Add functions to interact with ASan and MSan, and some sample uses

webrtc/base/sanitizer.h

Index: webrtc/base/sanitizer.h
diff --git a/webrtc/base/sanitizer.h b/webrtc/base/sanitizer.h
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+++ b/webrtc/base/sanitizer.h
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+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_BASE_SANITIZER_H_
+#define WEBRTC_BASE_SANITIZER_H_
+
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#define RTC_HAS_ASAN 1
+#endif
+#if __has_feature(memory_sanitizer)
+#define RTC_HAS_MSAN 1
+#endif
+#endif
+#ifndef RTC_HAS_ASAN
+#define RTC_HAS_ASAN 0
+#endif
+#ifndef RTC_HAS_MSAN
+#define RTC_HAS_MSAN 0
+#endif
+
+#if RTC_HAS_ASAN
+#include <sanitizer/asan_interface.h>
+#endif
+#if RTC_HAS_MSAN
+#include <sanitizer/msan_interface.h>
+#endif
+
+// Ask ASan to mark the memory range [ptr, ptr + element_size * num_elements)
+// as being unaddressable, so that reads and writes are not allowed. ASan may
+// narrow the range to the nearest alignment boundaries.
+static inline void rtc_AsanPoison(const volatile void* ptr,
+                                  size_t element_size,
+                                  size_t num_elements) {
+#if RTC_HAS_ASAN
+  ASAN_POISON_MEMORY_REGION(ptr, element_size * num_elements);
+#endif
+}
+
+// Ask ASan to mark the memory range [ptr, ptr + element_size * num_elements)
+// as being addressable, so that reads and writes are allowed. ASan may widen
+// the range to the nearest alignment boundaries.
+static inline void rtc_AsanUnpoison(const volatile void* ptr,
+                                    size_t element_size,
+                                    size_t num_elements) {
+#if RTC_HAS_ASAN
+  ASAN_UNPOISON_MEMORY_REGION(ptr, element_size * num_elements);
+#endif
+}
+
+// Ask MSan to mark the memory range [ptr, ptr + element_size * num_elements)
+// as being uninitialized.
+static inline void rtc_MsanMarkUninitialized(const volatile void* ptr,
+                                             size_t element_size,
+                                             size_t num_elements) {
+#if RTC_HAS_MSAN
+  __msan_poison(ptr, element_size * num_elements);
+#endif
+}
+
+// Force an MSan check (if any bits in the memory range [ptr, ptr +
+// element_size * num_elements) are uninitialized the call will crash with an
+// MSan report).
+static inline void rtc_MsanCheckInitialized(const volatile void* ptr,
+                                            size_t element_size,
+                                            size_t num_elements) {
+#if RTC_HAS_MSAN
+  __msan_check_mem_is_initialized(ptr, element_size * num_elements);
+#endif
+}
+
+#ifdef __cplusplus
+
+namespace rtc {
+
+template <typename T>
+inline void AsanPoison(const T& mem) {
+  rtc_AsanPoison(mem.data(), sizeof(mem.data()[0]), mem.size());
+}
+
+template <typename T>
+inline void AsanUnpoison(const T& mem) {
+  rtc_AsanUnpoison(mem.data(), sizeof(mem.data()[0]), mem.size());
+}
+
+template <typename T>
+inline void MsanMarkUninitialized(const T& mem) {
+  rtc_MsanMarkUninitialized(mem.data(), sizeof(mem.data()[0]), mem.size());
+}
+
+template <typename T>
+inline void MsanCheckInitialized(const T& mem) {
+  rtc_MsanCheckInitialized(mem.data(), sizeof(mem.data()[0]), mem.size());
+}
+
+}  // namespace rtc
+
+#endif  // __cplusplus
+
+#endif  // WEBRTC_BASE_SANITIZER_H_