[cfe] Use effective target in redirecting factory tear off lowering

The tear-off lowering for a redirecting factory called the
immediate target (even when this was also a redirecting factory)
instead of the effective target. This caused problem in backends
that don't support redirecting factories directly.

Closes #47916

Change-Id: Iafb11c42c1e99e70ed44b0835473a8c69e995b01
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/235780
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/front_end/lib/src/fasta/scope.dart

@@ -805,7 +805,7 @@ mixin ErroneousMemberBuilderMixin implements SourceMemberBuilder {
  }
 
  @override
- LibraryBuilder get library {
+ SourceLibraryBuilder get library {
  throw new UnsupportedError('AmbiguousMemberBuilder.library');
  }
 

pkg/front_end/lib/src/fasta/source/source_class_builder.dart

@@ -2808,6 +2808,9 @@ class _RedirectingConstructorsFieldBuilder extends DillFieldBuilder
  _RedirectingConstructorsFieldBuilder(Field field, SourceClassBuilder parent)
  : super(field, parent);
 
+ @override
+ SourceLibraryBuilder get library => super.library as SourceLibraryBuilder;
+
  @override
  void buildOutlineExpressions(
  SourceLibraryBuilder library,

pkg/front_end/lib/src/fasta/source/source_constructor_builder.dart

@@ -129,9 +129,6 @@ class DeclaredSourceConstructorBuilder extends SourceFunctionBuilderImpl
  super(metadata, modifiers, returnType, name, typeVariables, formals,
  compilationUnit, charOffset, nativeMethodName);
 
- @override
- SourceLibraryBuilder get library => super.library as SourceLibraryBuilder;
-
  @override
  SourceClassBuilder get classBuilder =>
  super.classBuilder as SourceClassBuilder;
@@ -783,6 +780,9 @@ class SyntheticSourceConstructorBuilder extends DillConstructorBuilder
  _synthesizedFunctionNode = synthesizedFunctionNode,
  super(constructor, constructorTearOff, parent);
 
+ @override
+ SourceLibraryBuilder get library => super.library as SourceLibraryBuilder;
+
  // TODO(johnniwinther,cstefantsova): Rename [actualOrigin] to avoid the
  // confusion with patches.
  MemberBuilder? get actualOrigin {

pkg/front_end/lib/src/fasta/source/source_factory_builder.dart

@@ -407,6 +407,11 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
  inferrer.helper = library.loader.createBodyBuilderForOutlineExpression(
  library, classBuilder, this, classBuilder!.scope, fileUri);
  Builder? targetBuilder = redirectionTarget.target;
+ if (targetBuilder is SourceMemberBuilder) {
+ // Ensure that target has been built.
+ targetBuilder.buildOutlineExpressions(targetBuilder.library,
+ classHierarchy, delayedActionPerformers, synthesizedFunctionNodes);
+ }
  if (targetBuilder is FunctionBuilder) {
  target = targetBuilder.member;
  } else if (targetBuilder is DillMemberBuilder) {
@@ -457,14 +462,34 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
  new RedirectingFactoryBody(target, typeArguments, function);
  function.body!.parent = function;
  }
- if (_factoryTearOff != null &&
- (target is Constructor || target is Procedure && target.isFactory)) {
- synthesizedFunctionNodes.add(buildRedirectingFactoryTearOffBody(
- _factoryTearOff!,
- target!,
- typeArguments ?? [],
- _tearOffTypeParameters!,
- library));
+ if (_factoryTearOff != null) {
+ Set<Procedure> seenTargets = {};
+ while (target is Procedure && target.isRedirectingFactory) {
+ if (!seenTargets.add(target)) {
+ // Cyclic dependency.
+ target = null;
+ break;
+ }
+ RedirectingFactoryBody body =
+ target.function.body as RedirectingFactoryBody;
+ if (typeArguments != null) {
+ Substitution substitution = Substitution.fromPairs(
+ target.function.typeParameters, typeArguments);
+ typeArguments =
+ body.typeArguments?.map(substitution.substituteType).toList();
+ } else {
+ typeArguments = body.typeArguments;
+ }
+ target = body.target;
+ }
+ if (target is Constructor || target is Procedure && target.isFactory) {
+ synthesizedFunctionNodes.add(buildRedirectingFactoryTearOffBody(
+ _factoryTearOff!,
+ target!,
+ typeArguments ?? [],
+ _tearOffTypeParameters!,
+ library));
+ }
  }
  if (isConst && isPatch) {
  _finishPatch();

pkg/front_end/lib/src/fasta/source/source_field_builder.dart

@@ -282,9 +282,6 @@ class SourceFieldBuilder extends SourceMemberBuilderImpl
  _typeEnsured = true;
  }
 
