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[sbcl/lichteblau.git] / src / code / cross-type.lisp
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1 ;;;; cross-compiler-only versions of TYPEP, TYPE-OF, and related functions
3 ;;;; This software is part of the SBCL system. See the README file for
4 ;;;; more information.
5 ;;;;
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
12 (in-package "SB!KERNEL")
14 ;;; Is X a fixnum in the target Lisp?
15 (defun fixnump (x)
16 (and (integerp x)
17 (<= sb!xc:most-negative-fixnum x sb!xc:most-positive-fixnum)))
19 ;;; (This was a useful warning when trying to get bootstrapping
20 ;;; to work, but it's mostly irrelevant noise now that the system
21 ;;; works.)
22 (define-condition cross-type-style-warning (style-warning)
23 ((call :initarg :call
24 :reader cross-type-style-warning-call)
25 (message :reader cross-type-style-warning-message
26 #+cmu :initarg #+cmu :message ; (to stop bogus non-STYLE WARNING)
28 (:report (lambda (c s)
29 (format
31 "cross-compilation-time type ambiguity (should be OK) in ~S:~%~A"
32 (cross-type-style-warning-call c)
33 (cross-type-style-warning-message c)))))
35 ;;; This warning is issued when giving up on a type calculation where a
36 ;;; conservative answer is acceptable. Since a conservative answer is
37 ;;; acceptable, the only downside is lost optimization opportunities.
38 (define-condition cross-type-giving-up-conservatively
39 (cross-type-style-warning)
40 ((message :initform "giving up conservatively"
41 #+cmu :reader #+cmu #.(gensym) ; (to stop bogus non-STYLE WARNING)
42 )))
44 ;;; This warning refers to the flexibility in the ANSI spec with
45 ;;; regard to run-time distinctions between floating point types.
46 ;;; (E.g. the cross-compilation host might not even distinguish
47 ;;; between SINGLE-FLOAT and DOUBLE-FLOAT, so a DOUBLE-FLOAT number
48 ;;; would test positive as SINGLE-FLOAT.) If the target SBCL does make
49 ;;; this distinction, then information is lost. It's not too hard to
50 ;;; contrive situations where this would be a problem. In practice we
51 ;;; don't tend to run into them because all widely used Common Lisp
52 ;;; environments do recognize the distinction between SINGLE-FLOAT and
53 ;;; DOUBLE-FLOAT, and we don't really need the other distinctions
54 ;;; (e.g. between SHORT-FLOAT and SINGLE-FLOAT), so we call
55 ;;; WARN-POSSIBLE-CROSS-TYPE-FLOAT-INFO-LOSS to test at runtime
56 ;;; whether we need to worry about this at all, and not warn unless we
57 ;;; do. If we *do* have to worry about this at runtime, my (WHN
58 ;;; 19990808) guess is that the system will break in multiple places,
59 ;;; so this is a real WARNING, not just a STYLE-WARNING.
60 ;;;
61 ;;; KLUDGE: If we ever try to support LONG-FLOAT or SHORT-FLOAT, this
62 ;;; situation will get a lot more complicated.
63 (defun warn-possible-cross-type-float-info-loss (call)
64 (when (or (subtypep 'single-float 'double-float)
65 (subtypep 'double-float 'single-float))
66 (warn "possible floating point information loss in ~S" call)))
68 (defun sb!xc:type-of (object)
69 (let ((raw-result (type-of object)))
70 (cond ((or (subtypep raw-result 'float)
71 (subtypep raw-result 'complex))
72 (warn-possible-cross-type-float-info-loss
73 `(sb!xc:type-of ,object))
74 raw-result)
75 ((subtypep raw-result 'integer)
76 (cond ((<= 0 object 1)
77 'bit)
78 (;; We can't rely on the host's opinion of whether
79 ;; it's a FIXNUM, but instead test against target
80 ;; MOST-fooITIVE-FIXNUM limits.
81 (fixnump object)
82 'fixnum)
84 'integer)))
85 ((subtypep raw-result 'simple-string)
86 `(simple-base-string ,(length object)))
87 ((subtypep raw-result 'string) 'base-string)
88 ((some (lambda (type) (subtypep raw-result type))
89 '(array character list symbol))
90 raw-result)
92 (error "can't handle TYPE-OF ~S in cross-compilation" object)))))
94 ;;; Is SYMBOL in the CL package? Note that we're testing this on the
95 ;;; cross-compilation host, which could do things any old way. In
96 ;;; particular, it might be in the CL package even though
97 ;;; SYMBOL-PACKAGE is not (FIND-PACKAGE :CL). So we test things
98 ;;; another way.
