[cfe] Move formal inference to SourceFunctionBuilderImpl hierarchy

This is a follow-up to
https://dart-review.googlesource.com/c/sdk/+/404822

Change-Id: Id0b41562de44a89515b65c80f082ba16c823b09b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/405006
Commit-Queue: Chloe Stefantsova <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>

Author: chloestefantsova

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

@@ -879,6 +879,9 @@ class DeclaredSourceConstructorBuilder
   void buildOutlineExpressions(ClassHierarchy classHierarchy,
       List<DelayedDefaultValueCloner> delayedDefaultValueCloners) {
     if (_hasBuiltOutlines) return;
+
+    inferFormals(formals, classHierarchy);
+
     if (isConst && isAugmenting) {
       origin.buildOutlineExpressions(
           classHierarchy, delayedDefaultValueCloners);

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

@@ -25,7 +25,6 @@ import '../builder/declaration_builders.dart';
 import '../builder/formal_parameter_builder.dart';
 import '../builder/function_builder.dart';
 import '../builder/metadata_builder.dart';
-import '../builder/omitted_type_builder.dart';
 import '../builder/type_builder.dart';
 import '../codes/cfe_codes.dart';
 import '../dill/dill_extension_type_member_builder.dart';
@@ -263,6 +262,9 @@ class SourceFactoryBuilder extends SourceFunctionBuilderImpl {
   void buildOutlineExpressions(ClassHierarchy classHierarchy,
       List<DelayedDefaultValueCloner> delayedDefaultValueCloners) {
     if (_hasBuiltOutlines) return;
+
+    inferFormals(formals, classHierarchy);
+
     if (_delayedDefaultValueCloner != null) {
       delayedDefaultValueCloners.add(_delayedDefaultValueCloner!);
     }
@@ -560,6 +562,9 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
   void buildOutlineExpressions(ClassHierarchy classHierarchy,
       List<DelayedDefaultValueCloner> delayedDefaultValueCloners) {
     if (_hasBuiltOutlines) return;
+
+    inferFormals(formals, classHierarchy);
+
     if (isConst && isAugmenting) {
       origin.buildOutlineExpressions(
           classHierarchy, delayedDefaultValueCloners);
@@ -583,31 +588,6 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
               createBodyBuilderContext(), declarationBuilder.scope, fileUri);
       Builder? targetBuilder = redirectionTarget.target;
 
-      // Inference of target's formals should happen before building of the
-      // outline expressions in members and before inferring target's type
-      // arguments.
-      //
-      // (1) The outline expressions, such as formal parameter initializers,
-      // need properly inferred type contexts. Among other things, it ensures
-      // that the required coercions, such as int-to-double conversion, are
-      // run.
-      //
-      // (2) Type arguments for the targets of redirecting factories can only
-      // be inferred if the formal parameters of the targets are inferred too.
-      // That may not be the case when the target's parameters are initializing
-      // parameters referring to fields with types that are to be inferred.
-      if (targetBuilder is SourceFunctionBuilderImpl) {
-        List<FormalParameterBuilder>? formals = targetBuilder.formals;
-        if (formals != null) {
-          for (FormalParameterBuilder formal in formals) {
-            TypeBuilder formalType = formal.type;
-            if (formalType is InferableTypeBuilder) {
-              formalType.inferType(classHierarchy);
-            }
-          }
-        }
-      }
-
       if (targetBuilder is SourceMemberBuilder) {
         // Ensure that target has been built.
         targetBuilder.buildOutlineExpressions(

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

@@ -423,6 +423,8 @@ abstract class SourceFunctionBuilderImpl extends SourceMemberBuilderImpl
   void buildOutlineExpressions(ClassHierarchy classHierarchy,
       List<DelayedDefaultValueCloner> delayedDefaultValueCloners) {
     if (!hasBuiltOutlineExpressions) {
+      inferFormals(formals, classHierarchy);
+
       DeclarationBuilder? classOrExtensionBuilder =
           isClassMember || isExtensionMember || isExtensionTypeMember
               ? parent as DeclarationBuilder
@@ -572,3 +574,16 @@ void reportAugmentationMismatch(
             origin.fileUri!, origin.fileOffset, noLength)
       ]);
 }
+
+/// Ensures the type of each of the [formals] is inferred.
+void inferFormals(
+    List<FormalParameterBuilder>? formals, ClassHierarchy classHierarchy) {
+  if (formals != null) {
+    for (FormalParameterBuilder formal in formals) {
+      TypeBuilder formalType = formal.type;
+      if (formalType is InferableTypeBuilder) {
+        formalType.inferType(classHierarchy);
+      }
+    }
+  }
+}