Re: Trouble writing Ada callback from C

[Vadim Godunko <vgodunko@gmail.com>]

On Sep 11, 11:57 am, Jerry <lancebo...@qwest.net> wrote:
> I have a problem with writing an Ada procedure, used as a callback
> from C, in which one of the arguments is an output char * (in the C
> version). The actual length of the returned "string" isn't known at
> calling time, even though the caller apparently allocates 40
> characters (see below). However, the actual number of characters
> returned by the C version is less than 40.
>
> My problem is how to pass probably a char_array back out which is the
> correct length, but which length is not known at the time the Ada
> callback is called from C.
>

subtype constrained_char_array is Interfaces.C.char_array (1 .. 40);

procedure Y (X : out constrained_char_array);
pragma Convention (C, Y);