# Copyright 1998-2020 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/>.
load_lib "trace-support.exp"
standard_testfile
if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug nowarnings nopie}]} {
return -1
}
# Tests:
# 1) Calculate the size taken by one trace frame.
# 2) Set up a trace experiment that will collect approximately 10 frames,
# requiring more than 512 but less than 1024 bytes of cache buffer.
# (most targets should have at least 1024 bytes of cache buffer!)
# Run and confirm that it collects all 10 frames.
# 3) Artificially limit the trace buffer to 4x + a bytes. Here x is the size
# of single trace frame and a is a small constant. Rerun the
# experiment. Confirm that the frame for the first tracepoint is collected,
# but frames for the last several tracepoints are not.
# 4) Set trace buffer to circular mode, with the buffer size as in
# step 3 above. Rerun the experiment. Confirm that the frame for the last
# tracepoint is collected but not for the first one.
#
# Set a tracepoint on given func. The tracepoint is set at entry
# address and not 'after prologue' address because we use
# 'tfind pc func' to find the corresponding trace frame afterwards,
# and that looks for entry address.
proc set_a_tracepoint { func } {
gdb_test "trace \*$func" "Tracepoint \[0-9\]+ at .*" \
"set tracepoint at $func"
gdb_trace_setactions "set actions for $func" "" "collect testload" "^$"
}
# Sets the tracepoints from func0 to func9 using set_a_tracepoint.
proc setup_tracepoints { } {
gdb_delete_tracepoints
set_a_tracepoint func0
set_a_tracepoint func1
set_a_tracepoint func2
set_a_tracepoint func3
set_a_tracepoint func4
set_a_tracepoint func5
set_a_tracepoint func6
set_a_tracepoint func7
set_a_tracepoint func8
set_a_tracepoint func9
}
# Start the trace, run to end and then stop the trace.
proc run_trace_experiment { } {
global decimal
setup_tracepoints
gdb_breakpoint "end" qualified
gdb_test "tstart" "\[\r\n\]*" "start trace experiment"
gdb_test "continue" "Continuing.*Breakpoint \[0-9\]+, end.*" \
"run to end"
gdb_test "tstop" "\[\r\n\]*" "stop trace experiment"
}
if { ![runto_main] } {
fail "can't run to main to check for trace support"
return -1
}
if { ![gdb_target_supports_trace] } {
unsupported "target does not support trace"
return 1
}
set test "set circular-trace-buffer on"
gdb_test_multiple "set circular-trace-buffer on" $test {
-re ".*Target does not support this command.*$gdb_prompt $" {
unsupported "target does not support circular trace buffer"
return 1
}
-re "$gdb_prompt $" {
pass $test
}
}
set circular_supported -1
set test "check whether circular buffer is supported"
gdb_test_multiple "tstatus" $test {
-re ".*Trace buffer is circular.*$gdb_prompt $" {
set circular_supported 1
pass $test
}
-re "$gdb_prompt $" {
pass $test
}
}
if { $circular_supported < 0 } {
unsupported "target does not support circular trace buffer"
return 1
}
gdb_test "show circular-trace-buffer" \
"Target's use of circular trace buffer is on." \
"show circular-trace-buffer (on)"
