Implement type inference of getters/setters based on inheritance.

pkg/front_end/lib/src/fasta/kernel/kernel_procedure_builder.dart

 // Copyright (c) 2016, 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.
 
 library fasta.kernel_procedure_builder;
 
+import 'package:front_end/src/fasta/kernel/kernel_shadow_ast.dart'
+    show KernelProcedure;
+
+import 'package:front_end/src/fasta/source/source_library_builder.dart'
+    show SourceLibraryBuilder;
+
+import 'package:front_end/src/fasta/type_inference/type_inference_listener.dart'
+    show TypeInferenceListener;
+
 import 'package:kernel/ast.dart'
     show
         Arguments,
         AsyncMarker,
         Constructor,
         ConstructorInvocation,
         DartType,
         DynamicType,
         EmptyStatement,
         Expression,
@@ skipping 141 matching lines @@
           }
         }
         if (containsTypeVariable(result.returnType, set)) {
           result.returnType = removeTypeVariables(result.returnType);
         }
       }
     }
     return function = result;
   }
 
-  Member build(LibraryBuilder library);
+  Member build(SourceLibraryBuilder library);
 
   void becomeNative(Loader loader) {
     target.isExternal = true;
     Builder constructor = loader.getNativeAnnotation();
     Arguments arguments =
         new Arguments(<Expression>[new StringLiteral(nativeMethodName)]);
     Expression annotation;
     if (constructor.isConstructor) {
       annotation = new ConstructorInvocation(constructor.target, arguments)
         ..isConst = true;
     } else {
       annotation = new StaticInvocation(constructor.target, arguments)
         ..isConst = true;
     }
     target.addAnnotation(annotation);
   }
 }
 
 class KernelProcedureBuilder extends KernelFunctionBuilder {
-  final Procedure procedure;
+  final KernelProcedure procedure;
   final int charOpenParenOffset;
 
   AsyncMarker actualAsyncModifier = AsyncMarker.Sync;
 
   final ConstructorReferenceBuilder redirectionTarget;
 
   KernelProcedureBuilder(
       List<MetadataBuilder> metadata,
       int modifiers,
       KernelTypeBuilder returnType,
       String name,
       List<TypeVariableBuilder> typeVariables,
       List<FormalParameterBuilder> formals,
       ProcedureKind kind,
       KernelLibraryBuilder compilationUnit,
       int charOffset,
       this.charOpenParenOffset,
       int charEndOffset,
       [String nativeMethodName,
       this.redirectionTarget])
-      : procedure = new Procedure(null, kind, null,
+      : procedure = new KernelProcedure(null, kind, null,
             fileUri: compilationUnit?.relativeFileUri)
           ..fileOffset = charOffset
           ..fileEndOffset = charEndOffset,
         super(metadata, modifiers, returnType, name, typeVariables, formals,
             compilationUnit, charOffset, nativeMethodName);
 
   ProcedureKind get kind => procedure.kind;
 
   AsyncMarker get asyncModifier => actualAsyncModifier;
 
   Statement get body {
     if (actualBody == null &&
         redirectionTarget == null &&
         !isAbstract &&
         !isExternal) {
       actualBody = new EmptyStatement();
     }
     return actualBody;
   }
 
   void set asyncModifier(AsyncMarker newModifier) {
     actualAsyncModifier = newModifier;
     if (function != null) {
       // No parent, it's an enum.
       function.asyncMarker = actualAsyncModifier;
       function.dartAsyncMarker = actualAsyncModifier;
     }
   }
 
-  Procedure build(LibraryBuilder library) {
+  bool get isEligibleForGetterSetterInference {
+    if (!isInstanceMember) return false;
+    if (isGetter) {
+      return returnType == null;
+    } else if (isSetter) {
+      return formals != null && formals.length > 0 && formals[0].type == null;
+    } else {
+      return false;
+    }
+  }
+
+  Procedure build(SourceLibraryBuilder library) {
     // TODO(ahe): I think we may call this twice on parts. Investigate.
     if (procedure.name == null) {
       procedure.function = buildFunction(library);
       procedure.function.parent = procedure;
       procedure.function.fileOffset = charOpenParenOffset;
       procedure.function.fileEndOffset = procedure.fileEndOffset;
       procedure.isAbstract = isAbstract;
       procedure.isStatic = isStatic;
       procedure.isExternal = isExternal;
       procedure.isConst = isConst;
       procedure.name = new Name(name, library.target);
     }
+    if (isEligibleForGetterSetterInference) {
+      library.loader.typeInferenceEngine.recordMember(procedure);
+    }
     return procedure;
   }
 
   Procedure get target => procedure;
+
+  @override
+  void prepareInitializerInference(
+      SourceLibraryBuilder library, ClassBuilder currentClass) {
+    if (isEligibleForGetterSetterInference) {
+      var typeInferenceEngine = library.loader.typeInferenceEngine;
+      var listener = new TypeInferenceListener();
+      typeInferenceEngine.createTopLevelTypeInferrer(
+          listener, procedure.enclosingClass?.thisType, procedure);
+    }
+  }
 }
 
 // TODO(ahe): Move this to own file?
 class KernelConstructorBuilder extends KernelFunctionBuilder {
   final Constructor constructor;
 
   final int charOpenParenOffset;
 
   bool hasMovedSuperInitializer = false;
 
@@ skipping 24 matching lines @@
   bool get isConstructor => true;
 
   AsyncMarker get asyncModifier => AsyncMarker.Sync;
 
   ProcedureKind get kind => null;
 
   bool get isRedirectingGenerativeConstructor {
     return isRedirectingGenerativeConstructorImplementation(constructor);
   }
 
-  Constructor build(LibraryBuilder library) {
+  Constructor build(SourceLibraryBuilder library) {
     if (constructor.name == null) {
       constructor.function = buildFunction(library);
       constructor.function.parent = constructor;
       constructor.function.fileOffset = charOpenParenOffset;
       constructor.function.fileEndOffset = constructor.fileEndOffset;
       constructor.isConst = isConst;
       constructor.isExternal = isExternal;
       constructor.name = new Name(name, library.target);
     }
     return constructor;
@@ skipping 61 matching lines @@
         }
       }
       initializers.add(initializer..parent = constructor);
       initializers.add(superInitializer);
       return;
     }
     initializers.add(initializer);
     initializer.parent = constructor;
   }
 }