Andrew's git - gitweb.git/blob

c9d3ef887f9897c7b952e363706696abf37017ce
   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 find_worktree
  41{
  42        # Git->repository->wc_path() does not honor changes to the working
  43        # tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
  44        # config variable.
  45        return Git::command_oneline('rev-parse', '--show-toplevel');
  46}
  47
  48sub print_tool_help
  49{
  50        # See the comment at the bottom of file_diff() for the reason behind
  51        # using system() followed by exit() instead of exec().
  52        my $rc = system(qw(git mergetool --tool-help=diff));
  53        exit($rc | ($rc >> 8));
  54}
  55
  56sub exit_cleanup
  57{
  58        my ($tmpdir, $status) = @_;
  59        my $errno = $!;
  60        rmtree($tmpdir);
  61        if ($status and $errno) {
  62                my ($package, $file, $line) = caller();
  63                warn "$file line $line: $errno\n";
  64        }
  65        exit($status | ($status >> 8));
  66}
  67
  68sub use_wt_file
  69{
  70        my ($repo, $workdir, $file, $sha1) = @_;
  71        my $null_sha1 = '0' x 40;
  72
  73        if (-l "$workdir/$file" || ! -e _) {
  74                return (0, $null_sha1);
  75        }
  76
  77        my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
  78        my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
  79        return ($use, $wt_sha1);
  80}
  81
  82sub changed_files
  83{
  84        my ($repo_path, $index, $worktree) = @_;
  85        $ENV{GIT_INDEX_FILE} = $index;
  86        $ENV{GIT_WORK_TREE} = $worktree;
  87        my $must_unset_git_dir = 0;
  88        if (not defined($ENV{GIT_DIR})) {
  89                $must_unset_git_dir = 1;
  90                $ENV{GIT_DIR} = $repo_path;
  91        }
  92
  93        my @refreshargs = qw/update-index --really-refresh -q --unmerged/;
  94        my @gitargs = qw/diff-files --name-only -z/;
  95        try {
  96                Git::command_oneline(@refreshargs);
  97        } catch Git::Error::Command with {};
  98
  99        my $line = Git::command_oneline(@gitargs);
 100        my @files;
 101        if (defined $line) {
 102                @files = split('\0', $line);
 103        } else {
 104                @files = ();
 105        }
 106
 107        delete($ENV{GIT_INDEX_FILE});
 108        delete($ENV{GIT_WORK_TREE});
 109        delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
 110
 111        return map { $_ => 1 } @files;
 112}
 113
 114sub setup_dir_diff
 115{
 116        my ($repo, $workdir, $symlinks) = @_;
 117
 118        my $repo_path = $repo->repo_path();
 119        my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 120        my $diffrtn = $repo->command_oneline(@gitargs);
 121        exit(0) unless defined($diffrtn);
 122
 123        # Build index info for left and right sides of the diff
 124        my $submodule_mode = '160000';
 125        my $symlink_mode = '120000';
 126        my $null_mode = '0' x 6;
 127        my $null_sha1 = '0' x 40;
 128        my $lindex = '';
 129        my $rindex = '';
 130        my $wtindex = '';
 131        my %submodule;
 132        my %symlink;
 133        my @working_tree = ();
 134        my %working_tree_dups = ();
 135        my @rawdiff = split('\0', $diffrtn);
 136
 137        my $i = 0;
 138        while ($i < $#rawdiff) {
 139                if ($rawdiff[$i] =~ /^::/) {
 140                        warn << 'EOF';
 141Combined diff formats ('-c' and '--cc') are not supported in
 142directory diff mode ('-d' and '--dir-diff').
