Annotate V8 for MemorySanitizer.

src/deoptimizer.cc

Index: src/deoptimizer.cc
===================================================================
--- src/deoptimizer.cc	(revision 17104)
+++ src/deoptimizer.cc	(working copy)
@@ -34,6 +34,7 @@
 #include "full-codegen.h"
 #include "global-handles.h"
 #include "macro-assembler.h"
+#include "msan.h"
 #include "prettyprinter.h"
 
 
@@ -108,6 +109,8 @@
                               Address from,
                               int fp_to_sp_delta,
                               Isolate* isolate) {
+  MSAN_RUNTIME_FUNCTION6(function, type, bailout_id, from, fp_to_sp_delta,
+                         isolate);
   Deoptimizer* deoptimizer = new Deoptimizer(isolate,

[danno, 2013/10/10 14:18:07]

This big unpoison of the stack is total overkill. The deoptimizer copies a
specific number of frames from the stack to the input_ of buffer of the
Deoptimizer. This is done after returning from this routine in the hand-written
assembly code of the deoptimizer. After that, the
Deoptimizer::ComputeOutputFrames method inspect this buffer to build the output
frames. You should be able to precisely unpoison just the input buffer for which
you have the exact size at the beginning of Deoptimizer::ComputeOutputFrames.

[Evgeniy Stepanov, 2013/10/10 15:08:54]

Thanks, this is very helpful!

                                              function,
                                              type,