git-fmt-merge-msg.perl

   1 #!/usr/bin/perl -w
   2 #
   3 # Copyright (c) 2005 Junio C Hamano
   4 #
   5 # Read .git/FETCH_HEAD and make a human readable merge message
   6 # by grouping branches and tags together to form a single line.
   7
   8 use strict;
   9
  10 my @src;
  11 my %src;
  12 sub andjoin {
  13         my ($label, $labels, $stuff) = @_;
  14         my $l = scalar @$stuff;
  15         my $m = '';
  16         if ($l == 0) {
  17                 return ();
  18         }
  19         if ($l == 1) {
  20                 $m = "$label$stuff->[0]";
  21         }
  22         else {
  23                 $m = ("$labels" .
  24                       join (', ', @{$stuff}[0..$l-2]) .
  25                       " and $stuff->[-1]");
  26         }
  27         return ($m);
  28 }
  29
  30 sub repoconfig {
  31         my $val;
  32         eval {
  33                 my $pid = open(my $fh, '-|');
  34                 if (!$pid) {
  35                         exec('git-repo-config', '--get', 'merge.summary');
  36                 }
  37                 ($val) = <$fh>;
  38                 close $fh;
  39         };
  40         return $val;
  41 }
  42
  43 sub current_branch {
  44         my $fh;
  45         my $pid = open($fh, '-|');
  46         die "$!" unless defined $pid;
  47         if (!$pid) {
  48             exec('git-symbolic-ref', 'HEAD') or die "$!";
  49         }
  50         my ($bra) = <$fh>;
  51         chomp($bra);
  52         close $fh or die "$!";
  53         $bra =~ s|^refs/heads/||;
  54         if ($bra ne 'master') {
  55                 $bra = " into $bra";
  56         } else {
  57                 $bra = "";
  58         }
  59         return $bra;
  60 }
  61
  62 sub shortlog {
  63         my ($tip) = @_;
  64         my ($fh, @result);
  65         my $pid = open($fh, '-|');
  66         die "$!" unless defined $pid;
  67         if (!$pid) {
  68             exec('git-log', '--topo-order',
  69                  '--pretty=oneline', $tip, '^HEAD') or die "$!";
  70         }
  71         while (<$fh>) {
  72                 s/^[0-9a-f]{40}\s+//;
  73                 push @result, $_;
  74         }
  75         close $fh or die "$!";
  76         return @result;
  77 }
  78
  79 my @origin = ();
  80 while (<>) {
  81         my ($bname, $tname, $gname, $src, $sha1, $origin);
  82         chomp;
  83         s/^([0-9a-f]*)  //;
  84         $sha1 = $1;
  85         next if (/^not-for-merge/);
  86         s/^     //;
  87         if (s/ of (.*)$//) {
  88                 $src = $1;
  89         } else {
  90                 # Pulling HEAD
  91                 $src = $_;
  92                 $_ = 'HEAD';
  93         }
  94         if (! exists $src{$src}) {
  95                 push @src, $src;
  96                 $src{$src} = {
  97                         BRANCH => [],
  98                         TAG => [],
  99                         GENERIC => [],
 100                         # &1 == has HEAD.
 101                         # &2 == has others.
 102                         HEAD_STATUS => 0,
 103                 };
 104         }
 105         if (/^branch (.*)$/) {
 106                 $origin = $1;
 107                 push @{$src{$src}{BRANCH}}, $1;
 108                 $src{$src}{HEAD_STATUS} |= 2;
 109         }
 110         elsif (/^tag (.*)$/) {
 111                 $origin = $_;
 112                 push @{$src{$src}{TAG}}, $1;
 113                 $src{$src}{HEAD_STATUS} |= 2;
 114         }
 115         elsif (/^HEAD$/) {
 116                 $origin = $src;
 117                 $src{$src}{HEAD_STATUS} |= 1;
 118         }
 119         else {
 120                 push @{$src{$src}{GENERIC}}, $_;
 121                 $src{$src}{HEAD_STATUS} |= 2;
 122                 $origin = $src;
 123         }
 124         if ($src eq '.' || $src eq $origin) {
 125                 $origin =~ s/^'(.*)'$/$1/;
 126                 push @origin, [$sha1, "$origin"];
 127         }
 128         else {
 129                 push @origin, [$sha1, "$origin of $src"];
 130         }
 131 }
 132
 133 my @msg;
 134 for my $src (@src) {
 135         if ($src{$src}{HEAD_STATUS} == 1) {
 136                 # Only HEAD is fetched, nothing else.
 137                 push @msg, $src;
 138                 next;
 139         }
 140         my @this;
 141         if ($src{$src}{HEAD_STATUS} == 3) {
 142                 # HEAD is fetched among others.
 143                 push @this, andjoin('', '', ['HEAD']);
 144         }
 145         push @this, andjoin("branch ", "branches ",
 146                            $src{$src}{BRANCH});
 147         push @this, andjoin("tag ", "tags ",
 148                            $src{$src}{TAG});
 149         push @this, andjoin("commit ", "commits ",
 150                             $src{$src}{GENERIC});
 151         my $this = join(', ', @this);
 152         if ($src ne '.') {
 153                 $this .= " of $src";
 154         }
 155         push @msg, $this;
 156 }
 157
 158 my $into = current_branch();
 159
 160 print "Merge ", join("; ", @msg), $into, "\n";
 161
 162 if (!repoconfig) {
 163         exit(0);
 164 }
 165
 166 # We limit the merge message to the latst 20 or so per each branch.
 167 my $limit = 20;
 168
 169 for (@origin) {
 170         my ($sha1, $name) = @$_;
 171         my @log = shortlog($sha1);
 172         if ($limit + 1 <= @log) {
 173                 print "\n* $name: (" . scalar(@log) . " commits)\n";
 174         }
 175         else {
 176                 print "\n* $name:\n";
 177         }
 178         my $cnt = 0;
 179         for my $log (@log) {
 180                 if ($limit < ++$cnt) {
 181                         print "  ...\n";
 182                         last;
 183                 }
 184                 print "  $log";
 185         }
 186 }