Array access fix: g++ darwin 4.2.1 compiler clamped array index to 0 when confronted with negative …

src/arguments.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 34 matching lines @@
 //     ... use args[i] here ...
 //   }
 
 class Arguments BASE_EMBEDDED {
  public:
   Arguments(int length, Object** arguments)
       : length_(length), arguments_(arguments) { }
 
   Object*& operator[] (int index) {
     ASSERT(0 <= index && index < length_);
-    return arguments_[-index];
+    return *(reinterpret_cast<Object**>(reinterpret_cast<intptr_t>(arguments_) -

[Jakob Kummerow, 2013/06/10 14:43:38]

The minus at the end of the line looks weird. I'd prefer to format as:

    return *(reinterpret_cast<Object**>(
        reinterpret_cast<intptr_t>(arguments_) - index * kPointerSize));

+                                        index * kPointerSize));
   }
 
   template <class S> Handle<S> at(int index) {
     Object** value = &((*this)[index]);
     // This cast checks that the object we're accessing does indeed have the
     // expected type.
     S::cast(*value);
     return Handle<S>(reinterpret_cast<S**>(value));
   }
 
@@ skipping 280 matching lines @@
   return __RT_impl_##Name(args, isolate);                             \
 }                                                                     \
 static Type __RT_impl_##Name(Arguments args, Isolate* isolate)
 
 #define RUNTIME_ARGUMENTS(isolate, args) \
   args.length(), args.arguments(), isolate
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARGUMENTS_H_