1%////////////////////////////////////////////////////////////////////////////// 2% 3% Copyright (c) 2007,2009 Daniel Adler <dadler@uni-goettingen.de>, 4% Tassilo Philipp <tphilipp@potion-studios.com> 5% 6% Permission to use, copy, modify, and distribute this software for any 7% purpose with or without fee is hereby granted, provided that the above 8% copyright notice and this permission notice appear in all copies. 9% 10% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17% 18%////////////////////////////////////////////////////////////////////////////// 19 20\newpage 21\section{Library Design} 22 23 24\subsection{Design considerations} 25 26The \product{dyncall} library encapsulates function call invocation semantics 27that depend on the compiler, operating system and architecture. 28The core library is driven by a function call invocation engine, 29named \emph{CallVM}, that encapsulates a call stack to foreign functions 30and manages the following three phases that constitute a truly dynamic function 31call: 32 33\begin{enumerate} 34\item Specify the calling convention. Some run-time platforms, such as 35Microsoft Windows on a 32-bit X86 architecture, even support multiple calling 36conventions. 37\item Specify the function call arguments in a specific order. The 38interface design dictates a \emph{left to right} order for C and C++ function 39calls in which the arguments are bound. 40\item Specify the target function address, expected return value and 41invoke the function call. 42\end{enumerate} 43 44The calling convention mode entirely depends on the way the foreign function 45has been compiled and specifies the low-level details on how a function 46actually expects input parameters (in memory, in registers or both) and how to 47return its result(s). 48 49 50