* Font Locking Preliminaries::
* Faces::
* Doc Comments::
+* Misc Font Locking::
* AWK Mode Font Locking::
Configuration Basics
* Font Locking Preliminaries::
* Faces::
* Doc Comments::
+* Misc Font Locking::
* AWK Mode Font Locking::
@end menu
@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-@node Doc Comments, AWK Mode Font Locking, Faces, Font Locking
+@node Doc Comments, Misc Font Locking, Faces, Font Locking
@comment node-name, next, previous, up
@section Documentation Comments
@cindex documentation comments
If you add support for another doc comment style, please consider
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
+@comment node-name, next, previous, up
+@section Miscellaneous Font Locking
+@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+In some languages, particularly in C++, there are constructs which are
+syntactically ambiguous---they could be either declarations or
+expressions, and @ccmode{} cannot tell for sure which. Often such a
+construct is one of the operators @samp{*} or @samp{&} surrounded by
+two identifiers.
+
+Experience shows that very often when such a construct is a
+declaration it will be written with the operator touching exactly one
+of the identifiers, like:
+
+@example
+foo *bar
+@end example
+or
+@example
+foo& bar
+@end example
+
+. Whether such code is fontified depends on the setting of
+@code{c-asymmetry-fontification-flag}.
+
+@defvar c-asymmetry-fontification-flag
+@vindex asymmetry-fontification-flag (c-)
+When @code{c-asymmetry-fontification-flag} is non-nil (which it is by
+default), code like the above, with white space either before or after
+the operator, but not both, is fontified as a declaration. When the
+variable is nil, such a construct gets the default face.
+@end defvar
+
+When the construct is an expression there will often be white space
+both before and after the operator or there will be no white space
+around it at all, like:
+
+@example
+foo * bar
+@end example
+or
+@example
+foo&bar
+@end example
+.
+
+Such code is not fontified as a declaration. (Typically, the
+identifiers don't get a non-default face.)
+
+For clarity's sake, we emphasize that the ``asymmetry'' rule in this
+section only applies when CC Mode cannot disambiguate a construct in
+any other way.
@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-@node AWK Mode Font Locking, , Doc Comments, Font Locking
+@node AWK Mode Font Locking, , Misc Font Locking, Font Locking
@comment node-name, next, previous, up
@section AWK Mode Font Locking
@comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
(setq pos (point)))))) ; acts to make the `while' form continue.
nil)
+(defun c-get-fontification-context (match-pos not-front-decl &optional toplev)
+ ;; Return a cons (CONTEXT . RESTRICTED-<>-ARGLISTS) for MATCH-POS.
+ ;; NOT-FRONT-DECL is non-nil when a declaration later in the buffer than
+ ;; MATCH-POS has already been parsed. TOPLEV is non-nil when MATCH-POS is
+ ;; known to be at "top level", i.e. outside any braces, or directly inside a
+ ;; namespace, class, etc.
+ ;;
+ ;; CONTEXT is the fontification context of MATCH-POS, and is one of the
+ ;; following:
+ ;; 'decl In a comma-separated declaration context (typically
+ ;; inside a function declaration arglist).
+ ;; '<> In an angle bracket arglist.
+ ;; 'arglist Some other type of arglist.
+ ;; 'top Some other context and point is at the top-level (either
+ ;; outside any braces or directly inside a class or namespace,
+ ;; etc.)
+ ;; nil Some other context or unknown context. Includes
+ ;; within the parens of an if, for, ... construct.
+ ;; 'not-decl Definitely not in a declaration.
+ ;;
+ ;; RESTRICTED-<>-ARGLISTS is non-nil when a scan of template/generic
+ ;; arguments lists (i.e. lists enclosed by <...>) is more strict about what
+ ;; characters it allows within the list.
