kernel-doc: support in-line comments on nested structs/unions

The parser at kernel-doc rejects names with dots in the middle.
Fix it, in order to support nested structs/unions.

--
The origin patch comes from Mauro [1] patching kernel-doc (perl)
parser of the Linux tree.

[1] https://www.mail-archive.com/linux-doc@vger.kernel.org/msg18197.html

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

docs/linuxdoc-howto/all-in-a-tumble.h

@@ -148,8 +148,17 @@ struct my_long_struct {
          * Here, the member description may contain several paragraphs.
          */
         int baz;
-        /** @foobar: Single line description. */
-        int foobar;
+	union {
+		/** @foobar: Single line description. */
+		int foobar;
+	};
+	/** @bar2: Description for struct @bar2 inside @my_long_struct */
+	struct {
+		/**
+		 * @bar2.barbar: Description for @barbar inside @foo.bar2
+		 */
+		int barbar;
+	} bar2;
 };
 /* parse-SNAP: */
 

linuxdoc/kernel_doc.py

@@ -157,7 +157,8 @@ def __getitem__(self, group):
 
 # state: 5 - gathering documentation outside main block
 doc_state5_start = RE(r"^\s*/\*\*\s*$")
-doc_state5_sect  = RE(r"\s*\*\s*(@[\w\s]+):(.*)")
+doc_state5_sect  = RE(r"\s*\*\s*(@\s*[\w][\w\.]*\s*):(.*)")
+
 doc_state5_end   = RE(r"^\s*\*/\s*$")
 doc_state5_oneline = RE(r"^\s*/\*\*\s*(@[\w\s]+):\s*(.*)\s*\*/\s*$")