Merge branch 'release/0.9.30'v0.9.30

7 files changed, 157 insertions, 174 deletions

diff --git a/core/vm/context.go b/core/vm/context.go
index de03f84f0..e33324b53 100644
--- a/core/vm/context.go
+++ b/core/vm/context.go
@@ -49,13 +49,13 @@ func NewContext(caller ContextRef, object ContextRef, value, gas, price *big.Int
 	return c
 }
 
-func (c *Context) GetOp(n *big.Int) OpCode {
+func (c *Context) GetOp(n uint64) OpCode {
 	return OpCode(c.GetByte(n))
 }
 
-func (c *Context) GetByte(n *big.Int) byte {
-	if n.Cmp(big.NewInt(int64(len(c.Code)))) < 0 {
-		return c.Code[n.Int64()]
+func (c *Context) GetByte(n uint64) byte {
+	if n < uint64(len(c.Code)) {
+		return c.Code[n]
 	}
 
 	return 0
diff --git a/core/vm/environment.go b/core/vm/environment.go
index 282d19578..c103049a2 100644
--- a/core/vm/environment.go
+++ b/core/vm/environment.go
@@ -8,6 +8,8 @@ import (
 	"github.com/ethereum/go-ethereum/core/state"
 )
 
+// Environment is is required by the virtual machine to get information from
+// it's own isolated environment. For an example see `core.VMEnv`
 type Environment interface {
 	State() *state.StateDB
 
@@ -20,6 +22,8 @@ type Environment interface {
 	GasLimit() *big.Int
 	Transfer(from, to Account, amount *big.Int) error
 	AddLog(*state.Log)
+	AddStructLog(StructLog)
+	StructLogs() []StructLog
 
 	VmType() Type
 
@@ -31,6 +35,19 @@ type Environment interface {
 	Create(me ContextRef, data []byte, gas, price, value *big.Int) ([]byte, error, ContextRef)
 }
 
+// StructLog is emited to the Environment each cycle and lists information about the curent internal state
+// prior to the execution of the statement.
+type StructLog struct {
+	Pc      uint64
+	Op      OpCode
+	Gas     *big.Int
+	GasCost *big.Int
+	Memory  []byte
+	Stack   []*big.Int
+	Storage map[common.Hash][]byte
+	Err     error
+}
+
 type Account interface {
 	SubBalance(amount *big.Int)
 	AddBalance(amount *big.Int)
diff --git a/core/vm/errors.go b/core/vm/errors.go
index fc3459de0..799eb6797 100644
--- a/core/vm/errors.go
+++ b/core/vm/errors.go
@@ -2,20 +2,14 @@ package vm
 
 import (
 	"fmt"
+
 	"github.com/ethereum/go-ethereum/params"
-	"math/big"
 )
 
-type OutOfGasError struct {
-	req, has *big.Int
-}
-
-func OOG(req, has *big.Int) OutOfGasError {
-	return OutOfGasError{req, has}
-}
+type OutOfGasError struct{}
 
 func (self OutOfGasError) Error() string {
-	return fmt.Sprintf("out of gas! require %v, have %v", self.req, self.has)
+	return "Out Of Gas"
 }
 
