[CFT] WITH_META_MODE: Working incremental build

[Craig Rodrigues]

On Fri, May 27, 2016 at 05:16:25PM -0700, Bryan Drewery wrote:
> The way that "meta mode" works is to enable the bmake "meta mode"
> feature that tracks the build command for each target and uses the
> filemon(4) [1] module to track all files read/written/executed for
> building target.  If any of these change (see src.conf(5) WITH_META_MODE
> for details) then the target will be rebuilt.  This means that even
> changes to CFLAGS or the cross compiler will be detected and cause
> rebuilds.  This is quite an aggressive system but it works and removes
> the need for cleaning any of the tree.  In this mode .depend.* files
> (WITH_FAST_DEPEND) are not generated since they are mostly redundant
> with filemon(4)'s tracking.

Excellent!!  You sent out this mail, nearly seven years to the
day when John Birrell originally committed this code to FreeBSD:

https://svnweb.freebsd.org/base?view=revision&revision=192702

It is fantastic that you and others have managed to continue with
this work, stabilize it, and get it into the mainstream of FreeBSD usage.

I think John would have been very happy with what you have achieved,
since he was always focused on pushing this work into FreeBSD,
rather than keeping it locked inside a single company as a proprietary solution.

--
Craig