bug#42360: closed ([feature/native-comp] miscompilation(?) of functions with non local exits)

[GNU bug Tracking System]

Your message dated Thu, 16 Jul 2020 19:47:30 +0000
with message-id <xjfo8offdil.fsf@sdf.org>
and subject line Re: bug#42360: [feature/native-comp] miscompilation(?) of 
functions with non local exits
has caused the debbugs.gnu.org bug report #42360,
regarding [feature/native-comp] miscompilation(?) of functions with non local 
exits
to be marked as done.

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42360: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=42360
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> --- Begin Message ---
>
>
>
> Subject: 
>
> [feature/native-comp] miscompilation(?) of functions with non local exits
>
>
>
>
> Date: 
>
> Wed, 15 Jul 2020 08:24:00 +0000
>
>
>
>
> Due to a recent modification native-comp is (probably?) miscompiling
> lexical scope functions with non local exits if they involve code with
> side effect on local variables.  Before fixing I prefer to double check
> the correct behavior we want.
>
> Considering the following piece of (lexical scoped) code:
>
> ===
> (let (x)
>   (ignore-errors
>     (setq x t)
>     (error "foo"))
>   x)
> ===
>
> Three options:
>
>   1- Because setq is evaluated the expression should always evaluate to
>   t.
>
>   2- Unwinding the original state of the stack is restored, when it was
>   saved 'x' was nil so the expression should evaluate to nil.
>
>   3- This is unspecified.
>
> The current stock implementaion does always 1 so I'm prone to just go
> for it but I wanted to double check to be on the safe side.
>
> FYI 1 implies C register variables cannot be used to implement Lisp
> local variable if non local exits are present.
>
> Thanks
>
>   Andrea
>
> --
> akrl@sdf.org
>
>
>
> --- End Message ---
> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#42360: [feature/native-comp] miscompilation(?) of functions with non local exits
>
>
>
>
> Date: 
>
> Thu, 16 Jul 2020 19:47:30 +0000
>
>
>
>
> User-agent: 
>
> Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux)
>
>
>
>
> Right I think we can close this.
>
> Thanks
>
>   Andrea
>
> -- 
> akrl@sdf.org
>
>
> --- End Message ---