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 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
19
20#ifndef XALLOC_H_
21# define XALLOC_H_
22
23# include <stddef.h>
24
25# ifndef __attribute__
26#  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
27#   define __attribute__(x)
28#  endif
29# endif
30
31# ifndef ATTRIBUTE_NORETURN
32#  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
33# endif
34
35/* If this pointer is non-zero, run the specified function upon each
36   allocation failure.  It is initialized to zero. */
37extern void (*xalloc_fail_func) (void);
38
39/* If XALLOC_FAIL_FUNC is undefined or a function that returns, this
40   message is output.  It is translated via gettext.
41   Its value is "memory exhausted".  */
42extern char const xalloc_msg_memory_exhausted[];
43
44/* This function is always triggered when memory is exhausted.  It is
45   in charge of honoring the two previous items.  It exits with status
46   exit_failure (defined in exitfail.h).  This is the
47   function to call when one wants the program to die because of a
48   memory allocation failure.  */
49extern void xalloc_die (void) ATTRIBUTE_NORETURN;
50
51void *xmalloc (size_t s);
52void *xnmalloc (size_t n, size_t s);
53void *xzalloc (size_t s);
54void *xcalloc (size_t n, size_t s);
55void *xrealloc (void *p, size_t s);
56void *xnrealloc (void *p, size_t n, size_t s);
57void *x2realloc (void *p, size_t *pn);
58void *x2nrealloc (void *p, size_t *pn, size_t s);
59void *xclone (void const *p, size_t s);
60char *xstrdup (const char *str);
61
62/* Return 1 if an array of N objects, each of size S, cannot exist due
63   to size arithmetic overflow.  S must be positive and N must be
64   nonnegative.  This is a macro, not an inline function, so that it
65   works correctly even when SIZE_MAX < N.
66
67   By gnulib convention, SIZE_MAX represents overflow in size
68   calculations, so the conservative dividend to use here is
69   SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
70   However, malloc (SIZE_MAX) fails on all known hosts where
71   sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
72   exactly-SIZE_MAX allocations on such hosts; this avoids a test and
73   branch when S is known to be 1.  */
74# define xalloc_oversized(n, s) \
75    ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
76
77/* These macros are deprecated; they will go away soon, and are retained
78   temporarily only to ease conversion to the functions described above.  */
79# define CCLONE(p, n) xclone (p, (n) * sizeof *(p))
80# define CLONE(p) xclone (p, sizeof *(p))
81# define NEW(type, var) type *var = xmalloc (sizeof (type))
82# define XCALLOC(type, n) xcalloc (n, sizeof (type))
83# define XMALLOC(type, n) xnmalloc (n, sizeof (type))
84# define XREALLOC(p, type, n) xnrealloc (p, n, sizeof (type))
85# define XFREE(p) free (p)
86
87#endif /* !XALLOC_H_ */
88