Extend electric-pair-mode actions to < and >, and also to ( and ) in literals

* lisp/progmodes/cc-cmds.el (c-electric-lt-gt): Actuate electric-pair-mode if
a < or > is typed in a context where this is meaningful (#include, or
template).
(c-electric-paren): Allow electric-pair-mode activity in a comment or string.

* lisp/progmodes/cc-defs.el (c-make-keywords-re): Fix a bug where lists of
source symbols could get overwritten when parameter adorn is set to
'appendable.

* list/progmodes/cc-langs.el (c-cpp-include-key): New lang const and var.

1 files changed, 13 insertions, 0 deletions

diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 4bd4914a2d7..53342713b4a 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -927,6 +927,19 @@ file name in angle brackets or quotes."
 	   '("include"))
   objc '("include" "import"))
 
+(c-lang-defconst c-cpp-include-key
+  ;; Matches an include directive anchored at BOL including any trailing
+  ;; whitespace, e.g. " # include  "
+  t (if (and (c-lang-const c-anchored-cpp-prefix)
+	     (c-lang-const c-cpp-include-directives))
+	(concat
+	 (c-lang-const c-anchored-cpp-prefix)
+	 (c-make-keywords-re 'appendable
+	   (c-lang-const c-cpp-include-directives))
+	 "[ \t]*")
+      "a\\`"))				; Doesn't match anything
+(c-lang-defvar c-cpp-include-key (c-lang-const c-cpp-include-key))
+
 (c-lang-defconst c-opt-cpp-macro-define
   "Cpp directive (without the prefix) that is followed by a macro
 definition, or nil if the language doesn't have any."