Implement type inference for PropertyGet.

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

 // Copyright (c) 2017, 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.
 
 /// This file declares a "shadow hierarchy" of concrete classes which extend
 /// the kernel class hierarchy, adding methods and fields needed by the
 /// BodyBuilder.
 ///
 /// Instances of these classes may be created using the factory methods in
 /// `ast_factory.dart`.
@@ skipping 1058 matching lines @@
     Member interfaceMember;
     if (receiverType is InterfaceType) {
       interfaceMember = inferrer.classHierarchy
           .getInterfaceMember(receiverType.classNode, name);
       if (interfaceMember is Procedure) {
         // Our non-strong golden files currently don't include interface
         // targets, so we can't store the interface target without causing tests
         // to fail.  TODO(paulberry): fix this.
         if (inferrer.strongMode) {
           inferrer.instrumentation?.record(Uri.parse(inferrer.uri), fileOffset,
-              'target', new InstrumentationValueForProcedure(interfaceMember));
+              'target', new InstrumentationValueForMember(interfaceMember));
           interfaceTarget = interfaceMember;
         }
         isOverloadedArithmeticOperator = inferrer.typeSchemaEnvironment
             .isOverloadedArithmeticOperator(interfaceMember);
       }
     }
     var calleeType =
         inferrer.getCalleeFunctionType(interfaceMember, receiverType, name);
     var inferredType = inferrer.inferInvocation(typeContext, typeNeeded,
         fileOffset, calleeType, calleeType.returnType, arguments,
@@ skipping 59 matching lines @@
     //   are disallowed here.
     // - The inference dependency of the identifier is the referent if the
     //   referent is a candidate for inference.  Otherwise there are no
     //   inference dependencies.
     // TODO(paulberry): implement the proper logic here.
   }
 
   @override
   DartType _inferExpression(
       KernelTypeInferrer inferrer, DartType typeContext, bool typeNeeded) {
-    // TODO(scheglov): implement.
-    return typeNeeded ? const DynamicType() : null;
+    typeNeeded =
+        inferrer.listener.propertyGetEnter(this, typeContext) || typeNeeded;
+    // First infer the receiver so we can look up the getter that was invoked.
+    var receiverType = inferrer.inferExpression(receiver, null, true);
+    Member interfaceMember;
+    if (receiverType is InterfaceType) {
+      interfaceMember = inferrer.classHierarchy
+          .getInterfaceMember(receiverType.classNode, name);
+      // Our non-strong golden files currently don't include interface targets,
+      // so we can't store the interface target without causing tests to fail.
+      // TODO(paulberry): fix this.
+      if (inferrer.strongMode) {
+        inferrer.instrumentation?.record(Uri.parse(inferrer.uri), fileOffset,
+            'target', new InstrumentationValueForMember(interfaceMember));
+        interfaceTarget = interfaceMember;
+      }
+    }
+    var inferredType =
+        inferrer.getCalleeType(interfaceMember, receiverType, name);
+    // TODO(paulberry): Infer tear-off type arguments if appropriate.
+    inferrer.listener.propertyGetExit(this, inferredType);
+    return typeNeeded ? inferredType : null;
   }
 }
 
 /// Shadow object for [PropertyGet].
 class KernelPropertySet extends PropertySet implements KernelExpression {
   KernelPropertySet(Expression receiver, Name name, Expression value,
       [Member interfaceTarget])
       : super(receiver, name, value, interfaceTarget);
 
   KernelPropertySet.byReference(Expression receiver, Name name,
@@ skipping 710 matching lines @@
               : inferrer.coreTypes.iterableClass);
     }
     var inferredType = inferrer.inferExpression(
         expression, typeContext, closureContext != null);
     closureContext.handleYield(inferrer, isYieldStar, inferredType);
     inferrer.listener.yieldStatementExit(this);
   }
 }
 
 class _UnfinishedCascade extends Expression {
-  getStaticType(types) {
-    return internalError("Internal error: Unsupported operation.");
-  }
-
   accept(v) {
     return internalError("Internal error: Unsupported operation.");
   }
 
   accept1(v, arg) {
     return internalError("Internal error: Unsupported operation.");
   }
 
+  getStaticType(types) {
+    return internalError("Internal error: Unsupported operation.");
+  }
+
+  transformChildren(v) {
+    return internalError("Internal error: Unsupported operation.");
+  }
+
   visitChildren(v) {
     return internalError("Internal error: Unsupported operation.");
   }
-
-  transformChildren(v) {
-    return internalError("Internal error: Unsupported operation.");
-  }
 }