xmalloc.c

libiconv是一个很不错的字符集转换库。程序接口也很简单

/* xmalloc.c -- malloc with out of memory checking
   Copyright (C) 1990-1996, 2000-2003 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#if HAVE_CONFIG_H
# include <config.h>
#endif

/* Specification.  */
#include "xmalloc.h"

#include <stdlib.h>

#include "error.h"
#include "exit.h"
#include "gettext.h"

#define _(str) gettext (str)


/* Exit value when the requested amount of memory is not available.
   The caller may set it to some other value.  */
int xmalloc_exit_failure = EXIT_FAILURE;

void
xalloc_die ()
{
  error (xmalloc_exit_failure, 0, _("memory exhausted"));
  /* The `noreturn' cannot be given to error, since it may return if
     its first argument is 0.  To help compilers understand the
     xalloc_die does terminate, call exit. */
  exit (EXIT_FAILURE);
}

static void *
fixup_null_alloc (size_t n)
{
  void *p;

  p = 0;
  if (n == 0)
    p = malloc ((size_t) 1);
  if (p == NULL)
    xalloc_die ();
  return p;
}

/* Allocate N bytes of memory dynamically, with error checking.  */

void *
xmalloc (size_t n)
{
  void *p;

  p = malloc (n);
  if (p == NULL)
    p = fixup_null_alloc (n);
  return p;
}

/* Allocate memory for N elements of S bytes, with error checking.  */

void *
xcalloc (size_t n, size_t s)
{
  void *p;

  p = calloc (n, s);
  if (p == NULL)
    p = fixup_null_alloc (n);
  return p;
}

/* Change the size of an allocated block of memory P to N bytes,
   with error checking.
   If P is NULL, run xmalloc.  */

void *
xrealloc (void *p, size_t n)
{
  if (p == NULL)
    return xmalloc (n);
  p = realloc (p, n);
  if (p == NULL)
    p = fixup_null_alloc (n);
  return p;
}