5:57 p.m.
On 6/7/21 5:49 PM, Hyeonggon Yoo wrote:
On Mon, Jun 07, 2021 at 05:27:27PM +0200, Vlastimil Babka wrote:
> On 6/7/21 2:25 PM, Hyeonggon Yoo wrote:
> > On Mon, Jun 07, 2021 at 01:40:02PM +0200, Vlastimil Babka wrote:
> >> On 6/6/21 1:08 PM, Hyeonggon Yoo wrote:
> >> > On Sat, Jun 05, 2021 at 02:10:46PM +0800, kernel test robot wrote:
> >>
> >> But what exactly is the gcc problem here?
> >> Did you have to reproduce it with specific gcc version and/or architecture?
> >>
> >
> > Before replying, I should say that I'm not an expert on gcc.
> > I just tried some ways to fix the error, and it seemed to me that
> > gcc is doing something wrong.
>
> I'm involving my gcc colleagues, will report results...
Well, it seems the bot's .config included CONFIG_PROFILE_ALL_BRANCHES as the
main factor to trigger the problem. And (according to my colleagues) it might
add too many instrumented if conditions to sustain the builtin-constant
tracking, which is not unlimited, or interact with optimizations in some other
corner case way.
I guess we could add IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) to the list of
conditions that excludes using BUILD_BUG_ON_MSG().
Thank you so much!
Hyeonggon