;;;; files for more information.
(in-package "SB!C")
-
-(file-comment
- "$Header$")
\f
;;;; cost estimation
;;;
;;; We special-case NULL, since it does have a source tranform and is
;;; interesting to us.
-(defun function-cost (name)
+(defun fun-guessed-cost (name)
(declare (symbol name))
(let ((info (info :function :info name))
- (call-cost (template-cost (template-or-lose 'call-named))))
+ (call-cost (template-cost (template-or-lose 'call-named))))
(if info
- (let ((templates (function-info-templates info)))
- (if templates
- (template-cost (first templates))
- (case name
- (null (template-cost (template-or-lose 'if-eq)))
- (t call-cost))))
- call-cost)))
+ (let ((templates (fun-info-templates info)))
+ (if templates
+ (template-cost (first templates))
+ (case name
+ (null (template-cost (template-or-lose 'if-eq)))
+ (t call-cost))))
+ call-cost)))
-;;; Return some sort of guess for the cost of doing a test against TYPE.
-;;; The result need not be precise as long as it isn't way out in space. The
-;;; units are based on the costs specified for various templates in the VM
-;;; definition.
+;;; Return some sort of guess for the cost of doing a test against
+;;; TYPE. The result need not be precise as long as it isn't way out
+;;; in space. The units are based on the costs specified for various
+;;; templates in the VM definition.
(defun type-test-cost (type)
(declare (type ctype type))
- (or (let ((check (type-check-template type)))
- (if check
- (template-cost check)
- (let ((found (cdr (assoc type *backend-type-predicates*
- :test #'type=))))
- (if found
- (+ (function-cost found) (function-cost 'eq))
- nil))))
+ (or (when (eq type *universal-type*)
+ 0)
+ (when (eq type *empty-type*)
+ 0)
+ (let ((check (type-check-template type)))
+ (if check
+ (template-cost check)
+ (let ((found (cdr (assoc type *backend-type-predicates*
+ :test #'type=))))
+ (if found
+ (+ (fun-guessed-cost found) (fun-guessed-cost 'eq))
+ nil))))
(typecase type
- (union-type
- (collect ((res 0 +))
- (dolist (mem (union-type-types type))
- (res (type-test-cost mem)))
- (res)))
- (member-type
- (* (length (member-type-members type))
- (function-cost 'eq)))
- (numeric-type
- (* (if (numeric-type-complexp type) 2 1)
- (function-cost
- (if (csubtypep type (specifier-type 'fixnum)) 'fixnump 'numberp))
- (+ 1
- (if (numeric-type-low type) 1 0)
- (if (numeric-type-high type) 1 0))))
- (t
- (function-cost 'typep)))))
+ (compound-type
+ (reduce #'+ (compound-type-types type) :key 'type-test-cost))
+ (member-type
+ (* (member-type-size type)
+ (fun-guessed-cost 'eq)))
+ (numeric-type
+ (* (if (numeric-type-complexp type) 2 1)
+ (fun-guessed-cost
+ (if (csubtypep type (specifier-type 'fixnum)) 'fixnump 'numberp))
+ (+ 1
+ (if (numeric-type-low type) 1 0)
+ (if (numeric-type-high type) 1 0))))
+ (cons-type
+ (+ (type-test-cost (specifier-type 'cons))
+ (fun-guessed-cost 'car)
+ (type-test-cost (cons-type-car-type type))
+ (fun-guessed-cost 'cdr)
+ (type-test-cost (cons-type-cdr-type type))))
+ (t
+ (fun-guessed-cost 'typep)))))
+
+(defun weaken-integer-type (type &key range-only)
+ ;; FIXME: Our canonicalization isn't quite ideal for this. We get
+ ;; types such as:
+ ;;
+ ;; (OR (AND (SATISFIES FOO) (INTEGER -100 -50))
+ ;; (AND (SATISFIES FOO) (INTEGER 100 200)))
+ ;;
+ ;; here, and weakening that into
+ ;;
+ ;; (AND (SATISFIES FOO) (INTEGER -100 200))
+ ;;
+ ;; is too much work to do here ... but if we canonicalized things
+ ;; differently, we could get it for free with trivial changes here.
+ (labels ((weaken-integer-type-part (type base)
+ (cond ((intersection-type-p type)
+ (let ((new (specifier-type base)))
+ (dolist (part (intersection-type-types type))
+ (when (if range-only
+ (numeric-type-p part)
+ (not (unknown-type-p part)))
+ (setf new (type-intersection
+ new (weaken-integer-type-part part t)))))
+ new))
+ ((union-type-p type)
+ (let ((low t) (high t) (rest *empty-type*))
+ (flet ((maximize (bound)
+ (if (and bound high)
+ (setf high (if (eq t high)
+ bound
+ (max high bound)))
+ (setf high nil)))
+ (minimize (bound)
+ (if (and bound low)
+ (setf low (if (eq t low)
+ bound
+ (min low bound)))
+ (setf low nil))))
+ (dolist (part (union-type-types type))
+ (let ((weak (weaken-integer-type-part part t)))
+ (cond ((numeric-type-p weak)
+ (minimize (numeric-type-low weak))
+ (maximize (numeric-type-high weak)))
+ ((not range-only)
+ (setf rest (type-union rest weak)))))))
+ (if (eq t low)
+ rest
+ (type-union rest
+ (specifier-type
+ `(integer ,(or low '*) ,(or high '*)))))))
+ (t
+ type))))
+ (weaken-integer-type-part type 'integer)))
+
+(defun-cached
+ (weaken-type :hash-bits 8
+ :hash-function (lambda (x)
+ (logand (type-hash-value x) #xFF)))
+ ((type eq))
+ (declare (type ctype type))
+ (cond ((named-type-p type)
+ type)
+ ((csubtypep type (specifier-type 'integer))
+ ;; Simple range checks are not that expensive, and we *don't*
+ ;; want to accidentally lose eg. array bounds checks due to
+ ;; weakening, so for integer types we simply collapse all
+ ;; ranges into one.
+ (weaken-integer-type type))
+ (t
+ (let ((min-cost (type-test-cost type))
+ (min-type type)
+ (found-super nil))
+ (dolist (x *backend-type-predicates*)
+ (let* ((stype (car x))
+ (samep (type= stype type)))
+ (when (or samep
+ (and (csubtypep type stype)
+ (not (union-type-p stype))))
+ (let ((stype-cost (type-test-cost stype)))
+ (when (or (< stype-cost min-cost)
+ samep)
+ ;; If the supertype is equal in cost to the type, we
+ ;; prefer the supertype. This produces a closer
+ ;; approximation of the right thing in the presence of
+ ;; poor cost info.
+ (setq found-super t
+ min-type stype
+ min-cost stype-cost))))))
+ ;; This used to return the *UNIVERSAL-TYPE* if no supertype was found,
+ ;; but that's too liberal: it's far too easy for the user to create
+ ;; a union type (which are excluded above), and then trick the compiler
+ ;; into trusting the union type... and finally ending up corrupting the
+ ;; heap once a bad object sneaks past the missing type check.
+ (if found-super
+ min-type
+ type)))))
+
+(defun weaken-values-type (type)
+ (declare (type ctype type))
+ (cond ((eq type *wild-type*) type)
+ ((not (values-type-p type))
+ (weaken-type type))
+ (t
+ (make-values-type :required (mapcar #'weaken-type
+ (values-type-required type))
+ :optional (mapcar #'weaken-type
+ (values-type-optional type))
+ :rest (acond ((values-type-rest type)
+ (weaken-type it)))))))
\f
;;;; checking strategy determination
-;;; Return the type we should test for when we really want to check for
-;;; Type. If speed, space or compilation speed is more important than safety,
-;;; then we return a weaker type if it is easier to check. First we try the
-;;; defined type weakenings, then look for any predicate that is cheaper.
-;;;
-;;; If the supertype is equal in cost to the type, we prefer the supertype.
-;;; This produces a closer approximation of the right thing in the presence of
-;;; poor cost info.
-(defun maybe-weaken-check (type cont)
- (declare (type ctype type) (type continuation cont))
- (cond ((policy (continuation-dest cont)
- (<= speed safety) (<= space safety) (<= cspeed safety))
- type)
- (t
- (let ((min-cost (type-test-cost type))
- (min-type type)
- (found-super nil))
- (dolist (x *backend-type-predicates*)
- (let ((stype (car x)))
- (when (and (csubtypep type stype)
- (not (union-type-p stype)))
- (let ((stype-cost (type-test-cost stype)))
- (when (or (< stype-cost min-cost)
- (type= stype type))
- (setq found-super t)
- (setq min-type stype min-cost stype-cost))))))
- (if found-super
- min-type
- *universal-type*)))))
+;;; Return the type we should test for when we really want to check
+;;; for TYPE. If type checking policy is "fast", then we return a
+;;; weaker type if it is easier to check. First we try the defined
+;;; type weakenings, then look for any predicate that is cheaper.
+(defun maybe-weaken-check (type policy)
+ (declare (type ctype type))
+ (ecase (policy policy type-check)
+ (0 *wild-type*)
+ (2 (weaken-values-type type))
+ (3 type)))
-;;; Like VALUES-TYPES, only mash any complex function types to FUNCTION.
-(defun no-function-values-types (type)
+;;; This is like VALUES-TYPES, only we mash any complex function types
+;;; to FUNCTION.
+(defun no-fun-values-types (type)
(declare (type ctype type))
(multiple-value-bind (res count) (values-types type)
- (values (mapcar #'(lambda (type)
- (if (function-type-p type)
- (specifier-type 'function)
- type))
- res)
- count)))
+ (values (mapcar (lambda (type)
+ (if (fun-type-p type)
+ (specifier-type 'function)
+ type))
+ res)
+ count)))
;;; Switch to disable check complementing, for evaluation.
(defvar *complement-type-checks* t)
-;;; Cont is a continuation we are doing a type check on and Types is a list
-;;; of types that we are checking its values against. If we have proven
-;;; that Cont generates a fixed number of values, then for each value, we check
-;;; whether it is cheaper to then difference between the proven type and
-;;; the corresponding type in Types. If so, we opt for a :HAIRY check with
-;;; that test negated. Otherwise, we try to do a simple test, and if that is
-;;; impossible, we do a hairy test with non-negated types. If true,
-;;; Force-Hairy forces a hairy type check.
