1# Copyright (C) 2014-2020 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# On decr_pc_after_break targets, GDB used to adjust the PC
17# incorrectly if a background single-step stopped somewhere where
18# PC-$decr_pc had a breakpoint, and the thread was not the current
19# thread, like:
20#
21#   ADDR1 nop <-- breakpoint here
22#   ADDR2 jmp PC
23#
24#  IOW, say thread A is stepping ADDR2's line in the background (an
25#  infinite loop), and the user switches focus to thread B.  GDB's
26#  adjust_pc_after_break logic would confuse the single-step stop of
27#  thread A for a hit of the breakpoint at ADDR1, and thus adjust
28#  thread A's PC to point at ADDR1 when it should not: the thread had
29#  been single-stepped, not continued.
30
31standard_testfile
32
33if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug pthreads}] == -1} {
34    return -1
35}
36
37clean_restart $binfile
38
39if ![runto_main] {
40    continue
41}
42
43# Make sure it's GDB's decr_pc logic that's being tested, not the
44# target's.
45gdb_test_no_output "set range-stepping off"
46
47delete_breakpoints
48
49gdb_breakpoint [gdb_get_line_number "set breakpoint here"]
50gdb_continue_to_breakpoint "run to nop breakpoint"
51gdb_test "info threads" "  1 .*\\\* 2 .*" "info threads shows all threads"
52
53gdb_test "next" "while.*" "next over nop"
54
55gdb_test_no_output "next&" "next& over inf loop"
56
57set test "switch to main thread"
58gdb_test_multiple "thread 1" $test {
59    -re "Cannot execute this command while the target is running.*$gdb_prompt $" {
60	unsupported $test
61
62	# With remote targets, we can't send any other remote packet
63	# until the target stops.  Switching thread wants to ask the
64	# remote side whether the thread is alive.
65	return
66    }
67    -re "Switching to thread 1.*\\(running\\)\r\n$gdb_prompt " {
68	# Prefer to match the prompt without an anchor.  If there's a
69	# bug and output comes after the prompt immediately, it's
70	# faster to handle that in the following test, instead of
71	# waiting for a timeout here.
72	pass $test
73    }
74}
75
76# Wait a bit.  Use gdb_expect instead of sleep so that any (bad) GDB
77# output is visible in the log.
78gdb_expect 4 {}
79
80set test "no output while stepping"
81gdb_test_multiple "" $test {
82    -timeout 1
83    timeout {
84	pass $test
85    }
86    -re "." {
87	# If we see any output, it's a failure.  On the original bug,
88	# this would be a breakpoint hit.
89	fail $test
90    }
91}
92