Is there such a policy?

Here's one :-)

package Perl::Critic::Policy::ControlStructures::ProhibitGotoLabel; use warnings; use strict; use base 'Perl::Critic::Policy'; use Perl::Critic::Utils qw/:severities/; # to locate the path where to place this file, do e.g.: # $ perl -MFile::Basename=dirname -MPerl::Critic::Policy::ControlStruc +tures::ProhibitUnreachableCode -le 'print dirname $INC{"Perl/Critic/P +olicy/ControlStructures/ProhibitUnreachableCode.pm"}' # or # $ dirname `perldoc -l Perl::Critic::Policy::ControlStructures::Prohi +bitUnreachableCode` our $VERSION = '0.001'; sub supported_parameters { return } sub default_severity { return $SEVERITY_MEDIUM } sub default_themes { return qw/core bugs/ } sub applies_to { return 'PPI::Token::Word' } =head1 DESCRIPTION A C<goto LABEL> is considered a bad practice by a number of people, as it can lead to hard-to-understand and brittle spaghetti code. Instead of a C<goto>, use different control structures, or place a label on a block (such as a loop's block) and use C<next LABEL>, C<last LABEL>, or C<redo LABEL> instead. C<goto &NAME> is very different from C<goto LABEL> and is not covered by this policy. C<goto EXPR> is ambiguous and this policy will report such cases when C<EXPR> does not begin with C<&>. Whether this is a false positive or not cannot be determined by a static parse. =cut my $DESC = q{goto LABEL used}; my $EXPL = q{Considered bad practice}; sub violates { my ($self, $elem) = @_; return if $elem->content() ne 'goto'; my $target = $elem->snext_sibling(); return $self->violation('Nothing following "goto"?', 'It seems there is a lone "goto" in your code?', $elem) if !$target; return if $target->isa('PPI::Token::Symbol') && $target->raw_type +eq '&' || $target->isa('PPI::Token::Cast') && $target->content +eq '&' || $target->isa('PPI::Token::Word') && $target->content +eq '__SUB__'; return $self->violation($DESC,$EXPL,$elem); } 1;

Test code:

#!/usr/bin/env perl use warnings; use strict; use feature 'current_sub'; # Perl 5.16, for __SUB__() # tests for Perl::Critic::Policy::ControlStructures::ProhibitGotoLabel # run me with e.g.: perl -c gototest.pl && perlcritic -3 gototest.pl goto FOO; # bad FOO: sub foo { } sub bar { goto &foo } # good my $i = 1; goto ("FOO", "BAR", "GLARCH")[$i]; # bad BAR: sub quz { goto __SUB__ } # good sub quz2 { goto __SUB__() } # good my $subref = \&foo; sub ab { goto &$subref; } # good sub cd { goto $subref; } # good, but false positive my $label = "XYZ"; goto $label; # bad (but ambigious) XYZ: __END__ gototest.pl syntax OK goto LABEL used at line 9, column 1. Considered bad practice. (Sever +ity: 3) goto LABEL used at line 16, column 1. Considered bad practice. (Seve +rity: 3) goto LABEL used at line 24, column 10. Considered bad practice. (Sev +erity: 3) goto LABEL used at line 27, column 1. Considered bad practice. (Seve +rity: 3)

Update: Added handling of __SUB__ keyword, thanks rir!


In reply to Re: Go to perl::critic (updated) by haukex
in thread Go to perl::critic by rir

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