tests/test-c-strstr.c

   1 /* Test of searching in a string.
   2    Copyright (C) 2007-2017 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 /* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
  18
  19 #include <config.h>
  20
  21 #include "c-strstr.h"
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "macros.h"
  27
  28 int
  29 main ()
  30 {
  31   {
  32     const char input[] = "foo";
  33     const char *result = c_strstr (input, "");
  34     ASSERT (result == input);
  35   }
  36
  37   {
  38     const char input[] = "foo";
  39     const char *result = c_strstr (input, "o");
  40     ASSERT (result == input + 1);
  41   }
  42
  43   {
  44     const char input[] = "ABC ABCDAB ABCDABCDABDE";
  45     const char *result = c_strstr (input, "ABCDABD");
  46     ASSERT (result == input + 15);
  47   }
  48
  49   {
  50     const char input[] = "ABC ABCDAB ABCDABCDABDE";
  51     const char *result = c_strstr (input, "ABCDABE");
  52     ASSERT (result == NULL);
  53   }
  54
  55   /* Check that a very long haystack is handled quickly if the needle is
  56      short and occurs near the beginning.  */
  57   {
  58     size_t repeat = 10000;
  59     size_t m = 1000000;
  60     const char *needle =
  61       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
  62       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
  63     char *haystack = (char *) malloc (m + 1);
  64     if (haystack != NULL)
  65       {
  66         memset (haystack, 'A', m);
  67         haystack[0] = 'B';
  68         haystack[m] = '\0';
  69
  70         for (; repeat > 0; repeat--)
  71           {
  72             ASSERT (c_strstr (haystack, needle) == haystack + 1);
  73           }
  74
  75         free (haystack);
  76       }
  77   }
  78
  79   /* Check that a very long needle is discarded quickly if the haystack is
  80      short.  */
  81   {
  82     size_t repeat = 10000;
  83     size_t m = 1000000;
  84     const char *haystack =
  85       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
  86       "ABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABAB";
  87     char *needle = (char *) malloc (m + 1);
  88     if (needle != NULL)
  89       {
  90         memset (needle, 'A', m);
  91         needle[m] = '\0';
  92
  93         for (; repeat > 0; repeat--)
  94           {
  95             ASSERT (c_strstr (haystack, needle) == NULL);
  96           }
  97
  98         free (needle);
  99       }
 100   }
 101
 102   /* Check that the asymptotic worst-case complexity is not quadratic.  */
 103   {
 104     size_t m = 1000000;
 105     char *haystack = (char *) malloc (2 * m + 2);
 106     char *needle = (char *) malloc (m + 2);
 107     if (haystack != NULL && needle != NULL)
 108       {
 109         const char *result;
 110
 111         memset (haystack, 'A', 2 * m);
 112         haystack[2 * m] = 'B';
 113         haystack[2 * m + 1] = '\0';
 114
 115         memset (needle, 'A', m);
 116         needle[m] = 'B';
 117         needle[m + 1] = '\0';
 118
 119         result = c_strstr (haystack, needle);
 120         ASSERT (result == haystack + m);
 121       }
 122     free (needle);
 123     free (haystack);
 124   }
 125
 126   return 0;
 127 }