Re: [PATCH] btrfs: Fix use of GCC_VERSION in messages.h

[David Sterba <dsterba@suse.cz>]

On Mon, Apr 28, 2025 at 03:01:35PM -0700, Nathan Chancellor wrote:
> Clang warns (or errors with CONFIG_WERROR=y):
> 
>   fs/btrfs/messages.h:188:5: error: 'GCC_VERSION' is not defined, evaluates to 0 [-Werror,-Wundef]
>     188 | #if GCC_VERSION >= 80000
>         |     ^
> 
> GCC_VERSION is defined in compiler-gcc.h, which is not included when
> building with clang. Use the always defined Kconfig symbol,
> CONFIG_GCC_VERSION, to do the comparison.
> 
> Additionally, as a comment above this #ifdef notes, clang supports
> __VA_OPT__, which is really what is needed for this block to function.
> Include a check for CONFIG_CC_IS_CLANG as well, since clang 13 is the
> minimum supported version for building the kernel.
> 
> Fixes: 14d740332aa0 ("btrfs: enhance ASSERT() to take optional format string")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Thanks, back then I verified that the minimum clang version required for
kernel compiles the code and using just GCC_VERSION looked correct from
other code but apparently not. Folded to the patch, thanks.