1#!perl
2use strict;
3use warnings;
4use Getopt::Long qw/GetOptions/;
5use Term::ANSIColor qw/color/;
6use constant GITCMD => 'git';
7
8sub usage {
9  print <<HERE;
10Usage: $0 [options] [<start-commit> [<end-commit>]]
11
12Scans the commit logs for commits that are potentially, illegitimately
13touching modules that are primarily maintained outside of the perl core.
14Also checks for commits that span multiple distributions in cpan/ or dist/.
15Makes sure that updated CPAN distributions also update Porting/Maintainers.pl,
16but otherwise ignores changes to that file (and MANIFEST).
17
18Skip the <start-commit> to go back indefinitely. <end-commit> defaults to
19HEAD.
20
21 -h/--help shows this help
22 -v/--verbose shows the output of "git show --stat <commit>" for each commit
23 -c/--color uses colored output
24HERE
25  exit(1);
26}
27
28our $Verbose = 0;
29our $Color   = 0;
30GetOptions(
31  'h|help'         => \&usage,
32  'v|verbose'      => \$Verbose,
33  'c|color|colour' => \$Color,
34);
35
36my $start_commit = shift;
37my $end_commit   = shift;
38$end_commit = 'HEAD' if not defined $end_commit;
39my $commit_range_cmd = defined($start_commit) ? " $start_commit..$end_commit" : "";
40
41# format: hash\0author\0committer\0short_msg
42our $LogCmd = GITCMD() . q{ log --no-color -M -C --name-only '--pretty=format:%h%x00%an%x00%cn%x00%s'} . $commit_range_cmd;
43our @ColumnSpec = qw(hash author committer commit_msg);
44
45open my $fh, '-|', $LogCmd
46  or die "Can't run '$LogCmd' to get the commit log: $!";
47
48my ($safe_commits, $unsafe_commits) = parse_log($fh);
49
50if (@$unsafe_commits) {
51  my $header = "Potentially unsafe commits:";
52  print color("red") if $Color;
53  print $header, "\n";
54  print("=" x length($header), "\n\n") if $Verbose;
55  print color("reset") if $Color;
56  print_commit_info($_) foreach reverse @$unsafe_commits;
57  print "\n";
58}
59
60if (@$safe_commits) {
61  my $header = "Presumably safe commits:";
62  print color("green") if $Color;
63  print $header, "\n";
64  print("=" x length($header), "\n") if $Verbose;
65  print color("reset") if $Color;
66  print_commit_info($_) foreach reverse @$safe_commits;
67  print "\n";
68}
69
70exit(0);
71
72
73
74# single-line info about the commit at hand
75sub print_commit_info {
76  my $commit = shift;
77
78  my $author_info = "by $commit->{author}"
79                    . ($commit->{author} eq $commit->{committer}
80                       ? ''
81                       : " committed by $commit->{committer}");
82
83  if ($Verbose) {
84    print color("yellow") if $Color;
85    my $header = "$commit->{hash} $author_info: $commit->{msg}";
86    print "$header\n", ("-" x length($header)), "\n";
87    print color("reset") if $Color;
88
89    my $cmd = GITCMD() . ' show --stat ' . ($Color?'--color ':'')
90              . $commit->{hash};
91    print `$cmd`; # make sure git knows this isn't a terminal
92    print "\n";
93  }
94  else {
95    print color("yellow") if $Color;
96    print "  $commit->{hash} $author_info: $commit->{msg}\n";
97    print color("reset") if $Color;
98  }
99}
100
101
102# check whether the commit at hand is safe, unsafe or uninteresting
103sub check_commit {
104  my $commit = shift;
105  my $safe   = shift;
106  my $unsafe = shift;
107
108  # Note to self: Adding any more greps and such will make this
109  # look even more silly. Just use a single foreach, smart guy!
110  my $touches_maintainers_pl = 0;
111  my @files = grep {
112                $touches_maintainers_pl = 1
113                  if $_ eq 'Porting/Maintainers.pl';
114                $_ ne 'MANIFEST' and $_ ne 'Porting/Maintainers.pl'
115              }
116              @{$commit->{files}};
117  my @touching_cpan = grep {/^cpan\//} @files;
118  return if not @touching_cpan;
119
120  # check for unsafe commits to cpan/
121  my %touched_cpan_dirs;
122  $touched_cpan_dirs{$_}++ for grep {defined $_}
123                               map {s/^cpan\/([^\/]*).*$/$1/; $_}
124                               @touching_cpan;
125
126  my $touches_multiple_cpan_dists = (keys(%touched_cpan_dirs) > 1);
127
128  my $touches_others              = @files - @touching_cpan;
129
130  if (@touching_cpan) {
131    if ($touches_others) {
132      $commit->{msg} = 'Touched files under cpan/ and other locations';
133      push @$unsafe, $commit;
134    }
135    elsif ($touches_multiple_cpan_dists) {
136      $commit->{msg} = 'Touched multiple directories under cpan/';
137      push @$unsafe, $commit;
138    }
139    elsif (not $touches_maintainers_pl) {
140      $commit->{msg} = 'Touched files under cpan/, but does not update '
141                       . 'Porting/Maintainers.pl';
142      push @$unsafe, $commit;
143    }
144    elsif ($commit->{commit_msg} =~ /(?:up(?:grad|dat)|import)(?:ed?|ing)/i) {
145      $commit->{msg} = 'Touched files under cpan/ with '
146                       . '"upgrading"-like commit message';
147      push @$safe, $commit;
148    }
149    else {
150      $commit->{msg} = 'Touched files under cpan/ without '
151                       . '"upgrading"-like commit message';
152      push @$unsafe, $commit;
153    }
154  }
155
156  # check for unsafe commits to dist/
157  my @touching_dist = grep {/^dist\//} @files;
158  my %touched_dist_dirs;
159  $touched_dist_dirs{$_}++ for grep {defined $_}
160                               map {s/^dist\/([^\/]*).*$/$1/; $_}
161                               @touching_dist;
162  $touches_others = @files - @touching_dist;
163  my $touches_multiple_dists = (keys(%touched_dist_dirs) > 1);
164
165  if (@touching_dist) {
166    if ($touches_others) {
167      $commit->{msg} = 'Touched files under dist/ and other locations';
168      push @$unsafe, $commit;
169    }
170    elsif ($touches_multiple_dists) {
171      $commit->{msg} = 'Touched multiple directories under cpan/';
172      push @$unsafe, $commit;
173    }
174  }
175}
176
177# given file handle, parse the git log output and put the resulting commit
178# structure into safe/unsafe compartments
179sub parse_log {
180  my $fh = shift;
181  my @safe_commits;
182  my @unsafe_commits;
183  my $commit;
184  while (defined(my $line = <$fh>)) {
185    chomp $line;
186    if (not $commit) {
187      next if $line =~ /^\s*$/;
188      my @cols = split /\0/, $line;
189      @cols == @ColumnSpec && !grep {!defined($_)} @cols
190        or die "Malformed commit header line: '$line'";
191      $commit = {
192        files => [],
193        map {$ColumnSpec[$_] => $cols[$_]} (0..$#cols)
194      };
195      next;
196    }
197    elsif ($line =~ /^\s*$/) { # within commit, blank line
198      check_commit($commit, \@safe_commits, \@unsafe_commits);
199      $commit = undef;
200    }
201    else { # within commit, non-blank (file) line
202      push @{$commit->{files}}, $line;
203    }
204  }
205
206  return(\@safe_commits, \@unsafe_commits);
207}
208
209