1 # -*- buffer-read-only: t -*-
2 # !!!!!!! DO NOT EDIT THIS FILE !!!!!!!
3 # This file is built by regen/warnings.pl.
4 # Any changes made here will be lost!
10 # Verify that we're called correctly so that warnings will work.
12 unless ( __FILE__ =~ /(^|[\/\\])\Q${\__PACKAGE__}\E\.pmc?$/ ) {
13 my (undef, $f, $l) = caller;
14 die("Incorrect use of pragma '${\__PACKAGE__}' at $f line $l.\n");
19 warnings - Perl pragma to control optional warnings
29 use warnings::register;
30 if (warnings::enabled()) {
31 warnings::warn("some warning");
34 if (warnings::enabled("void")) {
35 warnings::warn("void", "some warning");
38 if (warnings::enabled($object)) {
39 warnings::warn($object, "some warning");
42 warnings::warnif("some warning");
43 warnings::warnif("void", "some warning");
44 warnings::warnif($object, "some warning");
48 The C<warnings> pragma gives control over which warnings are enabled in
49 which parts of a Perl program. It's a more flexible alternative for
50 both the command line flag B<-w> and the equivalent Perl variable,
53 This pragma works just like the C<strict> pragma.
54 This means that the scope of the warning pragma is limited to the
55 enclosing block. It also means that the pragma setting will not
56 leak across files (via C<use>, C<require> or C<do>). This allows
57 authors to independently define the degree of warning checks that will
58 be applied to their module.
60 By default, optional warnings are disabled, so any legacy code that
61 doesn't attempt to control the warnings will work unchanged.
63 All warnings are enabled in a block by either of these:
68 Similarly all warnings are disabled in a block by either of these:
73 For example, consider the code below:
83 The code in the enclosing block has warnings enabled, but the inner
84 block has them disabled. In this case that means the assignment to the
85 scalar C<$c> will trip the C<"Scalar value @a[0] better written as $a[0]">
86 warning, but the assignment to the scalar C<$b> will not.
88 =head2 Default Warnings and Optional Warnings
90 Before the introduction of lexical warnings, Perl had two classes of
91 warnings: mandatory and optional.
93 As its name suggests, if your code tripped a mandatory warning, you
94 would get a warning whether you wanted it or not.
95 For example, the code below would always produce an C<"isn't numeric">
96 warning about the "2:".
100 With the introduction of lexical warnings, mandatory warnings now become
101 I<default> warnings. The difference is that although the previously
102 mandatory warnings are still enabled by default, they can then be
103 subsequently enabled or disabled with the lexical warning pragma. For
104 example, in the code below, an C<"isn't numeric"> warning will only
105 be reported for the C<$a> variable.
111 Note that neither the B<-w> flag or the C<$^W> can be used to
112 disable/enable default warnings. They are still mandatory in this case.
114 =head2 What's wrong with B<-w> and C<$^W>
116 Although very useful, the big problem with using B<-w> on the command
117 line to enable warnings is that it is all or nothing. Take the typical
118 scenario when you are writing a Perl program. Parts of the code you
119 will write yourself, but it's very likely that you will make use of
120 pre-written Perl modules. If you use the B<-w> flag in this case, you
121 end up enabling warnings in pieces of code that you haven't written.
123 Similarly, using C<$^W> to either disable or enable blocks of code is
124 fundamentally flawed. For a start, say you want to disable warnings in
125 a block of code. You might expect this to be enough to do the trick:
133 When this code is run with the B<-w> flag, a warning will be produced
134 for the C<$a> line: C<"Reversed += operator">.
136 The problem is that Perl has both compile-time and run-time warnings. To
137 disable compile-time warnings you need to rewrite the code like this:
145 The other big problem with C<$^W> is the way you can inadvertently
146 change the warning setting in unexpected places in your code. For example,
147 when the code below is run (without the B<-w> flag), the second call
148 to C<doit> will trip a C<"Use of uninitialized value"> warning, whereas
163 This is a side-effect of C<$^W> being dynamically scoped.
165 Lexical warnings get around these limitations by allowing finer control
166 over where warnings can or can't be tripped.
