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git/git-difftool.perl
Kenichi Saita 32eaf1de7f difftool --dir-diff: allow changing any clean working tree file
The temporary directory prepared by "difftool --dir-diff" to
show the result of a change can be modified by the user via
the tree diff program, and we try hard not to lose changes
to them after tree diff program returns to us.

However, the set of files to be copied back is computed
differently between --symlinks and --no-symlinks modes.  The
former checks all paths that start out as identical to the
working tree file, while the latter checks paths that
already had a local modification in the working tree,
allowing changes made in the tree diff program to paths that
did not have any local change to be lost.

Signed-off-by: Kenichi Saita <nitoyon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-29 12:50:08 -07:00

505 lines
13 KiB
Perl
Executable file

#!/usr/bin/perl
# Copyright (c) 2009, 2010 David Aguilar
# Copyright (c) 2012 Tim Henigan
#
# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
# git-difftool--helper script.
#
# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
# The GIT_DIFF* variables are exported for use by git-difftool--helper.
#
# Any arguments that are unknown to this script are forwarded to 'git diff'.
use 5.008;
use strict;
use warnings;
use Error qw(:try);
use File::Basename qw(dirname);
use File::Copy;
use File::Find;
use File::stat;
use File::Path qw(mkpath rmtree);
use File::Temp qw(tempdir);
use Getopt::Long qw(:config pass_through);
use Git;
sub usage
{
my $exitcode = shift;
print << 'USAGE';
usage: git difftool [-t|--tool=<tool>] [--tool-help]
[-x|--extcmd=<cmd>]
[-g|--gui] [--no-gui]
[--prompt] [-y|--no-prompt]
[-d|--dir-diff]
['git diff' options]
USAGE
exit($exitcode);
}
sub find_worktree
{
my ($repo) = @_;
# Git->repository->wc_path() does not honor changes to the working
# tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
# config variable.
my $worktree;
my $env_worktree = $ENV{GIT_WORK_TREE};
my $core_worktree = Git::config('core.worktree');
if (defined($env_worktree) and (length($env_worktree) > 0)) {
$worktree = $env_worktree;
} elsif (defined($core_worktree) and (length($core_worktree) > 0)) {
$worktree = $core_worktree;
} else {
$worktree = $repo->wc_path();
}
return $worktree;
}
sub print_tool_help
{
my $cmd = 'TOOL_MODE=diff';
$cmd .= ' && . "$(git --exec-path)/git-mergetool--lib"';
$cmd .= ' && show_tool_help';
# See the comment at the bottom of file_diff() for the reason behind
# using system() followed by exit() instead of exec().
my $rc = system('sh', '-c', $cmd);
exit($rc | ($rc >> 8));
}
sub exit_cleanup
{
my ($tmpdir, $status) = @_;
my $errno = $!;
rmtree($tmpdir);
if ($status and $errno) {
my ($package, $file, $line) = caller();
warn "$file line $line: $errno\n";
}
exit($status | ($status >> 8));
}
sub use_wt_file
{
my ($repo, $workdir, $file, $sha1) = @_;
my $null_sha1 = '0' x 40;
if (! -e "$workdir/$file") {
# If the file doesn't exist in the working tree, we cannot
# use it.
return (0, $null_sha1);
}
my $wt_sha1 = $repo->command_oneline('hash-object', "$workdir/$file");
my $use = ($sha1 eq $null_sha1) || ($sha1 eq $wt_sha1);
return ($use, $wt_sha1);
}
sub changed_files
{
my ($repo_path, $index, $worktree) = @_;
$ENV{GIT_INDEX_FILE} = $index;
$ENV{GIT_WORK_TREE} = $worktree;
my $must_unset_git_dir = 0;
if (not defined($ENV{GIT_DIR})) {
$must_unset_git_dir = 1;
$ENV{GIT_DIR} = $repo_path;
}
my @refreshargs = qw/update-index --really-refresh -q --unmerged/;
my @gitargs = qw/diff-files --name-only -z/;
try {
Git::command_oneline(@refreshargs);
} catch Git::Error::Command with {};
my $line = Git::command_oneline(@gitargs);
my @files;
if (defined $line) {
@files = split('\0', $line);
} else {
@files = ();
}
delete($ENV{GIT_INDEX_FILE});
delete($ENV{GIT_WORK_TREE});
delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
return map { $_ => 1 } @files;
}
sub setup_dir_diff
{
my ($repo, $workdir, $symlinks) = @_;
