Ensure that ClassElement.lookupConstructor fails when looking up default constructor using Selector…

lib/compiler/implementation/resolver.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.
 
 abstract class TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(TypeAnnotation annotation);
   bool isParameterChecked(Element element);
 }
@@ skipping 71 matching lines @@
         return resolveParameter(element);
       }
 
       compiler.unimplemented("resolve($element)",
                              node: element.parseNode(compiler));
     });
   }
 
   bool isNamedConstructor(Send node) => node.receiver !== null;
 
-  SourceString getConstructorName(Send node) {
-    return node.selector.asIdentifier().source;
+  Selector getRedirectingThisOrSuperConstructorSelector(
+      Send node,
+      SourceString className,

[kasperl, 2012/10/16 05:24:02]

Unused parameter.

[aam-me, 2012/10/16 12:07:49]

Quite amazing! Done.

+      ResolverVisitor visitor) {
+    if (!isNamedConstructor(node)) {

[kasperl, 2012/10/16 05:24:02]

Maybe invert this condition (get rid of !) so the positive case comes first?
Seems easier to understand that way.

[aam-me, 2012/10/16 12:07:49]

Agree. Done.

+      return new Selector.callDefaultConstructor(
+        visitor.enclosingElement.getLibrary());
+    } else {
+      SourceString constructorName = node.selector.asIdentifier().source;
+      return new Selector.callConstructor(
+          constructorName,
+          visitor.enclosingElement.getLibrary());
+    }
   }
 
   String constructorNameForDiagnostics(SourceString className,
                                    SourceString constructorName) {
     String classNameString = className.slowToString();
     String constructorNameString = constructorName.slowToString();
     return (constructorName === const SourceString(''))
         ? classNameString
         : "$classNameString.$constructorNameString";
    }
 
   FunctionElement resolveConstructorRedirection(InitializerResolver resolver,
                                                 FunctionElement constructor) {
     if (constructor.isPatched) {
       checkMatchingPatchSignatures(constructor, constructor.patch);
       constructor = constructor.patch;
     }
     FunctionExpression node = constructor.parseNode(compiler);
 
     // A synthetic constructor does not have a node.
     if (node === null) return null;
     if (node.initializers === null) return null;
     Link<Node> initializers = node.initializers.nodes;
     if (!initializers.isEmpty() &&
         Initializers.isConstructorRedirect(initializers.head)) {
       final ClassElement classElement = constructor.getEnclosingClass();
-      Selector selector;
-      if (isNamedConstructor(initializers.head)) {
-        SourceString constructorName = getConstructorName(initializers.head);
-        selector = new Selector.callConstructor(
-            constructorName,
-            resolver.visitor.enclosingElement.getLibrary());
-      } else {
-        selector = new Selector.callDefaultConstructor(
-            resolver.visitor.enclosingElement.getLibrary());
-      }
+      Selector selector =
+          getRedirectingThisOrSuperConstructorSelector(initializers.head,
+                                                       classElement.name,
+                                                       resolver.visitor);
       return classElement.lookupConstructor(selector);
     }
     return null;
   }
 
   void resolveRedirectingConstructor(InitializerResolver resolver,
                                      Node node,
                                      FunctionElement constructor,
                                      FunctionElement redirection) {
     Set<FunctionElement> seen = new Set<FunctionElement>();
@@ skipping 598 matching lines @@
       visitor.resolveArguments(call.argumentsNode);
     });
     Selector selector = visitor.mapping.getSelector(call);
     bool isSuperCall = Initializers.isSuperConstructorCall(call);
 
     ClassElement lookupTarget = getSuperOrThisLookupTarget(constructor,
                                                            isSuperCall,
                                                            call);
     final SourceString className = lookupTarget.name;
 