168 =head2 Controlling Warnings from the Command Line
170 There are three Command Line flags that can be used to control when
171 warnings are (or aren't) produced:
178 This is the existing flag. If the lexical warnings pragma is B<not>
179 used in any of you code, or any of the modules that you use, this flag
180 will enable warnings everywhere. See L<Backward Compatibility> for
181 details of how this flag interacts with lexical warnings.
186 If the B<-W> flag is used on the command line, it will enable all warnings
187 throughout the program regardless of whether warnings were disabled
188 locally using C<no warnings> or C<$^W =0>.
189 This includes all files that get
190 included via C<use>, C<require> or C<do>.
191 Think of it as the Perl equivalent of the "lint" command.
196 Does the exact opposite to the B<-W> flag, i.e. it disables all warnings.
200 =head2 Backward Compatibility
202 If you are used to working with a version of Perl prior to the
203 introduction of lexically scoped warnings, or have code that uses both
204 lexical warnings and C<$^W>, this section will describe how they interact.
206 How Lexical Warnings interact with B<-w>/C<$^W>:
212 If none of the three command line flags (B<-w>, B<-W> or B<-X>) that
213 control warnings is used and neither C<$^W> nor the C<warnings> pragma
214 are used, then default warnings will be enabled and optional warnings
216 This means that legacy code that doesn't attempt to control the warnings
221 The B<-w> flag just sets the global C<$^W> variable as in 5.005. This
222 means that any legacy code that currently relies on manipulating C<$^W>
223 to control warning behavior will still work as is.
227 Apart from now being a boolean, the C<$^W> variable operates in exactly
228 the same horrible uncontrolled global way, except that it cannot
229 disable/enable default warnings.
233 If a piece of code is under the control of the C<warnings> pragma,
234 both the C<$^W> variable and the B<-w> flag will be ignored for the
235 scope of the lexical warning.
239 The only way to override a lexical warnings setting is with the B<-W>
240 or B<-X> command line flags.
244 The combined effect of 3 & 4 is that it will allow code which uses
245 the C<warnings> pragma to control the warning behavior of $^W-type
246 code (using a C<local $^W=0>) if it really wants to, but not vice-versa.
248 =head2 Category Hierarchy
249 X<warning, categories>
251 A hierarchy of "categories" have been defined to allow groups of warnings
252 to be enabled/disabled in isolation.
254 The current hierarchy is:
266 | +- experimental::autoderef
268 | +- experimental::lexical_subs
270 | +- experimental::lexical_topic
272 | +- experimental::postderef
274 | +- experimental::regex_sets
276 | +- experimental::signatures
278 | +- experimental::smartmatch
376 Just like the "strict" pragma any of these categories can be combined
378 use warnings qw(void redefine);
379 no warnings qw(io syntax untie);
381 Also like the "strict" pragma, if there is more than one instance of the
382 C<warnings> pragma in a given scope the cumulative effect is additive.
384 use warnings qw(void); # only "void" warnings enabled
386 use warnings qw(io); # only "void" & "io" warnings enabled
388 no warnings qw(void); # only "io" warnings enabled
390 To determine which category a specific warning has been assigned to see
393 Note: Before Perl 5.8.0, the lexical warnings category "deprecated" was a
394 sub-category of the "syntax" category. It is now a top-level category
397 =head2 Fatal Warnings
400 The presence of the word "FATAL" in the category list will escalate any
401 warnings detected from the categories specified in the lexical scope
402 into fatal errors. In the code below, the use of C<time>, C<length>
403 and C<join> can all produce a C<"Useless use of xxx in void context">
411 use warnings FATAL => qw(void);
419 When run it produces this output
421 Useless use of time in void context at fatal line 3.
422 Useless use of length in void context at fatal line 7.
424 The scope where C<length> is used has escalated the C<void> warnings
425 category into a fatal error, so the program terminates immediately when it
426 encounters the warning.
