gdb/testsuite/gdb.base/foll-fork.exp

   1 #   Copyright 1997-2023 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 # Test relies on checking follow-fork output. Do not run if gdb debug is
  17 # enabled as it will be redirected to the log.
  18 if [gdb_debug_enabled] {
  19     untested "debug is enabled"
  20     return 0
  21 }
  22
  23 standard_testfile
  24
  25 if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
  26     return -1
  27 }
  28
  29 # Restart GDB and run the inferior to main.  Return 1 on success, 0 on failure.
  30
  31 proc setup {} {
  32     clean_restart $::testfile
  33
  34     if { ![runto_main] } {
  35         return 0
  36     }
  37
  38     return 1
  39 }
  40
  41 # Check that fork catchpoints are supported, as an indicator for whether
  42 # fork-following is supported.  Return 1 if they are, else 0.
  43
  44 proc_with_prefix check_fork_catchpoints {} {
  45   global gdb_prompt
  46
  47   if { ![setup] } {
  48       return
  49   }
  50
  51   # Verify that the system supports "catch fork".
  52   gdb_test "catch fork" "Catchpoint \[0-9\]* \\(fork\\)" "insert first fork catchpoint"
  53   set has_fork_catchpoints 0
  54   gdb_test_multiple "continue" "continue to first fork catchpoint" {
  55     -re ".*Your system does not support this type\r\nof catchpoint.*$gdb_prompt $" {
  56       unsupported "continue to first fork catchpoint"
  57     }
  58     -re ".*Catchpoint.*$gdb_prompt $" {
  59       set has_fork_catchpoints 1
  60       pass "continue to first fork catchpoint"
  61     }
  62   }
  63
  64   return $has_fork_catchpoints
  65 }
  66
  67 # Test follow-fork to ensure that the correct process is followed, that
  68 # the followed process stops where it is expected to stop, that processes
  69 # are detached (or not) as expected, and that the inferior list has the
  70 # expected contents after following the fork.  WHO is the argument to
  71 # the 'set follow-fork-mode' command, DETACH is the argument to the
  72 # 'set detach-on-fork' command, and CMD is the GDB command used to
  73 # execute the program past the fork.  If the value of WHO or DETACH is
  74 # 'default', the corresponding GDB command is skipped for that test.
  75 # The value of CMD must be either 'next 2' or 'continue'.
  76 proc_with_prefix test_follow_fork { follow-fork-mode detach-on-fork cmd } {
  77     global gdb_prompt
  78     global srcfile
  79     global testfile
  80
  81     # Start a new debugger session each time so defaults are legitimate.
  82     if { ![setup] } {
  83         return
  84     }
  85
  86     # The "Detaching..." and "Attaching..." messages may be hidden by
  87     # default.
  88     gdb_test_no_output "set verbose"
  89
  90     # Set follow-fork-mode if we aren't using the default.
  91     if {${follow-fork-mode} == "default"} {
  92         set follow-fork-mode "parent"
  93     } else {
  94         gdb_test_no_output "set follow-fork ${follow-fork-mode}"
  95     }
  96
  97     gdb_test "show follow-fork" \
  98     "Debugger response to a program call of fork or vfork is \"${follow-fork-mode}\"."
  99
 100     # Set detach-on-fork mode if we aren't using the default.
 101     if {${detach-on-fork} == "default"} {
 102         set detach-on-fork "on"
 103     } else {
 104         gdb_test_no_output "set detach-on-fork ${detach-on-fork}"
 105     }
 106
 107     gdb_test "show detach-on-fork" \
 108              "Whether gdb will detach.* fork is ${detach-on-fork}."
 109
 110     # Set a breakpoint after the fork if we aren't single-stepping
 111     # past the fork.
 112     if {$cmd == "continue"} {
 113         set bp_after_fork [gdb_get_line_number "set breakpoint here"]
 114         gdb_test "break ${srcfile}:$bp_after_fork" \
 115                  "Breakpoint.*, line $bp_after_fork.*" \
 116                  "set breakpoint after fork"
 117     }
 118
 119     # Set up the output we expect to see after we run.
