xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/testsuite/gdb.base/foll-fork.exp (revision 70f7362772ba52b749c976fb5e86e39a8b2c9afc)
1#   Copyright 1997-2020 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# Until "set follow-fork-mode" and "catch fork" are implemented on
17# other targets...
18#
19if { ![istarget "*-*-linux*"] && ![istarget "*-*-openbsd*"] } then {
20    continue
21}
22
23# Test relies on checking follow-fork output. Do not run if gdb debug is
24# enabled as it will be redirected to the log.
25if [gdb_debug_enabled] {
26    untested "debug is enabled"
27    return 0
28}
29
30standard_testfile
31
32if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
33    return -1
34}
35
36proc check_fork_catchpoints {} {
37  global gdb_prompt
38
39  # Verify that the system supports "catch fork".
40  gdb_test "catch fork" "Catchpoint \[0-9\]* \\(fork\\)" "insert first fork catchpoint"
41  set has_fork_catchpoints 0
42  gdb_test_multiple "continue" "continue to first fork catchpoint" {
43    -re ".*Your system does not support this type\r\nof catchpoint.*$gdb_prompt $" {
44      unsupported "continue to first fork catchpoint"
45    }
46    -re ".*Catchpoint.*$gdb_prompt $" {
47      set has_fork_catchpoints 1
48      pass "continue to first fork catchpoint"
49    }
50  }
51
52  if {$has_fork_catchpoints == 0} {
53    unsupported "fork catchpoints"
54    return -code return
55  }
56}
57
58# Test follow-fork to ensure that the correct process is followed, that
59# the followed process stops where it is expected to stop, that processes
60# are detached (or not) as expected, and that the inferior list has the
61# expected contents after following the fork.  WHO is the argument to
62# the 'set follow-fork-mode' command, DETACH is the argument to the
63# 'set detach-on-fork' command, and CMD is the GDB command used to
64# execute the program past the fork.  If the value of WHO or DETACH is
65# 'default', the corresponding GDB command is skipped for that test.
66# The value of CMD must be either 'next 2' or 'continue'.
67proc test_follow_fork { who detach cmd } {
68    global gdb_prompt
69    global srcfile
70    global testfile
71
72    with_test_prefix "follow $who, detach $detach, command \"$cmd\"" {
73
74	# Start a new debugger session each time so defaults are legitimate.
75	clean_restart $testfile
76
77	if ![runto_main] {
78	    untested "could not run to main"
79	    return -1
80	}
81
82	# The "Detaching..." and "Attaching..." messages may be hidden by
83	# default.
84	gdb_test_no_output "set verbose"
85
86	# Set follow-fork-mode if we aren't using the default.
87	if {$who == "default"} {
88	    set who "parent"
89	} else {
90	    gdb_test_no_output "set follow-fork $who"
91	}
92
93	gdb_test "show follow-fork" \
94	"Debugger response to a program call of fork or vfork is \"$who\"."
95
96	# Set detach-on-fork mode if we aren't using the default.
97	if {$detach == "default"} {
98	    set detach "on"
99	} else {
100	    gdb_test_no_output "set detach-on-fork $detach"
101	}
102
103	gdb_test "show detach-on-fork" \
104		 "Whether gdb will detach.* fork is $detach."
105
106	# Set a breakpoint after the fork if we aren't single-stepping
107	# past the fork.
108	if {$cmd == "continue"} {
109	    set bp_after_fork [gdb_get_line_number "set breakpoint here"]
110	    gdb_test "break ${srcfile}:$bp_after_fork" \
111		     "Breakpoint.*, line $bp_after_fork.*" \
112		     "set breakpoint after fork"
113	}
114
115	# Set up the output we expect to see after we run.
116	set expected_re ""
117	if {$who == "child"} {
118	    set expected_re "\\\[Attaching after.* fork to.*"
119	    if {$detach == "on"} {
120		append expected_re "\\\[Detaching after fork from .*"
121	    }
122	    append expected_re "set breakpoint here.*"
123	} elseif {$who == "parent" && $detach == "on"} {
124	    set expected_re "\\\[Detaching after fork from .*set breakpoint here.*"
125	} else {
126	    set expected_re ".*set breakpoint here.*"
127	}
128
129	# Test running past and following the fork, using the parameters
130	# set above.
131	gdb_test $cmd $expected_re "$cmd past fork"
132
133	# Check that we have the inferiors arranged correctly after
134	# following the fork.
135	set resume_unfollowed 0
136	if {$who == "parent" && $detach == "on"} {
137
138	    # Follow parent / detach child: the only inferior is the parent.
139	    gdb_test "info inferiors" "\\* 1 .* process.*"
140
141	} elseif {$who == "parent" && $detach == "off"} {
142
143	    # Follow parent / keep child: two inferiors under debug, the
144	    # parent is the current inferior.
145	    gdb_test "info inferiors" "\\* 1 .*process.* 2 .*process.*"
146
147	    gdb_test "inferior 2" "Switching to inferior 2 .*"
148	    set resume_unfollowed 1
149
150	} elseif {$who == "child" && $detach == "on"} {
151
152	    # Follow child / detach parent: the child is under debug and is
153	    # the current inferior.  The parent is listed but is not under
154	    # debug.
155	    gdb_test "info inferiors" " 1 .*<null>.*\\* 2 .*process.*"
156
157	} elseif {$who == "child" && $detach == "off"} {
158
159	    # Follow child / keep parent: two inferiors under debug, the
160	    # child is the current inferior.
161	    gdb_test "info inferiors" " 1 .*process.*\\* 2 .*process.*"
162
163	    gdb_test "inferior 1" "Switching to inferior 1 .*"
164	    set resume_unfollowed 1
165	}
166
167	if {$resume_unfollowed == 1} {
168	    if {$cmd == "next 2"} {
169
170		gdb_continue_to_end "continue unfollowed inferior to end"
171
172	    } elseif {$cmd == "continue"} {
173
174		gdb_continue_to_breakpoint \
175		    "continue unfollowed inferior to bp" \
176		    ".* set breakpoint here.*"
177	    }
178	}
179    }
180}
181
182set reading_in_symbols_re {(?:\r\nReading in symbols for [^\r\n]*)?}
183
184proc catch_fork_child_follow {} {
185    global gdb_prompt
186    global srcfile
187    global reading_in_symbols_re
188
189    set bp_after_fork [gdb_get_line_number "set breakpoint here"]
190
191    gdb_test "catch fork" \
192	"Catchpoint \[0-9\]* \\(fork\\)$reading_in_symbols_re" \
193	"explicit child follow, set catch fork"
194
195    # Verify that the catchpoint is mentioned in an "info breakpoints",
196    # and further that the catchpoint mentions no process id.
197    #
198    set test_name "info shows catchpoint without pid"
199    gdb_test_multiple "info breakpoints" "$test_name" {
200	-re ".*catchpoint.*keep y.*fork\[\r\n\]+$gdb_prompt $" {
201	    pass "$test_name"
202	}
203    }
204
205    gdb_test "continue" \
206	"Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
207	"explicit child follow, catch fork"
208
209    # Verify that the catchpoint is mentioned in an "info breakpoints",
210    # and further that the catchpoint managed to capture a process id.
211    #
212    set test_name "info shows catchpoint without pid"
213    gdb_test_multiple "info breakpoints" "$test_name" {
214	-re ".*catchpoint.*keep y.*fork, process.*$gdb_prompt $" {
215	    pass "$test_name"
216	}
217    }
218
219    gdb_test_no_output "set follow-fork child"
220
221    gdb_test "tbreak ${srcfile}:$bp_after_fork" \
222	"Temporary breakpoint.*, line $bp_after_fork.*" \
223	"set follow-fork child, tbreak"
224
225    set expected_re "\\\[Attaching after.* fork to.*\\\[Detaching after fork from"
226    append expected_re ".* at .*$bp_after_fork.*"
227    gdb_test "continue" $expected_re "set follow-fork child, hit tbreak"
228
229    # The parent has been detached; allow time for any output it might
230    # generate to arrive, so that output doesn't get confused with
231    # any expected debugger output from a subsequent testpoint.
232    #
233    exec sleep 1
234
235    gdb_test "delete breakpoints" \
236	"" \
237	"set follow-fork child, cleanup" \
238	"Delete all breakpoints. \\(y or n\\) $" \
239	"y"
240}
241
242proc catch_fork_unpatch_child {} {
243    global gdb_prompt
244    global srcfile
245
246    set bp_exit [gdb_get_line_number "at exit"]
247
248    gdb_test "break callee" "file .*$srcfile, line .*" \
249	"unpatch child, break at callee"
250    gdb_test "catch fork" "Catchpoint \[0-9\]* \\(fork\\)" \
251	"unpatch child, set catch fork"
252
253    gdb_test "continue" \
254	"Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
255	"unpatch child, catch fork"
256
257    # Delete all breakpoints and catchpoints.
258    delete_breakpoints
259
260    # Force $srcfile as the current GDB source can be in glibc sourcetree.
261    gdb_test "break $srcfile:$bp_exit" \
262	"Breakpoint .*file .*$srcfile, line .*" \
263	"unpatch child, breakpoint at exit call"
264
265    gdb_test_no_output "set follow-fork child" \
266	"unpatch child, set follow-fork child"
267
268    set test "unpatch child, unpatched parent breakpoints from child"
269    gdb_test_multiple "continue" $test {
270	-re "at exit.*$gdb_prompt $" {
271	    pass "$test"
272	}
273	-re "SIGTRAP.*$gdb_prompt $" {
274	    fail "$test"
275
276	    # Explicitly kill this child, so we can continue gracefully
277	    # with further testing...