 143EOF
 144                        exit(1);
 145                }
 146
 147                my ($lmode, $rmode, $lsha1, $rsha1, $status) =
 148                        split(' ', substr($rawdiff[$i], 1));
 149                my $src_path = $rawdiff[$i + 1];
 150                my $dst_path;
 151
 152                if ($status =~ /^[CR]/) {
 153                        $dst_path = $rawdiff[$i + 2];
 154                        $i += 3;
 155                } else {
 156                        $dst_path = $src_path;
 157                        $i += 2;
 158                }
 159
 160                if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
 161                        $submodule{$src_path}{left} = $lsha1;
 162                        if ($lsha1 ne $rsha1) {
 163                                $submodule{$dst_path}{right} = $rsha1;
 164                        } else {
 165                                $submodule{$dst_path}{right} = "$rsha1-dirty";
 166                        }
 167                        next;
 168                }
 169
 170                if ($lmode eq $symlink_mode) {
 171                        $symlink{$src_path}{left} =
 172                                $repo->command_oneline('show', "$lsha1");
 173                }
 174
 175                if ($rmode eq $symlink_mode) {
 176                        $symlink{$dst_path}{right} =
 177                                $repo->command_oneline('show', "$rsha1");
 178                }
 179
 180                if ($lmode ne $null_mode and $status !~ /^C/) {
 181                        $lindex .= "$lmode $lsha1\t$src_path\0";
 182                }
 183
 184                if ($rmode ne $null_mode) {
 185                        # Avoid duplicate working_tree entries
 186                        if ($working_tree_dups{$dst_path}++) {
 187                                next;
 188                        }
 189                        my ($use, $wt_sha1) = use_wt_file($repo, $workdir,
 190                                                          $dst_path, $rsha1);
 191                        if ($use) {
 192                                push @working_tree, $dst_path;
 193                                $wtindex .= "$rmode $wt_sha1\t$dst_path\0";
 194                        } else {
 195                                $rindex .= "$rmode $rsha1\t$dst_path\0";
 196                        }
 197                }
 198        }
 199
 200        # Setup temp directories
 201        my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
 202        my $ldir = "$tmpdir/left";
 203        my $rdir = "$tmpdir/right";
 204        mkpath($ldir) or exit_cleanup($tmpdir, 1);
 205        mkpath($rdir) or exit_cleanup($tmpdir, 1);
 206
 207        # If $GIT_DIR is not set prior to calling 'git update-index' and
 208        # 'git checkout-index', then those commands will fail if difftool
 209        # is called from a directory other than the repo root.
 210        my $must_unset_git_dir = 0;
 211        if (not defined($ENV{GIT_DIR})) {
 212                $must_unset_git_dir = 1;
 213                $ENV{GIT_DIR} = $repo_path;
 214        }
 215
 216        # Populate the left and right directories based on each index file
 217        my ($inpipe, $ctx);
 218        $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
 219        ($inpipe, $ctx) =
 220                $repo->command_input_pipe(qw(update-index -z --index-info));
 221        print($inpipe $lindex);
 222        $repo->command_close_pipe($inpipe, $ctx);
 223
 224        my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 225        exit_cleanup($tmpdir, $rc) if $rc != 0;
 226
 227        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 228        ($inpipe, $ctx) =
 229                $repo->command_input_pipe(qw(update-index -z --index-info));
 230        print($inpipe $rindex);
 231        $repo->command_close_pipe($inpipe, $ctx);
 232
 233        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
 234        exit_cleanup($tmpdir, $rc) if $rc != 0;
 235
 236        $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
 237        ($inpipe, $ctx) =
 238                $repo->command_input_pipe(qw(update-index --info-only -z --index-info));
 239        print($inpipe $wtindex);
 240        $repo->command_close_pipe($inpipe, $ctx);
 241
 242        # If $GIT_DIR was explicitly set just for the update/checkout
 243        # commands, then it should be unset before continuing.
 244        delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
 245        delete($ENV{GIT_INDEX_FILE});
 246
 247        # Changes in the working tree need special treatment since they are
 248        # not part of the index. Remove any trailing slash from $workdir
 249        # before starting to avoid double slashes in symlink targets.
 250        $workdir =~ s|/$||;
 251        for my $file (@working_tree) {
 252                my $dir = dirname($file);
 253                unless (-d "$rdir/$dir") {
 254                        mkpath("$rdir/$dir") or
 255                        exit_cleanup($tmpdir, 1);
 256                }
 257                if ($symlinks) {
 258                        symlink("$workdir/$file", "$rdir/$file") or
 259                        exit_cleanup($tmpdir, 1);
 260                } else {
 261                        copy("$workdir/$file", "$rdir/$file") or
 262                        exit_cleanup($tmpdir, 1);
 263
 264                        my $mode = stat("$workdir/$file")->mode;
 265                        chmod($mode, "$rdir/$file") or
 266                        exit_cleanup($tmpdir, 1);
 267                }
 268        }
 269
 270        # Changes to submodules require special treatment. This loop writes a
 271        # temporary file to both the left and right directories to show the
 272        # change in the recorded SHA1 for the submodule.
