Re: [Qemu-devel] [PATCH] HACKING: remove bogus restrictions

[Blue Swirl]

On Tue, Aug 28, 2012 at 5:21 PM, Michael S. Tsirkin <address@hidden> wrote:
> On Tue, Aug 28, 2012 at 05:13:24PM +0000, Blue Swirl wrote:
>> On Tue, Aug 28, 2012 at 4:01 PM, Michael S. Tsirkin <address@hidden> wrote:
>> > We copied HACKING from libvirt but it has some bogus stuff:
>> > neither underscore capital, double underscore, or underscore 't' suffixes
>> > are reserved in Posix/C: this appears to be based on misreading of the
>> > C standard. Using sane prefixes is enough to avoid conflicts.
>> >
>> > These rules are also widely violated in our codebase,
>> > and it does not make sense to rework it all, apparently for
>> > no benefit.
>>
>> NACK. The benefit is improved standards compliance. One day we could
>> find QEMU being ported to environment which conflicts with these
>> symbols.
>
> We are talking about stuff like __kvm_pv_eoi - so the chance is exactly 0.

How do you know for sure? The implementation could be that symbols are
converted by the compiler to use underscore prefixes.

> And if it does happen then you run a simple script and fix
> this one instance.

Then why not fix now? How about kvm_pv_eoi_state?

>
>> The tiny single benefit from violating the rules would be that you
>> could use a few additional possible classes of prefixes, in addition
>> to the infinite combinations already available.
>
> Benefit would be consistency with existing QEMU code
> which has both _t __  and _X, and consistency
> within HACKING itself.

There are plenty of bad things wrt style, but the plan is to get rid
of those eventually. It takes time since global reformatting etc. to
enforce the rules is not accepted.

>
>> >
>> > Signed-off-by: Michael S. Tsirkin <address@hidden>
>> > ---
>> >  HACKING | 4 ----
>> >  1 file changed, 4 deletions(-)
>> >
>> > diff --git a/HACKING b/HACKING
>> > index 471cf1d..0a941fc 100644
>> > --- a/HACKING
>> > +++ b/HACKING
>> > @@ -69,10 +69,6 @@ it points to, or it is aliased to another pointer that 
>> > is.
>> >  2.3. Typedefs
>> >  Typedefs are used to eliminate the redundant 'struct' keyword.
>> >
>> > -2.4. Reserved namespaces in C and POSIX
>> > -Underscore capital, double underscore, and underscore 't' suffixes should 
>> > be
>> > -avoided.
>> > -
>> >  3. Low level memory management
>> >
>> >  Use of the malloc/free/realloc/calloc/valloc/memalign/posix_memalign
>> > --
>> > MST