 120     set expected_re ""
 121     if {${follow-fork-mode} == "child"} {
 122         set expected_re "\\\[Attaching after.* fork to.*"
 123         if {${detach-on-fork} == "on"} {
 124             append expected_re "\\\[Detaching after fork from .*"
 125         }
 126         append expected_re "set breakpoint here.*"
 127     } elseif {${follow-fork-mode} == "parent" && ${detach-on-fork} == "on"} {
 128         set expected_re "\\\[Detaching after fork from .*set breakpoint here.*"
 129     } else {
 130         set expected_re ".*set breakpoint here.*"
 131     }
 132
 133     # Test running past and following the fork, using the parameters
 134     # set above.
 135     gdb_test $cmd $expected_re "$cmd past fork"
 136
 137     # Check that we have the inferiors arranged correctly after
 138     # following the fork.
 139     set resume_unfollowed 0
 140     if {${follow-fork-mode} == "parent" && ${detach-on-fork} == "on"} {
 141
 142         # Follow parent / detach child: the only inferior is the parent.
 143         gdb_test "info inferiors" "\\* 1 .* process.*"
 144
 145     } elseif {${follow-fork-mode} == "parent" && ${detach-on-fork} == "off"} {
 146
 147         # Follow parent / keep child: two inferiors under debug, the
 148         # parent is the current inferior.
 149         gdb_test "info inferiors" "\\* 1 .*process.* 2 .*process.*"
 150
 151         gdb_test "inferior 2" "Switching to inferior 2 .*"
 152         set resume_unfollowed 1
 153
 154     } elseif {${follow-fork-mode} == "child" && ${detach-on-fork} == "on"} {
 155
 156         # Follow child / detach parent: the child is under debug and is
 157         # the current inferior.  The parent is listed but is not under
 158         # debug.
 159         gdb_test "info inferiors" " 1 .*<null>.*\\* 2 .*process.*"
 160
 161     } elseif {${follow-fork-mode} == "child" && ${detach-on-fork} == "off"} {
 162
 163         # Follow child / keep parent: two inferiors under debug, the
 164         # child is the current inferior.
 165         gdb_test "info inferiors" " 1 .*process.*\\* 2 .*process.*"
 166
 167         gdb_test "inferior 1" "Switching to inferior 1 .*"
 168         set resume_unfollowed 1
 169     }
 170
 171     if {$resume_unfollowed == 1} {
 172         if {$cmd == "next 2"} {
 173
 174             gdb_continue_to_end "continue unfollowed inferior to end"
 175
 176         } elseif {$cmd == "continue"} {
 177
 178             gdb_continue_to_breakpoint \
 179                 "continue unfollowed inferior to bp" \
 180                 ".* set breakpoint here.*"
 181         }
 182     }
 183
 184     # If we end up with two inferiors, verify that they each end up with their
 185     # own program space.  Do this by setting a breakpoint, if we see two
 186     # locations it means there are two program spaces.
 187     if {${detach-on-fork} == "off" || ${follow-fork-mode} == "child"} {
 188         set bpnum "<unset>"
 189         gdb_test_multiple "break callee" "break callee" {
 190             -re -wrap "Breakpoint ($::decimal) at $::hex: callee\\. \\(2 locations\\)" {
 191                 set bpnum $expect_out(1,string)
 192                 pass $gdb_test_name
 193             }
 194         }
 195
 196         set any {[^\r\n]+}
 197
 198         set loc1_inf1 "$bpnum\\.1 $any inf 1"
 199         set loc1_inf2 "$bpnum\\.1 $any inf 2"
 200
 201         set loc2_inf1 "$bpnum\\.2 $any inf 1"
 202         set loc2_inf2 "$bpnum\\.2 $any inf 2"
 203
 204         gdb_test "info breakpoints $bpnum" \
 205             "($loc1_inf1\r\n$loc2_inf2|$loc1_inf2\r\n$loc2_inf1)" \
 206             "info breakpoints"
 207     }
 208 }
 209
 210 set reading_in_symbols_re {(?:\r\nReading in symbols for [^\r\n]*)?}
 211
 212 # Test the ability to catch a fork, specify that the child be
 213 # followed, and continue.  Make the catchpoint permanent.