278	    send_gdb "kill\n"
279	    gdb_expect {
280		-re ".*Kill the program being debugged.*y or n. $" {
281		    send_gdb "y\n"
282		    gdb_expect -re "$gdb_prompt $" {}
283		}
284	    }
285	}
286    }
287}
288
289proc tcatch_fork_parent_follow {} {
290    global gdb_prompt
291    global srcfile
292    global reading_in_symbols_re
293
294    set bp_after_fork [gdb_get_line_number "set breakpoint here"]
295
296    gdb_test "catch fork" \
297	"Catchpoint \[0-9\]* \\(fork\\)$reading_in_symbols_re" \
298	"explicit parent follow, set tcatch fork"
299
300# ??rehrauer: I don't yet know how to get the id of the tcatch
301# via this script, so that I can add a -do list to it.  For now,
302# do the follow stuff after the catch happens.
303
304    gdb_test "continue" \
305	"Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
306	"explicit parent follow, tcatch fork"
307
308    gdb_test_no_output "set follow-fork parent"
309
310    gdb_test "tbreak ${srcfile}:$bp_after_fork" \
311	"Temporary breakpoint.*, line $bp_after_fork.*" \
312	"set follow-fork parent, tbreak"
313
314    gdb_test "continue" \
315	"\\\[Detaching after fork from.* at .*$bp_after_fork.*" \
316	"set follow-fork parent, hit tbreak"
317
318    # The child has been detached; allow time for any output it might
319    # generate to arrive, so that output doesn't get confused with
320    # any expected debugger output from a subsequent testpoint.
321    #
322    exec sleep 1
323
324    gdb_test "delete breakpoints" \
325	"" \
326	"set follow-fork parent, cleanup" \
327	"Delete all breakpoints. \\(y or n\\) $" \
328	"y"
329}
330
331proc do_fork_tests {} {
332    global gdb_prompt
333    global testfile
334
335    # Verify that help is available for "set follow-fork-mode".
336    #
337    gdb_test "help set follow-fork-mode" \
338	"Set debugger response to a program call of fork or vfork..*
339A fork or vfork creates a new process.  follow-fork-mode can be:.*
340.*parent  - the original process is debugged after a fork.*
341.*child   - the new process is debugged after a fork.*
342The unfollowed process will continue to run..*
343By default, the debugger will follow the parent process..*"
344
345    # Verify that we can set follow-fork-mode, using an abbreviation
346    # for both the flag and its value.
347    #
348    gdb_test_no_output "set follow-fork ch"
349
350    gdb_test "show follow-fork" \
351	"Debugger response to a program call of fork or vfork is \"child\".*" \
352	"set follow-fork, using abbreviations"
353
354    # Verify that we cannot set follow-fork-mode to nonsense.
355    #
356    gdb_test "set follow-fork chork" "Undefined item: \"chork\".*" \
357	"set follow-fork to nonsense is prohibited"
358
359    gdb_test_no_output "set follow-fork parent" "reset parent"
360
361    # Check that fork catchpoints are supported, as an indicator for whether
362    # fork-following is supported.
363    if [runto_main] then { check_fork_catchpoints }
364
365    # Test the basic follow-fork functionality using all combinations of
366    # values for follow-fork-mode and detach-on-fork, using either a
367    # breakpoint or single-step to execute past the fork.
368    #
369    # The first loop should be sufficient to test the defaults.  There
370    # is no need to test using the defaults in other permutations (e.g.
371    # "default" "on", "parent" "default", etc.).
372    foreach cmd {"next 2" "continue"} {
373        test_follow_fork "default" "default" $cmd
374    }
375
376    # Now test all explicit permutations.
377    foreach who {"parent" "child"} {
378	foreach detach {"on" "off"} {
379	    foreach cmd {"next 2" "continue"} {
380		test_follow_fork $who $detach $cmd
381	    }
382	}
383    }
384
385    # Catchpoint tests.
386
387    # Restart to eliminate any effects of the follow-fork tests.
388    clean_restart $testfile
389    gdb_test_no_output "set verbose"
390
391    # Test the ability to catch a fork, specify that the child be
392    # followed, and continue.  Make the catchpoint permanent.
393    #
394    if [runto_main] then { catch_fork_child_follow }
395
396    # Test that parent breakpoints are successfully detached from the
397    # child at fork time, even if the user removes them from the
398    # breakpoints list after stopping at a fork catchpoint.
399    if [runto_main] then { catch_fork_unpatch_child }
400
401    # Test the ability to catch a fork, specify via a -do clause that
402    # the parent be followed, and continue.  Make the catchpoint temporary.
403    #
404    if [runto_main] then { tcatch_fork_parent_follow }
405}
406
407# This is a test of gdb's ability to follow the parent, child or both
408# parent and child of a Unix fork() system call.
409#
410do_fork_tests
411
412return 0
413