gdb/testsuite/gdb.base/watchpoint-unaligned.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2017-2021 Free Software Foundation, Inc.
   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 <stdint.h>
  19 #include <assert.h>
  20
  21 static int again;
  22
  23 static volatile struct
  24 {
  25   uint64_t alignment;
  26   union
  27     {
  28       uint64_t size8[1];
  29       uint32_t size4[2];
  30       uint16_t size2[4];
  31       uint8_t size1[8];
  32       uint64_t size8twice[2];
  33     }
  34   u;
  35 } data;
  36
  37 static int size = 0;
  38 static int offset;
  39
  40 static void
  41 write_size8twice (void)
  42 {
  43   static const uint64_t first = 1;
  44   static const uint64_t second = 2;
  45
  46 #ifdef __aarch64__
  47   asm volatile ("stp %1, %2, [%0]"
  48                 : /* output */
  49                 : "r" (data.u.size8twice), "r" (first), "r" (second) /* input */
  50                 : "memory" /* clobber */);
  51 #else
  52   data.u.size8twice[0] = first;
  53   data.u.size8twice[1] = second;
  54 #endif
  55 }
  56
  57 int
  58 main (void)
  59 {
  60   volatile uint64_t local;
  61
  62   assert (sizeof (data) == 8 + 2 * 8);
  63
  64   write_size8twice ();
  65
  66   while (size)
  67     {
  68       switch (size)
  69         {
  70 /* __s390x__ also defines __s390__ */
  71 #ifdef __s390__
  72 # define ACCESS(var) var = ~var
  73 #else
  74 # define ACCESS(var) local = var
  75 #endif
  76         case 8:
  77           ACCESS (data.u.size8[offset]);
  78           break;
  79         case 4:
  80           ACCESS (data.u.size4[offset]);
  81           break;
  82         case 2:
  83           ACCESS (data.u.size2[offset]);
  84           break;
  85         case 1:
  86           ACCESS (data.u.size1[offset]);
  87           break;
  88 #undef ACCESS
  89         default:
  90           assert (0);
  91         }
  92       size = 0;
  93       size = size; /* start_again */
  94     }
  95   return 0; /* final_return */
  96 }