--- old/src/jdk.jextract/share/classes/com/sun/tools/jextract/TypedefHandler.java	2019-04-05 16:11:27.000000000 +0530
+++ new/src/jdk.jextract/share/classes/com/sun/tools/jextract/TypedefHandler.java	2019-04-05 16:11:26.000000000 +0530
@@ -126,7 +126,7 @@
                 Cursor dc = defTree.cursor();
                 List<Tree> trees = replacements.computeIfAbsent(dc, k -> new ArrayList<>());
                 trees.add(((StructTree)defTree).withName(tt.name()));
-                log.print(Level.FINE, () -> "Typedef " + defTree.type().spelling() + " as " + tt.name());
+                log.print(Level.FINE, () -> "Typedef " + defTree.type().spelling() + " as " + tt.name());	
                 return null;
             } else if (defTree.name().equals(tt.name())) {
                 /*
@@ -140,6 +140,16 @@
             }
         }
 
+        /*
+         * There are typedefs on built-in types like struct __va_list_tag. These
+         * are not exposed as declaration cursor for any headers, but are available
+         * from Type objects. We've to walk and check null file path to detect these
+         * Cursors and create Trees.
+         */
+        Utils.getBuiltinRecordTypes(tt.type()).forEach(c -> {
+            decls.add(treeMaker.createTree(c));
+        });
+
         decls.add(tt);
         return null;
     }