1 /*
2 * Copyright (c) 2022 Red Hat
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #ifndef REALLOCARRAY_H
25 #define REALLOCARRAY_H
26
27 #if !defined(HAVE_REALLOCARRAY)
28
29 #include <stdlib.h> // size_t
30 #include <errno.h>
31
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35
36 /* taken from the X server */
37 /*
38 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
39 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
40 */
41 #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
42
43 static inline void *
reallocarray(void * optr,size_t nmemb,size_t size)44 reallocarray(void *optr, size_t nmemb, size_t size)
45 {
46 if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
47 nmemb > 0 && SIZE_MAX / nmemb < size) {
48 errno = ENOMEM;
49 return NULL;
50 }
51 return realloc(optr, size * nmemb);
52 }
53
54 #ifdef __cplusplus
55 }
56 #endif
57
58 #endif /* !defined(HAVE_REALLOCARRAY) */
59
60 #endif /* REALLOCARRAY_H */
61