 273        for my $path (keys %submodule) {
 274                my $ok = 0;
 275                if (defined($submodule{$path}{left})) {
 276                        $ok = write_to_file("$ldir/$path",
 277                                "Subproject commit $submodule{$path}{left}");
 278                }
 279                if (defined($submodule{$path}{right})) {
 280                        $ok = write_to_file("$rdir/$path",
 281                                "Subproject commit $submodule{$path}{right}");
 282                }
 283                exit_cleanup($tmpdir, 1) if not $ok;
 284        }
 285
 286        # Symbolic links require special treatment. The standard "git diff"
 287        # shows only the link itself, not the contents of the link target.
 288        # This loop replicates that behavior.
 289        for my $path (keys %symlink) {
 290                my $ok = 0;
 291                if (defined($symlink{$path}{left})) {
 292                        $ok = write_to_file("$ldir/$path",
 293                                        $symlink{$path}{left});
 294                }
 295                if (defined($symlink{$path}{right})) {
 296                        $ok = write_to_file("$rdir/$path",
 297                                        $symlink{$path}{right});
 298                }
 299                exit_cleanup($tmpdir, 1) if not $ok;
 300        }
 301
 302        return ($ldir, $rdir, $tmpdir, @working_tree);
 303}
 304
 305sub write_to_file
 306{
 307        my $path = shift;
 308        my $value = shift;
 309
 310        # Make sure the path to the file exists
 311        my $dir = dirname($path);
 312        unless (-d "$dir") {
 313                mkpath("$dir") or return 0;
 314        }
 315
 316        # If the file already exists in that location, delete it.  This
 317        # is required in the case of symbolic links.
 318        unlink($path);
 319
 320        open(my $fh, '>', $path) or return 0;
 321        print($fh $value);
 322        close($fh);
 323
 324        return 1;
 325}
 326
 327sub main
 328{
 329        # parse command-line options. all unrecognized options and arguments
 330        # are passed through to the 'git diff' command.
 331        my %opts = (
 332                difftool_cmd => undef,
 333                dirdiff => undef,
 334                extcmd => undef,
 335                gui => undef,
 336                help => undef,
 337                prompt => undef,
 338                symlinks => $^O ne 'cygwin' &&
 339                                $^O ne 'MSWin32' && $^O ne 'msys',
 340                tool_help => undef,
 341                trust_exit_code => undef,
 342        );
 343        GetOptions('g|gui!' => \$opts{gui},
 344                'd|dir-diff' => \$opts{dirdiff},
 345                'h' => \$opts{help},
 346                'prompt!' => \$opts{prompt},
 347                'y' => sub { $opts{prompt} = 0; },
 348                'symlinks' => \$opts{symlinks},
 349                'no-symlinks' => sub { $opts{symlinks} = 0; },
 350                't|tool:s' => \$opts{difftool_cmd},
 351                'tool-help' => \$opts{tool_help},
 352                'trust-exit-code' => \$opts{trust_exit_code},
 353                'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
 354                'x|extcmd:s' => \$opts{extcmd});
 355
 356        if (defined($opts{help})) {
 357                usage(0);
 358        }
 359        if (defined($opts{tool_help})) {
 360                print_tool_help();
 361        }
 362        if (defined($opts{difftool_cmd})) {
 363                if (length($opts{difftool_cmd}) > 0) {
 364                        $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
 365                } else {
 366                        print "No <tool> given for --tool=<tool>\n";
 367                        usage(1);
 368                }
 369        }
 370        if (defined($opts{extcmd})) {
 371                if (length($opts{extcmd}) > 0) {
 372                        $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
 373                } else {
 374                        print "No <cmd> given for --extcmd=<cmd>\n";
 375                        usage(1);
 376                }
 377        }
 378        if ($opts{gui}) {
 379                my $guitool = Git::config('diff.guitool');
 380                if (defined($guitool) && length($guitool) > 0) {
 381                        $ENV{GIT_DIFF_TOOL} = $guitool;
 382                }
 383        }
 384
 385        if (!defined $opts{trust_exit_code}) {
 386                $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
 387        }
 388        if ($opts{trust_exit_code}) {
 389                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
 390        } else {
 391                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
 392        }
 393
 394        # In directory diff mode, 'git-difftool--helper' is called once
 395        # to compare the a/b directories.  In file diff mode, 'git diff'
 396        # will invoke a separate instance of 'git-difftool--helper' for
 397        # each file that changed.
