Implemented function that returns code age.

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 986 matching lines @@
     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()) {
       if (FLAG_trace_code_flushing && shared->is_compiled()) {
         SmartArrayPointer<char> name = shared->DebugName()->ToCString();
-        PrintF("[code-flushing clears: %s]\n", *name);
+        PrintF("[code-flushing clears: %s - age: %d]\n", *name, code->GetAge());
       }
       shared->set_code(lazy_compile);
       candidate->set_code(lazy_compile);
     } else {
       candidate->set_code(code);
     }
 
     // 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;
@@ skipping 20 matching lines @@
   SharedFunctionInfo* next_candidate;
   while (candidate != NULL) {
     next_candidate = GetNextCandidate(candidate);
     ClearNextCandidate(candidate);
 
     Code* code = candidate->code();
     MarkBit code_mark = Marking::MarkBitFrom(code);
     if (!code_mark.Get()) {
       if (FLAG_trace_code_flushing && candidate->is_compiled()) {
         SmartArrayPointer<char> name = candidate->DebugName()->ToCString();
-        PrintF("[code-flushing clears: %s]\n", *name);
+        PrintF("[code-flushing clears: %s - age: %d]\n", *name, code->GetAge());
       }
       candidate->set_code(lazy_compile);
     }
 
     Object** code_slot =
         HeapObject::RawField(candidate, SharedFunctionInfo::kCodeOffset);
     isolate_->heap()->mark_compact_collector()->
         RecordSlot(code_slot, code_slot, *code_slot);
 
     candidate = next_candidate;
@@ skipping 3206 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal