;;;; -*- 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. ;;;; ;;;; This software is derived from the CMU CL system, which was ;;;; written at Carnegie Mellon University and released into the ;;;; public domain. The software is in the public domain and is ;;;; provided with absolutely no warranty. See the COPYING and CREDITS ;;;; files for more information. ( ;; ;; features present in all builds ;; ;; 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 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 ;; ;; features present in this particular build ;; ;; Setting this enables the compilation of documentation strings ;; from the system sources into the target Lisp executable. ;; Traditional Common Lisp folk will want this option set. ;; I (WHN) made it optional because I came to Common Lisp from ;; C++ through Scheme, so I'm accustomed to asking ;; Emacs about things that I'm curious about instead of asking ;; the executable I'm running. :sb-doc ;; 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 ;; 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: ;; * SBCL is compiled with a higher level of OPTIMIZE DEBUG, so that ;; the debugger can tell more about the state of the system. ;; * Various code to print debugging messages, and similar debugging code, ;; is compiled only when this feature is present. ;; ;; Note that the extra information recorded by the compiler at ;; this higher level of OPTIMIZE DEBUG includes the source location ;; forms. In order for the debugger to use this information, it has to ;; re-READ the source file. In an ordinary installation of SBCL, this ;; re-READing may not work very well, for either of two reasons: ;; * The sources aren't present on the system in the same location that ;; they were on the system where SBCL was compiled. ;; * SBCL is using the standard readtable, without the added hackage ;; which allows it to handle things like target features. ;; If you want to be able to use the extra debugging information, ;; therefore, be sure to keep the sources around, and run with the ;; 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.) ; :sb-show-assem ;; Compile the C runtime with support for low-level debugging output ;; through FSHOW and FSHOW_SIGNAL. If enabled, this feature allows ;; users to turn on such debugging output using environment variables at ;; run-time. ; :sb-qshow ;; Setting this makes SBCL more "fluid", i.e. more amenable to ;; modification at runtime, by suppressing various INLINE declarations, ;; compiler macro definitions, FREEZE-TYPE declarations; and by ;; suppressing various burning-our-ships-behind-us actions after ;; initialization is complete; and so forth. This tends to clobber the ;; performance of the system, so unless you have some special need for ;; this when hacking SBCL itself, you don't want this set. ; :sb-fluid ;; Enable code for collecting statistics on usage of various operations, ;; useful for performance tuning of the SBCL system itself. This code ;; is probably pretty stale (having not been tested since the fork from ;; base CMU CL) but might nonetheless be a useful starting point for ;; anyone who wants to collect such statistics in the future. ; :sb-dyncount ;; Enable code for detecting concurrent accesses to the same hash-table ;; in multiple threads. Note that this implementation is currently ;; (2007-09-11) somewhat too eager: even though in the current implementation ;; multiple readers are thread safe as long as there are no writers, this ;; code will also trap multiple readers. ; :sb-hash-table-debug ;; Enabled automatically by make-config.sh for platforms which implement ;; the %READ-CYCLE-COUNTER VOP. Can be disabled manually: affects TIME. ;; ;; FIXME: Should this be :SB-CYCLE-COUNTER instead? If so, then the same goes ;; for :COMPARE-AND-SWAP-VOPS as well, and a bunch of others. Perhaps ;; built-time convenience features like this should all live in eg. SB!INT ;; instead? ;; ; :cycle-counter ;; Enabled automatically for platforms which implement complex arithmetic ;; VOPs. Such platforms should implement real-complex, complex-real and ;; complex-complex addition and subtractions (for complex-single-float ;; and complex-double-float). They should also also implement complex-real ;; and real-complex multiplication, complex-real division, and ;; sb!vm::swap-complex, which swaps the real and imaginary parts. ;; Finally, they should implement conjugate and complex-real, real-complex ;; and complex-complex CL:= (complex-complex EQL would usually be a good ;; idea). ;; ; :complex-float-vops ;; Enabled automatically for platforms which implement VOPs for EQL ;; of single and double floats. ;; ; :float-eql-vops ;; Enabled automatically for platform that can implement inline constants. ;; ;; Such platform must implement 5 functions, in SB!VM: ;; * canonicalize-inline-constant: converts a constant descriptor (list) into ;; a canonical description, to be used as a key in an EQUAL hash table ;; and to guide the generation of the constant itself. ;; * inline-constant-value: given a canonical constant descriptor, computes ;; two values: ;; 1. A label that will be used to emit the constant (usually a ;; sb!assem:label) ;; 2. A value that will be returned to code generators referring to ;; the constant (on x86oids, an EA object) ;; * sort-inline-constants: Receives a vector of unique constants; ;; the car of each entry is the constant descriptor, and the cdr the ;; corresponding label. Destructively returns a vector of constants ;; sorted in emission order. It could actually perform arbitrary ;; modifications to the vector, e.g. to fuse constants of different ;; size. ;; * emit-constant-segment-header: receives the vector of sorted constants ;; and a flag (true iff speed > space). Expected to emit padding ;; of some sort between the ELSEWHERE segment and the constants, or some ;; metadata. ;; * emit-inline-constant: receives a constant descriptor and its associated ;; label. Emits the constant. ;; ;; Implementing this features