3 $strict::VERSION = "1.09";
5 # Verify that we're called correctly so that strictures will work.
6 unless ( __FILE__ =~ /(^|[\/\\])\Q${\__PACKAGE__}\E\.pmc?$/ ) {
7 # Can't use Carp, since Carp uses us!
8 my (undef, $f, $l) = caller;
9 die("Incorrect use of pragma '${\__PACKAGE__}' at $f line $l.\n");
12 my ( %bitmask, %explicit_bitmask );
28 $bits |= $_ for values %bitmask;
30 my $inline_all_bits = $bits;
31 *all_bits = sub () { $inline_all_bits };
34 $bits |= $_ for values %explicit_bitmask;
36 my $inline_all_explicit_bits = $bits;
37 *all_explicit_bits = sub () { $inline_all_explicit_bits };
44 if (exists $bitmask{$s}) {
45 $^H |= $explicit_bitmask{$s};
47 $bits |= $bitmask{$s};
55 Carp::croak("Unknown 'strict' tag(s) '@wrong'");
62 $^H |= @_ ? &bits : all_bits | all_explicit_bits;
73 $^H |= all_explicit_bits;
82 strict - Perl pragma to restrict unsafe constructs
97 If no import list is supplied, all possible restrictions are assumed.
98 (This is the safest mode to operate in, but is sometimes too strict for
99 casual programming.) Currently, there are three possible things to be
100 strict about: "subs", "vars", and "refs".
106 This generates a runtime error if you
107 use symbolic references (see L<perlref>).
113 print $$ref; # runtime error; normally ok
115 print $file "Hi!"; # error; note: no comma after $file
117 There is one exception to this rule:
122 is allowed so that C<goto &$AUTOLOAD> would not break under stricture.
127 This generates a compile-time error if you access a variable that was
128 neither explicitly declared (using any of C<my>, C<our>, C<state>, or C<use
129 vars>) nor fully qualified. (Because this is to avoid variable suicide
130 problems and subtle dynamic scoping issues, a merely C<local> variable isn't
131 good enough.) See L<perlfunc/my>, L<perlfunc/our>, L<perlfunc/state>,
132 L<perlfunc/local>, and L<vars>.
135 $X::foo = 1; # ok, fully qualified
136 my $foo = 10; # ok, my() var
137 local $baz = 9; # blows up, $baz not declared before
140 our $bar; # Declares $bar in current package
141 $bar = 'HgS'; # ok, global declared via pragma
143 The local() generated a compile-time error because you just touched a global
144 name without fully qualifying it.
146 Because of their special use by sort(), the variables $a and $b are
147 exempted from this check.
151 This disables the poetry optimization, generating a compile-time error if
152 you try to use a bareword identifier that's not a subroutine, unless it
153 is a simple identifier (no colons) and that it appears in curly braces or
154 on the left hand side of the C<< => >> symbol.
157 $SIG{PIPE} = Plumber; # blows up
158 $SIG{PIPE} = "Plumber"; # fine: quoted string is always ok
159 $SIG{PIPE} = \&Plumber; # preferred form
163 See L<perlmodlib/Pragmatic Modules>.
167 C<strict 'subs'>, with Perl 5.6.1, erroneously permitted to use an unquoted
168 compound identifier (e.g. C<Foo::Bar>) as a hash key (before C<< => >> or
169 inside curlies), but without forcing it always to a literal string.
171 Starting with Perl 5.8.1 strict is strict about its restrictions:
172 if unknown restrictions are used, the strict pragma will abort with
174 Unknown 'strict' tag(s) '...'
176 As of version 1.04 (Perl 5.10), strict verifies that it is used as
177 "strict" to avoid the dreaded Strict trap on case insensitive file