# Run the diff; exit immediately if no diff found
# 'Repository' and 'WorkingCopy' must be explicitly set to insure that
# if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
# by Git->repository->command*.
my $repo_path = $repo->repo_path();
my %repo_args = (Repository => $repo_path, WorkingCopy => $workdir);
my $diffrepo = Git->repository(%repo_args);
my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
my $diffrtn = $diffrepo->command_oneline(@gitargs);
exit(0) unless defined($diffrtn);
# Build index info for left and right sides of the diff
my $submodule_mode = '160000';
my $symlink_mode = '120000';
my $null_mode = '0' x 6;
my $null_sha1 = '0' x 40;
my $lindex = '';
my $rindex = '';
my $wtindex = '';
my %submodule;
my %symlink;
my @working_tree = ();
my @rawdiff = split('\0', $diffrtn);
my $i = 0;
while ($i < $#rawdiff) {
if ($rawdiff[$i] =~ /^::/) {
warn << 'EOF';
Combined diff formats ('-c' and '--cc') are not supported in
directory diff mode ('-d' and '--dir-diff').
EOF
exit(1);
}
my ($lmode, $rmode, $lsha1, $rsha1, $status) =
split(' ', substr($rawdiff[$i], 1));
my $src_path = $rawdiff[$i + 1];
my $dst_path;
if ($status =~ /^[CR]/) {
$dst_path = $rawdiff[$i + 2];
$i += 3;
} else {
$dst_path = $src_path;
$i += 2;
}
if ($lmode eq $submodule_mode or $rmode eq $submodule_mode) {
$submodule{$src_path}{left} = $lsha1;
if ($lsha1 ne $rsha1) {
$submodule{$dst_path}{right} = $rsha1;
} else {
$submodule{$dst_path}{right} = "$rsha1-dirty";
}
next;
}
if ($lmode eq $symlink_mode) {
$symlink{$src_path}{left} =
$diffrepo->command_oneline('show', "$lsha1");
}
if ($rmode eq $symlink_mode) {
$symlink{$dst_path}{right} =
$diffrepo->command_oneline('show', "$rsha1");
}
if ($lmode ne $null_mode and $status !~ /^C/) {
$lindex .= "$lmode $lsha1\t$src_path\0";
}
if ($rmode ne $null_mode) {
my ($use, $wt_sha1) = use_wt_file($repo, $workdir,
$dst_path, $rsha1);
if ($use) {
push @working_tree, $dst_path;
$wtindex .= "$rmode $wt_sha1\t$dst_path\0";
} else {
$rindex .= "$rmode $rsha1\t$dst_path\0";
}
}
}
# Setup temp directories
my $tmpdir = tempdir('git-difftool.XXXXX', CLEANUP => 0, TMPDIR => 1);
my $ldir = "$tmpdir/left";
my $rdir = "$tmpdir/right";
mkpath($ldir) or exit_cleanup($tmpdir, 1);
mkpath($rdir) or exit_cleanup($tmpdir, 1);
