=head1 NAME

ExtUtils::ParseXS - converts Perl XS code into C code

=head1 SYNOPSIS

  use ExtUtils::ParseXS;

  my $pxs = ExtUtils::ParseXS->new;
  $pxs->process_file( filename => 'foo.xs' );

  $pxs->process_file( filename => 'foo.xs',
                      output => 'bar.c',
                      'C++' => 1,
                      typemap => 'path/to/typemap',
                      hiertype => 1,
                      except => 1,
                      versioncheck => 1,
                      linenumbers => 1,
                      optimize => 1,
                      prototypes => 1,
                      die_on_error => 0,
                    );

  # Legacy non-OO interface using a singleton:
  use ExtUtils::ParseXS qw(process_file);
  process_file( filename => 'foo.xs' );

=head1 DESCRIPTION

C<ExtUtils::ParseXS> will compile XS code into C code by embedding the constructs
necessary to let C functions manipulate Perl values and creates the glue
necessary to let Perl access those functions.  The compiler uses typemaps to
determine how to map C function parameters and variables to Perl values.

The compiler will search for typemap files called I<typemap>.  It will use
the following search path to find default typemaps, with the rightmost
typemap taking precedence.

    ../../../typemap:../../typemap:../typemap:typemap

=head1 EXPORT

None by default.  C<process_file()> and/or C<report_error_count()>
may be exported upon request. Using the functional interface is
discouraged.

=head1 METHODS

=over 4

=item $pxs->new()

Returns a new, empty XS parser/compiler object.

=item $pxs->process_file()

This method processes an XS file and sends output to a C file.
The method may be called as a function (this is the legacy
interface) and will then use a singleton as invocant.

Named parameters control how the processing is done.
The following parameters are accepted:

=over 4

=item filename

This is the full pathname of the XS file to open and process.
process_file() will normally chdir() to the basename of the file.

The filename may be a reference to a string, in which case the lines of
the string form the contents of the "input" file, using the standard
C<open $fh, '<', \$string> mechanism.

=item B<C++>

Adds C<extern "C"> to the C code.  Default is false.

=item B<hiertype>

Retains C<::> in type names so that C++ hierarchical types can be
mapped.  Default is false.

=item B<except>

Adds exception handling stubs to the C code.  Default is false.

=item B<typemap>

Indicates that a user-supplied typemap should take precedence over the
default typemaps.  A single typemap may be specified as a string, or
multiple typemaps can be specified in an array reference, with the
last typemap having the highest precedence.

=item B<prototypes>

Generates prototype code for all xsubs.  Default is false.

=item B<versioncheck>

Makes sure at run time that the object file (derived from the C<.xs>
file) and the C<.pm> files have the same version number.  Default is
true.

=item B<linenumbers>

Adds C<#line> directives to the C output so error messages will look
like they came from the original XS file.  Default is true.

=item B<optimize>

Enables certain optimizations.  The only optimization that is currently
affected is the use of I<target>s by the output C code (see L<perlguts>).
Not optimizing may significantly slow down the generated code, but this is the way
B<xsubpp> of 5.005 and earlier operated.  Default is to optimize.

=item B<inout>

Enable recognition of C<IN>, C<OUT_LIST> and C<INOUT_LIST>
declarations.  Default is true.

=item B<argtypes>

Enable recognition of ANSI-like descriptions of function signature.
Default is true.

=item B<s>

I<Maintainer note:> I have no clue what this does.  Strips function prefixes?

=item B<die_on_error>

Normally ExtUtils::ParseXS will terminate the program with an C<exit(1)> after
printing the details of the exception to STDERR via (warn). This can be awkward
when it is used programmatically and not via xsubpp, so this option can be used
to cause it to die instead by providing a true value. When not provided this
defaults to the value of C<$ExtUtils::ParseXS::DIE_ON_ERROR> which in turn
defaults to false.

=back

=item $pxs->report_error_count()

This method returns the number of [a certain kind of] errors
encountered during processing of the XS file.

The method may be called as a function (this is the legacy
interface) and will then use a singleton as invocant.

=back

=head1 AUTHOR

Based on xsubpp code, written by Larry Wall.

Maintained by:

=over 4

=item *

Ken Williams, <ken@mathforum.org>

=item *

David Golden, <dagolden@cpan.org>

=item *

James Keenan, <jkeenan@cpan.org>

=item *

Steffen Mueller, <smueller@cpan.org>

=back

=head1 COPYRIGHT

Copyright 2002-2014 by Ken Williams, David Golden and other contributors.  All
rights reserved.

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

Based on the C<ExtUtils::xsubpp> code by Larry Wall and the Perl 5
Porters, which was released under the same license terms.

=head1 SEE ALSO

L<perl>, ExtUtils::xsubpp, ExtUtils::MakeMaker, L<perlxs>, L<perlxstut>.

=cut


