blob: 4ec6df6f1e47d7f6159a2ce6a5a5e110ce18f309 [file] [log] [blame]
/* Memory allocation on the stack.
Copyright (C) 1995, 1999, 2001-2003 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU Library General Public License as published
by the Free Software Foundation; either version 2, 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
USA. */
/* When this file is included, it may be preceded only by preprocessor
declarations. Thanks to AIX. Therefore we include it right after
"config.h", not later. */
#ifndef _ALLOCA_H
#define _ALLOCA_H
/* alloca(N) returns a pointer (void* or char*) to N bytes of memory
allocated on the stack, and 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.
#ifdef __GNUC__
# ifndef alloca
# define alloca __builtin_alloca
# endif
# ifdef _MSC_VER
# include <malloc.h>
# define alloca _alloca
# else
# include <alloca.h>
# else
# ifdef _AIX
#pragma alloca
# else
# ifdef __hpux /* This section must match that of bison generated files. */
# ifdef __cplusplus
extern "C" void *alloca (unsigned int);
# else /* not __cplusplus */
extern void *alloca ();
# endif /* not __cplusplus */
# else /* not __hpux */
# ifndef alloca
extern char *alloca ();
# endif
# endif /* __hpux */
# endif
# endif
# endif
#endif /* _ALLOCA_H */