 func IsOOGErr(err error) bool {
diff --git a/core/vm/logger.go b/core/vm/logger.go
new file mode 100644
index 000000000..0e2a417ae
--- /dev/null
+++ b/core/vm/logger.go
@@ -0,0 +1,51 @@
+package vm
+
+import (
+	"fmt"
+	"os"
+	"unicode"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+func StdErrFormat(logs []StructLog) {
+	fmt.Fprintf(os.Stderr, "VM STAT %d OPs\n", len(logs))
+	for _, log := range logs {
+		fmt.Fprintf(os.Stderr, "PC %08d: %s GAS: %v COST: %v", log.Pc, log.Op, log.Gas, log.GasCost)
+		if log.Err != nil {
+			fmt.Fprintf(os.Stderr, " ERROR: %v", log.Err)
+		}
+		fmt.Fprintf(os.Stderr, "\n")
+
+		fmt.Fprintln(os.Stderr, "STACK =", len(log.Stack))
+
+		for i := len(log.Stack) - 1; i >= 0; i-- {
+			fmt.Fprintf(os.Stderr, "%04d: %x\n", len(log.Stack)-i-1, common.LeftPadBytes(log.Stack[i].Bytes(), 32))
+		}
+
+		const maxMem = 10
+		addr := 0
+		fmt.Fprintln(os.Stderr, "MEM =", len(log.Memory))
+		for i := 0; i+16 <= len(log.Memory) && addr < maxMem; i += 16 {
+			data := log.Memory[i : i+16]
+			str := fmt.Sprintf("%04d: % x  ", addr*16, data)
+			for _, r := range data {
+				if r == 0 {
+					str += "."
+				} else if unicode.IsPrint(rune(r)) {
+					str += fmt.Sprintf("%s", string(r))
+				} else {
+					str += "?"
+				}
+			}
+			addr++
+			fmt.Fprintln(os.Stderr, str)
+		}
+
+		fmt.Fprintln(os.Stderr, "STORAGE =", len(log.Storage))
+		for h, item := range log.Storage {
+			fmt.Fprintf(os.Stderr, "%x: %x\n", h, common.LeftPadBytes(item, 32))
+		}
+		fmt.Fprintln(os.Stderr)
+	}
+}
diff --git a/core/vm/stack.go b/core/vm/stack.go
index bb232d0b9..2be5c3dbe 100644
--- a/core/vm/stack.go
+++ b/core/vm/stack.go
@@ -5,7 +5,7 @@ import (
 	"math/big"
 )
 
-func newStack() *stack {
+func newstack() *stack {
 	return &stack{}
 }
 
@@ -14,6 +14,10 @@ type stack struct {
 	ptr  int
 }
 
+func (st *stack) Data() []*big.Int {
+	return st.data[:st.ptr]
+}
+
 func (st *stack) push(d *big.Int) {
 	// NOTE push limit (1024) is checked in baseCheck
 	stackItem := new(big.Int).Set(d)
diff --git a/core/vm/virtual_machine.go b/core/vm/virtual_machine.go
index 6db284f42..1fd1dcd88 100644
--- a/core/vm/virtual_machine.go
+++ b/core/vm/virtual_machine.go
@@ -3,6 +3,4 @@ package vm
 type VirtualMachine interface {
 	Env() Environment
 	Run(context *Context, data []byte) ([]byte, error)
-	Printf(string, ...interface{}) VirtualMachine
-	Endl() VirtualMachine
 }
diff --git a/core/vm/vm.go b/core/vm/vm.go
index 2bd950385..c5ad761f6 100644
--- a/core/vm/vm.go
+++ b/core/vm/vm.go
@@ -7,16 +7,13 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/params"
 )
 
+// Vm implements VirtualMachine
 type Vm struct {
 	env Environment
 
-	logTy  byte
-	logStr string
-
 	err error
 	// For logging
 	debug bool
@@ -31,13 +28,13 @@ type Vm struct {
 	After func(*Context, error)
 }
 
+// New returns a new Virtual Machine
 func New(env Environment) *Vm {
-	lt := LogTyPretty
-
-	return &Vm{debug: Debug, env: env, logTy: lt, Recoverable: true}
+	return &Vm{env: env, debug: Debug, Recoverable: true}
 }
 
-func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
+// Run loops and evaluates the contract's code with the given input data
+func (self *Vm) Run(context *Context, input []byte) (ret []byte, err error) {
 	self.env.SetDepth(self.env.Depth() + 1)
 	defer self.env.SetDepth(self.env.Depth() - 1)
 
@@ -46,9 +43,32 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 		code   = context.Code
 		value  = context.value
 		price  = context.Price
-	)
 
