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

Russell King (Oracle)
2024-05-03T08:18:05Z

On Fri, May 03, 2024 at 10:15:16AM +1000, Stephen Rothwell wrote:
> Hi all,
>
> 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:

CC drivers/clk/clkdev.o
AR drivers/clk/built-in.a
AR drivers/built-in.a
AR built-in.a
AR vmlinux.a
LD vmlinux.o
OBJCOPY modules.builtin.modinfo
GEN modules.builtin
MODPOST Module.symvers
UPD include/generated/utsversion.h
CC init/version-timestamp.o
LD .tmp_vmlinux.kallsyms1
NM .tmp_vmlinux.kallsyms1.syms
KSYMS .tmp_vmlinux.kallsyms1.S
AS .tmp_vmlinux.kallsyms1.S
LD .tmp_vmlinux.kallsyms2
NM .tmp_vmlinux.kallsyms2.syms
KSYMS .tmp_vmlinux.kallsyms2.S
AS .tmp_vmlinux.kallsyms2.S
LD vmlinux
NM System.map

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.

--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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