XCMv4 (#1230)

# Note for reviewer

Most changes are just syntax changes necessary for the new version.
Most important files should be the ones under the `xcm` folder.

# Description 

Added XCMv4.

## Removed `Multi` prefix
The following types have been renamed:
- MultiLocation -> Location
- MultiAsset -> Asset
- MultiAssets -> Assets
- InteriorMultiLocation -> InteriorLocation
- MultiAssetFilter -> AssetFilter
- VersionedMultiAsset -> VersionedAsset
- WildMultiAsset -> WildAsset
- VersionedMultiLocation -> VersionedLocation

In order to fix a name conflict, the `Assets` in `xcm-executor` were
renamed to `HoldingAssets`, as they represent assets in holding.

## Removed `Abstract` asset id

It was not being used anywhere and this simplifies the code.

Now assets are just constructed as follows:

```rust
let asset: Asset = (AssetId(Location::new(1, Here)), 100u128).into();
```

No need for specifying `Concrete` anymore.

## Outcome is now a named fields struct

Instead of

```rust
pub enum Outcome {
  Complete(Weight),
  Incomplete(Weight, Error),
  Error(Error),
}
```

we now have

```rust
pub enum Outcome {
  Complete { used: Weight },
  Incomplete { used: Weight, error: Error },
  Error { error: Error },
}
```

## Added Reanchorable trait

Now both locations and assets implement this trait, making it easier to
reanchor both.

## New syntax for building locations and junctions

Now junctions are built using the following methods:

```rust
let location = Location {
    parents: 1,
    interior: [Parachain(1000), PalletInstance(50), GeneralIndex(1984)].into()
};
```

or

```rust
let location = Location::new(1, [Parachain(1000), PalletInstance(50), GeneralIndex(1984)]);
```

And they are matched like so:

```rust
match location.unpack() {
  (1, [Parachain(id)]) => ...
  (0, Here) => ...,
  (1, [_]) => ...,
}
```

This syntax is mandatory in v4, and has been also implemented for v2 and
v3 for easier migration.

This was needed to make all sizes smaller.

# TODO
- [x] Scaffold v4
- [x] Port github.com/paritytech/polkadot/pull/7236
- [x] Remove `Multi` prefix
- [x] Remove `Abstract` asset id

---------

Co-authored-by: command-bot <>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/bridge_to_bulletin_config.rs

@@ -48,7 +48,7 @@ use frame_support::{parameter_types, traits::PalletInfoAccess};
 use sp_runtime::RuntimeDebug;
 use xcm::{
 	latest::prelude::*,
-	prelude::{InteriorMultiLocation, NetworkId},
+	prelude::{InteriorLocation, NetworkId},
 };
 use xcm_builder::BridgeBlobDispatcher;
 
@@ -65,16 +65,16 @@ parameter_types! {
 	/// Bridge specific chain (network) identifier of the Rococo Bulletin Chain.
 	pub const RococoBulletinChainId: bp_runtime::ChainId = bp_runtime::POLKADOT_BULLETIN_CHAIN_ID;
 	/// Interior location (relative to this runtime) of the with-RococoBulletin messages pallet.
-	pub BridgeRococoToRococoBulletinMessagesPalletInstance: InteriorMultiLocation = X1(
+	pub BridgeRococoToRococoBulletinMessagesPalletInstance: InteriorLocation = [
 		PalletInstance(<BridgeRococoBulletinMessages as PalletInfoAccess>::index() as u8)
-	);
+	].into();
 	/// Rococo Bulletin Network identifier.
 	pub RococoBulletinGlobalConsensusNetwork: NetworkId = NetworkId::PolkadotBulletin;
 	/// Relative location of the Rococo Bulletin chain.
-	pub RococoBulletinGlobalConsensusNetworkLocation: MultiLocation = MultiLocation {
-		parents: 2,
-		interior: X1(GlobalConsensus(RococoBulletinGlobalConsensusNetwork::get()))
-	};
+	pub RococoBulletinGlobalConsensusNetworkLocation: Location = Location::new(
+		2,
+		[GlobalConsensus(RococoBulletinGlobalConsensusNetwork::get())]
+	);
 	/// All active lanes that the current bridge supports.
 	pub ActiveOutboundLanesToRococoBulletin: &'static [bp_messages::LaneId]
 		= &[XCM_LANE_FOR_ROCOCO_PEOPLE_TO_ROCOCO_BULLETIN];
@@ -94,11 +94,11 @@ parameter_types! {
 	/// A route (XCM location and bridge lane) that the Rococo People Chain -> Rococo Bulletin Chain
 	/// message is following.
 	pub FromRococoPeopleToRococoBulletinRoute: SenderAndLane = SenderAndLane::new(
-		ParentThen(X1(Parachain(RococoPeopleParaId::get().into()))).into(),
+		ParentThen(Parachain(RococoPeopleParaId::get().into()).into()).into(),
 		XCM_LANE_FOR_ROCOCO_PEOPLE_TO_ROCOCO_BULLETIN,
 	);
 	/// All active routes and their destinations.
-	pub ActiveLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))> = sp_std::vec![
+	pub ActiveLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorLocation))> = sp_std::vec![
 			(
 				FromRococoPeopleToRococoBulletinRoute::get(),
 				(RococoBulletinGlobalConsensusNetwork::get(), Here)
@@ -282,11 +282,11 @@ mod tests {
 			PriorityBoostPerMessage,
 		>(FEE_BOOST_PER_MESSAGE);
 
