Switch code flushing to use different JSFunction field.

src/mark-compact.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 843 matching lines @@
 // the marking stack.  Instead, we mark them as both marked and overflowed.
 // When the stack is in the overflowed state, objects marked as overflowed
 // have been reached and marked but their children have not been visited yet.
 // After emptying the marking stack, we clear the overflow flag and traverse
 // the heap looking for objects marked as overflowed, push them on the stack,
 // and continue with marking.  This process repeats until all reachable
 // objects have been marked.
 
 void CodeFlusher::ProcessJSFunctionCandidates() {
   Code* lazy_compile = isolate_->builtins()->builtin(Builtins::kLazyCompile);
+  Object* undefined = isolate_->heap()->undefined_value();
 
   JSFunction* candidate = jsfunction_candidates_head_;
   JSFunction* next_candidate;
   while (candidate != NULL) {
     next_candidate = GetNextCandidate(candidate);
+    ClearNextCandidate(candidate, undefined);
 
     SharedFunctionInfo* shared = candidate->shared();
 
     Code* code = shared->code();
     MarkBit code_mark = Marking::MarkBitFrom(code);
     if (!code_mark.Get()) {
       shared->set_code(lazy_compile);
       candidate->set_code(lazy_compile);
-    } else {
-      candidate->set_code(shared->code());
+    } else if (code == lazy_compile) {
+      candidate->set_code(lazy_compile);
     }
 
     // We are in the middle of a GC cycle so the write barrier in the code
     // setter did not record the slot update and we have to do that manually.
     Address slot = candidate->address() + JSFunction::kCodeEntryOffset;
     Code* target = Code::cast(Code::GetObjectFromEntryAddress(slot));
     isolate_->heap()->mark_compact_collector()->
         RecordCodeEntrySlot(slot, target);
 
     Object** shared_code_slot =
         HeapObject::RawField(shared, SharedFunctionInfo::kCodeOffset);
     isolate_->heap()->mark_compact_collector()->
         RecordSlot(shared_code_slot, shared_code_slot, *shared_code_slot);
 
     candidate = next_candidate;
   }
 
   jsfunction_candidates_head_ = NULL;
 }
 
 
 void CodeFlusher::ProcessSharedFunctionInfoCandidates() {
   Code* lazy_compile = isolate_->builtins()->builtin(Builtins::kLazyCompile);
 
   SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
   SharedFunctionInfo* next_candidate;
   while (candidate != NULL) {
     next_candidate = GetNextCandidate(candidate);
-    SetNextCandidate(candidate, NULL);
+    ClearNextCandidate(candidate);
 
     Code* code = candidate->code();
     MarkBit code_mark = Marking::MarkBitFrom(code);
     if (!code_mark.Get()) {
       candidate->set_code(lazy_compile);
     }
 
     Object** code_slot =
         HeapObject::RawField(candidate, SharedFunctionInfo::kCodeOffset);
     isolate_->heap()->mark_compact_collector()->
@@ skipping 2835 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal