gdb/testsuite/gdb.base/recurse.exp

   1 # Copyright 1992-2014 Free Software Foundation, Inc.
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 # This file was written by Jeff Law. (law@cs.utah.edu)
  17
  18
  19 standard_testfile
  20
  21 if {[prepare_for_testing $testfile.exp $testfile $srcfile debug]} {
  22     untested $testfile.exp
  23     return -1
  24 }
  25
  26 proc recurse_tests {} {
  27
  28     # Disable hardware watchpoints if necessary.
  29     if [target_info exists gdb,no_hardware_watchpoints] {
  30         gdb_test_no_output "set can-use-hw-watchpoints 0" ""
  31     }
  32
  33     if [runto recurse] then {
  34         # First we need to step over the assignment of b, so it has a known
  35         # value.
  36         gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in first instance"
  37         gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
  38             "set first instance watchpoint"
  39
  40         # Continue until initial set of b.
  41         if [gdb_test "continue" \
  42             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 10.*" \
  43             "continue to first instance watchpoint, first time"] then {
  44             gdb_suppress_tests
  45         }
  46
  47         # Continue inward for a few iterations
  48         gdb_test "continue" "Breakpoint.* recurse \\(a=9\\).*" \
  49             "continue to recurse (a = 9)"
  50         gdb_test "continue" "Breakpoint.* recurse \\(a=8\\).*" \
  51             "continue to recurse (a = 8)"
  52         gdb_test "continue" "Breakpoint.* recurse \\(a=7\\).*" \
  53             "continue to recurse (a = 7)"
  54         gdb_test "continue" "Breakpoint.* recurse \\(a=6\\).*" \
  55             "continue to recurse (a = 6)"
  56         gdb_test "continue" "Breakpoint.* recurse \\(a=5\\).*" \
  57             "continue to recurse (a = 5)"
  58
  59         # Put a watchpoint on another instance of b
  60         # First we need to step over the assignment of b, so it has a known
  61         # value.
  62         gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in second instance"
  63         gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \
  64             "set second instance watchpoint"
  65
  66         # Continue until initial set of b (second instance).
  67         if [gdb_test "continue" \
  68             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 5.*"\
  69             "continue to second instance watchpoint, first time"] then {
  70         gdb_suppress_tests
  71         }
  72
  73         # Continue inward for a few iterations
  74         gdb_test "continue" "Breakpoint.* recurse \\(a=4\\).*" \
  75             "continue to recurse (a = 4)"
  76         gdb_test "continue" "Breakpoint.* recurse \\(a=3\\).*" \
  77             "continue to recurse (a = 3)"
  78         gdb_test "continue" "Breakpoint.* recurse \\(a=2\\).*" \
  79             "continue to recurse (a = 2)"
  80         gdb_test "continue" "Breakpoint.* recurse \\(a=1\\).*" \
  81             "continue to recurse (a = 1)"
  82
  83         # Continue until second set of b (second instance).
  84         if [gdb_test "continue" \
  85             "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 5.*New value = 120.*return.*" \
  86             "continue to second instance watchpoint, second time"] then {
  87             gdb_suppress_tests
  88         }
  89
  90         # Continue again.  We should have a watchpoint go out of scope now
  91         if [gdb_test "continue" \
  92             "Continuing.*\[Ww\]atchpoint.*deleted.*recurse \\(a=6\\) .*" \
  93             "second instance watchpoint deleted when leaving scope"] then {
  94             gdb_suppress_tests
  95         }
  96
  97         # Continue until second set of b (first instance).
  98         # 24320 is allowed as the final value for b as that's the value
  99         # b would have on systems with 16bit integers.
 100         #
 101         # We could fix the test program to deal with this too.
 102         if [gdb_test "continue" \
 103             "Continuing.*\[Ww\]atchpoint.*b.*Old value = 10.*New value = \(3628800|24320\).*return.*" \
 104             "continue to first instance watchpoint, second time"] then {
 105             gdb_suppress_tests
 106         }
 107
 108         # Continue again.  We should have a watchpoint go out of scope now.
 109         #
 110         # The former version expected the test to return to main().
 111         # Now it expects the test to return to main or to stop in the
 112         # function's epilogue.
 113         #
 114         # The problem is that gdb needs to (but doesn't) understand
 115         # function epilogues in the same way as for prologues.
 116         #
 117         # If there is no hardware watchpoint (such as a x86 debug register),
 118         # then watchpoints are done "the hard way" by single-stepping the
 119         # target until the value of the watched variable changes.  If you
 120         # are single-stepping, you will eventually step into an epilogue.
 121         # When you do that, the "top" stack frame may become partially
 122         # deconstructed (as when you pop the frame pointer, for instance),
 123         # and from that point on, GDB can no longer make sense of the stack.
 124         #
 125         # A test which stops in the epilogue is trying to determine when GDB
 126         # leaves the stack frame in which the watchpoint was created.  It does
 127         # this basically by watching for the frame pointer to change.  When
 128         # the frame pointer changes, the test expects to be back in main, but
 129         # instead it is still in the epilogue of the callee.
 130         if [gdb_test "continue" \
 131             "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \
 132             "first instance watchpoint deleted when leaving scope"] then {
 133             gdb_suppress_tests
 134         }
 135     }
 136     gdb_stop_suppressing_tests
 137 }
 138
 139 # Preserve the old timeout, and set a new one that should be
 140 # sufficient to avoid timing out during this test.
 141 set oldtimeout $timeout
 142 set timeout [expr "$timeout + 60"]
 143 verbose "Timeout is now $timeout seconds" 2
 144
 145 recurse_tests
 146
 147 # Restore the preserved old timeout value.
 148 set timeout $oldtimeout
 149 verbose "Timeout is now $timeout seconds" 2
 150