diff --git a/.dart_tool/package_config.json b/.dart_tool/package_config.json
index d9dd292..ca8348b 100644
--- a/.dart_tool/package_config.json
+++ b/.dart_tool/package_config.json
@@ -118,7 +118,7 @@
       "name": "bazel_worker",
       "rootUri": "../third_party/pkg/bazel_worker",
       "packageUri": "lib/",
-      "languageVersion": "2.3"
+      "languageVersion": "2.12"
     },
     {
       "name": "benchmark_harness",
@@ -495,7 +495,7 @@
       "name": "protobuf",
       "rootUri": "../third_party/pkg/protobuf/protobuf",
       "packageUri": "lib/",
-      "languageVersion": "2.0"
+      "languageVersion": "2.12"
     },
     {
       "name": "pub",
diff --git a/DEPS b/DEPS
index c3a0f78..8e475fa 100644
--- a/DEPS
+++ b/DEPS
@@ -44,7 +44,7 @@
   # 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
   # has.
-  "co19_rev": "de1f3498dff1091b7ca715eb7f831e24ec1a8c64",
+  "co19_rev": "1653a8f5242599b7b8d40b9f1466f717556626d0",
   "co19_2_rev": "e48b3090826cf40b8037648f19d211e8eab1b4b6",
 
   # The internal benchmarks to use. See go/dart-benchmarks-internal
@@ -70,7 +70,7 @@
   # Revisions of /third_party/* dependencies.
   "args_tag": "1.6.0",
   "async_rev": "695b3ac280f107c84adf7488743abfdfaaeea68f",
-  "bazel_worker_rev": "26680d5e249b249c7216ab2fed0ac8ed4ee285c5",
+  "bazel_worker_rev": "060c55a933d39798681a4f533b161b81dc48d77e",
   "benchmark_harness_rev": "ec6b646f5443faa871e126ac1ba248c94ca06257",
   "boolean_selector_rev": "665e6921ab246569420376f827bff4585dff0b14",
   "boringssl_gen_rev": "429ccb1877f7987a6f3988228bc2440e61293499",
@@ -84,7 +84,7 @@
   "convert_rev": "dd3bd28f63be7cb8ab961f38bc73229e4473b555",
   "crypto_rev": "f7c48b334b1386bc5ab0f706fbcd6df8496a87fc",
   "csslib_rev": "6f77b3dcee957d3e2d5083f666221a220e9ed1f1",
-  "dart2js_info_rev" : "0632a623b08e1f601c7eba99e0186a581ae799e9",
+  "dart2js_info_rev" : "83504e459e13862cc6a61c147147ef7892a0d285",
 
   # Note: Updates to dart_style have to be coordinated with the infrastructure
   # team so that the internal formatter in `tools/sdks/dart-sdk/bin/dartfmt`
@@ -131,7 +131,7 @@
   "pedantic_rev": "a884ea2db943b8756cc94385990bd750aec06928",
   "ply_rev": "604b32590ffad5cbb82e4afef1d305512d06ae93",
   "pool_rev": "eedbd5fde84f9a1a8da643b475305a81841da599",
-  "protobuf_rev": "3746c8fd3f2b0147623a8e3db89c3ff4330de760",
+  "protobuf_rev": "0d03fd588df69e9863e2a2efc0059dee8f18d5b2",
   "pub_rev": "228e69e53862879c283c42b98086aa7536012a66",
   "pub_semver_tag": "v1.4.4",
   "resource_rev": "6b79867d0becf5395e5819a75720963b8298e9a7",
diff --git a/pkg/analysis_server/lib/src/lsp/constants.dart b/pkg/analysis_server/lib/src/lsp/constants.dart
index 8ee02fc..c58b195 100644
--- a/pkg/analysis_server/lib/src/lsp/constants.dart
+++ b/pkg/analysis_server/lib/src/lsp/constants.dart
@@ -68,11 +68,13 @@
     organizeImports,
     sendWorkspaceEdit,
     performRefactor,
+    fixAllOfErrorCodeInFile,
   ];
   static const sortMembers = 'edit.sortMembers';
   static const organizeImports = 'edit.organizeImports';
   static const sendWorkspaceEdit = 'edit.sendWorkspaceEdit';
   static const performRefactor = 'refactor.perform';
+  static const fixAllOfErrorCodeInFile = 'edit.fixAll.errorCodeInFile';
 }
 
 abstract class CustomMethods {
diff --git a/pkg/analysis_server/lib/src/lsp/handlers/commands/fix_all_of_error_code_in_file.dart b/pkg/analysis_server/lib/src/lsp/handlers/commands/fix_all_of_error_code_in_file.dart
new file mode 100644
index 0000000..d43b9d9
--- /dev/null
+++ b/pkg/analysis_server/lib/src/lsp/handlers/commands/fix_all_of_error_code_in_file.dart
@@ -0,0 +1,69 @@
+// 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 'package:analysis_server/lsp_protocol/protocol_generated.dart';
+import 'package:analysis_server/lsp_protocol/protocol_special.dart';
+import 'package:analysis_server/src/lsp/constants.dart';
+import 'package:analysis_server/src/lsp/handlers/commands/simple_edit_handler.dart';
+import 'package:analysis_server/src/lsp/handlers/handlers.dart';
+import 'package:analysis_server/src/lsp/lsp_analysis_server.dart';
+import 'package:analysis_server/src/lsp/mapping.dart';
+import 'package:analysis_server/src/lsp/progress.dart';
+import 'package:analysis_server/src/services/correction/bulk_fix_processor.dart';
+import 'package:analysis_server/src/services/correction/change_workspace.dart';
+
+/// This command allows a client to request request applying all fixes for a
+/// type of error.
+class FixAllOfErrorCodeInFileCommandHandler extends SimpleEditCommandHandler {
+  FixAllOfErrorCodeInFileCommandHandler(LspAnalysisServer server)
+      : super(server);
+
+  @override
+  String get commandName => 'Fix All of Error Code in File';
+
+  @override
+  Future<ErrorOr<void>> handle(List<dynamic> arguments,
+      ProgressReporter reporter, CancellationToken cancellationToken) async {
+    if (arguments == null ||
+        arguments.length != 3 ||
+        arguments[0] is! String ||
+        arguments[1] is! String ||
+        (arguments[2] is! int && arguments[2] != null)) {
+      return ErrorOr.error(ResponseError(
+        code: ServerErrorCodes.InvalidCommandArguments,
+        message: '$commandName requires three arguments: '
+            '1) an ErrorCode, '
+            '2) a file path, '
+            '3) a document version',
+      ));
+    }
+
+    final errorCode = arguments[0] as String;
+    final path = arguments[1] as String;
+    final clientDocumentVersion = arguments[2] as int;
+
+    if (fileHasBeenModified(path, clientDocumentVersion)) {
+      return fileModifiedError;
+    }
+
+    final result = await requireResolvedUnit(path);
+
+    if (cancellationToken.isCancellationRequested) {
+      return error(ErrorCodes.RequestCancelled, 'Request was cancelled');
+    }
+
+    return result.mapResult((result) async {
+      final workspace = DartChangeWorkspace(server.currentSessions);
+      final processor =
+          BulkFixProcessor(server.instrumentationService, workspace);
+
+      final changeBuilder = await processor.fixOfTypeInUnit(result, errorCode);
+
+      final edit =
+          createWorkspaceEdit(server, changeBuilder.sourceChange.edits);
+
+      return await sendWorkspaceEditToClient(edit);
+    });
+  }
+}
diff --git a/pkg/analysis_server/lib/src/lsp/handlers/commands/perform_refactor.dart b/pkg/analysis_server/lib/src/lsp/handlers/commands/perform_refactor.dart
index bd880eb..4a302a2 100644
--- a/pkg/analysis_server/lib/src/lsp/handlers/commands/perform_refactor.dart
+++ b/pkg/analysis_server/lib/src/lsp/handlers/commands/perform_refactor.dart
@@ -83,18 +83,14 @@
 
           // If the file changed while we were validating and preparing the change,
           // we should fail to avoid sending bad edits.
-          if (docVersion != null &&
-              docVersion !=
-                  server.getVersionedDocumentIdentifier(path).version) {
-            return error(ErrorCodes.ContentModified,
-                'Content was modified before refactor was applied');
+          if (fileHasBeenModified(path, docVersion)) {
+            return fileModifiedError;
           }
 
           final edit = createWorkspaceEdit(server, change.edits);
           return await sendWorkspaceEditToClient(edit);
         } on InconsistentAnalysisException {
-          return error(ErrorCodes.ContentModified,
-              'Content was modified before refactor was applied');
+          return fileModifiedError;
         } finally {
           _manager.end(cancellationToken);
           reporter.end();
diff --git a/pkg/analysis_server/lib/src/lsp/handlers/handler_code_actions.dart b/pkg/analysis_server/lib/src/lsp/handlers/handler_code_actions.dart
index 9d6fb0a..355cbde 100644
--- a/pkg/analysis_server/lib/src/lsp/handlers/handler_code_actions.dart
+++ b/pkg/analysis_server/lib/src/lsp/handlers/handler_code_actions.dart
@@ -12,9 +12,10 @@
 import 'package:analysis_server/src/lsp/handlers/handlers.dart';
 import 'package:analysis_server/src/lsp/lsp_analysis_server.dart';
 import 'package:analysis_server/src/lsp/mapping.dart';
-import 'package:analysis_server/src/protocol_server.dart';
+import 'package:analysis_server/src/protocol_server.dart' hide Position;
 import 'package:analysis_server/src/services/correction/assist.dart';
 import 'package:analysis_server/src/services/correction/assist_internal.dart';
+import 'package:analysis_server/src/services/correction/bulk_fix_processor.dart';
 import 'package:analysis_server/src/services/correction/change_workspace.dart';
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analysis_server/src/services/correction/fix/dart/top_level_declarations.dart';
@@ -23,7 +24,9 @@
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/analysis/session.dart'
     show InconsistentAnalysisException;
+import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisEngine;
+import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 import 'package:collection/collection.dart' show groupBy;
 
 class CodeActionHandler extends MessageHandler<CodeActionParams,
@@ -89,6 +92,21 @@
     });
   }
 
+  /// Creates a comparer for [CodeActions] that compares the column distance from [pos].
+  Function(CodeAction a, CodeAction b) _codeActionColumnDistanceComparer(
+      Position pos) {
+    Position posOf(CodeAction action) => action.diagnostics.isNotEmpty
+        ? action.diagnostics.first.range.start
+        : pos;
+
+    return (a, b) => _columnDistance(posOf(a), pos)
+        .compareTo(_columnDistance(posOf(b), pos));
+  }
+
+  /// Returns the distance (in columns, ignoring lines) between two positions.
+  int _columnDistance(Position a, Position b) =>
+      (a.character - b.character).abs();
+
   /// Wraps a command in a CodeAction if the client supports it so that a
   /// CodeActionKind can be supplied.
   Either2<Command, CodeAction> _commandOrCodeAction(
@@ -129,33 +147,80 @@
     );
   }
 
-  /// Dedupes actions that perform the same edit and merge their diagnostics
-  /// together. This avoids duplicates where there are multiple errors on
-  /// the same line that have the same fix (for example importing a
-  /// library that fixes multiple unresolved types).
-  List<CodeAction> _dedupeActions(Iterable<CodeAction> actions) {
-    final groups = groupBy(actions, (CodeAction action) => action.edit);
-    return groups.keys.map((edit) {
-      final first = groups[edit].first;
-      // Avoid constructing new CodeActions if there was only one in this group.
-      if (groups[edit].length == 1) {
-        return first;
+  /// Creates a CodeAction command to apply a particular fix for all instances of
+  /// a specific error in the file for [path].
+  CodeAction _createFixAllCommand(Fix fix, Diagnostic diagnostic, String path) {
+    final title = 'Apply all: ${fix.change.message}';
+    return CodeAction(
+      title: title,
+      kind: CodeActionKind.QuickFix,
+      diagnostics: [diagnostic],
+      command: Command(
+        command: Commands.fixAllOfErrorCodeInFile,
+        title: title,
+        arguments: [
+          diagnostic.code,
+          path,
+          server.getVersionedDocumentIdentifier(path).version
+        ],
+      ),
+    );
+  }
+
+  /// Dedupes/merges actions that have the same title, selecting the one nearest [pos].
+  ///
+  /// If actions perform the same edit/command, their diagnostics will be merged
+  /// together. Otherwise, the additional accounts are just dropped.
+  ///
+  /// The first diagnostic for an action is used to determine the position (using
+  /// its `start`). If there is no diagnostic, it will be treated as being at [pos].
+  ///
+  /// If multiple actions have the same position, one will arbitrarily be chosen.
+  List<CodeAction> _dedupeActions(Iterable<CodeAction> actions, Position pos) {
+    final groups = groupBy(actions, (CodeAction action) => action.title);
+    return groups.keys.map((title) {
+      final actions = groups[title];
+
+      // If there's only one in the group, just return it.
+      if (actions.length == 1) {
+        return actions.single;
       }
+
+      // Otherwise, find the action nearest to the caret.
+      actions.sort(_codeActionColumnDistanceComparer(pos));
+      final first = actions.first;
+
+      // Get any actions with the same fix (edit/command) for merging diagnostics.
+      final others = actions.skip(1).where(
+            (other) =>
+                // Compare either edits or commands based on which the selected action has.
+                first.edit != null
+                    ? first.edit == other.edit
+                    : first.command != null
+                        ? first.command == other.command
+                        : false,
+          );
+
       // Build a new CodeAction that merges the diagnostics from each same
       // code action onto a single one.
       return CodeAction(
-          title: first.title,
-          kind: first.kind,
-          // Merge diagnostics from all of the CodeActions.
-          diagnostics: groups[edit].expand((r) => r.diagnostics).toList(),
-          edit: first.edit,
-          command: first.command);
+        title: first.title,
+        kind: first.kind,
+        // Merge diagnostics from all of the matching CodeActions.
+        diagnostics: [
+          ...?first.diagnostics,
+          for (final other in others) ...?other.diagnostics,
+        ],
+        edit: first.edit,
+        command: first.command,
+      );
     }).toList();
   }
 