-		assert_eq!(
-			BridgeRococoToRococoBulletinMessagesPalletInstance::get(),
-			X1(PalletInstance(
-				bp_bridge_hub_rococo::WITH_BRIDGE_ROCOCO_TO_BULLETIN_MESSAGES_PALLET_INDEX
-			))
-		);
+		let expected: InteriorLocation = PalletInstance(
+			bp_bridge_hub_rococo::WITH_BRIDGE_ROCOCO_TO_BULLETIN_MESSAGES_PALLET_INDEX,
+		)
+		.into();
+
+		assert_eq!(BridgeRococoToRococoBulletinMessagesPalletInstance::get(), expected,);
 	}
 }

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/bridge_to_westend_config.rs

@@ -48,7 +48,7 @@ use frame_support::{parameter_types, traits::PalletInfoAccess};
 use sp_runtime::RuntimeDebug;
 use xcm::{
 	latest::prelude::*,
-	prelude::{InteriorMultiLocation, NetworkId},
+	prelude::{InteriorLocation, NetworkId},
 };
 use xcm_builder::BridgeBlobDispatcher;
 
@@ -58,12 +58,12 @@ parameter_types! {
 	pub const MaxUnconfirmedMessagesAtInboundLane: bp_messages::MessageNonce =
 		bp_bridge_hub_rococo::MAX_UNCONFIRMED_MESSAGES_IN_CONFIRMATION_TX;
 	pub const BridgeHubWestendChainId: bp_runtime::ChainId = bp_runtime::BRIDGE_HUB_WESTEND_CHAIN_ID;
-	pub BridgeRococoToWestendMessagesPalletInstance: InteriorMultiLocation = X1(PalletInstance(<BridgeWestendMessages as PalletInfoAccess>::index() as u8));
+	pub BridgeRococoToWestendMessagesPalletInstance: InteriorLocation = [PalletInstance(<BridgeWestendMessages as PalletInfoAccess>::index() as u8)].into();
 	pub WestendGlobalConsensusNetwork: NetworkId = NetworkId::Westend;
-	pub WestendGlobalConsensusNetworkLocation: MultiLocation = MultiLocation {
-		parents: 2,
-		interior: X1(GlobalConsensus(WestendGlobalConsensusNetwork::get()))
-	};
+	pub WestendGlobalConsensusNetworkLocation: Location = Location::new(
+		2,
+		[GlobalConsensus(WestendGlobalConsensusNetwork::get())]
+	);
 	// see the `FEE_BOOST_PER_MESSAGE` constant to get the meaning of this value
 	pub PriorityBoostPerMessage: u64 = 182_044_444_444_444;
 
@@ -74,26 +74,26 @@ parameter_types! {
 	pub ActiveOutboundLanesToBridgeHubWestend: &'static [bp_messages::LaneId] = &[XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND];
 	pub const AssetHubRococoToAssetHubWestendMessagesLane: bp_messages::LaneId = XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND;
 	pub FromAssetHubRococoToAssetHubWestendRoute: SenderAndLane = SenderAndLane::new(
-		ParentThen(X1(Parachain(AssetHubRococoParaId::get().into()))).into(),
+		ParentThen([Parachain(AssetHubRococoParaId::get().into())].into()).into(),
 		XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND,
 	);
-	pub ActiveLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorMultiLocation))> = sp_std::vec![
+	pub ActiveLanes: sp_std::vec::Vec<(SenderAndLane, (NetworkId, InteriorLocation))> = sp_std::vec![
 			(
 				FromAssetHubRococoToAssetHubWestendRoute::get(),
-				(WestendGlobalConsensusNetwork::get(), X1(Parachain(AssetHubWestendParaId::get().into())))
+				(WestendGlobalConsensusNetwork::get(), [Parachain(AssetHubWestendParaId::get().into())].into())
 			)
 	];
 
 	pub CongestedMessage: Xcm<()> = build_congestion_message(true).into();
 	pub UncongestedMessage: Xcm<()> = build_congestion_message(false).into();
 
-	pub BridgeHubWestendLocation: MultiLocation = MultiLocation {
-		parents: 2,
-		interior: X2(
+	pub BridgeHubWestendLocation: Location = Location::new(
+		2,
+		[
 			GlobalConsensus(WestendGlobalConsensusNetwork::get()),
 			Parachain(<bp_bridge_hub_westend::BridgeHubWestend as bp_runtime::Parachain>::PARACHAIN_ID)
-		)
-	};
+		]
+	);
 }
 pub const XCM_LANE_FOR_ASSET_HUB_ROCOCO_TO_ASSET_HUB_WESTEND: LaneId = LaneId([0, 0, 0, 2]);
 
