#   Copyright 2018-2019 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/>.

# When caching a proc using gdb_caching_proc, it will become less likely to
# be executed, and consequently it's going to be harder to detect that the
# proc is racy.  OTOH, in general the proc is easy to rerun.  So, run all
# uncached gdb_caching_procs a number of times and detect inconsistent results.
# The purpose of caching is to reduce runtime, so rerunning is somewhat
# counter-productive in that aspect, but it's better than uncached, because the
# number of reruns is constant-bounded, and the increase in runtime is bound to
# this test-case, and could be disabled on slow targets.

# Test gdb_caching_proc NAME
proc test_proc { name } {
    set real_name gdb_real__$name

    set resultlist [list]

    set first [$real_name]
    lappend resultlist $first

    # Ten repetitions was enough to trigger target_supports_scheduler_locking,
    # and costs about 20 seconds on an i7-6600U.
    set repeat 10

    set racy 0
    for {set i 0} {$i < $repeat} {incr i} {
	set rerun [$real_name]
	lappend resultlist $rerun
	if { $rerun != $first } {
	    set racy 1
	}
    }

    if { $racy  == 0 } {
	pass "$name consistency"
    } else {
	fail "$name consistency"
	verbose -log "$name: $resultlist"
    }
}

# Test gdb_caching_procs in FILE
proc test_file { file } {
    upvar obj obj
    set procnames [list]

    set fp [open $file]
    while { [gets $fp line] >= 0 } {
	if [regexp -- "^gdb_caching_proc \[ \t\]*(\[^ \t\]*)" $line \
		match procname] {
	    lappend procnames $procname
	}
    }
    close $fp

    if { [llength $procnames] == 0 } {
	return
    }

    if { [file tail $file] == "gdb.exp" } {
	# Already loaded
    } else {
	load_lib [file tail $file]
    }

    foreach procname $procnames {
	switch $procname {
	    "is_address_zero_readable" { set setup_gdb 1 }
	    "target_is_gdbserver" { set setup_gdb 1 }
	    default {set setup_gdb 0 }
	}

	if { $setup_gdb } {
	    clean_restart $obj
	}

	test_proc $procname

	if { $setup_gdb } {
	    gdb_exit
	}
    }
}

# Init
set me "gdb_caching_proc"
set src { int main() { return 0; } }
if { ![gdb_simple_compile $me $src executable] } {
    return 0
}

# Test gdb_caching_procs in gdb/testsuite/lib/*.exp
set files [eval glob -types f $srcdir/lib/*.exp]
foreach file $files {
    test_file $file
}

# Cleanup
remote_file build delete $obj