diff options
Diffstat (limited to 'lisp/emacs-lisp/macroexp.el')
| -rw-r--r-- | lisp/emacs-lisp/macroexp.el | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el index 51c6e8e0ca2..bae303c213c 100644 --- a/lisp/emacs-lisp/macroexp.el +++ b/lisp/emacs-lisp/macroexp.el @@ -369,6 +369,54 @@ Assumes the caller has bound `macroexpand-all-environment'." (macroexp--all-forms body)) (cdr form)) form))) + (`(setq ,(and var (pred symbolp) + (pred (not booleanp)) (pred (not keywordp))) + ,expr) + ;; Fast path for the setq common case. + (let ((new-expr (macroexp--expand-all expr))) + (if (eq new-expr expr) + form + `(,fn ,var ,new-expr)))) + (`(setq . ,args) + ;; Normalise to a sequence of (setq SYM EXPR). + ;; Malformed code is translated to code that signals an error + ;; at run time. + (let ((nargs (length args))) + (if (/= (logand nargs 1) 0) + (macroexp-warn-and-return + "odd number of arguments in `setq' form" + `(signal 'wrong-number-of-arguments '(setq ,nargs)) + nil 'compile-only fn) + (let ((assignments nil)) + (while (consp (cdr-safe args)) + (let* ((var (car args)) + (expr (cadr args)) + (new-expr (macroexp--expand-all expr)) + (assignment + (if (and (symbolp var) + (not (booleanp var)) (not (keywordp var))) + `(,fn ,var ,new-expr) + (macroexp-warn-and-return + (format-message "attempt to set %s `%s'" + (if (symbolp var) + "constant" + "non-variable") + var) + (cond + ((keywordp var) + ;; Accept `(setq :a :a)' for compatibility. + `(if (eq ,var ,new-expr) + ,var + (signal 'setting-constant (list ',var)))) + ((symbolp var) + `(signal 'setting-constant (list ',var))) + (t + `(signal 'wrong-type-argument + (list 'symbolp ',var)))) + nil 'compile-only var)))) + (push assignment assignments)) + (setq args (cddr args))) + (cons 'progn (nreverse assignments)))))) (`(,(and fun `(lambda . ,_)) . ,args) ;; Embedded lambda in function position. ;; If the byte-optimizer is loaded, try to unfold this, |