---
name: "xsubpp"
section: "1"
platform: "linux"
package: "perl"
version: "5.40.1-6+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux", "openbsd"]
url: "https://new.carta.tech/xsubpp"
---

# xsubpp(1)

compiler to convert Perl XS code into C code

## 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 *target*s 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)](/perl/1.md), [**perlxs**(1)](/perlxs/1.md), [**perlxstut**(1)](/perlxstut/1.md), ExtUtils::ParseXS