gl/tests/test-memchr.c

   1 /*
   2  * Copyright (C) 2008-2012 Free Software Foundation, Inc.
   3  * Written by Eric Blake and Bruno Haible
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 #include <string.h>
  21
  22 #include "signature.h"
  23 SIGNATURE_CHECK (memchr, void *, (void const *, int, size_t));
  24
  25 #include <stdlib.h>
  26
  27 #include "zerosize-ptr.h"
  28 #include "macros.h"
  29
  30 /* Calculating void * + int is not portable, so this wrapper converts
  31    to char * to make the tests easier to write.  */
  32 #define MEMCHR (char *) memchr
  33
  34 int
  35 main (void)
  36 {
  37   size_t n = 0x100000;
  38   char *input = malloc (n);
  39   ASSERT (input);
  40
  41   input[0] = 'a';
  42   input[1] = 'b';
  43   memset (input + 2, 'c', 1024);
  44   memset (input + 1026, 'd', n - 1028);
  45   input[n - 2] = 'e';
  46   input[n - 1] = 'a';
  47
  48   /* Basic behavior tests.  */
  49   ASSERT (MEMCHR (input, 'a', n) == input);
  50
  51   ASSERT (MEMCHR (input, 'a', 0) == NULL);
  52   ASSERT (MEMCHR (zerosize_ptr (), 'a', 0) == NULL);
  53
  54   ASSERT (MEMCHR (input, 'b', n) == input + 1);
  55   ASSERT (MEMCHR (input, 'c', n) == input + 2);
  56   ASSERT (MEMCHR (input, 'd', n) == input + 1026);
  57
  58   ASSERT (MEMCHR (input + 1, 'a', n - 1) == input + n - 1);
  59   ASSERT (MEMCHR (input + 1, 'e', n - 1) == input + n - 2);
  60   ASSERT (MEMCHR (input + 1, 0x789abc00 | 'e', n - 1) == input + n - 2);
  61
  62   ASSERT (MEMCHR (input, 'f', n) == NULL);
  63   ASSERT (MEMCHR (input, '\0', n) == NULL);
  64
  65   /* Check that a very long haystack is handled quickly if the byte is
  66      found near the beginning.  */
  67   {
  68     size_t repeat = 10000;
  69     for (; repeat > 0; repeat--)
  70       {
  71         ASSERT (MEMCHR (input, 'c', n) == input + 2);
  72       }
  73   }
  74
  75   /* Alignment tests.  */
  76   {
  77     int i, j;
  78     for (i = 0; i < 32; i++)
  79       {
  80         for (j = 0; j < 256; j++)
  81           input[i + j] = j;
  82         for (j = 0; j < 256; j++)
  83           {
  84             ASSERT (MEMCHR (input + i, j, 256) == input + i + j);
  85           }
  86       }
  87   }
  88
  89   /* Check that memchr() does not read past the first occurrence of the
  90      byte being searched.  See the Austin Group's clarification
  91      <http://www.opengroup.org/austin/docs/austin_454.txt>.
  92      Test both '\0' and something else, since some implementations
  93      special-case searching for NUL.
  94   */
  95   {
  96     char *page_boundary = (char *) zerosize_ptr ();
  97     /* Too small, and we miss cache line boundary tests; too large,
  98        and the test takes cubically longer to complete.  */
  99     int limit = 257;
 100
 101     if (page_boundary != NULL)
 102       {
 103         for (n = 1; n <= limit; n++)
 104           {
 105             char *mem = page_boundary - n;
 106             memset (mem, 'X', n);
 107             ASSERT (MEMCHR (mem, 'U', n) == NULL);
 108             ASSERT (MEMCHR (mem, 0, n) == NULL);
 109
 110             {
 111               size_t i;
 112               size_t k;
 113
 114               for (i = 0; i < n; i++)
 115                 {
 116                   mem[i] = 'U';
 117                   for (k = i + 1; k < n + limit; k++)
 118                     ASSERT (MEMCHR (mem, 'U', k) == mem + i);
 119                   mem[i] = 0;
 120                   for (k = i + 1; k < n + limit; k++)
 121                     ASSERT (MEMCHR (mem, 0, k) == mem + i);
 122                   mem[i] = 'X';
 123                 }
 124             }
 125           }
 126       }
 127   }
 128
 129   free (input);
 130
 131   return 0;
 132 }