Files
Bruno Larsen 1f3e37e057 gdb/reverse: Fix stepping over recursive functions
Currently, when using GDB to do reverse debugging, if we try to use the
command "reverse next" to skip a recursive function, instead of skipping
all of the recursive calls and stopping in the previous line, we stop at
the second to last recursive call, and need to manually step backwards
until we leave the first call.  This is well documented in PR gdb/16678.

This bug happens because when GDB notices that a reverse step has
entered into a function, GDB will add a step_resume_breakpoint at the
start of the function, then single step out of the prologue once that
breakpoint is hit.  The problem was happening because GDB wouldn't give
that step_resume_breakpoint a frame-id, so the first time the breakpoint
was hit, the inferior would be stopped.  This is fixed by giving the
current frame-id to the breakpoint.

This commit also changes gdb.reverse/step-reverse.c to contain a
recursive function and attempt to both, skip it altogether, and to skip
the second call from inside the first call, as this setup broke a
previous version of the patch.
2022-10-21 12:49:26 +02:00

314 lines
7.8 KiB
Plaintext

# Copyright 2008-2022 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/>. */
# This file is part of the GDB testsuite. It tests reverse stepping.
# Lots of code borrowed from "step-test.exp".
#
# Test step and next in reverse
#
if ![supports_reverse] {
return
}
standard_testfile
if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
return -1
}
runto_main
if [supports_process_record] {
# Activate process record/replay
gdb_test_no_output "record" "turn on process record"
}
# plain vanilla step/next (no count)
gdb_test "next" ".*NEXT TEST 1.*" "next test 1"
gdb_test "step" ".*STEP TEST 1.*" "step test 1"
# step/next with count
gdb_test "next 2" ".*NEXT TEST 2.*" "next test 2"
gdb_test "step 3" ".*STEP TEST 2.*" "step test 2"
# Next through a recursive function call.
gdb_test "next 2" "NEXT OVER THIS CALL.*" "next over recursion"
# step over call
gdb_test "next" ".*STEP INTO THIS CALL.*" "next over call"
# step into call
gdb_test "step" ".*ARRIVED IN CALLEE.*" "step into call"
# finish out of call
set test_message "finish out of fn call"
gdb_test_multiple "finish" "$test_message" {
-re "FINISH TEST.*$gdb_prompt $" {
pass "$test_message"
}
-re "STEP INTO THIS CALL.*$gdb_prompt $" {
send_gdb "step\n"
exp_continue
}
}
# stepi over flat code (no calls)
set test_message "simple stepi"
gdb_test_multiple "stepi" "$test_message" {
-re "STEPI TEST.*$gdb_prompt $" {
pass "$test_message"
}
-re "FINISH TEST.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "NEXTI TEST.*$gdb_prompt $" {
fail "$test_message (too far)"
}
}
# stepi into a function call
set alphanum_re "\[a-zA-Z0-9\]"
set pic_thunk_re "__$alphanum_re*\\.get_pc_thunk\\.$alphanum_re* \\(\\)"
set test_message "stepi into function call"
gdb_test_multiple "stepi" "$test_message" {
-re "ARRIVED IN CALLEE.*$gdb_prompt $" {
pass "$test_message"
}
-re "NEXTI TEST.*$gdb_prompt $" {
fail "$test_message (too far)"
}
-re "RETURN FROM CALLEE.*$gdb_prompt $" {
fail "$test_message (too far)"
}
-re "ENTER CALLEE.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "STEPI TEST.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "$pic_thunk_re.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
}
# stepi thru return of a function call
set test_message "stepi back from function call"
gdb_test_multiple "stepi" "$test_message" {
-re -wrap "NEXTI TEST.*" {
pass "$test_message"
}
-re "ARRIVED IN CALLEE.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "RETURN FROM CALLEE.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "STEPI TEST.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "ENTER CALLEE.*$gdb_prompt $" {
fail "$test_message (too far)"
}
}
###
###
###
# Set reverse execution direction
gdb_test_no_output "set exec-dir reverse" "set reverse execution"
# stepi backward thru return and into a function
set stepi_location [gdb_get_line_number "ARRIVED IN CALLEE" "$srcfile"]
set test_message "reverse stepi thru function return"
gdb_test_multiple "stepi" "$test_message" {
-re "NEXTI TEST.*$gdb_prompt $" {
fail "$test_message (start statement)"
}
-re "RETURN FROM CALLEE.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "$hex\[ \t\]*$stepi_location.*ARRIVED IN CALLEE.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "ARRIVED IN CALLEE.*$gdb_prompt $" {
pass "$test_message"
}
-re "ENTER CALLEE.*$gdb_prompt $" {
fail "$test_message (too far)"
}
-re "STEPI TEST.*$gdb_prompt $" {
fail "$test_message (too far)"
}
}
# stepi backward out of a function call
set stepi_location [gdb_get_line_number "STEPI TEST" "$srcfile"]
set test_message "reverse stepi from a function call"
gdb_test_multiple "stepi" "$test_message" {
-re "ARRIVED IN CALLEE.*$gdb_prompt $" {
fail "$test_message (start statement)"
}
-re "ENTER CALLEE.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "$pic_thunk_re.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "${hex} in main .*:$stepi_location.*STEPI TEST.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "STEPI TEST.*$gdb_prompt $" {
pass "$test_message"
}
-re "STEP INTO THIS CALL.*$gdb_prompt $" {
fail "$test_message (too far)"
}
}
# stepi backward over flat code (no calls)
set stepi_location [gdb_get_line_number "FINISH TEST" "$srcfile"]
set test_message "simple reverse stepi"
gdb_test_multiple "stepi" "$test_message" {
-re "STEPI TEST.*$gdb_prompt $" {
fail "$test_message (start statement)"
}
-re "$hex\[ \t\]*$stepi_location.* FINISH TEST.*$gdb_prompt $" {
send_gdb "stepi\n"
exp_continue
}
-re "$stepi_location.* FINISH TEST.*$gdb_prompt $" {
pass "$test_message"
}
-re "STEP INTO THIS CALL.*$gdb_prompt $" {
fail "$test_message (too far)"
}
}
# step backward into function (thru return)
gdb_test "step" "(RETURN FROM CALLEE|ARRIVED IN CALLEE).*" \
"reverse step into fn call"
# step backward out of called function (thru call)
set test_message "reverse step out of called fn"
gdb_test_multiple "step" "$test_message" {
-re "STEP INTO THIS CALL.*.*$gdb_prompt $" {
pass "$test_message"
}
-re "ARRIVED IN CALLEE.*$gdb_prompt $" {
send_gdb "step\n"
exp_continue
}
-re "ENTER CALLEE.*$gdb_prompt $" {
send_gdb "step\n"
exp_continue
}
}
# Next backward over call.
gdb_test "next" ".*NEXT OVER THIS CALL.*" "reverse next over call"
set step_out 0
gdb_test_multiple "next" "reverse next over recursion" {
-re -wrap ".*NEXT OVER THIS RECURSION.*" {
pass "$gdb_test_name"
}
-re -wrap ".*RECURSIVE CALL.*" {
fail "$gdb_test_name"
set step_out 1
}
}
if { "$step_out" == 1 } {
gdb_test_multiple "next" "stepping out of recursion" {
-re -wrap "NEXT OVER THIS RECURSION.*" {
set step_out 0
}
-re -wrap ".*" {
send_gdb "next\n"
exp_continue
}
}
}
# Step forward over recursion again so we can test stepping over calls
# inside the recursion itself.
gdb_test_no_output "set exec-dir forward" "forward again to test recursion"
gdb_test "next" "NEXT OVER THIS CALL.*" "reverse next over recursion again"
gdb_test_no_output "set exec-dir reverse" "reverse again to test recursion"
gdb_test "step" ".*EXIT RECURSIVE FUNCTION.*" "enter recursive function"
set seen_recursive_call 0
gdb_test_multiple "next" "step over recursion inside the recursion" {
-re -wrap ".*RECURSIVE CALL.*" {
incr seen_recursive_call
send_gdb "next\n"
exp_continue
}
-re -wrap ".*NEXT OVER THIS RECURSION.*" {
gdb_assert {"$seen_recursive_call" == 1} \
"step over recursion inside the recursion"
}
-re -wrap ".*" {
send_gdb "next\n"
exp_continue
}
}
# step/next backward with count
gdb_test "step 3" ".*REVERSE STEP TEST 1.*" "reverse step test 1"
gdb_test "next 2" ".*REVERSE NEXT TEST 1.*" "reverse next test 1"
# step/next backward without count
gdb_test "step" ".*STEP TEST 1.*" "reverse step test 2"
gdb_test "next" ".*NEXT TEST 1.*" "reverse next test 2"
# Finish test by running forward to the end.
# FIXME return to this later...
# gdb_test_no_output "set exec-dir forward" "set forward execution"
# gdb_continue_to_end "step-reverse.exp"