Closure call now returns the total usage as well

* Return the used gas value based on the UseGas and ReturnGas

4 files changed, 138 insertions, 104 deletions

diff --git a/ethchain/closure.go b/ethchain/closure.go
index c935ed50a..f2b46e461 100644
--- a/ethchain/closure.go
+++ b/ethchain/closure.go
@@ -22,8 +22,7 @@ type Closure struct {
 	Script []byte
 	State  *State
 
-	Gas   *big.Int
-	Price *big.Int
+	Gas, UsedGas, Price *big.Int
 
 	Args []byte
 }
@@ -74,10 +73,12 @@ func (c *Closure) Address() []byte {
 
 type DebugHook func(step int, op OpCode, mem *Memory, stack *Stack, stateObject *StateObject) bool
 
-func (c *Closure) Call(vm *Vm, args []byte, hook DebugHook) ([]byte, error) {
+func (c *Closure) Call(vm *Vm, args []byte, hook DebugHook) ([]byte, *big.Int, error) {
 	c.Args = args
 
-	return vm.RunClosure(c, hook)
+	ret, err := vm.RunClosure(c, hook)
+
+	return ret, c.UsedGas, err
 }
 
 func (c *Closure) Return(ret []byte) []byte {
@@ -93,10 +94,23 @@ func (c *Closure) Return(ret []byte) []byte {
 	return ret
 }
 
+func (c *Closure) UseGas(gas *big.Int) bool {
+	if c.Gas.Cmp(gas) < 0 {
+		return false
+	}
+
+	// Sub the amount of gas from the remaining
+	c.Gas.Sub(c.Gas, gas)
+	c.UsedGas.Add(c.UsedGas, gas)
+
+	return true
+}
+
 // Implement the Callee interface
 func (c *Closure) ReturnGas(gas, price *big.Int, state *State) {
 	// Return the gas to the closure
 	c.Gas.Add(c.Gas, gas)
+	c.UsedGas.Sub(c.UsedGas, gas)
 }
 
 func (c *Closure) Object() *StateObject {
diff --git a/ethchain/state_manager.go b/ethchain/state_manager.go
index 2d2a32e2f..1a9e9f601 100644
--- a/ethchain/state_manager.go
+++ b/ethchain/state_manager.go
@@ -106,7 +106,7 @@ func (sm *StateManager) ApplyTransactions(state *State, block *Block, txs []*Tra
 		usedGas, err := sm.ApplyTransaction(state, block, tx)
 		if err != nil {
 			ethutil.Config.Log.Infoln(err)
-			continue
+			//continue
 		}
 
 		accumelative := new(big.Int).Set(totalUsedGas.Add(totalUsedGas, usedGas))
@@ -119,7 +119,7 @@ func (sm *StateManager) ApplyTransactions(state *State, block *Block, txs []*Tra
 	return receipts, txs
 }
 
