Andrew's git - gitweb.git/blob

850ebbe5718b3b13404ff8c7e30de6df011b14cd
   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(dirname);
  17use File::Copy;
  18use File::stat;
  19use File::Path qw(mkpath);
  20use File::Temp qw(tempdir);
  21use Getopt::Long qw(:config pass_through);
  22use Git;
  23
  24my @working_tree;
  25my $rc;
  26my $repo = Git->repository();
  27my $repo_path = $repo->repo_path();
  28
  29sub usage
  30{
  31        my $exitcode = shift;
  32        print << 'USAGE';
  33usage: git difftool [-t|--tool=<tool>]
  34                    [-x|--extcmd=<cmd>]
  35                    [-g|--gui] [--no-gui]
  36                    [--prompt] [-y|--no-prompt]
  37                    [-d|--dir-diff]
  38                    ['git diff' options]
  39USAGE
  40        exit($exitcode);
  41}
  42
  43sub find_worktree
  44{
  45        # Git->repository->wc_path() does not honor changes to the working
  46        # tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
  47        # config variable.
  48        my $worktree;
  49        my $env_worktree = $ENV{GIT_WORK_TREE};
  50        my $core_worktree = Git::config('core.worktree');
  51
  52        if (defined($env_worktree) and (length($env_worktree) > 0)) {
  53                $worktree = $env_worktree;
  54        } elsif (defined($core_worktree) and (length($core_worktree) > 0)) {
  55                $worktree = $core_worktree;
  56        } else {
  57                $worktree = $repo->wc_path();
  58        }
  59
  60        return $worktree;
  61}
  62
  63my $workdir = find_worktree();
  64
  65sub setup_dir_diff
  66{
  67        # Run the diff; exit immediately if no diff found
  68        # 'Repository' and 'WorkingCopy' must be explicitly set to insure that
  69        # if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
  70        # by Git->repository->command*.
  71        my $diffrepo = Git->repository(Repository => $repo_path, WorkingCopy => $workdir);
  72        my $diffrtn = $diffrepo->command_oneline('diff', '--raw', '--no-abbrev', '-z', @ARGV);
  73        exit(0) if (length($diffrtn) == 0);
  74
  75        # Setup temp directories
  76        my $tmpdir = tempdir('git-diffall.XXXXX', CLEANUP => 1, TMPDIR => 1);
  77        my $ldir = "$tmpdir/left";
  78        my $rdir = "$tmpdir/right";
  79        mkpath($ldir) or die $!;
  80        mkpath($rdir) or die $!;
  81
  82        # Build index info for left and right sides of the diff
  83        my $submodule_mode = '160000';
  84        my $symlink_mode = '120000';
  85        my $null_mode = '0' x 6;
  86        my $null_sha1 = '0' x 40;
  87        my $lindex = '';
  88        my $rindex = '';
  89        my %submodule;
  90        my %symlink;
  91        my @rawdiff = split('\0', $diffrtn);
  92
  93        my $i = 0;
  94        while ($i < $#rawdiff) {
  95                if ($rawdiff[$i] =~ /^::/) {
  96                        print "Combined diff formats ('-c' and '--cc') are not supported in directory diff mode.\n";
  97                        exit(1);
  98                }
  99
 100                my ($lmode, $rmode, $lsha1, $rsha1, $status) = split(' ', substr($rawdiff[$i], 1));
 101                my $src_path = $rawdiff[$i + 1];
 102                my $dst_path;
 103
 104                if ($status =~ /^[CR]/) {
 105                        $dst_path = $rawdiff[$i + 2];
 106                        $i += 3;
 107                } else {
 108                        $dst_path = $src_path;
 109                        $i += 2;
 110                }
 111
 112                if (($lmode eq $submodule_mode) or ($rmode eq $submodule_mode)) {
 113                        $submodule{$src_path}{left} = $lsha1;
 114                        if ($lsha1 ne $rsha1) {
 115                                $submodule{$dst_path}{right} = $rsha1;
 116                        } else {
 117                                $submodule{$dst_path}{right} = "$rsha1-dirty";
 118                        }
 119                        next;
 120                }
 121
 122                if ($lmode eq $symlink_mode) {
 123                        $symlink{$src_path}{left} = $diffrepo->command_oneline('show', "$lsha1");
 124                }
 125
 126                if ($rmode eq $symlink_mode) {
 127                        $symlink{$dst_path}{right} = $diffrepo->command_oneline('show', "$rsha1");
 128                }
 129
 130                if (($lmode ne $null_mode) and ($status !~ /^C/)) {
 131                        $lindex .= "$lmode $lsha1\t$src_path\0";
 132                }
 133
 134                if ($rmode ne $null_mode) {
 135                        if ($rsha1 ne $null_sha1) {
 136                                $rindex .= "$rmode $rsha1\t$dst_path\0";
 137                        } else {
 138                                push(@working_tree, $dst_path);
 139                        }
 140                }
 141        }
 142
 143        # If $GIT_DIR is not set prior to calling 'git update-index' and
 144        # 'git checkout-index', then those commands will fail if difftool
 145        # is called from a directory other than the repo root.