-	self.Printf("(%d) (%x) %x (code=%d) gas: %v (d) %x", self.env.Depth(), caller.Address().Bytes()[:4], context.Address(), len(code), context.Gas, callData).Endl()
+		op       OpCode                  // current opcode
+		codehash = crypto.Sha3Hash(code) // codehash is used when doing jump dest caching
+		mem      = NewMemory()           // bound memory
+		stack    = newstack()            // local stack
+		statedb  = self.env.State()      // current state
+		// For optimisation reason we're using uint64 as the program counter.
+		// It's theoretically possible to go above 2^64. The YP defines the PC to be uint256. Pratically much less so feasible.
+		pc = uint64(0) // program counter
+
+		// jump evaluates and checks whether the given jump destination is a valid one
+		// if valid move the `pc` otherwise return an error.
+		jump = func(from uint64, to *big.Int) error {
+			if !context.jumpdests.has(codehash, code, to) {
+				nop := context.GetOp(to.Uint64())
+				return fmt.Errorf("invalid jump destination (%v) %v", nop, to)
+			}
+
+			pc = to.Uint64()
+
+			return nil
+		}
+
+		newMemSize *big.Int
+		cost       *big.Int
+	)
 
 	// User defer pattern to check for an error and, based on the error being nil or not, use all gas and return.
 	defer func() {
@@ -57,7 +77,8 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 		}
 
 		if err != nil {
-			self.Printf(" %v", err).Endl()
+			self.log(pc, op, context.Gas, cost, mem, stack, context, err)
+
 			// In case of a VM exception (known exceptions) all gas consumed (panics NOT included).
 			context.UseGas(context.Gas)
 
@@ -67,7 +88,7 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 	if context.CodeAddr != nil {
 		if p := Precompiled[context.CodeAddr.Str()]; p != nil {
-			return self.RunPrecompiled(p, callData, context)
+			return self.RunPrecompiled(p, input, context)
 		}
 	}
 
@@ -76,29 +97,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 		return context.Return(nil), nil
 	}
 
-	var (
-		op       OpCode
-		codehash = crypto.Sha3Hash(code)
-		mem      = NewMemory()
-		stack    = newStack()
-		pc       = new(big.Int)
-		statedb  = self.env.State()
-
-		jump = func(from *big.Int, to *big.Int) error {
-			if !context.jumpdests.has(codehash, code, to) {
-				nop := context.GetOp(to)
-				return fmt.Errorf("invalid jump destination (%v) %v", nop, to)
-			}
-
-			self.Printf(" ~> %v", to)
-			pc = to
-
-			self.Endl()
-
-			return nil
-		}
-	)
-
 	for {
 		// The base for all big integer arithmetic
 		base := new(big.Int)
@@ -106,63 +104,55 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 		// Get the memory location of pc
 		op = context.GetOp(pc)
 
-		self.Printf("(pc) %-3d -o- %-14s (m) %-4d (s) %-4d ", pc, op.String(), mem.Len(), stack.len())
-		newMemSize, gas, err := self.calculateGasAndSize(context, caller, op, statedb, mem, stack)
+		// calculate the new memory size and gas price for the current executing opcode
+		newMemSize, cost, err = self.calculateGasAndSize(context, caller, op, statedb, mem, stack)
 		if err != nil {
 			return nil, err
 		}
 
-		self.Printf("(g) %-3v (%v)", gas, context.Gas)
-
-		if !context.UseGas(gas) {
-			self.Endl()
-
-			tmp := new(big.Int).Set(context.Gas)
+		// Use the calculated gas. When insufficient gas is present, use all gas and return an
+		// Out Of Gas error
+		if !context.UseGas(cost) {
 
 			context.UseGas(context.Gas)
 
-			return context.Return(nil), OOG(gas, tmp)
+			return context.Return(nil), OutOfGasError{}
 		}
-
+		// Resize the memory calculated previously
 		mem.Resize(newMemSize.Uint64())
+		// Add a log message
+		self.log(pc, op, context.Gas, cost, mem, stack, context, nil)
 
 		switch op {
 		case ADD:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v + %v", y, x)
 
 			base.Add(x, y)
 
 			U256(base)
 
-			self.Printf(" = %v", base)
 			// pop result back on the stack
 			stack.push(base)
 		case SUB:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v - %v", x, y)
 
 			base.Sub(x, y)
 
 			U256(base)
 
-			self.Printf(" = %v", base)
 			// pop result back on the stack
 			stack.push(base)
 		case MUL:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v * %v", y, x)
 
 			base.Mul(x, y)
 
