Add benchmark for system::set_code intrinsic

fixes paritytech#13192

frame/system/benchmarking/src/lib.rs

@@ -22,7 +22,7 @@
 use codec::Encode;
 use frame_benchmarking::v1::{benchmarks, whitelisted_caller};
 use frame_support::{dispatch::DispatchClass, storage, traits::Get};
-use frame_system::{Call, Pallet as System, RawOrigin};
+use frame_system::{Call, EventRecord, Pallet as System, Phase, RawOrigin};
 use sp_core::storage::well_known_keys;
 use sp_runtime::traits::Hash;
 use sp_std::{prelude::*, vec};
@@ -49,9 +49,17 @@ benchmarks! {
 	}: _(RawOrigin::Root, Default::default())
 
 	set_code {
-		let runtime_blob = include_bytes!("../runtimes/kitchensink_runtime.compact.compressed.wasm");
+		let runtime_blob = include_bytes!("../res/kitchensink_runtime.compact.compressed.wasm");
 	}: _(RawOrigin::Root, runtime_blob.to_vec())
 	verify {
+		assert_eq!(
+		System::<T>::events(),
+			vec![EventRecord {
+				phase: Phase::Initialization,
+				event: frame_system::Event::<T>::CodeUpdated.into(),
+				topics: vec![],
+			}],
+		);
 	}
 
 	#[extra]

frame/system/src/lib.rs

@@ -404,10 +404,10 @@ pub mod pallet {
 		/// - 1 digest item.
 		/// - 1 event.
 		/// The weight of this function is dependent on the runtime, but generally this is very
-		/// expensive. We will treat this as a full block.
+		/// expensive.
 		/// # </weight>
 		#[pallet::call_index(2)]
-		#[pallet::weight((T::SystemWeightInfo::set_code(code.len() as u32), DispatchClass::Operational))]
+		#[pallet::weight((T::SystemWeightInfo::set_code(), DispatchClass::Operational))]
 		pub fn set_code(origin: OriginFor<T>, code: Vec<u8>) -> DispatchResultWithPostInfo {
 			ensure_root(origin)?;
 			Self::can_set_code(&code)?;
@@ -1624,13 +1624,18 @@ impl<T: Config> Pallet<T> {
 			.and_then(|v| RuntimeVersion::decode(&mut &v[..]).ok())
 			.ok_or(Error::<T>::FailedToExtractRuntimeVersion)?;
 
-		if new_version.spec_name != current_version.spec_name {
-			log::debug!("New: {new_version:?}, Current: {current_version:?}");
-			return Err(Error::<T>::InvalidSpecName.into());
-		}
+		// Disable checks if we are benchmarking `set_code` to make it possible to set arbitrary
+		// runtimes without modification
+		#[cfg(not(feature = "runtime-benchmarks"))]
+		{
+			if new_version.spec_name != current_version.spec_name {
+				log::debug!("New: {new_version:?}, Current: {current_version:?}");
+				return Err(Error::<T>::InvalidSpecName.into());
+			}
 
-		if new_version.spec_version <= current_version.spec_version {
-			return Err(Error::<T>::SpecVersionNeedsToIncrease.into());
+			if new_version.spec_version <= current_version.spec_version {
+				return Err(Error::<T>::SpecVersionNeedsToIncrease.into());
+			}
 		}
 
 		Ok(())

frame/system/src/weights.rs

@@ -50,7 +50,7 @@ use sp_std::marker::PhantomData;
 pub trait WeightInfo {
 	fn remark(b: u32, ) -> Weight;
 	fn remark_with_event(b: u32, ) -> Weight;
-	fn set_code(b: u32, ) -> Weight;
+	fn set_code() -> Weight;
 	fn set_heap_pages() -> Weight;
 	fn set_storage(i: u32, ) -> Weight;
 	fn kill_storage(i: u32, ) -> Weight;
@@ -106,7 +106,7 @@ impl<T: crate::Config> WeightInfo for SubstrateWeight<T> {
 			.saturating_add(Weight::from_ref_time(631_438).saturating_mul(i.into()))
 			.saturating_add(T::DbWeight::get().writes((1_u64).saturating_mul(i.into())))
 	}
-	fn set_code(b: u32) -> Weight {
+	fn set_code() -> Weight {
 		Weight::from_ref_time(1_000_000)
 	}
 	/// Storage: Skipped Metadata (r:0 w:0)
@@ -160,7 +160,7 @@ impl WeightInfo for () {
 			// Standard Error: 0
 			.saturating_add(Weight::from_ref_time(1_423).saturating_mul(b.into()))
 	}
-	fn set_code(b: u32) -> Weight {
+	fn set_code() -> Weight {
 		Weight::from_ref_time(1_000_000)
 	}
 	/// Storage: System Digest (r:1 w:1)