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, 1999,
   4    2000, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2010 Free Software
   5    Foundation, 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__
  35 enum { HAVE_GNU_CALLOC = 1 };
  36 #else
  37 enum { HAVE_GNU_CALLOC = 0 };
  38 #endif
  39
  40 /* Allocate N bytes of memory dynamically, with error checking.  */
  41
  42 void *
  43 xmalloc (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
  54 void *
  55 xrealloc (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
  69 void *
  70 x2realloc (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
  79 void *
  80 xzalloc (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
  88 void *
  89 xcalloc (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
 106 void *
 107 xmemdup (void const *p, size_t s)
 108 {
 109   return memcpy (xmalloc (s), p, s);
 110 }
 111
 112 /* Clone STRING.  */
 113
 114 char *
 115 xstrdup (char const *string)
 116 {
 117   return xmemdup (string, strlen (string) + 1);
 118 }