substituteType(rawBound);
-        if (!_typeSystem.isSubtypeOf2(argType, bound)) {
+        if (!_typeSystem.isSubtypeOf(argType, bound)) {
           _errorReporter.reportErrorForNode(
               CompileTimeErrorCode.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS,
               typeArgumentList[i],
diff --git a/pkg/analyzer/lib/src/fasta/ast_builder.dart b/pkg/analyzer/lib/src/fasta/ast_builder.dart
index 786cd50..426cf7b 100644
--- a/pkg/analyzer/lib/src/fasta/ast_builder.dart
+++ b/pkg/analyzer/lib/src/fasta/ast_builder.dart
@@ -1530,18 +1530,12 @@
     debugEvent("FunctionTypeAlias");
 
     if (equals == null) {
-      var parameters = pop() as FormalParameterList?;
+      var parameters = pop() as FormalParameterList;
       var typeParameters = pop() as TypeParameterList?;
       var name = pop() as SimpleIdentifier;
       var returnType = pop() as TypeAnnotation?;
       var metadata = pop() as List<Annotation>?;
       var comment = _findComment(metadata, typedefKeyword);
-
-      // TODO(scheglov) https://github.com/dart-lang/sdk/issues/41023
-      if (parameters == null) {
-        throw StateError('FunctionTypeAlias without parameters.');
-      }
-
       declarations.add(ast.functionTypeAlias(comment, metadata, typedefKeyword,
           returnType, name, typeParameters, parameters, semicolon));
     } else {
diff --git a/pkg/analyzer/lib/src/generated/error_verifier.dart b/pkg/analyzer/lib/src/generated/error_verifier.dart
index 912da39..148ef98 100644
--- a/pkg/analyzer/lib/src/generated/error_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/error_verifier.dart
@@ -1465,14 +1465,14 @@
     // Report specific problem when return type is incompatible
     FunctionType constructorType = declaration.declaredElement!.type;
     DartType constructorReturnType = constructorType.returnType;
-    if (!_typeSystem.isAssignableTo2(
+    if (!_typeSystem.isAssignableTo(
         redirectedReturnType, constructorReturnType)) {
       _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.REDIRECT_TO_INVALID_RETURN_TYPE,
           redirectedConstructor,
           [redirectedReturnType, constructorReturnType]);
       return;
-    } else if (!_typeSystem.isSubtypeOf2(redirectedType, constructorType)) {
+    } else if (!_typeSystem.isSubtypeOf(redirectedType, constructorType)) {
       // Check parameters.
       _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.REDIRECT_TO_INVALID_FUNCTION_TYPE,
@@ -1622,7 +1622,7 @@
       DartType actualStaticType,
       DartType expectedStaticType,
       ErrorCode errorCode) {
-    if (!_typeSystem.isAssignableTo2(actualStaticType, expectedStaticType)) {
+    if (!_typeSystem.isAssignableTo(actualStaticType, expectedStaticType)) {
       AstNode getErrorNode(AstNode node) {
         if (node is CascadeExpression) {
           return getErrorNode(node.target);
@@ -2327,7 +2327,7 @@
       iterableType = requiredSequenceType;
     }
 
-    if (!_typeSystem.isAssignableTo2(iterableType, requiredSequenceType)) {
+    if (!_typeSystem.isAssignableTo(iterableType, requiredSequenceType)) {
       _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.FOR_IN_OF_INVALID_TYPE,
         node.iterable,
@@ -2351,7 +2351,7 @@
       return true;
     }
 
-    if (!_typeSystem.isAssignableTo2(sequenceElementType, variableType)) {
+    if (!_typeSystem.isAssignableTo(sequenceElementType, variableType)) {
       _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.FOR_IN_OF_INVALID_ELEMENT_TYPE,
         node.iterable,
@@ -2521,7 +2521,7 @@
     Expression expression = initializer.expression;
     // test the static type of the expression
     DartType staticType = expression.staticType!;
-    if (_typeSystem.isAssignableTo2(staticType, fieldType)) {
+    if (_typeSystem.isAssignableTo(staticType, fieldType)) {
       return;
     }
     // report problem
@@ -3122,7 +3122,7 @@
       var first = positional.first;
       var type = first.declaredElement!.type;
       var listOfString = _typeProvider.listType2(_typeProvider.stringType);
-      if (!_typeSystem.isSubtypeOf2(listOfString, type)) {
+      if (!_typeSystem.isSubtypeOf(listOfString, type)) {
         _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.MAIN_FIRST_POSITIONAL_PARAMETER_TYPE,
           first.notDefault.typeOrSelf,
@@ -3281,11 +3281,11 @@
         superType = superType.withNullability(NullabilitySuffix.none);
       }
 
-      bool isSatisfied = _typeSystem.isSubtypeOf2(superType, constraint);
+      bool isSatisfied = _typeSystem.isSubtypeOf(superType, constraint);
       if (!isSatisfied) {
         for (int i = 0; i < mixinIndex && !isSatisfied; i++) {
           isSatisfied =
-              _typeSystem.isSubtypeOf2(_enclosingClass!.mixins[i], constraint);
+              _typeSystem.isSubtypeOf(_enclosingClass!.mixins[i], constraint);
         }
       }
       if (!isSatisfied) {
@@ -4176,7 +4176,7 @@
     DartType caseType = caseExpression.staticType!;
 
     // check types
-    if (!_typeSystem.isAssignableTo2(expressionType, caseType)) {
+    if (!_typeSystem.isAssignableTo(expressionType, caseType)) {
       _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.SWITCH_EXPRESSION_NOT_ASSIGNABLE,
           expression,
@@ -4190,7 +4190,7 @@
     var expression = node.expression;
     var type = node.expression.staticType!;
 
-    if (!_typeSystem.isAssignableTo2(type, _typeSystem.objectNone)) {
+    if (!_typeSystem.isAssignableTo(type, _typeSystem.objectNone)) {
       _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.THROW_OF_INVALID_TYPE,
         expression,
diff --git a/pkg/analyzer/lib/src/generated/ffi_verifier.dart b/pkg/analyzer/lib/src/generated/ffi_verifier.dart
index 299afe7..feca32d 100644
--- a/pkg/analyzer/lib/src/generated/ffi_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/ffi_verifier.dart
@@ -628,11 +628,11 @@
       InterfaceType objectType = typeSystem.objectStar;
       return checkCovariance
           ? /* everything is subtype of objectStar */ true
-          : typeSystem.isSubtypeOf2(objectType, dartType);
+          : typeSystem.isSubtypeOf(objectType, dartType);
     } else if (dartType is InterfaceType && nativeType is InterfaceType) {
       return checkCovariance
-          ? typeSystem.isSubtypeOf2(dartType, nativeType)
-          : typeSystem.isSubtypeOf2(nativeType, dartType);
+          ? typeSystem.isSubtypeOf(dartType, nativeType)
+          : typeSystem.isSubtypeOf(nativeType, dartType);
     } else {
       // If the [nativeType] is not a primitive int/double type then it has to
       // be a Pointer type atm.
@@ -785,7 +785,7 @@
     if (!_isValidFfiNativeType(targetType, false, true)) {
       final AstNode errorNode = node;
       _errorReporter.reportErrorForNode(
-          FfiCode.NON_CONSTANT_TYPE_ARGUMENT_WARNING, errorNode, ['[]']);
+          FfiCode.NON_CONSTANT_TYPE_ARGUMENT, errorNode, ['[]']);
     }
   }
 
@@ -796,7 +796,7 @@
     if (!_isValidFfiNativeType(targetType, false, true)) {
       final AstNode errorNode = node;
       _errorReporter.reportErrorForNode(
-          FfiCode.NON_CONSTANT_TYPE_ARGUMENT_WARNING, errorNode, ['ref']);
+          FfiCode.NON_CONSTANT_TYPE_ARGUMENT, errorNode, ['ref']);
     }
   }
 
@@ -805,7 +805,7 @@
     if (!_isValidFfiNativeType(targetType, false, true)) {
       final AstNode errorNode = node;
       _errorReporter.reportErrorForNode(
-          FfiCode.NON_CONSTANT_TYPE_ARGUMENT_WARNING, errorNode, ['ref']);
+          FfiCode.NON_CONSTANT_TYPE_ARGUMENT, errorNode, ['ref']);
     }
   }
 
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 14bea1b..e2c8920 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -1158,8 +1158,7 @@
     _enclosingFunction = node.declaredElement!;
 
     if (flowAnalysis != null) {
-      flowAnalysis!
-          .topLevelDeclaration_enter(node, node.parameters, node.body);
+      flowAnalysis!.topLevelDeclaration_enter(node, node.parameters, node.body);
       flowAnalysis!.executableDeclaration_enter(node, node.parameters, false);
     } else {
       _promoteManager.enterFunctionBody(node.body!);
@@ -1655,8 +1654,7 @@
     _enclosingFunction = node.declaredElement!;
 
     if (flowAnalysis != null) {
-      flowAnalysis!
-          .topLevelDeclaration_enter(node, node.parameters, node.body);
+      flowAnalysis!.topLevelDeclaration_enter(node, node.parameters, node.body);
       flowAnalysis!.executableDeclaration_enter(node, node.parameters, false);
     } else {
       _promoteManager.enterFunctionBody(node.body);
diff --git a/pkg/analyzer/lib/src/generated/static_type_analyzer.dart b/pkg/analyzer/lib/src/generated/static_type_analyzer.dart
index e7d2de5..ab454da 100644
--- a/pkg/analyzer/lib/src/generated/static_type_analyzer.dart
+++ b/pkg/analyzer/lib/src/generated/static_type_analyzer.dart
@@ -220,8 +220,8 @@
     var context = InferenceContext.getContext(
         (node as IntegerLiteralImpl).immediatelyNegated ? node.parent : node);
     if (context == null ||
-        _typeSystem.isAssignableTo2(_typeProvider.intType, context) ||
-        !_typeSystem.isAssignableTo2(_typeProvider.doubleType, context)) {
+        _typeSystem.isAssignableTo(_typeProvider.intType, context) ||
+        !_typeSystem.isAssignableTo(_typeProvider.doubleType, context)) {
       recordStaticType(node, _typeProvider.intType);
     } else {
       recordStaticType(node, _typeProvider.doubleType);
@@ -284,6 +284,7 @@
 
   @override
   void visitSuperExpression(SuperExpression node) {
+    _resolver.flowAnalysis?.flow?.thisOrSuper(node);
     var thisType = _resolver.thisType;
     if (thisType == null ||
         node.thisOrAncestorOfType<ExtensionDeclaration>() != null) {
@@ -304,6 +305,7 @@
   /// interface of the immediately enclosing class.</blockquote>
   @override
   void visitThisExpression(ThisExpression node) {
+    _resolver.flowAnalysis?.flow?.thisOrSuper(node);
     var thisType = _resolver.thisType;
     if (thisType == null) {
       // TODO(brianwilkerson) Report this error if it hasn't already been
diff --git a/pkg/analyzer/lib/src/summary2/linked_element_factory.dart b/pkg/analyzer/lib/src/summary2/linked_element_factory.dart
index 44aa3ee..080df22 100644
--- a/pkg/analyzer/lib/src/summary2/linked_element_factory.dart
+++ b/pkg/analyzer/lib/src/summary2/linked_element_factory.dart
@@ -297,7 +297,19 @@
     }
 
     // For class, mixin, extension - index members.
-    parent.nodeAccessor!.readIndex();
+    var parentNodeAccessor = parent.nodeAccessor;
+    // TODO(scheglov) https://github.com/dart-lang/sdk/issues/44841
+    if (parentNodeAccessor == null) {
+      var parentNodeCode = '<unknown>';
+      try {
+        parentNodeCode = '${parent.node}';
+      } catch (_) {}
+      throw '[reference: $reference]'
+          '[parent: $parent]'
+          '[parentNodeCode: $parentNodeCode]';
+    } else {
+      parentNodeAccessor.readIndex();
+    }
 
     // For any element - class, method, etc - read the node.
     var node = reference.nodeAccessor!.node;
diff --git a/pkg/analyzer/lib/src/task/strong/checker.dart b/pkg/analyzer/lib/src/task/strong/checker.dart
index 36ae705..948dd19 100644
--- a/pkg/analyzer/lib/src/task/strong/checker.dart
+++ b/pkg/analyzer/lib/src/task/strong/checker.dart
@@ -606,13 +606,13 @@
       return null; // unrelated
     }
 
-    if (rules.isSubtypeOf2(from, to)) {
+    if (rules.isSubtypeOf(from, to)) {
       // Sound subtype.
       // However we may still need cast if we have a call tearoff.
       return callTearoff;
     }
 
-    if (rules.isSubtypeOf2(to, from)) {
+    if (rules.isSubtypeOf(to, from)) {
       // Assignable, but needs cast.
       return true;
     }
@@ -799,12 +799,12 @@
     }
 
     // fromT <: toT, no coercion needed.
-    if (rules.isSubtypeOf2(from, to)) {
+    if (rules.isSubtypeOf(from, to)) {
       return false;
     }
 
     // Down cast or legal sideways cast, coercion needed.
-    if (rules.isAssignableTo2(from, to)) {
+    if (rules.isAssignableTo(from, to)) {
       return true;
     }
 
@@ -837,7 +837,7 @@
     // want to warn if it's a legal subtype.
     if (from is InterfaceType && rules.acceptsFunctionType(to)) {
       var type = rules.getCallMethodType(from);
-      if (type != null && rules.isSubtypeOf2(type, to)) {
+      if (type != null && rules.isSubtypeOf(type, to)) {
         return;
       }
     }
@@ -959,7 +959,7 @@
         nullabilitySuffix: _noneOrStarSuffix,
       );
 
-      if (rules.isSubtypeOf2(sequenceType, iterableType)) {
+      if (rules.isSubtypeOf(sequenceType, iterableType)) {
         _recordImplicitCast(node.iterable, sequenceType, from: iterableType);
         elementType = DynamicTypeImpl.instance;
       }
diff --git a/pkg/analyzer/lib/src/workspace/bazel.dart b/pkg/analyzer/lib/src/workspace/bazel.dart
index b6eda24..d02f16b 100644
--- a/pkg/analyzer/lib/src/workspace/bazel.dart
+++ b/pkg/analyzer/lib/src/workspace/bazel.dart
@@ -368,6 +368,11 @@
   /// The absolute path to the `bazel-genfiles` folder.
   final String genfiles;
 
+  /// Sometimes `BUILD` files are not preserved, and `xyz.packages` files
+  /// are created instead. But looking for them is expensive, so we want
+  /// to avoid this in cases when `BUILD` files are always available.
+  final bool _lookForBuildFileSubstitutes;
+
   /// The cache of packages. The key is the directory path, the value is
   /// the corresponding package.
   final Map<String, BazelWorkspacePackage> _directoryToPackage = {};
@@ -376,7 +381,13 @@
       StreamController<BazelFileNotification>.broadcast();
 
   BazelWorkspace._(
-      this.provider, this.root, this.readonly, this.binPaths, this.genfiles);
+    this.provider,
+    this.root,
+    this.readonly,
+    this.binPaths,
+    this.genfiles, {
+    required bool lookForBuildFileSubstitutes,
+  }) : _lookForBuildFileSubstitutes = lookForBuildFileSubstitutes;
 
   /// Stream of files that we tried to find along with their potential or actual
   /// paths.
@@ -511,30 +522,8 @@
         return packageRootedHere();
       }
 
-      // In some distributed build environments, BUILD files are not preserved.
-      // We can still look for a ".packages" file in order to determine a
-      // package's root. A ".packages" file found in [folder]'s sister path
-      // under a "bin" path among [binPaths] denotes a Dart package.
-      //
-      // For example, if this BazelWorkspace's [root] is
-      // "/build/work/abc123/workspace" with two "bin" folders,
-      // "/build/work/abc123/workspace/blaze-out/host/bin/" and
-      // "/build/work/abc123/workspace/blaze-out/k8-opt/bin/", and [folder]
-      // is at "/build/work/abc123/workspace/foo/bar", then we  must look for a
-      // file ending in ".packages" in the folders
-      // "/build/work/abc123/workspace/blaze-out/host/bin/foo/bar" and
-      // "/build/work/abc123/workspace/blaze-out/k8-opt/bin/foo/bar".
-
-      // [folder]'s path, relative to [root]. For example, "foo/bar".
-      String relative = context.relative(folder.path, from: root);
-      for (String bin in binPaths) {
-        Folder binChild =
-            provider.getFolder(context.normalize(context.join(bin, relative)));
-        if (binChild.exists &&
-            binChild.getChildren().any((c) => c.path.endsWith('.packages'))) {
-          // [folder]'s sister folder within [bin] contains a ".packages" file.
-          return packageRootedHere();
-        }
+      if (_hasBuildFileSubstitute(folder)) {
+        return packageRootedHere();
       }
 
       // Go up a folder.
@@ -542,6 +531,42 @@
     }
   }
 
+  /// In some distributed build environments, BUILD files are not preserved.
+  /// We can still look for a ".packages" file in order to determine a
+  /// package's root. A ".packages" file found in [folder]'s sister path
+  /// under a "bin" path among [binPaths] denotes a Dart package.
+  ///
+  /// For example, if the [root] of this BazelWorkspace is
+  /// "/build/work/abc123/workspace" with two "bin" folders,
+  /// "/build/work/abc123/workspace/blaze-out/host/bin/" and
+  /// "/build/work/abc123/workspace/blaze-out/k8-opt/bin/", and [folder]
+  /// is at "/build/work/abc123/workspace/foo/bar", then we  must look for a
+  /// file ending in ".packages" in the folders
+  /// "/build/work/abc123/workspace/blaze-out/host/bin/foo/bar" and
+  /// "/build/work/abc123/workspace/blaze-out/k8-opt/bin/foo/bar".
+  bool _hasBuildFileSubstitute(Folder folder) {
+    if (!_lookForBuildFileSubstitutes) {
+      return false;
+    }
+
+    path.Context context = provider.pathContext;
+
+    // [folder]'s path, relative to [root]. For example, "foo/bar".
+    String relative = context.relative(folder.path, from: root);
+
+    for (String bin in binPaths) {
+      Folder binChild =
+          provider.getFolder(context.normalize(context.join(bin, relative)));
+      if (binChild.exists &&
+          binChild.getChildren().any((c) => c.path.endsWith('.packages'))) {
+        // [folder]'s sister folder within [bin] contains a ".packages" file.
+        return true;
+      }
+    }
+
+    return false;
+  }
+
   String? _relativeToRoot(String p) {
     path.Context context = provider.pathContext;
     // genfiles
@@ -582,7 +607,11 @@
   ///   BazelWorkspace rooted at _f_ is returned.
   /// * If _f_ has a child file named "WORKSPACE", then a BazelWorkspace rooted
   ///   at _f_ is returned.
-  static BazelWorkspace? find(ResourceProvider provider, String filePath) {
+  static BazelWorkspace? find(
+    ResourceProvider provider,
+    String filePath, {
+    bool lookForBuildFileSubstitutes = true,
+  }) {
     Resource resource = provider.getResource(filePath);
     if (resource is File && resource.parent != null) {
       filePath = resource.parent!.path;
@@ -607,7 +636,8 @@
               _findSymlinkPrefix(provider, root, binPaths: binPaths);
           binPaths ??= [context.join(root, '$symlinkPrefix-bin')];
           return BazelWorkspace._(provider, root, readonlyRoot, binPaths,
-              context.join(root, '$symlinkPrefix-genfiles'));
+              context.join(root, '$symlinkPrefix-genfiles'),
+              lookForBuildFileSubstitutes: lookForBuildFileSubstitutes);
         }
       }
 
@@ -619,7 +649,8 @@
             _findSymlinkPrefix(provider, root, binPaths: binPaths);
         binPaths ??= [context.join(root, '$symlinkPrefix-bin')];
         return BazelWorkspace._(provider, root, null /* readonly */, binPaths,
-            context.join(root, '$symlinkPrefix-genfiles'));
+            context.join(root, '$symlinkPrefix-genfiles'),
+            lookForBuildFileSubstitutes: lookForBuildFileSubstitutes);
       }
 
       // Found the WORKSPACE file, must be a non-git workspace.
@@ -630,7 +661,8 @@
             _findSymlinkPrefix(provider, root, binPaths: binPaths);
         binPaths ??= [context.join(root, '$symlinkPrefix-bin')];
         return BazelWorkspace._(provider, root, null /* readonly */, binPaths,
-            context.join(root, '$symlinkPrefix-genfiles'));
+            context.join(root, '$symlinkPrefix-genfiles'),
+            lookForBuildFileSubstitutes: lookForBuildFileSubstitutes);
       }
 
       // Go up the folder.
diff --git a/pkg/analyzer/test/generated/type_system_test.dart b/pkg/analyzer/test/generated/type_system_test.dart
index 146d36f..6a50ac8 100644
--- a/pkg/analyzer/test/generated/type_system_test.dart
+++ b/pkg/analyzer/test/generated/type_system_test.dart
@@ -405,11 +405,11 @@
   }
 
   void _checkIsAssignableTo(DartType type1, DartType type2) {
-    expect(typeSystem.isAssignableTo2(type1, type2), true);
+    expect(typeSystem.isAssignableTo(type1, type2), true);
   }
 
   void _checkIsNotAssignableTo(DartType type1, DartType type2) {
-    expect(typeSystem.isAssignableTo2(type1, type2), false);
+    expect(typeSystem.isAssignableTo(type1, type2), false);
   }
 
   void _checkIsStrictAssignableTo(DartType type1, DartType type2) {
diff --git a/pkg/analyzer/test/id_tests/assigned_variables_test.dart b/pkg/analyzer/test/id_tests/assigned_variables_test.dart
index 1781d16..ef788ba 100644
--- a/pkg/analyzer/test/id_tests/assigned_variables_test.dart
+++ b/pkg/analyzer/test/id_tests/assigned_variables_test.dart
@@ -9,7 +9,6 @@
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
 import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
 import 'package:analyzer/src/util/ast_data_extractor.dart';
@@ -20,14 +19,12 @@
   Directory dataDir = Directory.fromUri(Platform.script.resolve(
       '../../../_fe_analyzer_shared/test/flow_analysis/assigned_variables/'
       'data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<_Data>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest: runTestFor(
-            const _AssignedVariablesDataComputer(), [analyzerNnbdConfig]));
-  });
+  return runTests<_Data>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest: runTestFor(
+          const _AssignedVariablesDataComputer(), [analyzerNnbdConfig]));
 }
 
 class _AssignedVariablesDataComputer extends DataComputer<_Data> {
diff --git a/pkg/analyzer/test/id_tests/constant_test.dart b/pkg/analyzer/test/id_tests/constant_test.dart
index 79e212b..58b19d2 100644
--- a/pkg/analyzer/test/id_tests/constant_test.dart
+++ b/pkg/analyzer/test/id_tests/constant_test.dart
@@ -9,7 +9,6 @@
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
@@ -21,14 +20,12 @@
 main(List<String> args) async {
   Directory dataDir = Directory.fromUri(Platform.script
       .resolve('../../../_fe_analyzer_shared/test/constants/data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<String>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest: runTestFor(
-            const ConstantsDataComputer(), [analyzerConstantUpdate2018Config]));
-  });
+  return runTests<String>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest: runTestFor(
+          const ConstantsDataComputer(), [analyzerConstantUpdate2018Config]));
 }
 
 class ConstantsDataComputer extends DataComputer<String> {
diff --git a/pkg/analyzer/test/id_tests/definite_assignment_test.dart b/pkg/analyzer/test/id_tests/definite_assignment_test.dart
index 72071678..dd3fe0b 100644
--- a/pkg/analyzer/test/id_tests/definite_assignment_test.dart
+++ b/pkg/analyzer/test/id_tests/definite_assignment_test.dart
@@ -8,7 +8,6 @@
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
 import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
@@ -21,14 +20,12 @@
   Directory dataDir = Directory.fromUri(Platform.script.resolve(
       '../../../_fe_analyzer_shared/test/flow_analysis/definite_assignment/'
       'data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<String>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest: runTestFor(
-            const _DefiniteAssignmentDataComputer(), [analyzerNnbdConfig]));
-  });
+  return runTests<String>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest: runTestFor(
+          const _DefiniteAssignmentDataComputer(), [analyzerNnbdConfig]));
 }
 
 class _DefiniteAssignmentDataComputer extends DataComputer<String> {
diff --git a/pkg/analyzer/test/id_tests/definite_unassignment_test.dart b/pkg/analyzer/test/id_tests/definite_unassignment_test.dart
index 0f3cf47..7e4d258 100644
--- a/pkg/analyzer/test/id_tests/definite_unassignment_test.dart
+++ b/pkg/analyzer/test/id_tests/definite_unassignment_test.dart
@@ -8,7 +8,6 @@
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
 import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
@@ -21,14 +20,12 @@
   Directory dataDir = Directory.fromUri(Platform.script.resolve(
       '../../../_fe_analyzer_shared/test/flow_analysis/definite_unassignment/'
       'data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<String>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest: runTestFor(
-            const _DefiniteAssignmentDataComputer(), [analyzerNnbdConfig]));
-  });
+  return runTests<String>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest: runTestFor(
+          const _DefiniteAssignmentDataComputer(), [analyzerNnbdConfig]));
 }
 
 class _DefiniteAssignmentDataComputer extends DataComputer<String> {
diff --git a/pkg/analyzer/test/id_tests/inheritance_test.dart b/pkg/analyzer/test/id_tests/inheritance_test.dart
index a8a7dea..299ff7c 100644
--- a/pkg/analyzer/test/id_tests/inheritance_test.dart
+++ b/pkg/analyzer/test/id_tests/inheritance_test.dart
@@ -8,7 +8,6 @@
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
@@ -20,21 +19,19 @@
 main(List<String> args) async {
   Directory dataDir = Directory.fromUri(Platform.script
       .resolve('../../../_fe_analyzer_shared/test/inheritance/data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<String>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest:
-            runTestFor(const _InheritanceDataComputer(), [analyzerNnbdConfig]),
-        skipMap: {
-          analyzerMarker: [
-            // These are CFE-centric tests for an opt-in/opt-out sdk.
-            'object_opt_in',
-            'object_opt_out',
-          ]
-        });
-  });
+  return runTests<String>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest:
+          runTestFor(const _InheritanceDataComputer(), [analyzerNnbdConfig]),
+      skipMap: {
+        analyzerMarker: [
+          // These are CFE-centric tests for an opt-in/opt-out sdk.
+          'object_opt_in',
+          'object_opt_out',
+        ]
+      });
 }
 