# Check if changing the trace buffer size is supported. This step is
# repeated twice. This helps in case the trace buffer size is 100.
set test_size 100
set test "change buffer size to $test_size"
gdb_test_multiple "set trace-buffer-size $test_size" $test {
-re ".*Target does not support this command.*$gdb_prompt $" {
unsupported "target does not support changing trace buffer size"
return 1
}
-re "$gdb_prompt $" {
pass $test
}
}
set test "check whether setting trace buffer size is supported"
gdb_test_multiple "tstatus" $test {
-re ".*Trace buffer has ($decimal) bytes of ($decimal) bytes free.*$gdb_prompt $" {
set total_size $expect_out(2,string)
if { $test_size != $total_size } {
unsupported "target does not support changing trace buffer size"
return 1
}
pass $test
}
}
set test_size 400
gdb_test_no_output "set trace-buffer-size $test_size" \
"change buffer size to $test_size"
gdb_test_multiple "tstatus" $test {
-re ".*Trace buffer has ($decimal) bytes of ($decimal) bytes free.*$gdb_prompt $" {
set total_size $expect_out(2,string)
if { $test_size != $total_size } {
unsupported "target does not support changing trace buffer size"
return 1
}
pass $test
}
}
gdb_test_no_output "set circular-trace-buffer off" \
"set circular-trace-buffer off"
gdb_test "show circular-trace-buffer" \
"Target's use of circular trace buffer is off." \
"show circular-trace-buffer (off)"
set total_size -1
set free_size -1
set frame_size -1
# Determine the size used by a single frame. Set a single tracepoint,
# run and then check the total and free size using the tstatus command.
# Then subtracting free from total gives us the size of a frame.
with_test_prefix "frame size" {
set_a_tracepoint func0
gdb_breakpoint "end" qualified
gdb_test "tstart" "\[\r\n\]*" "start trace"
gdb_test "continue" "Continuing.*Breakpoint \[0-9\]+, end.*" \
"run to end"
gdb_test "tstop" "\[\r\n\]*" "stop trace"
set test "get buffer size"
gdb_test_multiple "tstatus" $test {
-re ".*Trace buffer has ($decimal) bytes of ($decimal) bytes free.*$gdb_prompt $" {
set free_size $expect_out(1,string)
set total_size $expect_out(2,string)
pass $test
}
}
# Check that we get the total_size and free_size.
if { $total_size < 0 } {
return 1
}
if { $free_size < 0 } {
return 1
}
}
# Calculate the size of a single frame.
set frame_size "($total_size - $free_size)"
with_test_prefix "normal buffer" {
clean_restart $testfile
if { ![runto_main] } {
fail "can't run to main"
return 1
}
run_trace_experiment
# Check that the first frame is actually at func0.
gdb_test "tfind start" ".*#0 func0 .*" \
"first frame is at func0"
gdb_test "tfind pc func9" \
".*Found trace frame $decimal, tracepoint $decimal\r\n#0 func9 .*" \
"find frame for func9"
}
# Shrink the trace buffer so that it will not hold
# all ten trace frames. Verify that the frame for func0 is still
# collected, but the frame for func9 is not.
set buffer_size "((4 * $frame_size) + 10)"
with_test_prefix "small buffer" {
clean_restart $testfile
if { ![runto_main] } {
fail "can't run to main"
return 1
}
gdb_test_no_output "set trace-buffer-size $buffer_size" \
"shrink the target trace buffer"
run_trace_experiment
gdb_test "tfind start" ".*#0 func0 .*" \
"first frame is at func0"
gdb_test "tfind pc func9" ".* failed to find .*" \
"find frame for func9"
}
# Finally, make the buffer circular. Now when it runs out of
# space, it should wrap around and overwrite the earliest frames.
# This means that:
# 1) the first frame will be overwritten and therefore unavailable.
# 2) the earliest frame in the buffer will not be for func0.
# 3) the frame for func9 will be available (unlike "small buffer" case).
with_test_prefix "circular buffer" {
clean_restart $testfile
if { ![runto_main] } {
fail "can't run to main"
return 1
}
gdb_test_no_output "set trace-buffer-size $buffer_size" \
"shrink the target trace buffer"
gdb_test_no_output "set circular-trace-buffer on" \
"make the target trace buffer circular"
run_trace_experiment
gdb_test "tstatus" \
".*Buffer contains $decimal trace frames \\(of $decimal created total\\).*Trace buffer is circular.*" \
"trace buffer is circular"
# The first frame should not be at func0.
gdb_test "tfind start" ".*#0 func\[1-9\] .*" \
"first frame is NOT at func0"
gdb_test \
"tfind pc func9" \
".*Found trace frame $decimal, tracepoint $decimal\r\n#0 func9 .*" \
"find frame for func9"
}