Tools/Scripts/bisect-builds - external/Webkit - Git at Google

 #!/usr/bin/perl -w

 # Copyright (C) 2007, 2008, 2011 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 Computer, 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.

 # This script attempts to find the point at which a regression (or progression)
 # of behavior occurred by searching WebKit nightly builds.

 # To override the location where the nightly builds are downloaded or the path
 # to the Safari web browser, create a ~/.bisect-buildsrc file with one or more of
 # the following lines (use "~/" to specify a path from your home directory):
 #
 # $branch = "branch-name";
 # $nightlyDownloadDirectory = "~/path/to/nightly/downloads";
 # $safariPath = "/path/to/Safari.app";

 use strict;

 use File::Basename;
 use File::Path;
 use File::Spec;
 use File::Temp qw(tempfile);
 use FindBin;
 use Getopt::Long;
 use Time::HiRes qw(usleep);

 use lib $FindBin::Bin;
 use webkitdirs qw(safariPathFromSafariBundle);

 sub createTempFile($);
 sub downloadNightly($$$);
 sub findMacOSXVersion();
 sub findNearestNightlyIndex(\@$$);
 sub findSafariVersion($);
 sub loadSettings();
 sub makeNightlyList($$$$);
 sub max($$) { return $_[0] > $_[1] ? $_[0] : $_[1]; }
 sub mountAndRunNightly($$$$);
 sub parseRevisions($$;$);
 sub printStatus($$$);
 sub printTracLink($$);
 sub promptForTest($);

 loadSettings();

 my %validBranches = map { $_ => 1 } qw(feature-branch trunk);
 my $branch = $Settings::branch;
 my $nightlyDownloadDirectory = $Settings::nightlyDownloadDirectory;
 my $safariPath = $Settings::safariPath;

 my @nightlies;

 my $isProgression;
 my $localOnly;
 my @revisions;
 my $sanityCheck;
 my $showHelp;
 my $testURL;

 # Fix up -r switches in @ARGV
 @ARGV = map { /^(-r)(.+)$/ ? ($1, $2) : $_ } @ARGV;

 my $result = GetOptions(
     "b|branch=s"             => \$branch,
     "d|download-directory=s" => \$nightlyDownloadDirectory,
     "h|help"                 => \$showHelp,
     "l|local!"               => \$localOnly,
     "p|progression!"         => \$isProgression,
     "r|revisions=s"          => \&parseRevisions,
     "safari-path=s"          => \$safariPath,
     "s|sanity-check!"        => \$sanityCheck,
 );
 $testURL = shift @ARGV;

 $branch = "feature-branch" if $branch eq "feature";
 if (!exists $validBranches{$branch}) {
     print STDERR "ERROR: Invalid branch '$branch'\n";
     $showHelp = 1;
 }

 if (!$result || $showHelp || scalar(@ARGV) > 0) {
     print STDERR "Search WebKit nightly builds for changes in behavior.\n";
     print STDERR "Usage: " . basename($0) . " [options] [url]\n";
     print STDERR <<END;
   [-b|--branch name]             name of the nightly build branch (default: trunk)
   [-d|--download-directory dir]  nightly build download directory (default: ~/Library/Caches/WebKit-Nightlies)
   [-h|--help]                    show this help message
   [-l|--local]                   only use local (already downloaded) nightlies
   [-p|--progression]             searching for a progression, not a regression
   [-r|--revision M[:N]]          specify starting (and optional ending) revisions to search
   [--safari-path path]           path to Safari application bundle (default: /Applications/Safari.app)
   [-s|--sanity-check]            verify both starting and ending revisions before bisecting
 END
     exit 1;
 }

 my $nightlyWebSite = "http://nightly.webkit.org";
 my $nightlyBuildsURLBase = $nightlyWebSite . File::Spec->catdir("/builds", $branch, "mac");
 my $nightlyFilesURLBase = $nightlyWebSite . File::Spec->catdir("/files", $branch, "mac");

 $nightlyDownloadDirectory = glob($nightlyDownloadDirectory) if $nightlyDownloadDirectory =~ /^~/;
 $safariPath = glob($safariPath) if $safariPath =~ /^~/;
 $safariPath = safariPathFromSafariBundle($safariPath) if $safariPath =~ m#\.app/*#;

