Re: [Patch, Fortran] FINAL (prep patches 2/5): Add internal STRIDE intrinsicg

[Tobias Burnus <burnus at net-b dot de>]

Hi Steve,

Steve Kargl:
> On Mon, Dec 31, 2012 at 01:17:04PM +0100, Tobias Burnus wrote:
> > This new intrinsic is only internally available and will be used by the
> > finalization wrapper to handle noncontiguous arrays.
> What is the plan for when J3 decides to add a
> STRIDE intrinsic

Well, we then add it. As written, this intrinsic is *only* *internally* 
available.

Actually, I do hope that J3 will add a better access to Fortran's array 
descriptor. Currently, one can do a lot of manipulations from C (since 
ISO/IEC TS 29113:2012) but not from Fortran. The better access from 
Fortran also matches the wish of the UK's BSI Fortran Panel: 
ftp://ftp.nag.co.uk/sc22wg5/N1901-N1950/N1923.pdf (4th non-indent 
paragraph).

> At a minimum, please consider adding a leading underscore to the function.

If you had read the patch carefully, you had seen that the intrinsic is 
defined as GFC_PREFIX ("stride"), which expands on most systems to 
"_F._stride".

However, even if I had named it "stride" it were not available as it is 
marked as "make_from_module();". The latter implies that 
gfc_find_function (name)  won't find it. You have to use a symbol which 
has  "sym->intmod_sym_id" set - which is not possible from the user code.

The  "make_from_module();" technique has been added for procedures like 
"c_sizeof" which should be handled via the normal intrinsic handling 
(intrinsic.c, check.c, iresolve.c, trans-intrinsic.c), but where the 
procedure should only be available after using "USE ISO_C_BINDING".

By the way, the symbol also never appears in the tree / assembler as it 
is converted into the respective component access of the array 
descriptor, e.g.  "variable.dim[i].stride".

Tobias