From 79fa7d7b75fa71d4332675ca28608b484731e09a Mon Sep 17 00:00:00 2001 From: Alan Mackenzie Date: Tue, 21 Apr 2015 14:02:10 +0000 Subject: [PATCH] CC Mode: Do nothing in before/after-change-functions for text property changes Fixes bug#20266. lisp/progmodes/cc-mode.el (c-basic-common-init): Make yank-handled-properties buffer local, and remove 'category from it. (c-called-from-text-property-change-p): New function. (c-before-change): Don't do anything if a call of the new function returns non-nil. (c-after-change): Don't do much if a call of the new function returns non-nil. (c-extend-after-change-region): Put changes to text property 'fontified inside c-save-buffer-state. --- lisp/progmodes/cc-mode.el | 128 ++++++++++++++++++++++---------------- 1 file changed, 76 insertions(+), 52 deletions(-) diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el index 1f58ba1ee9b..3c1aec472cd 100644 --- a/lisp/progmodes/cc-mode.el +++ b/lisp/progmodes/cc-mode.el @@ -511,6 +511,14 @@ that requires a literal mode spec at compile time." (set (make-local-variable 'comment-line-break-function) 'c-indent-new-comment-line) + ;; Prevent time-wasting activity on C-y. + (when (boundp 'yank-handled-properties) + (make-local-variable 'yank-handled-properties) + (let ((yank-cat-handler (assq 'category yank-handled-properties))) + (when yank-cat-handler + (setq yank-handled-properties (remq yank-cat-handler + yank-handled-properties))))) + ;; For the benefit of adaptive file, which otherwise mis-fills. (setq fill-paragraph-handle-comment nil) @@ -839,6 +847,18 @@ Note that the style variables are always made local to the buffer." (defvar c-old-EOM 0) (make-variable-buffer-local 'c-old-EOM) +(defun c-called-from-text-property-change-p () + ;; Is the primitive which invoked `before-change-functions' or + ;; `after-change-functions' one which merely changes text properties? This + ;; function must be called directly from a member of one of the above hooks. + ;; + ;; In the following call, frame 0 is `backtrace-frame', frame 1 is + ;; `c-called-from-text-property-change-p', frame 2 is + ;; `c-before/after-change', frame 3 is the primitive invoking the change + ;; hook. + (memq (cadr (backtrace-frame 3)) + '(put-text-property remove-list-of-text-properties))) + (defun c-extend-region-for-CPP (beg end) ;; Set c-old-BOM or c-old-EOM respectively to BEG, END, each extended to the ;; beginning/end of any preprocessor construct they may be in. @@ -1009,8 +1029,9 @@ Note that the style variables are always made local to the buffer." ;; it/them from the cache. Don't worry about being inside a string ;; or a comment - "wrongly" removing a symbol from `c-found-types' ;; isn't critical. - (unless c-just-done-before-change ; Guard against a spurious second - ; invocation of before-change-functions. + (unless (or (c-called-from-text-property-change-p) + c-just-done-before-change) ; guard against a spurious second + ; invocation of before-change-functions. (setq c-just-done-before-change t) (setq c-maybe-stale-found-type nil) (save-restriction @@ -1105,51 +1126,53 @@ Note that the style variables are always made local to the buffer." ;; This calls the language variable c-before-font-lock-functions, if non nil. ;; This typically sets `syntax-table' properties. - (setq c-just-done-before-change nil) - (c-save-buffer-state (case-fold-search open-paren-in-column-0-is-defun-start) - ;; When `combine-after-change-calls' is used we might get calls - ;; with regions outside the current narrowing. This has been - ;; observed in Emacs 20.7. - (save-restriction - (save-match-data ; c-recognize-<>-arglists changes match-data - (widen) - - (when (> end (point-max)) - ;; Some emacsen might return positions past the end. This has been - ;; observed in Emacs 20.7 when rereading a buffer changed on disk - ;; (haven't been able to minimize it, but Emacs 21.3 appears to - ;; work). - (setq end (point-max)) - (when (> beg end) - (setq beg end))) - - ;; C-y is capable of spuriously converting category properties - ;; c--as-paren-syntax