tests/test-strstr.c

   1 /*
   2  * Copyright (C) 2004, 2007-2011 Free Software Foundation, Inc.
   3  * Written by Bruno Haible and Eric Blake
   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 (strstr, char *, (char const *, char const *));
  24
  25 #include <signal.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28
  29 #include "zerosize-ptr.h"
  30 #include "macros.h"
  31
  32 int
  33 main (int argc, char *argv[])
  34 {
  35 #if HAVE_DECL_ALARM
  36   /* Declare failure if test takes too long, by using default abort
  37      caused by SIGALRM.  All known platforms that lack alarm also have
  38      a quadratic strstr, and the replacement strstr is known to not
  39      take too long.  */
  40   signal (SIGALRM, SIG_DFL);
  41   alarm (50);
  42 #endif
  43
  44   {
  45     const char input[] = "foo";
  46     const char *result = strstr (input, "");
  47     ASSERT (result == input);
  48   }
  49
  50   {
  51     const char input[] = "foo";
  52     const char *result = strstr (input, "o");
  53     ASSERT (result == input + 1);
  54   }
  55
  56   {
  57     /* On some platforms, the memchr() functions reads past the first
  58        occurrence of the byte to be searched, leading to an out-of-bounds
  59        read access for strstr().
  60        See <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=521737>.
  61        This is a bug in memchr(), see the Austin Group's clarification
  62        <http://www.opengroup.org/austin/docs/austin_454.txt>.  */
  63     const char *fix = "aBaaaaaaaaaaax";
  64     char *page_boundary = (char *) zerosize_ptr ();
  65     size_t len = strlen (fix) + 1;
  66     char *input = page_boundary ? page_boundary - len : malloc (len);
  67     const char *result;
  68
  69     strcpy (input, fix);
  70     result = strstr (input, "B1x");
  71     ASSERT (result == NULL);
  72     if (!page_boundary)
  73       free (input);
  74   }
  75
  76   {
  77     const char input[] = "ABC ABCDAB ABCDABCDABDE";
  78     const char *result = strstr (input, "ABCDABD");
  79     ASSERT (result == input + 15);
  80   }
  81
  82   {
  83     const char input[] = "ABC ABCDAB ABCDABCDABDE";
  84     const char *result = strstr (input, "ABCDABE");
  85     ASSERT (result == NULL);
  86   }
  87
  88   {
  89     const char input[] = "ABC ABCDAB ABCDABCDABDE";
  90     const char *result = strstr (input, "ABCDABCD");
  91     ASSERT (result == input + 11);
  92   }
  93
  94   /* Check that a long periodic needle does not cause false positives.  */
  95   {
  96     const char input[] = "F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD"
  97                          "_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD"
  98                          "_C3_A7_20_EF_BF_BD";
  99     const char need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
 100     const char *result = strstr (input, need);
 101     ASSERT (result == NULL);
 102   }
 103   {
 104     const char input[] = "F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD"
 105                          "_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD"
 106                          "_C3_A7_20_EF_BF_BD_DA_B5_C2_A6_20"
 107                          "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
 108     const char need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
 109     const char *result = strstr (input, need);
 110     ASSERT (result == input + 115);
 111   }
 112
 113   /* Check that a very long haystack is handled quickly if the needle is
 114      short and occurs near the beginning.  */
 115   {
 116     size_t repeat = 10000;
 117     size_t m = 1000000;
 118     const char *needle =
 119       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
 120       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
 121     char *haystack = (char *) malloc (m + 1);
 122     if (haystack != NULL)
 123       {
 124         memset (haystack, 'A', m);
 125         haystack[0] = 'B';
 126         haystack[m] = '\0';
 127
 128         for (; repeat > 0; repeat--)
 129           {
 130             ASSERT (strstr (haystack, needle) == haystack + 1);
 131           }
 132
 133         free (haystack);
 134       }
 135   }
 136
 137   /* Check that a very long needle is discarded quickly if the haystack is
 138      short.  */
 139   {
 140     size_t repeat = 10000;
 141     size_t m = 1000000;
 142     const char *haystack =
 143       "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
 144       "ABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABAB";
 145     char *needle = (char *) malloc (m + 1);
 146     if (needle != NULL)
 147       {
 148         memset (needle, 'A', m);
 149         needle[m] = '\0';
 150
 151         for (; repeat > 0; repeat--)
 152           {
 153             ASSERT (strstr (haystack, needle) == NULL);
 154           }
 155
 156         free (needle);
 157       }
 158   }
 159
 160   /* Check that the asymptotic worst-case complexity is not quadratic.  */
 161   {
 162     size_t m = 1000000;
 163     char *haystack = (char *) malloc (2 * m + 2);
 164     char *needle = (char *) malloc (m + 2);
 165     if (haystack != NULL && needle != NULL)
 166       {
 167         const char *result;
 168
 169         memset (haystack, 'A', 2 * m);
 170         haystack[2 * m] = 'B';
 171         haystack[2 * m + 1] = '\0';
 172
 173         memset (needle, 'A', m);
 174         needle[m] = 'B';
 175         needle[m + 1] = '\0';
 176
 177         result = strstr (haystack, needle);
 178         ASSERT (result == haystack + m);
 179       }
 180     free (needle);
 181     free (haystack);
 182   }
 183
 184   /* Sublinear speed is only possible in memmem; strstr must examine
 185      every character of haystack to find its length.  */
 186
 187   return 0;
 188 }