Re: [boost] [wave] skip include directives

From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2006-05-15 16:39:04

Felipe Magno de Almeida wrote:

> > Wave is quite intelligent wrt skipping include files wherever 
> > possible. It supports the #pragma once directive and uses a 
> heuristic 
> > to recognize standard header guarding schemes to avoid duplicate 
> > inclusion of a file. So there is no need for you worry about that.
> 
> I mean when preprocessing different files. Usually they will 
> contain the same dependencies, being able to cache this 
> (using a graph for the
> dependencies) it could really improve preprocessing of lots of files.

How do you know that '...when preprocessing different files. Usually they
will 
> contain the same dependencies...'?

> This tool should preprocess entire subsets of boost, 
> preprocessing some headers again and again should be really slow.
> Pragma once wouldnt help here, since I want to cache a 
> preprocessing that would occur inside preprocessing two 
> different files.

IIUC in this case you will even have to switch off Waves #pragma once
support and the corresponding heuristics because otherwise it won't even
open a header file for the second time.

Anyway, it would be really helpful to know, what you're going to do with
Wave and how. All I've got so far is that you somehow want to analyze
include file dependencies. Sorry if I've missed this, but is this project
going to build an extention to the current bcp tool?

Regards Hartmut