path: root/libevmasm/Instruction.h

/*
    This file is part of cpp-ethereum.

    cpp-ethereum 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.

    cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file Instruction.h
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 */

#pragma once

#include <functional>
#include <libdevcore/Common.h>
#include <libdevcore/Assertions.h>
#include "Exceptions.h"

namespace dev
{
namespace solidity
{

DEV_SIMPLE_EXCEPTION(InvalidDeposit);
DEV_SIMPLE_EXCEPTION(InvalidOpcode);

/// Virtual machine bytecode instruction.
enum class Instruction: uint8_t
{
    STOP = 0x00,        ///< halts execution
    ADD,                ///< addition operation
    MUL,                ///< mulitplication operation
    SUB,                ///< subtraction operation
    DIV,                ///< integer division operation
    SDIV,               ///< signed integer division operation
    MOD,                ///< modulo remainder operation
    SMOD,               ///< signed modulo remainder operation
    ADDMOD,             ///< unsigned modular addition
    MULMOD,             ///< unsigned modular multiplication
    EXP,                ///< exponential operation
    SIGNEXTEND,         ///< extend length of signed integer

    LT = 0x10,          ///< less-than comparision
    GT,                 ///< greater-than comparision
    SLT,                ///< signed less-than comparision
    SGT,                ///< signed greater-than comparision
    EQ,                 ///< equality comparision
    ISZERO,             ///< simple not operator
    AND,                ///< bitwise AND operation
    OR,                 ///< bitwise OR operation
    XOR,                ///< bitwise XOR operation
    NOT,                ///< bitwise NOT opertation
    BYTE,               ///< retrieve single byte from word

    SHA3 = 0x20,        ///< compute SHA3-256 hash

    ADDRESS = 0x30,     ///< get address of currently executing account
    BALANCE,            ///< get balance of the given account
    ORIGIN,             ///< get execution origination address
    CALLER,             ///< get caller address
    CALLVALUE,          ///< get deposited value by the instruction/transaction responsible for this execution
    CALLDATALOAD,       ///< get input data of current environment
    CALLDATASIZE,       ///< get size of input data in current environment
    CALLDATACOPY,       ///< copy input data in current environment to memory
    CODESIZE,           ///< get size of code running in current environment
    CODECOPY,           ///< copy code running in current environment to memory
    GASPRICE,           ///< get price of gas in current environment
    EXTCODESIZE,        ///< get external code size (from another contract)
    EXTCODECOPY,        ///< copy external code (from another contract)

    BLOCKHASH = 0x40,   ///< get hash of most recent complete block
    COINBASE,           ///< get the block's coinbase address
    TIMESTAMP,          ///< get the block's timestamp
    NUMBER,             ///< get the block's number
    DIFFICULTY,         ///< get the block's difficulty
    GASLIMIT,           ///< get the block's gas limit

    POP = 0x50,         ///< remove item from stack
    MLOAD,              ///< load word from memory
    MSTORE,             ///< save word to memory
    MSTORE8,            ///< save byte to memory
    SLOAD,              ///< load word from storage
    SSTORE,             ///< save word to storage
    JUMP,               ///< alter the program counter
    JUMPI,              ///< conditionally alter the program counter
    PC,                 ///< get the program counter
    MSIZE,              ///< get the size of active memory
    GAS,                ///< get the amount of available gas
    JUMPDEST,           ///< set a potential jump destination

    PUSH1 = 0x60,       ///< place 1 byte item on stack
    PUSH2,              ///< place 2 byte item on stack
    PUSH3,              ///< place 3 byte item on stack
    PUSH4,              ///< place 4 byte item on stack
    PUSH5,              ///< place 5 byte item on stack
    PUSH6,              ///< place 6 byte item on stack
    PUSH7,              ///< place 7 byte item on stack
    PUSH8,              ///< place 8 byte item on stack
    PUSH9,              ///< place 9 byte item on stack
    PUSH10,             ///< place 10 byte item on stack
    PUSH11,             ///< place 11 byte item on stack
    PUSH12,             ///< place 12 byte item on stack
    PUSH13,             ///< place 13 byte item on stack
    PUSH14,             ///< place 14 byte item on stack
    PUSH15,             ///< place 15 byte item on stack
    PUSH16,             ///< place 16 byte item on stack
    PUSH17,             ///< place 17 byte item on stack
    PUSH18,             ///< place 18 byte item on stack
    PUSH19,             ///< place 19 byte item on stack
    PUSH20,             ///< place 20 byte item on stack
    PUSH21,             ///< place 21 byte item on stack
    PUSH22,             ///< place 22 byte item on stack
    PUSH23,             ///< place 23 byte item on stack
    PUSH24,             ///< place 24 byte item on stack
    PUSH25,             ///< place 25 byte item on stack
    PUSH26,             ///< place 26 byte item on stack
    PUSH27,             ///< place 27 byte item on stack
    PUSH28,             ///< place 28 byte item on stack
    PUSH29,             ///< place 29 byte item on stack
    PUSH30,             ///< place 30 byte item on stack
    PUSH31,             ///< place 31 byte item on stack
    PUSH32,             ///< place 32 byte item on stack

    DUP1 = 0x80,        ///< copies the highest item in the stack to the top of the stack
    DUP2,               ///< copies the second highest item in the stack to the top of the stack
    DUP3,               ///< copies the third highest item in the stack to the top of the stack
    DUP4,               ///< copies the 4th highest item in the stack to the top of the stack
    DUP5,               ///< copies the 5th highest item in the stack to the top of the stack
    DUP6,               ///< copies the 6th highest item in the stack to the top of the stack
    DUP7,               ///< copies the 7th highest item in the stack to the top of the stack
    DUP8,               ///< copies the 8th highest item in the stack to the top of the stack
    DUP9,               ///< copies the 9th highest item in the stack to the top of the stack
    DUP10,              ///< copies the 10th highest item in the stack to the top of the stack
    DUP11,              ///< copies the 11th highest item in the stack to the top of the stack
    DUP12,              ///< copies the 12th highest item in the stack to the top of the stack
    DUP13,              ///< copies the 13th highest item in the stack to the top of the stack
    DUP14,              ///< copies the 14th highest item in the stack to the top of the stack
    DUP15,              ///< copies the 15th highest item in the stack to the top of the stack
    DUP16,              ///< copies the 16th highest item in the stack to the top of the stack

