Re: [PATCH] btrfs: fix initialiser warning in fs/btrfs/tree-checker.c

[Qu Wenruo <wqu@suse.com>]

On 2021/9/20 06:46, Russell King (Oracle) wrote:
> On Mon, Sep 20, 2021 at 06:44:58AM +0800, Qu Wenruo wrote:
>>
>>
>> On 2021/9/20 06:40, Russell King (Oracle) wrote:
>>> Debian gcc 10.2.1 complains thusly:
>>>
>>> fs/btrfs/tree-checker.c:1071:9: warning: missing braces
>>> around initializer [-Wmissing-braces]
>>>     struct btrfs_root_item ri = { 0 };
>>>            ^
>>> fs/btrfs/tree-checker.c:1071:9: warning: (near initialization for 'ri.inode') [-Wmissing-braces]
>>>
>>> Fix it by removing the unnecessary '0' initialiser, leaving the
>>> braces.
>>
>> This should be a compiler bug.
>>
>> = { 0 }; is completely fine here, in fact = { }; would be more problematic.
>>
>> What's the compiler version? I haven't hit such problem for GCC 11.1.0
>> nor clang 12.0.1.
> 
> I just realised that it's not the compiler I thought it was - It's
> GCC 4.9.4 used on 32-bit ARM.

That's bare minimal GCC version required for kernel build.

I'm not sure if that old version has all the correct backports.

> 
> = { }; is not a problem for that version of GCC. Why do you think it's
> problematic?
> 

Isn't initialization with empty initializers against C89/90 standard?

Thanks,
Qu