NAME

Sub::StrictDecl - detect undeclared subroutines in compilation

SYNOPSIS

use Sub::StrictDecl;

no Sub::StrictDecl;

DESCRIPTION

This module provides optional checking of subroutine existence at compile time. This checking detects mistyped subroutine names and subroutines that the programmer forgot to import. Traditionally Perl does not detect these errors until runtime, so it is easy for errors to lurk in rarely-executed or untested code.

Specifically, where checking is enabled, any reference to a specific (compile-time-constant) package-based subroutine name is examined. If the named subroutine has never been declared then an error is signalled at compile time. This does not require that the subroutine be fully defined: a forward declaration such as "sub foo;" suffices to suppress the error. Imported subroutines qualify as declared. References that are checked include not only subroutine calls but also pure referencing such as "\&foo".

This checking is controlled by a lexically-scoped pragma. It is therefore applied only to code that explicitly wants the checking, and it is possible to locally disable checking if necessary. Checking might need to be turned off for code that makes special arrangements to put a subroutine in place at runtime, for example.

PACKAGE METHODS

Sub::StrictDecl->import

Turns on subroutine declaration checking in the lexical environment that is currently compiling.

Sub::StrictDecl->unimport

Turns off subroutine declaration checking in the lexical environment that is currently compiling.

SEE ALSO

Perl::Critic::StricterSubs, strict

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

Copyright (C) 2011 PhotoBox Ltd

Copyright (C) 2011, 2015, 2017 Andrew Main (Zefram) <zefram@fysh.org>

LICENSE

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.