ERC20 Asset Transactor

cumulus/parachains/integration-tests/emulated/chains/parachains/assets/asset-hub-westend/src/lib.rs

@@ -52,6 +52,7 @@ decl_test_parachains! {
 			PoolAssets: asset_hub_westend_runtime::PoolAssets,
 			AssetConversion: asset_hub_westend_runtime::AssetConversion,
 			SnowbridgeSystemFrontend: asset_hub_westend_runtime::SnowbridgeSystemFrontend,
+			Revive: asset_hub_westend_runtime::Revive,
 		}
 	},
 }

cumulus/parachains/runtimes/assets/asset-hub-rococo/Cargo.toml

@@ -150,6 +150,7 @@ runtime-benchmarks = [
 	"xcm/runtime-benchmarks",
 ]
 try-runtime = [
+	"assets-common/try-runtime",
 	"cumulus-pallet-aura-ext/try-runtime",
 	"cumulus-pallet-parachain-system/try-runtime",
 	"cumulus-pallet-weight-reclaim/try-runtime",

cumulus/parachains/runtimes/assets/asset-hub-westend/Cargo.toml

@@ -108,7 +108,9 @@ snowbridge-pallet-system-frontend = { workspace = true }
 snowbridge-runtime-common = { workspace = true }
 
 [dev-dependencies]
+alloy-core = { workspace = true, features = ["sol-types"] }
 asset-test-utils = { workspace = true, default-features = true }
+pallet-revive-fixtures = { workspace = true, default-features = true }
 parachains-runtimes-test-utils = { workspace = true, default-features = true }
 
 [build-dependencies]
@@ -163,6 +165,7 @@ runtime-benchmarks = [
 	"xcm/runtime-benchmarks",
 ]
 try-runtime = [
+	"assets-common/try-runtime",
 	"cumulus-pallet-aura-ext/try-runtime",
 	"cumulus-pallet-parachain-system/try-runtime",
 	"cumulus-pallet-weight-reclaim/try-runtime",
@@ -204,6 +207,7 @@ try-runtime = [
 	"sp-runtime/try-runtime",
 ]
 std = [
+	"alloy-core/std",
 	"assets-common/std",
 	"bp-asset-hub-rococo/std",
 	"bp-asset-hub-westend/std",

cumulus/parachains/runtimes/assets/asset-hub-westend/src/weights/xcm/mod.rs

@@ -16,9 +16,13 @@
 mod pallet_xcm_benchmarks_fungible;
 mod pallet_xcm_benchmarks_generic;
 
-use crate::{xcm_config::MaxAssetsIntoHolding, Runtime};
+use crate::{
+	xcm_config::{ERC20TransferGasLimit, MaxAssetsIntoHolding},
+	Runtime,
+};
 use alloc::vec::Vec;
-use frame_support::weights::Weight;
+use assets_common::IsLocalAccountKey20;
+use frame_support::{traits::Contains, weights::Weight};
 use pallet_xcm_benchmarks_fungible::WeightInfo as XcmFungibleWeight;
 use pallet_xcm_benchmarks_generic::WeightInfo as XcmGeneric;
 use sp_runtime::BoundedVec;
@@ -54,9 +58,33 @@ impl WeighAssets for AssetFilter {
 	}
 }
 
+trait WeighAsset {
+	/// Return one worst-case estimate: `weight`, or another.
+	fn weigh_asset(&self, weight: Weight) -> Weight;
+}
+
+impl WeighAsset for Asset {
+	fn weigh_asset(&self, weight: Weight) -> Weight {
+		// If the asset is a smart contract ERC20, then we know the gas limit,
+		// else we return the weight that was passed in, that's already
+		// the worst case for non-ERC20 assets.
+		if IsLocalAccountKey20::contains(&self.id.0) {
+			ERC20TransferGasLimit::get()
+		} else {
+			weight
+		}
+	}
+}
+
 impl WeighAssets for Assets {
 	fn weigh_assets(&self, weight: Weight) -> Weight {
-		weight.saturating_mul(self.inner().iter().count() as u64)
+		// We start with zero.
+		let mut final_weight = Weight::zero();
+		// For each asset, we add weight depending on the type of asset.
+		for asset in self.inner().iter() {
+			final_weight = final_weight.saturating_add(asset.weigh_asset(weight));
+		}
+		final_weight
 	}
 }
 

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

@@ -30,6 +30,7 @@ use frame_support::{
 		tokens::imbalance::{ResolveAssetTo, ResolveTo},
 		ConstU32, Contains, Equals, Everything, LinearStoragePrice, PalletInfoAccess,
 	},
+	PalletId,
 };
 use frame_system::EnsureRoot;
 use pallet_xcm::{AuthorizedAliasers, XcmPassthrough};
@@ -209,13 +210,39 @@ pub type PoolFungiblesTransactor = FungiblesAdapter<
 	CheckingAccount,
 >;
 
+parameter_types! {
+	/// Taken from the real gas and deposits of a standard ERC20 transfer call.
+	pub const ERC20TransferGasLimit: Weight = Weight::from_parts(700_000_000, 200_000);
+	pub const ERC20TransferStorageDepositLimit: Balance = 10_200_000_000;
+	pub ERC20TransfersCheckingAccount: AccountId = PalletId(*b"py/revch").into_account_truncating();
+}
+
+/// Transactor for ERC20 tokens.
+pub type ERC20Transactor = assets_common::ERC20Transactor<
+	// We need this for accessing pallet-revive.
+	Runtime,
+	// The matcher for smart contracts.
+	assets_common::ERC20Matcher,
+	// How to convert from a location to an account id.
+	LocationToAccountId,
+	// The maximum gas that can be used by a standard ERC20 transfer.
+	ERC20TransferGasLimit,
+	// The maximum storage deposit that can be used by a standard ERC20 transfer.
+	ERC20TransferStorageDepositLimit,
+	// We're generic over this so we can't escape specifying it.
+	AccountId,
+	// Checking account for ERC20 transfers.
+	ERC20TransfersCheckingAccount,
+>;
+
 /// Means for transacting assets on this chain.
 pub type AssetTransactors = (
 	FungibleTransactor,
 	FungiblesTransactor,
 	ForeignFungiblesTransactor,
 	PoolFungiblesTransactor,
 	UniquesTransactor,
+	ERC20Transactor,
 );
 
 /// This is the type we use to convert an (incoming) XCM origin into a local `Origin` instance,