old-cross-binutils/gdb/testsuite/gdb.base/sigstep.exp
Pedro Alves 1df4399f27 gdb.base/sigstep.exp: cleanup and make it easier to extend
Hacking on sigstep.exp, I found it harder to understand and extend
than ideal.

 - GDB is currently not restarted between the different
   tests/combinations in the file, and some parts of the tests' setup
   are done on the top level, and shared between tests.  It's not
   trivial to understand which breakpoints each test procedure expects
   to be set or not set.  And it's not trivial to disable parts of the
   test if you want quickly try out just a subset of the tests
   (running the whole file takes a bit).

 - Because GDB is currently not restarted between tests, if some test
   triggers a ptrace/kernel bug, the following tests may end up with
   cascading fails.  That makes it hard to add a test to cover a
   kernel bug that isn't fixed yet, with a xfail/kfail.  E.g,. note
   how with kernels with bug gdb/8744 (stepi over sigreturn syscall
   exits program) the test program exits, and nothing restarts it
   afterwards...

 - The manual test message prefix management gets a bit in the way.
   Nowadays, we have with_test_prefix which makes it simpler.

 - 'i' is used as parameter name in the various procedures, meaning
   'the command the test', which isn't as obvious as it could.

This commit addresses all that.

gdb/testsuite/
2014-10-28  Pedro Alves  <palves@redhat.com>

	* gdb.base/sigstep.exp: Use build_executable instead of
	prepare_for_testing.
	(top level): Move code that starts GDB, runs to main and creates a
	display to ...
	(restart): ... this new procedure.
	(top level): Move backtrace from signal handler test to ...
	(validate_backtrace): ... this new procedure.
	(advance, advancei): Rename parameter from 'i' to 'cmd'.  Use
	with_test_prefix.  Always restart GDB.
	(skip_to_handler): Rename parameter from 'i' to 'cmd'.  Use
	with_test_prefix.  Always restart GDB.  No need to delete
	breakpoints after the test.
	(test_skip_handler): Remove prefix parameter.
	(skip_over_handler, breakpoint_to_handler)
	(breakpoint_to_handler_entry, breakpoint_over_handler): Rename
	parameter from 'i' to 'cmd'.  Use with_test_prefix.  Always
	restart GDB.  No need to delete breakpoints after the test.
	(top level): Use foreach to call the test procedures with
	different commands.
2014-10-28 15:34:00 +00:00

