package indirect;
-use 5.008;
+use 5.008001;
use strict;
use warnings;
=head1 VERSION
-Version 0.11
+Version 0.21
=cut
our $VERSION;
BEGIN {
- $VERSION = '0.11';
+ $VERSION = '0.21';
}
=head1 SYNOPSIS
use indirect;
my $y = new Pear; # ok
{
- no indirect hook => sub { die "You really wanted $_[0]\->$_[1]" };
- my $z = new Pineapple 'fresh'; # croaks 'You really wanted Pineapple->new'
+ no indirect hook => sub { die "You really wanted $_[0]\->$_[1] at $_[2]:$_[3]" };
+ my $z = new Pineapple 'fresh'; # croaks 'You really wanted Pineapple->new at blurp.pm:13'
}
}
+ try { ... }; # warns
+
no indirect ':fatal';
if (defied $foo) { ... } # croaks, note the typo
=head1 DESCRIPTION
-When enabled (or disabled as some may prefer to say, since you actually turn it on by calling C<no indirect>), this pragma warns about indirect object syntax constructs that may have slipped into your code. This syntax is now considered harmful, since its parsing has many quirks and its use is error prone (when C<sub> isn't defined, C<sub $x> is actually interpreted as C<< $x->sub >>).
+When enabled (or disabled as some may prefer to say, since you actually turn it on by calling C<no indirect>), this pragma warns about indirect object syntax constructs that may have slipped into your code.
+
+This syntax is now considered harmful, since its parsing has many quirks and its use is error prone (when C<swoosh> isn't defined, C<swoosh $x> actually compiles to C<< $x->swoosh >>).
+In L<http://www.shadowcat.co.uk/blog/matt-s-trout/indirect-but-still-fatal>, Matt S. Trout gives an example of an indirect construct that can cause a particularly bewildering error.
-It currently does not warn when the object is enclosed between braces (like C<meth { $obj } @args>) or for core functions (C<print> or C<say>). This may change in the future, or may be added as optional features that would be enabled by passing options to C<unimport>.
+It currently does not warn for core functions (C<print>, C<say>, C<exec> or C<system>).
+This may change in the future, or may be added as optional features that would be enabled by passing options to C<unimport>.
This module is B<not> a source filter.
=cut
BEGIN {
- require XSLoader;
- XSLoader::load(__PACKAGE__, $VERSION);
+ if ($ENV{PERL_INDIRECT_PM_DISABLE}) {
+ *_tag = sub ($) { 1 };
+ *I_THREADSAFE = sub () { 1 };
+ *I_FORKSAFE = sub () { 1 };
+ } else {
+ require XSLoader;
+ XSLoader::load(__PACKAGE__, $VERSION);
+ }
}
=head1 METHODS
=item *
-If the key/value pair C<< hook => $hook >> comes first, C<$hook> will be called for each error with the object name as C<$_[0]> and the method name as C<$_[1]>.
+If the key/value pair C<< hook => $hook >> comes first, C<$hook> will be called for each error with a string representation of the object as C<$_[0]>, the method name as C<$_[1]>, the current file as C<$_[2]> and the line number as C<$_[3]>.
+If and only if the object is actually a block, C<$_[0]> is assured to start by C<'{'>.
=item *
=cut
-my $msg = sub { "Indirect call of method \"$_[1]\" on object \"$_[0]\"" };
-
sub unimport {
shift;
if ($arg eq 'hook') {
$hook = shift;
} elsif ($arg eq ':fatal') {
- $hook = sub { die $msg->(@_) };
+ $hook = sub { die msg(@_) };
}
last if $hook;
}
- $hook = sub { warn $msg->(@_) } unless defined $hook;
+ $hook = sub { warn msg(@_) } unless defined $hook;
$^H |= 0x00020000;
$^H{+(__PACKAGE__)} = _tag($hook);
();
}
+=head1 FUNCTIONS
+
+=head2 C<msg $object, $method, $file, $line>
+
+Returns the default error message generated by C<indirect> when an invalid construct is reported.
+
+=cut
+
+sub msg {
+ my $obj = $_[0];
+
+ join ' ', "Indirect call of method \"$_[1]\" on",
+ ($obj =~ /^\s*\{/ ? "a block" : "object \"$obj\""),
+ "at $_[2] line $_[3].\n";
+};
+
=head1 CONSTANTS
=head2 C<I_THREADSAFE>
-True iff the module could have been built when thread-safety features.
+True iff the module could have been built with thread-safety features enabled.
+
+=head2 C<I_FORKSAFE>
+
+True iff this module could have been built with fork-safety features enabled.
+This will always be true except on Windows where it's false for perl 5.10.0 and below .
+
+=head1 DIAGNOSTICS
+
+=head2 C<Indirect call of method "%s" on object "%s" at %s line %d.>
+
+The default warning/exception message thrown when an indirect call on an object is found.
+
+=head2 C<Indirect call of method "%s" on a block at %s line %d.>
+
+The default warning/exception message thrown when an indirect call on a block is found.
+
+=head1 ENVIRONMENT
+
+=head2 C<PERL_INDIRECT_PM_DISABLE>
+
+If this environment variable is set to true when the pragma is used for the first time, the XS code won't be loaded and, although the C<'indirect'> lexical hint will be set to true in the scope of use, the pragma itself won't do anything.
+In this case, the pragma will always be considered to be thread-safe, and as such L</I_THREADSAFE> will be true.
+This is useful for disabling C<indirect> in production environments.
+
+Note that clearing this variable after C<indirect> was loaded has no effect.
+If you want to reenable the pragma later, you also need to reload it by deleting the C<'indirect.pm'> entry from C<%INC>.
=head1 CAVEATS
+The implementation was tweaked to work around several limitations of vanilla C<perl> pragmas : it's thread safe, and doesn't suffer from a C<perl 5.8.x-5.10.0> bug that causes all pragmas to propagate into C<require>d scopes.
+
C<meth $obj> (no semicolon) at the end of a file won't be seen as an indirect object syntax, although it will as soon as there is another token before the end (as in C<meth $obj;> or C<meth $obj 1>).
With 5.8 perls, the pragma does not propagate into C<eval STRING>.
This is due to a shortcoming in the way perl handles the hints hash, which is addressed in perl 5.10.
+The search for indirect method calls happens before constant folding.
+Hence C<my $x = new Class if 0> will be caught.
+
=head1 DEPENDENCIES
-L<perl> 5.8.
+L<perl> 5.8.1.
L<XSLoader> (standard since perl 5.006).
=head1 BUGS
-Please report any bugs or feature requests to C<bug-indirect at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=indirect>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
+Please report any bugs or feature requests to C<bug-indirect at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=indirect>.
+I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
=head1 SUPPORT
Bram, for motivation and advices.
+Andrew Main and Florian Ragwitz, for testing on real-life code and reporting issues.
+
=head1 COPYRIGHT & LICENSE
-Copyright 2008-2009 Vincent Pit, all rights reserved.
+Copyright 2008,2009,2010 Vincent Pit, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
projects / perl / modules / indirect.git / blobdiff