package ExtUtils::MM;

use ExtUtils::MakeMaker::Config;

our $VERSION = '6.44';

require ExtUtils::Liblist;
require ExtUtils::MakeMaker;
our @ISA = qw(ExtUtils::Liblist ExtUtils::MakeMaker);

=head1 NAME

ExtUtils::MM - OS adjusted ExtUtils::MakeMaker subclass

=head1 SYNOPSIS

  require ExtUtils::MM;
  my $mm = MM->new(...);

=head1 DESCRIPTION

B<FOR INTERNAL USE ONLY>

ExtUtils::MM is a subclass of ExtUtils::MakeMaker which automatically
chooses the appropriate OS specific subclass for you
(ie. ExtUils::MM_Unix, etc...).

It also provides a convenient alias via the MM class (I didn't want
MakeMaker modules outside of ExtUtils/).

This class might turn out to be a temporary solution, but MM won't go
away.

=cut

do {
    # Convenient alias.
    package MM;
    our @ISA = qw(ExtUtils::MM);
    sub DESTROY {}
};

sub _is_win95 {
    # miniperl might not have the Win32 functions available and we need
    # to run in miniperl.
    return defined &Win32::IsWin95 ?? Win32::IsWin95() 
                                   !! ! defined env::var('SYSTEMROOT'); 
}

my %Is = %( () );
%Is{+VMS}    = $^OS_NAME eq 'VMS';
%Is{+OS2}    = $^OS_NAME eq 'os2';
%Is{+MacOS}  = $^OS_NAME eq 'MacOS';
if( $^OS_NAME eq 'MSWin32' ) {
    ( _is_win95() ?? %Is{+Win95} !! %Is{+Win32} ) = 1;
}
%Is{+UWIN}   = $^OS_NAME =~ m/^uwin(-nt)?$/;
%Is{+Cygwin} = $^OS_NAME eq 'cygwin';
%Is{+NW5}    = %Config{?osname} eq 'NetWare';  # intentional
%Is{+BeOS}   = $^OS_NAME =~ m/beos/i;    # XXX should this be that loose?
%Is{+DOS}    = $^OS_NAME eq 'dos';
if( %Is{?NW5} ) {
    $^OS_NAME = 'NetWare';
    delete %Is{Win32};
}
%Is{+VOS}    = $^OS_NAME eq 'vos';
%Is{+QNX}    = $^OS_NAME eq 'qnx';
%Is{+AIX}    = $^OS_NAME eq 'aix';
%Is{+Darwin} = $^OS_NAME eq 'darwin';

%Is{+Unix}   = !grep { $_ }, values %Is;

map { delete %Is{$_} unless %Is{?$_} }, keys %Is;
_assert( nelems(%Is) == 2 );
my@($OS) =  keys %Is;


my $class = "ExtUtils::MM_$OS";
eval "require $class" unless $^INCLUDED{?"ExtUtils/MM_$OS.pm"}; ## no critic
die $^EVAL_ERROR if $^EVAL_ERROR;
unshift @ISA, $class;


sub _assert {
    my $sanity = shift;
    die sprintf "Assert failed at \%s line \%d\n", < @(caller)[[1..2]] unless $sanity;
    return;
}