Thomas Jahns authored 3 years ago and Sergey Kosukhin committed 2 years ago

Co-authored-by: Sergey Kosukhin <sergey.kosukhin@mpimet.mpg.de>

Thomas Jahns authored 3 years ago and Sergey Kosukhin committed 2 years ago

* These variables are checked via the JSON files in PIO control setups
  and should not change type unless necessary. Consistency is not a
  necessity.

Both 'head -n 1' and 'sed 1q' exit after printing the first line, which closes
the pipe and kills the compiler's process leaving it no chance to clean any
temporary files it might have created (e.g. Intel compiler creates 'a.out' when
it is called with additional flags like -I, -L, etc., which is the case when
$CC/$FC is an MPI wrapper.

And make sure that the result is the same as for Fortran (FC).

The conditional indicates that FC is available and all required compiler flags
are known.

Instead of tinkering its analogue.

Remove declaration of the 'BUILD_C_INCLUDE' and 'BUILD_FC_INCLUDE' precious variables from the configure script since they are not used.

The shortcut for the ISO C99 test, which simplifies the implementation, is copied from PPM.

The idea is that when an additional feature is enabled, we should run the same
tests as without it plus additional tests for the feature.

The configure options enabling the interfaces are named consistently with the
options enabling Fortran interfaces.

1. Check for FC only if one of the Fortran interfaces is requested.

2. Fail if the Fortran ISO C interface is enabled but FC is not found.

3. Check for F77 only if the C Fortran interface is requested and either FC was
   not found or the user set F77 explicitly. In the latter case, we make sure
   that the generated library is compatible with both FC and F77.

4. Check for Fortran interfaces of MPI and YAXT only when needed and do not fail
   if either of them not found: we can still provide the C Fortran interface.

5. Refactor the Automake conditionals: remove redundant, rename the required in
   a consistent way. Conditionals from acx_options.m4 left unchanged since they
   might affect the integration into CDO.

6. General clean-up and refactoring.

7. Temporarily drop support for the experimental ruby and python interfaces.