diff --git a/meson.build b/meson.build index 466e31de0c2..a3724a16551 100644 --- a/meson.build +++ b/meson.build @@ -1089,6 +1089,10 @@ if cc.compiles('__uint128_t foo(void) { return 0; }', pre_args += '-DHAVE_UINT128' endif +if cc.has_function('reallocarray') + pre_args += '-DHAVE_REALLOCARRAY' +endif + # TODO: this is very incomplete if ['linux', 'cygwin', 'gnu', 'freebsd', 'gnu/kfreebsd', 'haiku', 'android'].contains(host_machine.system()) pre_args += '-D_GNU_SOURCE' diff --git a/src/util/reallocarray.h b/src/util/reallocarray.h new file mode 100644 index 00000000000..d072c60ba3f --- /dev/null +++ b/src/util/reallocarray.h @@ -0,0 +1,59 @@ +/* + * Copyright (c) 2022 Red Hat + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef REALLOCARRAY_H +#define REALLOCARRAY_H + +#if !defined(HAVE_REALLOCARRAY) + +#include // size_t + +#ifdef __cplusplus +extern "C" { +#endif + +/* taken from the X server */ +/* + * 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)) + +static inline void * +reallocarray(void *optr, size_t nmemb, size_t size) +{ + if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && + nmemb > 0 && SIZE_MAX / nmemb < size) { + errno = ENOMEM; + return NULL; + } + return realloc(optr, size * nmemb); +} + +#ifdef __cplusplus +} +#endif + +#endif /* !defined(HAVE_REALLOCARRAY) */ + +#endif /* REALLOCARRAY_H */