[FRAME] Simplify pallet config definition: remove RuntimeEvent associated type (#7229)

part of #3743

## Motivation

This PR removes the need for defining `RuntimeEvent` in the `Config`
trait of a pallet. It uses associated type bound feature under the hood
to make sure that `Event` of the pallet is convertible to the aggregated
runtime event type `frame_system::RuntimeEvent`.

This is an initial PR for `RuntimeEvent` type and will be followed with
other types, e.g `RuntimeCall`. As a demo, example pallets' config
definition is updated to use this feature.

With this change, we can do this (and have support for events):

```rs
#[pallet::config]
pub trait Config: frame_system::Config {
}
```

instead of this:

```rs
#[pallet::config]
pub trait Config: frame_system::Config {
        /// Overarching event type.
       type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
}
```

The latter will emit deprecation warnings and is redundant.

polkadot address: 16FqwPZ8GRC5U5D4Fu7W33nA55ZXzXGWHwmbnE1eT6pxuqcT

---------

Co-authored-by: Bastian Köcher <[email protected]>

Author: 2 people

bridges/modules/grandpa/src/lib.rs

@@ -98,6 +98,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config<I: 'static = ()>: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 

bridges/modules/messages/src/lib.rs

@@ -107,6 +107,7 @@ pub mod pallet {
 		// General types
 
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		/// Benchmarks results from runtime we're plugged into.

bridges/modules/parachains/src/lib.rs

@@ -183,6 +183,7 @@ pub mod pallet {
 		BoundedBridgeGrandpaConfig<Self::BridgesGrandpaPalletInstance>
 	{
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		/// Benchmarks results from runtime we're plugged into.

bridges/modules/relayers/src/lib.rs

@@ -74,6 +74,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config<I: 'static = ()>: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 

bridges/modules/xcm-bridge-hub-router/src/lib.rs

@@ -79,6 +79,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config<I: 'static = ()>: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		/// Benchmarks results from runtime we're plugged into.

bridges/modules/xcm-bridge-hub/src/lib.rs

@@ -194,6 +194,7 @@ pub mod pallet {
 		BridgeMessagesConfig<Self::BridgeMessagesPalletInstance>
 	{
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 

bridges/snowbridge/pallets/ethereum-client/src/lib.rs

@@ -90,6 +90,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		#[pallet::constant]
 		type ForkVersions: Get<ForkVersions>;

bridges/snowbridge/pallets/inbound-queue-v2/src/lib.rs

@@ -79,6 +79,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		/// The verifier for inbound messages from Ethereum.
 		type Verifier: Verifier;

bridges/snowbridge/pallets/inbound-queue/src/lib.rs

@@ -97,6 +97,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The verifier for inbound messages from Ethereum

bridges/snowbridge/pallets/outbound-queue-v2/src/lib.rs

@@ -114,6 +114,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		type Hashing: Hash<Output = H256>;

bridges/snowbridge/pallets/outbound-queue/src/lib.rs

@@ -139,6 +139,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		type Hashing: Hash<Output = H256>;

bridges/snowbridge/pallets/system-frontend/src/lib.rs

@@ -79,6 +79,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Origin check for XCM locations that can register token

bridges/snowbridge/pallets/system-v2/src/lib.rs

@@ -67,6 +67,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config + snowbridge_pallet_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Send messages to Ethereum

bridges/snowbridge/pallets/system/src/lib.rs

@@ -108,6 +108,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Send messages to Ethereum

cumulus/pallets/collator-selection/src/lib.rs

@@ -141,6 +141,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// Overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The currency mechanism.

cumulus/pallets/dmp-queue/src/lib.rs

@@ -59,6 +59,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type of the runtime.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The sink for all DMP messages that the lazy migration will use.

cumulus/pallets/parachain-system/src/lib.rs

@@ -248,6 +248,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config<OnSetCode = ParachainSetCode<Self>> {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Something which can be notified when the validation data is set.

