bug#27718: 26.0.50; (cl-typep instance-ab 'class-a) gives wrong answer when compiled

[Noam Postavsky]

On Mon, Jul 24, 2017 at 3:44 PM, Stefan Monnier
<monnier@iro.umontreal.ca> wrote:
>>> +  DEFSYM (Qbyte_compile_plist_environment, 
>>> "byte-compile-plist-environment");
>
>> I find having to hardcode byte-compile-plist-environment in get rather ugly.
>
> Hmm... I'm still not quite sure how best to deal with this, but it does
> occur to me that we could introduce a new `define-propval' value, which
> would be like `put' but for use at top-level.  It could differ from
> `put' in that the byte-compiler could keep track of those in
> byte-compile-plist-environment, and that they could record themselves in
> load-history for unload-feature to be able to undo them.
>
> It doesn't help on the `get' side, tho.

Right. We need `get' to be aware of what the compiler has read, so it
will need to have a reference to the compiler in there somewhere. We
could name it differently and point the reference in the other
direction, as in DEFSYM (Qalternate_plist_environment...) and have the
byte compiler use that instead, which might be slightly more
aesthetically pleasing. The other possibility is to introduce a
different kind of `get' and use that in places that need to be aware
of what the compiler has read.

I don't see a third option.