+(defun common-suffix (x y)
+ (let ((mismatch (mismatch x y :from-end t)))
+ (if mismatch
+ (subseq x mismatch)
+ x)))
+
+;;; If the LVAR has a single use, return NODE-SOURCE-FORM as a
+;;; singleton. Otherwise, return a list of the lowest common
+;;; ancestor source form of all the uses (if it can be found),
+;;; followed by all the uses' source forms.
+(defun lvar-all-sources (lvar)
+ (let ((use (lvar-uses lvar)))
+ (if (listp use)
+ (let ((forms '())
+ (path (node-source-path (first use))))
+ (dolist (use use (cons (if (find 'original-source-start path)
+ (find-original-source path)
+ "a hairy form")
+ forms))
+ (pushnew (node-source-form use) forms)
+ (setf path (common-suffix path
+ (node-source-path use)))))
+ (list (node-source-form use)))))
+