contracts: switch to wasmi gas metering (#14084)

* upgrade to wasmi 0.29

* prepare cleanup

* sync ref_time w engine from the stack frame

* proc_macro: sync gas in host funcs

save: compiles, only gas pushing left to macro

WIP proc macro

proc macro: done

* clean benchmarks & schedule: w_base = w_i64const

* scale gas values btw engine and gas meter

* (re)instrumentation & code_cache removed

* remove gas() host fn, continue clean-up

save

* address review comments

* move from CodeStorage&PrefabWasmModule to PristineCode&WasmBlob

* refactor: no reftime_limit&schedule passes, no CodeStorage

* bugs fixing

* fix tests: expected deposit amount

* fix prepare::tests

* update tests and fix bugs

tests::run_out_of_gas_engine, need 2 more

save: 2 bugs with gas syncs: 1 of 2 tests done

gas_syncs_no_overcharge bug fixed, test passes!

cleaned out debug prints

second bug is not a bug

disabled_chain_extension test fix (err msg)

tests run_out_of_fuel_host, chain_extension pass

all tests pass

* update docs

* bump wasmi 0.30.0

* benchmarks updated, tests pass

* refactoring

* s/OwnerInfo/CodeInfo/g;

* migration: draft, compiles

* migration: draft, runs

* migration: draft, runs (fixing)

* deposits repaid non pro rata

* deposits repaid pro rata

* better try-runtime output

* even better try-runtime output

* benchmark migration

* fix merge leftover

* add forgotten fixtures, fix docs

* address review comments

* ci fixes

* cleanup

* benchmarks::prepare to return DispatchError

* ".git/.scripts/commands/bench/bench.sh" pallet dev pallet_contracts

* store memory limits to CodeInfo

* ci: roll back weights

* ".git/.scripts/commands/bench-vm/bench-vm.sh" pallet dev pallet_contracts

* drive-by: update Readme and pallet rustdoc

* ".git/.scripts/commands/bench/bench.sh" pallet dev pallet_contracts

* ".git/.scripts/commands/bench/bench.sh" pallet dev pallet_contracts

* use wasmi 0.29

* ".git/.scripts/commands/bench/bench.sh" pallet dev pallet_contracts

* use wasmi 0.30 again

* query memory limits from wasmi

* better migration types

* ci: pull weights from master

* refactoring

* ".git/.scripts/commands/bench-vm/bench-vm.sh" pallet dev pallet_contracts

* addressing review comments

* refactor

* address review comments

* optimize migration

* ".git/.scripts/commands/bench/bench.sh" pallet dev pallet_contracts

* another review round comments addressed

* ci fix one

* clippy fix

* ci fix two

---------

Co-authored-by: command-bot <>

substrate/frame/contracts/src/wasm/runtime.rs

@@ -67,7 +67,6 @@ pub trait Environment<HostState> {
 }
 
 /// Type of a storage key.
-#[allow(dead_code)]
 enum KeyType {
 	/// Legacy fix sized key `[u8;32]`.
 	Fix,
@@ -174,9 +173,6 @@ impl HostError for TrapReason {}
 #[cfg_attr(test, derive(Debug, PartialEq, Eq))]
 #[derive(Copy, Clone)]
 pub enum RuntimeCosts {
-	/// Charge the gas meter with the cost of a metering block. The charged costs are
-	/// the supplied cost of the block plus the overhead of the metering itself.
-	MeteringBlock(u64),
 	/// Weight charged for copying data from the sandbox.
 	CopyFromContract(u32),
 	/// Weight charged for copying data to the sandbox.
@@ -277,7 +273,6 @@ impl RuntimeCosts {
 	fn token<T: Config>(&self, s: &HostFnWeights<T>) -> RuntimeToken {
 		use self::RuntimeCosts::*;
 		let weight = match *self {
-			MeteringBlock(amount) => s.gas.saturating_add(Weight::from_parts(amount, 0)),
 			CopyFromContract(len) => s.return_per_byte.saturating_mul(len.into()),
 			CopyToContract(len) => s.input_per_byte.saturating_mul(len.into()),
 			Caller => s.caller,
@@ -369,7 +364,7 @@ impl RuntimeCosts {
 macro_rules! charge_gas {
 	($runtime:expr, $costs:expr) => {{
 		let token = $costs.token(&$runtime.ext.schedule().host_fn_weights);
-		$runtime.ext.gas_meter().charge(token)
+		$runtime.ext.gas_meter_mut().charge(token)
 	}};
 }
 
