ubuntu-buildroot/output/build/host-m4-1.4.19/lib/xmalloca.h

70 lines
2.3 KiB
C

/* Safe automatic memory allocation with out of memory checking.
Copyright (C) 2003, 2005, 2007, 2009-2021 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#ifndef _XMALLOCA_H
#define _XMALLOCA_H
#include "malloca.h"
#include "xalloc.h"
#include "xalloc-oversized.h"
#ifdef __cplusplus
extern "C" {
#endif
/* xmalloca(N) is a checking safe variant of alloca(N). It allocates N bytes
of memory allocated on the stack, that must be freed using freea() before
the function returns. N should not have side effects.
Upon failure, it exits with an error message. */
#if HAVE_ALLOCA
# define xmalloca(N) \
((N) < 4032 - (2 * sa_alignment_max - 1) \
? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \
+ (2 * sa_alignment_max - 1)) \
& ~(uintptr_t)(2 * sa_alignment_max - 1)) \
: xmmalloca (N))
extern void * xmmalloca (size_t n);
#else
# define xmalloca(N) \
xmalloc (N)
#endif
/* xnmalloca(N,S) is an overflow-safe variant of xmalloca (N * S).
It allocates an array of N objects, each with S bytes of memory,
on the stack. S must be positive and N must be nonnegative,
and S and N should not have side effects.
The array must be freed using freea() before the function returns.
Upon failure, it exits with an error message. */
#if HAVE_ALLOCA
/* Rely on xmalloca (SIZE_MAX) calling xalloc_die (). */
# define xnmalloca(n, s) \
xmalloca (xalloc_oversized (n, s) ? (size_t) (-1) : (n) * (size_t) (s))
#else
# define xnmalloca(n, s) \
xnmalloc (n, s)
#endif
#ifdef __cplusplus
}
#endif
#endif /* _XMALLOCA_H */