This fixes bug #4192.
* etc/NEWS: Add a new entry.
* lisp/progmodes/cc-defs.el (c-font-lock-flush): New macro.
* lisp/progmodes/cc-cmds.el (c-toggle-comment-style): On toggling the comment
style, invoke c-font-lock-flush when c-mark-wrong-style-of-comment is non-nil,
to cause that marking to be done instead on the other style of comment.
* lisp/progmodes/cc-fonts.el (c-maybe-font-lock-wrong-style-comments): New
function.
(c-cpp-matchers): Call c-maybe-font-lock-wrong-style-comments when
appropriate.
* lisp/progmodes/cc-vars.el (c-mark-wrong-style-of-comment): New customizable
option.
* doc/misc/cc-mode.texi (top level, Indentation Commands, Guessing the Style,
Custom Macros): For some opening quote marks, correct '' to ``.
(Minor Modes): Add an xref to the new page "Wrong Comment Style" in a
footnote.
(Wrong Comment Style): New page.
syntactic recognition can be wrong. @ccmode{} manages to figure it
out correctly most of the time, though.
-Some macros, when invoked, ''have their own semicolon''. To get the
+Some macros, when invoked, ``have their own semicolon''. To get the
next line indented correctly, rather than as a continuation line,
@xref{Macros with ;}.
@table @asis
@item comment style
This specifies whether comment commands (such as @kbd{M-;}) insert
-block comments or line comments.
+block comments or line comments@footnote{You can emphasize
+non-default style comments in your code by giving their delimiters
+@code{font-lock-warning-face}. @xref{Wrong Comment Style}.}.
@item electric mode
When this is enabled, certain visible characters cause reformatting as
they are typed. This is normally helpful, but can be a nuisance when
* Font Locking Preliminaries::
* Faces::
* Doc Comments::
+* Wrong Comment Style::
* Misc Font Locking::
* AWK Mode Font Locking::
@end menu
@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-@node Doc Comments, Misc Font Locking, Faces, Font Locking
+@node Doc Comments, Wrong Comment Style, Faces, Font Locking
@comment node-name, next, previous, up
@section Documentation Comments
@cindex documentation comments
contributing it: send a note to @email{bug-cc-mode@@gnu.org}.
@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-@node Misc Font Locking, AWK Mode Font Locking, Doc Comments, Font Locking
+@node Wrong Comment Style, Misc Font Locking, Doc Comments, Font Locking
+@comment node-name, next, previous, up
+@section Marking ``Wrong'' style comments
+@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+Most languages supported by @ccmode{} have two styles of comments,
+namely block comments and line comments. Your project may have such a
+strong preference for one of them, that you wish ``wrong'' style
+comments to be clearly marked.
+
+You can get @ccmode{} to do this by setting the default comment style,
+if necessary, (@pxref{Minor Modes}) and setting the customizable
+option @code{c-mark-wrong-style-of-comment} to non-@code{nil}.
+
+@defvar c-mark-wrong-style-of-comment
+@vindex mark-wrong-style-of-comment (c-)
+When this customizable option is non-@code{nil}, comment delimiters
+which aren't of the default style will be fontified with
+@code{font-lock-warning-face}.
+@end defvar
+
+@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+@node Misc Font Locking, AWK Mode Font Locking, Wrong Comment Style, Font Locking
@comment node-name, next, previous, up
@section Miscellaneous Font Locking
@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Instead of specifying a style, you can get @ccmode{} to @dfn{guess}
your style by examining an already formatted code buffer. @ccmode{}
-then determines the ''most frequent'' offset (@pxref{c-offsets-alist})
+then determines the ``most frequent'' offset (@pxref{c-offsets-alist})
for each of the syntactic symbols (@pxref{Indentation Engine Basics})
-encountered in the buffer, and the ''most frequent'' value of
+encountered in the buffer, and the ``most frequent'' value of
c-basic-offset (@pxref{Customizing Indentation}), then merges the
-current style with these ''guesses'' to form a new style. This
+current style with these ``guesses'' to form a new style. This
combined style is known as the @dfn{guessed style}.
To do this, call @code{c-guess} (or one of the other 5 guessing
Because a macro can expand into anything at all, near where one is
invoked @ccmode{} can only indent and fontify code heuristically.
Sometimes it gets it wrong. Usually you should try to design your
-macros so that they ''look like ordinary code'' when you invoke them.
+macros so that they ``look like ordinary code'' when you invoke them.
However, two situations are so common that @ccmode{} handles them
specially: that is when certain macros needn't (or mustn't) be
followed by a @samp{;}, and when certain macros (or compiler
*** Declare 'define-overload' and 'define-child-mode' as obsolete
*** Rename several internal functions to use a ''mode-local-' prefix
+** CC Mode
+
++++
+*** You can now flag "wrong style" comments with font-lock-warning-face.
+To do this, use c-toggle-comment-style, if needed, to set the desired
+default comment style (block or line); then set the option
+c-mark-wrong-style-of-comment to non-nil.
+
\f
* New Modes and Packages in Emacs 27.1
(if c-block-comment-flag
(concat " " c-block-comment-ender)
""))
+ ;; If necessary, invert the sense of fontification of wrong style comments.
