Waf branch - Overview [2/6]

[Amar Takhar]

On 2015-02-08 16:07 +0100, Sebastian Huber wrote:
> Yes, this works fine. If I change e.g. threaddispatch.c then all tests 
> get re-linked. Very nice.

Great.


> What doesn't get noticed is the change of a C library header file, e.g. 
> <string.h>. This worked before due to the automatically generated 
> dependency files emitted by GCC.

Currently it only monitors files in the top source directory.  Scanning headers 
outside of the top srcdir will be slow.

I can add a knob to enable this on-demand but I would not want to leave it on as 
how often are we editing system headers?  It's a nontrivial slowdown of the 
build.

It may be possible to cache the system header hashes during configure to speedup 
the build later... how important is it to have this on all the time?  I have yet 
to run into a situation where it was imperative to have it always-enabled.


Amar.