Subject: bug#75135: 30.0.93; Infinite loop in comp--native-compile

From: [email-masked]
Date: Sat, 01 Mar 2025 21:52:51 -0800

Stefan Kangas <[email-masked]> writes:

> Andrea Corallo <[email-masked]> writes:
>
>> The attached should be fixing it, could you give it a try?
>
> Ping, Hugh, any chance you could try the below patch?  Thanks.

Currently running 30.1 (git commit 92e96a11752) I confirm that the
infinite loop still exists without the patch.

The problem is resolved with the patch.

Thanks for the fix.

Hugh

>> Circular objects are rare in code and we lived with this for a long
>> time, I'd suggest to install this only on master not to touch the
>> release branch.  Eli WDYT?
>>
>> Thanks
>>
>>   Andrea
>>
>> diff --git a/lisp/emacs-lisp/comp.el b/lisp/emacs-lisp/comp.el
>> index 2966ed255ac..f3b6b8fd606 100644
>> --- a/lisp/emacs-lisp/comp.el
>> +++ b/lisp/emacs-lisp/comp.el
>> @@ -2481,8 +2481,9 @@ comp--ssa-rename-insn
>>                   (setf (comp-vec-aref frame slot-n) mvar
>>                         (cadr insn) mvar))))
>>       (pcase insn
>> -       (`(setimm ,(pred targetp) ,_imm)
>> -        (new-lvalue))
>> +       (`(setimm ,lval ,_imm)
>> +        (when (targetp lval)
>> +          (new-lvalue)))
>>         (`(,(pred comp--assign-op-p) ,(pred targetp) . ,_)
>>          (let ((mvar (comp-vec-aref frame slot-n)))
>>            (setf (cddr insn) (cl-nsubst-if mvar #'targetp (cddr insn))))