[cmake-developers] CMake master slowdown in generation step

[Brad King]

On 04/04/2014 11:57 AM, Stephen Kelly wrote:
> I've pushed another commit which gets the time for the 2000 file testcase 
> from about 20s to about 4s for both Ninja and Makefiles. It fails a few unit 
> tests though and I don't have time right now to find out why. 4s is still a 
> bit much, so there's probably more opportunity.

So far your optimizations seem to be in areas that could have been
optimized before commit 8cd113ad1d715cc9ce865956870cd462d3659089
caused this major slowdown.  That one is:

 cmTarget: Store strings instead of cmSourceFile* to represent SOURCES

I suspect the performance drop is due to carrying around lots of
strings instead of raw pointers.  You'll have to find another
way to represent that.  Otherwise this performance drop is too
high a cost to pay for the target-sources feature and we will
have to revert that until another solution is found.

-Brad