Fix code flusher to process weak function links.

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 934 matching lines @@
         SetNextCandidate(candidate, next_candidate);
         ClearNextCandidate(function, undefined);
       }
 
       candidate = next_candidate;
     }
   }
 }
 
 
+void CodeFlusher::IteratePointersToFromSpace(ObjectVisitor* v) {
+  Heap* heap = isolate_->heap();
+
+  JSFunction** slot = &jsfunction_candidates_head_;
+  JSFunction* candidate = jsfunction_candidates_head_;
+  while (candidate != NULL) {
+    if (heap->InFromSpace(candidate)) {
+      v->VisitPointer(reinterpret_cast<Object**>(slot));
+    }
+    candidate = GetNextCandidate(*slot);

[ulan_google, 2012/10/26 09:15:28]

candidate = GetNextCandidate(candidate);

Would be more robust w.r.t. reordering of these two lines.

[Michael Starzinger, 2012/10/26 09:39:39]

We cannot use the candidate variable here, because the visitor most probably
updated the referenced stored at the slot. So we need to reload the reference
and candidate should be considered a stale value at this point.

+    slot = GetNextCandidateSlot(*slot);
+  }
+}
+
+
 MarkCompactCollector::~MarkCompactCollector() {
   if (code_flusher_ != NULL) {
     delete code_flusher_;
     code_flusher_ = NULL;
   }
 }
 
 
 static inline HeapObject* ShortCircuitConsString(Object** p) {
   // Optimization: If the heap object pointed to by p is a non-symbol
@@ skipping 2808 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal