#   Copyright 1998-2020 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 test helps making sure QTro support doesn't regress.  If the
# stub supports the newer qXfer:traceframe-info:read, then the QTro
# paths in the stub are never exercised.  PR remote/15455 is an
# example of a regression that unfortunately went unnoticed for long.

load_lib trace-support.exp

standard_testfile

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

if ![runto_main] {
    fail "can't run to main to check for trace support"
    return -1
}

# Check whether we're testing with the remote or extended-remote
# targets, and whether the target supports tracepoints.

if ![gdb_is_target_remote] {
    return -1
}

if ![gdb_target_supports_trace] {
    unsupported "current target does not support trace"
    return -1
}

# Run a trace session, stop it, and then inspect the resulting trace
# frame (IOW, returns while tfind mode is active).
proc prepare_for_trace_disassembly { } {
    global gdb_prompt
    gdb_breakpoint "end" qualified

    gdb_test "trace subr" "Tracepoint .*" \
	"tracepoint at subr"

    gdb_trace_setactions "define action" \
	"" \
	"collect parm" "^$"

    gdb_test_no_output "tstart"

    gdb_test "continue" ".*Breakpoint \[0-9\]+, end .*" \
	"advance through tracing"

    gdb_test "tstatus" ".*Collected 1 trace frame.*" \
	"collected 1 trace frame"

    gdb_test_no_output "tstop"

    gdb_tfind_test "tfind start" "start" "0"
}

clean_restart $testfile
runto_main

# Trace once, issuing a tstatus, so that GDB tries
# qXfer:trace-frame-info:read.
prepare_for_trace_disassembly

# Now check whether the packet is supported.
set traceframe_info_supported -1
set test "probe for traceframe-info support"
gdb_test_multiple "show remote traceframe-info-packet" $test {
    -re ".*Support for .* is auto-detected, currently (\[a-z\]*).*$gdb_prompt $" {
	set status $expect_out(1,string)

	if { $status == "enabled" } {
	    set traceframe_info_supported 1
	} else {
	    set traceframe_info_supported 0
	}

	pass $test
    }
}
if { $traceframe_info_supported == -1 } {
    return -1
}

# Check whether we're testing with our own GDBserver.
set is_gdbserver [target_is_gdbserver]
if { $is_gdbserver == -1 } {
    return -1
}

# Now disassemble (IOW, read from read-only memory) while inspecting a
# trace frame, twice.  Once with qXfer:traceframe-info:read left to
# auto, and once with it disabled, exercising the QTro fallback path
# in the stub side.
foreach tfinfo { auto off } {
    with_test_prefix "qXfer:traceframe-info:read $tfinfo" {

	clean_restart $testfile
	runto_main
	gdb_test_no_output "set remote traceframe-info-packet $tfinfo"

	prepare_for_trace_disassembly

	set test "trace disassembly"
	gdb_test_multiple "disassemble subr" $test {
	    -re "<(\.\[0-9\]+|)>:.*End of assembler dump.*$gdb_prompt $" {
		pass $test
	    }
	    -re "Cannot access memory.*$gdb_prompt $" {
		if { $traceframe_info_supported == 0 } {
		    # If qXfer:traceframe-info:read is not supported,
		    # then there should be QTro support.
		    fail $test
		} elseif { $tfinfo == off && $is_gdbserver == 1 } {
		    # We we're testing with GDBserver, we know both
		    # qXfer:traceframe-info:read and QTro are
		    # supported (although supporting the former only
		    # would be sufficient), so issue a FAIL instead of
		    # UNSUPPORTED, giving us better visibility of QTro
		    # regressions.
		    fail $test
		} else {
		    # Otherwise, qXfer:traceframe-info:read is
		    # supported, making QTro optional, so this isn't
		    # really a failure.
		    unsupported "$test (no QTro support)"
		}
	    }
	}
    }
}