Re: [Qemu-devel] [PATCH 4/7] compiler: add macro for GCC weak symbols

[Blue Swirl]

On Sat, Jul 28, 2012 at 6:50 AM, Peter Maydell <address@hidden> wrote:
> On 27 July 2012 16:31, Anthony Liguori <address@hidden> wrote:
>> Peter Maydell <address@hidden> writes:
>>> My approach to this is to avoid non-standard things
>>
>> http://en.wikipedia.org/wiki/C99#Implementations
>>
>> So unless you plan on compiling QEMU with xlc, pgi, or icc, I don't
>> think relying on "standard things" really helps.
>>
>> QEMU doesn't support C99, it supports GCC.
>
> OK, you could perhaps rephrase that as 'mainstream' rather than
> 'standards-compliant'. I don't think we need to be strict C99;
> I do think we have more than one working host OS and that patches
> that use functionality that's documented not to work on all gcc
> targets ought to come attached to a statement that they've been
> tested. (MacOSX isn't actually in MAINTAINERS as a host so is
> a bit of a red herring. Windows is listed.)

I'd also like to avoid a world where everything only targets GCC on
x86_64 on Linux with KVM. "Embrace and extend" may also be seen to
apply to GCC extensions.

>
> So if you really like weak symbols, go ahead. I'm just saying
> you're imposing a bigger testing burden on yourself than if
> you handled this some other way.
>
> (I do think it would be nice to care about building with CLANG,
> because there are some static analysis tools that we would
> then be able to run. That doesn't mean dropping all GCC
> extensions, though, because CLANG does support a lot of them.)
>
> -- PMM
>