1 ;;;; This file contains code which knows about both the type
2 ;;;; representation and the compiler IR1 representation. This stuff is
3 ;;;; used for doing type checking.
5 ;;;; This software is part of the SBCL system. See the README file for
8 ;;;; This software is derived from the CMU CL system, which was
9 ;;;; written at Carnegie Mellon University and released into the
10 ;;;; public domain. The software is in the public domain and is
11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
12 ;;;; files for more information.
14 ;;;; FIXME: This is a poor name for this file, since CTYPE is the name
15 ;;;; of the type used internally to represent Lisp types. It'd
16 ;;;; probably be good to rename this file to "call-type.lisp" or
17 ;;;; "ir1-type.lisp" or something.
21 ;;; These are the functions that are to be called when a problem is
22 ;;; detected. They are passed format arguments. If null, we don't do
23 ;;; anything. The error function is called when something is
24 ;;; definitely incorrect. The warning function is called when it is
25 ;;; somehow impossible to tell whether the call is correct.
27 ;;; FIXME: *ERROR-FUNCTION* and *WARNING-FUNCTION* are now misnomers.
28 ;;; As per the KLUDGE note below, what the Python compiler
29 ;;; considered a "definite incompatibility" could easily be conforming
30 ;;; ANSI Common Lisp (if the incompatibility is across a compilation
31 ;;; unit boundary, and we don't keep track of whether it is..), so we
32 ;;; have to just report STYLE-WARNINGs instead of ERRORs or full
33 ;;; WARNINGs; and unlike CMU CL, we don't use the condition system
34 ;;; at all when we're reporting notes.
35 (defvar *error-function*)
36 (defvar *warning-function*)
38 ;;; The function that we use for type checking. The derived type is
39 ;;; the first argument and the type we are testing against is the
40 ;;; second argument. The function should return values like CSUBTYPEP.
41 (defvar *test-function*)
42 ;;; FIXME: Why is this a variable? Explain.
44 (declaim (type (or function null) *error-function* *warning-function
47 ;;; *LOSSAGE-DETECTED* is set when a "definite incompatibility" is
48 ;;; detected. *SLIME-DETECTED* is set when we can't tell whether the
49 ;;; call is compatible or not.
51 ;;; KLUDGE: Common Lisp is a dynamic language, even if CMU CL was not.
52 ;;; As far as I can see, none of the "definite incompatibilities"
53 ;;; detected in this file are actually definite under the ANSI spec.
54 ;;; They would be incompatibilites if the use were within the same
55 ;;; compilation unit as the contradictory definition (as per the spec
56 ;;; section "3.2.2.3 Semantic Constraints") but the old Python code
57 ;;; doesn't keep track of whether that's the case. So until/unless we
58 ;;; upgrade the code to keep track of that, we have to handle all
59 ;;; these as STYLE-WARNINGs. -- WHN 2001-02-10
60 (defvar *lossage-detected*)
61 (defvar *slime-detected*)
62 ;;; FIXME: "SLIME" is vivid and concise, but "DEFINITE-CALL-LOSSAGE" and
63 ;;; "POSSIBLE-CALL-LOSSAGE" would be more mnemonic.
65 ;;; Signal a warning if appropriate and set *LOSSAGE-DETECTED*.
66 (declaim (ftype (function (string &rest t) (values)) note-lossage note-slime))
67 (defun note-lossage (format-string &rest format-args)
68 (setq *lossage-detected* t)
69 (when *error-function*
70 (apply *error-function* format-string format-args))
72 (defun note-slime (format-string &rest format-args)
73 (setq *slime-detected* t)
74 (when *warning-function*
75 (apply *warning-function* format-string format-args))
78 (declaim (special *compiler-error-context*))
80 ;;;; stuff for checking a call against a function type
82 ;;;; FIXME: This is stuff to look at when I get around to fixing
83 ;;;; function type inference and declarations.
