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# This file is part of the gdb testsuite.
17
18# Test stepping over permanent breakpoints.
19
20standard_testfile
21
22set options { debug }
23if { ![target_info exists gdb,nosignals] } {
24    lappend options "additional_flags=-DSIGNALS"
25}
26
27if {[build_executable "failed to prepare" $testfile $srcfile $options]} {
28    return -1
29}
30
31set line_bp [gdb_get_line_number "write permanent bp"]
32
33# The test proper.  ALWAYS_INSERTED indicates whether testing in
34# "breakpoint always-inserted" mode.  If SW_WATCHPOINT is true, set a
35# software watchpoint, which forces constantly single-stepping, and
36# exercises stepping the permanent breakpoint while delivering a
37# signal at the same time.
38
39proc test {always_inserted sw_watchpoint} {
40    global line_bp
41    global hex decimal
42    global gdb_prompt
43    global srcfile binfile
44
45    clean_restart $binfile
46
47    if ![runto_main] then {
48	return -1
49    }
50
51    gdb_test "set breakpoint always-inserted $always_inserted"
52
53    if {$sw_watchpoint} {
54	# Watching a convenience variable forces a software
55	# watchpoint.
56	gdb_test "watch \$dummy_convenience" "Watchpoint .*"
57    }
58
59    set address_bp ""
60    set address_after_bp ""
61
62    with_test_prefix "setup" {
63
64	# Set a breakpoint where we'll manually plant a permanent
65	# breakpoint.
66	set test "set probe breakpoint"
67	gdb_test_multiple "break $line_bp" $test {
68	    -re "Breakpoint .* at ($hex).*$gdb_prompt $" {
69		set address_bp $expect_out(1,string)
70		pass $test
71	    }
72	}
73	if {$address_bp == ""} {
74	    return
75	}
76
77	# Get the size of the instruction where the breakpoint will
78	# manually inserted.
79	set test "get size of instruction"
80	gdb_test_multiple "x/2i $address_bp" $test {
81	    -re ".*$hex <test\\+$decimal>:\[^\r\n\]+\r\n\[ \]+($hex).*\.\r\n$gdb_prompt $" {
82		set address_after_bp $expect_out(1,string)
83		pass $test
84	    }
85	}
86	if {$address_after_bp == ""} {
87	    return
88	}
89
90	# Write address range where the breakpoint is inserted to the
91	# corresponding variables in the inferior.
92	gdb_test "p /x addr_bp = $address_bp" " = $address_bp" \
93	    "write addr_bp"
94	gdb_test "p /x addr_after_bp = $address_after_bp" " = $address_after_bp" \
95	    "write addr_after_bp"
96
97	# Run the "setup" function in the inferior.  This memcpy's the
98	# breakpoint instruction to a buffer in the inferior.
99	gdb_test "next" "test_basics \\(\\).*" "next over setup"
100
101	delete_breakpoints
102
103	# We now have the breakpoint instruction stored in 'buffer'.  Poke it
104	# to memory manually.
105	set count [expr $address_after_bp - $address_bp]
106	for {set i 0} {$i < $count} {incr i} {
107	    set test "p /x addr_bp\[$i\] = buffer\[$i\]"
108	    gdb_test_multiple $test $test {
109		-re "Cannot access memory at address $hex.*$gdb_prompt $" {
110		    # Some targets (QEMU for one) will disallow writes to the
111		    # .text section under certain circumstances.  It is no use
112		    # continuing with the test at this point.  Just return.
113		    unsupported "cannot modify memory"
114		    return
115		}
116		-re " = .*$gdb_prompt $" {
117		    pass $test
118		}
119	    }
120	}
121    }
122
123    with_test_prefix "basics" {
124	# Run to the permanent breakpoint, just to make sure we've inserted it
125	# correctly.
126	# If the target fails to stop, the remainder of the test will not work
127	# so just return.  This can happen on some simulator targets where
128	# the running program doesn't see breakpoints that are visible to
129	# the execution engine, or where writes to the .text section are
130	# quietly ignored.
131	set test "permanent breakpoint causes random signal"
132	gdb_test_multiple "continue" $test {
133	    -re "exited normally.*$gdb_prompt $" {
134	        unsupported "failed to stop at permanent breakpoint"
135		return
136	    }
137	    -re "Program received signal SIGTRAP.*$gdb_prompt $" {
138	    	pass $test
139	    }
140	}
141
142	# Now set a breakpoint on top, thus creating a permanent breakpoint.
143	gdb_breakpoint "$line_bp"
144
145	# Depending on whether this is a decr_pc_after_break arch, the PC will
146	# be either pointing at the permanent breakpoint address, or just
147	# after.  Set the GDB breakpoint on top, and continue, twice.  At
148	# least once, GDB will need to step-over the permanent breakpoint.
149
150	gdb_test "continue" "Breakpoint .*" "stop at permanent breakpoint"
151
152	gdb_test "p \$prev_counter = counter" " = $decimal"
153
154	gdb_test "continue" "Breakpoint .*" "stop at permanent breakpoint twice"
155
156	# Check that indeed the continue made progress, instead of re-trapping
157	# without advancing.
158	gdb_test "p counter - \$prev_counter" " = 1"
159
160	gdb_test "info breakpoints" \
161	    "breakpoint.*keep.*y.*$hex.*in test at .*$srcfile:$line_bp.*already hit 2 times.*" \
162	    "info breakpoints show enabled breakpoint"
163
164	gdb_test "disable \$bpnum"
165
166	gdb_test "commands\nset \$commands_ran = 1\nend" "" \
167	    "set breakpoint commands"
168
169	gdb_test "info breakpoints" \
170	    "breakpoint.*keep.*n.*$hex.*in test at .*$srcfile:$line_bp.*already hit 2 times.*" \
171	    "info breakpoints shows disabled breakpoint"
172
173	# Run to the permanent breakpoint again.  This time, since it's
174	# disabled, it should act as if we hadn't created it in the first
175	# place.  IOW, we should get a random signal, and, the breakpoint's
176	# command should not run.
177	gdb_test "continue" "Program received signal SIGTRAP.*" \
178	    "disabled permanent breakpoint doesn't explain stop"
179
180	gdb_test "info breakpoints" \
181	    "breakpoint.*keep.*n.*$hex.*in test at .*$srcfile:$line_bp.*already hit 2 times.*" \
182	    "info breakpoints still shows same number of hits"
183
184	gdb_test "print \$commands_ran" " = void" \
185	    "breakpoint commands didn't run"
186
187	# Reenable the breakpoint, and check that it gets hit and accounted
188	# for this time.
189	gdb_test "enable \$bpnum" "" "reenable breakpoint"
190
191	gdb_test "continue" "Breakpoint .*" \
192	    "stop at permanent breakpoint thrice"
193
194	gdb_test "info breakpoints" \
195	    "breakpoint.*keep.*y.*$hex.*in test at .*$srcfile:$line_bp.*already hit 3 times.*" \
196	    "info breakpoints shows one more hit"
197
198	gdb_test "print \$commands_ran" " = 1" "breakpoint commands ran"
199
200	# Check that stepi advances only past the permanent breakpoint, and
201	# not a single instruction more.
202	gdb_test "stepi" "after permanent bp .*" \
203	    "single-step past permanent breakpoint"
204    }
205
206    with_test_prefix "next trips on permanent bp" {
207	delete_breakpoints
208
209	gdb_breakpoint "test_next"
210	gdb_continue_to_breakpoint "test_next"
211
212	gdb_breakpoint "$line_bp"
213	gdb_test "condition \$bpnum 0"
214
215	gdb_test "next" "after next .*"
216    }
217
218    if ![target_info exists gdb,nosignals] {
219
220	with_test_prefix "continue trips on nested permanent bp" {
221	    delete_breakpoints
222
223	    gdb_breakpoint "test_signal_nested"
224	    gdb_continue_to_breakpoint "test_signal_nested"
225
226	    gdb_breakpoint "$line_bp"
227	    gdb_continue_to_breakpoint "permanent bp"
228	    gdb_test "condition \$bpnum 0"
229
230	    # Let SIGALRM trigger.
231	    sleep 2
232
233	    # We're now stopped at a permanent breakpoint, with a
234	    # signal pending.
235	    gdb_breakpoint "test_signal_nested_done"
236	    gdb_continue_to_breakpoint "test_signal_nested_done"
237
238	    # Ensure that the handler did run.  There's one call to
239	    # test in the mainline code, and another in the signal
240	    # handler.
241	    gdb_test "p counter" " = 2"
242	}
243
244	if [can_single_step_to_signal_handler] {
245
246	    with_test_prefix "stepi signal with handler" {
247		delete_breakpoints
248
249		gdb_breakpoint "test_signal_with_handler"
250		gdb_continue_to_breakpoint "test_signal_with_handler"
251
252		gdb_breakpoint "$line_bp"
253
254		gdb_test "continue" "Breakpoint .*" "stop at permanent breakpoint"
255
256		gdb_test "queue-signal SIGUSR1"
257
258		set test "single-step to handler"
259		gdb_test_multiple "stepi" $test {
260		    -re "Program received signal SIGTRAP.*$gdb_prompt $" {
261			fail $test
262		    }
263		    -re "handler .*$gdb_prompt $" {
264			pass $test
265		    }
266		}
267
268		# Check that the mainline PC points at the permanent
269		# breakpoint.
270		gdb_test "up 2" "test .*" "up to mainline code"
271
272		gdb_test "p /x \$pc" " = $address_bp" \
273		    "mainline pc points at permanent breakpoint"
274
275		gdb_test "continue" "Breakpoint .*" \
276		    "stop at permanent breakpoint, out of handler"
277	    }
278
279	    with_test_prefix "stepi signal with no handler" {
280		gdb_breakpoint "test_signal_no_handler"
281		gdb_continue_to_breakpoint "test_signal_no_handler"
282
283		gdb_test "continue" "Breakpoint .*" "stop at permanent breakpoint"
284
285		gdb_test "queue-signal SIGUSR1"
286
287		gdb_test "stepi" "after permanent bp .*" \
288		    "single-step past permanent breakpoint"
289	    }
290	}
291    }
292}
293
294foreach always_inserted {off on} {
295    foreach sw_watchpoint {0 1} {
296	with_test_prefix "always_inserted=$always_inserted, sw_watchpoint=$sw_watchpoint" {
297	    test $always_inserted $sw_watchpoint
298	}
299    }
300}
301