    SWAP1 = 0x90,       ///< swaps the highest and second highest value on the stack
    SWAP2,              ///< swaps the highest and third highest value on the stack
    SWAP3,              ///< swaps the highest and 4th highest value on the stack
    SWAP4,              ///< swaps the highest and 5th highest value on the stack
    SWAP5,              ///< swaps the highest and 6th highest value on the stack
    SWAP6,              ///< swaps the highest and 7th highest value on the stack
    SWAP7,              ///< swaps the highest and 8th highest value on the stack
    SWAP8,              ///< swaps the highest and 9th highest value on the stack
    SWAP9,              ///< swaps the highest and 10th highest value on the stack
    SWAP10,             ///< swaps the highest and 11th highest value on the stack
    SWAP11,             ///< swaps the highest and 12th highest value on the stack
    SWAP12,             ///< swaps the highest and 13th highest value on the stack
    SWAP13,             ///< swaps the highest and 14th highest value on the stack
    SWAP14,             ///< swaps the highest and 15th highest value on the stack
    SWAP15,             ///< swaps the highest and 16th highest value on the stack
    SWAP16,             ///< swaps the highest and 17th highest value on the stack

    LOG0 = 0xa0,        ///< Makes a log entry; no topics.
    LOG1,               ///< Makes a log entry; 1 topic.
    LOG2,               ///< Makes a log entry; 2 topics.
    LOG3,               ///< Makes a log entry; 3 topics.
    LOG4,               ///< Makes a log entry; 4 topics.

    CREATE = 0xf0,      ///< create a new account with associated code
    CALL,               ///< message-call into an account
    CALLCODE,           ///< message-call with another account's code only
    RETURN,             ///< halt execution returning output data
    DELEGATECALL,       ///< like CALLCODE but keeps caller's value and sender
    SUICIDE = 0xff      ///< halt execution and register account for later deletion
};

/// @returns the number of PUSH Instruction _inst
inline unsigned getPushNumber(Instruction _inst)
{
    return (byte)_inst - unsigned(Instruction::PUSH1) + 1;
}

/// @returns the number of DUP Instruction _inst
inline unsigned getDupNumber(Instruction _inst)
{
    return (byte)_inst - unsigned(Instruction::DUP1) + 1;
}

/// @returns the number of SWAP Instruction _inst
inline unsigned getSwapNumber(Instruction _inst)
{
    return (byte)_inst - unsigned(Instruction::SWAP1) + 1;
}

/// @returns the PUSH<_number> instruction
inline Instruction pushInstruction(unsigned _number)
{
    assertThrow(1 <= _number && _number <= 32, InvalidOpcode, "Invalid PUSH instruction requested.");
    return Instruction(unsigned(Instruction::PUSH1) + _number - 1);
}

/// @returns the DUP<_number> instruction
inline Instruction dupInstruction(unsigned _number)
{
    assertThrow(1 <= _number && _number <= 16, InvalidOpcode, "Invalid DUP instruction requested.");
    return Instruction(unsigned(Instruction::DUP1) + _number - 1);
}

/// @returns the SWAP<_number> instruction
inline Instruction swapInstruction(unsigned _number)
{
    assertThrow(1 <= _number && _number <= 16, InvalidOpcode, "Invalid SWAP instruction requested.");
    return Instruction(unsigned(Instruction::SWAP1) + _number - 1);
}

/// @returns the LOG<_number> instruction
inline Instruction logInstruction(unsigned _number)
{
    assertThrow(_number <= 4, InvalidOpcode, "Invalid LOG instruction requested.");
    return Instruction(unsigned(Instruction::LOG0) + _number);
}

enum Tier
{
    ZeroTier = 0,   // 0, Zero
    BaseTier,       // 2, Quick
    VeryLowTier,    // 3, Fastest
    LowTier,        // 5, Fast
    MidTier,        // 8, Mid
    HighTier,       // 10, Slow
    ExtTier,        // 20, Ext
    SpecialTier,    // multiparam or otherwise special
    InvalidTier     // Invalid.
};

/// Information structure for a particular instruction.
struct InstructionInfo
{
    std::string name;   ///< The name of the instruction.
    int additional;     ///< Additional items required in memory for this instructions (only for PUSH).
    int args;           ///< Number of items required on the stack for this instruction (and, for the purposes of ret, the number taken from the stack).
    int ret;            ///< Number of items placed (back) on the stack by this instruction, assuming args items were removed.
    bool sideEffects;   ///< false if the only effect on the execution environment (apart from gas usage) is a change to a topmost segment of the stack
    int gasPriceTier;   ///< Tier for gas pricing.
};

/// Information on all the instructions.
InstructionInfo instructionInfo(Instruction _inst);

/// check whether instructions exists
bool isValidInstruction(Instruction _inst);

/// Convert from string mnemonic to Instruction type.
extern const std::map<std::string, Instruction> c_instructions;

/// Iterate through EVM code and call a function on each instruction.
void eachInstruction(bytes const& _mem, std::function<void(Instruction,u256 const&)> const& _onInstruction);

/// Convert from EVM code to simple EVM assembly language.
std::string disassemble(bytes const& _mem);

}
}