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>

polkadot/xcm/pallet-xcm-benchmarks/src/fungible/benchmarking.rs

@@ -24,7 +24,7 @@ use frame_support::{
 };
 use sp_runtime::traits::{Bounded, Zero};
 use sp_std::{prelude::*, vec};
-use xcm::latest::{prelude::*, MAX_ITEMS_IN_MULTIASSETS};
+use xcm::latest::{prelude::*, MAX_ITEMS_IN_ASSETS};
 use xcm_executor::traits::{ConvertLocation, FeeReason, TransactAsset};
 
 benchmarks_instance_pallet! {
@@ -43,7 +43,7 @@ benchmarks_instance_pallet! {
 	withdraw_asset {
 		let (sender_account, sender_location) = account_and_location::<T>(1);
 		let worst_case_holding = T::worst_case_holding(0);
-		let asset = T::get_multi_asset();
+		let asset = T::get_asset();
 
 		<AssetTransactorOf<T>>::deposit_asset(&asset, &sender_location, None).unwrap();
 		// check the assets of origin.
@@ -63,8 +63,8 @@ benchmarks_instance_pallet! {
 
 	transfer_asset {
 		let (sender_account, sender_location) = account_and_location::<T>(1);
-		let asset = T::get_multi_asset();
-		let assets: MultiAssets = vec![ asset.clone() ].into();
+		let asset = T::get_asset();
+		let assets: Assets = vec![ asset.clone() ].into();
 		// this xcm doesn't use holding
 
 		let dest_location = T::valid_destination()?;
@@ -95,10 +95,10 @@ benchmarks_instance_pallet! {
 		);
 		let sender_account_balance_before = T::TransactAsset::balance(&sender_account);
 
-		let asset = T::get_multi_asset();
+		let asset = T::get_asset();
 		<AssetTransactorOf<T>>::deposit_asset(&asset, &sender_location, None).unwrap();
 		assert!(T::TransactAsset::balance(&sender_account) > sender_account_balance_before);
-		let assets: MultiAssets = vec![ asset ].into();
+		let assets: Assets = vec![asset].into();
 		assert!(T::TransactAsset::balance(&dest_account).is_zero());
 
 		let mut executor = new_executor::<T>(sender_location);
@@ -129,7 +129,7 @@ benchmarks_instance_pallet! {
 				BenchmarkResult::from_weight(Weight::MAX)
 			))?;
 
-		let assets: MultiAssets = vec![ transferable_reserve_asset ].into();
+		let assets: Assets = vec![ transferable_reserve_asset ].into();
 
 		let mut executor = new_executor::<T>(trusted_reserve);
 		let instruction = Instruction::ReserveAssetDeposited(assets.clone());
@@ -143,7 +143,7 @@ benchmarks_instance_pallet! {
 	initiate_reserve_withdraw {
 		let (sender_account, sender_location) = account_and_location::<T>(1);
 		let holding = T::worst_case_holding(1);
-		let assets_filter = MultiAssetFilter::Definite(holding.clone().into_inner().into_iter().take(MAX_ITEMS_IN_MULTIASSETS).collect::<Vec<_>>().into());
+		let assets_filter = AssetFilter::Definite(holding.clone().into_inner().into_iter().take(MAX_ITEMS_IN_ASSETS).collect::<Vec<_>>().into());
 		let reserve = T::valid_destination().map_err(|_| BenchmarkError::Skip)?;
 
 		let (expected_fees_mode, expected_assets_in_holding) = T::DeliveryHelper::ensure_successful_delivery(
@@ -188,7 +188,7 @@ benchmarks_instance_pallet! {
 			)?;
 		}
 
-		let assets: MultiAssets = vec![ teleportable_asset ].into();
+		let assets: Assets = vec![ teleportable_asset ].into();
 
 		let mut executor = new_executor::<T>(trusted_teleporter);
 		let instruction = Instruction::ReceiveTeleportedAsset(assets.clone());
@@ -204,7 +204,7 @@ benchmarks_instance_pallet! {
 	}
 
 	deposit_asset {
-		let asset = T::get_multi_asset();
+		let asset = T::get_asset();
 		let mut holding = T::worst_case_holding(1);
 
 		// Add our asset to the holding.
@@ -230,7 +230,7 @@ benchmarks_instance_pallet! {
 	}
 
 	deposit_reserve_asset {
-		let asset = T::get_multi_asset();
+		let asset = T::get_asset();
 		let mut holding = T::worst_case_holding(1);
 
 		// Add our asset to the holding.
@@ -257,7 +257,7 @@ benchmarks_instance_pallet! {
 	}
 
 	initiate_teleport {
-		let asset = T::get_multi_asset();
+		let asset = T::get_asset();
 		let mut holding = T::worst_case_holding(0);
 
 		// Add our asset to the holding.