and c-cpp-delimiter into hard syntax-table - ;; properties. Remove these when it happens. - (when (eval-when-compile (memq 'category-properties c-emacs-features)) - (c-clear-char-property-with-value beg end 'syntax-table - c-<-as-paren-syntax) - (c-clear-char-property-with-value beg end 'syntax-table - c->-as-paren-syntax) - (c-clear-char-property-with-value beg end 'syntax-table nil)) - - (c-trim-found-types beg end old-len) ; maybe we don't need all of these. - (c-invalidate-sws-region-after beg end) - ;; (c-invalidate-state-cache beg) ; moved to `c-before-change'. - (c-invalidate-find-decl-cache beg) - - (when c-recognize-<>-arglists - (c-after-change-check-<>-operators beg end)) - - ;; (c-new-BEG c-new-END) will be the region to fontify. It may become - ;; larger than (beg end). - (setq c-new-BEG beg - c-new-END end) - (setq c-in-after-change-fontification t) - (save-excursion - (mapc (lambda (fn) - (funcall fn beg end old-len)) - c-before-font-lock-functions)))))) + ;; (c-new-BEG c-new-END) will be the region to fontify. It may become + ;; larger than (beg end). + (setq c-new-BEG beg c-new-END end) + + (unless (c-called-from-text-property-change-p) + (setq c-just-done-before-change nil) + (c-save-buffer-state (case-fold-search open-paren-in-column-0-is-defun-start) + ;; When `combine-after-change-calls' is used we might get calls + ;; with regions outside the current narrowing. This has been + ;; observed in Emacs 20.7. + (save-restriction + (save-match-data ; c-recognize-<>-arglists changes match-data + (widen) + + (when (> end (point-max)) + ;; Some emacsen might return positions past the end. This has been + ;; observed in Emacs 20.7 when rereading a buffer changed on disk + ;; (haven't been able to minimize it, but Emacs 21.3 appears to + ;; work). + (setq end (point-max)) + (when (> beg end) + (setq beg end))) + + ;; C-y is capable of spuriously converting category properties + ;; c--as-paren-syntax and c-cpp-delimiter into hard syntax-table + ;; properties. Remove these when it happens. + (when (eval-when-compile (memq 'category-properties c-emacs-features)) + (c-save-buffer-state () + (c-clear-char-property-with-value beg end 'syntax-table + c-<-as-paren-syntax) + (c-clear-char-property-with-value beg end 'syntax-table + c->-as-paren-syntax) + (c-clear-char-property-with-value beg end 'syntax-table nil))) + + (c-trim-found-types beg end old-len) ; maybe we don't need all of these. + (c-invalidate-sws-region-after beg end) + ;; (c-invalidate-state-cache beg) ; moved to `c-before-change'. + (c-invalidate-find-decl-cache beg) + + (when c-recognize-<>-arglists + (c-after-change-check-<>-operators beg end)) + + (setq c-in-after-change-fontification t) + (save-excursion + (mapc (lambda (fn) + (funcall fn beg end old-len)) + c-before-font-lock-functions))))))) (defun c-fl-decl-start (pos) ;; If the beginning of the line containing POS is in the middle of a "local" @@ -1322,7 +1345,7 @@ This function is called from `c-common-init', once per mode initialization." (add-hook 'font-lock-mode-hook 'c-after-font-lock-init nil t)) ;; Emacs 22 and later. -(defun c-extend-after-change-region (_beg _end _old-len) +(defun c-extend-after-change-region (beg end _old-len) "Extend the region to be fontified, if necessary." ;; Note: the parameter OLD-LEN is ignored here. This somewhat indirect ;; implementation exists because it is minimally different from the @@ -1336,10 +1359,11 @@ This function is called from `c-common-init', once per mode initialization." (when (eq font-lock-support-mode 'jit-lock-mode) (save-restriction (widen) - (if (< c-new-BEG beg) - (put-text-property c-new-BEG beg 'fontified nil)) - (if (> c-new-END end) - (put-text-property end c-new-END 'fontified nil)))) + (c-save-buffer-state () ; Protect the undo-list from put-text-property. + (if (< c-new-BEG beg) + (put-text-property c-new-BEG beg 'fontified nil)) + (if (> c-new-END end) + (put-text-property end c-new-END 'fontified nil))))) (cons c-new-BEG c-new-END)) ;; Emacs < 22 and XEmacs -- 2.39.5