Re: Renaming primitives.

[Blady <p.p11@orange.fr>]

Le 12/01/2024 à 04:59, Randy Brukardt a écrit :
> "Blady" <p.p11@orange.fr> wrote in message
> news:unoep3$2uqo6$2@dont-email.me...
>> Le 11/01/2024 à 03:18, Randy Brukardt a écrit :
>>> "Blady" <p.p11@orange.fr> wrote in message
>>> news:unls1j$2f0up$3@dont-email.me...
>>>> Is a procedure renaming equivalent to a simple call?
>>>
>>> General point: "Equivalent" is never true in programming language design.
>>> If
>>> construct A is equivalent in every way to construct B, then they have to
>>> be
>>> the same construct.
>>>
>>> For instance, in your example below, the two subprogram declarations have
>>> different identifiers which have different visibility (two declarations
>>> cannot be at exactly the same place), so there is at least one way that
>>> they're not equivalent.
>>>
>>> So, if you want to talk about "equivalence", you need to qualify that by
>>> what properties you are interested in.
>>
>> Well, I hadn't find a better word :-(
> 
> You have to say something like "equivalent in run-time behavior";
> "equivalent" by itself is always False.

Thanks, I like it.

>>> ...
>>>> What is happening if My_Generic_Handler change?
>>>
>>> Nothing. The names in a renaming are evaluated when the renaming is
>>> declared. If there are parts that could change, the compiler has to save
>>> the
>>> values at the point of the renaming. That's true for all forms of
>>> renaming
>>> (some names, like package names, can't change meaning so the example
>>> isn't
>>> possible, of course).
>>
>> Yet, the code:
>>     My_Log_3 ("Hei");
>>     My_Generic_Handler := My_Full_Handler'Access;
>>     My_Log_3 ("Hei");
>> gives:
>> Hei
>> Full Hei
>>
>> I thought that was correct, wasn't it?
> 
> Shouldn't be correct. The "name" is evaluated during a renaming, and the
> renamed entity does not change afterwards. So whatever subprogram My_Log_3
> designates for the first call should be the same for the second call.
> 
>> GNAT issue ?
> 
> Appears to be (of course, without seeing the full code I can't say
> definitively; people here often post snippets that aren't quite the same as
> the actual code they tried to run. I wouldn't expect that with you, but we
> all make mistakes. :-).

I quote you :-) and attached the full source code.
You might follow or comment on the created issue:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113350