path: root/libevmasm/AssemblyItem.cpp

/*
    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/>.
*/

#include <libevmasm/AssemblyItem.h>

#include <libdevcore/CommonData.h>
#include <libdevcore/FixedHash.h>

#include <fstream>

using namespace std;
using namespace dev;
using namespace dev::eth;

static_assert(sizeof(size_t) <= 8, "size_t must be at most 64-bits wide");

AssemblyItem AssemblyItem::toSubAssemblyTag(size_t _subId) const
{
    assertThrow(data() < (u256(1) << 64), Exception, "Tag already has subassembly set.");
    assertThrow(m_type == PushTag || m_type == Tag, Exception, "");
    size_t tag = size_t(u256(data()) & 0xffffffffffffffffULL);
    AssemblyItem r = *this;
    r.m_type = PushTag;
    r.setPushTagSubIdAndTag(_subId, tag);
    return r;
}

pair<size_t, size_t> AssemblyItem::splitForeignPushTag() const
{
    assertThrow(m_type == PushTag || m_type == Tag, Exception, "");
    u256 combined = u256(data());
    size_t subId = size_t((combined >> 64) - 1);
    size_t tag = size_t(combined & 0xffffffffffffffffULL);
    return make_pair(subId, tag);
}

void AssemblyItem::setPushTagSubIdAndTag(size_t _subId, size_t _tag)
{
    assertThrow(m_type == PushTag || m_type == Tag, Exception, "");
    u256 data = _tag;
    if (_subId != size_t(-1))
        data |= (u256(_subId) + 1) << 64;
    setData(data);
}

unsigned AssemblyItem::bytesRequired(unsigned _addressLength) const
{
    switch (m_type)
    {
    case Operation:
    case Tag: // 1 byte for the JUMPDEST
        return 1;
    case PushString:
        return 1 + 32;
    case Push:
        return 1 + max<unsigned>(1, dev::bytesRequired(data()));
    case PushSubSize:
    case PushProgramSize:
        return 1 + 4;       // worst case: a 16MB program
    case PushTag:
    case PushData:
    case PushSub:
        return 1 + _addressLength;
    case PushLibraryAddress:
    case PushDeployTimeAddress:
        return 1 + 20;
    default:
        break;
    }
    BOOST_THROW_EXCEPTION(InvalidOpcode());
}

int AssemblyItem::arguments() const
{
    if (type() == Operation)
        return instructionInfo(instruction()).args;
    else
        return 0;
}

int AssemblyItem::returnValues() const
{
    switch (m_type)
    {
    case Operation:
        return instructionInfo(instruction()).ret;
    case Push:
    case PushString:
    case PushTag:
    case PushData:
    case PushSub:
    case PushSubSize:
    case PushProgramSize:
    case PushLibraryAddress:
    case PushDeployTimeAddress:
        return 1;
    case Tag:
        return 0;
    default:
        break;
    }
    return 0;
}

bool AssemblyItem::canBeFunctional() const
{
    if (m_jumpType != JumpType::Ordinary)
        return false;
    switch (m_type)
    {
    case Operation:
        return !isDupInstruction(instruction()) && !isSwapInstruction(instruction());
    case Push:
    case PushString:
    case PushTag:
    case PushData:
    case PushSub:
    case PushSubSize:
    case PushProgramSize:
    case PushLibraryAddress:
    case PushDeployTimeAddress:
        return true;
    case Tag:
        return false;
    default:
        break;
    }
    return false;
}

string AssemblyItem::getJumpTypeAsString() const
{
    switch (m_jumpType)
    {
    case JumpType::IntoFunction:
        return "[in]";
    case JumpType::OutOfFunction:
        return "[out]";
    case JumpType::Ordinary:
    default:
        return "";
    }
}

string AssemblyItem::toAssemblyText() const
{
    string text;
    switch (type())
    {
    case Operation:
    {
        assertThrow(isValidInstruction(instruction()), AssemblyException, "Invalid instruction.");
        string name = instructionInfo(instruction()).name;
        transform(name.begin(), name.end(), name.begin(), [](unsigned char _c) { return tolower(_c); });
        text = name;
        break;
    }
    case Push:
        text = toHex(toCompactBigEndian(data(), 1), HexPrefix::Add);
        break;
    case PushString:
        text = string("data_") + toHex(data());
        break;
    case PushTag:
    {
        size_t sub{0};
        size_t tag{0};
        tie(sub, tag) = splitForeignPushTag();
        if (sub == size_t(-1))
            text = string("tag_") + to_string(tag);
        else
            text = string("tag_") + to_string(sub) + "_" + to_string(tag);
        break;
    }
    case Tag:
        assertThrow(data() < 0x10000, AssemblyException, "Declaration of sub-assembly tag.");
        text = string("tag_") + to_string(size_t(data())) + ":";
        break;
    case PushData:
        text = string("data_") + toHex(data());
        break;
    case PushSub:
        text = string("dataOffset(sub_") + to_string(size_t(data())) + ")";
        break;
    case PushSubSize:
        text = string("dataSize(sub_") + to_string(size_t(data())) + ")";
        break;
    case PushProgramSize:
        text = string("bytecodeSize");
        break;
    case PushLibraryAddress:
        text = string("linkerSymbol(\"") + toHex(data()) + string("\")");
        break;
    case PushDeployTimeAddress:
        text = string("deployTimeAddress()");
        break;
    case UndefinedItem:
        assertThrow(false, AssemblyException, "Invalid assembly item.");
        break;
    default:
        BOOST_THROW_EXCEPTION(InvalidOpcode());
    }
    if (m_jumpType == JumpType::IntoFunction || m_jumpType == JumpType::OutOfFunction)
    {
        text += "\t//";
        if (m_jumpType == JumpType::IntoFunction)
            text += " in";
        else
            text += " out";
    }
    return text;
}

ostream& dev::eth::operator<<(ostream& _out, AssemblyItem const& _item)
{
    switch (_item.type())
    {
    case Operation:
        _out << " " << instructionInfo(_item.instruction()).name;
        if (_item.instruction() == solidity::Instruction::JUMP || _item.instruction() == solidity::Instruction::JUMPI)
            _out << "\t" << _item.getJumpTypeAsString();
        break;
    case Push:
        _out << " PUSH " << hex << _item.data() << dec;
        break;
    case PushString:
        _out << " PushString"  << hex << (unsigned)_item.data() << dec;
        break;
    case PushTag:
    {
        size_t subId = _item.splitForeignPushTag().first;
        if (subId == size_t(-1))
            _out << " PushTag " << _item.splitForeignPushTag().second;
        else
            _out << " PushTag " << subId << ":" << _item.splitForeignPushTag().second;
        break;
    }
    case Tag:
        _out << " Tag " << _item.data();
        break;
    case PushData:
        _out << " PushData " << hex << (unsigned)_item.data() << dec;
        break;
    case PushSub:
        _out << " PushSub " << hex << size_t(_item.data()) << dec;
        break;
    case PushSubSize:
        _out << " PushSubSize " << hex << size_t(_item.data()) << dec;
        break;
    case PushProgramSize:
        _out << " PushProgramSize";
        break;
    case PushLibraryAddress:
    {
        string hash(h256((_item.data())).hex());
        _out << " PushLibraryAddress " << hash.substr(0, 8) + "..." + hash.substr(hash.length() - 8);
        break;
    }
    case PushDeployTimeAddress:
        _out << " PushDeployTimeAddress";
        break;
    case UndefinedItem:
        _out << " ???";
        break;
    default:
        BOOST_THROW_EXCEPTION(InvalidOpcode());
    }
    return _out;
}