1/* xalloc.h -- malloc with out-of-memory checking
2
3   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4   1999, 2000, 2003, 2004 Free Software Foundation, Inc.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 2, or (at your option)
9   any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program; if not, write to the Free Software Foundation,
18   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
19
20#ifndef XALLOC_H_
21# define XALLOC_H_
22
23# include <stddef.h>
24
25
26# ifdef __cplusplus
27extern "C" {
28# endif
29
30
31# ifndef __attribute__
32#  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
33#   define __attribute__(x)
34#  endif
35# endif
36
37# ifndef ATTRIBUTE_NORETURN
38#  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
39# endif
40
41/* This function is always triggered when memory is exhausted.
42   It must be defined by the application, either explicitly
43   or by using gnulib's xalloc-die module.  This is the
44   function to call when one wants the program to die because of a
45   memory allocation failure.  */
46extern void xalloc_die (void) ATTRIBUTE_NORETURN;
47
48void *xmalloc (size_t s);
49void *xnmalloc (size_t n, size_t s);
50void *xzalloc (size_t s);
51void *xcalloc (size_t n, size_t s);
52void *xrealloc (void *p, size_t s);
53void *xnrealloc (void *p, size_t n, size_t s);
54void *x2realloc (void *p, size_t *pn);
55void *x2nrealloc (void *p, size_t *pn, size_t s);
56void *xmemdup (void const *p, size_t s);
57char *xstrdup (char const *str);
58
59/* Return 1 if an array of N objects, each of size S, cannot exist due
60   to size arithmetic overflow.  S must be positive and N must be
61   nonnegative.  This is a macro, not an inline function, so that it
62   works correctly even when SIZE_MAX < N.
63
64   By gnulib convention, SIZE_MAX represents overflow in size
65   calculations, so the conservative dividend to use here is
66   SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
67   However, malloc (SIZE_MAX) fails on all known hosts where
68   sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
69   exactly-SIZE_MAX allocations on such hosts; this avoids a test and
70   branch when S is known to be 1.  */
71# define xalloc_oversized(n, s) \
72    ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
73
74# ifdef __cplusplus
75}
76# endif
77
78
79#endif /* !XALLOC_H_ */
80