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

@@ -93,10 +93,10 @@ parameter_types! {
 
 pub struct MatchAnyFungible;
 impl xcm_executor::traits::MatchesFungible<u64> for MatchAnyFungible {
-	fn matches_fungible(m: &MultiAsset) -> Option<u64> {
+	fn matches_fungible(m: &Asset) -> Option<u64> {
 		use sp_runtime::traits::SaturatedConversion;
 		match m {
-			MultiAsset { fun: Fungible(amount), .. } => Some((*amount).saturated_into::<u64>()),
+			Asset { fun: Fungible(amount), .. } => Some((*amount).saturated_into::<u64>()),
 			_ => None,
 		}
 	}
@@ -151,13 +151,12 @@ impl crate::Config for Test {
 	type XcmConfig = XcmConfig;
 	type AccountIdConverter = AccountIdConverter;
 	type DeliveryHelper = ();
-	fn valid_destination() -> Result<MultiLocation, BenchmarkError> {
-		let valid_destination: MultiLocation =
-			X1(AccountId32 { network: None, id: [0u8; 32] }).into();
+	fn valid_destination() -> Result<Location, BenchmarkError> {
+		let valid_destination: Location = [AccountId32 { network: None, id: [0u8; 32] }].into();
 
 		Ok(valid_destination)
 	}
-	fn worst_case_holding(depositable_count: u32) -> MultiAssets {
+	fn worst_case_holding(depositable_count: u32) -> Assets {
 		crate::mock_worst_case_holding(
 			depositable_count,
 			<XcmConfig as xcm_executor::Config>::MaxAssetsIntoHolding::get(),
@@ -170,19 +169,19 @@ pub type TrustedReserves = xcm_builder::Case<ReserveConcreteFungible>;
 
 parameter_types! {
 	pub const CheckingAccount: Option<(u64, MintLocation)> = Some((100, MintLocation::Local));
-	pub const ChildTeleporter: MultiLocation = Parachain(1000).into_location();
-	pub const TrustedTeleporter: Option<(MultiLocation, MultiAsset)> = Some((
+	pub ChildTeleporter: Location = Parachain(1000).into_location();
+	pub TrustedTeleporter: Option<(Location, Asset)> = Some((
 		ChildTeleporter::get(),
-		MultiAsset { id: Concrete(Here.into_location()), fun: Fungible(100) },
+		Asset { id: AssetId(Here.into_location()), fun: Fungible(100) },
 	));
-	pub const TrustedReserve: Option<(MultiLocation, MultiAsset)> = Some((
+	pub TrustedReserve: Option<(Location, Asset)> = Some((
 		ChildTeleporter::get(),
-		MultiAsset { id: Concrete(Here.into_location()), fun: Fungible(100) },
+		Asset { id: AssetId(Here.into_location()), fun: Fungible(100) },
 	));
-	pub const TeleportConcreteFungible: (MultiAssetFilter, MultiLocation) =
-		(Wild(AllOf { fun: WildFungible, id: Concrete(Here.into_location()) }), ChildTeleporter::get());
-	pub const ReserveConcreteFungible: (MultiAssetFilter, MultiLocation) =
-		(Wild(AllOf { fun: WildFungible, id: Concrete(Here.into_location()) }), ChildTeleporter::get());
+	pub TeleportConcreteFungible: (AssetFilter, Location) =
+		(Wild(AllOf { fun: WildFungible, id: AssetId(Here.into_location()) }), ChildTeleporter::get());
+	pub ReserveConcreteFungible: (AssetFilter, Location) =
+		(Wild(AllOf { fun: WildFungible, id: AssetId(Here.into_location()) }), ChildTeleporter::get());
 }
 
 impl xcm_balances_benchmark::Config for Test {
@@ -191,10 +190,10 @@ impl xcm_balances_benchmark::Config for Test {
 	type TrustedTeleporter = TrustedTeleporter;
 	type TrustedReserve = TrustedReserve;
 
-	fn get_multi_asset() -> MultiAsset {
+	fn get_asset() -> Asset {
 		let amount =
 			<Balances as frame_support::traits::fungible::Inspect<u64>>::minimum_balance() as u128;
-		MultiAsset { id: Concrete(Here.into()), fun: Fungible(amount) }
+		Asset { id: AssetId(Here.into()), fun: Fungible(amount) }
 	}
 }
 

polkadot/xcm/pallet-xcm-benchmarks/src/fungible/mod.rs

@@ -37,14 +37,14 @@ pub mod pallet {
 		type CheckedAccount: Get<Option<(Self::AccountId, xcm_builder::MintLocation)>>;
 
