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