path: root/vm/vm_jit.go

// +build evmjit

package vm

/*

void* evmjit_create();
int   evmjit_run(void* _jit, void* _data, void* _env);
void  evmjit_destroy(void* _jit);

// Shared library evmjit (e.g. libevmjit.so) is expected to be installed in /usr/local/lib
// More: https://github.com/ethereum/evmjit
#cgo LDFLAGS: -levmjit
*/
import "C"

import (
    "bytes"
    "errors"
    "fmt"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/state"
    "math/big"
    "unsafe"
)

type JitVm struct {
    env        Environment
    me         ContextRef
    callerAddr []byte
    price      *big.Int
    data       RuntimeData
}

type i256 [32]byte

type RuntimeData struct {
    gas          int64
    gasPrice     int64
    callData     *byte
    callDataSize uint64
    address      i256
    caller       i256
    origin       i256
    callValue    i256
    coinBase     i256
    difficulty   i256
    gasLimit     i256
    number       uint64
    timestamp    int64
    code         *byte
    codeSize     uint64
    codeHash     i256
}

func hash2llvm(h []byte) i256 {
    var m i256
    copy(m[len(m)-len(h):], h) // right aligned copy
    return m
}

func llvm2hash(m *i256) []byte {
    return C.GoBytes(unsafe.Pointer(m), C.int(len(m)))
}

func llvm2hashRef(m *i256) []byte {
    return (*[1 << 30]byte)(unsafe.Pointer(m))[:len(m):len(m)]
}

func address2llvm(addr []byte) i256 {
    n := hash2llvm(addr)
    bswap(&n)
    return n
}

// bswap swap bytes of the 256-bit integer on LLVM side
// TODO: Do not change memory on LLVM side, that can conflict with memory access optimizations
func bswap(m *i256) *i256 {
    for i, l := 0, len(m); i < l/2; i++ {
        m[i], m[l-i-1] = m[l-i-1], m[i]
    }
    return m
}

func trim(m []byte) []byte {
    skip := 0
    for i := 0; i < len(m); i++ {
        if m[i] == 0 {
            skip++
        } else {
            break
        }
    }
    return m[skip:]
}

func getDataPtr(m []byte) *byte {
    var p *byte
    if len(m) > 0 {
        p = &m[0]
    }
    return p
}

func big2llvm(n *big.Int) i256 {
    m := hash2llvm(n.Bytes())
    bswap(&m)
    return m
}

func llvm2big(m *i256) *big.Int {
    n := big.NewInt(0)
    for i := 0; i < len(m); i++ {
        b := big.NewInt(int64(m[i]))
        b.Lsh(b, uint(i)*8)
        n.Add(n, b)
    }
    return n
}

// llvm2bytesRef creates a []byte slice that references byte buffer on LLVM side (as of that not controller by GC)
// User must asure that referenced memory is available to Go until the data is copied or not needed any more
func llvm2bytesRef(data *byte, length uint64) []byte {
    if length == 0 {
        return nil
    }
    if data == nil {
        panic("Unexpected nil data pointer")
    }
    return (*[1 << 30]byte)(unsafe.Pointer(data))[:length:length]
}

func untested(condition bool, message string) {
    if condition {
        panic("Condition `" + message + "` tested. Remove assert.")
    }
}

func assert(condition bool, message string) {
    if !condition {
        panic("Assert `" + message + "` failed!")
    }
}

func NewJitVm(env Environment) *JitVm {
    return &JitVm{env: env}
}

func (self *JitVm) Run(me, caller ContextRef, code []byte, value, gas, price *big.Int, callData []byte) (ret []byte, err error) {
    // TODO: depth is increased but never checked by VM. VM should not know about it at all.
    self.env.SetDepth(self.env.Depth() + 1)

