Switch code flushing to use different JSFunction field.

src/mark-compact.h

 // 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 408 matching lines @@
         jsfunction_candidates_head_(NULL),
         shared_function_info_candidates_head_(NULL) {}
 
   void AddCandidate(SharedFunctionInfo* shared_info) {
     SetNextCandidate(shared_info, shared_function_info_candidates_head_);
     shared_function_info_candidates_head_ = shared_info;
   }
 
   void AddCandidate(JSFunction* function) {
     ASSERT(function->code() == function->shared()->code());
+    ASSERT(function->next_function_link()->IsUndefined());
     SetNextCandidate(function, jsfunction_candidates_head_);
     jsfunction_candidates_head_ = function;
   }
 
   void ProcessCandidates() {
     ProcessSharedFunctionInfoCandidates();
     ProcessJSFunctionCandidates();
   }
 
  private:
   void ProcessJSFunctionCandidates();
   void ProcessSharedFunctionInfoCandidates();
 
-  static JSFunction** GetNextCandidateField(JSFunction* candidate) {
-    return reinterpret_cast<JSFunction**>(
-        candidate->address() + JSFunction::kCodeEntryOffset);
-  }
-
   static JSFunction* GetNextCandidate(JSFunction* candidate) {
-    return *GetNextCandidateField(candidate);
+    Object* next_candidate = candidate->next_function_link();
+    return reinterpret_cast<JSFunction*>(next_candidate);
   }
 
   static void SetNextCandidate(JSFunction* candidate,
                                JSFunction* next_candidate) {
-    *GetNextCandidateField(candidate) = next_candidate;
+    candidate->set_next_function_link(next_candidate);
   }
 
-  static SharedFunctionInfo** GetNextCandidateField(
-      SharedFunctionInfo* candidate) {
-    Code* code = candidate->code();
-    return reinterpret_cast<SharedFunctionInfo**>(
-        code->address() + Code::kGCMetadataOffset);
+  static void ClearNextCandidate(JSFunction* candidate, Object* undefined) {
+    ASSERT(undefined->IsUndefined());
+    candidate->set_next_function_link(undefined, SKIP_WRITE_BARRIER);
   }
 
   static SharedFunctionInfo* GetNextCandidate(SharedFunctionInfo* candidate) {
-    return reinterpret_cast<SharedFunctionInfo*>(
-        candidate->code()->gc_metadata());
+    Object* next_candidate = candidate->code()->gc_metadata();
+    return reinterpret_cast<SharedFunctionInfo*>(next_candidate);
   }
 
   static void SetNextCandidate(SharedFunctionInfo* candidate,
                                SharedFunctionInfo* next_candidate) {
     candidate->code()->set_gc_metadata(next_candidate);
   }
 
+  static void ClearNextCandidate(SharedFunctionInfo* candidate) {
+    candidate->code()->set_gc_metadata(NULL, SKIP_WRITE_BARRIER);
+  }
+
   Isolate* isolate_;
   JSFunction* jsfunction_candidates_head_;
   SharedFunctionInfo* shared_function_info_candidates_head_;
 
   DISALLOW_COPY_AND_ASSIGN(CodeFlusher);
 };
 
 
 // Defined in isolate.h.
 class ThreadLocalTop;
@@ skipping 350 matching lines @@
 
   friend class Heap;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_H_