View file File name : strictures.pm Content :package strictures; use strict; use warnings FATAL => 'all'; BEGIN { *_PERL_LT_5_8_4 = ("$]" < 5.008004) ? sub(){1} : sub(){0}; # goto &UNIVERSAL::VERSION usually works on 5.8, but fails on some ARM # machines. Seems to always work on 5.10 though. *_CAN_GOTO_VERSION = ("$]" >= 5.010000) ? sub(){1} : sub(){0}; } our $VERSION = '2.000006'; $VERSION =~ tr/_//d; our @WARNING_CATEGORIES = grep { exists $warnings::Offsets{$_} } qw( closure chmod deprecated exiting experimental experimental::alpha_assertions experimental::autoderef experimental::bitwise experimental::const_attr experimental::declared_refs experimental::lexical_subs experimental::lexical_topic experimental::postderef experimental::private_use experimental::re_strict experimental::refaliasing experimental::regex_sets experimental::script_run experimental::signatures experimental::smartmatch experimental::win32_perlio glob imprecision io closed exec layer newline pipe syscalls unopened locale misc missing numeric once overflow pack portable recursion redefine redundant regexp severe debugging inplace internal malloc shadow signal substr syntax ambiguous bareword digit illegalproto parenthesis precedence printf prototype qw reserved semicolon taint threads uninitialized umask unpack untie utf8 non_unicode nonchar surrogate void void_unusual y2k ); sub VERSION { { no warnings; local $@; if (defined $_[1] && eval { &UNIVERSAL::VERSION; 1}) { $^H |= 0x20000 unless _PERL_LT_5_8_4; $^H{strictures_enable} = int $_[1]; } } _CAN_GOTO_VERSION ? goto &UNIVERSAL::VERSION : &UNIVERSAL::VERSION; } our %extra_load_states; our $Smells_Like_VCS; sub import { my $class = shift; my %opts = @_ == 1 ? %{$_[0]} : @_; if (!exists $opts{version}) { $opts{version} = exists $^H{strictures_enable} ? delete $^H{strictures_enable} : int $VERSION; } $opts{file} = (caller)[1]; $class->_enable(\%opts); } sub _enable { my ($class, $opts) = @_; my $version = $opts->{version}; $version = 'undef' if !defined $version; my $method = "_enable_$version"; if (!$class->can($method)) { require Carp; Carp::croak("Major version specified as $version - not supported!"); } $class->$method($opts); } sub _enable_1 { my ($class, $opts) = @_; strict->import; warnings->import(FATAL => 'all'); if (_want_extra($opts->{file})) { _load_extras(qw(indirect multidimensional bareword::filehandles)); indirect->unimport(':fatal') if $extra_load_states{indirect}; multidimensional->unimport if $extra_load_states{multidimensional}; bareword::filehandles->unimport if $extra_load_states{'bareword::filehandles'}; } } our @V2_NONFATAL = grep { exists $warnings::Offsets{$_} } ( 'exec', # not safe to catch 'recursion', # will be caught by other mechanisms 'internal', # not safe to catch 'malloc', # not safe to catch 'newline', # stat on nonexistent file with a newline in it 'experimental', # no reason for these to be fatal 'deprecated', # unfortunately can't make these fatal 'portable', # everything worked fine here, just may not elsewhere ); our @V2_DISABLE = grep { exists $warnings::Offsets{$_} } ( 'once' # triggers inconsistently, can't be fatalized ); sub _enable_2 { my ($class, $opts) = @_; strict->import; warnings->import; warnings->import(FATAL => @WARNING_CATEGORIES); warnings->unimport(FATAL => @V2_NONFATAL); warnings->import(@V2_NONFATAL); warnings->unimport(@V2_DISABLE); if (_want_extra($opts->{file})) { _load_extras(qw(indirect multidimensional bareword::filehandles)); indirect->unimport(':fatal') if $extra_load_states{indirect}; multidimensional->unimport if $extra_load_states{multidimensional}; bareword::filehandles->unimport if $extra_load_states{'bareword::filehandles'}; } } sub _want_extra_env { if (exists $ENV{PERL_STRICTURES_EXTRA}) { if (_PERL_LT_5_8_4 and $ENV{PERL_STRICTURES_EXTRA}) { die 'PERL_STRICTURES_EXTRA checks are not available on perls older' . "than 5.8.4: please unset \$ENV{PERL_STRICTURES_EXTRA}\n"; } return $ENV{PERL_STRICTURES_EXTRA} ? 1 : 0; } return undef; } sub _want_extra { my $file = shift; my $want_env = _want_extra_env(); return $want_env if defined $want_env; return ( !_PERL_LT_5_8_4 and $file =~ /^(?:t|xt|lib|blib)[\\\/]/ and defined $Smells_Like_VCS ? $Smells_Like_VCS : ( $Smells_Like_VCS = !!