package ExtUtils::Typemaps::OutputMap;
use 5.006001;
use strict;
use warnings;
our $VERSION = '3.18';

=head1 NAME

ExtUtils::Typemaps::OutputMap - Entry in the OUTPUT section of a typemap

=head1 SYNOPSIS

use ExtUtils::Typemaps;
...
my $output = $typemap->get_output_map('T_NV');
my $code = $output->code();
$output->code("...");

=head1 DESCRIPTION

Refer to L<ExtUtils::Typemaps> for details.

=head1 METHODS

=cut

=head2 new

Requires C<xstype> and C<code> parameters.

=cut

sub new {
my $prot = shift;
my $class = ref($prot)||$prot;
my %args = @_;

if (!ref($prot)) {
if (not defined $args{xstype} or not defined $args{code}) {
die("Need xstype and code parameters");
}
}

my $self = bless(
(ref($prot) ? {%$prot} : {})
=> $class
);

$self->{xstype} = $args{xstype} if defined $args{xstype};
$self->{code} = $args{code} if defined $args{code};
$self->{code} =~ s/^(?=\S)/\t/mg;

return $self;
}

=head2 code

Returns or sets the OUTPUT mapping code for this entry.

=cut

sub code {
$_[0]->{code} = $_[1] if @_ > 1;
return $_[0]->{code};
}

=head2 xstype

Returns the name of the XS type of the OUTPUT map.

=cut

sub xstype {
return $_[0]->{xstype};
}

=head2 cleaned_code

Returns a cleaned-up copy of the code to which certain transformations
have been applied to make it more ANSI compliant.

=cut

sub cleaned_code {
my $self = shift;
my $code = $self->code;

# Move C pre-processor instructions to column 1 to be strictly ANSI
# conformant. Some pre-processors are fussy about this.
$code =~ s/^\s+#/#/mg;
$code =~ s/\s*\z/\n/;

return $code;
}

=head2 targetable

This is an obscure optimization that used to live in C<ExtUtils::ParseXS>
directly.

In a nutshell, this will check whether the output code
involves calling C<set_iv>, C<set_uv>, C<set_nv>, C<set_pv> or C<set_pvn>
to set the special C<$arg> placeholder to a new value
B<AT THE END OF THE OUTPUT CODE>. If that is the case, the code is
eligible for using the C<TARG>-related macros to optimize this.
Thus the name of the method: C<targetable>.

If the optimization can not be applied, this returns undef.
If it can be applied, this method returns a hash reference containing
the following information:

type: Any of the characters i, u, n, p
with_size: Bool indicating whether this is the sv_setpvn variant
what: The code that actually evaluates to the output scalar
what_size: If "with_size", this has the string length (as code,
not constant)

=cut

sub targetable {
my $self = shift;
return $self->{targetable} if exists $self->{targetable};

our $bal; # ()-balanced
$bal = qr[
(?:
(?>[^()]+)
|
\( (??{ $bal }) \)
)*
]x;

# matches variations on (SV*)
my $sv_cast = qr[
(?:
\( \s* SV \s* \* \s* \) \s*
)?
]x;

my $size = qr[ # Third arg (to setpvn)
, \s* (??{ $bal })
]x;

my $code = $self->code;

# We can still bootstrap compile 're', because in code re.pm is
# available to miniperl, and does not attempt to load the XS code.
use re 'eval';

my ($type, $with_size, $arg, $sarg) =
($code =~
m[^
\s+
sv_set([iunp])v(n)? # Type, is_setpvn
\s*
\( \s*
$sv_cast \$arg \s* , \s*
( (??{ $bal }) ) # Set from
( (??{ $size }) )? # Possible sizeof set-from
\) \s* ; \s* $
]x
);

my $rv = undef;
if ($type) {
$rv = {
type => $type,
with_size => $with_size,
what => $arg,
what_size => $sarg,
};
}
$self->{targetable} = $rv;
return $rv;
}

=head1 SEE ALSO

L<ExtUtils::Typemaps>

=head1 AUTHOR

Steffen Mueller C<<[email protected]>>

=head1 COPYRIGHT & LICENSE

Copyright 2009, 2010, 2011, 2012 Steffen Mueller

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

=cut

1;