cumulus/pallets/solo-to-para/src/lib.rs

@@ -33,6 +33,7 @@ pub mod pallet {
 	pub trait Config:
 		frame_system::Config + parachain_system::Config + pallet_sudo::Config
 	{
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 	}
 

cumulus/pallets/xcm/src/lib.rs

@@ -39,6 +39,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		type XcmExecutor: ExecuteXcm<Self::RuntimeCall>;

cumulus/pallets/xcmp-queue/src/lib.rs

@@ -115,6 +115,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Information on the available XCMP channels.

cumulus/parachains/pallets/collective-content/src/lib.rs

@@ -69,6 +69,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config<I: 'static = ()>: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self, I>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>;
 

cumulus/parachains/pallets/ping/src/lib.rs

@@ -48,6 +48,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		type RuntimeOrigin: From<<Self as SystemConfig>::RuntimeOrigin>

docs/sdk/packages/guides/first-pallet/src/lib.rs

@@ -365,6 +365,7 @@ pub mod pallet_v2 {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type of the runtime.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>
 			+ TryInto<Event<Self>>;

docs/sdk/src/guides/your_first_pallet/mod.rs

@@ -673,6 +673,7 @@ pub mod pallet_v2 {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type of the runtime.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>>
 			+ IsType<<Self as frame_system::Config>::RuntimeEvent>
 			+ TryInto<Event<Self>>;

docs/sdk/src/polkadot_sdk/frame_runtime.rs

@@ -104,6 +104,7 @@ pub mod pallet {
 	pub trait Config: frame_system::Config {
 		/// A type that is not known now, but the runtime that will contain this pallet will
 		/// know it later, therefore we define it here as an associated type.
+		#[allow(deprecated)]
 		type RuntimeEvent: IsType<<Self as frame_system::Config>::RuntimeEvent> + From<Event<Self>>;
 
 		/// A parameterize-able value that we receive later via the `Get<_>` trait.

polkadot/runtime/common/src/assigned_slots/mod.rs

@@ -120,6 +120,7 @@ pub mod pallet {
 	#[pallet::disable_frame_system_supertrait_check]
 	pub trait Config: configuration::Config + paras::Config + slots::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Origin for assigning slots.

polkadot/runtime/common/src/auctions/mod.rs

@@ -90,6 +90,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The type representing the leasing system.

polkadot/runtime/common/src/claims/mod.rs

@@ -202,6 +202,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		type VestingSchedule: VestingSchedule<Self::AccountId, Moment = BlockNumberFor<Self>>;
 		#[pallet::constant]

polkadot/runtime/common/src/crowdloan/mod.rs

@@ -186,6 +186,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// `PalletId` for the crowdloan pallet. An appropriate value could be

polkadot/runtime/common/src/identity_migrator.rs

@@ -78,6 +78,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config + pallet_identity::Config {
 		/// Overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The origin that can reap identities. Expected to be `EnsureSigned<AccountId>` on the

polkadot/runtime/common/src/paras_registrar/mod.rs

@@ -121,6 +121,7 @@ pub mod pallet {
 	#[pallet::disable_frame_system_supertrait_check]
 	pub trait Config: configuration::Config + paras::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The aggregated origin type must support the `parachains` origin. We require that we can

polkadot/runtime/common/src/purchase/mod.rs

@@ -100,6 +100,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Balances Pallet

polkadot/runtime/common/src/slots/mod.rs

@@ -74,6 +74,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The currency type used for bidding.