 		/// A trusted location which we allow teleports from, and the asset we allow to teleport.
-		type TrustedTeleporter: Get<Option<(xcm::latest::MultiLocation, xcm::latest::MultiAsset)>>;
+		type TrustedTeleporter: Get<Option<(xcm::latest::Location, xcm::latest::Asset)>>;
 
 		/// A trusted location where reserve assets are stored, and the asset we allow to be
 		/// reserves.
-		type TrustedReserve: Get<Option<(xcm::latest::MultiLocation, xcm::latest::MultiAsset)>>;
+		type TrustedReserve: Get<Option<(xcm::latest::Location, xcm::latest::Asset)>>;
 
 		/// Give me a fungible asset that your asset transactor is going to accept.
-		fn get_multi_asset() -> xcm::latest::MultiAsset;
+		fn get_asset() -> xcm::latest::Asset;
 	}
 
 	#[pallet::pallet]

polkadot/xcm/pallet-xcm-benchmarks/src/generic/benchmarking.rs

@@ -77,7 +77,7 @@ benchmarks! {
 		let mut executor = new_executor::<T>(Default::default());
 		executor.set_holding(holding);
 
-		let fee_asset = Concrete(Here.into());
+		let fee_asset = AssetId(Here.into());
 
 		let instruction = Instruction::<XcmCallOf<T>>::BuyExecution {
 			fees: (fee_asset, 100_000_000u128).into(), // should be something inside of holding
@@ -95,7 +95,7 @@ benchmarks! {
 		let mut executor = new_executor::<T>(Default::default());
 		let (query_id, response) = T::worst_case_response();
 		let max_weight = Weight::MAX;
-		let querier: Option<MultiLocation> = Some(Here.into());
+		let querier: Option<Location> = Some(Here.into());
 		let instruction = Instruction::QueryResponse { query_id, response, max_weight, querier };
 		let xcm = Xcm(vec![instruction]);
 	}: {
@@ -174,15 +174,15 @@ benchmarks! {
 
 	descend_origin {
 		let mut executor = new_executor::<T>(Default::default());
-		let who = X2(OnlyChild, OnlyChild);
-		let instruction = Instruction::DescendOrigin(who);
+		let who = Junctions::from([OnlyChild, OnlyChild]);
+		let instruction = Instruction::DescendOrigin(who.clone());
 		let xcm = Xcm(vec![instruction]);
 	} : {
 		executor.bench_process(xcm)?;
 	} verify {
 		assert_eq!(
 			executor.origin(),
-			&Some(MultiLocation {
+			&Some(Location {
 				parents: 0,
 				interior: who,
 			}),
@@ -242,7 +242,7 @@ benchmarks! {
 			&origin,
 			assets.clone().into(),
 			&XcmContext {
-				origin: Some(origin),
+				origin: Some(origin.clone()),
 				message_id: [0; 32],
 				topic: None,
 			},
@@ -279,7 +279,7 @@ benchmarks! {
 		let origin = T::subscribe_origin()?;
 		let query_id = Default::default();
 		let max_response_weight = Default::default();
-		let mut executor = new_executor::<T>(origin);
+		let mut executor = new_executor::<T>(origin.clone());
 		let instruction = Instruction::SubscribeVersion { query_id, max_response_weight };
 		let xcm = Xcm(vec![instruction]);
 	} : {
@@ -299,14 +299,14 @@ benchmarks! {
 			query_id,
 			max_response_weight,
 			&XcmContext {
-				origin: Some(origin),
+				origin: Some(origin.clone()),
 				message_id: [0; 32],
 				topic: None,
 			},
 		).map_err(|_| "Could not start subscription")?;
 		assert!(<T::XcmConfig as xcm_executor::Config>::SubscriptionService::is_subscribed(&origin));
 
-		let mut executor = new_executor::<T>(origin);
+		let mut executor = new_executor::<T>(origin.clone());
 		let instruction = Instruction::UnsubscribeVersion;
 		let xcm = Xcm(vec![instruction]);
 	} : {
@@ -545,7 +545,7 @@ benchmarks! {
 	} verify {
 		use frame_support::traits::Get;
 		let universal_location = <T::XcmConfig as xcm_executor::Config>::UniversalLocation::get();
-		assert_eq!(executor.origin(), &Some(X1(alias).relative_to(&universal_location)));
+		assert_eq!(executor.origin(), &Some(Junctions::from([alias]).relative_to(&universal_location)));
 	}
 
