Bug in Elisp font-locking (was: Concern around use of eval)

[Tassilo Horn <tsdh@gnu.org>]

Thierry Volpiatto <thierry.volpiatto@gmail.com> writes:

>>     (defun lh/gen-predicate (label)
>>       (defalias (intern (concat "lh/" label "-p"))
>                   ^^^^^^
> In this case intern should not be highlighted, isn't it ?.

Indeed, it shouldn't be.  But the font-lock entry for definitions which
applies the function name face here matches next to `defun', `defmacro',
or `defalias' also `cl-defstruct', and that may have the two forms

  (defstruct struct-name ...)
  (defstruct (struct-name OPTIONS) ...)

and therefore, the regexp simply skips the paren.  The following patch
should fix that.

Cc-ing emacs-devel to ask if that's ok to commit.  Is it?  Or too much
hassle for just `defalias'?  (I think that's the only definition form
which is implemented as a function where the name may be provided by a
funcall.)

--8<---------------cut here---------------start------------->8---
diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index 6b30773..614fbc6 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -320,14 +320,18 @@
     `( ;; Definitions.
       (,(concat "(" el-defs-re "\\_>"
                 ;; Any whitespace and defined object.
-                "[ \t'\(]*"
-                "\\(\\(?:\\sw\\|\\s_\\)+\\)?")
+                "[ \t']*"
+               ;; With defstruct, the name may follow a paren,
+               ;; e.g. (defstruct (foo-struct opts)...).
+                "\\(([ \t']*\\)?\\(\\(?:\\sw\\|\\s_\\)+\\)?")
        (1 font-lock-keyword-face)
-       (2 (let ((type (get (intern-soft (match-string 1)) 'lisp-define-type)))
-            (cond ((eq type 'var) font-lock-variable-name-face)
-                  ((eq type 'type) font-lock-type-face)
-                  (t font-lock-function-name-face)))
-          nil t))
+       (3 (let ((type (get (intern-soft (match-string 1)) 'lisp-define-type)))
+           (cond ((eq type 'var) font-lock-variable-name-face)
+                 ((eq type 'type) font-lock-type-face)
+                 ;; If match-string 2 is non-nil, we encountered a
+                 ;; form like (defalias (intern (concat s "-p"))).
+                 ((not (match-string 2)) font-lock-function-name-face)))
+         nil t))
       ;; Emacs Lisp autoload cookies.  Supports the slightly different
       ;; forms used by mh-e, calendar, etc.
       ("^;;;###\\([-a-z]*autoload\\)" 1 font-lock-warning-face prepend))
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo