GNU libmicrohttpd  0.9.29
mhd_compat.c
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1 /*
2  This file is part of libmicrohttpd
3  Copyright (C) 2014-2016 Karlson2k (Evgeny Grin)
4 
5  This library is free software; you can redistribute it and/or
6  modify it under the terms of the GNU Lesser General Public
7  License as published by the Free Software Foundation; either
8  version 2.1 of the License, or (at your option) any later version.
9 
10  This library is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Lesser General Public License for more details.
14 
15  You should have received a copy of the GNU Lesser General Public
16  License along with this library; if not, write to the Free Software
17  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 
19 */
20 
27 #include "mhd_compat.h"
28 #if defined(_WIN32) && !defined(__CYGWIN__)
29 #include <stdint.h>
30 #include <time.h>
31 #ifndef HAVE_SNPRINTF
32 #include <stdio.h>
33 #include <stdarg.h>
34 #endif /* HAVE_SNPRINTF */
35 #endif /* _WIN32 && !__CYGWIN__ */
36 
37 #ifndef HAVE_CALLOC
38 #include <string.h> /* for memset() */
39 #endif /* ! HAVE_CALLOC */
40 
41 #if defined(_WIN32) && !defined(__CYGWIN__)
42 
43 #ifndef HAVE_SNPRINTF
44 /* Emulate snprintf function on W32 */
45 int
46 W32_snprintf (char *__restrict s,
47  size_t n,
48  const char *__restrict format,
49  ...)
50 {
51  int ret;
52  va_list args;
53 
54  if ( (0 != n) &&
55  (NULL != s) )
56  {
57  va_start (args,
58  format);
59  ret = _vsnprintf (s,
60  n,
61  format,
62  args);
63  va_end (args);
64  if ((int)n == ret)
65  s[n - 1] = 0;
66  if (ret >= 0)
67  return ret;
68  }
69  va_start(args,
70  format);
71  ret = _vscprintf (format,
72  args);
73  va_end(args);
74  if ( (0 <= ret) &&
75  (0 != n) &&
76  (NULL == s) )
77  return -1;
78 
79  return ret;
80 }
81 
82 #endif /* HAVE_SNPRINTF */
83 #endif /* _WIN32 && !__CYGWIN__ */
84 
85 #ifndef HAVE_CALLOC
86 
87 #ifdef __has_builtin
88 # if __has_builtin(__builtin_mul_overflow)
89 # define MHD_HAVE_NUL_OVERFLOW 1
90 # endif
91 #elif __GNUC__+0 >= 5
92 # define MHD_HAVE_NUL_OVERFLOW 1
93 #endif /* __GNUC__ >= 5 */
94 
95 
96 void *MHD_calloc_(size_t nelem, size_t elsize)
97 {
98  size_t alloc_size;
99  void *ptr;
100 #ifdef MHD_HAVE_NUL_OVERFLOW
101  if (__builtin_mul_overflow(nelem, elsize, &alloc_size) || 0 == alloc_size)
102  return NULL;
103 #else /* ! MHD_HAVE_NUL_OVERFLOW */
104  alloc_size = nelem * elsize;
105  if (0 == alloc_size || elsize != alloc_size / nelem)
106  return NULL;
107 #endif /* ! MHD_HAVE_NUL_OVERFLOW */
108  ptr = malloc (alloc_size);
109  if (NULL == ptr)
110  return NULL;
111  memset(ptr, 0, alloc_size);
112  return ptr;
113 }
114 #endif /* ! HAVE_CALLOC */
#define NULL
Definition: reason_phrase.c:31
Header for platform missing functions.
void * MHD_calloc_(size_t nelem, size_t elsize)
Definition: mhd_compat.c:96