 String supertypeToString(InterfaceType type) {
diff --git a/pkg/analyzer/test/id_tests/nullability_test.dart b/pkg/analyzer/test/id_tests/nullability_test.dart
index b2f1561..6b98e40 100644
--- a/pkg/analyzer/test/id_tests/nullability_test.dart
+++ b/pkg/analyzer/test/id_tests/nullability_test.dart
@@ -9,7 +9,6 @@
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_system.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
@@ -22,14 +21,12 @@
 main(List<String> args) async {
   Directory dataDir = Directory.fromUri(Platform.script.resolve(
       '../../../_fe_analyzer_shared/test/flow_analysis/nullability/data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<String>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest:
-            runTestFor(const _NullabilityDataComputer(), [analyzerNnbdConfig]));
-  });
+  return runTests<String>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest:
+          runTestFor(const _NullabilityDataComputer(), [analyzerNnbdConfig]));
 }
 
 class FlowTestBase {
diff --git a/pkg/analyzer/test/id_tests/reachability_test.dart b/pkg/analyzer/test/id_tests/reachability_test.dart
index aff26d2..7b4c957 100644
--- a/pkg/analyzer/test/id_tests/reachability_test.dart
+++ b/pkg/analyzer/test/id_tests/reachability_test.dart
@@ -8,7 +8,6 @@
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
 import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
 import 'package:analyzer/src/util/ast_data_extractor.dart';
@@ -19,14 +18,12 @@
 main(List<String> args) async {
   Directory dataDir = Directory.fromUri(Platform.script.resolve(
       '../../../_fe_analyzer_shared/test/flow_analysis/reachability/data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<Set<_ReachabilityAssertion>>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest: runTestFor(
-            const _ReachabilityDataComputer(), [analyzerNnbdConfig]));
-  });
+  return runTests<Set<_ReachabilityAssertion>>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest:
+          runTestFor(const _ReachabilityDataComputer(), [analyzerNnbdConfig]));
 }
 
 class FlowTestBase {
diff --git a/pkg/analyzer/test/id_tests/type_promotion_test.dart b/pkg/analyzer/test/id_tests/type_promotion_test.dart
index 302be7f..a5e0435 100644
--- a/pkg/analyzer/test/id_tests/type_promotion_test.dart
+++ b/pkg/analyzer/test/id_tests/type_promotion_test.dart
@@ -8,7 +8,6 @@
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/analysis/testing_data.dart';
 import 'package:analyzer/src/util/ast_data_extractor.dart';
@@ -19,14 +18,12 @@
   Directory dataDir = Directory.fromUri(Platform.script
       .resolve('../../../_fe_analyzer_shared/test/flow_analysis/type_promotion/'
           'data'));
-  await NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-    return runTests<DartType>(dataDir,
-        args: args,
-        createUriForFileName: createUriForFileName,
-        onFailure: onFailure,
-        runTest: runTestFor(
-            const _TypePromotionDataComputer(), [analyzerNnbdConfig]));
-  });
+  return runTests<DartType>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest:
+          runTestFor(const _TypePromotionDataComputer(), [analyzerNnbdConfig]));
 }
 
 class _TypePromotionDataComputer extends DataComputer<DartType> {
diff --git a/pkg/analyzer/test/id_tests/why_not_promoted_test.dart b/pkg/analyzer/test/id_tests/why_not_promoted_test.dart
new file mode 100644
index 0000000..6cef947
--- /dev/null
+++ b/pkg/analyzer/test/id_tests/why_not_promoted_test.dart
@@ -0,0 +1,84 @@
+// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:_fe_analyzer_shared/src/testing/id.dart' show ActualData, Id;
+import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
+import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/src/dart/analysis/testing_data.dart';
+import 'package:analyzer/src/dart/resolver/flow_analysis_visitor.dart';
+import 'package:analyzer/src/util/ast_data_extractor.dart';
+
+import '../util/id_testing_helper.dart';
+
+main(List<String> args) async {
+  Directory dataDir = Directory.fromUri(
+      Platform.script.resolve('../../../_fe_analyzer_shared/test/flow_analysis/'
+          'why_not_promoted/data'));
+  return runTests<String?>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest: runTestFor(
+          const _WhyNotPromotedDataComputer(), [analyzerNnbdConfig]));
+}
+
+class _WhyNotPromotedDataComputer extends DataComputer<String?> {
+  const _WhyNotPromotedDataComputer();
+
+  @override
+  DataInterpreter<String?> get dataValidator =>
+      const _WhyNotPromotedDataInterpreter();
+
+  @override
+  bool get supportsErrors => true;
+
+  @override
+  void computeUnitData(TestingData testingData, CompilationUnit unit,
+      Map<Id, ActualData<String?>> actualMap) {
+    var flowResult =
+        testingData.uriToFlowAnalysisData[unit.declaredElement!.source.uri]!;
+    _WhyNotPromotedDataExtractor(
+            unit.declaredElement!.source.uri, actualMap, flowResult)
+        .run(unit);
+  }
+}
+
+class _WhyNotPromotedDataExtractor extends AstDataExtractor<String?> {
+  final FlowAnalysisDataForTesting _flowResult;
+
+  _WhyNotPromotedDataExtractor(
+      Uri uri, Map<Id, ActualData<String?>> actualMap, this._flowResult)
+      : super(uri, actualMap);
+
+  @override
+  String? computeNodeValue(Id id, AstNode node) {
+    String? nonPromotionReason = _flowResult.nonPromotionReasons[node];
+    if (nonPromotionReason != null) {
+      return 'notPromoted($nonPromotionReason)';
+    }
+    return _flowResult.nonPromotionReasonTargets[node];
+  }
+}
+
+class _WhyNotPromotedDataInterpreter implements DataInterpreter<String?> {
+  const _WhyNotPromotedDataInterpreter();
+
+  @override
+  String getText(String? actualData, [String? indentation]) =>
+      actualData.toString();
+
+  @override
+  String? isAsExpected(String? actualData, String? expectedData) {
+    if (actualData == expectedData) {
+      return null;
+    } else {
+      return 'Expected $expectedData, got $actualData';
+    }
+  }
+
+  @override
+  bool isEmpty(String? actualData) => actualData == null;
+}
diff --git a/pkg/analyzer/test/src/dart/ast/to_source_visitor_test.dart b/pkg/analyzer/test/src/dart/ast/to_source_visitor_test.dart
index 4251d35..bdcdd67 100644
--- a/pkg/analyzer/test/src/dart/ast/to_source_visitor_test.dart
+++ b/pkg/analyzer/test/src/dart/ast/to_source_visitor_test.dart
@@ -2,6 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:analyzer/dart/analysis/utilities.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_ast_factory.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ -2272,11 +2273,16 @@
     _assertSource("@deprecated part 'a.dart';", directive);
   }
 
-  void test_visitPartOfDirective() {
-    _assertSource(
-        "part of l;",
-        AstTestFactory.partOfDirective(
-            AstTestFactory.libraryIdentifier2(["l"])));
+  void test_visitPartOfDirective_name() {
+    var unit = parseString(content: 'part of l;').unit;
+    var directive = unit.directives[0] as PartOfDirective;
+    _assertSource("part of l;", directive);
+  }
+
+  void test_visitPartOfDirective_uri() {
+    var unit = parseString(content: "part of 'a.dart';").unit;
+    var directive = unit.directives[0] as PartOfDirective;
+    _assertSource("part of 'a.dart';", directive);
   }
 
   void test_visitPartOfDirective_withMetadata() {
diff --git a/pkg/analyzer/test/src/dart/element/inheritance_manager3_test.dart b/pkg/analyzer/test/src/dart/element/inheritance_manager3_test.dart
index f1f5973..d584afe 100644
--- a/pkg/analyzer/test/src/dart/element/inheritance_manager3_test.dart
+++ b/pkg/analyzer/test/src/dart/element/inheritance_manager3_test.dart
@@ -3,7 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/src/dart/element/inheritance_manager3.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -1325,15 +1324,12 @@
     bool concrete = false,
     bool forSuper = false,
   }) {
-    ExecutableElement? member;
-    NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-      member = manager.getMember2(
-        findElement.classOrMixin(className),
-        Name(null, name),
-        concrete: concrete,
-        forSuper: forSuper,
-      );
-    });
+    var member = manager.getMember2(
+      findElement.classOrMixin(className),
+      Name(null, name),
+      concrete: concrete,
+      forSuper: forSuper,
+    );
 
     _assertExecutable(member, expected);
   }
diff --git a/pkg/analyzer/test/src/dart/element/replace_top_bottom_test.dart b/pkg/analyzer/test/src/dart/element/replace_top_bottom_test.dart
index 8a6db58..54a3fd6 100644
--- a/pkg/analyzer/test/src/dart/element/replace_top_bottom_test.dart
+++ b/pkg/analyzer/test/src/dart/element/replace_top_bottom_test.dart
@@ -2,7 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/resolver/variance.dart';
@@ -63,15 +62,13 @@
   }
 
   void _check(DartType type, String expectedStr, {String? typeStr}) {
-    NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-      if (typeStr != null) {
-        expect(_typeString(type), typeStr);
-      }
+    if (typeStr != null) {
+      expect(_typeString(type), typeStr);
+    }
 
-      var result = typeSystem.replaceTopAndBottom(type);
-      var resultStr = _typeString(result);
-      expect(resultStr, expectedStr);
-    });
+    var result = typeSystem.replaceTopAndBottom(type);
+    var resultStr = _typeString(result);
+    expect(resultStr, expectedStr);
   }
 
   String _typeString(DartType type) {
@@ -163,15 +160,13 @@
   }
 
   void _check(DartType type, String expectedStr, {String? typeStr}) {
-    NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-      if (typeStr != null) {
-        expect(_typeString(type), typeStr);
-      }
+    if (typeStr != null) {
+      expect(_typeString(type), typeStr);
+    }
 
-      var result = typeSystem.replaceTopAndBottom(type);
-      var resultStr = _typeString(result);
-      expect(resultStr, expectedStr);
-    });
+    var result = typeSystem.replaceTopAndBottom(type);
+    var resultStr = _typeString(result);
+    expect(resultStr, expectedStr);
   }
 
   String _typeString(DartType type) {
diff --git a/pkg/analyzer/test/src/dart/element/subtype_test.dart b/pkg/analyzer/test/src/dart/element/subtype_test.dart
index 2a22d03..4063e9f 100644
--- a/pkg/analyzer/test/src/dart/element/subtype_test.dart
+++ b/pkg/analyzer/test/src/dart/element/subtype_test.dart
@@ -287,7 +287,7 @@
   }) {
     assertExpectedString(T0, strT0);
     assertExpectedString(T1, strT1);
-    expect(typeSystem.isSubtypeOf2(T0, T1), isFalse);
+    expect(typeSystem.isSubtypeOf(T0, T1), isFalse);
   }
 
   void isNotSubtype2(
@@ -296,7 +296,7 @@
   ) {
     var T0 = _getTypeByStr(strT0);
     var T1 = _getTypeByStr(strT1);
-    expect(typeSystem.isSubtypeOf2(T0, T1), isFalse);
+    expect(typeSystem.isSubtypeOf(T0, T1), isFalse);
   }
 
   void isNotSubtype3({
@@ -314,7 +314,7 @@
   }) {
     assertExpectedString(T0, strT0);
     assertExpectedString(T1, strT1);
-    expect(typeSystem.isSubtypeOf2(T0, T1), isTrue);
+    expect(typeSystem.isSubtypeOf(T0, T1), isTrue);
   }
 
   void isSubtype2(
@@ -323,7 +323,7 @@
   ) {
     var T0 = _getTypeByStr(strT0);
     var T1 = _getTypeByStr(strT1);
-    expect(typeSystem.isSubtypeOf2(T0, T1), isTrue);
+    expect(typeSystem.isSubtypeOf(T0, T1), isTrue);
   }
 
   @override
@@ -5964,7 +5964,7 @@
   void _checkIsNotSubtypeOf(DartType type1, DartType type2) {
     var strType1 = _typeStr(type1);
     var strType2 = _typeStr(type2);
-    expect(typeSystem.isSubtypeOf2(type1, type2), false,
+    expect(typeSystem.isSubtypeOf(type1, type2), false,
         reason: '$strType1 was not supposed to be a subtype of $strType2');
   }
 
@@ -5976,7 +5976,7 @@
   void _checkIsSubtypeOf(DartType type1, DartType type2) {
     var strType1 = _typeStr(type1);
     var strType2 = _typeStr(type2);
-    expect(typeSystem.isSubtypeOf2(type1, type2), true,
+    expect(typeSystem.isSubtypeOf(type1, type2), true,
         reason: '$strType1 is not a subtype of $strType2');
   }
 
diff --git a/pkg/analyzer/test/src/dart/element/type_parameter_element_test.dart b/pkg/analyzer/test/src/dart/element/type_parameter_element_test.dart
index c809a6f..69ceb64 100644
--- a/pkg/analyzer/test/src/dart/element/type_parameter_element_test.dart
+++ b/pkg/analyzer/test/src/dart/element/type_parameter_element_test.dart
@@ -2,7 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -147,8 +146,6 @@
   }
 
   void _assertEqual(DartType T1, DartType T2, matcher) {
-    NullSafetyUnderstandingFlag.enableNullSafetyTypes(() async {
-      expect(T1 == T2, matcher);
-    });
+    expect(T1 == T2, matcher);
   }
 }
diff --git a/pkg/analyzer/test/src/dart/element/upper_lower_bound_test.dart b/pkg/analyzer/test/src/dart/element/upper_lower_bound_test.dart
index 2c3a877..c68511d 100644
--- a/pkg/analyzer/test/src/dart/element/upper_lower_bound_test.dart
+++ b/pkg/analyzer/test/src/dart/element/upper_lower_bound_test.dart
@@ -4,7 +4,6 @@
 
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_visitor.dart';
@@ -1435,8 +1434,8 @@
 
     // Check that the result is a lower bound.
     if (checkSubtype) {
-      expect(typeSystem.isSubtypeOf2(result, T1), true);
-      expect(typeSystem.isSubtypeOf2(result, T2), true);
+      expect(typeSystem.isSubtypeOf(result, T1), true);
+      expect(typeSystem.isSubtypeOf(result, T2), true);
     }
 
     // Check for symmetry.
@@ -3423,28 +3422,26 @@
   }
 
   void _checkLeastUpperBound(DartType T1, DartType T2, DartType expected) {
-    NullSafetyUnderstandingFlag.enableNullSafetyTypes(() async {
-      var expectedStr = _typeString(expected);
+    var expectedStr = _typeString(expected);
 
-      var result = typeSystem.getLeastUpperBound(T1, T2);
-      var resultStr = _typeString(result);
-      expect(result, expected, reason: '''
+    var result = typeSystem.getLeastUpperBound(T1, T2);
+    var resultStr = _typeString(result);
+    expect(result, expected, reason: '''
 expected: $expectedStr
 actual: $resultStr
 ''');
 
-      // Check that the result is an upper bound.
-      expect(typeSystem.isSubtypeOf2(T1, result), true);
-      expect(typeSystem.isSubtypeOf2(T2, result), true);
+    // Check that the result is an upper bound.
+    expect(typeSystem.isSubtypeOf(T1, result), true);
+    expect(typeSystem.isSubtypeOf(T2, result), true);
 
-      // Check for symmetry.
-      result = typeSystem.getLeastUpperBound(T2, T1);
-      resultStr = _typeString(result);
-      expect(result, expected, reason: '''
+    // Check for symmetry.
+    result = typeSystem.getLeastUpperBound(T2, T1);
+    resultStr = _typeString(result);
+    expect(result, expected, reason: '''
 expected: $expectedStr
 actual: $resultStr
 ''');
-    });
   }
 
   String _typeParametersStr(DartType type) {
diff --git a/pkg/analyzer/test/src/dart/micro/simple_file_resolver_test.dart b/pkg/analyzer/test/src/dart/micro/simple_file_resolver_test.dart
index 28d8657..b842d4b 100644
--- a/pkg/analyzer/test/src/dart/micro/simple_file_resolver_test.dart
+++ b/pkg/analyzer/test/src/dart/micro/simple_file_resolver_test.dart
@@ -502,6 +502,13 @@
     );
   }
 
+  test_part_notInLibrary_libraryDoesNotExist() async {
+    // TODO(scheglov) Should report CompileTimeErrorCode.URI_DOES_NOT_EXIST
+    await assertNoErrorsInCode(r'''
+part of 'a.dart';
+''');
+  }
+
   test_resolve_part_of() async {
     newFile('/workspace/dart/test/lib/a.dart', content: r'''
 part 'test.dart';
diff --git a/pkg/analyzer/test/src/dart/resolution/field_test.dart b/pkg/analyzer/test/src/dart/resolution/field_test.dart
index c8120a0..431a369 100644
--- a/pkg/analyzer/test/src/dart/resolution/field_test.dart
+++ b/pkg/analyzer/test/src/dart/resolution/field_test.dart
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analyzer/src/dart/error/hint_codes.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'context_collection_resolution.dart';
@@ -16,6 +17,19 @@
 
 @reflectiveTest
 class FieldTest extends PubPackageResolutionTest {
+  test_session_getterSetter() async {
+    await resolveTestCode('''
+class A {
+  var f = 0;
+}
+''');
+    var getter = findElement.getter('f');
+    expect(getter.session, result.session);
+
+    var setter = findElement.setter('f');
+    expect(setter.session, result.session);
+  }
+
   test_type_inferred_int() async {
     await resolveTestCode('''
 class A {
diff --git a/pkg/analyzer/test/src/dart/resolution/top_level_variable_test.dart b/pkg/analyzer/test/src/dart/resolution/top_level_variable_test.dart
index fd045d0..60e2338 100644
--- a/pkg/analyzer/test/src/dart/resolution/top_level_variable_test.dart
+++ b/pkg/analyzer/test/src/dart/resolution/top_level_variable_test.dart
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analyzer/src/dart/error/hint_codes.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'context_collection_resolution.dart';
@@ -16,6 +17,17 @@
 
 @reflectiveTest
 class TopLevelVariableTest extends PubPackageResolutionTest {
+  test_session_getterSetter() async {
+    await resolveTestCode('''
+var v = 0;
+''');
+    var getter = findElement.topGet('v');
+    expect(getter.session, result.session);
+
+    var setter = findElement.topSet('v');
+    expect(setter.session, result.session);
+  }
+
   test_type_inferred_int() async {
     await resolveTestCode('''
 var v = 0;
diff --git a/pkg/analyzer/test/src/diagnostics/ambiguous_import_test.dart b/pkg/analyzer/test/src/diagnostics/ambiguous_import_test.dart
index cb20c6d..fe447bc 100644
--- a/pkg/analyzer/test/src/diagnostics/ambiguous_import_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/ambiguous_import_test.dart
@@ -19,6 +19,27 @@
 
 @reflectiveTest
 class AmbiguousImportTest extends PubPackageResolutionTest {
+  test_annotation_getter() async {
+    newFile('$testPackageLibPath/a.dart', content: r'''
+const foo = 0;
+''');
+
+    newFile('$testPackageLibPath/b.dart', content: r'''
+const foo = 0;
+''');
+
+    await assertErrorsInCode(r'''
+import 'a.dart';
+import 'b.dart';
+
+@foo
+class A {}
+''', [
+      error(CompileTimeErrorCode.INVALID_ANNOTATION, 35, 4),
+      error(CompileTimeErrorCode.AMBIGUOUS_IMPORT, 36, 3),
+    ]);
+  }
+
   test_as() async {
     newFile("$testPackageLibPath/lib1.dart", content: '''
 library lib1;
diff --git a/pkg/analyzer/test/src/diagnostics/non_constant_type_argument_test.dart b/pkg/analyzer/test/src/diagnostics/non_constant_type_argument_test.dart
index b94d780..9df668f 100644
--- a/pkg/analyzer/test/src/diagnostics/non_constant_type_argument_test.dart
+++ b/pkg/analyzer/test/src/diagnostics/non_constant_type_argument_test.dart
@@ -72,6 +72,6 @@
 
 T genericRef<T extends Struct>(Pointer<T> p) =>
     p.ref;
-''', [error(FfiCode.NON_CONSTANT_TYPE_ARGUMENT_WARNING, 72, 5)]);
+''', [error(FfiCode.NON_CONSTANT_TYPE_ARGUMENT, 72, 5)]);
   }
 }
diff --git a/pkg/analyzer/test/src/lint/lint_rule_test.dart b/pkg/analyzer/test/src/lint/lint_rule_test.dart
index c6a04fb..5db743a 100644
--- a/pkg/analyzer/test/src/lint/lint_rule_test.dart
+++ b/pkg/analyzer/test/src/lint/lint_rule_test.dart
@@ -5,6 +5,7 @@
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/diagnostic/diagnostic.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/src/dart/ast/ast.dart';
@@ -80,7 +81,7 @@
 
   @override
   void reportErrorForNode(ErrorCode errorCode, AstNode node,
-      [List<Object?>? arguments]) {
+      [List<Object?>? arguments, List<DiagnosticMessage>? messages]) {
     code = errorCode;
   }
 
diff --git a/pkg/analyzer/test/src/summary/resynthesize_ast2_test.dart b/pkg/analyzer/test/src/summary/resynthesize_ast2_test.dart
index 7dd1655..e8bce34 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_ast2_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_ast2_test.dart
@@ -6,7 +6,6 @@
 
 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/dart/analysis/session.dart';
 import 'package:analyzer/src/dart/element/class_hierarchy.dart';
@@ -103,11 +102,7 @@
       ),
     );
 
-    var linkResult = NullSafetyUnderstandingFlag.enableNullSafetyTypes(
-      () {
-        return link(elementFactory, inputLibraries, true);
-      },
-    );
+    var linkResult = link(elementFactory, inputLibraries, true);
 
     elementFactory.addBundle(
       BundleReader(
diff --git a/pkg/analyzer/test/src/workspace/bazel_test.dart b/pkg/analyzer/test/src/workspace/bazel_test.dart
index 00f80db..07dee14 100644
--- a/pkg/analyzer/test/src/workspace/bazel_test.dart
+++ b/pkg/analyzer/test/src/workspace/bazel_test.dart
@@ -676,6 +676,23 @@
     expect(package, isNull);
   }
 
+  void test_findPackageFor_noBuildFile_disabledPackagesFile() {
+    _addResources([
+      '/ws/blaze-out/host/bin/some/code/code.packages',
+      '/ws/some/code/lib/code.dart',
+    ]);
+    workspace = BazelWorkspace.find(
+      resourceProvider,
+      convertPath('/ws/some/code'),
+      lookForBuildFileSubstitutes: false,
+    )!;
+
+    package = workspace.findPackageFor(
+      convertPath('/ws/some/code/lib/code.dart'),
+    );
+    expect(package, isNull);
+  }
+
   void test_findPackageFor_packagesFileExistsInOneOfSeveralBinPaths() {
     _addResources([
       '/ws/blaze-out/host/bin/some/code/code.packages',
diff --git a/pkg/analyzer/test/src/workspace/gn_test.dart b/pkg/analyzer/test/src/workspace/gn_test.dart
index 9441a01..d25eb2a 100644
--- a/pkg/analyzer/test/src/workspace/gn_test.dart
+++ b/pkg/analyzer/test/src/workspace/gn_test.dart
@@ -163,8 +163,8 @@
     newFile('/workspace/.fx-build-dir', content: '$buildDir\n');
     newFile(
         '/workspace/out/debug-x87_128/dartlang/gen/some/code/foo_package_config.json');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
   }
 
@@ -189,8 +189,8 @@
     }
   ]
 }''');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
     expect(workspace.packageMap.length, 1);
     expect(workspace.packageMap['flutter']![0].path,
@@ -218,8 +218,8 @@
     }
   ]
 }''');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
     expect(workspace.packageMap.length, 1);
     expect(workspace.packageMap['flutter']![0].path,
@@ -245,8 +245,8 @@
     }
   ]
 }''');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
     expect(workspace.packageMap.length, 1);
     expect(workspace.packageMap['flutter']![0].path,
@@ -273,8 +273,8 @@
     }
   ]
 }''');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
     expect(workspace.packageMap.length, 1);
     expect(workspace.packageMap['flutter']![0].path,
@@ -318,8 +318,8 @@
     }
   ]
 }''');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
     expect(workspace.packageMap.length, 1);
     expect(workspace.packageMap['rettulf']![0].path,
@@ -363,8 +363,8 @@
     }
   ]
 }''');
-    var workspace =
-        GnWorkspace.find(resourceProvider, convertPath('/workspace/some/code'))!;
+    var workspace = GnWorkspace.find(
+        resourceProvider, convertPath('/workspace/some/code'))!;
     expect(workspace.root, convertPath('/workspace'));
     expect(workspace.packageMap.length, 2);
     expect(workspace.packageMap['flutter']![0].path,
diff --git a/pkg/analyzer/tool/experiments/generate.dart b/pkg/analyzer/tool/experiments/generate.dart
index 5fc75f1..f57961d 100644
--- a/pkg/analyzer/tool/experiments/generate.dart
+++ b/pkg/analyzer/tool/experiments/generate.dart
@@ -210,7 +210,7 @@
     for (var key in keysSorted) {
       var entry = features[key] as YamlMap;
       bool shipped = entry['enabledIn'] != null;
-      bool expired = entry['expired'];
+      bool? expired = entry['expired'];
       out.write('''
       /// Expiration status of the experiment "$key"
       static const bool ${keyToIdentifier(key)} = ${expired == true};
diff --git a/pkg/analyzer/tool/messages/generate.dart b/pkg/analyzer/tool/messages/generate.dart
index 80b9579..17946b6 100644
--- a/pkg/analyzer/tool/messages/generate.dart
+++ b/pkg/analyzer/tool/messages/generate.dart
@@ -199,7 +199,7 @@
       }
       throw shouldRunFastaGenerateMessagesFirst;
     }
-    out.writeln('final fastaAnalyzerErrorCodes = <ErrorCode>[null,');
+    out.writeln('final fastaAnalyzerErrorCodes = <ErrorCode?>[null,');
     for (var entry in sorted) {
       List<String> name = nameForEntry(entry);
       out.writeln('_${name[1]},');
diff --git a/pkg/analyzer/tool/update_id_tests.dart b/pkg/analyzer/tool/update_id_tests.dart
index 4f7a5d6..44a9384 100644
--- a/pkg/analyzer/tool/update_id_tests.dart
+++ b/pkg/analyzer/tool/update_id_tests.dart
@@ -17,4 +17,5 @@
   'pkg/analyzer/test/id_tests/nullability_test.dart',
   'pkg/analyzer/test/id_tests/reachability_test.dart',
   'pkg/analyzer/test/id_tests/type_promotion_test.dart',
+  'pkg/analyzer/test/id_tests/why_not_promoted_test.dart',
 ];
diff --git a/pkg/compiler/lib/src/common_elements.dart b/pkg/compiler/lib/src/common_elements.dart
index ae898a3..38e856c 100644
--- a/pkg/compiler/lib/src/common_elements.dart
+++ b/pkg/compiler/lib/src/common_elements.dart
@@ -14,7 +14,6 @@
 import 'inferrer/abstract_value_domain.dart';
 import 'js_backend/native_data.dart' show NativeBasicData;
 import 'js_model/locals.dart';
-import 'kernel/dart2js_target.dart';
 import 'universe/selector.dart' show Selector;
 
 /// The common elements and types in Dart.
@@ -572,15 +571,6 @@
   ClassEntity get metaNoInlineClass;
 
   ClassEntity get metaTryInlineClass;
-
-  /// Returns `true` if [function] is allowed to be external.
-  ///
-  /// This returns `true` for foreign helpers, from environment constructors and
-  /// members of libraries that support native.
-  ///
-  /// This returns `false` for JS interop members which therefore must be
-  /// allowed to be external through the JS interop annotation handling.
-  bool isExternalAllowed(FunctionEntity function);
 }
 
 abstract class JCommonElements implements CommonElements {
@@ -2152,17 +2142,6 @@
   }
 
   @override
-  bool isExternalAllowed(FunctionEntity function) {
-    return isForeignHelper(function) ||
-        (function is ConstructorEntity &&
-            function.isFromEnvironmentConstructor) ||
-        maybeEnableNative(function.library.canonicalUri) ||
-        // TODO(johnniwinther): Remove this when importing dart:mirrors is
-        // a compile-time error.
-        function.library.canonicalUri == Uris.dart_mirrors;
-  }
-
-  @override
   bool operatorEqHandlesNullArgument(FunctionEntity function) {
     assert(function.name == '==',
         failedAt(function, "Unexpected function $function."));
diff --git a/pkg/compiler/lib/src/diagnostics/messages.dart b/pkg/compiler/lib/src/diagnostics/messages.dart
index a0be968..ae4793a 100644
--- a/pkg/compiler/lib/src/diagnostics/messages.dart
+++ b/pkg/compiler/lib/src/diagnostics/messages.dart
@@ -527,10 +527,10 @@
 
       MessageKind.NON_NATIVE_EXTERNAL: const MessageTemplate(
           MessageKind.NON_NATIVE_EXTERNAL,
-          "Only external js-interop functions are supported.",
+          "Non-native external members must be js-interop.",
           howToFix:
-              "Try removing 'external' keyword or annotating the function "
-              "as a js-interop function."),
+              "Try removing the 'external' keyword, making it 'native', or "
+              "annotating the function as a js-interop function."),
 
       MessageKind.NATIVE_NON_INSTANCE_IN_NON_NATIVE_CLASS: const MessageTemplate(
           MessageKind.NATIVE_NON_INSTANCE_IN_NON_NATIVE_CLASS,
diff --git a/pkg/compiler/lib/src/kernel/element_map_impl.dart b/pkg/compiler/lib/src/kernel/element_map_impl.dart
index fe5ce5f..f5f74d3 100644
--- a/pkg/compiler/lib/src/kernel/element_map_impl.dart
+++ b/pkg/compiler/lib/src/kernel/element_map_impl.dart
@@ -2084,6 +2084,8 @@
     assert(annotationData != null);
     if (!maybeEnableNative(node.enclosingLibrary.importUri)) return false;
     bool hasNativeBody = annotationData.hasNativeBody(node);
+    // TODO(rileyporter): Move this check on non-native external usage to
+    // js_interop_checks when `native` and `external` can be disambiguated.
     if (!hasNativeBody &&
         node.isExternal &&
         !_nativeBasicData.isJsInteropMember(_elementMap.getMember(node))) {
diff --git a/pkg/compiler/lib/src/kernel/native_basic_data.dart b/pkg/compiler/lib/src/kernel/native_basic_data.dart
index 0b83ce2..d030007 100644
--- a/pkg/compiler/lib/src/kernel/native_basic_data.dart
+++ b/pkg/compiler/lib/src/kernel/native_basic_data.dart
@@ -49,9 +49,9 @@
 
