indirect - Lexically warn about using the indirect object syntax.
VERSION
- Version 0.16
+ Version 0.23
SYNOPSIS
# In a script
}
try { ... }; # warns
- no indirect ':fatal';
+ no indirect ':fatal'; # or 'FATAL', or ':Fatal' ...
if (defied $foo) { ... } # croaks, note the typo
# From the command-line
DESCRIPTION
When enabled (or disabled as some may prefer to say, since you actually
turn it on by calling "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 "swoosh" isn't defined, "swoosh $x"
- actually compiles to "$x->swoosh").
+ 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 "swoosh" is not defined, "swoosh $x"
+ actually compiles to "$x->swoosh"). In
+ <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 for core functions ("print", "say", "exec" or
"system"). This may change in the future, or may be added as optional
This module is not a source filter.
METHODS
- "unimport [ hook => $hook | ':fatal' ]"
+ "unimport [ hook => $hook | ':fatal', 'FATAL', ... ]"
Magically called when "no indirect @opts" is encountered. Turns the
module on. The policy to apply depends on what is first found in @opts :
- * If it's the string ':fatal', the compilation will croak on the first
- indirect syntax met.
+ * If it is a string that matches "/^:?fatal$/i", the compilation will
+ croak on the first indirect syntax met.
* If the key/value pair "hook => $hook" comes first, $hook will be
called for each error with a string representation of the object as
True iff the module could have been built with thread-safety features
enabled.
+ "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 .
+
DIAGNOSTICS
"Indirect call of method "%s" on object "%s" at %s line %d."
The default warning/exception message thrown when an indirect call on an
The default warning/exception message thrown when an indirect call on a
block is found.
+ENVIRONMENT
+ "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 '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 "I_THREADSAFE" will be true. This is useful
+ for disabling "indirect" in production environments.
+
+ Note that clearing this variable after "indirect" was loaded has no
+ effect. If you want to re-enable the pragma later, you also need to
+ reload it by deleting the 'indirect.pm' entry from %INC.
+
CAVEATS
The implementation was tweaked to work around several limitations of
- vanilla "perl" pragmas : it's thread safe, and doesn't suffer from a
+ vanilla "perl" pragmas : it's thread safe, and does not suffer from a
"perl 5.8.x-5.10.0" bug that causes all pragmas to propagate into
"require"d scopes.
- "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 "meth $obj;" or "meth $obj 1").
+ Before "perl" 5.12, "meth $obj" (no semicolon) at the end of a file is
+ not seen as an indirect object syntax, although it is as soon as there
+ is another token before the end (as in "meth $obj;" or "meth $obj 1").
+ If you use "perl" 5.12 or greater, those constructs are correctly
+ reported.
With 5.8 perls, the pragma does not propagate into "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 "my $x = new Class if 0" will be caught.
+
DEPENDENCIES
- perl 5.8.
+ perl 5.8.1.
XSLoader (standard since perl 5.006).
reporting issues.
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