Re: [boost] Release Tools Analysis Part I: Build systems

From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2007-08-05 13:19:58

David Abrahams wrote:

> on Sun Aug 05 2007, Stefan Seefeld <seefeld-AT-sympatico.ca> wrote:
> 
> > FWIW, I submitted a patch to SCons providing a python 
> extension module 
> > around ucpp (http://pornin.nerim.net/ucpp/) to provide a 'more 
> > accurate' C/C++ dependency scanner, long before wave was around.
> 
> Does anyone know if ucpp is actually conforming?  Until very 
> recently, most preprocessors were badly broken (and maybe 
> most still are).  If it conforms, it would be interesting to 
> benchmark it against Wave.

Wave probably will be slower than ucpp. 

Several reasons: 
- ucpp is 'cheating' and doesn't do correct preprocessing, which saves it
some cycles
- Wave never has been written with maximum performance in mind, even if a
lot of effort has been invested recently to make it performant (if compared
to gcc's preprocessor Wave is on average still 3 times slower)
- Wave does more than pure preprocessing: it does C++ lexing, which adds
some overhead

OTOH, a real usecase in the Boost build system is a fine motivation and
benchmark allowing to optimize Wave further.

Regards Hartmut