@@ -327,11 +327,11 @@ mod tests {
 			PriorityBoostPerMessage,
 		>(FEE_BOOST_PER_MESSAGE);
 
-		assert_eq!(
-			BridgeRococoToWestendMessagesPalletInstance::get(),
-			X1(PalletInstance(
-				bp_bridge_hub_rococo::WITH_BRIDGE_ROCOCO_TO_WESTEND_MESSAGES_PALLET_INDEX
-			))
-		);
+		let expected: InteriorLocation = [PalletInstance(
+			bp_bridge_hub_rococo::WITH_BRIDGE_ROCOCO_TO_WESTEND_MESSAGES_PALLET_INDEX,
+		)]
+		.into();
+
+		assert_eq!(BridgeRococoToWestendMessagesPalletInstance::get(), expected,);
 	}
 }

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs

@@ -78,7 +78,7 @@ use bridge_hub_common::{
 use pallet_xcm::EnsureXcm;
 pub use sp_consensus_aura::sr25519::AuthorityId as AuraId;
 pub use sp_runtime::{MultiAddress, Perbill, Permill};
-use xcm::VersionedMultiLocation;
+use xcm::VersionedLocation;
 use xcm_config::{TreasuryAccount, XcmOriginToTransactDispatchOrigin, XcmRouter};
 
 #[cfg(any(feature = "std", test))]
@@ -385,7 +385,7 @@ impl cumulus_pallet_aura_ext::Config for Runtime {}
 
 parameter_types! {
 	/// The asset ID for the asset that we use to pay for message delivery fees.
-	pub FeeAssetId: AssetId = Concrete(xcm_config::TokenLocation::get());
+	pub FeeAssetId: AssetId = AssetId(xcm_config::TokenLocation::get());
 	/// The base fee for the message delivery fees.
 	pub const BaseDeliveryFee: u128 = CENTS.saturating_mul(3);
 }
@@ -517,7 +517,7 @@ pub mod benchmark_helpers {
 	use snowbridge_beacon_primitives::CompactExecutionHeader;
 	use snowbridge_pallet_inbound_queue::BenchmarkHelper;
 	use sp_core::H256;
-	use xcm::latest::{MultiAssets, MultiLocation, SendError, SendResult, SendXcm, Xcm, XcmHash};
+	use xcm::latest::{Assets, Location, SendError, SendResult, SendXcm, Xcm, XcmHash};
 
 	impl<T: snowbridge_pallet_ethereum_client::Config> BenchmarkHelper<T> for Runtime {
 		fn initialize_storage(block_hash: H256, header: CompactExecutionHeader) {
@@ -530,10 +530,10 @@ pub mod benchmark_helpers {
 		type Ticket = Xcm<()>;
 
 		fn validate(
-			_dest: &mut Option<MultiLocation>,
+			_dest: &mut Option<Location>,
 			xcm: &mut Option<Xcm<()>>,
 		) -> SendResult<Self::Ticket> {
-			Ok((xcm.clone().unwrap(), MultiAssets::new()))
+			Ok((xcm.clone().unwrap(), Assets::new()))
 		}
 		fn deliver(xcm: Xcm<()>) -> Result<XcmHash, SendError> {
 			let hash = xcm.using_encoded(sp_io::hashing::blake2_256);
@@ -542,7 +542,7 @@ pub mod benchmark_helpers {
 	}
 
 	impl snowbridge_pallet_system::BenchmarkHelper<RuntimeOrigin> for () {
-		fn make_xcm_origin(location: MultiLocation) -> RuntimeOrigin {
+		fn make_xcm_origin(location: Location) -> RuntimeOrigin {
 			RuntimeOrigin::from(pallet_xcm::Origin::Xcm(location))
 		}
 	}
@@ -1016,7 +1016,7 @@ impl_runtime_apis! {
 	}
 
 	impl snowbridge_system_runtime_api::ControlApi<Block> for Runtime {
-		fn agent_id(location: VersionedMultiLocation) -> Option<AgentId> {
+		fn agent_id(location: VersionedLocation) -> Option<AgentId> {
 			snowbridge_pallet_system::api::agent_id::<Runtime>(location)
 		}
 	}
@@ -1095,28 +1095,28 @@ impl_runtime_apis! {
 
 			use pallet_xcm::benchmarking::Pallet as PalletXcmExtrinsicsBenchmark;
 			impl pallet_xcm::benchmarking::Config for Runtime {
-				fn reachable_dest() -> Option<MultiLocation> {
+				fn reachable_dest() -> Option<Location> {
 					Some(Parent.into())
 				}
 
-				fn teleportable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+				fn teleportable_asset_and_dest() -> Option<(Asset, Location)> {
 					// Relay/native token can be teleported between BH and Relay.
 					Some((
-						MultiAsset {
+						Asset {
 							fun: Fungible(EXISTENTIAL_DEPOSIT),
-							id: Concrete(Parent.into())
+							id: AssetId(Parent.into())
 						},
 						Parent.into(),
 					))
 				}
 
