Remove use of caller() in strict.pm, and tighten Safe compartment

[p5sagit/p5-mst-13.2.git] / lib / strict.pm

diff --git a/lib/strict.pm b/lib/strict.pm
index 4e2baa3..d1479ed 100644 (file)
--- a/lib/strict.pm
+++ b/lib/strict.pm
@@ -1,5 +1,40 @@
 package strict;
 
+$strict::VERSION = "1.02";
+
+my %bitmask = (
+refs => 0x00000002,
+subs => 0x00000200,
+vars => 0x00000400
+);
+
+sub bits {
+    my $bits = 0;
+    my @wrong;
+    foreach my $s (@_) {
+       push @wrong, $s unless exists $bitmask{$s};
+        $bits |= $bitmask{$s} || 0;
+    }
+    if (@wrong) {
+        require Carp;
+        Carp::croak("Unknown 'strict' tag(s) '@wrong'");
+    }
+    $bits;
+}
+
+sub import {
+    shift;
+    $^H |= bits(@_ ? @_ : qw(refs subs vars));
+}
+
+sub unimport {
+    shift;
+    $^H &= ~ bits(@_ ? @_ : qw(refs subs vars));
+}
+
+1;
+__END__
+
 =head1 NAME
 
 strict - Perl pragma to restrict unsafe constructs
@@ -34,12 +69,22 @@ use symbolic references (see L<perlref>).
     print $$ref;       # ok
     $ref = "foo";
     print $$ref;       # runtime error; normally ok
+    $file = "STDOUT";
+    print $file "Hi!"; # error; note: no comma after $file
+
+There is one exception to this rule:
+
+    $bar = \&{'foo'};
+    &$bar;
+
+is allowed so that C<goto &$AUTOLOAD> would not break under stricture.
+
 
 =item C<strict vars>
 
 This generates a compile-time error if you access a variable that wasn't
-declared via C<use vars>,
-localized via C<my()> or wasn't fully qualified.  Because this is to avoid
+declared via "our" or C<use vars>,
+localized via C<my()>, or wasn't fully qualified.  Because this is to avoid
 variable suicide problems and subtle dynamic scoping issues, a merely
 local() variable isn't good enough.  See L<perlfunc/my> and
 L<perlfunc/local>.
@@ -50,12 +95,15 @@ L<perlfunc/local>.
     local $foo = 9;     # blows up
 
     package Cinna;
-    use vars qw/ $bar /;       # Declares $bar in current package
+    our $bar;                  # Declares $bar in current package
     $bar = 'HgS';              # ok, global declared via pragma
 
 The local() generated a compile-time error because you just touched a global
 name without fully qualifying it.
 
+Because of their special use by sort(), the variables $a and $b are
+exempted from this check.
+
 =item C<strict subs>
 
 This disables the poetry optimization, generating a compile-time error if
@@ -74,23 +122,4 @@ appears in curly braces or on the left hand side of the "=E<gt>" symbol.
 
 See L<perlmodlib/Pragmatic Modules>.
 
-
 =cut
-
-sub bits {
-    my $bits = 0;
-    foreach my $s (@_){ $bits |= $bitmask{$s} || 0; };
-    $bits;
-}
-
-sub import {
-    shift;
-    $^H |= bits(@_ ? @_ : qw(refs subs vars));
-}
-
-sub unimport {
-    shift;
-    $^H &= ~ bits(@_ ? @_ : qw(refs subs vars));
-}
-
-1;