 146        my $must_unset_git_dir = 0;
 147        if (not defined($ENV{GIT_DIR})) {
 148                $must_unset_git_dir = 1;
 149                $ENV{GIT_DIR} = $repo_path;
 150        }
 151
 152        # Populate the left and right directories based on each index file
 153        my ($inpipe, $ctx);
 154        $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
 155        ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
 156        print($inpipe $lindex);
 157        $repo->command_close_pipe($inpipe, $ctx);
 158        $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
 159        exit($rc | ($rc >> 8)) if ($rc != 0);
 160
 161        $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
 162        ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
 163        print($inpipe $rindex);
 164        $repo->command_close_pipe($inpipe, $ctx);
 165        $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
 166        exit($rc | ($rc >> 8)) if ($rc != 0);
 167
 168        # If $GIT_DIR was explicitly set just for the update/checkout
 169        # commands, then it should be unset before continuing.
 170        delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
 171        delete($ENV{GIT_INDEX_FILE});
 172
 173        # Changes in the working tree need special treatment since they are
 174        # not part of the index
 175        for my $file (@working_tree) {
 176                my $dir = dirname($file);
 177                unless (-d "$rdir/$dir") {
 178                        mkpath("$rdir/$dir") or die $!;
 179                }
 180                copy("$workdir/$file", "$rdir/$file") or die $!;
 181                chmod(stat("$workdir/$file")->mode, "$rdir/$file") or die $!;
 182        }
 183
 184        # Changes to submodules require special treatment. This loop writes a
 185        # temporary file to both the left and right directories to show the
 186        # change in the recorded SHA1 for the submodule.
 187        for my $path (keys %submodule) {
 188                if (defined($submodule{$path}{left})) {
 189                        write_to_file("$ldir/$path", "Subproject commit $submodule{$path}{left}");
 190                }
 191                if (defined($submodule{$path}{right})) {
 192                        write_to_file("$rdir/$path", "Subproject commit $submodule{$path}{right}");
 193                }
 194        }
 195
 196        # Symbolic links require special treatment. The standard "git diff"
 197        # shows only the link itself, not the contents of the link target.
 198        # This loop replicates that behavior.
 199        for my $path (keys %symlink) {
 200                if (defined($symlink{$path}{left})) {
 201                        write_to_file("$ldir/$path", $symlink{$path}{left});
 202                }
 203                if (defined($symlink{$path}{right})) {
 204                        write_to_file("$rdir/$path", $symlink{$path}{right});
 205                }
 206        }
 207
 208        return ($ldir, $rdir);
 209}
 210
 211sub write_to_file
 212{
 213        my $path = shift;
 214        my $value = shift;
 215
 216        # Make sure the path to the file exists
 217        my $dir = dirname($path);
 218        unless (-d "$dir") {
 219                mkpath("$dir") or die $!;
 220        }
 221
 222        # If the file already exists in that location, delete it.  This
 223        # is required in the case of symbolic links.
 224        unlink("$path");
 225
 226        open(my $fh, '>', "$path") or die $!;
 227        print($fh $value);
 228        close($fh);
 229}
 230
 231# parse command-line options. all unrecognized options and arguments
 232# are passed through to the 'git diff' command.
 233my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt);
 234GetOptions('g|gui!' => \$gui,
 235        'd|dir-diff' => \$dirdiff,
 236        'h' => \$help,
 237        'prompt!' => \$prompt,
 238        'y' => sub { $prompt = 0; },
 239        't|tool:s' => \$difftool_cmd,
 240        'x|extcmd:s' => \$extcmd);
 241
 242if (defined($help)) {
 243        usage(0);
 244}
 245if (defined($difftool_cmd)) {
 246        if (length($difftool_cmd) > 0) {
 247                $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
 248        } else {
 249                print "No <tool> given for --tool=<tool>\n";
 250                usage(1);
 251        }
 252}
 253if (defined($extcmd)) {
 254        if (length($extcmd) > 0) {
 255                $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
 256        } else {
 257                print "No <cmd> given for --extcmd=<cmd>\n";
 258                usage(1);
 259        }
 260}
 261if ($gui) {
 262        my $guitool = '';
 263        $guitool = Git::config('diff.guitool');
 264        if (length($guitool) > 0) {
 265                $ENV{GIT_DIFF_TOOL} = $guitool;
 266        }
 267}
 268
 269# In directory diff mode, 'git-difftool--helper' is called once
 270# to compare the a/b directories.  In file diff mode, 'git diff'
 271# will invoke a separate instance of 'git-difftool--helper' for
 272# each file that changed.
 273if (defined($dirdiff)) {
 274        my ($a, $b) = setup_dir_diff();
 275        if (defined($extcmd)) {
 276                $rc = system($extcmd, $a, $b);
 277        } else {
 278                $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
 279                $rc = system('git', 'difftool--helper', $a, $b);
 280        }
 281
 282        exit($rc | ($rc >> 8)) if ($rc != 0);
 283
 284        # If the diff including working copy files and those
 285        # files were modified during the diff, then the changes
 286        # should be copied back to the working tree
 287        for my $file (@working_tree) {
 288                copy("$b/$file", "$workdir/$file") or die $!;
 289                chmod(stat("$b/$file")->mode, "$workdir/$file") or die $!;
 290        }
 291} else {
 292        if (defined($prompt)) {
 293                if ($prompt) {
 294                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
 295                } else {
 296                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 297                }
 298        }
 299
 300        $ENV{GIT_PAGER} = '';
 301        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 302
 303        # ActiveState Perl for Win32 does not implement POSIX semantics of
 304        # exec* system call. It just spawns the given executable and finishes
 305        # the starting program, exiting with code 0.
 306        # system will at least catch the errors returned by git diff,
 307        # allowing the caller of git difftool better handling of failures.
 308        my $rc = system('git', 'diff', @ARGV);
 309        exit($rc | ($rc >> 8));
 310}