   Future<List<Either2<Command, CodeAction>>> _getAssistActions(
     HashSet<CodeActionKind> clientSupportedCodeActionKinds,
     bool clientSupportsLiteralCodeActions,
+    Range range,
     int offset,
     int length,
     ResolvedUnitResult unit,
@@ -178,7 +243,8 @@
       final assists = await processor.compute();
       assists.sort(Assist.SORT_BY_RELEVANCE);
 
-      final assistActions = _dedupeActions(assists.map(_createAssistAction));
+      final assistActions =
+          _dedupeActions(assists.map(_createAssistAction), range.start);
 
       return assistActions
           .map((action) => Either2<Command, CodeAction>.t2(action))
@@ -205,7 +271,7 @@
     final results = await Future.wait([
       _getSourceActions(
           kinds, supportsLiterals, supportsWorkspaceApplyEdit, path),
-      _getAssistActions(kinds, supportsLiterals, offset, length, unit),
+      _getAssistActions(kinds, supportsLiterals, range, offset, length, unit),
       _getRefactorActions(kinds, supportsLiterals, path, offset, length, unit),
       _getFixActions(
           kinds, supportsLiterals, supportedDiagnosticTags, range, unit),
@@ -230,40 +296,82 @@
 
     final lineInfo = unit.lineInfo;
     final codeActions = <CodeAction>[];
+    final fixAllCodeActions = <CodeAction>[];
     final fixContributor = DartFixContributor();
 
     try {
+      final errorCodeCounts = <ErrorCode, int>{};
+      // Count the errors by code so we know whether to include a fix-all.
+      for (final error in unit.errors) {
+        errorCodeCounts[error.errorCode] =
+            (errorCodeCounts[error.errorCode] ?? 0) + 1;
+      }
+
+      // Because an error code may appear multiple times, cache the possible fixes
+      // as we discover them to avoid re-computing them for a given diagnostic.
+      final possibleFixesForErrorCode = <ErrorCode, Set<FixKind>>{};
+      final workspace = DartChangeWorkspace(server.currentSessions);
+      final processor =
+          BulkFixProcessor(server.instrumentationService, workspace);
+
       for (final error in unit.errors) {
         // Server lineNumber is one-based so subtract one.
         var errorLine = lineInfo.getLocation(error.offset).lineNumber - 1;
-        if (errorLine >= range.start.line && errorLine <= range.end.line) {
-          var workspace = DartChangeWorkspace(server.currentSessions);
-          var context = DartFixContextImpl(
-              server.instrumentationService, workspace, unit, error, (name) {
-            var tracker = server.declarationsTracker;
-            return TopLevelDeclarationsProvider(tracker).get(
-              unit.session.analysisContext,
-              unit.path,
-              name,
-            );
-          });
-          final fixes = await fixContributor.computeFixes(context);
-          if (fixes.isNotEmpty) {
-            fixes.sort(Fix.SORT_BY_RELEVANCE);
+        if (errorLine < range.start.line || errorLine > range.end.line) {
+          continue;
+        }
+        var workspace = DartChangeWorkspace(server.currentSessions);
+        var context = DartFixContextImpl(
+            server.instrumentationService, workspace, unit, error, (name) {
+          var tracker = server.declarationsTracker;
+          return TopLevelDeclarationsProvider(tracker).get(
+            unit.session.analysisContext,
+            unit.path,
+            name,
+          );
+        });
+        final fixes = await fixContributor.computeFixes(context);
+        if (fixes.isNotEmpty) {
+          fixes.sort(Fix.SORT_BY_RELEVANCE);
 
-            final diagnostic = toDiagnostic(
-              unit,
-              error,
-              supportedTags: supportedDiagnosticTags,
-            );
-            codeActions.addAll(
-              fixes.map((fix) => _createFixAction(fix, diagnostic)),
-            );
+          final diagnostic = toDiagnostic(
+            unit,
+            error,
+            supportedTags: supportedDiagnosticTags,
+          );
+          codeActions.addAll(
+            fixes.map((fix) => _createFixAction(fix, diagnostic)),
+          );
+
+          // Only consider an apply-all if there's more than one of these errors.
+          if (errorCodeCounts[error.errorCode] > 1) {
+            // Find out which fixes the bulk processor can handle.
+            possibleFixesForErrorCode[error.errorCode] ??=
+                processor.producableFixesForError(unit, error).toSet();
+
+            // Get the intersection of single-fix kinds we created and those
+            // the bulk processor can handle.
+            final possibleFixes = possibleFixesForErrorCode[error.errorCode]
+                .intersection(fixes.map((f) => f.kind).toSet())
+                  // Exclude data-driven fixes as they're more likely to apply
+                  // different fixes for the same error/fix kind that users
+                  // might not expect.
+                  ..remove(DartFixKind.DATA_DRIVEN);
+
+            // Until we can apply a specific fix, only include apply-all when
+            // there's exactly one.
+            if (possibleFixes.length == 1) {
+              fixAllCodeActions.addAll(fixes.map(
+                  (fix) => _createFixAllCommand(fix, diagnostic, unit.path)));
+            }
           }
         }
       }
 
-      final dedupedActions = _dedupeActions(codeActions);
+      // Append all fix-alls to the very end.
+      codeActions.addAll(fixAllCodeActions);
+
+      final dedupedActions = _dedupeActions(codeActions, range.start);
 
       return dedupedActions
           .map((action) => Either2<Command, CodeAction>.t2(action))
diff --git a/pkg/analysis_server/lib/src/lsp/handlers/handler_execute_command.dart b/pkg/analysis_server/lib/src/lsp/handlers/handler_execute_command.dart
index 967e8e8..60416b4 100644
--- a/pkg/analysis_server/lib/src/lsp/handlers/handler_execute_command.dart
+++ b/pkg/analysis_server/lib/src/lsp/handlers/handler_execute_command.dart
@@ -5,6 +5,7 @@
 import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/lsp_protocol/protocol_special.dart';
 import 'package:analysis_server/src/lsp/constants.dart';
+import 'package:analysis_server/src/lsp/handlers/commands/fix_all_of_error_code_in_file.dart';
 import 'package:analysis_server/src/lsp/handlers/commands/organize_imports.dart';
 import 'package:analysis_server/src/lsp/handlers/commands/perform_refactor.dart';
 import 'package:analysis_server/src/lsp/handlers/commands/send_workspace_edit.dart';
@@ -24,6 +25,8 @@
           Commands.organizeImports: OrganizeImportsCommandHandler(server),
           Commands.performRefactor: PerformRefactorCommandHandler(server),
           Commands.sendWorkspaceEdit: SendWorkspaceEditCommandHandler(server),
+          Commands.fixAllOfErrorCodeInFile:
+              FixAllOfErrorCodeInFileCommandHandler(server),
         },
         super(server);
 
diff --git a/pkg/analysis_server/lib/src/lsp/handlers/handler_rename.dart b/pkg/analysis_server/lib/src/lsp/handlers/handler_rename.dart
index 7375cc2..71205a0 100644
--- a/pkg/analysis_server/lib/src/lsp/handlers/handler_rename.dart
+++ b/pkg/analysis_server/lib/src/lsp/handlers/handler_rename.dart
@@ -95,8 +95,9 @@
     // send the edits.
     final docIdentifier = await path.mapResult((path) => success(
         params.textDocument is VersionedTextDocumentIdentifier
-            ? params.textDocument
+            ? params.textDocument as VersionedTextDocumentIdentifier
             : server.getVersionedDocumentIdentifier(path)));
+
     final unit = await path.mapResult(requireResolvedUnit);
     final offset = await unit.mapResult((unit) => toOffset(unit.lineInfo, pos));
 
@@ -178,10 +179,8 @@
 
       // Before we send anything back, ensure the original file didn't change
       // while we were computing changes.
-      if (server.getVersionedDocumentIdentifier(path.result) !=
-          docIdentifier.result) {
-        return error(ErrorCodes.ContentModified,
-            'Document was modified while rename was being computed', null);
+      if (fileHasBeenModified(path.result, docIdentifier.result.version)) {
+        return fileModifiedError;
       }
 
       final workspaceEdit = createWorkspaceEdit(server, change.edits);
diff --git a/pkg/analysis_server/lib/src/lsp/handlers/handlers.dart b/pkg/analysis_server/lib/src/lsp/handlers/handlers.dart
index 41f20f4..96db148 100644
--- a/pkg/analysis_server/lib/src/lsp/handlers/handlers.dart
+++ b/pkg/analysis_server/lib/src/lsp/handlers/handlers.dart
@@ -55,6 +55,15 @@
 mixin Handler<P, R> {
   LspAnalysisServer server;
 
+  final fileModifiedError = error<R>(ErrorCodes.ContentModified,
+      'Document was modified before operation completed', null);
+
+  bool fileHasBeenModified(String path, int clientVersion) {
+    final serverDocIdentifier = server.getVersionedDocumentIdentifier(path);
+    return clientVersion != null &&
+        clientVersion != serverDocIdentifier.version;
+  }
+
   ErrorOr<LineInfo> getLineInfo(String path) {
     final lineInfo = server.getLineInfo(path);
 
diff --git a/pkg/analysis_server/lib/src/services/correction/bulk_fix_processor.dart b/pkg/analysis_server/lib/src/services/correction/bulk_fix_processor.dart
index a8f267c..0dae89c 100644
--- a/pkg/analysis_server/lib/src/services/correction/bulk_fix_processor.dart
+++ b/pkg/analysis_server/lib/src/services/correction/bulk_fix_processor.dart
@@ -75,6 +75,7 @@
 import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
 import 'package:analyzer_plugin/utilities/change_builder/conflicting_edit_exception.dart';
+import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 
 /// A fix producer that produces changes to fix multiple diagnostics.
 class BulkFixProcessor {
@@ -393,6 +394,92 @@
     return builder;
   }
 
+  /// Return a change builder that has been used to create all fixes for a
+  /// specific diagnostic code in the given [unit].
+  Future<ChangeBuilder> fixOfTypeInUnit(
+    ResolvedUnitResult unit,
+    String errorCode,
+  ) async {
+    final errorCodeLowercase = errorCode.toLowerCase();
+    final errors = unit.errors.where(
+      (error) => error.errorCode.name.toLowerCase() == errorCodeLowercase,
+    );
+
+    final analysisOptions = unit.session.analysisContext.analysisOptions;
+    final fixContext = DartFixContextImpl(
+      instrumentationService,
+      workspace,
+      unit,
+      null,
+      (name) => [],
+    );
+
+    for (var error in errors) {
+      final processor = ErrorProcessor.getProcessor(analysisOptions, error);
+      // Only fix errors not filtered out in analysis options.
+      if (processor == null || processor.severity != null) {
+        await _fixSingleError(fixContext, unit, error);
+      }
+    }
+
+    return builder;
+  }
+
+  /// Returns the potential [FixKind]s that may be available for a given diagnostic.
+  ///
+  /// The presence of a kind does not guarantee a fix will be produced, nor does
+  /// the absence of a kind mean that it definitely will not (some producers
+  /// do not provide FixKinds up-front). These results are intended as a hint
+  /// for populating something like a quick-fix menu with possible apply-all fixes.
+  Iterable<FixKind> producableFixesForError(
+    ResolvedUnitResult result,
+    AnalysisError diagnostic,
+  ) sync* {
+    final errorCode = diagnostic.errorCode;
+    if (errorCode is LintCode) {
+      final generators = lintProducerMap[errorCode.name];
+      if (generators != null) {
+        yield* generators.map((g) => g().fixKind).where((k) => k != null);
+      }
+      return;
+    }
+
+    final generator = nonLintProducerMap[errorCode];
+    if (generator != null) {
+      final kind = generator().fixKind;
+      if (kind != null) yield kind;
+    }
+
+    final multiGenerators = nonLintMultiProducerMap[errorCode];
+    if (multiGenerators != null) {
+      final fixContext = DartFixContextImpl(
+        instrumentationService,
+        workspace,
+        result,
+        null,
+        (name) => [],
+      );
+
+      var context = CorrectionProducerContext(
+        applyingBulkFixes: true,
+        dartFixContext: fixContext,
+        diagnostic: diagnostic,
+        resolvedResult: result,
+        selectionOffset: diagnostic.offset,
+        selectionLength: diagnostic.length,
+        workspace: workspace,
+      );
+
+      for (final multiGenerator in multiGenerators) {
+        final multiProducer = multiGenerator();
+        multiProducer.configure(context);
+        yield* multiProducer.producers
+            .map((p) => p.fixKind)
+            .where((k) => k != null);
+      }
+    }
+  }
+
   /// Use the change [builder] to create fixes for the diagnostics in the
   /// library associated with the analysis [result].
   Future<void> _fixErrorsInLibrary(ResolvedLibraryResult result) async {
diff --git a/pkg/analysis_server/test/lsp/code_actions_abstract.dart b/pkg/analysis_server/test/lsp/code_actions_abstract.dart
index df1425e..3f59ec8 100644
--- a/pkg/analysis_server/test/lsp/code_actions_abstract.dart
+++ b/pkg/analysis_server/test/lsp/code_actions_abstract.dart
@@ -4,6 +4,7 @@
 
 import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/lsp_protocol/protocol_special.dart';
+import 'package:analysis_server/src/lsp/constants.dart';
 import 'package:test/test.dart';
 
 import 'server_abstract.dart';
@@ -45,7 +46,7 @@
       [String wantedTitle]) {
     for (var codeAction in actions) {
       final id = codeAction.map(
-          (cmd) => cmd.command, (action) => action.command.command);
+          (cmd) => cmd.command, (action) => action.command?.command);
       final title =
           codeAction.map((cmd) => cmd.title, (action) => action.title);
       if (id == commandID && (wantedTitle == null || wantedTitle == title)) {
@@ -74,6 +75,15 @@
     }).toList();
   }
 
