fpm Compiler support and recognition

Came up in #220.

At some point we might have to determine which compiler is used with fpm, therefore I tried to collect some information on the various Fortran compilers around. I only have first hand access to a fraction of them, so most of these information are second hand from HPC documentations or build systems.

Feel free to correct or add information to this table. Alternatively, we could move this table to the wiki.

vendor	Fortran compiler	C compiler	Module output directory	Module include directory	OpenMP	Free for OSS
Gnu	`gfortran`	`gcc`	`-J`	`-I`	`-fopenmp`	:heavy_check_mark:
Intel	`ifort`	`icc`	`-module`	`-I`	`-qopenmp`	:heavy_check_mark:
Intel (Windows)	`ifort`	`icc`	`/module:path`	`/I`	`/Qopenmp`	:heavy_check_mark:
Intel oneAPI	`ifx`	`icx`	`-module`	`-I`	`-qopenmp`	:heavy_check_mark:
PGI	`pgfortran`	`pgcc`	`-module`	`-I`	`-mp`	:heavy_check_mark:
NVIDIA	`nvfortran`	`nvc`	`-module`	`-I`	`-mp`	:heavy_check_mark:
LLVM flang	`flang`	`clang`	`-module`	`-I`	`-mp`	:heavy_check_mark:
LFortran	`lfortran`	---	?	?	?	:heavy_check_mark:
Lahey/Futjitsu	`lfc`	?	`-M`	`-I`	`-openmp`	?
NAG	`nagfor`	?	`-mdir`	`-I`	`-openmp`	:x:
Cray	`crayftn`	`craycc`	`-J`	`-I`	`-homp`	?
IBM	`xlf90`	?	`-qmoddir`	`-I`	`-qsmp`	:heavy_check_mark:
Oracle/Sun	?	?	`-moddir=`	`-M`	`-xopenmp`	?
Silverfrost FTN95	`ftn95`	?	?	`/MOD_PATH`	?	?
Elbrus	?	`lcc`	`-J`	`-I`	`-fopenmp`	?
Hewlett Packard	?	?	?	?	?	discontinued
Watcom	?	?	?	?	?	discontinued
PathScale	?	?	`-module`	`-I`	`-mp`	discontinued
G95	?	?	`-fmod=`	`-I`	`-fopenmp`	discontinued
Open64	?	?	`-module`	`-I`	`-mp`	discontinued
Unisys	?	?	?	?	?	discontinued

For now it might be sufficient to only support GCC, since we only guarantee that fpm works when compiled with GCC right now.

First class compiler support requires access to the compiler to allow testing in a CI environment, some of the commercial compilers have free versions for open source developers available.

Oct 31 '20 11:10 awvwgk

Overview of compilers known by the meson build system can be found here, actual implementation is here.

Oct 31 '20 11:10 awvwgk

Awesome, thanks @awvwgk this is super useful! I've edited to include Intel differences on Windows.

Oct 31 '20 11:10 LKedward

Thanks for putting this together. It will be invaluable as we try to support more compilers.

Nov 02 '20 20:11 everythingfunctional

I have asked NAG to have free access for use in maintaining NAG support for Meson build system, but never got a reply. I did get replies to other email topics with NAG.
Intel (non-oneAPI) is also free for OSS on Windows
IBM XL is generally available at no cost assuming you have an IBM Power system to run it on.

Nov 06 '20 20:11 scivision

I found that Ubuntu Focal (ubuntu-20.04 image) has a flang package available.

Nov 22 '20 11:11 awvwgk

This Ubuntu flang possibly came from Debian. It might be quite out of date i.e. syntax bugs that might make issues for modern Fortran packages.

Nov 22 '20 19:11 scivision

@awvwgk This has to be the most comprehensive listing of Fortran compilers that I've ever seen. Bravo!

Oct 03 '22 04:10 rouson

Yes I think this would be great for the WIki insetad of Issue. Also, PGI is now also discontinued, replaced by NVIDIA

Oct 03 '22 19:10 scivision

Feel free to create a wiki page for it, the wiki should be still world-editable.

Oct 21 '22 18:10 awvwgk

The wiki isn't world editable

Oct 23 '22 17:10 scivision

That can be fixed. Try again.

Oct 23 '22 18:10 awvwgk

Thanks, I put an updated version of this table at https://github.com/fortran-lang/fpm/wiki/Compiler-support

Oct 26 '22 19:10 scivision