ExtUtils::Typemaps::OutputMap - Entry in the OUTPUT section of a typemap
use ExtUtils::Typemaps;
...
my $output = $typemap->get_output_map('T_NV');
my $code = $output->code();
$output->code("...");
Refer to ExtUtils::Typemaps for details.
Requires xstype
and code
parameters.
Returns or sets the OUTPUT mapping code for this entry.
Returns the name of the XS type of the OUTPUT map.
Returns a cleaned-up copy of the code to which certain transformations have been applied to make it more ANSI compliant.
This is an obscure but effective optimization that used to live in ExtUtils::ParseXS
directly. Not implementing it should never result in incorrect use of typemaps, just less efficient code.
In a nutshell, this will check whether the output code involves calling sv_setiv
, sv_setuv
, sv_setnv
, sv_setpv
or sv_setpvn
to set the special $arg
placeholder to a new value AT THE END OF THE OUTPUT CODE. If that is the case, the code is eligible for using the TARG
-related macros to optimize this. Thus the name of the method: targetable
.
If this optimization is applicable, ExtUtils::ParseXS
will emit a dXSTARG;
definition at the start of the generate XSUB code, and type (see below) dependent code to set TARG
and push it on the stack at the end of the generated XSUB code.
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, including leading comma)
Steffen Mueller <smueller@cpan.org
>
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.