gdb/testsuite/gdb.base/recurse.exp

   1 # Copyright 1992, 1994-1997, 1999-2000, 2007-2012 Free Software
   2 # 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
  20 set testfile "recurse"
  21 set srcfile ${testfile}.c
  22 set binfile ${objdir}/${subdir}/${testfile}
  23 if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  24      untested recurse.exp
  25      return -1
  26 }
  27
  28 # Start with a fresh gdb.
  29
  30 gdb_exit
  31 gdb_start
  32 gdb_reinitialize_dir $srcdir/$subdir
  33 gdb_load ${binfile}
  34
  35 proc recurse_tests {} {
  36
  37     # Disable hardware watchpoints if necessary.
  38     if [target_info exists gdb,no_hardware_watchpoints] {
  39         gdb_test_no_output "set can-use-hw-watchpoints 0" ""
  40     }
  41
  42     if [runto recurse] then {
  43         # First we need to step over the assignment of b, so it has a known
  44         # value.
  45         gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in first instance"
  46         gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
  47             "set first instance watchpoint"
  48
  49         # Continue until initial set of b.
  50         if [gdb_test "continue" \
  51             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 10.*" \
  52             "continue to first instance watchpoint, first time"] then {
  53             gdb_suppress_tests;
  54         }
  55
  56         # Continue inward for a few iterations
  57         gdb_test "continue" "Breakpoint.* recurse \\(a=9\\).*" \
  58             "continue to recurse (a = 9)"
  59         gdb_test "continue" "Breakpoint.* recurse \\(a=8\\).*" \
  60             "continue to recurse (a = 8)"
  61         gdb_test "continue" "Breakpoint.* recurse \\(a=7\\).*" \
  62             "continue to recurse (a = 7)"
  63         gdb_test "continue" "Breakpoint.* recurse \\(a=6\\).*" \
  64             "continue to recurse (a = 6)"
  65         gdb_test "continue" "Breakpoint.* recurse \\(a=5\\).*" \
  66             "continue to recurse (a = 5)"
  67
  68         # Put a watchpoint on another instance of b
  69         # First we need to step over the assignment of b, so it has a known
  70         # value.
  71         gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in second instance"
  72         gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
  73             "set second instance watchpoint"
  74
  75         # Continue until initial set of b (second instance).
  76         if [gdb_test "continue" \
  77             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 5.*"\
  78             "continue to second instance watchpoint, first time"] then {
  79         gdb_suppress_tests;
  80         }
  81
  82         # Continue inward for a few iterations
  83         gdb_test "continue" "Breakpoint.* recurse \\(a=4\\).*" \
  84             "continue to recurse (a = 4)"
  85         gdb_test "continue" "Breakpoint.* recurse \\(a=3\\).*" \
  86             "continue to recurse (a = 3)"
  87         gdb_test "continue" "Breakpoint.* recurse \\(a=2\\).*" \
  88             "continue to recurse (a = 2)"
  89         gdb_test "continue" "Breakpoint.* recurse \\(a=1\\).*" \
  90             "continue to recurse (a = 1)"
  91
  92         # Continue until second set of b (second instance).
  93         if [gdb_test "continue" \
  94             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 5.*New value = 120.*return.*" \
  95             "continue to second instance watchpoint, second time"] then {
  96             gdb_suppress_tests;
  97         }
  98
  99         # Continue again.  We should have a watchpoint go out of scope now
 100         if [gdb_test "continue" \
 101             "Continuing.*\[Ww\]atchpoint.*deleted.*recurse \\(a=6\\) .*" \
 102             "second instance watchpoint deleted when leaving scope"] then {
 103             gdb_suppress_tests;
 104         }
 105
 106         # Continue until second set of b (first instance).
 107         # 24320 is allowed as the final value for b as that's the value
 108         # b would have on systems with 16bit integers.
 109         #
 110         # We could fix the test program to deal with this too.
 111         if [gdb_test "continue" \
 112             "Continuing.*\[Ww\]atchpoint.*b.*Old value = 10.*New value = \(3628800|24320\).*return.*" \
 113             "continue to first instance watchpoint, second time"] then {
 114             gdb_suppress_tests
 115         }
 116
 117         # Continue again.  We should have a watchpoint go out of scope now.
 118         #
 119         # The former version expected the test to return to main().
 120         # Now it expects the test to return to main or to stop in the
 121         # function's epilogue.
 122         #
 123         # The problem is that gdb needs to (but doesn't) understand
 124         # function epilogues in the same way as for prologues.
 125         #
 126         # If there is no hardware watchpoint (such as a x86 debug register),
 127         # then watchpoints are done "the hard way" by single-stepping the
 128         # target until the value of the watched variable changes.  If you
 129         # are single-stepping, you will eventually step into an epilogue.
 130         # When you do that, the "top" stack frame may become partially
 131         # deconstructed (as when you pop the frame pointer, for instance),
 132         # and from that point on, GDB can no longer make sense of the stack.
 133         #
 134         # A test which stops in the epilogue is trying to determine when GDB
 135         # leaves the stack frame in which the watchpoint was created.  It does
 136         # this basically by watching for the frame pointer to change.  When
 137         # the frame pointer changes, the test expects to be back in main, but
 138         # instead it is still in the epilogue of the callee.
 139         if [gdb_test "continue" \
 140             "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \
 141             "first instance watchpoint deleted when leaving scope"] then {
 142             gdb_suppress_tests;
 143         }
 144     }
 145     gdb_stop_suppressing_tests;
 146 }
 147
 148 # Preserve the old timeout, and set a new one that should be
 149 # sufficient to avoid timing out during this test.
 150 set oldtimeout $timeout
 151 set timeout [expr "$timeout + 60"]
 152 verbose "Timeout is now $timeout seconds" 2
 153
 154 recurse_tests
 155
 156 # Restore the preserved old timeout value.
 157 set timeout $oldtimeout
 158 verbose "Timeout is now $timeout seconds" 2
 159