-;;;
-;;; When doing a non-negated check, we call MAYBE-WEAKEN-CHECK to weaken the
-;;; test to a convenient supertype (conditional on policy.) If debug-info is
-;;; not particularly important (debug <= 1) or speed is 3, then we allow
-;;; weakened checks to be simple, resulting in less informative error messages,
-;;; but saving space and possibly time.
-(defun maybe-negate-check (cont types force-hairy)
- (declare (type continuation cont) (list types))
- (multiple-value-bind (ptypes count)
- (no-function-values-types (continuation-proven-type cont))
- (if (eq count :unknown)
- (if (and (every #'type-check-template types) (not force-hairy))
- (values :simple types)
- (values :hairy
- (mapcar #'(lambda (x)
- (list nil (maybe-weaken-check x cont) x))
- types)))
- (let ((res (mapcar #'(lambda (p c)
- (let ((diff (type-difference p c))
- (weak (maybe-weaken-check c cont)))
- (if (and diff
- (< (type-test-cost diff)
- (type-test-cost weak))
- *complement-type-checks*)
- (list t diff c)
- (list nil weak c))))
- ptypes types)))
- (cond ((or force-hairy (find-if #'first res))
- (values :hairy res))
- ((every #'type-check-template types)
- (values :simple types))
- ((policy (continuation-dest cont)
- (or (<= debug 1) (and (= speed 3) (/= debug 3))))
- (let ((weakened (mapcar #'second res)))
- (if (every #'type-check-template weakened)
- (values :simple weakened)
- (values :hairy res))))
- (t
- (values :hairy res)))))))
+;;; LVAR is an lvar we are doing a type check on and TYPES is a list
+;;; of types that we are checking its values against. If we have
+;;; proven that LVAR generates a fixed number of values, then for each
+;;; value, we check whether it is cheaper to then difference between
+;;; the proven type and the corresponding type in TYPES. If so, we opt
+;;; for a :HAIRY check with that test negated. Otherwise, we try to do
+;;; a simple test, and if that is impossible, we do a hairy test with
+;;; non-negated types. If true, FORCE-HAIRY forces a hairy type check.
+(defun maybe-negate-check (lvar types original-types force-hairy n-required)
+ (declare (type lvar lvar) (list types original-types))
+ (let ((ptypes (values-type-out (lvar-derived-type lvar) (length types))))
+ (multiple-value-bind (hairy-res simple-res)
+ (loop for p in ptypes
+ and c in types
+ and a in original-types
+ and i from 0
+ for cc = (if (>= i n-required)
+ (type-union c (specifier-type 'null))
+ c)
+ for diff = (type-difference p cc)
+ collect (if (and diff
+ (< (type-test-cost diff)
+ (type-test-cost cc))
+ *complement-type-checks*)
+ (list t diff a)
+ (list nil cc a))
+ into hairy-res
+ collect cc into simple-res
+ finally (return (values hairy-res simple-res)))
+ (cond ((or force-hairy (find-if #'first hairy-res))
+ (values :hairy hairy-res))
+ ((every #'type-check-template simple-res)
+ (values :simple simple-res))
+ (t
+ (values :hairy hairy-res))))))
-;;; Determines whether Cont's assertion is:
-;;; -- Checkable by the back end (:SIMPLE), or
-;;; -- Not checkable by the back end, but checkable via an explicit test in
-;;; type check conversion (:HAIRY), or
+;;; Determines whether CAST's assertion is:
+;;; -- checkable by the back end (:SIMPLE), or
+;;; -- not checkable by the back end, but checkable via an explicit
+;;; test in type check conversion (:HAIRY), or
;;; -- not reasonably checkable at all (:TOO-HAIRY).
;;;
-;;; A type is checkable if it either represents a fixed number of values (as
-;;; determined by VALUES-TYPES), or it is the assertion for an MV-Bind. A type
-;;; is simply checkable if all the type assertions have a TYPE-CHECK-TEMPLATE.
-;;; In this :SIMPLE case, the second value is a list of the type restrictions
-;;; specified for the leading positional values.
+;;; We may check only fixed number of values; in any case the number
+;;; of generated values is trusted. If we know the number of produced
+;;; values, all of them are checked; otherwise if we know the number
+;;; of consumed -- only they are checked; otherwise the check is not
+;;; performed.
;;;
-;;; We force a check to be hairy even when there are fixed values if we are in
-;;; a context where we may be forced to use the unknown values convention
-;;; anyway. This is because IR2tran can't generate type checks for unknown
-;;; values continuations but people could still be depending on the check being
-;;; done. We only care about EXIT and RETURN (not MV-COMBINATION) since these
-;;; are the only contexts where the ultimate values receiver
+;;; A type is simply checkable if all the type assertions have a
+;;; TYPE-CHECK-TEMPLATE. In this :SIMPLE case, the second value is a
+;;; list of the type restrictions specified for the leading positional
+;;; values.
;;;
-;;; In the :HAIRY case, the second value is a list of triples of the form:
-;;; (Not-P Type Original-Type)
+;;; Old comment:
;;;
-;;; If true, the Not-P flag indicates a test that the corresponding value is
-;;; *not* of the specified Type. Original-Type is the type asserted on this
-;;; value in the continuation, for use in error messages. When Not-P is true,
-;;; this will be different from Type.
