On Thu, Apr 28, 2016 at 03:10:26PM +0200, Bernd Schmidt wrote:
> On 04/28/2016 12:35 PM, Jakub Jelinek wrote:
> >On Thu, Apr 28, 2016 at 12:31:40PM +0200, Bernd Schmidt wrote:
> >>I really don't see anything in that function that looks like a huge time
> >>sink, so I'm not that worried about it. I think it's likely to be buried way
> >>down in the noise.
> >
> >True, but the noise sums up, and the result is terrible speed of compiling
> >empty source files, something that e.g. Linux kernel or other packages
> >that have lots of small source files, care about a lot.
> >If initializing it early would buy us anything on code clarity etc., it
> >could be justified, but IMHO it doesn't, the code in libcpp already has the
> >delayed initialization anyway.
>
> Well, it does buy us early (and reliable) error checks against the
> environment variable.
I'm not sure we really care about the env var unless it actually needs to be
used. If we error only if it is used, people could e.g. use it in another
way, to verify their code doesn't contain any __TIME__ uses, compile with
the env var set to some invalid string and just compile everything with
that, it would diagnose any uses of __TIME__.
Jakub