 			U256(base)
 
-			self.Printf(" = %v", base)
 			// pop result back on the stack
 			stack.push(base)
 		case DIV:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v / %v", x, y)
 
 			if y.Cmp(common.Big0) != 0 {
 				base.Div(x, y)
@@ -170,14 +160,11 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 			U256(base)
 
-			self.Printf(" = %v", base)
 			// pop result back on the stack
 			stack.push(base)
 		case SDIV:
 			x, y := S256(stack.pop()), S256(stack.pop())
 
-			self.Printf(" %v / %v", x, y)
-
 			if y.Cmp(common.Big0) == 0 {
 				base.Set(common.Big0)
 			} else {
@@ -193,13 +180,10 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				U256(base)
 			}
 
-			self.Printf(" = %v", base)
 			stack.push(base)
 		case MOD:
 			x, y := stack.pop(), stack.pop()
 
-			self.Printf(" %v %% %v", x, y)
-
 			if y.Cmp(common.Big0) == 0 {
 				base.Set(common.Big0)
 			} else {
@@ -208,13 +192,10 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 			U256(base)
 
-			self.Printf(" = %v", base)
 			stack.push(base)
 		case SMOD:
 			x, y := S256(stack.pop()), S256(stack.pop())
 
-			self.Printf(" %v %% %v", x, y)
-
 			if y.Cmp(common.Big0) == 0 {
 				base.Set(common.Big0)
 			} else {
@@ -230,20 +211,15 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				U256(base)
 			}
 
-			self.Printf(" = %v", base)
 			stack.push(base)
 
 		case EXP:
 			x, y := stack.pop(), stack.pop()
 
-			self.Printf(" %v ** %v", x, y)
-
 			base.Exp(x, y, Pow256)
 
 			U256(base)
 
-			self.Printf(" = %v", base)
-
 			stack.push(base)
 		case SIGNEXTEND:
 			back := stack.pop()
@@ -260,15 +236,13 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 				num = U256(num)
 
-				self.Printf(" = %v", num)
-
 				stack.push(num)
 			}
 		case NOT:
 			stack.push(U256(new(big.Int).Not(stack.pop())))
 		case LT:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v < %v", x, y)
+
 			// x < y
 			if x.Cmp(y) < 0 {
 				stack.push(common.BigTrue)
@@ -277,7 +251,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 			}
 		case GT:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v > %v", x, y)
 
 			// x > y
 			if x.Cmp(y) > 0 {
@@ -288,7 +261,7 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 		case SLT:
 			x, y := S256(stack.pop()), S256(stack.pop())
-			self.Printf(" %v < %v", x, y)
+
 			// x < y
 			if x.Cmp(S256(y)) < 0 {
 				stack.push(common.BigTrue)
@@ -297,7 +270,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 			}
 		case SGT:
 			x, y := S256(stack.pop()), S256(stack.pop())
-			self.Printf(" %v > %v", x, y)
 
 			// x > y
 			if x.Cmp(y) > 0 {
@@ -308,7 +280,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 		case EQ:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v == %v", y, x)
 
 			// x == y
 			if x.Cmp(y) == 0 {
@@ -326,17 +297,14 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 		case AND:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v & %v", y, x)
 
 			stack.push(base.And(x, y))
 		case OR:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v | %v", x, y)
 
 			stack.push(base.Or(x, y))
 		case XOR:
 			x, y := stack.pop(), stack.pop()
-			self.Printf(" %v ^ %v", x, y)
 
 			stack.push(base.Xor(x, y))
 		case BYTE:
@@ -350,8 +318,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				base.Set(common.BigFalse)
 			}
 
-			self.Printf(" => 0x%x", base.Bytes())
-
 			stack.push(base)
 		case ADDMOD:
 			x := stack.pop()
@@ -365,8 +331,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				base = U256(base)
 			}
 
-			self.Printf(" %v + %v %% %v = %v", x, y, z, base)
-
 			stack.push(base)
 		case MULMOD:
 			x := stack.pop()
@@ -380,8 +344,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				U256(base)
 			}
 
