Get rid of verilog-no-change-functions

[Stefan Monnier <monnier@iro.umontreal.ca>]

I believe the patch below replaces a workaround with an actual fix.

It's indeed unsafe to call syntax-ppss when before-change-functions is
let-bound, but the patch avoids the problem by not let-binding
before-change-functions, relying on the cleaner
inhibit-modification-hooks, which was introduced way back in Emacs-21
for similar reasons.

Any objection to my applying this to Emacs's version of verilog-mode.el?


        Stefan


diff --git a/lisp/progmodes/verilog-mode.el b/lisp/progmodes/verilog-mode.el
index 5fcdba6..0f90d60 100644
--- a/lisp/progmodes/verilog-mode.el
+++ b/lisp/progmodes/verilog-mode.el
@@ -408,10 +408,6 @@ This function may be removed when Emacs 21 is no longer supported."
 	    ;; And GNU Emacs 22 has obsoleted last-command-char
 	    last-command-event)))
 
-(defvar verilog-no-change-functions nil
-  "True if `after-change-functions' is disabled.
-Use of `syntax-ppss' may break, as ppss's cache may get corrupted.")
-
 (defvar verilog-in-hooks nil
   "True when within a `verilog-run-hooks' block.")
 
@@ -422,14 +418,13 @@ Set `verilog-in-hooks' during this time, to assist AUTO caches."
      (run-hooks ,@hooks)))
 
 (defun verilog-syntax-ppss (&optional pos)
-  (when verilog-no-change-functions
-    (if verilog-in-hooks
-	(verilog-scan-cache-flush)
-      ;; else don't let the AUTO code itself get away with flushing the cache,
-      ;; as that'll make things very slow
-      (backtrace)
-      (error "%s: Internal problem; use of syntax-ppss when cache may be corrupt"
-	     (verilog-point-text))))
+  (if verilog-in-hooks
+      (verilog-scan-cache-flush)
+    ;; else don't let the AUTO code itself get away with flushing the cache,
+    ;; as that'll make things very slow
+    (backtrace)
+    (error "%s: Internal problem; use of syntax-ppss when cache may be corrupt"
+           (verilog-point-text)))
   (if (fboundp 'syntax-ppss)
       (syntax-ppss pos)
     (parse-partial-sexp (point-min) (or pos (point)))))
@@ -3230,9 +3225,7 @@ user-visible changes to the buffer must not be within a
 	  (buffer-undo-list t)
 	  (inhibit-read-only t)
 	  (inhibit-point-motion-hooks t)
-	  (verilog-no-change-functions t)
-	  before-change-functions
-	  after-change-functions
+	  (inhibit-modification-hooks t)
 	  deactivate-mark
 	  buffer-file-name ; Prevent primitives checking
 	  buffer-file-truename)	; for file modification
@@ -3246,9 +3239,7 @@ user-visible changes to the buffer must not be within a
   "Execute BODY forms, disabling all change hooks in BODY.
 For insignificant changes, see instead `verilog-save-buffer-state'."
   `(let* ((inhibit-point-motion-hooks t)
-	  (verilog-no-change-functions t)
-	  before-change-functions
-	  after-change-functions)
+	  (inhibit-modification-hooks t))
      (progn ,@body)))
 
 (defvar verilog-save-font-mod-hooked nil