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