Moved assembler stage processing to it's own file

5 files changed, 430 insertions, 213 deletions

diff --git a/ethchain/asm.go b/ethchain/asm.go
new file mode 100644
index 000000000..5f901f8a2
--- /dev/null
+++ b/ethchain/asm.go
@@ -0,0 +1,126 @@
+package ethchain
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+	"regexp"
+)
+
+func CompileInstr(s interface{}) ([]byte, error) {
+	switch s.(type) {
+	case string:
+		str := s.(string)
+		isOp := IsOpCode(str)
+		if isOp {
+			return []byte{OpCodes[str]}, nil
+		}
+
+		num := new(big.Int)
+		_, success := num.SetString(str, 0)
+		// Assume regular bytes during compilation
+		if !success {
+			num.SetBytes([]byte(str))
+		} else {
+			// tmp fix for 32 bytes
+			n := ethutil.BigToBytes(num, 256)
+			return n, nil
+		}
+
+		return num.Bytes(), nil
+	case int:
+		num := ethutil.BigToBytes(big.NewInt(int64(s.(int))), 256)
+		return num, nil
+	case []byte:
+		return ethutil.BigD(s.([]byte)).Bytes(), nil
+	}
+
+	return nil, nil
+}
+
+// Script compilation functions
+// Compiles strings to machine code
+func Assemble(instructions ...interface{}) (script []byte) {
+	//script = make([]string, len(instructions))
+
+	for _, val := range instructions {
+		instr, _ := CompileInstr(val)
+
+		//script[i] = string(instr)
+		script = append(script, instr...)
+	}
+
+	return
+}
+
+func Disassemble(script []byte) (asm []string) {
+	pc := new(big.Int)
+	for {
+		if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 {
+			return
+		}
+
+		// Get the memory location of pc
+		val := script[pc.Int64()]
+		// Get the opcode (it must be an opcode!)
+		op := OpCode(val)
+
+		asm = append(asm, fmt.Sprintf("%v", op))
+
+		switch op {
+		case oPUSH: // Push PC+1 on to the stack
+			pc.Add(pc, ethutil.Big1)
+			data := script[pc.Int64() : pc.Int64()+32]
+			val := ethutil.BigD(data)
+
+			var b []byte
+			if val.Int64() == 0 {
+				b = []byte{0}
+			} else {
+				b = val.Bytes()
+			}
+
+			asm = append(asm, fmt.Sprintf("0x%x", b))
+
+			pc.Add(pc, big.NewInt(31))
+		case oPUSH20:
+			pc.Add(pc, ethutil.Big1)
+			data := script[pc.Int64() : pc.Int64()+20]
+			val := ethutil.BigD(data)
+			var b []byte
+			if val.Int64() == 0 {
+				b = []byte{0}
+			} else {
+				b = val.Bytes()
+			}
+
+			asm = append(asm, fmt.Sprintf("0x%x", b))
+
+			pc.Add(pc, big.NewInt(19))
+		}
+
+		pc.Add(pc, ethutil.Big1)
+	}
+
+	return
+}
+
+func PreProcess(data string) (mainInput, initInput string) {
+	reg := "\\(\\)\\s*{([\\d\\w\\W\\n\\s]+?)}"
+	mainReg := regexp.MustCompile("main" + reg)
+	initReg := regexp.MustCompile("init" + reg)
+
+	main := mainReg.FindStringSubmatch(data)
+	if len(main) > 0 {
+		mainInput = main[1]
+	} else {
+		mainInput = data
+	}
+
+	init := initReg.FindStringSubmatch(data)
+	if len(init) > 0 {
+		initInput = init[1]
+	}
+
+	return
+}
diff --git a/ethchain/closure.go b/ethchain/closure.go
index 0fbe48f92..0762e8f49 100644
--- a/ethchain/closure.go
+++ b/ethchain/closure.go
@@ -71,7 +71,7 @@ func (c *Closure) Address() []byte {
 
 type DebugHook func(step int, op OpCode, mem *Memory, stack *Stack)
 
