tests/test-memrchr.c

   1 /*
   2  * Copyright (C) 2008-2024 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 <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 #include <string.h>
  21
  22 #include "signature.h"
  23 SIGNATURE_CHECK (memrchr, void *, (void const *, int, size_t));
  24
  25 #include <stdlib.h>
  26
  27 #include "zerosize-ptr.h"
  28 #include "macros.h"
  29
  30 /* Work around GCC bug 101494.  */
  31 #if 4 < __GNUC__ + (7 <= __GNUC_MINOR__) && __GNUC__ < 12
  32 # pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
  33 #endif
  34
  35 /* Calculating void * + int is not portable, so this wrapper converts
  36    to char * to make the tests easier to write.  */
  37 #define MEMRCHR (char *) memrchr
  38
  39 int
  40 main (void)
  41 {
  42   size_t n = 0x100000;
  43   char *input = malloc (n);
  44   ASSERT (input);
  45
  46   input[n - 1] = 'a';
  47   input[n - 2] = 'b';
  48   memset (input + n - 1026, 'c', 1024);
  49   memset (input + 2, 'd', n - 1028);
  50   input[1] = 'e';
  51   input[0] = 'a';
  52
  53   /* Basic behavior tests.  */
  54   ASSERT (MEMRCHR (input, 'a', n) == input + n - 1);
  55
  56   ASSERT (MEMRCHR (input, 'a', 0) == NULL);
  57   void *page_boundary = zerosize_ptr ();
  58   if (page_boundary)
  59     ASSERT (MEMRCHR (page_boundary, 'a', 0) == NULL);
  60
  61   ASSERT (MEMRCHR (input, 'b', n) == input + n - 2);
  62   ASSERT (MEMRCHR (input, 'c', n) == input + n - 3);
  63   ASSERT (MEMRCHR (input, 'd', n) == input + n - 1027);
  64
  65   ASSERT (MEMRCHR (input, 'a', n - 1) == input);
  66   ASSERT (MEMRCHR (input, 'e', n - 1) == input + 1);
  67
  68   ASSERT (MEMRCHR (input, 'f', n) == NULL);
  69   ASSERT (MEMRCHR (input, '\0', n) == NULL);
  70
  71   /* Check that a very long haystack is handled quickly if the byte is
  72      found near the end.  */
  73   {
  74     size_t repeat = 10000;
  75     for (; repeat > 0; repeat--)
  76       {
  77         ASSERT (MEMRCHR (input, 'c', n) == input + n - 3);
  78       }
  79   }
  80
  81   /* Alignment tests.  */
  82   {
  83     int i, j;
  84     for (i = 0; i < 32; i++)
  85       {
  86         for (j = 0; j < 256; j++)
  87           input[i + j] = j;
  88         for (j = 0; j < 256; j++)
  89           {
  90             ASSERT (MEMRCHR (input + i, j, 256) == input + i + j);
  91           }
  92       }
  93   }
  94
  95   free (input);
  96
  97   return test_exit_status;
  98 }