+  Future<Either2<Command, CodeAction>> getFixAllAction(
+      String title, Uri uri, String content) async {
+    final codeActions =
+        await getCodeActions(uri.toString(), range: rangeFromMarkers(content));
+    final fixAction =
+        findCommand(codeActions, Commands.fixAllOfErrorCodeInFile, title);
+    return fixAction;
+  }
+
   /// Verifies that executing the given code actions command on the server
   /// results in an edit being sent in the client that updates the file to match
   /// the expected content.
diff --git a/pkg/analysis_server/test/lsp/code_actions_fixes_test.dart b/pkg/analysis_server/test/lsp/code_actions_fixes_test.dart
index c424137..bf327be 100644
--- a/pkg/analysis_server/test/lsp/code_actions_fixes_test.dart
+++ b/pkg/analysis_server/test/lsp/code_actions_fixes_test.dart
@@ -12,6 +12,7 @@
 void main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(FixesCodeActionsTest);
+    defineReflectiveTests(FixesCodeActionsWithNullSafetyTest);
   });
 }
 
@@ -95,7 +96,7 @@
     expect(contents[mainFilePath], equals(expectedContent));
   }
 
-  Future<void> test_noDuplicates() async {
+  Future<void> test_noDuplicates_sameFix() async {
     const content = '''
     var a = [Test, Test, Te[[]]st];
     ''';
@@ -209,3 +210,153 @@
     expect(codeActions, isEmpty);
   }
 }
+
+@reflectiveTest
+class FixesCodeActionsWithNullSafetyTest extends AbstractCodeActionsTest {
+  @override
+  String get testPackageLanguageVersion => latestLanguageVersion;
+
+  Future<void> test_fixAll_notForAmbigiousProducers() async {
+    // The ReplaceWithIsEmpty producer does not provide a FixKind up-front, as
+    // it may produce `REPLACE_WITH_IS_EMPTY` or `REPLACE_WITH_IS_NOT_EMPTY`
+    // depending on the code.
+    // This test ensures this does not crash, and does not produce an apply-all.
+    registerLintRules();
+    newFile(analysisOptionsPath, content: '''
+linter:
+  rules:
+    - prefer_is_empty
+    ''');
+
+    const content = '''
+var a = [];
+var b = a.[[length]] == 0;
+var c = a.length == 0;
+    ''';
+
+    newFile(mainFilePath, content: withoutMarkers(content));
+    await initialize(
+      textDocumentCapabilities: withCodeActionKinds(
+          emptyTextDocumentClientCapabilities, [CodeActionKind.QuickFix]),
+    );
+
+    final allFixes = await getCodeActions(mainFileUri.toString(),
+        range: rangeFromMarkers(content));
+
+    // Expect only the single-fix, there should be no apply-all.
+    expect(allFixes, hasLength(1));
+    final fixTitle = allFixes.first.map((f) => f.title, (f) => f.title);
+    expect(fixTitle, equals("Replace with \'isEmpty\'"));
+  }
+
+  Future<void> test_fixAll_notWhenNoBatchFix() async {
+    // Some fixes (for example 'create function foo') are not available in the
+    // batch processor, so should not generate Apply-all fixes even if there
+    // are multiple.
+    const content = '''
+var a = [[foo]]();
+var b = bar();
+    ''';
+
+    newFile(mainFilePath, content: withoutMarkers(content));
+    await initialize(
+      textDocumentCapabilities: withCodeActionKinds(
+          emptyTextDocumentClientCapabilities, [CodeActionKind.QuickFix]),
+    );
+
+    final allFixes = await getCodeActions(mainFileUri.toString(),
+        range: rangeFromMarkers(content));
+
+    // Expect only the single-fix, there should be no apply-all.
+    expect(allFixes, hasLength(1));
+    final fixTitle = allFixes.first.map((f) => f.title, (f) => f.title);
+    expect(fixTitle, equals("Create function 'foo'"));
+  }
+
+  Future<void> test_fixAll_notWhenSingle() async {
+    const content = '''
+void f(String a) {
+  [[print(a!)]];
+}
+    ''';
+
+    newFile(mainFilePath, content: withoutMarkers(content));
+    await initialize(
+      textDocumentCapabilities: withCodeActionKinds(
+          emptyTextDocumentClientCapabilities, [CodeActionKind.QuickFix]),
+    );
+
+    final fixAction = await getFixAllAction(
+        "Apply all: Remove the '!'", mainFileUri, content);
+
+    // Should not appear if there was only a single error.
+    expect(fixAction, isNull);
+  }
+
+  Future<void> test_fixAll_whenMultiple() async {
+    const content = '''
+void f(String a) {
+  [[print(a!!)]];
+  print(a!!);
+}
+    ''';
+
+    const expectedContent = '''
+void f(String a) {
+  print(a);
+  print(a);
+}
+    ''';
+    newFile(mainFilePath, content: withoutMarkers(content));
+    await initialize(
+      textDocumentCapabilities: withCodeActionKinds(
+          emptyTextDocumentClientCapabilities, [CodeActionKind.QuickFix]),
+    );
+
+    final fixAction = await getFixAllAction(
+        "Apply all: Remove the '!'", mainFileUri, content);
+
+    expect(fixAction, isNotNull);
+
+    await verifyCodeActionEdits(
+        fixAction, withoutMarkers(content), expectedContent);
+  }
+
+  Future<void> test_noDuplicates_differentFix() async {
+    // For convenience, quick-fixes are usually returned for the entire line,
+    // though this can lead to duplicate entries (by title) when multiple
+    // diagnostics have their own fixes of the same type.
+    //
+    // Expect only the only one nearest to the start of the range to be returned.
+    const content = '''
+    main() {
+      var a = [];
+      print(a!!);^
+    }
+    ''';
+
+    newFile(mainFilePath, content: withoutMarkers(content));
+    await initialize(
+      textDocumentCapabilities: withCodeActionKinds(
+          emptyTextDocumentClientCapabilities, [CodeActionKind.QuickFix]),
+    );
+
+    final caretPos = positionFromMarker(content);
+
+    final codeActions = await getCodeActions(mainFileUri.toString(),
+        range: Range(start: caretPos, end: caretPos));
+    final removeNnaAction = findEditActions(codeActions,
+        CodeActionKind('quickfix.remove.nonNullAssertion'), "Remove the '!'");
+
+    // Expect only one of the fixes.
+    expect(removeNnaAction, hasLength(1));
+
+    // Ensure the action is for the diagnostic on the second bang which was
+    // closest to the range requested.
+    final secondBangPos =
+        positionFromOffset(withoutMarkers(content).indexOf('!);'), content);
+    expect(removeNnaAction.first.diagnostics, hasLength(1));
+    final diagStart = removeNnaAction.first.diagnostics.first.range.start;
+    expect(diagStart, equals(secondBangPos));
+  }
+}
diff --git a/pkg/analysis_server/test/lsp/server_abstract.dart b/pkg/analysis_server/test/lsp/server_abstract.dart
index 006ce0b..c6eae2c 100644
--- a/pkg/analysis_server/test/lsp/server_abstract.dart
+++ b/pkg/analysis_server/test/lsp/server_abstract.dart
@@ -589,18 +589,18 @@
     /// logic.
     void validateChangesCanBeApplied() {
       /// Check if a position is before (but not equal) to another position.
-      bool isBefore(Position p, Position other) =>
+      bool isBeforeOrEqual(Position p, Position other) =>
           p.line < other.line ||
-          (p.line == other.line && p.character < other.character);
+          (p.line == other.line && p.character <= other.character);
 
       /// Check if a position is after (but not equal) to another position.
-      bool isAfter(Position p, Position other) =>
+      bool isAfterOrEqual(Position p, Position other) =>
           p.line > other.line ||
-          (p.line == other.line && p.character > other.character);
-      // Check if two ranges intersect or touch.
+          (p.line == other.line && p.character >= other.character);
+      // Check if two ranges intersect.
       bool rangesIntersect(Range r1, Range r2) {
-        var endsBefore = isBefore(r1.end, r2.start);
-        var startsAfter = isAfter(r1.start, r2.end);
+        var endsBefore = isBeforeOrEqual(r1.end, r2.start);
+        var startsAfter = isAfterOrEqual(r1.start, r2.end);
         return !(endsBefore || startsAfter);
       }
 
@@ -1225,7 +1225,7 @@
     if (p1.line > p2.line) return 1;
 
     if (p1.character < p2.character) return -1;
-    if (p1.character > p2.character) return -1;
+    if (p1.character > p2.character) return 1;
 
     return 0;
   }
diff --git a/pkg/analysis_server/test/src/services/correction/fix/bulk/data_driven_test.dart b/pkg/analysis_server/test/src/services/correction/fix/bulk/data_driven_test.dart
index 8404c8b..88e911a 100644
--- a/pkg/analysis_server/test/src/services/correction/fix/bulk/data_driven_test.dart
+++ b/pkg/analysis_server/test/src/services/correction/fix/bulk/data_driven_test.dart
@@ -2,8 +2,11 @@
 // 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:analysis_server/src/services/correction/bulk_fix_processor.dart';
+import 'package:analysis_server/src/services/correction/dart/data_driven.dart';
 import 'package:analysis_server/src/services/correction/fix/data_driven/transform_set_manager.dart';
 import 'package:analyzer/src/test_utilities/package_config_file_builder.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'bulk_fix_processor.dart';
@@ -30,6 +33,7 @@
     defineReflectiveTests(WrongNumberOfTypeArgumentsExtensionTest);
     defineReflectiveTests(WrongNumberOfTypeArgumentsMethodTest);
     defineReflectiveTests(WrongNumberOfTypeArgumentsTest);
+    defineReflectiveTests(NoProducerOverlapsTest);
   });
 }
 
@@ -493,6 +497,39 @@
 }
 
 @reflectiveTest
+class NoProducerOverlapsTest {
+  void test_noProducerOverlaps() {
+    // Ensure that no error code is used by both data-driven fixes and
+    // non-data-driven fixes, as this could result in an LSP "Apply-all" code
+    // action accidentally executing data-driven fixes.
+
+    final dataDrivenCodes = <String>{};
+    final nonDataDrivenCodes = <String>{
+      ...BulkFixProcessor.lintProducerMap.keys,
+      ...BulkFixProcessor.nonLintProducerMap.keys.map((c) => c.uniqueName),
+    };
+
+    for (final code in BulkFixProcessor.nonLintMultiProducerMap.keys) {
+      for (final producerFunc
+          in BulkFixProcessor.nonLintMultiProducerMap[code]) {
+        final producer = producerFunc();
+        if (producer is DataDriven) {
+          dataDrivenCodes.add(code.uniqueName);
+        } else {
+          nonDataDrivenCodes.add(code.uniqueName);
+        }
+      }
+    }
+
+    final intersection = dataDrivenCodes.intersection(nonDataDrivenCodes);
+    if (intersection.isNotEmpty) {
+      fail(
+          'Error codes $intersection have both data-driven and non-data-driven fixes');
+    }
+  }
+}
+
+@reflectiveTest
 class NotEnoughPositionalArgumentsTest extends _DataDrivenTest {
   Future<void> test_addParameter() async {
     setPackageContent('''
diff --git a/pkg/dartdev/lib/src/commands/pub.dart b/pkg/dartdev/lib/src/commands/pub.dart
deleted file mode 100644
index e6162a5..0000000
--- a/pkg/dartdev/lib/src/commands/pub.dart
+++ /dev/null
@@ -1,89 +0,0 @@
-// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'dart:async';
-
-import 'package:args/args.dart';
-
-import '../core.dart';
-import '../experiments.dart';
-import '../sdk.dart';
-import '../vm_interop_handler.dart';
-
-class PubCommand extends DartdevCommand {
-  static const String cmdName = 'pub';
-
-  PubCommand() : super(cmdName, 'Work with packages.');
-
-  // TODO(jwren) as soon as pub commands are are implemented directly in
-  //  dartdev, remove this static list.
-  /// A list of all subcommands, used only for the implementation of
-  /// [usagePath], see below.
-  static List<String> pubSubcommands = [
-    'cache',
-    'deps',
-    'downgrade',
-    'get',
-    'global',
-    'logout',
-    'outdated',
-    'publish',
-    'run',
-    'upgrade',
-    'uploader',
-    'version',
-  ];
-
-  @override
-  ArgParser createArgParser() => ArgParser.allowAnything();
-
-  @override
-  void printUsage() {
-    // Override [printUsage] for invocations of 'dart help pub' which won't
-    // execute [run] below.  Without this, the 'dart help pub' reports the
-    // command pub with no commands or flags.
-    if (!Sdk.checkArtifactExists(sdk.pubSnapshot)) {
-      return;
-    }
-    final command = sdk.pubSnapshot;
-    final args = ['help'];
-
-    log.trace('$command ${args.first}');
-
-    // Call 'pub help'
-    VmInteropHandler.run(command, args, packageConfigOverride: null);
-  }
-
-  @override
-  FutureOr<int> run() async {
-    if (!Sdk.checkArtifactExists(sdk.pubSnapshot)) {
-      return 255;
-    }
-    final command = sdk.pubSnapshot;
-    var args = argResults.arguments;
-
-    // Pass any --enable-experiment options along.
-    if (args.isNotEmpty && wereExperimentsSpecified) {
-      List<String> experimentIds = specifiedExperiments;
-
-      if (args.first == 'run') {
-        args = [
-          ...args.sublist(0, 1),
-          '--$experimentFlagName=${experimentIds.join(',')}',
-          ...args.sublist(1),
-        ];
-      } else if (args.length > 1 && args[0] == 'global' && args[0] == 'run') {
-        args = [
-          ...args.sublist(0, 2),
-          '--$experimentFlagName=${experimentIds.join(',')}',
-          ...args.sublist(2),
-        ];
-      }
-    }
-
-    log.trace('$command ${args.join(' ')}');
-    VmInteropHandler.run(command, args, packageConfigOverride: null);
-    return 0;
-  }
-}
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index d65d47e..ae9ae5d 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -1415,7 +1415,11 @@
     }
 