-func (sm *StateManager) ApplyTransaction(state *State, block *Block, tx *Transaction) (*big.Int, error) {
+func (sm *StateManager) ApplyTransaction(state *State, block *Block, tx *Transaction) (totalGasUsed *big.Int, err error) {
 	/*
 		Applies transactions to the given state and creates new
 		state objects where needed.
@@ -129,9 +129,17 @@ func (sm *StateManager) ApplyTransaction(state *State, block *Block, tx *Transac
 		assume there's a return value. The return value will be set to
 		the script section of the state object.
 	*/
-	totalGasUsed := big.NewInt(0)
+	var (
+		addTotalGas = func(gas *big.Int) { totalGasUsed.Add(totalGasUsed, gas) }
+		gas         = new(big.Int)
+		script      []byte
+	)
+	totalGasUsed = big.NewInt(0)
+
 	// Apply the transaction to the current state
-	err := sm.Ethereum.TxPool().ProcessTransaction(tx, state, false)
+	gas, err = sm.Ethereum.TxPool().ProcessTransaction(tx, state, false)
+	addTotalGas(gas)
+
 	if tx.CreatesContract() {
 		if err == nil {
 			// Create a new state object and the transaction
@@ -141,30 +149,32 @@ func (sm *StateManager) ApplyTransaction(state *State, block *Block, tx *Transac
 				// Evaluate the initialization script
 				// and use the return value as the
 				// script section for the state object.
-				script, err := sm.EvalScript(state, contract.Init(), contract, tx, block)
+				script, gas, err = sm.EvalScript(state, contract.Init(), contract, tx, block)
+				addTotalGas(gas)
+
 				if err != nil {
-					return nil, fmt.Errorf("[STATE] Error during init script run %v", err)
+					err = fmt.Errorf("[STATE] Error during init script run %v", err)
+					return
 				}
 				contract.script = script
 				state.UpdateStateObject(contract)
 			} else {
-				return nil, fmt.Errorf("[STATE] Unable to create contract")
+				err = fmt.Errorf("[STATE] Unable to create contract")
 			}
 		} else {
-			return nil, fmt.Errorf("[STATE] contract creation tx:", err)
+			err = fmt.Errorf("[STATE] contract creation tx: %v", err)
 		}
 	} else {
 		// Find the state object at the "recipient" address. If
 		// there's an object attempt to run the script.
 		stateObject := state.GetStateObject(tx.Recipient)
 		if err == nil && stateObject != nil && len(stateObject.Script()) > 0 {
-			sm.EvalScript(state, stateObject.Script(), stateObject, tx, block)
-		} else if err != nil {
-			return nil, fmt.Errorf("[STATE] process:", err)
+			_, gas, err = sm.EvalScript(state, stateObject.Script(), stateObject, tx, block)
+			addTotalGas(gas)
 		}
 	}
 
-	return totalGasUsed, nil
+	return
 }
 
 func (sm *StateManager) Process(block *Block, dontReact bool) error {
@@ -349,7 +359,7 @@ func (sm *StateManager) Stop() {
 	sm.bc.Stop()
 }
 
-func (sm *StateManager) EvalScript(state *State, script []byte, object *StateObject, tx *Transaction, block *Block) (ret []byte, err error) {
+func (sm *StateManager) EvalScript(state *State, script []byte, object *StateObject, tx *Transaction, block *Block) (ret []byte, gas *big.Int, err error) {
 	account := state.GetAccount(tx.Sender())
 
 	err = account.ConvertGas(tx.Gas, tx.GasPrice)
@@ -369,7 +379,7 @@ func (sm *StateManager) EvalScript(state *State, script []byte, object *StateObj
 		Value:       tx.Value,
 		//Price:       tx.GasPrice,
 	})
-	ret, err = closure.Call(vm, tx.Data, nil)
+	ret, gas, err = closure.Call(vm, tx.Data, nil)
 
 	// Update the account (refunds)
 	state.UpdateStateObject(account)
diff --git a/ethchain/transaction_pool.go b/ethchain/transaction_pool.go
index ee026ffdd..7198026a8 100644
--- a/ethchain/transaction_pool.go
+++ b/ethchain/transaction_pool.go
@@ -91,28 +91,37 @@ func (pool *TxPool) addTransaction(tx *Transaction) {
 
 // Process transaction validates the Tx and processes funds from the
 // sender to the recipient.
-func (pool *TxPool) ProcessTransaction(tx *Transaction, state *State, toContract bool) (err error) {
+func (pool *TxPool) ProcessTransaction(tx *Transaction, state *State, toContract bool) (gas *big.Int, err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			ethutil.Config.Log.Infoln(r)
 			err = fmt.Errorf("%v", r)
 		}
 	}()
+
+	gas = new(big.Int)
+	addGas := func(g *big.Int) { gas.Add(gas, g) }
+
 	// Get the sender
 	sender := state.GetAccount(tx.Sender())
 
 	if sender.Nonce != tx.Nonce {
-		return fmt.Errorf("[TXPL] Invalid account nonce, state nonce is %d transaction nonce is %d instead", sender.Nonce, tx.Nonce)
+		err = fmt.Errorf("[TXPL] Invalid account nonce, state nonce is %d transaction nonce is %d instead", sender.Nonce, tx.Nonce)
+		return
 	}
 