 	export_message {
@@ -561,8 +561,8 @@ benchmarks! {
 
 		let (expected_fees_mode, expected_assets_in_holding) = T::DeliveryHelper::ensure_successful_delivery(
 			&origin,
-			&destination.into(),
-			FeeReason::Export { network, destination },
+			&destination.clone().into(),
+			FeeReason::Export { network, destination: destination.clone() },
 		);
 		let sender_account = T::AccountIdConverter::convert_location(&origin).unwrap();
 		let sender_account_balance_before = T::TransactAsset::balance(&sender_account);
@@ -575,7 +575,7 @@ benchmarks! {
 			executor.set_holding(expected_assets_in_holding.into());
 		}
 		let xcm = Xcm(vec![ExportMessage {
-			network, destination, xcm: inner_xcm,
+			network, destination: destination.clone(), xcm: inner_xcm,
 		}]);
 	}: {
 		executor.bench_process(xcm)?;
@@ -632,13 +632,13 @@ benchmarks! {
 
 		let (unlocker, owner, asset) = T::unlockable_asset()?;
 
-		let mut executor = new_executor::<T>(unlocker);
+		let mut executor = new_executor::<T>(unlocker.clone());
 
 		// We first place the asset in lock first...
 		<T::XcmConfig as xcm_executor::Config>::AssetLocker::prepare_lock(
 			unlocker,
 			asset.clone(),
-			owner,
+			owner.clone(),
 		)
 		.map_err(|_| BenchmarkError::Skip)?
 		.enact()
@@ -658,13 +658,13 @@ benchmarks! {
 
 		let (unlocker, owner, asset) = T::unlockable_asset()?;
 
-		let mut executor = new_executor::<T>(unlocker);
+		let mut executor = new_executor::<T>(unlocker.clone());
 
 		// We first place the asset in lock first...
 		<T::XcmConfig as xcm_executor::Config>::AssetLocker::prepare_lock(
 			unlocker,
 			asset.clone(),
-			owner,
+			owner.clone(),
 		)
 		.map_err(|_| BenchmarkError::Skip)?
 		.enact()
@@ -686,9 +686,9 @@ benchmarks! {
 
 		// We first place the asset in lock first...
 		<T::XcmConfig as xcm_executor::Config>::AssetLocker::prepare_lock(
-			locker,
+			locker.clone(),
 			asset.clone(),
-			owner,
+			owner.clone(),
 		)
 		.map_err(|_| BenchmarkError::Skip)?
 		.enact()
@@ -739,7 +739,7 @@ benchmarks! {
 
 		let mut executor = new_executor::<T>(origin);
 
-		let instruction = Instruction::AliasOrigin(target);
+		let instruction = Instruction::AliasOrigin(target.clone());
 		let xcm = Xcm(vec![instruction]);
 	}: {
 		executor.bench_process(xcm)?;

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

@@ -19,16 +19,16 @@
 use crate::{generic, mock::*, *};
 use codec::Decode;
 use frame_support::{
-	derive_impl, match_types, parameter_types,
-	traits::{Everything, OriginTrait},
+	derive_impl, parameter_types,
+	traits::{Contains, Everything, OriginTrait},
 	weights::Weight,
 };
 use sp_core::H256;
 use sp_runtime::traits::{BlakeTwo256, IdentityLookup, TrailingZeroInput};
 use xcm_builder::{
 	test_utils::{
-		Assets, TestAssetExchanger, TestAssetLocker, TestAssetTrap, TestSubscriptionService,
-		TestUniversalAliases,
+		AssetsInHolding, TestAssetExchanger, TestAssetLocker, TestAssetTrap,
+		TestSubscriptionService, TestUniversalAliases,
 	},
 	AliasForeignAccountId32, AllowUnpaidExecutionFrom,
 };
@@ -81,19 +81,15 @@ impl frame_system::Config for Test {
 /// The benchmarks in this pallet should never need an asset transactor to begin with.
 pub struct NoAssetTransactor;
 impl xcm_executor::traits::TransactAsset for NoAssetTransactor {
-	fn deposit_asset(
-		_: &MultiAsset,
-		_: &MultiLocation,
-		_: Option<&XcmContext>,
-	) -> Result<(), XcmError> {
+	fn deposit_asset(_: &Asset, _: &Location, _: Option<&XcmContext>) -> Result<(), XcmError> {
 		unreachable!();
 	}
 
 	fn withdraw_asset(
-		_: &MultiAsset,
-		_: &MultiLocation,
+		_: &Asset,
+		_: &Location,
 		_: Option<&XcmContext>,
-	) -> Result<Assets, XcmError> {
+	) -> Result<AssetsInHolding, XcmError> {
 		unreachable!();
 	}
 }
@@ -103,10 +99,11 @@ parameter_types! {
 	pub const MaxAssetsIntoHolding: u32 = 64;
 }
 
