[Patch, Fortran] PR 85599: warn about short-circuiting of logical expressions for non-pure functions

[Dominique d'Humières]

Hi Janus,

> after the dust of the heated discussion around this PR has settled a
> bit, here is another attempt to implement at least some basic warnings
> about compiler-dependent behavior concerning the short-circuiting of
> logical expressions. …

IMO your patch is missing the only point I agree with you on this issue, i.e.,
the short-circuit evaluation and the related portability issues should be 
documented.

With your patch what happens if check() is an external function?

Your patch is focusing on pr85599 and ignore pr57160.

What to do with

if(x>0 .and. sort(x)<10.0*log(x)) …

which is not portable to compilers computing the two expressions?

Cheers,

Dominique