Re: FC vs. F77 in Makefiles

[Mike Miller]

On Mon, Nov 24, 2014 at 10:57:40 -0500, John W. Eaton wrote:
> On 11/23/2014 09:24 PM, Rik wrote:
>>
>> All,
>>
>> I'm cleaning up configure.ac a bit and I came across this:
>>
>> FC=$F77
>> AC_SUBST(FC)
>>
>> which makes FC an alias for F77 in Makefiles.  However, all of the
>> Makefile
>> rules I see use $F77.  Is there something I'm missing or can we delete
>> this
>> as cruft?
>>
>> Just to test, I commented out the two lines in configure.ac and re-built
>> Octave and there were no issues.
>
>
> There are a number of places where FC appears, so you'll need to fix those
> if you eliminate the substitution.
>
> Maybe it would be best to use FC consistently instead of F77, including
> using the AC_PROG_FC macro instead of F77?  I'm not sure of the implications
> though.

My understanding of Automake is that it uses particular compiler
variables for predefined lists of source file extensions. It will
invoke the $(F77) compiler for files ending with .f and .for, and the
$(FC) compiler for files ending in .f90, .f95, .f03, and .f08. Since
all of our Fortran sources end in .f and .for, and are Fortran 77
compatible, I don't think $(FC) is (or can or should be) currently
used.

-- 
mike