   @override
   void extractJsInteropAnnotations(LibraryEntity library) {
-    DiagnosticReporter reporter = elementMap.reporter;
+    // Unused reporter, add back in if uncommenting report lines down below.
+    // DiagnosticReporter reporter = elementMap.reporter;
     KElementEnvironment elementEnvironment = elementMap.elementEnvironment;
-    KCommonElements commonElements = elementMap.commonElements;
 
     ir.Library libraryNode = elementMap.getLibraryNode(library);
     String libraryName = annotationData.getJsInteropLibraryName(libraryNode);
@@ -85,10 +85,6 @@
             // implicitly js-interop. For now we allow it.
             isJsLibrary = true;
           }
-        } else if (function.isExternal &&
-            !commonElements.isExternalAllowed(function)) {
-          reporter.reportErrorMessage(
-              function, MessageKind.NON_NATIVE_EXTERNAL);
         }
       }
     });
@@ -144,29 +140,10 @@
           }
         });
       } else {
-        elementEnvironment.forEachLocalClassMember(cls, (MemberEntity member) {
-          String memberName = getJsInteropName(
-              library, elementEnvironment.getMemberMetadata(member));
-          if (memberName == null && member is FunctionEntity) {
-            if (member.isExternal &&
-                !commonElements.isExternalAllowed(member)) {
-              reporter.reportErrorMessage(
-                  member, MessageKind.NON_NATIVE_EXTERNAL);
-            }
-          }
-        });
-        elementEnvironment.forEachConstructor(cls,
-            (ConstructorEntity constructor) {
-          String memberName = getJsInteropName(
-              library, elementEnvironment.getMemberMetadata(constructor));
-          if (memberName == null) {
-            if (constructor.isExternal &&
-                !commonElements.isExternalAllowed(constructor)) {
-              reporter.reportErrorMessage(
-                  constructor, MessageKind.NON_NATIVE_EXTERNAL);
-            }
-          }
-        });
+        // TODO(44754): For now, this call is required to correctly load
+        // the environment for some of the tests in the _2 directories.
+        elementEnvironment.forEachConstructor(
+            cls, (ConstructorEntity constructor) {});
       }
     });
 
diff --git a/pkg/front_end/lib/src/fasta/kernel/inference_visitor.dart b/pkg/front_end/lib/src/fasta/kernel/inference_visitor.dart
index d0363bb..c2ff740 100644
--- a/pkg/front_end/lib/src/fasta/kernel/inference_visitor.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/inference_visitor.dart
@@ -5,10 +5,13 @@
 // @dart = 2.9
 
 import 'dart:core' hide MapEntry;
+import 'dart:core' as core;
 
+import 'package:_fe_analyzer_shared/src/flow_analysis/flow_analysis.dart';
 import 'package:_fe_analyzer_shared/src/util/link.dart';
 import 'package:front_end/src/api_prototype/lowering_predicates.dart';
-import 'package:kernel/ast.dart';
+import 'package:kernel/ast.dart'
+    hide Reference; // Work around https://github.com/dart-lang/sdk/issues/44667
 import 'package:kernel/src/legacy_erasure.dart';
 import 'package:kernel/type_algebra.dart' show Substitution;
 import 'package:kernel/type_environment.dart';
@@ -4738,12 +4741,31 @@
 
     readResult ??= new ExpressionInferenceResult(readType, read);
     if (!inferrer.isTopLevel && readTarget.isNullable) {
+      Map<DartType, NonPromotionReason> whyNotPromoted =
+          inferrer.flowAnalysis?.whyNotPromoted(receiver);
+      List<LocatedMessage> context;
+      if (whyNotPromoted != null && whyNotPromoted.isNotEmpty) {
+        _WhyNotPromotedVisitor whyNotPromotedVisitor =
+            new _WhyNotPromotedVisitor(inferrer);
+        for (core.MapEntry<DartType, NonPromotionReason> entry
+            in whyNotPromoted.entries) {
+          if (entry.key.isPotentiallyNullable) continue;
+          if (inferrer.dataForTesting != null) {
+            inferrer.dataForTesting.flowAnalysisResult
+                .nonPromotionReasons[read] = entry.value.shortName;
+          }
+          LocatedMessage message = entry.value.accept(whyNotPromotedVisitor);
+          context = [message];
+          break;
+        }
+      }
       readResult = inferrer.wrapExpressionInferenceResultInProblem(
           readResult,
           templateNullablePropertyAccessError.withArguments(
               propertyName.text, receiverType, inferrer.isNonNullableByDefault),
           read.fileOffset,
-          propertyName.text.length);
+          propertyName.text.length,
+          context: context);
     }
     return readResult;
   }
@@ -5709,8 +5731,13 @@
     ExpressionInferenceResult readResult = _computePropertyGet(
         node.fileOffset, receiver, receiverType, node.name, typeContext,
         isThisReceiver: node.receiver is ThisExpression);
-    return inferrer.createNullAwareExpressionInferenceResult(
-        readResult.inferredType, readResult.expression, nullAwareGuards);
+    inferrer.flowAnalysis.propertyGet(node, node.receiver, node.name.name);
+    ExpressionInferenceResult expressionInferenceResult =
+        inferrer.createNullAwareExpressionInferenceResult(
+            readResult.inferredType, readResult.expression, nullAwareGuards);
+    inferrer.flowAnalysis
+        .forwardExpression(expressionInferenceResult.nullAwareAction, node);
+    return expressionInferenceResult;
   }
 
   @override
@@ -5973,6 +6000,7 @@
   @override
   ExpressionInferenceResult visitSuperPropertyGet(
       SuperPropertyGet node, DartType typeContext) {
+    inferrer.flowAnalysis.thisOrSuperPropertyGet(node, node.name.name);
     if (node.interfaceTarget != null) {
       inferrer.instrumentation?.record(
           inferrer.uriForInstrumentation,
@@ -6160,6 +6188,7 @@
 
   ExpressionInferenceResult visitThisExpression(
       ThisExpression node, DartType typeContext) {
+    inferrer.flowAnalysis.thisOrSuper(node);
     return new ExpressionInferenceResult(inferrer.thisType, node);
   }
 
@@ -6280,7 +6309,7 @@
         fileOffset: node.fileOffset,
         isVoidAllowed: declaredOrInferredType is VoidType);
     inferrer.flowAnalysis
-        .write(variable, rhsResult.inferredType, rhsResult.expression);
+        .write(node, variable, rhsResult.inferredType, rhsResult.expression);
     DartType resultType = rhsResult.inferredType;
     Expression resultExpression;
     if (variable.lateSetter != null) {
@@ -6956,6 +6985,44 @@
   }
 }
 
+class _WhyNotPromotedVisitor
+    implements
+        NonPromotionReasonVisitor<LocatedMessage, Node, Expression,
+            VariableDeclaration> {
+  final TypeInferrerImpl inferrer;
+
+  _WhyNotPromotedVisitor(this.inferrer);
+
+  @override
+  LocatedMessage visitDemoteViaExplicitWrite(
+      DemoteViaExplicitWrite<VariableDeclaration, Expression> reason) {
+    if (inferrer.dataForTesting != null) {
+      inferrer.dataForTesting.flowAnalysisResult
+          .nonPromotionReasonTargets[reason.writeExpression] = reason.shortName;
+    }
+    int offset = reason.writeExpression.fileOffset;
+    return templateVariableCouldBeNullDueToWrite
+        .withArguments(reason.variable.name)
+        .withLocation(inferrer.helper.uri, offset, noLength);
+  }
+
+  @override
+  LocatedMessage visitDemoteViaForEachVariableWrite(
+      DemoteViaForEachVariableWrite<VariableDeclaration, Node> reason) {
+    int offset = (reason.node as TreeNode).fileOffset;
+    return templateVariableCouldBeNullDueToWrite
+        .withArguments(reason.variable.name)
+        .withLocation(inferrer.helper.uri, offset, noLength);
+  }
+
+  @override
+  LocatedMessage visitFieldNotPromoted(FieldNotPromoted reason) {
+    return templateFieldNotPromoted
+        .withArguments(reason.propertyName)
+        .withoutLocation();
+  }
+}
+
 class ForInResult {
   final VariableDeclaration variable;
   final Expression iterable;
@@ -7005,7 +7072,8 @@
         isVoidAllowed: true);
 
     variableSet.value = rhs..parent = variableSet;
-    inferrer.flowAnalysis.write(variableSet.variable, rhsType, null);
+    inferrer.flowAnalysis
+        .write(variableSet, variableSet.variable, rhsType, null);
     return variableSet;
   }
 }
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_inference_engine.dart b/pkg/front_end/lib/src/fasta/type_inference/type_inference_engine.dart
index 9d674c0..f2cb2c4 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_inference_engine.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_inference_engine.dart
@@ -257,6 +257,14 @@
 
   /// The assigned variables information that computed for the member.
   AssignedVariablesForTesting<TreeNode, VariableDeclaration> assignedVariables;
+
+  /// For each expression that led to an error because it was not promoted, a
+  /// string describing the reason it was not promoted.
+  final Map<TreeNode, String> nonPromotionReasons = {};
+
+  /// For each auxiliary AST node pointed to by a non-promotion reason, a string
+  /// describing the non-promotion reason pointing to it.
+  final Map<TreeNode, String> nonPromotionReasonTargets = {};
 }
 
 /// CFE-specific implementation of [TypeOperations].
@@ -266,6 +274,9 @@
   TypeOperationsCfe(this.typeEnvironment);
 
   @override
+  DartType get topType => typeEnvironment.objectNullableRawType;
+
+  @override
   TypeClassification classifyType(DartType type) {
     if (type == null) {
       // Note: this can happen during top-level inference.
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart b/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
index 0b50fbb..cfdc40c 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
@@ -1784,7 +1784,8 @@
     return createNullAwareExpressionInferenceResult(
         result.inferredType,
         helper.wrapInProblem(
-            result.nullAwareAction, message, fileOffset, length),
+            result.nullAwareAction, message, fileOffset, length,
+            context: context),
         result.nullAwareGuards);
   }
 
diff --git a/pkg/front_end/messages.status b/pkg/front_end/messages.status
index 245cd2d..2eeae7a 100644
--- a/pkg/front_end/messages.status
+++ b/pkg/front_end/messages.status
@@ -344,6 +344,8 @@
 FieldNonNullableWithoutInitializerError/example: Fail
 FieldNonNullableWithoutInitializerWarning/analyzerCode: Fail
 FieldNonNullableWithoutInitializerWarning/example: Fail
+FieldNotPromoted/analyzerCode: Fail
+FieldNotPromoted/example: Fail
 FinalAndCovariant/part_wrapped_script2: Fail
 FinalAndCovariant/script2: Fail
 FinalFieldWithoutInitializer/example: Fail
@@ -484,6 +486,8 @@
 JsInteropDartClassExtendsJSClass/example: Fail # Web compiler specific
 JsInteropEnclosingClassJSAnnotation/analyzerCode: Fail # Web compiler specific
 JsInteropEnclosingClassJSAnnotation/example: Fail # Web compiler specific
+JsInteropExternalMemberNotJSAnnotated/analyzerCode: Fail # Web compiler specific
+JsInteropExternalMemberNotJSAnnotated/example: Fail # Web compiler specific
 JsInteropIndexNotSupported/analyzerCode: Fail # Web compiler specific
 JsInteropIndexNotSupported/example: Fail # Web compiler specific
 JsInteropJSClassExtendsDartClass/analyzerCode: Fail # Web compiler specific
@@ -793,6 +797,8 @@
 ValueForRequiredParameterNotProvidedWarning/example: Fail
 VarAsTypeName/part_wrapped_script1: Fail
 VarAsTypeName/script1: Fail # Too many problems
+VariableCouldBeNullDueToWrite/analyzerCode: Fail
+VariableCouldBeNullDueToWrite/example: Fail
 WeakWithStrongDillLibrary/analyzerCode: Fail
 WeakWithStrongDillLibrary/example: Fail
 WebLiteralCannotBeRepresentedExactly/analyzerCode: Fail
diff --git a/pkg/front_end/messages.yaml b/pkg/front_end/messages.yaml
index 2e197e9..aa9fe7d 100644
--- a/pkg/front_end/messages.yaml
+++ b/pkg/front_end/messages.yaml
@@ -4584,6 +4584,13 @@
   tip: "Use at most one of the 'in', 'out', or 'inout' modifiers."
   analyzerCode: ParserErrorCode.MULTIPLE_VARIANCE_MODIFIERS
 
+VariableCouldBeNullDueToWrite:
+  template: "Variable '#name' could be null due to a write occurring here."
+  tip: "Try null checking the variable after the write."
+
+FieldNotPromoted:
+  template: "'#name' refers to a property so it could not be promoted."
+
 NullablePropertyAccessError:
   template: "Property '#name' cannot be accessed on '#type' because it is potentially null."
   tip: "Try accessing using ?. instead."
@@ -4669,6 +4676,10 @@
   template: "This is the enclosing class."
   severity: CONTEXT
 
+JsInteropExternalMemberNotJSAnnotated:
+  template: "Only JS interop members may be 'external'."
+  tip: "Try removing the 'external' keyword or adding a JS interop annotation."
+
 JsInteropIndexNotSupported:
   template: "JS interop classes do not support [] and []= operator methods."
   tip: "Try replacing with a normal method."
diff --git a/pkg/front_end/test/id_tests/why_not_promoted_test.dart b/pkg/front_end/test/id_tests/why_not_promoted_test.dart
new file mode 100644
index 0000000..0b0b6ee
--- /dev/null
+++ b/pkg/front_end/test/id_tests/why_not_promoted_test.dart
@@ -0,0 +1,93 @@
+// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// @dart = 2.9
+
+import 'dart:io' show Directory, Platform;
+
+import 'package:_fe_analyzer_shared/src/testing/id.dart' show ActualData, Id;
+import 'package:_fe_analyzer_shared/src/testing/id_testing.dart'
+    show DataInterpreter, runTests;
+import 'package:_fe_analyzer_shared/src/testing/id_testing.dart';
+import 'package:front_end/src/fasta/builder/member_builder.dart';
+import 'package:front_end/src/fasta/type_inference/type_inference_engine.dart';
+import 'package:front_end/src/testing/id_testing_helper.dart';
+import 'package:front_end/src/testing/id_testing_utils.dart';
+import 'package:kernel/ast.dart' hide Variance, MapEntry;
+
+main(List<String> args) async {
+  Directory dataDir = new Directory.fromUri(
+      Platform.script.resolve('../../../_fe_analyzer_shared/test/flow_analysis/'
+          'why_not_promoted/data'));
+  await runTests<String>(dataDir,
+      args: args,
+      createUriForFileName: createUriForFileName,
+      onFailure: onFailure,
+      runTest: runTestFor(
+          const WhyNotPromotedDataComputer(), [cfeNonNullableOnlyConfig]));
+}
+
+class WhyNotPromotedDataComputer extends DataComputer<String> {
+  const WhyNotPromotedDataComputer();
+
+  @override
+  DataInterpreter<String> get dataValidator =>
+      const _WhyNotPromotedDataInterpreter();
+
+  /// Errors are supported for testing erroneous code. The reported errors are
+  /// not tested.
+  @override
+  bool get supportsErrors => true;
+
+  /// Function that computes a data mapping for [member].
+  ///
+  /// Fills [actualMap] with the data.
+  void computeMemberData(
+      TestConfig config,
+      InternalCompilerResult compilerResult,
+      Member member,
+      Map<Id, ActualData<String>> actualMap,
+      {bool verbose}) {
+    MemberBuilderImpl memberBuilder =
+        lookupMemberBuilder(compilerResult, member);
+    member.accept(new WhyNotPromotedDataExtractor(compilerResult, actualMap,
+        memberBuilder.dataForTesting.inferenceData.flowAnalysisResult));
+  }
+}
+
+class WhyNotPromotedDataExtractor extends CfeDataExtractor<String> {
+  final FlowAnalysisResult _flowResult;
+
+  WhyNotPromotedDataExtractor(InternalCompilerResult compilerResult,
+      Map<Id, ActualData<String>> actualMap, this._flowResult)
+      : super(compilerResult, actualMap);
+
+  @override
+  String computeNodeValue(Id id, TreeNode node) {
+    String nonPromotionReason = _flowResult.nonPromotionReasons[node];
+    if (nonPromotionReason != null) {
+      return 'notPromoted($nonPromotionReason)';
+    }
+    return _flowResult.nonPromotionReasonTargets[node];
+  }
+}
+
+class _WhyNotPromotedDataInterpreter implements DataInterpreter<String> {
+  const _WhyNotPromotedDataInterpreter();
+
+  @override
+  String getText(String actualData, [String indentation]) => actualData;
+
+  @override
+  String isAsExpected(String actualData, String expectedData) {
+    if (actualData == expectedData) {
+      return null;
+    } else {
+      return 'Expected $expectedData, got $actualData';
+    }
+  }
+
+  @override
+  bool isEmpty(String actualData) => actualData == null;
+}
diff --git a/pkg/front_end/test/lint_test.status b/pkg/front_end/test/lint_test.status
index 2728954..aaa6e98 100644
--- a/pkg/front_end/test/lint_test.status
+++ b/pkg/front_end/test/lint_test.status
@@ -20,6 +20,7 @@
 front_end/lib/src/fasta/kernel/body_builder/ImportsTwice: Fail
 front_end/lib/src/fasta/kernel/constant_evaluator/ExplicitType: Pass
 front_end/lib/src/fasta/kernel/expression_generator_helper/ImportsTwice: Fail
+front_end/lib/src/fasta/kernel/inference_visitor/ImportsTwice: Fail
 front_end/lib/src/fasta/kernel/kernel_api/Exports: Fail
 front_end/lib/src/fasta/kernel/kernel_ast_api/Exports: Fail
 front_end/lib/src/fasta/kernel/kernel_builder/Exports: Fail
diff --git a/pkg/front_end/test/spell_checking_list_code.txt b/pkg/front_end/test/spell_checking_list_code.txt
index 572493d..92adf25 100644
--- a/pkg/front_end/test/spell_checking_list_code.txt
+++ b/pkg/front_end/test/spell_checking_list_code.txt
@@ -498,6 +498,7 @@
 hacky
 hadn't
 hang
+happy
 hardcode
 harness
 hashes
@@ -847,6 +848,7 @@
 plugin
 pm
 pn
+pointed
 pointwise
 polluted
 pool
diff --git a/pkg/front_end/testcases/general_nnbd_opt_out/ffi_sample.dart.weak.transformed.expect b/pkg/front_end/testcases/general_nnbd_opt_out/ffi_sample.dart.weak.transformed.expect
index c53e92f..94630fc 100644
--- a/pkg/front_end/testcases/general_nnbd_opt_out/ffi_sample.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general_nnbd_opt_out/ffi_sample.dart.weak.transformed.expect
@@ -21,7 +21,7 @@
     : super ffi::Struct::_fromPointer(#pointer)
     ;
   static factory allocate(ffi::Allocator* allocator, core::double* x, core::double* y, ffi::Pointer<self::Coordinate*>* next) → self::Coordinate* {
-    return let final self::Coordinate* #t1 = ffi::StructPointer|get#ref<self::Coordinate*>(ffi::AllocatorAlloc|call<self::Coordinate*>(allocator)) in block {
+    return let final self::Coordinate* #t1 = new self::Coordinate::#fromTypedDataBase(allocator.{ffi::Allocator::allocate}<self::Coordinate*>(self::Coordinate::#sizeOf)!) in block {
       #t1.{self::Coordinate::x} = x;
       #t1.{self::Coordinate::y} = y;
       #t1.{self::Coordinate::next} = next;
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect
index ac239e8..79439bc 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect
@@ -37,7 +37,7 @@
   set next(ffi::Pointer<self::Coordinate> #externalFieldValue) → void
     return ffi::_storeIntPtr(this.{ffi::Struct::_addressOf}, (#C18).{core::List::[]}(ffi::_abi()), #externalFieldValue.{ffi::Pointer::address});
   static factory allocate(ffi::Allocator allocator, core::double x, core::double y, ffi::Pointer<self::Coordinate> next) → self::Coordinate {
-    return let final self::Coordinate #t1 = ffi::StructPointer|get#ref<self::Coordinate>(ffi::AllocatorAlloc|call<self::Coordinate>(allocator)) in block {
+    return let final self::Coordinate #t1 = new self::Coordinate::#fromTypedDataBase(allocator.{ffi::Allocator::allocate}<self::Coordinate>(self::Coordinate::#sizeOf)!) in block {
       #t1.{self::Coordinate::x} = x;
       #t1.{self::Coordinate::y} = y;
       #t1.{self::Coordinate::next} = next;
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect
index ac239e8..79439bc 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect
@@ -37,7 +37,7 @@
   set next(ffi::Pointer<self::Coordinate> #externalFieldValue) → void
     return ffi::_storeIntPtr(this.{ffi::Struct::_addressOf}, (#C18).{core::List::[]}(ffi::_abi()), #externalFieldValue.{ffi::Pointer::address});
   static factory allocate(ffi::Allocator allocator, core::double x, core::double y, ffi::Pointer<self::Coordinate> next) → self::Coordinate {
-    return let final self::Coordinate #t1 = ffi::StructPointer|get#ref<self::Coordinate>(ffi::AllocatorAlloc|call<self::Coordinate>(allocator)) in block {
+    return let final self::Coordinate #t1 = new self::Coordinate::#fromTypedDataBase(allocator.{ffi::Allocator::allocate}<self::Coordinate>(self::Coordinate::#sizeOf)!) in block {
       #t1.{self::Coordinate::x} = x;
       #t1.{self::Coordinate::y} = y;
       #t1.{self::Coordinate::next} = next;
diff --git a/pkg/front_end/tool/update_all.dart b/pkg/front_end/tool/update_all.dart
index 41ba6a1..c25162c 100644
--- a/pkg/front_end/tool/update_all.dart
+++ b/pkg/front_end/tool/update_all.dart
@@ -19,6 +19,7 @@
   'pkg/front_end/test/id_tests/nullability_test.dart',
   'pkg/front_end/test/id_tests/reachability_test.dart',
   'pkg/front_end/test/id_tests/type_promotion_test.dart',
+  'pkg/front_end/test/id_tests/why_not_promoted_test.dart',
   'pkg/front_end/test/language_versioning/language_versioning_test.dart',
   'pkg/front_end/test/patching/patching_test.dart',
   'pkg/front_end/test/static_types/static_type_test.dart',
diff --git a/pkg/js/CHANGELOG.md b/pkg/js/CHANGELOG.md
index 17e9aa3..571726d 100644
--- a/pkg/js/CHANGELOG.md
+++ b/pkg/js/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.6.3
+
+* Stable release for null safety.
+
 ## 0.6.3-nullsafety.3
 
 * Update SDK constraints to `>=2.12.0-0 <3.0.0` based on beta release
diff --git a/pkg/js/pubspec.yaml b/pkg/js/pubspec.yaml
index 90d0352..44b80a9 100644
--- a/pkg/js/pubspec.yaml
+++ b/pkg/js/pubspec.yaml
@@ -1,5 +1,5 @@
 name: js
-version: 0.6.3-nullsafety.3
+version: 0.6.3
 description: Annotations to create static Dart interfaces for JavaScript APIs.
 homepage: https://github.com/dart-lang/sdk/tree/master/pkg/js
 
diff --git a/pkg/meta/CHANGELOG.md b/pkg/meta/CHANGELOG.md
index e56752f..752be0d5 100644
--- a/pkg/meta/CHANGELOG.md
+++ b/pkg/meta/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.3.0
+
+* Stable release for null safety.
+
 ## 1.3.0-nullsafety.6
 
 * Update SDK constraints to `>=2.12.0-0 <3.0.0` based on beta release
diff --git a/pkg/meta/pubspec.yaml b/pkg/meta/pubspec.yaml
index 835f447..efe6370 100644
--- a/pkg/meta/pubspec.yaml
+++ b/pkg/meta/pubspec.yaml
@@ -1,5 +1,5 @@
 name: meta
-version: 1.3.0-nullsafety.6
+version: 1.3.0
 homepage: https://github.com/dart-lang/sdk/tree/master/pkg/meta
 description: >
  This library contains the declarations of annotations that developers can use
diff --git a/pkg/nnbd_migration/lib/src/decorated_type_operations.dart b/pkg/nnbd_migration/lib/src/decorated_type_operations.dart
index 4c776c8..0f9328a 100644
--- a/pkg/nnbd_migration/lib/src/decorated_type_operations.dart
+++ b/pkg/nnbd_migration/lib/src/decorated_type_operations.dart
@@ -21,6 +21,14 @@
       this._typeSystem, this._variableRepository, this._graph);
 
   @override
+  DecoratedType get topType {
+    // This is only needed for explaining to the user why fields aren't
+    // promoted, functionality of flow analysis that we don't take advantage of
+    // during migration.  So this method should never be called.
+    throw StateError('Unexpected call to topType');
+  }
+
+  @override
   TypeClassification classifyType(DecoratedType type) {
     if (type.type.isDartCoreNull) {
       return TypeClassification.nullOrEquivalent;
diff --git a/pkg/nnbd_migration/lib/src/edge_builder.dart b/pkg/nnbd_migration/lib/src/edge_builder.dart
index c074a4a..8138239 100644
--- a/pkg/nnbd_migration/lib/src/edge_builder.dart
+++ b/pkg/nnbd_migration/lib/src/edge_builder.dart
@@ -407,7 +407,7 @@
     }
 
     var expressionType = _handleAssignment(node.rightHandSide,
-        destinationExpression: node.leftHandSide,
+        assignmentExpression: node,
         compoundOperatorInfo: isCompound ? node : null,
         questionAssignNode: isQuestionAssign ? node : null,
         sourceIsSetupCall: sourceIsSetupCall);
@@ -1387,7 +1387,7 @@
       if (operand is SimpleIdentifier) {
         var element = getWriteOrReadElement(operand);
         if (element is PromotableElement) {
-          _flowAnalysis.write(element, writeType, null);
+          _flowAnalysis.write(node, element, writeType, null);
         }
       }
       return targetType;
@@ -1438,7 +1438,7 @@
         if (operand is SimpleIdentifier) {
           var element = getWriteOrReadElement(operand);
           if (element is PromotableElement) {
-            _flowAnalysis.write(element, staticType, null);
+            _flowAnalysis.write(node, element, staticType, null);
           }
         }
       }
@@ -2285,26 +2285,28 @@
   /// Creates the necessary constraint(s) for an assignment of the given
   /// [expression] to a destination whose type is [destinationType].
   ///
-  /// Optionally, the caller may supply a [destinationExpression] instead of
+  /// Optionally, the caller may supply an [assignmentExpression] instead of
   /// [destinationType].  In this case, then the type comes from visiting the
-  /// destination expression.  If the destination expression refers to a local
-  /// variable, we mark it as assigned in flow analysis at the proper time.
+  /// LHS of the assignment expression.  If the LHS of the assignment expression
+  /// refers to a local variable, we mark it as assigned in flow analysis at the
+  /// proper time.
   ///
   /// Set [wrapFuture] to true to handle assigning Future<flatten(T)> to R.
   DecoratedType _handleAssignment(Expression expression,
       {DecoratedType destinationType,
-      Expression destinationExpression,
+      AssignmentExpression assignmentExpression,
       AssignmentExpression compoundOperatorInfo,
       AssignmentExpression questionAssignNode,
       bool fromDefaultValue = false,
       bool wrapFuture = false,
       bool sourceIsSetupCall = false}) {
     assert(
-        (destinationExpression == null) != (destinationType == null),
-        'Either destinationExpression or destinationType should be supplied, '
+        (assignmentExpression == null) != (destinationType == null),
+        'Either assignmentExpression or destinationType should be supplied, '
         'but not both');
     PromotableElement destinationLocalVariable;
     if (destinationType == null) {
+      var destinationExpression = assignmentExpression.leftHandSide;
       if (destinationExpression is SimpleIdentifier) {
         var element = getWriteOrReadElement(destinationExpression);
         if (element is PromotableElement) {
@@ -2345,7 +2347,7 @@
               source: destinationType,
               destination: _createNonNullableType(compoundOperatorInfo),
               hard: _postDominatedLocals
-                  .isReferenceInScope(destinationExpression));
+                  .isReferenceInScope(assignmentExpression.leftHandSide));
           DecoratedType compoundOperatorType = getOrComputeElementType(
               compoundOperatorMethod,
               targetType: destinationType);
@@ -2403,8 +2405,8 @@
         }
       }
       if (destinationLocalVariable != null) {
-        _flowAnalysis.write(destinationLocalVariable, sourceType,
-            compoundOperatorInfo == null ? expression : null);
+        _flowAnalysis.write(assignmentExpression, destinationLocalVariable,
+            sourceType, compoundOperatorInfo == null ? expression : null);
       }
       if (questionAssignNode != null) {
         _flowAnalysis.ifNullExpression_end();
@@ -2419,9 +2421,9 @@
         _guards.removeLast();
       }
     }
-    if (destinationExpression != null) {
-      var element =
-          _postDominatedLocals.referencedElement(destinationExpression);
+    if (assignmentExpression != null) {
+      var element = _postDominatedLocals
+          .referencedElement(assignmentExpression.leftHandSide);
       if (element != null) {
         _postDominatedLocals.removeFromAllScopes(element);
         _elementsWrittenToInLocalFunction?.add(element);
diff --git a/pkg/nnbd_migration/lib/src/fix_builder.dart b/pkg/nnbd_migration/lib/src/fix_builder.dart
index 687b07b..0cb9d26 100644
--- a/pkg/nnbd_migration/lib/src/fix_builder.dart
+++ b/pkg/nnbd_migration/lib/src/fix_builder.dart
@@ -8,7 +8,6 @@
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/null_safety_understanding_flag.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/dart/element/type_provider.dart';
@@ -206,12 +205,10 @@
   /// makes note of changes that need to be made.
   void visitAll() {
     try {
-      NullSafetyUnderstandingFlag.enableNullSafetyTypes(() {
-        ElementTypeProvider.current = migrationResolutionHooks;
-        unit.accept(_FixBuilderPreVisitor(this));
-        unit.accept(_resolver);
-        unit.accept(_FixBuilderPostVisitor(this));
-      });
+      ElementTypeProvider.current = migrationResolutionHooks;
+      unit.accept(_FixBuilderPreVisitor(this));
+      unit.accept(_resolver);
+      unit.accept(_FixBuilderPostVisitor(this));
     } catch (exception, stackTrace) {
       if (listener != null) {
         listener.reportException(source, unit, exception, stackTrace);
diff --git a/pkg/vm/lib/transformations/ffi.dart b/pkg/vm/lib/transformations/ffi.dart
index e27e3f3..1c16b1b 100644
--- a/pkg/vm/lib/transformations/ffi.dart
+++ b/pkg/vm/lib/transformations/ffi.dart
@@ -206,6 +206,7 @@
   final Field pragmaOptions;
   final Procedure listElementAt;
   final Procedure numAddition;
+  final Procedure numMultiplication;
 
   final Library ffiLibrary;
   final Class allocatorClass;
@@ -267,6 +268,7 @@
         pragmaOptions = coreTypes.pragmaOptions,
         listElementAt = coreTypes.index.getMember('dart:core', 'List', '[]'),
         numAddition = coreTypes.index.getMember('dart:core', 'num', '+'),
+        numMultiplication = coreTypes.index.getMember('dart:core', 'num', '*'),
         ffiLibrary = index.getLibrary('dart:ffi'),
         allocatorClass = index.getClass('dart:ffi', 'Allocator'),
         nativeFunctionClass = index.getClass('dart:ffi', 'NativeFunction'),
@@ -410,6 +412,8 @@
     return FunctionType(argumentTypes, returnType, Nullability.legacy);
   }
 
