(CDT) A portable foreign function interface library
Compilers for high level languages generate code that follow 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. Thelibffi' 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 abovelibffi' that handles
type conversions for values passed between the two languages.