428 To explicitly turn off a "FATAL" warning you just disable the warning
429 it is associated with. So, for example, to disable the "void" warning
430 in the example above, either of these will do the trick:
432 no warnings qw(void);
433 no warnings FATAL => qw(void);
435 If you want to downgrade a warning that has been escalated into a fatal
436 error back to a normal warning, you can use the "NONFATAL" keyword. For
437 example, the code below will promote all warnings into fatal errors,
438 except for those in the "syntax" category.
440 use warnings FATAL => 'all', NONFATAL => 'syntax';
442 As of Perl 5.20, instead of C<< use warnings FATAL => 'all'; >> you can
445 use v5.20; # Perl 5.20 or greater is required for the following
446 use warnings 'FATAL'; # short form of "use warnings FATAL => 'all';"
448 If you want your program to be compatible with versions of Perl before
449 5.20, you must use C<< use warnings FATAL => 'all'; >> instead. (In
450 previous versions of Perl, the behavior of the statements
451 C<< use warnings 'FATAL'; >>, C<< use warnings 'NONFATAL'; >> and
452 C<< no warnings 'FATAL'; >> was unspecified; they did not behave as if
453 they included the C<< => 'all' >> portion. As of 5.20, they do.)
455 B<NOTE:> Users of FATAL warnings, especially
456 those using C<< FATAL => 'all' >>
457 should be fully aware that they are risking future portability of their
458 programs by doing so. Perl makes absolutely no commitments to not
459 introduce new warnings, or warnings categories in the future, and indeed
460 we explicitly reserve the right to do so. Code that may not warn now may
461 warn in a future release of Perl if the Perl5 development team deems it
462 in the best interests of the community to do so. Should code using FATAL
463 warnings break due to the introduction of a new warning we will NOT
464 consider it an incompatible change. Users of FATAL warnings should take
465 special caution during upgrades to check to see if their code triggers
466 any new warnings and should pay particular attention to the fine print of
467 the documentation of the features they use to ensure they do not exploit
468 features that are documented as risky, deprecated, or unspecified, or where
469 the documentation says "so don't do that", or anything with the same sense
470 and spirit. Use of such features in combination with FATAL warnings is
471 ENTIRELY AT THE USER'S RISK.
473 =head2 Reporting Warnings from a Module
474 X<warning, reporting> X<warning, registering>
476 The C<warnings> pragma provides a number of functions that are useful for
477 module authors. These are used when you want to report a module-specific
478 warning to a calling module has enabled warnings via the C<warnings>
481 Consider the module C<MyMod::Abc> below.
485 use warnings::register;
489 if ($path !~ m#^/#) {
490 warnings::warn("changing relative path to /var/abc")
491 if warnings::enabled();
492 $path = "/var/abc/$path";
498 The call to C<warnings::register> will create a new warnings category
499 called "MyMod::Abc", i.e. the new category name matches the current
500 package name. The C<open> function in the module will display a warning
501 message if it gets given a relative path as a parameter. This warnings
502 will only be displayed if the code that uses C<MyMod::Abc> has actually
503 enabled them with the C<warnings> pragma like below.
506 use warnings 'MyMod::Abc';
508 abc::open("../fred.txt");
510 It is also possible to test whether the pre-defined warnings categories are
511 set in the calling module with the C<warnings::enabled> function. Consider
512 this snippet of code:
517 warnings::warnif("deprecated",
518 "open is deprecated, use new instead");
526 The function C<open> has been deprecated, so code has been included to
527 display a warning message whenever the calling module has (at least) the
528 "deprecated" warnings category enabled. Something like this, say.
530 use warnings 'deprecated';
533 MyMod::Abc::open($filename);
535 Either the C<warnings::warn> or C<warnings::warnif> function should be
536 used to actually display the warnings message. This is because they can
537 make use of the feature that allows warnings to be escalated into fatal
538 errors. So in this case
541 use warnings FATAL => 'MyMod::Abc';
543 MyMod::Abc::open('../fred.txt');
545 the C<warnings::warnif> function will detect this and die after
546 displaying the warning message.
