+ (multiple-value-bind (forms decls) (parse-body body :doc-string-allowed nil)
+ (let ((n-list (gensym "N-LIST"))
+ (start (gensym "START")))
+ `(block nil
+ (let ((,n-list ,list))
+ (tagbody
+ ,start
+ (unless (endp ,n-list)
+ (let ((,var (car ,n-list)))
+ ,@decls
+ (setq ,n-list (cdr ,n-list))
+ (tagbody ,@forms))
+ (go ,start))))
+ ,(if result
+ `(let ((,var nil))
+ ,var
+ ,result)
+ nil)))))
+\f
+;;;; conditions, handlers, restarts
+
+;;; KLUDGE: we PROCLAIM these special here so that we can use restart
+;;; macros in the compiler before the DEFVARs are compiled.
+(sb!xc:proclaim
+ '(special *handler-clusters* *restart-clusters* *condition-restarts*))
+
+(defmacro-mundanely with-condition-restarts
+ (condition-form restarts-form &body body)
+ #!+sb-doc
+ "WITH-CONDITION-RESTARTS Condition-Form Restarts-Form Form*
+ Evaluates the Forms in a dynamic environment where the restarts in the list
+ Restarts-Form are associated with the condition returned by Condition-Form.
+ This allows FIND-RESTART, etc., to recognize restarts that are not related
+ to the error currently being debugged. See also RESTART-CASE."
+ (let ((n-cond (gensym)))
+ `(let ((*condition-restarts*
+ (cons (let ((,n-cond ,condition-form))
+ (cons ,n-cond
+ (append ,restarts-form
+ (cdr (assoc ,n-cond *condition-restarts*)))))
+ *condition-restarts*)))
+ ,@body)))
+
+(defmacro-mundanely restart-bind (bindings &body forms)
+ #!+sb-doc
+ "Executes forms in a dynamic context where the given restart bindings are
+ in effect. Users probably want to use RESTART-CASE. When clauses contain
+ the same restart name, FIND-RESTART will find the first such clause."
+ `(let ((*restart-clusters*
+ (cons (list
+ ,@(mapcar (lambda (binding)
+ (unless (or (car binding)
+ (member :report-function
+ binding
+ :test #'eq))
+ (warn "Unnamed restart does not have a ~
+ report function: ~S"
+ binding))
+ `(make-restart :name ',(car binding)
+ :function ,(cadr binding)
+ ,@(cddr binding)))
+ bindings))
+ *restart-clusters*)))
+ ,@forms))
+
+;;; Wrap the RESTART-CASE expression in a WITH-CONDITION-RESTARTS if
+;;; appropriate. Gross, but it's what the book seems to say...
+(defun munge-restart-case-expression (expression env)
+ (let ((exp (sb!xc:macroexpand expression env)))
+ (if (consp exp)
+ (let* ((name (car exp))
+ (args (if (eq name 'cerror) (cddr exp) (cdr exp))))
+ (if (member name '(signal error cerror warn))
+ (once-only ((n-cond `(coerce-to-condition
+ ,(first args)
+ (list ,@(rest args))
+ ',(case name
+ (warn 'simple-warning)
+ (signal 'simple-condition)
+ (t 'simple-error))
+ ',name)))
+ `(with-condition-restarts
+ ,n-cond
+ (car *restart-clusters*)
+ ,(if (eq name 'cerror)
+ `(cerror ,(second exp) ,n-cond)
+ `(,name ,n-cond))))
+ expression))
+ expression)))
+
+;;; FIXME: I did a fair amount of rearrangement of this code in order to
+;;; get WITH-KEYWORD-PAIRS to work cleanly. This code should be tested..
+(defmacro-mundanely restart-case (expression &body clauses &environment env)
+ #!+sb-doc
+ "(RESTART-CASE form
+ {(case-name arg-list {keyword value}* body)}*)
+ The form is evaluated in a dynamic context where the clauses have special
+ meanings as points to which control may be transferred (see INVOKE-RESTART).
+ When clauses contain the same case-name, FIND-RESTART will find the first
+ such clause. If Expression is a call to SIGNAL, ERROR, CERROR or WARN (or
+ macroexpands into such) then the signalled condition will be associated with
+ the new restarts."
+ (flet ((transform-keywords (&key report interactive test)
+ (let ((result '()))
+ (when report
+ (setq result (list* (if (stringp report)
+ `#'(lambda (stream)
+ (write-string ,report stream))
+ `#',report)
+ :report-function
+ result)))
+ (when interactive
+ (setq result (list* `#',interactive
+ :interactive-function
+ result)))
+ (when test
+ (setq result (list* `#',test :test-function result)))
+ (nreverse result)))
+ (parse-keyword-pairs (list keys)
+ (do ((l list (cddr l))
+ (k '() (list* (cadr l) (car l) k)))
+ ((or (null l) (not (member (car l) keys)))
+ (values (nreverse k) l)))))
+ (let ((block-tag (gensym))
+ (temp-var (gensym))
+ (data
+ (macrolet (;; KLUDGE: This started as an old DEFMACRO
+ ;; WITH-KEYWORD-PAIRS general utility, which was used
+ ;; only in this one place in the code. It was translated
+ ;; literally into this MACROLET in order to avoid some
+ ;; cross-compilation bootstrap problems. It would almost
+ ;; certainly be clearer, and it would certainly be more
+ ;; concise, to do a more idiomatic translation, merging
+ ;; this with the TRANSFORM-KEYWORDS logic above.
+ ;; -- WHN 19990925
+ (with-keyword-pairs ((names expression) &body forms)
+ (let ((temp (member '&rest names)))
+ (unless (= (length temp) 2)
+ (error "&REST keyword is ~:[missing~;misplaced~]."