- @override
- SourceLibraryBuilder get library => super.library as SourceLibraryBuilder;
-
  @override
  Member get member => _fieldEncoding.field;
 

pkg/front_end/lib/src/fasta/source/source_member_builder.dart

@@ -25,6 +25,9 @@ import 'source_class_builder.dart';
 abstract class SourceMemberBuilder implements MemberBuilder {
  MemberDataForTesting? get dataForTesting;
 
+ @override
+ SourceLibraryBuilder get library;
+
  /// Builds the core AST structures for this member as needed for the outline.
  void buildMembers(
  SourceLibraryBuilder library, void Function(Member, BuiltMemberKind) f);
@@ -87,6 +90,9 @@ abstract class SourceMemberBuilderImpl extends MemberBuilderImpl
  retainDataForTesting ? new MemberDataForTesting() : null,
  super(parent, charOffset, fileUri);
 
+ @override
+ SourceLibraryBuilder get library => super.library as SourceLibraryBuilder;
+
  bool get isRedirectingGenerativeConstructor => false;
 
  @override

pkg/front_end/testcases/dart2js/issue47916.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+abstract class A {
+ const factory A() = B;
+}
+
+abstract class B implements A {
+ const factory B() = C;
+}
+
+class C implements B {
+ const C();
+}
+
+main() {
+ A.new;
+}

pkg/front_end/testcases/dart2js/issue47916.dart.strong.expect

@@ -0,0 +1,34 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+abstract class A extends core::Object {
+ static final field dynamic _redirecting# = <dynamic>[#C1]/*isLegacy*/;
+ static factory •() → self::A
+ return self::B::•();
+ static method _#new#tearOff() → self::A
+ return new self::C::•();
+}
+abstract class B extends core::Object implements self::A {
+ static final field dynamic _redirecting# = <dynamic>[#C2]/*isLegacy*/;
+ static factory •() → self::B
+ return new self::C::•();
+ static method _#new#tearOff() → self::B
+ return new self::C::•();
+}
+class C extends core::Object implements self::B /*hasConstConstructor*/ {
+ const constructor •() → self::C
+ : super core::Object::•()
+ ;
+ static method _#new#tearOff() → self::C
+ return new self::C::•();
+}
+static method main() → dynamic {
+ #C3;
+}
+
+constants {
+ #C1 = constructor-tearoff self::A::•
+ #C2 = constructor-tearoff self::B::•
+ #C3 = static-tearoff self::A::_#new#tearOff
+}

pkg/front_end/testcases/dart2js/issue47916.dart.strong.transformed.expect

@@ -0,0 +1,34 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+abstract class A extends core::Object {
+ static final field dynamic _redirecting# = <dynamic>[#C1]/*isLegacy*/;
+ static factory •() → self::A
+ return self::B::•();
+ static method _#new#tearOff() → self::A
+ return new self::C::•();
+}
+abstract class B extends core::Object implements self::A {
+ static final field dynamic _redirecting# = <dynamic>[#C2]/*isLegacy*/;
+ static factory •() → self::B
+ return new self::C::•();
+ static method _#new#tearOff() → self::B
+ return new self::C::•();
+}
+class C extends core::Object implements self::B /*hasConstConstructor*/ {
+ const constructor •() → self::C
+ : super core::Object::•()
+ ;
+ static method _#new#tearOff() → self::C
+ return new self::C::•();
+}
+static method main() → dynamic {
+ #C3;
+}
+
+constants {
+ #C1 = constructor-tearoff self::A::•
+ #C2 = constructor-tearoff self::B::•
+ #C3 = static-tearoff self::A::_#new#tearOff
+}

pkg/front_end/testcases/dart2js/issue47916.dart.textual_outline.expect

@@ -0,0 +1,13 @@
+abstract class A {
+ const factory A() = B;
+}
+
+abstract class B implements A {
+ const factory B() = C;
+}
+
+class C implements B {
+ const C();
+}
+
+main() {}

pkg/front_end/testcases/dart2js/issue47916.dart.textual_outline_modelled.expect

@@ -0,0 +1,13 @@
+abstract class A {
+ const factory A() = B;
+}
+
+abstract class B implements A {
+ const factory B() = C;
+}
+
+class C implements B {
+ const C();
+}
+
+main() {}

