kc3-lang/gnulib/tests/test-memchr.c

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• Hash : 7b089321
  Author :
  Date : 2025-01-01T09:24:36
  

  maint: run 'make update-copyright'
  

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• tests/test-memchr.c

• /*
   * Copyright (C) 2008-2025 Free Software Foundation, Inc.
   * Written by Eric Blake and Bruno Haible
   *
   * 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/>.  */
  
  #include <config.h>
  
  #include <string.h>
  
  #include "signature.h"
  SIGNATURE_CHECK (memchr, void *, (void const *, int, size_t));
  
  #include <stdlib.h>
  
  #include "zerosize-ptr.h"
  #include "macros.h"
  
  /* Test the library, not the compiler+library.  */
  static void *
  lib_memchr (void const *s, int c, size_t n)
  {
    return memchr (s, c, n);
  }
  static void *(*volatile volatile_memchr) (void const *, int, size_t)
    = lib_memchr;
  #undef memchr
  #define memchr volatile_memchr
  
  int
  main (void)
  {
    size_t n = 0x100000;
    char *input = malloc (n);
    ASSERT (input);
  
    input[0] = 'a';
    input[1] = 'b';
    memset (input + 2, 'c', 1024);
    memset (input + 1026, 'd', n - 1028);
    input[n - 2] = 'e';
    input[n - 1] = 'a';
  
    /* Basic behavior tests.  */
    ASSERT (memchr (input, 'a', n) == input);
  
    ASSERT (memchr (input, 'a', 0) == NULL);
  
    {
      void *page_boundary = zerosize_ptr ();
      if (page_boundary)
        ASSERT (memchr (page_boundary, 'a', 0) == NULL);
    }
  
    ASSERT (memchr (input, 'b', n) == input + 1);
    ASSERT (memchr (input, 'c', n) == input + 2);
    ASSERT (memchr (input, 'd', n) == input + 1026);
  
    ASSERT (memchr (input + 1, 'a', n - 1) == input + n - 1);
    ASSERT (memchr (input + 1, 'e', n - 1) == input + n - 2);
    ASSERT (memchr (input + 1, 0x789abc00 | 'e', n - 1) == input + n - 2);
  
    ASSERT (memchr (input, 'f', n) == NULL);
    ASSERT (memchr (input, '\0', n) == NULL);
  
    /* Check that a very long haystack is handled quickly if the byte is
       found near the beginning.  */
    {
      size_t repeat = 10000;
      for (; repeat > 0; repeat--)
        {
          ASSERT (memchr (input, 'c', n) == input + 2);
        }
    }
  
    /* Alignment tests.  */
    {
      int i, j;
      for (i = 0; i < 32; i++)
        {
          for (j = 0; j < 256; j++)
            input[i + j] = j;
          for (j = 0; j < 256; j++)
            {
              ASSERT (memchr (input + i, j, 256) == input + i + j);
            }
        }
    }
  
    /* Check that memchr() does not read past the first occurrence of the
       byte being searched.  See the Austin Group's clarification
       <https://www.opengroup.org/austin/docs/austin_454.txt>.
       Test both '\0' and something else, since some implementations
       special-case searching for NUL.
    */
    {
      char *page_boundary = (char *) zerosize_ptr ();
      /* Too small, and we miss cache line boundary tests; too large,
         and the test takes cubically longer to complete.  */
      int limit = 257;
  
      if (page_boundary != NULL)
        {
          for (n = 1; n <= limit; n++)
            {
              char *mem = page_boundary - n;
              memset (mem, 'X', n);
              ASSERT (memchr (mem, 'U', n) == NULL);
              ASSERT (memchr (mem, 0, n) == NULL);
  
              {
                size_t i;
                size_t k;
  
                for (i = 0; i < n; i++)
                  {
                    mem[i] = 'U';
                    for (k = i + 1; k < n + limit; k++)
                      ASSERT (memchr (mem, 'U', k) == mem + i);
                    mem[i] = 0;
                    for (k = i + 1; k < n + limit; k++)
                      ASSERT (memchr (mem, 0, k) == mem + i);
                    mem[i] = 'X';
                  }
              }
            }
        }
    }
  
    free (input);
  
    /* Test zero-length operations on NULL pointers, allowed by
       <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3322.pdf>.  */
    ASSERT (memchr (NULL, '?', 0) == NULL);
  
    return test_exit_status;
  }
  

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