# This testcase is part of GDB, the GNU debugger.

# Copyright 2017-2021 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/>.

# This testcase exercises GDB's terminal ownership management
# (terminal_ours/terminal_inferior, etc.) when debugging multiple
# inferiors.  It tests debugging multiple inferiors started with
# different combinations of 'run'/'run+tty'/'attach', and ensures that
# the process that is sharing GDB's terminal/session is properly made
# the GDB terminal's foregound process group (i.e., "given the
# terminal").

standard_testfile

if ![can_spawn_for_attach] {
    return 0
}

if [build_executable "failed to prepare" $testfile $srcfile {debug}] {
    return -1
}

# Start the programs running and then wait for a bit, to be sure that
# they can be attached to.  We start these processes upfront in order
# to reuse them for the different iterations.  This makes the testcase
# faster, compared to calling spawn_wait_for_attach for each iteration
# in the testing matrix.

set spawn_id_list [spawn_wait_for_attach [list $binfile $binfile]]
set attach_spawn_id1 [lindex $spawn_id_list 0]
set attach_spawn_id2 [lindex $spawn_id_list 1]
set attach_pid1 [spawn_id_get_pid $attach_spawn_id1]
set attach_pid2 [spawn_id_get_pid $attach_spawn_id2]

# Create inferior WHICH_INF.  INF_HOW is how to create it.  This can
# be one of:
#
#  - "run" - for "run" command.
#  - "tty" - for "run" + "tty TTY".
#  - "attach" - for attaching to an existing process.
proc create_inferior {which_inf inf_how} {
    global binfile

    # Run to main and delete breakpoints.
    proc my_runto_main {} {
	if ![runto_main] {
	    return 0
	} else {
	    # Delete breakpoints otherwise GDB would try to step over
	    # the breakpoint at 'main' without resuming the other
	    # inferior, possibly masking the issue we're trying to
	    # test.
	    delete_breakpoints
	    return 1
	}
    }

    if {$inf_how == "run"} {
	if [my_runto_main] {
	    global inferior_spawn_id
	    return $inferior_spawn_id
	}
    } elseif {$inf_how == "tty"} {
	# Create the new PTY for the inferior.
	spawn -pty
	set inf_spawn_id $spawn_id
	set inf_tty_name $spawn_out(slave,name)
	gdb_test_no_output "tty $inf_tty_name" "tty TTY"

	if [my_runto_main] {
	    return $inf_spawn_id
	}
    } elseif {$inf_how == "attach"} {

	# Reuse the inferiors spawned at the start of the testcase (to
	# avoid having to wait the delay imposed by
	# spawn_wait_for_attach).
	global attach_spawn_id$which_inf
	set test_spawn_id [set attach_spawn_id$which_inf]
	set testpid [spawn_id_get_pid $test_spawn_id]
	if {[gdb_test "attach $testpid" \
		 "Attaching to program: .*, process $testpid.*(in|at).*" \
		 "attach"] == 0} {

	    # The program is now stopped, but if testing against
	    # gdbserver, then the inferior's output emmitted before it
	    # stopped isn't flushed unless we explicitly do so,
	    # because it is on a different spawn_id.  Do it now, to
	    # avoid confusing tests further below.
	    gdb_test_multiple "" "flush inferior output" {
		-timeout 1
		-i $test_spawn_id -re "pid=" {
		    exp_continue
		}
		timeout {
		    pass $gdb_test_name
		}
	    }

	    return $test_spawn_id
	}
    } else {
	error "unhandled inf_how: $inf_how"
    }

    return ""
}

# Print debug output.

proc send_debug {str} {
    # Uncomment for debugging.
    #send_user $str
}

# The core of the testcase.  See intro.  Creates two inferiors that
# both loop changing their terminal's settings and printing output,
# and checks whether they receive SIGTTOU.  INF1_HOW and INF2_HOW
# indicate how inferiors 1 and 2 should be created, respectively.  See
# 'create_inferior' above for what arguments these parameters accept.

