/* realloc() function that is glibc compatible.

   Copyright (C) 1997, 2003-2004, 2006-2007, 2009-2020 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 <https://www.gnu.org/licenses/>.  */

/* written by Jim Meyering and Bruno Haible */

#define _GL_USE_STDLIB_ALLOC 1

#include <config.h>

/* Only the AC_FUNC_REALLOC macro defines 'realloc' already in config.h.  */

#ifdef realloc

# define NEED_REALLOC_GNU 1

/* Whereas the gnulib module 'realloc-gnu' defines HAVE_REALLOC_GNU.  */

#elif GNULIB_REALLOC_GNU && !HAVE_REALLOC_GNU

# define NEED_REALLOC_GNU 1

#endif

/* Infer the properties of the system's malloc function.

   The gnulib module 'malloc-gnu' defines HAVE_MALLOC_GNU.  */

#if GNULIB_MALLOC_GNU && HAVE_MALLOC_GNU

# define SYSTEM_MALLOC_GLIBC_COMPATIBLE 1

#endif

#include <stdlib.h>

#include <errno.h>

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

   with error checking.  If N is zero, change it to 1.  If P is NULL,

   use malloc.  */

void *

rpl_realloc (void *p, size_t n)

{

  void *result;

#if NEED_REALLOC_GNU

  if (n == 0)

    {

      n = 1;

      /* In theory realloc might fail, so don't rely on it to free.  */

      free (p);

      p = NULL;

    }

#endif

  if (p == NULL)

    {

#if GNULIB_REALLOC_GNU && !NEED_REALLOC_GNU && !SYSTEM_MALLOC_GLIBC_COMPATIBLE

      if (n == 0)

        n = 1;

#endif

      result = malloc (n);

    }

  else

    result = realloc (p, n);

#if !HAVE_REALLOC_POSIX

  if (result == NULL)

    errno = ENOMEM;

#endif

  return result;

}