548 The three warnings functions, C<warnings::warn>, C<warnings::warnif>
549 and C<warnings::enabled> can optionally take an object reference in place
550 of a category name. In this case the functions will use the class name
551 of the object as the warnings category.
553 Consider this example:
558 use warnings::register;
571 if ($value % 2 && warnings::enabled($self))
572 { warnings::warn($self, "Odd numbers are unsafe") }
579 $self->check($value);
587 use warnings::register;
589 our @ISA = qw( Original );
599 The code below makes use of both modules, but it only enables warnings from
604 use warnings 'Derived';
605 my $a = Original->new();
607 my $b = Derived->new();
610 When this code is run only the C<Derived> object, C<$b>, will generate
613 Odd numbers are unsafe at main.pl line 7
615 Notice also that the warning is reported at the line where the object is first
618 When registering new categories of warning, you can supply more names to
619 warnings::register like this:
622 use warnings::register qw(format precision);
626 warnings::warnif('MyModule::format', '...');
632 =item use warnings::register
634 Creates a new warnings category with the same name as the package where
635 the call to the pragma is used.
637 =item warnings::enabled()
639 Use the warnings category with the same name as the current package.
641 Return TRUE if that warnings category is enabled in the calling module.
642 Otherwise returns FALSE.
644 =item warnings::enabled($category)
646 Return TRUE if the warnings category, C<$category>, is enabled in the
648 Otherwise returns FALSE.
650 =item warnings::enabled($object)
652 Use the name of the class for the object reference, C<$object>, as the
655 Return TRUE if that warnings category is enabled in the first scope
656 where the object is used.
657 Otherwise returns FALSE.
659 =item warnings::fatal_enabled()
661 Return TRUE if the warnings category with the same name as the current
662 package has been set to FATAL in the calling module.
663 Otherwise returns FALSE.
665 =item warnings::fatal_enabled($category)
667 Return TRUE if the warnings category C<$category> has been set to FATAL in
669 Otherwise returns FALSE.
671 =item warnings::fatal_enabled($object)
673 Use the name of the class for the object reference, C<$object>, as the
676 Return TRUE if that warnings category has been set to FATAL in the first
677 scope where the object is used.
678 Otherwise returns FALSE.
680 =item warnings::warn($message)
682 Print C<$message> to STDERR.
684 Use the warnings category with the same name as the current package.
686 If that warnings category has been set to "FATAL" in the calling module
687 then die. Otherwise return.
689 =item warnings::warn($category, $message)
691 Print C<$message> to STDERR.
693 If the warnings category, C<$category>, has been set to "FATAL" in the
694 calling module then die. Otherwise return.
696 =item warnings::warn($object, $message)
698 Print C<$message> to STDERR.
700 Use the name of the class for the object reference, C<$object>, as the
703 If that warnings category has been set to "FATAL" in the scope where C<$object>
704 is first used then die. Otherwise return.
707 =item warnings::warnif($message)
711 if (warnings::enabled())
712 { warnings::warn($message) }
714 =item warnings::warnif($category, $message)
718 if (warnings::enabled($category))
719 { warnings::warn($category, $message) }
721 =item warnings::warnif($object, $message)
725 if (warnings::enabled($object))
726 { warnings::warn($object, $message) }
728 =item warnings::register_categories(@names)
730 This registers warning categories for the given names and is primarily for
731 use by the warnings::register pragma.
