bug#48342: native-comp emacs gets into an infinite loop at startup if no .el files are available

[Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Dima Kogan <dima@secretsauce.net>
>> Cc: akrl@sdf.org, 48342@debbugs.gnu.org
>> Date: Tue, 11 May 2021 10:29:20 -0700
>> 
>> The maybe_swap_for_el() call in Frame #28 checks for the sources, sees
>> that the file on disk doesn't exist, and throws the warning as expected:
>> 
>> Code:
>>   call2 (intern_c_string ("display-warning")
>> Full context:
>>   https://github.com/emacs-mirror/emacs/blob/bb8b8d717f91a85ca41de9e82246e6975e1ed719/src/lread.c#L1713
>> 
>> Frame #26 is the (display-warning ...)
>> 
>> Frame #25 is (autoload-do-load ... 'display-warning)
>> 
>> Frame #23 is (load "warnings" ...)
>> 
>> The backtrace isn't right about the line number in frame #22, but that
>> function is in lread.c. It's trying to compile "warnings.el".
>
> I guess when we find that a source for some .elc file is not
> available, we should add its .el name to
> native-comp-deferred-compilation-deny-list?

Good idea that's probably the best fix.  I'll come-up with a patch for
this.

Thanks

  Andrea