Re: Merging scratch/no-purespace to remove unexec and purespace

[Andrea Corallo]

Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> Pip Cet via "Emacs development discussions." <emacs-devel@gnu.org>
> writes:
>
>> "Stefan Monnier" <monnier@iro.umontreal.ca> writes:
>>
>>>>> OTOH and IMHO, it would be preferable if that symbol could not crash
>>>>> Emacs.  Can we come up with a good way to fix that, while preserving the
>>>>> check that Andrea wants to keep?
>>>>
>>>> That sounds like a good thing to focus on, yes.  We need to have a value
>>>> in a vector that we Fread that is distinguishable from all other values.
>>>
>>> How 'bout an uninterned symbol `#:foo`?
>>
>> I think those are legal for native-compiled subrs to use (there's a
>> comment about it, at least), so that wouldn't do us any good, would it?
>>
>> Pip
>
> Uninterned symbols are unique, i.e. (eq '#:a '#:a) => nil.
> Wouldn't that help?

Yes. we want and still can use eq in the test, I guess the best is to
create and store an uninterned symbol somewhere, so we can use it to
mark and test those locations in the relocation vector.