tests/test-strncmp.c

   1 /* Test of strncmp() function.
   2    Copyright (C) 2024-2025 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 <string.h>
  21
  22 #include <stddef.h>
  23
  24 #include "macros.h"
  25
  26 /* Test the library, not the compiler+library.  */
  27 static int
  28 lib_strncmp (char const *s1, char const *s2, size_t n)
  29 {
  30   return strncmp (s1, s2, n);
  31 }
  32 static int (*volatile volatile_strncmp) (char const *, char const *, size_t)
  33   = lib_strncmp;
  34 #undef strncmp
  35 #define strncmp volatile_strncmp
  36
  37 int
  38 main (void)
  39 {
  40   /* Test zero-length operations on NULL pointers, allowed by
  41      <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3322.pdf>.  */
  42   ASSERT (strncmp (NULL, "x", 0) == 0);
  43   ASSERT (strncmp ("x", NULL, 0) == 0);
  44   ASSERT (strncmp (NULL, NULL, 0) == 0);
  45
  46   return test_exit_status;
  47 }