This follows on the footsteps of guenther@, who did a similar job in the kernel.
Basically, the old-style "make depend, then make all" bsd makefile pattern is GONE. More accurately, dependencies are now generated on the fly using gcc and clang's -M* options. Instead of a "magical" .depend file, this results in *.d files that get included through bsd.dep.mk. The "make depend" stage is still present before "make all", but it's only actually used by very few (<10) directories, and my goal is to eventually remove the need entirely. (Yes, there are more clean-up patches coming) Complex internal dependencies are now most often handled thru a new BUILDFIRST/BUILDLATER mechanism. Directories which need a separate configure stage (like perl) are handled (or will be handled) thru two stage makefiles. Benefits are four-folds: - less complexity. You will no longer meet with errors if you forget to "make depend" before you build something in a directory. (once the <10 problematic directories are fixed) - better cache behavior. make depend could be really slow, as it needed to more or less pull the whole source tree, dragging and kicking, through the buffer cache, thus completely flooding it on small machines, and resulting in slow performance. Now, the source tree is pulled more slowly in the cache, and gets compiled and analysed for dependencies at the same time. - better parallel behavior. mkdep was inherently sequential, whereas most directories have little inter-dependencies, so the compilation can run in parallel. - clang gains dependency analysis for free, without any need for the complicated patch I did a few weeks ago. Thanks again to everybody who helped.
