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