Re: Announcing Dolt, a drop-in Libtool replacement which cuts build times in half

[Richard Purdie <rpurdie@rpsys.net>]

Josh Triplett <josh <at> freedesktop.org> writes:
> Thus, I wrote Dolt, a drop-in replacement for libtool's compilation
> mode.  Dolt runs any necessary system-specific or
> configuration-specific logic as part of configure, writes out a simple
> shell script "doltcompile"[1], and substitutes it for libtool in the
> automake variables LTCOMPILE and LTCXXCOMPILE.  If you use automake,
> autoconf, and libtool, then using Dolt just requires two steps:
> 
> 1) add "DOLT" after the call to LT_INIT, AC_PATH_LIBTOOL, or
>    AM_PATH_LIBTOOL in your configure.ac or configure.in script, and
> 2) append dolt.m4 to your project's acinclude.m4.
> 
> For any system Dolt does not support, it will transparently fall back
> to libtool.

I work with Poky (pokylinux.org) and OpenEmbedded (openembedded.org) which are
cross compiling build systems and speed improvements like this are extremely
useful to us. Those systems also provide a testing ground where we can expose
changes like this to a wide variety of programs.

My main problem is this change is that the last part doesn't hold true, dolt
does not fall back to libtool transparently, the reason being the AC_SUBST
causes LTCOMPILE to become "", even if that section of the if block isn't called.

I've just hacked dolt into Poky's libtool recipes and will have the build time
differences from our automated builds in about 24 hours provided nothing breaks
and I'll report back.

Cheers,

Richard