85 ;;; A dummy version of SUBTYPEP useful when we want a functional like
86 ;;; SUBTYPEP that always returns true.
87 (defun always-subtypep (type1 type2)
88 (declare (ignore type1 type2))
91 ;;; Determine whether a use of a function is consistent with its type.
92 ;;; These values are returned:
93 ;;; T, T: the call is definitely valid.
94 ;;; NIL, T: the call is definitely invalid.
95 ;;; NIL, NIL: unable to determine whether the call is valid.
97 ;;; The ARGUMENT-TEST function is used to determine whether an
98 ;;; argument type matches the type we are checking against. Similarly,
99 ;;; the RESULT-TEST is used to determine whether the result type
100 ;;; matches the specified result.
102 ;;; Unlike the argument test, the result test may be called on values
103 ;;; or function types. If STRICT-RESULT is true and SAFETY is
104 ;;; non-zero, then the NODE-DERIVED-TYPE is always used. Otherwise, if
105 ;;; CONT's TYPE-CHECK is true, then the NODE-DERIVED-TYPE is
106 ;;; intersected with the CONT's ASSERTED-TYPE.
108 ;;; The error and warning functions are functions that are called to
109 ;;; explain the result. We bind *COMPILER-ERROR-CONTEXT* to the
110 ;;; combination node so that COMPILER-WARNING and related functions
111 ;;; will do the right thing if they are supplied.
112 (defun valid-function-use (call type &key
113 ((:argument-test *test-function*) #'csubtypep)
114 (result-test #'values-subtypep)
116 ((:error-function *error-function*))
117 ((:warning-function *warning-function*)))
118 (declare (type function result-test) (type combination call)
119 (type function-type type))
120 (let* ((*lossage-detected* nil)
121 (*slime-detected* nil)
122 (*compiler-error-context* call)
123 (args (combination-args call))
124 (nargs (length args))
125 (required (function-type-required type))
126 (min-args (length required))
127 (optional (function-type-optional type))
128 (max-args (+ min-args (length optional)))
129 (rest (function-type-rest type))
130 (keyp (function-type-keyp type)))
133 ((function-type-wild-args type)
135 (arg args (cdr arg)))
137 (check-arg-type (car arg) *wild-type* i)))
138 ((not (or optional keyp rest))
139 (if (/= nargs min-args)
141 "The function was called with ~R argument~:P, but wants exactly ~R."
143 (check-fixed-and-rest args required nil)))
146 "The function was called with ~R argument~:P, but wants at least ~R."
149 (check-fixed-and-rest args (append required optional) rest))
150 ((not (or keyp rest))
152 "The function was called with ~R argument~:P, but wants at most ~R."
154 ((and keyp (oddp (- nargs max-args)))
156 "The function has an odd number of arguments in the keyword portion."))
158 (check-fixed-and-rest args (append required optional) rest)
160 (check-key-args args max-args type))))
162 (let* ((dtype (node-derived-type call))
163 (return-type (function-type-returns type))
164 (cont (node-cont call))
166 (if (or (not (continuation-type-check cont))
167 (and strict-result (policy call (/= safety 0))))
169 (values-type-intersection (continuation-asserted-type cont)
171 (multiple-value-bind (int win) (funcall result-test out-type return-type)
173 (note-slime "can't tell whether the result is a ~S"
174 (type-specifier return-type)))
176 (note-lossage "The result is a ~S, not a ~S."
177 (type-specifier out-type)
178 (type-specifier return-type))))))
180 (cond (*lossage-detected* (values nil t))
181 (*slime-detected* (values nil nil))
184 ;;; Check that the derived type of the continuation CONT is compatible
185 ;;; with TYPE. N is the arg number, for error message purposes. We
186 ;;; return true if arg is definitely o.k. If the type is a magic
187 ;;; CONSTANT-TYPE, then we check for the argument being a constant
188 ;;; value of the specified type. If there is a manifest type error
189 ;;; (DERIVED-TYPE = NIL), then we flame about the asserted type even
190 ;;; when our type is satisfied under the test.
