go-ethereum/ethutil/parsing.go

109 lines
2.0 KiB
Go
Raw Normal View History

2014-02-15 00:56:09 +02:00
package ethutil
import (
"errors"
"fmt"
"math/big"
"strconv"
"strings"
)
// Op codes
var OpCodes = map[string]string{
"STOP": "0",
"ADD": "1",
"MUL": "2",
"SUB": "3",
"DIV": "4",
"SDIV": "5",
"MOD": "6",
"SMOD": "7",
"EXP": "8",
"NEG": "9",
"LT": "10",
"LE": "11",
"GT": "12",
"GE": "13",
"EQ": "14",
"NOT": "15",
"MYADDRESS": "16",
"TXSENDER": "17",
"PUSH": "48",
"POP": "49",
"LOAD": "54",
}
func CompileInstr(s string) (string, error) {
tokens := strings.Split(s, " ")
if OpCodes[tokens[0]] == "" {
return s, errors.New(fmt.Sprintf("OP not found: %s", tokens[0]))
}
code := OpCodes[tokens[0]] // Replace op codes with the proper numerical equivalent
op := new(big.Int)
op.SetString(code, 0)
args := make([]*big.Int, 6)
for i, val := range tokens[1:len(tokens)] {
num := new(big.Int)
num.SetString(val, 0)
args[i] = num
}
// Big int equation = op + x * 256 + y * 256**2 + z * 256**3 + a * 256**4 + b * 256**5 + c * 256**6
base := new(big.Int)
x := new(big.Int)
y := new(big.Int)
z := new(big.Int)
a := new(big.Int)
b := new(big.Int)
c := new(big.Int)
if args[0] != nil {
x.Mul(args[0], big.NewInt(256))
}
if args[1] != nil {
y.Mul(args[1], BigPow(256, 2))
}
if args[2] != nil {
z.Mul(args[2], BigPow(256, 3))
}
if args[3] != nil {
a.Mul(args[3], BigPow(256, 4))
}
if args[4] != nil {
b.Mul(args[4], BigPow(256, 5))
}
if args[5] != nil {
c.Mul(args[5], BigPow(256, 6))
}
base.Add(op, x)
base.Add(base, y)
base.Add(base, z)
base.Add(base, a)
base.Add(base, b)
base.Add(base, c)
return base.String(), nil
}
func Instr(instr string) (int, []string, error) {
base := new(big.Int)
base.SetString(instr, 0)
args := make([]string, 7)
for i := 0; i < 7; i++ {
// int(int(val) / int(math.Pow(256,float64(i)))) % 256
exp := BigPow(256, i)
num := new(big.Int)
num.Div(base, exp)
args[i] = num.Mod(num, big.NewInt(256)).String()
}
op, _ := strconv.Atoi(args[0])
return op, args[1:7], nil
}