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

[Anthony Liguori]

Peter Maydell <peter.maydell at linaro.org> writes:

> On 27 July 2012 15:27, Anthony Liguori <aliguori at us.ibm.com> wrote:
>> Peter Maydell <peter.maydell at linaro.org> writes:
>>> The GCC manual says "Weak symbols are supported for ELF targets,
>>> and also for a.out targets when using the GNU assembler and linker".
>>> Have you tested this on Windows and MacOSX ?
>>
>> Weak symbols are supposed to be supported by mingw32.
>>
>> I have no idea about MacOS X.
>>
>> I have no way to develop or test for MacOS X using free software so I
>> honestly don't care about it.
>
> 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.  There's no point in
debating about whether we should rely on extensions or not.  We already
do--extensively.

Regards,

Anthony Liguori


> -- if I
> write a patch which is pretty much standard C then it's the
> platform's problem if it mishandles it. If I write a patch
> that uses a compiler-specific or OS-specific thing then I
> have to also provide the relevant alternatives...so I try
> to avoid doing that :-)
>
> -- PMM