     ReturnStatementImpl fakeReturn = new ReturnStatementImpl(true, expression);
-
+    if (formals != null) {
+      for (int i = 0; i < formals.length; i++) {
+        typeInferrer?.flowAnalysis?.declare(formals[i].variable, true);
+      }
+    }
     Statement inferredStatement = typeInferrer?.inferFunctionBody(
         this, fileOffset, const DynamicType(), AsyncMarker.Sync, fakeReturn);
     assert(
diff --git a/pkg/vm/lib/transformations/protobuf_aware_treeshaker/transformer.dart b/pkg/vm/lib/transformations/protobuf_aware_treeshaker/transformer.dart
index 245d77d..2a88c7c 100644
--- a/pkg/vm/lib/transformations/protobuf_aware_treeshaker/transformer.dart
+++ b/pkg/vm/lib/transformations/protobuf_aware_treeshaker/transformer.dart
@@ -213,6 +213,17 @@
     node.body.accept(this);
   }
 
+  String _extractFieldName(Expression expression) {
+    if (expression is StringLiteral) {
+      return expression.value;
+    }
+    if (expression is ConditionalExpression) {
+      return _extractFieldName(expression.otherwise);
+    }
+    throw ArgumentError.value(
+        expression, 'expression', 'Unsupported  expression');
+  }
+
   void _changeCascadeEntry(Expression initializer) {
     if (initializer is MethodInvocation &&
         initializer.interfaceTarget?.enclosingClass == builderInfoClass &&
@@ -222,7 +233,7 @@
       if (!usedTagNumbers.contains(tagNumber)) {
         if (info != null) {
           final fieldName =
-              (initializer.arguments.positional[1] as StringLiteral).value;
+              _extractFieldName(initializer.arguments.positional[1]);
           info.removedMessageFields.add("${visitedClass.name}.$fieldName");
         }
 
diff --git a/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/foo.pb.dart b/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/foo.pb.dart
index cab7883..19c9bac5 100644
--- a/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/foo.pb.dart
+++ b/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/foo.pb.dart
@@ -2,38 +2,40 @@
 //  Generated code. Do not modify.
 //  source: foo.proto
 //
-// @dart = 2.3
-// ignore_for_file: camel_case_types,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type
+// @dart = 2.12
+// ignore_for_file: annotate_overrides,camel_case_types,unnecessary_const,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type,unnecessary_this,prefer_final_fields
 
 import 'dart:core' as $core;
 
 import 'package:protobuf/protobuf.dart' as $pb;
 
 class FooKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('FooKeep', createEmptyInstance: create)
-        ..aOM<BarKeep>(1, 'barKeep',
-            protoName: 'barKeep', subBuilder: BarKeep.create)
-        ..aOM<BarKeep>(2, 'barDrop',
-            protoName: 'barDrop', subBuilder: BarKeep.create)
-        ..m<$core.String, BarKeep>(3, 'mapKeep',
-            protoName: 'mapKeep',
-            entryClassName: 'FooKeep.MapKeepEntry',
-            keyFieldType: $pb.PbFieldType.OS,
-            valueFieldType: $pb.PbFieldType.OM,
-            valueCreator: BarKeep.create)
-        ..m<$core.String, ZopDrop>(4, 'mapDrop',
-            protoName: 'mapDrop',
-            entryClassName: 'FooKeep.MapDropEntry',
-            keyFieldType: $pb.PbFieldType.OS,
-            valueFieldType: $pb.PbFieldType.OM,
-            valueCreator: ZopDrop.create)
-        ..a<$core.int>(5, 'aKeep', $pb.PbFieldType.O3, protoName: 'aKeep')
-        ..aOM<HasKeep>(6, 'hasKeep',
-            protoName: 'hasKeep', subBuilder: HasKeep.create)
-        ..aOM<ClearKeep>(7, 'clearKeep',
-            protoName: 'clearKeep', subBuilder: ClearKeep.create)
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(const $core.bool.fromEnvironment('protobuf.omit_message_names') ? '' : 'FooKeep',
+      createEmptyInstance: create)
+    ..aOM<BarKeep>(1, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'barKeep',
+        protoName: 'barKeep', subBuilder: BarKeep.create)
+    ..aOM<BarKeep>(2, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'barDrop',
+        protoName: 'barDrop', subBuilder: BarKeep.create)
+    ..m<$core.String, BarKeep>(3, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'mapKeep',
+        protoName: 'mapKeep',
+        entryClassName: 'FooKeep.MapKeepEntry',
+        keyFieldType: $pb.PbFieldType.OS,
+        valueFieldType: $pb.PbFieldType.OM,
+        valueCreator: BarKeep.create)
+    ..m<$core.String, ZopDrop>(
+        4, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'mapDrop',
+        protoName: 'mapDrop',
+        entryClassName: 'FooKeep.MapDropEntry',
+        keyFieldType: $pb.PbFieldType.OS,
+        valueFieldType: $pb.PbFieldType.OM,
+        valueCreator: ZopDrop.create)
+    ..a<$core.int>(5, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'aKeep', $pb.PbFieldType.O3,
+        protoName: 'aKeep')
+    ..aOM<HasKeep>(6, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'hasKeep',
+        protoName: 'hasKeep', subBuilder: HasKeep.create)
+    ..aOM<ClearKeep>(7, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'clearKeep',
+        protoName: 'clearKeep', subBuilder: ClearKeep.create)
+    ..hasRequiredFields = false;
 
   FooKeep._() : super();
   factory FooKeep() => create();
@@ -43,9 +45,16 @@
   factory FooKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   FooKeep clone() => FooKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   FooKeep copyWith(void Function(FooKeep) updates) =>
-      super.copyWith((message) => updates(message as FooKeep));
+      super.copyWith((message) => updates(message as FooKeep))
+          as FooKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static FooKeep create() => FooKeep._();
@@ -54,7 +63,7 @@
   @$core.pragma('dart2js:noInline')
   static FooKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<FooKeep>(create);
-  static FooKeep _defaultInstance;
+  static FooKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   BarKeep get barKeep => $_getN(0);
@@ -132,11 +141,26 @@
 }
 
 class BarKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('BarKeep', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aKeep', $pb.PbFieldType.O3, protoName: 'aKeep')
-        ..a<$core.int>(2, 'bDrop', $pb.PbFieldType.O3, protoName: 'bDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'BarKeep',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aKeep',
+        $pb.PbFieldType.O3,
+        protoName: 'aKeep')
+    ..a<$core.int>(
+        2,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'bDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'bDrop')
+    ..hasRequiredFields = false;
 
   BarKeep._() : super();
   factory BarKeep() => create();
@@ -146,9 +170,16 @@
   factory BarKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   BarKeep clone() => BarKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   BarKeep copyWith(void Function(BarKeep) updates) =>
-      super.copyWith((message) => updates(message as BarKeep));
+      super.copyWith((message) => updates(message as BarKeep))
+          as BarKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static BarKeep create() => BarKeep._();
@@ -157,7 +188,7 @@
   @$core.pragma('dart2js:noInline')
   static BarKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<BarKeep>(create);
-  static BarKeep _defaultInstance;
+  static BarKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aKeep => $_getIZ(0);
@@ -185,10 +216,19 @@
 }
 
 class HasKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('HasKeep', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'HasKeep',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   HasKeep._() : super();
   factory HasKeep() => create();
@@ -198,9 +238,16 @@
   factory HasKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   HasKeep clone() => HasKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   HasKeep copyWith(void Function(HasKeep) updates) =>
-      super.copyWith((message) => updates(message as HasKeep));
+      super.copyWith((message) => updates(message as HasKeep))
+          as HasKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static HasKeep create() => HasKeep._();
@@ -209,7 +256,7 @@
   @$core.pragma('dart2js:noInline')
   static HasKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<HasKeep>(create);
-  static HasKeep _defaultInstance;
+  static HasKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
@@ -225,10 +272,19 @@
 }
 
 class ClearKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('ClearKeep', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'ClearKeep',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   ClearKeep._() : super();
   factory ClearKeep() => create();
@@ -238,9 +294,16 @@
   factory ClearKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   ClearKeep clone() => ClearKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   ClearKeep copyWith(void Function(ClearKeep) updates) =>
-      super.copyWith((message) => updates(message as ClearKeep));
+      super.copyWith((message) => updates(message as ClearKeep))
+          as ClearKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static ClearKeep create() => ClearKeep._();
@@ -249,7 +312,7 @@
   @$core.pragma('dart2js:noInline')
   static ClearKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<ClearKeep>(create);
-  static ClearKeep _defaultInstance;
+  static ClearKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
@@ -265,10 +328,19 @@
 }
 
 class ZopDrop extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('ZopDrop', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'ZopDrop',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   ZopDrop._() : super();
   factory ZopDrop() => create();
@@ -278,9 +350,16 @@
   factory ZopDrop.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   ZopDrop clone() => ZopDrop()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   ZopDrop copyWith(void Function(ZopDrop) updates) =>
-      super.copyWith((message) => updates(message as ZopDrop));
+      super.copyWith((message) => updates(message as ZopDrop))
+          as ZopDrop; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static ZopDrop create() => ZopDrop._();
@@ -289,7 +368,7 @@
   @$core.pragma('dart2js:noInline')
   static ZopDrop getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<ZopDrop>(create);
-  static ZopDrop _defaultInstance;
+  static ZopDrop? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
@@ -305,10 +384,19 @@
 }
 
 class MobDrop extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('MobDrop', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'MobDrop',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   MobDrop._() : super();
   factory MobDrop() => create();
@@ -318,9 +406,16 @@
   factory MobDrop.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   MobDrop clone() => MobDrop()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   MobDrop copyWith(void Function(MobDrop) updates) =>
-      super.copyWith((message) => updates(message as MobDrop));
+      super.copyWith((message) => updates(message as MobDrop))
+          as MobDrop; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static MobDrop create() => MobDrop._();
@@ -329,7 +424,7 @@
   @$core.pragma('dart2js:noInline')
   static MobDrop getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<MobDrop>(create);
-  static MobDrop _defaultInstance;
+  static MobDrop? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
diff --git a/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/name_mangling.pb.dart b/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/name_mangling.pb.dart
index bc76b27..c42141a 100644
--- a/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/name_mangling.pb.dart
+++ b/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/generated/name_mangling.pb.dart
@@ -2,17 +2,20 @@
 //  Generated code. Do not modify.
 //  source: name_mangling.proto
 //
-// @dart = 2.3
-// ignore_for_file: camel_case_types,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type
+// @dart = 2.12
+// ignore_for_file: annotate_overrides,camel_case_types,unnecessary_const,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type,unnecessary_this,prefer_final_fields
 
 import 'dart:core' as $core;
 
 import 'package:protobuf/protobuf.dart' as $pb;
 
 class AKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('AKeep', createEmptyInstance: create)
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'AKeep',
+      createEmptyInstance: create)
+    ..hasRequiredFields = false;
 
