pre fund contract [WIP]

frame/evm/src/lib.rs

@@ -79,6 +79,7 @@ use scale_info::TypeInfo;
 // Substrate
 use frame_support::{
 	dispatch::{DispatchResultWithPostInfo, Pays, PostDispatchInfo},
+	ensure,
 	storage::KeyPrefixIterator,
 	traits::{
 		fungible::{Balanced, Credit, Debt},
@@ -103,9 +104,8 @@ use fp_account::AccountId20;
 use fp_evm::GenesisAccount;
 pub use fp_evm::{
 	Account, AccountProvider, CallInfo, CreateInfo, ExecutionInfoV2 as ExecutionInfo,
-	FeeCalculator, IsPrecompileResult, LinearCostPrecompile, Log, Precompile, PrecompileFailure,
-	PrecompileHandle, PrecompileOutput, PrecompileResult, PrecompileSet,
-	TransactionValidationError, Vicinity,
+	FeeCalculator, IsPrecompileResult, Log, Precompile, PrecompileFailure, PrecompileHandle,
+	PrecompileOutput, PrecompileResult, PrecompileSet, TransactionValidationError, Vicinity,
 };
 
 pub use self::{
@@ -413,6 +413,7 @@ pub mod pallet {
 			access_list: Vec<(H160, Vec<H256>)>,
 		) -> DispatchResultWithPostInfo {
 			T::CallOrigin::ensure_address_origin(&source, origin)?;
+			Self::ensure_balance_for_contract_creation(&source)?;
 
 			let whitelist = <WhitelistedCreators<T>>::get();
 			let whitelist_disabled = <DisableWhitelistCheck<T>>::get();
@@ -453,6 +454,15 @@ pub mod pallet {
 					value: create_address,
 					..
 				} => {
+					let mini_balance = <<T as Config>::Currency as Currency<
+						<<T as Config>::AccountProvider as AccountProvider>::AccountId,
+					>>::minimum_balance();
+					T::Currency::transfer(
+						&T::AddressMapping::into_account_id(source),
+						&T::AddressMapping::into_account_id(create_address),
+						mini_balance,
+						ExistenceRequirement::AllowDeath,
+					)?;
 					Pallet::<T>::deposit_event(Event::<T>::Created {
 						address: create_address,
 					});
@@ -504,6 +514,7 @@ pub mod pallet {
 			access_list: Vec<(H160, Vec<H256>)>,
 		) -> DispatchResultWithPostInfo {
 			T::CallOrigin::ensure_address_origin(&source, origin)?;
+			Self::ensure_balance_for_contract_creation(&source)?;
 
 			let whitelist = <WhitelistedCreators<T>>::get();
 			let whitelist_disabled = <DisableWhitelistCheck<T>>::get();
@@ -545,6 +556,15 @@ pub mod pallet {
 					value: create_address,
 					..
 				} => {
+					let mini_balance = <<T as Config>::Currency as Currency<
+						<<T as Config>::AccountProvider as AccountProvider>::AccountId,
+					>>::minimum_balance();
+					T::Currency::transfer(
+						&T::AddressMapping::into_account_id(source),
+						&T::AddressMapping::into_account_id(create_address),
+						mini_balance,
+						ExistenceRequirement::AllowDeath,
+					)?;
 					Pallet::<T>::deposit_event(Event::<T>::Created {
 						address: create_address,
 					});
@@ -643,6 +663,10 @@ pub mod pallet {
 		Undefined,
 		/// Origin is not allowed to perform the operation.
 		NotAllowed,
+		/// Not enough balance to pay existential deposit
+		BalanceLowForExistentialDeposit,
+		/// Token transfer to new contract failed
+		TransferToNewContractFailed,
 		/// Address not allowed to deploy contracts either via CREATE or CALL(CREATE).
 		CreateOriginNotAllowed,
 	}
@@ -1095,6 +1119,45 @@ impl<T: Config> Pallet<T> {
 
 		T::FindAuthor::find_author(pre_runtime_digests).unwrap_or_default()
 	}
+
+	/// Ensure balance to pre fund contract creation.
+	pub fn ensure_balance_for_contract_creation(source: &H160) -> Result<(), Error<T>> {
+		let account_id = T::AddressMapping::into_account_id(*source);
+		let balance =
+			T::Currency::reducible_balance(&account_id, Preservation::Preserve, Fortitude::Polite);
+
+		let balance = UniqueSaturatedInto::<u64>::unique_saturated_into(balance);
+
+		let mini_balance = <<T as Config>::Currency as Currency<
+			<<T as Config>::AccountProvider as AccountProvider>::AccountId,
+		>>::minimum_balance();
+
+		let mini_balance = UniqueSaturatedInto::<u64>::unique_saturated_into(mini_balance);
+
+		ensure!(
+			balance >= mini_balance,
+			Error::<T>::BalanceLowForExistentialDeposit
+		);
+		Ok(())
+	}
+
+	/// transfer existential deposit to new contract
+	pub fn transfer_minimal_to_new_contract(
+		source: &H160,
+		create_address: &H160,
+	) -> Result<(), Error<T>> {
+		let mini_balance = <<T as Config>::Currency as Currency<
+			<<T as Config>::AccountProvider as AccountProvider>::AccountId,
+		>>::minimum_balance();
+		T::Currency::transfer(
+			&T::AddressMapping::into_account_id(*source),
+			&T::AddressMapping::into_account_id(*create_address),
+			mini_balance,
+			ExistenceRequirement::AllowDeath,
+		)
+		.map_err(|_| Error::<T>::TransferToNewContractFailed)?;
+		Ok(())
+	}
 }
 
 /// Handle withdrawing, refunding and depositing of transaction fees.

frame/evm/src/runner/stack.rs

@@ -578,6 +578,10 @@ where
 		proof_size_base_cost: Option<u64>,
 		config: &evm::Config,
 	) -> Result<CreateInfo, RunnerError<Self::Error>> {
+		Pallet::<T>::ensure_balance_for_contract_creation(&source).map_err(|_| RunnerError {
+			error: Error::<T>::BalanceLow,
+			weight: Weight::zero(),
+		})?;
 		let measured_proof_size_before = get_proof_size().unwrap_or_default();
 		let (_, weight) = T::FeeCalculator::min_gas_price();
 
@@ -609,7 +613,7 @@ where
 			)?;
 		}
 		let precompiles = T::PrecompilesValue::get();
-		Self::execute(
+		let result = Self::execute(
 			source,
 			value,
 			gas_limit,
@@ -628,7 +632,21 @@ where
 					executor.transact_create(source, value, init, gas_limit, access_list);
 				(reason, address)
 			},
-		)
+		);
+		if let Ok(CreateInfo {
+			exit_reason: ExitReason::Succeed(_),
+			value: create_address,
+			..
+		}) = &result
+		{
+			Pallet::<T>::transfer_minimal_to_new_contract(&source, create_address).map_err(
+				|_| RunnerError {
+					error: Error::<T>::BalanceLow,
+					weight: Weight::default(),
+				},
+			)?;
+		}
+		result
 	}
 
 	fn create2(
@@ -649,6 +667,10 @@ where
 		proof_size_base_cost: Option<u64>,
 		config: &evm::Config,
 	) -> Result<CreateInfo, RunnerError<Self::Error>> {
+		Pallet::<T>::ensure_balance_for_contract_creation(&source).map_err(|_| RunnerError {
+			error: Error::<T>::BalanceLow,
+			weight: Weight::zero(),
+		})?;
 		let measured_proof_size_before = get_proof_size().unwrap_or_default();
 		let (_, weight) = T::FeeCalculator::min_gas_price();
 
@@ -662,7 +684,6 @@ where
 					weight: Weight::zero(),
 				});
 			}
-
 			Self::validate(
 				source,
 				None,
@@ -681,7 +702,7 @@ where
 		}
 		let precompiles = T::PrecompilesValue::get();
 		let code_hash = H256::from(sp_io::hashing::keccak_256(&init));
-		Self::execute(
+		let result = Self::execute(
 			source,
 			value,
 			gas_limit,
@@ -704,7 +725,21 @@ where
 					executor.transact_create2(source, value, init, salt, gas_limit, access_list);
 				(reason, address)
 			},
-		)
+		);
+		if let Ok(CreateInfo {
+			exit_reason: ExitReason::Succeed(_),
+			value: create_address,
+			..
+		}) = &result
+		{
+			Pallet::<T>::transfer_minimal_to_new_contract(&source, create_address).map_err(
+				|_| RunnerError {
+					error: Error::<T>::BalanceLow,
+					weight: Weight::default(),
+				},
+			)?;
+		}
+		result
 	}
 }