+ temp))
+ (let* ((key-vars (ldiff names temp))
+ (keywords (mapcar #'keywordicate key-vars))
+ (key-var (gensym))
+ (rest-var (cadr temp)))
+ `(multiple-value-bind (,key-var ,rest-var)
+ (parse-keyword-pairs ,expression ',keywords)
+ (let ,(mapcar (lambda (var keyword)
+ `(,var (getf ,key-var
+ ,keyword)))
+ key-vars keywords)
+ ,@forms))))))
+ (mapcar (lambda (clause)
+ (with-keyword-pairs ((report interactive test
+ &rest forms)
+ (cddr clause))
+ (list (car clause) ;name=0
+ (gensym) ;tag=1
+ (transform-keywords :report report ;keywords=2
+ :interactive interactive
+ :test test)
+ (cadr clause) ;bvl=3
+ forms))) ;body=4
+ clauses))))
+ `(block ,block-tag
+ (let ((,temp-var nil))
+ (tagbody
+ (restart-bind
+ ,(mapcar (lambda (datum)
+ (let ((name (nth 0 datum))
+ (tag (nth 1 datum))
+ (keys (nth 2 datum)))
+ `(,name #'(lambda (&rest temp)
+ (setq ,temp-var temp)
+ (go ,tag))
+ ,@keys)))
+ data)
+ (return-from ,block-tag
+ ,(munge-restart-case-expression expression env)))
+ ,@(mapcan (lambda (datum)
+ (let ((tag (nth 1 datum))
+ (bvl (nth 3 datum))
+ (body (nth 4 datum)))
+ (list tag
+ `(return-from ,block-tag
+ (apply (lambda ,bvl ,@body)
+ ,temp-var)))))
+ data)))))))
+
+(defmacro-mundanely with-simple-restart ((restart-name format-string
+ &rest format-arguments)
+ &body forms)
+ #!+sb-doc
+ "(WITH-SIMPLE-RESTART (restart-name format-string format-arguments)
+ body)
+ If restart-name is not invoked, then all values returned by forms are
+ returned. If control is transferred to this restart, it immediately
+ returns the values NIL and T."
+ `(restart-case
+ ;; If there's just one body form, then don't use PROGN. This allows
+ ;; RESTART-CASE to "see" calls to ERROR, etc.
+ ,(if (= (length forms) 1) (car forms) `(progn ,@forms))
+ (,restart-name ()
+ :report (lambda (stream)
+ (format stream ,format-string ,@format-arguments))
+ (values nil t))))
+
+(defmacro-mundanely handler-bind (bindings &body forms)
+ #!+sb-doc
+ "(HANDLER-BIND ( {(type handler)}* ) body)
+ Executes body in a dynamic context where the given handler bindings are
+ in effect. Each handler must take the condition being signalled as an
+ argument. The bindings are searched first to last in the event of a
+ signalled condition."
+ (let ((member-if (member-if (lambda (x)
+ (not (proper-list-of-length-p x 2)))
+ bindings)))
+ (when member-if
+ (error "ill-formed handler binding: ~S" (first member-if))))
+ `(let ((*handler-clusters*
+ (cons (list ,@(mapcar (lambda (x) `(cons ',(car x) ,(cadr x)))
+ bindings))
+ *handler-clusters*)))
+ (multiple-value-prog1
+ (progn
+ ,@forms)
+ ;; Wait for any float exceptions.
+ #!+x86 (float-wait))))
+
+(defmacro-mundanely handler-case (form &rest cases)
+ "(HANDLER-CASE form
+ { (type ([var]) body) }* )
+ Execute FORM in a context with handlers established for the condition
+ types. A peculiar property allows type to be :NO-ERROR. If such a clause
+ occurs, and form returns normally, all its values are passed to this clause
+ as if by MULTIPLE-VALUE-CALL. The :NO-ERROR clause accepts more than one
+ var specification."
+ ;; FIXME: Replacing CADR, CDDDR and friends with DESTRUCTURING-BIND
+ ;; and names for the subexpressions would make it easier to
+ ;; understand the code below.
+ (let ((no-error-clause (assoc ':no-error cases)))
+ (if no-error-clause
+ (let ((normal-return (make-symbol "normal-return"))
+ (error-return (make-symbol "error-return")))
+ `(block ,error-return
+ (multiple-value-call (lambda ,@(cdr no-error-clause))
+ (block ,normal-return
+ (return-from ,error-return
+ (handler-case (return-from ,normal-return ,form)
+ ,@(remove no-error-clause cases)))))))
+ (let ((tag (gensym))
+ (var (gensym))
+ (annotated-cases (mapcar (lambda (case) (cons (gensym) case))
+ cases)))
+ `(block ,tag
+ (let ((,var nil))
+ (declare (ignorable ,var))
+ (tagbody
+ (handler-bind
+ ,(mapcar (lambda (annotated-case)
+ (list (cadr annotated-case)
+ `(lambda (temp)
+ ,(if (caddr annotated-case)
+ `(setq ,var temp)
+ '(declare (ignore temp)))
+ (go ,(car annotated-case)))))
+ annotated-cases)
+ (return-from ,tag
+ #!-x86 ,form
+ #!+x86 (multiple-value-prog1 ,form
+ ;; Need to catch FP errors here!
+ (float-wait))))
+ ,@(mapcan
+ (lambda (annotated-case)
+ (list (car annotated-case)
+ (let ((body (cdddr annotated-case)))
+ `(return-from
+ ,tag
+ ,(cond ((caddr annotated-case)
+ `(let ((,(caaddr annotated-case)
+ ,var))
+ ,@body))
+ (t
+ `(locally ,@body)))))))
+ annotated-cases))))))))
projects / sbcl.git / blobdiff