llvm dev - Mar 2010 - [LLVMdev] setting parameter attributes on function returns

everyone--

Maybe I'm missing it, but I don't see how to apply parameter attributes
to function return types in either the C-language or OCaml bindings.  Can
anybody help clue me in?  Thanks.


—
j h woodyatt <jhw at conjury.org>
http://jhw.vox.com/

On Mar 10, 2010, at 21:33, james woodyatt wrote:
> 
> Maybe I'm missing it, but I don't see how to apply parameter
attributes to function return types in either the C-language or OCaml bindings. 
Can anybody help clue me in?  Thanks.
I hope I can assume from the lack of response to my question that the answer is
No, I'm not missing anything: the functionality is missing from both the
C-language and OCaml bindings.  Should I also assume that this is an oversight
and that a patch would be welcome?


—
j h woodyatt <jhw at conjury.org>
http://jhw.vox.com/

On Mar 12, 2010, at 1:49 PM, james woodyatt wrote:
> On Mar 10, 2010, at 21:33, james woodyatt wrote:
>> 
>> Maybe I'm missing it, but I don't see how to apply parameter
attributes to function return types in either the C-language or OCaml bindings. 
Can anybody help clue me in?  Thanks.
> 
> I hope I can assume from the lack of response to my question that the
answer is No, I'm not missing anything: the functionality is missing from
both the C-language and OCaml bindings.  Should I also assume that this is an
oversight and that a patch would be welcome?
> 
I'll respond. :-)

What is it you want? You say "parameter attributes", but a return type
isn't a parameter (as far as I know). And I don't believe that C allows
you to specify an attribute on a return type itself.

Let's hypothesize, though. If you want to apply an attribute to a type, then
you may do so in the GCC way with the __attribute__(()) syntax:

struct A {
  int f[3];
} __attribute__((aligned(8)));

or:

typedef int foo __attribute__((aligned(13)));

and then use that in with your functions:

foo func() {
  foo f = 37;
  /* ... */
  return f;
}

If that's what you want, then we will place the attribute on the type itself
(assuming it's an attribute we support and haven't forgotten to
implement, etc.).

-bw