Andrew's git - gitweb.git/blob

   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;
  25use Git::I18N;
  26
  27sub usage
  28{
  29        my $exitcode = shift;
  30        print << 'USAGE';
  31usage: git difftool [-t|--tool=<tool>] [--tool-help]
  32                    [-x|--extcmd=<cmd>]
  33                    [-g|--gui] [--no-gui]
  34                    [--prompt] [-y|--no-prompt]
  35                    [-d|--dir-diff]
  36                    ['git diff' options]
  37USAGE
  38        exit($exitcode);
  39}
  40
  41sub print_tool_help
  42{
  43        # See the comment at the bottom of file_diff() for the reason behind
  44        # using system() followed by exit() instead of exec().
  45        my $rc = system(qw(git mergetool --tool-help=diff));
  46        exit($rc | ($rc >> 8));
  47}
  48
  49sub exit_cleanup
  50{
  51        my ($tmpdir, $status) = @_;
  52        my $errno = $!;
  53        rmtree($tmpdir);
  54        if ($status and $errno) {
  55                my ($package, $file, $line) = caller();
  56                warn "$file line $line: $errno\n";
  57        }
  58        exit($status | ($status >> 8));
  59}
  60
  61sub use_wt_file
  62{
  63        my ($workdir, $file, $sha1) = @_;
  64        my $null_sha1 = '0' x 40;
  65
  66        if (-l "$workdir/$file" || ! -e _) {
  67                return (0, $null_sha1);
  68        }
  69
  70        my $wt_sha1 = Git::command_oneline('hash-object', "$workdir/$file");
  71        my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
  72        return ($use, $wt_sha1);
  73}
  74
  75sub changed_files
  76{
  77        my ($repo_path, $index, $worktree) = @_;
  78        $ENV{GIT_INDEX_FILE} = $index;
  79
  80        my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
  81        my @refreshargs = (
  82                @gitargs, 'update-index',
  83                '--really-refresh', '-q', '--unmerged');
  84        try {
  85                Git::command_oneline(@refreshargs);
  86        } catch Git::Error::Command with {};
  87
  88        my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
  89        my $line = Git::command_oneline(@diffargs);
  90        my @files;
  91        if (defined $line) {
  92                @files = split('\0', $line);
  93        } else {
  94                @files = ();
  95        }
  96
  97        delete($ENV{GIT_INDEX_FILE});
  98
  99        return map { $_ => 1 } @files;
 100}
 101
 102sub setup_dir_diff
 103{
 104        my ($workdir, $symlinks) = @_;
 105        my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 106        my $diffrtn = Git::command_oneline(@gitargs);
 107        exit(0) unless defined($diffrtn);
 108
 109        # Build index info for left and right sides of the diff
 110        my $submodule_mode = '160000';
 111        my $symlink_mode = '120000';
 112        my $null_mode = '0' x 6;
 113        my $null_sha1 = '0' x 40;
 114        my $lindex = '';
 115        my $rindex = '';
 116        my $wtindex = '';
 117        my %submodule;
 118        my %symlink;
 119        my @working_tree = ();
 120        my %working_tree_dups = ();
 121        my @rawdiff = split('\0', $diffrtn);
 122
 123        my $i = 0;
 124        while ($i < $#rawdiff) {
 125                if ($rawdiff[$i] =~ /^::/) {
 126                        warn __ <<'EOF';
 127Combined diff formats ('-c' and '--cc') are not supported in
 128directory diff mode ('-d' and '--dir-diff').