lets VOP generators use sb!c:register-inline-constant ;; to get handles (as returned by sb!vm:inline-constant-value) from constant ;; descriptors. ;; ; :inline-constants ;; Peter Van Eynde's increase-bulletproofness code for CMU CL ;; ;; 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 ;; low-level thread primitives support ;; ;; As of SBCL 1.0.33.26, threads are part of the default build on ;; x86oid Linux. Other platforms that support them include ;; x86oid Darwin, FreeBSD, and Solaris. ; :sb-thread ;; futex support ;; ;; While on linux we are able to use futexes for our locking ;; primitive, on other platforms we don't have this luxury. ;; ; :sb-futex ;; 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-fs-segment-register-from-tls ;; On some x86oid operating systems (darwin) SIGTRAP is not reliably ;; delivered for the INT3 instruction, so we use the UD2 instruction ;; which generates SIGILL instead. ; :ud2-breakpoints ;; 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 ;; Record xref data for SBCL internals. This can be rather useful for ;; people who want to develop on SBCL itself because it'll make M-? ;; (slime-edit-uses) work which lists call/expansion/etc. sites. ;; It'll increase the core size by major 5-6mB, though. ; :sb-xref-for-internals ;; 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 ;; conforms to IEEE's standard. Here it definitely means that the ;; floating point arithmetic implementation conforms to IEEE's standard. ;; I (WHN 19990702) haven't tried to verify ;; that it does conform, but it should at least mostly conform (because ;; the underlying x86 hardware tries). :ieee-floating-point ;; 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 ;; some maintenance before it will work. (E.g. the LONG-FLOAT-only parts of ;; genesis are still implemented in terms of unportable CMU CL functions ;; which are not longer available at genesis time in SBCL.) A deeper ;; problem is SBCL's bootstrap process implicitly assumes that the ;; cross-compilation host will be able to make the same distinctions ;; between floating point types that it does. This assumption is ;; fundamentally sleazy, even though in practice it's unlikely to break down ;; w.r.t. distinguishing SINGLE-FLOAT from DOUBLE-FLOAT; it's much more ;; likely to break down w.r.t. distinguishing DOUBLE-FLOAT from LONG-FLOAT. ;; Still it's likely to be quite doable to get LONG-FLOAT support working ;; 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 ;; Enabled automatically on platforms that have VOPs to compute the ;; high half of a full word-by-word multiplication. When disabled, ;; SB-KERNEL:%MULTIPLY-HIGH is implemented in terms of ;; SB-BIGNUM:%MULTIPLY. ; :multiply-high-vops ;; SBCL has optional support for zlib-based compressed core files. Enable ;; this feature to compile it in. Obviously, doing so adds a dependency ;; on zlib. ; :sb-core-compression ;; On certain thread-enabled platforms, synchronization between threads ;; for the purpose of stopping and starting the world around GC can be ;; performed using safepoints instead of signals. Enable this feature ;; to compile with safepoints and to use them for GC. ;; (Replaces use of SIG_STOP_FOR_GC.) ; :sb-safepoint ;; When compiling with safepoints, the INTERRUPT-THREAD mechanism can ;; also use safepoints to roll the target thread to a point at which it ;; can be interrupted safely, instead of using a signal for this ;; purpose. Enable this feature in addition to :SB-SAFEPOINT to enable ;; such behaviour. ;; (Replaces use of SIGPIPE, except to wake up syscalls.) ; :sb-thruption ;; When compiling with safepoints and thruptions, the TIMER facility ;; can replace its use of setitimer with a background thread. ;; (Replaces use of SIGALRM.) ; :sb-wtimer ;; ;; 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 ;; for this too. So don't use :NIL or :IGNORE as the names of features.. ;; notes on :SB-XC and :SB-XC-HOST features (which aren't controlled by this ;; file, but are instead temporarily pushed onto *FEATURES* or ;; *TARGET-FEATURES* during some phases of cross-compilation): ;; ;; :SB-XC-HOST stands for "cross-compilation host" and is in *FEATURES* ;; during the first phase of cross-compilation bootstrapping, when the ;; host Lisp is being used to compile the cross-compiler. ;; ;; :SB-XC stands for "cross compiler", and is in *FEATURES* during the second ;; phase of cross-compilation bootstrapping, when the cross-compiler is ;; being used to create the first target Lisp. ;; notes on the :SB-ASSEMBLING feature (which isn't controlled by ;; this file): ;; ;; This is a flag for whether we're in the assembler. It's ;; temporarily pushed onto the *FEATURES* list in the setup for ;; the ASSEMBLE-FILE function. It would be a bad idea ;; to use it as a name for a permanent feature. ;; 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 ;; :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) ;; ;; (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. ;; ;; :compare-and-swap-vops ;; The backend implements compare-and-swap VOPs. ;; ;; :memory-barrier-vops ;; Memory barriers (for multi-threaded synchronization) have been ;; implemented for this platform. ;; ;; operating system features: ;; :unix = We're intended to run under some Unix-like OS. (This is not ;; exclusive with the features which indicate which particular ;; Unix-like OS we're intended to run under.) ;; :linux = We're intended to run under some version of Linux. ;; :bsd = We're intended to run under some version of BSD Unix. (This ;; 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 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. ;; :hpux = We're intended to run under HP-UX 11.11 or later ;; :osf1 = We're intended to run under Tru64 (aka Digital Unix ;; aka OSF/1). ;; :win32 = We're intended to under some version of Microsoft Windows. ;; (No others are supported by SBCL as of 1.0.8, but :hpux or :irix ;; support could be ported from CMU CL if anyone is sufficiently ;; motivated to do so.) )