191 (defun check-arg-type (cont type n)
192 (declare (type continuation cont) (type ctype type) (type index n))
194 ((not (constant-type-p type))
195 (let ((ctype (continuation-type cont)))
196 (multiple-value-bind (int win) (funcall *test-function* ctype type)
198 (note-slime "can't tell whether the ~:R argument is a ~S" n
199 (type-specifier type))
202 (note-lossage "The ~:R argument is a ~S, not a ~S." n
203 (type-specifier ctype)
204 (type-specifier type))
206 ((eq ctype *empty-type*)
207 (note-slime "The ~:R argument never returns a value." n)
210 ((not (constant-continuation-p cont))
211 (note-slime "The ~:R argument is not a constant." n)
214 (let ((val (continuation-value cont))
215 (type (constant-type-type type)))
216 (multiple-value-bind (res win) (ctypep val type)
218 (note-slime "can't tell whether the ~:R argument is a ~
220 n (type-specifier type) val)
223 (note-lossage "The ~:R argument is not a constant ~S:~% ~S"
224 n (type-specifier type) val)
228 ;;; Check that each of the type of each supplied argument intersects
229 ;;; with the type specified for that argument. If we can't tell, then
230 ;;; we complain about the slime.
231 (declaim (ftype (function (list list (or ctype null)) (values)) check-fixed-and-rest))
232 (defun check-fixed-and-rest (args types rest)
233 (do ((arg args (cdr arg))
234 (type types (cdr type))
236 ((or (null type) (null arg))
239 (check-arg-type arg rest n)
242 (check-arg-type (car arg) (car type) n))
245 ;;; Check that the &KEY args are of the correct type. Each key should
246 ;;; be known and the corresponding argument should be of the correct
247 ;;; type. If the key isn't a constant, then we can't tell, so we note
249 (declaim (ftype (function (list fixnum function-type) (values)) check-key-args))
250 (defun check-key-args (args pre-key type)
251 (do ((key (nthcdr pre-key args) (cddr key))
252 (n (1+ pre-key) (+ n 2)))
257 ((not (check-arg-type k (specifier-type 'symbol) n)))
258 ((not (constant-continuation-p k))
259 (note-slime "The ~:R argument (in keyword position) is not a constant."
262 (let* ((name (continuation-value k))
263 (info (find name (function-type-keywords type)
264 :key #'key-info-name)))
266 (unless (function-type-allowp type)
267 (note-lossage "~S is not a known argument keyword."
270 (check-arg-type (second key) (key-info-type info)
274 ;;; Construct a function type from a definition.
276 ;;; Due to the lack of a (LIST X) type specifier, we can't reconstruct
278 (declaim (ftype (function (functional) function-type) definition-type))
279 (defun definition-type (functional)
280 (if (lambda-p functional)
282 :required (mapcar #'leaf-type (lambda-vars functional))
283 :returns (tail-set-type (lambda-tail-set functional)))
288 (dolist (arg (optional-dispatch-arglist functional))
289 (let ((info (lambda-var-arg-info arg))
290 (type (leaf-type arg)))
292 (ecase (arg-info-kind info)
293 (:required (req type))
294 (:optional (opt type))
296 (keys (make-key-info :name (arg-info-key info)
298 ((:rest :more-context)
299 (setq rest *universal-type*))
308 :keyp (optional-dispatch-keyp functional)
309 :allowp (optional-dispatch-allowp functional)
310 :returns (tail-set-type
312 (optional-dispatch-main-entry functional))))))))
314 ;;;; approximate function types
316 ;;;; FIXME: This is stuff to look at when I get around to fixing function
317 ;;;; type inference and declarations.