( -e '.git' || -e '.svn' || -e '.hg' || -e '.bzr' || (-e '../../dist.ini' && (-e '../../.git' || -e '../../.svn' || -e '../../.hg' || -e '../../.bzr' )) )) ); } sub _load_extras { my @extras = @_; my @failed; foreach my $mod (@extras) { next if exists $extra_load_states{$mod}; $extra_load_states{$mod} = eval "require $mod; 1;" or do { push @failed, $mod; #work around 5.8 require bug (my $file = $mod) =~ s|::|/|g; delete $INC{"${file}.pm"}; }; } if (@failed) { my $failed = join ' ', @failed; my $extras = join ' ', @extras; print STDERR <<EOE; strictures.pm extra testing active but couldn't load all modules. Missing were: $failed Extra testing is auto-enabled in checkouts only, so if you're the author of a strictures-using module you need to run: cpan $extras but these modules are not required by your users. EOE } } 1; __END__ =head1 NAME strictures - Turn on strict and make most warnings fatal =head1 SYNOPSIS use strictures 2; is equivalent to use strict; use warnings FATAL => 'all'; use warnings NONFATAL => qw( exec recursion internal malloc newline experimental deprecated portable ); no warnings 'once'; except when called from a file which matches: (caller)[1] =~ /^(?:t|xt|lib|blib)[\\\/]/ and when either C<.git>, C<.svn>, C<.hg>, or C<.bzr> is present in the current directory (with the intention of only forcing extra tests on the author side) -- or when C<.git>, C<.svn>, C<.hg>, or C<.bzr> is present two directories up along with C<dist.ini> (which would indicate we are in a C<dzil test> operation, via L<Dist::Zilla>) -- or when the C<PERL_STRICTURES_EXTRA> environment variable is set, in which case it also does the equivalent of no indirect 'fatal'; no multidimensional; no bareword::filehandles; Note that C<PERL_STRICTURES_EXTRA> may at some point add even more tests, with only a minor version increase, but any changes to the effect of C<use strictures> in normal mode will involve a major version bump. If any of the extra testing modules are not present, L<strictures> will complain loudly, once, via C<warn()>, and then shut up. But you really should consider installing them, they're all great anti-footgun tools. =head1 DESCRIPTION I've been writing the equivalent of this module at the top of my code for about a year now. I figured it was time to make it shorter. Things like the importer in C<use Moose> don't help me because they turn warnings on but don't make them fatal -- which from my point of view is useless because I want an exception to tell me my code isn't warnings-clean. Any time I see a warning from my code, that indicates a mistake. Any time my code encounters a mistake, I want a crash -- not spew to STDERR and then unknown (and probably undesired) subsequent behaviour. I also want to ensure that obvious coding mistakes, like indirect object syntax (and not so obvious mistakes that cause things to accidentally compile as such) get caught, but not at the cost of an XS dependency and not at the cost of blowing things up on another machine. Therefore, L<strictures> turns on additional checking, but only when it thinks it's running in a test file in a VCS checkout -- although if this causes undesired behaviour this can be overridden by setting the C<PERL_STRICTURES_EXTRA> environment variable. If additional useful author side checks come to mind, I'll add them to the C<PERL_STRICTURES_EXTRA> code path only -- this will result in a minor version increase (e.g. 1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the mechanism of this code will result in a sub-version increase (e.g. 1.000000 to 1.000001 (1.0.1)). =head1 CATEGORY SELECTIONS strictures does not enable fatal warnings for all categories. =over 4 =item exec Includes a warning that can cause your program to continue running unintentionally after an internal fork. Not safe to fatalize. =item recursion Infinite recursion will end up overflowing the stack eventually anyway. =item internal Triggers deep within perl, in places that are not safe to trap. =item malloc Triggers deep within perl, in places that are not safe to trap. =item newline Includes a warning for using stat on a valid but suspect filename, ending in a newline. =item experimental Experimental features are used intentionally. =item deprecated Deprecations will inherently be added to in the future in unexpected ways, so making them fatal won't be reliable. =item portable Doesn't indicate an actual problem with the program, only that it may not behave properly if run on a different machine. =item once Can't be fatalized. Also triggers very inconsistently, so we just disable it. =back =head1 VERSIONS Depending on the version of strictures requested, different warnings will be enabled. If no specific version is requested, the current version's behavior will be used. Versions can be requested using perl's standard mechanism: use strictures 2; Or, by passing in a C<version> option: use strictures version => 2; =head2 VERSION 2 Equivalent to: use strict; use warnings FATAL => 'all'; use warnings