 129EOF
 130                        exit(1);
 131                }
 132
 133                my ($lmode, $rmode, $lsha1, $rsha1, $status) =
 134                        split(' ', substr($rawdiff[$i], 1));
 135                my $src_path = $rawdiff[$i + 1];
 136                my $dst_path;
 137
 138                if ($status =~ /^[CR]/) {
 139                        $dst_path = $rawdiff[$i + 2];
 140                        $i += 3;
 141                } else {
 142                        $dst_path = $src_path;
 143                        $i += 2;
 144                }
 145
 146                if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
 147                        $submodule{$src_path}{left} = $lsha1;
 148                        if ($lsha1 ne $rsha1) {
 149                                $submodule{$dst_path}{right} = $rsha1;
 150                        } else {
 151                                $submodule{$dst_path}{right} = "$rsha1-dirty";
 152                        }
 153                        next;
 154                }
 155
 156                if ($lmode eq $symlink_mode) {
 157                        $symlink{$src_path}{left} =
 158                                Git::command_oneline('show', $lsha1);
 159                }
 160
 161                if ($rmode eq $symlink_mode) {
 162                        $symlink{$dst_path}{right} =
 163                                Git::command_oneline('show', $rsha1);
 164                }
 165
 166                if ($lmode ne $null_mode and $status !~ /^C/) {
 167                        $lindex .= "$lmode $lsha1\t$src_path\0";
 168                }
 169
 170                if ($rmode ne $null_mode) {
 171                        # Avoid duplicate working_tree entries
 172                        if ($working_tree_dups{$dst_path}++) {
 173                                next;
 174                        }
 175                        my ($use, $wt_sha1) =
 176                                use_wt_file($workdir, $dst_path, $rsha1);
 177                        if ($use) {
 178                                push @working_tree, $dst_path;
 179                                $wtindex .= "$rmode $wt_sha1\t$dst_path\0";
 180                        } else {
 181                                $rindex .= "$rmode $rsha1\t$dst_path\0";
 182                        }
 183                }
 184        }
 185
 186        # Setup temp directories
 187        my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
 188        my $ldir = "$tmpdir/left";
 189        my $rdir = "$tmpdir/right";
 190        mkpath($ldir) or exit_cleanup($tmpdir, 1);
 191        mkpath($rdir) or exit_cleanup($tmpdir, 1);
 192
 193        # Populate the left and right directories based on each index file
 194        my ($inpipe, $ctx);
 195        $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
 196        ($inpipe, $ctx) =
 197                Git::command_input_pipe('update-index', '-z', '--index-info');
 198        print($inpipe $lindex);
 199        Git::command_close_pipe($inpipe, $ctx);
 200
 201        my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 202        exit_cleanup($tmpdir, $rc) if $rc != 0;
 203
 204        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 205        ($inpipe, $ctx) =
 206                Git::command_input_pipe('update-index', '-z', '--index-info');
 207        print($inpipe $rindex);
 208        Git::command_close_pipe($inpipe, $ctx);
 209
 210        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
 211        exit_cleanup($tmpdir, $rc) if $rc != 0;
 212
 213        $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
 214        ($inpipe, $ctx) =
 215                Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
 216        print($inpipe $wtindex);
 217        Git::command_close_pipe($inpipe, $ctx);
 218
 219        # If $GIT_DIR was explicitly set just for the update/checkout
 220        # commands, then it should be unset before continuing.
 221        delete($ENV{GIT_INDEX_FILE});
 222
 223        # Changes in the working tree need special treatment since they are
 224        # not part of the index. Remove any trailing slash from $workdir
 225        # before starting to avoid double slashes in symlink targets.
 226        $workdir =~ s|/$||;
 227        for my $file (@working_tree) {
 228                my $dir = dirname($file);
 229                unless (-d "$rdir/$dir") {
 230                        mkpath("$rdir/$dir") or
 231                        exit_cleanup($tmpdir, 1);
 232                }
 233                if ($symlinks) {
 234                        symlink("$workdir/$file", "$rdir/$file") or
 235                        exit_cleanup($tmpdir, 1);
 236                } else {
 237                        copy("$workdir/$file", "$rdir/$file") or
 238                        exit_cleanup($tmpdir, 1);
 239
 240                        my $mode = stat("$workdir/$file")->mode;
 241                        chmod($mode, "$rdir/$file") or
 242                        exit_cleanup($tmpdir, 1);
 243                }
 244        }
 245
 246        # Changes to submodules require special treatment. This loop writes a
 247        # temporary file to both the left and right directories to show the
 248        # change in the recorded SHA1 for the submodule.
