; cperl-mode: Avoid excessive regexp backtracking (Bug#8077)

* lisp/progmodes/cperl-mode.el (defconst): Add a word-start
assertion to cperl--single-attribute-rx
(cperl-after-sub-regexp): Dito
(cperl-init-faces): shorten matches of incomplete sub declarations

1 files changed, 8 insertions, 3 deletions

diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index 54547c4668a..809a7274a25 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -1305,7 +1305,8 @@ or \"${ foo }\" will not.")
     "A sequence for recommended version number schemes in Perl.")
 
   (defconst cperl--single-attribute-rx
-    `(sequence ,cperl--basic-identifier-rx
+    `(sequence word-start
+               ,cperl--basic-identifier-rx
                (optional (sequence "("
                           (0+ (not (in ")")))
                           ")")))
@@ -1552,7 +1553,7 @@ the last)."
         (if attr (concat
                   "\\("
                      cperl-maybe-white-and-comment-rex ; whitespace-comments
-                     "\\(\\sw\\|_\\)+"  ; attr-name
+                     "\\(\\<\\sw\\|_\\)+"       ; attr-name
                      ;; attr-arg (1 level of internal parens allowed!)
                      "\\((\\(\\\\.\\|[^\\()]\\|([^\\()]*)\\)*)\\)?"
                      "\\("              ; optional : (XXX allows trailing???)
@@ -6003,7 +6004,11 @@ default function."
                                    ;; ... or the start of a "sloppy" signature
                                    (sequence (eval cperl--sloppy-signature-rx)
                                              ;; arbtrarily continue "a few lines"
-                                             (repeat 0 200 (not (in "{"))))))))
+                                             (repeat 0 200 (not (in "{"))))
+                                   ;; make sure we have a reasonably
+                                   ;; short match for an incomplete sub
+                                   (not (in ";{("))
+                                   buffer-end))))
                   '(1 (if (match-beginning 3)
                           'font-lock-variable-name-face
                         'font-lock-function-name-face)