The libffi Home Page

Note: This page is out of date. libffi is now largely maintained as part of GCC. Hopefully this separate library will be brought up to date some time. Please contact me if you are interested in helping -- Anthony Green - green@redhat.com

libffi-1.20 was released on October 5, 1998. You can ftp it from sources.redhat.com:/pub/libffi/libffi-1.20.tar.gz. However, newer code is available. See below for details.

libffi is free software. It has a very liberal license.

What is libffi?

Compilers for high level languages generate code that follows certain conventions. These conventions are necessary, in part, for separate compilation to work. One such convention is the "calling convention". The "calling convention" is a set of assumptions made by the compiler about where function arguments will be found on entry to a function. A "calling convention" also specifies where the return value for a function is found.

Some programs may not know at the time of compilation what arguments are to be passed to a function. For instance, an interpreter may be told at run-time about the number and types of arguments used to call a given function. Libffi can be used in such programs to provide a bridge from the interpreter program to compiled code.

The libffi library provides a portable, high level programming interface to various calling conventions. This allows a programmer to call any function specified by a call interface description at run-time.

Ffi stands for Foreign Function Interface. A foreign function interface is the popular name for the interface that allows code written in one language to call code written in another language. The libffi library really only provides the lowest, machine dependent layer of a fully featured foreign function interface. A layer must exist above libffi that handles type conversions for values passed between the two languages.

Supported Platforms

Libffi has been ported to:

SunOS 4.1.3 & Solaris 2.x (Sparc v8)
Irix 5.3 & 6.2 (System V/o32 & n32)
Intel x86 - Linux (System V ABI)
Alpha Linux and OSF/1
m68k - Linux (System V ABI)
PowerPC - Linux (System V ABI)
ARM - Linux (System V ABI)

Libffi has been tested with the egcs 1.0.2 gcc compiler. Chances are that other versions will work. Libffi has also been built and tested with the SGI compiler tools. If you port libffi to another platform, please let me know! I assume that some will be easy (x86 NetBSD), and others will be more difficult (HP, AIX).

How to get it

You can download the latest version from sources.redhat.com:/pub/libffi/.

You can also check out the very latest version via anonymous cvs. Here's how:

 cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/libffi login
     (password is ``anoncvs'')
 cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/libffi co libffi

Once you have it checked out, you can update it with cvs update.

You can also view the cvs archive via cvsweb.

Mailing lists

For such a small piece of software, there are plenty of mailing lists available.

libffi-announce is a low volume mailing list for libffi release announcements
libffi-discuss is a mailing list for asking questions, reporting bugs, etc.

To subscribe to the libffi-announce mailing list, enter your e-mail address:

To subscribe to the libffi-discuss mailing list, enter your e-mail address:

Authors and Credits

Libffi was written by Anthony Green.

Portions of libffi were derived from Gianni Mariani's free gencall library for Silicon Graphics machines.
The sparc port was derived from code contributed by the fine folks at Visible Decisions Inc. Further enhancements were made by Gordon Irlam at Cygnus Solutions (now Red Hat).
The Alpha port was written by Richard Henderson at Red Hat.
Andreas Schwab ported libffi to m68k Linux and provided a number of bug fixes.
Geoffrey Keating ported libffi to the PowerPC.
Raffaele Sena ported libffi to the ARM.
Jesper Skov and Andrew Haley both did more than their fair share of stepping through the code and tracking down bugs.
Thanks to Tom Tromey for bug fixes and configuration help.
Thanks also to Jim Blandy, who provided some useful feedback on the libffi interface.

If you have a problem, or have found a bug, please send a note to libffi-discuss@sources.redhat.com or to me directly (green@redhat.com).