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.
Vala is a new programming language that aims to bring modern programming
language features to GNOME developers without imposing any additional
runtime requirements and without using a different ABI compared to
applications and libraries written in C.
valac, the Vala compiler, is a self-hosting compiler that translates
Vala source code into C source and header files. It uses the GObject
type system to create classes and interfaces declared in the Vala source
code. It's also planned to generate GIDL files when gobject-
introspection is ready.