git-cvsexportcommit.perl - jrn/git - Git at Google

 #!/usr/bin/perl -w

 # Known limitations:
 # - cannot add or remove binary files
 # - does not propagate permissions
 # - tells "ready for commit" even when things could not be completed
 #   (eg addition of a binary file)

 use strict;
 use Getopt::Std;
 use File::Temp qw(tempdir);
 use Data::Dumper;
 use File::Basename qw(basename dirname);

 unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
     die "GIT_DIR is not defined or is unreadable";
 }

 our ($opt_h, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m );

 getopts('hpvcfam:');

 $opt_h && usage();

 die "Need at least one commit identifier!" unless @ARGV;

 # setup a tempdir
 our ($tmpdir, $tmpdirname) = tempdir('git-cvsapplycommit-XXXXXX',
 				     TMPDIR => 1,
 				     CLEANUP => 1);

 # resolve target commit
 my $commit;
 $commit = pop @ARGV;
 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
 chomp $commit;
 if ($?) {
     die "The commit reference $commit did not resolve!";
 }

 # resolve what parent we want
 my $parent;
 if (@ARGV) {
     $parent = pop @ARGV;
     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
     chomp $parent;
     if ($?) {
 	die "The parent reference did not resolve!";
     }
 }

 # find parents from the commit itself
 my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
 my @parents;
 my $committer;
 my $author;
 my $stage = 'headers'; # headers, msg
 my $title;
 my $msg = '';

 foreach my $line (@commit) {
     chomp $line;
     if ($stage eq 'headers' && $line eq '') {
 	$stage = 'msg';
 	next;
     }

     if ($stage eq 'headers') {
 	if ($line =~ m/^parent (\w{40})$/) { # found a parent
 	    push @parents, $1;
 	} elsif ($line =~ m/^author (.+) \d+ \+\d+$/) {
 	    $author = $1;
 	} elsif ($line =~ m/^committer (.+) \d+ \+\d+$/) {
 	    $committer = $1;
 	}
     } else {
 	$msg .= $line . "\n";
 	unless ($title) {
 	    $title = $line;
 	}
     }
 }

 if ($parent) {
     my $found;
     # double check that it's a valid parent
     foreach my $p (@parents) {
 	if ($p eq $parent) {
 	    $found = 1;
 	    last;
 	}; # found it
     }
     die "Did not find $parent in the parents for this commit!" if !$found;
 } else { # we don't have a parent from the cmdline...
     if (@parents == 1) { # it's safe to get it from the commit
 	$parent = $parents[0];
     } else { # or perhaps not!
 	die "This commit has more than one parent -- please name the parent you want to use explicitly";
     }
 }

 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";

 # grab the commit message
 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 if ($opt_m) {
     print MSG $opt_m;
 }
 print MSG $msg;
 if ($opt_a) {
     print MSG "\n\nAuthor: $author\n";
     if ($author ne $committer) {
 	print MSG "Committer: $committer\n";
     }
 }
 close MSG;

 my (@afiles, @dfiles, @mfiles, @dirs);
 my @files = safe_pipe_capture('git-diff-tree', '-r', $parent, $commit);
 #print @files;
 $? && die "Error in git-diff-tree";
 foreach my $f (@files) {
     chomp $f;
     my @fields = split(m!\s+!, $f);
     if ($fields[4] eq 'A') {
         my $path = $fields[5];
 	push @afiles, $path;
         # add any needed parent directories
 	$path = dirname $path;
 	while (!-d $path and ! grep { $_ eq $path } @dirs) {
 	    unshift @dirs, $path;
 	    $path = dirname $path;
 	}
     }
     if ($fields[4] eq 'M') {
 	push @mfiles, $fields[5];
     }
     if ($fields[4] eq 'R') {
 	push @dfiles, $fields[5];
     }
 }
 $opt_v && print "The commit affects:\n ";
 $opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
 undef @files; # don't need it anymore

 # check that the files are clean and up to date according to cvs
 my $dirty;
 foreach my $d (@dirs) {
     if (-e $d) {
 	$dirty = 1;
 	warn "$d exists and is not a directory!\n";
     }
 }
 foreach my $f (@afiles) {
     # This should return only one value
     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
     if (-d dirname $f and $status[0] !~ m/Status: Unknown$/
 	and $status[0] !~ m/^File: no file /) {
  	$dirty = 1;
 	warn "File $f is already known in your CVS checkout -- perhaps it has been added by another user. Or this may indicate that it exists on a different branch. If this is the case, use -f to force the merge.\n";
 	warn "Status was: $status[0]\n";
     }
 }
 foreach my $f (@mfiles, @dfiles) {
     # TODO:we need to handle removed in cvs
     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
     unless ($status[0] =~ m/Status: Up-to-date$/) {
 	$dirty = 1;
 	warn "File $f not up to date in your CVS checkout!\n";
     }
 }
 if ($dirty) {
     if ($opt_f) {	warn "The tree is not clean -- forced merge\n";
 	$dirty = 0;
     } else {
 	die "Exiting: your CVS tree is not clean for this merge.";
     }
 }