99 (defun in-cl-package-p (symbol)
100 (eql (find-symbol (symbol-name symbol) :cl)
101 symbol))
103 ;;; This is like TYPEP, except that it asks whether HOST-OBJECT would
104 ;;; be of TARGET-TYPE when instantiated on the target SBCL. Since this
105 ;;; is hard to determine in some cases, and since in other cases we
106 ;;; just haven't bothered to try, it needs to return two values, just
107 ;;; like SUBTYPEP: the first value for its conservative opinion (never
108 ;;; T unless it's certain) and the second value to tell whether it's
109 ;;; certain.
110 (defun cross-typep (host-object raw-target-type)
111 (let ((target-type (type-expand raw-target-type)))
112 (flet ((warn-and-give-up ()
113 ;; We don't have to keep track of this as long as system
114 ;; performance is acceptable, since giving up
115 ;; conservatively is a safe way out.
116 #+nil
117 (warn 'cross-type-giving-up-conservatively
118 :call `(cross-typep ,host-object ,raw-target-type))
119 (values nil nil))
120 (warn-about-possible-float-info-loss ()
121 (warn-possible-cross-type-float-info-loss
122 `(cross-typep ,host-object ,raw-target-type)))
123 ;; a convenient idiom for making more matches to special cases:
124 ;; Test both forms of target type for membership in LIST.
126 ;; (In order to avoid having to use too much deep knowledge
127 ;; of types, it's sometimes convenient to test RAW-TARGET-TYPE
128 ;; as well as the expanded type, since we can get matches with
129 ;; just EQL. E.g. SIMPLE-STRING can be matched with EQL, while
130 ;; safely matching its expansion,
131 ;; (OR (SIMPLE-ARRAY CHARACTER (*)) (SIMPLE-BASE-STRING *))
132 ;; would require logic clever enough to know that, e.g., OR is
133 ;; commutative.)
134 (target-type-is-in (list)
135 (or (member raw-target-type list)
136 (member target-type list))))
137 (cond (;; Handle various SBCL-specific types which can't exist on
138 ;; the ANSI cross-compilation host. KLUDGE: This code will
139 ;; need to be tweaked by hand if the names of these types
140 ;; ever change, ugh!
141 (if (consp target-type)
142 (member (car target-type)
143 '(sb!alien:alien))
144 (member target-type
145 '(system-area-pointer
146 funcallable-instance
147 sb!alien-internals:alien-value)))
148 (values nil t))
149 (;; special case when TARGET-TYPE isn't a type spec, but
150 ;; instead a CLASS object.
151 (typep target-type 'class)
152 (bug "We don't support CROSS-TYPEP of CLASS type specifiers"))
153 ((and (symbolp target-type)
154 (find-classoid target-type nil)
155 (sb!xc:subtypep target-type 'cl:structure-object)
156 (typep host-object '(or symbol number list character)))
157 (values nil t))
158 ((and (symbolp target-type)
159 (find-class target-type nil)
160 (subtypep target-type 'sb!kernel::structure!object))
161 (values (typep host-object target-type) t))
162 (;; easy cases of arrays and vectors
163 (target-type-is-in
164 '(array simple-string simple-vector string vector))
165 (values (typep host-object target-type) t))
166 (;; general cases of vectors
167 (and (not (unknown-type-p (values-specifier-type target-type)))
168 (sb!xc:subtypep target-type 'cl:vector))
169 (if (vectorp host-object)
170 (warn-and-give-up) ; general-case vectors being way too hard
171 (values nil t))) ; but "obviously not a vector" being easy
172 (;; general cases of arrays
173 (and (not (unknown-type-p (values-specifier-type target-type)))
174 (sb!xc:subtypep target-type 'cl:array))
175 (if (arrayp host-object)
176 (warn-and-give-up) ; general-case arrays being way too hard
177 (values nil t))) ; but "obviously not an array" being easy
178 ((target-type-is-in '(*))
179 ;; KLUDGE: SBCL has * as an explicit wild type. While
180 ;; this is sort of logical (because (e.g. (ARRAY * 1)) is
181 ;; a valid type) it's not ANSI: looking at the ANSI
182 ;; definitions of complex types like like ARRAY shows
183 ;; that they consider * different from other type names.
