Merge experimental/gc branch to the bleeding_edge.

src/frames.cc

 // Copyright 2011 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 1144 matching lines @@
 // -------------------------------------------------------------------------
 
 
 Code* PcToCodeCache::GcSafeCastToCode(HeapObject* object, Address pc) {
   Code* code = reinterpret_cast<Code*>(object);
   ASSERT(code != NULL && code->contains(pc));
   return code;
 }
 
 
+static int GcSafeSizeOfCodeSpaceObject(HeapObject* object) {
+  MapWord map_word = object->map_word();
+  Map* map = map_word.IsForwardingAddress() ?
+      map_word.ToForwardingAddress()->map() : map_word.ToMap();
+  return object->SizeFromMap(map);
+}
+
+
 Code* PcToCodeCache::GcSafeFindCodeForPc(Address pc) {
   Heap* heap = isolate_->heap();
   // Check if the pc points into a large object chunk.
-  LargeObjectChunk* chunk = heap->lo_space()->FindChunkContainingPc(pc);
-  if (chunk != NULL) return GcSafeCastToCode(chunk->GetObject(), pc);
+  LargePage* large_page = heap->lo_space()->FindPageContainingPc(pc);
+  if (large_page != NULL) return GcSafeCastToCode(large_page->GetObject(), pc);
 
-  // Iterate through the 8K page until we reach the end or find an
-  // object starting after the pc.
+  // Iterate through the page until we reach the end or find an object starting
+  // after the pc.
   Page* page = Page::FromAddress(pc);
-  HeapObjectIterator iterator(page, heap->GcSafeSizeOfOldObjectFunction());
-  HeapObject* previous = NULL;
+
+  Address addr = page->skip_list()->StartFor(pc);
+
+  Address top = heap->code_space()->top();
+  Address limit = heap->code_space()->limit();
+
   while (true) {
-    HeapObject* next = iterator.next();
-    if (next == NULL || next->address() >= pc) {
-      return GcSafeCastToCode(previous, pc);
+    if (addr == top && addr != limit) {
+      addr = limit;
+      continue;
     }
-    previous = next;
+
+    HeapObject* obj = HeapObject::FromAddress(addr);
+    int obj_size = GcSafeSizeOfCodeSpaceObject(obj);
+    Address next_addr = addr + obj_size;
+    if (next_addr >= pc) return GcSafeCastToCode(obj, pc);
+    addr = next_addr;
   }
 }
 
 
 PcToCodeCache::PcToCodeCacheEntry* PcToCodeCache::GetCacheEntry(Address pc) {
   isolate_->counters()->pc_to_code()->Increment();
   ASSERT(IsPowerOf2(kPcToCodeCacheSize));
   uint32_t hash = ComputeIntegerHash(
       static_cast<uint32_t>(reinterpret_cast<uintptr_t>(pc)));
   uint32_t index = hash & (kPcToCodeCacheSize - 1);
@@ skipping 78 matching lines @@
   ZoneList<StackFrame*> list(10);
   for (StackFrameIterator it; !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame());
     list.Add(frame);
   }
   return list.ToVector();
 }
 
 
 } }  // namespace v8::internal