 249        for my $path (keys %submodule) {
 250                my $ok = 0;
 251                if (defined($submodule{$path}{left})) {
 252                        $ok = write_to_file("$ldir/$path",
 253                                "Subproject commit $submodule{$path}{left}");
 254                }
 255                if (defined($submodule{$path}{right})) {
 256                        $ok = write_to_file("$rdir/$path",
 257                                "Subproject commit $submodule{$path}{right}");
 258                }
 259                exit_cleanup($tmpdir, 1) if not $ok;
 260        }
 261
 262        # Symbolic links require special treatment. The standard "git diff"
 263        # shows only the link itself, not the contents of the link target.
 264        # This loop replicates that behavior.
 265        for my $path (keys %symlink) {
 266                my $ok = 0;
 267                if (defined($symlink{$path}{left})) {
 268                        $ok = write_to_file("$ldir/$path",
 269                                        $symlink{$path}{left});
 270                }
 271                if (defined($symlink{$path}{right})) {
 272                        $ok = write_to_file("$rdir/$path",
 273                                        $symlink{$path}{right});
 274                }
 275                exit_cleanup($tmpdir, 1) if not $ok;
 276        }
 277
 278        return ($ldir, $rdir, $tmpdir, @working_tree);
 279}
 280
 281sub write_to_file
 282{
 283        my $path = shift;
 284        my $value = shift;
 285
 286        # Make sure the path to the file exists
 287        my $dir = dirname($path);
 288        unless (-d "$dir") {
 289                mkpath("$dir") or return 0;
 290        }
 291
 292        # If the file already exists in that location, delete it.  This
 293        # is required in the case of symbolic links.
 294        unlink($path);
 295
 296        open(my $fh, '>', $path) or return 0;
 297        print($fh $value);
 298        close($fh);
 299
 300        return 1;
 301}
 302
 303sub main
 304{
 305        # parse command-line options. all unrecognized options and arguments
 306        # are passed through to the 'git diff' command.
 307        my %opts = (
 308                difftool_cmd => undef,
 309                dirdiff => undef,
 310                extcmd => undef,
 311                gui => undef,
 312                help => undef,
 313                prompt => undef,
 314                symlinks => $^O ne 'cygwin' &&
 315                                $^O ne 'MSWin32' && $^O ne 'msys',
 316                tool_help => undef,
 317                trust_exit_code => undef,
 318        );
 319        GetOptions('g|gui!' => \$opts{gui},
 320                'd|dir-diff' => \$opts{dirdiff},
 321                'h' => \$opts{help},
 322                'prompt!' => \$opts{prompt},
 323                'y' => sub { $opts{prompt} = 0; },
 324                'symlinks' => \$opts{symlinks},
 325                'no-symlinks' => sub { $opts{symlinks} = 0; },
 326                't|tool:s' => \$opts{difftool_cmd},
 327                'tool-help' => \$opts{tool_help},
 328                'trust-exit-code' => \$opts{trust_exit_code},
 329                'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
 330                'x|extcmd:s' => \$opts{extcmd});
 331
 332        if (defined($opts{help})) {
 333                usage(0);
 334        }
 335        if (defined($opts{tool_help})) {
 336                print_tool_help();
 337        }
 338        if (defined($opts{difftool_cmd})) {
 339                if (length($opts{difftool_cmd}) > 0) {
 340                        $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
 341                } else {
 342                        print __("No <tool> given for --tool=<tool>\n");
 343                        usage(1);
 344                }
 345        }
 346        if (defined($opts{extcmd})) {
 347                if (length($opts{extcmd}) > 0) {
 348                        $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
 349                } else {
 350                        print __("No <cmd> given for --extcmd=<cmd>\n");
 351                        usage(1);
 352                }
 353        }
 354        if ($opts{gui}) {
 355                my $guitool = Git::config('diff.guitool');
 356                if (defined($guitool) && length($guitool) > 0) {
 357                        $ENV{GIT_DIFF_TOOL} = $guitool;
 358                }
 359        }
 360
 361        if (!defined $opts{trust_exit_code}) {
 362                $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
 363        }
 364        if ($opts{trust_exit_code}) {
 365                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
 366        } else {
 367                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
 368        }
 369
 370        # In directory diff mode, 'git-difftool--helper' is called once
 371        # to compare the a/b directories.  In file diff mode, 'git diff'
 372        # will invoke a separate instance of 'git-difftool--helper' for
 373        # each file that changed.
