Merge libv1.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

 // Copyright (c) 2012, 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.
 
 part of resolution;
 
 abstract class TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(Node node);
@@ skipping 1065 matching lines @@
     return resolveTypeAnnotationInContext(scope, node, onFailure,
                                           whenResolved);
   }
 
   DartType resolveTypeAnnotationInContext(Scope scope, TypeAnnotation node,
                                           onFailure, whenResolved) {
     Element element = resolveTypeName(scope, node);
     DartType type;
     if (element == null) {
       onFailure(node, MessageKind.CANNOT_RESOLVE_TYPE, [node.typeName]);
-    } else if (element.isErroneous()) {
-      ErroneousElement error = element;
-      onFailure(node, error.messageKind, error.messageArguments);
+    } else if (element.isAmbiguous()) {
+      AmbiguousElement ambiguous = element;
+      onFailure(node, ambiguous.messageKind, ambiguous.messageArguments);
     } else if (!element.impliesType()) {
       onFailure(node, MessageKind.NOT_A_TYPE, [node.typeName]);
     } else {
       if (identical(element, compiler.types.voidType.element) ||
           identical(element, compiler.types.dynamicType.element)) {
         type = element.computeType(compiler);
       } else if (element.isClass()) {
         ClassElement cls = element;
         cls.ensureResolved(compiler);
         Link<DartType> arguments =
@@ skipping 93 matching lines @@
       typeResolver = new TypeResolver(compiler),
       scope = element.buildScope(),
       inCheckContext = compiler.enableTypeAssertions,
       inCatchBlock = false,
       super(compiler);
 
   Enqueuer get world => compiler.enqueuer.resolution;
 
   Element lookup(Node node, SourceString name) {
     Element result = scope.lookup(name);
-    if (!inInstanceContext && result != null && result.isInstanceMember()) {
-      error(node, MessageKind.NO_INSTANCE_AVAILABLE, [node]);
+    if (!Elements.isUnresolved(result)) {
+      if (!inInstanceContext && result.isInstanceMember()) {
+        error(node, MessageKind.NO_INSTANCE_AVAILABLE, [node]);
+        // TODO(johnniwinther): Create an ErroneousElement.
+      } else if (result.isAmbiguous()) {
+        AmbiguousElement ambiguous = result;
+        compiler.reportMessage(compiler.spanFromNode(node),
+            ambiguous.messageKind.error(ambiguous.messageArguments),
+            Diagnostic.ERROR);
+        return new ErroneousElement(ambiguous.messageKind,
+                                    ambiguous.messageArguments,
+                                    name, enclosingElement);
+      }
     }
     return result;
   }
 
   // Create, or reuse an already created, statement element for a statement.
   TargetElement getOrCreateTargetElement(Node statement) {
     TargetElement element = mapping[statement];
     if (element == null) {
       element = new TargetElement(statement,
                                   statementScope.nestingLevel,
@@ skipping 20 matching lines @@
   }
 
   visitInStaticContext(Node node) {
     inStaticContext(() => visit(node));
   }
 
   ErroneousElement warnAndCreateErroneousElement(Node node,
                                                  SourceString name,
                                                  MessageKind kind,
                                                  List<Node> arguments) {
-    return warnOnErroneousElement(node,
-        new ErroneousElement(kind, arguments, name, enclosingElement));
-  }
-
-  ErroneousElement warnOnErroneousElement(Node node,
-                                          ErroneousElement erroneousElement) {
-    ResolutionWarning warning =
-        new ResolutionWarning(erroneousElement.messageKind,
-                              erroneousElement.messageArguments);
+    ResolutionWarning warning = new ResolutionWarning(kind, arguments);
     compiler.reportWarning(node, warning);
-    return erroneousElement;
+    return new ErroneousElement(kind, arguments, name, enclosingElement);
   }
 
