NAME
    B::LintSubs - Perl compiler backend to check sub linkage

SYNOPSIS
    perl -MO=LintSubs [*FILE*] [-e PROGRAM]

DESCRIPTION
    When using "use strict", subroutine names are not checked at the
    callsite; this makes the following a perfectly valid program at
    compiletime, that only blows up at runtime

     use strict;
     foobar();

    When using the "B::LintSubs" checker instead, this is detected:

     $ perl -MO=LintSubs -e 'use strict;
                             foobar();'
     Undefined subroutine foobar called at -e line 2

    Imported functions from other modules are of course detected:

     $ perl -MO=LintSubs -e 'use strict; 
                             use List::Util qw( max );
                             $_ = max( 1, 2, 3 )'
     -e syntax OK

    In order to handle situations where external code is conditionally
    referenced at runtime, any fully-qualified references to other functions
    are printed with a warning, but not considered fatal. The programmer is
    assumed to Know What He Is Doing in this case:

     $ perl -MO=LintSubs -e 'if( 1 ) { require Data::Dumper; 
                                       Data::Dumper::Dump( "Hello" ) }'
     Unable to check call to Data::Dumper::Dump in foreign package at -e line 1
     -e syntax OK

AUTHOR
    Paul Evans <leonerd@leonerd.org.uk>

    Based on the "B::Lint" module by Malcolm Beattie,
    <mbeattie@sable.ox.ac.uk>.