Add EmittedEvent

Author: raymondkfcheung

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

@@ -846,6 +846,9 @@ pub mod pallet {
 	#[pallet::storage]
 	pub(crate) type RecordedXcm<T: Config> = StorageValue<_, Xcm<()>>;
 
+	#[pallet::storage]
+	pub(crate) type EmittedEvent<T: Config> = StorageValue<_, <T as frame_system::Config>::RuntimeEvent>;
+
 	#[pallet::genesis_config]
 	pub struct GenesisConfig<T: Config> {
 		#[serde(skip)]
@@ -2589,6 +2592,9 @@ impl<T: Config> Pallet<T> {
 
 				XcmDryRunApiError::VersionedConversionFailed
 			})?;
+		if let Some(failed_event) = Pallet::<Runtime>::emitted_event() {
+			tracing::debug!("Failed event: {:?}", failed_event);
+		}
 
 		// Should only get messages from this call since we cleared previous ones.
 		let forwarded_xcms =
@@ -3502,6 +3508,8 @@ impl<T: Config> CheckSuspension for Pallet<T> {
 }
 
 impl<T: Config> RecordXcm for Pallet<T> {
+	type RuntimeEvent = <T as frame_system::Config>::RuntimeEvent;
+
 	fn should_record() -> bool {
 		ShouldRecordXcm::<T>::get()
 	}
@@ -3517,6 +3525,21 @@ impl<T: Config> RecordXcm for Pallet<T> {
 	fn record(xcm: Xcm<()>) {
 		RecordedXcm::<T>::put(xcm);
 	}
+
+	fn record_last_event() {
+		let records = frame_system::Pallet::<T>::events();
+		if let Some(record) = records.last() {
+			let event = record.event.clone();
+			tracing::debug!("Record last event: {:?}", event);
+			EmittedEvent::<T>::put(event);
+		}
+	}
+
+	fn emitted_event() -> Option<Self::RuntimeEvent> {
+		let event = EmittedEvent::<T>::get();
+		tracing::debug!("Emitted event: {:?}", event);
+		event
+	}
 }
 
 /// Ensure that the origin `o` represents an XCM (`Transact`) origin.

polkadot/xcm/xcm-executor/src/lib.rs

@@ -459,6 +459,9 @@ impl<Config: config::Config> XcmExecutor<Config> {
 					error.clone(),
 					self.context.message_id,
 				);
+				if Config::XcmRecorder::should_record() {
+					Config::XcmRecorder::record_last_event();
+				}
 				Err(error.into())
 			},
 		}
@@ -854,6 +857,9 @@ impl<Config: config::Config> XcmExecutor<Config> {
 							error,
 							self.context.message_id,
 						);
+						if Config::XcmRecorder::should_record() {
+							Config::XcmRecorder::record_last_event();
+						}
 						*r = Err(ExecutorError {
 							index: i as u32,
 							xcm_error: error,

polkadot/xcm/xcm-executor/src/traits/record_xcm.rs

@@ -20,6 +20,8 @@ use xcm::latest::Xcm;
 
 /// Trait for recording XCMs.
 pub trait RecordXcm {
+	type RuntimeEvent;
+
 	/// Whether or not we should record incoming XCMs.
 	fn should_record() -> bool;
 	/// Enable or disable recording.
@@ -29,9 +31,15 @@ pub trait RecordXcm {
 	fn recorded_xcm() -> Option<Xcm<()>>;
 	/// Record `xcm`.
 	fn record(xcm: Xcm<()>);
+	/// Record the last event.
+	fn record_last_event();
+	/// Get emitted events.
+	fn emitted_event() -> Option<Self::RuntimeEvent>;
 }
 
 impl RecordXcm for () {
+	type RuntimeEvent = ();
+
 	fn should_record() -> bool {
 		false
 	}
@@ -43,4 +51,8 @@ impl RecordXcm for () {
 	}
 
 	fn record(_: Xcm<()>) {}
+
+	fn record_last_event() {}
+
+	fn emitted_event() -> Option<Self::RuntimeEvent> { None }
 }