Andrew's git - gitweb.git/blob - contrib/examples/git-difftool.perl

   1#!/usr/bin/perl
   2# Copyright (c) 2009, 2010 David Aguilar
   3# Copyright (c) 2012 Tim Henigan
   4#
   5# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
   6# git-difftool--helper script.
   7#
   8# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
   9# The GIT_DIFF* variables are exported for use by git-difftool--helper.
  10#
  11# Any arguments that are unknown to this script are forwarded to 'git diff'.
  12
  13use 5.008;
  14use strict;
  15use warnings;
  16use Error qw(:try);
  17use File::Basename qw(dirname);
  18use File::Copy;
  19use File::Find;
  20use File::stat;
  21use File::Path qw(mkpath rmtree);
  22use File::Temp qw(tempdir);
  23use Getopt::Long qw(:config pass_through);
  24use Git;
  25
  26sub usage
  27{
  28        my $exitcode = shift;
  29        print << 'USAGE';
  30usage: git difftool [-t|--tool=<tool>] [--tool-help]
  31                    [-x|--extcmd=<cmd>]
  32                    [-g|--gui] [--no-gui]
  33                    [--prompt] [-y|--no-prompt]
  34                    [-d|--dir-diff]
  35                    ['git diff' options]
  36USAGE
  37        exit($exitcode);
  38}
  39
  40sub print_tool_help
  41{
  42        # See the comment at the bottom of file_diff() for the reason behind
  43        # using system() followed by exit() instead of exec().
  44        my $rc = system(qw(git mergetool --tool-help=diff));
  45        exit($rc | ($rc >> 8));
  46}
  47
  48sub exit_cleanup
  49{
  50        my ($tmpdir, $status) = @_;
  51        my $errno = $!;
  52        rmtree($tmpdir);
  53        if ($status and $errno) {
  54                my ($package, $file, $line) = caller();
  55                warn "$file line $line: $errno\n";
  56        }
  57        exit($status | ($status >> 8));
  58}
  59
  60sub use_wt_file
  61{
  62        my ($workdir, $file, $sha1) = @_;
  63        my $null_sha1 = '0' x 40;
  64
  65        if (-l "$workdir/$file" || ! -e _) {
  66                return (0, $null_sha1);
  67        }
  68
  69        my $wt_sha1 = Git::command_oneline('hash-object', "$workdir/$file");
  70        my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
  71        return ($use, $wt_sha1);
  72}
  73
  74sub changed_files
  75{
  76        my ($repo_path, $index, $worktree) = @_;
  77        $ENV{GIT_INDEX_FILE} = $index;
  78
  79        my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
  80        my @refreshargs = (
  81                @gitargs, 'update-index',
  82                '--really-refresh', '-q', '--unmerged');
  83        try {
  84                Git::command_oneline(@refreshargs);
  85        } catch Git::Error::Command with {};
  86
  87        my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
  88        my $line = Git::command_oneline(@diffargs);
  89        my @files;
  90        if (defined $line) {
  91                @files = split('\0', $line);
  92        } else {
  93                @files = ();
  94        }
  95
  96        delete($ENV{GIT_INDEX_FILE});
  97
  98        return map { $_ => 1 } @files;
  99}
 100
 101sub setup_dir_diff
 102{
 103        my ($workdir, $symlinks) = @_;
 104        my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 105        my $diffrtn = Git::command_oneline(@gitargs);
 106        exit(0) unless defined($diffrtn);
 107
 108        # Build index info for left and right sides of the diff
 109        my $submodule_mode = '160000';
 110        my $symlink_mode = '120000';
 111        my $null_mode = '0' x 6;
 112        my $null_sha1 = '0' x 40;
 113        my $lindex = '';
 114        my $rindex = '';
 115        my $wtindex = '';
 116        my %submodule;
 117        my %symlink;
 118        my @working_tree = ();
 119        my %working_tree_dups = ();
 120        my @rawdiff = split('\0', $diffrtn);
 121
 122        my $i = 0;
 123        while ($i < $#rawdiff) {
 124                if ($rawdiff[$i] =~ /^::/) {
 125                        warn << 'EOF';
 126Combined diff formats ('-c' and '--cc') are not supported in
 127directory diff mode ('-d' and '--dir-diff').