-    SourceString constructorName;
-    Selector lookupSelector;
-    if (resolver.isNamedConstructor(call)) {
-      constructorName = resolver.getConstructorName(call);
-      lookupSelector = new Selector.callConstructor(
-          constructorName,
-          visitor.enclosingElement.getLibrary());
-    } else {
-      constructorName = const SourceString('');
-      lookupSelector = new Selector.callDefaultConstructor(
-          visitor.enclosingElement.getLibrary());
-    }
-
-    FunctionElement lookedupConstructor =
-        lookupTarget.lookupConstructor(lookupSelector);
+    Selector constructorSelector =
+        resolver.getRedirectingThisOrSuperConstructorSelector(call,
+                                                              className,
+                                                              visitor);
+    FunctionElement calledConstructor =
+        lookupTarget.lookupConstructor(constructorSelector);
 
     final bool isImplicitSuperCall = false;
-    verifyThatConstructorMatchesCall(lookedupConstructor,
+    verifyThatConstructorMatchesCall(calledConstructor,
                                      selector,
                                      isImplicitSuperCall,
                                      call,
-                                     constructorName,
-                                     className);
+                                     className,
+                                     constructorSelector);
 
-    visitor.useElement(call, lookedupConstructor);
-    visitor.world.registerStaticUse(lookedupConstructor);
-    return lookedupConstructor;
+    visitor.useElement(call, calledConstructor);
+    visitor.world.registerStaticUse(calledConstructor);
+    return calledConstructor;
   }
 
   void resolveImplicitSuperConstructorSend(FunctionElement constructor,
                                            FunctionExpression functionNode) {
     // If the class has a super resolve the implicit super call.
     ClassElement classElement = constructor.getEnclosingClass();
     ClassElement superClass = classElement.superclass;
     if (classElement != visitor.compiler.objectClass) {
       assert(superClass !== null);
       assert(superClass.resolutionState == STATE_DONE);
       SourceString constructorName = const SourceString('');
       Selector callToMatch = new Selector.call(
           constructorName,
           classElement.getLibrary(),
           0);
 
       final bool isSuperCall = true;
       ClassElement lookupTarget = getSuperOrThisLookupTarget(constructor,
                                                              isSuperCall,
                                                              functionNode);
+      Selector constructorSelector = new Selector.callDefaultConstructor(
+          visitor.enclosingElement.getLibrary());
+      Element calledConstructor = lookupTarget.lookupConstructor(
+          constructorSelector);
+
       final SourceString className = lookupTarget.name;
-      Element calledConstructor = lookupTarget.lookupConstructor(
-          new Selector.callDefaultConstructor(
-              visitor.enclosingElement.getLibrary()));
-
       final bool isImplicitSuperCall = true;
       verifyThatConstructorMatchesCall(calledConstructor,
                                        callToMatch,
                                        isImplicitSuperCall,
                                        functionNode,
                                        className,
-                                       const SourceString(''));
+                                       constructorSelector);
 
       visitor.world.registerStaticUse(calledConstructor);
     }
   }
 
   void verifyThatConstructorMatchesCall(
       FunctionElement lookedupConstructor,
       Selector call,
       bool isImplicitSuperCall,
       Node diagnosticNode,
       SourceString className,
-      SourceString constructorName) {
+      Selector constructorSelector) {
     if (lookedupConstructor === null
         || !lookedupConstructor.isGenerativeConstructor()) {
       var fullConstructorName =
-          visitor.compiler.resolver.constructorNameForDiagnostics(className,
-                                                              constructorName);
+          visitor.compiler.resolver.constructorNameForDiagnostics(
+              className,
+              constructorSelector.name);
       MessageKind kind = isImplicitSuperCall
           ? MessageKind.CANNOT_RESOLVE_CONSTRUCTOR_FOR_IMPLICIT
           : MessageKind.CANNOT_RESOLVE_CONSTRUCTOR;
       error(diagnosticNode, kind, [fullConstructorName]);
     } else {
       if (!call.applies(lookedupConstructor, visitor.compiler)) {
         MessageKind kind = isImplicitSuperCall
                            ? MessageKind.NO_MATCHING_CONSTRUCTOR_FOR_IMPLICIT
                            : MessageKind.NO_MATCHING_CONSTRUCTOR;
         error(diagnosticNode, kind);
@@ skipping 2393 matching lines @@
     return result;
   }
   Element lookup(SourceString name) => localLookup(name);
   Element lexicalLookup(SourceString name) => localLookup(name);
 
   Element add(Element newElement) {
     throw "Cannot add an element in a patch library scope";
   }
   String toString() => 'PatchLibraryScope($origin,$patch)';
 }