[ddc] Use exhaustive switch when deferring types
Now that the `DartType` class hierarchy is sealed if-else chains over
different `DartType`s can be replaced with exhaustive switch
statements.
Ensures the coverage of all types and provides compile time errors
when new types are added without handling them instead of the awkward
assertion logic that we had before.
Issue: https://github.com/dart-lang/sdk/issues/53566
Change-Id: I8b0274d00cfe77fe64c15647b19e75a222afdba8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/326902
Reviewed-by: Anna Gringauze <annagrin@google.com>
Commit-Queue: Nicholas Shahan <nshahan@google.com>
diff --git a/pkg/dev_compiler/lib/src/kernel/compiler.dart b/pkg/dev_compiler/lib/src/kernel/compiler.dart
index 19f274d..3ad5256 100644
--- a/pkg/dev_compiler/lib/src/kernel/compiler.dart
+++ b/pkg/dev_compiler/lib/src/kernel/compiler.dart
@@ -1206,50 +1206,67 @@
{bool emitNullability = true}) {
js_ast.Expression emitDeferredType(DartType t,
{bool emitNullability = true}) {
- if (t is InterfaceType) {
- _declareBeforeUse(t.classNode);
- if (t.typeArguments.isNotEmpty) {
- var typeRep = _emitGenericClassType(
- t,
- _options.newRuntimeTypes
- // No reason to defer type arguments in the new type
- // representation.
- ? t.typeArguments.map(_emitType)
- : t.typeArguments.map(emitDeferredType));
+ switch (t) {
+ case InterfaceType():
+ _declareBeforeUse(t.classNode);
+ if (t.typeArguments.isNotEmpty) {
+ var typeRep = _emitGenericClassType(
+ t,
+ _options.newRuntimeTypes
+ // No reason to defer type arguments in the new type
+ // representation.
+ ? t.typeArguments.map(_emitType)
+ : t.typeArguments.map(emitDeferredType));
+ return emitNullability
+ ? _emitNullabilityWrapper(typeRep, t.declaredNullability)
+ : typeRep;
+ }
+ return _emitInterfaceType(t, emitNullability: emitNullability);
+ case FutureOrType():
+ var normalizedType = _futureOrNormalizer.normalize(t);
+ if (normalizedType is FutureOrType) {
+ _declareBeforeUse(_coreTypes.deprecatedFutureOrClass);
+ var typeRep = _emitFutureOrTypeWithArgument(
+ emitDeferredType(normalizedType.typeArgument));
+ return emitNullability
+ ? _emitNullabilityWrapper(
+ typeRep, normalizedType.declaredNullability)
+ : typeRep;
+ }
+ return emitDeferredType(normalizedType,
+ emitNullability: emitNullability);
+ case RecordType():
+ var positional = t.positional.map(emitDeferredType);
+ var named = t.named.map((n) => emitDeferredType(n.type));
+ var typeRep = _emitRecordType(t, positional, named);
return emitNullability
- ? _emitNullabilityWrapper(typeRep, t.declaredNullability)
+ ? _emitNullabilityWrapper(typeRep, t.nullability)
: typeRep;
- }
- return _emitInterfaceType(t, emitNullability: emitNullability);
- } else if (t is FutureOrType) {
- var normalizedType = _futureOrNormalizer.normalize(t);
- if (normalizedType is FutureOrType) {
- _declareBeforeUse(_coreTypes.deprecatedFutureOrClass);
- var typeRep = _emitFutureOrTypeWithArgument(
- emitDeferredType(normalizedType.typeArgument));
- return emitNullability
- ? _emitNullabilityWrapper(
- typeRep, normalizedType.declaredNullability)
- : typeRep;
- }
- return emitDeferredType(normalizedType,
- emitNullability: emitNullability);
- } else if (t is RecordType) {
- var positional = t.positional.map(emitDeferredType);
- var named = t.named.map((n) => emitDeferredType(n.type));
- var typeRep = _emitRecordType(t, positional, named);
- return emitNullability
- ? _emitNullabilityWrapper(typeRep, t.nullability)
- : typeRep;
- } else if (t is TypeParameterType) {
- return _emitTypeParameterType(t, emitNullability: emitNullability);
- } else if (t is StructuralParameterType) {
- return _emitTypeParameterType(t, emitNullability: emitNullability);
+
+ case TypeParameterType():
+ case StructuralParameterType():
+ return _emitTypeParameterType(t, emitNullability: emitNullability);
+ case IntersectionType():
+ return _emitTypeParameterType(t.left,
+ emitNullability: emitNullability);
+ case ExtensionType():
+ return emitDeferredType(t.typeErasure);
+ case DynamicType():
+ case VoidType():
+ case NeverType():
+ case NullType():
+ // TODO(nshahan): It seems like a bug that `FunctionType`s have no
+ // special handling here when they do in `shouldDefer()`.
