gitpan / lexical-sealrequirehints Goto Github PK
View Code? Open in Web Editor NEWRead-only release history for Lexical-SealRequireHints
Home Page: http://metacpan.org/release/Lexical-SealRequireHints
Read-only release history for Lexical-SealRequireHints
Home Page: http://metacpan.org/release/Lexical-SealRequireHints
NAME Lexical::SealRequireHints - prevent leakage of lexical hints DESCRIPTION This module works around two historical bugs in Perl's handling of the "%^H" (lexical hints) variable. One bug causes lexical state in one file to leak into another that is "require"d/"use"d from it. This bug, [perl #68590], was present from Perl 5.6 up to Perl 5.10, fixed in Perl 5.11.0. The second bug causes lexical state (normally a blank "%^H" once the first bug is fixed) to leak outwards from "utf8.pm", if it is automatically loaded during Unicode regular expression matching, into whatever source is compiling at the time of the regexp match. This bug, [perl #73174], was present from Perl 5.8.7 up to Perl 5.11.5, fixed in Perl 5.12.0. Both of these bugs seriously damage the usability of any module relying on "%^H" for lexical scoping, on the affected Perl versions. It is in practice essential to work around these bugs when using such modules. On versions of Perl that require such a workaround, this module globally changes the behaviour of "require", including "use" and the implicit "require" performed in Unicode regular expression matching, so that it no longer exhibits these bugs. The workaround supplied by this module takes effect the first time its "import" method is called. Typically this will be done by means of a "use" statement. This should be done as early as possible, because it only affects "require"/"use" statements that are compiled after the workaround goes into effect. For "use" statements, and "require" statements that are executed immediately and only once, it suffices to invoke the workaround when loading the first module that will set up vulnerable lexical state. Delayed-action "require" statements, however, are more troublesome, and can require the workaround to be loaded much earlier. Ultimately, an affected Perl program may need to load the workaround as very nearly its first action. Invoking this module multiple times, from multiple modules, is not a problem: the workaround is only applied once, and applies to everything subsequently compiled. This module is implemented in XS, with a pure Perl backup version for systems that can't handle XS modules. The XS version has a better chance of playing nicely with other modules that modify "require" handling. The pure Perl version can't work at all on some Perl versions; users of those versions must use the XS. INSTALLATION perl Build.PL ./Build ./Build test ./Build install AUTHOR Andrew Main (Zefram) <[email protected]> COPYRIGHT Copyright (C) 2009, 2010, 2011, 2012 Andrew Main (Zefram) <[email protected]> LICENSE This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
A declarative, efficient, and flexible JavaScript library for building user interfaces.
๐ Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
An Open Source Machine Learning Framework for Everyone
The Web framework for perfectionists with deadlines.
A PHP framework for web artisans
Bring data to life with SVG, Canvas and HTML. ๐๐๐
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
Some thing interesting about web. New door for the world.
A server is a program made to process requests and deliver data to clients.
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
Some thing interesting about visualization, use data art
Some thing interesting about game, make everyone happy.
We are working to build community through open source technology. NB: members must have two-factor auth.
Open source projects and samples from Microsoft.
Google โค๏ธ Open Source for everyone.
Alibaba Open Source for everyone
Data-Driven Documents codes.
China tencent open source team.