man > xsubpp(1)

XSUBPP(1)                         Perl Programmers Reference Guide                         XSUBPP(1)

NAME
       xsubpp - compiler to convert Perl XS code into C code

SYNOPSIS
       xsubpp [-v] [-except] [-s pattern] [-prototypes] [-noversioncheck] [-nolinenumbers]
       [-nooptimize] [-typemap typemap] [-output filename]... file.xs

DESCRIPTION
       This compiler is typically run by the makefiles created by ExtUtils::MakeMaker or by
       Module::Build or other Perl module build tools.

       xsubpp 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.

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

       It will also use a default typemap installed as "ExtUtils::typemap".

OPTIONS
       Note that the "XSOPT" MakeMaker option may be used to add these options to any makefiles
       generated by MakeMaker.

       -hiertype
            Retains '::' in type names so that C++ hierarchical types can be mapped.

       -except
            Adds exception handling stubs to the C code.

       -typemap typemap
            Indicates that a user-supplied typemap should take precedence over the default typemaps.
            This  option  may  be  used  multiple  times,  with  the last typemap having the highest
            precedence.

       -output filename
            Specifies the name of the output file to generate.  If no file is specified, output will
            be written to standard output.

       -v   Prints the xsubpp version number to standard output, then exits.

       -prototypes
            By default xsubpp will not automatically generate prototype code  for  all  xsubs.  This
            flag will enable prototypes.

       -noversioncheck
            Disables  the  run  time test that determines if the object file (derived from the ".xs"
            file) and the ".pm" files have the same version number.

       -nolinenumbers
            Prevents the inclusion of '#line' directives in the output.

       -nooptimize
            Disables certain optimizations.  The only optimization that is currently affected is the
            use of targets by the output C code (see perlguts).  This may  significantly  slow  down
            the generated code, but this is the way xsubpp of 5.005 and earlier operated.

       -noinout
            Disable recognition of "IN", "OUT_LIST" and "INOUT_LIST" declarations.

       -noargtypes
            Disable recognition of ANSI-like descriptions of function signature.

       -C++ Currently  doesn't  do anything at all.  This flag has been a no-op for many versions of
            perl,  at  least  as  far  back  as  perl5.003_07.   It's  allowed  here  for  backwards
            compatibility.

       -s=... or -strip=...
            This option is obscure and discouraged.

            If specified, the given string will be stripped off from the beginning of the C function
            name  in  the generated XS functions (if it starts with that prefix).  This only applies
            to XSUBs without "CODE" or "PPCODE" blocks.  For example, the XS:

              void foo_bar(int i);

            when "xsubpp" is invoked with "-s foo_" will install a "foo_bar" function in  Perl,  but
            really  call  bar(i)  in  C. Most of the time, this is the opposite of what you want and
            failure modes are somewhat obscure, so please avoid this option where possible.

ENVIRONMENT
       No environment variables are used.

AUTHOR
       Originally by Larry Wall.  Turned into the "ExtUtils::ParseXS" module by Ken Williams.

MODIFICATION HISTORY
       See the file Changes.

SEE ALSO
       perl(1), perlxs(1), perlxstut(1), ExtUtils::ParseXS

perl v5.38.2                                 2026-06-12                                    XSUBPP(1)