+  /// The [NativeType] corresponding to [c]. Returns `null` for user-defined
+  /// structs.
   NativeType getType(Class c) {
     final int index = nativeTypesClasses.indexOf(c);
     if (index == -1) {
@@ -417,6 +421,23 @@
     }
     return NativeType.values[index];
   }
+
+  /// Expression that queries VM internals at runtime to figure out on which ABI
+  /// we are.
+  Expression runtimeBranchOnLayout(Map<Abi, int> values) {
+    return MethodInvocation(
+        ConstantExpression(
+            ListConstant(InterfaceType(intClass, Nullability.legacy), [
+              IntConstant(values[Abi.wordSize64]),
+              IntConstant(values[Abi.wordSize32Align32]),
+              IntConstant(values[Abi.wordSize32Align64])
+            ]),
+            InterfaceType(listClass, Nullability.legacy,
+                [InterfaceType(intClass, Nullability.legacy)])),
+        Name("[]"),
+        Arguments([StaticInvocation(abiMethod, Arguments([]))]),
+        listElementAt);
+  }
 }
 
 /// Contains all information collected by _FfiDefinitionTransformer that is
diff --git a/pkg/vm/lib/transformations/ffi_definitions.dart b/pkg/vm/lib/transformations/ffi_definitions.dart
index 853087e..b06c63f 100644
--- a/pkg/vm/lib/transformations/ffi_definitions.dart
+++ b/pkg/vm/lib/transformations/ffi_definitions.dart
@@ -496,23 +496,6 @@
         InterfaceType(pragmaClass, Nullability.nonNullable, [])));
   }
 
-  /// Expression that queries VM internals at runtime to figure out on which ABI
-  /// we are.
-  Expression _runtimeBranchOnLayout(Map<Abi, int> values) {
-    return MethodInvocation(
-        ConstantExpression(
-            ListConstant(InterfaceType(intClass, Nullability.legacy), [
-              IntConstant(values[Abi.wordSize64]),
-              IntConstant(values[Abi.wordSize32Align32]),
-              IntConstant(values[Abi.wordSize32Align64])
-            ]),
-            InterfaceType(listClass, Nullability.legacy,
-                [InterfaceType(intClass, Nullability.legacy)])),
-        Name("[]"),
-        Arguments([StaticInvocation(abiMethod, Arguments([]))]),
-        listElementAt);
-  }
-
   Statement _generateGetterStatement(DartType dartType, NativeType type,
       int fileOffset, Map<Abi, int> offsets) {
     final bool isPointer = type == NativeType.kPointer;
@@ -558,7 +541,7 @@
                               addressGetter)
                             ..fileOffset = fileOffset,
                           numAddition.name,
-                          Arguments([_runtimeBranchOnLayout(offsets)]),
+                          Arguments([runtimeBranchOnLayout(offsets)]),
                           numAddition)
                     ], types: [
                       dartType
@@ -594,9 +577,9 @@
                               typedDataOffsetInBytesGetter)
                             ..fileOffset = fileOffset,
                           numAddition.name,
-                          Arguments([_runtimeBranchOnLayout(offsets)]),
+                          Arguments([runtimeBranchOnLayout(offsets)]),
                           numAddition),
-                      _runtimeBranchOnLayout(lengths)
+                      runtimeBranchOnLayout(lengths)
                     ]),
                     byteBufferAsUint8List),
                 InterfaceType(objectClass, Nullability.nonNullable))
@@ -610,7 +593,7 @@
         Arguments([
           PropertyGet(ThisExpression(), addressOfField.name, addressOfField)
             ..fileOffset = fileOffset,
-          _runtimeBranchOnLayout(offsets)
+          runtimeBranchOnLayout(offsets)
         ]))
       ..fileOffset = fileOffset;
     if (isPointer) {
@@ -646,12 +629,12 @@
           Arguments([
             PropertyGet(ThisExpression(), addressOfField.name, addressOfField)
               ..fileOffset = fileOffset,
-            _runtimeBranchOnLayout(offsets),
+            runtimeBranchOnLayout(offsets),
             PropertyGet(
                 VariableGet(argument), addressOfField.name, addressOfField)
               ..fileOffset = fileOffset,
             ConstantExpression(IntConstant(0)),
-            _runtimeBranchOnLayout(lengths),
+            runtimeBranchOnLayout(lengths),
           ]))
         ..fileOffset = fileOffset);
     }
@@ -669,7 +652,7 @@
         Arguments([
           PropertyGet(ThisExpression(), addressOfField.name, addressOfField)
             ..fileOffset = fileOffset,
-          _runtimeBranchOnLayout(offsets),
+          runtimeBranchOnLayout(offsets),
           argumentExpression
         ]))
       ..fileOffset = fileOffset);
@@ -719,7 +702,7 @@
     final Field sizeOf = Field.immutable(name,
         isStatic: true,
         isFinal: true,
-        initializer: _runtimeBranchOnLayout(sizes),
+        initializer: runtimeBranchOnLayout(sizes),
         type: InterfaceType(intClass, Nullability.legacy),
         fileUri: struct.fileUri,
         getterReference: getterReference)
diff --git a/pkg/vm/lib/transformations/ffi_use_sites.dart b/pkg/vm/lib/transformations/ffi_use_sites.dart
index e963078..1f0aba6 100644
--- a/pkg/vm/lib/transformations/ffi_use_sites.dart
+++ b/pkg/vm/lib/transformations/ffi_use_sites.dart
@@ -27,7 +27,14 @@
 import 'package:kernel/type_environment.dart';
 
 import 'ffi.dart'
-    show FfiTransformerData, NativeType, FfiTransformer, optimizedTypes;
+    show
+        FfiTransformerData,
+        NativeType,
+        FfiTransformer,
+        nativeTypeSizes,
+        WORD_SIZE,
+        UNKNOWN,
+        wordSize;
 
 /// Checks and replaces calls to dart:ffi struct fields and methods.
 void transformLibraries(
@@ -177,19 +184,24 @@
       if (target == structPointerRef || target == structPointerElemAt) {
         final DartType nativeType = node.arguments.types[0];
 
-        _warningNativeTypeValid(nativeType, node, allowStructItself: false);
+        _ensureNativeTypeValid(nativeType, node, allowStructItself: false);
 
-        // TODO(http://dartbug.com/38721): Replace calls with direct
-        // constructor invocations.
+        return _replaceRef(node);
       } else if (target == sizeOfMethod) {
         final DartType nativeType = node.arguments.types[0];
 
+        // TODO(http://dartbug.com/38721): Change this to an error after
+        // package:ffi is no longer using sizeOf generically.
         if (!isFfiLibrary) {
           _warningNativeTypeValid(nativeType, node);
         }
 
-        // TODO(http://dartbug.com/38721): Replace calls with constant
-        // expressions.
+        if (nativeType is InterfaceType) {
+          Expression inlineSizeOf = _inlineSizeOf(nativeType);
+          if (inlineSizeOf != null) {
+            return inlineSizeOf;
+          }
+        }
       } else if (target == lookupFunctionMethod) {
         final DartType nativeType = InterfaceType(
             nativeFunctionClass, Nullability.legacy, [node.arguments.types[0]]);
@@ -303,8 +315,29 @@
 
         _ensureNativeTypeValid(nativeType, node);
 
-        // TODO(http://dartbug.com/38721): Inline the body to get rid of a
-        // generic invocation of sizeOf.
+        // TODO(http://dartbug.com/38721): Change this to an error.
+        if (nativeType is TypeParameterType) {
+          // Do not rewire generic invocations.
+          return node;
+        }
+
+        // Inline the body to get rid of a generic invocation of sizeOf.
+        // TODO(http://dartbug.com/39964): Add `allignmentOf<T>()` call.
+        Expression sizeInBytes = _inlineSizeOf(nativeType);
+        if (sizeInBytes != null) {
+          if (node.arguments.positional.length == 2) {
+            sizeInBytes = MethodInvocation(
+                node.arguments.positional[1],
+                numMultiplication.name,
+                Arguments([sizeInBytes]),
+                numMultiplication);
+          }
+          return MethodInvocation(
+              node.arguments.positional[0],
+              allocatorAllocateMethod.name,
+              Arguments([sizeInBytes], types: node.arguments.types),
+              allocatorAllocateMethod);
+        }
       }
     } on _FfiStaticTypeError {
       // It's OK to swallow the exception because the diagnostics issued will
@@ -315,6 +348,28 @@
     return node;
   }
 
+  Expression _inlineSizeOf(InterfaceType nativeType) {
+    final Class nativeClass = nativeType.classNode;
+    final NativeType nt = getType(nativeClass);
+    if (nt == null) {
+      // User-defined structs.
+      Field sizeOfField = nativeClass.fields.single;
+      return StaticGet(sizeOfField);
+    }
+    final int size = nativeTypeSizes[nt.index];
+    if (size == WORD_SIZE) {
+      return runtimeBranchOnLayout(wordSize);
+    }
+    if (size != UNKNOWN) {
+      return ConstantExpression(
+          IntConstant(size),
+          InterfaceType(listClass, Nullability.legacy,
+              [InterfaceType(intClass, Nullability.legacy)]));
+    }
+    // Size unknown.
+    return null;
+  }
+
   // We need to replace calls to 'DynamicLibrary.lookupFunction' with explicit
   // Kernel, because we cannot have a generic call to 'asFunction' in its body.
   //
@@ -383,6 +438,28 @@
     return StaticGet(field);
   }
 
+  Expression _replaceRef(StaticInvocation node) {
+    final dartType = node.arguments.types[0];
+    final clazz = (dartType as InterfaceType).classNode;
+    final constructor = clazz.constructors
+        .firstWhere((c) => c.name == Name("#fromTypedDataBase"));
+    Expression pointer = NullCheck(node.arguments.positional[0]);
+    if (node.arguments.positional.length == 2) {
+      pointer = MethodInvocation(
+          pointer,
+          offsetByMethod.name,
+          Arguments([
+            MethodInvocation(
+                node.arguments.positional[1],
+                numMultiplication.name,
+                Arguments([_inlineSizeOf(dartType)]),
+                numMultiplication)
+          ]),
+          offsetByMethod);
+    }
+    return ConstructorInvocation(constructor, Arguments([pointer]));
+  }
+
   @override
   visitMethodInvocation(MethodInvocation node) {
     super.visitMethodInvocation(node);
@@ -396,20 +473,26 @@
 
         _warningNativeTypeValid(nativeType, node);
 
+        // TODO(http://dartbug.com/38721): Change this to an error.
         if (nativeType is TypeParameterType) {
           // Do not rewire generic invocations.
           return node;
         }
-        final Class nativeClass = (nativeType as InterfaceType).classNode;
-        final NativeType nt = getType(nativeClass);
-        if (optimizedTypes.contains(nt)) {
-          final typeArguments = [
-            if (nt == NativeType.kPointer) _pointerTypeGetTypeArg(nativeType)
-          ];
-          return StaticInvocation(
-              elementAtMethods[nt],
-              Arguments([node.receiver, node.arguments.positional[0]],
-                  types: typeArguments));
+
+        Expression inlineSizeOf = _inlineSizeOf(nativeType);
+        if (inlineSizeOf != null) {
+          // Generates `receiver.offsetBy(inlineSizeOfExpression)`.
+          return MethodInvocation(
+              node.receiver,
+              offsetByMethod.name,
+              Arguments([
+                MethodInvocation(
+                    node.arguments.positional.single,
+                    numMultiplication.name,
+                    Arguments([inlineSizeOf]),
+                    numMultiplication)
+              ]),
+              offsetByMethod);
         }
       }
     } on _FfiStaticTypeError {
diff --git a/runtime/bin/dartutils.cc b/runtime/bin/dartutils.cc
index 41fb6f8..7289341 100644
--- a/runtime/bin/dartutils.cc
+++ b/runtime/bin/dartutils.cc
@@ -946,6 +946,32 @@
                                IOBuffer::Finalizer);
 }
 
+void CObject::ShrinkIOBuffer(Dart_CObject* cobject, int64_t new_length) {
+  if (cobject == nullptr) return;
+  ASSERT(cobject->type == Dart_CObject_kExternalTypedData);
+
+  const auto old_data = cobject->value.as_external_typed_data.data;
+  const auto old_length = cobject->value.as_external_typed_data.length;
+
+  // We only shrink IOBuffers, never grow them.
+  ASSERT(0 <= new_length && new_length <= old_length);
+
+  // We only reallocate if we think the freed space is worth reallocating.
+  // We consider it worthwhile when freed space is >=25% and we have at
+  // least 100 free bytes.
+  const auto free_memory = old_length - new_length;
+  if ((old_length >> 2) <= free_memory && 100 <= free_memory) {
+    const auto new_data = IOBuffer::Reallocate(old_data, new_length);
+    if (new_data != nullptr) {
+      cobject->value.as_external_typed_data.data = new_data;
+      cobject->value.as_external_typed_data.peer = new_data;
+    }
+  }
+
+  // The typed data object always has to have the shranken length.
+  cobject->value.as_external_typed_data.length = new_length;
+}
+
 void CObject::FreeIOBufferData(Dart_CObject* cobject) {
   ASSERT(cobject->type == Dart_CObject_kExternalTypedData);
   cobject->value.as_external_typed_data.callback(
diff --git a/runtime/bin/dartutils.h b/runtime/bin/dartutils.h
index f7f1d8d..7ff1580 100644
--- a/runtime/bin/dartutils.h
+++ b/runtime/bin/dartutils.h
@@ -353,6 +353,7 @@
                                              Dart_HandleFinalizer callback);
 
   static Dart_CObject* NewIOBuffer(int64_t length);
+  static void ShrinkIOBuffer(Dart_CObject* cobject, int64_t new_length);
   static void FreeIOBufferData(Dart_CObject* object);
 
   Dart_CObject* AsApiCObject() { return cobject_; }
@@ -568,9 +569,6 @@
   intptr_t Length() const {
     return cobject_->value.as_external_typed_data.length;
   }
-  void SetLength(intptr_t length) {
-    cobject_->value.as_external_typed_data.length = length;
-  }
   uint8_t* Data() const { return cobject_->value.as_external_typed_data.data; }
   void* Peer() const { return cobject_->value.as_external_typed_data.peer; }
   Dart_HandleFinalizer Callback() const {
diff --git a/runtime/bin/file.cc b/runtime/bin/file.cc
index cbeb39a..8e377a1 100644
--- a/runtime/bin/file.cc
+++ b/runtime/bin/file.cc
@@ -1246,9 +1246,12 @@
     CObject::FreeIOBufferData(io_buffer);
     return CObject::NewOSError();
   }
-  CObjectExternalUint8Array* external_array =
-      new CObjectExternalUint8Array(io_buffer);
-  external_array->SetLength(bytes_read);
+
+  // Possibly shrink the used malloc() storage if the actual number of bytes is
+  // significantly lower.
+  CObject::ShrinkIOBuffer(io_buffer, bytes_read);
+
+  auto external_array = new CObjectExternalUint8Array(io_buffer);
   CObjectArray* result = new CObjectArray(CObject::NewArray(2));
   result->SetAt(0, new CObjectIntptr(CObject::NewInt32(0)));
   result->SetAt(1, external_array);
@@ -1278,9 +1281,12 @@
     CObject::FreeIOBufferData(io_buffer);
     return CObject::NewOSError();
   }
-  CObjectExternalUint8Array* external_array =
-      new CObjectExternalUint8Array(io_buffer);
-  external_array->SetLength(bytes_read);
+
+  // Possibly shrink the used malloc() storage if the actual number of bytes is
+  // significantly lower.
+  CObject::ShrinkIOBuffer(io_buffer, bytes_read);
+
+  auto external_array = new CObjectExternalUint8Array(io_buffer);
   CObjectArray* result = new CObjectArray(CObject::NewArray(3));
   result->SetAt(0, new CObjectIntptr(CObject::NewInt32(0)));
   result->SetAt(1, new CObjectInt64(CObject::NewInt64(bytes_read)));
diff --git a/runtime/bin/io_buffer.cc b/runtime/bin/io_buffer.cc
index c0e8066..fce6d2c 100644
--- a/runtime/bin/io_buffer.cc
+++ b/runtime/bin/io_buffer.cc
@@ -28,7 +28,23 @@
 }
 
 uint8_t* IOBuffer::Allocate(intptr_t size) {
-  return reinterpret_cast<uint8_t*>(calloc(size, sizeof(uint8_t)));
+  return static_cast<uint8_t*>(calloc(size, sizeof(uint8_t)));
+}
+
+uint8_t* IOBuffer::Reallocate(uint8_t* buffer, intptr_t new_size) {
+  if (new_size == 0) {
+    // The call to `realloc()` below has a corner case if the new size is 0:
+    // It can return `nullptr` in that case even though `malloc(0)` would
+    // return a unique non-`nullptr` value.  To avoid returning `nullptr` on
+    // successful realloc, we handle this case specially.
+    auto new_buffer = IOBuffer::Allocate(0);
+    if (new_buffer != nullptr) {
+      free(buffer);
+      return new_buffer;
+    }
+    return buffer;
+  }
+  return static_cast<uint8_t*>(realloc(buffer, new_size));
 }
 
 }  // namespace bin
diff --git a/runtime/bin/io_buffer.h b/runtime/bin/io_buffer.h
index 79b4fb9..2823352 100644
--- a/runtime/bin/io_buffer.h
+++ b/runtime/bin/io_buffer.h
@@ -20,6 +20,9 @@
   // Allocate IO buffer storage.
   static uint8_t* Allocate(intptr_t size);
 
+  // Reallocate IO buffer storage.
+  static uint8_t* Reallocate(uint8_t* buffer, intptr_t new_size);
+
   // Function for disposing of IO buffer storage. All backing storage
   // for IO buffers must be freed using this function.
   static void Free(void* buffer) { free(buffer); }
diff --git a/runtime/lib/ffi.cc b/runtime/lib/ffi.cc
index d703d0b..3a6bb40 100644
--- a/runtime/lib/ffi.cc
+++ b/runtime/lib/ffi.cc
@@ -116,7 +116,7 @@
 DEFINE_NATIVE_ENTRY(Ffi_loadStruct, 0, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Pointer, pointer, arguments->NativeArgAt(0));
   const AbstractType& pointer_type_arg =
-      AbstractType::Handle(pointer.type_argument());
+      AbstractType::Handle(arguments->NativeTypeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, index, arguments->NativeArgAt(1));
 
   // TODO(36370): Make representation consistent with kUnboxedFfiIntPtr.
diff --git a/runtime/vm/compiler/offsets_extractor.cc b/runtime/vm/compiler/offsets_extractor.cc
index c89ff54..b0d76f8 100644
--- a/runtime/vm/compiler/offsets_extractor.cc
+++ b/runtime/vm/compiler/offsets_extractor.cc
@@ -18,17 +18,23 @@
 #include "vm/timeline.h"
 
 #if defined(TARGET_ARCH_ARM)
-#define ARCH_DEF "defined(TARGET_ARCH_ARM)"
+#define ARCH_DEF_CPU "defined(TARGET_ARCH_ARM)"
 #elif defined(TARGET_ARCH_X64)
-#define ARCH_DEF "defined(TARGET_ARCH_X64)"
+#define ARCH_DEF_CPU "defined(TARGET_ARCH_X64)"
 #elif defined(TARGET_ARCH_IA32)
-#define ARCH_DEF "defined(TARGET_ARCH_IA32)"
+#define ARCH_DEF_CPU "defined(TARGET_ARCH_IA32)"
 #elif defined(TARGET_ARCH_ARM64)
-#define ARCH_DEF "defined(TARGET_ARCH_ARM64)"
+#define ARCH_DEF_CPU "defined(TARGET_ARCH_ARM64)"
 #else
 #error Unknown architecture
 #endif
 
+#if defined(DART_COMPRESSED_POINTERS)
+#define ARCH_DEF ARCH_DEF_CPU " && defined(DART_COMPRESSED_POINTERS)"
+#else
+#define ARCH_DEF ARCH_DEF_CPU " && !defined(DART_COMPRESSED_POINTERS)"
+#endif
+
 namespace dart {
 
 void Assert::Fail(const char* format, ...) {
diff --git a/runtime/vm/compiler/runtime_offsets_extracted.h b/runtime/vm/compiler/runtime_offsets_extracted.h
index 63898cb..c4743e3 100644
--- a/runtime/vm/compiler/runtime_offsets_extracted.h
+++ b/runtime/vm/compiler/runtime_offsets_extracted.h
@@ -17,7 +17,7 @@
 
 #if !defined(PRODUCT)
 
