1 ;;;; This software is part of the SBCL system. See the README file for
4 ;;;; This software is derived from the CMU CL system, which was
5 ;;;; written at Carnegie Mellon University and released into the
6 ;;;; public domain. The software is in the public domain and is
7 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
8 ;;;; files for more information.
10 (in-package "SB!KERNEL")
12 (!begin-collecting-cold-init-forms)
14 ;;; Has the type system been properly initialized? (I.e. is it OK to
16 (defvar *type-system-initialized* #+sb-xc-host nil) ; (set in cold load)
18 ;;;; representations of types
20 ;;; A HAIRY-TYPE represents anything too weird to be described
21 ;;; reasonably or to be useful, such as NOT, SATISFIES, unknown types,
22 ;;; and unreasonably complicated types involving AND. We just remember
23 ;;; the original type spec.
24 (defstruct (hairy-type (:include ctype
25 (class-info (type-class-or-lose 'hairy))
27 (might-contain-other-types-p t))
30 ;; the Common Lisp type-specifier of the type we represent
31 (specifier nil :type t))
33 (!define-type-class hairy)
35 ;;; An UNKNOWN-TYPE is a type not known to the type system (not yet
36 ;;; defined). We make this distinction since we don't want to complain
37 ;;; about types that are hairy but defined.
38 (defstruct (unknown-type (:include hairy-type)
41 (defstruct (negation-type (:include ctype
42 (class-info (type-class-or-lose 'negation))
43 ;; FIXME: is this right? It's
44 ;; what they had before, anyway
46 (might-contain-other-types-p t))
49 (type (missing-arg) :type ctype))
51 (!define-type-class negation)
53 ;;; ARGS-TYPE objects are used both to represent VALUES types and
54 ;;; to represent FUNCTION types.
55 (defstruct (args-type (:include ctype)
58 ;; Lists of the type for each required and optional argument.
59 (required nil :type list)
60 (optional nil :type list)
61 ;; The type for the rest arg. NIL if there is no &REST arg.
62 (rest nil :type (or ctype null))
63 ;; true if &KEY arguments are specified
64 (keyp nil :type boolean)
65 ;; list of KEY-INFO structures describing the &KEY arguments
66 (keywords nil :type list)
67 ;; true if other &KEY arguments are allowed
68 (allowp nil :type boolean))
70 (defstruct (values-type
72 (class-info (type-class-or-lose 'values)))
73 (:constructor %make-values-type)
75 (define-cached-synonym make-values-type)
77 (!define-type-class values)
79 ;;; (SPECIFIER-TYPE 'FUNCTION) and its subtypes
80 (defstruct (fun-type (:include args-type
81 (class-info (type-class-or-lose 'function))))
82 ;; true if the arguments are unrestrictive, i.e. *
83 (wild-args nil :type boolean)
84 ;; type describing the return values. This is a values type
85 ;; when multiple values were specified for the return.
86 (returns (missing-arg) :type ctype))
88 ;;; The CONSTANT-TYPE structure represents a use of the CONSTANT-ARG
89 ;;; "type specifier", which is only meaningful in function argument
90 ;;; type specifiers used within the compiler. (It represents something
91 ;;; that the compiler knows to be a constant.)
92 (defstruct (constant-type
94 (class-info (type-class-or-lose 'constant)))
96 ;; The type which the argument must be a constant instance of for this type
98 (type (missing-arg) :type ctype))
100 ;;; The NAMED-TYPE is used to represent *, T and NIL. These types must
101 ;;; be super- or sub-types of all types, not just classes and * and
102 ;;; NIL aren't classes anyway, so it wouldn't make much sense to make
103 ;;; them built-in classes.
104 (defstruct (named-type (:include ctype
105 (class-info (type-class-or-lose 'named)))
107 (name nil :type symbol))
109 ;;; a list of all the float "formats" (i.e. internal representations;
110 ;;; nothing to do with #'FORMAT), in order of decreasing precision
111 (eval-when (:compile-toplevel :load-toplevel :execute)
112 (defparameter *float-formats*
113 '(long-float double-float single-float short-float)))
115 ;;; The type of a float format.
