Re: [PATCH RFC tools 1/6] tools: Refactor "xentoollog" into its own library

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-09-21 at 18:30 +0100, Andrew Cooper wrote:
> On 21/09/15 18:13, Ian Jackson wrote:
> > Andrew Cooper writes ("Re: [Xen-devel] [PATCH RFC tools 1/6] tools:
> > Refactor "xentoollog" into its own library"):
> > > On 21/09/15 17:17, Ian Jackson wrote:
> > > > Do you mean that statement expressions (originally a GNU extension)
> > > > should be avoided in tools code ?  A quick git-grep discovered that
> > > > xenctrl already contains numerous statement expressions.
> > > It is fine (in principle) to be used internally.  Not in a public
> > > header
> > > for what is supposed to be a clean API.
> > I don't understand why this distinction is relevant.  Either the
> > compiler supports it, or it doesn't.
> 
> There shouldn't be items in a public header which can't be used by all
> compilers which might want to compile it.
> 
> GCC is not the only compiler liable to encounter this new header file.
> 
[...]
> Please explain why you believe it to be unsuitable?  It is not perfect,
> but is far better than nothing.

It's a #define, so unless the including application actually uses it the
compiler proper (as opposed to cpp) will never see it.

Ian.