440 lines
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# Copyright 2004-2014 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# The program sigstep.c creates a very simple backtrace containing one
# signal handler and signal trampoline. A flag is set and then the
# handler returns. This is repeated at infinitum.
# This test runs the program up to the signal handler, and then
# attempts to step/next out of the handler and back into main.
if [target_info exists gdb,nosignals] {
verbose "Skipping sigstep.exp because of nosignals."
continue
}
standard_testfile
if {[build_executable $testfile.exp $testfile $srcfile debug]} {
untested $testfile.exp
return -1
}
set clear_done [gdb_get_line_number {done = 0}]
set infinite_loop [gdb_get_line_number {while (!done)}]
# Restart GDB, set a display showing $PC, and run to main.
proc restart {} {
global binfile
clean_restart $binfile
gdb_test "display/i \$pc"
runto_main
}
# Pass all the alarms straight through (but verbosely)
# gdb_test "handle SIGALRM print pass nostop"
# gdb_test "handle SIGVTALRM print pass nostop"
# gdb_test "handle SIGPROF print pass nostop"
# Run to the signal handler, validate the backtrace.
proc validate_backtrace {} {
with_test_prefix "validate backtrace" {
restart
gdb_test "break handler"
gdb_test "continue" ".* handler .*" "continue to stepi handler"
gdb_test_sequence "bt" "backtrace for nexti" {
"\[\r\n\]+.0 \[^\r\n\]* handler "
"\[\r\n\]+.1 .signal handler called."
"\[\r\n\]+.2 \[^\r\n\]* main "
}
}
}
validate_backtrace
proc advance { cmd } {
global gdb_prompt inferior_exited_re
with_test_prefix "$cmd from handler" {
restart
gdb_test "break handler"
# Get us into the handler
gdb_test "continue" ".* handler .*" "continue to handler"
set test "leave handler"
gdb_test_multiple "$cmd" "${test}" {
-re "Could not insert single-step breakpoint.*$gdb_prompt $" {
setup_kfail gdb/8841 "sparc*-*-openbsd*"
fail "$test (could not insert single-step breakpoint)"
}
-re "done = 1;.*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "\} .. handler .*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "$inferior_exited_re normally.*${gdb_prompt} $" {
setup_kfail gdb/8744 powerpc-*-*bsd*
fail "$test (program exited)"
}
-re "(while ..done|done = 0).*${gdb_prompt} $" {
# After stepping out of a function /r signal-handler, GDB will
# advance the inferior until it is at the first instruction of
# a code-line. While typically things return to the middle of
# the "while..." (and hence GDB advances the inferior to the
# "return..." line) it is also possible for the return to land
# on the first instruction of "while...". Accept both cases.
pass "$test"
}
}
}
}
proc advancei { cmd } {
global gdb_prompt inferior_exited_re
with_test_prefix "$cmd from handleri" {
restart
# Get us into the handler.
gdb_test "break handler"
gdb_test "continue" ".* handler .*" "continue to handler"
set program_exited 0
set test "leave handler"
gdb_test_multiple "$cmd" "${test}" {
-re "Cannot insert breakpoint 0.*${gdb_prompt} $" {
# Some platforms use a special read-only page for signal
# trampolines. We can't set a breakpoint there, and we
# don't gracefully fall back to single-stepping.
setup_kfail gdb/8841 "i?86-*-linux*"
setup_kfail gdb/8841 "*-*-openbsd*"
fail "$test (could not set breakpoint)"
return
}
-re "Could not insert single-step breakpoint.*$gdb_prompt $" {
setup_kfail gdb/8841 "sparc*-*-openbsd*"
fail "$test (could not insert single-step breakpoint)"
}
-re "Breakpoint \[0-9\]*, handler .*${gdb_prompt} $" {
fail "$test (hit breakpoint again)"
}
-re "done = 1;.*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "\} .. handler .*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "signal handler called.*${gdb_prompt} $" {
pass "$test"
}
-re "main .*${gdb_prompt} $" {
fail "$test (in main)"
}
-re "$inferior_exited_re normally.*${gdb_prompt} $" {
fail "$test (program exited)"
set program_exited 1
}
-re "Make handler return now.*y or n. $" {
send_gdb "y\n"
exp_continue -continue_timer
}
}
set test "leave signal trampoline"
gdb_test_multiple "$cmd" "${test}" {
-re "while .*${gdb_prompt} $" {
pass "$test (in main)"
}
-re "signal handler called.*${gdb_prompt} $" {
send_gdb "$cmd\n"
exp_continue -continue_timer
}
-re "return .*${gdb_prompt} $" {
fail "$test (stepped)"
}
-re "Make .*frame return now.*y or n. $" {
send_gdb "y\n"
exp_continue -continue_timer
}
-re "$inferior_exited_re normally.*${gdb_prompt} $" {
kfail gdb/8744 "$test (program exited)"
set program_exited 1
}
-re "The program is not being run.*${gdb_prompt} $" {
if { $program_exited } {
# Previously kfailed with an exit
pass "$test (the program is not being run)"
} else {
fail "$test (the program is not being run)"
}
}
}
}
}
# Check that we can step/next our way out of a signal handler.
foreach cmd {"step" "next"} {
advance $cmd
}
foreach cmd {"stepi" "nexti" "finish" "return"} {
advancei $cmd
}
# Check that we can step/next our way into / over a signal handler.
# There are at least the following cases: breakpoint @pc VS breakpoint
# in handler VS step / next / continue.
# Try stepping when there's a signal pending, and a breakpoint at the
# handler. Should step into the signal handler.
proc skip_to_handler { cmd } {
global infinite_loop
with_test_prefix "$cmd to handler" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
