Avoid object layout changes during GC.

src/runtime.cc

 // Copyright 2012 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 13091 matching lines @@
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MarkOneShotGetter) {
   ASSERT_EQ(args.length(), 1);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0);
   HandleScope scope(isolate);
   Handle<String> key = isolate->factory()->hidden_stack_trace_symbol();
   JSObject::SetHiddenProperty(fun, key, key);
   return *fun;
 }
 
 
-// Retrieve the raw stack trace collected on stack overflow and delete
-// it since it is used only once to avoid keeping it alive.
-RUNTIME_FUNCTION(MaybeObject*, Runtime_GetOverflowedRawStackTrace) {
+// Retrieve the stack trace.  This could be the raw stack trace collected
+// on stack overflow or the already formatted stack trace string.
+RUNTIME_FUNCTION(MaybeObject*, Runtime_GetOverflowedStackTrace) {
   ASSERT_EQ(args.length(), 1);

[Michael Starzinger, 2012/12/11 14:52:35]

This method should either have a NoHandleAllocation scope or it's own
HandleScope.

   CONVERT_ARG_CHECKED(JSObject, error_object, 0);
   String* key = isolate->heap()->hidden_stack_trace_symbol();
   Object* result = error_object->GetHiddenProperty(key);
-  RUNTIME_ASSERT(result->IsJSArray() || result->IsUndefined());
-  error_object->DeleteHiddenProperty(key);
+  RUNTIME_ASSERT(result->IsJSArray() ||
+                 result->IsString() ||
+                 result->IsUndefined());
   return result;
 }
 
 
+// Set or clear the stack trace attached to an stack overflow error object.
+RUNTIME_FUNCTION(MaybeObject*, Runtime_SetOverflowedStackTrace) {
+  ASSERT_EQ(args.length(), 2);

[Michael Starzinger, 2012/12/11 14:52:35]

Likewise.

+  CONVERT_ARG_HANDLE_CHECKED(JSObject, error_object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(HeapObject, value, 1);
+  Handle<String> key = isolate->factory()->hidden_stack_trace_symbol();
+  if (value->IsUndefined()) {
+    error_object->DeleteHiddenProperty(*key);
+  } else {
+    RUNTIME_ASSERT(value->IsString());
+    JSObject::SetHiddenProperty(error_object, key, value);
+  }
+  return *error_object;
+}
+
+
 // Returns V8 version as a string.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetV8Version) {
   ASSERT_EQ(args.length(), 0);
 
   NoHandleAllocation ha;
 
   const char* version_string = v8::V8::GetVersion();
 
   return isolate->heap()->AllocateStringFromOneByte(CStrVector(version_string),
                                                   NOT_TENURED);
@@ skipping 380 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal