blob: a3ddeec6197ef20544bfaf0672eef043ed94d5b1 [file] [log] [blame]
#!/usr/bin/perl
# Copyright © 2009-2010 Raphaël Hertzog <hertzog@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
use warnings;
use strict;
use Dpkg;
use Dpkg::Changelog::Debian;
use Dpkg::ErrorHandling;
use Dpkg::Gettext;
use Dpkg::Version;
use Getopt::Long;
use Scalar::Util qw(blessed);
textdomain("dpkg-dev");
sub merge_entries($$$);
sub merge_block($$$;&);
sub merge_entry_item($$$$);
sub merge_conflict($$);
sub get_conflict_block($$);
sub join_lines($);
BEGIN {
eval 'use Algorithm::Merge qw(merge);';
if ($@) {
eval q{
sub merge {
my ($o, $a, $b) = @_;
return @$a if join("\n", @$a) eq join("\n", @$b);
return get_conflict_block($a, $b);
}
};
}
}
sub version {
printf _g("Debian %s version %s.\n"), $progname, $version;
printf "\n" . _g("Copyright (C) 2009-2010 Raphael Hertzog.");
printf "\n" . _g(
"This is free software; see the GNU General Public License version 2 or
later for copying conditions. There is NO warranty.
");
}
sub usage {
printf(_g(
"Usage: %s [<option> ...] <old> <new-a> <new-b> [<out>]
Options:
--merge-prereleases, -m merge pre-releases together, ignores everything
after the last '~' in the version.
--help, -h, -? show this help message.
--version show the version.
"), $progname);
}
my $merge_prereleases;
unless (GetOptions('help|?' => sub { usage(); exit(0) },
'merge-prereleases|m' => \$merge_prereleases,
'version' => sub { version(); exit(0) })) {
usage();
exit(2);
}
my ($old, $new_a, $new_b, $out_file) = @ARGV;
unless (defined $old and defined $new_a and defined $new_b and
-e $old and -e $new_a and -e $new_b)
{
usage();
exit(2);
}
my ($cho, $cha, $chb, $res);
$cho = Dpkg::Changelog::Debian->new();
$cho->load($old);
$cha = Dpkg::Changelog::Debian->new();
$cha->load($new_a);
$chb = Dpkg::Changelog::Debian->new();
$chb->load($new_b);
my @o = reverse @$cho;
my @a = reverse @$cha;
my @b = reverse @$chb;
my @result; # Lines to output
my $exitcode = 0; # 1 if conflict encountered
unless (merge_block($cho, $cha, $chb, sub {
my $tail = $_[0]->get_unparsed_tail();
chomp $tail if defined $tail;
return $tail;
}))
{
merge_conflict($cha->get_unparsed_tail(), $chb->get_unparsed_tail());
}
while (1) {
my ($o, $a, $b) = get_items_to_merge();
last unless defined $o or defined $a or defined $b;
next if merge_block($o, $a, $b);
# We only have the usually conflicting cases left
if (defined $a and defined $b) {
# Same entry, merge sub-items separately for a nicer result
merge_entries($o, $a, $b);
} else {
# Non-existing on one side, changed on the other side
merge_conflict($a, $b);
}
}
if (defined($out_file) and $out_file ne "-") {
open(OUT, ">", $out_file) || syserr(_g("cannot write %s"), $out_file);
print OUT ((blessed $_) ? "$_" : "$_\n") foreach @result;
close(OUT) || syserr(_g("cannot write %s"), $out_file);
} else {
print ((blessed $_) ? "$_" : "$_\n") foreach @result;
}
exit $exitcode;
# Returns the next items to merge, all items returned correspond to the
# same minimal version among the 3 possible next items (undef is returned
# if the next item on the given changelog is skipped)
sub get_items_to_merge {
my @items = (shift @o, shift @a, shift @b);
my @arrays = (\@o, \@a, \@b);
my $minver;
foreach my $i (0 .. 2) {
if (defined $minver and defined $items[$i]) {
my $cmp = compare_versions($minver, $items[$i]->get_version());
if ($cmp > 0) {
$minver = $items[$i]->get_version();
foreach my $j (0 .. $i - 1) {
unshift @{$arrays[$j]}, $items[$j];
$items[$j] = undef;
}
} elsif ($cmp < 0) {
unshift @{$arrays[$i]}, $items[$i];
$items[$i] = undef;
}
} else {
$minver = $items[$i]->get_version() if defined $items[$i];
}
}
return @items;
}
# Compares the versions taking into account some oddities like the fact
# that we want backport/volatile versions to sort higher than the version
# on which they are based.
sub compare_versions {
my ($a, $b) = @_;
return 0 if not defined $a and not defined $b;
return 1 if not defined $b;
return -1 if not defined $a;
$a = $a->get_version() if ref($a) and $a->isa("Dpkg::Changelog::Entry");
$b = $b->get_version() if ref($b) and $b->isa("Dpkg::Changelog::Entry");
# Backport and volatile are not real prereleases
$a =~ s/~(bpo|vola)/+$1/;
$b =~ s/~(bpo|vola)/+$1/;
if ($merge_prereleases) {
$a =~ s/~[^~]*$//;
$b =~ s/~[^~]*$//;
}
return version_compare($a, $b);
}
# Merge changelog entries smartly by merging individually the different
# parts constituting an entry
sub merge_entries($$$) {
my ($o, $a, $b) = @_;
# NOTE: Only $o can be undef
# Merge the trailer line
unless (merge_entry_item("blank_after_trailer", $o, $a, $b)) {
unshift @result, "";
}
unless (merge_entry_item("trailer", $o, $a, $b)) {
merge_conflict($a->get_part('trailer'), $b->get_part('trailer'));
}
# Merge the changes
unless (merge_entry_item("blank_after_changes", $o, $a, $b)) {
unshift @result, "";
}
my @merged = merge(defined $o ? $o->get_part('changes') : [],
$a->get_part('changes'), $b->get_part('changes'),
{
CONFLICT => sub {
$exitcode = 1;
return get_conflict_block($_[0], $_[1]);
}
});
unshift @result, @merged;
# Merge the header line
unless (merge_entry_item("blank_after_header", $o, $a, $b)) {
unshift @result, "";
}
unless (merge_entry_item("header", $o, $a, $b)) {
merge_conflict($a->get_part('header'), $b->get_part('header'));
}
}
sub join_lines($) {
my $array = shift;
return join("\n", @$array) if ref($array) eq "ARRAY";
return $array;
}
# Try to merge the obvious cases, return 1 on success and 0 on failure
# O A B
# - x x => x
# o o b => b
# - - b => b
# o a o => a
# - a - => a
sub merge_block($$$;&) {
my ($o, $a, $b, $preprocess) = @_;
$preprocess = \&join_lines unless defined $preprocess;
$o = &$preprocess($o) if defined($o);
$a = &$preprocess($a) if defined($a);
$b = &$preprocess($b) if defined($b);
return 1 if not defined($a) and not defined($b);
if (defined($a) and defined($b) and ($a eq $b)) {
unshift @result, $a;
} elsif ((defined($a) and defined($o) and ($a eq $o)) or
(not defined($a) and not defined($o))) {
unshift @result, $b if defined $b;
} elsif ((defined($b) and defined($o) and ($b eq $o)) or
(not defined($b) and not defined($o))) {
unshift @result, $a if defined $a;
} else {
return 0;
}
return 1;
}
sub merge_entry_item($$$$) {
my ($item, $o, $a, $b) = @_;
if (blessed($o) and $o->isa('Dpkg::Changelog::Entry')) {
$o = $o->get_part($item);
} elsif (ref $o) {
$o = $o->{$item};
}
if (blessed($a) and $a->isa('Dpkg::Changelog::Entry')) {
$a = $a->get_part($item);
} elsif (ref $a) {
$a = $a->{$item};
}
if (blessed($b) and $b->isa('Dpkg::Changelog::Entry')) {
$b = $b->get_part($item);
} elsif (ref $b) {
$b = $b->{$item};
}
return merge_block($o, $a, $b);
}
sub merge_conflict($$) {
my ($a, $b) = @_;
unshift @result, get_conflict_block($a, $b);
$exitcode = 1;
}
sub get_conflict_block($$) {
my ($a, $b) = @_;
my (@a, @b);
push @a, $a if defined $a;
push @b, $b if defined $b;
@a = @{$a} if ref($a) eq "ARRAY";
@b = @{$b} if ref($b) eq "ARRAY";
return ("<<<<<<<", @a, "=======", @b, ">>>>>>>");
}