old-cross-binutils/gdb/testsuite/gdb.threads/wp-replication.exp
Yao Qi 4081c0f122 Simplify gdb.threads/wp-replication.exp on counting HW watchpoints
Nowadays, test gdb.threads/wp-replication.exp uses a while loop to
repeatedly insert HW watchpoint, resume and check no error message
coming out, in order to count HW watchpoints  There are some
drawbacks in this way,

 - the loop could be endless.  I think this is use to making trouble
   to S/390, since we had such comment

      # Some targets (like S/390) behave as though supporting
      # unlimited hardware watchpoints.  In this case we just take a
      # safe exit out of the loop.

   I hit this today too because a GDB internal error is triggered
   on "continue" in the loop, and $done is 0 invariantly, so the loop
   can't end.
 - the code counting hardware watchpoint is too complicated.  We can
   use "set breakpoint always-inserted on" to get the result of inserting
   HW watchpoint without resuming the inferior.  In this way,
   watch_count_done and empty_cycle in c file is no longer needed.

In this patch, I change to use "set breakpoint always-inserted on" trick,
and only iterate $NR_THREADS times, to count the HW watchpoint.  In this
way, the loop can't be endless, and GDB doesn't need to resume the inferior.

gdb/testsuite:

2015-10-30  Yao Qi  <yao.qi@linaro.org>

	* gdb.threads/wp-replication.c (watch_count_done): Remove.
	(empty_cycle): Remove.
	(main): Don't call empty_cycle.  Don't use watch_count_done.
	* gdb.threads/wp-replication.exp: Don't set breakpoint on
	empty_cycle.  Rewrite the code counting HW watchpoints.
2015-10-30 15:54:58 +00:00

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# This testcase is part of GDB, the GNU debugger.
# Copyright 2009-2015 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/>.
# Check that hardware watchpoints get correctly replicated to all
# existing threads when hardware watchpoints are created. This test
# creates one hardware watchpoint per thread until a maximum is
# reached. It originally addresses a deficiency seen on embedded
# powerpc targets with slotted hardware *point designs.
set NR_THREADS 10
set NR_TRIGGERS_PER_THREAD 2
# This test verifies that a hardware watchpoint gets replicated to
# every existing thread and is detected properly. This test is
# only meaningful on a target with hardware watchpoint support.
if {[skip_hw_watchpoint_tests]} {
return 0
}
standard_testfile
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "additional_flags=-DNR_THREADS=$NR_THREADS -DNR_TRIGGERS_PER_THREAD=$NR_TRIGGERS_PER_THREAD"]] != "" } {
return -1
}
clean_restart ${binfile}
# Force hardware watchpoints to be used.
gdb_test_no_output "set can-use-hw-watchpoints 1" ""
# Run to `main' where we begin our tests.
if ![runto_main] then {
fail "Failed to run to main"
return 0
}
# Set some default values.
set hwatch_count 0
set count 0
# Count the number of hardware watchpoints available on
# this target.
# So we get an immediate warning/error if the target doesn't support a
# hardware watchpoint or run out of hardware resource.
gdb_test_no_output "set breakpoint always-inserted on"
while { $count < $NR_THREADS } {
# Some targets do resource counting as we insert watchpoints.
# Such targets won't cause a watchpoint insertion failure, but
# will switch to software watchpoints silently. We check for
# both cases here.
gdb_test_multiple "watch watched_data\[$hwatch_count\]" \
"watch watched_data\[$hwatch_count\]" {
-re ".*Could not insert hardware watchpoint.*$gdb_prompt $" {
# End the loop.
set count $NR_THREADS
}
-re "Hardware watchpoint .*$gdb_prompt $" {
incr hwatch_count
}
-re "Watchpoint .*$gdb_prompt $" {
# End the loop.
set count $NR_THREADS
}
}
incr count
}
gdb_test_no_output "set breakpoint always-inserted off"
# Target cannot insert hardware watchpoints. It should have reported
# (through board settings) that it did not support them in the first place.
# Just exit.
if { $hwatch_count == 0} {
fail "No hardware watchpoints available"
return 0
}
# Set the testcase's internal variable indicating the number of
# hardware watchpoints the target supports.
gdb_test_no_output "set var hw_watch_count=${hwatch_count}" \
"set var hw_watch_count=${hwatch_count}"
# At this point, we know how many hardware watchpoints
# the target supports. Use that to do further testing.
delete_breakpoints
# Prepare to create all the threads.
gdb_test "break thread_started" \
"Breakpoint \[0-9\]+ at .*: file .*${srcfile}, line .*" \
"Breakpoint on thread_started"
# Move all threads to where they're supposed to be for testing.
for { set i 0 } { $i < $NR_THREADS } { incr i } {
# We want to set the maximum number of hardware watchpoints
# and make sure the target can handle that without an error.
# That will show us the watchpoints got replicated to all the
# threads correctly, and that no new watchpoints got created
# in the background for a specific thread.
if {$i < $hwatch_count} {
gdb_test "watch watched_data\[$i\]" \
"Hardware watchpoint .*" \
"watch watched_data\[$i\]"
} else {
verbose -log "Not setting watchpoint for watched_data\[$i\]\n"
}
gdb_test continue "Continuing\\..*Breakpoint \[0-9\]+, thread_started \\(\\) at .*$srcfile.*" \
"Thread $i hit breakpoint at thread_started"
}
# Let the threads run and change the watched data, leading
# to watchpoint triggers.
gdb_test_no_output "set var test_ready=1" \
"set var test_ready=1"
# Set the number of expected watchpoint triggers.
set TRIGGERS [expr "$NR_THREADS * $hwatch_count * $NR_TRIGGERS_PER_THREAD"]
# Move the threads and hit the watchpoints TRIGGERS times.
for { set i 1 } { $i <= $TRIGGERS } { incr i } {
gdb_test continue "Continuing\\..*Hardware watchpoint \[0-9\]+: watched_data\[\[0-9\]+\].*Old value = \[0-9\]+.*New value = \[0-9\]+.*thread_function \\(arg=$hex\\) at .*$srcfile.*" \
"Continue to watchpoint trigger $i out of ${TRIGGERS} on watched_data"
}