File | C:/usr/lib/strict.pm |
Statements Executed | 28 |
Total Time | 0 seconds |
Calls | P | F | Exclusive Time |
Inclusive Time |
Subroutine |
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2 | 2 | 1 | 0s | 0s | bits | strict::
2 | 2 | 2 | 0s | 0s | import | strict::
1 | 1 | 1 | 0s | 0s | unimport | strict::
Line | Stmts. | Exclusive Time | Avg. | Code |
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1 | package strict; | |||
2 | ||||
3 | 1 | 0s | 0s | $strict::VERSION = "1.03"; |
4 | ||||
5 | 1 | 0s | 0s | my %bitmask = ( |
6 | refs => 0x00000002, | |||
7 | subs => 0x00000200, | |||
8 | vars => 0x00000400 | |||
9 | ); | |||
10 | ||||
11 | sub bits { | |||
12 | 10 | 0s | 0s | my $bits = 0; |
13 | my @wrong; | |||
14 | foreach my $s (@_) { | |||
15 | 8 | 0s | 0s | push @wrong, $s unless exists $bitmask{$s}; |
16 | $bits |= $bitmask{$s} || 0; | |||
17 | } | |||
18 | if (@wrong) { | |||
19 | require Carp; | |||
20 | Carp::croak("Unknown 'strict' tag(s) '@wrong'"); | |||
21 | } | |||
22 | $bits; | |||
23 | } | |||
24 | ||||
25 | 1 | 0s | 0s | my $default_bits = bits(qw(refs subs vars)); # spent 0s making 1 call to strict::bits |
26 | ||||
27 | # spent 0s within strict::import which was called 2 times, avg 0s/call:
# once (0s+0s) at line 30 of C:/usr/lib/B.pm
# once (0s+0s) at line 3 of C:/Dokumente und Einstellungen/Entwicklung/Eigene Dateien/Perl/community/walkoptree.pl | |||
28 | 4 | 0s | 0s | shift; |
29 | $^H |= @_ ? bits(@_) : $default_bits; | |||
30 | } | |||
31 | ||||
32 | # spent 0s within strict::unimport which was called
# once (0s+0s) by B::BEGIN or B::walksymtable at line 237 of C:/usr/lib/B.pm | |||
33 | 2 | 0s | 0s | shift; |
34 | $^H &= ~ (@_ ? bits(@_) : $default_bits); # spent 0s making 1 call to strict::bits | |||
35 | } | |||
36 | ||||
37 | 1 | 0s | 0s | 1; |
38 | __END__ | |||
39 | ||||
40 | =head1 NAME | |||
41 | ||||
42 | strict - Perl pragma to restrict unsafe constructs | |||
43 | ||||
44 | =head1 SYNOPSIS | |||
45 | ||||
46 | use strict; | |||
47 | ||||
48 | use strict "vars"; | |||
49 | use strict "refs"; | |||
50 | use strict "subs"; | |||
51 | ||||
52 | use strict; | |||
53 | no strict "vars"; | |||
54 | ||||
55 | =head1 DESCRIPTION | |||
56 | ||||
57 | If no import list is supplied, all possible restrictions are assumed. | |||
58 | (This is the safest mode to operate in, but is sometimes too strict for | |||
59 | casual programming.) Currently, there are three possible things to be | |||
60 | strict about: "subs", "vars", and "refs". | |||
61 | ||||
62 | =over 6 | |||
63 | ||||
64 | =item C<strict refs> | |||
65 | ||||
66 | This generates a runtime error if you | |||
67 | use symbolic references (see L<perlref>). | |||
68 | ||||
69 | use strict 'refs'; | |||
70 | $ref = \$foo; | |||
71 | print $$ref; # ok | |||
72 | $ref = "foo"; | |||
73 | print $$ref; # runtime error; normally ok | |||
74 | $file = "STDOUT"; | |||
75 | print $file "Hi!"; # error; note: no comma after $file | |||
76 | ||||
77 | There is one exception to this rule: | |||
78 | ||||
79 | $bar = \&{'foo'}; | |||
80 | &$bar; | |||
81 | ||||
82 | is allowed so that C<goto &$AUTOLOAD> would not break under stricture. | |||
83 | ||||
84 | ||||
85 | =item C<strict vars> | |||
86 | ||||
87 | This generates a compile-time error if you access a variable that wasn't | |||
88 | declared via C<our> or C<use vars>, | |||
89 | localized via C<my()>, or wasn't fully qualified. Because this is to avoid | |||
90 | variable suicide problems and subtle dynamic scoping issues, a merely | |||
91 | local() variable isn't good enough. See L<perlfunc/my> and | |||
92 | L<perlfunc/local>. | |||
93 | ||||
94 | use strict 'vars'; | |||
95 | $X::foo = 1; # ok, fully qualified | |||
96 | my $foo = 10; # ok, my() var | |||
97 | local $foo = 9; # blows up | |||
98 | ||||
99 | package Cinna; | |||
100 | our $bar; # Declares $bar in current package | |||
101 | $bar = 'HgS'; # ok, global declared via pragma | |||
102 | ||||
103 | The local() generated a compile-time error because you just touched a global | |||
104 | name without fully qualifying it. | |||
105 | ||||
106 | Because of their special use by sort(), the variables $a and $b are | |||
107 | exempted from this check. | |||
108 | ||||
109 | =item C<strict subs> | |||
110 | ||||
111 | This disables the poetry optimization, generating a compile-time error if | |||
112 | you try to use a bareword identifier that's not a subroutine, unless it | |||
113 | is a simple identifier (no colons) and that it appears in curly braces or | |||
114 | on the left hand side of the C<< => >> symbol. | |||
115 | ||||
116 | use strict 'subs'; | |||
117 | $SIG{PIPE} = Plumber; # blows up | |||
118 | $SIG{PIPE} = "Plumber"; # just fine: quoted string is always ok | |||
119 | $SIG{PIPE} = \&Plumber; # preferred form | |||
120 | ||||
121 | =back | |||
122 | ||||
123 | See L<perlmodlib/Pragmatic Modules>. | |||
124 | ||||
125 | =head1 HISTORY | |||
126 | ||||
127 | C<strict 'subs'>, with Perl 5.6.1, erroneously permitted to use an unquoted | |||
128 | compound identifier (e.g. C<Foo::Bar>) as a hash key (before C<< => >> or | |||
129 | inside curlies), but without forcing it always to a literal string. | |||
130 | ||||
131 | Starting with Perl 5.8.1 strict is strict about its restrictions: | |||
132 | if unknown restrictions are used, the strict pragma will abort with | |||
133 | ||||
134 | Unknown 'strict' tag(s) '...' | |||
135 | ||||
136 | =cut |