Andrew's git / gitweb.git /
a5b371f72982fc807e3dce2a1adc40e310b0d0a8
   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 File::Basename qw(basename dirname);
  17use File::Copy;
  18use File::Compare;
  19use File::stat;
  20use File::Path qw(mkpath);
  21use File::Temp qw(tempdir);
  22use Getopt::Long qw(:config pass_through);
  23use Git;
  24
  25sub usage
  26{
  27        my $exitcode = shift;
  28        print << 'USAGE';
  29usage: git difftool [-t|--tool=<tool>] [--tool-help]
  30                    [-x|--extcmd=<cmd>]
  31                    [-g|--gui] [--no-gui]
  32                    [--prompt] [-y|--no-prompt]
  33                    [-d|--dir-diff]
  34                    ['git diff' options]
  35USAGE
  36        exit($exitcode);
  37}
  38
  39sub find_worktree
  40{
  41        my ($repo) = @_;
  42
  43        # Git->repository->wc_path() does not honor changes to the working
  44        # tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
  45        # config variable.
  46        my $worktree;
  47        my $env_worktree = $ENV{GIT_WORK_TREE};
  48        my $core_worktree = Git::config('core.worktree');
  49
  50        if (defined($env_worktree) and (length($env_worktree) > 0)) {
  51                $worktree = $env_worktree;
  52        } elsif (defined($core_worktree) and (length($core_worktree) > 0)) {
  53                $worktree = $core_worktree;
  54        } else {
  55                $worktree = $repo->wc_path();
  56        }
  57
  58        return $worktree;
  59}
  60
  61sub print_tool_help
  62{
  63        my ($cmd, @found, @notfound);
  64        my $gitpath = Git::exec_path();
  65
  66        my @files = map { basename($_) } glob("$gitpath/mergetools/*");
  67        my @tools = sort(grep { !m{^defaults$} } @files);
  68
  69        foreach my $tool (@tools) {
  70                $cmd  = "TOOL_MODE=diff";
  71                $cmd .= ' && . "$(git --exec-path)/git-mergetool--lib"';
  72                $cmd .= " && get_merge_tool_path $tool >/dev/null 2>&1";
  73                $cmd .= " && can_diff >/dev/null 2>&1";
  74                if (system('sh', '-c', $cmd) == 0) {
  75                        push(@found, $tool);
  76                } else {
  77                        push(@notfound, $tool);
  78                }
  79        }
  80
  81        print "'git difftool --tool=<tool>' may be set to one of the following:\n";
  82        print "\t$_\n" for (@found);
  83
  84        print "\nThe following tools are valid, but not currently available:\n";
  85        print "\t$_\n" for (@notfound);
  86
  87        print "\nNOTE: Some of the tools listed above only work in a windowed\n";
  88        print "environment. If run in a terminal-only session, they will fail.\n";
  89
  90        exit(0);
  91}
  92
  93sub setup_dir_diff
  94{
  95        my ($repo, $workdir, $symlinks) = @_;
  96
  97        # Run the diff; exit immediately if no diff found
  98        # 'Repository' and 'WorkingCopy' must be explicitly set to insure that
  99        # if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
 100        # by Git->repository->command*.
 101        my $repo_path = $repo->repo_path();
 102        my $diffrepo = Git->repository(Repository => $repo_path, WorkingCopy => $workdir);
 103        my $diffrtn = $diffrepo->command_oneline('diff', '--raw', '--no-abbrev', '-z', @ARGV);
 104        exit(0) if (length($diffrtn) == 0);
 105
 106        # Setup temp directories
 107        my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 1, TMPDIR => 1);
 108        my $ldir = "$tmpdir/left";
 109        my $rdir = "$tmpdir/right";
 110        mkpath($ldir) or die $!;
 111        mkpath($rdir) or die $!;
 112
 113        # Build index info for left and right sides of the diff
 114        my $submodule_mode = '160000';
 115        my $symlink_mode = '120000';
 116        my $null_mode = '0' x 6;
 117        my $null_sha1 = '0' x 40;
 118        my $lindex = '';
 119        my $rindex = '';
 120        my %submodule;
 121        my %symlink;
 122        my @working_tree = ();
 123        my @rawdiff = split('\0', $diffrtn);
 124
 125        my $i = 0;
 126        while ($i < $#rawdiff) {
 127                if ($rawdiff[$i] =~ /^::/) {
 128                        print "Combined diff formats ('-c' and '--cc') are not supported in directory diff mode.\n";
 129                        exit(1);
 130                }
 131
 132                my ($lmode, $rmode, $lsha1, $rsha1, $status) = split(' ', substr($rawdiff[$i], 1));
 133                my $src_path = $rawdiff[$i + 1];
 134                my $dst_path;
 135
 136                if ($status =~ /^[CR]/) {
 137                        $dst_path = $rawdiff[$i + 2];
 138                        $i += 3;
 139                } else {
 140                        $dst_path = $src_path;
 141                        $i += 2;
 142                }
 143
 144                if (($lmode eq $submodule_mode) or ($rmode eq $submodule_mode)) {
 145                        $submodule{$src_path}{left} = $lsha1;
 146                        if ($lsha1 ne $rsha1) {
