src/util/licence.pl

   1 #!/usr/bin/perl -w
   2 #
   3 # Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
   4 #
   5 # This program is free software; you can redistribute it and/or
   6 # modify it under the terms of the GNU General Public License as
   7 # published by the Free Software Foundation; either version 2 of the
   8 # License, or any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful, but
  11 # WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 # General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19 use strict;
  20 use warnings;
  21 use Getopt::Long;
  22
  23 # List of licences we can handle
  24 my $known_licences = {
  25   gpl_any => {
  26     desc => "GPL (any version)",
  27     can_subsume => {
  28       public_domain => 1,
  29       bsd3 => 1,
  30       bsd2 => 1,
  31       mit  => 1,
  32       isc  => 1,
  33     },
  34   },
  35   gpl2_or_later => {
  36     desc => "GPL version 2 (or, at your option, any later version)",
  37     can_subsume => {
  38       gpl_any => 1,
  39       public_domain => 1,
  40       bsd3 => 1,
  41       bsd2 => 1,
  42       mit  => 1,
  43       isc  => 1,
  44     },
  45   },
  46   gpl2_only => {
  47     desc => "GPL version 2 only",
  48     can_subsume => {
  49       gpl_any => 1,
  50       gpl2_or_later => 1,
  51       public_domain => 1,
  52       bsd3 => 1,
  53       bsd2 => 1,
  54       mit  => 1,
  55       isc  => 1,
  56     },
  57   },
  58   public_domain => {
  59     desc => "Public Domain",
  60     can_subsume => {},
  61   },
  62   bsd4 => {
  63     desc => "BSD Licence (with advertising clause)",
  64     can_subsume => {
  65       public_domain => 1,
  66       bsd3 => 1,
  67       bsd2 => 1,
  68       mit  => 1,
  69       isc  => 1,
  70     },
  71   },
  72   bsd3 => {
  73     desc => "BSD Licence (without advertising clause)",
  74     can_subsume => {
  75       public_domain => 1,
  76       bsd2 => 1,
  77       mit  => 1,
  78       isc  => 1,
  79     },
  80   },
  81   bsd2 => {
  82     desc => "BSD Licence (without advertising or endorsement clauses)",
  83     can_subsume => {
  84       public_domain => 1,
  85       mit  => 1,
  86       isc  => 1,
  87     },
  88   },
  89   mit => {
  90     desc => "MIT/X11/Xorg Licence",
  91     can_subsume => {
  92       public_domain => 1,
  93       isc => 1,
  94     },
  95   },
  96   isc => {
  97     desc => "ISC Licence",
  98     can_subsume => {
  99       public_domain => 1,
 100     },
 101   },
 102 };
 103
 104 # Parse command-line options
 105 my $verbosity = 1;
 106 Getopt::Long::Configure ( 'bundling', 'auto_abbrev' );
 107 GetOptions (
 108   'verbose|v+' => sub { $verbosity++; },
 109   'quiet|q+' => sub { $verbosity--; },
 110 ) or die "Could not parse command-line options\n";
 111
 112 # Parse licence list from command line
 113 my $licences = {};
 114 foreach my $licence ( @ARGV ) {
 115   die "Unknown licence \"$licence\"\n"
 116       unless exists $known_licences->{$licence};
 117   $licences->{$licence} = $known_licences->{$licence};
 118 }
 119 die "No licences specified\n" unless %$licences;
 120
 121 # Dump licence list
 122 if ( $verbosity >= 1 ) {
 123   print "The following licences appear within this file:\n";
 124   foreach my $licence ( keys %$licences ) {
 125     print "  ".$licences->{$licence}->{desc}."\n"
 126   }
 127 }
 128
 129 # Apply licence compatibilities to reduce to a single resulting licence
 130 foreach my $licence ( keys %$licences ) {
 131   # Skip already-deleted licences
 132   next unless exists $licences->{$licence};
 133   # Subsume any subsumable licences
 134   foreach my $can_subsume ( keys %{$licences->{$licence}->{can_subsume}} ) {
 135     if ( exists $licences->{$can_subsume} ) {
 136       print $licences->{$licence}->{desc}." subsumes ".
 137           $licences->{$can_subsume}->{desc}."\n"
 138           if $verbosity >= 1;
 139       delete $licences->{$can_subsume};
 140     }
 141   }
 142 }
 143
 144 # Print resulting licence
 145 die "Cannot reduce to a single resulting licence!\n"
 146     if ( keys %$licences ) != 1;
 147 ( my $licence ) = keys %$licences;
 148 print "The overall licence for this file is:\n  " if $verbosity >= 1;
 149 print $licences->{$licence}->{desc}."\n";