-				fn reserve_transferable_asset_and_dest() -> Option<(MultiAsset, MultiLocation)> {
+				fn reserve_transferable_asset_and_dest() -> Option<(Asset, Location)> {
 					// Reserve transfers are disabled on BH.
 					None
 				}
 
 				fn set_up_complex_asset_transfer(
-				) -> Option<(MultiAssets, u32, MultiLocation, Box<dyn FnOnce()>)> {
+				) -> Option<(Assets, u32, Location, Box<dyn FnOnce()>)> {
 					// BH only supports teleports to system parachain.
 					// Relay/native token can be teleported between BH and Relay.
 					let native_location = Parent.into();
@@ -1132,7 +1132,7 @@ impl_runtime_apis! {
 			use xcm_config::TokenLocation;
 
 			parameter_types! {
-				pub ExistentialDepositMultiAsset: Option<MultiAsset> = Some((
+				pub ExistentialDepositAsset: Option<Asset> = Some((
 					TokenLocation::get(),
 					ExistentialDeposit::get()
 				).into());
@@ -1143,17 +1143,17 @@ impl_runtime_apis! {
 				type AccountIdConverter = xcm_config::LocationToAccountId;
 				type DeliveryHelper = cumulus_primitives_utility::ToParentDeliveryHelper<
 					xcm_config::XcmConfig,
-					ExistentialDepositMultiAsset,
+					ExistentialDepositAsset,
 					xcm_config::PriceForParentDelivery,
 				>;
-				fn valid_destination() -> Result<MultiLocation, BenchmarkError> {
+				fn valid_destination() -> Result<Location, BenchmarkError> {
 					Ok(TokenLocation::get())
 				}
-				fn worst_case_holding(_depositable_count: u32) -> MultiAssets {
+				fn worst_case_holding(_depositable_count: u32) -> Assets {
 					// just concrete assets according to relay chain.
-					let assets: Vec<MultiAsset> = vec![
-						MultiAsset {
-							id: Concrete(TokenLocation::get()),
+					let assets: Vec<Asset> = vec![
+						Asset {
+							id: AssetId(TokenLocation::get()),
 							fun: Fungible(1_000_000 * UNITS),
 						}
 					];
@@ -1162,12 +1162,12 @@ impl_runtime_apis! {
 			}
 
 			parameter_types! {
-				pub const TrustedTeleporter: Option<(MultiLocation, MultiAsset)> = Some((
+				pub const TrustedTeleporter: Option<(Location, Asset)> = Some((
 					TokenLocation::get(),
-					MultiAsset { fun: Fungible(UNITS), id: Concrete(TokenLocation::get()) },
+					Asset { fun: Fungible(UNITS), id: AssetId(TokenLocation::get()) },
 				));
 				pub const CheckedAccount: Option<(AccountId, xcm_builder::MintLocation)> = None;
-				pub const TrustedReserve: Option<(MultiLocation, MultiAsset)> = None;
+				pub const TrustedReserve: Option<(Location, Asset)> = None;
 			}
 
 			impl pallet_xcm_benchmarks::fungible::Config for Runtime {
@@ -1177,9 +1177,9 @@ impl_runtime_apis! {
 				type TrustedTeleporter = TrustedTeleporter;
 				type TrustedReserve = TrustedReserve;
 
-				fn get_multi_asset() -> MultiAsset {
-					MultiAsset {
-						id: Concrete(TokenLocation::get()),
+				fn get_asset() -> Asset {
+					Asset {
+						id: AssetId(TokenLocation::get()),
 						fun: Fungible(UNITS),
 					}
 				}
@@ -1193,35 +1193,35 @@ impl_runtime_apis! {
 					(0u64, Response::Version(Default::default()))
 				}
 
-				fn worst_case_asset_exchange() -> Result<(MultiAssets, MultiAssets), BenchmarkError> {
+				fn worst_case_asset_exchange() -> Result<(Assets, Assets), BenchmarkError> {
 					Err(BenchmarkError::Skip)
 				}
 
-				fn universal_alias() -> Result<(MultiLocation, Junction), BenchmarkError> {
+				fn universal_alias() -> Result<(Location, Junction), BenchmarkError> {
 					Err(BenchmarkError::Skip)
 				}
 
-				fn transact_origin_and_runtime_call() -> Result<(MultiLocation, RuntimeCall), BenchmarkError> {
+				fn transact_origin_and_runtime_call() -> Result<(Location, RuntimeCall), BenchmarkError> {
 					Ok((TokenLocation::get(), frame_system::Call::remark_with_event { remark: vec![] }.into()))
 				}
 
-				fn subscribe_origin() -> Result<MultiLocation, BenchmarkError> {
+				fn subscribe_origin() -> Result<Location, BenchmarkError> {
 					Ok(TokenLocation::get())
 				}
 
