Re: [PATCH] staging: rtl8723bs: Mark ACPI table declaration as maybe unused

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Sep 26, 2018 at 12:02:09AM -0700, Nathan Chancellor wrote:
> Clang emits the following warning:
> 
> drivers/staging/rtl8723bs/os_dep/sdio_intf.c:25:36: warning: variable
> 'acpi_ids' is not needed and will not be emitted
> [-Wunneeded-internal-declaration]
> static const struct acpi_device_id acpi_ids[] = {
>                                    ^
> 1 warning generated.
> 
> Mark the declaration as maybe unused like a few other instances of this
> construct in the kernel.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/169
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/staging/rtl8723bs/os_dep/sdio_intf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8723bs/os_dep/sdio_intf.c b/drivers/staging/rtl8723bs/os_dep/sdio_intf.c
> index 6d02904de63f..3285bf36291b 100644
> --- a/drivers/staging/rtl8723bs/os_dep/sdio_intf.c
> +++ b/drivers/staging/rtl8723bs/os_dep/sdio_intf.c
> @@ -22,7 +22,7 @@ static const struct sdio_device_id sdio_ids[] =
>  	{ SDIO_DEVICE(0x024c, 0xb723), },
>  	{ /* end: all zeroes */				},
>  };
> -static const struct acpi_device_id acpi_ids[] = {
> +static const struct acpi_device_id acpi_ids[] __maybe_unused = {

But it is used.  No "maybe" at all here.  The MODULE_DEVICE_TABLE()
macro does a functional thing.  Why is gcc not reporting an issue with
this and clang is?

thanks,

greg k-h