@@ -485,25 +480,40 @@ impl<'a, E: Ext + 'a> Runtime<'a, E> {
 
 	/// Converts the sandbox result and the runtime state into the execution outcome.
 	pub fn to_execution_result(self, sandbox_result: Result<(), wasmi::Error>) -> ExecResult {
+		use wasmi::core::TrapCode::OutOfFuel;
 		use TrapReason::*;
+
 		match sandbox_result {
 			// Contract returned from main function -> no data was returned.
 			Ok(_) => Ok(ExecReturnValue { flags: ReturnFlags::empty(), data: Vec::new() }),
+			// `OutOfGas` when host asks engine to consume more than left in the _store_.
+			// We should never get this case, as gas meter is being charged (and hence raises error)
+			// first.
+			Err(wasmi::Error::Store(_)) => Err(Error::<E::T>::OutOfGas.into()),
 			// Contract either trapped or some host function aborted the execution.
 			Err(wasmi::Error::Trap(trap)) => {
-				// If we encoded a reason then it is some abort generated by a host function.
-				// Otherwise the trap came from the contract.
-				let reason: TrapReason = trap.downcast().ok_or(Error::<E::T>::ContractTrapped)?;
-				match reason {
-					Return(ReturnData { flags, data }) => {
-						let flags =
-							ReturnFlags::from_bits(flags).ok_or(Error::<E::T>::InvalidCallFlags)?;
-						Ok(ExecReturnValue { flags, data })
-					},
-					Termination =>
-						Ok(ExecReturnValue { flags: ReturnFlags::empty(), data: Vec::new() }),
-					SupervisorError(error) => return Err(error.into()),
+				if let Some(OutOfFuel) = trap.trap_code() {
+					// `OutOfGas` during engine execution.
+					return Err(Error::<E::T>::OutOfGas.into())
 				}
+				// If we encoded a reason then it is some abort generated by a host function.
+				if let Some(reason) = &trap.downcast_ref::<TrapReason>() {
+					match &reason {
+						Return(ReturnData { flags, data }) => {
+							let flags = ReturnFlags::from_bits(*flags)
+								.ok_or(Error::<E::T>::InvalidCallFlags)?;
+							return Ok(ExecReturnValue { flags, data: data.to_vec() })
+						},
+						Termination =>
+							return Ok(ExecReturnValue {
+								flags: ReturnFlags::empty(),
+								data: Vec::new(),
+							}),
+						SupervisorError(error) => return Err((*error).into()),
+					}
+				}
+				// Otherwise the trap came from the contract itself.
+				Err(Error::<E::T>::ContractTrapped.into())
 			},
 			// Any other error is returned only if instantiation or linking failed (i.e.
 			// wasm binary tried to import a function that is not provided by the host).
@@ -536,7 +546,7 @@ impl<'a, E: Ext + 'a> Runtime<'a, E> {
 	/// refunded to match the actual amount.
 	pub fn adjust_gas(&mut self, charged: ChargedAmount, actual_costs: RuntimeCosts) {
 		let token = actual_costs.token(&self.ext.schedule().host_fn_weights);
-		self.ext.gas_meter().adjust_gas(charged, token);
+		self.ext.gas_meter_mut().adjust_gas(charged, token);
 	}
 
 	/// Read designated chunk from the sandbox memory.
@@ -1004,18 +1014,6 @@ impl<'a, E: Ext + 'a> Runtime<'a, E> {
 // for every function.
 #[define_env(doc)]
 pub mod env {
-	/// Account for used gas. Traps if gas used is greater than gas limit.
-	///
-	/// NOTE: This is a implementation defined call and is NOT a part of the public API.
-	/// This call is supposed to be called only by instrumentation injected code.
-	/// It deals only with the *ref_time* Weight.
-	///
-	/// - `amount`: How much gas is used.
-	fn gas(ctx: _, _memory: _, amount: u64) -> Result<(), TrapReason> {
-		ctx.charge_gas(RuntimeCosts::MeteringBlock(amount))?;
-		Ok(())
-	}
-
 	/// Set the value at the given key in the contract storage.
 	///
 	/// Equivalent to the newer [`seal1`][`super::api_doc::Version1::set_storage`] version with the