-				fn claimable_asset() -> Result<(MultiLocation, MultiLocation, MultiAssets), BenchmarkError> {
+				fn claimable_asset() -> Result<(Location, Location, Assets), BenchmarkError> {
 					let origin = TokenLocation::get();
-					let assets: MultiAssets = (Concrete(TokenLocation::get()), 1_000 * UNITS).into();
-					let ticket = MultiLocation { parents: 0, interior: Here };
+					let assets: Assets = (AssetId(TokenLocation::get()), 1_000 * UNITS).into();
+					let ticket = Location { parents: 0, interior: Here };
 					Ok((origin, ticket, assets))
 				}
 
-				fn unlockable_asset() -> Result<(MultiLocation, MultiLocation, MultiAsset), BenchmarkError> {
+				fn unlockable_asset() -> Result<(Location, Location, Asset), BenchmarkError> {
 					Err(BenchmarkError::Skip)
 				}
 
 				fn export_message_origin_and_destination(
-				) -> Result<(MultiLocation, NetworkId, InteriorMultiLocation), BenchmarkError> {
+				) -> Result<(Location, NetworkId, InteriorLocation), BenchmarkError> {
 					// save XCM version for remote bridge hub
 					let _ = PolkadotXcm::force_xcm_version(
 						RuntimeOrigin::root(),
@@ -1241,12 +1241,12 @@ impl_runtime_apis! {
 						(
 							bridge_to_westend_config::FromAssetHubRococoToAssetHubWestendRoute::get().location,
 							NetworkId::Westend,
-							X1(Parachain(bridge_to_westend_config::AssetHubWestendParaId::get().into()))
+							[Parachain(bridge_to_westend_config::AssetHubWestendParaId::get().into())].into()
 						)
 					)
 				}
 
-				fn alias_origin() -> Result<(MultiLocation, MultiLocation), BenchmarkError> {
+				fn alias_origin() -> Result<(Location, Location), BenchmarkError> {
 					Err(BenchmarkError::Skip)
 				}
 			}
@@ -1296,7 +1296,7 @@ impl_runtime_apis! {
 						Runtime,
 						bridge_common_config::BridgeGrandpaWestendInstance,
 						bridge_to_westend_config::WithBridgeHubWestendMessageBridge,
-					>(params, generate_xcm_builder_bridge_message_sample(X2(GlobalConsensus(Rococo), Parachain(42))))
+					>(params, generate_xcm_builder_bridge_message_sample([GlobalConsensus(Rococo), Parachain(42)].into()))
 				}
 
 				fn prepare_message_delivery_proof(
@@ -1331,7 +1331,7 @@ impl_runtime_apis! {
 						Runtime,
 						bridge_common_config::BridgeGrandpaRococoBulletinInstance,
 						bridge_to_bulletin_config::WithRococoBulletinMessageBridge,
-					>(params, generate_xcm_builder_bridge_message_sample(X2(GlobalConsensus(Rococo), Parachain(42))))
+					>(params, generate_xcm_builder_bridge_message_sample([GlobalConsensus(Rococo), Parachain(42)].into()))
 				}
 
 				fn prepare_message_delivery_proof(

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/weights/xcm/mod.rs

@@ -24,14 +24,14 @@ use pallet_xcm_benchmarks_generic::WeightInfo as XcmGeneric;
 use sp_std::prelude::*;
 use xcm::{latest::prelude::*, DoubleEncoded};
 
-trait WeighMultiAssets {
-	fn weigh_multi_assets(&self, weight: Weight) -> Weight;
+trait WeighAssets {
+	fn weigh_assets(&self, weight: Weight) -> Weight;
 }
 
 const MAX_ASSETS: u64 = 100;
 
-impl WeighMultiAssets for MultiAssetFilter {
-	fn weigh_multi_assets(&self, weight: Weight) -> Weight {
+impl WeighAssets for AssetFilter {
+	fn weigh_assets(&self, weight: Weight) -> Weight {
 		match self {
 			Self::Definite(assets) => weight.saturating_mul(assets.inner().iter().count() as u64),
 			Self::Wild(asset) => match asset {
@@ -50,40 +50,36 @@ impl WeighMultiAssets for MultiAssetFilter {
 	}
 }
 
-impl WeighMultiAssets for MultiAssets {
-	fn weigh_multi_assets(&self, weight: Weight) -> Weight {
+impl WeighAssets for Assets {
+	fn weigh_assets(&self, weight: Weight) -> Weight {
 		weight.saturating_mul(self.inner().iter().count() as u64)
 	}
 }
 
