cc-mode: add support for Doxygen documentation style

* lisp/progmodes/cc-fonts.el (doxygen-font-lock-doc-comments,
  doxygen-font-lock-keywords): New constants defining Doxygen
  comment style support.
* lisp/progmodes/cc-vars.el (c-doc-comment-style): Updated docstring
  to mention now-supported Doxygen mode.

1 files changed, 15 insertions, 1 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 8fc23111590..753b7a7fd36 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -198,7 +198,6 @@ like cell phones, tablets or cameras.
 Previously, assigning a new template to an already defined tag had no
 effect.
 
-
 ** map.el
 
 *** Pcase 'map' pattern added keyword symbols abbreviation.
@@ -288,6 +287,21 @@ prefix on the Subject line in various languages.
 These new navigation commands are bound to 'n' and 'p' in
 'apropos-mode'.
 
+** cc-mode
+
+*** Added support for Doxygen documentation style.
+‘doxygen’ is now valid ‘c-doc-comment-style’ which recognises all
+comment styles supported by Doxygen (namely ‘///’, ‘//!’, ‘/** … */’
+and ‘/*! … */’.  ‘gtkdoc’ remains the default for C and C++ modes; to
+use ‘doxygen’ by default one might evaluate:
+
+    (setq-default c-doc-comment-style
+                  '((java-mode . javadoc)
+                    (pike-mode . autodoc)
+                    (c-mode    . doxygen)
+                    (c++-mode  . doxygen)))
+
+or use it in a custom ‘c-style’.
 
 * New Modes and Packages in Emacs 28.1