+;;; We force a check to be hairy even when there are fixed values
+;;; if we are in a context where we may be forced to use the
+;;; unknown values convention anyway. This is because IR2tran can't
+;;; generate type checks for unknown values lvars but people could
+;;; still be depending on the check being done. We only care about
+;;; EXIT and RETURN (not MV-COMBINATION) since these are the only
+;;; contexts where the ultimate values receiver
;;;
-;;; This allows us to take what has been proven about Cont's type into
-;;; consideration. If it is cheaper to test for the difference between the
-;;; derived type and the asserted type, then we check for the negation of this
-;;; type instead.
-(defun continuation-check-types (cont)
- (declare (type continuation cont))
- (let ((type (continuation-asserted-type cont))
- (dest (continuation-dest cont)))
- (assert (not (eq type *wild-type*)))
- (multiple-value-bind (types count) (no-function-values-types type)
- (cond ((not (eq count :unknown))
- (if (or (exit-p dest)
- (and (return-p dest)
- (multiple-value-bind (ignore count)
- (values-types (return-result-type dest))
- (declare (ignore ignore))
- (eq count :unknown))))
- (maybe-negate-check cont types t)
- (maybe-negate-check cont types nil)))
- ((and (mv-combination-p dest)
- (eq (basic-combination-kind dest) :local))
- (assert (values-type-p type))
- (maybe-negate-check cont (args-type-optional type) nil))
- (t
- (values :too-hairy nil))))))
-
-;;; Return true if Cont is a continuation whose type the back end is likely
-;;; to want to check. Since we don't know what template the back end is going
-;;; to choose to implement the continuation's DEST, we use a heuristic. We
-;;; always return T unless:
-;;; -- Nobody uses the value, or
-;;; -- Safety is totally unimportant, or
-;;; -- the continuation is an argument to an unknown function, or
-;;; -- the continuation is an argument to a known function that has no
-;;; IR2-Convert method or :fast-safe templates that are compatible with the
-;;; call's type.
+;;; In the :HAIRY case, the second value is a list of triples of
+;;; the form:
+;;; (NOT-P TYPE ORIGINAL-TYPE)
;;;
-;;; We must only return nil when it is *certain* that a check will not be done,
-;;; since if we pass up this chance to do the check, it will be too late. The
-;;; penalty for being too conservative is duplicated type checks.
+;;; If true, the NOT-P flag indicates a test that the corresponding
+;;; value is *not* of the specified TYPE. ORIGINAL-TYPE is the type
+;;; asserted on this value in the lvar, for use in error
+;;; messages. When NOT-P is true, this will be different from TYPE.
;;;
-;;; If there is a compile-time type error, then we always return true unless
-;;; the DEST is a full call. With a full call, the theory is that the type
-;;; error is probably from a declaration in (or on) the callee, so the callee
-;;; should be able to do the check. We want to let the callee do the check,
-;;; because it is possible that the error is really in the callee, not the
-;;; caller. We don't want to make people recompile all calls to a function
-;;; when they were originally compiled with a bad declaration (or an old type
-;;; assertion derived from a definition appearing after the call.)
-(defun probable-type-check-p (cont)
- (declare (type continuation cont))
- (let ((dest (continuation-dest cont)))
- (cond ((eq (continuation-type-check cont) :error)
- (if (and (combination-p dest) (eq (combination-kind dest) :error))
- nil
- t))
- ((or (not dest)
- (policy dest (zerop safety)))
- nil)
- ((basic-combination-p dest)
- (let ((kind (basic-combination-kind dest)))
- (cond ((eq cont (basic-combination-fun dest)) t)
- ((eq kind :local) t)
- ((member kind '(:full :error)) nil)
- ((function-info-ir2-convert kind) t)
- (t
- (dolist (template (function-info-templates kind) nil)
- (when (eq (template-policy template) :fast-safe)
- (multiple-value-bind (val win)
- (valid-function-use dest (template-type template))
- (when (or val (not win)) (return t)))))))))
- (t t))))
+;;; This allows us to take what has been proven about CAST's argument
+;;; type into consideration. If it is cheaper to test for the
+;;; difference between the derived type and the asserted type, then we
+;;; check for the negation of this type instead.
