Official Go implementation of the Ethereum protocol
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go-ethereum/ethchain/asm.go

127 lines
2.4 KiB

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) {
// Regexp for parsing anything between brackets
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
}