 374        if (defined($opts{dirdiff})) {
 375                dir_diff($opts{extcmd}, $opts{symlinks});
 376        } else {
 377                file_diff($opts{prompt});
 378        }
 379}
 380
 381sub dir_diff
 382{
 383        my ($extcmd, $symlinks) = @_;
 384        my $rc;
 385        my $error = 0;
 386        my $repo = Git->repository();
 387        my $repo_path = $repo->repo_path();
 388        my $workdir = $repo->wc_path();
 389        my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
 390
 391        if (defined($extcmd)) {
 392                $rc = system($extcmd, $a, $b);
 393        } else {
 394                $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 395                $rc = system('git', 'difftool--helper', $a, $b);
 396        }
 397        # If the diff including working copy files and those
 398        # files were modified during the diff, then the changes
 399        # should be copied back to the working tree.
 400        # Do not copy back files when symlinks are used and the
 401        # external tool did not replace the original link with a file.
 402        #
 403        # These hashes are loaded lazily since they aren't needed
 404        # in the common case of --symlinks and the difftool updating
 405        # files through the symlink.
 406        my %wt_modified;
 407        my %tmp_modified;
 408        my $indices_loaded = 0;
 409
 410        for my $file (@worktree) {
 411                next if $symlinks && -l "$b/$file";
 412                next if ! -f "$b/$file";
 413
 414                if (!$indices_loaded) {
 415                        %wt_modified = changed_files(
 416                                $repo_path, "$tmpdir/wtindex", $workdir);
 417                        %tmp_modified = changed_files(
 418                                $repo_path, "$tmpdir/wtindex", $b);
 419                        $indices_loaded = 1;
 420                }
 421
 422                if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
 423                        warn sprintf(__(
 424                                "warning: Both files modified:\n" .
 425                                "'%s/%s' and '%s/%s'.\n" .
 426                                "warning: Working tree file has been left.\n" .
 427                                "warning:\n"), $workdir, $file, $b, $file);
 428                        $error = 1;
 429                } elsif (exists $tmp_modified{$file}) {
 430                        my $mode = stat("$b/$file")->mode;
 431                        copy("$b/$file", "$workdir/$file") or
 432                        exit_cleanup($tmpdir, 1);
 433
 434                        chmod($mode, "$workdir/$file") or
 435                        exit_cleanup($tmpdir, 1);
 436                }
 437        }
 438        if ($error) {
 439                warn sprintf(__(
 440                        "warning: Temporary files exist in '%s'.\n" .
 441                        "warning: You may want to cleanup or recover these.\n"), $tmpdir);
 442                exit(1);
 443        } else {
 444                exit_cleanup($tmpdir, $rc);
 445        }
 446}
 447
 448sub file_diff
 449{
 450        my ($prompt) = @_;
 451
 452        if (defined($prompt)) {
 453                if ($prompt) {
 454                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
 455                } else {
 456                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 457                }
 458        }
 459
 460        $ENV{GIT_PAGER} = '';
 461        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 462
 463        # ActiveState Perl for Win32 does not implement POSIX semantics of
 464        # exec* system call. It just spawns the given executable and finishes
 465        # the starting program, exiting with code 0.
 466        # system will at least catch the errors returned by git diff,
 467        # allowing the caller of git difftool better handling of failures.
 468        my $rc = system('git', 'diff', @ARGV);
 469        exit($rc | ($rc >> 8));
 470}
 471
 472main();