Sub::StrictDecl - detect undeclared subroutines in compilation

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

       Copyright (C) 2011 PhotoBox Ltd

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

       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.

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

perl v5.40.0                                       2024-10-20                               Sub::StrictDecl(3pm)

       Sub::StrictDecl - detect undeclared subroutines in compilation

       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.

       Perl::Critic::StricterSubs, strict

               use Sub::StrictDecl;

               no Sub::StrictDecl;