[cfe] Remove FormalParameterBuilder._parent

Change-Id: I6b4e6dbbdfa4b1a3dad82d622b17d521644eb8bf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/398240
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/front_end/lib/src/builder/formal_parameter_builder.dart

@@ -20,11 +20,11 @@ import '../source/builder_factory.dart';
 import '../source/constructor_declaration.dart';
 import '../source/source_factory_builder.dart';
 import '../source/source_field_builder.dart';
-import '../source/source_function_builder.dart';
 import '../source/source_library_builder.dart';
 import 'builder.dart';
 import 'constructor_builder.dart';
 import 'declaration_builders.dart';
+import 'member_builder.dart';
 import 'omitted_type_builder.dart';
 import 'type_builder.dart';
 import 'variable_builder.dart';
@@ -53,8 +53,6 @@ class FormalParameterBuilder extends BuilderImpl
     implements VariableBuilder, ParameterBuilder, InferredTypeListener {
   static const String noNameSentinel = 'no name sentinel';
 
-  SourceFunctionBuilder? _parent;
-
   @override
   final int fileOffset;
 
@@ -107,15 +105,8 @@ class FormalParameterBuilder extends BuilderImpl
   }
 
   @override
-  SourceFunctionBuilder get parent {
-    assert(_parent != null, "Parent has not been set for $this.");
-    return _parent!;
-  }
-
-  void set parent(SourceFunctionBuilder value) {
-    assert(_parent == null, "Parent has already been set for $this.");
-    _parent = value;
-  }
+  // Coverage-ignore(suite): Not run.
+  Builder? get parent => null;
 
   @override
   bool get isRequiredPositional => kind.isRequiredPositional;
@@ -200,7 +191,6 @@ class FormalParameterBuilder extends BuilderImpl
         fileUri: fileUri,
         isExtensionThis: isExtensionThis,
         hasImmediatelyDeclaredInitializer: hasImmediatelyDeclaredInitializer)
-      .._parent = _parent
       ..variable = variable;
   }
 
@@ -215,7 +205,6 @@ class FormalParameterBuilder extends BuilderImpl
           fileUri: fileUri,
           isExtensionThis: isExtensionThis,
           hasImmediatelyDeclaredInitializer: hasImmediatelyDeclaredInitializer)
-        ..parent = parent
         ..variable = variable;
     } else if (isSuperInitializingFormal) {
       return new FormalParameterBuilder(
@@ -227,7 +216,6 @@ class FormalParameterBuilder extends BuilderImpl
           fileUri: fileUri,
           isExtensionThis: isExtensionThis,
           hasImmediatelyDeclaredInitializer: hasImmediatelyDeclaredInitializer)
-        ..parent = parent
         ..variable = variable;
     } else {
       return this;
@@ -249,7 +237,8 @@ class FormalParameterBuilder extends BuilderImpl
     }
   }
 
-  bool get needsDefaultValuesBuiltAsOutlineExpressions {
+  static bool needsDefaultValuesBuiltAsOutlineExpressions(
+      MemberBuilder memberBuilder) {
     // For modular compilation we need to include default values for optional
     // and named parameters in several cases:
     // * for const constructors to enable constant evaluation,
@@ -259,25 +248,27 @@ class FormalParameterBuilder extends BuilderImpl
     //   in mixin applications, and
     // * for factories, to uphold the invariant that optional parameters always
     //   have default values, even during modular compilation.
-    if (parent is ConstructorBuilder) {
+    if (memberBuilder is ConstructorBuilder) {
       return true;
-    } else if (parent is SourceFactoryBuilder) {
-      return parent.isFactory;
+    } else if (memberBuilder is SourceFactoryBuilder) {
+      return memberBuilder.isFactory;
     } else {
-      return parent.isClassInstanceMember;
+      return memberBuilder.isClassInstanceMember;
     }
   }
 
