Snapshots: Add --extra-code flag to mksnapshot which lets you specify a file

src/heap.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 2804 matching lines @@
   // There is a string and a number per entry so the length is twice the number
   // of entries.
   return number_string_cache_size * 2;
 }
 
 
 void Heap::AllocateFullSizeNumberStringCache() {
   // The idea is to have a small number string cache in the snapshot to keep
   // boot-time memory usage down.  If we expand the number string cache already
   // while creating the snapshot then that didn't work out.
-  ASSERT(!Serializer::enabled());
+  ASSERT(!Serializer::enabled() || FLAG_extra_code != NULL);
   MaybeObject* maybe_obj =
       AllocateFixedArray(FullSizeNumberStringCacheLength(), TENURED);
   Object* new_cache;
   if (maybe_obj->ToObject(&new_cache)) {
     // We don't bother to repopulate the cache with entries from the old cache.
     // It will be repopulated soon enough with new strings.
     set_number_string_cache(FixedArray::cast(new_cache));
   }
   // If allocation fails then we just return without doing anything.  It is only
   // a cache, so best effort is OK here.
@@ skipping 4316 matching lines @@
   } else {
     p ^= 0x1d1ed & (Page::kPageSize - 1);  // I died.
   }
   remembered_unmapped_pages_[remembered_unmapped_pages_index_] =
       reinterpret_cast<Address>(p);
   remembered_unmapped_pages_index_++;
   remembered_unmapped_pages_index_ %= kRememberedUnmappedPages;
 }
 
 } }  // namespace v8::internal