 147                                $submodule{$dst_path}{right} = $rsha1;
 148                        } else {
 149                                $submodule{$dst_path}{right} = "$rsha1-dirty";
 150                        }
 151                        next;
 152                }
 153
 154                if ($lmode eq $symlink_mode) {
 155                        $symlink{$src_path}{left} = $diffrepo->command_oneline('show', "$lsha1");
 156                }
 157
 158                if ($rmode eq $symlink_mode) {
 159                        $symlink{$dst_path}{right} = $diffrepo->command_oneline('show', "$rsha1");
 160                }
 161
 162                if (($lmode ne $null_mode) and ($status !~ /^C/)) {
 163                        $lindex .= "$lmode $lsha1\t$src_path\0";
 164                }
 165
 166                if ($rmode ne $null_mode) {
 167                        if ($rsha1 ne $null_sha1) {
 168                                $rindex .= "$rmode $rsha1\t$dst_path\0";
 169                        } else {
 170                                push(@working_tree, $dst_path);
 171                        }
 172                }
 173        }
 174
 175        # If $GIT_DIR is not set prior to calling 'git update-index' and
 176        # 'git checkout-index', then those commands will fail if difftool
 177        # is called from a directory other than the repo root.
 178        my $must_unset_git_dir = 0;
 179        if (not defined($ENV{GIT_DIR})) {
 180                $must_unset_git_dir = 1;
 181                $ENV{GIT_DIR} = $repo_path;
 182        }
 183
 184        # Populate the left and right directories based on each index file
 185        my ($inpipe, $ctx);
 186        $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
 187        ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
 188        print($inpipe $lindex);
 189        $repo->command_close_pipe($inpipe, $ctx);
 190        my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 191        exit($rc | ($rc >> 8)) if ($rc != 0);
 192
 193        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 194        ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
 195        print($inpipe $rindex);
 196        $repo->command_close_pipe($inpipe, $ctx);
 197        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
 198        exit($rc | ($rc >> 8)) if ($rc != 0);
 199
 200        # If $GIT_DIR was explicitly set just for the update/checkout
 201        # commands, then it should be unset before continuing.
 202        delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
 203        delete($ENV{GIT_INDEX_FILE});
 204
 205        # Changes in the working tree need special treatment since they are
 206        # not part of the index
 207        for my $file (@working_tree) {
 208                my $dir = dirname($file);
 209                unless (-d "$rdir/$dir") {
 210                        mkpath("$rdir/$dir") or die $!;
 211                }
 212                if ($symlinks) {
 213                        symlink("$workdir/$file", "$rdir/$file") or die $!;
 214                } else {
 215                        copy("$workdir/$file", "$rdir/$file") or die $!;
 216                        my $mode = stat("$workdir/$file")->mode;
 217                        chmod($mode, "$rdir/$file") or die $!;
 218                }
 219        }
 220
 221        # Changes to submodules require special treatment. This loop writes a
 222        # temporary file to both the left and right directories to show the
 223        # change in the recorded SHA1 for the submodule.
 224        for my $path (keys %submodule) {
 225                if (defined($submodule{$path}{left})) {
 226                        write_to_file("$ldir/$path", "Subproject commit $submodule{$path}{left}");
 227                }
 228                if (defined($submodule{$path}{right})) {
 229                        write_to_file("$rdir/$path", "Subproject commit $submodule{$path}{right}");
 230                }
 231        }
 232
 233        # Symbolic links require special treatment. The standard "git diff"
 234        # shows only the link itself, not the contents of the link target.
 235        # This loop replicates that behavior.
 236        for my $path (keys %symlink) {
 237                if (defined($symlink{$path}{left})) {
 238                        write_to_file("$ldir/$path", $symlink{$path}{left});
 239                }
 240                if (defined($symlink{$path}{right})) {
 241                        write_to_file("$rdir/$path", $symlink{$path}{right});
 242                }
 243        }
 244
 245        return ($ldir, $rdir, @working_tree);
 246}
 247
 248sub write_to_file
 249{
 250        my $path = shift;
 251        my $value = shift;
 252
 253        # Make sure the path to the file exists
 254        my $dir = dirname($path);
 255        unless (-d "$dir") {
 256                mkpath("$dir") or die $!;
 257        }
 258
 259        # If the file already exists in that location, delete it.  This
 260        # is required in the case of symbolic links.
