difftool: add a skeleton for the upcoming builtin
authorJohannes Schindelin <johannes.schindelin@gmx.de>
Tue, 17 Jan 2017 15:54:57 +0000 (16:54 +0100)
committerJunio C Hamano <gitster@pobox.com>
Tue, 17 Jan 2017 21:32:47 +0000 (13:32 -0800)
This adds a builtin difftool that still falls back to the legacy Perl
version, which has been renamed to `legacy-difftool`.

The idea is that the new, experimental, builtin difftool immediately hands
off to the legacy difftool for now, unless the config variable
difftool.useBuiltin is set to true.

This feature flag will be used in the upcoming Git for Windows v2.11.0
release, to allow early testers to opt-in to use the builtin difftool and
flesh out any bugs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
.gitignore
Makefile
builtin.h
builtin/difftool.c [new file with mode: 0644]
git-difftool.perl [deleted file]
git-legacy-difftool.perl [new file with mode: 0755]
git.c
t/t7800-difftool.sh
index 05cb58a3d4ef47295fa8ef02add44a0f0dd90d1f..f96e50ed40cc5283953ccbaa84694a9927070e42 100644 (file)
@@ -76,6 +76,7 @@
 /git-init-db
 /git-interpret-trailers
 /git-instaweb
+/git-legacy-difftool
 /git-log
 /git-ls-files
 /git-ls-remote
index f53fcc90d71b7e0ba95b94e9baf67d559085863c..7863bc2f3d2ee2127f879f1402d7197c3547895a 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -527,7 +527,7 @@ SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
 
 SCRIPT_PERL += git-add--interactive.perl
-SCRIPT_PERL += git-difftool.perl
+SCRIPT_PERL += git-legacy-difftool.perl
 SCRIPT_PERL += git-archimport.perl
 SCRIPT_PERL += git-cvsexportcommit.perl
 SCRIPT_PERL += git-cvsimport.perl
@@ -888,6 +888,7 @@ BUILTIN_OBJS += builtin/diff-files.o
 BUILTIN_OBJS += builtin/diff-index.o
 BUILTIN_OBJS += builtin/diff-tree.o
 BUILTIN_OBJS += builtin/diff.o
+BUILTIN_OBJS += builtin/difftool.o
 BUILTIN_OBJS += builtin/fast-export.o
 BUILTIN_OBJS += builtin/fetch-pack.o
 BUILTIN_OBJS += builtin/fetch.o
index b9122bc5f497ea2030aa4d5348c44da1a3bd8995..67f80519dafc4875434437a34e438453bc2c78c4 100644 (file)
--- a/builtin.h
+++ b/builtin.h
@@ -60,6 +60,7 @@ extern int cmd_diff_files(int argc, const char **argv, const char *prefix);
 extern int cmd_diff_index(int argc, const char **argv, const char *prefix);
 extern int cmd_diff(int argc, const char **argv, const char *prefix);
 extern int cmd_diff_tree(int argc, const char **argv, const char *prefix);
+extern int cmd_difftool(int argc, const char **argv, const char *prefix);
 extern int cmd_fast_export(int argc, const char **argv, const char *prefix);
 extern int cmd_fetch(int argc, const char **argv, const char *prefix);
 extern int cmd_fetch_pack(int argc, const char **argv, const char *prefix);
diff --git a/builtin/difftool.c b/builtin/difftool.c
new file mode 100644 (file)
index 0000000..53870bb
--- /dev/null
@@ -0,0 +1,63 @@
+/*
+ * "git difftool" builtin command
+ *
+ * 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'.
+ *
+ * Copyright (C) 2016 Johannes Schindelin
+ */
+#include "builtin.h"
+#include "run-command.h"
+#include "exec_cmd.h"
+
+/*
+ * NEEDSWORK: this function can go once the legacy-difftool Perl script is
+ * retired.
+ *
+ * We intentionally avoid reading the config directly here, to avoid messing up
+ * the GIT_* environment variables when we need to fall back to exec()ing the
+ * Perl script.
+ */
+static int use_builtin_difftool(void) {
+       struct child_process cp = CHILD_PROCESS_INIT;
+       struct strbuf out = STRBUF_INIT;
+       int ret;
+
+       argv_array_pushl(&cp.args,
+                        "config", "--bool", "difftool.usebuiltin", NULL);
+       cp.git_cmd = 1;
+       if (capture_command(&cp, &out, 6))
+               return 0;
+       strbuf_trim(&out);
+       ret = !strcmp("true", out.buf);
+       strbuf_release(&out);
+       return ret;
+}
+
+int cmd_difftool(int argc, const char **argv, const char *prefix)
+{
+       /*
+        * NEEDSWORK: Once the builtin difftool has been tested enough
+        * and git-legacy-difftool.perl is retired to contrib/, this preamble
+        * can be removed.