+ (when (and c-mark-wrong-style-of-comment
+ font-lock-mode
+ c-block-comment-starter
+ c-block-comment-ender)
+ (save-excursion
+ (save-restriction
+ (widen)
+ (goto-char (point-min))
+ (c-font-lock-flush (point-min) (point-max)))))
(c-update-modeline)
(c-keep-region-active))
`(cl-delete-duplicates ,cl-seq ,@cl-keys)
`(delete-duplicates ,cl-seq ,@cl-keys))))
+(defmacro c-font-lock-flush (beg end)
+ "Declare the region BEG...END's fontification as out-of-date.
+On XEmacs and older Emacsen, this refontifies that region immediately."
+ (if (fboundp 'font-lock-flush)
+ `(font-lock-flush ,beg ,end)
+ `(font-lock-fontify-region ,beg ,end)))
+
(defmacro c-point (position &optional point)
"Return the value of certain commonly referenced POSITIONs relative to POINT.
The current point is used if POINT isn't specified. POSITION can be
;; during compilation.
(cc-bytecomp-defvar c-preprocessor-face-name)
(cc-bytecomp-defvar c-reference-face-name)
+(cc-bytecomp-defvar c-block-comment-flag)
(cc-bytecomp-defun c-fontify-recorded-types-and-refs)
(cc-bytecomp-defun c-font-lock-declarators)
(cc-bytecomp-defun c-font-lock-objc-method)
(sws-depth (c-lang-const c-syntactic-ws-depth))
(nsws-depth (c-lang-const c-nonempty-syntactic-ws-depth)))
- `(;; The stuff after #error and #warning is a message, so
+ `(;; Fontify "invalid" comment delimiters
+ ,@(when (and (c-lang-const c-block-comment-starter)
+ (c-lang-const c-line-comment-starter))
+ `(c-maybe-font-lock-wrong-style-comments))
+
+ ;; The stuff after #error and #warning is a message, so
;; fontify it as a string.
,@(when (c-lang-const c-cpp-message-directives)
(let* ((re (c-make-keywords-re 'appendable ; nil
(parse-partial-sexp end limit nil nil state 'syntax-table)))
nil)
+(defun c-maybe-font-lock-wrong-style-comments (limit)
+ ;; This function will be called from font-lock-for a region bounded by POINT
+ ;; and LIMIT, as though it were to identify a keyword for
+ ;; font-lock-keyword-face. It always returns NIL to inhibit this and
+ ;; prevent a repeat invocation. See elisp/lispref page "Search-based
+ ;; Fontification".
+ ;;
+ ;; This function fontifies "invalid" comment delimiters with
+ ;; `font-lock-warning-face'. A delimiter is "invalid" when
+ ;; `c-mark-wrong-style-of-comment' is non-nil, and the delimiter style is
+ ;; not the default specified by `c-block-comment-flag'.
+ (when c-mark-wrong-style-of-comment
+ (let* ((lit (c-semi-pp-to-literal (point)))
+ (s (car lit)) ; parse-partial-sexp state.
+ )
+ ;; First, deal with and move out of any literal we start in.
+ (cond
+ ((null (cadr lit))) ; Not in a literal
+ ((eq (cadr lit) 'string)
+ (setq s (parse-partial-sexp (point) limit nil nil s 'syntax-table)))
+ ((and (not c-block-comment-flag) ; In an "invalid" block comment
+ (eq (cadr lit) 'c))
+ (setq s (parse-partial-sexp (point) limit nil nil s 'syntax-table))
+ ;; Font lock the block comment ender with warning face.
+ (when (not (nth 4 s))
+ (c-put-font-lock-face (- (point) (length c-block-comment-ender))
+ (point) font-lock-warning-face)))
+ (t ; In a line comment, or a "valid" block comment
+ (setq s (parse-partial-sexp (point) limit nil nil s 'syntax-table))))
+
+ (while (< (point) limit)
+ (setq s (parse-partial-sexp (point) limit nil nil s 'syntax-table))
+ (cond
+ ((or (nth 3 s) ; In a string
+ (and (nth 4 s) ; In a comment
+ (eq (nth 7 s) ; Comment style
+ (if c-block-comment-flag
+ nil ; Block comment
+ 1)))) ; Line comment
+ ;; Move over a "valid" literal.
+ (setq s (parse-partial-sexp (point) limit nil nil s 'syntax-table)))
+ ((nth 4 s) ; In an invalid comment
+ ;; Fontify the invalid comment opener.
+ (c-put-font-lock-face (nth 8 s) (point) font-lock-warning-face)
+ ;; Move to end of comment or LIMIT.
+ (setq s (parse-partial-sexp (point) limit nil nil s 'syntax-table))
+ ;; Fontify an invalid block comment ender, if that's what we have.
+ (when (and (not c-block-comment-flag)
+ (not (nth 4 s))) ; We're outside the comment
+ (c-put-font-lock-face (- (point) (length c-block-comment-ender))
+ (point) font-lock-warning-face)))))))
+ nil)
+
(c-lang-defconst c-basic-matchers-before
"Font lock matchers for basic keywords, labels, references and various
other easily recognizable things that should be fontified before generic
c-macro-names-with-semicolon: %s"
c-macro-names-with-semicolon))))))
+(defcustom c-mark-wrong-style-of-comment nil
+ "Fontify \"invalid\" comment delims with `font-lock-warning-face' if non-nil.
+\"Invalid\" means a line comment when the default comment style (set by
+`c-toggle-comment-style') is block, or a block comment otherwise."
+ :type 'boolean
+ :group 'c
+ :version 27.1)
+
(defvar c-file-style nil
"Variable interface for setting style via File Local Variables.
In a file's Local Variable section, you can set this variable to a
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