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.
Camlp5 is a preprocessor and pretty-printer for OCaml programs. It also
provides parsing and printing tools.
As a preprocessor, it allows to:
- extend the syntax of OCaml,
- redefine the whole syntax of the language.
As a pretty printer, it allows to:
- display OCaml programs in an elegant way,
- convert from one syntax to another,
- check the results of syntax extensions.
Camlp5 also provides some parsing and pretty printing tools:
- extensible grammars
- extensible printers
- stream parsers and lexers
- pretty print module
It works as a shell command and can also be used in the OCaml toplevel.
