From 757e66afdc1cd4f0a261d368cafd5009e04084a4 Mon Sep 17 00:00:00 2001 From: Alan Mackenzie Date: Sat, 30 Nov 2019 21:22:55 +0000 Subject: [PATCH] CC Mode. Fix fontification bug with unterminated quotes on adjacent lines In particular, with these unterminated quotes on each of two adjacent lines, the following text was spuriously fontified with string face. * lisp/progmodes/cc-defs.el (c-search-backward-char-property-with-value-on-char): New macro. * lisp/progmodes/cc-mode.el (c-clear-string-fences): Check whether there is an unmatched quote at a lower buffer position which should match the current quote, rather than wrongly assuming the latter is unmatched and marking it with a punctuation syntax. (c-font-lock-fontify-region): Ensure all pertinent parts of the buffer have string fence properties applied before performing any syntactic operations on it; in particular, this applies to a quote at an earlier buffer position which "matches" one inside the region about to be fontified. --- lisp/progmodes/cc-defs.el | 23 ++++++++ lisp/progmodes/cc-mode.el | 110 +++++++++++++++++++++++++------------- 2 files changed, 95 insertions(+), 38 deletions(-) diff --git a/lisp/progmodes/cc-defs.el b/lisp/progmodes/cc-defs.el index 6a9371e6f19..c6818819e74 100644 --- a/lisp/progmodes/cc-defs.el +++ b/lisp/progmodes/cc-defs.el @@ -1340,6 +1340,29 @@ nil; point is then left undefined." (search-forward-regexp "\\(\n\\|.\\)") ; to set the match-data. (point)))) +(defmacro c-search-backward-char-property-with-value-on-char + (property value char &optional limit) + "Search backward for a text-property PROPERTY having value VALUE on a +character with value CHAR. +LIMIT bounds the search. The value comparison is done with `equal'. +PROPERTY must be a constant. + +Leave point just before the character, and set the match data on +this character, and return point. If the search fails, return +nil; point is then left undefined." + `(let ((char-skip (concat "^" (char-to-string ,char))) + (-limit- (or ,limit (point-min))) + (-value- ,value)) + (while + (and + (progn (skip-chars-backward char-skip -limit-) + (> (point) -limit-)) + (not (equal (c-get-char-property (1- (point)) ,property) -value-))) + (backward-char)) + (when (> (point) -limit-) + (search-backward-regexp "\\(\n\\|.\\)") ; to set the match-data. + (point)))) + (defmacro c-search-forward-char-property-without-value-on-char (property value char &optional limit) "Search forward for a character CHAR without text property PROPERTY having diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el index 73160fc7a42..7fcc8a6d1c5 100644 --- a/lisp/progmodes/cc-mode.el +++ b/lisp/progmodes/cc-mode.el @@ -1233,6 +1233,15 @@ Note that the style variables are always made local to the buffer." ;; Check we haven't left any unbalanced "s. (save-excursion (setq pos beg) + ;; Is there already an unbalanced " before BEG? + (setq pos (c-min-property-position pos end 'c-fl-syn-tab)) + (when (< pos end) (goto-char pos)) + (when (and (save-match-data + (c-search-backward-char-property-with-value-on-char + 'c-fl-syn-tab '(15) ?\" + (max (- (point) 500) (point-min)))) + (not (equal (c-get-char-property (point) 'syntax-table) '(1)))) + (setq pos (1+ pos))) (while (< pos end) (setq pos (c-min-property-position pos end 'c-fl-syn-tab)) @@ -2234,44 +2243,69 @@ Note that this is a strict tail, so won't match, e.g. \"0x....