[Bug fortran/45424] F2008: Add is_contiguous intrinsic

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45424

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |burnus at gcc dot gnu.org

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-05-09 16:02:18 UTC ---
(In reply to comment #1)
> a) Array element with nonzero strides

I meant: A an array containing a single element and having a nonunity stride.


> type t
>   integer :: i, j
> end type t
> print *, is_contiguous(x(:)%i) ! Shall be false - but prints "true".

Those kind of arguments can get really tricky! Assume as component a:
    integer :: i(1) ! or "i(2)
or
    class(t), allocatable :: a
or
    integer, allocatable :: a(:)
which is accessed as "is_contiguous(x(:)%a(1))".

Intel and Cray handle it simply: by always returning "F" - even for "type t;
integer :: i; end type", which should have no padding and be contiguous in
memory. We could do the same - or we rule out BT_CLASS, arrays and coarrays and
do then a size check: whole derived type == expr->ts.type size.


Another issue are substrings. For those one needs to check that the substring
range matches the string length.