 214
 215 proc_with_prefix catch_fork_child_follow {} {
 216     global gdb_prompt
 217     global srcfile
 218     global reading_in_symbols_re
 219
 220     if { ![setup] } {
 221         return
 222     }
 223
 224     set bp_after_fork [gdb_get_line_number "set breakpoint here"]
 225
 226     gdb_test "catch fork" \
 227         "Catchpoint \[0-9\]* \\(fork\\)$reading_in_symbols_re" \
 228         "explicit child follow, set catch fork"
 229
 230     # Verify that the catchpoint is mentioned in an "info breakpoints",
 231     # and further that the catchpoint mentions no process id.
 232     gdb_test "info breakpoints" \
 233         ".*catchpoint.*keep y.*fork\[\r\n\]+" \
 234         "info breakpoints before fork"
 235
 236     gdb_test "continue" \
 237         "Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
 238         "explicit child follow, catch fork"
 239
 240     # Verify that the catchpoint is mentioned in an "info breakpoints",
 241     # and further that the catchpoint managed to capture a process id.
 242     gdb_test "info breakpoints" \
 243         ".*catchpoint.*keep y.*fork, process.*" \
 244         "info breakpoints after fork"
 245
 246     gdb_test_no_output "set follow-fork child"
 247
 248     gdb_test "tbreak ${srcfile}:$bp_after_fork" \
 249         "Temporary breakpoint.*, line $bp_after_fork.*" \
 250         "set follow-fork child, tbreak"
 251
 252     set expected_re "\\\[Attaching after.* fork to.*\\\[Detaching after fork from"
 253     append expected_re ".* at .*$bp_after_fork.*"
 254     gdb_test "continue" $expected_re "set follow-fork child, hit tbreak"
 255
 256     # The parent has been detached; allow time for any output it might
 257     # generate to arrive, so that output doesn't get confused with
 258     # any expected debugger output from a subsequent testpoint.
 259     #
 260     exec sleep 1
 261
 262     gdb_test "delete breakpoints" \
 263         "" \
 264         "set follow-fork child, cleanup" \
 265         "Delete all breakpoints. \\(y or n\\) $" \
 266         "y"
 267 }
 268
 269 # Test that parent breakpoints are successfully detached from the
 270 # child at fork time, even if the user removes them from the
 271 # breakpoints list after stopping at a fork catchpoint.
 272
 273 proc_with_prefix catch_fork_unpatch_child {} {
 274     global gdb_prompt
 275     global srcfile
 276
 277     if { ![setup] } {
 278         return
 279     }
 280
 281     set bp_exit [gdb_get_line_number "at exit"]
 282
 283     gdb_test "break callee" "file .*$srcfile, line .*" \
 284         "unpatch child, break at callee"
 285     gdb_test "catch fork" "Catchpoint \[0-9\]* \\(fork\\)" \
 286         "unpatch child, set catch fork"
 287
 288     gdb_test "continue" \
 289         "Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
 290         "unpatch child, catch fork"
 291
 292     # Delete all breakpoints and catchpoints.
 293     delete_breakpoints
 294
 295     # Force $srcfile as the current GDB source can be in glibc sourcetree.
 296     gdb_test "break $srcfile:$bp_exit" \
 297         "Breakpoint .*file .*$srcfile, line .*" \
 298         "unpatch child, breakpoint at exit call"
 299
 300     gdb_test_no_output "set follow-fork child" \
 301         "unpatch child, set follow-fork child"
 302
 303     set test "unpatch child, unpatched parent breakpoints from child"
 304     gdb_test_multiple "continue" $test {
 305         -re "at exit.*$gdb_prompt $" {
 306             pass "$test"
 307         }
 308         -re "SIGTRAP.*$gdb_prompt $" {
 309             fail "$test"
 310
 311             # Explicitly kill this child, so we can continue gracefully
 312             # with further testing...
 313             send_gdb "kill\n"
 314             gdb_expect {
 315                 -re ".*Kill the program being debugged.*y or n. $" {
 316                     send_gdb "y\n"
 317                     gdb_expect -re "$gdb_prompt $" {}
 318                 }
 319             }
 320         }
 321     }
 322 }
 323
 324 # Test the ability to catch a fork, specify via a -do clause that
 325 # the parent be followed, and continue.  Make the catchpoint temporary.
