/* xmalloc.c -- malloc with out of memory checking

   Copyright (C) 1990-2000, 2002-2006, 2008-2017 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#define XALLOC_INLINE _GL_EXTERN_INLINE

#include "xalloc.h"

#include <stdlib.h>

#include <string.h>

/* 1 if calloc is known to be compatible with GNU calloc.  This

   matters if we are not also using the calloc module, which defines

   HAVE_CALLOC_GNU and supports the GNU API even on non-GNU platforms.  */

#if defined HAVE_CALLOC_GNU || (defined __GLIBC__ && !defined __UCLIBC__)

enum { HAVE_GNU_CALLOC = 1 };

#else

enum { HAVE_GNU_CALLOC = 0 };

#endif

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

void *

xmalloc (size_t n)

{

  void *p = malloc (n);

  if (!p && n != 0)

    xalloc_die ();

  return p;

}

/* Change the size of an allocated block of memory P to N bytes,

   with error checking.  */

void *

xrealloc (void *p, size_t n)

{

  if (!n && p)

    {

      /* The GNU and C99 realloc behaviors disagree here.  Act like

         GNU, even if the underlying realloc is C99.  */

      free (p);

      return NULL;

    }

  p = realloc (p, n);

  if (!p && n)

    xalloc_die ();

  return p;

}

/* If P is null, allocate a block of at least *PN bytes; otherwise,

   reallocate P so that it contains more than *PN bytes.  *PN must be

   nonzero unless P is null.  Set *PN to the new block's size, and

   return the pointer to the new block.  *PN is never set to zero, and

   the returned pointer is never null.  */

void *

x2realloc (void *p, size_t *pn)

{

  return x2nrealloc (p, pn, 1);

}

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

   There's no need for xnzalloc (N, S), since it would be equivalent

   to xcalloc (N, S).  */

void *

xzalloc (size_t s)

{

  return memset (xmalloc (s), 0, s);

}

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

   checking.  S must be nonzero.  */

void *

xcalloc (size_t n, size_t s)

{

  void *p;

  /* Test for overflow, since objects with size greater than

     PTRDIFF_MAX cause pointer subtraction to go awry.  Omit size-zero

     tests if HAVE_GNU_CALLOC, since GNU calloc never returns NULL if

     successful.  */

  if (xalloc_oversized (n, s)

      || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))

    xalloc_die ();

  return p;

}

/* Clone an object P of size S, with error checking.  There's no need

   for xnmemdup (P, N, S), since xmemdup (P, N * S) works without any

   need for an arithmetic overflow check.  */

void *

xmemdup (void const *p, size_t s)

{

  return memcpy (xmalloc (s), p, s);

}

/* Clone STRING.  */

char *

xstrdup (char const *string)

{

  return xmemdup (string, strlen (string) + 1);

}