-func (c *Closure) Call(vm *Vm, args []byte, hook DebugHook) []byte {
+func (c *Closure) Call(vm *Vm, args []byte, hook DebugHook) ([]byte, error) {
 	c.Args = args
 
 	return vm.RunClosure(c, hook)
diff --git a/ethchain/stack.go b/ethchain/stack.go
index 2aca0a350..288360062 100644
--- a/ethchain/stack.go
+++ b/ethchain/stack.go
@@ -6,153 +6,6 @@ import (
 	"math/big"
 )
 
-type OpCode int
-
-// Op codes
-const (
-	// 0x0 range - arithmetic ops
-	oSTOP = 0x00
-	oADD  = 0x01
-	oMUL  = 0x02
-	oSUB  = 0x03
-	oDIV  = 0x04
-	oSDIV = 0x05
-	oMOD  = 0x06
-	oSMOD = 0x07
-	oEXP  = 0x08
-	oNEG  = 0x09
-	oLT   = 0x0a
-	oGT   = 0x0b
-	oEQ   = 0x0c
-	oNOT  = 0x0d
-
-	// 0x10 range - bit ops
-	oAND  = 0x10
-	oOR   = 0x11
-	oXOR  = 0x12
-	oBYTE = 0x13
-
-	// 0x20 range - crypto
-	oSHA3 = 0x20
-
-	// 0x30 range - closure state
-	oADDRESS      = 0x30
-	oBALANCE      = 0x31
-	oORIGIN       = 0x32
-	oCALLER       = 0x33
-	oCALLVALUE    = 0x34
-	oCALLDATA     = 0x35
-	oCALLDATASIZE = 0x36
-	oGASPRICE     = 0x37
-
-	// 0x40 range - block operations
-	oPREVHASH   = 0x40
-	oCOINBASE   = 0x41
-	oTIMESTAMP  = 0x42
-	oNUMBER     = 0x43
-	oDIFFICULTY = 0x44
-	oGASLIMIT   = 0x45
-
-	// 0x50 range - 'storage' and execution
-	oPUSH    = 0x50
-	oPUSH20  = 0x80
-	oPOP     = 0x51
-	oDUP     = 0x52
-	oSWAP    = 0x53
-	oMLOAD   = 0x54
-	oMSTORE  = 0x55
-	oMSTORE8 = 0x56
-	oSLOAD   = 0x57
-	oSSTORE  = 0x58
-	oJUMP    = 0x59
-	oJUMPI   = 0x5a
-	oPC      = 0x5b
-	oMSIZE   = 0x5c
-
-	// 0x60 range - closures
-	oCREATE = 0x60
-	oCALL   = 0x61
-	oRETURN = 0x62
-
-	// 0x70 range - other
-	oLOG     = 0x70 // XXX Unofficial
-	oSUICIDE = 0x7f
-)
-
-// Since the opcodes aren't all in order we can't use a regular slice
-var opCodeToString = map[OpCode]string{
-	// 0x0 range - arithmetic ops
-	oSTOP: "STOP",
-	oADD:  "ADD",
-	oMUL:  "MUL",
-	oSUB:  "SUB",
-	oDIV:  "DIV",
-	oSDIV: "SDIV",
-	oMOD:  "MOD",
-	oSMOD: "SMOD",
-	oEXP:  "EXP",
-	oNEG:  "NEG",
-	oLT:   "LT",
-	oGT:   "GT",
-	oEQ:   "EQ",
-	oNOT:  "NOT",
-
-	// 0x10 range - bit ops
-	oAND:  "AND",
-	oOR:   "OR",
-	oXOR:  "XOR",
-	oBYTE: "BYTE",
-
-	// 0x20 range - crypto
-	oSHA3: "SHA3",
-
-	// 0x30 range - closure state
-	oADDRESS:      "ADDRESS",
-	oBALANCE:      "BALANCE",
-	oORIGIN:       "ORIGIN",
-	oCALLER:       "CALLER",
-	oCALLVALUE:    "CALLVALUE",
-	oCALLDATA:     "CALLDATA",
-	oCALLDATASIZE: "CALLDATASIZE",
-	oGASPRICE:     "TXGASPRICE",
-
-	// 0x40 range - block operations
-	oPREVHASH:   "PREVHASH",
-	oCOINBASE:   "COINBASE",
-	oTIMESTAMP:  "TIMESTAMP",
-	oNUMBER:     "NUMBER",
-	oDIFFICULTY: "DIFFICULTY",
-	oGASLIMIT:   "GASLIMIT",
-
-	// 0x50 range - 'storage' and execution
-	oPUSH:    "PUSH",
-	oPOP:     "POP",
-	oDUP:     "DUP",
-	oSWAP:    "SWAP",
-	oMLOAD:   "MLOAD",
-	oMSTORE:  "MSTORE",
-	oMSTORE8: "MSTORE8",
-	oSLOAD:   "SLOAD",
-	oSSTORE:  "SSTORE",
-	oJUMP:    "JUMP",
-	oJUMPI:   "JUMPI",
-	oPC:      "PC",
-	oMSIZE:   "MSIZE",
-
-	// 0x60 range - closures
-	oCREATE: "CREATE",
-	oCALL:   "CALL",
-	oRETURN: "RETURN",
-
-	// 0x70 range - other
-	oLOG:     "LOG",
-	oSUICIDE: "SUICIDE",
-}
-
-func (o OpCode) String() string {
-	return opCodeToString[o]
-}
-
 type OpType int
 
