1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
package Perl::Critic::Utils::McCabe;
use 5.010001;
use strict;
use warnings;
use Readonly;
use Perl::Critic::Utils qw{ :data_conversion :classification };
use Exporter 'import';
#-----------------------------------------------------------------------------
our $VERSION = '1.156';
#-----------------------------------------------------------------------------
Readonly::Array our @EXPORT_OK =>
qw( calculate_mccabe_of_sub calculate_mccabe_of_main );
#-----------------------------------------------------------------------------
Readonly::Hash my %LOGIC_OPS =>
hashify( qw( && || ||= &&= or and xor ? <<= >>= ) );
Readonly::Hash my %LOGIC_KEYWORDS =>
hashify( qw( if else elsif unless until while for foreach ) );
#-----------------------------------------------------------------------------
sub calculate_mccabe_of_sub {
my ( $sub ) = @_;
my $count = 1; # Minimum score is 1
$count += _count_logic_keywords( $sub );
$count += _count_logic_operators( $sub );
return $count;
}
#-----------------------------------------------------------------------------
sub calculate_mccabe_of_main {
my ( $doc ) = @_;
my $count = 1; # Minimum score is 1
$count += _count_main_logic_operators_and_keywords( $doc );
return $count;
}
#-----------------------------------------------------------------------------
sub _count_main_logic_operators_and_keywords {
my ( $doc ) = @_;
# I can't leverage Perl::Critic::Document's fast search mechanism here
# because we're not searching for elements by class name. So to speed
# things up, search for both keywords and operators at the same time.
my $wanted = sub {
my (undef, $elem) = @_;
# Only count things that *are not* in a subroutine. Returning an
# explicit 'undef' here prevents PPI from descending into the node.
## no critic (ProhibitExplicitReturnUndef)
return undef if $elem->isa('PPI::Statement::Sub');
if ( $elem->isa('PPI::Token::Word') ) {
return 0 if is_hash_key( $elem );
return exists $LOGIC_KEYWORDS{$elem};
}
elsif ($elem->isa('PPI::Token::Operator') ) {
return exists $LOGIC_OPS{$elem};
}
};
my $logic_operators_and_keywords = $doc->find( $wanted );
my $count = $logic_operators_and_keywords ?
scalar @{$logic_operators_and_keywords} : 0;
return $count;
}
#-----------------------------------------------------------------------------
sub _count_logic_keywords {
my ( $sub ) = @_;
my $count = 0;
# Here, I'm using this round-about method of finding elements so
# that I can take advantage of Perl::Critic::Document's faster
# find() mechanism. It can only search for elements by class name.
my $keywords_ref = $sub->find('PPI::Token::Word');
if ( $keywords_ref ) { # should always be true due to "sub" keyword
my @filtered = grep { ! is_hash_key($_) } @{ $keywords_ref };
$count = grep { exists $LOGIC_KEYWORDS{$_} } @filtered;
}
return $count;
}
#-----------------------------------------------------------------------------
sub _count_logic_operators {
my ( $sub ) = @_;
my $count = 0;
# Here, I'm using this round-about method of finding elements so
# that I can take advantage of Perl::Critic::Document's faster
# find() mechanism. It can only search for elements by class name.
my $operators_ref = $sub->find('PPI::Token::Operator');
if ( $operators_ref ) {
$count = grep { exists $LOGIC_OPS{$_} } @{ $operators_ref };
}
return $count;
}
1;
__END__
#-----------------------------------------------------------------------------
=pod
=for stopwords McCabe
=head1 NAME
Perl::Critic::Utils::McCabe - Functions that calculate the McCabe score of source code.
=head1 DESCRIPTION
Provides approximations of McCabe scores. The McCabe score of a set
of code describes the number of possible paths through it. The
functions here approximate the McCabe score by summing the number of
conditional statements and operators within a set of code. See
L<http://en.wikipedia.org/wiki/Cyclomatic_complexity> for
some discussion about the McCabe number and other complexity metrics.
=head1 INTERFACE SUPPORT
This is considered to be a public module. Any changes to its
interface will go through a deprecation cycle.
=head1 IMPORTABLE SUBS
=over
=item C<calculate_mccabe_of_sub( $sub )>
Calculates an approximation of the McCabe number of the code in a
L<PPI::Statement::Sub|PPI::Statement::Sub>.
=item C<calculate_mccabe_of_main( $doc )>
Calculates an approximation of the McCabe number of all the code in a
L<PPI::Statement::Document|PPI::Statement::Document> that is B<not>
contained in a subroutine.
=back
=head1 AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
=head1 COPYRIGHT
Copyright (c) 2005-2011 Imaginative Software Systems. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself. The full text of this license
can be found in the LICENSE file included with this module.
=cut
# Local Variables:
# mode: cperl
# cperl-indent-level: 4
# fill-column: 78
# indent-tabs-mode: nil
# c-indentation-style: bsd
# End:
# ex: set ts=8 sts=4 sw=4 tw=78 ft=perl expandtab shiftround :
|
