GNU bug report logs - #41357
28.0.50; GC may miss to mark calle safe register content

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Message #38 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Paul Eggert <eggert <at> cs.ucla.edu>
Cc: bug-gnu-emacs <at> gnu.org, akrl <at> sdf.org
Subject: Re: 28.0.50; GC may miss to mark calle safe register content
Date: Sun, 17 May 2020 20:24:23 +0300

> Cc: bug-gnu-emacs <at> gnu.org
> From: Paul Eggert <eggert <at> cs.ucla.edu>
> Date: Sun, 17 May 2020 10:08:00 -0700
> 
> It's a low-level problem in which the garbage collector is not seeing some
> objects that it should see, because at the machine level the object addresses
> are in registers that the garbage collector hasn't saved and thus won't see when
> it scans memory.

Since we write in C and in Lisp, not in assembly, I struggle to see
how a Lisp object could appear in a register without leaving any trace
on the stack.  I'm probably missing something.

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