string/test-memmem.c

   1 /* Test and measure memmem functions.
   2    Copyright (C) 2008-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define TEST_MAIN
  20 #define TEST_NAME "memmem"
  21 #define BUF1PAGES 20
  22 #define ITERATIONS 500
  23 #include "test-string.h"
  24
  25 typedef char *(*proto_t) (const void *, size_t, const void *, size_t);
  26
  27 IMPL (memmem, 1)
  28
  29 /* Naive implementation to verify results.  */
  30 void *
  31 simple_memmem (const void *haystack, size_t haystack_len, const void *needle,
  32                size_t needle_len)
  33 {
  34   const char *begin;
  35   const char *const last_possible
  36     = (const char *) haystack + haystack_len - needle_len;
  37
  38   if (needle_len == 0)
  39     /* The first occurrence of the empty string is deemed to occur at
  40        the beginning of the string.  */
  41     return (void *) haystack;
  42
  43   /* Sanity check, otherwise the loop might search through the whole
  44      memory.  */
  45   if (__glibc_unlikely (haystack_len < needle_len))
  46     return NULL;
  47
  48   for (begin = (const char *) haystack; begin <= last_possible; ++begin)
  49     if (begin[0] == ((const char *) needle)[0]
  50         && !memcmp ((const void *) &begin[1],
  51                     (const void *) ((const char *) needle + 1),
  52                     needle_len - 1))
  53       return (void *) begin;
  54
  55   return NULL;
  56 }
  57
  58 static int
  59 check_result (impl_t *impl, const void *haystack, size_t haystack_len,
  60              const void *needle, size_t needle_len, const void *expected)
  61 {
  62   void *res;
  63
  64   res = CALL (impl, haystack, haystack_len, needle, needle_len);
  65   if (res != expected)
  66     {
  67       error (0, 0, "Wrong result in function %s %p %p", impl->name,
  68              res, expected);
  69       ret = 1;
  70       return -1;
  71     }
  72
  73   return 0;
  74 }
  75
  76 static void
  77 do_one_test (impl_t *impl, const void *haystack, size_t haystack_len,
  78              const void *needle, size_t needle_len, const void *expected)
  79 {
  80   if (check_result (impl, haystack, haystack_len, needle, needle_len,
  81                     expected) < 0)
  82     return;
  83 }
  84
  85 static void
  86 do_test (const char *str, size_t len, size_t idx)
  87 {
  88   char tmpbuf[len];
  89
  90   memcpy (tmpbuf, buf1 + idx, len);
  91   memcpy (buf1 + idx, str, len);
  92
  93   FOR_EACH_IMPL (impl, 0)
  94     do_one_test (impl, buf1, BUF1PAGES * page_size, str, len, buf1 + idx);
  95
  96   memcpy (buf1 + idx, tmpbuf, len);
  97 }
  98
  99 static void
 100 do_random_tests (void)
 101 {
 102   for (size_t n = 0; n < ITERATIONS; ++n)
 103     {
 104       char tmpbuf[32];
 105
 106       size_t shift = random () % 11;
 107       size_t rel = random () % ((2 << (shift + 1)) * 64);
 108       size_t idx = MIN ((2 << shift) * 64 + rel, BUF1PAGES * page_size - 2);
 109       size_t len = random () % (sizeof (tmpbuf) - 1) + 1;
 110       len = MIN (len, BUF1PAGES * page_size - idx - 1);
 111       memcpy (tmpbuf, buf1 + idx, len);
 112       for (size_t i = random () % len / 2 + 1; i > 0; --i)
 113         {
 114           size_t off = random () % len;
 115           char ch = '0' + random () % 10;
 116
 117           buf1[idx + off] = ch;
 118         }
 119
 120       FOR_EACH_IMPL (impl, 0)
 121         do_one_test (impl, buf1, BUF1PAGES * page_size, buf1 + idx, len,
 122                      buf1 + idx);
 123
 124       memcpy (buf1 + idx, tmpbuf, len);
 125     }
 126 }
 127
 128 static void
 129 check1 (void)
 130 {
 131
 132   const char search_buf_data[5] = { 0x56, 0x34, 0x12, 0x78, 0x78 };
 133   const char pattern[2] = { 0x78, 0x56 };
 134   void *search_buf = (void *) buf1 + page_size - sizeof search_buf_data;
 135   void *exp_result;
 136
 137   memcpy (search_buf, search_buf_data, sizeof search_buf_data);
 138   exp_result = simple_memmem (search_buf, sizeof search_buf_data,
 139                               pattern, sizeof pattern);
 140   FOR_EACH_IMPL (impl, 0)
 141     check_result (impl, search_buf, sizeof search_buf_data,
 142                   pattern, sizeof pattern, exp_result);
 143 }
 144
 145 static const char *const strs[] =
 146   {
 147     "00000", "00112233", "0123456789", "0000111100001111",
 148     "00000111110000022222", "012345678901234567890",
 149     "abc0", "aaaa0", "abcabc0"
 150   };
 151
 152
 153 int
 154 test_main (void)
 155 {
 156   size_t i;
 157
 158   test_init ();
 159
 160   check1 ();
 161
 162   printf ("%23s", "");
 163   FOR_EACH_IMPL (impl, 0)
 164     printf ("\t%s", impl->name);
 165   putchar ('\n');
 166
 167   for (i = 0; i < BUF1PAGES * page_size; ++i)
 168     buf1[i] = 60 + random () % 32;
 169
 170   for (i = 0; i < sizeof (strs) / sizeof (strs[0]); ++i)
 171     for (size_t j = 0; j < 120; j += 7)
 172       {
 173         size_t len = strlen (strs[i]);
 174
 175         do_test (strs[i], len, j);
 176       }
 177
 178   do_random_tests ();
 179   return ret;
 180 }
 181
 182 #include <support/test-driver.c>