| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 1992, 1996, 1997, 1998, 1999 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 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. |
| 8 | |
| 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. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, write to the Free |
| 16 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 17 | 02111-1307 USA. */ |
| 18 | |
| 19 | #ifndef _ALLOCA_H |
| 20 | #define _ALLOCA_H 1 |
| 21 | |
| 22 | #include <features.h> |
| 23 | |
| 24 | #define __need_size_t |
| 25 | #include <stddef.h> |
| 26 | |
| 27 | __BEGIN_DECLS |
| 28 | |
| 29 | /* Remove any previous definitions. */ |
| 30 | #undef alloca |
| 31 | |
| 32 | /* Allocate a block that will be freed when the calling function exits. */ |
| 33 | extern void *alloca (size_t __size) __THROW; |
| 34 | |
| 35 | #ifdef __GNUC__ |
| 36 | # define alloca(size) __builtin_alloca (size) |
| 37 | #endif /* GCC. */ |
| 38 | |
| 39 | #ifdef _LIBC |
| 40 | # define __MAX_ALLOCA_CUTOFF 65536 |
| 41 | |
| 42 | # include <bits/stackinfo.h> |
| 43 | # ifdef _STACK_GROWS_DOWN |
| 44 | # define extend_alloca(buf, len, newlen) \ |
| 45 | (__typeof (buf)) ({ size_t __newlen = (newlen); \ |
| 46 | char *__newbuf = alloca (__newlen); \ |
| 47 | if (__newbuf + __newlen == (char *) buf) \ |
| 48 | len += __newlen; \ |
| 49 | else \ |
| 50 | len = __newlen; \ |
| 51 | __newbuf; }) |
| 52 | # elif defined _STACK_GROWS_UP |
| 53 | # define extend_alloca(buf, len, newlen) \ |
| 54 | (__typeof (buf)) ({ size_t __newlen = (newlen); \ |
| 55 | char *__newbuf = alloca (__newlen); \ |
| 56 | char *__buf = (buf); \ |
| 57 | if (__buf + __newlen == __newbuf) \ |
| 58 | { \ |
| 59 | len += __newlen; \ |
| 60 | __newbuf = __buf; \ |
| 61 | } \ |
| 62 | else \ |
| 63 | len = __newlen; \ |
| 64 | __newbuf; }) |
| 65 | # else |
| 66 | # error unknown stack |
| 67 | # define extend_alloca(buf, len, newlen) \ |
| 68 | alloca (((len) = (newlen))) |
| 69 | # endif |
| 70 | |
| 71 | extern int __libc_alloca_cutoff (size_t size); |
| 72 | #endif |
| 73 | |
| 74 | __END_DECLS |
| 75 | |
| 76 | #endif /* alloca.h */ |