Re: linux-next: build failure after merge of the arm tree

From: Stephen Rothwell
Date: Fri May 03 2024 - 08:08:47 EST


Hi Russell,

On Fri, 3 May 2024 09:18:00 +0100 "Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx> wrote:
>
> On Fri, May 03, 2024 at 10:15:16AM +1000, Stephen Rothwell wrote:
> >
> > After merging the arm tree, today's linux-next build (x86_64 allmodconfig)
> > failed like this:
> >
> > drivers/clk/clkdev.c: In function 'vclkdev_alloc':
> > drivers/clk/clkdev.c:195:16: error: assignment to '__va_list_tag (*)[1]' from incompatible pointer type '__va_list_tag **' [-Werror=incompatible-pointer-types]
> > 195 | fmt.va = &ap;
> > | ^
> > cc1: all warnings being treated as errors
>
> This builds perfectly fine for me - this is on debian stable with
> arm-linux-gnueabihf-gcc (Debian 10.2.1-6) 10.2.1 20210110:
>
> No warnings, no errors.
>
> va_format is defined as:
>
> struct va_format {
> const char *fmt;
> va_list *va;
> };
>
> and what we have here is a "va_list ap".
>
> Therefore, the assignment:
>
> fmt.va = &ap;
>
> is correct.
>
> What certainly won't work is:
>
> fmt.va = ap;
>
> and there aren't any other reasonable alternatives.
>
> My conclusion: your compiler is being stupid.

Definitely possible. My build is an x86_64 allmodconfig cross build
hosted on PowerPC64LE.

$ x86_64-linux-gnu-gcc --version
x86_64-linux-gnu-gcc (Debian 13.2.0-7) 13.2.0

It still fails for me even just building your tree. :-(

And if I revert commit 5d998425e37b it does not fail (of course).

--
Cheers,
Stephen Rothwell

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