184 ;; Someday we should probably get rid of this non-ANSIism
185 ;; in base SBCL, but until we do, we might as well here
186 ;; in the cross compiler. And in order to make sure that
187 ;; we don't continue doing it after we someday patch
188 ;; SBCL's type system so that * is no longer a type, we
189 ;; make this assertion. -- WHN 2001-08-08
190 (aver (typep (values-specifier-type '*) 'named-type))
191 (values t t))
192 (;; Many simple types are guaranteed to correspond exactly
193 ;; between any host ANSI Common Lisp and the target
194 ;; Common Lisp. (Some array types are too, but they
195 ;; were picked off earlier.)
196 (target-type-is-in
197 '(atom bit character complex cons float function integer keyword
198 list nil null number rational real signed-byte symbol t
199 unsigned-byte))
200 (values (typep host-object target-type) t))
201 (;; Floating point types are guaranteed to correspond,
202 ;; too, but less exactly.
203 (target-type-is-in
204 '(single-float double-float))
205 (cond ((floatp host-object)
206 (warn-about-possible-float-info-loss)
207 (values (typep host-object target-type) t))
209 (values nil t))))
210 (;; Complexes suffer the same kind of problems as arrays
211 (and (not (unknown-type-p (values-specifier-type target-type)))
212 (sb!xc:subtypep target-type 'cl:complex))
213 (if (complexp host-object)
214 (warn-and-give-up) ; general-case complexes being way too hard
215 (values nil t))) ; but "obviously not a complex" being easy
216 ;; Some types require translation between the cross-compilation
217 ;; host Common Lisp and the target SBCL.
218 ((target-type-is-in '(classoid))
219 (values (typep host-object 'classoid) t))
220 ((target-type-is-in '(fixnum))
221 (values (fixnump host-object) t))
222 ;; Some types are too hard to handle in the positive
223 ;; case, but at least we can be confident in a large
224 ;; fraction of the negative cases..
225 ((target-type-is-in
226 '(base-string simple-base-string simple-string))
227 (if (stringp host-object)
228 (warn-and-give-up)
229 (values nil t)))
230 ((target-type-is-in '(character base-char))
231 (cond ((typep host-object 'standard-char)
232 (values t t))
233 ((not (characterp host-object))
234 (values nil t))
236 (warn-and-give-up))))
237 ((target-type-is-in '(stream instance))
238 ;; Neither target CL:STREAM nor target SB!KERNEL:INSTANCE
239 ;; is implemented as a STRUCTURE-OBJECT, so they'll fall
240 ;; through the tests above. We don't want to assume too
241 ;; much about them here, but at least we know enough
242 ;; about them to say that neither T nor NIL nor indeed
243 ;; any other symbol in the cross-compilation host is one.
244 ;; That knowledge suffices to answer so many of the
245 ;; questions that the cross-compiler asks that it's well
246 ;; worth special-casing it here.
247 (if (symbolp host-object)
248 (values nil t)
249 (warn-and-give-up)))
250 ;; various hacks for composite types..
251 ((consp target-type)
252 (let ((first (first target-type))
253 (rest (rest target-type)))
254 (case first
255 ;; Many complex types are guaranteed to correspond exactly
256 ;; between any host ANSI Common Lisp and the target SBCL.
257 ((integer member mod rational real signed-byte unsigned-byte)
258 (values (typep host-object target-type) t))
259 ;; Floating point types are guaranteed to correspond,
260 ;; too, but less exactly.
261 ((single-float double-float)
262 (cond ((floatp host-object)
263 (warn-about-possible-float-info-loss)
264 (values (typep host-object target-type) t))
266 (values nil t))))
267 ;; Some complex types have translations that are less
268 ;; trivial.
269 (and (every/type #'cross-typep host-object rest))
270 (or (any/type #'cross-typep host-object rest))
271 ;; If we want to work with the KEYWORD type, we need
272 ;; to grok (SATISFIES KEYWORDP).
273 (satisfies
274 (destructuring-bind (predicate-name) rest
275 (if (and (in-cl-package-p predicate-name)
276 (fboundp predicate-name))
277 ;; Many predicates like KEYWORDP, ODDP, PACKAGEP,
278 ;; and NULL correspond between host and target.
279 ;; But we still need to handle errors, because
280 ;; the code which calls us may not understand
281 ;; that a type is unreachable. (E.g. when compiling
282 ;; (AND STRING (SATISFIES ARRAY-HAS-FILL-POINTER-P))
283 ;; CTYPEP may be called on the SATISFIES expression
284 ;; even for non-STRINGs.)
285 (multiple-value-bind (result error?)
286 (ignore-errors (funcall predicate-name
287 host-object))
288 (if error?