+(defun cast-check-types (cast force-hairy)
+ (declare (type cast cast))
+ (let* ((ctype (coerce-to-values (cast-type-to-check cast)))
+ (atype (coerce-to-values (cast-asserted-type cast)))
+ (dtype (node-derived-type cast))
+ (value (cast-value cast))
+ (lvar (node-lvar cast))
+ (dest (and lvar (lvar-dest lvar)))
+ (n-consumed (cond ((not lvar)
+ nil)
+ ((lvar-single-value-p lvar)
+ 1)
+ ((and (mv-combination-p dest)
+ (eq (mv-combination-kind dest) :local))
+ (let ((fun-ref (lvar-use (mv-combination-fun dest))))
+ (length (lambda-vars (ref-leaf fun-ref)))))))
+ (n-required (length (values-type-required dtype))))
+ (aver (not (eq ctype *wild-type*)))
+ (cond ((and (null (values-type-optional dtype))
+ (not (values-type-rest dtype)))
+ ;; we [almost] know how many values are produced
+ (maybe-negate-check value
+ (values-type-out ctype n-required)
+ (values-type-out atype n-required)
+ ;; backend checks only consumed values
+ (not (eql n-required n-consumed))
+ n-required))
+ ((lvar-single-value-p lvar)
+ ;; exactly one value is consumed
+ (principal-lvar-single-valuify lvar)
+ (flet ((get-type (type)
+ (acond ((args-type-required type)
+ (car it))
+ ((args-type-optional type)
+ (car it))
+ (t (bug "type ~S is too hairy" type)))))
+ (multiple-value-bind (ctype atype)
+ (values (get-type ctype) (get-type atype))
+ (maybe-negate-check value
+ (list ctype) (list atype)
+ force-hairy
+ n-required))))
+ ((and (mv-combination-p dest)
+ (eq (mv-combination-kind dest) :local))
+ ;; we know the number of consumed values
+ (maybe-negate-check value
+ (adjust-list (values-type-types ctype)
+ n-consumed
+ *universal-type*)
+ (adjust-list (values-type-types atype)
+ n-consumed
+ *universal-type*)
+ force-hairy
+ n-required))
+ (t
+ (values :too-hairy nil)))))
-;;; Return a form that we can convert to do a hairy type check of the
-;;; specified Types. Types is a list of the format returned by
-;;; Continuation-Check-Types in the :HAIRY case. In place of the actual
-;;; value(s) we are to check, we use 'DUMMY. This constant reference is later
-;;; replaced with the actual values continuation.
+;;; Return T is the cast appears to be from the declaration of the callee,
+;;; and should be checked externally -- that is, by the callee and not the caller.
+(defun cast-externally-checkable-p (cast)
+ (declare (type cast cast))
+ (let* ((lvar (node-lvar cast))
+ (dest (and lvar (lvar-dest lvar))))
+ (and (combination-p dest)
+ ;; The theory is that the type assertion is from a declaration on the
+ ;; callee, so the callee should be able to do the check. We want to
+ ;; let the callee do the check, because it is possible that by the
+ ;; time of call that declaration will be changed and we do not want
+ ;; to make people recompile all calls to a function when they were
+ ;; originally compiled with a bad declaration.
+ ;;
+ ;; ALMOST-IMMEDIATELY-USED-P ensures that we don't delegate casts
+ ;; that occur before nodes that can cause observable side effects --
+ ;; most commonly other non-external casts: so the order in which
+ ;; possible type errors are signalled matches with the evaluation
+ ;; order.
+ ;;
+ ;; FIXME: We should let more cases be handled by the callee then we
+ ;; currently do, see: https://bugs.launchpad.net/sbcl/+bug/309104
+ ;; This is not fixable quite here, though, because flow-analysis has
+ ;; deleted the LVAR of the cast by the time we get here, so there is
+ ;; no destination. Perhaps we should mark cases inserted by
+ ;; ASSERT-CALL-TYPE explicitly, and delete those whose destination is
+ ;; deemed unreachable?
+ (almost-immediately-used-p lvar cast)
+ (values (values-subtypep (lvar-externally-checkable-type lvar)
+ (cast-type-to-check cast))))))
+
+;;; Return true if CAST's value is an lvar whose type the back end is
+;;; likely to be able to check (see GENERATE-TYPE-CHECKS). Since we
+;;; don't know what template the back end is going to choose to
+;;; implement the continuation's DEST, we use a heuristic.
;;;
-;;; Note that we don't attempt to check for required values being unsupplied.
-;;; Such checking is impossible to efficiently do at the source level because
-;;; our fixed-values conventions are optimized for the common MV-Bind case.
+;;; We always return T unless nobody uses the value (the backend
+;;; cannot check unused LVAR chains).
;;;
-;;; We can always use Multiple-Value-Bind, since the macro is clever about
-;;; binding a single variable.
-(defun make-type-check-form (types)
- (collect ((temps))
- (dotimes (i (length types))
- (temps (gensym)))
-
- `(multiple-value-bind ,(temps)
- 'dummy
- ,@(mapcar #'(lambda (temp type)
- (let* ((spec
- (let ((*unparse-function-type-simplify* t))
- (type-specifier (second type))))
- (test (if (first type) `(not ,spec) spec)))
- `(unless (typep ,temp ',test)
- (%type-check-error
- ,temp
- ',(type-specifier (third type))))))
- (temps) types)
- (values ,@(temps)))))
-
-;;; Splice in explicit type check code immediately before the node which is
-;;; Cont's Dest. This code receives the value(s) that were being passed to
-;;; Cont, checks the type(s) of the value(s), then passes them on to Cont.
-(defun convert-type-check (cont types)
- (declare (type continuation cont) (type list types))
- (with-ir1-environment (continuation-dest cont)
-
- ;; Ensuring that CONT starts a block lets us freely manipulate its uses.
- (ensure-block-start cont)
-
- ;; Make a new continuation and move CONT's uses to it.