735 See also L<perlmodlib/Pragmatic Modules> and L<perldiag>.
741 # Warnings Categories added in Perl 5.008
784 'uninitialized' => 82,
790 # Warnings Categories added in Perl 5.011
793 'illegalproto' => 94,
795 # Warnings Categories added in Perl 5.013
801 # Warnings Categories added in Perl 5.017
803 'experimental' => 102,
804 'experimental::lexical_subs'=> 104,
805 'experimental::lexical_topic'=> 106,
806 'experimental::regex_sets'=> 108,
807 'experimental::smartmatch'=> 110,
809 # Warnings Categories added in Perl 5.019
811 'experimental::autoderef'=> 112,
812 'experimental::postderef'=> 114,
813 'experimental::signatures'=> 116,
818 'all' => "\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55", # [0..59]
819 'ambiguous' => "\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00", # [29]
820 'bareword' => "\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00", # [30]
821 'closed' => "\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [6]
822 'closure' => "\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [1]
823 'debugging' => "\x00\x00\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [22]
824 'deprecated' => "\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [2]
825 'digit' => "\x00\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00", # [31]
826 'exec' => "\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [7]
827 'exiting' => "\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [3]
828 'experimental' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40\x55\x15", # [51..58]
829 'experimental::autoderef'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01", # [56]
830 'experimental::lexical_subs'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00", # [52]
831 'experimental::lexical_topic'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00", # [53]
832 'experimental::postderef'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04", # [57]
833 'experimental::regex_sets'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00", # [54]
834 'experimental::signatures'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10", # [58]
835 'experimental::smartmatch'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40\x00", # [55]
836 'glob' => "\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [4]
837 'illegalproto' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00", # [47]
838 'imprecision' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00", # [46]
839 'inplace' => "\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [23]
840 'internal' => "\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00", # [24]
841 'io' => "\x00\x54\x55\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40", # [5..11,59]
842 'layer' => "\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [8]
843 'malloc' => "\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00", # [25]
844 'misc' => "\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [12]
845 'newline' => "\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [9]
846 'non_unicode' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00", # [48]
847 'nonchar' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00", # [49]
848 'numeric' => "\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [13]
849 'once' => "\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [14]
850 'overflow' => "\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [15]
851 'pack' => "\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [16]
852 'parenthesis' => "\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00", # [32]
853 'pipe' => "\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [10]
854 'portable' => "\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [17]
855 'precedence' => "\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00", # [33]
856 'printf' => "\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00", # [34]
857 'prototype' => "\x00\x00\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00", # [35]
858 'qw' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00", # [36]
859 'recursion' => "\x00\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [18]
860 'redefine' => "\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [19]
861 'regexp' => "\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [20]
862 'reserved' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00", # [37]
863 'semicolon' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\x00\x00", # [38]
864 'severe' => "\x00\x00\x00\x00\x00\x54\x05\x00\x00\x00\x00\x00\x00\x00\x00", # [21..25]
865 'signal' => "\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00", # [26]
866 'substr' => "\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00", # [27]
867 'surrogate' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00", # [50]
868 'syntax' => "\x00\x00\x00\x00\x00\x00\x00\x55\x55\x15\x00\x40\x00\x00\x00", # [28..38,47]
869 'syscalls' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40", # [59]
870 'taint' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00", # [39]
