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libffi
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<h1>The libffi Home Page</h1>
<h3>Note: This page is out of date. libffi is now largely maintained as part of <a href="http://gcc.gnu.org">GCC</a>. 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</h3>
<b>libffi-1.20</b> was released on October 5, 1998. You can ftp it
from <a
href="ftp://sources.redhat.com:/pub/libffi/libffi-1.20.tar.gz">sources.redhat.com:/pub/libffi/libffi-1.20.tar.gz</a>.
However, newer code is available. See below for details.
<p>
libffi is free software. It has a very <a
href="http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/libffi/LICENSE?rev=1.1&cvsroot=libffi&hideattic=1&sortbydate=0">liberal
license</a>.
<h2>What is libffi?</h2>
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.
<p>
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.
<p>
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.
<p>
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.
<h2>Supported Platforms</h2>
Libffi has been ported to:
<ul>
<li> SunOS 4.1.3 & Solaris 2.x (Sparc v8)
<li> Irix 5.3 & 6.2 (System V/o32 & n32)
<li> Intel x86 - Linux (System V ABI)
<li> Alpha Linux and OSF/1
<li> m68k - Linux (System V ABI)
<li> PowerPC - Linux (System V ABI)
<li> ARM - Linux (System V ABI)
</ul>
Libffi has been tested with the <a
href="http://www.cygnus.com/egcs/">egcs</a> 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).
<h2>How to get it</h2>
You can download the latest version from <a href="ftp://sources.redhat.com/pub/libffi/">sources.redhat.com:/pub/libffi/</a>.
<p>
You can also check out the very latest version via anonymous cvs.
Here's how:
<pre>
cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/libffi login
(password is ``anoncvs'')
cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/libffi co libffi
</pre>
Once you have it checked out, you can update it with <tt>cvs update</tt>.
<p>
You can also <a
href="http://sources.redhat.com/cgi-bin/cvsweb.cgi/libffi/?cvsroot=libffi">
view the cvs archive</a> via cvsweb.
<h2>Mailing lists</h2>
For such a small piece of software, there are plenty of mailing lists
available.
<ul>
<li><a href="/ml/libffi-announce/"><tt>libffi-announce</tt></a> is a
low volume mailing list for libffi release announcements
<li><a href="/ml/libffi-discuss/"><tt>libffi-discuss</tt></a> is a
mailing list for asking questions, reporting bugs, etc.
</ul>
<p>To subscribe to the <code>libffi-announce</code> mailing list, enter your
e-mail address:
<form method="get" action="/cgi-bin/subscribe-sourceware">
<input type="hidden" name="listname" value="libffi-announce">
<input type="text" name="username" size="16"> <input type="Submit" name="submi
t" value="Sign me up!">
</form>
<br>To subscribe to the <code>libffi-discuss</code> mailing list, enter your
e-mail address:
<form method="get" action="/cgi-bin/subscribe-sourceware">
<input type="hidden" name="listname" value="libffi-discuss">
<input type="text" name="username" size="16"> <input type="Submit" name="submi
t" value="Sign me up!">
</form>
<p>
<h2>Authors and Credits</h2>
Libffi was written by <a href="http://people.redhat.com/green/"><b>Anthony Green</b></a>.
<ul>
<li> Portions of libffi were derived from <b><a href="http://mariani.ws/~gianni/">Gianni Mariani</a></b>'s free gencall
library for Silicon Graphics machines.
<li> The sparc port was derived from code contributed by the fine folks at
<b><a href="http://www.vdi.com">Visible Decisions Inc</a></b>. Further enhancements were made by <b>Gordon Irlam</b> at Cygnus Solutions (now Red Hat).
<li>The Alpha port was written by <b>Richard Henderson</b> at Red Hat.
<li><b>Andreas Schwab</b> ported libffi to m68k Linux and provided a number of
bug fixes.
<li><b>Geoffrey Keating</b> ported libffi to the PowerPC.
<li><b>Raffaele Sena</b> ported libffi to the ARM.
<li><b>Jesper Skov</b> and <b>Andrew Haley</b> both did more than their fair share of
stepping through the code and tracking down bugs.
<li>
Thanks to <b>Tom Tromey</b> for bug fixes and configuration help.
<li>
Thanks also to <b>Jim Blandy</b>, who provided some useful feedback on the libffi
interface.
</ul>
<p>
If you have a problem, or have found a bug, please send a note to
<a href="mailto:libffi-discuss@sources.redhat.com">libffi-discuss@sources.redhat.com</a> or
to me directly (<a href="mailto:green@redhat.com">green@redhat.com</a>).
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