+	txTotalBytes := big.NewInt(int64(len(tx.Data)))
+	txTotalBytes.Div(txTotalBytes, ethutil.Big32)
+	addGas(new(big.Int).Mul(txTotalBytes, GasSStore))
+
 	// Make sure there's enough in the sender's account. Having insufficient
 	// funds won't invalidate this transaction but simple ignores it.
 	//totAmount := new(big.Int).Add(tx.Value, new(big.Int).Mul(TxFee, TxFeeRat))
 	totAmount := new(big.Int).Add(tx.Value, new(big.Int).Mul(tx.Gas, tx.GasPrice))
 	if sender.Amount.Cmp(totAmount) < 0 {
-		return fmt.Errorf("[TXPL] Insufficient amount in sender's (%x) account", tx.Sender())
+		err = fmt.Errorf("[TXPL] Insufficient amount in sender's (%x) account", tx.Sender())
+		return
 	}
-	//fmt.Println(tx)
 
 	// Get the receiver
 	receiver := state.GetAccount(tx.Recipient)
@@ -120,6 +129,7 @@ func (pool *TxPool) ProcessTransaction(tx *Transaction, state *State, toContract
 
 	// Send Tx to self
 	if bytes.Compare(tx.Recipient, tx.Sender()) == 0 {
+		addGas(GasTx)
 		// Subtract the fee
 		sender.SubAmount(new(big.Int).Mul(GasTx, tx.GasPrice))
 	} else {
diff --git a/ethchain/vm.go b/ethchain/vm.go
index 9821a839a..29eb4aaf5 100644
--- a/ethchain/vm.go
+++ b/ethchain/vm.go
@@ -21,11 +21,10 @@ var (
 	GasTx      = big.NewInt(500)
 )
 
-func CalculateTxGas(initSize, scriptSize *big.Int) *big.Int {
+func CalculateTxGas(initSize *big.Int) *big.Int {
 	totalGas := new(big.Int)
-	totalGas.Add(totalGas, GasCreate)
 
-	txTotalBytes := new(big.Int).Add(initSize, scriptSize)
+	txTotalBytes := new(big.Int).Set(initSize)
 	txTotalBytes.Div(txTotalBytes, ethutil.Big32)
 	totalGas.Add(totalGas, new(big.Int).Mul(txTotalBytes, GasSStore))
 
@@ -92,12 +91,14 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 	pc := big.NewInt(0)
 	// Current step count
 	step := 0
+	prevStep := 0
 
 	if ethutil.Config.Debug {
 		ethutil.Config.Log.Debugf("#   op\n")
 	}
 
 	for {
+		prevStep = step
 		// The base for all big integer arithmetic
 		base := new(big.Int)
 
@@ -111,16 +112,16 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 		}
 
 		gas := new(big.Int)
-		useGas := func(amount *big.Int) {
+		setStepGasUsage := func(amount *big.Int) {
 			gas.Add(gas, amount)
 		}
 
 		switch op {
-		case oSHA3:
-			useGas(GasSha)
-		case oSLOAD:
-			useGas(GasSLoad)
-		case oSSTORE:
+		case SHA3:
+			setStepGasUsage(GasSha)
+		case SLOAD:
+			setStepGasUsage(GasSLoad)
+		case SSTORE:
 			var mult *big.Int
 			y, x := stack.Peekn()
 			val := closure.GetMem(x)
@@ -131,67 +132,64 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			} else {
 				mult = ethutil.Big1
 			}
-			useGas(new(big.Int).Mul(mult, GasSStore))
-		case oBALANCE:
-			useGas(GasBalance)
-		case oCREATE:
+			setStepGasUsage(new(big.Int).Mul(mult, GasSStore))
+		case BALANCE:
+			setStepGasUsage(GasBalance)
+		case CREATE:
 			require(3)
 
 			args := stack.Get(big.NewInt(3))
 			initSize := new(big.Int).Add(args[1], args[0])
 
-			useGas(CalculateTxGas(initSize, ethutil.Big0))
-		case oCALL:
-			useGas(GasCall)
-		case oMLOAD, oMSIZE, oMSTORE8, oMSTORE:
-			useGas(GasMemory)
+			setStepGasUsage(CalculateTxGas(initSize))
+		case CALL:
+			setStepGasUsage(GasCall)
+		case MLOAD, MSIZE, MSTORE8, MSTORE:
+			setStepGasUsage(GasMemory)
 		default:
-			useGas(GasStep)
+			setStepGasUsage(GasStep)
 		}
 
