LiveEdit: implement stack manipulations for x64

src/debug.h

 // Copyright 2006-2008 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 382 matching lines @@
   static void GenerateSlot(MacroAssembler* masm);
   static void GenerateLoadICDebugBreak(MacroAssembler* masm);
   static void GenerateStoreICDebugBreak(MacroAssembler* masm);
   static void GenerateKeyedLoadICDebugBreak(MacroAssembler* masm);
   static void GenerateKeyedStoreICDebugBreak(MacroAssembler* masm);
   static void GenerateConstructCallDebugBreak(MacroAssembler* masm);
   static void GenerateReturnDebugBreak(MacroAssembler* masm);
   static void GenerateStubNoRegistersDebugBreak(MacroAssembler* masm);
   static void GenerateSlotDebugBreak(MacroAssembler* masm);
   static void GeneratePlainReturnLiveEdit(MacroAssembler* masm);
+
+  // FrameDropper is a code replacement for a JavaScript frame with possibly
+  // several frames above.
+  // There is no calling conventions here, because it never actually gets
+  // called, it only gets returned to.
   static void GenerateFrameDropperLiveEdit(MacroAssembler* masm);
 
   // Called from stub-cache.cc.
   static void GenerateCallICDebugBreak(MacroAssembler* masm);
 
   // Describes how exactly a frame has been dropped from stack.
   enum FrameDropMode {
     // No frame has been dropped.
     FRAMES_UNTOUCHED,
     // The top JS frame had been calling IC stub. IC stub mustn't be called now.
@@ skipping 11 matching lines @@
                                     Object** restarter_frame_function_pointer);
 
   // Initializes an artificial stack frame. The data it contains is used for:
   //  a. successful work of frame dropper code which eventually gets control,
   //  b. being compatible with regular stack structure for various stack
   //     iterators.
   // Returns address of stack allocated pointer to restarted function,
   // the value that is called 'restarter_frame_function_pointer'. The value
   // at this address (possibly updated by GC) may be used later when preparing
   // 'step in' operation.
-  // The implementation is architecture-specific.
-  // TODO(LiveEdit): consider reviewing it as architecture-independent.
   static Object** SetUpFrameDropperFrame(StackFrame* bottom_js_frame,
                                          Handle<Code> code);
 
   static const int kFrameDropperFrameSize;
 
+  // Architecture-specific constant.
+  static const bool kFrameDropperSupported;
+
  private:
   static bool CompileDebuggerScript(int index);
   static void ClearOneShot();
   static void ActivateStepIn(StackFrame* frame);
   static void ClearStepIn();
   static void ActivateStepOut(StackFrame* frame);
   static void ClearStepOut();
   static void ClearStepNext();
   // Returns whether the compile succeeded.
   static void RemoveDebugInfo(Handle<DebugInfo> debug_info);
@@ skipping 560 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(MessageDispatchHelperThread);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #endif  // V8_DEBUG_H_