 const (
@@ -177,6 +30,10 @@ func (st *Stack) Data() []*big.Int {
 	return st.data
 }
 
+func (st *Stack) Len() int {
+	return len(st.data)
+}
+
 func (st *Stack) Pop() *big.Int {
 	str := st.data[len(st.data)-1]
 
diff --git a/ethchain/types.go b/ethchain/types.go
new file mode 100644
index 000000000..24aad82c3
--- /dev/null
+++ b/ethchain/types.go
@@ -0,0 +1,230 @@
+package ethchain
+
+type OpCode int
+
+// Op codes
+const (
+	// 0x0 range - arithmetic ops
+	oSTOP = 0x00
+	oADD  = 0x01
+	oMUL  = 0x02
+	oSUB  = 0x03
+	oDIV  = 0x04
+	oSDIV = 0x05
+	oMOD  = 0x06
+	oSMOD = 0x07
+	oEXP  = 0x08
+	oNEG  = 0x09
+	oLT   = 0x0a
+	oGT   = 0x0b
+	oEQ   = 0x0c
+	oNOT  = 0x0d
+
+	// 0x10 range - bit ops
+	oAND  = 0x10
+	oOR   = 0x11
+	oXOR  = 0x12
+	oBYTE = 0x13
+
+	// 0x20 range - crypto
+	oSHA3 = 0x20
+
+	// 0x30 range - closure state
+	oADDRESS      = 0x30
+	oBALANCE      = 0x31
+	oORIGIN       = 0x32
+	oCALLER       = 0x33
+	oCALLVALUE    = 0x34
+	oCALLDATA     = 0x35
+	oCALLDATASIZE = 0x36
+	oGASPRICE     = 0x37
+
+	// 0x40 range - block operations
+	oPREVHASH   = 0x40
+	oCOINBASE   = 0x41
+	oTIMESTAMP  = 0x42
+	oNUMBER     = 0x43
+	oDIFFICULTY = 0x44
+	oGASLIMIT   = 0x45
+
+	// 0x50 range - 'storage' and execution
+	oPUSH    = 0x50
+	oPUSH20  = 0x80
+	oPOP     = 0x51
+	oDUP     = 0x52
+	oSWAP    = 0x53
+	oMLOAD   = 0x54
+	oMSTORE  = 0x55
+	oMSTORE8 = 0x56
+	oSLOAD   = 0x57
+	oSSTORE  = 0x58
+	oJUMP    = 0x59
+	oJUMPI   = 0x5a
+	oPC      = 0x5b
+	oMSIZE   = 0x5c
+
+	// 0x60 range - closures
+	oCREATE = 0x60
+	oCALL   = 0x61
+	oRETURN = 0x62
+
+	// 0x70 range - other
+	oLOG     = 0x70 // XXX Unofficial
+	oSUICIDE = 0x7f
+)
+
+// Since the opcodes aren't all in order we can't use a regular slice
+var opCodeToString = map[OpCode]string{
+	// 0x0 range - arithmetic ops
+	oSTOP: "STOP",
+	oADD:  "ADD",
+	oMUL:  "MUL",
+	oSUB:  "SUB",
+	oDIV:  "DIV",
+	oSDIV: "SDIV",
+	oMOD:  "MOD",
+	oSMOD: "SMOD",
+	oEXP:  "EXP",
+	oNEG:  "NEG",
+	oLT:   "LT",
+	oGT:   "GT",
+	oEQ:   "EQ",
+	oNOT:  "NOT",
+
+	// 0x10 range - bit ops
+	oAND:  "AND",
+	oOR:   "OR",
+	oXOR:  "XOR",
+	oBYTE: "BYTE",
+
+	// 0x20 range - crypto
+	oSHA3: "SHA3",
+
+	// 0x30 range - closure state
+	oADDRESS:      "ADDRESS",
+	oBALANCE:      "BALANCE",
+	oORIGIN:       "ORIGIN",
+	oCALLER:       "CALLER",
+	oCALLVALUE:    "CALLVALUE",
+	oCALLDATA:     "CALLDATA",
+	oCALLDATASIZE: "CALLDATASIZE",
