Instrument makeCallVariantGasEIP4762 with multi gas

Author: MishkaRogachev

core/vm/operations_gas_test.go

@@ -460,6 +460,7 @@ type GasCallFuncTestCase struct {
 	targetEmpty      bool   // whether the target account is empty (no balance/code)
 	isEIP158         bool   // whether EIP-158 rules apply (empty account handling)
 	isEIP4762        bool   // whether EIP-4762 rules apply (Verkle trees)
+	addWitnessGas    bool   // whether to add witness gas for EIP-4762
 	isEIP2929        bool   // whether EIP-2929 rules apply (access lists)
 	isSystemCall     bool   // whether this is a system call (bypasses some gas costs)
 	memorySize       uint64 // memory size for the operation (triggers memory expansion)
@@ -576,6 +577,12 @@ func testGasCallFuncFuncWithCases(t *testing.T, config *params.ChainConfig, gasC
 				}
 			}
 
+			// For EIP-4762 (Witnesses gas)
+			if tc.addWitnessGas && !contract.IsSystemCall {
+				// Calculated in `touchAddressAndChargeGas` WitnessBranchReadCost + WitnessChunkReadCost = 2100
+				expectedMultiGas.SafeIncrement(multigas.ResourceKindStorageAccess, 2100)
+			}
+
 			// Call the function
 			multiGas, _, err := gasCallFunc(evm, contract, stack, mem, tc.memorySize)
 			if err != nil {
@@ -760,7 +767,7 @@ func TestGasCallCode(t *testing.T) {
 }
 
 // CALL decorated with makeCallVariantGasCallEIP2929 gas function test
-func TestGasCallEIP2929(t *testing.T) {
+func TestCallVariantGasCallEIP2929(t *testing.T) {
 	testCases := []GasCallFuncTestCase{
 		{
 			name:             "Cold access to existing account",
@@ -793,3 +800,35 @@ func TestGasCallEIP2929(t *testing.T) {
 	gasCallEIP2929 = makeCallVariantGasCallEIP2929(gasCall, 1)
 	testGasCallFuncFuncWithCases(t, params.TestChainConfig, gasCallEIP2929, testCases, false)
 }
+
+func TestVariantGasEIP4762(t *testing.T) {
+	testCases := []GasCallFuncTestCase{
+		{
+			name:             "EIP4762 non-system call with witness cost",
+			transfersValue:   false,
+			valueTransferGas: 50000,
+			targetExists:     true,
+			targetEmpty:      false,
+			isEIP158:         true,
+			isEIP4762:        true,
+			addWitnessGas:    true,
+			isSystemCall:     false,
+			memorySize:       64,
+		},
+		{
+			name:             "EIP4762 system call skips witness cost",
+			transfersValue:   false,
+			valueTransferGas: 50000,
+			targetExists:     true,
+			targetEmpty:      false,
+			isEIP158:         true,
+			isEIP4762:        true,
+			addWitnessGas:    true,
+			isSystemCall:     true,
+			memorySize:       64,
+		},
+	}
+
+	gasCallEIP4762 = makeCallVariantGasEIP4762(gasCallCode)
+	testGasCallFuncFuncWithCases(t, params.TestChainConfig, gasCallEIP4762, testCases, true)
+}

core/vm/operations_verkle.go

@@ -93,16 +93,18 @@ func makeCallVariantGasEIP4762(oldCalculator gasFunc) gasFunc {
 			return multigas.ZeroGas(), 0, err
 		}
 		if contract.IsSystemCall {
-			return multigas.ZeroGas(), gas, nil
+			return multiGas, gas, nil
 		}
 		if _, isPrecompile := evm.precompile(contract.Address()); isPrecompile {
-			return multigas.ZeroGas(), gas, nil
+			return multiGas, gas, nil
 		}
 		witnessGas := evm.AccessEvents.MessageCallGas(contract.Address())
 		if witnessGas == 0 {
 			witnessGas = params.WarmStorageReadCostEIP2929
 		}
-		return multiGas, witnessGas + gas, nil
+		multiGas.SafeIncrement(multigas.ResourceKindStorageAccess, witnessGas)
+		singleGas, _ := multiGas.SingleGas()
+		return multiGas, singleGas, nil
 	}
 }