Andrew's git / gitweb.git / git-difftool.perl
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git-difftool.perlon commit add--interactive: handle EOF in prompt_yesno (d5addcf)
   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        # Go to the root of the worktree so that the left index files
 187        # are properly setup -- the index is toplevel-relative.
 188        chdir($workdir);
 189
 190        # Setup temp directories
 191        my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
 192        my $ldir = "$tmpdir/left";
 193        my $rdir = "$tmpdir/right";
 194        mkpath($ldir) or exit_cleanup($tmpdir, 1);
 195        mkpath($rdir) or exit_cleanup($tmpdir, 1);
 196
 197        # Populate the left and right directories based on each index file
 198        my ($inpipe, $ctx);
 199        $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
 200        ($inpipe, $ctx) =
 201                Git::command_input_pipe('update-index', '-z', '--index-info');
 202        print($inpipe $lindex);
 203        Git::command_close_pipe($inpipe, $ctx);
 204
 205        my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 206        exit_cleanup($tmpdir, $rc) if $rc != 0;
 207
 208        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 209        ($inpipe, $ctx) =
 210                Git::command_input_pipe('update-index', '-z', '--index-info');
 211        print($inpipe $rindex);
 212        Git::command_close_pipe($inpipe, $ctx);
 213
 214        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
 215        exit_cleanup($tmpdir, $rc) if $rc != 0;
 216
 217        $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
 218        ($inpipe, $ctx) =
 219                Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
 220        print($inpipe $wtindex);
 221        Git::command_close_pipe($inpipe, $ctx);
 222
 223        # If $GIT_DIR was explicitly set just for the update/checkout
 224        # commands, then it should be unset before continuing.
 225        delete($ENV{GIT_INDEX_FILE});
 226
 227        # Changes in the working tree need special treatment since they are
 228        # not part of the index. Remove any trailing slash from $workdir
 229        # before starting to avoid double slashes in symlink targets.
 230        $workdir =~ s|/$||;
 231        for my $file (@working_tree) {
 232                my $dir = dirname($file);
 233                unless (-d "$rdir/$dir") {
 234                        mkpath("$rdir/$dir") or
 235                        exit_cleanup($tmpdir, 1);
 236                }
 237                if ($symlinks) {
 238                        symlink("$workdir/$file", "$rdir/$file") or
 239                        exit_cleanup($tmpdir, 1);
 240                } else {
 241                        copy("$workdir/$file", "$rdir/$file") or
 242                        exit_cleanup($tmpdir, 1);
 243
 244                        my $mode = stat("$workdir/$file")->mode;
 245                        chmod($mode, "$rdir/$file") or
 246                        exit_cleanup($tmpdir, 1);
 247                }
 248        }
 249
 250        # Changes to submodules require special treatment. This loop writes a
 251        # temporary file to both the left and right directories to show the
 252        # change in the recorded SHA1 for the submodule.
 253        for my $path (keys %submodule) {
 254                my $ok = 0;
 255                if (defined($submodule{$path}{left})) {
 256                        $ok = write_to_file("$ldir/$path",
 257                                "Subproject commit $submodule{$path}{left}");
 258                }
 259                if (defined($submodule{$path}{right})) {
 260                        $ok = write_to_file("$rdir/$path",
 261                                "Subproject commit $submodule{$path}{right}");
 262                }
 263                exit_cleanup($tmpdir, 1) if not $ok;
 264        }
 265
 266        # Symbolic links require special treatment. The standard "git diff"
 267        # shows only the link itself, not the contents of the link target.
 268        # This loop replicates that behavior.
 269        for my $path (keys %symlink) {
 270                my $ok = 0;
 271                if (defined($symlink{$path}{left})) {
 272                        $ok = write_to_file("$ldir/$path",
 273                                        $symlink{$path}{left});
 274                }
 275                if (defined($symlink{$path}{right})) {
 276                        $ok = write_to_file("$rdir/$path",
 277                                        $symlink{$path}{right});
 278                }
 279                exit_cleanup($tmpdir, 1) if not $ok;
 280        }
 281
 282        return ($ldir, $rdir, $tmpdir, @working_tree);
 283}
 284
 285sub write_to_file
 286{
 287        my $path = shift;
 288        my $value = shift;
 289
 290        # Make sure the path to the file exists
 291        my $dir = dirname($path);
 292        unless (-d "$dir") {
 293                mkpath("$dir") or return 0;
 294        }
 295
 296        # If the file already exists in that location, delete it.  This
 297        # is required in the case of symbolic links.
 298        unlink($path);
 299
 300        open(my $fh, '>', $path) or return 0;
 301        print($fh $value);
 302        close($fh);
 303
 304        return 1;
 305}
 306
 307sub main
 308{
 309        # parse command-line options. all unrecognized options and arguments
 310        # are passed through to the 'git diff' command.