# If $GIT_DIR is not set prior to calling 'git update-index' and
# 'git checkout-index', then those commands will fail if difftool
# is called from a directory other than the repo root.
my $must_unset_git_dir = 0;
if (not defined($ENV{GIT_DIR})) {
$must_unset_git_dir = 1;
$ENV{GIT_DIR} = $repo_path;
}
# Populate the left and right directories based on each index file
my ($inpipe, $ctx);
$ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
($inpipe, $ctx) =
$repo->command_input_pipe(qw(update-index -z --index-info));
print($inpipe $lindex);
$repo->command_close_pipe($inpipe, $ctx);
my $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
exit_cleanup($tmpdir, $rc) if $rc != 0;
$ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
($inpipe, $ctx) =
$repo->command_input_pipe(qw(update-index -z --index-info));
print($inpipe $rindex);
$repo->command_close_pipe($inpipe, $ctx);
$rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
exit_cleanup($tmpdir, $rc) if $rc != 0;
$ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
($inpipe, $ctx) =
$repo->command_input_pipe(qw(update-index --info-only -z --index-info));
print($inpipe $wtindex);
$repo->command_close_pipe($inpipe, $ctx);
# If $GIT_DIR was explicitly set just for the update/checkout
# commands, then it should be unset before continuing.
delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
delete($ENV{GIT_INDEX_FILE});
# Changes in the working tree need special treatment since they are
# not part of the index. Remove any trailing slash from $workdir
# before starting to avoid double slashes in symlink targets.
$workdir =~ s|/$||;
for my $file (@working_tree) {
my $dir = dirname($file);
unless (-d "$rdir/$dir") {
mkpath("$rdir/$dir") or
exit_cleanup($tmpdir, 1);
}
if ($symlinks) {
symlink("$workdir/$file", "$rdir/$file") or
exit_cleanup($tmpdir, 1);
} else {
copy("$workdir/$file", "$rdir/$file") or
exit_cleanup($tmpdir, 1);
my $mode = stat("$workdir/$file")->mode;
chmod($mode, "$rdir/$file") or
exit_cleanup($tmpdir, 1);
}
}
# Changes to submodules require special treatment. This loop writes a
# temporary file to both the left and right directories to show the
# change in the recorded SHA1 for the submodule.
for my $path (keys %submodule) {
my $ok;
if (defined($submodule{$path}{left})) {
$ok = write_to_file("$ldir/$path",
"Subproject commit $submodule{$path}{left}");
}
if (defined($submodule{$path}{right})) {
$ok = write_to_file("$rdir/$path",
"Subproject commit $submodule{$path}{right}");
}
exit_cleanup($tmpdir, 1) if not $ok;
}
# Symbolic links require special treatment. The standard "git diff"
# shows only the link itself, not the contents of the link target.
# This loop replicates that behavior.
for my $path (keys %symlink) {
my $ok;
if (defined($symlink{$path}{left})) {
$ok = write_to_file("$ldir/$path",
$symlink{$path}{left});
}
if (defined($symlink{$path}{right})) {
$ok = write_to_file("$rdir/$path",
$symlink{$path}{right});
}
exit_cleanup($tmpdir, 1) if not $ok;
}
return ($ldir, $rdir, $tmpdir, @working_tree);
}
sub write_to_file
{
my $path = shift;
my $value = shift;
# Make sure the path to the file exists
my $dir = dirname($path);
unless (-d "$dir") {
mkpath("$dir") or return 0;
}
# If the file already exists in that location, delete it. This
# is required in the case of symbolic links.
unlink($path);
open(my $fh, '>', $path) or return 0;
print($fh $value);
close($fh);
return 1;
