bump for release
[uclibc-ng.git] / include / alloca.h
blobb3a1e4a6a169e691c4b50bbb2030301bef84c3e2
1 /* Copyright (C) 1992, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library 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 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
18 #ifndef _ALLOCA_H
19 #define _ALLOCA_H 1
21 #include <features.h>
23 #define __need_size_t
24 #include <stddef.h>
26 __BEGIN_DECLS
28 /* Remove any previous definitions. */
29 #undef alloca
31 /* Allocate a block that will be freed when the calling function exits. */
32 extern void *alloca (size_t __size) __THROW;
34 #ifdef __GNUC__
35 # define alloca(size) __builtin_alloca (size)
36 #endif /* GCC. */
38 #ifdef _LIBC
39 # define __MAX_ALLOCA_CUTOFF 65536
41 # include <bits/stackinfo.h>
42 # ifdef _STACK_GROWS_DOWN
43 # define extend_alloca(buf, len, newlen) \
44 (__typeof (buf)) ({ size_t __newlen = (newlen); \
45 char *__newbuf = alloca (__newlen); \
46 if (__newbuf + __newlen == (char *) buf) \
47 len += __newlen; \
48 else \
49 len = __newlen; \
50 __newbuf; })
51 # elif defined _STACK_GROWS_UP
52 # define extend_alloca(buf, len, newlen) \
53 (__typeof (buf)) ({ size_t __newlen = (newlen); \
54 char *__newbuf = alloca (__newlen); \
55 char *__buf = (buf); \
56 if (__buf + __newlen == __newbuf) \
57 { \
58 len += __newlen; \
59 __newbuf = __buf; \
60 } \
61 else \
62 len = __newlen; \
63 __newbuf; })
64 # else
65 # error unknown stack
66 # define extend_alloca(buf, len, newlen) \
67 alloca (((len) = (newlen)))
68 # endif
70 extern int __libc_alloca_cutoff (size_t size);
71 #endif
73 __END_DECLS
75 #endif /* alloca.h */