xref: /dflybsd-src/contrib/cvs-1.12/lib/xalloc.h (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
1*86d7f5d3SJohn Marino /* xalloc.h -- malloc with out-of-memory checking
2*86d7f5d3SJohn Marino 
3*86d7f5d3SJohn Marino    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4*86d7f5d3SJohn Marino    1999, 2000, 2003, 2004 Free Software Foundation, Inc.
5*86d7f5d3SJohn Marino 
6*86d7f5d3SJohn Marino    This program is free software; you can redistribute it and/or modify
7*86d7f5d3SJohn Marino    it under the terms of the GNU General Public License as published by
8*86d7f5d3SJohn Marino    the Free Software Foundation; either version 2, or (at your option)
9*86d7f5d3SJohn Marino    any later version.
10*86d7f5d3SJohn Marino 
11*86d7f5d3SJohn Marino    This program is distributed in the hope that it will be useful,
12*86d7f5d3SJohn Marino    but WITHOUT ANY WARRANTY; without even the implied warranty of
13*86d7f5d3SJohn Marino    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*86d7f5d3SJohn Marino    GNU General Public License for more details.
15*86d7f5d3SJohn Marino 
16*86d7f5d3SJohn Marino    You should have received a copy of the GNU General Public License
17*86d7f5d3SJohn Marino    along with this program; if not, write to the Free Software Foundation,
18*86d7f5d3SJohn Marino    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
19*86d7f5d3SJohn Marino 
20*86d7f5d3SJohn Marino #ifndef XALLOC_H_
21*86d7f5d3SJohn Marino # define XALLOC_H_
22*86d7f5d3SJohn Marino 
23*86d7f5d3SJohn Marino # include <stddef.h>
24*86d7f5d3SJohn Marino 
25*86d7f5d3SJohn Marino 
26*86d7f5d3SJohn Marino # ifdef __cplusplus
27*86d7f5d3SJohn Marino extern "C" {
28*86d7f5d3SJohn Marino # endif
29*86d7f5d3SJohn Marino 
30*86d7f5d3SJohn Marino 
31*86d7f5d3SJohn Marino # ifndef __attribute__
32*86d7f5d3SJohn Marino #  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
33*86d7f5d3SJohn Marino #   define __attribute__(x)
34*86d7f5d3SJohn Marino #  endif
35*86d7f5d3SJohn Marino # endif
36*86d7f5d3SJohn Marino 
37*86d7f5d3SJohn Marino # ifndef ATTRIBUTE_NORETURN
38*86d7f5d3SJohn Marino #  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
39*86d7f5d3SJohn Marino # endif
40*86d7f5d3SJohn Marino 
41*86d7f5d3SJohn Marino /* This function is always triggered when memory is exhausted.
42*86d7f5d3SJohn Marino    It must be defined by the application, either explicitly
43*86d7f5d3SJohn Marino    or by using gnulib's xalloc-die module.  This is the
44*86d7f5d3SJohn Marino    function to call when one wants the program to die because of a
45*86d7f5d3SJohn Marino    memory allocation failure.  */
46*86d7f5d3SJohn Marino extern void xalloc_die (void) ATTRIBUTE_NORETURN;
47*86d7f5d3SJohn Marino 
48*86d7f5d3SJohn Marino void *xmalloc (size_t s);
49*86d7f5d3SJohn Marino void *xnmalloc (size_t n, size_t s);
50*86d7f5d3SJohn Marino void *xzalloc (size_t s);
51*86d7f5d3SJohn Marino void *xcalloc (size_t n, size_t s);
52*86d7f5d3SJohn Marino void *xrealloc (void *p, size_t s);
53*86d7f5d3SJohn Marino void *xnrealloc (void *p, size_t n, size_t s);
54*86d7f5d3SJohn Marino void *x2realloc (void *p, size_t *pn);
55*86d7f5d3SJohn Marino void *x2nrealloc (void *p, size_t *pn, size_t s);
56*86d7f5d3SJohn Marino void *xmemdup (void const *p, size_t s);
57*86d7f5d3SJohn Marino char *xstrdup (char const *str);
58*86d7f5d3SJohn Marino 
59*86d7f5d3SJohn Marino /* Return 1 if an array of N objects, each of size S, cannot exist due
60*86d7f5d3SJohn Marino    to size arithmetic overflow.  S must be positive and N must be
61*86d7f5d3SJohn Marino    nonnegative.  This is a macro, not an inline function, so that it
62*86d7f5d3SJohn Marino    works correctly even when SIZE_MAX < N.
63*86d7f5d3SJohn Marino 
64*86d7f5d3SJohn Marino    By gnulib convention, SIZE_MAX represents overflow in size
65*86d7f5d3SJohn Marino    calculations, so the conservative dividend to use here is
66*86d7f5d3SJohn Marino    SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
67*86d7f5d3SJohn Marino    However, malloc (SIZE_MAX) fails on all known hosts where
68*86d7f5d3SJohn Marino    sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
69*86d7f5d3SJohn Marino    exactly-SIZE_MAX allocations on such hosts; this avoids a test and
70*86d7f5d3SJohn Marino    branch when S is known to be 1.  */
71*86d7f5d3SJohn Marino # define xalloc_oversized(n, s) \
72*86d7f5d3SJohn Marino     ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
73*86d7f5d3SJohn Marino 
74*86d7f5d3SJohn Marino # ifdef __cplusplus
75*86d7f5d3SJohn Marino }
76*86d7f5d3SJohn Marino # endif
77*86d7f5d3SJohn Marino 
78*86d7f5d3SJohn Marino 
79*86d7f5d3SJohn Marino #endif /* !XALLOC_H_ */
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