proc coretest {inf1_how inf2_how} {
    global binfile
    global inferior_spawn_id
    global gdb_spawn_id
    global decimal

    clean_restart $binfile

    with_test_prefix "inf1" {
	set inf1_spawn_id [create_inferior 1 $inf1_how]
    }

    set num 2
    gdb_test "add-inferior" "Added inferior $num.*" \
	"add empty inferior $num"
    gdb_test "inferior $num" "Switching to inferior $num.*" \
	"switch to inferior $num"
    gdb_file_cmd ${binfile}

    with_test_prefix "inf2" {
	set inf2_spawn_id [create_inferior 2 $inf2_how]
    }

    gdb_test_no_output "set schedule-multiple on"

    # "run" makes each inferior be a process group leader.  When we
    # run both inferiors in GDB's terminal/session, only one can end
    # up as the terminal's foreground process group, so it's expected
    # that the other receives a SIGTTOU.
    set expect_ttou [expr {$inf1_how == "run" && $inf2_how == "run"}]

    global gdb_prompt

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

    set pid1 -1
    set pid2 -1

    set test "info inferiors"
    gdb_test_multiple $test $test {
	-re "1${any}process ($decimal)${any}\r\n" {
	    set pid1 $expect_out(1,string)
	    send_debug "pid1=$pid1\n"
	    exp_continue
	}
	-re "2${any}process ($decimal)${any}\r\n" {
	    set pid2 $expect_out(1,string)
	    send_debug "pid2=$pid2\n"
	    exp_continue
	}
	-re "$gdb_prompt $" {
	    pass $test
	}
    }

    # Helper for the gdb_test_multiple call below.  Issues a PASS if
    # we've seen each inferior print at least 3 times, otherwise
    # continues waiting for inferior output.
    proc pass_or_exp_continue {} {
	uplevel 1 {
	    if {$count1 >= 3 && $count2 >= 3} {
		if $expect_ttou {
		    fail "$gdb_test_name (expected SIGTTOU)"
		} else {
		    pass $gdb_test_name
		}
	    } else {
		exp_continue
	    }
	}
    }

    set infs_spawn_ids [list $inf1_spawn_id $inf2_spawn_id]
    send_debug "infs_spawn_ids=$infs_spawn_ids\n"

    set count1 0
    set count2 0

    # We're going to interrupt with Ctrl-C.  For this to work we must
    # be sure to consume the "Continuing." message first, or GDB may
    # still own the terminal.  Also, note that in the attach case, we
    # flushed inferior output right after attaching, so that we're
    # sure that the "pid=" lines we see are emitted by the inferior
    # after it is continued, instead of having been emitted before it
    # was attached to.
    gdb_test_multiple "continue" "continue, hand over terminal" {
	-re "Continuing" {
	    pass $gdb_test_name
	}
    }

    gdb_test_multiple "" "continue" {
	-i $infs_spawn_ids -re "pid=$pid1, count=" {
	    incr count1
	    pass_or_exp_continue
	}
	-i $infs_spawn_ids -re "pid=$pid2, count=" {
	    incr count2
	    pass_or_exp_continue
	}
	-i $gdb_spawn_id -re "received signal SIGTTOU.*$gdb_prompt " {
	    if $expect_ttou {
		pass "$gdb_test_name (expected SIGTTOU)"
	    } else {
		fail "$gdb_test_name (SIGTTOU)"
	    }
	}
    }

    send_gdb "\003"
    if {$expect_ttou} {
	gdb_test "" "Quit" "stop with control-c (Quit)"
    } else {
	gdb_test "" "received signal SIGINT.*" "stop with control-c (SIGINT)"
    }

    # Useful for debugging in case the Ctrl-C above fails.
    with_test_prefix "final" {
	gdb_test "info inferiors"
	gdb_test "info threads"
    }
}

set how_modes {"run" "attach" "tty"}

foreach_with_prefix inf1_how $how_modes {
    foreach_with_prefix inf2_how $how_modes {
	if {($inf1_how == "tty" || $inf2_how == "tty")
	    && [target_info gdb_protocol] == "extended-remote"} {
	    # No way to specify the inferior's tty in the remote
	    # protocol.
	    unsupported "no support for \"tty\" in the RSP"
	    continue
	}

	coretest $inf1_how $inf2_how
    }
}

kill_wait_spawned_process $attach_spawn_id1
kill_wait_spawned_process $attach_spawn_id2