+;;;; various extensions (including SB-INT "internal extensions")
+;;;; available both in the cross-compilation host Lisp and in the
+;;;; target SBCL, but which can't be defined on the target until until
+;;;; some significant amount of machinery (e.g. error-handling) is
+;;;; defined
+
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.
-(in-package "SB!EXT")
+(in-package "SB!IMPL")
-(file-comment
- "$Header$")
+;;; Is X a list for which LENGTH is meaningful, i.e. a list which is
+;;; not improper and which is not circular?
+(defun list-with-length-p (x)
+ (values (ignore-errors (list-length x))))
-(defun featurep (x)
- #!+sb-doc
- "If X is an atom, see whether it is present in *FEATURES*. Also
- handle arbitrary combinations of atoms using NOT, AND, OR."
- (if (consp x)
- (case (car x)
- ((:not not)
- (if (cddr x)
- (error "too many subexpressions in feature expression: ~S" x)
- (not (featurep (cadr x)))))
- ((:and and) (every #'featurep (cdr x)))
- ((:or or) (some #'featurep (cdr x)))
- (t
- (error "unknown operator in feature expression: ~S." x)))
- (not (null (memq x *features*)))))
-
-;;; KLUDGE: This is a wrapper around stale code for working with floating point
-;;; infinities. I believe that I will eventually eliminate floating point
-;;; infinities from the code, since they're a pain to cross-compile, since they
-;;; significantly increase the number of conditions which need to be tested in
-;;; numeric functions, and since the benefits which they provide (which are
-;;; admittedly significant) are unfortunately not portable. I haven't actually
-;;; done the dirty deed yet, though, and until then, I've wrapped various
-;;; infinity-returning forms in this macro. -- WHN 1999
-(defmacro infinite (x)
- (declare (ignorable x))
- #!-sb-infinities '(error 'floating-point-overflow)
- #!+sb-infinities x)
-
-;;; Given a list of keyword substitutions `(,OLD ,NEW), and a
-;;; keyword-argument-list-style list of alternating keywords and arbitrary
-;;; values, return a new keyword-argument-list-style list with all
-;;; substitutions applied to it.
-;;;
-;;; Note: If efficiency mattered, we could do less consing. (But if efficiency
-;;; mattered, why would we be using keyword arguments at all, much less
-;;; renaming keyword arguments?)
+;;; not used in 0.7.8, but possibly useful for defensive programming
+;;; in e.g. (COERCE ... 'VECTOR)
+;;;(defun list-length-or-die (x)
+;;; (or (list-length x)
+;;; ;; not clear how to do this best:
+;;; ;; * Should this be a TYPE-ERROR? Colloquially that'd make
+;;; ;; lots of sense, but since I'm not sure how to express
+;;; ;; "noncircular list" as a Lisp type expression, coding
+;;; ;; it seems awkward.
+;;; ;; * Should the ERROR object include the offending value?
+;;; ;; Ordinarily that's helpful, but if the user doesn't have
+;;; ;; his printer set up to deal with cyclicity, we might not
+;;; ;; be doing him a favor by printing the object here.
+;;; ;; -- WHN 2002-10-19
+;;; (error "can't calculate length of cyclic list")))
+
+;;; This is used in constructing arg lists for debugger printing,
+;;; and when needing to print unbound slots in PCL.
+(defstruct (unprintable-object
+ (:constructor make-unprintable-object (string))
+ (:print-object (lambda (x s)
+ (print-unreadable-object (x s)
+ (write-string (unprintable-object-string x) s))))
+ (:copier nil))
+ string)
+
+;;; Used internally, but it would be nice to provide something
+;;; like this for users as well.
;;;
-;;; KLUDGE: It would probably be good to get rid of this. -- WHN 19991201
-(defun rename-keyword-args (rename-list keyword-args)
- (declare (type list rename-list keyword-args))
- ;; Walk through RENAME-LIST modifying RESULT as per each element in
- ;; RENAME-LIST.