-#if defined(TARGET_ARCH_ARM)
+#if defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     76;
 static constexpr dart::compiler::target::word
@@ -545,9 +545,9 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 8;
-#endif  // defined(TARGET_ARCH_ARM)
+#endif  // defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_X64)
+#if defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     116;
 static constexpr dart::compiler::target::word
@@ -1083,9 +1083,9 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_X64)
+#endif  // defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_IA32)
+#if defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     76;
 static constexpr dart::compiler::target::word
@@ -1610,9 +1610,9 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 8;
-#endif  // defined(TARGET_ARCH_IA32)
+#endif  // defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_ARM64)
+#if defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     116;
 static constexpr dart::compiler::target::word
@@ -2149,11 +2149,1088 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_ARM64)
+#endif  // defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word Function_usage_counter_offset =
+    116;
+static constexpr dart::compiler::target::word
+    ICData_receivers_static_type_offset = 32;
+static constexpr dart::compiler::target::word
+    ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word ContextScope_element_size = 64;
+static constexpr dart::compiler::target::word
+    ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word ExceptionHandlers_element_size =
+    12;
+static constexpr dart::compiler::target::word ObjectPool_elements_start_offset =
+    16;
+static constexpr dart::compiler::target::word ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetJIT = 40;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetAOT = 22;
+static constexpr dart::compiler::target::word
+    Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word OldPage_kBytesPerCardLog2 = 10;
+static constexpr dart::compiler::target::word
+    NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_kTestResult = 0;
+static constexpr dart::compiler::target::word TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_count_offset =
+    32;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_size_offset =
+    40;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_name_offset =
+    0;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word Array_data_offset = 24;
+static constexpr dart::compiler::target::word Array_length_offset = 16;
+static constexpr dart::compiler::target::word Array_tags_offset = 0;
+static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word Class_declaration_type_offset =
+    104;
+static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
+    164;
+static constexpr dart::compiler::target::word Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word
+    SharedClassTable_class_heap_stats_table_offset = 0;
+static constexpr dart::compiler::target::word Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word Code_saved_instructions_offset =
+    48;
+static constexpr dart::compiler::target::word Code_owner_offset = 56;
+static constexpr dart::compiler::target::word Context_num_variables_offset = 8;
+static constexpr dart::compiler::target::word Context_parent_offset = 16;
+static constexpr dart::compiler::target::word Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word Field_guarded_cid_offset = 80;
+static constexpr dart::compiler::target::word
+    Field_guarded_list_length_in_object_offset_offset = 88;
+static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
+    48;
+static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Function_code_offset = 72;
+static constexpr dart::compiler::target::word Function_data_offset = 56;
+static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
+    8, 16};
+static constexpr dart::compiler::target::word Function_kind_tag_offset = 104;
+static constexpr dart::compiler::target::word Function_packed_fields_offset =
+    108;
+static constexpr dart::compiler::target::word Function_parameter_names_offset =
+    40;
+static constexpr dart::compiler::target::word Function_signature_offset = 48;
+static constexpr dart::compiler::target::word FutureOr_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word GrowableObjectArray_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word OldPage_card_table_offset = 40;
+static constexpr dart::compiler::target::word
+    CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word ICData_owner_offset = 40;
+static constexpr dart::compiler::target::word ICData_state_bits_offset = 52;
+static constexpr dart::compiler::target::word Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word Isolate_current_tag_offset = 40;
+static constexpr dart::compiler::target::word Isolate_default_tag_offset = 48;
+static constexpr dart::compiler::target::word Isolate_ic_miss_code_offset = 56;
+static constexpr dart::compiler::target::word
+    Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word Isolate_single_step_offset = 96;
+static constexpr dart::compiler::target::word Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word LinkedHashMap_data_offset = 32;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
+    24;
+static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
+    40;
+static constexpr dart::compiler::target::word LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word MarkingStackBlock_top_offset = 8;
+static constexpr dart::compiler::target::word MegamorphicCache_buckets_offset =
+    24;
+static constexpr dart::compiler::target::word MegamorphicCache_mask_offset = 32;
+static constexpr dart::compiler::target::word Mint_value_offset = 8;
+static constexpr dart::compiler::target::word NativeArguments_argc_tag_offset =
+    8;
+static constexpr dart::compiler::target::word NativeArguments_argv_offset = 16;
+static constexpr dart::compiler::target::word NativeArguments_retval_offset =
+    24;
+static constexpr dart::compiler::target::word NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word ObjectStore_double_type_offset =
+    256;
+static constexpr dart::compiler::target::word ObjectStore_int_type_offset = 136;
+static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
+    312;
+static constexpr dart::compiler::target::word ObjectStore_type_type_offset = 96;
+static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
+static constexpr dart::compiler::target::word PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word Pointer_type_arguments_offset =
+    16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_target_offset =
+    8;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word StoreBufferBlock_pointers_offset =
+    16;
+static constexpr dart::compiler::target::word StoreBufferBlock_top_offset = 8;
+static constexpr dart::compiler::target::word String_hash_offset = 4;
+static constexpr dart::compiler::target::word String_length_offset = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word Thread_active_exception_offset =
+    1392;
+static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
+    1400;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
+    1472;
+static constexpr dart::compiler::target::word
+    Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 208;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1488;
+static constexpr dart::compiler::target::word
+    Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 432;
+static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
+    608;
+static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
+    440;
+static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
+    680;
+static constexpr dart::compiler::target::word
+    Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word Thread_execution_state_offset =
+    1432;
+static constexpr dart::compiler::target::word
+    Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word Thread_float_not_address_offset =
+    688;
+static constexpr dart::compiler::target::word
+    Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
+    1408;
+static constexpr dart::compiler::target::word
+    Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
+    1464;
+static constexpr dart::compiler::target::word Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word Thread_field_table_values_offset =
+    128;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 264;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 192;
+static constexpr dart::compiler::target::word
+    Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1416;
+static constexpr dart::compiler::target::word
+    Thread_saved_shadow_call_stack_offset = 1424;
+static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
+    1440;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word Thread_stack_limit_offset = 64;
+static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
+    112;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
+    152;
+static constexpr dart::compiler::target::word
+    Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word Thread_top_offset = 96;
+static constexpr dart::compiler::target::word Thread_top_resource_offset = 40;
+static constexpr dart::compiler::target::word
+    Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
+    216;
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
+    72;
+static constexpr dart::compiler::target::word Thread_callback_code_offset =
+    1448;
+static constexpr dart::compiler::target::word
+    Thread_callback_stack_return_offset = 1456;
+static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
+    16;
+static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
+static constexpr dart::compiler::target::word Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word Type_hash_offset = 40;
+static constexpr dart::compiler::target::word Type_type_class_id_offset = 24;
+static constexpr dart::compiler::target::word Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word TypeParameter_index_offset = 60;
+static constexpr dart::compiler::target::word TypeParameter_nullability_offset =
+    63;
+static constexpr dart::compiler::target::word
+    TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word TypeArguments_length_offset = 16;
+static constexpr dart::compiler::target::word TypeArguments_nullability_offset =
+    32;
+static constexpr dart::compiler::target::word TypeArguments_types_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_bound_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_flags_offset = 62;
+static constexpr dart::compiler::target::word TypeParameter_name_offset = 24;
+static constexpr dart::compiler::target::word TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word TypedDataBase_length_offset = 16;
+static constexpr dart::compiler::target::word TypedDataView_data_offset = 24;
+static constexpr dart::compiler::target::word
+    TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_value_offset = 16;
+static constexpr dart::compiler::target::word Array_elements_start_offset = 24;
+static constexpr dart::compiler::target::word Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word TypeArguments_element_size = 8;
+static constexpr dart::compiler::target::word ClassTable_elements_start_offset =
+    0;
+static constexpr dart::compiler::target::word ClassTable_element_size = 1;
+static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
+static constexpr dart::compiler::target::word AbstractType_InstanceSize = 24;
+static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word Array_header_size = 24;
+static constexpr dart::compiler::target::word Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word Class_InstanceSize = 200;
+static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word Code_InstanceSize = 176;
+static constexpr dart::compiler::target::word CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word CompressedStackMaps_HeaderSize =
+    16;
+static constexpr dart::compiler::target::word Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word Context_header_size = 24;
+static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
+static constexpr dart::compiler::target::word Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
+static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Field_InstanceSize = 96;
+static constexpr dart::compiler::target::word Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word Function_InstanceSize = 128;
+static constexpr dart::compiler::target::word FunctionType_InstanceSize = 72;
+static constexpr dart::compiler::target::word FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
+static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word Instructions_UnalignedHeaderSize =
+    16;
+static constexpr dart::compiler::target::word
+    InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
+    120;
+static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
+static constexpr dart::compiler::target::word Library_InstanceSize = 160;
+static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
+static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
+static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word NativeArguments_StructSize = 32;
+static constexpr dart::compiler::target::word Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
+static constexpr dart::compiler::target::word PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 40;
+static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word Script_InstanceSize = 104;
+static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word String_InstanceSize = 16;
+static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 40;
+static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 64;
+static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataBase_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
+static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word Function_usage_counter_offset =
+    116;
+static constexpr dart::compiler::target::word
+    ICData_receivers_static_type_offset = 32;
+static constexpr dart::compiler::target::word
+    ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word ContextScope_element_size = 64;
+static constexpr dart::compiler::target::word
+    ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word ExceptionHandlers_element_size =
+    12;
+static constexpr dart::compiler::target::word ObjectPool_elements_start_offset =
+    16;
+static constexpr dart::compiler::target::word ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetJIT = 48;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetAOT = 20;
+static constexpr dart::compiler::target::word
+    Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word OldPage_kBytesPerCardLog2 = 10;
+static constexpr dart::compiler::target::word
+    NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_kTestResult = 0;
+static constexpr dart::compiler::target::word TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_count_offset =
+    32;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_size_offset =
+    40;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_name_offset =
+    0;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word Array_data_offset = 24;
+static constexpr dart::compiler::target::word Array_length_offset = 16;
+static constexpr dart::compiler::target::word Array_tags_offset = 0;
+static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word Class_declaration_type_offset =
+    104;
+static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
+    164;
+static constexpr dart::compiler::target::word Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word
+    SharedClassTable_class_heap_stats_table_offset = 0;
+static constexpr dart::compiler::target::word Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word Code_saved_instructions_offset =
+    48;
+static constexpr dart::compiler::target::word Code_owner_offset = 56;
+static constexpr dart::compiler::target::word Context_num_variables_offset = 8;
+static constexpr dart::compiler::target::word Context_parent_offset = 16;
+static constexpr dart::compiler::target::word Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word Field_guarded_cid_offset = 80;
+static constexpr dart::compiler::target::word
+    Field_guarded_list_length_in_object_offset_offset = 88;
+static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
+    48;
+static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Function_code_offset = 72;
+static constexpr dart::compiler::target::word Function_data_offset = 56;
+static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
+    8, 16};
+static constexpr dart::compiler::target::word Function_kind_tag_offset = 104;
+static constexpr dart::compiler::target::word Function_packed_fields_offset =
+    108;
+static constexpr dart::compiler::target::word Function_parameter_names_offset =
+    40;
+static constexpr dart::compiler::target::word Function_signature_offset = 48;
+static constexpr dart::compiler::target::word FutureOr_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word GrowableObjectArray_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word OldPage_card_table_offset = 40;
+static constexpr dart::compiler::target::word
+    CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word ICData_owner_offset = 40;
+static constexpr dart::compiler::target::word ICData_state_bits_offset = 52;
+static constexpr dart::compiler::target::word Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word Isolate_current_tag_offset = 40;
+static constexpr dart::compiler::target::word Isolate_default_tag_offset = 48;
+static constexpr dart::compiler::target::word Isolate_ic_miss_code_offset = 56;
+static constexpr dart::compiler::target::word
+    Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word Isolate_single_step_offset = 96;
+static constexpr dart::compiler::target::word Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word LinkedHashMap_data_offset = 32;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
+    24;
+static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
+    40;
+static constexpr dart::compiler::target::word LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word MarkingStackBlock_top_offset = 8;
+static constexpr dart::compiler::target::word MegamorphicCache_buckets_offset =
+    24;
+static constexpr dart::compiler::target::word MegamorphicCache_mask_offset = 32;
+static constexpr dart::compiler::target::word Mint_value_offset = 8;
+static constexpr dart::compiler::target::word NativeArguments_argc_tag_offset =
+    8;
+static constexpr dart::compiler::target::word NativeArguments_argv_offset = 16;
+static constexpr dart::compiler::target::word NativeArguments_retval_offset =
+    24;
+static constexpr dart::compiler::target::word NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word ObjectStore_double_type_offset =
+    256;
+static constexpr dart::compiler::target::word ObjectStore_int_type_offset = 136;
+static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
+    312;
+static constexpr dart::compiler::target::word ObjectStore_type_type_offset = 96;
+static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
+static constexpr dart::compiler::target::word PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word Pointer_type_arguments_offset =
+    16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_target_offset =
+    8;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word StoreBufferBlock_pointers_offset =
+    16;
+static constexpr dart::compiler::target::word StoreBufferBlock_top_offset = 8;
+static constexpr dart::compiler::target::word String_hash_offset = 4;
+static constexpr dart::compiler::target::word String_length_offset = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word Thread_active_exception_offset =
+    1464;
+static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
+    1472;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
+    1544;
+static constexpr dart::compiler::target::word
+    Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 208;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1560;
+static constexpr dart::compiler::target::word
+    Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 432;
+static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
+    608;
+static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
+    440;
+static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
+    680;
+static constexpr dart::compiler::target::word
+    Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word Thread_execution_state_offset =
+    1504;
+static constexpr dart::compiler::target::word
+    Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word Thread_float_not_address_offset =
+    688;
+static constexpr dart::compiler::target::word
+    Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
+    1480;
+static constexpr dart::compiler::target::word
+    Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
+    1536;
+static constexpr dart::compiler::target::word Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word Thread_field_table_values_offset =
+    128;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 264;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 192;
+static constexpr dart::compiler::target::word
+    Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1488;
+static constexpr dart::compiler::target::word
+    Thread_saved_shadow_call_stack_offset = 1496;
+static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
+    1512;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word Thread_stack_limit_offset = 64;
+static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
+    112;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
+    152;
+static constexpr dart::compiler::target::word
+    Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word Thread_top_offset = 96;
+static constexpr dart::compiler::target::word Thread_top_resource_offset = 40;
+static constexpr dart::compiler::target::word
+    Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
+    216;
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
+    72;
+static constexpr dart::compiler::target::word Thread_callback_code_offset =
+    1520;
+static constexpr dart::compiler::target::word
+    Thread_callback_stack_return_offset = 1528;
+static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
+    16;
+static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
+static constexpr dart::compiler::target::word Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word Type_hash_offset = 40;
+static constexpr dart::compiler::target::word Type_type_class_id_offset = 24;
+static constexpr dart::compiler::target::word Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word TypeParameter_index_offset = 60;
+static constexpr dart::compiler::target::word TypeParameter_nullability_offset =
+    63;
+static constexpr dart::compiler::target::word
+    TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word TypeArguments_length_offset = 16;
+static constexpr dart::compiler::target::word TypeArguments_nullability_offset =
+    32;
+static constexpr dart::compiler::target::word TypeArguments_types_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_bound_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_flags_offset = 62;
+static constexpr dart::compiler::target::word TypeParameter_name_offset = 24;
+static constexpr dart::compiler::target::word TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word TypedDataBase_length_offset = 16;
+static constexpr dart::compiler::target::word TypedDataView_data_offset = 24;
+static constexpr dart::compiler::target::word
+    TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_value_offset = 16;
+static constexpr dart::compiler::target::word Array_elements_start_offset = 24;
+static constexpr dart::compiler::target::word Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word TypeArguments_element_size = 8;
+static constexpr dart::compiler::target::word ClassTable_elements_start_offset =
+    0;
+static constexpr dart::compiler::target::word ClassTable_element_size = 1;
+static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
+static constexpr dart::compiler::target::word AbstractType_InstanceSize = 24;
+static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word Array_header_size = 24;
+static constexpr dart::compiler::target::word Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word Class_InstanceSize = 200;
+static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word Code_InstanceSize = 176;
+static constexpr dart::compiler::target::word CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word CompressedStackMaps_HeaderSize =
+    16;
+static constexpr dart::compiler::target::word Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word Context_header_size = 24;
+static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
+static constexpr dart::compiler::target::word Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
+static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Field_InstanceSize = 96;
+static constexpr dart::compiler::target::word Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word Function_InstanceSize = 128;
+static constexpr dart::compiler::target::word FunctionType_InstanceSize = 72;
+static constexpr dart::compiler::target::word FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
+static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word Instructions_UnalignedHeaderSize =
+    16;
+static constexpr dart::compiler::target::word
+    InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
+    120;
+static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
+static constexpr dart::compiler::target::word Library_InstanceSize = 160;
+static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
+static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
+static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word NativeArguments_StructSize = 32;
+static constexpr dart::compiler::target::word Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
+static constexpr dart::compiler::target::word PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 40;
+static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word Script_InstanceSize = 104;
+static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word String_InstanceSize = 16;
+static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 40;
+static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 64;
+static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataBase_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
+static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
 
 #else  // !defined(PRODUCT)
 
-#if defined(TARGET_ARCH_ARM)
+#if defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     76;
 static constexpr dart::compiler::target::word
@@ -2675,9 +3752,9 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 8;
-#endif  // defined(TARGET_ARCH_ARM)
+#endif  // defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_X64)
+#if defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     116;
 static constexpr dart::compiler::target::word
@@ -3207,9 +4284,9 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_X64)
+#endif  // defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_IA32)
+#if defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     76;
 static constexpr dart::compiler::target::word
@@ -3728,9 +4805,9 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 16;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 8;
-#endif  // defined(TARGET_ARCH_IA32)
+#endif  // defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_ARM64)
+#if defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word Function_usage_counter_offset =
     116;
 static constexpr dart::compiler::target::word
@@ -4261,13 +5338,1078 @@
 static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
 static constexpr dart::compiler::target::word
     WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_ARM64)
+#endif  // defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word Function_usage_counter_offset =
+    116;
+static constexpr dart::compiler::target::word
+    ICData_receivers_static_type_offset = 32;
+static constexpr dart::compiler::target::word
+    ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word ContextScope_element_size = 64;
+static constexpr dart::compiler::target::word
+    ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word ExceptionHandlers_element_size =
+    12;
+static constexpr dart::compiler::target::word ObjectPool_elements_start_offset =
+    16;
+static constexpr dart::compiler::target::word ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetJIT = 40;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetAOT = 22;
+static constexpr dart::compiler::target::word
+    Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word OldPage_kBytesPerCardLog2 = 10;
+static constexpr dart::compiler::target::word
+    NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_kTestResult = 0;
+static constexpr dart::compiler::target::word TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_count_offset =
+    32;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_size_offset =
+    40;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_name_offset =
+    0;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word Array_data_offset = 24;
+static constexpr dart::compiler::target::word Array_length_offset = 16;
+static constexpr dart::compiler::target::word Array_tags_offset = 0;
+static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word Class_declaration_type_offset =
+    104;
+static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
+    164;
+static constexpr dart::compiler::target::word Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word Code_saved_instructions_offset =
+    48;
+static constexpr dart::compiler::target::word Code_owner_offset = 56;
+static constexpr dart::compiler::target::word Context_num_variables_offset = 8;
+static constexpr dart::compiler::target::word Context_parent_offset = 16;
+static constexpr dart::compiler::target::word Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word Field_guarded_cid_offset = 80;
+static constexpr dart::compiler::target::word
+    Field_guarded_list_length_in_object_offset_offset = 88;
+static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
+    48;
+static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Function_code_offset = 72;
+static constexpr dart::compiler::target::word Function_data_offset = 56;
+static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
+    8, 16};
+static constexpr dart::compiler::target::word Function_kind_tag_offset = 104;
+static constexpr dart::compiler::target::word Function_packed_fields_offset =
+    108;
+static constexpr dart::compiler::target::word Function_parameter_names_offset =
+    40;
+static constexpr dart::compiler::target::word Function_signature_offset = 48;
+static constexpr dart::compiler::target::word FutureOr_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word GrowableObjectArray_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word OldPage_card_table_offset = 40;
+static constexpr dart::compiler::target::word
+    CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word ICData_owner_offset = 40;
+static constexpr dart::compiler::target::word ICData_state_bits_offset = 52;
+static constexpr dart::compiler::target::word Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word Isolate_current_tag_offset = 40;
+static constexpr dart::compiler::target::word Isolate_default_tag_offset = 48;
+static constexpr dart::compiler::target::word Isolate_ic_miss_code_offset = 56;
+static constexpr dart::compiler::target::word
+    Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word LinkedHashMap_data_offset = 32;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
+    24;
+static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
+    40;
+static constexpr dart::compiler::target::word LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word MarkingStackBlock_top_offset = 8;
+static constexpr dart::compiler::target::word MegamorphicCache_buckets_offset =
+    24;
+static constexpr dart::compiler::target::word MegamorphicCache_mask_offset = 32;
+static constexpr dart::compiler::target::word Mint_value_offset = 8;
+static constexpr dart::compiler::target::word NativeArguments_argc_tag_offset =
+    8;
+static constexpr dart::compiler::target::word NativeArguments_argv_offset = 16;
+static constexpr dart::compiler::target::word NativeArguments_retval_offset =
+    24;
+static constexpr dart::compiler::target::word NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word ObjectStore_double_type_offset =
+    256;
+static constexpr dart::compiler::target::word ObjectStore_int_type_offset = 136;
+static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
+    312;
+static constexpr dart::compiler::target::word ObjectStore_type_type_offset = 96;
+static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
+static constexpr dart::compiler::target::word PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word Pointer_type_arguments_offset =
+    16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_target_offset =
+    8;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word StoreBufferBlock_pointers_offset =
+    16;
+static constexpr dart::compiler::target::word StoreBufferBlock_top_offset = 8;
+static constexpr dart::compiler::target::word String_hash_offset = 4;
+static constexpr dart::compiler::target::word String_length_offset = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word Thread_active_exception_offset =
+    1392;
+static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
+    1400;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
+    1472;
+static constexpr dart::compiler::target::word
+    Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 208;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1488;
+static constexpr dart::compiler::target::word
+    Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 432;
+static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
+    608;
+static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
+    440;
+static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
+    680;
+static constexpr dart::compiler::target::word
+    Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word Thread_execution_state_offset =
+    1432;
+static constexpr dart::compiler::target::word
+    Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word Thread_float_not_address_offset =
+    688;
+static constexpr dart::compiler::target::word
+    Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
+    1408;
+static constexpr dart::compiler::target::word
+    Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
+    1464;
+static constexpr dart::compiler::target::word Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word Thread_field_table_values_offset =
+    128;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 264;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 192;
+static constexpr dart::compiler::target::word
+    Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1416;
+static constexpr dart::compiler::target::word
+    Thread_saved_shadow_call_stack_offset = 1424;
+static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
+    1440;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word Thread_stack_limit_offset = 64;
+static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
+    112;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
+    152;
+static constexpr dart::compiler::target::word
+    Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word Thread_top_offset = 96;
+static constexpr dart::compiler::target::word Thread_top_resource_offset = 40;
+static constexpr dart::compiler::target::word
+    Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
+    216;
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
+    72;
+static constexpr dart::compiler::target::word Thread_callback_code_offset =
+    1448;
+static constexpr dart::compiler::target::word
+    Thread_callback_stack_return_offset = 1456;
+static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
+    16;
+static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
+static constexpr dart::compiler::target::word Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word Type_hash_offset = 40;
+static constexpr dart::compiler::target::word Type_type_class_id_offset = 24;
+static constexpr dart::compiler::target::word Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word TypeParameter_index_offset = 60;
+static constexpr dart::compiler::target::word TypeParameter_nullability_offset =
+    63;
+static constexpr dart::compiler::target::word
+    TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word TypeArguments_length_offset = 16;
+static constexpr dart::compiler::target::word TypeArguments_nullability_offset =
+    32;
+static constexpr dart::compiler::target::word TypeArguments_types_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_bound_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_flags_offset = 62;
+static constexpr dart::compiler::target::word TypeParameter_name_offset = 24;
+static constexpr dart::compiler::target::word TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word TypedDataBase_length_offset = 16;
+static constexpr dart::compiler::target::word TypedDataView_data_offset = 24;
+static constexpr dart::compiler::target::word
+    TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_value_offset = 16;
+static constexpr dart::compiler::target::word Array_elements_start_offset = 24;
+static constexpr dart::compiler::target::word Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word TypeArguments_element_size = 8;
+static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
+static constexpr dart::compiler::target::word AbstractType_InstanceSize = 24;
+static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word Array_header_size = 24;
+static constexpr dart::compiler::target::word Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word Class_InstanceSize = 200;
+static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word Code_InstanceSize = 144;
+static constexpr dart::compiler::target::word CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word CompressedStackMaps_HeaderSize =
+    16;
+static constexpr dart::compiler::target::word Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word Context_header_size = 24;
+static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
+static constexpr dart::compiler::target::word Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
+static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Field_InstanceSize = 96;
+static constexpr dart::compiler::target::word Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word Function_InstanceSize = 128;
+static constexpr dart::compiler::target::word FunctionType_InstanceSize = 72;
+static constexpr dart::compiler::target::word FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
+static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word Instructions_UnalignedHeaderSize =
+    16;
+static constexpr dart::compiler::target::word
+    InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
+    120;
+static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
+static constexpr dart::compiler::target::word Library_InstanceSize = 160;
+static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
+static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
+static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word NativeArguments_StructSize = 32;
+static constexpr dart::compiler::target::word Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
+static constexpr dart::compiler::target::word PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 24;
+static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word Script_InstanceSize = 88;
+static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word String_InstanceSize = 16;
+static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 40;
+static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 64;
+static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataBase_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
+static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word Function_usage_counter_offset =
+    116;
+static constexpr dart::compiler::target::word
+    ICData_receivers_static_type_offset = 32;
+static constexpr dart::compiler::target::word
+    ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word ContextScope_element_size = 64;
+static constexpr dart::compiler::target::word
+    ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word ExceptionHandlers_element_size =
+    12;
+static constexpr dart::compiler::target::word ObjectPool_elements_start_offset =
+    16;
+static constexpr dart::compiler::target::word ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetJIT = 48;
+static constexpr dart::compiler::target::word
+    Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    Instructions_kPolymorphicEntryOffsetAOT = 20;
+static constexpr dart::compiler::target::word
+    Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word OldPage_kBytesPerCardLog2 = 10;
+static constexpr dart::compiler::target::word
+    NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_kTestResult = 0;
+static constexpr dart::compiler::target::word TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_count_offset =
+    32;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_size_offset =
+    40;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word ArgumentsDescriptor_name_offset =
+    0;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word Array_data_offset = 24;
+static constexpr dart::compiler::target::word Array_length_offset = 16;
+static constexpr dart::compiler::target::word Array_tags_offset = 0;
+static constexpr dart::compiler::target::word Array_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word Class_declaration_type_offset =
+    104;
+static constexpr dart::compiler::target::word Class_num_type_arguments_offset =
+    164;
+static constexpr dart::compiler::target::word Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word Code_saved_instructions_offset =
+    48;
+static constexpr dart::compiler::target::word Code_owner_offset = 56;
+static constexpr dart::compiler::target::word Context_num_variables_offset = 8;
+static constexpr dart::compiler::target::word Context_parent_offset = 16;
+static constexpr dart::compiler::target::word Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word Field_guarded_cid_offset = 80;
+static constexpr dart::compiler::target::word
+    Field_guarded_list_length_in_object_offset_offset = 88;
+static constexpr dart::compiler::target::word Field_guarded_list_length_offset =
+    48;
+static constexpr dart::compiler::target::word Field_is_nullable_offset = 82;
+static constexpr dart::compiler::target::word Field_kind_bits_offset = 90;
+static constexpr dart::compiler::target::word Function_code_offset = 72;
+static constexpr dart::compiler::target::word Function_data_offset = 56;
+static constexpr dart::compiler::target::word Function_entry_point_offset[] = {
+    8, 16};
+static constexpr dart::compiler::target::word Function_kind_tag_offset = 104;
+static constexpr dart::compiler::target::word Function_packed_fields_offset =
+    108;
+static constexpr dart::compiler::target::word Function_parameter_names_offset =
+    40;
+static constexpr dart::compiler::target::word Function_signature_offset = 48;
+static constexpr dart::compiler::target::word FutureOr_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word GrowableObjectArray_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word OldPage_card_table_offset = 40;
+static constexpr dart::compiler::target::word
+    CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word ICData_owner_offset = 40;
+static constexpr dart::compiler::target::word ICData_state_bits_offset = 52;
+static constexpr dart::compiler::target::word Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word Isolate_current_tag_offset = 40;
+static constexpr dart::compiler::target::word Isolate_default_tag_offset = 48;
+static constexpr dart::compiler::target::word Isolate_ic_miss_code_offset = 56;
+static constexpr dart::compiler::target::word
+    Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word LinkedHashMap_data_offset = 32;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word LinkedHashMap_hash_mask_offset =
+    24;
+static constexpr dart::compiler::target::word LinkedHashMap_index_offset = 16;
+static constexpr dart::compiler::target::word
+    LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word LinkedHashMap_used_data_offset =
+    40;
+static constexpr dart::compiler::target::word LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word MarkingStackBlock_top_offset = 8;
+static constexpr dart::compiler::target::word MegamorphicCache_buckets_offset =
+    24;
+static constexpr dart::compiler::target::word MegamorphicCache_mask_offset = 32;
+static constexpr dart::compiler::target::word Mint_value_offset = 8;
+static constexpr dart::compiler::target::word NativeArguments_argc_tag_offset =
+    8;
+static constexpr dart::compiler::target::word NativeArguments_argv_offset = 16;
+static constexpr dart::compiler::target::word NativeArguments_retval_offset =
+    24;
+static constexpr dart::compiler::target::word NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word ObjectStore_double_type_offset =
+    256;
+static constexpr dart::compiler::target::word ObjectStore_int_type_offset = 136;
+static constexpr dart::compiler::target::word ObjectStore_string_type_offset =
+    312;
+static constexpr dart::compiler::target::word ObjectStore_type_type_offset = 96;
+static constexpr dart::compiler::target::word OneByteString_data_offset = 16;
+static constexpr dart::compiler::target::word PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word Pointer_type_arguments_offset =
+    16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_target_offset =
+    8;
+static constexpr dart::compiler::target::word
+    SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word StoreBufferBlock_pointers_offset =
+    16;
+static constexpr dart::compiler::target::word StoreBufferBlock_top_offset = 8;
+static constexpr dart::compiler::target::word String_hash_offset = 4;
+static constexpr dart::compiler::target::word String_length_offset = 8;
+static constexpr dart::compiler::target::word SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word Thread_active_exception_offset =
+    1464;
+static constexpr dart::compiler::target::word Thread_active_stacktrace_offset =
+    1472;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word Thread_api_top_scope_offset =
+    1544;
+static constexpr dart::compiler::target::word
+    Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word Thread_bool_false_offset = 208;
+static constexpr dart::compiler::target::word Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word Thread_dart_stream_offset = 1560;
+static constexpr dart::compiler::target::word
+    Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word Thread_optimize_stub_offset = 432;
+static constexpr dart::compiler::target::word Thread_deoptimize_entry_offset =
+    608;
+static constexpr dart::compiler::target::word Thread_deoptimize_stub_offset =
+    440;
+static constexpr dart::compiler::target::word Thread_double_abs_address_offset =
+    680;
+static constexpr dart::compiler::target::word
+    Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word Thread_execution_state_offset =
+    1504;
+static constexpr dart::compiler::target::word
+    Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word Thread_float_not_address_offset =
+    688;
+static constexpr dart::compiler::target::word
+    Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word Thread_global_object_pool_offset =
+    1480;
+static constexpr dart::compiler::target::word
+    Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word Thread_exit_through_ffi_offset =
+    1536;
+static constexpr dart::compiler::target::word Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word Thread_field_table_values_offset =
+    128;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    Thread_late_initialization_error_shared_without_fpu_regs_stub_offset = 264;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word Thread_object_null_offset = 192;
+static constexpr dart::compiler::target::word
+    Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word Thread_resume_pc_offset = 1488;
+static constexpr dart::compiler::target::word
+    Thread_saved_shadow_call_stack_offset = 1496;
+static constexpr dart::compiler::target::word Thread_safepoint_state_offset =
+    1512;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word Thread_stack_limit_offset = 64;
+static constexpr dart::compiler::target::word Thread_saved_stack_limit_offset =
+    112;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word Thread_store_buffer_block_offset =
+    152;
+static constexpr dart::compiler::target::word
+    Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word Thread_top_offset = 96;
+static constexpr dart::compiler::target::word Thread_top_resource_offset = 40;
+static constexpr dart::compiler::target::word
+    Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word Thread_write_barrier_code_offset =
+    216;
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word Thread_write_barrier_mask_offset =
+    72;
+static constexpr dart::compiler::target::word Thread_callback_code_offset =
+    1520;
+static constexpr dart::compiler::target::word
+    Thread_callback_stack_return_offset = 1528;
+static constexpr dart::compiler::target::word TimelineStream_enabled_offset =
+    16;
+static constexpr dart::compiler::target::word TwoByteString_data_offset = 16;
+static constexpr dart::compiler::target::word Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word Type_hash_offset = 40;
+static constexpr dart::compiler::target::word Type_type_class_id_offset = 24;
+static constexpr dart::compiler::target::word Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word TypeParameter_index_offset = 60;
+static constexpr dart::compiler::target::word TypeParameter_nullability_offset =
+    63;
+static constexpr dart::compiler::target::word
+    TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word TypeArguments_length_offset = 16;
+static constexpr dart::compiler::target::word TypeArguments_nullability_offset =
+    32;
+static constexpr dart::compiler::target::word TypeArguments_types_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_bound_offset = 40;
+static constexpr dart::compiler::target::word TypeParameter_flags_offset = 62;
+static constexpr dart::compiler::target::word TypeParameter_name_offset = 24;
+static constexpr dart::compiler::target::word TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word TypedDataBase_length_offset = 16;
+static constexpr dart::compiler::target::word TypedDataView_data_offset = 24;
+static constexpr dart::compiler::target::word
+    TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word WeakProperty_value_offset = 16;
+static constexpr dart::compiler::target::word Array_elements_start_offset = 24;
+static constexpr dart::compiler::target::word Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word TypeArguments_element_size = 8;
+static constexpr dart::compiler::target::word Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
+static constexpr dart::compiler::target::word AbstractType_InstanceSize = 24;
+static constexpr dart::compiler::target::word ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word Array_header_size = 24;
+static constexpr dart::compiler::target::word Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word Class_InstanceSize = 200;
+static constexpr dart::compiler::target::word Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word Code_InstanceSize = 144;
+static constexpr dart::compiler::target::word CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word CompressedStackMaps_HeaderSize =
+    16;
+static constexpr dart::compiler::target::word Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word Context_header_size = 24;
+static constexpr dart::compiler::target::word ContextScope_InstanceSize = 16;
+static constexpr dart::compiler::target::word Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word DynamicLibrary_InstanceSize = 16;
+static constexpr dart::compiler::target::word ExceptionHandlers_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word
+    ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word ExternalTypedData_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word FfiTrampolineData_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Field_InstanceSize = 96;
+static constexpr dart::compiler::target::word Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word Function_InstanceSize = 128;
+static constexpr dart::compiler::target::word FunctionType_InstanceSize = 72;
+static constexpr dart::compiler::target::word FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word GrowableObjectArray_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word ICData_InstanceSize = 56;
+static constexpr dart::compiler::target::word Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word Instructions_UnalignedHeaderSize =
+    16;
+static constexpr dart::compiler::target::word
+    InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word KernelProgramInfo_InstanceSize =
+    120;
+static constexpr dart::compiler::target::word LanguageError_InstanceSize = 48;
+static constexpr dart::compiler::target::word Library_InstanceSize = 160;
+static constexpr dart::compiler::target::word LibraryPrefix_InstanceSize = 40;
+static constexpr dart::compiler::target::word LinkedHashMap_InstanceSize = 56;
+static constexpr dart::compiler::target::word LocalVarDescriptors_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word MegamorphicCache_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word MirrorReference_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word NativeArguments_StructSize = 32;
+static constexpr dart::compiler::target::word Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word OneByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word PatchClass_InstanceSize = 48;
+static constexpr dart::compiler::target::word PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word ReceivePort_InstanceSize = 24;
+static constexpr dart::compiler::target::word RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word Script_InstanceSize = 88;
+static constexpr dart::compiler::target::word SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word SingleTargetCache_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word String_InstanceSize = 16;
+static constexpr dart::compiler::target::word SubtypeTestCache_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word TwoByteString_InstanceSize = 16;
+static constexpr dart::compiler::target::word Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word TypeArguments_InstanceSize = 40;
+static constexpr dart::compiler::target::word TypeParameter_InstanceSize = 64;
+static constexpr dart::compiler::target::word TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataBase_InstanceSize = 24;
+static constexpr dart::compiler::target::word TypedDataView_InstanceSize = 40;
+static constexpr dart::compiler::target::word UnhandledException_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word UnlinkedCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word WeakProperty_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
 
