Annotate ThreadData::PushToHeadOfList for MemorySanitizer.

base/compiler_specific.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_COMPILER_SPECIFIC_H_
 #define BASE_COMPILER_SPECIFIC_H_
 
 #include "build/build_config.h"
 
 #if defined(COMPILER_MSVC)
@@ skipping 148 matching lines @@
 #define PRINTF_FORMAT(format_param, dots_param)
 #endif
 
 // WPRINTF_FORMAT is the same, but for wide format strings.
 // This doesn't appear to yet be implemented in any compiler.
 // See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38308 .
 #define WPRINTF_FORMAT(format_param, dots_param)
 // 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_