binutils-gdb/gdb/testsuite/gdb.threads/foll-fork-other-thread.exp

# Copyright 2022-2025 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Test catching a vfork/fork in one thread, and then doing a "next" in
# another thread, in different combinations of "set follow-fork
# parent/child", and other execution modes.

require allow_fork_tests

standard_testfile

# Line where to stop the main thread.
set break_here_line [gdb_get_line_number "break here"]

# Build executables, one for each fork flavor.
foreach_with_prefix fork_func {fork vfork} {
    set opts [list debug pthreads additional_flags=-DFORK_FUNC=${fork_func}]
    if { [build_executable "failed to prepare" \
	    ${testfile}-${fork_func} ${srcfile} $opts] } {
	return
    }
}

# Run the test with the given parameters:
#
#   - FORK_FUNC: fork flavor, "fork" or "vfork".
#   - FOLLOW: "set follow-fork" value, either "parent" or "child".
#   - TARGET-NON-STOP: "maintenance set target-non-stop" value, "auto", "on" or
#     "off".
#   - NON-STOP: "set non-stop" value, "on" or "off".
#   - DISPLACED-STEPPING: "set displaced-stepping" value, "auto", "on" or "off".

proc do_test { fork_func follow target-non-stop non-stop displaced-stepping } {
    save_vars { ::GDBFLAGS } {
	append ::GDBFLAGS " -ex \"maintenance set target-non-stop ${target-non-stop}\""
	append ::GDBFLAGS " -ex \"set non-stop ${non-stop}\""
	clean_restart ${::binfile}-${fork_func}
    }

    gdb_test_no_output "set displaced-stepping ${displaced-stepping}"

    if { ![runto_main] } {
	return
    }

    delete_breakpoints

    gdb_test "catch $fork_func" "Catchpoint .*"

    # Verify that the catchpoint is mentioned in an "info breakpoints",
    # and further that the catchpoint mentions no process id.
    gdb_test "info breakpoints" \
	".*catchpoint.*keep y.*fork" \
	"info breakpoints before fork"

    gdb_test "continue" \
	"Catchpoint \[0-9\]* \\(.?forked process \[0-9\]*\\),.*" \
	"explicit child follow, catch fork"

    # Verify that the catchpoint is mentioned in an "info breakpoints",
    # and further that the catchpoint managed to capture a process id.
    gdb_test "info breakpoints" \
	".*catchpoint.*keep y.*fork, process.*" \
	"info breakpoints after fork"

    gdb_test "thread 1" "Switching to .*"

    gdb_test_no_output "set scheduler-locking on"

    # Advance the next-ing thread to the point where we'll execute the
    # next.
    gdb_test "break $::srcfile:$::break_here_line" "Breakpoint $::decimal at $::hex.*"
    gdb_test "continue" "hit Breakpoint $::decimal, main.*"

    # Disable schedlock and step.  The pending fork should no longer
    # be pending afterwards.

    gdb_test "set scheduler-locking off"

    # Make sure GDB doesn't try to step over the breakpoint at PC
    # first, we want to make sure that GDB doesn't lose focus of the
    # step/next in this thread.  A breakpoint would make GDB switch
    # focus anyhow, thus hide a potential bug.
    delete_breakpoints

    gdb_test_no_output "set follow-fork $follow"

    set any "\[^\r\n\]*"

    if {$follow == "child"} {

	# For fork, GDB detaches from the parent at follow-fork time.
	# For vfork, GDB detaches from the parent at child exit/exec
	# time.
	if {$fork_func == "fork"} {
	    set detach_parent \
		[multi_line \
		     "\\\[Detaching after $fork_func from parent process $any\\\]" \
		     "\\\[Inferior 1 $any detached\\\]"]
	} else {
	    set detach_parent ""
	}

	gdb_test "next" \
	    [multi_line \
		 "\\\[Attaching after $any $fork_func to child $any\\\]" \
		 "\\\[New inferior 2 $any\\\]" \
		 "$detach_parent.*warning: Not resuming: switched threads before following fork child\\." \
		 "\\\[Switching to $any\\\]" \
		 ".*"] \
	    "next aborts resumption"

	# The child should be stopped inside the fork implementation
	# in the runtime.  Exactly at which instruction/function is
	# system dependent, but we can check that our
	# "gdb_forker_thread" function appears in the backtrace.
	gdb_test "bt" " in gdb_forker_thread ${any} at ${any}${::srcfile}:.*"

	# The child is now thread 1.
	gdb_test "print \$_thread" " = 1"

	if {$fork_func == "fork"} {
	    gdb_test "continue" \
		[multi_line \
		     "Continuing." \
		     "\\\[Inferior 2 \\\(process $any\\\) exited normally\\\]"] \
		"continue to exit"
	} else {
	    gdb_test "continue" \
		[multi_line \
		     "Continuing." \
		     "\\\[Detaching vfork parent process $any after child exit\\\]" \
		     "\\\[Inferior 1 \\\(process $any\\\) detached\\\]" \
		     "\\\[Inferior 2 \\\(process $any\\\) exited normally\\\]"] \
		"continue to exit"
	}
    } else {
	gdb_test "next" \
	    "\\\[Detaching after $fork_func from child process ${any}\\\].* other line .*" \
	    "next to other line"

	gdb_test "print \$_thread" " = 1"

	gdb_test "continue" \
	    [multi_line \
		 "Continuing." \
		 "\\\[Inferior 1 \\\(process $any\\\) exited normally\\\]"] \
	    "continue to exit"
    }
}

foreach_with_prefix fork_func {fork vfork} {
    foreach_with_prefix follow {child} {
	foreach_with_prefix target-non-stop {auto on off} {
	    foreach_with_prefix non-stop {off} {
		foreach_with_prefix displaced-stepping {auto on off} {
		    do_test ${fork_func} ${follow} ${target-non-stop} ${non-stop} ${displaced-stepping}
		}
	    }
	}
    }
}