 #endif  // !defined(PRODUCT)
 
 #if !defined(PRODUCT)
 
-#if defined(TARGET_ARCH_ARM)
+#if defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word
     AOT_ContextScope_elements_start_offset = 12;
 static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
@@ -4856,9 +6998,9 @@
     16;
 static constexpr dart::compiler::target::word
     AOT_WeakSerializationReference_InstanceSize = 8;
-#endif  // defined(TARGET_ARCH_ARM)
+#endif  // defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_X64)
+#if defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word
     AOT_ContextScope_elements_start_offset = 16;
 static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
@@ -5451,12 +7593,12 @@
     32;
 static constexpr dart::compiler::target::word
     AOT_WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_X64)
+#endif  // defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_IA32)
-#endif  // defined(TARGET_ARCH_IA32)
+#if defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
+#endif  // defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_ARM64)
+#if defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word
     AOT_ContextScope_elements_start_offset = 16;
 static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
@@ -6050,11 +8192,1202 @@
     32;
 static constexpr dart::compiler::target::word
     AOT_WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_ARM64)
+#endif  // defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word
+    AOT_ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_element_size = 12;
+static constexpr dart::compiler::target::word
+    AOT_ObjectPool_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word AOT_Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word AOT_Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetJIT = 40;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetAOT = 22;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_kBytesPerCardLog2 =
+    10;
+static constexpr dart::compiler::target::word
+    AOT_NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word AOT_String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word AOT_SubtypeTestCache_kTestResult =
+    0;
+static constexpr dart::compiler::target::word AOT_TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AOT_AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_count_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_size_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_name_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_data_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_length_offset = 16;
+static constexpr dart::compiler::target::word AOT_Array_tags_offset = 0;
+static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_Class_declaration_type_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Class_num_type_arguments_offset = 164;
+static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    AOT_Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word
+    AOT_SharedClassTable_class_heap_stats_table_offset = 0;
+static constexpr dart::compiler::target::word AOT_Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word AOT_Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word AOT_Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word AOT_Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Code_saved_instructions_offset = 48;
+static constexpr dart::compiler::target::word AOT_Code_owner_offset = 56;
+static constexpr dart::compiler::target::word AOT_Context_num_variables_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_Context_parent_offset = 16;
+static constexpr dart::compiler::target::word AOT_Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word AOT_Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word AOT_Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word AOT_Field_guarded_cid_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_in_object_offset_offset = 76;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_offset = 48;
+static constexpr dart::compiler::target::word AOT_Field_is_nullable_offset = 74;
+static constexpr dart::compiler::target::word AOT_Field_kind_bits_offset = 78;
+static constexpr dart::compiler::target::word AOT_Function_code_offset = 72;
+static constexpr dart::compiler::target::word AOT_Function_data_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_Function_entry_point_offset[] = {8, 16};
+static constexpr dart::compiler::target::word AOT_Function_kind_tag_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Function_packed_fields_offset = 84;
+static constexpr dart::compiler::target::word
+    AOT_Function_parameter_names_offset = 40;
+static constexpr dart::compiler::target::word AOT_Function_signature_offset =
+    48;
+static constexpr dart::compiler::target::word
+    AOT_FutureOr_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_card_table_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word AOT_ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word AOT_ICData_owner_offset = 32;
+static constexpr dart::compiler::target::word AOT_ICData_state_bits_offset = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word AOT_Isolate_current_tag_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_Isolate_default_tag_offset =
+    48;
+static constexpr dart::compiler::target::word AOT_Isolate_ic_miss_code_offset =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word AOT_Isolate_single_step_offset =
+    96;
+static constexpr dart::compiler::target::word AOT_Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_data_offset =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_hash_mask_offset = 24;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_used_data_offset = 40;
+static constexpr dart::compiler::target::word AOT_LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_MarkingStackBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_buckets_offset = 24;
+static constexpr dart::compiler::target::word AOT_MegamorphicCache_mask_offset =
+    32;
+static constexpr dart::compiler::target::word AOT_Mint_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_argc_tag_offset = 8;
+static constexpr dart::compiler::target::word AOT_NativeArguments_argv_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_retval_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_double_type_offset = 256;
+static constexpr dart::compiler::target::word AOT_ObjectStore_int_type_offset =
+    136;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_string_type_offset = 312;
+static constexpr dart::compiler::target::word AOT_ObjectStore_type_type_offset =
+    96;
+static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Pointer_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_target_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word
+    AOT_StoreBufferBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_StoreBufferBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_String_hash_offset = 4;
+static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_exception_offset = 1392;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_stacktrace_offset = 1400;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
+    1472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
+    208;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
+    1488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
+    432;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_entry_offset = 608;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_stub_offset = 440;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_abs_address_offset = 680;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word AOT_Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word
+    AOT_Thread_execution_state_offset = 1432;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_not_address_offset = 688;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word
+    AOT_Thread_global_object_pool_offset = 1408;
+static constexpr dart::compiler::target::word
+    AOT_Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_through_ffi_offset = 1464;
+static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Thread_field_table_values_offset = 128;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    AOT_Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
+        264;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
+    192;
+static constexpr dart::compiler::target::word
+    AOT_Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
+    1416;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_shadow_call_stack_offset = 1424;
+static constexpr dart::compiler::target::word
+    AOT_Thread_safepoint_state_offset = 1440;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_stack_limit_offset = 112;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word
+    AOT_Thread_store_buffer_block_offset = 152;
+static constexpr dart::compiler::target::word
+    AOT_Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word AOT_Thread_top_offset = 96;
+static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_code_offset = 216;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_mask_offset = 72;
+static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
+    1448;
+static constexpr dart::compiler::target::word
+    AOT_Thread_callback_stack_return_offset = 1456;
+static constexpr dart::compiler::target::word
+    AOT_TimelineStream_enabled_offset = 16;
+static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word AOT_Type_hash_offset = 40;
+static constexpr dart::compiler::target::word AOT_Type_type_class_id_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word AOT_Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word AOT_FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word AOT_TypeParameter_index_offset =
+    60;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_nullability_offset = 63;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word AOT_TypeArguments_length_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_nullability_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypeArguments_types_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_bound_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_flags_offset =
+    62;
+static constexpr dart::compiler::target::word AOT_TypeParameter_name_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_length_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_TypedDataView_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    AOT_TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word AOT_UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_value_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Array_elements_start_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word AOT_TypeArguments_element_size =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_ClassTable_elements_start_offset = 0;
+static constexpr dart::compiler::target::word AOT_ClassTable_element_size = 1;
+static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
+static constexpr dart::compiler::target::word AOT_AbstractType_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
+static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 184;
+static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 152;
+static constexpr dart::compiler::target::word AOT_CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_CompressedStackMaps_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Context_header_size = 24;
+static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_FfiTrampolineData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
+static constexpr dart::compiler::target::word AOT_Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_FunctionType_InstanceSize =
+    72;
+static constexpr dart::compiler::target::word AOT_FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_UnalignedHeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_KernelProgramInfo_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 152;
+static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_LocalVarDescriptors_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_NativeArguments_StructSize =
+    32;
+static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_String_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
+    64;
+static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word
+    AOT_ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_element_size = 12;
+static constexpr dart::compiler::target::word
+    AOT_ObjectPool_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word AOT_Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word AOT_Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetJIT = 48;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetAOT = 20;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_kBytesPerCardLog2 =
+    10;
+static constexpr dart::compiler::target::word
+    AOT_NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word AOT_String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word AOT_SubtypeTestCache_kTestResult =
+    0;
+static constexpr dart::compiler::target::word AOT_TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AOT_AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_count_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_size_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_name_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_data_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_length_offset = 16;
+static constexpr dart::compiler::target::word AOT_Array_tags_offset = 0;
+static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_Class_declaration_type_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Class_num_type_arguments_offset = 164;
+static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    AOT_Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word
+    AOT_SharedClassTable_class_heap_stats_table_offset = 0;
+static constexpr dart::compiler::target::word AOT_Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word AOT_Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word AOT_Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word AOT_Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Code_saved_instructions_offset = 48;
+static constexpr dart::compiler::target::word AOT_Code_owner_offset = 56;
+static constexpr dart::compiler::target::word AOT_Context_num_variables_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_Context_parent_offset = 16;
+static constexpr dart::compiler::target::word AOT_Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word AOT_Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word AOT_Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word AOT_Field_guarded_cid_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_in_object_offset_offset = 76;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_offset = 48;
+static constexpr dart::compiler::target::word AOT_Field_is_nullable_offset = 74;
+static constexpr dart::compiler::target::word AOT_Field_kind_bits_offset = 78;
+static constexpr dart::compiler::target::word AOT_Function_code_offset = 72;
+static constexpr dart::compiler::target::word AOT_Function_data_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_Function_entry_point_offset[] = {8, 16};
+static constexpr dart::compiler::target::word AOT_Function_kind_tag_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Function_packed_fields_offset = 84;
+static constexpr dart::compiler::target::word
+    AOT_Function_parameter_names_offset = 40;
+static constexpr dart::compiler::target::word AOT_Function_signature_offset =
+    48;
+static constexpr dart::compiler::target::word
+    AOT_FutureOr_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_card_table_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word AOT_ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word AOT_ICData_owner_offset = 32;
+static constexpr dart::compiler::target::word AOT_ICData_state_bits_offset = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word AOT_Isolate_current_tag_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_Isolate_default_tag_offset =
+    48;
+static constexpr dart::compiler::target::word AOT_Isolate_ic_miss_code_offset =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word AOT_Isolate_single_step_offset =
+    96;
+static constexpr dart::compiler::target::word AOT_Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_data_offset =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_hash_mask_offset = 24;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_used_data_offset = 40;
+static constexpr dart::compiler::target::word AOT_LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_MarkingStackBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_buckets_offset = 24;
+static constexpr dart::compiler::target::word AOT_MegamorphicCache_mask_offset =
+    32;
+static constexpr dart::compiler::target::word AOT_Mint_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_argc_tag_offset = 8;
+static constexpr dart::compiler::target::word AOT_NativeArguments_argv_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_retval_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_double_type_offset = 256;
+static constexpr dart::compiler::target::word AOT_ObjectStore_int_type_offset =
+    136;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_string_type_offset = 312;
+static constexpr dart::compiler::target::word AOT_ObjectStore_type_type_offset =
+    96;
+static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Pointer_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_target_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word
+    AOT_StoreBufferBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_StoreBufferBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_String_hash_offset = 4;
+static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_exception_offset = 1464;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_stacktrace_offset = 1472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
+    1544;
+static constexpr dart::compiler::target::word
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
+    208;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
+    1560;
+static constexpr dart::compiler::target::word
+    AOT_Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
+    432;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_entry_offset = 608;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_stub_offset = 440;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_abs_address_offset = 680;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word AOT_Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word
+    AOT_Thread_execution_state_offset = 1504;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_not_address_offset = 688;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word
+    AOT_Thread_global_object_pool_offset = 1480;
+static constexpr dart::compiler::target::word
+    AOT_Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_through_ffi_offset = 1536;
+static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Thread_field_table_values_offset = 128;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    AOT_Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
+        264;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
+    192;
+static constexpr dart::compiler::target::word
+    AOT_Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
+    1488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_shadow_call_stack_offset = 1496;
+static constexpr dart::compiler::target::word
+    AOT_Thread_safepoint_state_offset = 1512;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_stack_limit_offset = 112;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word
+    AOT_Thread_store_buffer_block_offset = 152;
+static constexpr dart::compiler::target::word
+    AOT_Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word AOT_Thread_top_offset = 96;
+static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_code_offset = 216;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_mask_offset = 72;
+static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
+    1520;
+static constexpr dart::compiler::target::word
+    AOT_Thread_callback_stack_return_offset = 1528;
+static constexpr dart::compiler::target::word
+    AOT_TimelineStream_enabled_offset = 16;
+static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word AOT_Type_hash_offset = 40;
+static constexpr dart::compiler::target::word AOT_Type_type_class_id_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word AOT_Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word AOT_FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word AOT_TypeParameter_index_offset =
+    60;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_nullability_offset = 63;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word AOT_TypeArguments_length_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_nullability_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypeArguments_types_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_bound_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_flags_offset =
+    62;
+static constexpr dart::compiler::target::word AOT_TypeParameter_name_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_length_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_TypedDataView_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    AOT_TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word AOT_UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_value_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Array_elements_start_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word AOT_TypeArguments_element_size =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_ClassTable_elements_start_offset = 0;
+static constexpr dart::compiler::target::word AOT_ClassTable_element_size = 1;
+static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
+static constexpr dart::compiler::target::word AOT_AbstractType_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
+static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 184;
+static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 152;
+static constexpr dart::compiler::target::word AOT_CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_CompressedStackMaps_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Context_header_size = 24;
+static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_FfiTrampolineData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
+static constexpr dart::compiler::target::word AOT_Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_FunctionType_InstanceSize =
+    72;
+static constexpr dart::compiler::target::word AOT_FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_UnalignedHeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_KernelProgramInfo_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 152;
+static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_LocalVarDescriptors_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_NativeArguments_StructSize =
+    32;
+static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_String_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
+    64;
+static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
 
 #else  // !defined(PRODUCT)
 
-#if defined(TARGET_ARCH_ARM)
+#if defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word
     AOT_ContextScope_elements_start_offset = 12;
 static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
@@ -6636,9 +9969,9 @@
     16;
 static constexpr dart::compiler::target::word
     AOT_WeakSerializationReference_InstanceSize = 8;
-#endif  // defined(TARGET_ARCH_ARM)
+#endif  // defined(TARGET_ARCH_ARM) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_X64)
+#if defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word
     AOT_ContextScope_elements_start_offset = 16;
 static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
@@ -7224,12 +10557,12 @@
     32;
 static constexpr dart::compiler::target::word
     AOT_WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_X64)
+#endif  // defined(TARGET_ARCH_X64) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_IA32)
-#endif  // defined(TARGET_ARCH_IA32)
+#if defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
+#endif  // defined(TARGET_ARCH_IA32) && !defined(DART_COMPRESSED_POINTERS)
 
-#if defined(TARGET_ARCH_ARM64)
+#if defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
 static constexpr dart::compiler::target::word
     AOT_ContextScope_elements_start_offset = 16;
 static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
@@ -7816,7 +11149,1184 @@
     32;
 static constexpr dart::compiler::target::word
     AOT_WeakSerializationReference_InstanceSize = 16;
-#endif  // defined(TARGET_ARCH_ARM64)
+#endif  // defined(TARGET_ARCH_ARM64) && !defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word
+    AOT_ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_element_size = 12;
+static constexpr dart::compiler::target::word
+    AOT_ObjectPool_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word AOT_Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word AOT_Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetJIT = 40;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetAOT = 22;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_kBytesPerCardLog2 =
+    10;
+static constexpr dart::compiler::target::word
+    AOT_NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word AOT_String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word AOT_SubtypeTestCache_kTestResult =
+    0;
+static constexpr dart::compiler::target::word AOT_TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AOT_AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_count_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_size_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_name_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_data_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_length_offset = 16;
+static constexpr dart::compiler::target::word AOT_Array_tags_offset = 0;
+static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_Class_declaration_type_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Class_num_type_arguments_offset = 164;
+static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    AOT_Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word AOT_Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word AOT_Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word AOT_Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word AOT_Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Code_saved_instructions_offset = 48;
+static constexpr dart::compiler::target::word AOT_Code_owner_offset = 56;
+static constexpr dart::compiler::target::word AOT_Context_num_variables_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_Context_parent_offset = 16;
+static constexpr dart::compiler::target::word AOT_Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word AOT_Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word AOT_Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word AOT_Field_guarded_cid_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_in_object_offset_offset = 76;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_offset = 48;
+static constexpr dart::compiler::target::word AOT_Field_is_nullable_offset = 74;
+static constexpr dart::compiler::target::word AOT_Field_kind_bits_offset = 78;
+static constexpr dart::compiler::target::word AOT_Function_code_offset = 72;
+static constexpr dart::compiler::target::word AOT_Function_data_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_Function_entry_point_offset[] = {8, 16};
+static constexpr dart::compiler::target::word AOT_Function_kind_tag_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Function_packed_fields_offset = 84;
+static constexpr dart::compiler::target::word
+    AOT_Function_parameter_names_offset = 40;
+static constexpr dart::compiler::target::word AOT_Function_signature_offset =
+    48;
+static constexpr dart::compiler::target::word
+    AOT_FutureOr_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_card_table_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word AOT_ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word AOT_ICData_owner_offset = 32;
+static constexpr dart::compiler::target::word AOT_ICData_state_bits_offset = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word AOT_Isolate_current_tag_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_Isolate_default_tag_offset =
+    48;
+static constexpr dart::compiler::target::word AOT_Isolate_ic_miss_code_offset =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word AOT_Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_data_offset =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_hash_mask_offset = 24;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_used_data_offset = 40;
+static constexpr dart::compiler::target::word AOT_LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_MarkingStackBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_buckets_offset = 24;
+static constexpr dart::compiler::target::word AOT_MegamorphicCache_mask_offset =
+    32;
+static constexpr dart::compiler::target::word AOT_Mint_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_argc_tag_offset = 8;
+static constexpr dart::compiler::target::word AOT_NativeArguments_argv_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_retval_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_double_type_offset = 256;
+static constexpr dart::compiler::target::word AOT_ObjectStore_int_type_offset =
+    136;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_string_type_offset = 312;
+static constexpr dart::compiler::target::word AOT_ObjectStore_type_type_offset =
+    96;
+static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Pointer_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_target_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word
+    AOT_StoreBufferBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_StoreBufferBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_String_hash_offset = 4;
+static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_exception_offset = 1392;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_stacktrace_offset = 1400;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
+    1472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
+    208;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
+    1488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
+    432;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_entry_offset = 608;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_stub_offset = 440;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_abs_address_offset = 680;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word AOT_Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word
+    AOT_Thread_execution_state_offset = 1432;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_not_address_offset = 688;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word
+    AOT_Thread_global_object_pool_offset = 1408;
+static constexpr dart::compiler::target::word
+    AOT_Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_through_ffi_offset = 1464;
+static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Thread_field_table_values_offset = 128;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    AOT_Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
+        264;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
+    192;
+static constexpr dart::compiler::target::word
+    AOT_Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
+    1416;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_shadow_call_stack_offset = 1424;
+static constexpr dart::compiler::target::word
+    AOT_Thread_safepoint_state_offset = 1440;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_stack_limit_offset = 112;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word
+    AOT_Thread_store_buffer_block_offset = 152;
+static constexpr dart::compiler::target::word
+    AOT_Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word AOT_Thread_top_offset = 96;
+static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_code_offset = 216;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_mask_offset = 72;
+static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
+    1448;
+static constexpr dart::compiler::target::word
+    AOT_Thread_callback_stack_return_offset = 1456;
+static constexpr dart::compiler::target::word
+    AOT_TimelineStream_enabled_offset = 16;
+static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word AOT_Type_hash_offset = 40;
+static constexpr dart::compiler::target::word AOT_Type_type_class_id_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word AOT_Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word AOT_FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word AOT_TypeParameter_index_offset =
+    60;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_nullability_offset = 63;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word AOT_TypeArguments_length_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_nullability_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypeArguments_types_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_bound_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_flags_offset =
+    62;
+static constexpr dart::compiler::target::word AOT_TypeParameter_name_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_length_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_TypedDataView_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    AOT_TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word AOT_UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_value_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Array_elements_start_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word AOT_TypeArguments_element_size =
+    8;
+static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, -1,   -1,   1336, 1344,
+        1352, 1360, 1368, -1,   1376, 1384, -1,   -1};
+static constexpr dart::compiler::target::word AOT_AbstractType_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
+static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 184;
+static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_CompressedStackMaps_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Context_header_size = 24;
+static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_FfiTrampolineData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
+static constexpr dart::compiler::target::word AOT_Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_FunctionType_InstanceSize =
+    72;
+static constexpr dart::compiler::target::word AOT_FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_UnalignedHeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_KernelProgramInfo_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 152;
+static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_LocalVarDescriptors_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_NativeArguments_StructSize =
+    32;
+static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_String_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
+    64;
+static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_X64) && defined(DART_COMPRESSED_POINTERS)
+
+#if defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
+static constexpr dart::compiler::target::word
+    AOT_ContextScope_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ContextScope_element_size =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_elements_start_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_element_size = 12;
+static constexpr dart::compiler::target::word
+    AOT_ObjectPool_elements_start_offset = 16;
+static constexpr dart::compiler::target::word AOT_ObjectPool_element_size = 8;
+static constexpr dart::compiler::target::word AOT_Array_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word AOT_Array_kMaxNewSpaceElements =
+    32765;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetJIT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetJIT = 48;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kMonomorphicEntryOffsetAOT = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kPolymorphicEntryOffsetAOT = 20;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kBarePayloadAlignment = 4;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_kNonBarePayloadAlignment = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_kBytesPerCardLog2 =
+    10;
+static constexpr dart::compiler::target::word
+    AOT_NativeEntry_kNumCallWrapperArguments = 2;
+static constexpr dart::compiler::target::word AOT_String_kMaxElements =
+    2305843009213693951;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kFunctionTypeArguments = 5;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceClassIdOrFunction = 1;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kDestinationType = 2;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceDelayedFunctionTypeArguments = 7;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceParentFunctionTypeArguments = 6;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstanceTypeArguments = 3;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kInstantiatorTypeArguments = 4;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_kTestEntryLength = 8;
+static constexpr dart::compiler::target::word AOT_SubtypeTestCache_kTestResult =
+    0;
+static constexpr dart::compiler::target::word AOT_TypeArguments_kMaxElements =
+    576460752303423487;
+static constexpr dart::compiler::target::word
+    AOT_AbstractType_type_test_stub_entry_point_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_count_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_size_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_first_named_entry_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_named_entry_size = 16;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_name_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_position_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_positional_count_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_ArgumentsDescriptor_type_args_len_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_data_offset = 24;
+static constexpr dart::compiler::target::word AOT_Array_length_offset = 16;
+static constexpr dart::compiler::target::word AOT_Array_tags_offset = 0;
+static constexpr dart::compiler::target::word AOT_Array_type_arguments_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_Class_declaration_type_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Class_num_type_arguments_offset = 164;
+static constexpr dart::compiler::target::word AOT_Class_super_type_offset = 88;
+static constexpr dart::compiler::target::word
+    AOT_Class_host_type_arguments_field_offset_in_words_offset = 176;
+static constexpr dart::compiler::target::word AOT_Closure_context_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Closure_delayed_type_arguments_offset = 24;
+static constexpr dart::compiler::target::word AOT_Closure_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Closure_function_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word AOT_Closure_hash_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_Closure_instantiator_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_ClosureData_default_type_arguments_info_offset = 40;
+static constexpr dart::compiler::target::word AOT_Code_object_pool_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_Code_saved_instructions_offset = 48;
+static constexpr dart::compiler::target::word AOT_Code_owner_offset = 56;
+static constexpr dart::compiler::target::word AOT_Context_num_variables_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_Context_parent_offset = 16;
+static constexpr dart::compiler::target::word AOT_Double_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_external_data_offset = 16;
+static constexpr dart::compiler::target::word AOT_Float32x4_value_offset = 8;
+static constexpr dart::compiler::target::word AOT_Float64x2_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Field_initializer_function_offset = 32;
+static constexpr dart::compiler::target::word
+    AOT_Field_host_offset_or_field_id_offset = 40;
+static constexpr dart::compiler::target::word AOT_Field_guarded_cid_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_in_object_offset_offset = 76;
+static constexpr dart::compiler::target::word
+    AOT_Field_guarded_list_length_offset = 48;
+static constexpr dart::compiler::target::word AOT_Field_is_nullable_offset = 74;
+static constexpr dart::compiler::target::word AOT_Field_kind_bits_offset = 78;
+static constexpr dart::compiler::target::word AOT_Function_code_offset = 72;
+static constexpr dart::compiler::target::word AOT_Function_data_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_Function_entry_point_offset[] = {8, 16};
+static constexpr dart::compiler::target::word AOT_Function_kind_tag_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Function_packed_fields_offset = 84;
+static constexpr dart::compiler::target::word
+    AOT_Function_parameter_names_offset = 40;
+static constexpr dart::compiler::target::word AOT_Function_signature_offset =
+    48;
+static constexpr dart::compiler::target::word
+    AOT_FutureOr_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_length_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word AOT_OldPage_card_table_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_CallSiteData_arguments_descriptor_offset = 16;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedMask = 3;
+static constexpr dart::compiler::target::word AOT_ICData_NumArgsTestedShift = 0;
+static constexpr dart::compiler::target::word AOT_ICData_entries_offset = 24;
+static constexpr dart::compiler::target::word AOT_ICData_owner_offset = 32;
+static constexpr dart::compiler::target::word AOT_ICData_state_bits_offset = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_shared_class_table_offset = 72;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_class_table_table_offset = 80;
+static constexpr dart::compiler::target::word AOT_Isolate_current_tag_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_Isolate_default_tag_offset =
+    48;
+static constexpr dart::compiler::target::word AOT_Isolate_ic_miss_code_offset =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_Isolate_cached_object_store_offset = 64;
+static constexpr dart::compiler::target::word AOT_Isolate_user_tag_offset = 32;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_data_offset =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_deleted_keys_offset = 48;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_hash_mask_offset = 24;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_index_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_type_arguments_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_LinkedHashMap_used_data_offset = 40;
+static constexpr dart::compiler::target::word AOT_LocalHandle_ptr_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_MarkingStackBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_MarkingStackBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_buckets_offset = 24;
+static constexpr dart::compiler::target::word AOT_MegamorphicCache_mask_offset =
+    32;
+static constexpr dart::compiler::target::word AOT_Mint_value_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_argc_tag_offset = 8;
+static constexpr dart::compiler::target::word AOT_NativeArguments_argv_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_retval_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_NativeArguments_thread_offset = 0;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_double_type_offset = 256;
+static constexpr dart::compiler::target::word AOT_ObjectStore_int_type_offset =
+    136;
+static constexpr dart::compiler::target::word
+    AOT_ObjectStore_string_type_offset = 312;
+static constexpr dart::compiler::target::word AOT_ObjectStore_type_type_offset =
+    96;
+static constexpr dart::compiler::target::word AOT_OneByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_PointerBase_data_field_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Pointer_type_arguments_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_entry_point_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_lower_limit_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_target_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_upper_limit_offset = 26;
+static constexpr dart::compiler::target::word
+    AOT_StoreBufferBlock_pointers_offset = 16;
+static constexpr dart::compiler::target::word AOT_StoreBufferBlock_top_offset =
+    8;
+static constexpr dart::compiler::target::word AOT_String_hash_offset = 4;
+static constexpr dart::compiler::target::word AOT_String_length_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_cache_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_Thread_AllocateArray_entry_point_offset = 720;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_exception_offset = 1464;
+static constexpr dart::compiler::target::word
+    AOT_Thread_active_stacktrace_offset = 1472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_code_offset = 224;
+static constexpr dart::compiler::target::word
+    AOT_Thread_array_write_barrier_entry_point_offset = 512;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_entry_point_offset = 528;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_with_fpu_regs_stub_offset = 344;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_entry_point_offset = 536;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_mint_without_fpu_regs_stub_offset = 352;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_entry_point_offset = 544;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_stub_offset = 360;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_entry_point_offset = 552;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_parameterized_stub_offset = 368;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_entry_point_offset = 560;
+static constexpr dart::compiler::target::word
+    AOT_Thread_allocate_object_slow_stub_offset = 376;
+static constexpr dart::compiler::target::word AOT_Thread_api_top_scope_offset =
+    1544;
+static constexpr dart::compiler::target::word
+    AOT_Thread_auto_scope_native_wrapper_entry_point_offset = 648;
+static constexpr dart::compiler::target::word AOT_Thread_bool_false_offset =
+    208;
+static constexpr dart::compiler::target::word AOT_Thread_bool_true_offset = 200;
+static constexpr dart::compiler::target::word
+    AOT_Thread_bootstrap_native_wrapper_entry_point_offset = 632;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_entry_point_offset = 520;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_to_runtime_stub_offset = 256;
+static constexpr dart::compiler::target::word AOT_Thread_dart_stream_offset =
+    1560;
+static constexpr dart::compiler::target::word
+    AOT_Thread_dispatch_table_array_offset = 88;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_entry_offset =
+    600;
+static constexpr dart::compiler::target::word AOT_Thread_optimize_stub_offset =
+    432;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_entry_offset = 608;
+static constexpr dart::compiler::target::word
+    AOT_Thread_deoptimize_stub_offset = 440;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_abs_address_offset = 680;
+static constexpr dart::compiler::target::word
+    AOT_Thread_double_negate_address_offset = 672;
+static constexpr dart::compiler::target::word AOT_Thread_end_offset = 104;
+static constexpr dart::compiler::target::word
+    AOT_Thread_enter_safepoint_stub_offset = 480;
+static constexpr dart::compiler::target::word
+    AOT_Thread_execution_state_offset = 1504;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_safepoint_stub_offset = 488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_stub_offset = 496;
+static constexpr dart::compiler::target::word
+    AOT_Thread_call_native_through_safepoint_entry_point_offset = 616;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_allocation_stub_code_offset = 240;
+static constexpr dart::compiler::target::word
+    AOT_Thread_fix_callers_target_code_offset = 232;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_absolute_address_offset = 704;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_negate_address_offset = 696;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_not_address_offset = 688;
+static constexpr dart::compiler::target::word
+    AOT_Thread_float_zerow_address_offset = 712;
+static constexpr dart::compiler::target::word
+    AOT_Thread_global_object_pool_offset = 1480;
+static constexpr dart::compiler::target::word
+    AOT_Thread_invoke_dart_code_stub_offset = 248;
+static constexpr dart::compiler::target::word
+    AOT_Thread_exit_through_ffi_offset = 1536;
+static constexpr dart::compiler::target::word AOT_Thread_isolate_offset = 80;
+static constexpr dart::compiler::target::word
+    AOT_Thread_field_table_values_offset = 128;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_return_stub_offset = 448;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_deopt_from_throw_stub_offset = 456;
+static constexpr dart::compiler::target::word
+    AOT_Thread_lazy_specialize_type_test_stub_offset = 472;
+static constexpr dart::compiler::target::word
+    AOT_Thread_marking_stack_block_offset = 160;
+static constexpr dart::compiler::target::word
+    AOT_Thread_megamorphic_call_checked_entry_offset = 584;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_entry_offset = 592;
+static constexpr dart::compiler::target::word
+    AOT_Thread_switchable_call_miss_stub_offset = 400;
+static constexpr dart::compiler::target::word
+    AOT_Thread_no_scope_native_wrapper_entry_point_offset = 640;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_with_fpu_regs_stub_offset = 272;
+static constexpr dart::compiler::target::word
+    AOT_Thread_late_initialization_error_shared_without_fpu_regs_stub_offset =
+        264;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_with_fpu_regs_stub_offset = 288;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_error_shared_without_fpu_regs_stub_offset = 280;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_with_fpu_regs_stub_offset = 304;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_arg_error_shared_without_fpu_regs_stub_offset = 296;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_with_fpu_regs_stub_offset = 320;
+static constexpr dart::compiler::target::word
+    AOT_Thread_null_cast_error_shared_without_fpu_regs_stub_offset = 312;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_with_fpu_regs_stub_offset = 336;
+static constexpr dart::compiler::target::word
+    AOT_Thread_range_error_shared_without_fpu_regs_stub_offset = 328;
+static constexpr dart::compiler::target::word AOT_Thread_object_null_offset =
+    192;
+static constexpr dart::compiler::target::word
+    AOT_Thread_predefined_symbols_address_offset = 656;
+static constexpr dart::compiler::target::word AOT_Thread_resume_pc_offset =
+    1488;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_shadow_call_stack_offset = 1496;
+static constexpr dart::compiler::target::word
+    AOT_Thread_safepoint_state_offset = 1512;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_stub_offset = 464;
+static constexpr dart::compiler::target::word
+    AOT_Thread_slow_type_test_entry_point_offset = 624;
+static constexpr dart::compiler::target::word AOT_Thread_stack_limit_offset =
+    64;
+static constexpr dart::compiler::target::word
+    AOT_Thread_saved_stack_limit_offset = 112;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_flags_offset = 120;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_entry_point_offset = 576;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_with_fpu_regs_stub_offset = 392;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_entry_point_offset = 568;
+static constexpr dart::compiler::target::word
+    AOT_Thread_stack_overflow_shared_without_fpu_regs_stub_offset = 384;
+static constexpr dart::compiler::target::word
+    AOT_Thread_store_buffer_block_offset = 152;
+static constexpr dart::compiler::target::word
+    AOT_Thread_top_exit_frame_info_offset = 144;
+static constexpr dart::compiler::target::word AOT_Thread_top_offset = 96;
+static constexpr dart::compiler::target::word AOT_Thread_top_resource_offset =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_Thread_unboxed_int64_runtime_arg_offset = 184;
+static constexpr dart::compiler::target::word AOT_Thread_vm_tag_offset = 176;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_code_offset = 216;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_entry_point_offset = 504;
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_mask_offset = 72;
+static constexpr dart::compiler::target::word AOT_Thread_callback_code_offset =
+    1520;
+static constexpr dart::compiler::target::word
+    AOT_Thread_callback_stack_return_offset = 1528;
+static constexpr dart::compiler::target::word
+    AOT_TimelineStream_enabled_offset = 16;
+static constexpr dart::compiler::target::word AOT_TwoByteString_data_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_arguments_offset = 32;
+static constexpr dart::compiler::target::word AOT_Type_hash_offset = 40;
+static constexpr dart::compiler::target::word AOT_Type_type_class_id_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Type_type_state_offset = 48;
+static constexpr dart::compiler::target::word AOT_Type_nullability_offset = 49;
+static constexpr dart::compiler::target::word AOT_FunctionType_hash_offset = 56;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_packed_fields_offset = 64;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_parameter_types_offset = 40;
+static constexpr dart::compiler::target::word
+    AOT_FunctionType_type_parameters_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_parameterized_class_id_offset = 56;
+static constexpr dart::compiler::target::word AOT_TypeParameter_index_offset =
+    60;
+static constexpr dart::compiler::target::word
+    AOT_TypeParameter_nullability_offset = 63;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_instantiations_offset = 8;
+static constexpr dart::compiler::target::word AOT_TypeArguments_length_offset =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_nullability_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypeArguments_types_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_bound_offset =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_flags_offset =
+    62;
+static constexpr dart::compiler::target::word AOT_TypeParameter_name_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_TypeRef_type_offset = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_length_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_TypedDataView_data_offset =
+    24;
+static constexpr dart::compiler::target::word
+    AOT_TypedDataView_offset_in_bytes_offset = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_data_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_exception_offset = 8;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_stacktrace_offset = 16;
+static constexpr dart::compiler::target::word AOT_UserTag_tag_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_expected_cid_offset = 16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_entrypoint_offset = 24;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_target_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_key_offset = 8;
+static constexpr dart::compiler::target::word AOT_WeakProperty_value_offset =
+    16;
+static constexpr dart::compiler::target::word AOT_Array_elements_start_offset =
+    24;
+static constexpr dart::compiler::target::word AOT_Array_element_size = 8;
+static constexpr dart::compiler::target::word
+    AOT_TypeArguments_elements_start_offset = 40;
+static constexpr dart::compiler::target::word AOT_TypeArguments_element_size =
+    8;
+static constexpr dart::compiler::target::word AOT_Code_entry_point_offset[] = {
+    8, 24, 16, 32};
+static constexpr dart::compiler::target::word
+    AOT_Thread_write_barrier_wrappers_thread_offset[] = {
+        1304, 1312, 1320, 1328, 1336, 1344, 1352, 1360, 1368, 1376, 1384,
+        1392, 1400, 1408, 1416, -1,   -1,   -1,   -1,   1424, 1432, -1,
+        -1,   1440, 1448, 1456, -1,   -1,   -1,   -1,   -1,   -1};
+static constexpr dart::compiler::target::word AOT_AbstractType_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_ApiError_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Array_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Array_header_size = 24;
+static constexpr dart::compiler::target::word AOT_Bool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Capability_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_Class_InstanceSize = 184;
+static constexpr dart::compiler::target::word AOT_Closure_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_ClosureData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Code_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_CodeSourceMap_HeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_CompressedStackMaps_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Context_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Context_header_size = 24;
+static constexpr dart::compiler::target::word AOT_ContextScope_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Double_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_DynamicLibrary_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_ExceptionHandlers_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_ExternalOneByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTwoByteString_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_ExternalTypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_FfiTrampolineData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Field_InstanceSize = 80;
+static constexpr dart::compiler::target::word AOT_Float32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Float64x2_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Function_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_FunctionType_InstanceSize =
+    72;
+static constexpr dart::compiler::target::word AOT_FutureOr_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_GrowableObjectArray_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_ICData_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Instance_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_Instructions_UnalignedHeaderSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_InstructionsSection_UnalignedHeaderSize = 40;
+static constexpr dart::compiler::target::word AOT_Int32x4_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_Integer_InstanceSize = 8;
+static constexpr dart::compiler::target::word
+    AOT_KernelProgramInfo_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_LanguageError_InstanceSize =
+    48;
+static constexpr dart::compiler::target::word AOT_Library_InstanceSize = 152;
+static constexpr dart::compiler::target::word AOT_LibraryPrefix_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_LinkedHashMap_InstanceSize =
+    56;
+static constexpr dart::compiler::target::word
+    AOT_LocalVarDescriptors_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_MegamorphicCache_InstanceSize = 48;
+static constexpr dart::compiler::target::word AOT_Mint_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_MirrorReference_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word
+    AOT_MonomorphicSmiableCall_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Namespace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_NativeArguments_StructSize =
+    32;
+static constexpr dart::compiler::target::word AOT_Number_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_Object_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_ObjectPool_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_OneByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_PatchClass_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_PcDescriptors_HeaderSize = 16;
+static constexpr dart::compiler::target::word AOT_Pointer_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_ReceivePort_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_RegExp_InstanceSize = 120;
+static constexpr dart::compiler::target::word AOT_Script_InstanceSize = 88;
+static constexpr dart::compiler::target::word AOT_SendPort_InstanceSize = 24;
+static constexpr dart::compiler::target::word
+    AOT_SingleTargetCache_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_Smi_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_StackTrace_InstanceSize = 40;
+static constexpr dart::compiler::target::word AOT_String_InstanceSize = 16;
+static constexpr dart::compiler::target::word
+    AOT_SubtypeTestCache_InstanceSize = 16;
+static constexpr dart::compiler::target::word AOT_LoadingUnit_InstanceSize = 32;
+static constexpr dart::compiler::target::word
+    AOT_TransferableTypedData_InstanceSize = 8;
+static constexpr dart::compiler::target::word AOT_TwoByteString_InstanceSize =
+    16;
+static constexpr dart::compiler::target::word AOT_Type_InstanceSize = 56;
+static constexpr dart::compiler::target::word AOT_TypeArguments_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word AOT_TypeParameter_InstanceSize =
+    64;
+static constexpr dart::compiler::target::word AOT_TypeRef_InstanceSize = 32;
+static constexpr dart::compiler::target::word AOT_TypedData_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_TypedDataBase_InstanceSize =
+    24;
+static constexpr dart::compiler::target::word AOT_TypedDataView_InstanceSize =
+    40;
+static constexpr dart::compiler::target::word
+    AOT_UnhandledException_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UnlinkedCall_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word AOT_UnwindError_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_UserTag_InstanceSize = 24;
+static constexpr dart::compiler::target::word AOT_WeakProperty_InstanceSize =
+    32;
+static constexpr dart::compiler::target::word
+    AOT_WeakSerializationReference_InstanceSize = 16;
+#endif  // defined(TARGET_ARCH_ARM64) && defined(DART_COMPRESSED_POINTERS)
 
