an interesting idea, but...

[Zack Weinberg]

On 23 Sep 1998 14:35:21 +0200, Andreas Schwab wrote:
>Zack Weinberg <zack@rabi.columbia.edu> writes:
>
>|> Durning a build, cpp is invoked (number of active suffixes)+1 times
>|> for each source file in the library.  Profiling suggests there would
>|> be upwards of 25% improvement in build time from invoking it only
>|> once.  This is easy to put into the makefiles, but there's a problem:
>|> a lot of code cares about whether it's going into the static, shared,
>|> or profiled library.  It finds out with #ifdefs.  If I run cpp once,
>|> all this code is miscompiled.
>|> 
>|> Any thoughts on how to work around the problem?
>
>Speeding up cpp would probably be easier.  Perhaps cpplib can help here.

It's worth a try, but I think the main performance penalty is from
scanning the -I list over and over again.  Cpplib wouldn't help that
much.

zw