[PATCH v2 01/10] kbuild: don't enable CC_CAN_LINK if the dummy program generates warnings

[Thomas Weißschuh]

On Thu, Nov 13, 2025 at 09:27:41PM -0700, Nathan Chancellor wrote:
> On Tue, Oct 14, 2025 at 03:05:16PM +0200, Thomas Weißschuh wrote:
> > It is possible that the kernel toolchain generates warnings when used
> > together with the system toolchain. This happens for example when the
> > older kernel toolchain does not handle new versions of sframe debug
> > information. While these warnings where ignored during the evaluation
> > of CC_CAN_LINK, together with CONFIG_WERROR the actual userprog build
> > will later fail.
> > 
> > Example warning:
> > 
> > .../x86_64-linux/13.2.0/../../../../x86_64-linux/bin/ld:
> > error in /lib/../lib64/crt1.o(.sframe); no .sframe will be created
> > collect2: error: ld returned 1 exit status
> > 
> > Make sure that the very simple example program does not generate
> > warnings already to avoid breaking the userprog compilations.
> > 
> > Fixes: ec4a3992bc0b ("kbuild: respect CONFIG_WERROR for linker and assembler")
> > Fixes: 3f0ff4cc6ffb ("kbuild: respect CONFIG_WERROR for userprogs")
> > Signed-off-by: Thomas Weißschuh <thomas.weissschuh at linutronix.de>
> 
> Reviewed-by: Nathan Chancellor <nathan at kernel.org>

Thanks!

> While this makes sense as a way to immediately fix the problem and align
> cc-can-link.sh with the other test functions like cc-option and like, it
> is rather unfortunate that this particular warning causes an error since
> the rest of the userprogs infrastructure does not care about SFrame...
> I wonder if there is a way to avoid it since I think this warning does
> not point to a fundamental problem.

I did not find any way to avoid this specific warning, unfortunately.
This patch should make sense in any case. If we find a way to avoid the
sframe warning then that should go on top.

(...)


Thomas