Re: [Patch, Fortran, OOP] PR 43388: [F2008] ALLOCATE with MOLD=

[Janus Weil <janus at gcc dot gnu dot org>]

>> Unfortunately I don't have access to any other compiler supporting
>> this feature (is there any?). Can someone check if NAG supports MOLD
>> and if yes if it allows SOURCE together with MOLD?
>
> I cannot try NAG but I can try crayftn:
>
>
> $ cat test.f90
> integer, allocatable :: a, b, c
> allocate (a, source=b)
> allocate (a, mold=c)
> allocate (a, source=b, mold=c)
> end
>
> $ ftn test.f90
> /opt/cray/xt-asyncpe/3.9/bin/ftn: INFO: linux target is being used
>
> allocate (a, source=b, mold=c)
> ? ? ? ? ? ? ? ? ? ?^
> ftn-1922 crayftn: ERROR $MAIN, File = test.f90, Line = 4, Column = 21
> ?Only one source-expr may be specified for an ALLOCATE statement.


Ok, since at least the Cray compiler and Dick Hendrickson (and Steve?)
seem to support Tobias' interpretation that SOURCE and MOLD cannot
appear together, I probably have to face the fact that my initial
naive interpretation was incorrect.

So, what does that mean for the implementation? One can argue that we
don't need an expr4 if SOURCE and MOLD cannot appear together. But
then, if I put either of them into expr3, what is the best way to
distinguish between SOURCE and MOLD at resolution stage? I guess I
could just put a one-bit flag 'mold' into gfc_code.ext.alloc. Any
better ideas?

Cheers,
Janus