gdb/testsuite/gdb.base/vfork-follow-parent.exp

# Copyright 2021-2024 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 running into vfork while "detach-on-fork" is off and "follow-fork-mode"
# is parent.  This shows a "Can not resume the parent process..." message.  If
# the user wants to resume execution, they have to use either "set
# schedule-multiple on" or "set detach-on-fork on".  Test these two resolution
# methods.

standard_testfile .c vforked-prog.c

set binfile ${testfile}-exit
set binfile2 ${testfile}-exec
set binfile3 vforked-prog

if { [build_executable "compile $binfile3" $binfile3 $srcfile2] } {
    untested "failed to compile third test binary"
    return -1
}

if { [is_remote target] } {
    gdb_remote_download target [standard_output_file $binfile3]
}

set opts [list debug additional_flags=-DTEST_EXIT]
if { [build_executable "compile ${binfile}" ${binfile} ${srcfile} ${opts}] } {
    untested "failed to compile first test binary"
    return
}

set opts [list debug additional_flags=-DTEST_EXEC]
if { [build_executable "compile ${binfile2}" ${binfile2} ${srcfile} ${opts}] } {
    untested "failed to compile second test binary"
    return
}

# Test running to the "Can not resume the parent..." message.  Then, resolve
# the situation using the method in RESOLUTION_METHOD, either "detach-on-fork"
# or "schedule-multiple" (the two alternatives the message suggests to the
# user).

proc do_test { exec_file resolution_method target_non_stop non_stop } {
    save_vars { ::GDBFLAGS } {
	append ::GDBFLAGS " -ex \"maint set target-non-stop ${target_non_stop}\""
	append ::GDBFLAGS " -ex \"set non-stop ${non_stop}\""
	clean_restart $exec_file
    }

    gdb_test_no_output "set detach-on-fork off"

    if { ![runto_main] } {
	return
    }

    # Delete the breakpoint on main so we don't bit the breakpoint in
    # the case that the vfork child performs an exec.
    delete_breakpoints

    gdb_test "break break_parent"

    gdb_test "continue" \
	"Can not resume the parent process over vfork .*" \
	"continue to vfork"

    # Try to continue again from there, expecting the same message.  It
    # exercises a different code path in GDB.
    gdb_test "continue" \
	"Can not resume the parent process over vfork .*" \
	"try to continue from vfork"

    # Unblock the execution using the specified resolution method.
    if { $resolution_method == "detach-on-fork" } {
	# Make GDB detach the child.
	gdb_test "set detach-on-fork on"
	gdb_test "print unblock_parent = 1" " = 1"
    } elseif { $resolution_method == "schedule-multiple" } {
	# Make GDB resume both inferiors.  The parent is blocked while the
	# children executes, so the continue will make the child reach the
	# end.
	gdb_test "set schedule-multiple on"
	gdb_test "continue" "$::inferior_exited_re normally.*" \
	    "continue to end of inferior 2"
	gdb_test -no-prompt-anchor "inferior 1" ".*Switching to inferior 1.*"
	gdb_test "print unblock_parent = 1" " = 1"
    } else {
	error "invalid resolution method: $resolution_method"
    }

    # Continue from the vfork call to the breakpoint.
    gdb_test "continue" "Breakpoint $::decimal, break_parent .*" \
	"continue to break_parent"
}

foreach_with_prefix exec_file [list $binfile $binfile2] {
    foreach_with_prefix target-non-stop {on off} {
	# This test was written assuming non-stop mode is off.
	foreach_with_prefix non-stop {off} {
	    if {!${target-non-stop} && ${non-stop}} {
		continue
	    }
	    foreach_with_prefix resolution_method {detach-on-fork schedule-multiple} {
		do_test $exec_file $resolution_method ${target-non-stop} ${non-stop}
	    }
	}
    }
}