    // TODO: Move it to Env.Call() or sth
    if Precompiled[string(me.Address())] != nil {
        // if it's address of precopiled contract
        // fallback to standard VM
        stdVm := New(self.env)
        return stdVm.Run(me, caller, code, value, gas, price, callData)
    }

    if self.me != nil {
        panic("JitVm.Run() can be called only once per JitVm instance")
    }

    self.me = me
    self.callerAddr = caller.Address()
    self.price = price

    self.data.gas = gas.Int64()
    self.data.gasPrice = price.Int64()
    self.data.callData = getDataPtr(callData)
    self.data.callDataSize = uint64(len(callData))
    self.data.address = address2llvm(self.me.Address())
    self.data.caller = address2llvm(caller.Address())
    self.data.origin = address2llvm(self.env.Origin())
    self.data.callValue = big2llvm(value)
    self.data.coinBase = address2llvm(self.env.Coinbase())
    self.data.difficulty = big2llvm(self.env.Difficulty())
    self.data.gasLimit = big2llvm(self.env.GasLimit())
    self.data.number = self.env.BlockNumber().Uint64()
    self.data.timestamp = self.env.Time()
    self.data.code = getDataPtr(code)
    self.data.codeSize = uint64(len(code))
    self.data.codeHash = hash2llvm(crypto.Sha3(code)) // TODO: Get already computed hash?

    jit := C.evmjit_create()
    retCode := C.evmjit_run(jit, unsafe.Pointer(&self.data), unsafe.Pointer(self))

    if retCode < 0 {
        err = errors.New("OOG from JIT")
        gas.SetInt64(0) // Set gas to 0, JIT does not bother
    } else {
        gas.SetInt64(self.data.gas)
        if retCode == 1 { // RETURN
            ret = C.GoBytes(unsafe.Pointer(self.data.callData), C.int(self.data.callDataSize))
        } else if retCode == 2 { // SUICIDE
            // TODO: Suicide support logic should be moved to Env to be shared by VM implementations
            state := self.Env().State()
            receiverAddr := llvm2hashRef(bswap(&self.data.address))
            receiver := state.GetOrNewStateObject(receiverAddr)
            balance := state.GetBalance(me.Address())
            receiver.AddBalance(balance)
            state.Delete(me.Address())
        }
    }

    C.evmjit_destroy(jit)
    return
}

func (self *JitVm) Printf(format string, v ...interface{}) VirtualMachine {
    return self
}

func (self *JitVm) Endl() VirtualMachine {
    return self
}

func (self *JitVm) Env() Environment {
    return self.env
}

//export env_sha3
func env_sha3(dataPtr *byte, length uint64, resultPtr unsafe.Pointer) {
    data := llvm2bytesRef(dataPtr, length)
    hash := crypto.Sha3(data)
    result := (*i256)(resultPtr)
    *result = hash2llvm(hash)
}

//export env_sstore
func env_sstore(vmPtr unsafe.Pointer, indexPtr unsafe.Pointer, valuePtr unsafe.Pointer) {
    vm := (*JitVm)(vmPtr)
    index := llvm2hash(bswap((*i256)(indexPtr)))
    value := llvm2hash(bswap((*i256)(valuePtr)))
    value = trim(value)
    if len(value) == 0 {
        prevValue := vm.env.State().GetState(vm.me.Address(), index)
        if len(prevValue) != 0 {
            vm.Env().State().Refund(vm.callerAddr, GasSStoreRefund)
        }
    }

    vm.env.State().SetState(vm.me.Address(), index, value)
}

//export env_sload
func env_sload(vmPtr unsafe.Pointer, indexPtr unsafe.Pointer, resultPtr unsafe.Pointer) {
    vm := (*JitVm)(vmPtr)
    index := llvm2hash(bswap((*i256)(indexPtr)))
    value := vm.env.State().GetState(vm.me.Address(), index)
    result := (*i256)(resultPtr)
    *result = hash2llvm(value)
    bswap(result)
}

//export env_balance
func env_balance(_vm unsafe.Pointer, _addr unsafe.Pointer, _result unsafe.Pointer) {
    vm := (*JitVm)(_vm)
    addr := llvm2hash((*i256)(_addr))
    balance := vm.Env().State().GetBalance(addr)
    result := (*i256)(_result)
    *result = big2llvm(balance)
}

//export env_blockhash
func env_blockhash(_vm unsafe.Pointer, _number unsafe.Pointer, _result unsafe.Pointer) {
    vm := (*JitVm)(_vm)
    number := llvm2big((*i256)(_number))
    result := (*i256)(_result)

    currNumber := vm.Env().BlockNumber()
    limit := big.NewInt(0).Sub(currNumber, big.NewInt(256))
    if number.Cmp(limit) >= 0 && number.Cmp(currNumber) < 0 {
        hash := vm.Env().GetHash(uint64(number.Int64()))
        *result = hash2llvm(hash)
    } else {
        *result = i256{}
    }
}