871 'threads' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00", # [40]
872 'uninitialized' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00", # [41]
873 'unopened' => "\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [11]
874 'unpack' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\x00", # [42]
875 'untie' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00", # [43]
876 'utf8' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x15\x00\x00", # [44,48..50]
877 'void' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00", # [45]
881 'all' => "\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa", # [0..59]
882 'ambiguous' => "\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00", # [29]
883 'bareword' => "\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00", # [30]
884 'closed' => "\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [6]
885 'closure' => "\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [1]
886 'debugging' => "\x00\x00\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [22]
887 'deprecated' => "\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [2]
888 'digit' => "\x00\x00\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00", # [31]
889 'exec' => "\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [7]
890 'exiting' => "\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [3]
891 'experimental' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80\xaa\x2a", # [51..58]
892 'experimental::autoderef'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02", # [56]
893 'experimental::lexical_subs'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00", # [52]
894 'experimental::lexical_topic'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00", # [53]
895 'experimental::postderef'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08", # [57]
896 'experimental::regex_sets'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00", # [54]
897 'experimental::signatures'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20", # [58]
898 'experimental::smartmatch'=> "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80\x00", # [55]
899 'glob' => "\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [4]
900 'illegalproto' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80\x00\x00\x00", # [47]
901 'imprecision' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00", # [46]
902 'inplace' => "\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [23]
903 'internal' => "\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00", # [24]
904 'io' => "\x00\xa8\xaa\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80", # [5..11,59]
905 'layer' => "\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [8]
906 'malloc' => "\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00", # [25]
907 'misc' => "\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [12]
908 'newline' => "\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [9]
909 'non_unicode' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00", # [48]
910 'nonchar' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00", # [49]
911 'numeric' => "\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [13]
912 'once' => "\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [14]
913 'overflow' => "\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [15]
914 'pack' => "\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [16]
915 'parenthesis' => "\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00", # [32]
916 'pipe' => "\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [10]
917 'portable' => "\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [17]
918 'precedence' => "\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00", # [33]
919 'printf' => "\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00", # [34]
920 'prototype' => "\x00\x00\x00\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00", # [35]
921 'qw' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00", # [36]
922 'recursion' => "\x00\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [18]
923 'redefine' => "\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [19]
924 'regexp' => "\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [20]
925 'reserved' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00", # [37]
926 'semicolon' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x00\x00", # [38]
927 'severe' => "\x00\x00\x00\x00\x00\xa8\x0a\x00\x00\x00\x00\x00\x00\x00\x00", # [21..25]
928 'signal' => "\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00", # [26]
929 'substr' => "\x00\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00", # [27]
930 'surrogate' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00", # [50]
931 'syntax' => "\x00\x00\x00\x00\x00\x00\x00\xaa\xaa\x2a\x00\x80\x00\x00\x00", # [28..38,47]
932 'syscalls' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80", # [59]
933 'taint' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00", # [39]
