1/* xmalloc.c -- malloc with out of memory checking
2
3 Copyright (C) 1990-2000, 2002-2006, 2008-2019 Free Software Foundation, Inc.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18#include <config.h>
19
20#define XALLOC_INLINE _GL_EXTERN_INLINE
21
22#include "xalloc.h"
23
24#include <stdlib.h>
25#include <string.h>
26
27/* 1 if calloc is known to be compatible with GNU calloc. This
28 matters if we are not also using the calloc module, which defines
29 HAVE_CALLOC_GNU and supports the GNU API even on non-GNU platforms. */
30#if defined HAVE_CALLOC_GNU || (defined __GLIBC__ && !defined __UCLIBC__)
31enum { HAVE_GNU_CALLOC = 1 };
32#else
33enum { HAVE_GNU_CALLOC = 0 };
34#endif
35
36/* Allocate N bytes of memory dynamically, with error checking. */
37
38void *
39xmalloc (size_t n)
40{
41 void *p = malloc (n);
42 if (!p && n != 0)
43 xalloc_die ();
44 return p;
45}
46
47/* Change the size of an allocated block of memory P to N bytes,
48 with error checking. */
49
50void *
51xrealloc (void *p, size_t n)
52{
53 if (!n && p)
54 {
55 /* The GNU and C99 realloc behaviors disagree here. Act like
56 GNU, even if the underlying realloc is C99. */
57 free (p);
58 return NULL;
59 }
60
61 p = realloc (p, n);
62 if (!p && n)
63 xalloc_die ();
64 return p;
65}
66
67/* If P is null, allocate a block of at least *PN bytes; otherwise,
68 reallocate P so that it contains more than *PN bytes. *PN must be
69 nonzero unless P is null. Set *PN to the new block's size, and
70 return the pointer to the new block. *PN is never set to zero, and
71 the returned pointer is never null. */
72
73void *
74x2realloc (void *p, size_t *pn)
75{
76 return x2nrealloc (p, pn, 1);
77}
78
79/* Allocate S bytes of zeroed memory dynamically, with error checking.
80 There's no need for xnzalloc (N, S), since it would be equivalent
81 to xcalloc (N, S). */
82
83void *
84xzalloc (size_t s)
85{
86 return memset (xmalloc (s), 0, s);
87}
88
89/* Allocate zeroed memory for N elements of S bytes, with error
90 checking. S must be nonzero. */
91
92void *
93xcalloc (size_t n, size_t s)
94{
95 void *p;
96 /* Test for overflow, since objects with size greater than
97 PTRDIFF_MAX cause pointer subtraction to go awry. Omit size-zero
98 tests if HAVE_GNU_CALLOC, since GNU calloc never returns NULL if
99 successful. */
100 if (xalloc_oversized (n, s)
101 || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
102 xalloc_die ();
103 return p;
104}
105
106/* Clone an object P of size S, with error checking. There's no need
107 for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any
108 need for an arithmetic overflow check. */
109
110void *
111xmemdup (void const *p, size_t s)
112{
113 return memcpy (xmalloc (s), p, s);
114}
115
116/* Clone STRING. */
117
118char *
119xstrdup (char const *string)
120{
121 return xmemdup (string, strlen (string) + 1);
122}
123