//export env_call
func env_call(_vm unsafe.Pointer, _gas *int64, _receiveAddr unsafe.Pointer, _value unsafe.Pointer, inDataPtr unsafe.Pointer, inDataLen uint64, outDataPtr *byte, outDataLen uint64, _codeAddr unsafe.Pointer) bool {
    vm := (*JitVm)(_vm)

    //fmt.Printf("env_call (depth %d)\n", vm.Env().Depth())

    defer func() {
        if r := recover(); r != nil {
            fmt.Printf("Recovered in env_call (depth %d, out %p %d): %s\n", vm.Env().Depth(), outDataPtr, outDataLen, r)
        }
    }()

    balance := vm.Env().State().GetBalance(vm.me.Address())
    value := llvm2big((*i256)(_value))

    if balance.Cmp(value) >= 0 {
        receiveAddr := llvm2hash((*i256)(_receiveAddr))
        inData := C.GoBytes(inDataPtr, C.int(inDataLen))
        outData := llvm2bytesRef(outDataPtr, outDataLen)
        codeAddr := llvm2hash((*i256)(_codeAddr))
        gas := big.NewInt(*_gas)
        var out []byte
        var err error
        if bytes.Equal(codeAddr, receiveAddr) {
            out, err = vm.env.Call(vm.me, codeAddr, inData, gas, vm.price, value)
        } else {
            out, err = vm.env.CallCode(vm.me, codeAddr, inData, gas, vm.price, value)
        }
        *_gas = gas.Int64()
        if err == nil {
            copy(outData, out)
            return true
        }
    }

    return false
}

//export env_create
func env_create(_vm unsafe.Pointer, _gas *int64, _value unsafe.Pointer, initDataPtr unsafe.Pointer, initDataLen uint64, _result unsafe.Pointer) {
    vm := (*JitVm)(_vm)

    value := llvm2big((*i256)(_value))
    initData := C.GoBytes(initDataPtr, C.int(initDataLen)) // TODO: Unnecessary if low balance
    result := (*i256)(_result)
    *result = i256{}

    gas := big.NewInt(*_gas)
    ret, suberr, ref := vm.env.Create(vm.me, nil, initData, gas, vm.price, value)
    if suberr == nil {
        dataGas := big.NewInt(int64(len(ret))) // TODO: Nto the best design. env.Create can do it, it has the reference to gas counter
        dataGas.Mul(dataGas, GasCreateByte)
        gas.Sub(gas, dataGas)
        *result = hash2llvm(ref.Address())
    }
    *_gas = gas.Int64()
}

//export env_log
func env_log(_vm unsafe.Pointer, dataPtr unsafe.Pointer, dataLen uint64, _topic1 unsafe.Pointer, _topic2 unsafe.Pointer, _topic3 unsafe.Pointer, _topic4 unsafe.Pointer) {
    vm := (*JitVm)(_vm)

    data := C.GoBytes(dataPtr, C.int(dataLen))

    topics := make([][]byte, 0, 4)
    if _topic1 != nil {
        topics = append(topics, llvm2hash((*i256)(_topic1)))
    }
    if _topic2 != nil {
        topics = append(topics, llvm2hash((*i256)(_topic2)))
    }
    if _topic3 != nil {
        topics = append(topics, llvm2hash((*i256)(_topic3)))
    }
    if _topic4 != nil {
        topics = append(topics, llvm2hash((*i256)(_topic4)))
    }

    vm.Env().AddLog(state.NewLog(vm.me.Address(), topics, data, vm.env.BlockNumber().Uint64()))
}

//export env_extcode
func env_extcode(_vm unsafe.Pointer, _addr unsafe.Pointer, o_size *uint64) *byte {
    vm := (*JitVm)(_vm)
    addr := llvm2hash((*i256)(_addr))
    code := vm.Env().State().GetCode(addr)
    *o_size = uint64(len(code))
    return getDataPtr(code)
}