319 ;;;; Approximate function types provide a condensed representation of all the
320 ;;;; different ways that a function has been used. If we have no declared or
321 ;;;; defined type for a function, then we build an approximate function type by
322 ;;;; examining each use of the function. When we encounter a definition or
323 ;;;; proclamation, we can check the actual type for compatibity with the
326 (defstruct (approximate-function-type (:copier nil))
327 ;; the smallest and largest numbers of arguments that this function
328 ;; has been called with.
329 (min-args call-arguments-limit :type fixnum)
330 (max-args 0 :type fixnum)
331 ;; A list of lists of the all the types that have been used in each argument
333 (types () :type list)
334 ;; A list of APPROXIMATE-KEY-INFO structures describing all the
335 ;; things that looked like &KEY arguments. There are distinct
336 ;; structures describing each argument position in which the keyword
338 (keys () :type list))
340 (defstruct (approximate-key-info (:copier nil))
341 ;; The keyword name of this argument. Although keyword names don't
342 ;; have to be keywords, we only match on keywords when figuring an
344 (name (required-argument) :type keyword)
345 ;; The position at which this keyword appeared. 0 if it appeared as the
346 ;; first argument, etc.
347 (position (required-argument) :type fixnum)
348 ;; A list of all the argument types that have been used with this keyword.
349 (types nil :type list)
350 ;; True if this keyword has appeared only in calls with an obvious
351 ;; :allow-other-keys.
352 (allowp nil :type (member t nil)))
354 ;;; Return an APPROXIMATE-FUNCTION-TYPE representing the context of
355 ;;; CALL. If TYPE is supplied and not null, then we merge the
356 ;;; information into the information already accumulated in TYPE.
357 (declaim (ftype (function (combination
358 &optional (or approximate-function-type null))
359 approximate-function-type)
361 (defun note-function-use (call &optional type)
362 (let* ((type (or type (make-approximate-function-type)))
363 (types (approximate-function-type-types type))
364 (args (combination-args call))
365 (nargs (length args))
366 (allowp (some #'(lambda (x)
367 (and (constant-continuation-p x)
368 (eq (continuation-value x) :allow-other-keys)))
371 (setf (approximate-function-type-min-args type)
372 (min (approximate-function-type-min-args type) nargs))
373 (setf (approximate-function-type-max-args type)
374 (max (approximate-function-type-max-args type) nargs))
376 (do ((old types (cdr old))
377 (arg args (cdr arg)))
379 (setf (approximate-function-type-types type)
381 (mapcar #'(lambda (x)
382 (list (continuation-type x)))
384 (when (null arg) (return))
385 (pushnew (continuation-type (car arg))
389 (collect ((keys (approximate-function-type-keys type) cons))
390 (do ((arg args (cdr arg))
392 ((or (null arg) (null (cdr arg)))
393 (setf (approximate-function-type-keys type) (keys)))
394 (let ((key (first arg))
396 (when (constant-continuation-p key)
397 (let ((name (continuation-value key)))
398 (when (keywordp name)
401 (and (eq (approximate-key-info-name x) name)
402 (= (approximate-key-info-position x)
405 (val-type (continuation-type val)))
408 (approximate-key-info-types old)
411 (setf (approximate-key-info-allowp old) nil)))
413 (keys (make-approximate-key-info
417 :types (list val-type))))))))))))
420 ;;; This is similar to VALID-FUNCTION-USE, but checks an
421 ;;; APPROXIMATE-FUNCTION-TYPE against a real function type.
