Enhance SafeStackFrameIterator to avoid triggering assertions in debug mode.

src/mips/frames-mips.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
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@@ skipping 34 matching lines @@
   // The marker and function offsets overlap. If the marker isn't a
   // smi then the frame is a JavaScript frame -- and the marker is
   // really the function.
   const int offset = StandardFrameConstants::kMarkerOffset;
   Object* marker = Memory::Object_at(state->fp + offset);
   if (!marker->IsSmi()) return JAVA_SCRIPT;
   return static_cast<StackFrame::Type>(Smi::cast(marker)->value());
 }
 
 
-StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {
-  if (fp == 0) return NONE;
-  // Compute frame type and stack pointer.
+Address ExitFrame::ComputeStackPointer(Address fp) {
   Address sp = fp + ExitFrameConstants::kSPDisplacement;
   const int offset = ExitFrameConstants::kCodeOffset;
   Object* code = Memory::Object_at(fp + offset);
   bool is_debug_exit = code->IsSmi();
   if (is_debug_exit) {
     sp -= kNumJSCallerSaved * kPointerSize;
   }
-  // Fill in the state.
-  state->sp = sp;
-  state->fp = fp;
-  state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
-  return EXIT;
+  return sp;
 }
 
 
 void ExitFrame::Iterate(ObjectVisitor* v) const {
   // Do nothing
 }
 
 
 int JavaScriptFrame::GetProvidedParametersCount() const {
   return ComputeParametersCount();
@@ skipping 13 matching lines @@
 
 
 Address InternalFrame::GetCallerStackPointer() const {
   return fp() + StandardFrameConstants::kCallerSPOffset;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS