gdb/testsuite/gdb.base/bt-on-fatal-signal.exp

# Copyright 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 the 'maint set backtrace-on-fatal-signal' behaviour.  Start up
# GDB, turn on backtrace-on-fatal-signal, then send fatal signals to
# GDB and ensure we see the backtrace.

standard_testfile

# The logic for sending signals to GDB might now work when using a
# remote host (will the signal go to GDB, or the program that
# established the connection to the remote host?), so just skip this
# test for remote host setups.
if {[is_remote host]} {
    untested $testfile
    return -1
}

if {[prepare_for_testing "failed to prepare" $testfile $srcfile]} {
    return -1
}

# Check we can run to main.  If this works this time then we just
# assume that it will work later on (when we repeatedly restart GDB).
if ![runto_main] then {
    return -1
}

# Check that the backtrace-on-fatal-signal feature is supported.  If
# this target doesn't have the backtrace function available then
# trying to turn this on will give an error, in which case we just
# skip this test.
gdb_test_multiple "maint set backtrace-on-fatal-signal on" "" {
    -re "support for this feature is not compiled into GDB" {
	untested $testfile
	return -1
    }
    -re "$gdb_prompt $" {
	pass $gdb_test_name
    }
}

# Now the actual test loop.
foreach test_data {{SEGV "Segmentation fault"} \
		       {FPE "Floating point exception"} \
		       {BUS "Bus error"} \
		       {ABRT "Aborted"}} {
    set sig [lindex ${test_data} 0]
    set msg [lindex ${test_data} 1]
    with_test_prefix ${sig} {

	# Restart GDB.
	clean_restart $binfile

	# Capture the pid of GDB.
	set testpid [spawn_id_get_pid $gdb_spawn_id]

	# Start the inferior.
	runto_main

	# Turn on the backtrace-on-fatal-signal feature.
	gdb_test_no_output "maint set backtrace-on-fatal-signal on"

	# Flags for various bits of the output we expect to see, we
	# check for these in the gdb_test_multiple below.
	set saw_fatal_msg false
	set saw_bt_start false
	set saw_bt_end false
	set internal_error_msg_count 0

	# Send the fatal signal to GDB.
	remote_exec host "kill -${sig} ${testpid}"

	# Scan GDB's output for the backtrace.  As the output we get
	# here includes the standard "internal error" message, which
	# gdb_test_multiple will usually handle, we are forced to make
	# extensive use of the "-early" flag here so that all our
	# patterns are applied before gdb_test_multiple can check for
	# the internal error pattern.
	gdb_test_multiple "" "scan for backtrace" {
	    -early -re "^\r\n" {
		exp_continue
	    }
	    -early -re "^Fatal signal: ${msg}\r\n" {
		set saw_fatal_msg true
		exp_continue
	    }
	    -early -re "^----- Backtrace -----\r\n" {
		set saw_bt_start true
		exp_continue
	    }
	    -early -re ".+\r\n---------------------\r\n" {
		set saw_bt_end true
		exp_continue
	    }
	    -early -re "^A fatal error internal to GDB has been detected, further\r\n" {
		incr internal_error_msg_count
		exp_continue
	    }
	    -early -re "^debugging is not possible.  GDB will now terminate\\.\r\n" {
		incr internal_error_msg_count
		exp_continue
	    }
	    eof {
		# Catch the eof case as this indicates that GDB has
		# gone away, which in this case, is what we expect to
		# happen.
		gdb_assert { $saw_fatal_msg }
		gdb_assert { $saw_bt_start }
		gdb_assert { $saw_bt_end }
		gdb_assert { [expr $internal_error_msg_count == 2] }
	    }
	    -re "$gdb_prompt $" {
		# GDB should terminate, we should never get back to
		# the prompt.
		fail $gdb_test_name
	    }
	}

	# GDB should be dead and gone by this point, but just to be
	# sure, force an exit.
	gdb_exit
    }
}