Benchmark Barrier for Accurate Weighting on Early Rejection

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

@@ -100,8 +100,9 @@ use pallet_xcm::{EnsureXcm, IsVoiceOfBody};
 use polkadot_runtime_common::{BlockHashCount, SlowAdjustingFeeUpdate};
 #[cfg(feature = "runtime-benchmarks")]
 use xcm::latest::prelude::{
-	Asset, Assets as XcmAssets, Fungible, Here, InteriorLocation, Junction, Junction::*, Location,
-	NetworkId, NonFungible, ParentThen, Response, WeightLimit, XCM_VERSION,
+	Asset, Assets as XcmAssets, Fungible, Here, Instruction, InteriorLocation, Junction,
+	Junction::*, Location, NetworkId, NonFungible, ParentThen, Response, WeightLimit, Xcm,
+	XCM_VERSION,
 };
 use xcm::{
 	latest::prelude::{AssetId, BodyId},
@@ -2016,6 +2017,10 @@ impl_runtime_apis! {
 						Location::new(1, [Parachain(1001), AccountId32 { id: [111u8; 32], network: None }]),
 					))
 				}
+
+				fn worst_case_for_not_passing_barrier() -> Result<Xcm<Instruction<Self>>, BenchmarkError> {
+					Err(BenchmarkError::Skip)
+				}
 			}
 
 			type XcmBalances = pallet_xcm_benchmarks::fungible::Pallet::<Runtime>;

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

@@ -120,8 +120,9 @@ use frame_support::traits::PalletInfoAccess;
 
 #[cfg(feature = "runtime-benchmarks")]
 use xcm::latest::prelude::{
-	Asset, Assets as XcmAssets, Fungible, Here, InteriorLocation, Junction, Junction::*, Location,
-	NetworkId, NonFungible, ParentThen, Response, WeightLimit, XCM_VERSION,
+	Asset, Assets as XcmAssets, Fungible, Here, Instruction, InteriorLocation, Junction,
+	Junction::*, Location, NetworkId, NonFungible, ParentThen, Response, WeightLimit, Xcm,
+	XCM_VERSION,
 };
 
 use xcm_runtime_apis::{
@@ -2562,6 +2563,29 @@ pallet_revive::impl_runtime_apis_plus_revive!(
 						Location::new(1, [Parachain(1001), AccountId32 { id: [111u8; 32], network: None }]),
 					))
 				}
+
+				fn worst_case_for_not_passing_barrier() -> Result<Xcm<Instruction<Self>>, BenchmarkError> {
+					use xcm::latest::prelude::{ClearOrigin, SetAppendix, SetTopic};
+
+					let nested_limit = xcm_executor::RECURSION_LIMIT as usize - 2;
+
+					// Within the recursion limit, this is fine.
+					let mut set_topic = Xcm(vec![SetTopic([42; 32])]);
+					for _ in 0..nested_limit {
+						set_topic = Xcm(vec![SetAppendix(set_topic)]);
+					}
+					let set_topics = Xcm(vec![SetAppendix(set_topic); nested_limit]);
+
+					// Exceed the recursion limit, this will be rejected.
+					let mut clear_origin = Xcm(vec![SetAppendix(Xcm(vec![ClearOrigin]))]);
+					for _ in 0..=nested_limit {
+						clear_origin = Xcm(vec![SetAppendix(clear_origin)]);
+					}
+
+					let xcm = Xcm(vec![SetAppendix(set_topics), SetAppendix(clear_origin)]);
+
+					Ok(xcm)
+				}
 			}
 
 			type XcmBalances = pallet_xcm_benchmarks::fungible::Pallet::<Runtime>;

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

@@ -17,8 +17,8 @@ mod pallet_xcm_benchmarks_fungible;
 mod pallet_xcm_benchmarks_generic;
 
 use crate::{
-	xcm_config::{ERC20TransferGasLimit, MaxAssetsIntoHolding},
-	Runtime,
+	xcm_config::{ERC20TransferGasLimit, MaxAssetsIntoHolding, MaxInstructions},
+	Runtime, RuntimeCall,
 };
 use alloc::vec::Vec;
 use assets_common::IsLocalAccountKey20;
@@ -30,6 +30,8 @@ use xcm::{
 	latest::{prelude::*, AssetTransferFilter},
 	DoubleEncoded,
 };
+use xcm_builder::WeightInfoBounds;
+use xcm_executor::traits::WeightBounds;
 
 trait WeighAssets {
 	fn weigh_assets(&self, weight: Weight) -> Weight;
@@ -303,3 +305,26 @@ impl<Call> XcmWeightInfo<Call> for AssetHubWestendXcmWeight<Call> {
 		XcmGeneric::<Runtime>::execute_with_origin()
 	}
 }
+
+pub struct AssetHubWestendXcmWeightInfoBounds;
+impl WeightBounds<RuntimeCall> for AssetHubWestendXcmWeightInfoBounds {
+	fn weight(
+		message: &mut Xcm<RuntimeCall>,
+		weight_limit: Weight,
+	) -> Result<Weight, InstructionError> {
+		WeightInfoBounds::<AssetHubWestendXcmWeight<RuntimeCall>, RuntimeCall, MaxInstructions>::weight(
+			message,
+			weight_limit,
+		)
+	}
+
+	fn instr_weight(instruction: &mut Instruction<RuntimeCall>) -> Result<Weight, XcmError> {
+		WeightInfoBounds::<AssetHubWestendXcmWeight<RuntimeCall>, RuntimeCall, MaxInstructions>::instr_weight(
+			instruction,
+		)
+	}
+
+	fn barrier_check_weight() -> Option<Weight> {
+		Some(XcmGeneric::<Runtime>::barrier_check())
+	}
+}