# Copyright 1998, 2007, 2008 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/>.

# Please email any bugs, comments, and/or additions to this file to:
# bug-gdb@prep.ai.mit.edu

if [istarget "m68k-*-elf"] then {
    pass "Test not supported on this target"
    return;
}

load_lib "trace-support.exp"

if $tracelevel then {
	strace $tracelevel
}

set prms_id 0
set bug_id 0

set testfile "circ"
set srcfile ${testfile}.c
set binfile $objdir/$subdir/$testfile

if { [gdb_compile "$srcdir/$subdir/$srcfile" $binfile \
	executable {debug nowarnings}] != "" } {
    untested circ.exp
    return -1
}

# Tests:
# 1) Set up a trace experiment that will collect approximately 10 frames,
#    requiring more than 512 but less than 1024 bytes of cache buffer.
#    (most targets should have at least 1024 bytes of cache buffer!)
#    Run and confirm that it collects all 10 frames.
# 2) Artificially limit the trace buffer to 512 bytes, and rerun the
#    experiment.  Confirm that the first several frames are collected,
#    but that the last several are not.
# 3) Set trace buffer to circular mode, still with the artificial limit
#    of 512 bytes, and rerun the experiment.  Confirm that the last 
#    several frames are collected, but the first several are not.
#

# return 0 for success, 1 for failure
proc run_trace_experiment { pass } {
    gdb_run_cmd 

    if [gdb_test "tstart" \
	    "\[\r\n\]*" \
	    "start trace experiment, pass $pass"] then { return 1; }
    if [gdb_test "continue" \
	    "Continuing.*Breakpoint \[0-9\]+, end.*" \
	    "run to end, pass $pass"] then { return 1; }
    if [gdb_test "tstop" \
	    "\[\r\n\]*" \
	    "stop trace experiment, pass $pass"] then { return 1; }
    return 0;
}

# return 0 for success, 1 for failure
proc set_a_tracepoint { func } {
    if [gdb_test "trace $func" \
	    "Tracepoint \[0-9\]+ at .*" \
	    "set tracepoint at $func"] then {
	return 1;
    }
    if [gdb_trace_setactions "set actions for $func" \
	    "" \
	    "collect testload" "^$"] then {
	return 1;
    }
    return 0;
}

# return 0 for success, 1 for failure
proc setup_tracepoints { } {
    gdb_delete_tracepoints
    if [set_a_tracepoint func0] then { return 1; }
    if [set_a_tracepoint func1] then { return 1; }
    if [set_a_tracepoint func2] then { return 1; }
    if [set_a_tracepoint func3] then { return 1; }
    if [set_a_tracepoint func4] then { return 1; }
    if [set_a_tracepoint func5] then { return 1; }
    if [set_a_tracepoint func6] then { return 1; }
    if [set_a_tracepoint func7] then { return 1; }
    if [set_a_tracepoint func8] then { return 1; }
    if [set_a_tracepoint func9] then { return 1; }
    return 0;
}

# return 0 for success, 1 for failure
proc trace_buffer_normal { } {
    if [gdb_test "maint packet QTBuffer:size:ffffffff" \
	    "received: .OK." ""] then { 
	pass "This test cannot be run on this target"
	return 1;
    }
    if [gdb_test "maint packet QTBuffer:circular:0" \
	    "received: .OK." ""] then { 
	pass "This test cannot be run on this target"
	return 1;
    }
    return 0;
}

# return 0 for success, 1 for failure
proc gdb_trace_circular_tests { } {

    # We generously give ourselves one "pass" if we successfully 
    # detect that this test cannot be run on this target!
    if { ![gdb_target_supports_trace] } then { 
	pass "Current target does not support trace"
	return 1;
    }

    if [trace_buffer_normal] then { return 1; }

    gdb_test "break begin" "" ""
    gdb_test "break end"   "" ""
    gdb_test "tstop"       "" ""
    gdb_test "tfind none"  "" ""

    if [setup_tracepoints] then { return 1; }

    # First, run the trace experiment with default attributes:
    # Make sure it behaves as expected.
    if [run_trace_experiment 1] then { return 1; }
    if [gdb_test "tfind start" \
	    "#0  func0 .*" \
	    "find frame zero, pass 1"] then { return 1; }

    if [gdb_test "tfind 9" \
	    "#0  func9 .*" \
	    "find frame nine, pass 1"] then { return 1; }

    if [gdb_test "tfind none" \
	    "#0  end .*" \
	    "quit trace debugging, pass 1"] then { return 1; }

    # Then, shrink the trace buffer so that it will not hold
    # all ten trace frames.  Verify that frame zero is still
    # collected, but frame nine is not.
    if [gdb_test "maint packet QTBuffer:size:200" \
	    "received: .OK." "shrink the target trace buffer"] then { 
	return 1;
    }
    if [run_trace_experiment 2] then { return 1; }
    if [gdb_test "tfind start" \
	    "#0  func0 .*" \
	    "find frame zero, pass 2"] then { return 1; }

    if [gdb_test "tfind 9" \
	    ".* failed to find .*" \
	    "fail to find frame nine, pass 2"] then { return 1; }

    if [gdb_test "tfind none" \
	    "#0  end .*" \
	    "quit trace debugging, pass 2"] then { return 1; }

    # Finally, make the buffer circular.  Now when it runs out of
    # space, it should wrap around and overwrite the earliest frames.
    # This means that:
    #   1) frame zero will be overwritten and therefore unavailable
    #   2) the earliest frame in the buffer will be other-than-zero
    #   3) frame nine will be available (unlike on pass 2).
    if [gdb_test "maint packet QTBuffer:circular:1" \
	    "received: .OK." "make the target trace buffer circular"] then { 
	return 1;
    }
    if [run_trace_experiment 3] then { return 1; }
    if [gdb_test "tfind start" \
	    "#0  func\[1-9\] .*" \
	    "first frame is NOT frame zero, pass 3"] then { return 1; }

    if [gdb_test "tfind 9" \
	    "#0  func9 .*" \
	    "find frame nine, pass 3"] then { return 1; }

    if [gdb_test "tfind none" \
	    "#0  end .*" \
	    "quit trace debugging, pass 3"] then { return 1; }

    return 0;
}

# Start with a fresh gdb.

gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
gdb_load $binfile
 
if [target_info exists gdb_stub] {
    gdb_step_for_stub;
}
# Body of test encased in a proc so we can return prematurely.
if { ![gdb_trace_circular_tests] } then {
    # Set trace buffer attributes back to normal
    trace_buffer_normal;
}

# Finished!
gdb_test "tfind none" "" ""
