# This testcase is part of GDB, the GNU debugger.
#
# Copyright 2025-2026 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 what happens if we try to start gdbserver with an empty string
# for the executable name.  In theory we could choose to accept this
# for the extended-remote case, indeed, in the extended-remote case
# it's OK to start gdbserver with no program name or arguments.
#
# But actually specifying an empty executable name seems different,
# and wrong, so for now at least, we don't allow this.  If that
# position changes in the future, then this test will need updating.

# Skip test if target does not support argument passing.
require {!target_info exists noargs}

load_lib gdbserver-support.exp

standard_testfile

require allow_gdbserver_tests

set gdbserver [find_gdbserver]
if { $gdbserver == "" } {
    unsupported "could not find gdbserver"
    return
}

clean_restart

# Try starting gdbserver in extended, and non-extended mode.
foreach_with_prefix proto { extended-remote remote } {

    if { $proto eq "extended-remote" } {
	set server_flag "--multi"
    } else {
	set server_flag ""
    }

    # Try starting gdbserver with and without arguments.
    foreach_with_prefix args { " a b c" "" } {
	# Start gdbserver on its own.  This makes it easier to check
	# the error message that gdbserver emits.  The program name is
	# the empty string.  gdbserver should exit.
	set gdbserver_cmd \
	    "$gdbserver $server_flag --once - \"\"${args}"

	set spawn_id [remote_spawn target $gdbserver_cmd]
	set testname "start gdbserver"
	expect {
	    -i $spawn_id

	    -re "No program to debug\r\nExiting" { pass $testname }

	    eof { fail $testname }
	    timeout { fail $testname }
	}

	catch {
	    close -i $spawn_id
	    wait -nowait -i $spawn_id
	}

	# Try connecting to gdbserver from GDB.  The connection should
	# immediately close as gdbserver exits.  The inferior should
	# be left with no connection.
	gdb_test "disconnect" ".*" \
	    "disconnect before remote connection"

	gdb_test "target $proto | ${::gdbserver} $server_flag --once - \"\"${args}" \
	    [multi_line \
		 "Remote debugging using \\| \[^\r\n\]+" \
		 "Remote communication error\\.  Target disconnected: .*"] \
	    "start gdbserver over stdin"

	gdb_test "info inferiors" \
	    "\\*\\s+1\\s+<null>\\s*" \
	    "check inferior 1 has no connection"
    }
}