   /// Builds the default value from this [initializerToken] if this is a
   /// formal parameter on a const constructor or instance method.
-  void buildOutlineExpressions(SourceLibraryBuilder libraryBuilder) {
-    if (needsDefaultValuesBuiltAsOutlineExpressions) {
+  void buildOutlineExpressions(SourceLibraryBuilder libraryBuilder,
+      DeclarationBuilder? declarationBuilder,
+      {required bool buildDefaultValue}) {
+    if (buildDefaultValue) {
       if (initializerToken != null) {
-        final DeclarationBuilder declarationBuilder =
-            parent.declarationBuilder!;
-        LookupScope scope = declarationBuilder.scope;
-        BodyBuilderContext bodyBuilderContext =
-            new ParameterBodyBuilderContext(this);
+        LookupScope scope =
+            declarationBuilder?.scope ?? // Coverage-ignore(suite): Not run.
+                libraryBuilder.scope;
+        BodyBuilderContext bodyBuilderContext = new ParameterBodyBuilderContext(
+            libraryBuilder, declarationBuilder, this);
         BodyBuilder bodyBuilder = libraryBuilder.loader
             .createBodyBuilderForOutlineExpression(
                 libraryBuilder, bodyBuilderContext, scope, fileUri);

pkg/front_end/lib/src/kernel/body_builder_context.dart

@@ -1023,11 +1023,11 @@ class RedirectingFactoryBodyBuilderContext extends BodyBuilderContext
 
 class ParameterBodyBuilderContext extends BodyBuilderContext {
   factory ParameterBodyBuilderContext(
+      LibraryBuilder libraryBuilder,
+      DeclarationBuilder? declarationBuilder,
       FormalParameterBuilder formalParameterBuilder) {
-    final DeclarationBuilder declarationBuilder =
-        formalParameterBuilder.parent.declarationBuilder!;
-    return new ParameterBodyBuilderContext._(declarationBuilder.libraryBuilder,
-        declarationBuilder, formalParameterBuilder);
+    return new ParameterBodyBuilderContext._(
+        libraryBuilder, declarationBuilder, formalParameterBuilder);
   }
 
   ParameterBodyBuilderContext._(

pkg/front_end/lib/src/source/source_enum_builder.dart

@@ -176,14 +176,12 @@ class SourceEnumBuilder extends SourceClassBuilder {
                 Modifiers.empty, stringType, "#name", fileOffset,
                 fileUri: fileUri, hasImmediatelyDeclaredInitializer: false);
         member.formals!.insert(0, nameFormalParameterBuilder);
-        nameFormalParameterBuilder.parent = member;
 
         FormalParameterBuilder indexFormalParameterBuilder =
             new FormalParameterBuilder(FormalParameterKind.requiredPositional,
                 Modifiers.empty, intType, "#index", fileOffset,
                 fileUri: fileUri, hasImmediatelyDeclaredInitializer: false);
         member.formals!.insert(0, indexFormalParameterBuilder);
-        indexFormalParameterBuilder.parent = member;
       }
     }
 

pkg/front_end/lib/src/source/source_function_builder.dart

@@ -143,11 +143,6 @@ abstract class SourceFunctionBuilderImpl extends SourceMemberBuilderImpl
   SourceFunctionBuilderImpl(this.metadata, this.modifiers, this.name,
       this.typeParameters, this.formals, this.nativeMethodName) {
     returnType.registerInferredTypeListener(this);
-    if (formals != null) {
-      for (int i = 0; i < formals!.length; i++) {
-        formals![i].parent = this;
-      }
-    }
   }
 
   @override
@@ -512,7 +507,9 @@ abstract class SourceFunctionBuilderImpl extends SourceMemberBuilderImpl
         // buildOutlineExpressions to clear initializerToken to prevent
         // consuming too much memory.
         for (FormalParameterBuilder formal in formals!) {
-          formal.buildOutlineExpressions(libraryBuilder);
+          formal.buildOutlineExpressions(libraryBuilder, declarationBuilder,
+              buildDefaultValue: FormalParameterBuilder
+                  .needsDefaultValuesBuiltAsOutlineExpressions(this));
         }
       }
       hasBuiltOutlineExpressions = true;

pkg/front_end/test/coverage_suite_expected.dart

@@ -290,7 +290,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/builder/formal_parameter_builder.dart": (
-    hitCount: 188,
+    hitCount: 169,
     missCount: 0,
   ),
   // 100.0%.
@@ -565,7 +565,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/kernel/body_builder_context.dart": (
-    hitCount: 357,
+    hitCount: 354,
     missCount: 0,
   ),
   // 100.0%.
@@ -905,7 +905,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/source/source_enum_builder.dart": (
-    hitCount: 517,
+    hitCount: 515,
     missCount: 0,
   ),
   // 100.0%.
@@ -931,7 +931,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/source/source_function_builder.dart": (
-    hitCount: 345,
+    hitCount: 339,
     missCount: 0,
   ),
   // 100.0%.