;;;; E.g. you can use code like this:
;;;; (lambda (list)
;;;; (flet ((enable (x) (pushnew x list))
-;;;; (disable (x) (setf list (remove x list))))
+;;;; (disable (x) (setf list (remove x list))))
;;;; #+nil (enable :sb-show)
;;;; (enable :sb-after-xc-core)
;;;; #+nil (disable :sb-doc)
;; been either made unconditional, deleted, or rewritten into
;; unrecognizability, but some remains. What remains is not maintained
;; or tested in current SBCL, but I haven't gone out of my way to
- ;; break it, either.
+ ;; break it, either.
;;
; :high-security
; :high-security-support
;; low-level thread primitives support
;;
- ;; As of SBCL 0.8, this is only supposed to work in x86 Linux, on which
- ;; system it's implemented using clone(2) and the %fs segment register.
- ;; Note that no consistent effort to audit the SBCL library code for
- ;; thread safety has been performed, so caveat executor.
+ ;; As of SBCL 0.8, this is only supposed to work in x86 Linux with
+ ;; NPTL support (usually kernel 2.6, though sme Red Hat distributions
+ ;; with older kernels also have it) and is implemented using clone(2)
+ ;; and the %fs segment register. Note that no consistent effort to
+ ;; audit the SBCL library code for thread safety has been performed,
+ ;; so caveat executor.
; :sb-thread
- ;; Kernel support for futexes (so-called "fast userspace mutexes") is
- ;; available in Linux 2.6 and some versions of 2.4 (Red Hat vendor
- ;; kernels, possibly other vendors too). We can take advantage of
- ;; these to do faster and probably more reliable mutex and condition
- ;; variable support. An SBCL built with this feature will fall back
- ;; to the old system if the futex() syscall is not available at
- ;; runtime
- ; :sb-futex
-
;; Support for detection of unportable code (when applied to the
;; COMMON-LISP package, or SBCL-internal pacakges) or bad-neighbourly
;; code (when applied to user-level packages), relating to material
;; alteration to packages or to bindings in symbols in packages.
:sb-package-locks
-
+
+ ;; Support for the entirety of the 21-bit character space defined by
+ ;; the Unicode consortium, rather than the classical 8-bit ISO-8859-1
+ ;; character set.
+ :sb-unicode
+
;; This affects the definition of a lot of things in bignum.lisp. It
;; doesn't seem to be documented anywhere what systems it might apply
;; to. It doesn't seem to be needed for X86 systems anyway.
;; notes on local features (which are set automatically by the
;; configuration script, and should not be set here unless you
;; really, really know what you're doing):
- ;;
+ ;;
;; machine architecture features:
;; :x86
;; any Intel 386 or better, or compatibles like the AMD K6 or K7
;; :mips
;; any MIPS CPU (in little-endian mode with :little-endian -- currently
;; untested)
- ;;
+ ;;
;; (CMU CL also had a :pentium feature, which affected the definition
;; of some floating point vops. It was present but not enabled or
;; documented in the CMU CL code that SBCL is derived from, and has
;; :control-stack-grows-downward-not-upward
;; On the X86, the Lisp control stack grows downward. On the
;; other supported CPU architectures as of sbcl-0.7.1.40, the
- ;; system stack grows upward.
+ ;; system stack grows upward.
;; Note that there are other stack-related differences between the
;; X86 port and the other ports. E.g. on the X86, the Lisp control
;; stack coincides with the C stack, meaning that on the X86 there's
;; just parameterized by #!+X86, but it'd probably be better to
;; use new flags like :CONTROL-STACK-CONTAINS-C-STACK.
;;
+ ;; :stack-allocatable-closures
+ ;; The compiler can allocate dynamic-extent closures on stack.
+ ;;
;; operating system features:
;; :linux = We're intended to run under some version of Linux.
;; :bsd = We're intended to run under some version of BSD Unix. (This