aboutsummaryrefslogtreecommitdiffstats
path: root/libevmasm/AssemblyItem.h
blob: 7fcaa14510688e92202b8f62aa6ad1790dcc5a60 (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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/*
    This file is part of solidity.

    solidity is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    solidity is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file AssemblyItem.h
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 */

#pragma once

#include <iostream>
#include <sstream>
#include <libdevcore/Common.h>
#include <libdevcore/Assertions.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/SourceLocation.h>
#include "Exceptions.h"
using namespace dev::solidity;

namespace dev
{
namespace eth
{

enum AssemblyItemType {
    UndefinedItem,
    Operation,
    Push,
    PushString,
    PushTag,
    PushSub,
    PushSubSize,
    PushProgramSize,
    Tag,
    PushData,
    PushLibraryAddress ///< Push a currently unknown address of another (library) contract.
};

class Assembly;

class AssemblyItem
{
public:
    enum class JumpType { Ordinary, IntoFunction, OutOfFunction };

    AssemblyItem(u256 _push, SourceLocation const& _location = SourceLocation()):
        AssemblyItem(Push, _push, _location) { }
    AssemblyItem(solidity::Instruction _i, SourceLocation const& _location = SourceLocation()):
        m_type(Operation),
        m_instruction(_i),
        m_location(_location)
    {}
    AssemblyItem(AssemblyItemType _type, u256 _data = 0, SourceLocation const& _location = SourceLocation()):
        m_type(_type),
        m_location(_location)
    {
        if (m_type == Operation)
            m_instruction = Instruction(byte(_data));
        else
            m_data = std::make_shared<u256>(_data);
    }

    AssemblyItem tag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(Tag, data()); }
    AssemblyItem pushTag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(PushTag, data()); }
    /// Converts the tag to a subassembly tag. This has to be called in order to move a tag across assemblies.
    /// @param _subId the identifier of the subassembly the tag is taken from.
    AssemblyItem toSubAssemblyTag(size_t _subId) const;
    /// @returns splits the data of the push tag into sub assembly id and actual tag id.
    /// The sub assembly id of non-foreign push tags is -1.
    std::pair<size_t, size_t> splitForeignPushTag() const;
    /// Sets sub-assembly part and tag for a push tag.
    void setPushTagSubIdAndTag(size_t _subId, size_t _tag);

    AssemblyItemType type() const { return m_type; }
    u256 const& data() const { assertThrow(m_type != Operation, Exception, ""); return *m_data; }
    //void setType(AssemblyItemType const _type) { m_type = _type; }
    void setData(u256 const& _data) { assertThrow(m_type != Operation, Exception, ""); m_data = std::make_shared<u256>(_data); }

    /// @returns the instruction of this item (only valid if type() == Operation)
    Instruction instruction() const { assertThrow(m_type == Operation, Exception, ""); return m_instruction; }

    /// @returns true if the type and data of the items are equal.
    bool operator==(AssemblyItem const& _other) const
    {
        if (type() != _other.type())
            return false;
        if (type() == Operation)
            return instruction() == _other.instruction();
        else
            return data() == _other.data();
    }
    bool operator!=(AssemblyItem const& _other) const { return !operator==(_other); }
    /// Less-than operator compatible with operator==.
    bool operator<(AssemblyItem const& _other) const
    {
        if (type() != _other.type())
            return type() < _other.type();
        else if (type() == Operation)
            return instruction() < _other.instruction();
        else
            return data() < _other.data();
    }

    /// @returns an upper bound for the number of bytes required by this item, assuming that
    /// the value of a jump tag takes @a _addressLength bytes.
    unsigned bytesRequired(unsigned _addressLength) const;
    int deposit() const;

    /// @returns true if the assembly item can be used in a functional context.
    bool canBeFunctional() const;

    void setLocation(SourceLocation const& _location) { m_location = _location; }
    SourceLocation const& location() const { return m_location; }

    void setJumpType(JumpType _jumpType) { m_jumpType = _jumpType; }
    JumpType getJumpType() const { return m_jumpType; }
    std::string getJumpTypeAsString() const;

    void setPushedValue(u256 const& _value) const { m_pushedValue = std::make_shared<u256>(_value); }
    u256 const* pushedValue() const { return m_pushedValue.get(); }

    std::string toAssemblyText() const;

private:
    AssemblyItemType m_type;
    Instruction m_instruction; ///< Only valid if m_type == Operation
    std::shared_ptr<u256> m_data; ///< Only valid if m_type != Operation
    SourceLocation m_location;
    JumpType m_jumpType = JumpType::Ordinary;
    /// Pushed value for operations with data to be determined during assembly stage,
    /// e.g. PushSubSize, PushTag, PushSub, etc.
    mutable std::shared_ptr<u256> m_pushedValue;
};

using AssemblyItems = std::vector<AssemblyItem>;

std::ostream& operator<<(std::ostream& _out, AssemblyItem const& _item);
inline std::ostream& operator<<(std::ostream& _out, AssemblyItems const& _items)
{
    for (AssemblyItem const& item: _items)
        _out << item;
    return _out;
}

}
}