Re: [PATCH 1/6] Kbuild: compile kernel with gnu11 std

From: Linus Torvalds
Date: Tue Mar 01 2022 - 15:18:05 EST


On Tue, Mar 1, 2022 at 10:00 AM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> All warnings (new ones prefixed by >>):
>
> >> cc1: warning: result of '-117440512 << 16' requires 44 bits to represent, but 'int' only has 32 bits [-Wshift-overflow=]

So that's potentially an interesting warning, but this email doesn't
actually tell *where* that warning happens.

I'm not entirely sure why this warning is new to this '-std=gnu11'
change, but it's intriguing.

Instead it then gives the location for another warning:

> arch/mips/pci/pci-rc32434.c: In function 'rc32434_pcibridge_init':
> arch/mips/pci/pci-rc32434.c:111:22: warning: variable 'dummyread' set but not used [-Wunused-but-set-variable]
> 111 | unsigned int dummyread, pcicntlval;
> | ^~~~~~~~~

but that wasn't the new one (and that 'dummyread' is obviously
_intentionally_ set but not used, as implied by the name).

Is there some place to actually see the full log (or some way to get a
better pointer to just the new warning) to see that actual shift
overflow thing?

Linus