oops. antlr was ok, it was javalr grammar.

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 9754]

tool/playground/JavaLR.g4

@@ -820,7 +820,7 @@ WS  :  (' '|'\r'|'\t'|'\u000C'|'\n')+ {$channel=HIDDEN;}
     ;
 
 COMMENT
-    :   '/*' . '*/' {$channel=HIDDEN;}
+    :   '/*' .* '*/' {$channel=HIDDEN;}
     ;
 
 LINE_COMMENT

tool/playground/TestJavaLR.java

@@ -101,7 +101,7 @@ class TestJavaLR {
 				f.getName().substring(f.getName().length()-5).equals(".java"))
 			|| f.getName().equals("input") )
 		{
-//			System.err.println(f.getAbsolutePath());
+			System.err.println(f.getAbsolutePath());
 			parseFile(f.getAbsolutePath());
 		}
 	}