+	oGASPRICE:     "TXGASPRICE",
+
+	// 0x40 range - block operations
+	oPREVHASH:   "PREVHASH",
+	oCOINBASE:   "COINBASE",
+	oTIMESTAMP:  "TIMESTAMP",
+	oNUMBER:     "NUMBER",
+	oDIFFICULTY: "DIFFICULTY",
+	oGASLIMIT:   "GASLIMIT",
+
+	// 0x50 range - 'storage' and execution
+	oPUSH:    "PUSH",
+	oPOP:     "POP",
+	oDUP:     "DUP",
+	oSWAP:    "SWAP",
+	oMLOAD:   "MLOAD",
+	oMSTORE:  "MSTORE",
+	oMSTORE8: "MSTORE8",
+	oSLOAD:   "SLOAD",
+	oSSTORE:  "SSTORE",
+	oJUMP:    "JUMP",
+	oJUMPI:   "JUMPI",
+	oPC:      "PC",
+	oMSIZE:   "MSIZE",
+
+	// 0x60 range - closures
+	oCREATE: "CREATE",
+	oCALL:   "CALL",
+	oRETURN: "RETURN",
+
+	// 0x70 range - other
+	oLOG:     "LOG",
+	oSUICIDE: "SUICIDE",
+}
+
+func (o OpCode) String() string {
+	return opCodeToString[o]
+}
+
+// Op codes for assembling
+var OpCodes = map[string]byte{
+	// 0x0 range - arithmetic ops
+	"STOP": 0x00,
+	"ADD":  0x01,
+	"MUL":  0x02,
+	"SUB":  0x03,
+	"DIV":  0x04,
+	"SDIV": 0x05,
+	"MOD":  0x06,
+	"SMOD": 0x07,
+	"EXP":  0x08,
+	"NEG":  0x09,
+	"LT":   0x0a,
+	"GT":   0x0b,
+	"EQ":   0x0c,
+	"NOT":  0x0d,
+
+	// 0x10 range - bit ops
+	"AND":  0x10,
+	"OR":   0x11,
+	"XOR":  0x12,
+	"BYTE": 0x13,
+
+	// 0x20 range - crypto
+	"SHA3": 0x20,
+
+	// 0x30 range - closure state
+	"ADDRESS":      0x30,
+	"BALANCE":      0x31,
+	"ORIGIN":       0x32,
+	"CALLER":       0x33,
+	"CALLVALUE":    0x34,
+	"CALLDATA":     0x35,
+	"CALLDATASIZE": 0x36,
+	"GASPRICE":     0x38,
+
+	// 0x40 range - block operations
+	"PREVHASH":   0x40,
+	"COINBASE":   0x41,
+	"TIMESTAMP":  0x42,
+	"NUMBER":     0x43,
+	"DIFFICULTY": 0x44,
+	"GASLIMIT":   0x45,
+
+	// 0x50 range - 'storage' and execution
+	"PUSH": 0x50,
+
+	"PUSH20": 0x80,
+
+	"POP":     0x51,
+	"DUP":     0x52,
+	"SWAP":    0x53,
+	"MLOAD":   0x54,
+	"MSTORE":  0x55,
+	"MSTORE8": 0x56,
+	"SLOAD":   0x57,
+	"SSTORE":  0x58,
+	"JUMP":    0x59,
+	"JUMPI":   0x5a,
+	"PC":      0x5b,
+	"MSIZE":   0x5c,
+
+	// 0x60 range - closures
+	"CREATE": 0x60,
+	"CALL":   0x61,
+	"RETURN": 0x62,
+
+	// 0x70 range - other
+	"LOG":     0x70,
+	"SUICIDE": 0x7f,
+}
+
+func IsOpCode(s string) bool {
+	for key, _ := range OpCodes {
+		if key == s {
+			return true
+		}
+	}
+	return false
+}
diff --git a/ethchain/vm.go b/ethchain/vm.go
index b88cd2861..33d667457 100644
--- a/ethchain/vm.go
+++ b/ethchain/vm.go
@@ -48,7 +48,19 @@ func NewVm(state *State, vars RuntimeVars) *Vm {
 
