Re: [patch #8186] ax_pthread adds -pthread when it should not on OSX when compiling with clang

[Peter Johansson]

On 09/25/2013 04:56 PM, Daniel Richard G. wrote:
> On Tue, 2013 Sep 24 13:06+1000, Peter Johansson wrote:
> > I noticed that gnulib adds '-Werror -Wunknown-warning-option' to
> > CFLAGS when Clang is in use, before trying to detect whether an option
> > is OK or not. Perhaps that approach would be useful here too.
> Where is that option documented? I can't find anything but secondhand
> references to it.

Hi Daniel,

I few minutes with google failed for me to.

> While I trust that the gnulib folks know what they
> are doing, that option specifically addresses warning flags (-Wxxxx)
> and not something like -pthread. But if said option is listed in a
> document somewhere, the option that we may want to use should be in
> there as well.

Sorry if I was too brief. My thought was that perhaps it'd be better to 
have feature test, i.e., actually test if the compiler runs with 
'-pthread', and then the mentioned option would be useful on Clang. 
Building a database with ifs and cases of course works as long as it 
works, but when it breaks down it's my experience that it's better to 
just reimplement as a feature test rather than adding another if 
statement. But it might be complicated in this case. Not sure, since I 
haven't looked at the macro in detail.

Thanks,
Peter