+;;;; -*- Lisp -*-
+
;;;; tags which are set during the build process and which end up in
;;;; CL:*FEATURES* in the target SBCL, plus some comments about other
;;;; 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. If you define a function
+;;;; in customize-target-features.lisp, it will be used to transform
+;;;; the target features list after it's read and before it's used.
+;;;; 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))
+;;;; By thus editing a local file (one which is not in the source
+;;;; distribution, and which is in .cvsignore) your customizations
+;;;; will remain local even if you do things like "cvs update",
+;;;; will not show up if you try to submit a patch with "cvs diff",
+;;;; and might even stay out of the way if you use other non-CVS-based
+;;;; methods to upgrade the files or store your configuration.
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;; our standard
:ansi-cl :common-lisp
;; FIXME: Isn't there a :x3jsomething feature which we should set too?
+ ;; No. CLHS says ":x3j13 [...] A conforming implementation might or
+ ;; might not contain such a feature." -- CSR, 2002-02-21
;; our dialect
:sbcl
;; Douglas Thomas Crosher's conservative generational GC (the only one
- ;; we currently support)
- :gencgc
+ ;; we currently support for X86).
+ ;; :gencgc used to be here; CSR moved it into
+ ;; local-target-features.lisp-expr via make-config.sh, as alpha,
+ ;; sparc and ppc ports don't currently support it. -- CSR, 2002-02-21
;; We're running under a UNIX. This is sort of redundant, and it was also
;; sort of redundant under CMU CL, which we inherited it from: neither SBCL
;; 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.
+ ;; 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.
+ ;; This test does not affect the target system (in much the same way
+ ;; as :sb-after-xc-core, below).
:sb-test
- ;; 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, or trying to debug assembly
+ ;; code for a port to a new CPU) 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 when
+ ;; you modify SBCL's own source code, as in slam.sh. Otherwise
+ ;; you don't need it.
+ ; :sb-after-xc-core
+
;; Enable extra debugging output in the assem.lisp assembler/scheduler
;; code. (This is the feature which was called :DEBUG in the
;; original CMU CL code.)
;; anyone who wants to collect such statistics in the future.
; :sb-dyncount
- ;; Peter Van Eynde's increase-bulletproofness code
+ ;; Peter Van Eynde's increase-bulletproofness code for CMU CL
;;
- ;; This is not maintained or tested in current SBCL, but I haven't
- ;; gone out of my way to remove or break it, either.
+ ;; Some of the code which was #+high-security before the fork has now
+ ;; 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.
;;
; :high-security
; :high-security-support
; :mp
; :mp-i486
- ;; KLUDGE: used to suppress stale code related to floating point infinities.
- ;; I intend to delete this code completely some day, since it was a pain
- ;; for me to try to work with and since all benefits it provides are
- ;; non-portable. Until I actually pull the trigger, though, I've left
- ;; various stale code in place protected with #!-SB-INFINITIES.
- ; :sb-infinities
-
;; 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.
+ ;; doesn't seem to be documented anywhere what systems it might apply
+ ;; to. It doesn't seem to be needed for X86 systems anyway.
; :32x16-divide
- ;; This is probably true for some processor types, but not X86. It affects
- ;; a lot of floating point code.
+ ;; This is probably true for some processor types, but not X86. It
+ ;; affects a lot of floating point code.
; :negative-zero-is-not-zero
- ;; This is mentioned in cmu-user.tex, which says that it enables
- ;; the compiler to reason about integer arithmetic. It also seems to
- ;; control other fancy numeric reasoning, e.g. knowing the result type of
- ;; a remainder calculation given the type of its inputs.
- ;;
- ;; CROSS-FLOAT-INFINITY-KLUDGE: The :PROPAGATE-FLOAT-TYPE and
- ;; :PROPAGATE-FUN-TYPE features are problematic when building
- ;; the cross-compiler itself. Their implementation depends on
- ;; floating point infinities, which might not be supported in the
- ;; cross-compilation host. In order to avoid this problem, while
- ;; still supporting these features in the target Lisp compiler,
- ;; we use the :WILL-PROPAGATE-FLOAT-TYPE feature when building
- ;; the cross-compiler, and munge it into :PROPAGATE-FLOAT-TYPE
- ;; only when building the target compiler; and similarly for
- ;; :WILL-PROPAGATE-FUN-TYPE.
- ;:will-propagate-float-type ; (becomes :PROPAGATE-FLOAT-TYPE)
-
- ;; According to cmu-user.tex, this enables the compiler to infer result
- ;; types for mathematical functions like SQRT, EXPT, and LOG, allowing
- ;; it to e.g. eliminate the possibility that a complex result will be
- ;; generated. This applies only to the target compiler, not the
- ;; cross-compiler: see CROSS-FLOAT-INFINITY-KLUDGE.
- ;:will-propagate-fun-type ; (becomes :PROPAGATE-FUN-TYPE)
-
- ;; It's unclear to me what this does (but it was enabled in the code that I
- ;; picked up from Peter Van Eynde). -- WHN 19990224
- :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
;; the underlying x86 hardware tries).
:ieee-floating-point
- ;; This seems to be the pre-GENCGC garbage collector for CMU CL, which was
- ;; AFAIK never supported for the X86.
- ; :gengc
-
;; CMU CL had, and we inherited, code to support 80-bit LONG-FLOAT on the x86
;; architecture. Nothing has been done to actively destroy the long float
;; support, but it hasn't been thoroughly maintained, and needs at least
;; phase of cross-compilation bootstrapping, when the cross-compiler is
;; being used to create the first target Lisp.
- ;; notes on the :PROPAGATE-FLOAT-TYPE and :PROPAGATE-FUN-TYPE
- ;; features: See the comments on CROSS-FLOAT-INFINITY-KLUDGE.
-
;; notes on the :SB-ASSEMBLING feature (which isn't controlled by
;; this file):
;;
;; 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
+ ;; :sparc
+ ;; any Sun UltraSPARC (possibly also non-Ultras -- currently untested)
+ ;; :ppc
+ ;; any PowerPC CPU
+ ;;
+ ;; (No other CPUs are supported by SBCL as of 0.7.5, but MIPS or HPPA
+ ;; 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 has
+ ;; now been moved to the backend-subfeatures mechanism.)
+ ;;
+ ;; properties derived from the machine architecture
+ ;; :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.
+ ;; 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
+ ;; stuff on the control stack that the Lisp-level debugger doesn't
+ ;; understand very well. As of sbcl-0.7.1.40 things like that are
+ ;; just parameterized by #!+X86, but it'd probably be better to
+ ;; use new flags like :CONTROL-STACK-CONTAINS-C-STACK.
;;
;; operating system features:
;; :linux = We're intended to run under some version of Linux.
;; is not exclusive with the features which indicate which
;; particular version of BSD we're intended to run under.)
;; :freebsd = We're intended to run under FreeBSD.
- ;; :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.)
+ ;; :openbsd = We're intended to run under OpenBSD.
+ ;; :sunos = We're intended to run under Solaris user environment
+ ;; with the SunOS kernel.
+ ;; :osf1 = We're intended to run under Tru64 (aka Digital Unix
+ ;; aka OSF/1).
+ ;; (No others are supported by SBCL as of 0.7.5, but :hpux or
+ ;; :irix support could be ported from CMU CL if anyone is
+ ;; sufficiently motivated to do so, and it'd even be possible,
+ ;; though harder, to port the system to Microsoft Windows.)
)
projects / sbcl.git / blobdiff