 ###
 ### NOTE: if you are planning to die() past this point
 ###       you MUST call cleanupcvs(@files) before die()
 ###


 print "Creating new directories\n";
 foreach my $d (@dirs) {
     unless (mkdir $d) {
         warn "Could not mkdir $d: $!";
 	$dirty = 1;
     }
     `cvs add $d`;
     if ($?) {
 	$dirty = 1;
 	warn "Failed to cvs add directory $d -- you may need to do it manually";
     }
 }

 print "'Patching' binary files\n";

 my @bfiles = grep(m/^Binary/, safe_pipe_capture('git-diff-tree', '-p', $parent, $commit));
 @bfiles = map { chomp } @bfiles;
 foreach my $f (@bfiles) {
     # check that the file in cvs matches the "old" file
     # extract the file to $tmpdir and compare with cmp
     my $tree = safe_pipe_capture('git-rev-parse', "$parent^{tree}");
     chomp $tree;
     my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
     chomp $blob;
     `git-cat-file blob $blob > $tmpdir/blob`;
     if (system('cmp', '-s', $f, "$tmpdir/blob")) {
 	warn "Binary file $f in CVS does not match parent.\n";
 	$dirty = 1;
 	next;
     }

     # replace with the new file
      `git-cat-file blob $blob > $f`;

     # TODO: something smart with file modes

 }
 if ($dirty) {
     cleanupcvs(@files);
     die "Exiting: Binary files in CVS do not match parent";
 }

 ## apply non-binary changes
 my $fuzz = $opt_p ? 0 : 2;

 print "Patching non-binary files\n";
 print `(git-diff-tree -p $parent -p $commit | patch -p1 -F $fuzz ) 2>&1`;

 my $dirtypatch = 0;
 if (($? >> 8) == 2) {
     cleanupcvs(@files);
     die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
 } elsif (($? >> 8) == 1) { # some hunks failed to apply
     $dirtypatch = 1;
 }

 foreach my $f (@afiles) {
     system('cvs', 'add', $f);
     if ($?) {
 	$dirty = 1;
 	warn "Failed to cvs add $f -- you may need to do it manually";
     }
 }

 foreach my $f (@dfiles) {
     system('cvs', 'rm', '-f', $f);
     if ($?) {
 	$dirty = 1;
 	warn "Failed to cvs rm -f $f -- you may need to do it manually";
     }
 }

 print "Commit to CVS\n";
 print "Patch: $title\n";
 my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
 my $cmd = "cvs commit -F .msg $commitfiles";

 if ($dirtypatch) {
     print "NOTE: One or more hunks failed to apply cleanly.\n";
     print "Resolve the conflicts and then commit using:\n";
     print "\n    $cmd\n\n";
     exit(1);
 }


 if ($opt_c) {
     print "Autocommit\n  $cmd\n";
     print safe_pipe_capture('cvs', 'commit', '-F', '.msg', @afiles, @mfiles, @dfiles);
     if ($?) {
 	cleanupcvs(@files);
 	die "Exiting: The commit did not succeed";
     }
     print "Committed successfully to CVS\n";
 } else {
     print "Ready for you to commit, just run:\n\n   $cmd\n";
 }
 sub usage {
 	print STDERR <<END;
 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 END
 	exit(1);
 }

 # ensure cvs is clean before we die
 sub cleanupcvs {
     my @files = @_;
     foreach my $f (@files) {
 	system('cvs', '-q', 'update', '-C', $f);
 	if ($?) {
 	    warn "Warning! Failed to cleanup state of $f\n";
 	}
     }
 }

 # An alternative to `command` that allows input to be passed as an array
 # to work around shell problems with weird characters in arguments
 # if the exec returns non-zero we die
 sub safe_pipe_capture {
     my @output;
     if (my $pid = open my $child, '-|') {
 	@output = (<$child>);
 	close $child or die join(' ',@_).": $! $?";
     } else {
 	exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
     }
     return wantarray ? @output : join('',@output);
 }
	#!/usr/bin/perl -w