116 (deftype float-format () `(member ,@*float-formats*))
118 ;;; A NUMERIC-TYPE represents any numeric type, including things
120 (defstruct (numeric-type (:include ctype
121 (class-info (type-class-or-lose 'number)))
122 (:constructor %make-numeric-type)
124 ;; the kind of numeric type we have, or NIL if not specified (just
125 ;; NUMBER or COMPLEX)
127 ;; KLUDGE: A slot named CLASS for a non-CLASS value is bad.
128 ;; Especially when a CLASS value *is* stored in another slot (called
129 ;; CLASS-INFO:-). Perhaps this should be called CLASS-NAME? Also
130 ;; weird that comment above says "Numeric-Type is used to represent
131 ;; all numeric types" but this slot doesn't allow COMPLEX as an
132 ;; option.. how does this fall into "not specified" NIL case above?
133 ;; Perhaps someday we can switch to CLOS and make NUMERIC-TYPE
134 ;; be an abstract base class and INTEGER-TYPE, RATIONAL-TYPE, and
135 ;; whatnot be concrete subclasses..
136 (class nil :type (member integer rational float nil) :read-only t)
137 ;; "format" for a float type (i.e. type specifier for a CPU
138 ;; representation of floating point, e.g. 'SINGLE-FLOAT -- nothing
139 ;; to do with #'FORMAT), or NIL if not specified or not a float.
140 ;; Formats which don't exist in a given implementation don't appear
142 (format nil :type (or float-format null) :read-only t)
143 ;; Is this a complex numeric type? Null if unknown (only in NUMBER).
145 ;; FIXME: I'm bewildered by FOO-P names for things not intended to
146 ;; interpreted as truth values. Perhaps rename this COMPLEXNESS?
147 (complexp :real :type (member :real :complex nil) :read-only t)
148 ;; The upper and lower bounds on the value, or NIL if there is no
149 ;; bound. If a list of a number, the bound is exclusive. Integer
150 ;; types never have exclusive bounds, i.e. they may have them on
151 ;; input, but they're canonicalized to inclusive bounds before we
153 (low nil :type (or number cons null) :read-only t)
154 (high nil :type (or number cons null) :read-only t))
156 ;;; Impose canonicalization rules for NUMERIC-TYPE. Note that in some
157 ;;; cases, despite the name, we return *EMPTY-TYPE* instead of a
159 (defun make-numeric-type (&key class format (complexp :real) low high
161 ;; if interval is empty
164 (if (or (consp low) (consp high)) ; if either bound is exclusive
165 (>= (type-bound-number low) (type-bound-number high))
168 (multiple-value-bind (canonical-low canonical-high)
171 ;; INTEGER types always have their LOW and HIGH bounds
172 ;; represented as inclusive, not exclusive values.
173 (values (if (consp low)
174 (1+ (type-bound-number low))
177 (1- (type-bound-number high))
179 #!+negative-zero-is-not-zero
181 ;; Canonicalize a low bound of (-0.0) to 0.0, and a high
182 ;; bound of (+0.0) to -0.0.
183 (values (if (and (consp low)
186 (minusp (float-sign (car low))))
187 (float 0.0 (car low))
189 (if (and (consp high)
192 (plusp (float-sign (car high))))
193 (float -0.0 (car high))
196 ;; no canonicalization necessary
198 (when (and (eq class 'rational)
199 (integerp canonical-low)
200 (integerp canonical-high)
201 (= canonical-low canonical-high))
202 (setf class 'integer))
203 (%make-numeric-type :class class
208 :enumerable enumerable))))
210 (defun modified-numeric-type (base
212 (class (numeric-type-class base))
213 (format (numeric-type-format base))
214 (complexp (numeric-type-complexp base))
215 (low (numeric-type-low base))
216 (high (numeric-type-high base))
217 (enumerable (numeric-type-enumerable base)))
218 (make-numeric-type :class class
223 :enumerable enumerable))
225 ;;; An ARRAY-TYPE is used to represent any array type, including
226 ;;; things such as SIMPLE-STRING.
227 (defstruct (array-type (:include ctype
228 (class-info (type-class-or-lose 'array)))
229 (:constructor %make-array-type)
231 ;; the dimensions of the array, or * if unspecified. If a dimension
232 ;; is unspecified, it is *.
233 (dimensions '* :type (or list (member *)))
234 ;; Is this not a simple array type? (:MAYBE means that we don't know.)