 128EOF
 129                        exit(1);
 130                }
 131
 132                my ($lmode, $rmode, $lsha1, $rsha1, $status) =
 133                        split(' ', substr($rawdiff[$i], 1));
 134                my $src_path = $rawdiff[$i + 1];
 135                my $dst_path;
 136
 137                if ($status =~ /^[CR]/) {
 138                        $dst_path = $rawdiff[$i + 2];
 139                        $i += 3;
 140                } else {
 141                        $dst_path = $src_path;
 142                        $i += 2;
 143                }
 144
 145                if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
 146                        $submodule{$src_path}{left} = $lsha1;
 147                        if ($lsha1 ne $rsha1) {
 148                                $submodule{$dst_path}{right} = $rsha1;
 149                        } else {
 150                                $submodule{$dst_path}{right} = "$rsha1-dirty";
 151                        }
 152                        next;
 153                }
 154
 155                if ($lmode eq $symlink_mode) {
 156                        $symlink{$src_path}{left} =
 157                                Git::command_oneline('show', $lsha1);
 158                }
 159
 160                if ($rmode eq $symlink_mode) {
 161                        $symlink{$dst_path}{right} =
 162                                Git::command_oneline('show', $rsha1);
 163                }
 164
 165                if ($lmode ne $null_mode and $status !~ /^C/) {
 166                        $lindex .= "$lmode $lsha1\t$src_path\0";
 167                }
 168
 169                if ($rmode ne $null_mode) {
 170                        # Avoid duplicate working_tree entries
 171                        if ($working_tree_dups{$dst_path}++) {
 172                                next;
 173                        }
 174                        my ($use, $wt_sha1) =
 175                                use_wt_file($workdir, $dst_path, $rsha1);
 176                        if ($use) {
 177                                push @working_tree, $dst_path;
 178                                $wtindex .= "$rmode $wt_sha1\t$dst_path\0";
 179                        } else {
 180                                $rindex .= "$rmode $rsha1\t$dst_path\0";
 181                        }
 182                }
 183        }
 184
 185        # Go to the root of the worktree so that the left index files
 186        # are properly setup -- the index is toplevel-relative.
 187        chdir($workdir);
 188
 189        # Setup temp directories
 190        my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
 191        my $ldir = "$tmpdir/left";
 192        my $rdir = "$tmpdir/right";
 193        mkpath($ldir) or exit_cleanup($tmpdir, 1);
 194        mkpath($rdir) or exit_cleanup($tmpdir, 1);
 195
 196        # Populate the left and right directories based on each index file
 197        my ($inpipe, $ctx);
 198        $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
 199        ($inpipe, $ctx) =
 200                Git::command_input_pipe('update-index', '-z', '--index-info');
 201        print($inpipe $lindex);
 202        Git::command_close_pipe($inpipe, $ctx);
 203
 204        my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 205        exit_cleanup($tmpdir, $rc) if $rc != 0;
 206
 207        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 208        ($inpipe, $ctx) =
 209                Git::command_input_pipe('update-index', '-z', '--index-info');
 210        print($inpipe $rindex);
 211        Git::command_close_pipe($inpipe, $ctx);
 212
 213        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
 214        exit_cleanup($tmpdir, $rc) if $rc != 0;
 215
 216        $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
 217        ($inpipe, $ctx) =
 218                Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
 219        print($inpipe $wtindex);
 220        Git::command_close_pipe($inpipe, $ctx);
 221
 222        # If $GIT_DIR was explicitly set just for the update/checkout
 223        # commands, then it should be unset before continuing.
 224        delete($ENV{GIT_INDEX_FILE});
 225
 226        # Changes in the working tree need special treatment since they are
 227        # not part of the index. Remove any trailing slash from $workdir
 228        # before starting to avoid double slashes in symlink targets.
