4 use warnings FATAL => 'all';
7 *_PERL_LT_5_8_4 = ($] < 5.008004) ? sub(){1} : sub(){0};
8 # goto &UNIVERSAL::VERSION usually works on 5.8, but fails on some ARM
9 # machines. Seems to always work on 5.10 though.
10 *_CAN_GOTO_VERSION = ($] >= 5.010000) ? sub(){1} : sub(){0};
13 our $VERSION = '2.000002';
14 $VERSION = eval $VERSION;
16 our @WARNING_CATEGORIES = grep { exists $warnings::Offsets{$_} } qw(
22 experimental::autoderef
24 experimental::const_attr
25 experimental::lexical_subs
26 experimental::lexical_topic
27 experimental::postderef
28 experimental::re_strict
29 experimental::refaliasing
30 experimental::regex_sets
31 experimental::signatures
32 experimental::smartmatch
33 experimental::win32_perlio
94 if (defined $_[1] && eval { &UNIVERSAL::VERSION; 1}) {
96 unless _PERL_LT_5_8_4;
97 $^H{strictures_enable} = int $_[1];
100 _CAN_GOTO_VERSION ? goto &UNIVERSAL::VERSION : &UNIVERSAL::VERSION;
103 our %extra_load_states;
105 our $Smells_Like_VCS;
109 my %opts = @_ == 1 ? %{$_[0]} : @_;
110 if (!exists $opts{version}) {
112 = exists $^H{strictures_enable} ? delete $^H{strictures_enable}
115 $opts{file} = (caller)[1];
116 $class->_enable(\%opts);
120 my ($class, $opts) = @_;
121 my $version = $opts->{version};
123 if !defined $version;
124 my $method = "_enable_$version";
125 if (!$class->can($method)) {
127 Carp::croak("Major version specified as $version - not supported!");
129 $class->$method($opts);
133 my ($class, $opts) = @_;
135 warnings->import(FATAL => 'all');
137 if (_want_extra($opts->{file})) {
138 _load_extras(qw(indirect multidimensional bareword::filehandles));
139 indirect->unimport(':fatal')
140 if $extra_load_states{indirect};
141 multidimensional->unimport
142 if $extra_load_states{multidimensional};
143 bareword::filehandles->unimport
144 if $extra_load_states{'bareword::filehandles'};
148 our @V2_NONFATAL = grep { exists $warnings::Offsets{$_} } (
149 'exec', # not safe to catch
150 'recursion', # will be caught by other mechanisms
151 'internal', # not safe to catch
152 'malloc', # not safe to catch
153 'newline', # stat on nonexistent file with a newline in it
154 'experimental', # no reason for these to be fatal
155 'deprecated', # unfortunately can't make these fatal
156 'portable', # everything worked fine here, just may not elsewhere
158 our @V2_DISABLE = grep { exists $warnings::Offsets{$_} } (
159 'once' # triggers inconsistently, can't be fatalized
163 my ($class, $opts) = @_;
166 warnings->import(FATAL => @WARNING_CATEGORIES);
167 warnings->unimport(FATAL => @V2_NONFATAL);
168 warnings->import(@V2_NONFATAL);
169 warnings->unimport(@V2_DISABLE);
171 if (_want_extra($opts->{file})) {
172 _load_extras(qw(indirect multidimensional bareword::filehandles));
173 indirect->unimport(':fatal')
174 if $extra_load_states{indirect};
175 multidimensional->unimport
176 if $extra_load_states{multidimensional};
177 bareword::filehandles->unimport
178 if $extra_load_states{'bareword::filehandles'};
182 sub _want_extra_env {
183 if (exists $ENV{PERL_STRICTURES_EXTRA}) {
184 if (_PERL_LT_5_8_4 and $ENV{PERL_STRICTURES_EXTRA}) {
185 die 'PERL_STRICTURES_EXTRA checks are not available on perls older'
186 . "than 5.8.4: please unset \$ENV{PERL_STRICTURES_EXTRA}\n";
188 return $ENV{PERL_STRICTURES_EXTRA} ? 1 : 0;
195 my $want_env = _want_extra_env();
197 if defined $want_env;
200 and $file =~ /^(?:t|xt|lib|blib)[\\\/]/
201 and defined $Smells_Like_VCS ? $Smells_Like_VCS
202 : ( $Smells_Like_VCS = !!(
203 -e '.git' || -e '.svn' || -e '.hg' || -e '.bzr'
204 || (-e '../../dist.ini'
205 && (-e '../../.git' || -e '../../.svn' || -e '../../.hg' || -e '../../.bzr' ))
213 foreach my $mod (@extras) {
215 if exists $extra_load_states{$mod};
217 $extra_load_states{$mod} = eval "require $mod; 1;" or do {
220 #work around 5.8 require bug
221 (my $file = $mod) =~ s|::|/|g;
222 delete $INC{"${file}.pm"};
227 my $failed = join ' ', @failed;
228 my $extras = join ' ', @extras;
230 strictures.pm extra testing active but couldn't load all modules. Missing were:
234 Extra testing is auto-enabled in checkouts only, so if you're the author
235 of a strictures-using module you need to run:
239 but these modules are not required by your users.
