1/* xmalloc.c -- malloc with out of memory checking
2
3   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4   1999, 2000, 2002, 2003, 2004, 2005, 2006, 2008-2009 Free Software Foundation,
5   Inc.
6
7   This program is free software: you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include <config.h>
21
22#if ! HAVE_INLINE
23# define static_inline
24#endif
25#include "xalloc.h"
26#undef static_inline
27
28#include <stdlib.h>
29#include <string.h>
30
31/* 1 if calloc is known to be compatible with GNU calloc.  This
32   matters if we are not also using the calloc module, which defines
33   HAVE_CALLOC and supports the GNU API even on non-GNU platforms.  */
34#if defined HAVE_CALLOC || defined __GLIBC__
35enum { HAVE_GNU_CALLOC = 1 };
36#else
37enum { HAVE_GNU_CALLOC = 0 };
38#endif
39
40/* Allocate N bytes of memory dynamically, with error checking.  */
41
42void *
43xmalloc (size_t n)
44{
45  void *p = malloc (n);
46  if (!p && n != 0)
47    xalloc_die ();
48  return p;
49}
50
51/* Change the size of an allocated block of memory P to N bytes,
52   with error checking.  */
53
54void *
55xrealloc (void *p, size_t n)
56{
57  p = realloc (p, n);
58  if (!p && n != 0)
59    xalloc_die ();
60  return p;
61}
62
63/* If P is null, allocate a block of at least *PN bytes; otherwise,
64   reallocate P so that it contains more than *PN bytes.  *PN must be
65   nonzero unless P is null.  Set *PN to the new block's size, and
66   return the pointer to the new block.  *PN is never set to zero, and
67   the returned pointer is never null.  */
68
69void *
70x2realloc (void *p, size_t *pn)
71{
72  return x2nrealloc (p, pn, 1);
73}
74
75/* Allocate S bytes of zeroed memory dynamically, with error checking.
76   There's no need for xnzalloc (N, S), since it would be equivalent
77   to xcalloc (N, S).  */
78
79void *
80xzalloc (size_t s)
81{
82  return memset (xmalloc (s), 0, s);
83}
84
85/* Allocate zeroed memory for N elements of S bytes, with error
86   checking.  S must be nonzero.  */
87
88void *
89xcalloc (size_t n, size_t s)
90{
91  void *p;
92  /* Test for overflow, since some calloc implementations don't have
93     proper overflow checks.  But omit overflow and size-zero tests if
94     HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
95     returns NULL if successful.  */
96  if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
97      || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
98    xalloc_die ();
99  return p;
100}
101
102/* Clone an object P of size S, with error checking.  There's no need
103   for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
104   need for an arithmetic overflow check.  */
105
106void *
107xmemdup (void const *p, size_t s)
108{
109  return memcpy (xmalloc (s), p, s);
110}
111
112/* Clone STRING.  */
113
114char *
115xstrdup (char const *string)
116{
117  return xmemdup (string, strlen (string) + 1);
118}
119