[PATCH 08/25] Fix co-array allocation

[Toon Moene]

On 09/20/2018 10:01 PM, Thomas Koenig wrote:

> Hi Damian,
> 
>> On a related note, two Sourcery Institute developers have attempted to 
>> edit
>> the GCC build system to make the downloading and building of OpenCoarrays
>> automatically part of the gfortran build process.  Neither developer
>> succeeded.
> 
> We addressed integrating OpenCoarray into the gcc source tree at the
> recent Gcc summit during the gfortran BoF session.
> 
> Feedback from people working for big Linux distributions was that they
> would prefer to package OpenCoarrays as a separate library.
> (They also mentioned it was quite hard to build.)

Well, Linux distributors have to fit the build of OpenCoarrays into 
*their* build system, which might be just as complicated as we trying it 
to force it into *gcc's* build system ...

For an individual, OpenCoarrays is not hard to build, and the web page 
www.opencoarrays.org offers multiple solutions:

"Installation via package management is generally the easiest and most 
reliable option.   See below for the package-management installation 
options for Linux, macOS, and FreeBSD.  Alternatively, download and 
build the latest OpenCoarrays release  via the contained installation 
scripts or with CMake."

I choose the cmake based one, because I already had cmake installed to 
be able to build ECMWF's (ecmwf.int) eccodes package. It probably helped 
that I also already had openmpi installed. From my command history:

  1754  tar zxvf ~/Downloads/OpenCoarrays-2.2.0.tar.gz
  1755  cd OpenCoarrays-2.2.0/
  1756  ls
  1757  less README.md
  1758  cd ..
  1759  mkdir opencoarrays-build
  1760  cd opencoarrays-build
  1761  (export FC=gfortran; export CC=gcc; cmake ../OpenCoarrays-2.2.0/ 
-DCMAKE_INSTALL_PREFIX=$HOME/opencoarrays)
  1762  make
  1763  make test
  1764  make install

After that, it was a breeze to test my mock weather program 
(moene.org/~toon/random-weather.f90), that I had built until then only 
with -fcoarray=single.

-- 
Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/
Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news