 var Pow256 = ethutil.BigPow(2, 256)
 
-func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
+var isRequireError = false
+
+func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) (ret []byte, err error) {
+	// Recover from any require exception
+	defer func() {
+		if r := recover(); r != nil && isRequireError {
+			fmt.Println(r)
+
+			ret = closure.Return(nil)
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
 	// If the amount of gas supplied is less equal to 0
 	if closure.Gas.Cmp(big.NewInt(0)) <= 0 {
 		// TODO Do something
@@ -58,6 +70,13 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 	mem := &Memory{}
 	// New stack (should this be shared?)
 	stack := NewStack()
+	require := func(m int) {
+		if stack.Len()-1 > m {
+			isRequireError = true
+			panic(fmt.Sprintf("stack = %d, req = %d", stack.Len(), m))
+		}
+	}
+
 	// Instruction pointer
 	pc := big.NewInt(0)
 	// Current step count
@@ -121,7 +140,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		if closure.Gas.Cmp(gas) < 0 {
 			ethutil.Config.Log.Debugln("Insufficient gas", closure.Gas, gas)
 
-			return closure.Return(nil)
+			return closure.Return(nil), fmt.Errorf("insufficient gas %v %v", closure.Gas, gas)
 		}
 
 		switch op {
@@ -129,10 +148,11 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			stack.Print()
 			mem.Print()
 		case oSTOP: // Stop the closure
-			return closure.Return(nil)
+			return closure.Return(nil), nil
 
-		// 0x20 range
+			// 0x20 range
 		case oADD:
+			require(2)
 			x, y := stack.Popn()
 			// (x + y) % 2 ** 256
 			base.Add(x, y)
@@ -140,6 +160,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// Pop result back on the stack
 			stack.Push(base)
 		case oSUB:
+			require(2)
 			x, y := stack.Popn()
 			// (x - y) % 2 ** 256
 			base.Sub(x, y)
@@ -147,6 +168,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// Pop result back on the stack
 			stack.Push(base)
 		case oMUL:
+			require(2)
 			x, y := stack.Popn()
 			// (x * y) % 2 ** 256
 			base.Mul(x, y)
@@ -154,12 +176,14 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// Pop result back on the stack
 			stack.Push(base)
 		case oDIV:
+			require(2)
 			x, y := stack.Popn()
 			// floor(x / y)
 			base.Div(x, y)
 			// Pop result back on the stack
 			stack.Push(base)
 		case oSDIV:
+			require(2)
 			x, y := stack.Popn()
 			// n > 2**255
 			if x.Cmp(Pow256) > 0 {
@@ -176,10 +200,12 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// Push result on to the stack
 			stack.Push(z)
 		case oMOD:
+			require(2)
 			x, y := stack.Popn()
 			base.Mod(x, y)
 			stack.Push(base)
 		case oSMOD:
+			require(2)
 			x, y := stack.Popn()
 			// n > 2**255
 			if x.Cmp(Pow256) > 0 {
@@ -196,14 +222,17 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// Push result on to the stack
 			stack.Push(z)
 		case oEXP:
+			require(2)
 			x, y := stack.Popn()
 			base.Exp(x, y, Pow256)
 