-match_types! {
-	pub type OnlyParachains: impl Contains<MultiLocation> = {
-		MultiLocation { parents: 0, interior: X1(Parachain(_)) }
-	};
+pub struct OnlyParachains;
+impl Contains<Location> for OnlyParachains {
+	fn contains(location: &Location) -> bool {
+		matches!(location.unpack(), (0, [Parachain(_)]))
+	}
 }
 
 type Aliasers = AliasForeignAccountId32<OnlyParachains>;
@@ -153,13 +150,13 @@ impl crate::Config for Test {
 	type XcmConfig = XcmConfig;
 	type AccountIdConverter = AccountIdConverter;
 	type DeliveryHelper = ();
-	fn valid_destination() -> Result<MultiLocation, BenchmarkError> {
-		let valid_destination: MultiLocation =
+	fn valid_destination() -> Result<Location, BenchmarkError> {
+		let valid_destination: Location =
 			Junction::AccountId32 { network: None, id: [0u8; 32] }.into();
 
 		Ok(valid_destination)
 	}
-	fn worst_case_holding(depositable_count: u32) -> MultiAssets {
+	fn worst_case_holding(depositable_count: u32) -> Assets {
 		crate::mock_worst_case_holding(
 			depositable_count,
 			<XcmConfig as xcm_executor::Config>::MaxAssetsIntoHolding::get(),
@@ -172,48 +169,47 @@ impl generic::Config for Test {
 	type RuntimeCall = RuntimeCall;
 
 	fn worst_case_response() -> (u64, Response) {
-		let assets: MultiAssets = (Concrete(Here.into()), 100).into();
+		let assets: Assets = (AssetId(Here.into()), 100).into();
 		(0, Response::Assets(assets))
 	}
 
-	fn worst_case_asset_exchange() -> Result<(MultiAssets, MultiAssets), BenchmarkError> {
+	fn worst_case_asset_exchange() -> Result<(Assets, Assets), BenchmarkError> {
 		Ok(Default::default())
 	}
 
-	fn universal_alias() -> Result<(MultiLocation, Junction), BenchmarkError> {
+	fn universal_alias() -> Result<(Location, Junction), BenchmarkError> {
 		Ok((Here.into(), GlobalConsensus(ByGenesis([0; 32]))))
 	}
 
 	fn transact_origin_and_runtime_call(
-	) -> Result<(MultiLocation, <Self as generic::Config>::RuntimeCall), BenchmarkError> {
+	) -> Result<(Location, <Self as generic::Config>::RuntimeCall), BenchmarkError> {
 		Ok((Default::default(), frame_system::Call::remark_with_event { remark: vec![] }.into()))
 	}
 
-	fn subscribe_origin() -> Result<MultiLocation, BenchmarkError> {
+	fn subscribe_origin() -> Result<Location, BenchmarkError> {
 		Ok(Default::default())
 	}
 
-	fn claimable_asset() -> Result<(MultiLocation, MultiLocation, MultiAssets), BenchmarkError> {
-		let assets: MultiAssets = (Concrete(Here.into()), 100).into();
-		let ticket = MultiLocation { parents: 0, interior: X1(GeneralIndex(0)) };
+	fn claimable_asset() -> Result<(Location, Location, Assets), BenchmarkError> {
+		let assets: Assets = (AssetId(Here.into()), 100).into();
+		let ticket = Location { parents: 0, interior: [GeneralIndex(0)].into() };
 		Ok((Default::default(), ticket, assets))
 	}
 
-	fn unlockable_asset() -> Result<(MultiLocation, MultiLocation, MultiAsset), BenchmarkError> {
-		let assets: MultiAsset = (Concrete(Here.into()), 100).into();
+	fn unlockable_asset() -> Result<(Location, Location, Asset), BenchmarkError> {
+		let assets: Asset = (AssetId(Here.into()), 100).into();
 		Ok((Default::default(), account_id_junction::<Test>(1).into(), assets))
 	}
 
 	fn export_message_origin_and_destination(
-	) -> Result<(MultiLocation, NetworkId, InteriorMultiLocation), BenchmarkError> {
+	) -> Result<(Location, NetworkId, InteriorLocation), BenchmarkError> {
 		// No MessageExporter in tests
 		Err(BenchmarkError::Skip)
 	}
 
