This changes the buildlink3.mk files to use an include guard for the
recursive include. The use of BUILDLINK_DEPTH, BUILDLINK_DEPENDS,
BUILDLINK_PACKAGES and BUILDLINK_ORDER is handled by a single new
variable BUILDLINK_TREE. Each buildlink3.mk file adds a pair of
enter/exit marker, which can be used to reconstruct the tree and
to determine first level includes. Avoiding := for large variables
(BUILDLINK_ORDER) speeds up parse time as += has linear complexity.
The include guard reduces system time by avoiding reading files over and
over again. For complex packages this reduces both %user and %sys time to
half of the former time.
and add a new helper target and script, "show-buildlink3", that outputs
a listing of the buildlink3.mk files included as well as the depth at
which they are included.
For example, "make show-buildlink3" in fonts/Xft2 displays:
zlib
fontconfig
iconv
zlib
freetype2
expat
freetype2
Xrender
renderproto
The Stanford GraphBase is a highly portable collection of programs and
data for researchers who study combinatorial algorithms and data
structures. All files are in the public domain and usable with only
one restriction: They must not be changed! A ``change file'' mechanism
allows local customization while the master files stay intact.
The programs are intended to be interesting in themselves as examples
of ``literate programming.'' Thus, the Stanford GraphBase can also be
regarded as a collection of approximately 30 essays for programmers to
enjoy reading, whether or not they are doing algorithmic research.
The programs are written in CWEB, a combination of TeX and C that is
easy to use by anyone who knows those languages and easy to read by
anyone familiar with the rudiments of C.