- (let* ((new-start (make-continuation))
- (dest (continuation-dest cont))
- (prev (node-prev dest)))
- (continuation-starts-block new-start)
- (substitute-continuation-uses new-start cont)
-
- ;; Setting TYPE-CHECK in CONT to :DELETED indicates that the check has
- ;; been done.
- (setf (continuation-%type-check cont) :deleted)
-
- ;; Make the DEST node start its block so that we can splice in the
- ;; type check code.
- (when (continuation-use prev)
- (node-ends-block (continuation-use prev)))
-
- (let* ((prev-block (continuation-block prev))
- (new-block (continuation-block new-start))
- (dummy (make-continuation)))
-
- ;; Splice in the new block before DEST, giving the new block all of
- ;; DEST's predecessors.
- (dolist (block (block-pred prev-block))
- (change-block-successor block prev-block new-block))
-
- ;; Convert the check form, using the new block start as START and a
- ;; dummy continuation as CONT.
- (ir1-convert new-start dummy (make-type-check-form types))
-
- ;; TO DO: Why should this be true? -- WHN 19990601
- (assert (eq (continuation-block dummy) new-block))
-
- ;; KLUDGE: Comments at the head of this function in CMU CL said that
- ;; somewhere in here we
- ;; Set the new block's start and end cleanups to the *start*
- ;; cleanup of PREV's block. This overrides the incorrect
- ;; default from WITH-IR1-ENVIRONMENT.
- ;; Unfortunately I can't find any code which corresponds to this.
- ;; Perhaps it was a stale comment? Or perhaps I just don't
- ;; understand.. -- WHN 19990521
-
- (let ((node (continuation-use dummy)))
- (setf (block-last new-block) node)
- ;; Change the use to a use of CONT. (We need to use the dummy
- ;; continuation to get the control transfer right, because we want to
- ;; go to PREV's block, not CONT's.)
- (delete-continuation-use node)
- (add-continuation-use node cont))
- ;; Link the new block to PREV's block.
- (link-blocks new-block prev-block))
-
- ;; MAKE-TYPE-CHECK-FORM generated a form which checked the type of
- ;; 'DUMMY, not a real form. At this point we convert to the real form by
- ;; finding 'DUMMY and overwriting it with the new continuation. (We can
- ;; find 'DUMMY because no LET conversion has been done yet.) The
- ;; [mv-]combination code from the mv-bind in the check form will be the
- ;; use of the new check continuation. We substitute for the first
- ;; argument of this node.
- (let* ((node (continuation-use cont))
- (args (basic-combination-args node))
- (victim (first args)))
- (assert (and (= (length args) 1)
- (eq (constant-value
- (ref-leaf
- (continuation-use victim)))
- 'dummy)))
- (substitute-continuation new-start victim)))
+;;; The logic used to be more complex, but most of the cases that used
+;;; to be checked here are now dealt with differently . FIXME: but
+;;; here's one we used to do, don't anymore, but could still benefit
+;;; from, if we reimplemented it (elsewhere):
+;;;
+;;; -- If the lvar is an argument to a known function that has
+;;; no IR2-CONVERT method or :FAST-SAFE templates that are
+;;; compatible with the call's type: return NIL.
+;;;
+;;; The code used to look like something like this:
+;;; ...
+;;; (:known
+;;; (let ((info (basic-combination-fun-info dest)))
+;;; (if (fun-info-ir2-convert info)
+;;; t
+;;; (dolist (template (fun-info-templates info) nil)
+;;; (when (eq (template-ltn-policy template)
+;;; :fast-safe)
+;;; (multiple-value-bind (val win)
+;;; (valid-fun-use dest (template-type template))
+;;; (when (or val (not win)) (return t)))))))))))))
+;;;
+;;; ADP says: It is still interesting. When we have a :SAFE template
+;;; and the type assertion is derived from the destination function
+;;; type, the check is unneccessary. We cannot return NIL here (the
+;;; whole function has changed its meaning, and here NIL *forces*
+;;; hairy check), but the functionality is interesting.
+(defun probable-type-check-p (cast)
+ (declare (type cast cast))
+ (let* ((lvar (node-lvar cast))
+ (dest (and lvar (lvar-dest lvar))))
+ (cond ((not dest) nil)
+ (t t))))
- ;; Invoking local call analysis converts this call to a LET.
- (local-call-analyze *current-component*))
+;;; Return a lambda form that we can convert to do a hairy type check
+;;; of the specified TYPES. TYPES is a list of the format returned by
+;;; LVAR-CHECK-TYPES in the :HAIRY case.
+;;;
+;;; Note that we don't attempt to check for required values being
+;;; unsupplied. Such checking is impossible to efficiently do at the
+;;; source level because our fixed-values conventions are optimized
+;;; for the common MV-BIND case.
+(defun make-type-check-form (types)
+ (let ((temps (make-gensym-list (length types))))
+ `(multiple-value-bind ,temps
+ 'dummy
+ ,@(mapcar (lambda (temp type)
+ (let* ((spec
+ (let ((*unparse-fun-type-simplify* t))
+ (type-specifier (second type))))
+ (test (if (first type) `(not ,spec) spec)))
+ `(unless (typep ,temp ',test)
+ (%type-check-error
+ ,temp
+ ',(type-specifier (third type))))))
+ temps
+ types)
+ (values ,@temps))))
- (values))
+;;; Splice in explicit type check code immediately before CAST. This
+;;; code receives the value(s) that were being passed to CAST-VALUE,
+;;; checks the type(s) of the value(s), then passes them further.