 $nightlyDownloadDirectory = File::Spec->catdir($nightlyDownloadDirectory, $branch);
 if (! -d $nightlyDownloadDirectory) {
     mkpath($nightlyDownloadDirectory, 0, 0755) || die "Could not create $nightlyDownloadDirectory: $!";
 }

 @nightlies = makeNightlyList($localOnly, $nightlyDownloadDirectory, findMacOSXVersion(), findSafariVersion($safariPath));

 my $startIndex = $revisions[0] ? findNearestNightlyIndex(@nightlies, $revisions[0], 'ceil') : 0;
 my $endIndex = $revisions[1] ? findNearestNightlyIndex(@nightlies, $revisions[1], 'floor') : $#nightlies;

 my $tempFile = createTempFile($testURL);

 if ($sanityCheck) {
     my $didReproduceBug;

     do {
         printf "\nChecking starting revision r%s...\n",
             $nightlies[$startIndex]->{rev};
         downloadNightly($nightlies[$startIndex]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
         mountAndRunNightly($nightlies[$startIndex]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
         $didReproduceBug = promptForTest($nightlies[$startIndex]->{rev});
         $startIndex-- if $didReproduceBug < 0;
     } while ($didReproduceBug < 0);
     die "ERROR: Bug reproduced in starting revision!  Do you need to test an earlier revision or for a progression?"
         if $didReproduceBug && !$isProgression;
     die "ERROR: Bug not reproduced in starting revision!  Do you need to test an earlier revision or for a regression?"
         if !$didReproduceBug && $isProgression;

     do {
         printf "\nChecking ending revision r%s...\n",
             $nightlies[$endIndex]->{rev};
         downloadNightly($nightlies[$endIndex]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
         mountAndRunNightly($nightlies[$endIndex]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
         $didReproduceBug = promptForTest($nightlies[$endIndex]->{rev});
         $endIndex++ if $didReproduceBug < 0;
     } while ($didReproduceBug < 0);
     die "ERROR: Bug NOT reproduced in ending revision!  Do you need to test a later revision or for a progression?"
         if !$didReproduceBug && !$isProgression;
     die "ERROR: Bug reproduced in ending revision!  Do you need to test a later revision or for a regression?"
         if $didReproduceBug && $isProgression;
 }

 printStatus($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev}, $isProgression);

 my %brokenRevisions = ();
 while (abs($endIndex - $startIndex) > 1) {
     my $index = $startIndex + int(($endIndex - $startIndex) / 2);

     my $didReproduceBug;
     do {
         if (exists $nightlies[$index]) {
             my $buildsLeft = max(max(0, $endIndex - $index - 1), max(0, $index - $startIndex - 1));
             my $plural = $buildsLeft == 1 ? "" : "s";
             printf "\nChecking revision r%s (%d build%s left to test after this)...\n", $nightlies[$index]->{rev}, $buildsLeft, $plural;
             downloadNightly($nightlies[$index]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
             mountAndRunNightly($nightlies[$index]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
             $didReproduceBug = promptForTest($nightlies[$index]->{rev});
         }
         if ($didReproduceBug < 0) {
             $brokenRevisions{$nightlies[$index]->{rev}} = $nightlies[$index]->{file};
             delete $nightlies[$index];
             $endIndex--;
             $index = $startIndex + int(($endIndex - $startIndex) / 2);
         }
     } while ($didReproduceBug < 0);

     if ($didReproduceBug && !$isProgression || !$didReproduceBug && $isProgression) {
         $endIndex = $index;
     } else {
         $startIndex = $index;
     }

     print "\nBroken revisions skipped: r" . join(", r", keys %brokenRevisions) . "\n"
         if scalar keys %brokenRevisions > 0;
     printStatus($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev}, $isProgression);
 }

 printTracLink($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev});

 unlink $tempFile if $tempFile;

 exit 0;

 sub createTempFile($)
 {
     my ($url) = @_;

     return undef if !$url;

     my ($fh, $tempFile) = tempfile(
         basename($0) . "-XXXXXXXX",
         DIR => File::Spec->tmpdir(),
         SUFFIX => ".html",
         UNLINK => 0,
     );
     print $fh "<meta http-equiv=\"refresh\" content=\"0; $url\">\n";
     close($fh);