 398        if (defined($opts{dirdiff})) {
 399                dir_diff($opts{extcmd}, $opts{symlinks});
 400        } else {
 401                file_diff($opts{prompt});
 402        }
 403}
 404
 405sub dir_diff
 406{
 407        my ($extcmd, $symlinks) = @_;
 408        my $rc;
 409        my $error = 0;
 410        my $repo = Git->repository();
 411        my $workdir = find_worktree();
 412        my ($a, $b, $tmpdir, @worktree) =
 413                setup_dir_diff($repo, $workdir, $symlinks);
 414
 415        if (defined($extcmd)) {
 416                $rc = system($extcmd, $a, $b);
 417        } else {
 418                $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 419                $rc = system('git', 'difftool--helper', $a, $b);
 420        }
 421        # If the diff including working copy files and those
 422        # files were modified during the diff, then the changes
 423        # should be copied back to the working tree.
 424        # Do not copy back files when symlinks are used and the
 425        # external tool did not replace the original link with a file.
 426        #
 427        # These hashes are loaded lazily since they aren't needed
 428        # in the common case of --symlinks and the difftool updating
 429        # files through the symlink.
 430        my %wt_modified;
 431        my %tmp_modified;
 432        my $indices_loaded = 0;
 433
 434        for my $file (@worktree) {
 435                next if $symlinks && -l "$b/$file";
 436                next if ! -f "$b/$file";
 437
 438                if (!$indices_loaded) {
 439                        %wt_modified = changed_files($repo->repo_path(),
 440                                "$tmpdir/wtindex", "$workdir");
 441                        %tmp_modified = changed_files($repo->repo_path(),
 442                                "$tmpdir/wtindex", "$b");
 443                        $indices_loaded = 1;
 444                }
 445
 446                if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
 447                        my $errmsg = "warning: Both files modified: ";
 448                        $errmsg .= "'$workdir/$file' and '$b/$file'.\n";
 449                        $errmsg .= "warning: Working tree file has been left.\n";
 450                        $errmsg .= "warning:\n";
 451                        warn $errmsg;
 452                        $error = 1;
 453                } elsif (exists $tmp_modified{$file}) {
 454                        my $mode = stat("$b/$file")->mode;
 455                        copy("$b/$file", "$workdir/$file") or
 456                        exit_cleanup($tmpdir, 1);
 457
 458                        chmod($mode, "$workdir/$file") or
 459                        exit_cleanup($tmpdir, 1);
 460                }
 461        }
 462        if ($error) {
 463                warn "warning: Temporary files exist in '$tmpdir'.\n";
 464                warn "warning: You may want to cleanup or recover these.\n";
 465                exit(1);
 466        } else {
 467                exit_cleanup($tmpdir, $rc);
 468        }
 469}
 470
 471sub file_diff
 472{
 473        my ($prompt) = @_;
 474
 475        if (defined($prompt)) {
 476                if ($prompt) {
 477                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
 478                } else {
 479                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 480                }
 481        }
 482
 483        $ENV{GIT_PAGER} = '';
 484        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 485
 486        # ActiveState Perl for Win32 does not implement POSIX semantics of
 487        # exec* system call. It just spawns the given executable and finishes
 488        # the starting program, exiting with code 0.
 489        # system will at least catch the errors returned by git diff,
 490        # allowing the caller of git difftool better handling of failures.
 491        my $rc = system('git', 'diff', @ARGV);
 492        exit($rc | ($rc >> 8));
 493}
 494
 495main();