lib/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 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__
  40 enum { HAVE_GNU_CALLOC = 1 };
  41 #else
  42 enum { HAVE_GNU_CALLOC = 0 };
  43 #endif
  44
  45 /* Allocate N bytes of memory dynamically, with error checking.  */
  46
  47 void *
  48 xmalloc (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
  59 void *
  60 xrealloc (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
  74 void *
  75 x2realloc (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
  84 void *
  85 xzalloc (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
  93 void *
  94 xcalloc (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
 111 void *
 112 xmemdup (void const *p, size_t s)
 113 {
 114   return memcpy (xmalloc (s), p, s);
 115 }
 116
 117 /* Clone STRING.  */
 118
 119 char *
 120 xstrdup (char const *string)
 121 {
 122   return xmemdup (string, strlen (string) + 1);
 123 }