github.com/neatlab/neatio@v1.7.3-0.20220425043230-d903e92fcc75/chain/core/vm/evm.go

package vm

import (
	"math/big"
	"sync/atomic"
	"time"

	"github.com/neatlab/neatio/params"
	"github.com/neatlab/neatio/utilities/common"
	"github.com/neatlab/neatio/utilities/crypto"
)

var emptyCodeHash = crypto.Keccak256Hash(nil)

type (
	CanTransferFunc func(StateDB, common.Address, *big.Int) bool

	TransferFunc func(StateDB, common.Address, common.Address, *big.Int)

	GetHashFunc func(uint64) common.Hash
)

func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, error) {
	if contract.CodeAddr != nil {
		precompiles := PrecompiledContractsHomestead
		if evm.chainRules.IsByzantium {
			precompiles = PrecompiledContractsByzantium
		}
		if evm.chainRules.IsIstanbul {
			precompiles = PrecompiledContractsIstanbul
		}
		if p := precompiles[*contract.CodeAddr]; p != nil {
			return RunPrecompiledContract(p, input, contract)
		}
	}
	for _, interpreter := range evm.interpreters {
		if interpreter.CanRun(contract.Code) {
			if evm.interpreter != interpreter {

				defer func(i Interpreter) {
					evm.interpreter = i
				}(evm.interpreter)
				evm.interpreter = interpreter
			}
			return interpreter.Run(contract, input, readOnly)
		}
	}
	return nil, ErrNoCompatibleInterpreter
}

type Context struct {
	CanTransfer CanTransferFunc

	Transfer TransferFunc

	GetHash GetHashFunc

	Origin   common.Address
	GasPrice *big.Int

	Coinbase    common.Address
	GasLimit    uint64
	BlockNumber *big.Int
	Time        *big.Int
	Difficulty  *big.Int
}

type EVM struct {
	Context

	StateDB StateDB

	depth int

	chainConfig *params.ChainConfig

	chainRules params.Rules

	vmConfig Config

	interpreters []Interpreter
	interpreter  Interpreter

	abort int32

	callGasTemp uint64
}

func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM {
	evm := &EVM{
		Context:      ctx,
		StateDB:      statedb,
		vmConfig:     vmConfig,
		chainConfig:  chainConfig,
		chainRules:   chainConfig.Rules(ctx.BlockNumber),
		interpreters: make([]Interpreter, 0, 1),
	}

	if chainConfig.IsEWASM(ctx.BlockNumber) {

		panic("No supported ewasm interpreter yet.")
	}

	evm.interpreters = append(evm.interpreters, NewEVMInterpreter(evm, vmConfig))
	evm.interpreter = evm.interpreters[0]

	return evm
}

func (evm *EVM) Cancel() {
	atomic.StoreInt32(&evm.abort, 1)
}

func (evm *EVM) Cancelled() bool {
	return atomic.LoadInt32(&evm.abort) == 1
}

func (evm *EVM) Interpreter() Interpreter {
	return evm.interpreter
}

func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
	if evm.vmConfig.NoRecursion && evm.depth > 0 {
		return nil, gas, nil
	}

	if evm.depth > int(params.CallCreateDepth) {
		return nil, gas, ErrDepth
	}

	if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) {
		return nil, gas, ErrInsufficientBalance
	}

	var (
		to       = AccountRef(addr)
		snapshot = evm.StateDB.Snapshot()
	)
	if !evm.StateDB.Exist(addr) {
		precompiles := PrecompiledContractsHomestead
		if evm.chainRules.IsByzantium {
			precompiles = PrecompiledContractsByzantium
		}
		if evm.chainRules.IsIstanbul {
			precompiles = PrecompiledContractsIstanbul
		}
		if precompiles[addr] == nil && evm.chainRules.IsEIP158 && value.Sign() == 0 {

			if evm.vmConfig.Debug && evm.depth == 0 {
				evm.vmConfig.Tracer.CaptureStart(caller.Address(), addr, false, input, gas, value)
				evm.vmConfig.Tracer.CaptureEnd(ret, 0, 0, nil)
			}
			return nil, gas, nil
		}
		evm.StateDB.CreateAccount(addr)
	}
	evm.Transfer(evm.StateDB, caller.Address(), to.Address(), value)

	contract := NewContract(caller, to, value, gas)
	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))

	start := time.Now()

	if evm.vmConfig.Debug && evm.depth == 0 {
		evm.vmConfig.Tracer.CaptureStart(caller.Address(), addr, false, input, gas, value)

		defer func() {
			evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err)
		}()
	}
	ret, err = run(evm, contract, input, false)

	if err != nil {
		evm.StateDB.RevertToSnapshot(snapshot)
		if err != ErrExecutionReverted {
			contract.UseGas(contract.Gas)
		}
	}
	return ret, contract.Gas, err
}

func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
	if evm.vmConfig.NoRecursion && evm.depth > 0 {
		return nil, gas, nil
	}

	if evm.depth > int(params.CallCreateDepth) {
		return nil, gas, ErrDepth
	}

	if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
		return nil, gas, ErrInsufficientBalance
	}

	var (
		snapshot = evm.StateDB.Snapshot()
		to       = AccountRef(caller.Address())
	)