     return $tempFile;
 }

 sub downloadNightly($$$)
 {
     my ($filename, $urlBase, $directory) = @_;
     my $path = File::Spec->catfile($directory, $filename);
     if (! -f $path) {
         print "Downloading $filename to $directory...\n";
         `curl -# -o '$path' '$urlBase/$filename'`;
     }
 }

 sub findMacOSXVersion()
 {
     my $version;
     open(SW_VERS, "-|", "/usr/bin/sw_vers") || die;
     while (<SW_VERS>) {
         $version = $1 if /^ProductVersion:\s+([^\s]+)/;
     }
     close(SW_VERS);
     return $version;
 }

 sub findNearestNightlyIndex(\@$$)
 {
     my ($nightlies, $revision, $round) = @_;

     my $lowIndex = 0;
     my $highIndex = $#{$nightlies};

     return $highIndex if uc($revision) eq 'HEAD' || $revision >= $nightlies->[$highIndex]->{rev};
     return $lowIndex if $revision <= $nightlies->[$lowIndex]->{rev};

     while (abs($highIndex - $lowIndex) > 1) {
         my $index = $lowIndex + int(($highIndex - $lowIndex) / 2);
         if ($revision < $nightlies->[$index]->{rev}) {
             $highIndex = $index;
         } elsif ($revision > $nightlies->[$index]->{rev}) {
             $lowIndex = $index;
         } else {
             return $index;
         }
     }

     return ($round eq "floor") ? $lowIndex : $highIndex;
 }

 sub findSafariVersion($)
 {
     my ($path) = @_;
     my $versionPlist = File::Spec->catdir(dirname(dirname($path)), "version.plist");
     my $version;
     open(PLIST, "< $versionPlist") || die;
     while (<PLIST>) {
         if (m#^\s*<key>CFBundleShortVersionString</key>#) {
             $version = <PLIST>;
             $version =~ s#^\s*<string>([0-9.]+)[^<]*</string>\s*[\r\n]*#$1#;
         }
     }
     close(PLIST);
     return $version;
 }

 sub loadSettings()
 {
     package Settings;

     our $branch = "trunk";
     our $nightlyDownloadDirectory = File::Spec->catdir($ENV{HOME}, "Library/Caches/WebKit-Nightlies");
     our $safariPath = "/Applications/Safari.app";

     my $rcfile = File::Spec->catdir($ENV{HOME}, ".bisect-buildsrc");
     return if !-f $rcfile;

     my $result = do $rcfile;
     die "Could not parse $rcfile: $@" if $@;
 }

 sub makeNightlyList($$$$)
 {
     my ($useLocalFiles, $localDirectory, $macOSXVersion, $safariVersion) = @_;
     my @files;

     if ($useLocalFiles) {
         opendir(DIR, $localDirectory) || die "$!";
         foreach my $file (readdir(DIR)) {
             if ($file =~ /^WebKit-SVN-r([0-9]+)\.dmg$/) {
                 push(@files, +{ rev => $1, file => $file });
             }
         }
         closedir(DIR);
     } else {
         open(NIGHTLIES, "curl -s $nightlyBuildsURLBase/all |") || die;

         while (my $line = <NIGHTLIES>) {
             chomp $line;
             my ($revision, $timestamp, $url) = split(/,/, $line);
             my $nightly = basename($url);
             push(@files, +{ rev => $revision, file => $nightly });
         }
         close(NIGHTLIES);
     }

