1 /* Memory allocation on the stack.
2 Copyright (C) 1995, 1999, 2001-2007, 2015 Free Software Foundation,
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* When this file is included, it may be preceded only by preprocessor
19 declarations. Thanks to AIX. Therefore we include it right after
20 "config.h", not later. */
22 /* Avoid using the symbol _ALLOCA_H here, as Bison assumes _ALLOCA_H
23 means there is a real alloca function. */
27 /* alloca(N) returns a pointer (void* or char*) to N bytes of memory
28 allocated on the stack, and which will last until the function returns.
29 Use of alloca should be avoided:
30 - inside arguments of function calls - undefined behaviour,
31 - in inline functions - the allocation may actually last until the
32 calling function returns,
33 - for huge N (say, N >= 65536) - you never know how large (or small)
34 the stack is, and when the stack cannot fulfill the memory allocation
35 request, the program just crashes.
40 # define alloca __builtin_alloca
44 # define alloca _alloca
52 # ifdef __hpux /* This section must match that of bison generated files. */
54 extern "C" void *alloca (unsigned int);
55 # else /* not __cplusplus */
56 extern void *alloca ();
57 # endif /* not __cplusplus */
58 # else /* not __hpux */
60 extern char *alloca ();
69 #endif /* _GL_ALLOCA_H */