--- /dev/null
+#!/usr/bin/perl
+# Copyright (c) 2009, 2010 David Aguilar
+# Copyright (c) 2012 Tim Henigan
+#
+# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
+# git-difftool--helper script.
+#
+# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
+# The GIT_DIFF* variables are exported for use by git-difftool--helper.
+#
+# Any arguments that are unknown to this script are forwarded to 'git diff'.
+
+use 5.008;
+use strict;
+use warnings;
+use Error qw(:try);
+use File::Basename qw(dirname);
+use File::Copy;
+use File::Find;
+use File::stat;
+use File::Path qw(mkpath rmtree);
+use File::Temp qw(tempdir);
+use Getopt::Long qw(:config pass_through);
+use Git;
+
+sub usage
+{
+ my $exitcode = shift;
+ print << 'USAGE';
+usage: git difftool [-t|--tool=<tool>] [--tool-help]
+ [-x|--extcmd=<cmd>]
+ [-g|--gui] [--no-gui]
+ [--prompt] [-y|--no-prompt]
+ [-d|--dir-diff]
+ ['git diff' options]
+USAGE
+ exit($exitcode);
+}
+
+sub print_tool_help
+{
+ # See the comment at the bottom of file_diff() for the reason behind
+ # using system() followed by exit() instead of exec().
+ my $rc = system(qw(git mergetool --tool-help=diff));
+ exit($rc | ($rc >> 8));
+}
+
+sub exit_cleanup
+{
+ my ($tmpdir, $status) = @_;
+ my $errno = $!;
+ rmtree($tmpdir);
+ if ($status and $errno) {
+ my ($package, $file, $line) = caller();
+ warn "$file line $line: $errno\n";
+ }
+ exit($status | ($status >> 8));
+}
+
+sub use_wt_file
+{
+ my ($workdir, $file, $sha1) = @_;
+ my $null_sha1 = '0' x 40;
+
+ if (-l "$workdir/$file" || ! -e _) {
+ return (0, $null_sha1);
+ }
+
+ my $wt_sha1 = Git::command_oneline('hash-object', "$workdir/$file");
+ my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
+ return ($use, $wt_sha1);
+}
+
+sub changed_files
+{
+ my ($repo_path, $index, $worktree) = @_;
+ $ENV{GIT_INDEX_FILE} = $index;
+
+ my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
+ my @refreshargs = (
+ @gitargs, 'update-index',
+ '--really-refresh', '-q', '--unmerged');
+ try {
+ Git::command_oneline(@refreshargs);
+ } catch Git::Error::Command with {};
+
+ my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
+ my $line = Git::command_oneline(@diffargs);
+ my @files;
+ if (defined $line) {
+ @files = split('\0', $line);
+ } else {
+ @files = ();
+ }
+
+ delete($ENV{GIT_INDEX_FILE});
+
+ return map { $_ => 1 } @files;
+}
+
+sub setup_dir_diff
+{
+ my ($workdir, $symlinks) = @_;
+ my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
+ my $diffrtn = Git::command_oneline(@gitargs);
+ exit(0) unless defined($diffrtn);
+
+ # Build index info for left and right sides of the diff
+ my $submodule_mode = '160000';
+ my $symlink_mode = '120000';
+ my $null_mode = '0' x 6;
+ my $null_sha1 = '0' x 40;
+ my $lindex = '';
+ my $rindex = '';
+ my $wtindex = '';
+ my %submodule;
+ my %symlink;
+ my @working_tree = ();
+ my %working_tree_dups = ();
+ my @rawdiff = split('\0', $diffrtn);
+
+ my $i = 0;
+ while ($i < $#rawdiff) {
+ if ($rawdiff[$i] =~ /^::/) {
+ warn << 'EOF';
+Combined diff formats ('-c' and '--cc') are not supported in
+directory diff mode ('-d' and '--dir-diff').
+EOF
+ exit(1);
+ }
+
+ my ($lmode, $rmode, $lsha1, $rsha1, $status) =
+ split(' ', substr($rawdiff[$i], 1));
+ my $src_path = $rawdiff[$i + 1];
+ my $dst_path;
+
+ if ($status =~ /^[CR]/) {
+ $dst_path = $rawdiff[$i + 2];
+ $i += 3;
+ } else {
+ $dst_path = $src_path;
+ $i += 2;
+ }
+
+ if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
+ $submodule{$src_path}{left} = $lsha1;
+ if ($lsha1 ne $rsha1) {
+ $submodule{$dst_path}{right} = $rsha1;
+ } else {
+ $submodule{$dst_path}{right} = "$rsha1-dirty";
+ }
+ next;
+ }
+
+ if ($lmode eq $symlink_mode) {
+ $symlink{$src_path}{left} =
+ Git::command_oneline('show', $lsha1);
+ }
+
+ if ($rmode eq $symlink_mode) {
+ $symlink{$dst_path}{right} =
+ Git::command_oneline('show', $rsha1);
+ }
+
+ if ($lmode ne $null_mode and $status !~ /^C/) {
+ $lindex .= "$lmode $lsha1\t$src_path\0";
+ }
+
+ if ($rmode ne $null_mode) {
+ # Avoid duplicate working_tree entries
+ if ($working_tree_dups{$dst_path}++) {
+ next;
+ }
+ my ($use, $wt_sha1) =
+ use_wt_file($workdir, $dst_path, $rsha1);
+ if ($use) {
+ push @working_tree, $dst_path;
+ $wtindex .= "$rmode $wt_sha1\t$dst_path\0";
+ } else {
+ $rindex .= "$rmode $rsha1\t$dst_path\0";
+ }
+ }
+ }
+
++ # Go to the root of the worktree so that the left index files
++ # are properly setup -- the index is toplevel-relative.
