gdb/testsuite/gdb.cp/gdb2495.exp

# Copyright 2009-2024 Free Software Foundation, Inc.

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# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
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#
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
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# 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 behavior gating this
# functionality.
#
# PR c++/9600.

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

require allow_cplus_tests

require {!target_info exists gdb,nosignals}

standard_testfile .cc

# Some targets can't do function calls, so don't even bother with this
# test.
require {!target_info exists gdb,cannot_call_functions}

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

if {![runto_main]} {
    return
}

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

# Test normal baseline behavior. 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 behavior.
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 behavior 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]} {
    return
}


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

# Turn on unwind on signal behavior.
gdb_test_no_output "set unwind-on-signal on"

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

# Check to see if new behavior interferes with
# normal signal handling in inferior function calls.
gdb_test "p exceptions.raise_signal(1)" \
    [multi_line \
	 "The program being debugged received signal SIGABRT, Aborted" \
	 "while in a function called from GDB\\.  GDB has restored the context" \
	 "to what it was before the call\\.  To change this behavior use" \
	 "\"set unwind-on-signal off\"\\.  Evaluation of the expression containing" \
	 "the function \\(SimpleException::raise_signal\\(int\\)\\) will be abandoned\\."]\
    "check for unwind-on-signal off message"

# And reverse - turn off again.
gdb_test_no_output "set unwind-on-signal off"

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

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