package re;
-$VERSION = 0.02;
+our $VERSION = 0.05;
=head1 NAME
use re 'taint';
($x) = ($^X =~ /^(.*)$/s); # $x is tainted here
+ $pat = '(?{ $foo = 1 })';
use re 'eval';
- /foo(?{ $foo = 1 })bar/; # won't fail (when not under -T switch)
+ /foo${pat}bar/; # won't fail (when not under -T switch)
{
no re 'taint'; # the default
($x) = ($^X =~ /^(.*)$/s); # $x is not tainted here
no re 'eval'; # the default
- /foo(?{ $foo = 1 })bar/; # disallowed (with or without -T switch)
+ /foo${pat}bar/; # disallowed (with or without -T switch)
}
+ use re 'debug'; # NOT lexically scoped (as others are)
+ /^(.*)$/s; # output debugging info during
+ # compile and run time
+
+ use re 'debugcolor'; # same as 'debug', but with colored output
+ ...
+
+ use re qw(Debug All); # Finer tuned debugging options.
+ use re qw(Debug More); # Similarly not lexically scoped.
+ no re qw(Debug ALL); # Turn of all re dugging and unload the module.
+
+(We use $^X in these examples because it's tainted by default.)
+
=head1 DESCRIPTION
When C<use re 'taint'> is in effect, and a tainted string is the target
other transformations.
When C<use re 'eval'> is in effect, a regex is allowed to contain
-C<(?{ ... })> zero-width assertions (which may not be interpolated in
-the regex). That is normally disallowed, since it is a potential security
-risk. Note that this pragma is ignored when perl detects tainted data,
-i.e. evaluation is always disallowed with tainted data. See
-L<perlre/(?{ code })>.
+C<(?{ ... })> zero-width assertions even if regular expression contains
+variable interpolation. That is normally disallowed, since it is a
+potential security risk. Note that this pragma is ignored when the regular
+expression is obtained from tainted data, i.e. evaluation is always
+disallowed with tainted regular expresssions. See L<perlre/(?{ code })>.
+
+For the purpose of this pragma, interpolation of precompiled regular
+expressions (i.e., the result of C<qr//>) is I<not> considered variable
+interpolation. Thus:
+
+ /foo${pat}bar/
+
+I<is> allowed if $pat is a precompiled regular expression, even
+if $pat contains C<(?{ ... })> assertions.
+
+When C<use re 'debug'> is in effect, perl emits debugging messages when
+compiling and using regular expressions. The output is the same as that
+obtained by running a C<-DDEBUGGING>-enabled perl interpreter with the
+B<-Dr> switch. It may be quite voluminous depending on the complexity
+of the match. Using C<debugcolor> instead of C<debug> enables a
+form of output that can be used to get a colorful display on terminals
+that understand termcap color sequences. Set C<$ENV{PERL_RE_TC}> to a
+comma-separated list of C<termcap> properties to use for highlighting
+strings on/off, pre-point part on/off.
+See L<perldebug/"Debugging regular expressions"> for additional info.
+
+Similarly C<use re 'Debug'> produces debugging output, the difference
+being that it allows the fine tuning of what debugging output will be
+emitted. Following the 'Debug' keyword one of several options may be
+provided: COMPILE, EXECUTE, TRIE_COMPILE, TRIE_EXECUTE, TRIE_MORE,
+OPTIMISE, OFFSETS and ALL. Additionally the special keywords 'All' and
+'More' may be provided. 'All' represents everything but OPTIMISE and
+OFFSETS and TRIE_MORE, and 'More' is similar but include TRIE_MORE.
+Saying C<< no re Debug => 'EXECUTE' >> will disable executing debug
+statements and saying C<< use re Debug => 'EXECUTE' >> will turn it on. Note
+that these flags can be set directly via ${^RE_DEBUG_FLAGS} by using the
+following flag values:
+
+ RE_DEBUG_COMPILE 1
+ RE_DEBUG_EXECUTE 2
+ RE_DEBUG_TRIE_COMPILE 4
+ RE_DEBUG_TRIE_EXECUTE 8
+ RE_DEBUG_TRIE_MORE 16
+ RE_DEBUG_OPTIMISE 32
+ RE_DEBUG_OFFSETS 64
+
+The directive C<use re 'debug'> and its equivalents are I<not> lexically
+scoped, as the other directives are. They have both compile-time and run-time
+effects.