++ chdir($workdir);
++
+ # Setup temp directories
+ my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
+ my $ldir = "$tmpdir/left";
+ my $rdir = "$tmpdir/right";
+ mkpath($ldir) or exit_cleanup($tmpdir, 1);
+ mkpath($rdir) or exit_cleanup($tmpdir, 1);
+
+ # Populate the left and right directories based on each index file
+ my ($inpipe, $ctx);
+ $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
+ ($inpipe, $ctx) =
+ Git::command_input_pipe('update-index', '-z', '--index-info');
+ print($inpipe $lindex);
+ Git::command_close_pipe($inpipe, $ctx);
+
+ my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
+ exit_cleanup($tmpdir, $rc) if $rc != 0;
+
+ $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
+ ($inpipe, $ctx) =
+ Git::command_input_pipe('update-index', '-z', '--index-info');
+ print($inpipe $rindex);
+ Git::command_close_pipe($inpipe, $ctx);
+
+ $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
+ exit_cleanup($tmpdir, $rc) if $rc != 0;
+
+ $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
+ ($inpipe, $ctx) =
+ Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
+ print($inpipe $wtindex);
+ Git::command_close_pipe($inpipe, $ctx);
+
+ # If $GIT_DIR was explicitly set just for the update/checkout
+ # commands, then it should be unset before continuing.
+ delete($ENV{GIT_INDEX_FILE});
+
+ # Changes in the working tree need special treatment since they are
+ # not part of the index. Remove any trailing slash from $workdir
+ # before starting to avoid double slashes in symlink targets.
+ $workdir =~ s|/$||;
+ for my $file (@working_tree) {
+ my $dir = dirname($file);
+ unless (-d "$rdir/$dir") {
+ mkpath("$rdir/$dir") or
+ exit_cleanup($tmpdir, 1);
+ }
+ if ($symlinks) {
+ symlink("$workdir/$file", "$rdir/$file") or
+ exit_cleanup($tmpdir, 1);
+ } else {
+ copy("$workdir/$file", "$rdir/$file") or
+ exit_cleanup($tmpdir, 1);
+
+ my $mode = stat("$workdir/$file")->mode;
+ chmod($mode, "$rdir/$file") or
+ exit_cleanup($tmpdir, 1);
+ }
+ }
+
+ # Changes to submodules require special treatment. This loop writes a
+ # temporary file to both the left and right directories to show the
+ # change in the recorded SHA1 for the submodule.
+ for my $path (keys %submodule) {
+ my $ok = 0;
+ if (defined($submodule{$path}{left})) {
+ $ok = write_to_file("$ldir/$path",
+ "Subproject commit $submodule{$path}{left}");
+ }
+ if (defined($submodule{$path}{right})) {
+ $ok = write_to_file("$rdir/$path",
+ "Subproject commit $submodule{$path}{right}");
+ }
+ exit_cleanup($tmpdir, 1) if not $ok;
+ }
+
+ # Symbolic links require special treatment. The standard "git diff"
+ # shows only the link itself, not the contents of the link target.
+ # This loop replicates that behavior.
+ for my $path (keys %symlink) {
+ my $ok = 0;
+ if (defined($symlink{$path}{left})) {
+ $ok = write_to_file("$ldir/$path",
+ $symlink{$path}{left});
+ }
+ if (defined($symlink{$path}{right})) {
+ $ok = write_to_file("$rdir/$path",
+ $symlink{$path}{right});
+ }
+ exit_cleanup($tmpdir, 1) if not $ok;
+ }
+
+ return ($ldir, $rdir, $tmpdir, @working_tree);
+}
+
+sub write_to_file
+{
+ my $path = shift;
+ my $value = shift;
+
+ # Make sure the path to the file exists
+ my $dir = dirname($path);
+ unless (-d "$dir") {
+ mkpath("$dir") or return 0;
+ }
+
+ # If the file already exists in that location, delete it. This
+ # is required in the case of symbolic links.
+ unlink($path);
+
+ open(my $fh, '>', $path) or return 0;
+ print($fh $value);
+ close($fh);
+
+ return 1;
+}
+
+sub main
+{
+ # parse command-line options. all unrecognized options and arguments
+ # are passed through to the 'git diff' command.