pkg/front_end/testcases/dart2js/issue47916.dart.weak.expect

@@ -0,0 +1,34 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+abstract class A extends core::Object {
+ static final field dynamic _redirecting# = <dynamic>[#C1]/*isLegacy*/;
+ static factory •() → self::A
+ return self::B::•();
+ static method _#new#tearOff() → self::A
+ return new self::C::•();
+}
+abstract class B extends core::Object implements self::A {
+ static final field dynamic _redirecting# = <dynamic>[#C2]/*isLegacy*/;
+ static factory •() → self::B
+ return new self::C::•();
+ static method _#new#tearOff() → self::B
+ return new self::C::•();
+}
+class C extends core::Object implements self::B /*hasConstConstructor*/ {
+ const constructor •() → self::C
+ : super core::Object::•()
+ ;
+ static method _#new#tearOff() → self::C
+ return new self::C::•();
+}
+static method main() → dynamic {
+ #C3;
+}
+
+constants {
+ #C1 = constructor-tearoff self::A::•
+ #C2 = constructor-tearoff self::B::•
+ #C3 = static-tearoff self::A::_#new#tearOff
+}

pkg/front_end/testcases/dart2js/issue47916.dart.weak.modular.expect

@@ -0,0 +1,34 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+abstract class A extends core::Object {
+ static final field dynamic _redirecting# = <dynamic>[#C1]/*isLegacy*/;
+ static factory •() → self::A
+ return self::B::•();
+ static method _#new#tearOff() → self::A
+ return new self::C::•();
+}
+abstract class B extends core::Object implements self::A {
+ static final field dynamic _redirecting# = <dynamic>[#C2]/*isLegacy*/;
+ static factory •() → self::B
+ return new self::C::•();
+ static method _#new#tearOff() → self::B
+ return new self::C::•();
+}
+class C extends core::Object implements self::B /*hasConstConstructor*/ {
+ const constructor •() → self::C
+ : super core::Object::•()
+ ;
+ static method _#new#tearOff() → self::C
+ return new self::C::•();
+}
+static method main() → dynamic {
+ #C3;
+}
+
+constants {
+ #C1 = constructor-tearoff self::A::•
+ #C2 = constructor-tearoff self::B::•
+ #C3 = static-tearoff self::A::_#new#tearOff
+}

pkg/front_end/testcases/dart2js/issue47916.dart.weak.outline.expect

@@ -0,0 +1,33 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+abstract class A extends core::Object {
+ static final field dynamic _redirecting# = <dynamic>[self::A::•]/*isLegacy*/;
+ static factory •() → self::A
+ return self::B::•();
+ static method _#new#tearOff() → self::A
+ return new self::C::•();
+}
+abstract class B extends core::Object implements self::A {
+ static final field dynamic _redirecting# = <dynamic>[self::B::•]/*isLegacy*/;
+ static factory •() → self::B
+ return new self::C::•();
+ static method _#new#tearOff() → self::B
+ return new self::C::•();
+}
+class C extends core::Object implements self::B /*hasConstConstructor*/ {
+ const constructor •() → self::C
+ : super core::Object::•()
+ ;
+ static method _#new#tearOff() → self::C
+ return new self::C::•();
+}
+static method main() → dynamic
+ ;
+
+
+Extra constant evaluation status:
+Evaluated: ConstructorTearOff @ org-dartlang-testcase:///issue47916.dart:5:16 -> ConstructorTearOffConstant(A.)
+Evaluated: ConstructorTearOff @ org-dartlang-testcase:///issue47916.dart:9:16 -> ConstructorTearOffConstant(B.)
+Extra constant evaluation: evaluated: 9, effectively constant: 2

pkg/front_end/testcases/dart2js/issue47916.dart.weak.transformed.expect

@@ -0,0 +1,34 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+abstract class A extends core::Object {
+ static final field dynamic _redirecting# = <dynamic>[#C1]/*isLegacy*/;
+ static factory •() → self::A
+ return self::B::•();
+ static method _#new#tearOff() → self::A
+ return new self::C::•();
+}
+abstract class B extends core::Object implements self::A {
+ static final field dynamic _redirecting# = <dynamic>[#C2]/*isLegacy*/;
+ static factory •() → self::B
+ return new self::C::•();
+ static method _#new#tearOff() → self::B
+ return new self::C::•();
+}
+class C extends core::Object implements self::B /*hasConstConstructor*/ {
+ const constructor •() → self::C
+ : super core::Object::•()
+ ;
+ static method _#new#tearOff() → self::C
+ return new self::C::•();
+}
+static method main() → dynamic {
+ #C3;
+}
+
+constants {
+ #C1 = constructor-tearoff self::A::•
+ #C2 = constructor-tearoff self::B::•
+ #C3 = static-tearoff self::A::_#new#tearOff
+}