 #endif  // !defined(PRODUCT)
 
diff --git a/sdk/lib/_internal/vm/lib/ffi_allocation_patch.dart b/sdk/lib/_internal/vm/lib/ffi_allocation_patch.dart
index 5b794e6..daa428e 100644
--- a/sdk/lib/_internal/vm/lib/ffi_allocation_patch.dart
+++ b/sdk/lib/_internal/vm/lib/ffi_allocation_patch.dart
@@ -9,8 +9,6 @@
 import 'dart:isolate';
 
 extension AllocatorAlloc on Allocator {
-  // TODO(http://dartbug.com/38721): Implement this in the CFE to remove the
-  // invocation of sizeOf<T> to enable tree shaking.
   // TODO(http://dartbug.com/39964): Add `alignmentOf<T>()` call.
   @patch
   Pointer<T> call<T extends NativeType>([int count = 1]) {
diff --git a/sdk/lib/_internal/vm/lib/ffi_patch.dart b/sdk/lib/_internal/vm/lib/ffi_patch.dart
index 8bc4c14..dd18559 100644
--- a/sdk/lib/_internal/vm/lib/ffi_patch.dart
+++ b/sdk/lib/_internal/vm/lib/ffi_patch.dart
@@ -204,6 +204,13 @@
 Pointer<S> _loadPointer<S extends NativeType>(
     Pointer pointer, int offsetInBytes) native "Ffi_loadPointer";
 
+S _loadStructNoStruct<S extends Struct>(Pointer<S> pointer, int index) {
+  if (S == Struct) {
+    throw ArgumentError("S should be a subtype of Struct.");
+  }
+  return _loadStruct(pointer, index);
+}
+
 S _loadStruct<S extends Struct>(Pointer<S> pointer, int index)
     native "Ffi_loadStruct";
 
@@ -511,10 +518,10 @@
 
 extension StructPointer<T extends Struct> on Pointer<T> {
   @patch
-  T get ref => _loadStruct(this, 0);
+  T get ref => _loadStructNoStruct(this, 0);
 
   @patch
-  T operator [](int index) => _loadStruct(this, index);
+  T operator [](int index) => _loadStructNoStruct(this, index);
 }
 
 extension NativePort on SendPort {
diff --git a/sdk/lib/ffi/ffi.dart b/sdk/lib/ffi/ffi.dart
index 22ea459..aef06c1 100644
--- a/sdk/lib/ffi/ffi.dart
+++ b/sdk/lib/ffi/ffi.dart
@@ -545,9 +545,7 @@
   /// The [address] must be aligned according to the struct alignment rules of
   /// the platform.
   ///
-  /// Support for invoking this extension method with non-constant [T] will be
-  /// removed in the next stable version of Dart and it will become mandatory
-  /// to invoke it with a compile-time constant [T].
+  /// This extension method must be invoked with a compile-time constant [T].
   external T get ref;
 
   /// Creates a reference to access the fields of this struct backed by native
@@ -556,9 +554,7 @@
   /// The [address] must be aligned according to the struct alignment rules of
   /// the platform.
   ///
-  /// Support for invoking this extension method with non-constant [T] will be
-  /// removed in the next stable version of Dart and it will become mandatory
-  /// to invoke it with a compile-time constant [T].
+  /// This extension method must be invoked with a compile-time constant [T].
   external T operator [](int index);
 }
 
diff --git a/tests/co19/co19-dart2js.status b/tests/co19/co19-dart2js.status
index 3208f10..9d54f24 100644
--- a/tests/co19/co19-dart2js.status
+++ b/tests/co19/co19-dart2js.status
@@ -17,27 +17,30 @@
 Language/Expressions/Shift/integer_t01: SkipByDesign # big integer cannot be represented in JavaScript
 Language/Expressions/Shift/integer_t02: SkipByDesign # big integer cannot be represented in JavaScript
 Language/Expressions/Spawning_an_Isolate/new_isolate_t01: SkipByDesign
+Language/Functions/External_Functions/not_connected_to_a_body_t01: SkipByDesign # Non-JS-interop external members are not supported
 Language/Libraries_and_Scripts/Scripts/main_optional_parameters_t01: SkipByDesign # https://github.com/dart-lang/co19/issues/952
 Language/Libraries_and_Scripts/Scripts/main_optional_parameters_t03: SkipByDesign # https://github.com/dart-lang/co19/issues/952
+Language/Libraries_and_Scripts/Scripts/top_level_syntax_t01: SkipByDesign # Non-JS-interop external members are not supported
+Language/Libraries_and_Scripts/top_level_syntax_t01: SkipByDesign # Non-JS-interop external members are not supported
 Language/Metadata/before*: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/523.
 Language/Reference/Operator_Precedence/precedence_15_unary_prefix_t08: SkipByDesign # binary '~' produces different results in JavaScript and Dart
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t01: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t02: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t03: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A02_t01: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A02_t04: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t01: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t02: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t03: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t04: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t06: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A04_t01: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A04_t02: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t01: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t02: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t03: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/syntax_A01_t03: SkipByDesign # External variables are not supported by dart2js
-LanguageFeatures/Abstract-external-fields/syntax_A02_t03: SkipByDesign # External variables are not supported by dart2js
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t01: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t02: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t03: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A02_t01: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A02_t04: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t01: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t02: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t03: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t04: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t06: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A04_t01: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A04_t02: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t01: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t02: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t03: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/syntax_A01_t03: SkipByDesign # Non-JS-interop external members are not supported
+LanguageFeatures/Abstract-external-fields/syntax_A02_t03: SkipByDesign # Non-JS-interop external members are not supported
 LibTest/core/DateTime/DateTime.fromMicrosecondsSinceEpoch_A01_t01: SkipByDesign # microseconds are not supported in JavaScript
 LibTest/core/DateTime/microsecond_A01_t01: SkipByDesign # microseconds are not supported in JavaScript
 LibTest/core/DateTime/microsecondsSinceEpoch_A01_t01: SkipByDesign # microseconds are not supported in JavaScript
diff --git a/tests/co19/co19-dartdevc.status b/tests/co19/co19-dartdevc.status
index 776d905..e0a2172 100644
--- a/tests/co19/co19-dartdevc.status
+++ b/tests/co19/co19-dartdevc.status
@@ -68,10 +68,30 @@
 Language/Expressions/Shift/integer_t01: SkipByDesign # big integer cannot be represented in JavaScript
 Language/Expressions/Shift/integer_t02: SkipByDesign # big integer cannot be represented in JavaScript
 Language/Expressions/Spawning_an_Isolate/new_isolate_t01: SkipByDesign # dart:isolate not supported.
+Language/Functions/External_Functions/not_connected_to_a_body_t01: SkipByDesign # External variables are not supported
+Language/Libraries_and_Scripts/Scripts/top_level_syntax_t01: SkipByDesign # External variables are not supported
+Language/Libraries_and_Scripts/top_level_syntax_t01: SkipByDesign # External variables are not supported
 Language/Metadata/before*: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/523.
 Language/Reference/Operator_Precedence/precedence_15_unary_prefix_t08: SkipByDesign # binary '~' produces different results in JavaScript and Dart
 Language/Types/Interface_Types/subtype_t27: Skip # Times out
 Language/Types/Interface_Types/subtype_t28: Skip # Times out
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t01: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t02: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A01_t03: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A02_t01: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A02_t04: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t01: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t02: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t03: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t04: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A03_t06: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A04_t01: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A04_t02: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t01: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t02: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/static_analysis_external_A05_t03: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/syntax_A01_t03: SkipByDesign # External variables are not supported
+LanguageFeatures/Abstract-external-fields/syntax_A02_t03: SkipByDesign # External variables are not supported
 LibTest/core/DateTime/DateTime.fromMicrosecondsSinceEpoch_A01_t01: SkipByDesign # microseconds are not supported in JavaScript
 LibTest/core/DateTime/microsecond_A01_t01: SkipByDesign # microseconds are not supported in JavaScript
 LibTest/core/DateTime/microsecondsSinceEpoch_A01_t01: SkipByDesign # microseconds are not supported in JavaScript
diff --git a/tests/co19_2/co19_2-dart2js.status b/tests/co19_2/co19_2-dart2js.status
index dddded9..0d620e8 100644
--- a/tests/co19_2/co19_2-dart2js.status
+++ b/tests/co19_2/co19_2-dart2js.status
@@ -5,6 +5,9 @@
 [ $compiler == dart2js ]
 Language/Expressions/Null/instance_of_class_null_t01: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/522.
 Language/Expressions/Spawning_an_Isolate/new_isolate_t01: SkipByDesign
+Language/Functions/External_Functions/not_connected_to_a_body_t01: SkipByDesign # Non-JS-interop external members are not supported
+Language/Libraries_and_Scripts/Scripts/top_level_syntax_t01: SkipByDesign # Non-JS-interop external members are not supported
+Language/Libraries_and_Scripts/top_level_syntax_t01: SkipByDesign # Non-JS-interop external members are not supported
 Language/Metadata/before*: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/523.
 LibTest/io/*: SkipByDesign # dart:io not supported.
 LibTest/isolate/*: SkipByDesign # dart:isolate not supported.
diff --git a/tests/co19_2/co19_2-dartdevc.status b/tests/co19_2/co19_2-dartdevc.status
index 087f30b..7497344 100644
--- a/tests/co19_2/co19_2-dartdevc.status
+++ b/tests/co19_2/co19_2-dartdevc.status
@@ -56,6 +56,9 @@
 Language/Expressions/Function_Invocation/async_generator_invokation_t10: Skip # Times out
 Language/Expressions/Null/instance_of_class_null_t01: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/522.
 Language/Expressions/Spawning_an_Isolate/new_isolate_t01: SkipByDesign # dart:isolate not supported.
+Language/Functions/External_Functions/not_connected_to_a_body_t01: SkipByDesign # External variables are not supported
+Language/Libraries_and_Scripts/Scripts/top_level_syntax_t01: SkipByDesign # External variables are not supported
+Language/Libraries_and_Scripts/top_level_syntax_t01: SkipByDesign # External variables are not supported
 Language/Metadata/before*: Skip # dart:mirrors not supported https://github.com/dart-lang/co19/issues/523.
 Language/Types/Interface_Types/subtype_t27: Skip # Times out
 Language/Types/Interface_Types/subtype_t28: Skip # Times out
diff --git a/tests/dart2js/jsinterop_test.dart b/tests/dart2js/jsinterop_test.dart
index 34784e4..994f1f1 100644
--- a/tests/dart2js/jsinterop_test.dart
+++ b/tests/dart2js/jsinterop_test.dart
@@ -52,10 +52,10 @@
   Class.generative();
   factory Class.fact() => null as dynamic;
 
-  // NON_NATIVE_EXTERNAL               //# 08: compile-time error
+  // GENERIC  //# 08: compile-time error
   external Class.externalGenerative(); //# 08: continued
 
-  // NON_NATIVE_EXTERNAL                 //# 09: compile-time error
+  // GENERIC  //# 09: compile-time error
   external factory Class.externalFact(); //# 09: continued
 
   @JS('a') // GENERIC  //# 10: compile-time error
@@ -104,22 +104,22 @@
   @JS('a') // GENERIC  //# 21: compile-time error
   static staticJsInteropMethod() {} //# 21: continued
 
-  // NON_NATIVE_EXTERNAL               //# 22: compile-time error
+  // GENERIC  //# 22: compile-time error
   external get externalInstanceGetter; //# 22: continued
 
-  // NON_NATIVE_EXTERNAL                  //# 23: compile-time error
+  // GENERIC  //# 23: compile-time error
   external set externalInstanceSetter(_); //# 23: continued
 
-  // NON_NATIVE_EXTERNAL             //# 24: compile-time error
+  // GENERIC  //# 24: compile-time error
   external externalInstanceMethod(); //# 24: continued
 
-  // NON_NATIVE_EXTERNAL             //# 25: compile-time error
+  // GENERIC  //# 25: compile-time error
   external static get externalStaticGetter; //# 25: continued
 
-  // NON_NATIVE_EXTERNAL                //# 26: compile-time error
+  // GENERIC  //# 26: compile-time error
   external static set externalStaticSetter(_); //# 26: continued
 
-  // NON_NATIVE_EXTERNAL           //# 27: compile-time error
+  // GENERIC  //# 27: compile-time error
   external static externalStaticMethod(); //# 27: continued
 
   @JS('a') // GENERIC  //# 28: compile-time error
diff --git a/tests/dart2js/non_jsinterop_test.dart b/tests/dart2js/non_jsinterop_test.dart
index 91af080..550ea27 100644
--- a/tests/dart2js/non_jsinterop_test.dart
+++ b/tests/dart2js/non_jsinterop_test.dart
@@ -32,13 +32,13 @@
 @JS('a') // JS_INTEROP_NON_EXTERNAL_MEMBER  //# 04: compile-time error
 topLevelJsInteropFunction() {} //# 04: continued
 
-// NON_NATIVE_EXTERNAL               //# 05: compile-time error
+// GENERIC  //# 05: compile-time error
 external get externalTopLevelGetter; //# 05: continued
 
-// NON_NATIVE_EXTERNAL                  //# 06: compile-time error
+// GENERIC  //# 06: compile-time error
 external set externalTopLevelSetter(_); //# 06: continued
 
-// NON_NATIVE_EXTERNAL               //# 07: compile-time error
+// GENERIC  //# 07: compile-time error
 external externalTopLevelFunction(); //# 07: continued
 
 @JS('a')
@@ -54,10 +54,10 @@
   Class.generative();
   factory Class.fact() => null as dynamic;
 
-  // NON_NATIVE_EXTERNAL               //# 08: compile-time error
+  // GENERIC  //# 08: compile-time error
   external Class.externalGenerative(); //# 08: continued
 
-  // NON_NATIVE_EXTERNAL                 //# 09: compile-time error
+  // GENERIC  //# 09: compile-time error
   external factory Class.externalFact(); //# 09: continued
 
   @JS('a') // GENERIC  //# 11: compile-time error
@@ -103,22 +103,22 @@
   @JS('a') // GENERIC  //# 21: compile-time error
   static staticJsInteropMethod() {} //# 21: continued
 
-  // NON_NATIVE_EXTERNAL               //# 22: compile-time error
+  // GENERIC  //# 22: compile-time error
   external get externalInstanceGetter; //# 22: continued
 
-  // NON_NATIVE_EXTERNAL                  //# 23: compile-time error
+  // GENERIC  //# 23: compile-time error
   external set externalInstanceSetter(_); //# 23: continued
 
-  // NON_NATIVE_EXTERNAL             //# 24: compile-time error
+  // GENERIC  //# 24: compile-time error
   external externalInstanceMethod(); //# 24: continued
 
-  // NON_NATIVE_EXTERNAL             //# 25: compile-time error
+  // GENERIC  //# 25: compile-time error
   external static get externalStaticGetter; //# 25: continued
 
-  // NON_NATIVE_EXTERNAL                //# 26: compile-time error
+  // GENERIC  //# 26: compile-time error
   external static set externalStaticSetter(_); //# 26: continued
 
-  // NON_NATIVE_EXTERNAL           //# 27: compile-time error
+  // GENERIC  //# 27: compile-time error
   external static externalStaticMethod(); //# 27: continued
 
   @JS('a') // GENERIC  //# 28: compile-time error
diff --git a/tests/dart2js_2/jsinterop_test.dart b/tests/dart2js_2/jsinterop_test.dart
index ea9d508..5ee057c 100644
--- a/tests/dart2js_2/jsinterop_test.dart
+++ b/tests/dart2js_2/jsinterop_test.dart
@@ -54,10 +54,10 @@
   Class.generative();
   factory Class.fact() => null as dynamic;
 
-  // NON_NATIVE_EXTERNAL               //# 08: compile-time error
+  // GENERIC  //# 08: compile-time error
   external Class.externalGenerative(); //# 08: continued
 
-  // NON_NATIVE_EXTERNAL                 //# 09: compile-time error
+  // GENERIC  //# 09: compile-time error
   external factory Class.externalFact(); //# 09: continued
 
   @JS('a') // GENERIC  //# 10: compile-time error
@@ -106,22 +106,22 @@
   @JS('a') // GENERIC  //# 21: compile-time error
   static staticJsInteropMethod() {} //# 21: continued
 