	# Known limitations:
	# - cannot add or remove binary files
	# - does not propagate permissions
	# - tells "ready for commit" even when things could not be completed
	# (eg addition of a binary file)

	use strict;
	use Getopt::Std;
	use File::Temp qw(tempdir);
	use Data::Dumper;
	use File::Basename qw(basename dirname);

	unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
	die "GIT_DIR is not defined or is unreadable";
	}

	our ($opt_h, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m );

	getopts('hpvcfam:');

	$opt_h && usage();

	die "Need at least one commit identifier!" unless @ARGV;

	# setup a tempdir
	our ($tmpdir, $tmpdirname) = tempdir('git-cvsapplycommit-XXXXXX',
	TMPDIR => 1,
	CLEANUP => 1);

	# resolve target commit
	my $commit;
	$commit = pop @ARGV;
	$commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
	chomp $commit;
	if ($?) {
	die "The commit reference $commit did not resolve!";
	}

	# resolve what parent we want
	my $parent;
	if (@ARGV) {
	$parent = pop @ARGV;
	$parent = safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
	chomp $parent;
	if ($?) {
	die "The parent reference did not resolve!";
	}
	}

	# find parents from the commit itself
	my @commit = safe_pipe_capture('git-cat-file', 'commit', $commit);
	my @parents;
	my $committer;
	my $author;
	my $stage = 'headers'; # headers, msg
	my $title;
	my $msg = '';

	foreach my $line (@commit) {
	chomp $line;
	if ($stage eq 'headers' && $line eq '') {
	$stage = 'msg';
	next;
	}

	if ($stage eq 'headers') {
	if ($line =~ m/^parent (\w{40})$/) { # found a parent
	push @parents, $1;
	} elsif ($line =~ m/^author (.+) \d+ \+\d+$/) {
	$author = $1;
	} elsif ($line =~ m/^committer (.+) \d+ \+\d+$/) {
	$committer = $1;
	}
	} else {
	$msg .= $line . "\n";
	unless ($title) {
	$title = $line;
	}
	}
	}

	if ($parent) {
	my $found;
	# double check that it's a valid parent
	foreach my $p (@parents) {
	if ($p eq $parent) {
	$found = 1;
	last;
	}; # found it
	}
	die "Did not find $parent in the parents for this commit!" if !$found;
	} else { # we don't have a parent from the cmdline...
	if (@parents == 1) { # it's safe to get it from the commit
	$parent = $parents[0];
	} else { # or perhaps not!
	die "This commit has more than one parent -- please name the parent you want to use explicitly";
	}
	}

	$opt_v && print "Applying to CVS commit $commit from parent $parent\n";

	# grab the commit message
	open(MSG, ">.msg") or die "Cannot open .msg for writing";
	if ($opt_m) {
	print MSG $opt_m;
	}
	print MSG $msg;
	if ($opt_a) {
	print MSG "\n\nAuthor: $author\n";
	if ($author ne $committer) {
	print MSG "Committer: $committer\n";
	}
	}
	close MSG;

	my (@afiles, @dfiles, @mfiles, @dirs);
	my @files = safe_pipe_capture('git-diff-tree', '-r', $parent, $commit);
	#print @files;
	$? && die "Error in git-diff-tree";
	foreach my $f (@files) {
	chomp $f;
	my @fields = split(m!\s+!, $f);
	if ($fields[4] eq 'A') {
	my $path = $fields[5];
	push @afiles, $path;
	# add any needed parent directories
	$path = dirname $path;
	while (!-d $path and ! grep { $_ eq $path } @dirs) {
	unshift @dirs, $path;
	$path = dirname $path;
	}
	}
	if ($fields[4] eq 'M') {
	push @mfiles, $fields[5];
	}
	if ($fields[4] eq 'R') {
	push @dfiles, $fields[5];
	}
	}
	$opt_v && print "The commit affects:\n ";
	$opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
	undef @files; # don't need it anymore

	# check that the files are clean and up to date according to cvs
	my $dirty;
	foreach my $d (@dirs) {
	if (-e $d) {
	$dirty = 1;
	warn "$d exists and is not a directory!\n";
	}
	}
	foreach my $f (@afiles) {
	# This should return only one value
	my @status = grep(m/^File/, safe_pipe_capture('cvs', '-q', 'status' ,$f));
	if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
	if (-d dirname $f and $status[0] !~ m/Status: Unknown$/
	and $status[0] !~ m/^File: no file /) {
	$dirty = 1;
	warn "File $f is already known in your CVS checkout -- perhaps it has been added by another user. Or this may indicate that it exists on a different branch. If this is the case, use -f to force the merge.\n";
	warn "Status was: $status[0]\n";
	}
	}
	foreach my $f (@mfiles, @dfiles) {
	# TODO:we need to handle removed in cvs
	my @status = grep(m/^File/, safe_pipe_capture('cvs', '-q', 'status' ,$f));
	if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
	unless ($status[0] =~ m/Status: Up-to-date$/) {
	$dirty = 1;
	warn "File $f not up to date in your CVS checkout!\n";
	}
	}
	if ($dirty) {
	if ($opt_f) { warn "The tree is not clean -- forced merge\n";
	$dirty = 0;
	} else {
	die "Exiting: your CVS tree is not clean for this merge.";
	}
	}

	###
	### NOTE: if you are planning to die() past this point
	### you MUST call cleanupcvs(@files) before die()
	###


	print "Creating new directories\n";
	foreach my $d (@dirs) {
	unless (mkdir $d) {
	warn "Could not mkdir $d: $!";
	$dirty = 1;
	}
	`cvs add $d`;
	if ($?) {
	$dirty = 1;
	warn "Failed to cvs add directory $d -- you may need to do it manually";
	}
	}

	print "'Patching' binary files\n";

	my @bfiles = grep(m/^Binary/, safe_pipe_capture('git-diff-tree', '-p', $parent, $commit));
	@bfiles = map { chomp } @bfiles;
	foreach my $f (@bfiles) {
	# check that the file in cvs matches the "old" file
	# extract the file to $tmpdir and compare with cmp
	my $tree = safe_pipe_capture('git-rev-parse', "$parent^{tree}");
	chomp $tree;
	my $blob = `git-ls-tree $tree "$f" \| cut -f 1 \| cut -d ' ' -f 3`;
	chomp $blob;
	`git-cat-file blob $blob > $tmpdir/blob`;
	if (system('cmp', '-s', $f, "$tmpdir/blob")) {
	warn "Binary file $f in CVS does not match parent.\n";
	$dirty = 1;
	next;
	}

	# replace with the new file
	`git-cat-file blob $blob > $f`;

	# TODO: something smart with file modes

	}
	if ($dirty) {
	cleanupcvs(@files);
	die "Exiting: Binary files in CVS do not match parent";
	}

	## apply non-binary changes
	my $fuzz = $opt_p ? 0 : 2;

	print "Patching non-binary files\n";
	print `(git-diff-tree -p $parent -p $commit \| patch -p1 -F $fuzz ) 2>&1`;

	my $dirtypatch = 0;
	if (($? >> 8) == 2) {
	cleanupcvs(@files);
	die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
	} elsif (($? >> 8) == 1) { # some hunks failed to apply
	$dirtypatch = 1;
	}

	foreach my $f (@afiles) {
	system('cvs', 'add', $f);
	if ($?) {
	$dirty = 1;
	warn "Failed to cvs add $f -- you may need to do it manually";
	}
	}

	foreach my $f (@dfiles) {
	system('cvs', 'rm', '-f', $f);
	if ($?) {
	$dirty = 1;
	warn "Failed to cvs rm -f $f -- you may need to do it manually";
	}
	}

	print "Commit to CVS\n";
	print "Patch: $title\n";
	my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
	my $cmd = "cvs commit -F .msg $commitfiles";

	if ($dirtypatch) {
	print "NOTE: One or more hunks failed to apply cleanly.\n";
	print "Resolve the conflicts and then commit using:\n";
	print "\n $cmd\n\n";
	exit(1);
	}


	if ($opt_c) {
	print "Autocommit\n $cmd\n";
	print safe_pipe_capture('cvs', 'commit', '-F', '.msg', @afiles, @mfiles, @dfiles);
	if ($?) {
	cleanupcvs(@files);
	die "Exiting: The commit did not succeed";
	}
	print "Committed successfully to CVS\n";
	} else {
	print "Ready for you to commit, just run:\n\n $cmd\n";
	}
	sub usage {
	print STDERR <<END;
	Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
	END
	exit(1);
	}

	# ensure cvs is clean before we die
	sub cleanupcvs {
	my @files = @_;
	foreach my $f (@files) {
	system('cvs', '-q', 'update', '-C', $f);
	if ($?) {
	warn "Warning! Failed to cleanup state of $f\n";
	}
	}
	}

	# An alternative to `command` that allows input to be passed as an array
	# to work around shell problems with weird characters in arguments
	# if the exec returns non-zero we die
	sub safe_pipe_capture {
	my @output;
	if (my $pid = open my $child, '-\|') {
	@output = (<$child>);
	close $child or die join(' ',@_).": $! $?";
	} else {
	exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
	}
	return wantarray ? @output : join('',@output);
	}