See L<perlmodlib/Pragmatic Modules>.
=cut
+# N.B. File::Basename contains a literal for 'taint' as a fallback. If
+# taint is changed here, File::Basename must be updated as well.
my %bitmask = (
-taint => 0x00100000,
-eval => 0x00200000,
+taint => 0x00100000, # HINT_RE_TAINT
+eval => 0x00200000, # HINT_RE_EVAL
);
+sub setcolor {
+ eval { # Ignore errors
+ require Term::Cap;
+
+ my $terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning.
+ my $props = $ENV{PERL_RE_TC} || 'md,me,so,se,us,ue';
+ my @props = split /,/, $props;
+ my $colors = join "\t", map {$terminal->Tputs($_,1)} @props;
+
+ $colors =~ s/\0//g;
+ $ENV{PERL_RE_COLORS} = $colors;
+ };
+}
+
+my %flags = (
+ COMPILE => 1,
+ EXECUTE => 2,
+ TRIE_COMPILE => 4,
+ TRIE_EXECUTE => 8,
+ TRIE_MORE => 16,
+ OPTIMISE => 32,
+ OPTIMIZE => 32, # alias
+ OFFSETS => 64,
+ ALL => 127,
+ All => 15,
+ More => 31,
+);
+
+my $installed = 0;
+
sub bits {
my $on = shift;
my $bits = 0;
- unless(@_) {
+ unless (@_) {
require Carp;
Carp::carp("Useless use of \"re\" pragma");
}
- foreach my $s (@_){
- if ($s eq 'debug') {
- eval <<'EOE';
- use DynaLoader;
- @ISA = ('DynaLoader');
- bootstrap re;
-EOE
- install() if $on;
- uninstall() unless $on;
- next;
- }
- $bits |= $bitmask{$s} || 0;
+ foreach my $idx (0..$#_){
+ my $s=$_[$idx];
+ if ($s eq 'Debug' or $s eq 'Debugcolor') {
+ setcolor() if $s eq 'Debugcolor';
+ ${^RE_DEBUG_FLAGS} = 0 unless defined ${^RE_DEBUG_FLAGS};
+ require XSLoader;
+ XSLoader::load('re');
+ for my $idx ($idx+1..$#_) {
+ if ($flags{$_[$idx]}) {
+ if ($on) {
+ ${^RE_DEBUG_FLAGS} |= $flags{$_[$idx]};
+ } else {
+ ${^RE_DEBUG_FLAGS} &= ~ $flags{$_[$idx]};
+ }
+ } else {
+ require Carp;
+ Carp::carp("Unknown \"re\" Debug flag '$_[$idx]', possible flags: ",
+ join(", ",sort { $flags{$a} <=> $flags{$b} } keys %flags ) );
+ }
+ }
+ if ($on) {
+ install() unless $installed;
+ $installed = 1;
+ } elsif (!${^RE_DEBUG_FLAGS}) {
+ uninstall() if $installed;
+ $installed = 0;
+ }
+ last;
+ } elsif ($s eq 'debug' or $s eq 'debugcolor') {
+ setcolor() if $s eq 'debugcolor';
+ require XSLoader;
+ XSLoader::load('re');
+ if ($on) {
+ install() unless $installed;
+ $installed=1;
+ } else {
+ uninstall() if $installed;
+ $installed=0;
+ }
+ } elsif (exists $bitmask{$s}) {
+ $bits |= $bitmask{$s};
+ } else {
+ require Carp;
+ Carp::carp("Unknown \"re\" subpragma '$s' (known ones are: ",
+ join(', ', map {qq('$_')} 'debug', 'debugcolor', sort keys %bitmask),
+ ")");
+ }
}
$bits;
}
sub import {
shift;
- $^H |= bits(1,@_);
+ $^H |= bits(1, @_);
}
sub unimport {
shift;
- $^H &= ~ bits(0,@_);
+ $^H &= ~ bits(0, @_);
}
1;
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