#!/usr/bin/perl

# Copyright (C) 2007 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. 
# 3.  Neither the name of Apple Inc. ("Apple") nor the names of
#     its contributors may be used to endorse or promote products derived
#     from this software without specific prior written permission. 
#
# 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.

# Script to run the Mac OS X leaks tool with more expressive '-exclude' lists.

use strict;
use warnings;

use File::Basename;
use Getopt::Long;

sub runLeaks($);
sub parseLeaksOutput(\@);
sub removeMatchingRecords(\@$\@);
sub reportError($);

sub main()
{
    # Read options.
    my $usage =
        "Usage: " . basename($0) . " [options] pid | executable name\n" .
        "  --exclude-callstack regexp   Exclude leaks whose call stacks match the regular expression 'regexp'.\n" .
        "  --exclude-type regexp        Exclude leaks whose data types match the regular expression 'regexp'.\n" .
        "  --help                       Show this help message.\n";

    my @callStacksToExclude = ();
    my @typesToExclude = ();
    my $help = 0;

    my $getOptionsResult = GetOptions(
        'exclude-callstack:s' => \@callStacksToExclude,
        'exclude-type:s' => \@typesToExclude,
        'help' => \$help
    );
    my $pidOrExecutableName = $ARGV[0];

    if (!$getOptionsResult || $help) {
        print STDERR $usage;
        return 1;
    }

    if (!$pidOrExecutableName) {
        reportError("Missing argument: pid | executable.");
        print STDERR $usage;
        return 1;
    }

    # Run leaks tool.
    my $leaksOutput = runLeaks($pidOrExecutableName);
    if (!$leaksOutput) {
        return 1;
    }

    my $leakList = parseLeaksOutput(@$leaksOutput);
    if (!$leakList) {
        return 1;
    }

    # Filter output.
    my $leakCount = @$leakList;
    removeMatchingRecords(@$leakList, "callStack", @callStacksToExclude);
    removeMatchingRecords(@$leakList, "type", @typesToExclude);
    my $excludeCount = $leakCount - @$leakList;

    # Dump results.
    print $leaksOutput->[0];
    print $leaksOutput->[1];
    foreach my $leak (@$leakList) {
        print $leak->{"leaksOutput"};
    }

    if ($excludeCount) {
        print "$excludeCount leaks excluded (not printed)\n";
    }

    return 0;
}

exit(main());

# Returns the output of the leaks tool in list form.
sub runLeaks($)
{
    my ($pidOrExecutableName) = @_;
    
    my @leaksOutput = `leaks $pidOrExecutableName`;
    if (!@leaksOutput) {
        reportError("Error running leaks tool.");
        return;
    }
    
    return \@leaksOutput;
}

# Returns a list of hash references with the keys { address, size, type, callStack, leaksOutput }
sub parseLeaksOutput(\@)
{
    my ($leaksOutput) = @_;

    # Format:
    #   Process 00000: 1234 nodes malloced for 1234 KB
    #   Process 00000: XX leaks for XXX total leaked bytes.    
    #   Leak: 0x00000000 size=1234 [instance of 'blah']
    #       0x00000000 0x00000000 0x00000000 0x00000000 a..d.e.e
    #       ...
    #       Call stack: leak_caller() | leak() | malloc
    #
    #   We treat every line except for  Process 00000: and Leak: as optional

    # Skip header section until the first two "Process " lines.
    # FIXME: In the future we may wish to propagate the header section through to our output.
    until ($leaksOutput->[0] =~ /^Process /) {
        shift @$leaksOutput;
    }

    my ($leakCount) = ($leaksOutput->[1] =~ /[[:blank:]]+([0-9]+)[[:blank:]]+leaks?/);
    if (!defined($leakCount)) {
        reportError("Could not parse leak count reported by leaks tool.");
        return;
    }

    my @leakList = ();
    for my $line (@$leaksOutput) {
        next if $line =~ /^Process/;
        next if $line =~ /^node buffer added/;
        
        if ($line =~ /^Leak: /) {
            my ($address) = ($line =~ /Leak: ([[:xdigit:]x]+)/);
            if (!defined($address)) {
                reportError("Could not parse Leak address.");
                return;
            }

            my ($size) = ($line =~ /size=([[:digit:]]+)/);
            if (!defined($size)) {
                reportError("Could not parse Leak size.");
                return;
            }

            my ($type) = ($line =~ /'([^']+)'/); #'
            if (!defined($type)) {
                $type = ""; # The leaks tool sometimes omits the type.
            }

            my %leak = (
                "address" => $address,
                "size" => $size,
                "type" => $type,
                "callStack" => "", # The leaks tool sometimes omits the call stack.
                "leaksOutput" => $line
            );
            push(@leakList, \%leak);
        } else {
            $leakList[$#leakList]->{"leaksOutput"} .= $line;
            if ($line =~ /Call stack:/) {
                $leakList[$#leakList]->{"callStack"} = $line;
            }
        }
    }
    
    if (@leakList != $leakCount) {
        my $parsedLeakCount = @leakList;
        reportError("Parsed leak count($parsedLeakCount) does not match leak count reported by leaks tool($leakCount).");
        return;
    }

    return \@leakList;
}

sub removeMatchingRecords(\@$\@)
{
    my ($recordList, $key, $regexpList) = @_;
    
    RECORD: for (my $i = 0; $i < @$recordList;) {
        my $record = $recordList->[$i];

        foreach my $regexp (@$regexpList) {
            if ($record->{$key} =~ $regexp) {
                splice(@$recordList, $i, 1);
                next RECORD;
            }
        }
        
        $i++;
    }
}

sub reportError($)
{
    my ($errorMessage) = @_;
    
    print STDERR basename($0) . ": $errorMessage\n";
}