Makefile.PL

#!/usr/bin/perl -w

# A template for Makefile.PL.
# - Set the $PACKAGE variable to the name of your module.
# - Set $LAST_API_CHANGE to reflect the last version you changed the API 
#   of your module.
# - Fill in your dependencies in PREREQ_PM
# Alternatively, you can say the hell with this and use h2xs.

BEGIN { require 5.006; }
use strict;

use lib qw(lib inc);    # build ourself with ourself
use File::Spec;
use ExtUtils::MakeMaker;


BEGIN {
    die "You have File::Spec version $File::Spec::VERSION\n".
      "ExtUtils::MakeMaker requires File::Spec >= 0.8 to build at all.\n"
        if $File::Spec::VERSION < 0.8;
}

my $PACKAGE = 'ExtUtils::MakeMaker';
my $version = do { no strict 'refs'; ${$PACKAGE.'::VERSION'}; };
$version =~ s/_//;  # for X.Y_Z alpha releases
(my $PACKAGE_FILE = $PACKAGE) =~ s|::|/|g;
my $LAST_API_CHANGE = 5.50;

my $Is_VMS = $^O eq 'VMS';


eval "require $PACKAGE";

unless ($@) { # Make sure we did find the module.
    print <<"CHANGE_WARN" if $version < $LAST_API_CHANGE;

NOTE: There have been API changes between this version and any older
than version $LAST_API_CHANGE!  Please read the Changes file if you
are upgrading from a version older than $LAST_API_CHANGE.

CHANGE_WARN
}

# Test::Harnesses prior to 2.00 shoved all of @INC onto the command line
# when a test had -T.  This made it too long.  So we need a Test::Harness
# > 2.00 on VMS for t/testlib.t
my %prereq = ( );
$prereq{'Test::Harness'} = 2.00 if $^O eq 'VMS';


my $MM = WriteMakefile(
    NAME            => $PACKAGE,
    VERSION_FROM    => "lib/$PACKAGE_FILE.pm", # finds $VERSION
    PREREQ_PM       => { %prereq,

                         # splitpath(), rel2abs()
                         'File::Spec'       => 0.8,

                         # manifypods needs Pod::Man
                         'Pod::Man'         => 0,

                         'File::Basename'   => 0,
                         DirHandle          => 0,
                       },
    MIN_PERL_VERSION => '5.006',

    PMLIBDIRS       => [qw(lib inc)],
    # PMLIBPARENTDIRS is an experimental feature
    PMLIBPARENTDIRS => [qw(lib inc)],

    EXE_FILES       => [qw(bin/instmodsh)],

    META_MERGE      => {
        no_index => {
            # "in" is a PAUSE misparse.
            package => ['DynaLoader', 'in'],
        },
        resources => {
            license     =>      'http://dev.perl.org/licenses/',
            homepage    =>      'http://makemaker.org',
            bugtracker  =>      'http://rt.cpan.org/NoAuth/Bugs.html?Dist=ExtUtils-MakeMaker',
            repository  =>      'http://github.com/schwern/extutils-makemaker',
            MailingList =>      'makemaker@perl.org',
        },
    },

    META_ADD        => {
        # We don't need ourself to install ourself.
        configure_requires => {},
        build_requires     => {},
    },

    INSTALLDIRS     => 'perl',

    LICENSE         => 'perl',

    ABSTRACT_FROM   => "lib/$PACKAGE_FILE.pm",
    AUTHOR          => 'Michael G Schwern <schwern@pobox.com>',
);

if( !$Is_VMS && $MM->{PERL} =~ /\S\s+\S/ ) {
    require Test::Harness;
    my $th_version = defined $Test::Harness::VERSION ? $Test::Harness::VERSION
                                                     : 0;
    print <<SPACE_WARN if $th_version < 2.27;

NOTE: Your Perl looks like it contains a space in the path name.
MakeMaker is now OK with that but your version of Test::Harness is not
which means 'make test' will likely puke.

You will have to install this new version of MakeMaker, then upgrade
Test::Harness from CPAN, then run the MakeMaker tests.

SPACE_WARN

}


{
    package MY;

    # Make sure PERLRUN uses the MakeMaker about to be installed
    # and not the currently installed one.
    sub init_PERL {
        my($self) = shift;
        $self->SUPER::init_PERL;
        
        for my $key (qw(PERLRUN FULLPERLRUN ABSPERLRUN)) {
            $self->{$key}     .= q[ "-I$(INST_ARCHLIB)" "-I$(INST_LIB)"];
        }
    }

    sub init_PM {
        my $self = shift;

        $self->SUPER::init_PM;

        # Only override older versions of modules with ours in inc/
        for my $inc (grep /^inc/, keys %{$self->{PM}}) {
            next unless $inc =~ /\.pm$/;

            my $installed = _find_installed($inc);
            next unless defined $installed;

            # Shut up "isn't numeric" warning on X.Y_Z versions.
            local $^W = 0;
            my $installed_version = $self->parse_version($installed);
            my $inc_version       = $self->parse_version($inc);
            if( $installed_version >= $inc_version ) {
                delete $self->{PM}{$inc};
            }
            else {
                my $module = _module_name($inc);
                print qq{Using included version of $module ($inc_version) as it is newer than the installed version ($installed_version).\n};
            }
        }

        _remove_MANIFEST_SKIP($self);
    }

    # If ExtUtils::Manifest isn't included don't include MANIFEST.SKIP either.
    sub _remove_MANIFEST_SKIP {
        my $self = shift;
        
        return if grep /Manifest\.pm$/i, keys %{$self->{PM}};
        my($maniskip_key)    = grep /MANIFEST\.SKIP$/i, keys %{$self->{PM}};
        return unless $maniskip_key;
        
        return delete $self->{PM}{$maniskip_key};
    }

    sub _find_installed {
        my $file = shift;

        $file =~ s{^(\W*)inc\W}{$1}i;

        foreach my $inc (grep { $_ ne 'inc' } @INC) {
            my $path = File::Spec->catfile($inc, $file);
            return $path if -r $path;
        }

        return;
    }

    sub _module_name {
        my $path = shift;
        
        my($vol, $dirs, $file) = File::Spec->splitpath($path);
        my @dirs = File::Spec->splitdir($dirs);
        shift @dirs;  # remove inc

        $file =~ s{\.pm$}{};
        
        return join '::', grep { length } @dirs, $file;
    }
}