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


  use ExtUtils::ParseXS qw(process_file);
  process_file( filename => 'foo.xs' );

  process_file( filename => 'foo.xs',
                output => 'bar.c',
                'C++' => 1,
                typemap => 'path/to/typemap',
                hiertype => 1,
                except => 1,
                prototypes => 1,
                versioncheck => 1,
                linenumbers => 1,
                optimize => 1,
                prototypes => 1,

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 typemap. It will use the following search path to find default typemaps, with the rightmost typemap taking precedence.



None by default. process_file() may be exported upon request.



This function processes an XS file and sends output to a C file. Named parameters control how the processing is done. The following parameters are accepted:


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


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


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


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.


Generates prototype code for all xsubs. Default is false.


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


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


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


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


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


I have no clue what this does. Strips function prefixes?


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


Based on xsubpp code, written by Larry Wall.

Maintained by Ken Williams, <>


Copyright 2002-2003 Ken Williams. 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 ExtUtils::xsubpp code by Larry Wall and the Perl 5 Porters, which was released under the same license terms.


perl, ExtUtils::xsubpp, ExtUtils::MakeMaker, perlxs, perlxstut.