-  // NON_NATIVE_EXTERNAL               //# 22: compile-time error
+  // GENERIC  //# 22: compile-time error
   external get externalInstanceGetter; //# 22: continued
 
-  // NON_NATIVE_EXTERNAL                  //# 23: compile-time error
+  // GENERIC  //# 23: compile-time error
   external set externalInstanceSetter(_); //# 23: continued
 
-  // NON_NATIVE_EXTERNAL             //# 24: compile-time error
+  // GENERIC  //# 24: compile-time error
   external externalInstanceMethod(); //# 24: continued
 
-  // NON_NATIVE_EXTERNAL             //# 25: compile-time error
+  // GENERIC  //# 25: compile-time error
   external static get externalStaticGetter; //# 25: continued
 
-  // NON_NATIVE_EXTERNAL                //# 26: compile-time error
+  // GENERIC  //# 26: compile-time error
   external static set externalStaticSetter(_); //# 26: continued
 
-  // NON_NATIVE_EXTERNAL           //# 27: compile-time error
+  // GENERIC  //# 27: compile-time error
   external static externalStaticMethod(); //# 27: continued
 
   @JS('a') // GENERIC  //# 28: compile-time error
diff --git a/tests/dart2js_2/non_jsinterop_test.dart b/tests/dart2js_2/non_jsinterop_test.dart
index 7b533ac..5406438 100644
--- a/tests/dart2js_2/non_jsinterop_test.dart
+++ b/tests/dart2js_2/non_jsinterop_test.dart
@@ -34,13 +34,13 @@
 @JS('a') // JS_INTEROP_NON_EXTERNAL_MEMBER  //# 04: compile-time error
 topLevelJsInteropFunction() {} //# 04: continued
 
-// NON_NATIVE_EXTERNAL               //# 05: compile-time error
+// GENERIC  //# 05: compile-time error
 external get externalTopLevelGetter; //# 05: continued
 
-// NON_NATIVE_EXTERNAL                  //# 06: compile-time error
+// GENERIC  //# 06: compile-time error
 external set externalTopLevelSetter(_); //# 06: continued
 
-// NON_NATIVE_EXTERNAL               //# 07: compile-time error
+// GENERIC  //# 07: compile-time error
 external externalTopLevelFunction(); //# 07: continued
 
 @JS('a')
@@ -56,10 +56,10 @@
   Class.generative();
   factory Class.fact() => null as dynamic;
 
-  // NON_NATIVE_EXTERNAL               //# 08: compile-time error
+  // GENERIC  //# 08: compile-time error
   external Class.externalGenerative(); //# 08: continued
 
-  // NON_NATIVE_EXTERNAL                 //# 09: compile-time error
+  // GENERIC  //# 09: compile-time error
   external factory Class.externalFact(); //# 09: continued
 
   @JS('a') // GENERIC  //# 11: compile-time error
@@ -105,22 +105,22 @@
   @JS('a') // GENERIC  //# 21: compile-time error
   static staticJsInteropMethod() {} //# 21: continued
 
-  // NON_NATIVE_EXTERNAL               //# 22: compile-time error
+  // GENERIC  //# 22: compile-time error
   external get externalInstanceGetter; //# 22: continued
 
-  // NON_NATIVE_EXTERNAL                  //# 23: compile-time error
+  // GENERIC  //# 23: compile-time error
   external set externalInstanceSetter(_); //# 23: continued
 
-  // NON_NATIVE_EXTERNAL             //# 24: compile-time error
+  // GENERIC  //# 24: compile-time error
   external externalInstanceMethod(); //# 24: continued
 
-  // NON_NATIVE_EXTERNAL             //# 25: compile-time error
+  // GENERIC  //# 25: compile-time error
   external static get externalStaticGetter; //# 25: continued
 
-  // NON_NATIVE_EXTERNAL                //# 26: compile-time error
+  // GENERIC  //# 26: compile-time error
   external static set externalStaticSetter(_); //# 26: continued
 
-  // NON_NATIVE_EXTERNAL           //# 27: compile-time error
+  // GENERIC  //# 27: compile-time error
   external static externalStaticMethod(); //# 27: continued
 
   @JS('a') // GENERIC  //# 28: compile-time error
diff --git a/tests/ffi/sizeof_test.dart b/tests/ffi/sizeof_test.dart
index fd02efc..35cb36c 100644
--- a/tests/ffi/sizeof_test.dart
+++ b/tests/ffi/sizeof_test.dart
@@ -8,6 +8,20 @@
 
 import "package:expect/expect.dart";
 
+import "coordinate.dart";
+
+get is32Bit => 4 == sizeOf<IntPtr>();
+get is64Bit => 8 == sizeOf<IntPtr>();
+
 void main() async {
-  Expect.equals(true, 4 == sizeOf<Pointer>() || 8 == sizeOf<Pointer>());
+  if (is32Bit) {
+    Expect.equals(4, sizeOf<Pointer>());
+    // Struct is 20 bytes on ia32 and arm32-iOS, but 24 bytes on arm32-Android
+    // and arm32-Linux due to alignment.
+    Expect.isTrue(20 == sizeOf<Coordinate>() || 24 == sizeOf<Coordinate>());
+  } else if (is64Bit) {
+    Expect.equals(8, sizeOf<Pointer>());
+    Expect.equals(24, sizeOf<Coordinate>());
+  }
+  Expect.throws(() => sizeOf<Void>());
 }
diff --git a/tests/ffi/structs_test.dart b/tests/ffi/structs_test.dart
index e339437..68ee219 100644
--- a/tests/ffi/structs_test.dart
+++ b/tests/ffi/structs_test.dart
@@ -18,6 +18,7 @@
   for (int i = 0; i < 100; i++) {
     testStructAllocate();
     testStructFromAddress();
+    testStructIndexedAccess();
     testStructWithNulls();
     testTypeTest();
     testUtf8();
@@ -25,7 +26,7 @@
   }
 }
 
-/// allocates each coordinate separately in c memory
+/// Allocates each coordinate separately in c memory.
 void testStructAllocate() {
   final c1 = calloc<Coordinate>()
     ..ref.x = 10.0
@@ -54,7 +55,7 @@
   calloc.free(c3);
 }
 
-/// allocates coordinates consecutively in c memory
+/// Allocates coordinates consecutively in c memory.
 void testStructFromAddress() {
   Pointer<Coordinate> c1 = calloc(3);
   Pointer<Coordinate> c2 = c1.elementAt(1);
@@ -84,6 +85,34 @@
   calloc.free(c1);
 }
 
+/// Allocates coordinates consecutively in c memory.
+void testStructIndexedAccess() {
+  Pointer<Coordinate> cs = calloc(3);
+  cs[0]
+    ..x = 10.0
+    ..y = 10.0
+    ..next = cs.elementAt(2);
+  cs[1]
+    ..x = 20.0
+    ..y = 20.0
+    ..next = cs;
+  cs[2]
+    ..x = 30.0
+    ..y = 30.0
+    ..next = cs.elementAt(1);
+
+  Coordinate currentCoordinate = cs.ref;
+  Expect.equals(10.0, currentCoordinate.x);
+  currentCoordinate = currentCoordinate.next.ref;
+  Expect.equals(30.0, currentCoordinate.x);
+  currentCoordinate = currentCoordinate.next.ref;
+  Expect.equals(20.0, currentCoordinate.x);
+  currentCoordinate = currentCoordinate.next.ref;
+  Expect.equals(10.0, currentCoordinate.x);
+
+  calloc.free(cs);
+}
+
 void testStructWithNulls() {
   final coordinate = calloc<Coordinate>()
     ..ref.x = 10.0
diff --git a/tests/ffi/vmspecific_static_checks_test.dart b/tests/ffi/vmspecific_static_checks_test.dart
index 94a11e1..c2150f8 100644
--- a/tests/ffi/vmspecific_static_checks_test.dart
+++ b/tests/ffi/vmspecific_static_checks_test.dart
@@ -610,18 +610,18 @@
 void testRefStruct() {
   final myStructPointer = calloc<TestStruct13>();
   Pointer<Struct> structPointer = myStructPointer;
-  structPointer.ref; //# 1330: ok
+  structPointer.ref; //# 1330: compile-time error
   calloc.free(myStructPointer);
 }
 
-T genericRef<T extends Struct>(Pointer<T> p) => //# 1200: ok
-    p.ref; //# 1200: ok
+T genericRef<T extends Struct>(Pointer<T> p) => //# 1200: compile-time error
+    p.ref; //# 1200: compile-time error
 
-T genericRef2<T extends Struct>(Pointer<T> p) => //# 1201: ok
-    p.cast<T>().ref; //# 1201: ok
+T genericRef2<T extends Struct>(Pointer<T> p) => //# 1201: compile-time error
+    p.cast<T>().ref; //# 1201: compile-time error
 
-T genericRef3<T extends Struct>(Pointer<T> p) => //# 1202: ok
-    p[0]; //# 1202: ok
+T genericRef3<T extends Struct>(Pointer<T> p) => //# 1202: compile-time error
+    p[0]; //# 1202: compile-time error
 
 void testSizeOfGeneric() {
   int generic<T extends Pointer>() {
diff --git a/tests/ffi_2/sizeof_test.dart b/tests/ffi_2/sizeof_test.dart
index fd02efc..35cb36c 100644
--- a/tests/ffi_2/sizeof_test.dart
+++ b/tests/ffi_2/sizeof_test.dart
@@ -8,6 +8,20 @@
 
 import "package:expect/expect.dart";
 
+import "coordinate.dart";
+
+get is32Bit => 4 == sizeOf<IntPtr>();
+get is64Bit => 8 == sizeOf<IntPtr>();
+
 void main() async {
-  Expect.equals(true, 4 == sizeOf<Pointer>() || 8 == sizeOf<Pointer>());
+  if (is32Bit) {
+    Expect.equals(4, sizeOf<Pointer>());
+    // Struct is 20 bytes on ia32 and arm32-iOS, but 24 bytes on arm32-Android
+    // and arm32-Linux due to alignment.
+    Expect.isTrue(20 == sizeOf<Coordinate>() || 24 == sizeOf<Coordinate>());
+  } else if (is64Bit) {
+    Expect.equals(8, sizeOf<Pointer>());
+    Expect.equals(24, sizeOf<Coordinate>());
+  }
+  Expect.throws(() => sizeOf<Void>());
 }
diff --git a/tests/ffi_2/structs_test.dart b/tests/ffi_2/structs_test.dart
index e339437..68ee219 100644
--- a/tests/ffi_2/structs_test.dart
+++ b/tests/ffi_2/structs_test.dart
@@ -18,6 +18,7 @@
   for (int i = 0; i < 100; i++) {
     testStructAllocate();
     testStructFromAddress();
+    testStructIndexedAccess();
     testStructWithNulls();
     testTypeTest();
     testUtf8();
@@ -25,7 +26,7 @@
   }
 }
 
-/// allocates each coordinate separately in c memory
+/// Allocates each coordinate separately in c memory.
 void testStructAllocate() {
   final c1 = calloc<Coordinate>()
     ..ref.x = 10.0
@@ -54,7 +55,7 @@
   calloc.free(c3);
 }
 
-/// allocates coordinates consecutively in c memory
+/// Allocates coordinates consecutively in c memory.
 void testStructFromAddress() {
   Pointer<Coordinate> c1 = calloc(3);
   Pointer<Coordinate> c2 = c1.elementAt(1);
@@ -84,6 +85,34 @@
   calloc.free(c1);
 }
 
+/// Allocates coordinates consecutively in c memory.
+void testStructIndexedAccess() {
+  Pointer<Coordinate> cs = calloc(3);
+  cs[0]
+    ..x = 10.0
+    ..y = 10.0
+    ..next = cs.elementAt(2);
+  cs[1]
+    ..x = 20.0
+    ..y = 20.0
+    ..next = cs;
+  cs[2]
+    ..x = 30.0
+    ..y = 30.0
+    ..next = cs.elementAt(1);
+
+  Coordinate currentCoordinate = cs.ref;
+  Expect.equals(10.0, currentCoordinate.x);
+  currentCoordinate = currentCoordinate.next.ref;
+  Expect.equals(30.0, currentCoordinate.x);
+  currentCoordinate = currentCoordinate.next.ref;
+  Expect.equals(20.0, currentCoordinate.x);
+  currentCoordinate = currentCoordinate.next.ref;
+  Expect.equals(10.0, currentCoordinate.x);
+
+  calloc.free(cs);
+}
+
 void testStructWithNulls() {
   final coordinate = calloc<Coordinate>()
     ..ref.x = 10.0
diff --git a/tests/ffi_2/vmspecific_static_checks_test.dart b/tests/ffi_2/vmspecific_static_checks_test.dart
index 369a8de..88e5b2c 100644
--- a/tests/ffi_2/vmspecific_static_checks_test.dart
+++ b/tests/ffi_2/vmspecific_static_checks_test.dart
@@ -608,18 +608,18 @@
 void testRefStruct() {
   final myStructPointer = calloc<TestStruct13>();
   Pointer<Struct> structPointer = myStructPointer;
-  structPointer.ref; //# 1330: ok
+  structPointer.ref; //# 1330: compile-time error
   calloc.free(myStructPointer);
 }
 
-T genericRef<T extends Struct>(Pointer<T> p) => //# 1200: ok
-    p.ref; //# 1200: ok
+T genericRef<T extends Struct>(Pointer<T> p) => //# 1200: compile-time error
+    p.ref; //# 1200: compile-time error
 
-T genericRef2<T extends Struct>(Pointer<T> p) => //# 1201: ok
-    p.cast<T>().ref; //# 1201: ok
+T genericRef2<T extends Struct>(Pointer<T> p) => //# 1201: compile-time error
+    p.cast<T>().ref; //# 1201: compile-time error
 
-T genericRef3<T extends Struct>(Pointer<T> p) => //# 1202: ok
-    p[0]; //# 1202: ok
+T genericRef3<T extends Struct>(Pointer<T> p) => //# 1202: compile-time error
+    p[0]; //# 1202: compile-time error
 
 void testSizeOfGeneric() {
   int generic<T extends Pointer>() {
diff --git a/tests/language/language_dart2js.status b/tests/language/language_dart2js.status
index e0b4991..dbac77c 100644
--- a/tests/language/language_dart2js.status
+++ b/tests/language/language_dart2js.status
@@ -4,6 +4,7 @@
 # Sections in this file should contain "$compiler == dart2js".
 
 [ $compiler == dart2js ]
+external_abstract_fields/external_fields_test: SkipByDesign # Non-JS-interop external members are not supported
 mixin_method_override_test/G5: Skip # Issue 34354
 number/int64_literal_runtime*_test: Skip # This is testing Dart 2.0 int64 semantics
 vm/*: SkipByDesign # Tests for the VM.
diff --git a/tests/language/language_dartdevc.status b/tests/language/language_dartdevc.status
index d92526e..0c012d1 100644
--- a/tests/language/language_dartdevc.status
+++ b/tests/language/language_dartdevc.status
@@ -18,6 +18,7 @@
 
 [ $compiler == dartdevc || $compiler == dartdevk ]
 async_star/throw_in_catch_test: Skip # Times out. Issue 29920
+external_abstract_fields/external_fields_test: SkipByDesign # Non-JS-interop external members are not supported
 number/int64_literal_runtime*_test: Skip # This is testing Dart 2.0 int64 semantics.
 superinterface_variance/*: Skip # Issue dart-lang/language#113
 vm/*: SkipByDesign # VM only tests.; VM only tests.
diff --git a/tests/language_2/language_2_dart2js.status b/tests/language_2/language_2_dart2js.status
index e0b4991..dbac77c 100644
--- a/tests/language_2/language_2_dart2js.status
+++ b/tests/language_2/language_2_dart2js.status
@@ -4,6 +4,7 @@
 # Sections in this file should contain "$compiler == dart2js".
 
 [ $compiler == dart2js ]
+external_abstract_fields/external_fields_test: SkipByDesign # Non-JS-interop external members are not supported
 mixin_method_override_test/G5: Skip # Issue 34354
 number/int64_literal_runtime*_test: Skip # This is testing Dart 2.0 int64 semantics
 vm/*: SkipByDesign # Tests for the VM.
diff --git a/tests/language_2/language_2_dartdevc.status b/tests/language_2/language_2_dartdevc.status
index d92526e..0c012d1 100644
--- a/tests/language_2/language_2_dartdevc.status
+++ b/tests/language_2/language_2_dartdevc.status
@@ -18,6 +18,7 @@
 
 [ $compiler == dartdevc || $compiler == dartdevk ]
 async_star/throw_in_catch_test: Skip # Times out. Issue 29920
+external_abstract_fields/external_fields_test: SkipByDesign # Non-JS-interop external members are not supported
 number/int64_literal_runtime*_test: Skip # This is testing Dart 2.0 int64 semantics.
 superinterface_variance/*: Skip # Issue dart-lang/language#113
 vm/*: SkipByDesign # VM only tests.; VM only tests.
diff --git a/tests/lib/js/external_nonjs_static_test.dart b/tests/lib/js/external_nonjs_static_test.dart
new file mode 100644
index 0000000..47b6252
--- /dev/null
+++ b/tests/lib/js/external_nonjs_static_test.dart
@@ -0,0 +1,101 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Checks for static errors using external without the @JS() annotation,
+// in a library without a @JS() annotation
+
+library external_nonjs_static_test;
+
+import 'package:js/js.dart';
+
+external var topLevelField;
+//           ^
+// [web] Only JS interop members may be 'external'.
+
+external final topLevelFinalField;
+//             ^
+// [web] Only JS interop members may be 'external'.
+
+external get topLevelGetter;
+//           ^
+// [web] Only JS interop members may be 'external'.
+
+external set topLevelSetter(_);
+//           ^
+// [web] Only JS interop members may be 'external'.
+
+external topLevelFunction();
+//       ^
+// [web] Only JS interop members may be 'external'.
+
+class Constructors {
+  external Constructors();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external Constructors.namedConstructor();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external factory Constructors.namedFactory();
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class Members {
+  external var field;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external final finalField;
+  //             ^
+  // [web] Only JS interop members may be 'external'.
+
+  external get instanceGetter;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external set instanceSetter(_);
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external instanceMethod();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class StaticMembers {
+  external static var staticField;
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static final staticFinalField;
+  //                    ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static get staticGetter;
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static set staticSetter(_);
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static staticMethod();
+  //              ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+@anonymous
+class AnonymousClass {
+  external var field;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external factory AnonymousClass({var field});
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+main() {}
diff --git a/tests/lib/js/external_static_test.dart b/tests/lib/js/external_static_test.dart
new file mode 100644
index 0000000..8fac26db
--- /dev/null
+++ b/tests/lib/js/external_static_test.dart
@@ -0,0 +1,89 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Checks for static errors using external without the @JS() annotation,
+// in a library with a @JS() annotation
+
+@JS()
+library external_static_test;
+
+import 'package:js/js.dart';
+
+// external top level members ok in @JS() library.
+external var topLevelField;
+external final topLevelFinalField;
+external get topLevelGetter;
+external set topLevelSetter(_);
+external topLevelFunction();
+
+class Constructors {
+  external Constructors();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external Constructors.namedConstructor();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external factory Constructors.namedFactory();
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class Members {
+  external var field;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external final finalField;
+  //             ^
+  // [web] Only JS interop members may be 'external'.
+
+  external get instanceGetter;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external set instanceSetter(_);
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external instanceMethod();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class StaticMembers {
+  external static var staticField;
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static final staticFinalField;
+  //                    ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static get staticGetter;
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static set staticSetter(_);
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static staticMethod();
+  //              ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+@anonymous
+class AnonymousClass {
+  external var field;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external factory AnonymousClass({var field});
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+main() {}
diff --git a/tests/lib_2/js/external_nonjs_static_test.dart b/tests/lib_2/js/external_nonjs_static_test.dart
new file mode 100644
index 0000000..3359f0b
--- /dev/null
+++ b/tests/lib_2/js/external_nonjs_static_test.dart
@@ -0,0 +1,73 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Checks for static errors using external without the @JS() annotation,
+// in a library without a @JS() annotation
+
+library external_nonjs_static_test;
+
+import 'package:js/js.dart';
+
+external get topLevelGetter;
+//           ^
+// [web] Only JS interop members may be 'external'.
+
+external set topLevelSetter(_);
+//           ^
+// [web] Only JS interop members may be 'external'.
+
+external topLevelFunction();
+//       ^
+// [web] Only JS interop members may be 'external'.
+
+class Constructors {
+  external Constructors();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external Constructors.namedConstructor();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external factory Constructors.namedFactory();
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class Members {
+  external get instanceGetter;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external set instanceSetter(_);
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external instanceMethod();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class StaticMembers {
+  external static get staticGetter;
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static set staticSetter(_);
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static staticMethod();
+  //              ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+@anonymous
+class AnonymousClass {
+  external factory AnonymousClass();
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+main() {}
diff --git a/tests/lib_2/js/external_static_test.dart b/tests/lib_2/js/external_static_test.dart
new file mode 100644
index 0000000..9326b9e
--- /dev/null
+++ b/tests/lib_2/js/external_static_test.dart
@@ -0,0 +1,67 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Checks for static errors using external without the @JS() annotation,
+// in a library with a @JS() annotation
+
+@JS()
+library external_static_test;
+
+import 'package:js/js.dart';
+
+// external top level members ok in @JS() library.
+external get topLevelGetter;
+external set topLevelSetter(_);
+external topLevelFunction();
+
+class Constructors {
+  external Constructors();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external Constructors.namedConstructor();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+
+  external factory Constructors.namedFactory();
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class Members {
+  external get instanceGetter;
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external set instanceSetter(_);
+  //           ^
+  // [web] Only JS interop members may be 'external'.
+
+  external instanceMethod();
+  //       ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+class StaticMembers {
+  external static get staticGetter;
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static set staticSetter(_);
+  //                  ^
+  // [web] Only JS interop members may be 'external'.
+
+  external static staticMethod();
+  //              ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+@anonymous
+class AnonymousClass {
+  external factory AnonymousClass();
+  //               ^
+  // [web] Only JS interop members may be 'external'.
+}
+
+main() {}
diff --git a/tests/standalone/io/large_file_read_small_file_test.dart b/tests/standalone/io/large_file_read_small_file_test.dart
new file mode 100644
index 0000000..a4bedf3
--- /dev/null
+++ b/tests/standalone/io/large_file_read_small_file_test.dart
@@ -0,0 +1,54 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:expect/expect.dart';
+import 'package:path/path.dart' as path;
+
+Future runWithTempDir(Future Function(String dir) callback) async {
+  final tempDir = Directory.systemTemp.createTempSync("large_file_read");
+  try {
+    await callback(tempDir.path);
+  } finally {
+    tempDir.delete(recursive: true);
+  }
+}
+
+main() async {
+  // MSAN's malloc implementation will not free memory when shrinking
+  // allocations via realloc (e.g. realloc(malloc(1 GB), new_size=10) will
+  // hold on to the 1 GB).
+  if (Platform.executable.contains('MSAN')) return;
+
+  await runWithTempDir((String dir) async {
+    final file = File(path.join(dir, 'hello_world.txt'));
+    await file.writeAsString('hello world');
+    final RandomAccessFile randomAccessFile = await file.open();
+
+    try {
+      final buffers = [];
+      for (int i = 0; i < 10 * 1000; ++i) {
+        // We issue a 10 MB read but get only a small typed data back. We hang on
+        // to those buffers. If the implementation actually malloc()ed 10 MB then
+        // we would hang on to 100 GB and this test would OOM.
+        // If the implementation instead correctly shrinks the buffer before
+        // giving it to Dart as external typed data, we only consume ~ 100 KB.
+        buffers.add(await randomAccessFile.read(10 * 1024 * 1024));
+        await randomAccessFile.setPosition(0);
+
+        // To avoid machines becoming unusable if the test fails, we'll fail
+        // explicitly if we hit 2 GB.
+        if (ProcessInfo.currentRss > 2 * 1024 * 1024 * 1024) {
+          throw 'The dart:io implementation is buggy and uses too much memory';
+        }
+      }
+      for (final buffer in buffers) {
+        Expect.equals('hello world'.length, buffer.length);
+      }
+    } finally {
+      randomAccessFile.close();
+    }
+  });
+}
diff --git a/tests/standalone_2/io/large_file_read_small_file_test.dart b/tests/standalone_2/io/large_file_read_small_file_test.dart
new file mode 100644
index 0000000..a4bedf3
--- /dev/null
+++ b/tests/standalone_2/io/large_file_read_small_file_test.dart
@@ -0,0 +1,54 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:expect/expect.dart';
+import 'package:path/path.dart' as path;
+
+Future runWithTempDir(Future Function(String dir) callback) async {
+  final tempDir = Directory.systemTemp.createTempSync("large_file_read");
+  try {
+    await callback(tempDir.path);
+  } finally {
+    tempDir.delete(recursive: true);
+  }
+}
+
+main() async {
+  // MSAN's malloc implementation will not free memory when shrinking
+  // allocations via realloc (e.g. realloc(malloc(1 GB), new_size=10) will
+  // hold on to the 1 GB).
+  if (Platform.executable.contains('MSAN')) return;
+
+  await runWithTempDir((String dir) async {
+    final file = File(path.join(dir, 'hello_world.txt'));
+    await file.writeAsString('hello world');
+    final RandomAccessFile randomAccessFile = await file.open();
+
+    try {
+      final buffers = [];
+      for (int i = 0; i < 10 * 1000; ++i) {
+        // We issue a 10 MB read but get only a small typed data back. We hang on
+        // to those buffers. If the implementation actually malloc()ed 10 MB then
+        // we would hang on to 100 GB and this test would OOM.
+        // If the implementation instead correctly shrinks the buffer before
+        // giving it to Dart as external typed data, we only consume ~ 100 KB.
+        buffers.add(await randomAccessFile.read(10 * 1024 * 1024));
+        await randomAccessFile.setPosition(0);
+
+        // To avoid machines becoming unusable if the test fails, we'll fail
+        // explicitly if we hit 2 GB.
+        if (ProcessInfo.currentRss > 2 * 1024 * 1024 * 1024) {
+          throw 'The dart:io implementation is buggy and uses too much memory';
+        }
+      }
+      for (final buffer in buffers) {
+        Expect.equals('hello world'.length, buffer.length);
+      }
+    } finally {
+      randomAccessFile.close();
+    }
+  });
+}
diff --git a/tools/VERSION b/tools/VERSION
index b2a510b..0513cb3 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 12
 PATCH 0
-PRERELEASE 282
+PRERELEASE 283
 PRERELEASE_PATCH 0
\ No newline at end of file
diff --git a/tools/generate_package_config.dart b/tools/generate_package_config.dart
index 9369cce..08b7920 100644
--- a/tools/generate_package_config.dart
+++ b/tools/generate_package_config.dart
@@ -48,6 +48,8 @@
         'pkg/_fe_analyzer_shared/test/flow_analysis/reachability/'),
     packageDirectory(
         'pkg/_fe_analyzer_shared/test/flow_analysis/type_promotion/'),
+    packageDirectory(
+        'pkg/_fe_analyzer_shared/test/flow_analysis/why_not_promoted//'),
     packageDirectory('pkg/_fe_analyzer_shared/test/inheritance/'),
   ];
 
diff --git a/tools/run_offsets_extractor.sh b/tools/run_offsets_extractor.sh
index d3fd6ec9..c9c011b 100755
--- a/tools/run_offsets_extractor.sh
+++ b/tools/run_offsets_extractor.sh
@@ -23,7 +23,7 @@
 rm -rf "${TEMP}" "${TEMP_HEADER}" "${TEMP_JIT}" "${TEMP_AOT}"
 
 # We're regenerating the file, but we want to keep all the comments etc at the
-# top of the file. So just delete everything after the first "#if defined".
+# top of the file. So just delete everything after the first "#if ".
 LINE=$(grep "#if " "$FILE" -n | head -n 1 | sed "s/^\([0-9]*\):.*/\1/")
 head -n $(expr $LINE - 1) "$FILE" >"$TEMP_HEADER"
 
@@ -43,6 +43,8 @@
 run release x64 ReleaseX64
 run release ia32 ReleaseIA32
 run release simarm64 ReleaseSIMARM64
+run release x64_comp_ptr ReleaseX64_COMP_PTR
+run release simarm64_comp_ptr ReleaseSIMARM64_COMP_PTR
 echo "" >>"$TEMP_JIT"
 echo "" >>"$TEMP_AOT"
 echo "#else  // !defined(PRODUCT)" >>"$TEMP_JIT"
@@ -51,6 +53,8 @@
 run product x64 ProductX64
 run product ia32 ProductIA32
 run product simarm64 ProductSIMARM64
+run product x64_comp_ptr ProductX64_COMP_PTR
+run product simarm64_comp_ptr ProductSIMARM64_COMP_PTR
 echo "" >>"$TEMP_JIT"
 echo "" >>"$TEMP_AOT"
 echo "#endif  // !defined(PRODUCT)" >>"$TEMP_JIT"