}
sub main
{
# parse command-line options. all unrecognized options and arguments
# are passed through to the 'git diff' command.
my %opts = (
difftool_cmd => undef,
dirdiff => undef,
extcmd => undef,
gui => undef,
help => undef,
prompt => undef,
symlinks => $^O ne 'cygwin' &&
$^O ne 'MSWin32' && $^O ne 'msys',
tool_help => undef,
);
GetOptions('g|gui!' => \$opts{gui},
'd|dir-diff' => \$opts{dirdiff},
'h' => \$opts{help},
'prompt!' => \$opts{prompt},
'y' => sub { $opts{prompt} = 0; },
'symlinks' => \$opts{symlinks},
'no-symlinks' => sub { $opts{symlinks} = 0; },
't|tool:s' => \$opts{difftool_cmd},
'tool-help' => \$opts{tool_help},
'x|extcmd:s' => \$opts{extcmd});
if (defined($opts{help})) {
usage(0);
}
if (defined($opts{tool_help})) {
print_tool_help();
}
if (defined($opts{difftool_cmd})) {
if (length($opts{difftool_cmd}) > 0) {
$ENV{GIT_DIFF_TOOL} = $opts{difftool_cmd};
} else {
print "No <tool> given for --tool=<tool>\n";
usage(1);
}
}
if (defined($opts{extcmd})) {
if (length($opts{extcmd}) > 0) {
$ENV{GIT_DIFFTOOL_EXTCMD} = $opts{extcmd};
} else {
print "No <cmd> given for --extcmd=<cmd>\n";
usage(1);
}
}
if ($opts{gui}) {
my $guitool = Git::config('diff.guitool');
if (defined($guitool) && length($guitool) > 0) {
$ENV{GIT_DIFF_TOOL} = $guitool;
}
}
# In directory diff mode, 'git-difftool--helper' is called once
# to compare the a/b directories. In file diff mode, 'git diff'
# will invoke a separate instance of 'git-difftool--helper' for
# each file that changed.
if (defined($opts{dirdiff})) {
dir_diff($opts{extcmd}, $opts{symlinks});
} else {
file_diff($opts{prompt});
}
}
sub dir_diff
{
my ($extcmd, $symlinks) = @_;
my $rc;
my $error = 0;
my $repo = Git->repository();
my $workdir = find_worktree($repo);
my ($a, $b, $tmpdir, @worktree) =
setup_dir_diff($repo, $workdir, $symlinks);
if (defined($extcmd)) {
$rc = system($extcmd, $a, $b);
} else {
$ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
$rc = system('git', 'difftool--helper', $a, $b);
}
# If the diff including working copy files and those
# files were modified during the diff, then the changes
# should be copied back to the working tree.
# Do not copy back files when symlinks are used and the
# external tool did not replace the original link with a file.
#
# These hashes are loaded lazily since they aren't needed
# in the common case of --symlinks and the difftool updating
# files through the symlink.
my %wt_modified;
my %tmp_modified;
my $indices_loaded = 0;
for my $file (@worktree) {
next if $symlinks && -l "$b/$file";
next if ! -f "$b/$file";
if (!$indices_loaded) {
%wt_modified = changed_files($repo->repo_path(),
"$tmpdir/wtindex", "$workdir");
%tmp_modified = changed_files($repo->repo_path(),
"$tmpdir/wtindex", "$b");
$indices_loaded = 1;
}
if (exists $wt_modified{$file} and exists $tmp_modified{$file}) {
my $errmsg = "warning: Both files modified: ";
$errmsg .= "'$workdir/$file' and '$b/$file'.\n";
$errmsg .= "warning: Working tree file has been left.\n";
$errmsg .= "warning:\n";
warn $errmsg;
$error = 1;
} elsif (exists $tmp_modified{$file}) {
my $mode = stat("$b/$file")->mode;
copy("$b/$file", "$workdir/$file") or
exit_cleanup($tmpdir, 1);
chmod($mode, "$workdir/$file") or
exit_cleanup($tmpdir, 1);
}
}
if ($error) {
warn "warning: Temporary files exist in '$tmpdir'.\n";
warn "warning: You may want to cleanup or recover these.\n";
exit(1);
} else {
exit_cleanup($tmpdir, $rc);
}
}
sub file_diff
{
my ($prompt) = @_;
if (defined($prompt)) {
if ($prompt) {
$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
} else {
$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
}
}
$ENV{GIT_PAGER} = '';
$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
# ActiveState Perl for Win32 does not implement POSIX semantics of
# exec* system call. It just spawns the given executable and finishes
# the starting program, exiting with code 0.
# system will at least catch the errors returned by git diff,
# allowing the caller of git difftool better handling of failures.
my $rc = system('git', 'diff', @ARGV);
exit($rc | ($rc >> 8));
}
main();