- (do ((result (copy-list keyword-args))) ; may be modified below
- ((null rename-list) result)
- (destructuring-bind (old new) (pop rename-list)
- (declare (type keyword old new))
- ;; Walk through RESULT renaming any OLD keyword argument to NEW.
- (do ((in-result result (cddr in-result)))
- ((null in-result))
- (declare (type list in-result))
- (when (eq (car in-result) old)
- (setf (car in-result) new))))))
-
-;;; ANSI Common Lisp's READ-SEQUENCE function, unlike most of the
-;;; other ANSI input functions, is defined to communicate end of file
-;;; status with its return value, not by signalling. This is not the
-;;; behavior we usually want. This is a wrapper which give the
-;;; behavior we usually want, causing READ-SEQUENCE to communicate
-;;; end-of-file status by signalling.
-(defun read-sequence-or-die (sequence stream &key start end)
- ;; implementation using READ-SEQUENCE
- #-no-ansi-read-sequence
- (let ((read-end (read-sequence sequence
- stream
- :start start
- :end end)))
- (unless (= read-end end)
- (error 'end-of-file :stream stream))
- (values))
- ;; workaround for broken READ-SEQUENCE
- #+no-ansi-read-sequence
- (progn
- (assert (<= start end))
- (let ((etype (stream-element-type stream)))
- (cond ((equal etype '(unsigned-byte 8))
- (do ((i start (1+ i)))
- ((>= i end)
- (values))
- (setf (aref sequence i)
- (read-byte stream))))
- (t (error "unsupported element type ~S" etype))))))
+;;; FIXME / IMPORTANT: If the slot is raw, the address is correct only for
+;;; instances of the specified class, not its subclasses!
+#!+sb-thread
+(defmacro define-structure-slot-addressor (name &key structure slot)
+ (let* ((dd (find-defstruct-description structure t))
+ (slotd (when dd (find slot (dd-slots dd) :key #'dsd-name)))
+ (index (when slotd (dsd-index slotd)))
+ (raw-type (dsd-raw-type slotd)))
+ (unless index
+ (error "Slot ~S not found in ~S." slot structure))
+ `(progn
+ (declaim (inline ,name))
+ (defun ,name (instance)
+ (declare (type ,structure instance) (optimize speed))
+ (sb!ext:truly-the
+ sb!vm:word
+ (+ (sb!kernel:get-lisp-obj-address instance)
+ (- (* ,(if (eq t raw-type)
+ (+ sb!vm:instance-slots-offset index)
+ (- (1+ (sb!kernel::dd-instance-length dd)) sb!vm:instance-slots-offset index
+ (1- (sb!kernel::raw-slot-words raw-type))))
+ sb!vm:n-word-bytes)
+ sb!vm:instance-pointer-lowtag)))))))
+
+(defmacro compare-and-swap (place old new &environment env)
+ "Atomically stores NEW in PLACE if OLD matches the current value of PLACE.
+Two values are considered to match if they are EQ. Returns the previous value
+of PLACE: if the returned value is EQ to OLD, the swap was carried out.
+
+PLACE must be an accessor form whose CAR is one of the following:
+
+ CAR, CDR, FIRST, REST, SYMBOL-PLIST, SYMBOL-VALUE, SVREF
+
+or the name of a DEFSTRUCT created accessor for a slot whose declared type is
+either FIXNUM or T. Results are unspecified if the slot has a declared type
+other then FIXNUM or T.
+
+EXPERIMENTAL: Interface subject to change."
+ (flet ((invalid-place ()
+ (error "Invalid first argument to COMPARE-AND-SWAP: ~S" place)))
+ (unless (consp place)
+ (invalid-place))
+ ;; FIXME: Not the nicest way to do this...