   Element visitIdentifier(Identifier node) {
     if (node.isThis()) {
       if (!inInstanceContext) {
         error(node, MessageKind.NO_INSTANCE_AVAILABLE, [node]);
       }
       return null;
     } else if (node.isSuper()) {
       if (!inInstanceContext) error(node, MessageKind.NO_SUPER_IN_STATIC);
       if ((ElementCategory.SUPER & allowedCategory) == 0) {
         error(node, MessageKind.INVALID_USE_OF_SUPER);
       }
       return null;
     } else {
       Element element = lookup(node, node.source);
       if (element == null) {
         if (!inInstanceContext) {
           element = warnAndCreateErroneousElement(node, node.source,
                                                   MessageKind.CANNOT_RESOLVE,
                                                   [node]);
         }
       } else if (element.isErroneous()) {
-        element = warnOnErroneousElement(node, element);
+        // Use the erroneous element.
       } else {
         if ((element.kind.category & allowedCategory) == 0) {
           // TODO(ahe): Improve error message. Need UX input.
           error(node, MessageKind.GENERIC, ["is not an expression $element"]);
         }
       }
       if (!Elements.isUnresolved(element)
           && element.kind == ElementKind.CLASS) {
         ClassElement classElement = element;
         classElement.ensureResolved(compiler);
@@ skipping 579 matching lines @@
       visit(link.head);
     }
   }
 
   visitOperator(Operator node) {
     unimplemented(node, 'operator');
   }
 
   visitReturn(Return node) {
     if (node.isRedirectingFactoryBody) {
-      unimplemented(node, 'redirecting constructors');
+      handleRedirectingFactoryBody(node);
+    } else {
+      visit(node.expression);
     }
-    visit(node.expression);
+  }
+
+  void handleRedirectingFactoryBody(Return node) {
+    Element redirectionTarget = resolveRedirectingFactory(node);
+    var type = mapping.getType(node.expression);
+    if (type is InterfaceType && !type.arguments.isEmpty) {
+      unimplemented(node.expression, 'type arguments on redirecting factory');
+    }
+    useElement(node.expression, redirectionTarget);
+    assert(invariant(node, enclosingElement.isFactoryConstructor()));
+    FunctionElement constructor = enclosingElement;
+    if (constructor.modifiers.isConst() &&
+        !redirectionTarget.modifiers.isConst()) {
+      error(node, MessageKind.CONSTRUCTOR_IS_NOT_CONST);
+    }
+    // TODO(ahe): Check that this doesn't lead to a cycle.  For now,
+    // just make sure that the redirection target isn't itself a
+    // redirecting factory.
+    { // This entire block is temporary code per the above TODO.
+      FunctionElement targetImplementation = redirectionTarget.implementation;
+      FunctionExpression function = targetImplementation.parseNode(compiler);
+      if (function.body != null && function.body.asReturn() != null
+          && function.body.asReturn().isRedirectingFactoryBody) {
+        unimplemented(node.expression, 'redirecing to redirecting factory');
+      }
+    }
+    constructor.defaultImplementation = redirectionTarget;
+    world.registerStaticUse(redirectionTarget);
   }
 
   visitThrow(Throw node) {
     if (!inCatchBlock && node.expression == null) {
       error(node, MessageKind.THROW_WITHOUT_EXPRESSION);
     }
     visit(node.expression);
   }
 
   visitVariableDefinitions(VariableDefinitions node) {
@@ skipping 53 matching lines @@
 
   /**
    * Try to resolve the constructor that is referred to by [node].
    * Note: this function may return an ErroneousFunctionElement instead of
    * [null], if there is no corresponding constructor, class or library.
    */
   FunctionElement resolveConstructor(NewExpression node) {
     return node.accept(new ConstructorResolver(compiler, this));
   }
 
+  FunctionElement resolveRedirectingFactory(Return node) {
+    return node.accept(new ConstructorResolver(compiler, this));
+  }
+
   DartType resolveTypeRequired(TypeAnnotation node) {
     bool old = typeRequired;
     typeRequired = true;
     DartType result = resolveTypeAnnotation(node);
     typeRequired = old;
     return result;
   }
 
   void analyzeTypeArgument(DartType annotation, DartType argument) {
     if (argument == null) return;
@@ skipping 932 matching lines @@
   }
 
   failOrReturnErroneousElement(Element enclosing, Node diagnosticNode,
                                SourceString targetName, MessageKind kind,
                                List arguments) {
     if (inConstContext) {
       error(diagnosticNode, kind, arguments);
     } else {
       ResolutionWarning warning  = new ResolutionWarning(kind, arguments);
       compiler.reportWarning(diagnosticNode, warning);
-      return new ErroneousFunctionElement(kind, arguments, targetName,
-                                          enclosing);
+      return new ErroneousElement(kind, arguments, targetName, enclosing);
     }
   }
 
