Convert double interface into abstract class

runtime/vm/class_finalizer.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/class_finalizer.h"
 
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/longjump.h"
@@ skipping 239 matching lines @@
                 "class '%s' and superclass '%s' are not "
                 "both classes or both interfaces",
                 class_name.ToCString(),
                 super_class_name.ToCString());
   }
   // If cls belongs to core lib or to core lib's implementation, restrictions
   // about allowed interfaces are lifted.
   if ((cls.library() != Library::CoreLibrary()) &&
       (cls.library() != Library::CoreImplLibrary())) {
     // Prevent extending core implementation classes.
+    bool is_error = false;
     switch (super_class.id()) {
       case kNumberCid:
       case kIntegerCid:
       case kSmiCid:
       case kMintCid:
       case kBigintCid:
       case kDoubleCid:
       case kOneByteStringCid:
       case kTwoByteStringCid:
       case kFourByteStringCid:
@@ skipping 18 matching lines @@
       case kExternalUint32ArrayCid:
       case kInt64ArrayCid:
       case kExternalInt64ArrayCid:
       case kUint64ArrayCid:
       case kExternalUint64ArrayCid:
       case kFloat32ArrayCid:
       case kExternalFloat32ArrayCid:
       case kFloat64ArrayCid:
       case kExternalFloat64ArrayCid:
       case kDartFunctionCid:
-      case kWeakPropertyCid: {
-        const Script& script = Script::Handle(cls.script());
-        ReportError(script, cls.token_pos(),
-                    "'%s' is not allowed to extend '%s'",
-                    String::Handle(cls.Name()).ToCString(),
-                    String::Handle(super_class.Name()).ToCString());
+      case kWeakPropertyCid:
+        is_error = true;
         break;
-      }
-      default: break;
+      default:
+        // Special case: classes for which we don't have a known class id.
+        if (Type::Handle(Type::Double()).type_class() == super_class.raw()) {
+          is_error = true;
+        }

[siva, 2012/08/29 23:49:36]

I presume this is tied to the TODO you have in double.dart
once we do patching this check is not needed?

Maybe you can add a TODO :
// remove once we add patching of double class.

+        break;
+    }
+    if (is_error) {
+      const Script& script = Script::Handle(cls.script());
+      ReportError(script, cls.token_pos(),
+                  "'%s' is not allowed to extend '%s'",
+                  String::Handle(cls.Name()).ToCString(),
+                  String::Handle(super_class.Name()).ToCString());
     }
   }
   return;
 }
 
 
 void ClassFinalizer::ResolveFactoryClass(const Class& interface) {
   ASSERT(interface.is_interface());
   if (interface.is_finalized() ||
       !interface.HasFactoryClass() ||
@@ skipping 903 matching lines @@
                   String::Handle(interface_class.Name()).ToCString());
     }
     // Verify that unless cls belongs to core lib, it cannot extend or implement
     // any of bool, num, int, double, String, Function, Dynamic.
     // The exception is signature classes, which are compiler generated and
     // represent a function type, therefore implementing the Function interface.
     if (!cls_belongs_to_core_lib) {
       if (interface.IsBoolInterface() ||
           interface.IsNumberType() ||
           interface.IsIntInterface() ||
-          interface.IsDoubleInterface() ||
+          interface.IsDoubleType() ||
           interface.IsStringInterface() ||
           (interface.IsFunctionType() && !cls.IsSignatureClass()) ||
           interface.IsDynamicType()) {
         const Script& script = Script::Handle(cls.script());
         ReportError(script, cls.token_pos(),
                     "'%s' is not allowed to extend or implement '%s'",
                     String::Handle(cls.Name()).ToCString(),
                     String::Handle(interface_class.Name()).ToCString());
       }
     }
@@ skipping 151 matching lines @@
 void ClassFinalizer::ReportError(const char* format, ...) {
   va_list args;
   va_start(args, format);
   const Error& error = Error::Handle(
       Parser::FormatError(Script::Handle(), -1, "Error", format, args));
   va_end(args);
   ReportError(error);
 }
 
 }  // namespace dart