aboutsummaryrefslogtreecommitdiffstats
path: root/ethchain/asm.go
blob: a6c85cb6020e98a06fe399a3a4864f1e0d8f259b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
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
}