   AKeep._() : super();
   factory AKeep() => create();
@@ -22,9 +25,16 @@
   factory AKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   AKeep clone() => AKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   AKeep copyWith(void Function(AKeep) updates) =>
-      super.copyWith((message) => updates(message as AKeep));
+      super.copyWith((message) => updates(message as AKeep))
+          as AKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static AKeep create() => AKeep._();
@@ -33,14 +43,22 @@
   @$core.pragma('dart2js:noInline')
   static AKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<AKeep>(create);
-  static AKeep _defaultInstance;
+  static AKeep? _defaultInstance;
 }
 
 class NameManglingKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('NameManglingKeep', createEmptyInstance: create)
-        ..aOM<AKeep>(10, 'clone', subBuilder: AKeep.create)
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'NameManglingKeep',
+      createEmptyInstance: create)
+    ..aOM<AKeep>(
+        10,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'clone',
+        subBuilder: AKeep.create)
+    ..hasRequiredFields = false;
 
   NameManglingKeep._() : super();
   factory NameManglingKeep() => create();
@@ -50,9 +68,16 @@
   factory NameManglingKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   NameManglingKeep clone() => NameManglingKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   NameManglingKeep copyWith(void Function(NameManglingKeep) updates) =>
-      super.copyWith((message) => updates(message as NameManglingKeep));
+      super.copyWith((message) => updates(message as NameManglingKeep))
+          as NameManglingKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static NameManglingKeep create() => NameManglingKeep._();
@@ -62,7 +87,7 @@
   @$core.pragma('dart2js:noInline')
   static NameManglingKeep getDefault() => _defaultInstance ??=
       $pb.GeneratedMessage.$_defaultFor<NameManglingKeep>(create);
-  static NameManglingKeep _defaultInstance;
+  static NameManglingKeep? _defaultInstance;
 
   @$pb.TagNumber(10)
   AKeep get clone_10 => $_getN(0);
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/create_test.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/create_test.dart.expect
index 8726004..3c20021 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/create_test.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/create_test.dart.expect
@@ -13,7 +13,7 @@
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.barKeep] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pb::FooKeep::barKeep} = let final pb::BarKeep* #t2 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pb::BarKeep::aKeep} = 5;
     } =>#t2;
-    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String*, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep*>*] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapKeep] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapKeep}.{core::Map::[]=}("foo", let final pb::BarKeep* #t3 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
+    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep>] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapKeep] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapKeep}.{core::Map::[]=}("foo", let final pb::BarKeep* #t3 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pb::BarKeep::aKeep} = 2;
     } =>#t3);
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pb::FooKeep::aKeep} = 43;
@@ -26,7 +26,7 @@
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.clearClearKeep] [@vm.inferred-type.metadata=!? (skip check)] foo.{pb::FooKeep::clearClearKeep}();
   });
 }
-library foo.pb.dart;
+library foo.pb.dart /*isNonNullableByDefault*/;
 import self as self;
 import "package:protobuf/protobuf.dart" as pro;
 import "dart:core" as core;
@@ -35,99 +35,99 @@
 import "package:protobuf/protobuf.dart" as $pb;
 
 class FooKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t1 = new pro::BuilderInfo::•("FooKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep*>(1, "barKeep", #C1);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t1 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "FooKeep") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep>(1, (#C1) ?{core::String} "" : "barKeep", "barKeep", #C2);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String*, self::BarKeep*>(3, "mapKeep", "FooKeep.MapKeepEntry", #C2, "mapKeep", #C1, #C3);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String, self::BarKeep>(3, (#C1) ?{core::String} "" : "mapKeep", "FooKeep.MapKeepEntry", #C3, "mapKeep", #C2, #C4);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int*>(5, "aKeep", #C4);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep*>(6, "hasKeep", #C5);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep*>(7, "clearKeep", #C6);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int>(5, (#C1) ?{core::String} "" : "aKeep", #C5, "aKeep");
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep>(6, (#C1) ?{core::String} "" : "hasKeep", "hasKeep", #C6);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep>(7, (#C1) ?{core::String} "" : "clearKeep", "clearKeep", #C7);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t1;
-  constructor _() → self::FooKeep*
+  constructor _() → self::FooKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::FooKeep*
+  static factory •() → self::FooKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::FooKeep::_i;
-  @#C9
-  static method create() → self::FooKeep*
+  @#C10
+  static method create() → self::FooKeep
     return new self::FooKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C11
-  get barKeep() → self::BarKeep*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getN] [@vm.inferred-type.metadata=foo.pb.dart::BarKeep? (skip check)] this.{pro::GeneratedMessage::$_getN}<self::BarKeep*>(0);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C11
-  set barKeep([@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C12
+  get barKeep() → self::BarKeep
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getN] [@vm.inferred-type.metadata=foo.pb.dart::BarKeep? (skip check)] this.{pro::GeneratedMessage::$_getN}<self::BarKeep>(0);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C12
+  set barKeep([@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.setField] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::setField}(1, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C13
-  get mapKeep() → core::Map<core::String*, self::BarKeep*>*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String*, self::BarKeep*>(2);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=()->i]  @#C15
-  get aKeep() → core::int*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C14
+  get mapKeep() → core::Map<core::String, self::BarKeep>
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String, self::BarKeep>(2);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=()->i]  @#C16
+  get aKeep() → core::int
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getIZ] [@vm.inferred-type.metadata=int (skip check)] this.{pro::GeneratedMessage::$_getIZ}(4);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=(i)->b]  @#C15
-  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi (value: 43)] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=(i)->b]  @#C16
+  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi (value: 43)] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(4, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7,getterSelectorId:8]  @#C17
-  method hasHasKeep() → core::bool*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7,getterSelectorId:8]  @#C18
+  method hasHasKeep() → core::bool
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_has] [@vm.inferred-type.metadata=dart.core::bool (skip check)] this.{pro::GeneratedMessage::$_has}(5);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9,getterSelectorId:10]  @#C19
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9,getterSelectorId:10]  @#C20
   method clearClearKeep() → void
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.clearField] [@vm.inferred-type.metadata=dart.core::Null? (skip check) (value: null)] this.{pro::GeneratedMessage::clearField}(7);
 }
 class BarKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t2 = new pro::BuilderInfo::•("BarKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int*>(1, "aKeep", #C4);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t2 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "BarKeep") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int>(1, (#C1) ?{core::String} "" : "aKeep", #C5, "aKeep");
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t2;
-  constructor _() → self::BarKeep*
+  constructor _() → self::BarKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::BarKeep*
+  static factory •() → self::BarKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::BarKeep::_i;
-  @#C9
-  static method create() → self::BarKeep*
+  @#C10
+  static method create() → self::BarKeep
     return new self::BarKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=()->i]  @#C11
-  get aKeep() → core::int*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=()->i]  @#C12
+  get aKeep() → core::int
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getIZ] [@vm.inferred-type.metadata=int (skip check)] this.{pro::GeneratedMessage::$_getIZ}(0);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=(i)->b]  @#C11
-  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=(i)->b]  @#C12
+  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(0, v);
   }
 }
 class HasKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t3 = new pro::BuilderInfo::•("HasKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t3 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "HasKeep") in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t3;
-  constructor _() → self::HasKeep*
+  constructor _() → self::HasKeep
     : super pro::GeneratedMessage::•()
     ;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::HasKeep::_i;
-  @#C9
-  static method create() → self::HasKeep*
+  @#C10
+  static method create() → self::HasKeep
     return new self::HasKeep::_();
 }
 class ClearKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t4 = new pro::BuilderInfo::•("ClearKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t4 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "ClearKeep") in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t4;
-  constructor _() → self::ClearKeep*
+  constructor _() → self::ClearKeep
     : super pro::GeneratedMessage::•()
     ;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::ClearKeep::_i;
-  @#C9
-  static method create() → self::ClearKeep*
+  @#C10
+  static method create() → self::ClearKeep
     return new self::ClearKeep::_();
 }
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/decode_test.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/decode_test.dart.expect
index f59d5b9..73d4dc4 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/decode_test.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/decode_test.dart.expect
@@ -19,7 +19,7 @@
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.clearClearKeep] [@vm.inferred-type.metadata=!? (skip check)] foo.{pb::FooKeep::clearClearKeep}();
   });
 }
-library foo.pb.dart;
+library foo.pb.dart /*isNonNullableByDefault*/;
 import self as self;
 import "package:protobuf/protobuf.dart" as pro;
 import "dart:core" as core;
@@ -28,111 +28,87 @@
 import "package:protobuf/protobuf.dart" as $pb;
 
 class FooKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t1 = new pro::BuilderInfo::•("FooKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep*>(1, "barKeep", #C1);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t1 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "FooKeep", createEmptyInstance: #C2) in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep>(1, (#C1) ?{core::String} "" : "barKeep", "barKeep", #C3);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String*, self::BarKeep*>(3, "mapKeep", "FooKeep.MapKeepEntry", #C2, "mapKeep", #C1, #C3);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String, self::BarKeep>(3, (#C1) ?{core::String} "" : "mapKeep", "FooKeep.MapKeepEntry", #C4, "mapKeep", #C3, #C5);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int*>(5, "aKeep", #C4);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep*>(6, "hasKeep", #C5);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep*>(7, "clearKeep", #C6);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int>(5, (#C1) ?{core::String} "" : "aKeep", #C6, "aKeep");
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep>(6, (#C1) ?{core::String} "" : "hasKeep", "hasKeep", #C7);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep>(7, (#C1) ?{core::String} "" : "clearKeep", "clearKeep", #C8);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t1;
-  constructor _() → self::FooKeep*
+  constructor _() → self::FooKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::FooKeep*
-    return [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::create();
-  static factory fromBuffer([@vm.inferred-type.metadata=dart.core::_GrowableList?<dart.core::int*>] core::List<core::int*>* i) → self::FooKeep*
-    return let final self::FooKeep* #t2 = [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::create() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromBuffer] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::GeneratedMessage::mergeFromBuffer}(i, #C7);
+  static factory fromBuffer([@vm.inferred-type.metadata=dart.core::_GrowableList?<dart.core::int*>] core::List<core::int> i) → self::FooKeep
+    return let final self::FooKeep #t2 = [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::create() in block {
+      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromBuffer] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::GeneratedMessage::mergeFromBuffer}(i, #C9);
     } =>#t2;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:1,getterSelectorId:2]  method clone() → self::FooKeep*
-    return let final self::FooKeep* #t3 = [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::•() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromMessage] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::GeneratedMessage::mergeFromMessage}(this);
-    } =>#t3;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::FooKeep::_i;
-  @#C10
-  static method create() → self::FooKeep*
+  @#C12
+  static method create() → self::FooKeep
     return new self::FooKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C12
-  get barKeep() → self::BarKeep*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getN] [@vm.inferred-type.metadata=foo.pb.dart::BarKeep? (skip check)] this.{pro::GeneratedMessage::$_getN}<self::BarKeep*>(0);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:5]  @#C14
-  get mapKeep() → core::Map<core::String*, self::BarKeep*>*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String*, self::BarKeep*>(2);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:6] [@vm.unboxing-info.metadata=()->i]  @#C16
-  get aKeep() → core::int*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:2]  @#C14
+  get barKeep() → self::BarKeep
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getN] [@vm.inferred-type.metadata=foo.pb.dart::BarKeep? (skip check)] this.{pro::GeneratedMessage::$_getN}<self::BarKeep>(0);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  @#C16
+  get mapKeep() → core::Map<core::String, self::BarKeep>
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String, self::BarKeep>(2);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4] [@vm.unboxing-info.metadata=()->i]  @#C18
+  get aKeep() → core::int
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getIZ] [@vm.inferred-type.metadata=int (skip check)] this.{pro::GeneratedMessage::$_getIZ}(4);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7,getterSelectorId:8]  @#C18
-  method hasHasKeep() → core::bool*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6]  @#C20
+  method hasHasKeep() → core::bool
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_has] [@vm.inferred-type.metadata=dart.core::bool (skip check)] this.{pro::GeneratedMessage::$_has}(5);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9,getterSelectorId:10]  @#C20
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7,getterSelectorId:8]  @#C22
   method clearClearKeep() → void
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.clearField] [@vm.inferred-type.metadata=dart.core::Null? (skip check) (value: null)] this.{pro::GeneratedMessage::clearField}(7);
 }
 class BarKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t4 = new pro::BuilderInfo::•("BarKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::a}<core::int*>(1, "aKeep", #C4);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::hasRequiredFields} = false;
-  } =>#t4;
-  constructor _() → self::BarKeep*
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t3 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "BarKeep", createEmptyInstance: #C3) in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::a}<core::int>(1, (#C1) ?{core::String} "" : "aKeep", #C6, "aKeep");
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::hasRequiredFields} = false;
+  } =>#t3;
+  constructor _() → self::BarKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::BarKeep*
-    return [@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:1,getterSelectorId:2]  method clone() → self::BarKeep*
-    return let final self::BarKeep* #t5 = [@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep::•() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromMessage] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::GeneratedMessage::mergeFromMessage}(this);
-    } =>#t5;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::BarKeep::_i;
-  @#C10
-  static method create() → self::BarKeep*
+  @#C12
+  static method create() → self::BarKeep
     return new self::BarKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:11] [@vm.unboxing-info.metadata=()->i]  @#C12
-  get aKeep() → core::int*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:9] [@vm.unboxing-info.metadata=()->i]  @#C14
+  get aKeep() → core::int
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getIZ] [@vm.inferred-type.metadata=int (skip check)] this.{pro::GeneratedMessage::$_getIZ}(0);
 }
 class HasKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t6 = new pro::BuilderInfo::•("HasKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t6.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t6.{pro::BuilderInfo::hasRequiredFields} = false;
-  } =>#t6;
-  constructor _() → self::HasKeep*
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t4 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "HasKeep", createEmptyInstance: #C7) in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::hasRequiredFields} = false;
+  } =>#t4;
+  constructor _() → self::HasKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::HasKeep*
-    return [@vm.inferred-type.metadata=foo.pb.dart::HasKeep] self::HasKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:1,getterSelectorId:2]  method clone() → self::HasKeep*
-    return let final self::HasKeep* #t7 = [@vm.inferred-type.metadata=foo.pb.dart::HasKeep] self::HasKeep::•() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromMessage] [@vm.inferred-type.metadata=!? (skip check)] #t7.{pro::GeneratedMessage::mergeFromMessage}(this);
-    } =>#t7;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::HasKeep::_i;
-  @#C10
-  static method create() → self::HasKeep*
+  @#C12
+  static method create() → self::HasKeep
     return new self::HasKeep::_();
 }
 class ClearKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t8 = new pro::BuilderInfo::•("ClearKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t8.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t8.{pro::BuilderInfo::hasRequiredFields} = false;
-  } =>#t8;
-  constructor _() → self::ClearKeep*
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t5 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "ClearKeep", createEmptyInstance: #C8) in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::BuilderInfo::hasRequiredFields} = false;
+  } =>#t5;
+  constructor _() → self::ClearKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::ClearKeep*
-    return [@vm.inferred-type.metadata=foo.pb.dart::ClearKeep] self::ClearKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:1,getterSelectorId:2]  method clone() → self::ClearKeep*
-    return let final self::ClearKeep* #t9 = [@vm.inferred-type.metadata=foo.pb.dart::ClearKeep] self::ClearKeep::•() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromMessage] [@vm.inferred-type.metadata=!? (skip check)] #t9.{pro::GeneratedMessage::mergeFromMessage}(this);
-    } =>#t9;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::ClearKeep::_i;
-  @#C10
-  static method create() → self::ClearKeep*
+  @#C12
+  static method create() → self::ClearKeep
     return new self::ClearKeep::_();
 }
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/encode_all_fields.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/encode_all_fields.dart.expect
index 66a360a..09a43b0 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/encode_all_fields.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/encode_all_fields.dart.expect
@@ -15,10 +15,10 @@
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pb::BarKeep::aKeep} = 5;
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.bDrop] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pb::BarKeep::bDrop} = 4;
     } =>#t2;
-    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String*, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep*>*] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapKeep] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapKeep}.{core::Map::[]=}("foo", let final pb::BarKeep* #t3 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
+    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep>] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapKeep] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapKeep}.{core::Map::[]=}("foo", let final pb::BarKeep* #t3 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pb::BarKeep::aKeep} = 42;
     } =>#t3);
-    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String*, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::ZopDrop*>*] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapDrop] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapDrop}.{core::Map::[]=}("zop", let final pb::ZopDrop* #t4 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::ZopDrop] pb::ZopDrop::•() in block {
+    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::ZopDrop>] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapDrop] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapDrop}.{core::Map::[]=}("zop", let final pb::ZopDrop* #t4 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::ZopDrop] pb::ZopDrop::•() in block {
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::ZopDrop.aDrop] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pb::ZopDrop::aDrop} = 3;
     } =>#t4);
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pb::FooKeep::aKeep} = 43;
@@ -33,7 +33,7 @@
   }
   core::print("];");
 }
-library foo.pb.dart;
+library foo.pb.dart /*isNonNullableByDefault*/;
 import self as self;
 import "package:protobuf/protobuf.dart" as pro;
 import "dart:core" as core;
@@ -42,123 +42,123 @@
 import "package:protobuf/protobuf.dart" as $pb;
 