-			self.Printf(" %v + %v %% %v = %v", x, y, z, base)
-
 			stack.push(base)
 
 		case SHA3:
@@ -390,55 +352,45 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 			stack.push(common.BigD(data))
 
-			self.Printf(" => (%v) %x", size, data)
 		case ADDRESS:
 			stack.push(common.Bytes2Big(context.Address().Bytes()))
 
-			self.Printf(" => %x", context.Address())
 		case BALANCE:
 			addr := common.BigToAddress(stack.pop())
 			balance := statedb.GetBalance(addr)
 
 			stack.push(balance)
 
-			self.Printf(" => %v (%x)", balance, addr)
 		case ORIGIN:
 			origin := self.env.Origin()
 
 			stack.push(origin.Big())
 
-			self.Printf(" => %x", origin)
 		case CALLER:
 			caller := context.caller.Address()
 			stack.push(common.Bytes2Big(caller.Bytes()))
 
-			self.Printf(" => %x", caller)
 		case CALLVALUE:
 			stack.push(value)
 
-			self.Printf(" => %v", value)
 		case CALLDATALOAD:
-			data := getData(callData, stack.pop(), common.Big32)
-
-			self.Printf(" => 0x%x", data)
+			data := getData(input, stack.pop(), common.Big32)
 
 			stack.push(common.Bytes2Big(data))
 		case CALLDATASIZE:
-			l := int64(len(callData))
+			l := int64(len(input))
 			stack.push(big.NewInt(l))
 
-			self.Printf(" => %d", l)
 		case CALLDATACOPY:
 			var (
 				mOff = stack.pop()
 				cOff = stack.pop()
 				l    = stack.pop()
 			)
-			data := getData(callData, cOff, l)
+			data := getData(input, cOff, l)
 
 			mem.Set(mOff.Uint64(), l.Uint64(), data)
 
-			self.Printf(" => [%v, %v, %v]", mOff, cOff, l)
 		case CODESIZE, EXTCODESIZE:
 			var code []byte
 			if op == EXTCODESIZE {
@@ -452,7 +404,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 			l := big.NewInt(int64(len(code)))
 			stack.push(l)
 
-			self.Printf(" => %d", l)
 		case CODECOPY, EXTCODECOPY:
 			var code []byte
 			if op == EXTCODECOPY {
@@ -472,12 +423,9 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 
 			mem.Set(mOff.Uint64(), l.Uint64(), codeCopy)
 
-			self.Printf(" => [%v, %v, %v] %x", mOff, cOff, l, codeCopy)
 		case GASPRICE:
 			stack.push(context.Price)
 
-			self.Printf(" => %x", context.Price)
-
 		case BLOCKHASH:
 			num := stack.pop()
 
@@ -488,56 +436,47 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				stack.push(common.Big0)
 			}
 
-			self.Printf(" => 0x%x", stack.peek().Bytes())
 		case COINBASE:
 			coinbase := self.env.Coinbase()
 
 			stack.push(coinbase.Big())
 
-			self.Printf(" => 0x%x", coinbase)
 		case TIMESTAMP:
 			time := self.env.Time()
 
 			stack.push(big.NewInt(time))
 
-			self.Printf(" => 0x%x", time)
 		case NUMBER:
 			number := self.env.BlockNumber()
 
 			stack.push(U256(number))
 
-			self.Printf(" => 0x%x", number.Bytes())
 		case DIFFICULTY:
 			difficulty := self.env.Difficulty()
 
 			stack.push(difficulty)
 
-			self.Printf(" => 0x%x", difficulty.Bytes())
 		case GASLIMIT:
-			self.Printf(" => %v", self.env.GasLimit())
 
 			stack.push(self.env.GasLimit())
 
 		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 - PUSH1 + 1))
-			byts := getData(code, new(big.Int).Add(pc, big.NewInt(1)), a)
+			size := uint64(op - PUSH1 + 1)
+			byts := getData(code, new(big.Int).SetUint64(pc+1), new(big.Int).SetUint64(size))
 			// push value to stack
 			stack.push(common.Bytes2Big(byts))
-			pc.Add(pc, a)
+			pc += size
 