 229        $workdir =~ s|/$||;
 230        for my $file (@working_tree) {
 231                my $dir = dirname($file);
 232                unless (-d "$rdir/$dir") {
 233                        mkpath("$rdir/$dir") or
 234                        exit_cleanup($tmpdir, 1);
 235                }
 236                if ($symlinks) {
 237                        symlink("$workdir/$file", "$rdir/$file") or
 238                        exit_cleanup($tmpdir, 1);
 239                } else {
 240                        copy("$workdir/$file", "$rdir/$file") or
 241                        exit_cleanup($tmpdir, 1);
 242
 243                        my $mode = stat("$workdir/$file")->mode;
 244                        chmod($mode, "$rdir/$file") or
 245                        exit_cleanup($tmpdir, 1);
 246                }
 247        }
 248
 249        # Changes to submodules require special treatment. This loop writes a
 250        # temporary file to both the left and right directories to show the
 251        # change in the recorded SHA1 for the submodule.
 252        for my $path (keys %submodule) {
 253                my $ok = 0;
 254                if (defined($submodule{$path}{left})) {
 255                        $ok = write_to_file("$ldir/$path",
 256                                "Subproject commit $submodule{$path}{left}");
 257                }
 258                if (defined($submodule{$path}{right})) {
 259                        $ok = write_to_file("$rdir/$path",
 260                                "Subproject commit $submodule{$path}{right}");
 261                }
 262                exit_cleanup($tmpdir, 1) if not $ok;
 263        }
 264
 265        # Symbolic links require special treatment. The standard "git diff"
 266        # shows only the link itself, not the contents of the link target.
 267        # This loop replicates that behavior.
 268        for my $path (keys %symlink) {
 269                my $ok = 0;
 270                if (defined($symlink{$path}{left})) {
 271                        $ok = write_to_file("$ldir/$path",
 272                                        $symlink{$path}{left});
 273                }
 274                if (defined($symlink{$path}{right})) {
 275                        $ok = write_to_file("$rdir/$path",
 276                                        $symlink{$path}{right});
 277                }
 278                exit_cleanup($tmpdir, 1) if not $ok;
 279        }
 280
 281        return ($ldir, $rdir, $tmpdir, @working_tree);
 282}
 283
 284sub write_to_file
 285{
 286        my $path = shift;
 287        my $value = shift;
 288
 289        # Make sure the path to the file exists
 290        my $dir = dirname($path);
 291        unless (-d "$dir") {
 292                mkpath("$dir") or return 0;
 293        }
 294
 295        # If the file already exists in that location, delete it.  This
 296        # is required in the case of symbolic links.
 297        unlink($path);
 298
 299        open(my $fh, '>', $path) or return 0;
 300        print($fh $value);
 301        close($fh);
 302
 303        return 1;
 304}
 305
 306sub main
 307{
 308        # parse command-line options. all unrecognized options and arguments
 309        # are passed through to the 'git diff' command.
 310        my %opts = (
 311                difftool_cmd => undef,
 312                dirdiff => undef,
 313                extcmd => undef,
 314                gui => undef,
 315                help => undef,
 316                prompt => undef,
 317                symlinks => $^O ne 'cygwin' &&
 318                                $^O ne 'MSWin32' && $^O ne 'msys',
 319                tool_help => undef,
 320                trust_exit_code => undef,
 321        );
 322        GetOptions('g|gui!' => \$opts{gui},
 323                'd|dir-diff' => \$opts{dirdiff},
 324                'h' => \$opts{help},
 325                'prompt!' => \$opts{prompt},
 326                'y' => sub { $opts{prompt} = 0; },
 327                'symlinks' => \$opts{symlinks},
 328                'no-symlinks' => sub { $opts{symlinks} = 0; },
 329                't|tool:s' => \$opts{difftool_cmd},
 330                'tool-help' => \$opts{tool_help},
 331                'trust-exit-code' => \$opts{trust_exit_code},
 332                'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
 333                'x|extcmd:s' => \$opts{extcmd});
 334
 335        if (defined($opts{help})) {
 336                usage(0);
 337        }
 338        if (defined($opts{tool_help})) {
 339                print_tool_help();
 340        }
 341        if (defined($opts{difftool_cmd})) {
 342                if (length($opts{difftool_cmd}) > 0) {
 343                        $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
 344                } else {
 345                        print "No <tool> given for --tool=<tool>\n";
 346                        usage(1);
 347                }
 348        }
 349        if (defined($opts{extcmd})) {
 350                if (length($opts{extcmd}) > 0) {
 351                        $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
 352                } else {
 353                        print "No <cmd> given for --extcmd=<cmd>\n";
 354                        usage(1);
 355                }
 356        }
 357        if ($opts{gui}) {
 358                my $guitool = Git::config('diff.guitool');
 359                if (defined($guitool) && length($guitool) > 0) {
 360                        $ENV{GIT_DIFF_TOOL} = $guitool;
 361                }
 362        }
 363
 364        if (!defined $opts{trust_exit_code}) {
 365                $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
 366        }
 367        if ($opts{trust_exit_code}) {
 368                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
 369        } else {
 370                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
 371        }
 372
 373        # In directory diff mode, 'git-difftool--helper' is called once
 374        # to compare the a/b directories.  In file diff mode, 'git diff'
 375        # will invoke a separate instance of 'git-difftool--helper' for
 376        # each file that changed.
