Annotate V8 for MemorySanitizer.

src/frames.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 15 matching lines @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
 #include "ast.h"
 #include "deoptimizer.h"
 #include "frames-inl.h"
 #include "full-codegen.h"
 #include "lazy-instance.h"
 #include "mark-compact.h"
+#include "msan.h"
 #include "safepoint-table.h"
 #include "scopeinfo.h"
 #include "string-stream.h"
 #include "vm-state-inl.h"
 
 #include "allocation-inl.h"
 
 namespace v8 {
 namespace internal {
 
@@ skipping 371 matching lines @@
                            Code* holder) {
   Address pc = *pc_address;
   ASSERT(GcSafeCodeContains(holder, pc));
   unsigned pc_offset = static_cast<unsigned>(pc - holder->instruction_start());
   Object* code = holder;
   v->VisitPointer(&code);
   if (code != holder) {
     holder = reinterpret_cast<Code*>(code);
     pc = holder->instruction_start() + pc_offset;
     *pc_address = pc;
+    MSAN_MEMORY_IS_INITIALIZED(pc_address, sizeof(*pc_address));
   }
 }
 
 
 void StackFrame::SetReturnAddressLocationResolver(
     ReturnAddressLocationResolver resolver) {
   ASSERT(return_address_location_resolver_ == NULL);
   return_address_location_resolver_ = resolver;
 }
 
@@ skipping 1190 matching lines @@
   ZoneList<StackFrame*> list(10, zone);
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 } }  // namespace v8::internal