-			self.Printf(" => 0x%x", byts)
 		case POP:
 			stack.pop()
 		case DUP1, DUP2, DUP3, DUP4, DUP5, DUP6, DUP7, DUP8, DUP9, DUP10, DUP11, DUP12, DUP13, DUP14, DUP15, DUP16:
 			n := int(op - DUP1 + 1)
 			stack.dup(n)
 
-			self.Printf(" => [%d] 0x%x", n, stack.peek().Bytes())
 		case SWAP1, SWAP2, SWAP3, SWAP4, SWAP5, SWAP6, SWAP7, SWAP8, SWAP9, SWAP10, SWAP11, SWAP12, SWAP13, SWAP14, SWAP15, SWAP16:
 			n := int(op - SWAP1 + 2)
 			stack.swap(n)
 
-			self.Printf(" => [%d]", n)
 		case LOG0, LOG1, LOG2, LOG3, LOG4:
 			n := int(op - LOG0)
 			topics := make([]common.Hash, n)
@@ -550,38 +489,32 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 			log := state.NewLog(context.Address(), topics, data, self.env.BlockNumber().Uint64())
 			self.env.AddLog(log)
 
-			self.Printf(" => %v", log)
 		case MLOAD:
 			offset := stack.pop()
 			val := common.BigD(mem.Get(offset.Int64(), 32))
 			stack.push(val)
 
-			self.Printf(" => 0x%x", val.Bytes())
 		case MSTORE:
 			// pop value of the stack
 			mStart, val := stack.pop(), stack.pop()
 			mem.Set(mStart.Uint64(), 32, common.BigToBytes(val, 256))
 
-			self.Printf(" => 0x%x", val)
 		case MSTORE8:
 			off, val := stack.pop().Int64(), stack.pop().Int64()
 
 			mem.store[off] = byte(val & 0xff)
 
-			self.Printf(" => [%v] 0x%x", off, mem.store[off])
 		case SLOAD:
 			loc := common.BigToHash(stack.pop())
 			val := common.Bytes2Big(statedb.GetState(context.Address(), loc))
 			stack.push(val)
 
-			self.Printf(" {0x%x : 0x%x}", loc, val.Bytes())
 		case SSTORE:
 			loc := common.BigToHash(stack.pop())
 			val := stack.pop()
 
 			statedb.SetState(context.Address(), loc, val)
 
-			self.Printf(" {0x%x : 0x%x}", loc, val.Bytes())
 		case JUMP:
 			if err := jump(pc, stack.pop()); err != nil {
 				return nil, err
@@ -599,17 +532,14 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				continue
 			}
 
-			self.Printf(" ~> false")
-
 		case JUMPDEST:
 		case PC:
-			stack.push(pc)
+			stack.push(new(big.Int).SetUint64(pc))
 		case MSIZE:
 			stack.push(big.NewInt(int64(mem.Len())))
 		case GAS:
 			stack.push(context.Gas)
 
-			self.Printf(" => %x", context.Gas)
 		case CREATE:
 
 			var (
@@ -619,14 +549,12 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 				gas          = new(big.Int).Set(context.Gas)
 				addr         common.Address
 			)
-			self.Endl()
 
 			context.UseGas(context.Gas)
 			ret, suberr, ref := self.env.Create(context, input, gas, price, value)
 			if suberr != nil {
 				stack.push(common.BigFalse)
 
-				self.Printf(" (*) 0x0 %v", suberr)
 			} else {
 				// gas < len(ret) * CreateDataGas == NO_CODE
 				dataGas := big.NewInt(int64(len(ret)))
@@ -651,7 +579,6 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 			retOffset, retSize := stack.pop(), stack.pop()
 
 			address := common.BigToAddress(addr)
-			self.Printf(" => %x", address).Endl()
 
 			// Get the arguments from the memory
 			args := mem.Get(inOffset.Int64(), inSize.Int64())
@@ -673,47 +600,41 @@ func (self *Vm) Run(context *Context, callData []byte) (ret []byte, err error) {
 			if err != nil {
 				stack.push(common.BigFalse)
 