# Advance to the infinite loop.
gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
# Make the signal pending.
sleep 1
# Insert the handler breakpoint.
gdb_test "break handler" ".*" "break handler"
# Step into the handler.
gdb_test "$cmd" " handler .*" "performing $cmd"
}
}
foreach cmd {"step" "next" "continue"} {
skip_to_handler $cmd
}
# Try stepping when there's a signal pending, and a breakpoint at the
# handler's entry-point. Should step into the signal handler stopping
# at the entry-point.
# Some systems (e.x., GNU/Linux as of 2004-08-30), when delivering a
# signal, resume the process at the first instruction of the signal
# handler and not the first instruction of the signal trampoline. The
# stack is constructed such that the signal handler still appears to
# have been called by the trampoline code. This test checks that it
# is possible to stop the inferior, even at that first instruction.
proc skip_to_handler_entry { cmd } {
global infinite_loop
with_test_prefix "$cmd to handler entry" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
# Advance to the infinite loop.
gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
# Make the signal pending.
sleep 1
# Insert / remove the handler breakpoint.
gdb_test "break *handler" ".*" "break handler"
gdb_test "$cmd" " handler .*" "performing $cmd"
}
}
foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
skip_to_handler_entry $cmd
}
# Get the address of where a single-step should land.
proc get_next_pc {test} {
global gdb_prompt
global hex
set next ""
gdb_test_multiple "x/2i \$pc" $test {
-re "$hex .*:\[^\r\n\]+\r\n\[ \]+($hex).*\.\r\n$gdb_prompt $" {
set next $expect_out(1,string)
pass $test
}
}
return $next
}
# Test that the command skipped over the handler.
proc test_skip_handler {cmd} {
if {$cmd == "stepi" || $cmd == "nexti"} {
set next_pc [get_next_pc "get next PC"]
gdb_test "$cmd" "dummy = 0.*" "performing $cmd"
gdb_test "p /x \$pc" " = $next_pc" "advanced"
} else {
gdb_test "$cmd" "done = 0.*" "performing $cmd"
}
}
# Try stepping when there's a signal pending but no breakpoints.
# Should skip the handler advancing to the next line.
proc skip_over_handler { cmd } {
global infinite_loop
global clear_done
with_test_prefix "$cmd over handler" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $clear_done" ".*" "break clear done"
# Advance to the infinite loop.
gdb_test "advance $infinite_loop" ".*" "advance to infinite loop"
# Make the signal pending.
sleep 1
test_skip_handler $cmd
}
}
foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
skip_over_handler $cmd
}
# Try stepping when there's a signal pending, a pre-existing
# breakpoint at the current instruction, and a breakpoint in the
# handler. Should advance to the signal handler.
proc breakpoint_to_handler { cmd } {
global infinite_loop
with_test_prefix "$cmd on breakpoint, to handler" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $infinite_loop" ".*" "break infinite loop"
gdb_test "break handler" ".*" "break handler"
# Continue to the infinite loop.
gdb_test "continue" "while ..done.*" "continue to infinite loop"
# Make the signal pending.
sleep 1
gdb_test "$cmd" " handler .*" "performing $cmd"
}
}
foreach cmd {"step" "next" "continue"} {
breakpoint_to_handler $cmd
}
# Try stepping when there's a signal pending, and a breakpoint at the
# handler's entry instruction and a breakpoint at the current
# instruction. Should step into the signal handler and breakpoint at
# that entry instruction.
# Some systems (e.x., GNU/Linux as of 2004-08-30), when delivering a
# signal, resume the process at the first instruction of the signal
# handler and not the first instruction of the signal trampoline. The
# stack is constructed such that the signal handler still appears to
# have been called by the trampoline code. This test checks that it
# is possible to stop the inferior, even at that first instruction.
proc breakpoint_to_handler_entry { cmd } {
global infinite_loop
with_test_prefix "$cmd on breakpoint, to handler entry" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $infinite_loop" ".*" "break infinite loop"
gdb_test "break *handler" ".*" "break handler"
# Continue to the infinite loop.
gdb_test "continue" "while ..done.*" "continue to infinite loop"
# Make the signal pending.
sleep 1
gdb_test "$cmd" " handler .*" "performing $cmd"
}
}
foreach cmd {"step" "next" "continue"} {
breakpoint_to_handler_entry $cmd
}
# Try stepping when there's a signal pending, and a pre-existing
# breakpoint at the current instruction, and no breakpoint in the
# handler. Should advance to the next line/instruction.
proc breakpoint_over_handler { cmd } {
global infinite_loop
global clear_done
with_test_prefix "$cmd on breakpoint, skip handler" {
restart
# Use the real-time itimer, as otherwize the process never gets
# enough time to expire the timer.
gdb_test_no_output "set itimer = itimer_real"
gdb_test "break $infinite_loop" ".*" "break infinite loop"
gdb_test "break $clear_done" ".*" "break clear done"
# Continue to the infinite loop
gdb_test "continue" "while ..done.*" "continue to infinite loop"
# Make the signal pending
sleep 1
test_skip_handler $cmd
}
}
foreach cmd {"stepi" "nexti" "step" "next" "continue"} {
breakpoint_over_handler $cmd
}