string/testcopy.c

   1 /* Copyright (C) 1990-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Torbjorn Granlund (tege@sics.se).
   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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <malloc.h>
  23
  24 int
  25 main (void)
  26 {
  27   char *mem, *memp;
  28   char *rand_mem;
  29   char *lo_around, *hi_around;
  30   int size, max_size;
  31   int src_off, dst_off;
  32   int i;
  33   int space_around = 10;
  34
  35   max_size = 256;
  36
  37   mem = malloc (max_size + 2 * max_size + 2 * space_around);
  38   rand_mem = malloc (max_size);
  39   lo_around = malloc (space_around);
  40   hi_around = malloc (space_around);
  41   memp = mem + space_around;
  42
  43   /* Fill RAND_MEM with random bytes, each non-zero.  */
  44   for (i = 0; i < max_size; i++)
  45     {
  46       int x;
  47       do
  48         x = random ();
  49       while (x == 0);
  50       rand_mem[i] = x;
  51     }
  52
  53   for (size = 0; size < max_size; size++)
  54     {
  55       printf("phase %d\n", size);
  56       for (src_off = 0; src_off <= 16; src_off++)
  57         {
  58           for (dst_off = 0; dst_off <= 16; dst_off++)
  59             {
  60               /* Put zero around the intended destination, to check
  61                  that it's not clobbered.  */
  62               for (i = 1; i < space_around; i++)
  63                 {
  64                   memp[dst_off - i] = 0;
  65                   memp[dst_off + size - 1 + i] = 0;
  66                 }
  67
  68               /* Fill the source area with known contents.  */
  69               for (i = 0; i < size; i++)
  70                 memp[src_off + i] = rand_mem[i];
  71
  72               /* Remember the contents around the destination area.
  73                  (It might not be what we wrote some lines above, since
  74                  the src area and the dst area overlap.)  */
  75               for (i = 1; i < space_around; i++)
  76                 {
  77                   lo_around[i] = memp[dst_off - i];
  78                   hi_around[i] = memp[dst_off + size - 1 + i];
  79                 }
  80
  81               memmove (memp + dst_off, memp + src_off, size);
  82
  83               /* Check that the destination area has the same
  84                  contents we wrote to the source area.  */
  85               for (i = 0; i < size; i++)
  86                 {
  87                   if (memp[dst_off + i] != rand_mem[i])
  88                     abort ();
  89                 }
  90
  91               /* Check that the area around the destination is not
  92                  clobbered.  */
  93               for (i = 1; i < space_around; i++)
  94                 {
  95                   if (memp[dst_off - i] != lo_around[i])
  96                     abort ();
  97                   if (memp[dst_off + size - 1 + i] != hi_around[i])
  98                     abort ();
  99                 }
 100             }
 101         }
 102     }
 103
 104   puts ("Test succeeded.");
 105
 106   return 0;
 107 }