;;;; CL:*FEATURES* tags which have special meaning to SBCL or which
;;;; have a special conventional meaning
;;;;
-;;;; Note that the preferred way to customize the features of a local
-;;;; build of SBCL is not to edit this file, but to tweak
-;;;; customize-target-features.lisp.
+;;;; Note that the recommended way to customize the features of a
+;;;; local build of SBCL is not to edit this file, but instead to
+;;;; tweak customize-target-features.lisp. E.g. you can use code like
+;;;; this:
+;;;; (lambda (list)
+;;;; (flet ((enable (x) (pushnew x list))
+;;;; (disable (x) (setf list (remove x list))))
+;;;; #+nil (enable :sb-show)
+;;;; (enable :sb-after-xc-core)
+;;;; #+nil (disable :sb-doc)
+;;;; list))
+;;;; That way, because customize-target-features.lisp is in
+;;;; .cvsignore, your local changes will remain local even if you use
+;;;; "cvs diff" to submit patches to SBCL.
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
:sbcl
;; Douglas Thomas Crosher's conservative generational GC (the only one
- ;; we currently support)
+ ;; we currently support for X86)
:gencgc
;; We're running under a UNIX. This is sort of redundant, and it was also
;; the executable I'm running.
:sb-doc
- ;; When this is set, EVAL is implemented as an "IR1 interpreter":
- ;; code is compiled into the compiler's first internal representation,
- ;; then the IR1 is interpreted. When this is not set, EVAL is implemented
- ;; as a little bit of hackery wrapped around a call to COMPILE, i.e.
- ;; the system becomes a "compiler-only implementation" of Common Lisp.
- ;; As of sbcl-0.6.7, the compiler-only implementation is prototype code,
- ;; and much less mature than the old IR1 interpreter. Thus, the safe
- ;; thing is to leave :SB-INTERPRETER set. However, the compiler-only
- ;; system is noticeably smaller, so you might want to omit
- ;; :SB-INTERPRETER if you have a small machine.
- ;;
- ;; Probably, the compiler-only implementation will become more
- ;; stable someday, and support for the IR1 interpreter will then be
- ;; dropped. This will make the system smaller and easier to maintain
- ;; not only because we no longer need to support the interpreter,
- ;; but because code elsewhere in the system (the dumper, the debugger,
- ;; etc.) no longer needs special cases for interpreted code.
- :sb-interpreter
-
;; Do regression and other tests when building the system. You
;; might or might not want this if you're not a developer,
;; depending on how paranoid you are. You probably do want it if
;; you are a developer.
:sb-test
- ;; :SB-PROPAGATE-FLOAT-TYPE and :SB-PROPAGATE-FUN-TYPE enable
- ;; some numeric optimizer code in the target compiler. They
- ;; correspond to the :PROPAGATE-FLOAT-TYPE and :PROPAGATE-FUN-TYPE
- ;; features in the original CMU CL code, and while documentation
- ;; existed for those, it seemed a little inconsistent. Despite the
- ;; name, :SB-PROPAGATE-FLOAT-TYPE seems to control not only
- ;; floating point optimizations, but some integer optimizations as
- ;; well.
- ;;
- ;; CROSS-FLOAT-INFINITY-KLUDGE:
- ;; * Even when these target features are enabled, the optimizations
- ;; aren't enabled in the cross-compiler, because some of them
- ;; depend on floating point infinities, which aren't in general
- ;; supported on the cross-compilation host.
- ;; * This is supported by hacking the features out of the
- ;; *SHEBANG-FEATURES* list while we're building the cross-compiler.
- ;; This is ugly and confusing and weird, but all the alternatives
- ;; that I could think of seem messy and error-prone. That doesn't
- ;; mean there's not a better way, though. Suggestions are welcome;
- ;; or if you'd like to submit patches to make this code work
- ;; without requiring floating point infinities, so that the entire
- ;; problem goes away, that might be even better! -- WHN 2001-03-22
- :sb-propagate-float-type
- :sb-propagate-fun-type
-
- ;; Setting this makes more debugging information available.
- ;; If you aren't hacking or troubleshooting SBCL itself, you
- ;; probably don't want this set.
+ ;; Make more debugging information available (for debugging SBCL
+ ;; itself). If you aren't hacking or troubleshooting SBCL itself,
+ ;; you probably don't want this set.
;;
;; At least two varieties of debugging information are enabled by this
;; option:
;; readtable configured so that the system sources can be read.
; :sb-show
+ ;; Build SBCL with the old CMU CL low level debugger, "ldb". If
+ ;; are aren't messing with CMU CL at a very low level (e.g.
+ ;; trying to diagnose GC problems) you shouldn't need this.
+ ; :sb-ldb
+
;; This isn't really a target Lisp feature at all, but controls
;; whether the build process produces an after-xc.core file. This
;; can be useful for shortening the edit/compile/debug cycle if
;; affects a lot of floating point code.
; :negative-zero-is-not-zero
- ;; It's unclear to me what this does (but it was enabled in the code
- ;; that I picked up from Peter Van Eynde, called CONSTRAIN-FLOAT-TYPE
- ;; instead of SB-CONSTRAIN-FLOAT-TYPE). -- WHN 19990224
- :sb-constrain-float-type
-
;; This is set in classic CMU CL, and presumably there it means
;; that the floating point arithmetic implementation
;; conforms to IEEE's standard. Here it definitely means that the
;; really, really know what you're doing):
;;
;; machine architecture features:
- ;; :x86 ; any Intel 386 or better, or compatibles like the AMD K6 or K7
- ;; (No others are supported by SBCL as of 0.6.7, but :alpha or
- ;; :sparc support could be ported from CMU CL if anyone is
- ;; sufficiently motivated to do so.)
- ;; (CMU CL also had a :pentium feature, which affected the definition
- ;; of some floating point vops. It was present but not enabled in the
- ;; CMU CL code that SBCL is derived from, and is present but stale
- ;; in SBCL as of 0.6.7.)
+ ;; :x86
+ ;; any Intel 386 or better, or compatibles like the AMD K6 or K7
+ ;; :alpha
+ ;; DEC/Compaq Alpha CPU
+ ;; (No other CPUs are supported by SBCL as of 0.6.12.15, but SPARC or
+ ;; PowerPC support could be ported from CMU CL if anyone is
+ ;; sufficiently motivated to do so, or if you're *really* motivated,
+ ;; you could write a port from scratch for a new CPU architecture.)
+ ;; (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 is
+ ;; present but stale in SBCL as of 0.6.12.)
;;
;; operating system features:
;; :linux = We're intended to run under some version of Linux.
;; :openbsd = We're intended to run under FreeBSD.
;; (No others are supported by SBCL as of 0.6.7, but :hpux or
;; :solaris support could be ported from CMU CL if anyone is
- ;; sufficiently motivated to do so.)
+ ;; sufficiently motivated to do so, and it'd even be possible,
+ ;; though harder, to port the system to Microsoft Windows.)
)
projects / sbcl.git / blobdiff