Re: [Qemu-devel] [PATCH 07/10] pseries: Clean up error handling in spapr_rtas_register()

[Eric Blake <eblake@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1434 bytes --]

On 01/19/2016 05:21 PM, Alexey Kardashevskiy wrote:

>> You could drop the redundant () while touching this, as in:
> 
> 
> Seriously? Why? I personally find it really annoying (but I stay silent)
> when people omit braces in cases like this.
> 
> 
>> assert(token >= RTAS_TOKEN_BASE && token < RTAS_TOKEN_MAX);

Because it's the prevailing style. I estimate that less than 10% of qemu
over-parenthesizes, mostly because && and || are well-known C operator
precedence:

$ git grep ' && ' | wc
   6462   57034  482477
$ git grep ') && (' | wc
    578    6151   48655

Of course, that's a rough estimate, as it has false positives on 'if
(foo() && (b || c))', and false negatives on conditionals where there is
a unary rather than binary operator on either side of &&; but I'm sure
you could write a Coccinelle script if you wanted more accurate counting.

But you are equally right that as long as HACKING doesn't document it,
and checkpatch.pl doesn't flag it, then you can over-parenthesize binary
arguments to the short-circuiting operators to your aesthetic tastes.

And for other operators, like '&' and '|', I definitely recommend the
parenthesis, particularly if you manage to trigger a gcc or clang
warning (in spite of the precedence being unambiguous) if you omit the
parenthesis.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]