249 strictures - turn on strict and make most warnings fatal
258 use warnings FATAL => 'all';
259 use warnings NONFATAL => qw(
271 except when called from a file which matches:
273 (caller)[1] =~ /^(?:t|xt|lib|blib)[\\\/]/
275 and when either C<.git>, C<.svn>, C<.hg>, or C<.bzr> is present in the current
276 directory (with the intention of only forcing extra tests on the author side)
277 -- or when C<.git>, C<.svn>, C<.hg>, or C<.bzr> is present two directories up
278 along with C<dist.ini> (which would indicate we are in a C<dzil test> operation,
279 via L<Dist::Zilla>) -- or when the C<PERL_STRICTURES_EXTRA> environment variable
280 is set, in which case it also does the equivalent of
284 no bareword::filehandles;
286 Note that C<PERL_STRICTURES_EXTRA> may at some point add even more tests, with
287 only a minor version increase, but any changes to the effect of C<use
288 strictures> in normal mode will involve a major version bump.
290 If any of the extra testing modules are not present, L<strictures> will
291 complain loudly, once, via C<warn()>, and then shut up. But you really
292 should consider installing them, they're all great anti-footgun tools.
296 I've been writing the equivalent of this module at the top of my code for
297 about a year now. I figured it was time to make it shorter.
299 Things like the importer in C<use Moose> don't help me because they turn
300 warnings on but don't make them fatal -- which from my point of view is
301 useless because I want an exception to tell me my code isn't warnings-clean.
303 Any time I see a warning from my code, that indicates a mistake.
305 Any time my code encounters a mistake, I want a crash -- not spew to STDERR
306 and then unknown (and probably undesired) subsequent behaviour.
308 I also want to ensure that obvious coding mistakes, like indirect object
309 syntax (and not so obvious mistakes that cause things to accidentally compile
310 as such) get caught, but not at the cost of an XS dependency and not at the
311 cost of blowing things up on another machine.
313 Therefore, L<strictures> turns on additional checking, but only when it thinks
314 it's running in a test file in a VCS checkout -- although if this causes
315 undesired behaviour this can be overridden by setting the
316 C<PERL_STRICTURES_EXTRA> environment variable.
318 If additional useful author side checks come to mind, I'll add them to the
319 C<PERL_STRICTURES_EXTRA> code path only -- this will result in a minor version
320 increase (e.g. 1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the
321 mechanism of this code will result in a sub-version increase (e.g. 1.000000 to
324 =head1 CATEGORY SELECTIONS
326 strictures does not enable fatal warnings for all categories.
332 Includes a warning that can cause your program to continue running
333 unintentionally after an internal fork. Not safe to fatalize.
337 Infinite recursion will end up overflowing the stack eventually anyway.
341 Triggers deep within perl, in places that are not safe to trap.
345 Triggers deep within perl, in places that are not safe to trap.
349 Includes a warning for using stat on a valid but suspect filename, ending in a
354 Experimental features are used intentionally.
358 Deprecations will inherently be added to in the future in unexpected ways,
359 so making them fatal won't be reliable.
363 Doesn't indicate an actual problem with the program, only that it may not
364 behave properly if run on a different machine.
