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

webrtc/modules/audio_coding/codecs/ilbc/create_augmented_vec.c

 /*
  *  Copyright (c) 2011 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.
  */
 
 /******************************************************************
 
  iLBC Speech Coder ANSI-C Source Code
 
  WebRtcIlbcfix_CreateAugmentedVec.c
 
 ******************************************************************/
 
 #include "defines.h"
 #include "constants.h"
+#include "webrtc/base/sanitizer.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 
 /*----------------------------------------------------------------*
  *  Recreate a specific codebook vector from the augmented part.
  *
  *----------------------------------------------------------------*/
 
 void WebRtcIlbcfix_CreateAugmentedVec(
     size_t index,          /* (i) Index for the augmented vector to be
                               created */
     const int16_t* buffer, /* (i) Pointer to the end of the codebook memory
                               that is used for creation of the augmented
                               codebook */
     int16_t* cbVec) {      /* (o) The constructed codebook vector */
   size_t ilow;
   const int16_t *ppo, *ppi;
   int16_t cbVecTmp[4];
   /* Interpolation starts 4 elements before cbVec+index, but must not start
      outside |cbVec|; clamping interp_len to stay within |cbVec|.
    */
   size_t interp_len = WEBRTC_SPL_MIN(index, 4);
 
+  rtc_MsanCheckInitialized(buffer - index - interp_len, sizeof(buffer[0]),
+                           index + interp_len);

[kwiberg-webrtc, 2016/08/30 19:55:28]

This is another example of a rtc_MsanCheckInitialized() call that one would
really rather not have, but which is probably best to leave in given that it
unfortunately describes the way the surrounding code works.

+
   ilow = index - interp_len;
 
   /* copy the first noninterpolated part */
   ppo = buffer-index;
   WEBRTC_SPL_MEMCPY_W16(cbVec, ppo, index);
 
   /* interpolation */
   ppo = buffer - interp_len;
   ppi = buffer - index - interp_len;
 
@@ skipping 15 matching lines @@
      tempbuff2+SUBL+5. Since ppo=buffer-index, we cannot read any more than
      |index| elements from |ppo|.
 
      |cbVec| is declared to be SUBL elements long in WebRtcIlbcfix_CbConstruct.
      Therefore, we can only write SUBL-index elements to cbVec+index.
 
      These two conditions limit the number of elements to copy.
    */
   WEBRTC_SPL_MEMCPY_W16(cbVec+index, ppo, WEBRTC_SPL_MIN(SUBL-index, index));
 }