 261        unlink("$path");
 262
 263        open(my $fh, '>', "$path") or die $!;
 264        print($fh $value);
 265        close($fh);
 266}
 267
 268sub main
 269{
 270        # parse command-line options. all unrecognized options and arguments
 271        # are passed through to the 'git diff' command.
 272        my %opts = (
 273                difftool_cmd => undef,
 274                dirdiff => undef,
 275                extcmd => undef,
 276                gui => undef,
 277                help => undef,
 278                prompt => undef,
 279                symlinks => $^O ne 'MSWin32' && $^O ne 'msys',
 280                tool_help => undef,
 281        );
 282        GetOptions('g|gui!' => \$opts{gui},
 283                'd|dir-diff' => \$opts{dirdiff},
 284                'h' => \$opts{help},
 285                'prompt!' => \$opts{prompt},
 286                'y' => sub { $opts{prompt} = 0; },
 287                'symlinks' => \$opts{symlinks},
 288                'no-symlinks' => sub { $opts{symlinks} = 0; },
 289                't|tool:s' => \$opts{difftool_cmd},
 290                'tool-help' => \$opts{tool_help},
 291                'x|extcmd:s' => \$opts{extcmd});
 292
 293        if (defined($opts{help})) {
 294                usage(0);
 295        }
 296        if (defined($opts{tool_help})) {
 297                print_tool_help();
 298        }
 299        if (defined($opts{difftool_cmd})) {
 300                if (length($opts{difftool_cmd}) > 0) {
 301                        $ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
 302                } else {
 303                        print "No <tool> given for --tool=<tool>\n";
 304                        usage(1);
 305                }
 306        }
 307        if (defined($opts{extcmd})) {
 308                if (length($opts{extcmd}) > 0) {
 309                        $ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
 310                } else {
 311                        print "No <cmd> given for --extcmd=<cmd>\n";
 312                        usage(1);
 313                }
 314        }
 315        if ($opts{gui}) {
 316                my $guitool = Git::config('diff.guitool');
 317                if (length($guitool) > 0) {
 318                        $ENV{GIT_DIFF_TOOL} = $guitool;
 319                }
 320        }
 321
 322        # In directory diff mode, 'git-difftool--helper' is called once
 323        # to compare the a/b directories.  In file diff mode, 'git diff'
 324        # will invoke a separate instance of 'git-difftool--helper' for
 325        # each file that changed.
 326        if (defined($opts{dirdiff})) {
 327                dir_diff($opts{extcmd}, $opts{symlinks});
 328        } else {
 329                file_diff($opts{prompt});
 330        }
 331}
 332
 333sub dir_diff
 334{
 335        my ($extcmd, $symlinks) = @_;
 336
 337        my $rc;
 338        my $repo = Git->repository();
 339
 340        my $workdir = find_worktree($repo);
 341        my ($a, $b, @worktree) = setup_dir_diff($repo, $workdir, $symlinks);
 342        if (defined($extcmd)) {
 343                $rc = system($extcmd, $a, $b);
 344        } else {
 345                $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 346                $rc = system('git', 'difftool--helper', $a, $b);
 347        }
 348
 349        exit($rc | ($rc >> 8)) if ($rc != 0);
 350
 351        # If the diff including working copy files and those
 352        # files were modified during the diff, then the changes
 353        # should be copied back to the working tree.
 354        # Do not copy back files when symlinks are used and the
 355        # external tool did not replace the original link with a file.
 356        for my $file (@worktree) {
 357                next if $symlinks && -l "$b/$file";
 358                if (-f "$b/$file" && compare("$b/$file", "$workdir/$file")) {
 359                        copy("$b/$file", "$workdir/$file") or die $!;
 360                        my $mode = stat("$b/$file")->mode;
 361                        chmod($mode, "$workdir/$file") or die $!;
 362                }
 363        }
 364        exit(0);
 365}
 366
 367sub file_diff
 368{
 369        my ($prompt) = @_;
 370
 371        if (defined($prompt)) {
 372                if ($prompt) {
 373                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
 374                } else {
 375                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 376                }
 377        }
 378
 379        $ENV{GIT_PAGER} = '';
 380        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 381
 382        # ActiveState Perl for Win32 does not implement POSIX semantics of
 383        # exec* system call. It just spawns the given executable and finishes
 384        # the starting program, exiting with code 0.
 385        # system will at least catch the errors returned by git diff,
 386        # allowing the caller of git difftool better handling of failures.
 387        my $rc = system('git', 'diff', @ARGV);
 388        exit($rc | ($rc >> 8));
 389}
 390
 391main();