[XCM] add generic location to account converter that also works with external ecosystems

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/xcm_config.rs

@@ -105,12 +105,13 @@ pub type LocationToAccountId = (
 	AccountId32Aliases<RelayNetwork, AccountId>,
 	// Foreign locations alias into accounts according to a hash of their standard description.
 	HashedDescription<AccountId, DescribeFamily<DescribeAllTerminal>>,
-	// Different global consensus parachain sovereign account.
-	// (Used for over-bridge transfers and reserve processing)
-	GlobalConsensusParachainConvertsFor<UniversalLocation, AccountId>,
-	// Ethereum contract sovereign account.
-	// (Used to get convert ethereum contract locations to sovereign account)
+	GlobalLocationToAccount<UniversalLocation, AccountId>,
+);
+
+pub type GlobalLocationToAccount<UniversalLocation, AccountId> = (
+    GlobalConsensusParachainConvertsFor<UniversalLocation, AccountId>,
 	EthereumLocationsConverterFor<AccountId>,
+    ExternalConsensusLocationsConverterFor<UniversalLocation, AccountId>,
 );
 
 /// Means for transacting the native currency on this chain.

cumulus/parachains/runtimes/assets/asset-hub-westend/src/xcm_config.rs

@@ -98,14 +98,16 @@ pub type LocationToAccountId = (
 	AccountId32Aliases<RelayNetwork, AccountId>,
 	// Foreign locations alias into accounts according to a hash of their standard description.
 	HashedDescription<AccountId, DescribeFamily<DescribeAllTerminal>>,
-	// Different global consensus parachain sovereign account.
-	// (Used for over-bridge transfers and reserve processing)
-	GlobalConsensusParachainConvertsFor<UniversalLocation, AccountId>,
-	// Ethereum contract sovereign account.
-	// (Used to get convert ethereum contract locations to sovereign account)
+	GlobalLocationToAccount<UniversalLocation, AccountId>,
+);
+
+pub type GlobalLocationToAccount<UniversalLocation, AccountId> = (
+    GlobalConsensusParachainConvertsFor<UniversalLocation, AccountId>,
 	EthereumLocationsConverterFor<AccountId>,
+    ExternalConsensusLocationsConverterFor<UniversalLocation, AccountId>,
 );
 
+
 /// Means for transacting the native currency on this chain.
 pub type FungibleTransactor = FungibleAdapter<
 	// Use this currency:

polkadot/xcm/xcm-builder/src/location_conversion.rs

@@ -119,6 +119,7 @@
 	DescribeBodyTerminal,
 );
 
+
 pub struct DescribeFamily<DescribeInterior>(PhantomData<DescribeInterior>);
 impl<Suffix: DescribeLocation> DescribeLocation for DescribeFamily<Suffix> {
 	fn describe_location(l: &Location) -> Option<Vec<u8>> {
@@ -412,6 +413,7 @@
 	}
 }
 
+
 /// Converts a location which is a top-level parachain (i.e. a parachain held on a
 /// Relay-chain which provides its own consensus) into a 32-byte `AccountId`.
 ///
@@ -458,6 +460,48 @@
 	}
 }
 
+/// Converts locations from external global consensus systems (e.g., Ethereum, other parachains) into `AccountId`.
+/// This includes handling child locations (e.g., `AccountId(Alice)`) and extending the functionality of
+/// `GlobalConsensusParachainConvertsFor` and `EthereumLocationsConverterFor`.
+pub struct ExternalConsensusLocationsConverterFor<UniversalLocation, AccountId>(PhantomData<(UniversalLocation, AccountId)>);
+
+impl<UniversalLocation: Get<InteriorLocation>, AccountId: From<[u8; 32]> + Clone>
+    ConvertLocation<AccountId> for ExternalConsensusLocationsConverterFor<UniversalLocation, AccountId>
+{
+    fn convert_location(location: &Location) -> Option<AccountId> {
+        let universal_source = UniversalLocation::get();
+        log::trace!(
+			target: "xcm::location_conversion",
+			"ExternalConsensusLocationsConverterFor universal_source: {:?}, location: {:?}",
+			universal_source, location,
+		);
+
+		let owned_location = location.clone();
+        let (remote_network, remote_location) = ensure_is_remote(universal_source, owned_location).ok()?;
+
+        // replaces and extends `EthereumLocationsConverterFor` and `GlobalConsensusParachainConvertsFor`
+        let acc_id: AccountId = if let Ethereum { chain_id } = &remote_network {
+            match remote_location.as_slice() {
+               // equivalent to `EthereumLocationsConverterFor`
+               [] => (b"ethereum-chain", chain_id).using_encoded(blake2_256).into(),
+               // equivalent to `EthereumLocationsConverterFor`
+               [AccountKey20 { network: _, key }] => (b"ethereum-chain", chain_id, *key).using_encoded(blake2_256).into(),
+               // extends `EthereumLocationsConverterFor`
+               tail =>(b"ethereum-chain", chain_id, tail).using_encoded(blake2_256).into(),
+            }
+        } else {
+            match remote_location.as_slice() {
+                // equivalent to `GlobalConsensusParachainConvertsFor`
+			    [Parachain(para_id)] => (b"glblcnsnss/prchn_", remote_network, para_id).using_encoded(blake2_256).into(),
+    			// converts everything else based on hash of encoded location tail
+	    		tail => (b"glblcnsnss", remote_network, tail).using_encoded(blake2_256).into(),
+	    	}
+		};
+		Some(acc_id)
+    }
+}
+
+
 #[cfg(test)]
 mod tests {
 	use super::*;
@@ -1010,4 +1054,5 @@
 			actual_description
 		);
 	}
+
 }

prdoc/pr_7313.prdoc

@@ -0,0 +1,17 @@
+title: [XCM] add generic location to account converter that also works with external ecosystems.
+
+doc:
+- audience: Runtime User
+  description: |- 
+    Adds a new `ExternalConsensusLocationsConverterFor` struct to handle external global 
+    consensus locations and their child locations.
+    This struct extends the functionality of existing converters (`GlobalConsensusParachainConvertsFor`
+    and `EthereumLocationsConverterFor`) while maintaining backward compatibility.
+
+crates:
+  - name: xcm-builder
+    bump: minor 
+  - name: asset-hub-rococo-runtime
+    bump: minor
+  - name: asset-hub-westend-runtime
+    bump: minor