gdb/testsuite/gdb.base/watch-read.exp

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2010 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 # This file was written by Pedro Alves <pedro@codesourcery.com>
  19
  20 # This file is part of the gdb testsuite.
  21
  22 #
  23 # Tests involving read watchpoints, and other kinds of watchpoints
  24 # watching the same memory as read watchpoints.
  25 #
  26
  27 set testfile "watch-read"
  28 set srcfile ${testfile}.c
  29
  30 if { [target_info exists gdb,no_hardware_watchpoints] } {
  31     untested ${testfile}.exp
  32     return -1
  33 }
  34
  35 if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
  36     untested ${testfile}.exp
  37     return -1
  38 }
  39
  40 if { ![runto main] } then {
  41     fail "run to main"
  42     return
  43 }
  44
  45 set read_line [gdb_get_line_number "read line" $srcfile]
  46
  47 # Test running to a read of `global', with a read watchpoint set
  48 # watching it.
  49
  50 gdb_test "rwatch global" \
  51     "Hardware read watchpoint .*: global" \
  52     "set hardware read watchpoint on global variable"
  53
  54 # The first read is on entry to the loop.
  55
  56 gdb_test "continue" \
  57     "read watchpoint .*: global.*.*Value = 0.*in main.*$srcfile:$read_line.*" \
  58     "read watchpoint triggers on first read"
  59
  60 # The second read happens on second loop iteration, after `global'
  61 # having been incremented.  On architectures where gdb has to emulate
  62 # read watchpoints with access watchpoints, this tests the
  63 # only-report-if-value-changed logic.  On targets that support real
  64 # read watchpoints, this tests that GDB ignores the watchpoint's old
  65 # value, knowing that some untrapped write could have changed it, and
  66 # so reports the read watchpoint unconditionally.
  67
  68 gdb_test "continue" \
  69     "read watchpoint .*: global.*.*Value = 1.*in main.*$srcfile:$read_line.*" \
  70     "read watchpoint triggers on read after value changed"
  71
  72 # The following tests check that when the user sets a write or access
  73 # watchpoint watching the same memory as a read watchpoint, GDB also
  74 # applies the only-report-if-value-changed logic even on targets that
  75 # support real read watchpoints.
  76
  77 # The program should be stopped at the read line.  Set a write
  78 # watchpoint (leaving the read watchpoint) and continue.  Only the
  79 # write watchpoint should be reported as triggering.
  80
  81 gdb_test "watch global" \
  82     "atchpoint .*: global" \
  83     "set write watchpoint on global variable"
  84
  85 gdb_test "continue" \
  86     "atchpoint .*: global.*Old value = 1.*New value = 2.*" \
  87     "write watchpoint triggers"
  88
  89 set exp ""
  90 set exp "${exp}2.*read watchpoint.*keep y.*global.*breakpoint already hit 2 times.*"
  91 set exp "${exp}3.*watchpoint.*keep y.*global.*breakpoint already hit 1 time.*"
  92 gdb_test "info watchpoints" \
  93     "$exp" \
  94     "only write watchpoint triggers when value changes"
  95
  96 # The program is now stopped at the write line.  Continuing should
  97 # stop at the read line, and only the read watchpoint should be
  98 # reported as triggering.
  99
 100 gdb_test "continue" \
 101     "read watchpoint .*: global.*Value = 2.*in main.*$srcfile:$read_line.*" \
 102     "read watchpoint triggers when value doesn't change, trapping reads and writes"
 103
 104 set exp ""
 105 set exp "${exp}2.*read watchpoint.*keep y.*global.*breakpoint already hit 3 times.*"
 106 set exp "${exp}3.*watchpoint.*keep y.*global.*breakpoint already hit 1 time.*"
 107 gdb_test "info watchpoints" \
 108     "$exp" \
 109     "only read watchpoint triggers when value doesn't change"