Annotate ThreadData::PushToHeadOfList for MemorySanitizer.

base/compiler_specific.h

Index: base/compiler_specific.h
diff --git a/base/compiler_specific.h b/base/compiler_specific.h
index 5d7d9d11019bd22bc0a9c9e28f06ccb036566a5e..0d1d9d26e54cc757abdfec0b4a67331b1aa95815 100644
--- a/base/compiler_specific.h
+++ b/base/compiler_specific.h
@@ -166,4 +166,25 @@
 // If available, it would look like:
 //   __attribute__((format(wprintf, format_param, dots_param)))
 
+
+// MemorySanitizer annotations.
+#ifdef MEMORY_SANITIZER
+extern "C" {
+  void __msan_unpoison(const void *p, unsigned long s);
+  void __msan_print_shadow(const void *p, unsigned long s);

[Alexander Potapenko, 2013/03/20 11:43:08]

Please remove __msan_print_shadow since it's unlikely to be used in Chrome

+}
+
+// Mark a memory region fully initialized.
+// Use this to annotate the code that deliberately reads uninitialized data,
+// for example a GC scavenging root set pointers from stack.
+#define MSAN_UNPOISON(p, s)  __msan_unpoison(p, s)
+
+// Dump MSan shadow of the memory region to stderr.
+// MSan shadow is a bitmask with 1's in place of uninitialized bits.
+#define MSAN_PRINT_SHADOW(p, s)  __msan_print_shadow(p, s)
+#else // MEMORY_SANITIZER
+#define MSAN_UNPOISON(p, s)
+#define MSAN_PRINT_SHADOW(p, s)
+#endif // MEMORY_SANITIZER
+
 #endif  // BASE_COMPILER_SPECIFIC_H_