polkadot/runtime/parachains/src/coretime/mod.rs

@@ -118,6 +118,7 @@ pub mod pallet {
 	pub trait Config: frame_system::Config + assigner_coretime::Config + on_demand::Config {
 		type RuntimeOrigin: From<<Self as frame_system::Config>::RuntimeOrigin>
 			+ Into<result::Result<Origin, <Self as Config>::RuntimeOrigin>>;
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		/// The ParaId of the coretime chain.
 		#[pallet::constant]

polkadot/runtime/parachains/src/disputes.rs

@@ -372,6 +372,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config + configuration::Config + session_info::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		type RewardValidators: RewardValidators;
 		type SlashingHandler: SlashingHandler<BlockNumberFor<Self>>;

polkadot/runtime/parachains/src/hrmp.rs

@@ -259,6 +259,7 @@ pub mod pallet {
 		frame_system::Config + configuration::Config + paras::Config + dmp::Config
 	{
 		/// The outer event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		type RuntimeOrigin: From<crate::Origin>

polkadot/runtime/parachains/src/inclusion/mod.rs

@@ -286,6 +286,7 @@ pub mod pallet {
 		+ configuration::Config
 		+ scheduler::Config
 	{
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		type DisputesHandler: disputes::DisputesHandler<BlockNumberFor<Self>>;
 		type RewardValidators: RewardValidators;

polkadot/runtime/parachains/src/on_demand/mod.rs

@@ -117,6 +117,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config + configuration::Config + paras::Config {
 		/// The runtime's definition of an event.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// The runtime's definition of a Currency.

polkadot/runtime/parachains/src/paras/mod.rs

@@ -628,6 +628,7 @@ pub mod pallet {
 		+ shared::Config
 		+ frame_system::offchain::CreateInherent<Call<Self>>
 	{
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		#[pallet::constant]

polkadot/runtime/rococo/src/validator_manager.rs

@@ -37,6 +37,7 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config: frame_system::Config + pallet_session::Config {
 		/// The overreaching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// Privileged origin that can add or remove validators.

polkadot/runtime/test-runtime/src/lib.rs

@@ -693,6 +693,7 @@ pub mod pallet_test_notifier {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config + pallet_xcm::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: IsType<<Self as frame_system::Config>::RuntimeEvent> + From<Event<Self>>;
 		type RuntimeOrigin: IsType<<Self as frame_system::Config>::RuntimeOrigin>
 			+ Into<Result<pallet_xcm::Origin, <Self as Config>::RuntimeOrigin>>;

polkadot/xcm/pallet-xcm/src/lib.rs

@@ -241,6 +241,7 @@ pub mod pallet {
 	/// The module configuration trait.
 	pub trait Config: frame_system::Config {
 		/// The overarching event type.
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 
 		/// A lockable currency.

polkadot/xcm/pallet-xcm/src/mock.rs

@@ -67,6 +67,7 @@ pub mod pallet_test_notifier {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config + crate::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: IsType<<Self as frame_system::Config>::RuntimeEvent> + From<Event<Self>>;
 		type RuntimeOrigin: IsType<<Self as frame_system::Config>::RuntimeOrigin>
 			+ Into<Result<crate::Origin, <Self as Config>::RuntimeOrigin>>;
@@ -232,10 +233,10 @@ impl SendXcm for TestPaidForPara3000SendXcm {
 	) -> SendResult<(Location, Xcm<()>)> {
 		if let Some(dest) = dest.as_ref() {
 			if !dest.eq(&Para3000Location::get()) {
-				return Err(SendError::NotApplicable)
+				return Err(SendError::NotApplicable);
 			}
 		} else {
-			return Err(SendError::NotApplicable)
+			return Err(SendError::NotApplicable);
 		}
 
 		let pair = (dest.take().unwrap(), msg.take().unwrap());

polkadot/xcm/xcm-simulator/fuzzer/src/parachain.rs

@@ -157,6 +157,7 @@ pub mod mock_msg_queue {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		type XcmExecutor: ExecuteXcm<Self::RuntimeCall>;
 	}

polkadot/xcm/xcm-simulator/src/mock_message_queue.rs

@@ -35,6 +35,7 @@ pub mod pallet {
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {
+		#[allow(deprecated)]
 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
 		type XcmExecutor: ExecuteXcm<Self::RuntimeCall>;
 	}