Implements pallet versioning (#7208)

* Start

* Make macro work

* Rename `ModuleToIndex` to `PalletRuntimeSetup`

Besides the renaming it also adds support getting the name of a pallet
as configured in the runtime.

* Rename it to `PalletInfo`

* Remove accidentally added files

* Some work

* Make everything compile

* Adds a test and fixes some bugs

* Implement ordering for `PalletVersion`

* Apply suggestions from code review

* Review feedback

* Update frame/support/src/dispatch.rs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* Update frame/support/src/dispatch.rs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* Fix compilation

* Fix test

* Fix doc test

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>
Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

substrate/frame/support/test/src/lib.rs

@@ -22,12 +22,19 @@
 #![warn(missing_docs)]
 #![deny(warnings)]
 
+#[cfg(test)]
+mod pallet_version;
+
 /// The configuration trait
-pub trait Trait {
+pub trait Trait: 'static {
 	/// The runtime origin type.
-	type Origin;
+	type Origin: codec::Codec + codec::EncodeLike + Default;
 	/// The block number type.
-	type BlockNumber;
+	type BlockNumber: codec::Codec + codec::EncodeLike + Default;
+	/// The information about the pallet setup in the runtime.
+	type PalletInfo: frame_support::traits::PalletInfo;
+	/// The db weights.
+	type DbWeight: frame_support::traits::Get<frame_support::weights::RuntimeDbWeight>;
 }
 
 frame_support::decl_module! {

substrate/frame/support/test/src/pallet_version.rs

@@ -0,0 +1,32 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use frame_support::{crate_to_pallet_version, traits::PalletVersion};
+
+#[test]
+fn ensure_that_current_pallet_version_is_correct() {
+	let expected = PalletVersion {
+		major: env!("CARGO_PKG_VERSION_MAJOR").parse().unwrap(),
+		minor: env!("CARGO_PKG_VERSION_MINOR").parse().unwrap(),
+		patch: env!("CARGO_PKG_VERSION_PATCH").parse().unwrap(),
+	};
+
+	assert_eq!(
+		expected,
+		crate_to_pallet_version!(),
+	)
+}