Support type variables on redirecting factory constructors.

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 get currentElement;
   Set<Node> get superUses;
 
@@ skipping 2474 matching lines @@
 
   void handleRedirectingFactoryBody(Return node) {
     final isSymbolConstructor = enclosingElement == compiler.symbolConstructor;
     if (!enclosingElement.isFactoryConstructor()) {
       compiler.reportErrorCode(
           node, MessageKind.FACTORY_REDIRECTION_IN_NON_FACTORY);
       compiler.reportErrorCode(
           enclosingElement, MessageKind.MISSING_FACTORY_KEYWORD);
     }
     Element redirectionTarget = resolveRedirectingFactory(node);
-    var type = mapping.getType(node.expression);
-    if (type is InterfaceType && !type.isRaw) {
-      unimplemented(node.expression, 'type arguments on redirecting factory');
-    }
     useElement(node.expression, redirectionTarget);
     FunctionElement constructor = enclosingElement;
     if (constructor.modifiers.isConst() &&
         !redirectionTarget.modifiers.isConst()) {
       error(node, MessageKind.CONSTRUCTOR_IS_NOT_CONST);
     }
     constructor.defaultImplementation = redirectionTarget;
-    if (Elements.isUnresolved(redirectionTarget)) return;
+    if (Elements.isUnresolved(redirectionTarget) ||
+        !redirectionTarget.isConstructor()) {
+      compiler.backend.registerThrowNoSuchMethod(mapping);

[ngeoffray, 2013/05/30 08:23:14]

Do you really need to make it explicit in both cases? I'd understand the backend
needs the helper if it is unresolved, but what about the if it's not a
constructor? What do we emit?

[karlklose, 2013/05/30 11:44:23]

The test is not necessary, I removed it.

+      return;
+    }
+
+    // Compute the signature of the target method taking into account the
+    // type arguments that are specified in the redirection, and store it on
+    // the return node.
+    ClassElement targetClass = redirectionTarget.getEnclosingClass();
+    InterfaceType type = mapping.getType(node.expression)
+        .subst(currentClass.typeVariables, targetClass.typeVariables);
+    mapping.setType(node, type);
+
+    // Check that the target constructor is type compatible with the
+    // redirecting constructor.
+    FunctionType targetType = redirectionTarget.computeType(compiler)
+        .subst(type.typeArguments, targetClass.typeVariables);
+    FunctionType constructorType = constructor.computeType(compiler);
+    if (!compiler.types.isSubtype(targetType, constructorType)) {
+      compiler.backend.registerThrowNoSuchMethod(mapping);

[ngeoffray, 2013/05/30 08:23:14]

I think you can remove the registering here.

[karlklose, 2013/05/30 11:44:23]

I have added logic to test whether we need this.

+      warning(node, MessageKind.INVALID_ARGUMENTS,
+              {'methodName': redirectionTarget.name});
+    }
 
     // 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');
+        unimplemented(node.expression, 'redirecting to redirecting factory');
       }
     }
     world.registerStaticUse(redirectionTarget);
     world.registerInstantiatedClass(
         redirectionTarget.enclosingElement.declaration, mapping);
     if (isSymbolConstructor) {
       // Make sure that collection_dev.Symbol.validated is registered.
       assert(invariant(node, compiler.symbolValidatedConstructor != null));
       world.registerStaticUse(compiler.symbolValidatedConstructor);
     }
@@ skipping 1463 matching lines @@
     return e;
   }
 
   /// Assumed to be called by [resolveRedirectingFactory].
   Element visitReturn(Return node) {
     Node expression = node.expression;
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }