Re: [libvirt] [PATCH 1/2] util: Turn virFirewallAddRule() into a macro
On Tue, 2017-01-03 at 13:46 +0100, Martin Kletzander wrote:
> To solve the issue, turn virFirewallAddRule() from a very thin
> wrapper around virFirewallAddRuleFullV() to a macro that expands
> to a call to virFirewallAddRuleFull() - itself a very thin wrapper
> around the aforementioned virFirewallAddRuleFullV() - with no loss
> of functionality or type safety.
> ---
> This only seems to be required on very specific combinations
> of Clang and host OS, eg. I need it on Clang 3.9 / Fedora
> rawhide but not on Clang 3.8 or 4.0 / Debian sid.
We sent various patches for this (me, Jan and maybe other people as
well). I never realized it's not a problem with different versions of
clang.
Oh, must have missed the previous attempts to fix this.
I would say it's not a problem for us to solve it in this case,
however, as I wrote in my solution, it works, but it's undefined from
the specification point of view. Can it work just because
virFirewallAddRule() gets optimized into inline function? it shouldn't
be, though... I don't know.
I lean towards merging this or a comparable solution. It's
true that we aren't currently hitting this on our main
targets, but relying on undefined behavior is definitely
something we want to avoid, plus I don't see any real
drawbacks in changing this to a macro.
--
Andrea Bolognani / Red Hat / Virtualization