 class FooKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t1 = new pro::BuilderInfo::•("FooKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep*>(1, "barKeep", #C1);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t1 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "FooKeep") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep>(1, (#C1) ?{core::String} "" : "barKeep", "barKeep", #C2);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String*, self::BarKeep*>(3, "mapKeep", "FooKeep.MapKeepEntry", #C2, "mapKeep", #C1, #C3);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String*, self::ZopDrop*>(4, "mapDrop", "FooKeep.MapDropEntry", #C2, "mapDrop", #C4, #C3);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int*>(5, "aKeep", #C5);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep*>(6, "hasKeep", #C6);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep*>(7, "clearKeep", #C7);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String, self::BarKeep>(3, (#C1) ?{core::String} "" : "mapKeep", "FooKeep.MapKeepEntry", #C3, "mapKeep", #C2, #C4);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String, self::ZopDrop>(4, (#C1) ?{core::String} "" : "mapDrop", "FooKeep.MapDropEntry", #C3, "mapDrop", #C5, #C4);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int>(5, (#C1) ?{core::String} "" : "aKeep", #C6, "aKeep");
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep>(6, (#C1) ?{core::String} "" : "hasKeep", "hasKeep", #C7);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep>(7, (#C1) ?{core::String} "" : "clearKeep", "clearKeep", #C8);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t1;
-  constructor _() → self::FooKeep*
+  constructor _() → self::FooKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::FooKeep*
+  static factory •() → self::FooKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::FooKeep::_i;
-  @#C10
-  static method create() → self::FooKeep*
+  @#C11
+  static method create() → self::FooKeep
     return new self::FooKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2]  @#C12
-  set barKeep([@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2]  @#C13
+  set barKeep([@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.setField] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::setField}(1, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  @#C14
-  get mapKeep() → core::Map<core::String*, self::BarKeep*>*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String*, self::BarKeep*>(2);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C16
-  get mapDrop() → core::Map<core::String*, self::ZopDrop*>*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String*, self::ZopDrop*>(3);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5] [@vm.unboxing-info.metadata=(i)->b]  @#C18
-  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi (value: 43)] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  @#C15
+  get mapKeep() → core::Map<core::String, self::BarKeep>
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String, self::BarKeep>(2);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C17
+  get mapDrop() → core::Map<core::String, self::ZopDrop>
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String, self::ZopDrop>(3);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5] [@vm.unboxing-info.metadata=(i)->b]  @#C19
+  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi (value: 43)] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(4, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:6]  @#C20
-  set hasKeep([@vm.inferred-type.metadata=foo.pb.dart::HasKeep] self::HasKeep* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:6]  @#C21
+  set hasKeep([@vm.inferred-type.metadata=foo.pb.dart::HasKeep] self::HasKeep v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.setField] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::setField}(6, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7]  @#C22
-  set clearKeep([@vm.inferred-type.metadata=foo.pb.dart::ClearKeep] self::ClearKeep* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7]  @#C23
+  set clearKeep([@vm.inferred-type.metadata=foo.pb.dart::ClearKeep] self::ClearKeep v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.setField] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::setField}(7, v);
   }
 }
 class BarKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t2 = new pro::BuilderInfo::•("BarKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int*>(1, "aKeep", #C5);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int*>(2, "bDrop", #C5);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t2 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "BarKeep") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int>(1, (#C1) ?{core::String} "" : "aKeep", #C6, "aKeep");
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int>(2, (#C1) ?{core::String} "" : "bDrop", #C6, "bDrop");
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t2;
-  constructor _() → self::BarKeep*
+  constructor _() → self::BarKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::BarKeep*
+  static factory •() → self::BarKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::BarKeep::_i;
-  @#C10
-  static method create() → self::BarKeep*
+  @#C11
+  static method create() → self::BarKeep
     return new self::BarKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:8] [@vm.unboxing-info.metadata=(i)->b]  @#C12
-  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:8] [@vm.unboxing-info.metadata=(i)->b]  @#C13
+  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(0, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9] [@vm.unboxing-info.metadata=(i)->b]  @#C24
-  set bDrop([@vm.inferred-type.metadata=dart.core::_Smi (value: 4)] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9] [@vm.unboxing-info.metadata=(i)->b]  @#C25
+  set bDrop([@vm.inferred-type.metadata=dart.core::_Smi (value: 4)] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(1, v);
   }
 }
 class HasKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t3 = new pro::BuilderInfo::•("HasKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t3 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "HasKeep") in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t3;
-  constructor _() → self::HasKeep*
+  constructor _() → self::HasKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::HasKeep*
+  static factory •() → self::HasKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::HasKeep] self::HasKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::HasKeep::_i;
-  @#C10
-  static method create() → self::HasKeep*
+  @#C11
+  static method create() → self::HasKeep
     return new self::HasKeep::_();
 }
 class ClearKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t4 = new pro::BuilderInfo::•("ClearKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t4 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "ClearKeep") in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t4;
-  constructor _() → self::ClearKeep*
+  constructor _() → self::ClearKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::ClearKeep*
+  static factory •() → self::ClearKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::ClearKeep] self::ClearKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::ClearKeep::_i;
-  @#C10
-  static method create() → self::ClearKeep*
+  @#C11
+  static method create() → self::ClearKeep
     return new self::ClearKeep::_();
 }
 class ZopDrop extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t5 = new pro::BuilderInfo::•("ZopDrop") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::BuilderInfo::a}<core::int*>(1, "aDrop", #C5);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t5 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "ZopDrop") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::BuilderInfo::a}<core::int>(1, (#C1) ?{core::String} "" : "aDrop", #C6, "aDrop");
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t5;
-  constructor _() → self::ZopDrop*
+  constructor _() → self::ZopDrop
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::ZopDrop*
+  static factory •() → self::ZopDrop
     return [@vm.inferred-type.metadata=foo.pb.dart::ZopDrop] self::ZopDrop::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::ZopDrop::_i;
-  @#C10
-  static method create() → self::ZopDrop*
+  @#C11
+  static method create() → self::ZopDrop
     return new self::ZopDrop::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:10] [@vm.unboxing-info.metadata=(i)->b]  @#C12
-  set aDrop([@vm.inferred-type.metadata=dart.core::_Smi (value: 3)] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:10] [@vm.unboxing-info.metadata=(i)->b]  @#C13
+  set aDrop([@vm.inferred-type.metadata=dart.core::_Smi (value: 3)] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(0, v);
   }
 }
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/freeze_test.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/freeze_test.dart.expect
index 6423786..50cebc8 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/freeze_test.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/freeze_test.dart.expect
@@ -16,7 +16,7 @@
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.barKeep] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pb::FooKeep::barKeep} = let final pb::BarKeep* #t2 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pb::BarKeep::aKeep} = 5;
     } =>#t2;
-    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String*, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep*>*] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapKeep] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapKeep}.{core::Map::[]=}("foo", let final pb::BarKeep* #t3 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
+    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<dart.core::String, library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep>] [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.mapKeep] [@vm.inferred-type.metadata=!] #t1.{pb::FooKeep::mapKeep}.{core::Map::[]=}("foo", let final pb::BarKeep* #t3 = [@vm.inferred-type.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep] pb::BarKeep::•() in block {
       [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::BarKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pb::BarKeep::aKeep} = 2;
     } =>#t3);
     [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.aKeep] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pb::FooKeep::aKeep} = 43;
@@ -30,7 +30,7 @@
     exp::expect(() → void => [@vm.direct-call.metadata=library file:pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart::FooKeep.clearClearKeep] [@vm.inferred-type.metadata=!? (skip check)] foo.{pb::FooKeep::clearClearKeep}(), [@vm.inferred-type.metadata=library package:test_api/src/frontend/throws_matcher.dart::Throws] thr::throwsA(#C2));
   });
 }
-library foo.pb.dart;
+library foo.pb.dart /*isNonNullableByDefault*/;
 import self as self;
 import "package:protobuf/protobuf.dart" as pro;
 import "dart:core" as core;
@@ -39,99 +39,99 @@
 import "package:protobuf/protobuf.dart" as $pb;
 
