build time optimization

[Stephan Bergmann]

On 05/24/2012 09:23 AM, David Ostrovsky wrote:
> I'm thinking about another magic configure option, like
> --with-external-lib-directory=/opt/libo
> this would install all dependend libs to this directory during first
> build and this would *survive* the make clean
> call, so the next time all external lib artifacts would be reused from
> there.

The line what to keep across a "make clean" and what to through away 
could be a gray one.  On the one hand, some low-level LO modules (e.g., 
soltools) do not really change much these days, so you could argue to 
not rebuild them, either.  On the other hand, the external modules *do* 
depend on LO code (its build machinery), so not re-building them after a 
"make clean" is unsound if you modified any LO code they depend on.

In the end, I'd question why you do "make clean" anyway, if you are 
after fast build times.  These days, our dependency tracking has 
apparently become fine enough that there are hardly any apparent build 
failures resulting from missing dependencies any longer.

(And, btw, most of the --with-external-libs should work just fine.  You 
typically only need a few select --without-external-* overrides.)

Stephan