     if (eval "v$macOSXVersion" ge v10.5) {
         if ($safariVersion eq "4 Public Beta") {
             @files = grep { $_->{rev} >= 39682 } @files;
         } elsif (eval "v$safariVersion" ge v3.2) {
             @files = grep { $_->{rev} >= 37348 } @files;
         } elsif (eval "v$safariVersion" ge v3.1) {
             @files = grep { $_->{rev} >= 29711 } @files;
         } elsif (eval "v$safariVersion" ge v3.0) {
             @files = grep { $_->{rev} >= 25124 } @files;
         } elsif (eval "v$safariVersion" ge v2.0) {
             @files = grep { $_->{rev} >= 19594 } @files;
         } else {
             die "Requires Safari 2.0 or newer";
         }
     } elsif (eval "v$macOSXVersion" ge v10.4) {
         if ($safariVersion eq "4 Public Beta") {
             @files = grep { $_->{rev} >= 39682 } @files;
         } elsif (eval "v$safariVersion" ge v3.2) {
             @files = grep { $_->{rev} >= 37348 } @files;
         } elsif (eval "v$safariVersion" ge v3.1) {
             @files = grep { $_->{rev} >= 29711 } @files;
         } elsif (eval "v$safariVersion" ge v3.0) {
             @files = grep { $_->{rev} >= 19992 } @files;
         } elsif (eval "v$safariVersion" ge v2.0) {
             @files = grep { $_->{rev} >= 11976 } @files;
         } else {
             die "Requires Safari 2.0 or newer";
         }
     } else {
         die "Requires Mac OS X 10.4 (Tiger) or 10.5 (Leopard)";
     }

     my $nightlycmp = sub { return $a->{rev} <=> $b->{rev}; };

     return sort $nightlycmp @files;
 }

 sub mountAndRunNightly($$$$)
 {
     my ($filename, $directory, $safari, $tempFile) = @_;
     my $mountPath = "/Volumes/WebKit";
     my $webkitApp = File::Spec->catfile($mountPath, "WebKit.app");
     my $diskImage = File::Spec->catfile($directory, $filename);
     my $devNull = File::Spec->devnull();

     my $i = 0;
     while (-e $mountPath) {
         $i++;
         usleep 100 if $i > 1;
         `hdiutil detach '$mountPath' 2> $devNull`;
         die "Could not unmount $diskImage at $mountPath" if $i > 100;
     }
     die "Can't mount $diskImage: $mountPath already exists!" if -e $mountPath;

     print "Mounting disk image and running WebKit...\n";
     `hdiutil attach '$diskImage'`;
     $i = 0;
     while (! -e $webkitApp) {
         usleep 100;
         $i++;
         die "Could not mount $diskImage at $mountPath" if $i > 100;
     }

     my $frameworkPath;
     if (-d "/Volumes/WebKit/WebKit.app/Contents/Frameworks") {
         my $osXVersion = join('.', (split(/\./, findMacOSXVersion()))[0..1]);
         $frameworkPath = "/Volumes/WebKit/WebKit.app/Contents/Frameworks/$osXVersion";
     } else {
         $frameworkPath = "/Volumes/WebKit/WebKit.app/Contents/Resources";
     }

     $tempFile ||= "";
     `DYLD_FRAMEWORK_PATH=$frameworkPath WEBKIT_UNSET_DYLD_FRAMEWORK_PATH=YES $safari $tempFile`;

     `hdiutil detach '$mountPath' 2> $devNull`;
 }

 sub parseRevisions($$;$)
 {
     my ($optionName, $value, $ignored) = @_;

     if ($value =~ /^r?([0-9]+|HEAD):?$/i) {
         push(@revisions, $1);
         die "Too many revision arguments specified" if scalar @revisions > 2;
     } elsif ($value =~ /^r?([0-9]+):?r?([0-9]+|HEAD)$/i) {
         $revisions[0] = $1;
         $revisions[1] = $2;
     } else {
         die "Unknown revision '$value':  expected 'M' or 'M:N'";
     }
 }

 sub printStatus($$$)
 {
     my ($startRevision, $endRevision, $isProgression) = @_;
     printf "\n%s: r%s  %s: r%s\n",
         $isProgression ? "Fails" : "Works", $startRevision,
         $isProgression ? "Works" : "Fails", $endRevision;
 }

 sub printTracLink($$)
 {
     my ($startRevision, $endRevision) = @_;
     printf("http://trac.webkit.org/log/trunk/?rev=%s&stop_rev=%s\n", $endRevision, $startRevision + 1);
 }

 sub promptForTest($)
 {
     my ($revision) = @_;
     print "Did the bug reproduce in r$revision (yes/no/broken)? ";
     my $answer = <STDIN>;
     return 1 if $answer =~ /^(1|y.*)$/i;
     return -1 if $answer =~ /^(-1|b.*)$/i; # Broken
     return 0;
 }
	#!/usr/bin/perl -w

	# Copyright (C) 2007, 2008, 2011 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 Computer, 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.

