gdb/testsuite/gdb.base/recurse.exp

   1 # Copyright 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2007, 2008, 2009, 2010
   2 # Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 # This file was written by Jeff Law. (law@cs.utah.edu)
  18
  19 if $tracelevel then {
  20     strace $tracelevel
  21 }
  22
  23
  24 set testfile "recurse"
  25 set srcfile ${testfile}.c
  26 set binfile ${objdir}/${subdir}/${testfile}
  27 if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  28      untested recurse.exp
  29      return -1
  30 }
  31
  32 # Start with a fresh gdb.
  33
  34 gdb_exit
  35 gdb_start
  36 gdb_reinitialize_dir $srcdir/$subdir
  37 gdb_load ${binfile}
  38
  39 proc recurse_tests {} {
  40
  41     # Disable hardware watchpoints if necessary.
  42     if [target_info exists gdb,no_hardware_watchpoints] {
  43         gdb_test_no_output "set can-use-hw-watchpoints 0" ""
  44     }
  45
  46     if [runto recurse] then {
  47         # First we need to step over the assignment of b, so it has a known
  48         # value.
  49         gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in first instance"
  50         gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
  51             "set first instance watchpoint"
  52
  53         # Continue until initial set of b.
  54         if [gdb_test "continue" \
  55             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 10.*" \
  56             "continue to first instance watchpoint, first time"] then {
  57             gdb_suppress_tests;
  58         }
  59
  60         # Continue inward for a few iterations
  61         gdb_test "continue" "Breakpoint.* recurse \\(a=9\\).*" \
  62             "continue to recurse (a = 9)"
  63         gdb_test "continue" "Breakpoint.* recurse \\(a=8\\).*" \
  64             "continue to recurse (a = 8)"
  65         gdb_test "continue" "Breakpoint.* recurse \\(a=7\\).*" \
  66             "continue to recurse (a = 7)"
  67         gdb_test "continue" "Breakpoint.* recurse \\(a=6\\).*" \
  68             "continue to recurse (a = 6)"
  69         gdb_test "continue" "Breakpoint.* recurse \\(a=5\\).*" \
  70             "continue to recurse (a = 5)"
  71
  72         # Put a watchpoint on another instance of b
  73         # First we need to step over the assignment of b, so it has a known
  74         # value.
  75         gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in second instance"
  76         gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
  77             "set second instance watchpoint"
  78
  79         # Continue until initial set of b (second instance).
  80         if [gdb_test "continue" \
  81             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 5.*"\
  82             "continue to second instance watchpoint, first time"] then {
  83         gdb_suppress_tests;
  84         }
  85
  86         # Continue inward for a few iterations
  87         gdb_test "continue" "Breakpoint.* recurse \\(a=4\\).*" \
  88             "continue to recurse (a = 4)"
  89         gdb_test "continue" "Breakpoint.* recurse \\(a=3\\).*" \
  90             "continue to recurse (a = 3)"
  91         gdb_test "continue" "Breakpoint.* recurse \\(a=2\\).*" \
  92             "continue to recurse (a = 2)"
  93         gdb_test "continue" "Breakpoint.* recurse \\(a=1\\).*" \
  94             "continue to recurse (a = 1)"
  95
  96         # Continue until second set of b (second instance).
  97         if [gdb_test "continue" \
  98             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 5.*New value = 120.*return.*" \
  99             "continue to second instance watchpoint, second time"] then {
 100             gdb_suppress_tests;
 101         }
 102
 103         # Continue again.  We should have a watchpoint go out of scope now
 104         if [gdb_test "continue" \
 105             "Continuing.*\[Ww\]atchpoint.*deleted.*recurse \\(a=6\\) .*" \
 106             "second instance watchpoint deleted when leaving scope"] then {
 107             gdb_suppress_tests;
 108         }
 109
 110         # Continue until second set of b (first instance).
 111         # 24320 is allowed as the final value for b as that's the value
 112         # b would have on systems with 16bit integers.
 113         #
 114         # We could fix the test program to deal with this too.
 115         if [gdb_test "continue" \
 116             "Continuing.*\[Ww\]atchpoint.*b.*Old value = 10.*New value = \(3628800|24320\).*return.*" \
 117             "continue to first instance watchpoint, second time"] then {
 118             gdb_suppress_tests
 119         }
 120
 121         # Continue again.  We should have a watchpoint go out of scope now.
 122         #
 123         # The former version expected the test to return to main().
 124         # Now it expects the test to return to main or to stop in the
 125         # function's epilogue.
 126         #
 127         # The problem is that gdb needs to (but doesn't) understand
 128         # function epilogues in the same way as for prologues.
 129         #
 130         # If there is no hardware watchpoint (such as a x86 debug register),
 131         # then watchpoints are done "the hard way" by single-stepping the
 132         # target until the value of the watched variable changes.  If you
 133         # are single-stepping, you will eventually step into an epilogue.
 134         # When you do that, the "top" stack frame may become partially
 135         # deconstructed (as when you pop the frame pointer, for instance),
 136         # and from that point on, GDB can no longer make sense of the stack.
 137         #
 138         # A test which stops in the epilogue is trying to determine when GDB
 139         # leaves the stack frame in which the watchpoint was created.  It does
 140         # this basically by watching for the frame pointer to change.  When
 141         # the frame pointer changes, the test expects to be back in main, but
 142         # instead it is still in the epilogue of the callee.
 143         if [gdb_test "continue" \
 144             "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \
 145             "first instance watchpoint deleted when leaving scope"] then {
 146             gdb_suppress_tests;
 147         }
 148     }
 149     gdb_stop_suppressing_tests;
 150 }
 151
 152 # Preserve the old timeout, and set a new one that should be
 153 # sufficient to avoid timing out during this test.
 154 set oldtimeout $timeout
 155 set timeout [expr "$timeout + 60"]
 156 verbose "Timeout is now $timeout seconds" 2
 157
 158 recurse_tests
 159
 160 # Restore the preserved old timeout value.
 161 set timeout $oldtimeout
 162 verbose "Timeout is now $timeout seconds" 2
 163