 			stack.Push(base)
 		case oNEG:
+			require(1)
 			base.Sub(Pow256, stack.Pop())
 			stack.Push(base)
 		case oLT:
+			require(2)
 			x, y := stack.Popn()
 			// x < y
 			if x.Cmp(y) < 0 {
@@ -212,6 +241,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 				stack.Push(ethutil.BigFalse)
 			}
 		case oGT:
+			require(2)
 			x, y := stack.Popn()
 			// x > y
 			if x.Cmp(y) > 0 {
@@ -220,6 +250,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 				stack.Push(ethutil.BigFalse)
 			}
 		case oEQ:
+			require(2)
 			x, y := stack.Popn()
 			// x == y
 			if x.Cmp(y) == 0 {
@@ -228,6 +259,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 				stack.Push(ethutil.BigFalse)
 			}
 		case oNOT:
+			require(1)
 			x := stack.Pop()
 			if x.Cmp(ethutil.BigFalse) == 0 {
 				stack.Push(ethutil.BigTrue)
@@ -235,8 +267,9 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 				stack.Push(ethutil.BigFalse)
 			}
 
-		// 0x10 range
+			// 0x10 range
 		case oAND:
+			require(2)
 			x, y := stack.Popn()
 			if (x.Cmp(ethutil.BigTrue) >= 0) && (y.Cmp(ethutil.BigTrue) >= 0) {
 				stack.Push(ethutil.BigTrue)
@@ -245,6 +278,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			}
 
 		case oOR:
+			require(2)
 			x, y := stack.Popn()
 			if (x.Cmp(ethutil.BigInt0) >= 0) || (y.Cmp(ethutil.BigInt0) >= 0) {
 				stack.Push(ethutil.BigTrue)
@@ -252,9 +286,11 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 				stack.Push(ethutil.BigFalse)
 			}
 		case oXOR:
+			require(2)
 			x, y := stack.Popn()
 			stack.Push(base.Xor(x, y))
 		case oBYTE:
+			require(2)
 			val, th := stack.Popn()
 			if th.Cmp(big.NewInt(32)) < 0 {
 				stack.Push(big.NewInt(int64(len(val.Bytes())-1) - th.Int64()))
@@ -262,13 +298,14 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 				stack.Push(ethutil.BigFalse)
 			}
 
-		// 0x20 range
+			// 0x20 range
 		case oSHA3:
+			require(2)
 			size, offset := stack.Popn()
 			data := mem.Get(offset.Int64(), size.Int64())
 
 			stack.Push(ethutil.BigD(data))
-		// 0x30 range
+			// 0x30 range
 		case oADDRESS:
 			stack.Push(ethutil.BigD(closure.Object().Address()))
 		case oBALANCE:
@@ -281,6 +318,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// FIXME: Original value of the call, not the current value
 			stack.Push(closure.Value)
 		case oCALLDATA:
+			require(1)
 			offset := stack.Pop()
 			mem.Set(offset.Int64(), int64(len(closure.Args)), closure.Args)
 		case oCALLDATASIZE:
@@ -288,7 +326,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		case oGASPRICE:
 			// TODO
 
-		// 0x40 range
+			// 0x40 range
 		case oPREVHASH:
 			stack.Push(ethutil.BigD(vm.vars.PrevHash))
 		case oCOINBASE:
@@ -300,7 +338,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		case oDIFFICULTY:
 			stack.Push(vm.vars.Diff)
 		case oGASLIMIT:
-			// TODO
+		// TODO
 
