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 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 2, or (at your option)
10   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, write to the Free Software Foundation,
19   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
20
21#include <config.h>
22
23#if ! HAVE_INLINE
24# define static_inline
25#endif
26#include "xalloc.h"
27#undef static_inline
28
29#include <stdlib.h>
30#include <string.h>
31
32#ifndef SIZE_MAX
33# define SIZE_MAX ((size_t) -1)
34#endif
35
36/* 1 if calloc is known to be compatible with GNU calloc.  This
37   matters if we are not also using the calloc module, which defines
38   HAVE_CALLOC and supports the GNU API even on non-GNU platforms.  */
39#if defined HAVE_CALLOC || defined __GLIBC__
40enum { HAVE_GNU_CALLOC = 1 };
41#else
42enum { HAVE_GNU_CALLOC = 0 };
43#endif
44
45/* Allocate N bytes of memory dynamically, with error checking.  */
46
47void *
48xmalloc (size_t n)
49{
50  void *p = malloc (n);
51  if (!p && n != 0)
52    xalloc_die ();
53  return p;
54}
55
56/* Change the size of an allocated block of memory P to N bytes,
57   with error checking.  */
58
59void *
60xrealloc (void *p, size_t n)
61{
62  p = realloc (p, n);
63  if (!p && n != 0)
64    xalloc_die ();
65  return p;
66}
67
68/* If P is null, allocate a block of at least *PN bytes; otherwise,
69   reallocate P so that it contains more than *PN bytes.  *PN must be
70   nonzero unless P is null.  Set *PN to the new block's size, and
71   return the pointer to the new block.  *PN is never set to zero, and
72   the returned pointer is never null.  */
73
74void *
75x2realloc (void *p, size_t *pn)
76{
77  return x2nrealloc (p, pn, 1);
78}
79
80/* Allocate S bytes of zeroed memory dynamically, with error checking.
81   There's no need for xnzalloc (N, S), since it would be equivalent
82   to xcalloc (N, S).  */
83
84void *
85xzalloc (size_t s)
86{
87  return memset (xmalloc (s), 0, s);
88}
89
90/* Allocate zeroed memory for N elements of S bytes, with error
91   checking.  S must be nonzero.  */
92
93void *
94xcalloc (size_t n, size_t s)
95{
96  void *p;
97  /* Test for overflow, since some calloc implementations don't have
98     proper overflow checks.  But omit overflow and size-zero tests if
99     HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
100     returns NULL if successful.  */
101  if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
102      || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
103    xalloc_die ();
104  return p;
105}
106
107/* Clone an object P of size S, with error checking.  There's no need
108   for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
109   need for an arithmetic overflow check.  */
110
111void *
112xmemdup (void const *p, size_t s)
113{
114  return memcpy (xmalloc (s), p, s);
115}
116
117/* Clone STRING.  */
118
119char *
120xstrdup (char const *string)
121{
122  return xmemdup (string, strlen (string) + 1);
123}
124