third_party/libwebp/utils/utils.c

   1 // Copyright 2012 Google Inc. All Rights Reserved.
   2 //
   3 // Use of this source code is governed by a BSD-style license
   4 // that can be found in the COPYING file in the root of the source
   5 // tree. An additional intellectual property rights grant can be found
   6 // in the file PATENTS. All contributing project authors may
   7 // be found in the AUTHORS file in the root of the source tree.
   8 // -----------------------------------------------------------------------------
   9 //
  10 // Misc. common utility functions
  11 //
  12 // Author: Skal (pascal.massimino@gmail.com)
  13
  14 #include <stdlib.h>
  15 #include "./utils.h"
  16
  17 #if defined(__cplusplus) || defined(c_plusplus)
  18 extern "C" {
  19 #endif
  20
  21 //------------------------------------------------------------------------------
  22 // Checked memory allocation
  23
  24 // Returns 0 in case of overflow of nmemb * size.
  25 static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
  26   const uint64_t total_size = nmemb * size;
  27   if (nmemb == 0) return 1;
  28   if ((uint64_t)size > WEBP_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
  29   if (total_size != (size_t)total_size) return 0;
  30   return 1;
  31 }
  32
  33 void* WebPSafeMalloc(uint64_t nmemb, size_t size) {
  34   if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
  35   assert(nmemb * size > 0);
  36   return malloc((size_t)(nmemb * size));
  37 }
  38
  39 void* WebPSafeCalloc(uint64_t nmemb, size_t size) {
  40   if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
  41   assert(nmemb * size > 0);
  42   return calloc((size_t)nmemb, size);
  43 }
  44
  45 //------------------------------------------------------------------------------
  46
  47 #if defined(__cplusplus) || defined(c_plusplus)
  48 }    // extern "C"
  49 #endif