 		// 0x50 range
 		case oPUSH: // Push PC+1 on to the stack
@@ -324,34 +362,44 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			pc.Add(pc, big.NewInt(19))
 			step++
 		case oPOP:
+			require(1)
 			stack.Pop()
 		case oDUP:
+			require(1)
 			stack.Push(stack.Peek())
 		case oSWAP:
+			require(2)
 			x, y := stack.Popn()
 			stack.Push(y)
 			stack.Push(x)
 		case oMLOAD:
+			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
+			require(2)
 			// Pop value of the stack
 			val, mStart := stack.Popn()
 			mem.Set(mStart.Int64(), 32, ethutil.BigToBytes(val, 256))
 		case oMSTORE8:
+			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:
+			require(1)
 			loc := stack.Pop()
 			val := closure.GetMem(loc)
 			stack.Push(val.BigInt())
 		case oSSTORE:
+			require(2)
 			val, loc := stack.Popn()
 			closure.SetMem(loc, ethutil.NewValue(val))
 		case oJUMP:
+			require(1)
 			pc = stack.Pop()
 		case oJUMPI:
+			require(2)
 			cond, pos := stack.Popn()
 			if cond.Cmp(ethutil.BigTrue) == 0 {
 				pc = pos
@@ -360,8 +408,10 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			stack.Push(pc)
 		case oMSIZE:
 			stack.Push(big.NewInt(int64(mem.Len())))
-		// 0x60 range
+			// 0x60 range
+		case oCREATE:
 		case oCALL:
+			require(8)
 			// Closure addr
 			addr := stack.Pop()
 			// Pop gas and value of the stack.
@@ -377,14 +427,20 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 			// Create a new callable closure
 			closure := NewClosure(closure, contract, contract.script, vm.state, gas, value)
 			// Executer the closure and get the return value (if any)
-			ret := closure.Call(vm, args, hook)
+			ret, err := closure.Call(vm, args, hook)
+			if err != nil {
+				stack.Push(ethutil.BigFalse)
+			} else {
+				stack.Push(ethutil.BigTrue)
+			}
 
 			mem.Set(retOffset.Int64(), retSize.Int64(), ret)
 		case oRETURN:
+			require(2)
 			size, offset := stack.Popn()
 			ret := mem.Get(offset.Int64(), size.Int64())
 
-			return closure.Return(ret)
+			return closure.Return(ret), nil
 		case oSUICIDE:
 			/*
 				recAddr := stack.Pop().Bytes()
@@ -405,7 +461,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		default:
 			ethutil.Config.Log.Debugf("Invalid opcode %x\n", op)
 
-			return closure.Return(nil)
+			return closure.Return(nil), fmt.Errorf("Invalid opcode %x", op)
 		}
 
 		pc.Add(pc, ethutil.Big1)
@@ -415,55 +471,3 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		}
 	}
 }
-
-func Disassemble(script []byte) (asm []string) {
-	pc := new(big.Int)
-	for {
-		if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 {
-			return
-		}
-
-		// Get the memory location of pc
-		val := script[pc.Int64()]
-		// Get the opcode (it must be an opcode!)
-		op := OpCode(val)
-
-		asm = append(asm, fmt.Sprintf("%v", op))
-
-		switch op {
-		case oPUSH: // Push PC+1 on to the stack
-			pc.Add(pc, ethutil.Big1)
-			data := script[pc.Int64() : pc.Int64()+32]
-			val := ethutil.BigD(data)
-
-			var b []byte
-			if val.Int64() == 0 {
-				b = []byte{0}
-			} else {
-				b = val.Bytes()
-			}
-
-			asm = append(asm, fmt.Sprintf("0x%x", b))
-
-			pc.Add(pc, big.NewInt(31))
-		case oPUSH20:
-			pc.Add(pc, ethutil.Big1)
-			data := script[pc.Int64() : pc.Int64()+20]
-			val := ethutil.BigD(data)
-			var b []byte
-			if val.Int64() == 0 {
-				b = []byte{0}
-			} else {
-				b = val.Bytes()
-			}
-
-			asm = append(asm, fmt.Sprintf("0x%x", b))
-
-			pc.Add(pc, big.NewInt(19))
-		}
-
-		pc.Add(pc, ethutil.Big1)
-	}
-
-	return
-}