vm: move interpreter.readOnly check and remove operation.writes field

blockchain/vm/instructions.go

@@ -581,6 +581,9 @@ func opGas(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte
 }
 
 func opCreate(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	if interpreter.readOnly {
+		return nil, ErrWriteProtection
+	}
 	var (
 		value        = scope.Stack.pop()
 		offset, size = scope.Stack.pop(), scope.Stack.pop()
@@ -624,6 +627,9 @@ func opCreate(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]b
 }
 
 func opCreate2(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	if interpreter.readOnly {
+		return nil, ErrWriteProtection
+	}
 	var (
 		endowment    = scope.Stack.pop()
 		offset, size = scope.Stack.pop(), scope.Stack.pop()

blockchain/vm/interpreter.go

@@ -219,17 +219,6 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte) (ret []byte, err
 		} else if sLen > operation.maxStack {
 			return nil, fmt.Errorf("stack limit reached %d (%d)", sLen, operation.maxStack)
 		}
-		// If the operation is valid, enforce and write restrictions
-		if in.readOnly {
-			// If the interpreter is operating in readonly mode, make sure no
-			// state-modifying operation is performed. The 3rd stack item
-			// for a call operation is the value. Transferring value from one
-			// account to the others means the state is modified and should also
-			// return with an error.
-			if operation.writes || (op == CALL && stack.Back(2).Sign() != 0) {
-				return nil, ErrWriteProtection
-			}
-		}
 
 		// Static portion of gas
 		cost = operation.constantGas // For tracing

blockchain/vm/jump_table.go

@@ -52,8 +52,6 @@ type operation struct {
 	// computationCost represents approximated execution time of an operation.
 	// This value will be used to limit the execution time of a transaction on EVM.
 	computationCost uint64
-
-	writes bool // determines whether this a state modifying operation
 }
 
 var (
@@ -149,7 +147,6 @@ func newConstantinopleInstructionSet() JumpTable {
 		minStack:        minStack(4, 1),
 		maxStack:        maxStack(4, 1),
 		memorySize:      memoryCreate2,
-		writes:          true,
 		computationCost: params.Create2ComputationCost,
 	}
 	return instructionSet
@@ -571,7 +568,6 @@ func newFrontierInstructionSet() JumpTable {
 			dynamicGas:      gasSStore,
 			minStack:        minStack(2, 0),
 			maxStack:        maxStack(2, 0),
-			writes:          true,
 			computationCost: params.SstoreComputationCost,
 		},
 		JUMP: {
@@ -1070,7 +1066,6 @@ func newFrontierInstructionSet() JumpTable {
 			minStack:        minStack(2, 0),
 			maxStack:        maxStack(2, 0),
 			memorySize:      memoryLog,
-			writes:          true,
 			computationCost: params.Log0ComputationCost,
 		},
 		LOG1: {
@@ -1079,7 +1074,6 @@ func newFrontierInstructionSet() JumpTable {
 			minStack:        minStack(3, 0),
 			maxStack:        maxStack(3, 0),
 			memorySize:      memoryLog,
-			writes:          true,
 			computationCost: params.Log1ComputationCost,
 		},
 		LOG2: {
@@ -1088,7 +1082,6 @@ func newFrontierInstructionSet() JumpTable {
 			minStack:        minStack(4, 0),
 			maxStack:        maxStack(4, 0),
 			memorySize:      memoryLog,
-			writes:          true,
 			computationCost: params.Log2ComputationCost,
 		},
 		LOG3: {
@@ -1097,7 +1090,6 @@ func newFrontierInstructionSet() JumpTable {
 			minStack:        minStack(5, 0),
 			maxStack:        maxStack(5, 0),
 			memorySize:      memoryLog,
-			writes:          true,
 			computationCost: params.Log3ComputationCost,
 		},
 		LOG4: {
@@ -1106,7 +1098,6 @@ func newFrontierInstructionSet() JumpTable {
 			minStack:        minStack(6, 0),
 			maxStack:        maxStack(6, 0),
 			memorySize:      memoryLog,
-			writes:          true,
 			computationCost: params.Log4ComputationCost,
 		},
 		CREATE: {
@@ -1116,7 +1107,6 @@ func newFrontierInstructionSet() JumpTable {
 			minStack:        minStack(3, 1),
 			maxStack:        maxStack(3, 1),
 			memorySize:      memoryCreate,
-			writes:          true,
 			computationCost: params.CreateComputationCost,
 		},
 		CALL: {
@@ -1150,7 +1140,6 @@ func newFrontierInstructionSet() JumpTable {
 			dynamicGas:      gasSelfdestruct,
 			minStack:        minStack(1, 0),
 			maxStack:        maxStack(1, 0),
-			writes:          true,
 			computationCost: params.SelfDestructComputationCost,
 		},
 	}

blockchain/vm/logger_json.go

@@ -44,6 +44,7 @@ func (l *JSONLogger) CaptureStart(env *EVM, from common.Address, to common.Addre
 }
 
 // CaptureState outputs state information on the logger.
+// TODO: Add rData (return data) later
 func (l *JSONLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint64, scope *ScopeContext, depth int, err error) {
 	memory := scope.Memory
 	stack := scope.Stack
@@ -74,6 +75,7 @@ func (l *JSONLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint
 
 // CaptureFault outputs state information on the logger.
 func (l *JSONLogger) CaptureFault(env *EVM, pc uint64, op OpCode, gas, cost uint64, scope *ScopeContext, depth int, err error) {
+	l.CaptureState(env, pc, op, gas, cost, scope, depth, err)
 }
 
 // CaptureEnd is triggered at end of execution.