feat(core,internal/ethapi): add MaxUsedGas field to eth_simulateV1 response #31735 #32789 #34820

core/state_transition.go

@@ -33,7 +33,8 @@ import (
 // ExecutionResult includes all output after executing given evm
 // message no matter the execution itself is successful or not.
 type ExecutionResult struct {
-	UsedGas    uint64 // Total used gas but include the refunded gas
+	UsedGas    uint64 // Total used gas, refunded gas is deducted
+	MaxUsedGas uint64 // Maximum gas consumed during execution, excluding gas refunds.
 	Err        error  // Any error encountered during the execution(listed in core/vm/errors.go)
 	ReturnData []byte // Returned data from evm(function result or data supplied with revert opcode)
 }
@@ -478,9 +479,13 @@ func (st *stateTransition) execute(owner common.Address) (*ExecutionResult, erro
 		ret, st.gasRemaining, vmerr = st.evm.Call(msg.From, st.to(), msg.Data, st.gasRemaining, value)
 	}
 
+	// Record the gas used excluding gas refunds. This value represents the actual
+	// gas allowance required to complete execution.
+	peakGasUsed := st.gasUsed()
+
 	// Compute refund counter, capped to a refund quotient.
-	gasRefund := st.calcRefund()
-	st.gasRemaining += gasRefund
+	st.gasRemaining += st.calcRefund()
+
 	if rules.IsPrague {
 		// After EIP-7623: Data-heavy transactions pay the floor gas.
 		if st.gasUsed() < floorDataGas {
@@ -490,6 +495,9 @@ func (st *stateTransition) execute(owner common.Address) (*ExecutionResult, erro
 				t.OnGasChange(prev, st.gasRemaining, tracing.GasChangeTxDataFloor)
 			}
 		}
+		if peakGasUsed < floorDataGas {
+			peakGasUsed = floorDataGas
+		}
 	}
 	st.returnGas()
 
@@ -514,6 +522,7 @@ func (st *stateTransition) execute(owner common.Address) (*ExecutionResult, erro
 
 	return &ExecutionResult{
 		UsedGas:    st.gasUsed(),
+		MaxUsedGas: peakGasUsed,
 		Err:        vmerr,
 		ReturnData: ret,
 	}, nil

ethclient/ethclient.go

@@ -833,13 +833,15 @@ type SimulateCallResult struct {
 	ReturnValue []byte       `json:"returnData"`
 	Logs        []*types.Log `json:"logs"`
 	GasUsed     uint64       `json:"gasUsed"`
+	MaxUsedGas  uint64       `json:"maxUsedGas"`
 	Status      uint64       `json:"status"`
 	Error       *CallError   `json:"error,omitempty"`
 }
 
 type simulateCallResultMarshaling struct {
 	ReturnValue hexutil.Bytes
 	GasUsed     hexutil.Uint64
+	MaxUsedGas  hexutil.Uint64
 	Status      hexutil.Uint64
 }
 

ethclient/ethclient_test.go

@@ -917,6 +917,12 @@ func TestSimulateV1(t *testing.T) {
 	if results[0].Calls[0].Error != nil {
 		t.Errorf("expected no error, got %v", results[0].Calls[0].Error)
 	}
+	if results[0].Calls[0].MaxUsedGas == 0 {
+		t.Error("expected maxUsedGas to be set")
+	}
+	if results[0].Calls[0].MaxUsedGas < results[0].Calls[0].GasUsed {
+		t.Errorf("expected maxUsedGas >= gasUsed, got %d < %d", results[0].Calls[0].MaxUsedGas, results[0].Calls[0].GasUsed)
+	}
 }
 
 // TestSimulateV1WithBlockOverrides tests simulate v 1 with block overrides.

internal/ethapi/simulate.go

@@ -68,6 +68,7 @@ type simCallResult struct {
 	ReturnValue hexutil.Bytes  `json:"returnData"`
 	Logs        []*types.Log   `json:"logs"`
 	GasUsed     hexutil.Uint64 `json:"gasUsed"`
+	MaxUsedGas  hexutil.Uint64 `json:"maxUsedGas"`
 	Status      hexutil.Uint64 `json:"status"`
 	Error       *callError     `json:"error,omitempty"`
 }
@@ -225,7 +226,7 @@ func (sim *simulator) processBlock(ctx context.Context, block *simBlock, header,
 		gasUsed += result.UsedGas
 		receipts[i] = core.MakeReceipt(evm, result, sim.state, blockContext.BlockNumber, common.Hash{}, tx, gasUsed, root)
 		logs := tracer.Logs()
-		callRes := simCallResult{ReturnValue: result.Return(), Logs: logs, GasUsed: hexutil.Uint64(result.UsedGas)}
+		callRes := simCallResult{ReturnValue: result.Return(), Logs: logs, GasUsed: hexutil.Uint64(result.UsedGas), MaxUsedGas: hexutil.Uint64(result.MaxUsedGas)}
 		if result.Failed() {
 			callRes.Status = hexutil.Uint64(types.ReceiptStatusFailed)
 			if errors.Is(result.Err, vm.ErrExecutionReverted) {