json-writer: provide the way to define extra key and value pair

With the original code, json-writer emits the following form for
TAG_ROLE_DESCRIPTION:

      {"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION",
			"parserName": "LANG!KIND", ...

This commit is PREPARATION for changing the form like:

      {"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION",
			"parserName": "LANG",
			"kindName": "KIND", ...

In the "parserName" field, two values are embedded.  With this change,
by specifying jsonObjectKey in the ptag definition, json-writer split
the value for parserName into two subvalues.  The first subvalue is
for "parserName" key, and the second subvalue is for the key specified
with jsonObjectKey.

This extension is for newer file format. So it is disabled now.

Signed-off-by: Masatake YAMATO <[email protected]>

Author: masatake

main/ptag_p.h

@@ -69,6 +69,9 @@ struct sPtagDesc {
 	bool (* makeTag) (ptagDesc *, langType, const void *);
 
 	ptagFlag flags;
+
+	/* See writer-json.c */
+	const char *jsonObjectKey;
 };
 
 extern bool makePtagIfEnabled (ptagType type, langType language, const void *data);

main/writer-json.c

@@ -241,8 +241,23 @@ static int writeJsonPtagEntry (tagWriter *writer CTAGS_ATTR_UNUSED,
 {
 #define OPT(X) ((X)?(X):"")
 	json_t *response;
+	char *parserName0 = NULL;
 
-	if (parserName)
+	const char *rest = ((JSON_WRITER_MAJOR > 0) && parserName && desc->jsonObjectKey)
+		? strchr(parserName, '!')
+		: NULL;
+	if (rest)
+	{
+		parserName0 = eStrndup(parserName, rest - parserName);
+		response = json_pack ("{ss ss ss ss ss ss}",
+				      "_type", "ptag",
+				      "name", desc->name,
+				      "parserName", parserName0,
+				      desc->jsonObjectKey, rest + 1,
+				      "path", OPT(fileName),
+				      "pattern", OPT(pattern));
+	}
+	else if (parserName)
 	{
 		response = json_pack ("{ss ss ss ss ss}",
 				      "_type", "ptag",
@@ -264,6 +279,8 @@ static int writeJsonPtagEntry (tagWriter *writer CTAGS_ATTR_UNUSED,
 	int length = mio_printf (mio, "%s\n", buf);
 	free (buf);
 	json_decref (response);
+	if (parserName0)
+		eFree(parserName0);
 
 	return length;
 #undef OPT