# Copyright 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/>.

# Check that GDB can attach to a process started using 'unshare'.  The
# inferior is started in a separate mnt namespace.

require can_spawn_for_attach

standard_testfile

if {[prepare_for_testing "failed to prepare" $testfile $srcfile] == -1} {
    return
}

# This test relies (at least in some parts) on the sysroot being
# 'target:'.  Grab the current sysroot now so we can skip those tests
# if the board file has changed the sysroot.
set sysroot ""
set test "show sysroot"
gdb_test_multiple $test $test {
    -re -wrap "The current system root is \"(.*)\"\\." {
	set sysroot $expect_out(1,string)
    }
}

# Start a process using 'unshare FLAGS', then attach to the process
# from GDB.  Check that the attach worked as expected.
proc run_test { flags } {

    # If FLAGS contains '--mount' then a separate mnt namespace will
    # be created, in which case the executable will have been read
    # from the 'target:'.  Otherwise, the executable will have been
    # read from the local filesystem, and there will be no prefix.
    #
    # Of course, this only applies if the sysroot is 'target:', some
    # boards change this, so skip these tests on those boards.
    if { [lsearch -exact [split $flags " "] "--mount"] != -1 } {
	if { $::sysroot ne "target:" } {
	    return
	}

	set prefix "target:"
    } else {
	set prefix ""
    }

    set unshare_cmd "unshare $flags"

    # Run '/bin/true' using UNSHARE_CMD.  If the flags in UNSHARE_CMD
    # aren't supported then this will fail, this means we shouldn't
    # spawn the command with our test executable and try attaching.
    #
    # This will also fail if /bin/true isn't present, or doesn't work
    # as we expect.  But this should be fine for many targets.
    set res [remote_exec target "$unshare_cmd /bin/true"]
    if { [lindex $res 0] != 0 } {
	unsupported "unshare flags not supported"
	return
    }

    set inferior_spawn_id \
	[spawn_wait_for_attach [list "$unshare_cmd $::binfile"]]
    if { $inferior_spawn_id == -1 } {
	unsupported "failed to spawn for attach"
	return
    }

    set inferior_pid [spawn_id_get_pid $inferior_spawn_id]

    clean_restart

    set saw_bad_warning false
    gdb_test_multiple "attach $inferior_pid" "attach to inferior" {
	-re "^attach $::decimal\r\n" {
	    exp_continue
	}

	-re "^warning: \[^\r\n\]+: could not open as an executable file: \[^\r\n\]+\r\n" {
	    set saw_bad_warning true
	    exp_continue
	}

	-re "^warning: \[^\r\n\]+: can't open to read symbols: \[^\r\n\]+\r\n" {
	    set saw_bad_warning true
	    exp_continue
	}

	-re "^warning: Could not load vsyscall page because no executable was specified\r\n" {
	    # This warning is a secondary consequence of the above bad
	    # warnings, so don't count this as a bad warnings, ignore
	    # it instead.
	    exp_continue
	}

	-re "^warning:\\s+$::decimal\\s*\[^\r\n\]+: No such file or directory\r\n" {
	    # This unrelated warning is seen when GDB stops in libc,
	    # and the source code for libc is not available.
	    exp_continue
	}

	-re "^warning: \[^\r\n\]+\r\n" {
	    # If we ignore "other" warnings then, should the above
	    # warnings strings change we'll start ignoring the bad
	    # warnings, and the test will appear to pass.
	    #
	    # If you are seeing a warning here that really has nothing
	    # to do with the test failing, then the correct solution
	    # is to add a new regexp to specifically match _that_
	    # warning, and ignore it.
	    set saw_bad_warning true
	    exp_continue
	}

	-re "^$::gdb_prompt $" {
	    gdb_assert { !$saw_bad_warning } $gdb_test_name
	}

	-re "^\[^\r\n\]*\r\n" {
	    exp_continue
	}
    }

    # Ensure GDB could access the executable.
    set binfile_re [string_to_regexp $::binfile]
    gdb_test "info inferiors" \
	"\r\n\\*\\s+$::decimal\\s+\[^\r\n\]+\\s+${prefix}${binfile_re}\\s*"
}

set test_flags [list \
		    "--mount --map-root-user" \
		    "--user" \
		    "--user --map-root-user"]

foreach_with_prefix flags $test_flags {
    run_test $flags
}