+        */
+       if (!use_builtin_difftool()) {
+               const char *path = mkpath("%s/git-legacy-difftool",
+                                         git_exec_path());
+
+               if (sane_execvp(path, (char **)argv) < 0)
+                       die_errno("could not exec %s", path);
+
+               return 0;
+       }
+       prefix = setup_git_directory();
+       trace_repo_setup(prefix);
+       setup_work_tree();
+
+       die("TODO");
+}
diff --git a/git-difftool.perl b/git-difftool.perl
deleted file mode 100755 (executable)
index a5790d0..0000000
+++ /dev/null
@@ -1,470 +0,0 @@
-#!/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 print_tool_help
-{
-       # See the comment at the bottom of file_diff() for the reason behind
-       # using system() followed by exit() instead of exec().
-       my $rc = system(qw(git mergetool --tool-help=diff));
-       exit($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 | ($status >> 8));
-}
-
-sub use_wt_file
-{
-       my ($workdir, $file, $sha1) = @_;
-       my $null_sha1 = '0' x 40;
-
-       if (-l "$workdir/$file" || ! -e _) {
-               return (0, $null_sha1);
-       }
-
-       my $wt_sha1 = Git::command_oneline('hash-object', "$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;
-
-       my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
-       my @refreshargs = (
-               @gitargs, 'update-index',
-               '--really-refresh', '-q', '--unmerged');
-       try {
-               Git::command_oneline(@refreshargs);
-       } catch Git::Error::Command with {};
-
-       my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
-       my $line = Git::command_oneline(@diffargs);
-       my @files;
-       if (defined $line) {
-               @files = split('\0', $line);
-       } else {
-               @files = ();
-       }
-
-       delete($ENV{GIT_INDEX_FILE});
-
-       return map { $_ => 1 } @files;
-}
-
-sub setup_dir_diff
-{
-       my ($workdir, $symlinks) = @_;
-       my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
-       my $diffrtn = Git::command_oneline(@gitargs);
-       exit(0) unless defined($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 %working_tree_dups = ();
-       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} =
-                               Git::command_oneline('show', $lsha1);
-               }
-
-               if ($rmode eq $symlink_mode) {
-                       $symlink{$dst_path}{right} =
-                               Git::command_oneline('show', $rsha1);
-               }
-
-               if ($lmode ne $null_mode and $status !~ /^C/) {
-                       $lindex .= "$lmode $lsha1\t$src_path\0";
-               }
-
-               if ($rmode ne $null_mode) {
-                       # Avoid duplicate working_tree entries
-                       if ($working_tree_dups{$dst_path}++) {
-                               next;
-                       }
-                       my ($use, $wt_sha1) =
-                               use_wt_file($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);
-
-       # Populate the left and right directories based on each index file
-       my ($inpipe, $ctx);
-       $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
-       ($inpipe, $ctx) =
-               Git::command_input_pipe('update-index', '-z', '--index-info');
-       print($inpipe $lindex);
-       Git::command_close_pipe($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, $ctx) =
-               Git::command_input_pipe('update-index', '-z', '--index-info');
-       print($inpipe $rindex);
-       Git::command_close_pipe($inpipe, $ctx);
-
-       $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
-       exit_cleanup($tmpdir, $rc) if $rc != 0;
-
-       $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
-       ($inpipe, $ctx) =
-               Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
-       print($inpipe $wtindex);
-       Git::command_close_pipe($inpipe, $ctx);
-
-       # If $GIT_DIR was explicitly set just for the update/checkout
-       # commands, then it should be unset before continuing.
-       delete($ENV{GIT_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 $ok = 0;
-               if (defined($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 $ok = 0;
-               if (defined($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,
-               trust_exit_code => 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},
-               'trust-exit-code' => \$opts{trust_exit_code},
-               'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
-               'x|extcmd:s' => \$opts{extcmd});
-
-       if (defined($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;
-               }
-       }
-
-       if (!defined $opts{trust_exit_code}) {
-               $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
-       }
-       if ($opts{trust_exit_code}) {
-               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
-       } else {
-               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
-       }
-
-       # In directory diff mode, 'git-difftool--helper' is called once
-       # to compare the a/b directories.  In file diff mode, 'git diff'
-       # will invoke a separate instance of 'git-difftool--helper' for
-       # each file that changed.
-       if (defined($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 $repo_path = $repo->repo_path();
-       my $workdir = $repo->wc_path();
-       my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($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(
-                               $repo_path, "$tmpdir/wtindex", $workdir);
-                       %tmp_modified = changed_files(
-                               $repo_path, "$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();
diff --git a/git-legacy-difftool.perl b/git-legacy-difftool.perl
new file mode 100755 (executable)
index 0000000..a5790d0
--- /dev/null
@@ -0,0 +1,470 @@
+#!/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 print_tool_help
+{
+       # See the comment at the bottom of file_diff() for the reason behind
+       # using system() followed by exit() instead of exec().
+       my $rc = system(qw(git mergetool --tool-help=diff));
+       exit($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 | ($status >> 8));
+}
+
+sub use_wt_file
+{
+       my ($workdir, $file, $sha1) = @_;
+       my $null_sha1 = '0' x 40;
+
+       if (-l "$workdir/$file" || ! -e _) {
+               return (0, $null_sha1);
+       }
+
+       my $wt_sha1 = Git::command_oneline('hash-object', "$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;
+
+       my @gitargs = ('--git-dir', $repo_path, '--work-tree', $worktree);
+       my @refreshargs = (
+               @gitargs, 'update-index',
+               '--really-refresh', '-q', '--unmerged');
+       try {
+               Git::command_oneline(@refreshargs);
+       } catch Git::Error::Command with {};
+
+       my @diffargs = (@gitargs, 'diff-files', '--name-only', '-z');
+       my $line = Git::command_oneline(@diffargs);
+       my @files;
+       if (defined $line) {
+               @files = split('\0', $line);
+       } else {
+               @files = ();
+       }
+
+       delete($ENV{GIT_INDEX_FILE});
+
+       return map { $_ => 1 } @files;
+}
+
+sub setup_dir_diff
+{
+       my ($workdir, $symlinks) = @_;
+       my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
+       my $diffrtn = Git::command_oneline(@gitargs);
+       exit(0) unless defined($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 %working_tree_dups = ();
+       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} =
+                               Git::command_oneline('show', $lsha1);
+               }
+
+               if ($rmode eq $symlink_mode) {
+                       $symlink{$dst_path}{right} =
+                               Git::command_oneline('show', $rsha1);
+               }
+
+               if ($lmode ne $null_mode and $status !~ /^C/) {
+                       $lindex .= "$lmode $lsha1\t$src_path\0";
+               }
+
+               if ($rmode ne $null_mode) {
+                       # Avoid duplicate working_tree entries
+                       if ($working_tree_dups{$dst_path}++) {
+                               next;
+                       }
+                       my ($use, $wt_sha1) =
+                               use_wt_file($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);
+
+       # Populate the left and right directories based on each index file
+       my ($inpipe, $ctx);
+       $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
+       ($inpipe, $ctx) =
+               Git::command_input_pipe('update-index', '-z', '--index-info');
+       print($inpipe $lindex);
+       Git::command_close_pipe($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, $ctx) =
+               Git::command_input_pipe('update-index', '-z', '--index-info');
+       print($inpipe $rindex);
+       Git::command_close_pipe($inpipe, $ctx);
+
+       $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
+       exit_cleanup($tmpdir, $rc) if $rc != 0;
+
+       $ENV{GIT_INDEX_FILE} = "$tmpdir/wtindex";
+       ($inpipe, $ctx) =
+               Git::command_input_pipe('update-index', '--info-only', '-z', '--index-info');
+       print($inpipe $wtindex);
+       Git::command_close_pipe($inpipe, $ctx);
+
+       # If $GIT_DIR was explicitly set just for the update/checkout
+       # commands, then it should be unset before continuing.
+       delete($ENV{GIT_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 $ok = 0;
+               if (defined($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 $ok = 0;
+               if (defined($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,
+               trust_exit_code => 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},
+               'trust-exit-code' => \$opts{trust_exit_code},
+               'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
+               'x|extcmd:s' => \$opts{extcmd});
+
+       if (defined($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;
+               }
+       }
+
+       if (!defined $opts{trust_exit_code}) {
+               $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
+       }
+       if ($opts{trust_exit_code}) {
+               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
+       } else {
+               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
+       }
+
+       # In directory diff mode, 'git-difftool--helper' is called once
+       # to compare the a/b directories.  In file diff mode, 'git diff'
+       # will invoke a separate instance of 'git-difftool--helper' for
+       # each file that changed.
+       if (defined($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 $repo_path = $repo->repo_path();
+       my $workdir = $repo->wc_path();
+       my ($a, $b, $tmpdir, @worktree) = setup_dir_diff($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(
+                               $repo_path, "$tmpdir/wtindex", $workdir);
+                       %tmp_modified = changed_files(
+                               $repo_path, "$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 | ($rc >> 8));
+}
+
+main();
diff --git a/git.c b/git.c
index e8b2baf2d15c8a68553780c3137c55c3fea99b11..a8e6a15657a5aba77226aef9d1c0b38a88f5e2d5 100644 (file)
--- a/git.c
+++ b/git.c
@@ -424,6 +424,12 @@ static struct cmd_struct commands[] = {
        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
        { "diff-index", cmd_diff_index, RUN_SETUP },
        { "diff-tree", cmd_diff_tree, RUN_SETUP },
+       /*
+        * NEEDSWORK: Once the redirection to git-legacy-difftool.perl in
+        * builtin/difftool.c has been removed, this entry should be changed to
+        * RUN_SETUP | NEED_WORK_TREE
+        */
+       { "difftool", cmd_difftool },
        { "fast-export", cmd_fast_export, RUN_SETUP },
        { "fetch", cmd_fetch, RUN_SETUP },
        { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
index 70a2de461af58119f507a915104ba139dd0245df..b6a6c30f24313bd829c3c534e581ddac4a155ff0 100755 (executable)
@@ -23,6 +23,8 @@ prompt_given ()
        test "$prompt" = "Launch 'test-tool' [Y/n]? branch"
 }
 
+# NEEDSWORK: lose all the PERL prereqs once legacy-difftool is retired.
+
 # Create a file on master and change it on branch
 test_expect_success PERL 'setup' '
        echo master >file &&