Support mixin application typedef as mixin in the VM (issues 9383, 12773).

runtime/vm/parser.cc

 // 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.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 3775 matching lines @@
     ConsumeToken();
     const intptr_t type_pos = TokenPos();
     super_type = ParseType(ClassFinalizer::kResolveTypeParameters);
     if (super_type.IsTypeParameter()) {
       ErrorMsg(type_pos,
                "class '%s' may not extend type parameter '%s'",
                class_name.ToCString(),
                String::Handle(super_type.UserVisibleName()).ToCString());
     }
     if (CurrentToken() == Token::kWITH) {
-      super_type = ParseMixins(super_type);
+      super_type = ParseMixins(pending_classes, super_type);
     }
   } else {
     // No extends clause: implicitly extend Object, unless Object itself.
     if (!cls.IsObjectClass()) {
       super_type = Type::ObjectType();
     }
   }
   ASSERT(!super_type.IsNull() || cls.IsObjectClass());
   cls.set_super_type(super_type);
 
@@ skipping 189 matching lines @@
   if (type.IsTypeParameter()) {
     ErrorMsg(type_pos,
              "class '%s' may not extend type parameter '%s'",
              class_name.ToCString(),
              String::Handle(type.UserVisibleName()).ToCString());
   }
 
   if (CurrentToken() != Token::kWITH) {
     ErrorMsg("mixin application 'with Type' expected");
   }
-  type = ParseMixins(type);
+  type = ParseMixins(pending_classes, type);
 
   // TODO(12773): Treat the mixin application as an alias, not as a base
   // class whose super class is the mixin application! This is difficult because
   // of issues involving subsitution of type parameters
   mixin_application.set_super_type(type);
   mixin_application.set_is_synthesized_class();
 
   // This mixin application typedef needs an implicit constructor, but it is
   // too early to call 'AddImplicitConstructor(mixin_application)' here,
   // because this class should be lazily compiled.
@@ skipping 365 matching lines @@
                "type parameter '%s' may not be used in interface list",
                String::Handle(interface.UserVisibleName()).ToCString());
     }
     all_interfaces.Add(interface);
   } while (CurrentToken() == Token::kCOMMA);
   cls_interfaces = Array::MakeArray(all_interfaces);
   cls.set_interfaces(cls_interfaces);
 }
 
 
-RawAbstractType* Parser::ParseMixins(const AbstractType& super_type) {
+RawAbstractType* Parser::ParseMixins(const GrowableObjectArray& pending_classes,
+                                     const AbstractType& super_type) {
   TRACE_PARSER("ParseMixins");
   ASSERT(CurrentToken() == Token::kWITH);
   ASSERT(super_type.IsType());  // TODO(regis): Could be a BoundedType.
   AbstractType& mixin_super_type = AbstractType::Handle(super_type.raw());
 
   const GrowableObjectArray& mixin_apps =
       GrowableObjectArray::Handle(GrowableObjectArray::New());
   AbstractType& mixin_type = AbstractType::Handle();
   Class& mixin_app_class = Class::Handle();
-  Array& mixin_app_interfaces = Array::Handle();
   String& mixin_app_class_name = String::Handle();
   String& mixin_type_class_name = String::Handle();
   do {
     ConsumeToken();
     const intptr_t mixin_pos = TokenPos();
     mixin_type = ParseType(ClassFinalizer::kResolveTypeParameters);
     if (mixin_type.IsTypeParameter()) {
       ErrorMsg(mixin_pos,
                "mixin type '%s' may not be a type parameter",
                String::Handle(mixin_type.UserVisibleName()).ToCString());
     }
 
     // The name of the mixin application class is a combination of
     // the super class name and mixin class name.
     mixin_app_class_name = mixin_super_type.ClassName();
     mixin_app_class_name = String::Concat(mixin_app_class_name,
                                           Symbols::Ampersand());
     mixin_type_class_name = mixin_type.ClassName();
     mixin_app_class_name = String::Concat(mixin_app_class_name,
                                           mixin_type_class_name);
     mixin_app_class_name = Symbols::New(mixin_app_class_name);
 
     mixin_app_class = Class::New(mixin_app_class_name, script_, mixin_pos);
     mixin_app_class.set_super_type(mixin_super_type);
     mixin_app_class.set_mixin(Type::Cast(mixin_type));
     mixin_app_class.set_library(library_);
     mixin_app_class.set_is_synthesized_class();
+    pending_classes.Add(mixin_app_class, Heap::kOld);
 
-    // Add the mixin type to the interfaces that the mixin application
-    // class implements. This is necessary so that type tests work.
-    mixin_app_interfaces = Array::New(1);
-    mixin_app_interfaces.SetAt(0, mixin_type);
-    mixin_app_class.set_interfaces(mixin_app_interfaces);
+    // The class finalizer will add the mixin type to the interfaces that the
+    // mixin application class implements. This is necessary so that type tests
+    // work. The mixin class may not be resolved yet, so it is not possible to
+    // add the interface with the correct type arguments here.
 
     // Add the synthesized class to the list of mixin apps.
     mixin_apps.Add(mixin_app_class);
 
     // This mixin application class becomes the type class of the super type of
     // the next mixin application class. It is however too early to provide the
     // correct super type arguments. We use the raw type for now.
     mixin_super_type = Type::New(mixin_app_class,
                                  Object::null_abstract_type_arguments(),
                                  mixin_pos);
@@ skipping 6071 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart