Correctly fontify C++ direct initializations with parens inside functions

Or, more clearly, when something looks like a function declaration and it's
inside a function, fontify it as a direct initialization.

For this purpose, introduce a "brace stack" for each buffer, where an entry on
the brace stack states how deeply nested a particular position is inside
braces inside a "top level", which includes classes and namespaces.

Also introduce a new "context", "top", with which c-font-lock-declarations
signals to c-forward-decl-or-cast-1 that point is at the top level.

* lisp/progmodes/cc-langs.el (c-get-state-before-change-functions): add
c-truncate-bs-cache.
(c-flat-decl-block-kwds, c-brace-stack-thing-key, c-brace-stack-no-semi-key)
(c-type-decl-operator-prefix-key): new language constants/variables.

* lisp/progmodes/cc-engine.el (c-bs-interval, c-bs-cache, c-bs-cache-limit)
(c-bs-prev-pos, c-bs-prev-stack): New mostly local variables for the brace
stack cache.
(c-init-bs-cache, c-truncate-bs-cache, c-truncate-bs-cache, c-brace-stack-at)
(c-bs-at-toplevel-p): New functions which manipulate the brace stack (cache).
(c-find-decl-prefix-search): Keep track of whether we're at top level.
(c-find-decl-spots): New local variable cfd-top-level which records what it
says.  On calling cfd-fun, pass cfd-top-level as an additional argument.
(c-forward-declarator): Add new element DECORATED to the result list.  Set it
to non-nil when a match for c-type-decl-operator-prefix-key is found.
(c-forward-decl-or-cast-1): Handle the newly introduced context "top".
Introduce "CASE 9.5", which recognizes direct initializations.

* lisp/progmodes/cc-fonts.el (c-font-lock-complex-decl-prepare)
(c-font-lock-enum-tail, c-font-lock-cut-off-declarators)
(c-font-lock-enclosing-decls, c-simple-decl-matchers, c-basic-matchers-after):
Add appropriate `not-top' argument to calls to c-font-lock-declarators.
(c-font-lock-declarators): Additional parameter `not-top'.  Use not-top to
participate in the decision whether to fontify an identifier as a function or
a variable.
(c-font-lock-declarations): The internal lambda function takes an additional
argument `toplev' from c-find-decl-spots, which it uses in determining the
"context" of a declaration.  Add appropriate `not-top' argument to calls to
c-font-lock-declarators.
(c-font-lock-objc-methods): Add extra parameter to internal lambda function,
like for c-font-lock-declarators.

* lisp/progmodes/cc-mode.el (c-basic-common-init): Initialize the brace stack
cache.

1 files changed, 61 insertions, 2 deletions

diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index ae6e6a3071f..3c328489ec1 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -479,10 +479,12 @@ so that all identifiers are recognized as words.")
 	c-before-change-check-<>-operators
 	c-depropertize-CPP
 	c-before-after-change-digit-quote
-	c-invalidate-macro-cache)
+	c-invalidate-macro-cache
+	c-truncate-bs-cache)
   (c objc) '(c-extend-region-for-CPP
 	     c-depropertize-CPP
-	     c-invalidate-macro-cache)
+	     c-invalidate-macro-cache
+	     c-truncate-bs-cache)
   ;; java 'c-before-change-check-<>-operators
   awk 'c-awk-record-region-clear-NL)
 (c-lang-defvar c-get-state-before-change-functions
@@ -2588,6 +2590,41 @@ Note that Java specific rules are currently applied to tell this from
 (c-lang-defvar c-opt-inexpr-brace-list-key
   (c-lang-const c-opt-inexpr-brace-list-key))
 
+(c-lang-defconst c-flat-decl-block-kwds
+  ;; Keywords that can introduce another declaration level, i.e. where a
+  ;; following "{" isn't a function block or brace list.  Note that, for
+  ;; historical reasons, `c-decl-block-key' is NOT constructed from this lang
+  ;; const.
+  t (c--delete-duplicates
+     (append (c-lang-const c-class-decl-kwds)
+	     (c-lang-const c-other-block-decl-kwds)
+	     (c-lang-const c-inexpr-class-kwds))
+     :test 'string-equal))
+
+(c-lang-defconst c-brace-stack-thing-key
+  ;; Regexp matching any keyword or operator relevant to the brace stack (see
+  ;; `c-update-brace-stack' in cc-engine.el).
+  t (c-make-keywords-re 'appendable
+      (append
+       (c-lang-const c-flat-decl-block-kwds)
+       (if (c-lang-const c-recognize-<>-arglists)
+	   '("{" "}" ";" "," ")" ":" "<")
+	 '("{" "}" ";" "," ")" ":")))))
+(c-lang-defvar c-brace-stack-thing-key (c-lang-const c-brace-stack-thing-key))
+
+(c-lang-defconst c-brace-stack-no-semi-key
+  ;; Regexp matching any keyword or operator relevant to the brace stack when
+  ;; a semicolon is not relevant (see `c-update-brace-stack' in
+  ;; cc-engine.el).
+  t (c-make-keywords-re 'appendable
+      (append
+       (c-lang-const c-flat-decl-block-kwds)
+       (if (c-lang-const c-recognize-<>-arglists)
+	   '("{" "}" "<")
+	 '("{" "}")))))
+(c-lang-defvar c-brace-stack-no-semi-key
+  (c-lang-const c-brace-stack-no-semi-key))
+
 (c-lang-defconst c-decl-block-key
   ;; Regexp matching keywords in any construct that contain another
   ;; declaration level, i.e. that isn't followed by a function block
@@ -3031,6 +3068,28 @@ Identifier syntax is in effect when this is matched \(see
 (c-lang-defvar c-type-decl-prefix-key (c-lang-const c-type-decl-prefix-key)
   'dont-doc)
 
+(c-lang-defconst c-type-decl-operator-prefix-key
+  "Regexp matching any declarator operator which isn't a keyword
+that might precede the identifier in a declaration, e.g. the
+\"*\" in \"char *argv\".  The end of the first submatch is taken
+as the end of the operator.  Identifier syntax is in effect when
+this is matched \(see `c-identifier-syntax-table')."
+  t ;; Default to a regexp that never matches.
+    "\\<\\>"
+  ;; Check that there's no "=" afterwards to avoid matching tokens
+  ;; like "*=".
+  (c objc) (concat "\\(\\*\\)"
+		   "\\([^=]\\|$\\)")
+  c++  (concat "\\("
+	       "\\.\\.\\."
+	       "\\|"
+	       "\\*"
+	       "\\)"
+	       "\\([^=]\\|$\\)")
+  pike "\\(\\*\\)\\([^=]\\|$\\)")
+(c-lang-defvar c-type-decl-operator-prefix-key
+  (c-lang-const c-type-decl-operator-prefix-key))
+
 (c-lang-defconst c-type-decl-suffix-key
   "Regexp matching the declarator operators that might follow after the
 identifier in a declaration, e.g. the \"[\" in \"char argv[]\".  This