934 'threads' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00", # [40]
935 'uninitialized' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00", # [41]
936 'unopened' => "\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", # [11]
937 'unpack' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x20\x00\x00\x00\x00", # [42]
938 'untie' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00", # [43]
939 'utf8' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x2a\x00\x00", # [44,48..50]
940 'void' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00", # [45]
943 $NONE = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
944 $DEFAULT = "\x10\x01\x00\x00\x00\x50\x04\x00\x00\x00\x00\x00\x00\x55\x15", # [2,56,52,53,57,54,58,55,4,22,23,25]
948 $All = "" ; vec($All, $Offsets{'all'}, 2) = 3 ;
952 require Carp; # this initializes %CarpInternal
953 local $Carp::CarpInternal{'warnings'};
954 delete $Carp::CarpInternal{'warnings'};
964 foreach my $word ( @_ ) {
965 if ($word eq 'FATAL') {
969 elsif ($word eq 'NONFATAL') {
973 elsif ($catmask = $Bits{$word}) {
975 $mask |= $DeadBits{$word} if $fatal ;
976 $mask &= ~($DeadBits{$word}|$All) if $no_fatal ;
979 { Croaker("Unknown warnings category '$word'")}
987 # called from B::Deparse.pm
988 push @_, 'all' unless @_ ;
989 return _bits(undef, @_) ;
996 my $mask = ${^WARNING_BITS} // ($^W ? $Bits{all} : $DEFAULT) ;
998 if (vec($mask, $Offsets{'all'}, 1)) {
999 $mask |= $Bits{'all'} ;
1000 $mask |= $DeadBits{'all'} if vec($mask, $Offsets{'all'}+1, 1);
1003 # append 'all' when implied (after a lone "FATAL" or "NONFATAL")
1004 push @_, 'all' if @_==1 && ( $_[0] eq 'FATAL' || $_[0] eq 'NONFATAL' );
1006 # Empty @_ is equivalent to @_ = 'all' ;
1007 ${^WARNING_BITS} = @_ ? _bits($mask, @_) : $mask | $Bits{all} ;
1015 my $mask = ${^WARNING_BITS} // ($^W ? $Bits{all} : $DEFAULT) ;
1017 if (vec($mask, $Offsets{'all'}, 1)) {
1018 $mask |= $Bits{'all'} ;
1019 $mask |= $DeadBits{'all'} if vec($mask, $Offsets{'all'}+1, 1);
1022 # append 'all' when implied (empty import list or after a lone "FATAL")
1023 push @_, 'all' if !@_ || @_==1 && $_[0] eq 'FATAL';
1025 foreach my $word ( @_ ) {
1026 if ($word eq 'FATAL') {
1029 elsif ($catmask = $Bits{$word}) {
1030 $mask &= ~($catmask | $DeadBits{$word} | $All);
1033 { Croaker("Unknown warnings category '$word'")}
1036 ${^WARNING_BITS} = $mask ;
1039 my %builtin_type; @builtin_type{qw(SCALAR ARRAY HASH CODE REF GLOB LVALUE Regexp)} = ();
1041 sub MESSAGE () { 4 };
1043 sub NORMAL () { 1 };
1051 my $has_message = $wanted & MESSAGE;
1053 unless (@_ == 1 || @_ == ($has_message ? 2 : 0)) {
1054 my $sub = (caller 1)[3];
1055 my $syntax = $has_message ? "[category,] 'message'" : '[category]';
1056 Croaker("Usage: $sub($syntax)");
1059 my $message = pop if $has_message;
1062 # check the category supplied.
1064 if (my $type = ref $category) {
1065 Croaker("not an object")
1066 if exists $builtin_type{$type};
1070 $offset = $Offsets{$category};
1071 Croaker("Unknown warnings category '$category'")
1072 unless defined $offset;
1075 $category = (caller(1))[0] ;
1076 $offset = $Offsets{$category};
1077 Croaker("package '$category' not registered for warnings")
1078 unless defined $offset ;
1086 while (do { { package DB; $pkg = (caller($i++))[0] } } ) {
1087 last unless @DB::args && $DB::args[0] =~ /^$category=/ ;
1092 $i = _error_loc(); # see where Carp will allocate the error
1095 # Default to 0 if caller returns nothing. Default to $DEFAULT if it
1096 # explicitly returns undef.
1097 my(@callers_bitmask) = (caller($i))[9] ;
1098 my $callers_bitmask =
1099 @callers_bitmask ? $callers_bitmask[0] // $DEFAULT : 0 ;
1102 foreach my $type (FATAL, NORMAL) {
1103 next unless $wanted & $type;
1105 push @results, (vec($callers_bitmask, $offset + $type - 1, 1) ||
1106 vec($callers_bitmask, $Offsets{'all'} + $type - 1, 1));
1109 # &enabled and &fatal_enabled
1110 return $results[0] unless $has_message;
1112 # &warnif, and the category is neither enabled as warning nor as fatal
1113 return if $wanted == (NORMAL | FATAL | MESSAGE)
1114 && !($results[0] || $results[1]);
1117 Carp::croak($message) if $results[0];
1118 # will always get here for &warn. will only get here for &warnif if the
1119 # category is enabled
1120 Carp::carp($message);
1128 vec($mask, $bit, 1) = 1;
1132 sub register_categories
1136 for my $name (@names) {
1137 if (! defined $Bits{$name}) {
1138 $Bits{$name} = _mkMask($LAST_BIT);
1139 vec($Bits{'all'}, $LAST_BIT, 1) = 1;
1140 $Offsets{$name} = $LAST_BIT ++;
1141 foreach my $k (keys %Bits) {
1142 vec($Bits{$k}, $LAST_BIT, 1) = 0;
1144 $DeadBits{$name} = _mkMask($LAST_BIT);
1145 vec($DeadBits{'all'}, $LAST_BIT++, 1) = 1;
1152 goto &Carp::short_error_loc; # don't introduce another stack frame
1157 return __chk(NORMAL, @_);
1162 return __chk(FATAL, @_);
1167 return __chk(FATAL | MESSAGE, @_);
1172 return __chk(NORMAL | FATAL | MESSAGE, @_);
1175 # These are not part of any public interface, so we can delete them to save
1177 delete @warnings::{qw(NORMAL FATAL MESSAGE)};