new style of property/function callbacks

src/x64/macro-assembler-x64.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 1208 matching lines @@
   // convention requires to put the pointer to the return value slot into
   // rcx (rcx must be preserverd until CallApiFunctionAndReturn).  Saves
   // context (rsi).  Clobbers rax.  Allocates arg_stack_space * kPointerSize
   // inside the exit frame (not GCed) accessible via StackSpaceOperand.
   void PrepareCallApiFunction(int arg_stack_space);
 
   // Calls an API function.  Allocates HandleScope, extracts returned value
   // from handle and propagates exceptions.  Clobbers r14, r15, rbx and
   // caller-save registers.  Restores context.  On return removes
   // stack_space * kPointerSize (GCed).
-  void CallApiFunctionAndReturn(Address function_address, int stack_space);
+  void CallApiFunctionAndReturn(
+      Address function_address,

[tfarina, 2013/05/03 16:33:46]

super tiny nit: doesn't fit in 80 column above? without having to wrap?

+      int stack_space,
+      int return_value_offset);
 
   // Before calling a C-function from generated code, align arguments on stack.
   // After aligning the frame, arguments must be stored in esp[0], esp[4],
   // etc., not pushed. The argument count assumes all arguments are word sized.
   // The number of slots reserved for arguments depends on platform. On Windows
   // stack slots are reserved for the arguments passed in registers. On other
   // platforms stack slots are only reserved for the arguments actually passed
   // on the stack.
   void PrepareCallCFunction(int num_arguments);
 
@@ skipping 272 matching lines @@
     masm->popfq();                                                           \
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_