-				self.Printf("%v").Endl()
 			} else {
 				stack.push(common.BigTrue)
 
 				mem.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 			}
-			self.Printf("resume %x (%v)", context.Address(), context.Gas)
+
 		case RETURN:
 			offset, size := stack.pop(), stack.pop()
 			ret := mem.GetPtr(offset.Int64(), size.Int64())
 
-			self.Printf(" => [%v, %v] (%d) 0x%x", offset, size, len(ret), ret).Endl()
-
 			return context.Return(ret), nil
 		case SUICIDE:
 			receiver := statedb.GetOrNewStateObject(common.BigToAddress(stack.pop()))
 			balance := statedb.GetBalance(context.Address())
 
-			self.Printf(" => (%x) %v", receiver.Address().Bytes()[:4], balance)
-
 			receiver.AddBalance(balance)
 
 			statedb.Delete(context.Address())
 
 			fallthrough
 		case STOP: // Stop the context
-			self.Endl()
 
 			return context.Return(nil), nil
 		default:
-			self.Printf("(pc) %-3v Invalid opcode %x\n", pc, op).Endl()
 
 			return nil, fmt.Errorf("Invalid opcode %x", op)
 		}
 
-		pc.Add(pc, One)
+		pc++
 
-		self.Endl()
 	}
 }
 
+// calculateGasAndSize calculates the required given the opcode and stack items calculates the new memorysize for
+// the operation. This does not reduce gas or resizes the memory.
 func (self *Vm) calculateGasAndSize(context *Context, caller ContextRef, op OpCode, statedb *state.StateDB, mem *Memory, stack *stack) (*big.Int, *big.Int, error) {
 	var (
 		gas                 = new(big.Int)
@@ -855,40 +776,38 @@ func (self *Vm) calculateGasAndSize(context *Context, caller ContextRef, op OpCo
 	return newMemSize, gas, nil
 }
 
-func (self *Vm) RunPrecompiled(p *PrecompiledAccount, callData []byte, context *Context) (ret []byte, err error) {
-	gas := p.Gas(len(callData))
+// RunPrecompile runs and evaluate the output of a precompiled contract defined in contracts.go
+func (self *Vm) RunPrecompiled(p *PrecompiledAccount, input []byte, context *Context) (ret []byte, err error) {
+	gas := p.Gas(len(input))
 	if context.UseGas(gas) {
-		ret = p.Call(callData)
-		self.Printf("NATIVE_FUNC => %x", ret)
-		self.Endl()
+		ret = p.Call(input)
 
 		return context.Return(ret), nil
 	} else {
-		self.Printf("NATIVE_FUNC => failed").Endl()
-
-		tmp := new(big.Int).Set(context.Gas)
-
-		return nil, OOG(gas, tmp)
-	}
-}
-
-func (self *Vm) Printf(format string, v ...interface{}) VirtualMachine {
-	if self.debug {
-		self.logStr += fmt.Sprintf(format, v...)
+		return nil, OutOfGasError{}
 	}
-
-	return self
 }
 
-func (self *Vm) Endl() VirtualMachine {
-	if self.debug {
-		glog.V(0).Infoln(self.logStr)
-		self.logStr = ""
+// log emits a log event to the environment for each opcode encountered. This is not to be confused with the
+// LOG* opcode.
+func (self *Vm) log(pc uint64, op OpCode, gas, cost *big.Int, memory *Memory, stack *stack, context *Context, err error) {
+	if Debug {
+		mem := make([]byte, len(memory.Data()))
+		copy(mem, memory.Data())
+		stck := make([]*big.Int, len(stack.Data()))
+		copy(stck, stack.Data())
+
+		object := context.self.(*state.StateObject)
+		storage := make(map[common.Hash][]byte)
+		object.EachStorage(func(k, v []byte) {
+			storage[common.BytesToHash(k)] = v
+		})
+
+		self.env.AddStructLog(StructLog{pc, op, new(big.Int).Set(gas), cost, mem, stck, storage, err})
 	}
-
-	return self
 }
 
+// Environment returns the current workable state of the VM
 func (self *Vm) Env() Environment {
 	return self.env
 }