 pub struct BridgeHubRococoXcmWeight<Call>(core::marker::PhantomData<Call>);
 impl<Call> XcmWeightInfo<Call> for BridgeHubRococoXcmWeight<Call> {
-	fn withdraw_asset(assets: &MultiAssets) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::withdraw_asset())
+	fn withdraw_asset(assets: &Assets) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::withdraw_asset())
 	}
-	fn reserve_asset_deposited(assets: &MultiAssets) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::reserve_asset_deposited())
+	fn reserve_asset_deposited(assets: &Assets) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::reserve_asset_deposited())
 	}
-	fn receive_teleported_asset(assets: &MultiAssets) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::receive_teleported_asset())
+	fn receive_teleported_asset(assets: &Assets) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::receive_teleported_asset())
 	}
 	fn query_response(
 		_query_id: &u64,
 		_response: &Response,
 		_max_weight: &Weight,
-		_querier: &Option<MultiLocation>,
+		_querier: &Option<Location>,
 	) -> Weight {
 		XcmGeneric::<Runtime>::query_response()
 	}
-	fn transfer_asset(assets: &MultiAssets, _dest: &MultiLocation) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::transfer_asset())
+	fn transfer_asset(assets: &Assets, _dest: &Location) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::transfer_asset())
 	}
-	fn transfer_reserve_asset(
-		assets: &MultiAssets,
-		_dest: &MultiLocation,
-		_xcm: &Xcm<()>,
-	) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::transfer_reserve_asset())
+	fn transfer_reserve_asset(assets: &Assets, _dest: &Location, _xcm: &Xcm<()>) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::transfer_reserve_asset())
 	}
 	fn transact(
 		_origin_type: &OriginKind,
@@ -111,44 +107,36 @@ impl<Call> XcmWeightInfo<Call> for BridgeHubRococoXcmWeight<Call> {
 	fn clear_origin() -> Weight {
 		XcmGeneric::<Runtime>::clear_origin()
 	}
-	fn descend_origin(_who: &InteriorMultiLocation) -> Weight {
+	fn descend_origin(_who: &InteriorLocation) -> Weight {
 		XcmGeneric::<Runtime>::descend_origin()
 	}
 	fn report_error(_query_response_info: &QueryResponseInfo) -> Weight {
 		XcmGeneric::<Runtime>::report_error()
 	}
 
-	fn deposit_asset(assets: &MultiAssetFilter, _dest: &MultiLocation) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::deposit_asset())
+	fn deposit_asset(assets: &AssetFilter, _dest: &Location) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::deposit_asset())
 	}
-	fn deposit_reserve_asset(
-		assets: &MultiAssetFilter,
-		_dest: &MultiLocation,
-		_xcm: &Xcm<()>,
-	) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::deposit_reserve_asset())
+	fn deposit_reserve_asset(assets: &AssetFilter, _dest: &Location, _xcm: &Xcm<()>) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::deposit_reserve_asset())
 	}
-	fn exchange_asset(_give: &MultiAssetFilter, _receive: &MultiAssets, _maximal: &bool) -> Weight {
+	fn exchange_asset(_give: &AssetFilter, _receive: &Assets, _maximal: &bool) -> Weight {
 		Weight::MAX
 	}
 	fn initiate_reserve_withdraw(
-		assets: &MultiAssetFilter,
-		_reserve: &MultiLocation,
+		assets: &AssetFilter,
+		_reserve: &Location,
 		_xcm: &Xcm<()>,
 	) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::initiate_reserve_withdraw())
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::initiate_reserve_withdraw())
 	}
-	fn initiate_teleport(
-		assets: &MultiAssetFilter,
-		_dest: &MultiLocation,
-		_xcm: &Xcm<()>,
-	) -> Weight {
-		assets.weigh_multi_assets(XcmFungibleWeight::<Runtime>::initiate_teleport())
+	fn initiate_teleport(assets: &AssetFilter, _dest: &Location, _xcm: &Xcm<()>) -> Weight {
+		assets.weigh_assets(XcmFungibleWeight::<Runtime>::initiate_teleport())
 	}
-	fn report_holding(_response_info: &QueryResponseInfo, _assets: &MultiAssetFilter) -> Weight {
+	fn report_holding(_response_info: &QueryResponseInfo, _assets: &AssetFilter) -> Weight {
 		XcmGeneric::<Runtime>::report_holding()
 	}
-	fn buy_execution(_fees: &MultiAsset, _weight_limit: &WeightLimit) -> Weight {
+	fn buy_execution(_fees: &Asset, _weight_limit: &WeightLimit) -> Weight {
 		XcmGeneric::<Runtime>::buy_execution()
 	}
 	fn refund_surplus() -> Weight {
@@ -163,7 +151,7 @@ impl<Call> XcmWeightInfo<Call> for BridgeHubRococoXcmWeight<Call> {
 	fn clear_error() -> Weight {
 		XcmGeneric::<Runtime>::clear_error()
 	}
-	fn claim_asset(_assets: &MultiAssets, _ticket: &MultiLocation) -> Weight {
+	fn claim_asset(_assets: &Assets, _ticket: &Location) -> Weight {
 		XcmGeneric::<Runtime>::claim_asset()
 	}
 	fn trap(_code: &u64) -> Weight {
@@ -175,13 +163,13 @@ impl<Call> XcmWeightInfo<Call> for BridgeHubRococoXcmWeight<Call> {
 	fn unsubscribe_version() -> Weight {
 		XcmGeneric::<Runtime>::unsubscribe_version()
 	}
-	fn burn_asset(assets: &MultiAssets) -> Weight {
-		assets.weigh_multi_assets(XcmGeneric::<Runtime>::burn_asset())
+	fn burn_asset(assets: &Assets) -> Weight {
+		assets.weigh_assets(XcmGeneric::<Runtime>::burn_asset())
 	}
-	fn expect_asset(assets: &MultiAssets) -> Weight {
-		assets.weigh_multi_assets(XcmGeneric::<Runtime>::expect_asset())
+	fn expect_asset(assets: &Assets) -> Weight {
+		assets.weigh_assets(XcmGeneric::<Runtime>::expect_asset())
 	}
-	fn expect_origin(_origin: &Option<MultiLocation>) -> Weight {
+	fn expect_origin(_origin: &Option<Location>) -> Weight {
 		XcmGeneric::<Runtime>::expect_origin()
 	}
 	fn expect_error(_error: &Option<(u32, XcmError)>) -> Weight {
@@ -215,16 +203,16 @@ impl<Call> XcmWeightInfo<Call> for BridgeHubRococoXcmWeight<Call> {
 		let inner_encoded_len = inner.encode().len() as u32;
 		XcmGeneric::<Runtime>::export_message(inner_encoded_len)
 	}
-	fn lock_asset(_: &MultiAsset, _: &MultiLocation) -> Weight {
+	fn lock_asset(_: &Asset, _: &Location) -> Weight {
 		Weight::MAX
 	}
-	fn unlock_asset(_: &MultiAsset, _: &MultiLocation) -> Weight {
+	fn unlock_asset(_: &Asset, _: &Location) -> Weight {
 		Weight::MAX
 	}
-	fn note_unlockable(_: &MultiAsset, _: &MultiLocation) -> Weight {
+	fn note_unlockable(_: &Asset, _: &Location) -> Weight {
 		Weight::MAX
 	}
-	fn request_unlock(_: &MultiAsset, _: &MultiLocation) -> Weight {
+	fn request_unlock(_: &Asset, _: &Location) -> Weight {
 		Weight::MAX
 	}
 	fn set_fees_mode(_: &bool) -> Weight {
@@ -236,11 +224,11 @@ impl<Call> XcmWeightInfo<Call> for BridgeHubRococoXcmWeight<Call> {
 	fn clear_topic() -> Weight {
 		XcmGeneric::<Runtime>::clear_topic()
 	}
-	fn alias_origin(_: &MultiLocation) -> Weight {
+	fn alias_origin(_: &Location) -> Weight {
 		// XCM Executor does not currently support alias origin operations
 		Weight::MAX
 	}
-	fn unpaid_execution(_: &WeightLimit, _: &Option<MultiLocation>) -> Weight {
+	fn unpaid_execution(_: &WeightLimit, _: &Option<Location>) -> Weight {
 		XcmGeneric::<Runtime>::unpaid_execution()
 	}
 }

