[cfe-dev] [RFC] Embedding compilation database info in object files.

[Chandler Carruth]

On Fri, Jul 19, 2013 at 2:08 AM, David Chisnall <David.Chisnall at cl.cam.ac.uk
> wrote:

> On 19 Jul 2013, at 10:01, Chandler Carruth <chandlerc at google.com> wrote:
>
> > There is no need to have it be a separate process at all. Just start a
> background thread and join it before terminating.
>
> Have you benchmarked the difference between clang with and without
> pthreads linked in?  A lot of libc and STL things become more expensive
> (including malloc(), although not by much) when pthreads are linked, even
> if they're not used.


Yes, I have, and on my systems none of these things are true. I don't know
whether or why they are true for you, but I don't think it should guide the
decision of how to architect the Clang driver.

In the not too distant future we will almost certainly want to build Clang
as a multithreaded binary (if possible to do so) so that we can take
advantage of threads internally.

 These may be dwarfed by the CPU time of the compilation, but it isn't free.
>

Sure, it isn't free. I'm not suggesting that it is. But I am suggesting
that it is a totally viable fallback strategy for this use case, and that
the cost is negligible while still being non-zero.
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