235 (complexp :maybe :type (member t nil :maybe))
236 ;; the element type as originally specified
237 (element-type (missing-arg) :type ctype)
238 ;; the element type as it is specialized in this implementation
239 (specialized-element-type *wild-type* :type ctype))
240 (define-cached-synonym make-array-type)
242 ;;; A MEMBER-TYPE represent a use of the MEMBER type specifier. We
243 ;;; bother with this at this level because MEMBER types are fairly
244 ;;; important and union and intersection are well defined.
245 (defstruct (member-type (:include ctype
246 (class-info (type-class-or-lose 'member))
249 (:constructor %make-member-type (members))
250 #-sb-xc-host (:pure nil))
251 ;; the things in the set, with no duplications
252 (members nil :type list))
253 (defun make-member-type (&key members)
254 (declare (type list members))
255 ;; make sure that we've removed duplicates
256 (aver (= (length members) (length (remove-duplicates members))))
257 ;; if we have a pair of zeros (e.g. 0.0d0 and -0.0d0), then we can
258 ;; canonicalize to (DOUBLE-FLOAT 0.0d0 0.0d0), because numeric
259 ;; ranges are compared by arithmetic operators (while MEMBERship is
260 ;; compared by EQL). -- CSR, 2003-04-23
261 (let ((singlep (subsetp '(-0.0f0 0.0f0) members))
262 (doublep (subsetp '(-0.0d0 0.0d0) members))
264 (longp (subsetp '(-0.0l0 0.0l0) members)))
265 (if (or singlep doublep #!+long-float longp)
268 (push (ctype-of 0.0f0) union-types)
269 (setf members (set-difference members '(-0.0f0 0.0f0))))
271 (push (ctype-of 0.0d0) union-types)
272 (setf members (set-difference members '(-0.0d0 0.0d0))))
275 (push (ctype-of 0.0l0) union-types)
276 (setf members (set-difference members '(-0.0l0 0.0l0))))
277 (aver (not (null union-types)))
281 (cons (%make-member-type members)
283 (%make-member-type members))))
285 ;;; A COMPOUND-TYPE is a type defined out of a set of types, the
286 ;;; common parent of UNION-TYPE and INTERSECTION-TYPE.
287 (defstruct (compound-type (:include ctype
288 (might-contain-other-types-p t))
291 (types nil :type list :read-only t))
293 ;;; A UNION-TYPE represents a use of the OR type specifier which we
294 ;;; couldn't canonicalize to something simpler. Canonical form:
295 ;;; 1. All possible pairwise simplifications (using the UNION2 type
296 ;;; methods) have been performed. Thus e.g. there is never more
297 ;;; than one MEMBER-TYPE component. FIXME: As of sbcl-0.6.11.13,
298 ;;; this hadn't been fully implemented yet.
299 ;;; 2. There are never any UNION-TYPE components.
300 (defstruct (union-type (:include compound-type
301 (class-info (type-class-or-lose 'union)))
302 (:constructor %make-union-type (enumerable types))
304 (define-cached-synonym make-union-type)
306 ;;; An INTERSECTION-TYPE represents a use of the AND type specifier
307 ;;; which we couldn't canonicalize to something simpler. Canonical form:
308 ;;; 1. All possible pairwise simplifications (using the INTERSECTION2
309 ;;; type methods) have been performed. Thus e.g. there is never more
310 ;;; than one MEMBER-TYPE component.
311 ;;; 2. There are never any INTERSECTION-TYPE components: we've
312 ;;; flattened everything into a single INTERSECTION-TYPE object.
313 ;;; 3. There are never any UNION-TYPE components. Either we should
314 ;;; use the distributive rule to rearrange things so that
315 ;;; unions contain intersections and not vice versa, or we
316 ;;; should just punt to using a HAIRY-TYPE.
317 (defstruct (intersection-type (:include compound-type
318 (class-info (type-class-or-lose
320 (:constructor %make-intersection-type
324 ;;; Return TYPE converted to canonical form for a situation where the
325 ;;; "type" '* (which SBCL still represents as a type even though ANSI
326 ;;; CL defines it as a related but different kind of placeholder) is
327 ;;; equivalent to type T.
328 (defun type-*-to-t (type)
329 (if (type= type *wild-type*)
333 ;;; A CONS-TYPE is used to represent a CONS type.
