Re: Why can't objects be static in Ada?

[Mark Lorenzen <mark.lorenzen@gmail.com>]

On Thursday, April 11, 2019 at 2:40:40 PM UTC+2, Lucretia wrote:
> Someone sent in a pull request to my bindings and had to change a few constants to functions because objects can't be static. For an example:
> 
>    type Sizes is
>       record
>          Width  : Dimension;
>          Height : Dimension;
>       end record with
>      Convention => C;
> 
>    Zero_Size : constant Sizes := (others => Natural_Dimension'First);
> 
> Why can't Zero_Size be compiled as static in this pre-elaborated package?
> 
> This seems to be a major flaw in Ada imo.
> 
> Luke.

I don't think it's not an Ada flaw. From an Ada perspective the object is constant - irrespective if it's static (it's value is set at compile-time) or not.

I guess it's compiler-dependent. There are a number of cases where GNAT could be better at generating static objects. This is especially true for objects of a (discriminated) record type.

Try adding "Restrictions (No_Elaboration_Code)" to the spec and see if it forces GNAT into doing what you want to.

Regards,
Mark L