+(defun convert-type-check (cast types)
+ (declare (type cast cast) (type list types))
+ (let ((value (cast-value cast))
+ (length (length types)))
+ (filter-lvar value (make-type-check-form types))
+ (reoptimize-lvar (cast-value cast))
+ (setf (cast-type-to-check cast) *wild-type*)
+ (setf (cast-%type-check cast) nil)
+ (let* ((atype (cast-asserted-type cast))
+ (atype (cond ((not (values-type-p atype))
+ atype)
+ ((= length 1)
+ (single-value-type atype))
+ (t
+ (make-values-type
+ :required (values-type-out atype length)))))
+ (dtype (node-derived-type cast))
+ (dtype (make-values-type
+ :required (values-type-out dtype length))))
+ (setf (cast-asserted-type cast) atype)
+ (setf (node-derived-type cast) dtype)))
-;;; Emit a type warning for Node. If the value of node is being used for a
-;;; variable binding, we figure out which one for source context. If the value
-;;; is a constant, we print it specially. We ignore nodes whose type is NIL,
-;;; since they are supposed to never return.
-(defun do-type-warning (node)
- (declare (type node node))
- (let* ((*compiler-error-context* node)
- (cont (node-cont node))
- (atype-spec (type-specifier (continuation-asserted-type cont)))
- (dtype (node-derived-type node))
- (dest (continuation-dest cont))
- (what (when (and (combination-p dest)
- (eq (combination-kind dest) :local))
- (let ((lambda (combination-lambda dest))
- (pos (position-or-lose cont (combination-args dest))))
- (format nil "~:[A possible~;The~] binding of ~S"
- (and (continuation-use cont)
- (eq (functional-kind lambda) :let))
- (leaf-name (elt (lambda-vars lambda) pos)))))))
- (cond ((eq dtype *empty-type*))
- ((and (ref-p node) (constant-p (ref-leaf node)))
- (compiler-warning "~:[This~;~:*~A~] is not a ~<~%~9T~:;~S:~>~% ~S"
- what atype-spec (constant-value (ref-leaf node))))
- (t
- (compiler-warning
- "~:[Result~;~:*~A~] is a ~S, ~<~%~9T~:;not a ~S.~>"
- what (type-specifier dtype) atype-spec))))
(values))
-;;; Mark Cont as being a continuation with a manifest type error. We set
-;;; the kind to :ERROR, and clear any FUNCTION-INFO if the continuation is an
-;;; argument to a known call. The last is done so that the back end doesn't
-;;; have to worry about type errors in arguments to known functions. This
-;;; clearing is inhibited for things with IR2-CONVERT methods, since we can't
-;;; do a full call to funny functions.
-(defun mark-error-continuation (cont)
- (declare (type continuation cont))
- (setf (continuation-%type-check cont) :error)
- (let ((dest (continuation-dest cont)))
- (when (and (combination-p dest)
- (let ((kind (basic-combination-kind dest)))
- (or (eq kind :full)
- (and (function-info-p kind)
- (not (function-info-ir2-convert kind))))))
- (setf (basic-combination-kind dest) :error)))
+;;; Check all possible arguments of CAST and emit type warnings for
+;;; those with type errors. If the value of USE is being used for a
+;;; variable binding, we figure out which one for source context. If
+;;; the value is a constant, we print it specially.
+(defun cast-check-uses (cast)
+ (declare (type cast cast))
+ (let* ((lvar (node-lvar cast))
+ (dest (and lvar (lvar-dest lvar)))
+ (value (cast-value cast))
+ (atype (cast-asserted-type cast))
+ (condition 'type-warning)
+ (not-ok-uses '()))
+ (do-uses (use value)
+ (let ((dtype (node-derived-type use)))
+ (if (values-types-equal-or-intersect dtype atype)
+ (setf condition 'type-style-warning)
+ (push use not-ok-uses))))
+ (dolist (use (nreverse not-ok-uses))
+ (let* ((*compiler-error-context* use)
+ (dtype (node-derived-type use))
+ (atype-spec (type-specifier atype))
+ (what (when (and (combination-p dest)
+ (eq (combination-kind dest) :local))
+ (let ((lambda (combination-lambda dest))
+ (pos (position-or-lose
+ lvar (combination-args dest))))
+ (format nil "~:[A possible~;The~] binding of ~S"
+ (and (lvar-has-single-use-p lvar)
+ (eq (functional-kind lambda) :let))
+ (leaf-source-name (elt (lambda-vars lambda)
+ pos)))))))
+ (cond ((and (ref-p use) (constant-p (ref-leaf use)))
+ (warn condition
+ :format-control
+ "~:[This~;~:*~A~] is not a ~<~%~9T~:;~S:~>~% ~S"
+ :format-arguments
+ (list what atype-spec
+ (constant-value (ref-leaf use)))))
+ (t
+ (warn condition
+ :format-control
+ "~:[Result~;~:*~A~] is a ~S, ~<~%~9T~:;not a ~S.~>"
+ :format-arguments
+ (list what (type-specifier dtype) atype-spec)))))))
(values))
-;;; Loop over all blocks in Component that have TYPE-CHECK set, looking for
-;;; continuations with TYPE-CHECK T. We do two mostly unrelated things: detect
-;;; compile-time type errors and determine if and how to do run-time type
-;;; checks.
