diff -Naurp c.c c.c
--- c.c	2009-07-04 21:02:43.000000000 -0700
+++ c.c	2019-03-30 20:52:42.000000000 -0700
@@ -619,7 +619,7 @@ static const char *keywordString (const 
 	return name;
 }
 
-static void __unused__ pt (tokenInfo *const token)
+static void __ctags__unused__ pt (tokenInfo *const token)
 {
 	if (isType (token, TOKEN_NAME))
 		printf ("type: %-12s: %-13s   line: %lu\n",
@@ -634,7 +634,7 @@ static void __unused__ pt (tokenInfo *co
 			tokenString (token->type), token->lineNumber);
 }
 
-static void __unused__ ps (statementInfo *const st)
+static void __ctags__unused__ ps (statementInfo *const st)
 {
 	unsigned int i;
 	printf ("scope: %s   decl: %s   gotName: %s   gotParenName: %s\n",
diff -Naurp eiffel.c eiffel.c
--- eiffel.c	2009-06-28 16:09:31.000000000 -0700
+++ eiffel.c	2019-03-30 20:52:42.000000000 -0700
@@ -803,7 +803,7 @@ static void findKeyword (tokenInfo *cons
 
 static boolean parseType (tokenInfo *const token);
 
-static void parseGeneric (tokenInfo *const token, boolean declaration __unused__)
+static void parseGeneric (tokenInfo *const token, boolean declaration __ctags__unused__)
 {
 	unsigned int depth = 0;
 #ifdef TYPE_REFERENCE_TOOL
diff -Naurp general.h general.h
--- general.h	2007-05-02 20:21:08.000000000 -0700
+++ general.h	2019-03-30 20:52:42.000000000 -0700
@@ -57,10 +57,10 @@
  *  to prevent warnings about unused variables.
  */
 #if (__GNUC__ > 2  ||  (__GNUC__ == 2  &&  __GNUC_MINOR__ >= 7)) && !defined (__GNUG__)
-# define __unused__  __attribute__((unused))
+# define __ctags__unused__  __attribute__((unused))
 # define __printf__(s,f)  __attribute__((format (printf, s, f)))
 #else
-# define __unused__
+# define __ctags__unused__
 # define __printf__(s,f)
 #endif
 
diff -Naurp lregex.c lregex.c
--- lregex.c	2007-09-09 19:36:48.000000000 -0700
+++ lregex.c	2019-03-30 20:52:42.000000000 -0700
@@ -538,11 +538,11 @@ extern void findRegexTags (void)
 #endif  /* HAVE_REGEX */
 
 extern void addTagRegex (
-		const langType language __unused__,
-		const char* const regex __unused__,
-		const char* const name __unused__,
-		const char* const kinds __unused__,
-		const char* const flags __unused__)
+		const langType language __ctags__unused__,
+		const char* const regex __ctags__unused__,
+		const char* const name __ctags__unused__,
+		const char* const kinds __ctags__unused__,
+		const char* const flags __ctags__unused__)
 {
 #ifdef HAVE_REGEX
 	Assert (regex != NULL);
@@ -564,10 +564,10 @@ extern void addTagRegex (
 }
 
 extern void addCallbackRegex (
-		const langType language __unused__,
-		const char* const regex __unused__,
-		const char* const flags __unused__,
-		const regexCallback callback __unused__)
+		const langType language __ctags__unused__,
+		const char* const regex __ctags__unused__,
+		const char* const flags __ctags__unused__,
+		const regexCallback callback __ctags__unused__)
 {
 #ifdef HAVE_REGEX
 	Assert (regex != NULL);
@@ -581,7 +581,7 @@ extern void addCallbackRegex (
 }
 
 extern void addLanguageRegex (
-		const langType language __unused__, const char* const regex __unused__)
+		const langType language __ctags__unused__, const char* const regex __ctags__unused__)
 {
 #ifdef HAVE_REGEX
 	if (! regexBroken)
@@ -602,7 +602,7 @@ extern void addLanguageRegex (
 */
 
 extern boolean processRegexOption (const char *const option,
-								   const char *const parameter __unused__)
+								   const char *const parameter __ctags__unused__)
 {
 	boolean handled = FALSE;
 	const char* const dash = strchr (option, '-');
@@ -624,7 +624,7 @@ extern boolean processRegexOption (const
 	return handled;
 }
 
-extern void disableRegexKinds (const langType language __unused__)
+extern void disableRegexKinds (const langType language __ctags__unused__)
 {
 #ifdef HAVE_REGEX
 	if (language <= SetUpper  &&  Sets [language].count > 0)
@@ -639,8 +639,8 @@ extern void disableRegexKinds (const lan
 }
 
 extern boolean enableRegexKind (
-		const langType language __unused__,
-		const int kind __unused__, const boolean mode __unused__)
+		const langType language __ctags__unused__,
+		const int kind __ctags__unused__, const boolean mode __ctags__unused__)
 {
 	boolean result = FALSE;
 #ifdef HAVE_REGEX
@@ -660,7 +660,7 @@ extern boolean enableRegexKind (
 	return result;
 }
 