289 (values nil nil)
290 (values result t)))
291 ;; For symbols not in the CL package, it's not
292 ;; in general clear how things correspond
293 ;; between host and target, so we punt.
294 (warn-and-give-up))))
295 ;; Some complex types are too hard to handle in the
296 ;; positive case, but at least we can be confident in
297 ;; a large fraction of the negative cases..
298 ((base-string simple-base-string simple-string)
299 (if (stringp host-object)
300 (warn-and-give-up)
301 (values nil t)))
302 ((vector simple-vector)
303 (if (vectorp host-object)
304 (warn-and-give-up)
305 (values nil t)))
306 ((array simple-array)
307 (if (arrayp host-object)
308 (warn-and-give-up)
309 (values nil t)))
310 (function
311 (if (functionp host-object)
312 (warn-and-give-up)
313 (values nil t)))
314 ;; And the Common Lisp type system is complicated,
315 ;; and we don't try to implement everything.
316 (otherwise (warn-and-give-up)))))
317 ;; And the Common Lisp type system is complicated, and
318 ;; we don't try to implement everything.
320 (warn-and-give-up))))))
322 ;;; This is an incomplete TYPEP which runs at cross-compile time to
323 ;;; tell whether OBJECT is the host Lisp representation of a target
324 ;;; SBCL type specified by TARGET-TYPE-SPEC. It need make no pretense
325 ;;; to completeness, since it need only handle the cases which arise
326 ;;; when building SBCL itself, e.g. testing that range limits FOO and
327 ;;; BAR in (INTEGER FOO BAR) are INTEGERs.
328 (defun sb!xc:typep (host-object target-type-spec &optional (env nil env-p))
329 (declare (ignore env))
330 (aver (null env-p)) ; 'cause we're too lazy to think about it
331 (multiple-value-bind (opinion certain-p)
332 (cross-typep host-object target-type-spec)
333 ;; A program that calls TYPEP doesn't want uncertainty and
334 ;; probably can't handle it.
335 (if certain-p
336 opinion
337 (error "uncertain in SB!XC:TYPEP ~S ~S"
338 host-object
339 target-type-spec))))
341 ;;; This is an incomplete, portable implementation for use at
342 ;;; cross-compile time only.
343 (defun ctypep (obj ctype)
344 (check-type ctype ctype)
345 (let (;; the Common Lisp type specifier corresponding to CTYPE
346 (type (type-specifier ctype)))
347 (check-type type (or symbol cons))
348 (cross-typep obj type)))
350 (defun ctype-of (x)
351 (typecase x
352 (function
353 (if (typep x 'generic-function)
354 ;; Since at cross-compile time we build a CLOS-free bootstrap
355 ;; version of SBCL, it's unclear how to explain to it what a
356 ;; generic function is.
357 (error "not implemented: cross CTYPE-OF generic function")
358 ;; There's no ANSI way to find out what the function is
359 ;; declared to be, so we just return the CTYPE for the
360 ;; most-general function.
361 *universal-fun-type*))
362 (symbol
363 (make-member-type :members (list x)))
364 (number
365 (ctype-of-number x))
366 (string
367 (make-array-type :dimensions (array-dimensions x)
368 :complexp (not (typep x 'simple-array))
369 :element-type (specifier-type 'base-char)
370 :specialized-element-type (specifier-type 'base-char)))
371 (array
372 (let ((etype (specifier-type (array-element-type x))))
373 (make-array-type :dimensions (array-dimensions x)
374 :complexp (not (typep x 'simple-array))
375 :element-type etype
376 :specialized-element-type etype)))
377 (cons (specifier-type 'cons))
378 (character
379 (cond ((typep x 'standard-char)
380 ;; (Note that SBCL doesn't distinguish between BASE-CHAR and
381 ;; CHARACTER.)
382 (specifier-type 'base-char))
383 ((not (characterp x))
384 nil)
386 ;; Beyond this, there seems to be no portable correspondence.
387 (error "can't map host Lisp CHARACTER ~S to target Lisp" x))))
388 (structure!object
389 (find-classoid (uncross (class-name (class-of x)))))
391 ;; There might be more cases which we could handle with
392 ;; sufficient effort; since all we *need* to handle are enough
393 ;; cases for bootstrapping, we don't try to be complete here,. If
394 ;; future maintainers make the bootstrap code more complicated,
395 ;; they can also add new cases here to handle it. -- WHN 2000-11-11
396 (error "can't handle ~S in cross CTYPE-OF" x))))