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# Test that GDB doesn't get confused in the following scenario
17# (PR breakpoints/17000).  Say, we have this program:
18#
19#  =>  0xff000001  INSN1
20#      0xff000002  INSN2
21#
22# The PC currently points at INSN1.
23#
24# 1 - User sets a breakpoint at 0xff000002 (INSN2).
25#
26# 2 - User steps.  On software single-step archs, this sets a software
27#     single-step breakpoint at 0xff000002 (INSN2) too.
28#
29# 3 - User deletes breakpoint (INSN2) before the single-step finishes.
30#
31# 4 - The single-step finishes, and GDB removes the single-step
32#     breakpoint.
33
34# Test relies on checking gdb debug output. Do not run if gdb debug is
35# enabled as any debug will be redirected to the log.
36if [gdb_debug_enabled] {
37    untested "debug is enabled"
38    return 0
39}
40
41standard_testfile
42
43if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
44    return -1
45}
46
47if ![runto_main] {
48    fail "can't run to main"
49    return 0
50}
51
52delete_breakpoints
53
54# With the all-stop RSP, we can't talk to the target while it's
55# running, until we get back the stop reply.  If not using single-step
56# breakpoints, then the "del" in stepi_del_break below will try to
57# delete the user breakpoint from the target, which will fail, with
58# "Cannot execute this command while the target is running.".  On
59# software single-step targets, that del shouldn't trigger any RSP
60# traffic.  Hardware-step targets that can't access memory while the
61# target is running, either remote or native, are likewise affected.
62# So we just skip the test if not using software single-stepping.  We
63# detect that by looking for 'to_resume (..., step)' in "debug
64# target" output.
65
66# Probe for software single-step breakpoint use.
67
68gdb_test_no_output "set debug target 1"
69set hardware_step 0
70set test "probe target hardware step"
71gdb_test_multiple "si" $test {
72    -re "resume \\(\[^\r\n\]+, step, .*$gdb_prompt $" {
73	set hardware_step 1
74	pass $test
75    }
76    -re "$gdb_prompt $" {
77	pass $test
78    }
79}
80
81if { $hardware_step } {
82    unsupported "target doesn't use software single-stepping"
83    return
84}
85
86gdb_test "set debug target 0" "->log_command.*\\)"
87
88set line_re "\[^\r\n\]*"
89
90gdb_test "b test:label" "Breakpoint .*"
91gdb_continue_to_breakpoint "run past setup"
92delete_breakpoints
93
94# So we can precisely control breakpoint insertion order.
95gdb_test_no_output "set breakpoint always-inserted on"
96
97# Capture disassembly output.  PREFIX is used as test prefix.  The
98# current instruction indicator (=>) is stripped away.
99proc disassemble { prefix } {
100    with_test_prefix "$prefix" {
101	set output [capture_command_output "disassemble test" ""]
102	return [string map {"=>" "  "} $output]
103    }
104}
105
106# Issue a stepi and immediately delete the user breakpoint that is set
107# at the same address as the software single-step breakpoint.  Do this
108# in a user defined command, so that the stepi's trap doesn't have a
109# chance to be handled before further input is processed.  We then
110# compare before/after disassembly.  GDB should be able to handle
111# deleting the user breakpoint before deleting the single-step
112# breakpoint.  E.g., we shouldn't see breakpoint instructions in the
113# disassembly.
114
115set disasm_before [disassemble "before"]
116
117gdb_test "b test:label2" ".*" "set breakpoint where si will land"
118
119set test "define stepi_del_break"
120gdb_test_multiple $test $test {
121    -re "Type commands for definition of \"stepi_del_break\".\r\nEnd with a line saying just \"end\".\r\n>$" {
122	gdb_test "si&\ndel \$bpnum\nend" "" $test
123    }
124}
125
126set command "stepi_del_break"
127set test $command
128gdb_test_multiple $command $test {
129    -re "^$command\r\n$gdb_prompt " {
130	# Note no end anchor, because "si&" finishes and prints the
131	# current frame/line after the prompt is printed.
132	pass $test
133    }
134}
135
136# Now consume the output of the finished "si&".
137set test "si& finished"
138gdb_test_multiple "" $test {
139    -re "must be a single line \\\*/\r\n" {
140	pass $test
141    }
142}
143
144set disasm_after [disassemble "after"]
145
146set test "before/after disassembly matches"
147if ![string compare $disasm_before $disasm_after]  {
148    pass $test
149} else {
150    fail $test
151}
152