	# This script attempts to find the point at which a regression (or progression)
	# of behavior occurred by searching WebKit nightly builds.

	# To override the location where the nightly builds are downloaded or the path
	# to the Safari web browser, create a ~/.bisect-buildsrc file with one or more of
	# the following lines (use "~/" to specify a path from your home directory):
	#
	# $branch = "branch-name";
	# $nightlyDownloadDirectory = "~/path/to/nightly/downloads";
	# $safariPath = "/path/to/Safari.app";

	use strict;

	use File::Basename;
	use File::Path;
	use File::Spec;
	use File::Temp qw(tempfile);
	use FindBin;
	use Getopt::Long;
	use Time::HiRes qw(usleep);

	use lib $FindBin::Bin;
	use webkitdirs qw(safariPathFromSafariBundle);

	sub createTempFile($);
	sub downloadNightly($$$);
	sub findMacOSXVersion();
	sub findNearestNightlyIndex(\@$$);
	sub findSafariVersion($);
	sub loadSettings();
	sub makeNightlyList($$$$);
	sub max($$) { return $_[0] > $_[1] ? $_[0] : $_[1]; }
	sub mountAndRunNightly($$$$);
	sub parseRevisions($$;$);
	sub printStatus($$$);
	sub printTracLink($$);
	sub promptForTest($);

	loadSettings();

	my %validBranches = map { $_ => 1 } qw(feature-branch trunk);
	my $branch = $Settings::branch;
	my $nightlyDownloadDirectory = $Settings::nightlyDownloadDirectory;
	my $safariPath = $Settings::safariPath;

	my @nightlies;

	my $isProgression;
	my $localOnly;
	my @revisions;
	my $sanityCheck;
	my $showHelp;
	my $testURL;

	# Fix up -r switches in @ARGV
	@ARGV = map { /^(-r)(.+)$/ ? ($1, $2) : $_ } @ARGV;

	my $result = GetOptions(
	"b\|branch=s" => \$branch,
	"d\|download-directory=s" => \$nightlyDownloadDirectory,
	"h\|help" => \$showHelp,
	"l\|local!" => \$localOnly,
	"p\|progression!" => \$isProgression,
	"r\|revisions=s" => \&parseRevisions,
	"safari-path=s" => \$safariPath,
	"s\|sanity-check!" => \$sanityCheck,
	);
	$testURL = shift @ARGV;

	$branch = "feature-branch" if $branch eq "feature";
	if (!exists $validBranches{$branch}) {
	print STDERR "ERROR: Invalid branch '$branch'\n";
	$showHelp = 1;
	}

	if (!$result \|\| $showHelp \|\| scalar(@ARGV) > 0) {
	print STDERR "Search WebKit nightly builds for changes in behavior.\n";
	print STDERR "Usage: " . basename($0) . " [options] [url]\n";
	print STDERR <<END;
	[-b\|--branch name] name of the nightly build branch (default: trunk)
	[-d\|--download-directory dir] nightly build download directory (default: ~/Library/Caches/WebKit-Nightlies)
	[-h\|--help] show this help message
	[-l\|--local] only use local (already downloaded) nightlies
	[-p\|--progression] searching for a progression, not a regression
	[-r\|--revision M[:N]] specify starting (and optional ending) revisions to search
	[--safari-path path] path to Safari application bundle (default: /Applications/Safari.app)
	[-s\|--sanity-check] verify both starting and ending revisions before bisecting
	END
	exit 1;
	}

	my $nightlyWebSite = "http://nightly.webkit.org";
	my $nightlyBuildsURLBase = $nightlyWebSite . File::Spec->catdir("/builds", $branch, "mac");
	my $nightlyFilesURLBase = $nightlyWebSite . File::Spec->catdir("/files", $branch, "mac");

	$nightlyDownloadDirectory = glob($nightlyDownloadDirectory) if $nightlyDownloadDirectory =~ /^~/;
	$safariPath = glob($safariPath) if $safariPath =~ /^~/;
	$safariPath = safariPathFromSafariBundle($safariPath) if $safariPath =~ m#\.app/*#;