 class FooKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t1 = new pro::BuilderInfo::•("FooKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep*>(1, "barKeep", #C1);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t1 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "FooKeep") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::BarKeep>(1, (#C1) ?{core::String} "" : "barKeep", "barKeep", #C2);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String*, self::BarKeep*>(3, "mapKeep", "FooKeep.MapKeepEntry", #C2, "mapKeep", #C1, #C3);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.m] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::m}<core::String, self::BarKeep>(3, (#C1) ?{core::String} "" : "mapKeep", "FooKeep.MapKeepEntry", #C3, "mapKeep", #C2, #C4);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int*>(5, "aKeep", #C4);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep*>(6, "hasKeep", #C5);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep*>(7, "clearKeep", #C6);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::a}<core::int>(5, (#C1) ?{core::String} "" : "aKeep", #C5, "aKeep");
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::HasKeep>(6, (#C1) ?{core::String} "" : "hasKeep", "hasKeep", #C6);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::aOM}<self::ClearKeep>(7, (#C1) ?{core::String} "" : "clearKeep", "clearKeep", #C7);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t1;
-  constructor _() → self::FooKeep*
+  constructor _() → self::FooKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::FooKeep*
+  static factory •() → self::FooKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::FooKeep] self::FooKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::FooKeep::_i;
-  @#C9
-  static method create() → self::FooKeep*
+  @#C10
+  static method create() → self::FooKeep
     return new self::FooKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C11
-  get barKeep() → self::BarKeep*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getN] [@vm.inferred-type.metadata=foo.pb.dart::BarKeep? (skip check)] this.{pro::GeneratedMessage::$_getN}<self::BarKeep*>(0);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C11
-  set barKeep([@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C12
+  get barKeep() → self::BarKeep
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getN] [@vm.inferred-type.metadata=foo.pb.dart::BarKeep? (skip check)] this.{pro::GeneratedMessage::$_getN}<self::BarKeep>(0);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C12
+  set barKeep([@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.setField] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::setField}(1, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C13
-  get mapKeep() → core::Map<core::String*, self::BarKeep*>*
-    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String*, self::BarKeep*>(2);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=()->i]  @#C15
-  get aKeep() → core::int*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:4]  @#C14
+  get mapKeep() → core::Map<core::String, self::BarKeep>
+    return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getMap] [@vm.inferred-type.metadata=! (skip check)] this.{pro::GeneratedMessage::$_getMap}<core::String, self::BarKeep>(2);
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=()->i]  @#C16
+  get aKeep() → core::int
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getIZ] [@vm.inferred-type.metadata=int (skip check)] this.{pro::GeneratedMessage::$_getIZ}(4);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=(i)->b]  @#C15
-  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi (value: 43)] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:5,getterSelectorId:6] [@vm.unboxing-info.metadata=(i)->b]  @#C16
+  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi (value: 43)] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(4, v);
   }
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7,getterSelectorId:8]  @#C17
-  method hasHasKeep() → core::bool*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:7,getterSelectorId:8]  @#C18
+  method hasHasKeep() → core::bool
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_has] [@vm.inferred-type.metadata=dart.core::bool (skip check)] this.{pro::GeneratedMessage::$_has}(5);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9,getterSelectorId:10]  @#C19
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:9,getterSelectorId:10]  @#C20
   method clearClearKeep() → void
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.clearField] [@vm.inferred-type.metadata=dart.core::Null? (skip check) (value: null)] this.{pro::GeneratedMessage::clearField}(7);
 }
 class BarKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t2 = new pro::BuilderInfo::•("BarKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int*>(1, "aKeep", #C4);
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t2 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "BarKeep") in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.a] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::a}<core::int>(1, (#C1) ?{core::String} "" : "aKeep", #C5, "aKeep");
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t2;
-  constructor _() → self::BarKeep*
+  constructor _() → self::BarKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::BarKeep*
+  static factory •() → self::BarKeep
     return [@vm.inferred-type.metadata=foo.pb.dart::BarKeep] self::BarKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::BarKeep::_i;
-  @#C9
-  static method create() → self::BarKeep*
+  @#C10
+  static method create() → self::BarKeep
     return new self::BarKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=()->i]  @#C11
-  get aKeep() → core::int*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=()->i]  @#C12
+  get aKeep() → core::int
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_getIZ] [@vm.inferred-type.metadata=int (skip check)] this.{pro::GeneratedMessage::$_getIZ}(0);
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=(i)->b]  @#C11
-  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi] core::int* v) → void {
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:11,getterSelectorId:12] [@vm.unboxing-info.metadata=(i)->b]  @#C12
+  set aKeep([@vm.inferred-type.metadata=dart.core::_Smi] core::int v) → void {
     [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_setSignedInt32] [@vm.inferred-type.metadata=!? (skip check)] this.{pro::GeneratedMessage::$_setSignedInt32}(0, v);
   }
 }
 class HasKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t3 = new pro::BuilderInfo::•("HasKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t3 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "HasKeep") in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t3;
-  constructor _() → self::HasKeep*
+  constructor _() → self::HasKeep
     : super pro::GeneratedMessage::•()
     ;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::HasKeep::_i;
-  @#C9
-  static method create() → self::HasKeep*
+  @#C10
+  static method create() → self::HasKeep
     return new self::HasKeep::_();
 }
 class ClearKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t4 = new pro::BuilderInfo::•("ClearKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t4 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "ClearKeep") in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.add] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::add}<Null>(0, null, null, null, null, null, null);
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t4;
-  constructor _() → self::ClearKeep*
+  constructor _() → self::ClearKeep
     : super pro::GeneratedMessage::•()
     ;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::ClearKeep::_i;
-  @#C9
-  static method create() → self::ClearKeep*
+  @#C10
+  static method create() → self::ClearKeep
     return new self::ClearKeep::_();
 }
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart
index cab7883..19c9bac5 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/foo.pb.dart
@@ -2,38 +2,40 @@
 //  Generated code. Do not modify.
 //  source: foo.proto
 //
-// @dart = 2.3
-// ignore_for_file: camel_case_types,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type
+// @dart = 2.12
+// ignore_for_file: annotate_overrides,camel_case_types,unnecessary_const,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type,unnecessary_this,prefer_final_fields
 
 import 'dart:core' as $core;
 
 import 'package:protobuf/protobuf.dart' as $pb;
 
 class FooKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('FooKeep', createEmptyInstance: create)
-        ..aOM<BarKeep>(1, 'barKeep',
-            protoName: 'barKeep', subBuilder: BarKeep.create)
-        ..aOM<BarKeep>(2, 'barDrop',
-            protoName: 'barDrop', subBuilder: BarKeep.create)
-        ..m<$core.String, BarKeep>(3, 'mapKeep',
-            protoName: 'mapKeep',
-            entryClassName: 'FooKeep.MapKeepEntry',
-            keyFieldType: $pb.PbFieldType.OS,
-            valueFieldType: $pb.PbFieldType.OM,
-            valueCreator: BarKeep.create)
-        ..m<$core.String, ZopDrop>(4, 'mapDrop',
-            protoName: 'mapDrop',
-            entryClassName: 'FooKeep.MapDropEntry',
-            keyFieldType: $pb.PbFieldType.OS,
-            valueFieldType: $pb.PbFieldType.OM,
-            valueCreator: ZopDrop.create)
-        ..a<$core.int>(5, 'aKeep', $pb.PbFieldType.O3, protoName: 'aKeep')
-        ..aOM<HasKeep>(6, 'hasKeep',
-            protoName: 'hasKeep', subBuilder: HasKeep.create)
-        ..aOM<ClearKeep>(7, 'clearKeep',
-            protoName: 'clearKeep', subBuilder: ClearKeep.create)
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(const $core.bool.fromEnvironment('protobuf.omit_message_names') ? '' : 'FooKeep',
+      createEmptyInstance: create)
+    ..aOM<BarKeep>(1, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'barKeep',
+        protoName: 'barKeep', subBuilder: BarKeep.create)
+    ..aOM<BarKeep>(2, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'barDrop',
+        protoName: 'barDrop', subBuilder: BarKeep.create)
+    ..m<$core.String, BarKeep>(3, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'mapKeep',
+        protoName: 'mapKeep',
+        entryClassName: 'FooKeep.MapKeepEntry',
+        keyFieldType: $pb.PbFieldType.OS,
+        valueFieldType: $pb.PbFieldType.OM,
+        valueCreator: BarKeep.create)
+    ..m<$core.String, ZopDrop>(
+        4, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'mapDrop',
+        protoName: 'mapDrop',
+        entryClassName: 'FooKeep.MapDropEntry',
+        keyFieldType: $pb.PbFieldType.OS,
+        valueFieldType: $pb.PbFieldType.OM,
+        valueCreator: ZopDrop.create)
+    ..a<$core.int>(5, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'aKeep', $pb.PbFieldType.O3,
+        protoName: 'aKeep')
+    ..aOM<HasKeep>(6, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'hasKeep',
+        protoName: 'hasKeep', subBuilder: HasKeep.create)
+    ..aOM<ClearKeep>(7, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'clearKeep',
+        protoName: 'clearKeep', subBuilder: ClearKeep.create)
+    ..hasRequiredFields = false;
 
   FooKeep._() : super();
   factory FooKeep() => create();
@@ -43,9 +45,16 @@
   factory FooKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   FooKeep clone() => FooKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   FooKeep copyWith(void Function(FooKeep) updates) =>
-      super.copyWith((message) => updates(message as FooKeep));
+      super.copyWith((message) => updates(message as FooKeep))
+          as FooKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static FooKeep create() => FooKeep._();
@@ -54,7 +63,7 @@
   @$core.pragma('dart2js:noInline')
   static FooKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<FooKeep>(create);
-  static FooKeep _defaultInstance;
+  static FooKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   BarKeep get barKeep => $_getN(0);
@@ -132,11 +141,26 @@
 }
 
 class BarKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('BarKeep', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aKeep', $pb.PbFieldType.O3, protoName: 'aKeep')
-        ..a<$core.int>(2, 'bDrop', $pb.PbFieldType.O3, protoName: 'bDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'BarKeep',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aKeep',
+        $pb.PbFieldType.O3,
+        protoName: 'aKeep')
+    ..a<$core.int>(
+        2,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'bDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'bDrop')
+    ..hasRequiredFields = false;
 
   BarKeep._() : super();
   factory BarKeep() => create();
@@ -146,9 +170,16 @@
   factory BarKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   BarKeep clone() => BarKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   BarKeep copyWith(void Function(BarKeep) updates) =>
-      super.copyWith((message) => updates(message as BarKeep));
+      super.copyWith((message) => updates(message as BarKeep))
+          as BarKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static BarKeep create() => BarKeep._();
@@ -157,7 +188,7 @@
   @$core.pragma('dart2js:noInline')
   static BarKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<BarKeep>(create);
-  static BarKeep _defaultInstance;
+  static BarKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aKeep => $_getIZ(0);
@@ -185,10 +216,19 @@
 }
 
 class HasKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('HasKeep', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'HasKeep',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   HasKeep._() : super();
   factory HasKeep() => create();
@@ -198,9 +238,16 @@
   factory HasKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   HasKeep clone() => HasKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   HasKeep copyWith(void Function(HasKeep) updates) =>
-      super.copyWith((message) => updates(message as HasKeep));
+      super.copyWith((message) => updates(message as HasKeep))
+          as HasKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static HasKeep create() => HasKeep._();
@@ -209,7 +256,7 @@
   @$core.pragma('dart2js:noInline')
   static HasKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<HasKeep>(create);
-  static HasKeep _defaultInstance;
+  static HasKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
@@ -225,10 +272,19 @@
 }
 
 class ClearKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('ClearKeep', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'ClearKeep',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   ClearKeep._() : super();
   factory ClearKeep() => create();
@@ -238,9 +294,16 @@
   factory ClearKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   ClearKeep clone() => ClearKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   ClearKeep copyWith(void Function(ClearKeep) updates) =>
-      super.copyWith((message) => updates(message as ClearKeep));
+      super.copyWith((message) => updates(message as ClearKeep))
+          as ClearKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static ClearKeep create() => ClearKeep._();
@@ -249,7 +312,7 @@
   @$core.pragma('dart2js:noInline')
   static ClearKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<ClearKeep>(create);
-  static ClearKeep _defaultInstance;
+  static ClearKeep? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
@@ -265,10 +328,19 @@
 }
 
 class ZopDrop extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('ZopDrop', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'ZopDrop',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   ZopDrop._() : super();
   factory ZopDrop() => create();
@@ -278,9 +350,16 @@
   factory ZopDrop.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   ZopDrop clone() => ZopDrop()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   ZopDrop copyWith(void Function(ZopDrop) updates) =>
-      super.copyWith((message) => updates(message as ZopDrop));
+      super.copyWith((message) => updates(message as ZopDrop))
+          as ZopDrop; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static ZopDrop create() => ZopDrop._();
@@ -289,7 +368,7 @@
   @$core.pragma('dart2js:noInline')
   static ZopDrop getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<ZopDrop>(create);
-  static ZopDrop _defaultInstance;
+  static ZopDrop? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
@@ -305,10 +384,19 @@
 }
 
 class MobDrop extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('MobDrop', createEmptyInstance: create)
-        ..a<$core.int>(1, 'aDrop', $pb.PbFieldType.O3, protoName: 'aDrop')
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'MobDrop',
+      createEmptyInstance: create)
+    ..a<$core.int>(
+        1,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'aDrop',
+        $pb.PbFieldType.O3,
+        protoName: 'aDrop')
+    ..hasRequiredFields = false;
 
   MobDrop._() : super();
   factory MobDrop() => create();
@@ -318,9 +406,16 @@
   factory MobDrop.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   MobDrop clone() => MobDrop()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   MobDrop copyWith(void Function(MobDrop) updates) =>
-      super.copyWith((message) => updates(message as MobDrop));
+      super.copyWith((message) => updates(message as MobDrop))
+          as MobDrop; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static MobDrop create() => MobDrop._();
@@ -329,7 +424,7 @@
   @$core.pragma('dart2js:noInline')
   static MobDrop getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<MobDrop>(create);
-  static MobDrop _defaultInstance;
+  static MobDrop? _defaultInstance;
 
   @$pb.TagNumber(1)
   $core.int get aDrop => $_getIZ(0);
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/name_mangling.pb.dart b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/name_mangling.pb.dart
index bc76b27..c42141a 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/name_mangling.pb.dart
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/generated/name_mangling.pb.dart
@@ -2,17 +2,20 @@
 //  Generated code. Do not modify.
 //  source: name_mangling.proto
 //
-// @dart = 2.3
-// ignore_for_file: camel_case_types,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type
+// @dart = 2.12
+// ignore_for_file: annotate_overrides,camel_case_types,unnecessary_const,non_constant_identifier_names,library_prefixes,unused_import,unused_shown_name,return_of_invalid_type,unnecessary_this,prefer_final_fields
 
 import 'dart:core' as $core;
 
 import 'package:protobuf/protobuf.dart' as $pb;
 
 class AKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('AKeep', createEmptyInstance: create)
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'AKeep',
+      createEmptyInstance: create)
+    ..hasRequiredFields = false;
 