 311        my %opts = (
 312                difftool_cmd => undef,
 313                dirdiff => undef,
 314                extcmd => undef,
 315                gui => undef,
 316                help => undef,
 317                prompt => undef,
 318                symlinks => $^O ne 'cygwin' &&
 319                                $^O ne 'MSWin32' && $^O ne 'msys',
 320                tool_help => undef,
 321                trust_exit_code => undef,
 322        );
 323        GetOptions('g|gui!' => \$opts{gui},
 324                'd|dir-diff' => \$opts{dirdiff},
 325                'h' => \$opts{help},
 326                'prompt!' => \$opts{prompt},
 327                'y' => sub { $opts{prompt} = 0; },
 328                'symlinks' => \$opts{symlinks},
 329                'no-symlinks' => sub { $opts{symlinks} = 0; },
 330                't|tool:s' => \$opts{difftool_cmd},
 331                'tool-help' => \$opts{tool_help},
 332                'trust-exit-code' => \$opts{trust_exit_code},
 333                'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
 334                'x|extcmd:s' => \$opts{extcmd});
 335
 336        if (defined($opts{help})) {
 337                usage(0);
 338        }
 339        if (defined($opts{tool_help})) {
 340                print_tool_help();
 341        }
 342        if (defined($opts{difftool_cmd})) {
 343                if (length($opts{difftool_cmd}) > 0) {
 344                        $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
 345                } else {
 346                        print __("No <tool> given for --tool=<tool>\n");
 347                        usage(1);
 348                }
 349        }
 350        if (defined($opts{extcmd})) {
 351                if (length($opts{extcmd}) > 0) {
 352                        $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
 353                } else {
 354                        print __("No <cmd> given for --extcmd=<cmd>\n");
 355                        usage(1);
 356                }
 357        }
 358        if ($opts{gui}) {
 359                my $guitool = Git::config('diff.guitool');
 360                if (defined($guitool) && length($guitool) > 0) {
 361                        $ENV{GIT_DIFF_TOOL} = $guitool;
 362                }
 363        }
 364
 365        if (!defined $opts{trust_exit_code}) {
 366                $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
 367        }
 368        if ($opts{trust_exit_code}) {
 369                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
 370        } else {
 371                $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
 372        }
 373
 374        # In directory diff mode, 'git-difftool--helper' is called once
 375        # to compare the a/b directories.  In file diff mode, 'git diff'
 376        # will invoke a separate instance of 'git-difftool--helper' for
 377        # each file that changed.
 378        if (defined($opts{dirdiff})) {
 379                dir_diff($opts{extcmd}, $opts{symlinks});
 380        } else {
 381                file_diff($opts{prompt});
 382        }
 383}
 384
 385sub dir_diff
 386{
 387        my ($extcmd, $symlinks) = @_;
 388        my $rc;
 389        my $error = 0;
 390        my $repo = Git->repository();
 391        my $repo_path = $repo->repo_path();
 392        my $workdir = $repo->wc_path();
 393        my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($workdir, $symlinks);
 394
 395        if (defined($extcmd)) {
 396                $rc = system($extcmd, $a, $b);
 397        } else {
 398                $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 399                $rc = system('git', 'difftool--helper', $a, $b);
 400        }
 401        # If the diff including working copy files and those
 402        # files were modified during the diff, then the changes
 403        # should be copied back to the working tree.
 404        # Do not copy back files when symlinks are used and the
 405        # external tool did not replace the original link with a file.
 406        #
 407        # These hashes are loaded lazily since they aren't needed
 408        # in the common case of --symlinks and the difftool updating
 409        # files through the symlink.
 410        my %wt_modified;
 411        my %tmp_modified;
 412        my $indices_loaded = 0;
 413
 414        for my $file (@worktree) {
 415                next if $symlinks && -l "$b/$file";
 416                next if ! -f "$b/$file";
 417
 418                if (!$indices_loaded) {
 419                        %wt_modified = changed_files(
 420                                $repo_path, "$tmpdir/wtindex", $workdir);
 421                        %tmp_modified = changed_files(
 422                                $repo_path, "$tmpdir/wtindex", $b);
 423                        $indices_loaded = 1;
 424                }
 425
 426                if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
 427                        warn sprintf(__(
 428                                "warning: Both files modified:\n" .
 429                                "'%s/%s' and '%s/%s'.\n" .
 430                                "warning: Working tree file has been left.\n" .
 431                                "warning:\n"), $workdir, $file, $b, $file);
 432                        $error = 1;
 433                } elsif (exists $tmp_modified{$file}) {
 434                        my $mode = stat("$b/$file")->mode;
 435                        copy("$b/$file", "$workdir/$file") or
 436                        exit_cleanup($tmpdir, 1);
 437
 438                        chmod($mode, "$workdir/$file") or
 439                        exit_cleanup($tmpdir, 1);
 440                }
 441        }
 442        if ($error) {
 443                warn sprintf(__(
 444                        "warning: Temporary files exist in '%s'.\n" .
 445                        "warning: You may want to cleanup or recover these.\n"), $tmpdir);
 446                exit(1);
 447        } else {
 448                exit_cleanup($tmpdir, $rc);
 449        }
 450}
 451
 452sub file_diff
 453{
 454        my ($prompt) = @_;
 455
 456        if (defined($prompt)) {
 457                if ($prompt) {
 458                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
 459                } else {
 460                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 461                }
 462        }
 463
 464        $ENV{GIT_PAGER} = '';
 465        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 466
 467        # ActiveState Perl for Win32 does not implement POSIX semantics of
 468        # exec* system call. It just spawns the given executable and finishes
 469        # the starting program, exiting with code 0.
 470        # system will at least catch the errors returned by git diff,
 471        # allowing the caller of git difftool better handling of failures.
 472        my $rc = system('git', 'diff', @ARGV);
 473        exit($rc | ($rc >> 8));
 474}
 475
 476main();