-		if closure.Gas.Cmp(gas) < 0 {
+		if !closure.UseGas(gas) {
 			ethutil.Config.Log.Debugln("Insufficient gas", closure.Gas, gas)
 
 			return closure.Return(nil), fmt.Errorf("insufficient gas %v %v", closure.Gas, gas)
 		}
 
-		// Sub the amount of gas from the remaining
-		closure.Gas.Sub(closure.Gas, gas)
-
 		switch op {
-		case oLOG:
+		case LOG:
 			stack.Print()
 			mem.Print()
 			// 0x20 range
-		case oADD:
+		case ADD:
 			require(2)
 			x, y := stack.Popn()
 			// (x + y) % 2 ** 256
 			base.Add(x, y)
 			// Pop result back on the stack
 			stack.Push(base)
-		case oSUB:
+		case SUB:
 			require(2)
 			x, y := stack.Popn()
 			// (x - y) % 2 ** 256
 			base.Sub(x, y)
 			// Pop result back on the stack
 			stack.Push(base)
-		case oMUL:
+		case MUL:
 			require(2)
 			x, y := stack.Popn()
 			// (x * y) % 2 ** 256
 			base.Mul(x, y)
 			// Pop result back on the stack
 			stack.Push(base)
-		case oDIV:
+		case DIV:
 			require(2)
 			x, y := stack.Popn()
 			// floor(x / y)
 			base.Div(x, y)
 			// Pop result back on the stack
 			stack.Push(base)
-		case oSDIV:
+		case SDIV:
 			require(2)
 			x, y := stack.Popn()
 			// n > 2**255
@@ -208,12 +206,12 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			}
 			// Push result on to the stack
 			stack.Push(z)
-		case oMOD:
+		case MOD:
 			require(2)
 			x, y := stack.Popn()
 			base.Mod(x, y)
 			stack.Push(base)
-		case oSMOD:
+		case SMOD:
 			require(2)
 			x, y := stack.Popn()
 			// n > 2**255
@@ -230,17 +228,17 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			}
 			// Push result on to the stack
 			stack.Push(z)
-		case oEXP:
+		case EXP:
 			require(2)
 			x, y := stack.Popn()
 			base.Exp(x, y, Pow256)
 
 			stack.Push(base)
-		case oNEG:
+		case NEG:
 			require(1)
 			base.Sub(Pow256, stack.Pop())
 			stack.Push(base)
-		case oLT:
+		case LT:
 			require(2)
 			x, y := stack.Popn()
 			// x < y
@@ -249,7 +247,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			} else {
 				stack.Push(ethutil.BigFalse)
 			}
-		case oGT:
+		case GT:
 			require(2)
 			x, y := stack.Popn()
 			// x > y
@@ -258,7 +256,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			} else {
 				stack.Push(ethutil.BigFalse)
 			}
-		case oEQ:
+		case EQ:
 			require(2)
 			x, y := stack.Popn()
 			// x == y
@@ -267,7 +265,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			} else {
 				stack.Push(ethutil.BigFalse)
 			}
-		case oNOT:
+		case NOT:
 			require(1)
 			x := stack.Pop()
 			if x.Cmp(ethutil.BigFalse) == 0 {
@@ -277,7 +275,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			}
 
 			// 0x10 range
-		case oAND:
+		case AND:
 			require(2)
 			x, y := stack.Popn()
 			if (x.Cmp(ethutil.BigTrue) >= 0) && (y.Cmp(ethutil.BigTrue) >= 0) {
@@ -286,7 +284,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 				stack.Push(ethutil.BigFalse)
 			}
 
-		case oOR:
+		case OR:
 			require(2)
 			x, y := stack.Popn()
 			if (x.Cmp(ethutil.BigInt0) >= 0) || (y.Cmp(ethutil.BigInt0) >= 0) {
@@ -294,11 +292,11 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			} else {
 				stack.Push(ethutil.BigFalse)
 			}
-		case oXOR:
+		case XOR:
 			require(2)
 			x, y := stack.Popn()
 			stack.Push(base.Xor(x, y))
-		case oBYTE:
+		case BYTE:
 			require(2)
 			val, th := stack.Popn()
 			if th.Cmp(big.NewInt(32)) < 0 {
@@ -308,92 +306,92 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			}
 