+ (destructuring-bind (op &rest args) place
+ (case op
+ ((car first)
+ `(%compare-and-swap-car (the cons ,@args) ,old ,new))
+ ((cdr rest)
+ `(%compare-and-swap-cdr (the cons ,@args) ,old ,new))
+ (symbol-plist
+ `(%compare-and-swap-symbol-plist (the symbol ,@args) ,old (the list ,new)))
+ (symbol-value
+ (destructuring-bind (name) args
+ (flet ((slow (symbol)
+ (with-unique-names (n-symbol n-old n-new)
+ `(let ((,n-symbol ,symbol)
+ (,n-old ,old)
+ (,n-new ,new))
+ (declare (symbol ,n-symbol))
+ (about-to-modify-symbol-value ,n-symbol 'compare-and-swap ,n-new)
+ (%compare-and-swap-symbol-value ,n-symbol ,n-old ,n-new)))))
+ (if (sb!xc:constantp name env)
+ (let ((cname (constant-form-value name env)))
+ (if (eq :special (info :variable :kind cname))
+ ;; Since we know the symbol is a special, we can just generate
+ ;; the type check.
+ `(%compare-and-swap-symbol-value
+ ',cname ,old (the ,(info :variable :type cname) ,new))
+ (slow (list 'quote cname))))
+ (slow name)))))
+ (svref
+ (let ((vector (car args))
+ (index (cadr args)))
+ (unless (and vector index (not (cddr args)))
+ (invalid-place))
+ (with-unique-names (v)
+ `(let ((,v ,vector))
+ (declare (simple-vector ,v))
+ (%compare-and-swap-svref ,v (%check-bound ,v (length ,v) ,index) ,old ,new)))))
+ (t
+ (let ((dd (info :function :structure-accessor op)))
+ (if dd
+ (let* ((structure (dd-name dd))
+ (slotd (find op (dd-slots dd) :key #'dsd-accessor-name))
+ (index (dsd-index slotd))
+ (type (dsd-type slotd)))
+ (unless (eq t (dsd-raw-type slotd))
+ (error "Cannot use COMPARE-AND-SWAP with structure accessor for a typed slot: ~S"
+ place))
+ (when (dsd-read-only slotd)
+ (error "Cannot use COMPARE-AND-SWAP with structure accessor for a read-only slot: ~S"
+ place))
+ `(truly-the (values ,type &optional)
+ (%compare-and-swap-instance-ref (the ,structure ,@args)
+ ,index
+ (the ,type ,old) (the ,type ,new))))
+ (error "Invalid first argument to COMPARE-AND-SWAP: ~S" place))))))))
+
+(macrolet ((def (name lambda-list ref &optional set)
+ #!+compare-and-swap-vops
+ (declare (ignore ref set))
+ `(defun ,name (,@lambda-list old new)
+ #!+compare-and-swap-vops
+ (,name ,@lambda-list old new)
+ #!-compare-and-swap-vops
+ (let ((current (,ref ,@lambda-list)))
+ (when (eq current old)
+ ,(if set
+ `(,set ,@lambda-list new)
+ `(setf (,ref ,@lambda-list) new)))
+ current))))
+ (def %compare-and-swap-car (cons) car)
+ (def %compare-and-swap-cdr (cons) cdr)
+ (def %compare-and-swap-instance-ref (instance index) %instance-ref %instance-set)
+ (def %compare-and-swap-symbol-plist (symbol) symbol-plist)
+ (def %compare-and-swap-symbol-value (symbol) symbol-value)
+ (def %compare-and-swap-svref (vector index) svref))
+
+(defmacro atomic-incf (place &optional (diff 1))
+ #!+sb-doc
+ "Atomically increments PLACE by DIFF, and returns the value of PLACE before
+the increment.
+
+The incrementation is done using word-size modular arithmetic: on 32 bit
+platforms ATOMIC-INCF of #xFFFFFFFF by one results in #x0 being stored in
+PLACE.
+
+PLACE must be an accessor form whose CAR is the name of a DEFSTRUCT accessor
+whose declared type is (UNSIGNED-BYTE 32) on 32 bit platforms,
+and (UNSIGNED-BYTE 64) on 64 bit platforms.
