PING**2
On 25.08.21 20:58, Tobias Burnus wrote:
Early *PING*.
(I also should still review several Fortan patches... There are lots of
patches waiting for review :-/)
On 20.08.21 19:24, Tobias Burnus wrote:
The following is about interoperability (BIND(C)) only.
* The patch adds a missing check for pointer + contiguous.
(Rejected to avoid copy-in issues? Or checking issues?)
* And it corrects an issue regarding len > 1 characters. While
subroutine foo(x)
character(len=2) :: x(*)
is valid Fortran code (the argument can be "abce" or ['a','b','c','d']
or ...)
– and would work also with bind(C) as the len=2 does not need to be
passed
as hidden argument as len is a constant.
However, it is not valid nonetheless.
OK? Comments?
Tobias
PS: Referenced locations in the standard (F2018):
C1554 If proc-language-binding-spec is specified for a procedure,
each of its dummy arguments shall be an interoperable procedure (18.3.6)
or a variable that is interoperable (18.3.4, 18.3.5), assumed-shape,
assumed-rank, assumed-type, of type CHARACTER with assumed length,
or that has the ALLOCATABLE or POINTER attribute.
18.3.1: "... If the type is character, the length type parameter is
interoperable if and only if its value is one. ..."
"18.3.4 Interoperability of scalar variables":
"... A named scalar Fortran variable is interoperable ... if it
is of type character12its length is not assumed or declared by
an expression that is not a constant expression."
18.3.5: Likewise but for arrays.
18.3.6 "... Fortran procedure interface is interoperable with a C
function prototype ..."
"(5) any dummy argument without the VALUE attribute corresponds
to a formal parameter of the prototype that is of a pointer type,
and either
• the dummy argument is interoperable with an entity of the
referenced type ..."
(Remark: those are passed as byte stream)
"• the dummy argument is a nonallocatable nonpointer variable of
type
CHARACTER with assumed character length and the formal
parameter is
a pointer to CFI_cdesc_t,
• the dummy argument is allocatable, assumed-shape,
assumed-rank, or
a pointer without the CONTIGUOUS attribute, and the formal
parameter
is a pointer to CFI_cdesc_t, or
(Remark: those two use an array descriptor, also for
explicit-size/assumed-size
arrays or for scalars.)
• the dummy argument is assumed-type ..."
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