422 (declaim (ftype (function (approximate-function-type function-type
423 &optional function function function)
424 (values boolean boolean))
425 valid-approximate-type))
426 (defun valid-approximate-type (call-type type &optional
427 (*test-function* #'types-intersect)
429 #'compiler-style-warning)
430 (*warning-function* #'compiler-note))
431 (let* ((*lossage-detected* nil)
432 (*slime-detected* nil)
433 (required (function-type-required type))
434 (min-args (length required))
435 (optional (function-type-optional type))
436 (max-args (+ min-args (length optional)))
437 (rest (function-type-rest type))
438 (keyp (function-type-keyp type)))
440 (when (function-type-wild-args type)
441 (return-from valid-approximate-type (values t t)))
443 (let ((call-min (approximate-function-type-min-args call-type)))
444 (when (< call-min min-args)
446 "~:@<The function was previously called with ~R argument~:P, ~
447 but wants at least ~R.~:>"
450 (let ((call-max (approximate-function-type-max-args call-type)))
451 (cond ((<= call-max max-args))
452 ((not (or keyp rest))
454 "~:@<The function was previously called with ~R argument~:P, ~
455 but wants at most ~R.~:>"
457 ((and keyp (oddp (- call-max max-args)))
459 "~:@<The function was previously called with an odd number of ~
460 arguments in the keyword portion.~:>")))
462 (when (and keyp (> call-max max-args))
463 (check-approximate-keywords call-type max-args type)))
465 (check-approximate-fixed-and-rest call-type (append required optional)
468 (cond (*lossage-detected* (values nil t))
469 (*slime-detected* (values nil nil))
472 ;;; Check that each of the types used at each arg position is
473 ;;; compatible with the actual type.
474 (declaim (ftype (function (approximate-function-type list (or ctype null))
476 check-approximate-fixed-and-rest))
477 (defun check-approximate-fixed-and-rest (call-type fixed rest)
478 (do ((types (approximate-function-type-types call-type) (cdr types))
480 (arg fixed (cdr arg)))
482 (let ((decl-type (or (car arg) rest)))
483 (unless decl-type (return))
484 (check-approximate-arg-type (car types) decl-type "~:R" n)))
487 ;;; Check that each of the call-types is compatible with DECL-TYPE,
488 ;;; complaining if not or if we can't tell.
489 (declaim (ftype (function (list ctype string &rest t) (values))
490 check-approximate-arg-type))
491 (defun check-approximate-arg-type (call-types decl-type context &rest args)
492 (let ((losers *empty-type*))
493 (dolist (ctype call-types)
494 (multiple-value-bind (int win) (funcall *test-function* ctype decl-type)
497 (note-slime "can't tell whether previous ~? argument type ~S is a ~S"
498 context args (type-specifier ctype) (type-specifier decl-type)))
500 (setq losers (type-union ctype losers))))))
502 (unless (eq losers *empty-type*)
503 (note-lossage "~:(~?~) argument should be a ~S but was a ~S in a previous call."
504 context args (type-specifier decl-type) (type-specifier losers))))
507 ;;; Check the types of each manifest keyword that appears in a keyword
508 ;;; argument position. Check the validity of all keys that appeared in
509 ;;; valid keyword positions.
511 ;;; ### We could check the APPROXIMATE-FUNCTION-TYPE-TYPES to make
512 ;;; sure that all arguments in keyword positions were manifest
514 (defun check-approximate-keywords (call-type max-args type)
515 (let ((call-keys (approximate-function-type-keys call-type))
516 (keys (function-type-keywords type)))
518 (let ((name (key-info-name key)))
519 (collect ((types nil append))
520 (dolist (call-key call-keys)
521 (let ((pos (approximate-key-info-position call-key)))
522 (when (and (eq (approximate-key-info-name call-key) name)
523 (> pos max-args) (evenp (- pos max-args)))
524 (types (approximate-key-info-types call-key)))))
525 (check-approximate-arg-type (types) (key-info-type key) "~S" name))))
527 (unless (function-type-allowp type)
528 (collect ((names () adjoin))
529 (dolist (call-key call-keys)
530 (let ((pos (approximate-key-info-position call-key)))
531 (when (and (> pos max-args) (evenp (- pos max-args))
532 (not (approximate-key-info-allowp call-key)))
533 (names (approximate-key-info-name call-key)))))
535 (dolist (name (names))
536 (unless (find name keys :key #'key-info-name)
537 (note-lossage "Function previously called with unknown argument keyword ~S."