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/xcm_config.rs

@@ -32,7 +32,7 @@ use bp_messages::LaneId;
 use bp_relayers::{PayRewardFromAccount, RewardsAccountOwner, RewardsAccountParams};
 use bp_runtime::ChainId;
 use frame_support::{
-	match_types, parameter_types,
+	parameter_types,
 	traits::{ConstU32, Contains, Equals, Everything, Nothing},
 };
 use frame_system::EnsureRoot;
@@ -69,19 +69,19 @@ use xcm_executor::{
 };
 
 parameter_types! {
-	pub const TokenLocation: MultiLocation = MultiLocation::parent();
+	pub const TokenLocation: Location = Location::parent();
 	pub RelayChainOrigin: RuntimeOrigin = cumulus_pallet_xcm::Origin::Relay.into();
 	pub RelayNetwork: NetworkId = NetworkId::Rococo;
-	pub UniversalLocation: InteriorMultiLocation =
-		X2(GlobalConsensus(RelayNetwork::get()), Parachain(ParachainInfo::parachain_id().into()));
+	pub UniversalLocation: InteriorLocation =
+		[GlobalConsensus(RelayNetwork::get()), Parachain(ParachainInfo::parachain_id().into())].into();
 	pub const MaxInstructions: u32 = 100;
 	pub const MaxAssetsIntoHolding: u32 = 64;
 	pub TreasuryAccount: AccountId = TREASURY_PALLET_ID.into_account_truncating();
-	pub RelayTreasuryLocation: MultiLocation = (Parent, PalletInstance(rococo_runtime_constants::TREASURY_PALLET_ID)).into();
-	pub SiblingPeople: MultiLocation = (Parent, Parachain(rococo_runtime_constants::system_parachain::PEOPLE_ID)).into();
+	pub RelayTreasuryLocation: Location = (Parent, PalletInstance(rococo_runtime_constants::TREASURY_PALLET_ID)).into();
+	pub SiblingPeople: Location = (Parent, Parachain(rococo_runtime_constants::system_parachain::PEOPLE_ID)).into();
 }
 
