LiveEdit: implement stack manipulations for x64

src/x64/debug-x64.cc

 // Copyright 2010 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 184 matching lines @@
 
 
 void Debug::GenerateSlotDebugBreak(MacroAssembler* masm) {
   // In the places where a debug break slot is inserted no registers can contain
   // object pointers.
   Generate_DebugBreakCallHelper(masm, 0, true);
 }
 
 
 void Debug::GeneratePlainReturnLiveEdit(MacroAssembler* masm) {
-  masm->Abort("LiveEdit frame dropping is not supported on x64");
+  masm->ret(0);
 }
 
 
 void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
-  masm->Abort("LiveEdit frame dropping is not supported on x64");
+  ExternalReference restarter_frame_function_slot =
+      ExternalReference(Debug_Address::RestarterFrameFunctionPointer());
+  __ movq(rax, restarter_frame_function_slot);
+  __ movq(Operand(rax, 0), Immediate(0));
+
+  // We do not know our frame height, but set rsp based on rbp.
+  __ lea(rsp, Operand(rbp, -1 * kPointerSize));
+
+  __ pop(rdi);  // Function.
+  __ pop(rbp);
+
+  // Load context from the function.
+  __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
+
+  // Get function code.
+  __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+  __ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
+  __ lea(rdx, FieldOperand(rdx, Code::kHeaderSize));
+
+  // Re-run JSFunction, rdi is function, rsi is context.
+  __ jmp(rdx);
 }
 
+const bool Debug::kFrameDropperSupported = true;
+
 #undef __
 
 
-Object** Debug::SetUpFrameDropperFrame(StackFrame* bottom_js_frame,
-                                       Handle<Code> code) {
-  UNREACHABLE();
-  return NULL;
-}
-const int Debug::kFrameDropperFrameSize = -1;
 
 
 void BreakLocationIterator::ClearDebugBreakAtReturn() {
   rinfo()->PatchCode(original_rinfo()->pc(),
                      Assembler::kJSReturnSequenceLength);
 }
 
 
 bool BreakLocationIterator::IsDebugBreakAtReturn()  {
   return Debug::IsDebugBreakAtReturn(rinfo());
@@ skipping 27 matching lines @@
   ASSERT(IsDebugBreakSlot());
   rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength);
 }
 
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64