   Selector createConstructorSelector(SourceString constructorName) {
     return constructorName == const SourceString('')
         ? new Selector.callDefaultConstructor(
             resolver.enclosingElement.getLibrary())
         : new Selector.callConstructor(
             constructorName,
             resolver.enclosingElement.getLibrary());
@@ skipping 20 matching lines @@
     } else if (inConstContext && !result.modifiers.isConst()) {
       error(diagnosticNode, MessageKind.CONSTRUCTOR_IS_NOT_CONST);
     }
     return result;
   }
 
   visitNewExpression(NewExpression node) {
     inConstContext = node.isConst();
     Node selector = node.send.selector;
     Element e = visit(selector);
-    if (!Elements.isUnresolved(e) && identical(e.kind, ElementKind.CLASS)) {
+    return finishConstructorReference(e, node.send.selector, node);
+  }
+
+  /// Finishes resolution of a constructor reference and records the
+  /// type of the constructed instance on [expression].
+  FunctionElement finishConstructorReference(Element e,
+                                             Node diagnosticNode,
+                                             Node expression) {
+    // Find the unnamed constructor if the reference resolved to a
+    // class.
+    if (!Elements.isUnresolved(e) && e.isClass()) {
       ClassElement cls = e;
       cls.ensureResolved(compiler);
       if (cls.isInterface() && (cls.defaultClass == null)) {
-        error(selector, MessageKind.CANNOT_INSTANTIATE_INTERFACE, [cls.name]);
+        // TODO(ahe): Remove this check and error message when we
+        // don't have interfaces anymore.
+        error(diagnosticNode,
+              MessageKind.CANNOT_INSTANTIATE_INTERFACE, [cls.name]);
       }
-      e = lookupConstructor(cls, selector, const SourceString(''));
+      // The unnamed constructor may not exist, so [e] may become unresolved.
+      e = lookupConstructor(cls, diagnosticNode, const SourceString(''));
     }
     if (type == null) {
       if (Elements.isUnresolved(e)) {
         type = compiler.dynamicClass.computeType(compiler);
       } else {
         type = e.getEnclosingClass().computeType(compiler).asRaw();
       }
     }
-    resolver.mapping.setType(node, type);
+    resolver.mapping.setType(expression, type);
     return e;
   }
 
   visitTypeAnnotation(TypeAnnotation node) {
     assert(invariant(node, type == null));
     type = resolver.resolveTypeRequired(node);
     return resolver.mapping[node];
   }
 
   visitSend(Send node) {
@@ skipping 27 matching lines @@
     return e;
   }
 
   Element visitIdentifier(Identifier node) {
     SourceString name = node.source;
     Element e = resolver.lookup(node, name);
     // TODO(johnniwinther): Change errors to warnings, cf. 11.11.1.
     if (e == null) {
       return failOrReturnErroneousElement(resolver.enclosingElement, node, name,
                                           MessageKind.CANNOT_RESOLVE, [name]);
+    } else if (e.isErroneous()) {
+      return e;
     } else if (identical(e.kind, ElementKind.TYPEDEF)) {
       error(node, MessageKind.CANNOT_INSTANTIATE_TYPEDEF, [name]);
     } else if (identical(e.kind, ElementKind.TYPE_VARIABLE)) {
       error(node, MessageKind.CANNOT_INSTANTIATE_TYPE_VARIABLE, [name]);
     } else if (!identical(e.kind, ElementKind.CLASS)
         && !identical(e.kind, ElementKind.PREFIX)) {
       error(node, MessageKind.NOT_A_TYPE, [name]);
     }
     return e;
   }
+
+  /// Assumed to be called by [resolveRedirectingFactory].
+  Element visitReturn(Return node) {
+    Node expression = node.expression;
+    return finishConstructorReference(visit(expression),
+                                      expression, expression);
+  }
 }