[liveedit] reimplement frame restarting.

src/mips64/macro-assembler-mips64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
@@ skipping 4032 matching lines @@
 
 void MacroAssembler::DebugBreak() {
   PrepareCEntryArgs(0);
   PrepareCEntryFunction(
       ExternalReference(Runtime::kHandleDebuggerStatement, isolate()));
   CEntryStub ces(isolate(), 1);
   DCHECK(AllowThisStubCall(&ces));
   Call(ces.GetCode(), RelocInfo::DEBUGGER_STATEMENT);
 }
 
+void MacroAssembler::MaybeDropFrames() {
+  // Check whether we need to drop frames to restart a function on the stack.
+  ExternalReference restart_fp =
+      ExternalReference::debug_restart_fp_address(isolate());
+  li(a1, Operand(restart_fp));
+  ld(a1, MemOperand(a1));
+  Jump(isolate()->builtins()->FrameDropperTrampoline(), RelocInfo::CODE_TARGET,
+       ne, a1, Operand(zero_reg));
+}
 
 // ---------------------------------------------------------------------------
 // Exception handling.
 
 void MacroAssembler::PushStackHandler() {
   // Adjust this code if not the case.
   STATIC_ASSERT(StackHandlerConstants::kSize == 1 * kPointerSize);
   STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
 
   // Link the current handler as the next handler.
@@ skipping 2869 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64