 			// 0x20 range
-		case oSHA3:
+		case SHA3:
 			require(2)
 			size, offset := stack.Popn()
 			data := mem.Get(offset.Int64(), size.Int64())
 
 			stack.Push(ethutil.BigD(data))
 			// 0x30 range
-		case oADDRESS:
+		case ADDRESS:
 			stack.Push(ethutil.BigD(closure.Object().Address()))
-		case oBALANCE:
+		case BALANCE:
 			stack.Push(closure.object.Amount)
-		case oORIGIN:
+		case ORIGIN:
 			stack.Push(ethutil.BigD(vm.vars.Origin))
-		case oCALLER:
+		case CALLER:
 			stack.Push(ethutil.BigD(closure.Callee().Address()))
-		case oCALLVALUE:
+		case CALLVALUE:
 			stack.Push(vm.vars.Value)
-		case oCALLDATALOAD:
+		case CALLDATALOAD:
 			require(1)
 			offset := stack.Pop().Int64()
 			val := closure.Args[offset : offset+32]
 
 			stack.Push(ethutil.BigD(val))
-		case oCALLDATASIZE:
+		case CALLDATASIZE:
 			stack.Push(big.NewInt(int64(len(closure.Args))))
-		case oGASPRICE:
+		case GASPRICE:
 			stack.Push(closure.Price)
 
 			// 0x40 range
-		case oPREVHASH:
+		case PREVHASH:
 			stack.Push(ethutil.BigD(vm.vars.PrevHash))
-		case oCOINBASE:
+		case COINBASE:
 			stack.Push(ethutil.BigD(vm.vars.Coinbase))
-		case oTIMESTAMP:
+		case TIMESTAMP:
 			stack.Push(big.NewInt(vm.vars.Time))
-		case oNUMBER:
+		case NUMBER:
 			stack.Push(big.NewInt(int64(vm.vars.BlockNumber)))
-		case oDIFFICULTY:
+		case DIFFICULTY:
 			stack.Push(vm.vars.Diff)
-		case oGASLIMIT:
+		case GASLIMIT:
 			// TODO
 			stack.Push(big.NewInt(0))
 
 			// 0x50 range
-		case oPUSH1, oPUSH2, oPUSH3, oPUSH4, oPUSH5, oPUSH6, oPUSH7, oPUSH8, oPUSH9, oPUSH10, oPUSH11, oPUSH12, oPUSH13, oPUSH14, oPUSH15, oPUSH16, oPUSH17, oPUSH18, oPUSH19, oPUSH20, oPUSH21, oPUSH22, oPUSH23, oPUSH24, oPUSH25, oPUSH26, oPUSH27, oPUSH28, oPUSH29, oPUSH30, oPUSH31, oPUSH32:
-			a := big.NewInt(int64(op) - int64(oPUSH1) + 1)
+		case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
+			a := big.NewInt(int64(op) - int64(PUSH1) + 1)
 			pc.Add(pc, ethutil.Big1)
 			data := closure.Gets(pc, a)
 			val := ethutil.BigD(data.Bytes())
 			// Push value to stack
 			stack.Push(val)
 			pc.Add(pc, a.Sub(a, big.NewInt(1)))
-			step++
 
