1 /* Safe automatic memory allocation with out of memory checking.
2    Copyright (C) 2003, 2005, 2007, 2009-2020 Free Software Foundation, Inc.
3    Written by Bruno Haible <bruno@clisp.org>, 2003.
4 
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.
9 
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.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
17 
18 #ifndef _XMALLOCA_H
19 #define _XMALLOCA_H
20 
21 #include "malloca.h"
22 #include "xalloc.h"
23 
24 
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28 
29 
30 /* xmalloca(N) is a checking safe variant of alloca(N).  It allocates N bytes
31    of memory allocated on the stack, that must be freed using freea() before
32    the function returns.  Upon failure, it exits with an error message.  */
33 #if HAVE_ALLOCA
34 # define xmalloca(N) \
35   ((N) < 4032 - (2 * sa_alignment_max - 1)                                   \
36    ? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \
37                 + (2 * sa_alignment_max - 1))                                \
38                & ~(uintptr_t)(2 * sa_alignment_max - 1))                     \
39    : xmmalloca (N))
40 extern void * xmmalloca (size_t n);
41 #else
42 # define xmalloca(N) \
43   xmalloc (N)
44 #endif
45 
46 /* xnmalloca(N,S) is an overflow-safe variant of xmalloca (N * S).
47    It allocates an array of N objects, each with S bytes of memory,
48    on the stack.  S must be positive and N must be nonnegative.
49    The array must be freed using freea() before the function returns.
50    Upon failure, it exits with an error message.  */
51 #if HAVE_ALLOCA
52 /* Rely on xmalloca (SIZE_MAX) calling xalloc_die ().  */
53 # define xnmalloca(n, s) \
54     xmalloca (xalloc_oversized ((n), (s)) ? (size_t) (-1) : (n) * (s))
55 #else
56 # define xnmalloca(n, s) \
57     xnmalloc ((n), (s))
58 #endif
59 
60 
61 #ifdef __cplusplus
62 }
63 #endif
64 
65 
66 #endif /* _XMALLOCA_H */
67