Generate better func decls for void returns

Author: michaelwu

src/gen.rs

@@ -889,14 +889,10 @@ fn cfuncty_to_rs(ctx: &mut GenCtx,
                  aty: &[(String, Type)],
                  var: bool) -> ast::FnDecl {
 
-    let ret = P(match *rty {
-        TVoid => ast::Ty {
-            id: ast::DUMMY_NODE_ID,
-            node: ast::TyTup(vec![]),
-            span: ctx.span
-        },
-        _ => cty_to_rs(ctx, rty)
-    });
+    let ret = match *rty {
+        TVoid => ast::DefaultReturn(ctx.span),
+        _ => ast::Return(P(cty_to_rs(ctx, rty)))
+    };
 
     let mut unnamed: usize = 0;
     let args: Vec<ast::Arg> = aty.iter().map(|arg| {
@@ -937,7 +933,7 @@ fn cfuncty_to_rs(ctx: &mut GenCtx,
     let var = !args.is_empty() && var;
     return ast::FnDecl {
         inputs: args,
-        output: ast::Return(ret),
+        output: ret,
         variadic: var
     };
 }

tests/test_func.rs

@@ -43,7 +43,7 @@ fn func_proto() {
 fn with_func_ptr_arg() {
     assert_bind_eq("headers/func_with_func_ptr_arg.h", "
         extern \"C\" {
-            pub fn foo(bar: ::std::option::Option<extern \"C\" fn() -> () >) -> ();
+            pub fn foo(bar: ::std::option::Option<extern \"C\" fn()>);
         }
     ");
 }
@@ -52,7 +52,7 @@ fn with_func_ptr_arg() {
 fn with_array_arg() {
     assert_bind_eq("headers/func_with_array_arg.h", "
         extern \"C\" {
-            pub fn f(x: *mut ::libc::c_int) -> ();
+            pub fn f(x: *mut ::libc::c_int);
         }
     ");
 }