+ my %opts = (
+ difftool_cmd => undef,
+ dirdiff => undef,
+ extcmd => undef,
+ gui => undef,
+ help => undef,
+ prompt => undef,
+ symlinks => $^O ne 'cygwin' &&
+ $^O ne 'MSWin32' && $^O ne 'msys',
+ tool_help => undef,
+ trust_exit_code => undef,
+ );
+ GetOptions('g|gui!' => \$opts{gui},
+ 'd|dir-diff' => \$opts{dirdiff},
+ 'h' => \$opts{help},
+ 'prompt!' => \$opts{prompt},
+ 'y' => sub { $opts{prompt} = 0; },
+ 'symlinks' => \$opts{symlinks},
+ 'no-symlinks' => sub { $opts{symlinks} = 0; },
+ 't|tool:s' => \$opts{difftool_cmd},
+ 'tool-help' => \$opts{tool_help},
+ 'trust-exit-code' => \$opts{trust_exit_code},
+ 'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
+ 'x|extcmd:s' => \$opts{extcmd});
+
+ if (defined($opts{help})) {
+ usage(0);
+ }
+ if (defined($opts{tool_help})) {
+ print_tool_help();
+ }
+ if (defined($opts{difftool_cmd})) {
+ if (length($opts{difftool_cmd}) > 0) {
+ $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
+ } else {
+ print "No <tool> given for --tool=<tool>\n";
+ usage(1);
+ }
+ }
+ if (defined($opts{extcmd})) {
+ if (length($opts{extcmd}) > 0) {
+ $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
+ } else {
+ print "No <cmd> given for --extcmd=<cmd>\n";
+ usage(1);
+ }
+ }
+ if ($opts{gui}) {
+ my $guitool = Git::config('diff.guitool');
+ if (defined($guitool) && length($guitool) > 0) {
+ $ENV{GIT_DIFF_TOOL} = $guitool;
+ }
+ }
+
+ if (!defined $opts{trust_exit_code}) {
+ $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
+ }
+ if ($opts{trust_exit_code}) {
+ $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
+ } else {
+ $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
+ }
+
+ # In directory diff mode, 'git-difftool--helper' is called once
+ # to compare the a/b directories. In file diff mode, 'git diff'
+ # will invoke a separate instance of 'git-difftool--helper' for
+ # each file that changed.
+ if (defined($opts{dirdiff})) {
+ dir_diff($opts{extcmd}, $opts{symlinks});
+ } else {
+ file_diff($opts{prompt});
+ }
+}
+
+sub dir_diff
+{
+ my ($extcmd, $symlinks) = @_;
+ my $rc;
+ my $error = 0;
+ my $repo = Git->repository();
+ my $repo_path = $repo->repo_path();
+ my $workdir = $repo->wc_path();
+ my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
+
+ if (defined($extcmd)) {
+ $rc = system($extcmd, $a, $b);
+ } else {
+ $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
+ $rc = system('git', 'difftool--helper', $a, $b);
+ }
+ # If the diff including working copy files and those
+ # files were modified during the diff, then the changes
+ # should be copied back to the working tree.
+ # Do not copy back files when symlinks are used and the
+ # external tool did not replace the original link with a file.
+ #
+ # These hashes are loaded lazily since they aren't needed
+ # in the common case of --symlinks and the difftool updating
+ # files through the symlink.
+ my %wt_modified;
+ my %tmp_modified;
+ my $indices_loaded = 0;
+
+ for my $file (@worktree) {
+ next if $symlinks && -l "$b/$file";
+ next if ! -f "$b/$file";
+
+ if (!$indices_loaded) {
+ %wt_modified = changed_files(
+ $repo_path, "$tmpdir/wtindex", $workdir);
+ %tmp_modified = changed_files(
+ $repo_path, "$tmpdir/wtindex", $b);
+ $indices_loaded = 1;
+ }
+
+ if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
+ my $errmsg = "warning: Both files modified: ";
+ $errmsg .= "'$workdir/$file' and '$b/$file'.\n";
+ $errmsg .= "warning: Working tree file has been left.\n";
+ $errmsg .= "warning:\n";
+ warn $errmsg;
+ $error = 1;
+ } elsif (exists $tmp_modified{$file}) {
+ my $mode = stat("$b/$file")->mode;
+ copy("$b/$file", "$workdir/$file") or
+ exit_cleanup($tmpdir, 1);
+
+ chmod($mode, "$workdir/$file") or
+ exit_cleanup($tmpdir, 1);
+ }
+ }
+ if ($error) {
+ warn "warning: Temporary files exist in '$tmpdir'.\n";
+ warn "warning: You may want to cleanup or recover these.\n";
+ exit(1);
+ } else {
+ exit_cleanup($tmpdir, $rc);
+ }
+}
+
+sub file_diff
+{
+ my ($prompt) = @_;
+
+ if (defined($prompt)) {
+ if ($prompt) {
+ $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
+ } else {
+ $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
+ }
+ }
+
+ $ENV{GIT_PAGER} = '';
+ $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
+
+ # ActiveState Perl for Win32 does not implement POSIX semantics of
+ # exec* system call. It just spawns the given executable and finishes
+ # the starting program, exiting with code 0.
+ # system will at least catch the errors returned by git diff,
+ # allowing the caller of git difftool better handling of failures.
+ my $rc = system('git', 'diff', @ARGV);
+ exit($rc | ($rc >> 8));
+}
+
+main();