1 use runtime::{Class, Object, Sel};
2 use {Encode, EncodeArguments};
3 use super::MessageError;
4
verify_message_signature<A, R>(cls: &Class, sel: Sel) -> Result<(), MessageError> where A: EncodeArguments, R: Encode5 pub fn verify_message_signature<A, R>(cls: &Class, sel: Sel)
6 -> Result<(), MessageError>
7 where A: EncodeArguments, R: Encode {
8 let method = match cls.instance_method(sel) {
9 Some(method) => method,
10 None => return Err(MessageError(
11 format!("Method {:?} not found on class {:?}",
12 sel, cls)
13 )),
14 };
15
16 let ret = R::encode();
17 let expected_ret = method.return_type();
18 if ret != expected_ret {
19 return Err(MessageError(
20 format!("Return type code {:?} does not match expected {:?} for method {:?}",
21 ret, expected_ret, method.name())
22 ));
23 }
24
25 let self_and_cmd = [<*mut Object>::encode(), Sel::encode()];
26 let args = A::encodings();
27 let args = args.as_ref();
28
29 let count = self_and_cmd.len() + args.len();
30 let expected_count = method.arguments_count();
31 if count != expected_count {
32 return Err(MessageError(
33 format!("Method {:?} accepts {} arguments, but {} were given",
34 method.name(), expected_count, count)
35 ));
36 }
37
38 for (i, arg) in self_and_cmd.iter().chain(args).enumerate() {
39 let expected = method.argument_type(i).unwrap();
40 if *arg != expected {
41 return Err(MessageError(
42 format!("Method {:?} expected argument at index {} with type code {:?} but was given {:?}",
43 method.name(), i, expected, arg)
44 ));
45 }
46 }
47
48 Ok(())
49 }
50