-	fn alias_origin() -> Result<(MultiLocation, MultiLocation), BenchmarkError> {
-		let origin: MultiLocation =
-			(Parachain(1), AccountId32 { network: None, id: [0; 32] }).into();
-		let target: MultiLocation = AccountId32 { network: None, id: [0; 32] }.into();
+	fn alias_origin() -> Result<(Location, Location), BenchmarkError> {
+		let origin: Location = (Parachain(1), AccountId32 { network: None, id: [0; 32] }).into();
+		let target: Location = AccountId32 { network: None, id: [0; 32] }.into();
 		Ok((origin, target))
 	}
 }
@@ -233,9 +229,9 @@ where
 	<RuntimeOrigin as OriginTrait>::AccountId: Decode,
 {
 	fn convert_origin(
-		_origin: impl Into<MultiLocation>,
+		_origin: impl Into<Location>,
 		_kind: OriginKind,
-	) -> Result<RuntimeOrigin, MultiLocation> {
+	) -> Result<RuntimeOrigin, Location> {
 		Ok(RuntimeOrigin::signed(
 			<RuntimeOrigin as OriginTrait>::AccountId::decode(&mut TrailingZeroInput::zeroes())
 				.expect("infinite length input; no invalid inputs for type; qed"),

polkadot/xcm/pallet-xcm-benchmarks/src/generic/mod.rs

@@ -26,10 +26,7 @@ pub mod pallet {
 	use frame_benchmarking::BenchmarkError;
 	use frame_support::{dispatch::GetDispatchInfo, pallet_prelude::Encode};
 	use sp_runtime::traits::Dispatchable;
-	use xcm::latest::{
-		InteriorMultiLocation, Junction, MultiAsset, MultiAssets, MultiLocation, NetworkId,
-		Response,
-	};
+	use xcm::latest::{Asset, Assets, InteriorLocation, Junction, Location, NetworkId, Response};
 
 	#[pallet::config]
 	pub trait Config<I: 'static = ()>: frame_system::Config + crate::Config {
@@ -53,44 +50,44 @@ pub mod pallet {
 		/// from, whereas the second element represents the assets that are being exchanged to.
 		///
 		/// If set to `Err`, benchmarks which rely on an `exchange_asset` will be skipped.
-		fn worst_case_asset_exchange() -> Result<(MultiAssets, MultiAssets), BenchmarkError>;
+		fn worst_case_asset_exchange() -> Result<(Assets, Assets), BenchmarkError>;
 
-		/// A `(MultiLocation, Junction)` that is one of the `UniversalAliases` configured by the
+		/// A `(Location, Junction)` that is one of the `UniversalAliases` configured by the
 		/// XCM executor.
 		///
 		/// If set to `Err`, benchmarks which rely on a universal alias will be skipped.
-		fn universal_alias() -> Result<(MultiLocation, Junction), BenchmarkError>;
+		fn universal_alias() -> Result<(Location, Junction), BenchmarkError>;
 
-		/// The `MultiLocation` and `RuntimeCall` used for successful transaction XCMs.
+		/// The `Location` and `RuntimeCall` used for successful transaction XCMs.
 		///
 		/// If set to `Err`, benchmarks which rely on a `transact_origin_and_runtime_call` will be
 		/// skipped.
 		fn transact_origin_and_runtime_call(
-		) -> Result<(MultiLocation, <Self as crate::generic::Config<I>>::RuntimeCall), BenchmarkError>;
+		) -> Result<(Location, <Self as crate::generic::Config<I>>::RuntimeCall), BenchmarkError>;
 
-		/// A valid `MultiLocation` we can successfully subscribe to.
+		/// A valid `Location` we can successfully subscribe to.
 		///
 		/// If set to `Err`, benchmarks which rely on a `subscribe_origin` will be skipped.
-		fn subscribe_origin() -> Result<MultiLocation, BenchmarkError>;
+		fn subscribe_origin() -> Result<Location, BenchmarkError>;
 
 		/// Return an origin, ticket, and assets that can be trapped and claimed.
-		fn claimable_asset() -> Result<(MultiLocation, MultiLocation, MultiAssets), BenchmarkError>;
+		fn claimable_asset() -> Result<(Location, Location, Assets), BenchmarkError>;
 
 		/// Return an unlocker, owner and assets that can be locked and unlocked.
-		fn unlockable_asset() -> Result<(MultiLocation, MultiLocation, MultiAsset), BenchmarkError>;
+		fn unlockable_asset() -> Result<(Location, Location, Asset), BenchmarkError>;
 
-		/// A `(MultiLocation, NetworkId, InteriorMultiLocation)` we can successfully export message
+		/// A `(Location, NetworkId, InteriorLocation)` we can successfully export message
 		/// to.
 		///
 		/// If set to `Err`, benchmarks which rely on `export_message` will be skipped.
 		fn export_message_origin_and_destination(
-		) -> Result<(MultiLocation, NetworkId, InteriorMultiLocation), BenchmarkError>;
+		) -> Result<(Location, NetworkId, InteriorLocation), BenchmarkError>;
 
