From fffa53ff1afe097fe38f7664df5debe9811201d1 Mon Sep 17 00:00:00 2001 From: Philipp Stephani Date: Tue, 13 Sep 2022 17:12:57 +0200 Subject: Have 'cl-case' warn about suspicious cases * lisp/emacs-lisp/cl-macs.el (cl-case): Warn if the user passes a nil key list (which would never match). Warn about quoted symbols that should probably be unquoted. * test/lisp/emacs-lisp/cl-macs-tests.el (cl-case-warning): New unit test (bug#51368). --- lisp/emacs-lisp/cl-macs.el | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'lisp/emacs-lisp') diff --git a/lisp/emacs-lisp/cl-macs.el b/lisp/emacs-lisp/cl-macs.el index 946d2c09a92..5d330f32d66 100644 --- a/lisp/emacs-lisp/cl-macs.el +++ b/lisp/emacs-lisp/cl-macs.el @@ -788,6 +788,21 @@ compared by `eql'. ((eq (car c) 'cl--ecase-error-flag) `(error "cl-ecase failed: %s, %s" ,temp ',(reverse head-list))) + ((null (car c)) + (macroexp-warn-and-return + "Case nil will never match" + nil 'suspicious)) + ((and (consp (car c)) (not (cddar c)) + (memq (caar c) '(quote function))) + (macroexp-warn-and-return + (format-message + (concat "Case %s will match `%s'. If " + "that's intended, write %s " + "instead. Otherwise, don't " + "quote `%s'.") + (car c) (caar c) (list (cadar c) (caar c)) + (cadar c)) + `(cl-member ,temp ',(car c)) 'suspicious)) ((listp (car c)) (setq head-list (append (car c) head-list)) `(cl-member ,temp ',(car c))) -- cgit v1.2.3