Re: [Qemu-devel] [PULL 00/11] Ide patches

[John Snow]

On 09/16/2017 10:34 AM, Peter Maydell wrote:
> On 16 September 2017 at 02:03, John Snow <address@hidden> wrote:
>> The following changes since commit 5faf2d376af3cb4eb92da44c2580e08d39832caa:
>>
>>   Merge remote-tracking branch 'remotes/huth/tags/check-20170915' into 
>> staging (2017-09-15 20:29:44 +0100)
>>
>> are available in the git repository at:
>>
>>   https://github.com/jnsnow/qemu.git tags/ide-pull-request
>>
>> for you to fetch changes up to 2a94e34d3ecef91727f467cc012587c632099d40:
>>
>>   AHCI: remove DPRINTF macro (2017-09-15 20:36:18 -0400)
>>
>> ----------------------------------------------------------------
>>
>> ----------------------------------------------------------------
> 
> Hi; I'm afraid this doesn't build with clang:
> 
> /home/petmay01/linaro/qemu-for-merges/hw/ide/core.c:70:15: error:
> comparison of unsigned enum expression >= 0 is always true
> [-Werror,-Wtautological-compare]
>     if (enval >= 0 && enval < IDE_DMA__COUNT) {
>         ~~~~~ ^  ~
> 1 error generated.
> 
> (It's impdef whether an enum with all positive values is
> a signed type or unsigned type, so just deleting the
> comparison against 0 would also be wrong...)
> 
> thanks
> -- PMM
> 

Huh, impdef in the general case, but is it undefined for gnu99? I'm
wondering why Clang can be so certain about this comparison being
useless. Is this a Clang "bug"?

--js