Make int an 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 283 matching lines @@
       case kFloat32ArrayCid:
       case kExternalFloat32ArrayCid:
       case kFloat64ArrayCid:
       case kExternalFloat64ArrayCid:
       case kDartFunctionCid:
       case kWeakPropertyCid:
         is_error = true;
         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()) {
+        if (Type::Handle(Type::Double()).type_class() == super_class.raw() ||
+            Type::Handle(Type::IntType()).type_class() == super_class.raw()) {

[regis, 2012/09/12 16:30:25]

I do not quite understand why kIntegerCid (and actually kDoubleCid) are not
sufficient here. I guess they refer to the implementation rather than the
interface, but then, how did it work for int before?
Lasse, it is not fair to ask you those questions, but maybe you can add a TODO
with my name if you cannot answer them. Thanks! 

[Lasse Reichstein Nielsen, 2012/09/13 07:19:21]

I think it worked for int before because it was an interface, and you can't
extend an interface anyway. I.e., it was caught somewhere else.
I have no idea why this works the way it does (or how it works at all) - I have
been working entirely by pattern-matching.
Adding TODO.

           is_error = true;
         }
         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());
@@ skipping 916 matching lines @@
                   "'%s' is used where an interface or class name is expected",
                   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.IsBoolType() ||
           interface.IsNumberType() ||
-          interface.IsIntInterface() ||
+          interface.IsIntType() ||
           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 152 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