-/// Type for specifying how a `MultiLocation` can be converted into an `AccountId`. This is used
+/// Type for specifying how a `Location` can be converted into an `AccountId`. This is used
 /// when determining ownership of accounts for asset transacting and when attempting to use XCM
 /// `Transact` in order to determine the dispatch Origin.
 pub type LocationToAccountId = (
@@ -100,7 +100,7 @@ pub type CurrencyTransactor = CurrencyAdapter<
 	Balances,
 	// Use this currency when it is a fungible asset matching the given location or name:
 	IsConcrete<TokenLocation>,
-	// Do a simple punn to convert an AccountId32 MultiLocation into a native chain account ID:
+	// Do a simple punn to convert an AccountId32 Location into a native chain account ID:
 	LocationToAccountId,
 	// Our chain's account ID type (we can't get away without mentioning it explicitly):
 	AccountId,
@@ -132,11 +132,11 @@ pub type XcmOriginToTransactDispatchOrigin = (
 	XcmPassthrough<RuntimeOrigin>,
 );
 
-match_types! {
-	pub type ParentOrParentsPlurality: impl Contains<MultiLocation> = {
-		MultiLocation { parents: 1, interior: Here } |
-		MultiLocation { parents: 1, interior: X1(Plurality { .. }) }
-	};
+pub struct ParentOrParentsPlurality;
+impl Contains<Location> for ParentOrParentsPlurality {
+	fn contains(location: &Location) -> bool {
+		matches!(location.unpack(), (1, []) | (1, [Plurality { .. }]))
+	}
 }
 
 /// A call filter for the XCM Transact instruction. This is a temporary measure until we properly
@@ -331,7 +331,7 @@ impl xcm_executor::Config for XcmConfig {
 pub type PriceForParentDelivery =
 	ExponentialPrice<FeeAssetId, BaseDeliveryFee, TransactionByteFee, ParachainSystem>;
 
-/// Converts a local signed origin into an XCM multilocation.
+/// Converts a local signed origin into an XCM location.
 /// Forms the basis for local origins sending/executing XCMs.
 pub type LocalOriginToLocation = SignedToAccountId32<RuntimeOrigin, AccountId, RelayNetwork>;
 
@@ -407,14 +407,10 @@ impl<
 		BridgeLaneId,
 	>
 {
-	fn handle_fee(
-		fee: MultiAssets,
-		maybe_context: Option<&XcmContext>,
-		reason: FeeReason,
-	) -> MultiAssets {
+	fn handle_fee(fee: Assets, maybe_context: Option<&XcmContext>, reason: FeeReason) -> Assets {
 		if matches!(reason, FeeReason::Export { network: bridged_network, destination }
 				if bridged_network == DestNetwork::get() &&
-					destination == X1(Parachain(DestParaId::get().into())))
+					destination == [Parachain(DestParaId::get().into())])
 		{
 			// We have 2 relayer rewards accounts:
 			// - the SA of the source parachain on this BH: this pays the relayers for delivering
@@ -445,14 +441,14 @@ impl<
 					Fungible(total_fee) => {
 						let source_fee = total_fee / 2;
 						deposit_or_burn_fee::<AssetTransactor, _>(
-							MultiAsset { id: asset.id, fun: Fungible(source_fee) }.into(),
+							Asset { id: asset.id.clone(), fun: Fungible(source_fee) }.into(),
 							maybe_context,
 							source_para_account.clone(),
 						);
 
 						let dest_fee = total_fee - source_fee;
 						deposit_or_burn_fee::<AssetTransactor, _>(
-							MultiAsset { id: asset.id, fun: Fungible(dest_fee) }.into(),
+							Asset { id: asset.id, fun: Fungible(dest_fee) }.into(),
 							maybe_context,
 							dest_para_account.clone(),
 						);
@@ -467,7 +463,7 @@ impl<
 				}
 			}
 
-			return MultiAssets::new()
+			return Assets::new()
 		}
 
 		fee
@@ -477,10 +473,10 @@ impl<
 pub struct XcmFeeManagerFromComponentsBridgeHub<WaivedLocations, HandleFee>(
 	PhantomData<(WaivedLocations, HandleFee)>,
 );
-impl<WaivedLocations: Contains<MultiLocation>, FeeHandler: HandleFee> FeeManager
+impl<WaivedLocations: Contains<Location>, FeeHandler: HandleFee> FeeManager
 	for XcmFeeManagerFromComponentsBridgeHub<WaivedLocations, FeeHandler>
 {
-	fn is_waived(origin: Option<&MultiLocation>, fee_reason: FeeReason) -> bool {
+	fn is_waived(origin: Option<&Location>, fee_reason: FeeReason) -> bool {
 		let Some(loc) = origin else { return false };
 		if let Export { network, destination: Here } = fee_reason {
 			return !(network == EthereumNetwork::get())
@@ -488,7 +484,7 @@ impl<WaivedLocations: Contains<MultiLocation>, FeeHandler: HandleFee> FeeManager
 		WaivedLocations::contains(loc)
 	}
 
-	fn handle_fee(fee: MultiAssets, context: Option<&XcmContext>, reason: FeeReason) {
+	fn handle_fee(fee: Assets, context: Option<&XcmContext>, reason: FeeReason) {
 		FeeHandler::handle_fee(fee, context, reason);
 	}
 }