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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-15 09:47:20 +00:00
emacs/lib/alloca.in.h
Paul Eggert e2f3544379 Update from Gnulib
This incorporates:
2019-03-10 alloca-opt: Fix conflict mingw's new <alloca.h> file
2019-03-03 getloadavg: Write NULL for the null pointer
Reported by Michal Privoznik <mprivozn@redhat.com>.
* lib/getloadavg.c (getloadavg): Write NULL instead of 0.
* build-aux/config.guess, build-aux/move-if-change:
* doc/misc/texinfo.tex, lib/alloca.in.h, lib/getloadavg.c:
* m4/alloca.m4:
Copy from Gnulib.
* lib/gnulib.mk.in: Regenerate.
2019-03-10 23:05:30 -07:00

72 lines
2.3 KiB
C

/* Memory allocation on the stack.
Copyright (C) 1995, 1999, 2001-2004, 2006-2019 Free Software Foundation,
Inc.
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, 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/>.
*/
/* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H
means there is a real alloca function. */
#ifndef _GL_ALLOCA_H
#define _GL_ALLOCA_H
/* alloca (N) returns a pointer to N bytes of memory
allocated on the stack, which will last until the function returns.
Use of alloca should be avoided:
- inside arguments of function calls - undefined behaviour,
- in inline functions - the allocation may actually last until the
calling function returns,
- for huge N (say, N >= 65536) - you never know how large (or small)
the stack is, and when the stack cannot fulfill the memory allocation
request, the program just crashes.
*/
#ifndef alloca
# ifdef __GNUC__
/* Some version of mingw have an <alloca.h> that causes trouble when
included after 'alloca' gets defined as a macro. As a workaround, include
this <alloca.h> first and define 'alloca' as a macro afterwards. */
# if (defined _WIN32 && ! defined __CYGWIN__) && @HAVE_ALLOCA_H@
# include_next <alloca.h>
# endif
# define alloca __builtin_alloca
# elif defined _AIX
# define alloca __alloca
# elif defined _MSC_VER
# include <malloc.h>
# define alloca _alloca
# elif defined __DECC && defined __VMS
# define alloca __ALLOCA
# elif defined __TANDEM && defined _TNS_E_TARGET
# ifdef __cplusplus
extern "C"
# endif
void *_alloca (unsigned short);
# pragma intrinsic (_alloca)
# define alloca _alloca
# elif defined __MVS__
# include <stdlib.h>
# else
# include <stddef.h>
# ifdef __cplusplus
extern "C"
# endif
void *alloca (size_t);
# endif
#endif
#endif /* _GL_ALLOCA_H */