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

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2010-2013 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 is part of the gdb testsuite.
  19
  20 #
  21 # Tests involving read watchpoints, and other kinds of watchpoints
  22 # watching the same memory as read watchpoints.
  23 #
  24
  25 standard_testfile .c
  26
  27 if {[skip_hw_watchpoint_access_tests]} {
  28     return 0
  29 }
  30
  31 if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
  32     untested ${testfile}.exp
  33     return -1
  34 }
  35
  36 if { ![runto main] } then {
  37     fail "run to main"
  38     return
  39 }
  40
  41 set read_line [gdb_get_line_number "read line" $srcfile]
  42
  43 # Test running to a read of `global', with a read watchpoint set
  44 # watching it.
  45
  46 gdb_test "rwatch global" \
  47     "Hardware read watchpoint .*: global" \
  48     "set hardware read watchpoint on global variable"
  49
  50 # The first read is on entry to the loop.
  51
  52 gdb_test "continue" \
  53     "read watchpoint .*: global.*.*Value = 0.*in main.*$srcfile:$read_line.*" \
  54     "read watchpoint triggers on first read"
  55
  56 # The second read happens on second loop iteration, after `global'
  57 # having been incremented.  On architectures where gdb has to emulate
  58 # read watchpoints with access watchpoints, this tests the
  59 # only-report-if-value-changed logic.  On targets that support real
  60 # read watchpoints, this tests that GDB ignores the watchpoint's old
  61 # value, knowing that some untrapped write could have changed it, and
  62 # so reports the read watchpoint unconditionally.
  63
  64 gdb_test "continue" \
  65     "read watchpoint .*: global.*.*Value = 1.*in main.*$srcfile:$read_line.*" \
  66     "read watchpoint triggers on read after value changed"
  67
  68 # The following tests check that when the user sets a write or access
  69 # watchpoint watching the same memory as a read watchpoint, GDB also
  70 # applies the only-report-if-value-changed logic even on targets that
  71 # support real read watchpoints.
  72
  73 # The program should be stopped at the read line.  Set a write
  74 # watchpoint (leaving the read watchpoint) and continue.  Only the
  75 # write watchpoint should be reported as triggering.
  76
  77 gdb_test "watch global" \
  78     "atchpoint .*: global" \
  79     "set write watchpoint on global variable"
  80
  81 gdb_test "continue" \
  82     "atchpoint .*: global.*Old value = 1.*New value = 2.*" \
  83     "write watchpoint triggers"
  84
  85 set exp ""
  86 set exp "${exp}2.*read watchpoint.*keep y.*global.*breakpoint already hit 2 times.*"
  87 set exp "${exp}3.*watchpoint.*keep y.*global.*breakpoint already hit 1 time.*"
  88 gdb_test "info watchpoints" \
  89     "$exp" \
  90     "only write watchpoint triggers when value changes"
  91
  92 # The program is now stopped at the write line.  Continuing should
  93 # stop at the read line, and only the read watchpoint should be
  94 # reported as triggering.
  95
  96 gdb_test "continue" \
  97     "read watchpoint .*: global.*Value = 2.*in main.*$srcfile:$read_line.*" \
  98     "read watchpoint triggers when value doesn't change, trapping reads and writes"
  99
 100 set exp ""
 101 set exp "${exp}2.*read watchpoint.*keep y.*global.*breakpoint already hit 3 times.*"
 102 set exp "${exp}3.*watchpoint.*keep y.*global.*breakpoint already hit 1 time.*"
 103 gdb_test "info watchpoints" \
 104     "$exp" \
 105     "only read watchpoint triggers when value doesn't change"