   AKeep._() : super();
   factory AKeep() => create();
@@ -22,9 +25,16 @@
   factory AKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   AKeep clone() => AKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   AKeep copyWith(void Function(AKeep) updates) =>
-      super.copyWith((message) => updates(message as AKeep));
+      super.copyWith((message) => updates(message as AKeep))
+          as AKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static AKeep create() => AKeep._();
@@ -33,14 +43,22 @@
   @$core.pragma('dart2js:noInline')
   static AKeep getDefault() =>
       _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<AKeep>(create);
-  static AKeep _defaultInstance;
+  static AKeep? _defaultInstance;
 }
 
 class NameManglingKeep extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i =
-      $pb.BuilderInfo('NameManglingKeep', createEmptyInstance: create)
-        ..aOM<AKeep>(10, 'clone', subBuilder: AKeep.create)
-        ..hasRequiredFields = false;
+  static final $pb.BuilderInfo _i = $pb.BuilderInfo(
+      const $core.bool.fromEnvironment('protobuf.omit_message_names')
+          ? ''
+          : 'NameManglingKeep',
+      createEmptyInstance: create)
+    ..aOM<AKeep>(
+        10,
+        const $core.bool.fromEnvironment('protobuf.omit_field_names')
+            ? ''
+            : 'clone',
+        subBuilder: AKeep.create)
+    ..hasRequiredFields = false;
 
   NameManglingKeep._() : super();
   factory NameManglingKeep() => create();
@@ -50,9 +68,16 @@
   factory NameManglingKeep.fromJson($core.String i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
       create()..mergeFromJson(i, r);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
+      'Will be removed in next major version')
   NameManglingKeep clone() => NameManglingKeep()..mergeFromMessage(this);
+  @$core.Deprecated('Using this can add significant overhead to your binary. '
+      'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
+      'Will be removed in next major version')
   NameManglingKeep copyWith(void Function(NameManglingKeep) updates) =>
-      super.copyWith((message) => updates(message as NameManglingKeep));
+      super.copyWith((message) => updates(message as NameManglingKeep))
+          as NameManglingKeep; // ignore: deprecated_member_use
   $pb.BuilderInfo get info_ => _i;
   @$core.pragma('dart2js:noInline')
   static NameManglingKeep create() => NameManglingKeep._();
@@ -62,7 +87,7 @@
   @$core.pragma('dart2js:noInline')
   static NameManglingKeep getDefault() => _defaultInstance ??=
       $pb.GeneratedMessage.$_defaultFor<NameManglingKeep>(create);
-  static NameManglingKeep _defaultInstance;
+  static NameManglingKeep? _defaultInstance;
 
   @$pb.TagNumber(10)
   AKeep get clone_10 => $_getN(0);
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/name_mangling_test.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/name_mangling_test.dart.expect
index 599d0eb..7f311bf 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/name_mangling_test.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/protobuf_handler/lib/name_mangling_test.dart.expect
@@ -12,7 +12,7 @@
     core::print("Has clone field");
   }
 }
-library name_mangling.pb.dart;
+library name_mangling.pb.dart /*isNonNullableByDefault*/;
 import self as self;
 import "package:protobuf/protobuf.dart" as pro;
 import "dart:core" as core;
@@ -21,48 +21,36 @@
 import "package:protobuf/protobuf.dart" as $pb;
 
 class AKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t1 = new pro::BuilderInfo::•("AKeep") in block {
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t1 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "AKeep", #C2) in block {
     [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t1.{pro::BuilderInfo::hasRequiredFields} = false;
   } =>#t1;
-  constructor _() → self::AKeep*
+  constructor _() → self::AKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::AKeep*
-    return [@vm.inferred-type.metadata=name_mangling.pb.dart::AKeep] self::AKeep::create();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:1,getterSelectorId:2]  method clone() → self::AKeep*
-    return let final self::AKeep* #t2 = [@vm.inferred-type.metadata=name_mangling.pb.dart::AKeep] self::AKeep::•() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromMessage] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::GeneratedMessage::mergeFromMessage}(this);
-    } =>#t2;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  get info_() → pro::BuilderInfo*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::AKeep::_i;
-  @#C3
-  static method create() → self::AKeep*
+  @#C5
+  static method create() → self::AKeep
     return new self::AKeep::_();
 }
 class NameManglingKeep extends pro::GeneratedMessage {
-[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo* _i = let final pro::BuilderInfo* #t3 = new pro::BuilderInfo::•("NameManglingKeep") in block {
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::aOM}<self::AKeep*>(10, "clone", #C4);
-    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::BuilderInfo::hasRequiredFields} = false;
-  } =>#t3;
-  constructor _() → self::NameManglingKeep*
+[@vm.inferred-type.metadata=protobuf::BuilderInfo?]  static final field pro::BuilderInfo _i = let final pro::BuilderInfo #t2 = new pro::BuilderInfo::•((#C1) ?{core::String} "" : "NameManglingKeep", #C6) in block {
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.aOM] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::aOM}<self::AKeep>(10, (#C1) ?{core::String} "" : "clone", #C2);
+    [@vm.direct-call.metadata=protobuf::BuilderInfo.hasRequiredFields] [@vm.inferred-type.metadata=!? (skip check)] #t2.{pro::BuilderInfo::hasRequiredFields} = false;
+  } =>#t2;
+  constructor _() → self::NameManglingKeep
     : super pro::GeneratedMessage::•()
     ;
-  static factory •() → self::NameManglingKeep*
-    return [@vm.inferred-type.metadata=name_mangling.pb.dart::NameManglingKeep] self::NameManglingKeep::create();
-  static factory fromBuffer([@vm.inferred-type.metadata=dart.core::_GrowableList<dart.core::int*>] core::List<core::int*>* i) → self::NameManglingKeep*
-    return let final self::NameManglingKeep* #t4 = [@vm.inferred-type.metadata=name_mangling.pb.dart::NameManglingKeep] self::NameManglingKeep::create() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromBuffer] [@vm.inferred-type.metadata=!? (skip check)] #t4.{pro::GeneratedMessage::mergeFromBuffer}(i, #C5);
-    } =>#t4;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:1,getterSelectorId:2]  method clone() → self::NameManglingKeep*
-    return let final self::NameManglingKeep* #t5 = [@vm.inferred-type.metadata=name_mangling.pb.dart::NameManglingKeep] self::NameManglingKeep::•() in block {
-      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromMessage] [@vm.inferred-type.metadata=!? (skip check)] #t5.{pro::GeneratedMessage::mergeFromMessage}(this);
-    } =>#t5;
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:3]  get info_() → pro::BuilderInfo*
+  static factory fromBuffer([@vm.inferred-type.metadata=dart.core::_GrowableList<dart.core::int*>] core::List<core::int> i) → self::NameManglingKeep
+    return let final self::NameManglingKeep #t3 = [@vm.inferred-type.metadata=name_mangling.pb.dart::NameManglingKeep] self::NameManglingKeep::create() in block {
+      [@vm.direct-call.metadata=protobuf::GeneratedMessage.mergeFromBuffer] [@vm.inferred-type.metadata=!? (skip check)] #t3.{pro::GeneratedMessage::mergeFromBuffer}(i, #C7);
+    } =>#t3;
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasNonThisUses:false,hasTearOffUses:false,getterSelectorId:1]  get info_() → pro::BuilderInfo
     return [@vm.inferred-type.metadata=protobuf::BuilderInfo?] self::NameManglingKeep::_i;
-  @#C3
-  static method create() → self::NameManglingKeep*
+  @#C5
+  static method create() → self::NameManglingKeep
     return new self::NameManglingKeep::_();
-[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:4,getterSelectorId:5]  @#C7
-  method hasClone_10() → core::bool*
+[@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  @#C9
+  method hasClone_10() → core::bool
     return [@vm.direct-call.metadata=protobuf::GeneratedMessage.$_has] [@vm.inferred-type.metadata=dart.core::bool (skip check)] this.{pro::GeneratedMessage::$_has}(0);
 }
diff --git a/runtime/vm/compiler/backend/flow_graph_compiler.cc b/runtime/vm/compiler/backend/flow_graph_compiler.cc
index 546e56c..57ba87a 100644
--- a/runtime/vm/compiler/backend/flow_graph_compiler.cc
+++ b/runtime/vm/compiler/backend/flow_graph_compiler.cc
@@ -2786,21 +2786,6 @@
   if (dst_type.IsNull()) {
     __ Comment("AssertAssignable for runtime type");
     // kDstTypeReg should already contain the destination type.
-    const bool null_safety = isolate()->use_strict_null_safety_checks();
-    GenerateStubCall(token_pos,
-                     StubCode::GetTypeIsTopTypeForSubtyping(null_safety),
-                     PcDescriptorsLayout::kOther, locs, deopt_id);
-    // TypeTestABI::kSubtypeTestCacheReg is 0 if the type is a top type.
-    __ BranchIfZero(TypeTestABI::kSubtypeTestCacheReg, &done,
-                    compiler::Assembler::kNearJump);
-
-    GenerateStubCall(token_pos,
-                     StubCode::GetNullIsAssignableToType(null_safety),
-                     PcDescriptorsLayout::kOther, locs, deopt_id);
-    // TypeTestABI::kSubtypeTestCacheReg is 0 if the object is null and is
-    // assignable.
-    __ BranchIfZero(TypeTestABI::kSubtypeTestCacheReg, &done,
-                    compiler::Assembler::kNearJump);
   } else {
     __ Comment("AssertAssignable for compile-time type");
     GenerateCallerChecksForAssertAssignable(receiver_type, dst_type, &done);
diff --git a/runtime/vm/compiler/backend/flow_graph_compiler_ia32.cc b/runtime/vm/compiler/backend/flow_graph_compiler_ia32.cc
index 2c29653..e0cb95a 100644
--- a/runtime/vm/compiler/backend/flow_graph_compiler_ia32.cc
+++ b/runtime/vm/compiler/backend/flow_graph_compiler_ia32.cc
@@ -361,14 +361,16 @@
     const bool null_safety =
         Isolate::Current()->use_strict_null_safety_checks();
     GenerateStubCall(token_pos,
-                     StubCode::GetTypeIsTopTypeForSubtyping(null_safety),
+                     null_safety ? StubCode::TypeIsTopTypeForSubtypingNullSafe()
+                                 : StubCode::TypeIsTopTypeForSubtyping(),
                      PcDescriptorsLayout::kOther, locs, deopt_id);
     // TypeTestABI::kSubtypeTestCacheReg is 0 if the type is a top type.
     __ BranchIfZero(TypeTestABI::kSubtypeTestCacheReg, &is_assignable,
                     compiler::Assembler::kNearJump);
 
     GenerateStubCall(token_pos,
-                     StubCode::GetNullIsAssignableToType(null_safety),
+                     null_safety ? StubCode::NullIsAssignableToTypeNullSafe()
+                                 : StubCode::NullIsAssignableToType(),
                      PcDescriptorsLayout::kOther, locs, deopt_id);
     // TypeTestABI::kSubtypeTestCacheReg is 0 if the object is null and is
     // assignable.
diff --git a/runtime/vm/stub_code.cc b/runtime/vm/stub_code.cc
index 3dea626..7f8f3a3 100644
--- a/runtime/vm/stub_code.cc
+++ b/runtime/vm/stub_code.cc
@@ -277,16 +277,6 @@
   return Code::null();
 }
 
-const Code& StubCode::GetTypeIsTopTypeForSubtyping(bool null_safety) {
-  return null_safety ? StubCode::TypeIsTopTypeForSubtypingNullSafe()
-                     : StubCode::TypeIsTopTypeForSubtyping();
-}
-
-const Code& StubCode::GetNullIsAssignableToType(bool null_safety) {
-  return null_safety ? StubCode::NullIsAssignableToTypeNullSafe()
-                     : StubCode::NullIsAssignableToType();
-}
-
 #if !defined(TARGET_ARCH_IA32)
 CodePtr StubCode::GetBuildMethodExtractorStub(
     compiler::ObjectPoolBuilder* pool) {
diff --git a/runtime/vm/stub_code.h b/runtime/vm/stub_code.h
index d54ee02..a946cd5 100644
--- a/runtime/vm/stub_code.h
+++ b/runtime/vm/stub_code.h
@@ -68,10 +68,6 @@
   static CodePtr GetBuildMethodExtractorStub(compiler::ObjectPoolBuilder* pool);
 #endif
 
-  static const Code& GetTypeIsTopTypeForSubtyping(bool null_safety);
-
-  static const Code& GetNullIsAssignableToType(bool null_safety);
-
 #if !defined(DART_PRECOMPILED_RUNTIME)
   // Generate the stub and finalize the generated code into the stub
   // code executable area.
diff --git a/tools/VERSION b/tools/VERSION
index 171a1a9..82152ac 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 12
 PATCH 0
-PRERELEASE 60
+PRERELEASE 61
 PRERELEASE_PATCH 0
\ No newline at end of file