Your patch makes the error always occur at run time.  We can preserve the intent of producing an error at link time with the attached patch which was NOT accepted upstream.  I think they do not like the name QLNULL.  In any event, it does work for all optimizations and applies to the latest master branch of qemu.

Joe

-----Original Message-----
From: openembedded-core@lists.openembedded.org <openembedded-core@lists.openembedded.org> On Behalf Of Khem Raj
Sent: Monday, September 14, 2020 8:23 AM
To: Yu, Mingli <Mingli.Yu@windriver.com>
Cc: Ross Burton <ross@burtonini.com>; OE-core <openembedded-core@lists.openembedded.org>
Subject: Re: [OE-core] [PATCH] qemu: always define unknown_lock_type

On Sun, Sep 13, 2020 at 11:29 PM Yu, Mingli <mingli.yu@windriver.com> wrote:
>
>
>
> On 9/14/20 2:02 PM, Khem Raj wrote:
> >
> >
> > On 9/13/20 10:44 PM, Yu, Mingli wrote:
> >>
> >>
> >> On 9/14/20 1:26 PM, Khem Raj wrote:
> >>>
> >>>
> >>> On 9/13/20 6:50 PM, Yu, Mingli wrote:
> >>>>
> >>>>
> >>>> On 9/10/20 6:41 PM, Ross Burton wrote:
> >>>>> On Thu, 10 Sep 2020 at 04:03, Yu, Mingli 
> >>>>> <mingli.yu@windriver.com>
> >>>>> wrote:
> >>>>>> +Upstream-Status: Submitted [qemu-devel mailing list]
> >>>>>
> >>>>> https://lists.nongnu.org/archive/cgi-bin/namazu.cgi?query=unknow
> >>>>> n_lock_type&submit=Search%21&idxname=qemu-devel&max=20&result=no
> >>>>> rmal&sort=score
> >>>>>
> >>>>>
> >>>>> doesn't find this patch, can you link to it please?
> >>>>>
> >>>>
> >>>> Hi Ross,
> >>>>
> >>>> The link is
> >>>> https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg03873
> >>>> .html,
> >>>> will include the link in V2.
> >>>
> >>> are you compiling without __OPTIMIZE__ defined ? qemu may not work
> >>
> >> Hi Khem,
> >>
> >> I didn't especially customize something for __OPTIMIZE__,  could 
> >> you help guide where to define it?
> >
> > perhaps you are not using one of -O<n> option ?
>
> -Og passed to the compiler as DEBUG_BUILD = "1" defined in local.conf.

Does qemu work when built with -Og