[PATCH] fortran/28548 -- Optional argument fails.

[Paul Thomas]

Steve,

OK with the proviso that the error is turned into a warning; yes, I 
think that Martin is correct about the standard stating that this is 
only an error if the argument is missing.   Applying a runtime error 
looked horribly messy, although a library function might be the way 
around it.   I have suggested a new wording in a Bugzilla atachment to 
the PR.  This means that the dg-error's in the original testcase must be 
changed to dg-warning's.  Would it be an idea to make this conditional 
on -pedantic too?

I do apologise for not reading the section 12.4.1.5 carefully enough and 
thank you, Steve, for covering my a**e whilst I was away.  An upside is 
that we have all learned that attr.elemental is not always what it 
appears to be!

Best regards and thanks

Paul

>The attach patch appears to fix the problem noted in
>fortran/28548.  The problem is that the internal functions
>__convert_* are marked as elemental Fortran procedures,
>so that the elemental infrastructure can be used to deal
>with both scalar and array arguments.  Enforcement of
>section 12.4.1.5 of the standard is catching these 
>functions (as it should if these weren't internal functions).
>
>I've bootstrapped and regression tested this patch on
>i386-*-freebsd.
>
>2006-08-01  Steven G. Kargl <kargls@comcast.net>
>
>	PR fortran/28548
>	* resolve.c (resolve_elemental_actual): Special case __convert_*
>	with respect to section 12.4.1.5.
>
>	* gfortran.dg/internal_convert.f90: New test.
>
>  
>
>------------------------------------------------------------------------
>
>Index: resolve.c
>===================================================================
>--- resolve.c	(revision 115827)
>+++ resolve.c	(working copy)
>@@ -1012,7 +1012,8 @@
> 	    && arg->expr->symtree->n.sym->attr.optional
> 	    && formal_optional
> 	    && arg->expr->rank
>-	    && (set_by_optional || arg->expr->rank != rank)) 
>+	    && (set_by_optional || arg->expr->rank != rank)
>+	    && !(isym && isym->generic_id == GFC_ISYM_CONVERSION))
> 	{
> 	  gfc_error ("'%s' at %L is an array and OPTIONAL; it cannot "
> 		     "therefore be an actual argument of an ELEMENTAL " 
>  
>
>------------------------------------------------------------------------
>
>! { dg-do compile }
>! Test fix for PR fortran/28548.
>!
>SUBROUTINE foo(a, d)
>  real a
>  integer, dimension(3), optional :: d
>  if (present(d)) d = d + a
>END SUBROUTINE
>  
>