(j3.2006) TKR for C Interop
Wed Feb 28 16:42:33 EST 2007
On Wednesday 28 February 2007 13:01, Bill Long wrote:
> Struct components either have documented names or not.? This is direction
OK, I was not aware of "small-group" decisions to change the API to a mixed
struct/function approach (which is fine by me, modulo some details I complain
For such an approach, the Fortran->C descriptor function should set the rank
and type information to invalid values if they are not available (say 0 for
rank and -1 for size of the element in bytes), or set them to valid values if
they are available in the Fortran descriptor.
> The other functions create/destroy a shell C descriptor
Why is this necessary? If we expect that the C descriptor will not match most
vendors descriptors (and Craig can easily tell you this for several
compilers), what is the point of making the C struct soo opaque? Let's allow
the programmer to directly declare C descriptors without "creating" and
"destroying" them. Some components of the C struct can still be opaque.
In C, structs are either of fixed size (this means rank-independent in our
particular case), or they have flexible array members. I don't know of an
in-between alternative. Which one of these two is this C struct you are
BTW, C also has "incomplete types" which have unspecified size:
"The use of a type specifier of the syntactic classes
<structure-type-reference> ... without a preceding definition...is alowed
when the size of the structure is not required, including when declaring:
1. pointers to the structure
2. a typedef name as a synonym for the structure"
This is like a "handle" to a descriptor.
I see more open (and more fundamental) questions than just the triplets.
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