[Info-vax] Architecture specific code in VMS Fortran

[Joseph Huber]

Tom Wade wrote:

> Hello,
> 
> I've checked out the HP Fortran manuals for compiler directives in code
> that can select based on the
> architecture (VAX/Alpha/IA64).  It seems the CDEC$ IF DEFINED stuff is the
> way to go, but although it describes how to define and test variables, I
> can't see a list of predefined variables such as
> the current architecture.  I want to do something like
> 
> CDEC$ IF DEFINED (VAX)
> 
>   <code to be compiled only if on VAX>
> CDEC$ ENDIF
> 

Since I also found no way to do it, I'm used to use standard C preprocessor 
directives for conditional compilation.
Then either use C/COMMENTS=AS_IS/NOLINE_DIRECTIVES/PREPROC=fortranoutputfile 
or 
the Sun studio FPP Fortran preprocessor 
(see 
http://developers.sun.com/sunstudio/products/previous/fortran/whitepapers/wp-
fpp/index.html or download from http://www.netlib.org/fortran/).

For my use I added some predefined macros in init.c like
#ifdef __VMS
 dodef2("__VMS","1",1);
#endif
#ifdef __vax
 dodef2("__vax","1",1);
#endif
#ifdef __alpha
 dodef2("__alpha","1",1);
#endif

Using standard preprocessor has the advantage of making source files working 
with u*x compiler suites like gfortran.
  
-- 
 
 Joseph Huber   - http://www.huber-joseph.de