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%//////////////////////////////////////////////////////////////////////////////
%
% Copyright (c) 2007,2009 Daniel Adler <dadler@uni-goettingen.de>,
% Tassilo Philipp <tphilipp@potion-studios.com>
%
% Permission to use, copy, modify, and distribute this software for any
% purpose with or without fee is hereby granted, provided that the above
% copyright notice and this permission notice appear in all copies.
%
% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
%
%//////////////////////////////////////////////////////////////////////////////
\newpage
\section{Library Design}
\subsection{Design considerations}
The \product{dyncall} library encapsulates function call invocation semantics
that depend on the compiler, operating system and architecture.
The core library is driven by a function call invocation engine,
named \emph{CallVM}, that encapsulates a call stack to foreign functions
and manages the following three phases that constitute a truly dynamic function
call:
\begin{enumerate}
\item Specify the calling convention. Some run-time platforms, such as
Microsoft Windows on a 32-bit X86 architecture, even support multiple calling
conventions.
\item Specify the function call arguments in a specific order. The
interface design dictates a \emph{left to right} order for C and C++ function
calls in which the arguments are bound.
\item Specify the target function address, expected return value and
invoke the function call.
\end{enumerate}
The calling convention mode entirely depends on the way the foreign function
has been compiled and specifies the low-level details on how a function
actually expects input parameters (in memory, in registers or both) and how to
return its result(s).
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