gl/xmalloc.c

   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 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 #ifndef SIZE_MAX
  32 # define SIZE_MAX ((size_t) -1)
  33 #endif
  34
  35 /* 1 if calloc is known to be compatible with GNU calloc.  This
  36    matters if we are not also using the calloc module, which defines
  37    HAVE_CALLOC and supports the GNU API even on non-GNU platforms.  */
  38 #if defined HAVE_CALLOC || defined __GLIBC__
  39 enum { HAVE_GNU_CALLOC = 1 };
  40 #else
  41 enum { HAVE_GNU_CALLOC = 0 };
  42 #endif
  43
  44 /* Allocate N bytes of memory dynamically, with error checking.  */
  45
  46 void *
  47 xmalloc (size_t n)
  48 {
  49   void *p = malloc (n);
  50   if (!p && n != 0)
  51     xalloc_die ();
  52   return p;
  53 }
  54
  55 /* Change the size of an allocated block of memory P to N bytes,
  56    with error checking.  */
  57
  58 void *
  59 xrealloc (void *p, size_t n)
  60 {
  61   p = realloc (p, n);
  62   if (!p && n != 0)
  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
  73 void *
  74 x2realloc (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
  83 void *
  84 xzalloc (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
  92 void *
  93 xcalloc (size_t n, size_t s)
  94 {
  95   void *p;
  96   /* Test for overflow, since some calloc implementations don't have
  97      proper overflow checks.  But omit overflow and size-zero tests if
  98      HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
  99      returns NULL if successful.  */
 100   if ((! HAVE_GNU_CALLOC && 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
 110 void *
 111 xmemdup (void const *p, size_t s)
 112 {
 113   return memcpy (xmalloc (s), p, s);
 114 }
 115
 116 /* Clone STRING.  */
 117
 118 char *
 119 xstrdup (char const *string)
 120 {
 121   return xmemdup (string, strlen (string) + 1);
 122 }