	contract := NewContract(caller, to, value, gas)
	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))

	ret, err = run(evm, contract, input, false)
	if err != nil {
		evm.StateDB.RevertToSnapshot(snapshot)
		if err != ErrExecutionReverted {
			contract.UseGas(contract.Gas)
		}
	}
	return ret, contract.Gas, err
}

func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
	if evm.vmConfig.NoRecursion && evm.depth > 0 {
		return nil, gas, nil
	}

	if evm.depth > int(params.CallCreateDepth) {
		return nil, gas, ErrDepth
	}

	var (
		snapshot = evm.StateDB.Snapshot()
		to       = AccountRef(caller.Address())
	)

	contract := NewContract(caller, to, nil, gas).AsDelegate()
	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))

	ret, err = run(evm, contract, input, false)
	if err != nil {
		evm.StateDB.RevertToSnapshot(snapshot)
		if err != ErrExecutionReverted {
			contract.UseGas(contract.Gas)
		}
	}
	return ret, contract.Gas, err
}

func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
	if evm.vmConfig.NoRecursion && evm.depth > 0 {
		return nil, gas, nil
	}

	if evm.depth > int(params.CallCreateDepth) {
		return nil, gas, ErrDepth
	}

	var (
		to       = AccountRef(addr)
		snapshot = evm.StateDB.Snapshot()
	)

	contract := NewContract(caller, to, new(big.Int), gas)
	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))

	evm.StateDB.AddBalance(addr, bigZero)

	ret, err = run(evm, contract, input, true)
	if err != nil {
		evm.StateDB.RevertToSnapshot(snapshot)
		if err != ErrExecutionReverted {
			contract.UseGas(contract.Gas)
		}
	}
	return ret, contract.Gas, err
}

type codeAndHash struct {
	code []byte
	hash common.Hash
}

func (c *codeAndHash) Hash() common.Hash {
	if c.hash == (common.Hash{}) {
		c.hash = crypto.Keccak256Hash(c.code)
	}
	return c.hash
}

func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64, value *big.Int, address common.Address) ([]byte, common.Address, uint64, error) {

	if evm.depth > int(params.CallCreateDepth) {
		return nil, common.Address{}, gas, ErrDepth
	}
	if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
		return nil, common.Address{}, gas, ErrInsufficientBalance
	}
	nonce := evm.StateDB.GetNonce(caller.Address())
	evm.StateDB.SetNonce(caller.Address(), nonce+1)

	contractHash := evm.StateDB.GetCodeHash(address)
	if evm.StateDB.GetNonce(address) != 0 || (contractHash != (common.Hash{}) && contractHash != emptyCodeHash) {
		return nil, common.Address{}, 0, ErrContractAddressCollision
	}

	snapshot := evm.StateDB.Snapshot()
	evm.StateDB.CreateAccount(address)
	if evm.chainRules.IsEIP158 {
		evm.StateDB.SetNonce(address, 1)
	}
	evm.Transfer(evm.StateDB, caller.Address(), address, value)

	contract := NewContract(caller, AccountRef(address), value, gas)
	contract.SetCodeOptionalHash(&address, codeAndHash)

	if evm.vmConfig.NoRecursion && evm.depth > 0 {
		return nil, address, gas, nil
	}

	if evm.vmConfig.Debug && evm.depth == 0 {
		evm.vmConfig.Tracer.CaptureStart(caller.Address(), address, true, codeAndHash.code, gas, value)
	}
	start := time.Now()

	ret, err := run(evm, contract, nil, false)

	maxCodeSizeExceeded := evm.chainRules.IsEIP158 && len(ret) > params.MaxCodeSize

	if err == nil && !maxCodeSizeExceeded {
		createDataGas := uint64(len(ret)) * params.CreateDataGas
		if contract.UseGas(createDataGas) {
			evm.StateDB.SetCode(address, ret)
		} else {
			err = ErrCodeStoreOutOfGas
		}
	}

	if maxCodeSizeExceeded || (err != nil && (evm.chainRules.IsHomestead || err != ErrCodeStoreOutOfGas)) {
		evm.StateDB.RevertToSnapshot(snapshot)
		if err != ErrExecutionReverted {
			contract.UseGas(contract.Gas)
		}
	}

	if maxCodeSizeExceeded && err == nil {
		err = ErrMaxCodeSizeExceeded
	}
	if evm.vmConfig.Debug && evm.depth == 0 {
		evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err)
	}
	return ret, address, contract.Gas, err

}

func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
	contractAddr = crypto.CreateAddress(caller.Address(), evm.StateDB.GetNonce(caller.Address()))
	return evm.create(caller, &codeAndHash{code: code}, gas, value, contractAddr)
}

func (evm *EVM) Create2(caller ContractRef, code []byte, gas uint64, endowment *big.Int, salt *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
	codeAndHash := &codeAndHash{code: code}
	contractAddr = crypto.CreateAddress2(caller.Address(), common.BigToHash(salt), codeAndHash.Hash().Bytes())
	return evm.create(caller, codeAndHash, gas, endowment, contractAddr)
}

func (evm *EVM) ChainConfig() *params.ChainConfig { return evm.chainConfig }