\".") ;; line was fouled up by context fontification. (save-restriction (widen) - (let (new-beg new-end new-region case-fold-search) - (if (and c-in-after-change-fontification - (< beg c-new-END) (> end c-new-BEG)) - ;; Region and the latest after-change fontification region overlap. - ;; Determine the upper and lower bounds of our adjusted region - ;; separately. - (progn - (if (<= beg c-new-BEG) - (setq c-in-after-change-fontification nil)) - (setq new-beg - (if (and (>= beg (c-point 'bol c-new-BEG)) - (<= beg c-new-BEG)) - ;; Either jit-lock has accepted `c-new-BEG', or has - ;; (probably) extended the change region spuriously to - ;; BOL, which position likely has a syntactically - ;; different position. To ensure correct fontification, - ;; we start at `c-new-BEG', assuming any characters to the - ;; left of `c-new-BEG' on the line do not require - ;; fontification. - c-new-BEG - (setq new-region (c-before-context-fl-expand-region beg end) - new-end (cdr new-region)) - (car new-region))) - (setq new-end - (if (and (>= end (c-point 'bol c-new-END)) - (<= end c-new-END)) - c-new-END - (or new-end - (cdr (c-before-context-fl-expand-region beg end)))))) - ;; Context (etc.) fontification. - (setq new-region (c-before-context-fl-expand-region beg end) - new-beg (car new-region) new-end (cdr new-region))) - (c-save-buffer-state nil - (unwind-protect - (progn (c-restore-string-fences new-beg new-end) - (funcall (default-value 'font-lock-fontify-region-function) - new-beg new-end verbose)) - (c-clear-string-fences)))))) + (let (new-beg new-end new-region case-fold-search string-fence-beg lim) + ;; Check how far back we need to extend the region where we reapply the + ;; string fence syntax-table properties. These must be in place for the + ;; coming fontification operations. + (save-excursion + (goto-char (if c-in-after-change-fontification + (min beg c-new-BEG) + beg)) + (setq lim (max (- (point) 500) (point-min))) + (while + (progn + (skip-chars-backward "^\"" lim) + (or (bobp) (backward-char)) + (save-excursion + (eq (logand (skip-chars-backward "\\\\") 1) 1)))) + (setq string-fence-beg + (cond ((c-get-char-property (point) 'c-fl-syn-tab) + (point)) + (c-in-after-change-fontification + c-new-BEG) + (t beg))) + (c-save-buffer-state nil + ;; Temporarily reapply the string fence syntax-table properties. + (c-with-extended-string-fences + string-fence-beg (if c-in-after-change-fontification + (max end c-new-END) + end) + + (if (and c-in-after-change-fontification + (< beg c-new-END) (> end c-new-BEG)) + ;; Region and the latest after-change fontification region overlap. + ;; Determine the upper and lower bounds of our adjusted region + ;; separately. + (progn + (if (<= beg c-new-BEG) + (setq c-in-after-change-fontification nil)) + (setq new-beg + (if (and (>= beg (c-point 'bol c-new-BEG)) + (<= beg c-new-BEG)) + ;; Either jit-lock has accepted `c-new-BEG', or has + ;; (probably) extended the change region spuriously + ;; to BOL, which position likely has a + ;; syntactically different position. To ensure + ;; correct fontification, we start at `c-new-BEG', + ;; assuming any characters to the left of + ;; `c-new-BEG' on the line do not require + ;; fontification. + c-new-BEG + (setq new-region (c-before-context-fl-expand-region beg end) + new-end (cdr new-region)) + (car new-region))) + (setq new-end + (if (and (>= end (c-point 'bol c-new-END)) + (<= end c-new-END)) + c-new-END + (or new-end + (cdr (c-before-context-fl-expand-region beg end)))))) + ;; Context (etc.) fontification. + (setq new-region (c-before-context-fl-expand-region beg end) + new-beg (car new-region) new-end (cdr new-region))) + ;; Finally invoke font lock's functionality. + (funcall (default-value 'font-lock-fontify-region-function) + new-beg new-end verbose))))))) (defun c-after-font-lock-init () ;; Put on `font-lock-mode-hook'. This function ensures our after-change -- 2.39.5