+ (let ((type (and (> match-pos (point-min))
+ (c-get-char-property (1- match-pos) 'c-type))))
+ (cond ((not (memq (char-before match-pos) '(?\( ?, ?\[ ?< ?{)))
+ (cons (and toplev 'top) nil))
+ ;; A control flow expression or a decltype
+ ((and (eq (char-before match-pos) ?\()
+ (save-excursion
+ (goto-char match-pos)
+ (backward-char)
+ (c-backward-token-2)
+ (or (looking-at c-block-stmt-2-key)
+ (looking-at c-block-stmt-1-2-key)
+ (looking-at c-typeof-key))))
+ (cons nil t))
+ ;; Near BOB.
+ ((<= match-pos (point-min))
+ (cons 'arglist t))
+ ;; Got a cached hit in a declaration arglist.
+ ((eq type 'c-decl-arg-start)
+ (cons 'decl nil))
+ ;; We're inside (probably) a brace list.
+ ((eq type 'c-not-decl)
+ (cons 'not-decl nil))
+ ;; Inside a C++11 lambda function arglist.
+ ((and (c-major-mode-is 'c++-mode)
+ (eq (char-before match-pos) ?\()
+ (save-excursion
+ (goto-char match-pos)
+ (c-backward-token-2)
+ (and
+ (c-safe (goto-char (scan-sexps (point) -1)))
+ (c-looking-at-c++-lambda-capture-list))))
+ (c-put-char-property (1- match-pos) 'c-type
+ 'c-decl-arg-start)
+ (cons 'decl nil))
+ ;; We're inside a brace list.
+ ((and (eq (char-before match-pos) ?{)
+ (save-excursion
+ (goto-char (1- match-pos))
+ (consp
+ (c-looking-at-or-maybe-in-bracelist))))
+ (c-put-char-property (1- match-pos) 'c-type
+ 'c-not-decl)
+ (cons 'not-decl nil))
+ ;; We're inside an "ordinary" open brace.
+ ((eq (char-before match-pos) ?{)
+ (cons (and toplev 'top) nil))
+ ;; Inside an angle bracket arglist.
+ ((or (eq type 'c-<>-arg-sep)
+ (eq (char-before match-pos) ?<))
+ (cons '<> nil))
+ ;; Got a cached hit in some other type of arglist.
+ (type
+ (cons 'arglist t))
+ (not-front-decl
+ ;; The point is within the range of a previously
+ ;; encountered type decl expression, so the arglist
+ ;; is probably one that contains declarations.
+ ;; However, if `c-recognize-paren-inits' is set it
+ ;; might also be an initializer arglist.
+ ;;
+ ;; The result of this check is cached with a char
+ ;; property on the match token, so that we can look
+ ;; it up again when refontifying single lines in a
+ ;; multiline declaration.
+ (c-put-char-property (1- match-pos)
+ 'c-type 'c-decl-arg-start)
+ (cons 'decl nil))
+ ;; Got an open paren preceded by an arith operator.
+ ((and (eq (char-before match-pos) ?\()
+ (save-excursion
+ (and (zerop (c-backward-token-2 2))
+ (looking-at c-arithmetic-op-regexp))))
+ (cons nil nil))
+ ;; At start of a declaration inside a declaration paren.
+ ((save-excursion
+ (and (memq (char-before match-pos) '(?\( ?\,))
+ (c-go-up-list-backward match-pos)
+ (eq (char-after) ?\()
+ (let ((type (c-get-char-property (point) 'c-type)))
+ (or (memq type '(c-decl-arg-start c-decl-type-start))
+ (and
+ (progn (c-backward-syntactic-ws) t)
+ (c-back-over-compound-identifier)
+ (progn
+ (c-backward-syntactic-ws)
+ (or (bobp)
+ (progn
+ (setq type (c-get-char-property (1- (point))
+ 'c-type))
+ (memq type '(c-decl-arg-start
+ c-decl-type-start))))))))))
+ (cons 'decl nil))
+ (t (cons 'arglist t)))))
+
(defun c-font-lock-declarations (limit)
;; Fontify all the declarations, casts and labels from the point to LIMIT.
;; Assumes that strings and comments have been fontified already.
;; "<" for the sake of C++-style template arglists.
;; Ignore "(" when it's part of a control flow construct
;; (e.g. "for (").
- (let ((type (and (> match-pos (point-min))
- (c-get-char-property (1- match-pos) 'c-type))))
- (cond ((not (memq (char-before match-pos) '(?\( ?, ?\[ ?< ?{)))
- (setq context (and toplev 'top)
- c-restricted-<>-arglists nil))
- ;; A control flow expression or a decltype
- ((and (eq (char-before match-pos) ?\()
- (save-excursion
- (goto-char match-pos)
- (backward-char)
- (c-backward-token-2)
- (or (looking-at c-block-stmt-2-key)
- (looking-at c-block-stmt-1-2-key)
- (looking-at c-typeof-key))))
- (setq context nil
- c-restricted-<>-arglists t))
- ;; Near BOB.
- ((<= match-pos (point-min))
- (setq context 'arglist
- c-restricted-<>-arglists t))
- ;; Got a cached hit in a declaration arglist.
- ((eq type 'c-decl-arg-start)
- (setq context 'decl
- c-restricted-<>-arglists nil))
- ;; We're inside (probably) a brace list.
- ((eq type 'c-not-decl)
- (setq context 'not-decl
- c-restricted-<>-arglists nil))
- ;; Inside a C++11 lambda function arglist.
- ((and (c-major-mode-is 'c++-mode)
- (eq (char-before match-pos) ?\()
- (save-excursion
- (goto-char match-pos)
- (c-backward-token-2)
- (and
- (c-safe (goto-char (scan-sexps (point) -1)))
- (c-looking-at-c++-lambda-capture-list))))
- (setq context 'decl
- c-restricted-<>-arglists nil)
- (c-put-char-property (1- match-pos) 'c-type
- 'c-decl-arg-start))
- ;; We're inside a brace list.
- ((and (eq (char-before match-pos) ?{)
- (save-excursion
- (goto-char (1- match-pos))
- (consp
- (c-looking-at-or-maybe-in-bracelist))))
- (setq context 'not-decl
- c-restricted-<>-arglists nil)
- (c-put-char-property (1- match-pos) 'c-type
- 'c-not-decl))
- ;; We're inside an "ordinary" open brace.
- ((eq (char-before match-pos) ?{)
- (setq context (and toplev 'top)
- c-restricted-<>-arglists nil))
- ;; Inside an angle bracket arglist.
- ((or (eq type 'c-<>-arg-sep)
- (eq (char-before match-pos) ?<))
- (setq context '<>
- c-restricted-<>-arglists nil))
- ;; Got a cached hit in some other type of arglist.
- (type
- (setq context 'arglist
- c-restricted-<>-arglists t))
- ((if inside-macro
- (< match-pos max-type-decl-end-before-token)
- (< match-pos max-type-decl-end))
- ;; The point is within the range of a previously
- ;; encountered type decl expression, so the arglist
- ;; is probably one that contains declarations.
- ;; However, if `c-recognize-paren-inits' is set it
- ;; might also be an initializer arglist.
- (setq context 'decl
- c-restricted-<>-arglists nil)
- ;; The result of this check is cached with a char
- ;; property on the match token, so that we can look
- ;; it up again when refontifying single lines in a
- ;; multiline declaration.
- (c-put-char-property (1- match-pos)
- 'c-type 'c-decl-arg-start))
- ;; Got an open paren preceded by an arith operator.
- ((and (eq (char-before match-pos) ?\()
- (save-excursion
- (and (zerop (c-backward-token-2 2))
- (looking-at c-arithmetic-op-regexp))))
- (setq context nil
- c-restricted-<>-arglists nil))
- (t (setq context 'arglist
- c-restricted-<>-arglists t))))
+ (let ((got-context
+ (c-get-fontification-context
+ match-pos
+ (< match-pos (if inside-macro
+ max-type-decl-end-before-token
+ max-type-decl-end))
+ toplev)))
+ (setq context (car got-context)
+ c-restricted-<>-arglists (cdr got-context)))
;; Check we haven't missed a preceding "typedef".
(when (not (looking-at c-typedef-key))
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