334 (defstruct (cons-type (:include ctype (class-info (type-class-or-lose 'cons)))
336 ;; ANSI says that for CAR and CDR subtype
337 ;; specifiers '* is equivalent to T. In order
338 ;; to avoid special cases in SUBTYPEP and
339 ;; possibly elsewhere, we slam all CONS-TYPE
340 ;; objects into canonical form w.r.t. this
341 ;; equivalence at creation time.
342 %make-cons-type (car-raw-type
345 (car-type (type-*-to-t car-raw-type))
346 (cdr-type (type-*-to-t cdr-raw-type))))
348 ;; the CAR and CDR element types (to support ANSI (CONS FOO BAR) types)
350 ;; FIXME: Most or all other type structure slots could also be :READ-ONLY.
351 (car-type (missing-arg) :type ctype :read-only t)
352 (cdr-type (missing-arg) :type ctype :read-only t))
353 (defun make-cons-type (car-type cdr-type)
354 (if (or (eq car-type *empty-type*)
355 (eq cdr-type *empty-type*))
357 (%make-cons-type car-type cdr-type)))
361 ;;; Return the type structure corresponding to a type specifier. We
362 ;;; pick off structure types as a special case.
364 ;;; Note: VALUES-SPECIFIER-TYPE-CACHE-CLEAR must be called whenever a
365 ;;; type is defined (or redefined).
366 (defun-cached (values-specifier-type
367 :hash-function (lambda (x)
368 (logand (sxhash x) #x3FF))
370 :init-wrapper !cold-init-forms)
371 ((orig equal-but-no-car-recursion))
372 (let ((u (uncross orig)))
373 (or (info :type :builtin u)
374 (let ((spec (type-expand u)))
376 ((and (not (eq spec u))
377 (info :type :builtin spec)))
378 ((eq (info :type :kind spec) :instance)
379 (find-classoid spec))
380 ((typep spec 'classoid)
381 ;; There doesn't seem to be any way to translate
382 ;; (TYPEP SPEC 'BUILT-IN-CLASS) into something which can be
383 ;; executed on the host Common Lisp at cross-compilation time.
385 "stub: (TYPEP SPEC 'BUILT-IN-CLASS) on xc host")
386 (if (typep spec 'built-in-classoid)
387 (or (built-in-classoid-translation spec) spec)
390 (let* (;; FIXME: This automatic promotion of FOO-style
391 ;; specs to (FOO)-style specs violates the ANSI
392 ;; standard. Unfortunately, we can't fix the
393 ;; problem just by removing it, since then things
394 ;; downstream should break. But at some point we
395 ;; should fix this and the things downstream too.
396 (lspec (if (atom spec) (list spec) spec))
397 (fun (info :type :translator (car lspec))))
400 ((or (and (consp spec) (symbolp (car spec)))
402 (when (and *type-system-initialized*
403 (not (eq (info :type :kind spec)
404 :forthcoming-defclass-type)))
405 (signal 'parse-unknown-type :specifier spec))
406 ;; (The RETURN-FROM here inhibits caching.)
407 (return-from values-specifier-type
408 (make-unknown-type :specifier spec)))
410 (error "bad thing to be a type specifier: ~S"
413 ;;; This is like VALUES-SPECIFIER-TYPE, except that we guarantee to
414 ;;; never return a VALUES type.
415 (defun specifier-type (x)
416 (let ((res (values-specifier-type x)))
417 (when (values-type-p res)
418 (error "VALUES type illegal in this context:~% ~S" x))
421 (defun single-value-specifier-type (x)
422 (let ((res (specifier-type x)))
423 (if (eq res *wild-type*)
427 ;;; Similar to MACROEXPAND, but expands DEFTYPEs. We don't bother
428 ;;; returning a second value.
429 (defun type-expand (form)
430 (let ((def (cond ((symbolp form)
431 (info :type :expander form))
432 ((and (consp form) (symbolp (car form)))
433 (info :type :expander (car form)))
436 (type-expand (funcall def (if (consp form) form (list form))))
439 ;;; Note that the type NAME has been (re)defined, updating the
440 ;;; undefined warnings and VALUES-SPECIFIER-TYPE cache.
441 (defun %note-type-defined (name)
442 (declare (symbol name))
443 (note-name-defined name :type)
444 (when (boundp 'sb!kernel::*values-specifier-type-cache-vector*)
445 (values-specifier-type-cache-clear))
448 (!defun-from-collected-cold-init-forms !early-type-cold-init)