Re: Multiple pragma Imports

[Matthew Heaney <matthew_heaney@acm.org>]

dewar@gnat.com writes:

> I thought I would give a heads up on a problem we
> have found in GNAT that we suspect exists in other
> compilers (certainly DEC Ada 83 for example). Consider
> the following:
> 
>    function Junk return Integer;
>    pragma Import (C, Junk, "junk");
> 
>    function Junk return My_Integer;
>    pragma Import (C, Junk, "junk");
> 
> We have seen this pattern in several bindings, including
> the x11 bindings from Intermetrics. But the above code is
> in fact illegal.

[snip]

> I would be delighted to find out that my analysis is
> incorrect here, but I am pretty sure it is right, and I
> have discussed it with other folk, including Bob Duff,
> before posting here.


I really miss the DEC pragmas here, where you could specify the argument
type, the return type (for a function), and even the argument passing
mechanism, right there in the pragma.  

The Import pragma seems a bit anemic (as the example above
demonstrates), and I would have preferred that DEC pragmas been designed
into the language.

I've never liked the fact that one pragma applies to multiple
subprograms, for example:

  <declare a few "+" functions>
  <declare a few "-" functions>

private

  pragma Inline ("+");
  pragma Inline ("-");


I'd rather be able to specify each subprogram individually in the
pragma.