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

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

On Tuesday, April 16, 2019 at 11:07:24 PM UTC+2, Niklas Holsti wrote:
> On 19-04-16 23:56 , Lucretia wrote:
> > On Tuesday, 16 April 2019 13:11:36 UTC+1, Mark Lorenzen  wrote:
> >
> >> How can it be ensured that a library written in Ada does not
> >> require any elaboration. Pragma Pure? I think that such libraries
> >> are "nice" but pragma Pure is too restrictive for that purpose. In
> >> such cases it would be good, if e.g. the OP's problem could be
> >> solved at compile time without any elaboration.
> 
> Why are you so fixated on elaboration? Many non-Ada libraries require 
> initialization calls. Moreover, I believe a C++ program can have 
> compiler-generated initialization code similar to Ada elaboration code.
> 
> > I don't think it can, going by this thread. I also think this is why
> > Ada will fail in other environments, i.e. not security or safety
> > critical stuff, but where performance is important.
> 
> Performance is plenty important in many embedded real-time applications, 
> where Ada works just fine.
> 
> Elaboration of library items consumes execution time only at the start 
> of a program. Do you have some stringent start-up deadlines?
> 
> -- 
> Niklas Holsti
> Tidorum Ltd
> niklas holsti tidorum fi
>        .      @       .

Let's say I'm writing a static library in Ada that is to be used by a program written in C.

I can define a C-friendly API and export the API subprograms, but what happens if the library needs elaboration? Using GPRbuild I can define the library as a "standalone library" such that the binder generates the necessary initialization subprogram that performs elaboration. This is of course tool specific with the implications that this imposes.

Regards,
Mark L