NONFATAL => qw( exec recursion internal malloc newline experimental deprecated portable ); no warnings 'once'; # and if in dev mode: no indirect 'fatal'; no multidimensional; no bareword::filehandles; Additionally, any warnings created by modules using L<warnings::register> or C<warnings::register_categories()> will not be fatalized. =head2 VERSION 1 Equivalent to: use strict; use warnings FATAL => 'all'; # and if in dev mode: no indirect 'fatal'; no multidimensional; no bareword::filehandles; =head1 METHODS =head2 import This method does the setup work described above in L</DESCRIPTION>. Optionally accepts a C<version> option to request a specific version's behavior. =head2 VERSION This method traps the C<< strictures->VERSION(1) >> call produced by a use line with a version number on it and does the version check. =head1 EXTRA TESTING RATIONALE Every so often, somebody complains that they're deploying via C<git pull> and that they don't want L<strictures> to enable itself in this case -- and that setting C<PERL_STRICTURES_EXTRA> to 0 isn't acceptable (additional ways to disable extra testing would be welcome but the discussion never seems to get that far). In order to allow us to skip a couple of stages and get straight to a productive conversation, here's my current rationale for turning the extra testing on via a heuristic: The extra testing is all stuff that only ever blows up at compile time; this is intentional. So the oft-raised concern that it's different code being tested is only sort of the case -- none of the modules involved affect the final optree to my knowledge, so the author gets some additional compile time crashes which he/she then fixes, and the rest of the testing is completely valid for all environments. The point of the extra testing -- especially C<no indirect> -- is to catch mistakes that newbie users won't even realise are mistakes without help. For example, foo { ... }; where foo is an & prototyped sub that you forgot to import -- this is pernicious to track down since all I<seems> fine until it gets called and you get a crash. Worse still, you can fail to have imported it due to a circular require, at which point you have a load order dependent bug which I've seen before now I<only> show up in production due to tiny differences between the production and the development environment. I wrote L<http://shadow.cat/blog/matt-s-trout/indirect-but-still-fatal/> to explain this particular problem before L<strictures> itself existed. As such, in my experience so far L<strictures>' extra testing has I<avoided> production versus development differences, not caused them. Additionally, L<strictures>' policy is very much "try and provide as much protection as possible for newbies -- who won't think about whether there's an option to turn on or not" -- so having only the environment variable is not sufficient to achieve that (I get to explain that you need to add C<use strict> at least once a week on freenode #perl -- newbies sometimes completely skip steps because they don't understand that that step is important). I make no claims that the heuristic is perfect -- it's already been evolved significantly over time, especially for 1.004 where we changed things to ensure it only fires on files in your checkout (rather than L<strictures>-using modules you happened to have installed, which was just silly). However, I hope the above clarifies why a heuristic approach is not only necessary but desirable from a point of view of providing new users with as much safety as possible, and will allow any future discussion on the subject to focus on "how do we minimise annoyance to people deploying from checkouts intentionally". =head1 SEE ALSO =over 4 =item * L<indirect> =item * L<multidimensional> =item * L<bareword::filehandles> =back =head1 COMMUNITY AND SUPPORT =head2 IRC channel irc.perl.org #toolchain (or bug 'mst' in query on there or freenode) =head2 Git repository Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is: git clone git://git.shadowcat.co.uk/p5sagit/strictures.git The web interface to the repository is at: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit/strictures.git =head1 AUTHOR mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk> =head1 CONTRIBUTORS Karen Etheridge (cpan:ETHER) <ether@cpan.org> Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@gmail.com> haarg - Graham Knop (cpan:HAARG) <haarg@haarg.org> =head1 COPYRIGHT Copyright (c) 2010 the strictures L</AUTHOR> and L</CONTRIBUTORS> as listed above. =head1 LICENSE This library is free software and may be distributed under the same terms as perl itself. =cut