gdb/testsuite/gdb.cp/gdb2495.exp

# Copyright 2009-2020 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/>.


# In gdb inferior function calls, if a C++ exception is raised in the
# dummy-frame, and the exception handler is (normally, and expected to
# be) out-of-frame, the default C++ handler will (wrongly) be called
# in an inferior function call.
# This is incorrect as an exception can normally and legally be handled
# out-of-frame.  The confines of the dummy frame prevent the unwinder
# from finding the correct handler (or any handler, unless it is
# in-frame).  The default handler calls std::terminate.  This will kill
# the inferior.  Assert that terminate should never be called in an
# inferior function call.  These tests test the functionality around
# unwinding that sequence and also tests the flag behaviour gating this
# functionality.
#
# PR c++/9600.

# This test is largely based of gdb.base/callfuncs.exp.

if { [skip_cplus_tests] } { continue }

if [target_info exists gdb,nosignals] {
    verbose "Skipping gdb2495.exp because of nosignals."
    continue
}

standard_testfile .cc

# Create and source the file that provides information about the compiler
# used to compile the test case.
if [get_compiler_info "c++"] {
    return -1
}

# Some targets can't do function calls, so don't even bother with this
# test.
if [target_info exists gdb,cannot_call_functions] {
    unsupported "this target can not call functions"
    continue
}

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

if ![runto_main] then {
    perror "couldn't run to main"
    continue
}

# See http://sourceware.org/gdb/bugs/2495

# Test normal baseline behaviour. Call a function that
# does not raise an exception.
gdb_test "p exceptions.no_throw_function()" " = 1"
# And one that does but handles it in-frame.
gdb_test "p exceptions.throw_function_with_handler()" " = 2"
# Both should return normally.

# Test basic unwind.  Call a function that raises an exception but
# does not handle it.  It should be rewound.
gdb_test "p exceptions.throw_function()" \
    "The program being debugged entered a std::terminate call, .*" \
    "call a function that raises an exception without a handler."

# Make sure that after rewinding we are back at the call parent.
gdb_test "bt" \
    "#0  main.*" \
    "bt after returning from a popped frame"

# Make sure the only breakpoint is the one set via the runto_main
# call and that the std::terminate breakpoint has evaporated and
# cleaned-up.
gdb_test "info breakpoints" \
    "gdb2495\.cc.*"

# Turn off this new behaviour.
gdb_test_no_output "set unwind-on-terminating-exception off"

# Check that it is turned off.
gdb_test "show unwind-on-terminating-exception" \
    "exception is unhandled while in a call dummy is off.*" \
    "turn off unwind on terminating exception flag"

# Check that the old behaviour is restored.
gdb_test "p exceptions.throw_function()" \
    "The program being debugged was signaled while in a function called .*" \
    "call a function that raises an exception with unwinding off.."

# Restart the inferior back at main.
if ![runto_main] then {
    perror "couldn't run to main"
    continue
}


# Check to see if the new behaviour alters the unwind signal
# behaviour; it should not.  Test both on and off states.

# Turn on unwind on signal behaviour.
gdb_test_no_output "set unwindonsignal on"

# Check that it is turned on.
gdb_test "show unwindonsignal" \
    "signal is received while in a call dummy is on.*" \
    "turn on unwind on signal"

# Check to see if new behaviour interferes with
# normal signal handling in inferior function calls.
gdb_test "p exceptions.raise_signal(1)" \
    "To change this behavior use \"set unwindonsignal off\".*"

# And reverse - turn off again.
gdb_test_no_output "set unwindonsignal off"

# Check that it is actually turned off.
gdb_test "show unwindonsignal" \
    "signal is received while in a call dummy is off.*" \
    "turn off unwind on signal"

# Check to see if new behaviour interferes with
# normal signal handling in inferior function calls.
gdb_test "p exceptions.raise_signal(1)" \
    "To change this behavior use \"set unwindonsignal on\".*"