Add LeakSanitizer annotations to base/debug/leak_annotations.h

base/debug/leak_annotations.h

 // Copyright (c) 2011 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_DEBUG_LEAK_ANNOTATIONS_H_
 #define BASE_DEBUG_LEAK_ANNOTATIONS_H_
 
 #include "build/build_config.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_NACL) && \
     defined(USE_HEAPCHECKER)
 
 #include "third_party/tcmalloc/chromium/src/gperftools/heap-checker.h"
 
 // Annotate a program scope as having memory leaks. Tcmalloc's heap leak

[Alexander Potapenko, 2013/06/13 10:47:56]

Can you please move the descriptions of the annotations to the top of the file?
Make sure to reflect the difference between their semantics in Heapcheck and
LSan.

 // checker will ignore them. Note that these annotations may mask real bugs
 // and should not be used in the production code.
 #define ANNOTATE_SCOPED_MEMORY_LEAK \
     HeapLeakChecker::Disabler heap_leak_checker_disabler
 
 // Annotate an object pointer as referencing a leaky object. This object and all
 // the heap objects referenced by it will be ignored by the heap checker.
 //
 // X should be referencing an active allocated object. If it is not, the
 // annotation will be ignored.
 // No object should be annotated with ANNOTATE_SCOPED_MEMORY_LEAK twice.
 // Once an object is annotated with ANNOTATE_SCOPED_MEMORY_LEAK, it cannot be
 // deleted.
 #define ANNOTATE_LEAKING_OBJECT_PTR(X) \
     HeapLeakChecker::IgnoreObject(X)
 
+#elif defined(LEAK_SANITIZER)
+
+// LeakSanitizer supports the same annotations as HeapChecker above.
+// Beware that LeakSanitizer does not report a fatal error when an object is
+// annotated twice, or an annotated object is deleted. This can be a source of
+// discrepancy between LSan and HeapChecker builds.
+
+extern "C" {
+void __lsan_disable();
+void __lsan_enable();
+void __lsan_ignore_object(const void *p);
+}  // extern "C"
+
+namespace __lsan {
+class ScopedLeakSanitizerDisabler {
+ public:
+  ScopedLeakSanitizerDisabler() { __lsan_disable(); }
+  ~ScopedLeakSanitizerDisabler() { __lsan_enable(); }
+ private:
+  // Disallow copy and assign.
+  ScopedLeakSanitizerDisabler(const ScopedLeakSanitizerDisabler&);

[jar (doing other things), 2013/06/12 18:43:59]

explicit?

+  void operator=(const ScopedLeakSanitizerDisabler&);
+};
+}  // namespace __lsan
+
+#define ANNOTATE_SCOPED_MEMORY_LEAK \
+    __lsan::ScopedLeakSanitizerDisabler leak_sanitizer_disabler
+
+#define ANNOTATE_LEAKING_OBJECT_PTR(X) __lsan_ignore_object(X);
+
 #else
 
-// If tcmalloc is not used, the annotations should be no-ops.
+// If neither HeapChecker nor LSan are used, the annotations should be no-ops.
 #define ANNOTATE_SCOPED_MEMORY_LEAK ((void)0)
 #define ANNOTATE_LEAKING_OBJECT_PTR(X) ((void)0)
 
 #endif
 
 #endif  // BASE_DEBUG_LEAK_ANNOTATIONS_H_