540 ;;;; ASSERT-DEFINITION-TYPE
542 ;;; Intersect LAMBDA's var types with TYPES, giving a warning if there
543 ;;; is a mismatch. If all intersections are non-null, we return lists
544 ;;; of the variables and intersections, otherwise we return NIL, NIL.
545 (defun try-type-intersections (vars types where)
546 (declare (list vars types) (string where))
548 (mapc (lambda (var type)
549 (let* ((vtype (leaf-type var))
550 (int (type-approx-intersection2 vtype type)))
552 ((eq int *empty-type*)
554 "Definition's declared type for variable ~A:~% ~S~@
555 conflicts with this type from ~A:~% ~S"
556 (leaf-name var) (type-specifier vtype)
557 where (type-specifier type))
558 (return-from try-type-intersections (values nil nil)))
562 (values vars (res))))
564 ;;; Check that the optional-dispatch OD conforms to Type. We return
565 ;;; the values of TRY-TYPE-INTERSECTIONS if there are no syntax
566 ;;; problems, otherwise NIL, NIL.
568 ;;; Note that the variables in the returned list are the actual
569 ;;; original variables (extracted from the optional dispatch arglist),
570 ;;; rather than the variables that are arguments to the main entry.
571 ;;; This difference is significant only for &KEY args with hairy
572 ;;; defaults. Returning the actual vars allows us to use the right
573 ;;; variable name in warnings.
575 ;;; A slightly subtle point: with keywords and optionals, the type in
576 ;;; the function type is only an assertion on calls --- it doesn't
577 ;;; constrain the type of default values. So we have to union in the
578 ;;; type of the default. With optionals, we can't do any assertion
579 ;;; unless the default is constant.
581 ;;; With keywords, we exploit our knowledge about how hairy keyword
582 ;;; defaulting is done when computing the type assertion to put on the
583 ;;; main-entry argument. In the case of hairy keywords, the default
584 ;;; has been clobbered with NIL, which is the value of the main-entry
585 ;;; arg in the unsupplied case, whatever the actual default value is.
586 ;;; So we can just assume the default is constant, effectively
587 ;;; unioning in NULL, and not totally blow off doing any type
589 (defun find-optional-dispatch-types (od type where)
590 (declare (type optional-dispatch od) (type function-type type)
592 (let* ((min (optional-dispatch-min-args od))
593 (req (function-type-required type))
594 (opt (function-type-optional type)))
595 (flet ((frob (x y what)
598 "The definition has ~R ~A arg~P, but ~A has ~R."
600 (frob min (length req) "fixed")
601 (frob (- (optional-dispatch-max-args od) min) (length opt) "optional"))
602 (flet ((frob (x y what)
605 "The definition ~:[doesn't have~;has~] ~A, but ~
606 ~A ~:[doesn't~;does~]."
608 (frob (optional-dispatch-keyp od) (function-type-keyp type)
610 (unless (optional-dispatch-keyp od)
611 (frob (not (null (optional-dispatch-more-entry od)))
612 (not (null (function-type-rest type)))
614 (frob (optional-dispatch-allowp od) (function-type-allowp type)
615 "&ALLOW-OTHER-KEYS"))
617 (when *lossage-detected*
618 (return-from find-optional-dispatch-types (values nil nil)))
622 (let ((keys (function-type-keywords type))
623 (arglist (optional-dispatch-arglist od)))
624 (dolist (arg arglist)
626 ((lambda-var-arg-info arg)
627 (let* ((info (lambda-var-arg-info arg))
628 (default (arg-info-default info))
629 (def-type (when (constantp default)
630 (ctype-of (eval default)))))
631 (ecase (arg-info-kind info)
633 (let* ((key (arg-info-key info))
634 (kinfo (find key keys :key #'key-info-name)))
637 (res (type-union (key-info-type kinfo)
638 (or def-type (specifier-type 'null)))))
641 "Defining a ~S keyword not present in ~A."
