User guide

18-83
DirectC Interface
function return_pointer
function return_reg
_____________________ [DirectC interface] _________
Mixing Direct And Abstract Access
If you want some C/C++ functions to use direct access and others to
use abstract access you can do so by using a combination of "A" or
"C" entries for abstract or direct access in the declaration of the
function and the use of the +abstract suffix. The following table
shows the result of these combinations:
Specifying the DirectC.h File
The C/C++ functions need the DirectC.h file in order to use abstract
access. This file is located in $VCS_HOME/include (and there is a
symbolic link to it at $VCS_HOME/’vcs -platform’/lib/DirectC.h). You
need to tell VCS where to look for it. You can accomplish this in the
following three ways:
• Copy the $VCS_HOME/include/DirectC.h file to you current
directory. VCS will always look there for it.
• Establish a link in the current directory to the $VCS_HOME/
include/DirectC.h file.
no +abstract suffix include the +abstract suffix
extern
(no mode specified)
direct access abstract access
extern "A" abstract access abstract access
extern "C" direct access direct access