368 Can't be fatalized. Also triggers very inconsistently, so we just disable it.
374 Depending on the version of strictures requested, different warnings will be
375 enabled. If no specific version is requested, the current version's behavior
376 will be used. Versions can be requested using perl's standard mechanism:
380 Or, by passing in a C<version> option:
382 use strictures version => 2;
389 use warnings FATAL => 'all';
390 use warnings NONFATAL => qw(
402 # and if in dev mode:
405 no bareword::filehandles;
407 Additionally, any warnings created by modules using L<warnings::register> or
408 C<warnings::register_categories()> will not be fatalized.
415 use warnings FATAL => 'all';
416 # and if in dev mode:
419 no bareword::filehandles;
425 This method does the setup work described above in L</DESCRIPTION>. Optionally
426 accepts a C<version> option to request a specific version's behavior.
430 This method traps the C<< strictures->VERSION(1) >> call produced by a use line
431 with a version number on it and does the version check.
433 =head1 EXTRA TESTING RATIONALE
435 Every so often, somebody complains that they're deploying via C<git pull>
436 and that they don't want L<strictures> to enable itself in this case -- and that
437 setting C<PERL_STRICTURES_EXTRA> to 0 isn't acceptable (additional ways to
438 disable extra testing would be welcome but the discussion never seems to get
441 In order to allow us to skip a couple of stages and get straight to a
442 productive conversation, here's my current rationale for turning the
443 extra testing on via a heuristic:
445 The extra testing is all stuff that only ever blows up at compile time;
446 this is intentional. So the oft-raised concern that it's different code being
447 tested is only sort of the case -- none of the modules involved affect the
448 final optree to my knowledge, so the author gets some additional compile
449 time crashes which he/she then fixes, and the rest of the testing is
450 completely valid for all environments.
452 The point of the extra testing -- especially C<no indirect> -- is to catch
453 mistakes that newbie users won't even realise are mistakes without
458 where foo is an & prototyped sub that you forgot to import -- this is
459 pernicious to track down since all I<seems> fine until it gets called
460 and you get a crash. Worse still, you can fail to have imported it due
461 to a circular require, at which point you have a load order dependent
462 bug which I've seen before now I<only> show up in production due to tiny
463 differences between the production and the development environment. I wrote
464 L<http://shadow.cat/blog/matt-s-trout/indirect-but-still-fatal/> to explain
465 this particular problem before L<strictures> itself existed.
467 As such, in my experience so far L<strictures>' extra testing has
468 I<avoided> production versus development differences, not caused them.
470 Additionally, L<strictures>' policy is very much "try and provide as much
471 protection as possible for newbies -- who won't think about whether there's
472 an option to turn on or not" -- so having only the environment variable
473 is not sufficient to achieve that (I get to explain that you need to add
474 C<use strict> at least once a week on freenode #perl -- newbies sometimes
475 completely skip steps because they don't understand that that step
478 I make no claims that the heuristic is perfect -- it's already been evolved
479 significantly over time, especially for 1.004 where we changed things to
480 ensure it only fires on files in your checkout (rather than L<strictures>-using
481 modules you happened to have installed, which was just silly). However, I
482 hope the above clarifies why a heuristic approach is not only necessary but
483 desirable from a point of view of providing new users with as much safety as
484 possible, and will allow any future discussion on the subject to focus on "how
485 do we minimise annoyance to people deploying from checkouts intentionally".
501 L<bareword::filehandles>
505 =head1 COMMUNITY AND SUPPORT
509 irc.perl.org #toolchain
511 (or bug 'mst' in query on there or freenode)
513 =head2 Git repository
515 Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
517 git clone git://git.shadowcat.co.uk/p5sagit/strictures.git
519 The web interface to the repository is at:
521 http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit/strictures.git
525 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
529 Karen Etheridge (cpan:ETHER) <ether@cpan.org>
531 Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@gmail.com>
533 haarg - Graham Knop (cpan:HAARG) <haarg@haarg.org>
537 Copyright (c) 2010 the strictures L</AUTHOR> and L</CONTRIBUTORS>
542 This library is free software and may be distributed under the same terms