	$nightlyDownloadDirectory = File::Spec->catdir($nightlyDownloadDirectory, $branch);
	if (! -d $nightlyDownloadDirectory) {
	mkpath($nightlyDownloadDirectory, 0, 0755) \|\| die "Could not create $nightlyDownloadDirectory: $!";
	}

	@nightlies = makeNightlyList($localOnly, $nightlyDownloadDirectory, findMacOSXVersion(), findSafariVersion($safariPath));

	my $startIndex = $revisions[0] ? findNearestNightlyIndex(@nightlies, $revisions[0], 'ceil') : 0;
	my $endIndex = $revisions[1] ? findNearestNightlyIndex(@nightlies, $revisions[1], 'floor') : $#nightlies;

	my $tempFile = createTempFile($testURL);

	if ($sanityCheck) {
	my $didReproduceBug;

	do {
	printf "\nChecking starting revision r%s...\n",
	$nightlies[$startIndex]->{rev};
	downloadNightly($nightlies[$startIndex]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
	mountAndRunNightly($nightlies[$startIndex]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
	$didReproduceBug = promptForTest($nightlies[$startIndex]->{rev});
	$startIndex-- if $didReproduceBug < 0;
	} while ($didReproduceBug < 0);
	die "ERROR: Bug reproduced in starting revision! Do you need to test an earlier revision or for a progression?"
	if $didReproduceBug && !$isProgression;
	die "ERROR: Bug not reproduced in starting revision! Do you need to test an earlier revision or for a regression?"
	if !$didReproduceBug && $isProgression;

	do {
	printf "\nChecking ending revision r%s...\n",
	$nightlies[$endIndex]->{rev};
	downloadNightly($nightlies[$endIndex]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
	mountAndRunNightly($nightlies[$endIndex]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
	$didReproduceBug = promptForTest($nightlies[$endIndex]->{rev});
	$endIndex++ if $didReproduceBug < 0;
	} while ($didReproduceBug < 0);
	die "ERROR: Bug NOT reproduced in ending revision! Do you need to test a later revision or for a progression?"
	if !$didReproduceBug && !$isProgression;
	die "ERROR: Bug reproduced in ending revision! Do you need to test a later revision or for a regression?"
	if $didReproduceBug && $isProgression;
	}

	printStatus($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev}, $isProgression);

	my %brokenRevisions = ();
	while (abs($endIndex - $startIndex) > 1) {
	my $index = $startIndex + int(($endIndex - $startIndex) / 2);

	my $didReproduceBug;
	do {
	if (exists $nightlies[$index]) {
	my $buildsLeft = max(max(0, $endIndex - $index - 1), max(0, $index - $startIndex - 1));
	my $plural = $buildsLeft == 1 ? "" : "s";
	printf "\nChecking revision r%s (%d build%s left to test after this)...\n", $nightlies[$index]->{rev}, $buildsLeft, $plural;
	downloadNightly($nightlies[$index]->{file}, $nightlyFilesURLBase, $nightlyDownloadDirectory);
	mountAndRunNightly($nightlies[$index]->{file}, $nightlyDownloadDirectory, $safariPath, $tempFile);
	$didReproduceBug = promptForTest($nightlies[$index]->{rev});
	}
	if ($didReproduceBug < 0) {
	$brokenRevisions{$nightlies[$index]->{rev}} = $nightlies[$index]->{file};
	delete $nightlies[$index];
	$endIndex--;
	$index = $startIndex + int(($endIndex - $startIndex) / 2);
	}
	} while ($didReproduceBug < 0);

	if ($didReproduceBug && !$isProgression \|\| !$didReproduceBug && $isProgression) {
	$endIndex = $index;
	} else {
	$startIndex = $index;
	}

	print "\nBroken revisions skipped: r" . join(", r", keys %brokenRevisions) . "\n"
	if scalar keys %brokenRevisions > 0;
	printStatus($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev}, $isProgression);
	}

	printTracLink($nightlies[$startIndex]->{rev}, $nightlies[$endIndex]->{rev});

	unlink $tempFile if $tempFile;

	exit 0;

	sub createTempFile($)
	{
	my ($url) = @_;

	return undef if !$url;

	my ($fh, $tempFile) = tempfile(
	basename($0) . "-XXXXXXXX",
	DIR => File::Spec->tmpdir(),
	SUFFIX => ".html",
	UNLINK => 0,
	);
	print $fh "<meta http-equiv=\"refresh\" content=\"0; $url\">\n";
	close($fh);