 326
 327 proc_with_prefix tcatch_fork_parent_follow {} {
 328     global gdb_prompt
 329     global srcfile
 330     global reading_in_symbols_re
 331
 332     if { ![setup] } {
 333         return
 334     }
 335
 336     set bp_after_fork [gdb_get_line_number "set breakpoint here"]
 337
 338     gdb_test "catch fork" \
 339         "Catchpoint \[0-9\]* \\(fork\\)$reading_in_symbols_re" \
 340         "explicit parent follow, set tcatch fork"
 341
 342 # ??rehrauer: I don't yet know how to get the id of the tcatch
 343 # via this script, so that I can add a -do list to it.  For now,
 344 # do the follow stuff after the catch happens.
 345
 346     gdb_test "continue" \
 347         "Catchpoint \[0-9\]* \\(forked process \[0-9\]*\\),.*" \
 348         "explicit parent follow, tcatch fork"
 349
 350     gdb_test_no_output "set follow-fork parent"
 351
 352     gdb_test "tbreak ${srcfile}:$bp_after_fork" \
 353         "Temporary breakpoint.*, line $bp_after_fork.*" \
 354         "set follow-fork parent, tbreak"
 355
 356     gdb_test "continue" \
 357         "\\\[Detaching after fork from.* at .*$bp_after_fork.*" \
 358         "set follow-fork parent, hit tbreak"
 359
 360     # The child has been detached; allow time for any output it might
 361     # generate to arrive, so that output doesn't get confused with
 362     # any expected debugger output from a subsequent testpoint.
 363     #
 364     exec sleep 1
 365
 366     gdb_test "delete breakpoints" \
 367         "" \
 368         "set follow-fork parent, cleanup" \
 369         "Delete all breakpoints. \\(y or n\\) $" \
 370         "y"
 371 }
 372
 373 # Test simple things about the "set follow-fork-mode" command.
 374
 375 proc_with_prefix test_set_follow_fork_command {} {
 376     clean_restart
 377
 378     # Verify that help is available for "set follow-fork-mode".
 379     #
 380     gdb_test "help set follow-fork-mode" \
 381         "Set debugger response to a program call of fork or vfork..*
 382 A fork or vfork creates a new process.  follow-fork-mode can be:.*
 383 .*parent  - the original process is debugged after a fork.*
 384 .*child   - the new process is debugged after a fork.*
 385 The unfollowed process will continue to run..*
 386 By default, the debugger will follow the parent process..*"
 387
 388     # Verify that we can set follow-fork-mode, using an abbreviation
 389     # for both the flag and its value.
 390     #
 391     gdb_test_no_output "set follow-fork ch"
 392
 393     gdb_test "show follow-fork" \
 394         "Debugger response to a program call of fork or vfork is \"child\".*" \
 395         "set follow-fork, using abbreviations"
 396
 397     # Verify that we cannot set follow-fork-mode to nonsense.
 398     #
 399     gdb_test "set follow-fork chork" "Undefined item: \"chork\".*" \
 400         "set follow-fork to nonsense is prohibited"
 401
 402     gdb_test_no_output "set follow-fork parent" "reset parent"
 403 }
 404
 405 test_set_follow_fork_command
 406
 407 if { ![check_fork_catchpoints] } {
 408     untested "follow-fork not supported"
 409     return
 410 }
 411
 412 # Test the basic follow-fork functionality using all combinations of
 413 # values for follow-fork-mode and detach-on-fork, using either a
 414 # breakpoint or single-step to execute past the fork.
 415 #
 416 # The first loop should be sufficient to test the defaults.  There
 417 # is no need to test using the defaults in other permutations (e.g.
 418 # "default" "on", "parent" "default", etc.).
 419 foreach_with_prefix cmd {"next 2" "continue"} {
 420     test_follow_fork "default" "default" $cmd
 421 }
 422
 423 # Now test all explicit permutations.
 424 foreach_with_prefix follow-fork-mode {"parent" "child"} {
 425     foreach_with_prefix detach-on-fork {"on" "off"} {
 426         foreach_with_prefix cmd {"next 2" "continue"} {
 427             test_follow_fork ${follow-fork-mode} ${detach-on-fork} $cmd
 428         }
 429     }
 430 }
 431
 432 # Catchpoint tests.
 433
 434 catch_fork_child_follow
 435 catch_fork_unpatch_child
 436 tcatch_fork_parent_follow