1# Copyright 1992-2017 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 19standard_testfile 20 21if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} { 22 return -1 23} 24 25proc recurse_tests {} { 26 27 # Disable hardware watchpoints if necessary. 28 if [target_info exists gdb,no_hardware_watchpoints] { 29 gdb_test_no_output "set can-use-hw-watchpoints 0" "" 30 } 31 32 if [runto recurse] then { 33 # First we need to step over the assignment of b, so it has a known 34 # value. 35 gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in first instance" 36 gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \ 37 "set first instance watchpoint" 38 39 # Continue until initial set of b. 40 if [gdb_test "continue" \ 41 "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 10.*" \ 42 "continue to first instance watchpoint, first time"] then { 43 gdb_suppress_tests 44 } 45 46 # Continue inward for a few iterations 47 gdb_test "continue" "Breakpoint.* recurse \\(a=9\\).*" \ 48 "continue to recurse (a = 9)" 49 gdb_test "continue" "Breakpoint.* recurse \\(a=8\\).*" \ 50 "continue to recurse (a = 8)" 51 gdb_test "continue" "Breakpoint.* recurse \\(a=7\\).*" \ 52 "continue to recurse (a = 7)" 53 gdb_test "continue" "Breakpoint.* recurse \\(a=6\\).*" \ 54 "continue to recurse (a = 6)" 55 gdb_test "continue" "Breakpoint.* recurse \\(a=5\\).*" \ 56 "continue to recurse (a = 5)" 57 58 # Put a watchpoint on another instance of b 59 # First we need to step over the assignment of b, so it has a known 60 # value. 61 gdb_test "next" "if \\(a == 1\\)" "next over b = 0 in second instance" 62 gdb_test "watch b" ".*\[Ww\]atchpoint \[0-9]*: b" \ 63 "set second instance watchpoint" 64 65 # Continue until initial set of b (second instance). 66 if [gdb_test "continue" \ 67 "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 0.*New value = 5.*"\ 68 "continue to second instance watchpoint, first time"] then { 69 gdb_suppress_tests 70 } 71 72 # Continue inward for a few iterations 73 gdb_test "continue" "Breakpoint.* recurse \\(a=4\\).*" \ 74 "continue to recurse (a = 4)" 75 gdb_test "continue" "Breakpoint.* recurse \\(a=3\\).*" \ 76 "continue to recurse (a = 3)" 77 gdb_test "continue" "Breakpoint.* recurse \\(a=2\\).*" \ 78 "continue to recurse (a = 2)" 79 gdb_test "continue" "Breakpoint.* recurse \\(a=1\\).*" \ 80 "continue to recurse (a = 1)" 81 82 # Continue until second set of b (second instance). 83 if [gdb_test "continue" \ 84 "Continuing.*\[Ww\]atchpoint.*: b.*Old value = 5.*New value = 120.*return.*" \ 85 "continue to second instance watchpoint, second time"] then { 86 gdb_suppress_tests 87 } 88 89 # Continue again. We should have a watchpoint go out of scope now 90 if [gdb_test "continue" \ 91 "Continuing.*\[Ww\]atchpoint.*deleted.*recurse \\(a=6\\) .*" \ 92 "second instance watchpoint deleted when leaving scope"] then { 93 gdb_suppress_tests 94 } 95 96 # Continue until second set of b (first instance). 97 # 24320 is allowed as the final value for b as that's the value 98 # b would have on systems with 16bit integers. 99 # 100 # We could fix the test program to deal with this too. 101 if [gdb_test "continue" \ 102 "Continuing.*\[Ww\]atchpoint.*b.*Old value = 10.*New value = \(3628800|24320\).*return.*" \ 103 "continue to first instance watchpoint, second time"] then { 104 gdb_suppress_tests 105 } 106 107 # Continue again. We should have a watchpoint go out of scope now. 108 # 109 # The former version expected the test to return to main(). 110 # Now it expects the test to return to main or to stop in the 111 # function's epilogue. 112 # 113 # The problem is that gdb needs to (but doesn't) understand 114 # function epilogues in the same way as for prologues. 115 # 116 # If there is no hardware watchpoint (such as a x86 debug register), 117 # then watchpoints are done "the hard way" by single-stepping the 118 # target until the value of the watched variable changes. If you 119 # are single-stepping, you will eventually step into an epilogue. 120 # When you do that, the "top" stack frame may become partially 121 # deconstructed (as when you pop the frame pointer, for instance), 122 # and from that point on, GDB can no longer make sense of the stack. 123 # 124 # A test which stops in the epilogue is trying to determine when GDB 125 # leaves the stack frame in which the watchpoint was created. It does 126 # this basically by watching for the frame pointer to change. When 127 # the frame pointer changes, the test expects to be back in main, but 128 # instead it is still in the epilogue of the callee. 129 if [gdb_test "continue" \ 130 "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \ 131 "first instance watchpoint deleted when leaving scope"] then { 132 gdb_suppress_tests 133 } 134 } 135 gdb_stop_suppressing_tests 136} 137 138# Preserve the old timeout, and set a new one that should be 139# sufficient to avoid timing out during this test. 140set oldtimeout $timeout 141set timeout [expr "$timeout + 60"] 142verbose "Timeout is now $timeout seconds" 2 143 144recurse_tests 145 146# Restore the preserved old timeout value. 147set timeout $oldtimeout 148verbose "Timeout is now $timeout seconds" 2 149 150