+;;;; -*- 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 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. (You must create this file
+;;;; first; it is not in the SBCL distribution, and is in fact
+;;;; explicitly excluded from the distribution in places like
+;;;; .cvsignore.) 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". In the
+ ;; ideal world you would not need this unless you are messing with
+ ;; SBCL 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). However,
+ ;; experience shows that sooner or later everyone lose()'s, in which
+ ;; case SB-LDB can at least provide an informative backtrace.
+ :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
- ;; multiprocessing support
+ ;; low-level thread primitives support
;;
- ;; This is not maintained or tested in current SBCL. I haven't gone out
- ;; of my way to break it, but since it's derived from an old version of
- ;; CMU CL where multiprocessing was pretty shaky, it's likely to be very
- ;; flaky now.
- ;; :MP enables multiprocessing
- ;; :MP-I486 is used, only within the multiprocessing code, to control
- ;; what seems to control processor-version-specific code. It's
- ;; probably for 486 or later, i.e. could be set as long as
- ;; you know you're not running on a 386, but it doesn't seem
- ;; to be documented anywhere, so that's just a guess.
- ; :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
+ ;; 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
- ;; 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.
- ; :32x16-divide
+ ;; lutex support
+ ;;
+ ;; While on linux we are able to use futexes for our locking
+ ;; primitive, on other platforms we don't have this luxury. NJF's
+ ;; lutexes present a locking API similar to the futex-based API that
+ ;; allows for sb-thread support on x86 OS X, Solaris and
+ ;; FreeBSD.
+ ;;
+ ; :sb-lutex
- ;; This is probably true for some processor types, but not X86. It affects
- ;; a lot of floating point code.
- ; :negative-zero-is-not-zero
+ ;; On some operating systems the FS segment register (used for SBCL's
+ ;; thread local storage) is not reliably preserved in signal
+ ;; handlers, so we need to restore its value from the pthread thread
+ ;; local storage.
+ ; :restore-tls-segment-register-from-tls
- ;; 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
+ ;; 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
+
+ ;; Support for a full evaluator that can execute all the CL special
+ ;; forms, as opposed to the traditional SBCL evaluator which called
+ ;; COMPILE for everything complicated.
+ :sb-eval
+
+ ;; Record source location information for variables, classes, conditions,
+ ;; packages, etc. Gives much better information on M-. in Slime, but
+ ;; increases core size by about 100kB.
+ :sb-source-locations
+
+ ;; 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.
+ ; :32x16-divide
;; This is set in classic CMU CL, and presumably there it means
;; that the floating point arithmetic implementation
;; 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
;; again, if anyone's sufficiently motivated.
; :long-float
+ ;; Some platforms don't use a 32-bit off_t by default, and thus can't
+ ;; handle files larger than 2GB. This feature will control whether
+ ;; we'll try to use platform-specific compilation options to enable a
+ ;; 64-bit off_t. The intent is for this feature to be automatically
+ ;; enabled by make-config.sh on platforms where it's needed and known
+ ;; to work, you shouldn't be enabling it manually. You might however
+ ;; want to disable it, if you need to pass file descriptors to
+ ;; foreign code that uses a 32-bit off_t.
+ ; :largefile
+
;;
;; miscellaneous notes on other things which could have special significance
;; in the *FEATURES* list
;;
+ ;; Any target feature which affects binary compatibility of fasl files
+ ;; needs to be recorded in *FEATURES-POTENTIALLY-AFFECTING-FASL-FORMAT*
+ ;; (elsewhere).
+
;; notes on the :NIL and :IGNORE features:
;;
;; #+NIL is used to comment out forms. Occasionally #+IGNORE is used
;; 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):
;;
;; 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
- ;; (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
+ ;; :x86-64
+ ;; any x86-64 CPU running in 64-bit mode
+ ;; :alpha
+ ;; DEC/Compaq Alpha CPU
+ ;; :sparc
+ ;; any Sun UltraSPARC (possibly also non-Ultras -- currently untested)
+ ;; :ppc
+ ;; any PowerPC CPU
+ ;; :hppa
+ ;; any PA-RISC CPU
+ ;; :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
+ ;; 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.
+ ;;
+ ;; :stack-allocatable-closures
+ ;; The compiler can allocate dynamic-extent closures on stack.
+ ;;
+ ;; :alien-callbacks
+ ;; Alien callbacks have been implemented for this platform.
;;
;; 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.
+ ;; :netbsd = We're intended to run under NetBSD.
+ ;; :darwin = We're intended to run under Darwin (including MacOS X).
+ ;; :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 0.9.6, 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