-extern void printRegexKinds (const langType language __unused__, boolean indent __unused__)
+extern void printRegexKinds (const langType language __ctags__unused__, boolean indent __ctags__unused__)
 {
 #ifdef HAVE_REGEX
 	if (language <= SetUpper  &&  Sets [language].count > 0)
diff -Naurp lua.c lua.c
--- lua.c	2006-10-11 20:26:40.000000000 -0700
+++ lua.c	2019-03-30 20:52:42.000000000 -0700
@@ -37,7 +37,7 @@ static kindOption LuaKinds [] = {
 */
 
 /* for debugging purposes */
-static void __unused__ print_string (char *p, char *q)
+static void __ctags__unused__ print_string (char *p, char *q)
 {
 	for ( ; p != q; p++)
 		fprintf (errout, "%c", *p);
diff -Naurp main.c main.c
--- main.c	2007-06-06 21:35:21.000000000 -0700
+++ main.c	2019-03-30 20:52:42.000000000 -0700
@@ -522,7 +522,7 @@ static void makeTags (cookedArgs *args)
  *		Start up code
  */
 
-extern int main (int __unused__ argc, char **argv)
+extern int main (int __ctags__unused__ argc, char **argv)
 {
 	cookedArgs *args;
 #ifdef VMS
diff -Naurp options.c options.c
--- options.c	2007-09-04 19:00:44.000000000 -0700
+++ options.c	2019-03-30 20:52:42.000000000 -0700
@@ -730,7 +730,7 @@ static void processEtagsInclude (
 }
 
 static void processExcludeOption (
-		const char *const option __unused__, const char *const parameter)
+		const char *const option __ctags__unused__, const char *const parameter)
 {
 	const char *const fileName = parameter + 1;
 	if (parameter [0] == '\0')
@@ -867,7 +867,7 @@ static void processFieldsOption (
 }
 
 static void processFilterTerminatorOption (
-		const char *const option __unused__, const char *const parameter)
+		const char *const option __ctags__unused__, const char *const parameter)
 {
 	freeString (&Option.filterTerminator);
 	Option.filterTerminator = stringCopy (parameter);
@@ -930,8 +930,8 @@ static void printProgramIdentification (
 }
 
 static void processHelpOption (
-		const char *const option __unused__,
-		const char *const parameter __unused__)
+		const char *const option __ctags__unused__,
+		const char *const parameter __ctags__unused__)
 {
 	printProgramIdentification ();
 	putchar ('\n');
@@ -1139,8 +1139,8 @@ static void processLanguagesOption (
 }
 
 static void processLicenseOption (
-		const char *const option __unused__,
-		const char *const parameter __unused__)
+		const char *const option __ctags__unused__,
+		const char *const parameter __ctags__unused__)
 {
 	printProgramIdentification ();
 	puts ("");
@@ -1166,8 +1166,8 @@ static void processListKindsOption (
 }
 
 static void processListMapsOption (
-		const char *const __unused__ option,
-		const char *const __unused__ parameter)
+		const char *const __ctags__unused__ option,
+		const char *const __ctags__unused__ parameter)
 {
 	if (parameter [0] == '\0' || strcasecmp (parameter, "all") == 0)
 	    printLanguageMaps (LANG_AUTO);
@@ -1183,8 +1183,8 @@ static void processListMapsOption (
 }
 
 static void processListLanguagesOption (
-		const char *const option __unused__,
-		const char *const parameter __unused__)
+		const char *const option __ctags__unused__,
+		const char *const parameter __ctags__unused__)
 {
 	printLanguageList ();
 	exit (0);
@@ -1358,8 +1358,8 @@ static void processIgnoreOption (const c
 }
 
 static void processVersionOption (
-		const char *const option __unused__,
-		const char *const parameter __unused__)
+		const char *const option __ctags__unused__,
+		const char *const parameter __ctags__unused__)
 {
 	printProgramIdentification ();
 	exit (0);
diff -Naurp parse.c parse.c
--- parse.c	2007-07-30 22:35:33.000000000 -0700
+++ parse.c	2019-03-30 20:52:42.000000000 -0700
@@ -376,7 +376,7 @@ extern void freeParserResources (void)
 */
 
 extern void processLanguageDefineOption (
-		const char *const option, const char *const parameter __unused__)
+		const char *const option, const char *const parameter __ctags__unused__)
 {
 #ifdef HAVE_REGEX
 	if (parameter [0] == '\0')
diff -Naurp python.c python.c
--- python.c	2009-07-06 20:55:23.000000000 -0700
+++ python.c	2019-03-30 20:52:42.000000000 -0700
@@ -135,7 +135,7 @@ static boolean isIdentifierCharacter (in
  * extract all relevant information and create a tag.
  */
 static void makeFunctionTag (vString *const function,
-	vString *const parent, int is_class_parent, const char *arglist __unused__)
+	vString *const parent, int is_class_parent, const char *arglist __ctags__unused__)
 {
 	tagEntryInfo tag;
 	initTagEntry (&tag, vStringValue (function));
diff -Naurp routines.c routines.c
--- routines.c	2007-06-06 21:35:21.000000000 -0700
+++ routines.c	2019-03-30 20:52:42.000000000 -0700
@@ -526,7 +526,7 @@ static boolean isPathSeparator (const in
 
 #if ! defined (HAVE_STAT_ST_INO)
 
-static void canonicalizePath (char *const path __unused__)
+static void canonicalizePath (char *const path __ctags__unused__)
 {
 #if defined (MSDOS_STYLE_PATH)
 	char *p;