-		/// A `(MultiLocation, MultiLocation)` that is one of the `Aliasers` configured by the XCM
+		/// A `(Location, Location)` that is one of the `Aliasers` configured by the XCM
 		/// executor.
 		///
 		/// If set to `Err`, benchmarks which rely on a universal alias will be skipped.
-		fn alias_origin() -> Result<(MultiLocation, MultiLocation), BenchmarkError>;
+		fn alias_origin() -> Result<(Location, Location), BenchmarkError>;
 
 		/// Returns a valid pallet info for `ExpectPallet` or `QueryPallet` benchmark.
 		///

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

@@ -41,18 +41,18 @@ pub trait Config: frame_system::Config {
 	/// `TransactAsset` is implemented.
 	type XcmConfig: XcmConfig;
 
-	/// A converter between a multi-location to a sovereign account.
+	/// A converter between a location to a sovereign account.
 	type AccountIdConverter: ConvertLocation<Self::AccountId>;
 
 	/// Helper that ensures successful delivery for XCM instructions which need `SendXcm`.
 	type DeliveryHelper: EnsureDelivery;
 
 	/// Does any necessary setup to create a valid destination for XCM messages.
-	/// Returns that destination's multi-location to be used in benchmarks.
-	fn valid_destination() -> Result<MultiLocation, BenchmarkError>;
+	/// Returns that destination's location to be used in benchmarks.
+	fn valid_destination() -> Result<Location, BenchmarkError>;
 
 	/// Worst case scenario for a holding account in this runtime.
-	fn worst_case_holding(depositable_count: u32) -> MultiAssets;
+	fn worst_case_holding(depositable_count: u32) -> Assets;
 }
 
 const SEED: u32 = 0;
@@ -66,21 +66,21 @@ pub type AssetTransactorOf<T> = <<T as Config>::XcmConfig as XcmConfig>::AssetTr
 /// The call type of executor's config. Should eventually resolve to the same overarching call type.
 pub type XcmCallOf<T> = <<T as Config>::XcmConfig as XcmConfig>::RuntimeCall;
 
-pub fn mock_worst_case_holding(depositable_count: u32, max_assets: u32) -> MultiAssets {
+pub fn mock_worst_case_holding(depositable_count: u32, max_assets: u32) -> Assets {
 	let fungibles_amount: u128 = 100;
 	let holding_fungibles = max_assets / 2 - depositable_count;
 	let holding_non_fungibles = holding_fungibles;
 	(0..holding_fungibles)
 		.map(|i| {
-			MultiAsset {
-				id: Concrete(GeneralIndex(i as u128).into()),
+			Asset {
+				id: AssetId(GeneralIndex(i as u128).into()),
 				fun: Fungible(fungibles_amount * i as u128),
 			}
 			.into()
 		})
-		.chain(core::iter::once(MultiAsset { id: Concrete(Here.into()), fun: Fungible(u128::MAX) }))
-		.chain((0..holding_non_fungibles).map(|i| MultiAsset {
-			id: Concrete(GeneralIndex(i as u128).into()),
+		.chain(core::iter::once(Asset { id: AssetId(Here.into()), fun: Fungible(u128::MAX) }))
+		.chain((0..holding_non_fungibles).map(|i| Asset {
+			id: AssetId(GeneralIndex(i as u128).into()),
 			fun: NonFungible(asset_instance_from(i)),
 		}))
 		.collect::<Vec<_>>()
@@ -94,11 +94,11 @@ pub fn asset_instance_from(x: u32) -> AssetInstance {
 	AssetInstance::Array4(instance)
 }
 
-pub fn new_executor<T: Config>(origin: MultiLocation) -> ExecutorOf<T> {
+pub fn new_executor<T: Config>(origin: Location) -> ExecutorOf<T> {
 	ExecutorOf::<T>::new(origin, [0; 32])
 }
 
-/// Build a multi-location from an account id.
+/// Build a location from an account id.
 fn account_id_junction<T: frame_system::Config>(index: u32) -> Junction {
 	let account: T::AccountId = account("account", index, SEED);
 	let mut encoded = account.encode();
@@ -108,8 +108,8 @@ fn account_id_junction<T: frame_system::Config>(index: u32) -> Junction {
 	Junction::AccountId32 { network: None, id }
 }
 
