Mercurial > irccd
view extern/libcompat/src/recallocarray.c @ 969:d7501067de95
extern: add (set|get)progname polyfills
author | David Demelier <markand@malikania.fr> |
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date | Wed, 03 Feb 2021 12:37:46 +0100 |
parents | 243f9f51b0ff |
children |
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/* $OpenBSD: recallocarray.c,v 1.1 2017/03/06 18:44:21 otto Exp $ */ /* * Copyright (c) 2008, 2017 Otto Moerbeek <otto@drijf.net> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <errno.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <unistd.h> /* * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW */ #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) void * recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size) { size_t oldsize, newsize; void *newptr; if (ptr == NULL) return calloc(newnmemb, size); if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && newnmemb > 0 && SIZE_MAX / newnmemb < size) { errno = ENOMEM; return NULL; } newsize = newnmemb * size; if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && oldnmemb > 0 && SIZE_MAX / oldnmemb < size) { errno = EINVAL; return NULL; } oldsize = oldnmemb * size; newptr = malloc(newsize); if (newptr == NULL) return NULL; if (newsize > oldsize) { memcpy(newptr, ptr, oldsize); memset((char *)newptr + oldsize, 0, newsize - oldsize); } else memcpy(newptr, ptr, newsize); memset(ptr, 0, oldsize); free(ptr); return newptr; }