Re: non-recursive build system

[Davidlohr Bueso <dave@gnu.org>]

On Tue, 2012-06-12 at 12:03 +0200, Karel Zak wrote:
> 
>  The original version was implemented by Diego Elio 'Flameeyes' Pettenò
>  two years ago:
>      http://thread.gmane.org/gmane.linux.utilities.util-linux-ng/3297
> 
>  See also:
>      http://www.flameeyes.eu/autotools-mythbuster/automake/nonrecursive.html
> 
>  My current version is available at github, 'non-recursive' branch:
>      https://github.com/karelzak/util-linux/commits/non-recursive
> 
> 
>  Notes:
> 
>  * generate one Makefile for whole package
> 
>  * make(1) has all information to run tasks in parallel 
> 
>  * numbers (make -j)
> 
>              recursive | non-recursive
>              ----------+--------------
>     2 cores: 14.5 sec  | 13.2 sec
>    16 cores:  9.5 sec  |  4.3 sec
> 
>    (... more CPU cores means more fun;-)

Nice, are these real cores or HT?

> 
>  * automake variables and rules are defined in subdir/Makemodule.am files
>    (create one huge Makefile.am is too crazy idea)
> 
>  * top-level Makefile.am includes all Makemodule.am files
> 
>  * $(top_srcdir) prefix for lib/ and include/ is unnecessary, just use
>    lib/bar.c and include/bar.h in makefiles
> 
>  * lib/ has been converted to libcommon.la, it means that
>        foo_LDADD = libcommon.la
>    is enough to use arbitrary stuff from lib/.
> 
>  * all rules are interpreted from top-level directory, it means that
>        cd subdir; make
>    or
>        make -C subdir
>    does not work.
> 
>  * binaries are stored in top-level (build) directory, you don't
>    have to care about directories, just type:
> 
> 	$ make mount
> 	$ ./mount --help
> 
>  * all build targets (including test binaries) are visible for bash completion
>    scripts (e.g. /etc/bash_completion.d/make), so <tab> is your good friend
> 
> 
>  * disadvantages:
> 
>     - full paths in makefiles (e.g. foo_SOURCE = subdir/foo.c)
> 
>     - we can't use the same name for subdir/ and for a final binary
>       Necessary changes:
>        - remove partx/ directory, move partx.c to disk-utils/
>        - remove getopt/ directory, move getopt.c to misc-utils/
>        - remove hwclock/ directory, move hwclock.c to sys-utils/
>        - rename fdisk/ to fdisks/

fdisk-utils?

>        - rename mount/ to mount-deprecated/ (we use new sys-utils/mount.c)
> 
>       Note that consolidate the code and remove some subdirs (e.g. getopt/) is
>       probably a good idea independently on the build-system changes.
> 

Thanks,
Davidlohr