	return $tempFile;
	}

	sub downloadNightly($$$)
	{
	my ($filename, $urlBase, $directory) = @_;
	my $path = File::Spec->catfile($directory, $filename);
	if (! -f $path) {
	print "Downloading $filename to $directory...\n";
	`curl -# -o '$path' '$urlBase/$filename'`;
	}
	}

	sub findMacOSXVersion()
	{
	my $version;
	open(SW_VERS, "-\|", "/usr/bin/sw_vers") \|\| die;
	while (<SW_VERS>) {
	$version = $1 if /^ProductVersion:\s+([^\s]+)/;
	}
	close(SW_VERS);
	return $version;
	}

	sub findNearestNightlyIndex(\@$$)
	{
	my ($nightlies, $revision, $round) = @_;

	my $lowIndex = 0;
	my $highIndex = $#{$nightlies};

	return $highIndex if uc($revision) eq 'HEAD' \|\| $revision >= $nightlies->[$highIndex]->{rev};
	return $lowIndex if $revision <= $nightlies->[$lowIndex]->{rev};

	while (abs($highIndex - $lowIndex) > 1) {
	my $index = $lowIndex + int(($highIndex - $lowIndex) / 2);
	if ($revision < $nightlies->[$index]->{rev}) {
	$highIndex = $index;
	} elsif ($revision > $nightlies->[$index]->{rev}) {
	$lowIndex = $index;
	} else {
	return $index;
	}
	}

	return ($round eq "floor") ? $lowIndex : $highIndex;
	}

	sub findSafariVersion($)
	{
	my ($path) = @_;
	my $versionPlist = File::Spec->catdir(dirname(dirname($path)), "version.plist");
	my $version;
	open(PLIST, "< $versionPlist") \|\| die;
	while (<PLIST>) {
	if (m#^\s*<key>CFBundleShortVersionString</key>#) {
	$version = <PLIST>;
	$version =~ s#^\s<string>([0-9.]+)[^<]</string>\s[\r\n]#$1#;
	}
	}
	close(PLIST);
	return $version;
	}

	sub loadSettings()
	{
	package Settings;

	our $branch = "trunk";
	our $nightlyDownloadDirectory = File::Spec->catdir($ENV{HOME}, "Library/Caches/WebKit-Nightlies");
	our $safariPath = "/Applications/Safari.app";

	my $rcfile = File::Spec->catdir($ENV{HOME}, ".bisect-buildsrc");
	return if !-f $rcfile;

	my $result = do $rcfile;
	die "Could not parse $rcfile: $@" if $@;
	}

	sub makeNightlyList($$$$)
	{
	my ($useLocalFiles, $localDirectory, $macOSXVersion, $safariVersion) = @_;
	my @files;

	if ($useLocalFiles) {
	opendir(DIR, $localDirectory) \|\| die "$!";
	foreach my $file (readdir(DIR)) {
	if ($file =~ /^WebKit-SVN-r([0-9]+)\.dmg$/) {
	push(@files, +{ rev => $1, file => $file });
	}
	}
	closedir(DIR);
	} else {
	open(NIGHTLIES, "curl -s $nightlyBuildsURLBase/all \|") \|\| die;

	while (my $line = <NIGHTLIES>) {
	chomp $line;
	my ($revision, $timestamp, $url) = split(/,/, $line);
	my $nightly = basename($url);
	push(@files, +{ rev => $revision, file => $nightly });
	}
	close(NIGHTLIES);
	}

