1/* Memory allocation on the stack. 2 Copyright (C) 1995, 1999, 2001-2007 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 16 17/* When this file is included, it may be preceded only by preprocessor 18 declarations. Thanks to AIX. Therefore we include it right after 19 "config.h", not later. */ 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 (void* or char*) to N bytes of memory 27 allocated on the stack, and 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# else 41# ifdef _MSC_VER 42# include <malloc.h> 43# define alloca _alloca 44# else 45# if HAVE_ALLOCA_H 46# include <alloca.h> 47# else 48# ifdef _AIX 49 #pragma alloca 50# else 51# ifdef __hpux /* This section must match that of bison generated files. */ 52# ifdef __cplusplus 53extern "C" void *alloca (unsigned int); 54# else /* not __cplusplus */ 55extern void *alloca (); 56# endif /* not __cplusplus */ 57# else /* not __hpux */ 58# ifndef alloca 59extern char *alloca (); 60# endif 61# endif /* __hpux */ 62# endif 63# endif 64# endif 65# endif 66#endif 67 68#endif /* _GL_ALLOCA_H */ 69