binutils-gdb/gdb/testsuite/gdb.threads/signal-while-stepping-over-bp-other-thread.exp
Simon Marchi 3c55062cc1 gdb/testsuite: fix race in gdb.threads/signal-while-stepping-over-bp-other-thread.exp
Commit 3ec3145c5d ("gdb: introduce scoped debug prints") updated some
tests using "set debug infrun" to handle the fact that a debug print is
now shown after the prompt, after an inferior stop.  The same issue
happens in gdb.threads/signal-while-stepping-over-bp-other-thread.exp.
If I run it in a loop, it eventually fails like these other tests.

The problem is that the testsuite expects to see $gdb_prompt followed by
the end of the buffer.  It happens that expect reads $gdb_prompt and the
debug print at the same time, in which case the regexp never matches and
we get a timeout.

The fix is the same as was done in 3ec3145c5d, make the testsuite
believe that the prompt is the standard GDB prompt followed by that
debug print.

Since that test uses gdb_test_sequence, and the expected prompt is in
gdb_test_sequence, add a -prompt switch to gdb_test_sequence to override
the prompt used for that call.

gdb/testsuite/ChangeLog:

	* lib/gdb.exp (gdb_test_sequence): Accept -prompt switch.
	* gdb.threads/signal-while-stepping-over-bp-other-thread.exp:
	Pass prompt containing debug print to gdb_test_sequence.

Change-Id: I33161c53ddab45cdfeadfd50b964f8dc3caa9729
2021-01-06 10:53:22 -05:00

119 lines
3.8 KiB
Plaintext

# Copyright (C) 2011-2021 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/>.
# Test that GDB doesn't inadvertently resume the stepped thread when a
# signal arrives while stepping over the breakpoint that last caused a
# stop, when the thread that hit that breakpoint is not the stepped
# thread.
# Test relies on checking gdb debug output. Do not run if gdb debug is
# enabled as any debug will be redirected to the log.
if [gdb_debug_enabled] {
continue
}
standard_testfile
set executable ${testfile}
if [target_info exists gdb,nosignals] {
verbose "Skipping ${testfile}.exp because of nosignals."
return -1
}
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
executable [list debug "incdir=${objdir}"]] != "" } {
return -1
}
proc get_value {var test} {
global expect_out
global gdb_prompt
global decimal
set value -1
gdb_test_multiple "print $var" "$test" {
-re ".*= ($decimal).*\r\n$gdb_prompt $" {
set value $expect_out(1,string)
pass "$test"
}
}
return ${value}
}
# Start with a fresh gdb.
clean_restart $executable
if ![runto_main] {
return -1
}
gdb_breakpoint [gdb_get_line_number "set wait-thread-2 breakpoint here"]
gdb_continue_to_breakpoint "run to wait-thread-2 breakpoint"
gdb_test "info threads" "" "info threads with thread 2"
gdb_breakpoint [gdb_get_line_number "set wait-thread-3 breakpoint here"]
gdb_continue_to_breakpoint "run to breakpoint"
gdb_test "info threads" "" "info threads with thread 3"
gdb_test "set scheduler-locking on"
gdb_breakpoint [gdb_get_line_number "set breakpoint child_two here"]
gdb_breakpoint [gdb_get_line_number "set breakpoint child_one here"]
gdb_test "thread 3" "" "switch to thread 3 to run to its breakpoint"
gdb_continue_to_breakpoint "run to breakpoint in thread 3"
gdb_test "thread 2" "" "switch to thread 2 to run to its breakpoint"
gdb_continue_to_breakpoint "run to breakpoint in thread 2"
delete_breakpoints
gdb_test "b *\$pc" "" "set breakpoint to be stepped over"
# Make sure the first loop breaks without hitting the breakpoint
# again.
gdb_test "p *myp = 0" " = 0" "force loop break in thread 2"
# We want "print" to make sure the target reports the signal to the
# core.
gdb_test "handle SIGUSR1 print nostop pass" "" ""
gdb_test "thread 1" "" "switch to thread 1 to queue signal in thread 2"
gdb_test "next 2" "pthread_join .*" "queue signal in thread 2"
gdb_test "thread 3" "" "switch to thread 3 for stepping"
set my_number [get_value "my_number" "get my_number"]
set cnt_before [get_value "args\[$my_number\]" "get count before step"]
gdb_test "set scheduler-locking off"
# Make sure we're exercising the paths we want to.
gdb_test "set debug infrun 1"
set test "step"
gdb_test_sequence $test $test -prompt "$gdb_prompt \\\[infrun\\\] fetch_inferior_event: exit\r\n$" {
"need to step-over"
"resume_1: step=1,"
"signal arrived while stepping over breakpoint"
"stepped to a different line"
"callme"
}
set cnt_after [get_value "args\[$my_number\]" "get count after step"]
# Test that GDB doesn't inadvertently resume the stepped thread when a
# signal arrives while stepping over a breakpoint in another thread.
gdb_assert { $cnt_before + 1 == $cnt_after } "stepped thread under control"