alloca.in.h revision 05436638acc7c010349a69c3395f1a57c642dc62
1/* Memory allocation on the stack. 2 3 Copyright (C) 1995, 1999, 2001-2004, 2006-2012 Free Software Foundation, 4 Inc. 5 6 This program is free software; you can redistribute it and/or modify it 7 under the terms of the GNU General Public License as published 8 by the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public 17 License along with this program; if not, see 18 <http://www.gnu.org/licenses/>. 19 */ 20 21/* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H 22 means there is a real alloca function. */ 23#ifndef _GL_ALLOCA_H 24#define _GL_ALLOCA_H 25 26/* alloca (N) returns a pointer to N bytes of memory 27 allocated on the stack, which will last until the function returns. 28 Use of alloca should be avoided: 29 - inside arguments of function calls - undefined behaviour, 30 - in inline functions - the allocation may actually last until the 31 calling function returns, 32 - for huge N (say, N >= 65536) - you never know how large (or small) 33 the stack is, and when the stack cannot fulfill the memory allocation 34 request, the program just crashes. 35 */ 36 37#ifndef alloca 38# ifdef __GNUC__ 39# define alloca __builtin_alloca 40# elif defined _AIX 41# define alloca __alloca 42# elif defined _MSC_VER 43# include <malloc.h> 44# define alloca _alloca 45# elif defined __DECC && defined __VMS 46# define alloca __ALLOCA 47# elif defined __TANDEM && defined _TNS_E_TARGET 48# ifdef __cplusplus 49extern "C" 50# endif 51void *_alloca (unsigned short); 52# pragma intrinsic (_alloca) 53# define alloca _alloca 54# else 55# include <stddef.h> 56# ifdef __cplusplus 57extern "C" 58# endif 59void *alloca (size_t); 60# endif 61#endif 62 63#endif /* _GL_ALLOCA_H */ 64