+ case FunctionType():
+ case TypedefType():
+ return _emitType(t);
+ case AuxiliaryType():
+ throwUnsupportedAuxiliaryType(t);
+ case InvalidType():
+ throwUnsupportedInvalidType(t);
}
- return _emitType(t);
}
- assert(isKnownDartTypeImplementor(t));
var savedEmittingDeferredType = _emittingDeferredType;
_emittingDeferredType = true;
var deferredClassRep =
@@ -1261,37 +1278,44 @@
bool shouldDefer(InterfaceType t) {
var visited = <DartType>{};
bool defer(DartType t) {
- assert(isKnownDartTypeImplementor(t));
- if (t is InterfaceType) {
- var tc = t.classNode;
- if (c == tc) return true;
- if (tc == _coreTypes.objectClass || !visited.add(t)) return false;
- if (t.typeArguments.any(defer)) return true;
- var mixin = tc.mixedInType;
- return mixin != null && defer(mixin.asInterfaceType) ||
- defer(tc.supertype!.asInterfaceType);
+ switch (t) {
+ case InterfaceType(classNode: var tc):
+ if (c == tc) return true;
+ if (tc == _coreTypes.objectClass || !visited.add(t)) return false;
+ if (t.typeArguments.any(defer)) return true;
+ var mixin = tc.mixedInType;
+ return mixin != null && defer(mixin.asInterfaceType) ||
+ defer(tc.supertype!.asInterfaceType);
+ case FutureOrType():
+ if (c == _coreTypes.deprecatedFutureOrClass) return true;
+ if (!visited.add(t)) return false;
+ if (defer(t.typeArgument)) return true;
+ return defer(
+ _coreTypes.deprecatedFutureOrClass.supertype!.asInterfaceType);
+ case TypedefType():
+ return t.typeArguments.any(defer);
+ case FunctionType():
+ return defer(t.returnType) ||
+ t.positionalParameters.any(defer) ||
+ t.namedParameters.any((np) => defer(np.type)) ||
+ t.typeParameters.any((tp) => defer(tp.bound));
+ case RecordType():
+ return t.positional.any(defer) || t.named.any((n) => defer(n.type));
+ case ExtensionType():
+ return defer(t.typeErasure);
+ case DynamicType():
+ case VoidType():
+ case NeverType():
+ case NullType():
+ case IntersectionType():
+ case TypeParameterType():
+ case StructuralParameterType():
+ return false;
+ case AuxiliaryType():
+ throwUnsupportedAuxiliaryType(t);
+ case InvalidType():
+ throwUnsupportedInvalidType(t);
}
- if (t is FutureOrType) {
- if (c == _coreTypes.deprecatedFutureOrClass) return true;
- if (!visited.add(t)) return false;
- if (defer(t.typeArgument)) return true;
- return defer(
- _coreTypes.deprecatedFutureOrClass.supertype!.asInterfaceType);
- }
- if (t is TypedefType) {
- return t.typeArguments.any(defer);
- }
- if (t is FunctionType) {
- return defer(t.returnType) ||
- t.positionalParameters.any(defer) ||
- t.namedParameters.any((np) => defer(np.type)) ||
- t.typeParameters.any((tp) => defer(tp.bound));
- }
- if (t is RecordType) {
- return t.positional.any(defer) || t.named.any((n) => defer(n.type));
- }
- if (t is ExtensionType) return defer(t.typeErasure);
- return false;
}
return defer(t);
diff --git a/pkg/dev_compiler/lib/src/kernel/kernel_helpers.dart b/pkg/dev_compiler/lib/src/kernel/kernel_helpers.dart
index 825c118..d310da8 100644
--- a/pkg/dev_compiler/lib/src/kernel/kernel_helpers.dart
+++ b/pkg/dev_compiler/lib/src/kernel/kernel_helpers.dart
@@ -8,6 +8,13 @@
import 'package:kernel/kernel.dart' hide Pattern;
import 'package:kernel/src/replacement_visitor.dart';
+Never throwUnsupportedInvalidType(InvalidType type) => throw UnsupportedError(
+ 'Unsupported invalid type $type (${type.runtimeType}).');
+
+Never throwUnsupportedAuxiliaryType(AuxiliaryType type) =>
+ throw UnsupportedError(
+ 'Unsupported auxiliary type $type (${type.runtimeType}).');
+
Constructor? unnamedConstructor(Class c) =>
c.constructors.firstWhereOrNull((c) => c.name.text == '');