+
+DIFF defaults to 1, and must be a (SIGNED-BYTE 32) on 32 bit platforms,
+and (SIGNED-BYTE 64) on 64 bit platforms.
+
+EXPERIMENTAL: Interface subject to change."
+ (flet ((invalid-place ()
+ (error "Invalid first argument to ATOMIC-INCF: ~S" place)))
+ (unless (consp place)
+ (invalid-place))
+ (destructuring-bind (op &rest args) place
+ (when (cdr args)
+ (invalid-place))
+ (let ((dd (info :function :structure-accessor op)))
+ (if dd
+ (let* ((structure (dd-name dd))
+ (slotd (find op (dd-slots dd) :key #'dsd-accessor-name))
+ (index (dsd-index slotd))
+ (type (dsd-type slotd)))
+ (declare (ignorable structure index))
+ (unless (and (eq 'sb!vm:word (dsd-raw-type slotd))
+ (type= (specifier-type type) (specifier-type 'sb!vm:word)))
+ (error "ATOMIC-INCF requires a slot of type (UNSIGNED-BYTE ~S), not ~S: ~S"
+ sb!vm:n-word-bits type place))
+ (when (dsd-read-only slotd)
+ (error "Cannot use ATOMIC-INCF with structure accessor for a read-only slot: ~S"
+ place))
+ #!+(or x86 x86-64)
+ `(truly-the sb!vm:word
+ (%raw-instance-atomic-incf/word (the ,structure ,@args)
+ ,index
+ (the sb!vm:signed-word ,diff)))
+ ;; No threads outside x86 and x86-64 for now, so this is easy...
+ #!-(or x86 x86-64)
+ (with-unique-names (structure old)
+ `(sb!sys:without-interrupts
+ (let* ((,structure ,@args)
+ (,old (,op ,structure)))
+ (setf (,op ,structure) (logand #.(1- (ash 1 sb!vm:n-word-bits))
+ (+ ,old (the sb!vm:signed-word ,diff))))
+ ,old))))
+ (invalid-place))))))
+
+(defun call-hooks (kind hooks &key (on-error :error))
+ (dolist (hook hooks)
+ (handler-case
+ (funcall hook)
+ (serious-condition (c)
+ (if (eq :warn on-error)
+ (warn "Problem running ~A hook ~S:~% ~A" kind hook c)
+ (with-simple-restart (continue "Skip this ~A hook." kind)
+ (error "Problem running ~A hook ~S:~% ~A" kind hook c)))))))
+
+;;;; DEFGLOBAL
+
+(defmacro-mundanely defglobal (name value &optional (doc nil docp))
+ #!+sb-doc
+ "Defines NAME as a global variable that is always bound. VALUE is evaluated
+and assigned to NAME both at compile- and load-time, but only if NAME is not
+already bound.
+
+Global variables share their values between all threads, and cannot be
+locally bound, declared special, defined as constants, and neither bound
+nor defined as symbol macros.
+
+See also the declarations SB-EXT:GLOBAL and SB-EXT:ALWAYS-BOUND."
+ `(progn
+ (eval-when (:compile-toplevel)
+ (let ((boundp (boundp ',name)))
+ (%compiler-defglobal ',name (unless boundp ,value) boundp)))
+ (eval-when (:load-toplevel :execute)
+ (let ((boundp (boundp ',name)))
+ (%defglobal ',name (unless boundp ,value) boundp ',doc ,docp
+ (sb!c:source-location))))))
+
+(defun %compiler-defglobal (name value boundp)
+ (sb!xc:proclaim `(global ,name))
+ (unless boundp
+ #-sb-xc-host
+ (set-symbol-global-value name value)
+ #+sb-xc-host
+ (set name value))
+ (sb!xc:proclaim `(always-bound ,name)))
+
+(defun %defglobal (name value boundp doc docp source-location)
+ (%compiler-defglobal name value boundp)
+ (when docp
+ (setf (fdocumentation name 'variable) doc))
+ (sb!c:with-source-location (source-location)
+ (setf (info :source-location :variable name) source-location))
+ name)
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