	if (eval "v$macOSXVersion" ge v10.5) {
	if ($safariVersion eq "4 Public Beta") {
	@files = grep { $_->{rev} >= 39682 } @files;
	} elsif (eval "v$safariVersion" ge v3.2) {
	@files = grep { $_->{rev} >= 37348 } @files;
	} elsif (eval "v$safariVersion" ge v3.1) {
	@files = grep { $_->{rev} >= 29711 } @files;
	} elsif (eval "v$safariVersion" ge v3.0) {
	@files = grep { $_->{rev} >= 25124 } @files;
	} elsif (eval "v$safariVersion" ge v2.0) {
	@files = grep { $_->{rev} >= 19594 } @files;
	} else {
	die "Requires Safari 2.0 or newer";
	}
	} elsif (eval "v$macOSXVersion" ge v10.4) {
	if ($safariVersion eq "4 Public Beta") {
	@files = grep { $_->{rev} >= 39682 } @files;
	} elsif (eval "v$safariVersion" ge v3.2) {
	@files = grep { $_->{rev} >= 37348 } @files;
	} elsif (eval "v$safariVersion" ge v3.1) {
	@files = grep { $_->{rev} >= 29711 } @files;
	} elsif (eval "v$safariVersion" ge v3.0) {
	@files = grep { $_->{rev} >= 19992 } @files;
	} elsif (eval "v$safariVersion" ge v2.0) {
	@files = grep { $_->{rev} >= 11976 } @files;
	} else {
	die "Requires Safari 2.0 or newer";
	}
	} else {
	die "Requires Mac OS X 10.4 (Tiger) or 10.5 (Leopard)";
	}

	my $nightlycmp = sub { return $a->{rev} <=> $b->{rev}; };

	return sort $nightlycmp @files;
	}

	sub mountAndRunNightly($$$$)
	{
	my ($filename, $directory, $safari, $tempFile) = @_;
	my $mountPath = "/Volumes/WebKit";
	my $webkitApp = File::Spec->catfile($mountPath, "WebKit.app");
	my $diskImage = File::Spec->catfile($directory, $filename);
	my $devNull = File::Spec->devnull();

	my $i = 0;
	while (-e $mountPath) {
	$i++;
	usleep 100 if $i > 1;
	`hdiutil detach '$mountPath' 2> $devNull`;
	die "Could not unmount $diskImage at $mountPath" if $i > 100;
	}
	die "Can't mount $diskImage: $mountPath already exists!" if -e $mountPath;

	print "Mounting disk image and running WebKit...\n";
	`hdiutil attach '$diskImage'`;
	$i = 0;
	while (! -e $webkitApp) {
	usleep 100;
	$i++;
	die "Could not mount $diskImage at $mountPath" if $i > 100;
	}

	my $frameworkPath;
	if (-d "/Volumes/WebKit/WebKit.app/Contents/Frameworks") {
	my $osXVersion = join('.', (split(/\./, findMacOSXVersion()))[0..1]);
	$frameworkPath = "/Volumes/WebKit/WebKit.app/Contents/Frameworks/$osXVersion";
	} else {
	$frameworkPath = "/Volumes/WebKit/WebKit.app/Contents/Resources";
	}

	$tempFile \|\|= "";
	`DYLD_FRAMEWORK_PATH=$frameworkPath WEBKIT_UNSET_DYLD_FRAMEWORK_PATH=YES $safari $tempFile`;

	`hdiutil detach '$mountPath' 2> $devNull`;
	}

	sub parseRevisions($$;$)
	{
	my ($optionName, $value, $ignored) = @_;

	if ($value =~ /^r?([0-9]+\|HEAD):?$/i) {
	push(@revisions, $1);
	die "Too many revision arguments specified" if scalar @revisions > 2;
	} elsif ($value =~ /^r?([0-9]+):?r?([0-9]+\|HEAD)$/i) {
	$revisions[0] = $1;
	$revisions[1] = $2;
	} else {
	die "Unknown revision '$value': expected 'M' or 'M:N'";
	}
	}

	sub printStatus($$$)
	{
	my ($startRevision, $endRevision, $isProgression) = @_;
	printf "\n%s: r%s %s: r%s\n",
	$isProgression ? "Fails" : "Works", $startRevision,
	$isProgression ? "Works" : "Fails", $endRevision;
	}

	sub printTracLink($$)
	{
	my ($startRevision, $endRevision) = @_;
	printf("http://trac.webkit.org/log/trunk/?rev=%s&stop_rev=%s\n", $endRevision, $startRevision + 1);
	}

	sub promptForTest($)
	{
	my ($revision) = @_;
	print "Did the bug reproduce in r$revision (yes/no/broken)? ";
	my $answer = <STDIN>;
	return 1 if $answer =~ /^(1\|y.*)$/i;
	return -1 if $answer =~ /^(-1\|b.*)$/i; # Broken
	return 0;
	}