+;;; Loop over all blocks in COMPONENT that have TYPE-CHECK set,
+;;; looking for CASTs with TYPE-CHECK T. We do two mostly unrelated
+;;; things: detect compile-time type errors and determine if and how
+;;; to do run-time type checks.
;;;
-;;; If there is a compile-time type error, then we mark the continuation and
-;;; emit a warning if appropriate. This part loops over all the uses of the
-;;; continuation, since after we convert the check, the :DELETED kind will
-;;; inhibit warnings about the types of other uses.
+;;; If there is a compile-time type error, then we mark the CAST and
+;;; emit a warning if appropriate. This part loops over all the uses
+;;; of the continuation, since after we convert the check, the
+;;; :DELETED kind will inhibit warnings about the types of other uses.
;;;
-;;; If a continuation is too complex to be checked by the back end, or is
-;;; better checked with explicit code, then convert to an explicit test.
-;;; Assertions that can checked by the back end are passed through. Assertions
-;;; that can't be tested are flamed about and marked as not needing to be
-;;; checked.
+;;; If the cast is too complex to be checked by the back end, or is
+;;; better checked with explicit code, then convert to an explicit
+;;; test. Assertions that can checked by the back end are passed
+;;; through. Assertions that can't be tested are flamed about and
+;;; marked as not needing to be checked.
;;;
-;;; If we determine that a type check won't be done, then we set TYPE-CHECK
-;;; to :NO-CHECK. In the non-hairy cases, this is just to prevent us from
-;;; wasting time coming to the same conclusion again on a later iteration. In
-;;; the hairy case, we must indicate to LTN that it must choose a safe
-;;; implementation, since IR2 conversion will choke on the check.
+;;; If we determine that a type check won't be done, then we set
+;;; TYPE-CHECK to :NO-CHECK. In the non-hairy cases, this is just to
+;;; prevent us from wasting time coming to the same conclusion again
+;;; on a later iteration. In the hairy case, we must indicate to LTN
+;;; that it must choose a safe implementation, since IR2 conversion
+;;; will choke on the check.
;;;
;;; The generation of the type checks is delayed until all the type
;;; check decisions have been made because the generation of the type
;;; which may lead to inappropriate template choices due to the
;;; modification of argument types.
(defun generate-type-checks (component)
- (collect ((conts))
+ (collect ((casts))
(do-blocks (block component)
(when (block-type-check block)
- (do-nodes (node cont block)
- (let ((type-check (continuation-type-check cont)))
- (unless (member type-check '(nil :error :deleted))
- (let ((atype (continuation-asserted-type cont)))
- (do-uses (use cont)
- (unless (values-types-intersect (node-derived-type use)
- atype)
- (mark-error-continuation cont)
- (unless (policy node (= brevity 3))
- (do-type-warning use))))))
- (when (and (eq type-check t)
- (not *byte-compiling*))
- (cond ((probable-type-check-p cont)
- (conts cont))
- (t
- (setf (continuation-%type-check cont) :no-check))))))
- (setf (block-type-check block) nil)))
- (dolist (cont (conts))
- (multiple-value-bind (check types) (continuation-check-types cont)
- (ecase check
- (:simple)
- (:hairy
- (convert-type-check cont types))
- (:too-hairy
- (let* ((context (continuation-dest cont))
- (*compiler-error-context* context))
- (when (policy context (>= safety brevity))
- (compiler-note
- "type assertion too complex to check:~% ~S."
- (type-specifier (continuation-asserted-type cont)))))
- (setf (continuation-%type-check cont) :deleted))))))
+ ;; CAST-EXTERNALLY-CHECKABLE-P wants the backward pass
+ (do-nodes-backwards (node nil block)
+ (when (and (cast-p node)
+ (cast-type-check node))
+ (cast-check-uses node)
+ (cond ((cast-externally-checkable-p node)
+ (setf (cast-%type-check node) :external))
+ (t
+ ;; it is possible that NODE was marked :EXTERNAL by
+ ;; the previous pass
+ (setf (cast-%type-check node) t)
+ (casts (cons node (not (probable-type-check-p node))))))))
+ (setf (block-type-check block) nil)))
+ (dolist (cast (casts))
+ (destructuring-bind (cast . force-hairy) cast
+ (multiple-value-bind (check types)
+ (cast-check-types cast force-hairy)
+ (ecase check
+ (:simple)
+ (:hairy
+ (convert-type-check cast types))
+ (:too-hairy
+ (let ((*compiler-error-context* cast))
+ (when (policy cast (>= safety inhibit-warnings))
+ (compiler-notify
+ "type assertion too complex to check:~% ~S."
+ (type-specifier (coerce-to-values (cast-asserted-type cast))))))
+ (setf (cast-type-to-check cast) *wild-type*)
+ (setf (cast-%type-check cast) nil)))))))
(values))