-		case oPOP:
+			step += int(op) - int(PUSH1) + 1
+		case POP:
 			require(1)
 			stack.Pop()
-		case oDUP:
+		case DUP:
 			require(1)
 			stack.Push(stack.Peek())
-		case oSWAP:
+		case SWAP:
 			require(2)
 			x, y := stack.Popn()
 			stack.Push(y)
 			stack.Push(x)
-		case oMLOAD:
+		case MLOAD:
 			require(1)
 			offset := stack.Pop()
 			stack.Push(ethutil.BigD(mem.Get(offset.Int64(), 32)))
-		case oMSTORE: // Store the value at stack top-1 in to memory at location stack top
+		case MSTORE: // Store the value at stack top-1 in to memory at location stack top
 			require(2)
 			// Pop value of the stack
 			val, mStart := stack.Popn()
 			mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(val, 256))
-		case oMSTORE8:
+		case MSTORE8:
 			require(2)
 			val, mStart := stack.Popn()
 			base.And(val, new(big.Int).SetInt64(0xff))
 			mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(base, 256))
-		case oSLOAD:
+		case SLOAD:
 			require(1)
 			loc := stack.Pop()
 			val := closure.GetMem(loc)
 			//fmt.Println("get", val.BigInt(), "@", loc)
 			stack.Push(val.BigInt())
-		case oSSTORE:
+		case SSTORE:
 			require(2)
 			val, loc := stack.Popn()
 			//fmt.Println("storing", val, "@", loc)
@@ -401,13 +399,13 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 
 			// Add the change to manifest
 			vm.state.manifest.AddStorageChange(closure.Object(), loc.Bytes(), val)
-		case oJUMP:
+		case JUMP:
 			require(1)
 			pc = stack.Pop()
 			// Reduce pc by one because of the increment that's at the end of this for loop
 			//pc.Sub(pc, ethutil.Big1)
 			continue
-		case oJUMPI:
+		case JUMPI:
 			require(2)
 			cond, pos := stack.Popn()
 			if cond.Cmp(ethutil.BigTrue) == 0 {
@@ -415,12 +413,12 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 				//pc.Sub(pc, ethutil.Big1)
 				continue
 			}
-		case oPC:
+		case PC:
 			stack.Push(pc)
-		case oMSIZE:
+		case MSIZE:
 			stack.Push(big.NewInt(int64(mem.Len())))
 			// 0x60 range
-		case oCREATE:
+		case CREATE:
 			require(3)
 
 			value := stack.Pop()
@@ -439,9 +437,10 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			// Transfer all remaining gas to the new
 			// contract so it may run the init script
 			gas := new(big.Int).Set(closure.Gas)
-			closure.Gas.Sub(closure.Gas, gas)
+			closure.UseGas(gas)
+
 			// Create the closure
-			closure := NewClosure(closure.callee,
+			c := NewClosure(closure.callee,
 				closure.Object(),
 				contract.initScript,
 				vm.state,
@@ -449,7 +448,8 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 				closure.Price)
 			// Call the closure and set the return value as
 			// main script.
-			closure.Script, err = closure.Call(vm, nil, hook)
+			c.Script, _, err = c.Call(vm, nil, hook)
+
 			if err != nil {
 				stack.Push(ethutil.BigFalse)
 
@@ -460,7 +460,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 
 				vm.state.UpdateStateObject(contract)
 			}
-		case oCALL:
+		case CALL:
 			require(7)
 			// Closure addr
 			addr := stack.Pop()
@@ -492,7 +492,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 					// Copy
 					gas = new(big.Int).Set(closure.Gas)
 				}
-				closure.Gas.Sub(closure.Gas, gas)
+				closure.UseGas(gas)
 
 				// Add the value to the state object
 				contract.AddAmount(value)
@@ -500,7 +500,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 				// Create a new callable closure
 				closure := NewClosure(closure.Object(), contract, contract.script, vm.state, gas, closure.Price)
 				// Executer the closure and get the return value (if any)
-				ret, err := closure.Call(vm, args, hook)
+				ret, _, err := closure.Call(vm, args, hook)
 				if err != nil {
 					stack.Push(ethutil.BigFalse)
 					// Reset the changes applied this object
@@ -516,13 +516,13 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 				ethutil.Config.Log.Debugf("Contract %x not found\n", addr.Bytes())
 				stack.Push(ethutil.BigFalse)
 			}
-		case oRETURN:
+		case RETURN:
 			require(2)
 			size, offset := stack.Popn()
 			ret := mem.Get(offset.Int64(), size.Int64())
 
 			return closure.Return(ret), nil
-		case oSUICIDE:
+		case SUICIDE:
 			require(1)
 
 			receiver := vm.state.GetAccount(stack.Pop().Bytes())
@@ -532,7 +532,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 			closure.object.state.Purge()
 
 			fallthrough
-		case oSTOP: // Stop the closure
+		case STOP: // Stop the closure
 			return closure.Return(nil), nil
 		default:
 			ethutil.Config.Log.Debugf("Invalid opcode %x\n", op)
@@ -543,7 +543,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err erro
 		pc.Add(pc, ethutil.Big1)
 
 		if hook != nil {
-			if !hook(step-1, op, mem, stack, closure.Object()) {
+			if !hook(prevStep, op, mem, stack, closure.Object()) {
 				return nil, nil
 			}
 		}