#!/usr/bin/env perl

# Copyright (C) 2014-2015 Apple Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1.  Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer. 
# 2.  Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution. 
#
# THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

use strict;
use FindBin;
use Getopt::Long qw(:config pass_through);
use POSIX;

# First we run the test once to determine what the number of static OSR exits is. Then
# we run it for each static OSR exit index, and for each index, we force exit on the
# first dynamic time that exit is taken, the last, and something in the middle.

my $verbose = 0;

# We allow flags to be passed via environment variables, which is rather useful for
# running with the run-jsc-stress-tests harness.
if (defined($ENV{JS_OSRFUZZ_VERBOSE})) {
    $verbose = $ENV{JS_OSRFUZZ_VERBOSE};
}

GetOptions(
    'verbose' => \$verbose
);

my $commandString = shift @ARGV;

my $staticCheckCount;

sub fail {
    my $context = shift;
    select((select(STDOUT), $ |= 1)[0]); # This is a perlism for flush. We need to do it this way to support older perls.
    select((select(STDERR), $ |= 1)[0]);
    die "Failure for command $commandString: $context";
}

if (shift @ARGV) {
    die "Ignoring garbage arguments; only the first non-option argument is used as the command string.";
}

open (my $testInput, "$commandString |") or fail("Cannot execute initial command when getting static OSR exit count");
while (my $inputLine = <$testInput>) {
    chomp($inputLine);
    my $handled = 0;
    if ($inputLine =~ /^JSC OSR EXIT FUZZ:/) {
        if ($' =~ /encountered ([0-9]+) static checks\./) {
            $staticCheckCount = $1;
        }
        $handled = 1;
    }
    if (!$handled || $verbose) {
        print "staticCheckCount: $inputLine\n";
    }
}
close($testInput);

if ($verbose) {
    print "Static check count: $staticCheckCount\n";
}

if (!$staticCheckCount) {
    print "OSR exit fuzz testing not supported by jsc binary.\n";
    exit 0;
}

for (my $staticCheckIndex = 1; $staticCheckIndex <= $staticCheckCount; ++$staticCheckIndex) {
    if ($verbose) {
        print "Detecting number of dynamic checks for static check at index $staticCheckIndex.\n";
    }
    open (my $testInput, "$commandString --fireOSRExitFuzzAtStatic=$staticCheckIndex |") or fail("Cannot execute command for static check index $staticCheckIndex");
    my $dynamicCheckCount;
    while (my $inputLine = <$testInput>) {
        chomp($inputLine);
        my $handled = 0;
        if ($inputLine =~ /^JSC OSR EXIT FUZZ:/) {
            if ($' =~ /encountered ([0-9]+) dynamic checks\./) {
                $dynamicCheckCount = $1;
            }
            $handled = 1;
        }
        if (!$handled || $verbose) {
            print "dynamicCheckCount: $inputLine\n";
        }
    }
    close($testInput);
    
    if ($verbose) {
        print "Dynamic check count: $dynamicCheckCount\n";
    }
    
    # Now test triggering the exit at three points: always, immediately, at the last possible
    # moment, and somewhere in between. We use "0" to mean always.
    my @triggers = (0, 1, int((1 + $dynamicCheckCount) / 2), $dynamicCheckCount);
    for (my $triggerIndex = 0; $triggerIndex < scalar @triggers; ++$triggerIndex) {
        my $dynamicCheckIndex = $triggers[$triggerIndex];
        if ($verbose) {
            if ($dynamicCheckIndex == 0) {
                print "Running with static check index = $staticCheckIndex and all dynamic check indices.\n";
            } else {
                print "Running with static check index = $staticCheckIndex and dynamic check index = $dynamicCheckIndex.\n";
            }
        }
        my $optionToUse;
        if ($dynamicCheckIndex == 0) {
            $optionToUse = "--fireOSRExitFuzzAtOrAfter=1";
        } else {
            $optionToUse = "--fireOSRExitFuzzAt=$dynamicCheckIndex";
        }
        open ($testInput, "$commandString --fireOSRExitFuzzAtStatic=$staticCheckIndex $optionToUse |") or fail("Cannot execute command for static check index $staticCheckIndex and dynamic check index $dynamicCheckIndex");
        while (my $inputLine = <$testInput>) {
            chomp($inputLine);
            my $handled = 0;
            if ($inputLine =~ /^JSC OSR EXIT FUZZ:/) {
                $handled = 1;
            }
            if (!$handled || $verbose) {
                print "testRun: $inputLine\n";
            }
        }
        close($testInput);
    }
    if ($verbose) {
        print "\n";
    }
}

if ($verbose) {
    print "Success!\n";
}