R devel - Nov 2014 - Using FPP preprocessor for Fortran Code

Dear R Developers,

For package seriation I use Fortran code. I recently got a request to add

#if defined(__ICC) || defined(__INTEL_COMPILER)
       USE IFPORT
#endif

to the code since the Intel Fortran compiler otherwise has problems with 
rand(). However, to enable the FPP preprocessor I have to either add a 
compiler flag (-cpp for gFortran) which is possibly not portable or 
change the extension to .F, .fpp, .FPP (and a few others) which 
automatically invokes the preprocessor (hopefully on all platforms). I 
tried .fpp and added the following to Makevars:

OBJECTS=arsa.o bburcg.o bbwrcg.o bea.o criterion.o dist.o fprintf.o 
greedy.o optimal.o stress.o

%.o: %.fpp
         $(F77) $(ALL_FFLAGS) -c $< -o $@

It seems to work (I tried Linux and Windows) but R CMD check gives me:

* checking if this is a source package ... WARNING
Subdirectory ?src? contains:
   arsa.fpp bburcg.fpp

Is there a different preferred method to do this? Is it possible to add 
support for Fortran with the fpp preprocessor (.fpp files) to the R 
package building process?

Thanks,
Michael

-- 
   Michael Hahsler, Assistant Professor
   Department of Engineering Management, Information, and Systems
   Department of Computer Science and Engineering (by courtesy)
   Bobby B. Lyle School of Engineering
   Southern Methodist University, Dallas, Texas

   office: Caruth Hall, suite 337, room 311
   email:  mhahsler at lyle.smu.edu
   web:    http://lyle.smu.edu/~mhahsler

On 30/11/2014 06:46, Michael Hahsler wrote:
> Dear R Developers,
>
> For package seriation I use Fortran code. I recently got a request to add
>
> #if defined(__ICC) || defined(__INTEL_COMPILER)
>        USE IFPORT
> #endif
>
> to the code since the Intel Fortran compiler otherwise has problems with
> rand(). However, to enable the FPP preprocessor I have to either add a
'Writing R Extensions' advises you not to use system RNGs, so this is a 
good time to comply.  ?6.6 of 'Writing R Extensions' describes how to 
use the R RNG from Fortran.
> compiler flag (-cpp for gFortran) which is possibly not portable or
> change the extension to .F, .fpp, .FPP (and a few others) which
> automatically invokes the preprocessor (hopefully on all platforms). I
Many compilers do not know about .fpp or .FPP, and .F is not portable to 
case-independent file systems.
> tried .fpp and added the following to Makevars:
>
> OBJECTS=arsa.o bburcg.o bbwrcg.o bea.o criterion.o dist.o fprintf.o
> greedy.o optimal.o stress.o
>
> %.o: %.fpp
>          $(F77) $(ALL_FFLAGS) -c $< -o $@
>
> It seems to work (I tried Linux and Windows) but R CMD check gives me:
>
> * checking if this is a source package ... WARNING
> Subdirectory ?src? contains:
>    arsa.fpp bburcg.fpp
>
> Is there a different preferred method to do this? Is it possible to add
> support for Fortran with the fpp preprocessor (.fpp files) to the R
> package building process?
The support is as described in 'Writing R Extensions' ?1.1.5.

You could add flags in PKG_FFLAGS, but you would have to use a configure 
script to find the right one (-xpp=fpp is also used).

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Emeritus Professor of Applied Statistics, University of Oxford
1 South Parks Road, Oxford OX1 3TG, UK