643 (res *universal-type*)))))
644 (:required (res (pop req)))
646 (res (type-union (pop opt) (or def-type *universal-type*))))
648 (when (function-type-rest type)
649 (res (specifier-type 'list))))
651 (when (function-type-rest type)
652 (res *universal-type*)))
654 (when (function-type-rest type)
655 (res (specifier-type 'fixnum)))))
657 (when (arg-info-supplied-p info)
658 (res *universal-type*)
659 (vars (arg-info-supplied-p info)))))
665 (unless (find (key-info-name key) arglist
667 (let ((info (lambda-var-arg-info x)))
669 (arg-info-key info)))))
671 "The definition lacks the ~S key present in ~A."
672 (key-info-name key) where))))
674 (try-type-intersections (vars) (res) where))))
676 ;;; Check that Type doesn't specify any funny args, and do the
678 (defun find-lambda-types (lambda type where)
679 (declare (type clambda lambda) (type function-type type) (string where))
680 (flet ((frob (x what)
683 "The definition has no ~A, but the ~A did."
685 (frob (function-type-optional type) "&OPTIONAL arguments")
686 (frob (function-type-keyp type) "&KEY arguments")
687 (frob (function-type-rest type) "&REST argument"))
688 (let* ((vars (lambda-vars lambda))
689 (nvars (length vars))
690 (req (function-type-required type))
692 (unless (= nvars nreq)
693 (note-lossage "The definition has ~R arg~:P, but the ~A has ~R."
695 (if *lossage-detected*
697 (try-type-intersections vars req where))))
699 ;;; Check for syntactic and type conformance between the definition
700 ;;; FUNCTIONAL and the specified FUNCTION-TYPE. If they are compatible
701 ;;; and REALLY-ASSERT is T, then add type assertions to the definition
702 ;;; from the FUNCTION-TYPE.
704 ;;; If there is a syntactic or type problem, then we call
705 ;;; ERROR-FUNCTION with an error message using WHERE as context
706 ;;; describing where FUNCTION-TYPE came from.
708 ;;; If there is no problem, we return T (even if REALLY-ASSERT was
709 ;;; false). If there was a problem, we return NIL.
710 (defun assert-definition-type
711 (functional type &key (really-assert t)
712 ((:error-function *error-function*)
713 #'compiler-style-warning)
715 (where "previous declaration"))
716 (declare (type functional functional)
717 (type function *error-function*)
719 (unless (function-type-p type) (return-from assert-definition-type t))
720 (let ((*lossage-detected* nil))
721 (multiple-value-bind (vars types)
722 (if (function-type-wild-args type)
724 (etypecase functional
726 (find-optional-dispatch-types functional type where))
728 (find-lambda-types functional type where))))
729 (let* ((type-returns (function-type-returns type))
730 (return (lambda-return (main-entry functional)))
732 (continuation-asserted-type (return-result return)))))
734 ((and atype (not (values-types-intersect atype type-returns)))
736 "The result type from ~A:~% ~S~@
737 conflicts with the definition's result type assertion:~% ~S"
738 where (type-specifier type-returns) (type-specifier atype))
740 (*lossage-detected* nil)
741 ((not really-assert) t)
744 (assert-continuation-type (return-result return) atype))
745 (loop for var in vars and type in types do
746 (cond ((basic-var-sets var)
747 (when (and warning-function
748 (not (csubtypep (leaf-type var) type)))
749 (funcall warning-function
750 "Assignment to argument: ~S~% ~
751 prevents use of assertion from function ~
753 (leaf-name var) where (type-specifier type))))
755 (setf (leaf-type var) type)
756 (dolist (ref (leaf-refs var))
757 (derive-node-type ref type)))))