-pub fn account_and_location<T: Config>(index: u32) -> (T::AccountId, MultiLocation) {
-	let location: MultiLocation = account_id_junction::<T>(index).into();
+pub fn account_and_location<T: Config>(index: u32) -> (T::AccountId, Location) {
+	let location: Location = account_id_junction::<T>(index).into();
 	let account = T::AccountIdConverter::convert_location(&location).unwrap();
 
 	(account, location)
@@ -121,21 +121,21 @@ pub trait EnsureDelivery {
 	/// Prepare all requirements for successful `XcmSender: SendXcm` passing (accounts, balances,
 	/// channels ...). Returns:
 	/// - possible `FeesMode` which is expected to be set to executor
-	/// - possible `MultiAssets` which are expected to be subsume to the Holding Register
+	/// - possible `Assets` which are expected to be subsume to the Holding Register
 	fn ensure_successful_delivery(
-		origin_ref: &MultiLocation,
-		dest: &MultiLocation,
+		origin_ref: &Location,
+		dest: &Location,
 		fee_reason: FeeReason,
-	) -> (Option<FeesMode>, Option<MultiAssets>);
+	) -> (Option<FeesMode>, Option<Assets>);
 }
 
 /// `()` implementation does nothing which means no special requirements for environment.
 impl EnsureDelivery for () {
 	fn ensure_successful_delivery(
-		_origin_ref: &MultiLocation,
-		_dest: &MultiLocation,
+		_origin_ref: &Location,
+		_dest: &Location,
 		_fee_reason: FeeReason,
-	) -> (Option<FeesMode>, Option<MultiAssets>) {
+	) -> (Option<FeesMode>, Option<Assets>) {
 		// doing nothing
 		(None, None)
 	}

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

@@ -22,8 +22,8 @@ use xcm::latest::Weight;
 pub struct DevNull;
 impl xcm::opaque::latest::SendXcm for DevNull {
 	type Ticket = ();
-	fn validate(_: &mut Option<MultiLocation>, _: &mut Option<Xcm<()>>) -> SendResult<()> {
-		Ok(((), MultiAssets::new()))
+	fn validate(_: &mut Option<Location>, _: &mut Option<Xcm<()>>) -> SendResult<()> {
+		Ok(((), Assets::new()))
 	}
 	fn deliver(_: ()) -> Result<XcmHash, SendError> {
 		Ok([0; 32])
@@ -31,13 +31,13 @@ impl xcm::opaque::latest::SendXcm for DevNull {
 }
 
 impl xcm_executor::traits::OnResponse for DevNull {
-	fn expecting_response(_: &MultiLocation, _: u64, _: Option<&MultiLocation>) -> bool {
+	fn expecting_response(_: &Location, _: u64, _: Option<&Location>) -> bool {
 		false
 	}
 	fn on_response(
-		_: &MultiLocation,
+		_: &Location,
 		_: u64,
-		_: Option<&MultiLocation>,
+		_: Option<&Location>,
 		_: Response,
 		_: Weight,
 		_: &XcmContext,
@@ -48,9 +48,9 @@ impl xcm_executor::traits::OnResponse for DevNull {
 
 pub struct AccountIdConverter;
 impl xcm_executor::traits::ConvertLocation<u64> for AccountIdConverter {
-	fn convert_location(ml: &MultiLocation) -> Option<u64> {
-		match ml {
-			MultiLocation { parents: 0, interior: X1(Junction::AccountId32 { id, .. }) } =>
+	fn convert_location(ml: &Location) -> Option<u64> {
+		match ml.unpack() {
+			(0, [Junction::AccountId32 { id, .. }]) =>
 				Some(<u64 as codec::Decode>::decode(&mut &*id.to_vec()).unwrap()),
 			_ => None,
 		}
@@ -58,14 +58,14 @@ impl xcm_executor::traits::ConvertLocation<u64> for AccountIdConverter {
 }
 
 parameter_types! {
-	pub UniversalLocation: InteriorMultiLocation = Junction::Parachain(101).into();
+	pub UniversalLocation: InteriorLocation = Junction::Parachain(101).into();
 	pub UnitWeightCost: Weight = Weight::from_parts(10, 10);
-	pub WeightPrice: (AssetId, u128, u128) = (Concrete(Here.into()), 1_000_000, 1024);
+	pub WeightPrice: (AssetId, u128, u128) = (AssetId(Here.into()), 1_000_000, 1024);
 }
 
 pub struct AllAssetLocationsPass;
-impl ContainsPair<MultiAsset, MultiLocation> for AllAssetLocationsPass {
-	fn contains(_: &MultiAsset, _: &MultiLocation) -> bool {
+impl ContainsPair<Asset, Location> for AllAssetLocationsPass {
+	fn contains(_: &Asset, _: &Location) -> bool {
 		true
 	}
 }