[desktop-discuss] [xwin-discuss] libtool performace improvements ... / was: Re: [Fwd: Announcing Dolt, a drop-in Libtool replacement which cuts build times in half]

[Bob Friesenhahn]

On Thu, 10 Apr 2008, Moinak Ghosh wrote:
>
>  One other optimization that I was considering was to use
>  pre-generated config.cache files. For eg. in the drivers
>  subdirectory the config.cache generated for the first driver
>  built is copied to a common location and then that is passed as a
>  parameter while calling configure for the rest of the drivers. This
>  avoids a whole plethora of redundant checks the results of which
>  are already in the cache.

This works if the build options are the same for all builds and the 
configure scripts make the same decisions based on the same 
information.  That is not always the case.

Another choice is to create a config.site file or a file referenced by 
the CONFIG_SITE environment variable which includes a 
carefully-crafted set of pre-known cached settings which are safe for 
all drivers.

Yet another choice is to have a single config.h shared across all 
drivers and a mega configure script which tests everything the drivers 
need, or have the drivers test only special things that they need and 
have them include the mega config.h as well as their own config.h.

As far as the libtool performance issue goes, the issue is being taken 
very seriously right now and libtool will certainly become faster. 
One important suggestion (that bash is very slow) came from this list.

Libtool 2.2 (current release) is already 60% faster than Libtool 
1.5.X.

Bob
======================================
Bob Friesenhahn
bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/