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 it 5 under the terms of the GNU Library General Public License as published 6 by the Free Software Foundation; either version 2, or (at your option) 7 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 GNU 12 Library General Public License for more details. 13 14 You should have received a copy of the GNU Library General Public 15 License along with this program; if not, write to the Free Software 16 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 17 USA. */ 18 19/* When this file is included, it may be preceded only by preprocessor 20 declarations. Thanks to AIX. Therefore we include it right after 21 "config.h", not later. */ 22 23/* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H 24 means there is a real alloca function. */ 25#ifndef _GL_ALLOCA_H 26#define _GL_ALLOCA_H 27 28/* alloca(N) returns a pointer (void* or char*) to N bytes of memory 29 allocated on the stack, and which will last until the function returns. 30 Use of alloca should be avoided: 31 - inside arguments of function calls - undefined behaviour, 32 - in inline functions - the allocation may actually last until the 33 calling function returns, 34 - for huge N (say, N >= 65536) - you never know how large (or small) 35 the stack is, and when the stack cannot fulfill the memory allocation 36 request, the program just crashes. 37 */ 38 39#ifndef alloca 40# ifdef __GNUC__ 41# define alloca __builtin_alloca 42# else 43# ifdef _MSC_VER 44# include <malloc.h> 45# define alloca _alloca 46# else 47# if HAVE_ALLOCA_H 48# include <alloca.h> 49# else 50# ifdef _AIX 51 #pragma alloca 52# else 53# ifdef __hpux /* This section must match that of bison generated files. */ 54# ifdef __cplusplus 55extern "C" void *alloca (unsigned int); 56# else /* not __cplusplus */ 57extern void *alloca (); 58# endif /* not __cplusplus */ 59# else /* not __hpux */ 60# ifndef alloca 61extern char *alloca (); 62# endif 63# endif /* __hpux */ 64# endif 65# endif 66# endif 67# endif 68#endif 69 70#endif /* _GL_ALLOCA_H */ 71