path: root/ethutil/parsing.go

package ethutil

import (
    "math/big"
    "strconv"
)

// Op codes
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,
    "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
}

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))
        }

        return num.Bytes(), nil
    case int:
        return big.NewInt(int64(s.(int))).Bytes(), nil
    case []byte:
        return BigD(s.([]byte)).Bytes(), nil
    }

    return nil, 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
}

// Script compilation functions
// Compiles strings to machine code
func Assemble(instructions ...interface{}) (script []string) {
    script = make([]string, len(instructions))

    for i, val := range instructions {
        instr, _ := CompileInstr(val)

        script[i] = string(instr)
    }

    return
}