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From: David Abrahams (dave_at_[hidden])
Date: 2003-12-02 09:59:24

Vladimir Prus <ghost_at_[hidden]> writes:

> I'm trying to make the final optimization pass on generated headers. As you
> know, when constructing "exe", V2 adds implicit -I paths to all target paths,
> so that #includes of generated headers work.
> This was optimized recently, but still, those extra includes cause performance
> problems. For example, for Boost regression tests, I bet that <boost/
> config.hpp> is scanned once for *each tested library*, since when each
> library is compiled it has additional -I option, which is different for each
> library. So, scanner has no choice but to rescan header several times with
> those different extra include paths.
> I think I know a good solution. Now, the action class which compiles cpp files
> just adds <include> properties for targets in the same main target. Why don't
> we find only targets which type is derived from "H", and add paths of those
> targets?
> So, if no headers are generated, you get no extra include paths, and there's
> no penalty to pay.
> I even implemented this solution. All tests pass and for regression tests I
> get 2x speedup over current code (and besides, over v1, too).
> Anybody sees any serious problems with the above?

No, and I am really excited about the 2x speedup! Great work!

Dave Abrahams
Boost Consulting

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