gdb/testsuite/gdb.threads/wp-replication.exp

# This testcase is part of GDB, the GNU debugger.

# Copyright 2009-2021 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/>.

# 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 {
    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 .*"
    } 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"
}