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.
Blurb:
Gambit-C includes a Scheme interpreter and a Scheme compiler which can
be used to build standalone executables. Because the compiler generates
portable C code it is fairly easy to port to any platform with a decent
C compiler.
The Gambit-C system conforms to the R4RS, R5RS and IEEE Scheme standards.
The full numeric tower is implemented, including: infinite precision
integers (bignums), rationals, inexact reals (floating point numbers),
and complex numbers. Gambit-C supports a number of extensions to the
standards including (non-exhaustively):
- an optimizing compiler
- with several powerful transformations (automatic function inlining,
partial evaluation, etc)
- that generates properly tail-recursive portable C code
- a scalable thread system that can handle millions of concurrent threads
- an I/O system fully integrated with the thread system that supports
regular files, ttys, sockets (client and server, with TCP or UDP),
directories, processes, and pipes
- an infix syntax extension (SIX) that allows mixing code in the
standard prefix syntax with code in a C-like syntax
- SRFIs 0, 4, 6, 8, 9, 18, 21, 22, 23, 27, 39
- a REPL/debugger with
- a continuation inspection facility (i.e. "backtrace")
- a single-stepping mode
- error messages with location of error (file, line, and column number)
- emacs compatible line-editing with history
- very efficient bignum implementation
- a foreign function interface for C
- a memory management system that grows and shrinks the heap based on
the program's needs
- a linker that builds standalone executables and shared libraries
- dynamic loading of compiled modules and libraries (supported on many
platforms)
- Unicode support for characters, strings, I/O and source code
- object finalization, pretty printing, keyword objects optional and
keyword parameters (with the syntax and semantics of DSSSL)
- configurable reader with control over case sensitivity
- write/read invariance of symbols, e.g. (string->symbol "B;123") => |B;123|
- write/read invariance of floating point numbers
- unhygienic macros and more!
