X64: Implement debugger hooks.

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 220 matching lines @@
   static void PrepareStep(StepAction step_action, int step_count);
   static void ClearStepping();
   static bool StepNextContinue(BreakLocationIterator* break_location_iterator,
                                JavaScriptFrame* frame);
   static Handle<DebugInfo> GetDebugInfo(Handle<SharedFunctionInfo> shared);
   static bool HasDebugInfo(Handle<SharedFunctionInfo> shared);
 
   // Returns whether the operation succeeded.
   static bool EnsureDebugInfo(Handle<SharedFunctionInfo> shared);
 
+  // Returns true if the current stub call is patched to call the debugger.
   static bool IsDebugBreak(Address addr);
+  // Returns true if the current return statement has been patched to be
+  // a debugger breakpoint.
   static bool IsDebugBreakAtReturn(RelocInfo* rinfo);
 
   // Check whether a code stub with the specified major key is a possible break
   // point location.
   static bool IsSourceBreakStub(Code* code);
   static bool IsBreakStub(Code* code);
 
   // Find the builtin to use for invoking the debug break
   static Handle<Code> FindDebugBreak(Handle<Code> code, RelocInfo::Mode mode);
 
@@ skipping 107 matching lines @@
 
   // Garbage collection notifications.
   static void AfterGarbageCollection();
 
   // Code generation assumptions.
   static const int kIa32CallInstructionLength = 5;
   static const int kIa32JSReturnSequenceLength = 6;
 
   // The x64 JS return sequence is padded with int3 to make it large
   // enough to hold a call instruction when the debugger patches it.
+  static const int kX64CallInstructionLength = 13;
   static const int kX64JSReturnSequenceLength = 13;
 
   // Code generator routines.
   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 GenerateReturnDebugBreakEntry(MacroAssembler* masm);
@@ skipping 467 matching lines @@
   Debug::AddressId id_;
   int reg_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #endif  // V8_DEBUG_H_