 377        if (defined($opts{dirdiff})) {
 378                dir_diff($opts{extcmd}, $opts{symlinks});
 379        } else {
 380                file_diff($opts{prompt});
 381        }
 382}
 383
 384sub dir_diff
 385{
 386        my ($extcmd, $symlinks) = @_;
 387        my $rc;
 388        my $error = 0;
 389        my $repo = Git->repository();
 390        my $repo_path = $repo->repo_path();
 391        my $workdir = $repo->wc_path();
 392        my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
 393
 394        if (defined($extcmd)) {
 395                $rc = system($extcmd, $a, $b);
 396        } else {
 397                $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 398                $rc = system('git', 'difftool--helper', $a, $b);
 399        }
 400        # If the diff including working copy files and those
 401        # files were modified during the diff, then the changes
 402        # should be copied back to the working tree.
 403        # Do not copy back files when symlinks are used and the
 404        # external tool did not replace the original link with a file.
 405        #
 406        # These hashes are loaded lazily since they aren't needed
 407        # in the common case of --symlinks and the difftool updating
 408        # files through the symlink.
 409        my %wt_modified;
 410        my %tmp_modified;
 411        my $indices_loaded = 0;
 412
 413        for my $file (@worktree) {
 414                next if $symlinks && -l "$b/$file";
 415                next if ! -f "$b/$file";
 416
 417                if (!$indices_loaded) {
 418                        %wt_modified = changed_files(
 419                                $repo_path, "$tmpdir/wtindex", $workdir);
 420                        %tmp_modified = changed_files(
 421                                $repo_path, "$tmpdir/wtindex", $b);
 422                        $indices_loaded = 1;
 423                }
 424
 425                if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
 426                        my $errmsg = "warning: Both files modified: ";
 427                        $errmsg .= "'$workdir/$file' and '$b/$file'.\n";
 428                        $errmsg .= "warning: Working tree file has been left.\n";
 429                        $errmsg .= "warning:\n";
 430                        warn $errmsg;
 431                        $error = 1;
 432                } elsif (exists $tmp_modified{$file}) {
 433                        my $mode = stat("$b/$file")->mode;
 434                        copy("$b/$file", "$workdir/$file") or
 435                        exit_cleanup($tmpdir, 1);
 436
 437                        chmod($mode, "$workdir/$file") or
 438                        exit_cleanup($tmpdir, 1);
 439                }
 440        }
 441        if ($error) {
 442                warn "warning: Temporary files exist in '$tmpdir'.\n";
 443                warn "warning: You may want to cleanup or recover these.\n";
 444                exit(1);
 445        } else {
 446                exit_cleanup($tmpdir, $rc);
 447        }
 448}
 449
 450sub file_diff
 451{
 452        my ($prompt) = @_;
 453
 454        if (defined($prompt)) {
 455                if ($prompt) {
 456                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
 457                } else {
 458                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 459                }
 460        }
 461
 462        $ENV{GIT_PAGER} = '';
 463        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 464
 465        # ActiveState Perl for Win32 does not implement POSIX semantics of
 466        # exec* system call. It just spawns the given executable and finishes
 467        # the starting program, exiting with code 0.
 468        # system will at least catch the errors returned by git diff,
 469        # allowing the caller of git difftool better handling of failures.
 470        my $rc = system('git', 'diff', @ARGV);
 471        exit($rc | ($rc >> 8));
 472}
 473
 474main();