[Mesa-users] f90 modules in f77

[Travis Metcalfe]

Thanks, this is helpful. When I add "use [module], only: [variable]" to my 
fixed-source code, I can then "print *,[variable]" as long as the variable 
is declared as "public" in the module. Works just like a common block.

Travis


On Fri, 8 Dec 2017, Rob Farmer wrote:

>> However, we're not using any F77 compilers. The F77 program will be
> compiled with an F90 compiler, right? In that case, it should be no
> problem. Just add the "use blahblah" to the F77 program.
>
>> As an aside: thinking of a file as 'F77' or 'F90' is not quite right. You
> should think of .f files as 'fixed-source' files (with formatting
> constraints, e.g. start on the 6th column); and .f90 files are
> 'free-source' files (without these constraints). Both can contain valid
> Fortran 77/90/95/2003/etc code. In that respect, any valid fixed-source
> Fortran 77 file is automatically a valid fixed-source Fortran 90 file.
>
> As an example look at the code in $MESA_DIR/net/test/src These are .f files
> but have use module statements, some are modules themselves
>
> Rob
>
> On 8 December 2017 at 19:14, RICHARD H D TOWNSEND via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
>
>> I think it would be difficult to use an F90 module from an F77 program
>> compiled with an F77 compiler.
>>
>> However, we're not using any F77 compilers. The F77 program will be
>> compiled with an F90 compiler, right? In that case, it should be no
>> problem. Just add the "use blahblah" to the F77 program.
>>
>> As an aside: thinking of a file as 'F77' or 'F90' is not quite right. You
>> should think of .f files as 'fixed-source' files (with formatting
>> constraints, e.g. start on the 6th column); and .f90 files are
>> 'free-source' files (without these constraints). Both can contain valid
>> Fortran 77/90/95/2003/etc code. In that respect, any valid fixed-source
>> Fortran 77 file is automatically a valid fixed-source Fortran 90 file.
>>
>> cheers,
>>
>> Rich
>>
>>> On Dec 8, 2017, at 12:05 PM, Travis Metcalfe <travis at spsci.org> wrote:
>>>
>>> Hello,
>>>
>>> I'm looking for a way to share data between some older f77 code and the
>> MESA/GYRE modules. In f77, subroutines could share data with each other
>> through common blocks. This appears to be replaced with modules and "use
>> [module name]" in f90.
>>>
>>> What I have been unable to find online or in the mesa-users archive is
>> how to use an f90 module from an f77 program. Is it possible?
>>>
>>> Thanks,
>>>
>>> Travis
>>
>>
>