1  /* Test of realloc function.
       2     Copyright (C) 2010-2021 Free Software Foundation, Inc.
       3  
       4     This program is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU General Public License as published by
       6     the Free Software Foundation; either version 3 of the License, or
       7     (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #include <config.h>
      18  
      19  /* Specification.  */
      20  #include <stdlib.h>
      21  
      22  #include <errno.h>
      23  #include <stdint.h>
      24  
      25  #include "macros.h"
      26  
      27  int
      28  main (int argc, char **argv)
      29  {
      30    /* Check that realloc (NULL, 0) is not a NULL pointer.  */
      31    void *volatile p = realloc (NULL, 0);
      32    ASSERT (p != NULL);
      33  
      34    /* Check that realloc (p, n) fails when p is non-null and n exceeds
      35       PTRDIFF_MAX.  */
      36    if (PTRDIFF_MAX < SIZE_MAX)
      37      {
      38        size_t one = argc != 12345;
      39        p = realloc (p, PTRDIFF_MAX + one);
      40        ASSERT (p == NULL);
      41        /* Avoid a test failure due to glibc bug
      42           <https://sourceware.org/bugzilla/show_bug.cgi?id=27870>.  */
      43        if (!getenv ("MALLOC_CHECK_"))
      44          ASSERT (errno == ENOMEM);
      45      }
      46  
      47    free (p);
      48    return 0;
      49  }