Auto merge of #347 - impowski:typedef_type_cleanup, r=fitzgen

Wrap Type into Option

Fix #129

Author: bors-servo

libbindgen/src/clang.rs

@@ -402,12 +402,12 @@ impl Cursor {
 
     /// Given that this cursor's referent is a `typedef`, get the `Type` that is
     /// being aliased.
-    pub fn typedef_type(&self) -> Type {
-        unsafe {
-            Type {
-                x: clang_getTypedefDeclUnderlyingType(self.x),
-            }
-        }
+    pub fn typedef_type(&self) -> Option<Type> {
+        let inner = Type {
+            x: unsafe { clang_getTypedefDeclUnderlyingType(self.x) }
+        };
+
+        if inner.is_valid() { Some(inner) } else { None }
     }
 
     /// Get the linkage kind for this cursor's referent.

libbindgen/src/ir/ty.rs

@@ -660,7 +660,7 @@ impl Type {
 
                                         name = current.spelling();
 
-                                        let inner_ty = cur.typedef_type();
+                                        let inner_ty = cur.typedef_type().expect("Not valid Type?");
                                         inner = Item::from_ty(
                                             &inner_ty,
                                             Some(cur),
@@ -825,7 +825,7 @@ impl Type {
                 TypeKind::Function(signature)
             }
             CXType_Typedef => {
-                let inner = cursor.typedef_type();
+                let inner = cursor.typedef_type().expect("Not valid Type?");
                 let inner =
                     Item::from_ty_or_ref(inner, location, parent_id, ctx);
                 TypeKind::Alias(ty.spelling(), inner)