1# Copyright 2009-2023 Free Software Foundation, Inc.
2
3# This program is free software; you can redistribute it and/or modify
4# it under the terms of the GNU General Public License as published by
5# the Free Software Foundation; either version 3 of the License, or
6# (at your option) any later version.
7#
8# This program is distributed in the hope that it will be useful,
9# but WITHOUT ANY WARRANTY; without even the implied warranty of
10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11# GNU General Public License for more details.
12#
13# You should have received a copy of the GNU General Public License
14# along with this program.  If not, see <http://www.gnu.org/licenses/>.
15
16
17# In gdb inferior function calls, if a C++ exception is raised in the
18# dummy-frame, and the exception handler is (normally, and expected to
19# be) out-of-frame, the default C++ handler will (wrongly) be called
20# in an inferior function call.
21# This is incorrect as an exception can normally and legally be handled
22# out-of-frame.  The confines of the dummy frame prevent the unwinder
23# from finding the correct handler (or any handler, unless it is
24# in-frame).  The default handler calls std::terminate.  This will kill
25# the inferior.  Assert that terminate should never be called in an
26# inferior function call.  These tests test the functionality around
27# unwinding that sequence and also tests the flag behaviour gating this
28# functionality.
29#
30# PR c++/9600.
31
32# This test is largely based of gdb.base/callfuncs.exp.
33
34if { [skip_cplus_tests] } { return }
35
36if [target_info exists gdb,nosignals] {
37    verbose "Skipping gdb2495.exp because of nosignals."
38    return
39}
40
41standard_testfile .cc
42
43# Some targets can't do function calls, so don't even bother with this
44# test.
45if [target_info exists gdb,cannot_call_functions] {
46    unsupported "this target can not call functions"
47    return
48}
49
50if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug c++}]} {
51    return -1
52}
53
54if {![runto_main]} {
55    return
56}
57
58# See http://sourceware.org/gdb/bugs/2495
59
60# Test normal baseline behaviour. Call a function that
61# does not raise an exception.
62gdb_test "p exceptions.no_throw_function()" " = 1"
63# And one that does but handles it in-frame.
64gdb_test "p exceptions.throw_function_with_handler()" " = 2"
65# Both should return normally.
66
67# Test basic unwind.  Call a function that raises an exception but
68# does not handle it.  It should be rewound.
69gdb_test "p exceptions.throw_function()" \
70    "The program being debugged entered a std::terminate call, .*" \
71    "call a function that raises an exception without a handler."
72
73# Make sure that after rewinding we are back at the call parent.
74gdb_test "bt" \
75    "#0  main.*" \
76    "bt after returning from a popped frame"
77
78# Make sure the only breakpoint is the one set via the runto_main
79# call and that the std::terminate breakpoint has evaporated and
80# cleaned-up.
81gdb_test "info breakpoints" \
82    "gdb2495\.cc.*"
83
84# Turn off this new behaviour.
85gdb_test_no_output "set unwind-on-terminating-exception off"
86
87# Check that it is turned off.
88gdb_test "show unwind-on-terminating-exception" \
89    "exception is unhandled while in a call dummy is off.*" \
90    "turn off unwind on terminating exception flag"
91
92# Check that the old behaviour is restored.
93gdb_test "p exceptions.throw_function()" \
94    "The program being debugged was signaled while in a function called .*" \
95    "call a function that raises an exception with unwinding off.."
96
97# Restart the inferior back at main.
98if {![runto_main]} {
99    return
100}
101
102
103# Check to see if the new behaviour alters the unwind signal
104# behaviour; it should not.  Test both on and off states.
105
106# Turn on unwind on signal behaviour.
107gdb_test_no_output "set unwindonsignal on"
108
109# Check that it is turned on.
110gdb_test "show unwindonsignal" \
111    "signal is received while in a call dummy is on.*" \
112    "turn on unwind on signal"
113
114# Check to see if new behaviour interferes with
115# normal signal handling in inferior function calls.
116gdb_test "p exceptions.raise_signal(1)" \
117    "To change this behavior use \"set unwindonsignal off\".*" \
118    "check for unwindonsignal off message"
119
120# And reverse - turn off again.
121gdb_test_no_output "set unwindonsignal off"
122
123# Check that it is actually turned off.
124gdb_test "show unwindonsignal" \
125    "signal is received while in a call dummy is off.*" \
126    "turn off unwind on signal"
127
128# Check to see if new behaviour interferes with
129# normal signal handling in inferior function calls.
130gdb_test "p exceptions.raise_signal(1)" \
131    "To change this behavior use \"set unwindonsignal on\".*" \
132    "check for unwindonsignal on message"
133