Fix cycle dependency in sp-runtime-interface (#4353)

* Fix cycle dependency in `sp-runtime-interface`

* Fixes tests

substrate/primitives/runtime-interface/src/pass_by.rs

@@ -35,7 +35,70 @@ use sp_std::{marker::PhantomData, convert::TryFrom};
 #[cfg(not(feature = "std"))]
 use sp_std::{slice, vec::Vec};
 
-pub use sp_runtime_interface_proc_macro::{PassByCodec, PassByInner, PassByEnum};
+/// Derive macro for implementing [`PassBy`] with the [`Codec`] strategy.
+///
+/// This requires that the type implements [`Encode`](codec::Encode) and [`Decode`](codec::Decode)
+/// from `parity-scale-codec`.
+///
+/// # Example
+///
+/// ```
+/// # use sp_runtime_interface::pass_by::PassByCodec;
+/// # use codec::{Encode, Decode};
+/// #[derive(PassByCodec, Encode, Decode)]
+/// struct EncodableType {
+///     name: Vec<u8>,
+///     param: u32,
+/// }
+/// ```
+pub use sp_runtime_interface_proc_macro::PassByCodec;
+
+/// Derive macro for implementing [`PassBy`] with the [`Inner`] strategy.
+///
+/// Besides implementing [`PassBy`], this derive also implements the helper trait [`PassByInner`].
+///
+/// The type is required to be a struct with just one field. The field type needs to implement
+/// the required traits to pass it between the wasm and the native side. (See the runtime interface
+/// crate for more information about these traits.)
+///
+/// # Example
+///
+/// ```
+/// # use sp_runtime_interface::pass_by::PassByInner;
+/// #[derive(PassByInner)]
+/// struct Data([u8; 32]);
+/// ```
+///
+/// ```
+/// # use sp_runtime_interface::pass_by::PassByInner;
+/// #[derive(PassByInner)]
+/// struct Data {
+///     data: [u8; 32],
+/// }
+/// ```
+pub use sp_runtime_interface_proc_macro::PassByInner;
+
+/// Derive macro for implementing [`PassBy`] with the [`Enum`] strategy.
+///
+/// Besides implementing [`PassBy`], this derive also implements `TryFrom<u8>` and
+/// `From<Self> for u8` for the type.
+///
+/// The type is required to be an enum with only unit variants and at maximum `256` variants. Also
+/// it is required that the type implements `Copy`.
+///
+/// # Example
+///
+/// ```
+/// # use sp_runtime_interface::pass_by::PassByEnum;
+/// #[derive(PassByEnum, Copy, Clone)]
+/// enum Data {
+///     Okay,
+///     NotOkay,
+///     // This will not work with the derive.
+///     //Why(u32),
+/// }
+/// ```
+pub use sp_runtime_interface_proc_macro::PassByEnum;
 
 /// Something that should be passed between wasm and the host using the given strategy.
 ///