Fontify CPP expressions correctly when starting in the middle of such a

construct.  Mainly for when jit-lock etc. starts a chunk here.

cc-fonts.el (c-font-lock-context): new buffer local variable.
(c-make-font-lock-search-form): new function, extracted from
c-make-font-lock-search-function.
(c-make-font-lock-search-function): Use the above function.
(c-make-font-lock-context-search-function): New function.
(c-cpp-matchers): Enhance the preprocessor expression case with the above
function
(c-font-lock-complex-decl-prepare):  Test for being in a CPP form which
takes an expression.

cc-langs.el (c-cpp-expr-intro-re): New lang-variable.

1 files changed, 10 insertions, 0 deletions

diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 35097242cb7..153ef0880c7 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -815,6 +815,16 @@ expression."
   t (if (c-lang-const c-opt-cpp-prefix)
 	'("if" "elif")))
 
+(c-lang-defconst c-cpp-expr-intro-re
+  "Regexp which matches the start of a CPP directive which contains an
+expression, or nil if there aren't any in the language."
+  t (if (c-lang-const c-cpp-expr-directives)
+	(concat
+	 (c-lang-const c-opt-cpp-prefix)
+	 (c-make-keywords-re t (c-lang-const c-cpp-expr-directives)))))
+(c-lang-defvar c-cpp-expr-intro-re
+  (c-lang-const c-cpp-expr-intro-re))
+
 (c-lang-defconst c-cpp-expr-functions
   "List of functions in cpp expressions."
   t    (if (c-lang-const c-opt-cpp-prefix)