Auto merge of #354 - Nashenas88:master, r=emilio

Followed Resolved Type Ref instead of panicking

This could fix #353, but I would really want everyone to review in case I'm missing something important. The compilation continues for the code I'm working with. Also, should I add a regression test for this? I could simply use the code in the referenced issue.

Author: bors-servo

libbindgen/src/codegen/mod.rs

@@ -2013,7 +2013,11 @@ impl CodeGenerator for Function {
         let signature = signature_item.kind().expect_type();
         let signature = match *signature.kind() {
             TypeKind::Function(ref sig) => sig,
-            _ => panic!("How?"),
+            TypeKind::ResolvedTypeRef(ref item_id) => {
+                let item = ctx.resolve_item(*item_id);
+                return self.codegen(ctx, result, _whitelisted_items, item);
+            },
+            _ => panic!("How?")
         };
 
         let fndecl = utils::rust_fndecl_from_signature(ctx, signature_item);

libbindgen/tests/expectations/tests/resolved_type_def_function.rs

@@ -0,0 +1,7 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(non_snake_case)]
+
+
+pub type FuncType = ::std::option::Option<unsafe extern "C" fn()>;

libbindgen/tests/headers/resolved_type_def_function.h

@@ -0,0 +1,2 @@
+typedef void (FuncType) ();
+extern FuncType Func;