(eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
+(define-condition duplicate-case-key-warning (style-warning)
+ ((key :initarg :key
+ :reader case-warning-key)
+ (case-kind :initarg :case-kind
+ :reader case-warning-case-kind)
+ (occurrences :initarg :occurrences
+ :type (cons (integer 0) (cons t null))
+ :reader duplicate-case-key-warning-occurrences))
+ (:report
+ (lambda (condition stream)
+ (format stream
+ "Duplicate key ~S in ~S form, ~
+ occurring in~{~#[~; and~]~{ the ~:R clause:~%~< ~S~:>~}~^,~}."
+ (case-warning-key condition)
+ (case-warning-case-kind condition)
+ (duplicate-case-key-warning-occurrences condition)))))
+
;;; CASE-BODY returns code for all the standard "case" macros. NAME is
;;; the macro name, and KEYFORM is the thing to case on. MULTI-P
;;; indicates whether a branch may fire off a list of keys; otherwise,
(warn "no clauses in ~S" name))
(let ((keyform-value (gensym))
(clauses ())
- (keys ()))
+ (keys ())
+ (keys-seen (make-hash-table :test #'eql)))
(do* ((cases cases (cdr cases))
- (case (car cases) (car cases)))
+ (case (car cases) (car cases))
+ (case-position 1 (1+ case-position)))
((null cases) nil)
- (unless (list-of-length-at-least-p case 1)
- (error "~S -- bad clause in ~S" case name))
- (destructuring-bind (keyoid &rest forms) case
- (cond (;; an OTHERWISE-CLAUSE
- ;;
- ;; By the way... The old code here tried gave
- ;; STYLE-WARNINGs for normal-clauses which looked as
- ;; though they might've been intended to be
- ;; otherwise-clauses. As Tony Martinez reported on
- ;; sbcl-devel 2004-11-09 there are sometimes good
- ;; reasons to write clauses like that; and as I noticed
- ;; when trying to understand the old code so I could
- ;; understand his patch, trying to guess which clauses
- ;; don't have good reasons is fundamentally kind of a
- ;; mess. SBCL does issue style warnings rather
- ;; enthusiastically, and I have often justified that by
- ;; arguing that we're doing that to detect issues which
- ;; are tedious for programmers to detect for by
- ;; proofreading (like small typoes in long symbol
- ;; names, or duplicate function definitions in large
- ;; files). This doesn't seem to be an issue like that,
- ;; and I can't think of a comparably good justification
- ;; for giving STYLE-WARNINGs for legal code here, so
- ;; now we just hope the programmer knows what he's
- ;; doing. -- WHN 2004-11-20
- (and (not errorp) ; possible only in CASE or TYPECASE,
- ; not in [EC]CASE or [EC]TYPECASE
- (memq keyoid '(t otherwise))
- (null (cdr cases)))
- (push `(t nil ,@forms) clauses))
- ((and multi-p (listp keyoid))
- (setf keys (append keyoid keys))
- (push `((or ,@(mapcar (lambda (key)
- `(,test ,keyform-value ',key))
- keyoid))
- nil
- ,@forms)
- clauses))
- (t
- (push keyoid keys)
- (push `((,test ,keyform-value ',keyoid)
- nil
- ,@forms)
- clauses)))))
+ (flet ((check-clause (case-keys)
+ (loop for k in case-keys
+ for existing = (gethash k keys-seen)
+ do (when existing
+ (let ((sb!c::*current-path*
+ (when (boundp 'sb!c::*source-paths*)
+ (or (gethash case sb!c::*source-paths*)
+ sb!c::*current-path*))))
+ (warn 'duplicate-case-key-warning
+ :key k
+ :case-kind name
+ :occurrences `(,existing (,case-position (,case)))))))
+ (let ((record (list case-position (list case))))
+ (dolist (k case-keys)
+ (setf (gethash k keys-seen) record)))))
+ (unless (list-of-length-at-least-p case 1)
+ (error "~S -- bad clause in ~S" case name))
+ (destructuring-bind (keyoid &rest forms) case
+ (cond (;; an OTHERWISE-CLAUSE
+ ;;
+ ;; By the way... The old code here tried gave
+ ;; STYLE-WARNINGs for normal-clauses which looked as
+ ;; though they might've been intended to be
+ ;; otherwise-clauses. As Tony Martinez reported on
+ ;; sbcl-devel 2004-11-09 there are sometimes good
+ ;; reasons to write clauses like that; and as I noticed
+ ;; when trying to understand the old code so I could
+ ;; understand his patch, trying to guess which clauses
+ ;; don't have good reasons is fundamentally kind of a
+ ;; mess. SBCL does issue style warnings rather
+ ;; enthusiastically, and I have often justified that by
+ ;; arguing that we're doing that to detect issues which
+ ;; are tedious for programmers to detect for by
+ ;; proofreading (like small typoes in long symbol
+ ;; names, or duplicate function definitions in large
+ ;; files). This doesn't seem to be an issue like that,
+ ;; and I can't think of a comparably good justification
+ ;; for giving STYLE-WARNINGs for legal code here, so
+ ;; now we just hope the programmer knows what he's
+ ;; doing. -- WHN 2004-11-20
+ (and (not errorp) ; possible only in CASE or TYPECASE,
+ ; not in [EC]CASE or [EC]TYPECASE
+ (memq keyoid '(t otherwise))
+ (null (cdr cases)))
+ (push `(t nil ,@forms) clauses))
+ ((and multi-p (listp keyoid))
+ (setf keys (append keyoid keys))
+ (check-clause keyoid)
+ (push `((or ,@(mapcar (lambda (key)
+ `(,test ,keyform-value ',key))
+ keyoid))
+ nil
+ ,@forms)
+ clauses))
+ (t
+ (push keyoid keys)
+ (check-clause (list keyoid))
+ (push `((,test ,keyform-value ',keyoid)
+ nil
+ ,@forms)
+ clauses))))))
(case-body-aux name keyform keyform-value clauses keys errorp proceedp
`(,(if multi-p 'member 'or) ,@keys))))
projects / sbcl.git / commitdiff