imp(evm): stateless custom precompiles

CHANGELOG.md

@@ -40,6 +40,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### State Machine Breaking
 
+* (evm) [\#1272](https://github.com/evmos/ethermint/pull/1272) Implement modular interface for the EVM.
 * (deps) [\#1159](https://github.com/evmos/ethermint/pull/1159) Bump Geth version to `v1.10.19`.
 * (deps) [#1167](https://github.com/evmos/ethermint/pull/1167) Bump ibc-go to [`v4.0.0-rc2`](https://github.com/cosmos/ibc-go/releases/tag/v4.0.0-rc2)
 * (ante) [#1176](https://github.com/evmos/ethermint/pull/1176) Fix invalid tx hashes; Remove `Size_` field and validate `Hash`/`From` fields in ante handler,

app/ante/eth.go

@@ -305,7 +305,7 @@ func (ctd CanTransferDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate
 
 		// check that caller has enough balance to cover asset transfer for **topmost** call
 		// NOTE: here the gas consumed is from the context with the infinite gas meter
-		if coreMsg.Value().Sign() > 0 && !evm.Context.CanTransfer(stateDB, coreMsg.From(), coreMsg.Value()) {
+		if coreMsg.Value().Sign() > 0 && !evm.Context().CanTransfer(stateDB, coreMsg.From(), coreMsg.Value()) {
 			return ctx, sdkerrors.Wrapf(
 				sdkerrors.ErrInsufficientFunds,
 				"failed to transfer %s from address %s using the EVM block context transfer function",

app/ante/interfaces.go

@@ -11,6 +11,7 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/evmos/ethermint/x/evm/statedb"
 	evmtypes "github.com/evmos/ethermint/x/evm/types"
+	evm "github.com/evmos/ethermint/x/evm/vm"
 	feemarkettypes "github.com/evmos/ethermint/x/feemarket/types"
 )
 
@@ -26,7 +27,7 @@ type EVMKeeper interface {
 	statedb.Keeper
 	DynamicFeeEVMKeeper
 
-	NewEVM(ctx sdk.Context, msg core.Message, cfg *evmtypes.EVMConfig, tracer vm.EVMLogger, stateDB vm.StateDB) *vm.EVM
+	NewEVM(ctx sdk.Context, msg core.Message, cfg *evmtypes.EVMConfig, tracer vm.EVMLogger, stateDB vm.StateDB) evm.EVM
 	DeductTxCostsFromUserBalance(
 		ctx sdk.Context, msgEthTx evmtypes.MsgEthereumTx, txData evmtypes.TxData, denom string, homestead, istanbul, london bool,
 	) (fees sdk.Coins, priority int64, err error)

app/app.go

@@ -106,6 +106,7 @@ import (
 	"github.com/evmos/ethermint/x/evm"
 	evmkeeper "github.com/evmos/ethermint/x/evm/keeper"
 	evmtypes "github.com/evmos/ethermint/x/evm/types"
+	"github.com/evmos/ethermint/x/evm/vm/geth"
 	"github.com/evmos/ethermint/x/feemarket"
 	feemarketkeeper "github.com/evmos/ethermint/x/feemarket/keeper"
 	feemarkettypes "github.com/evmos/ethermint/x/feemarket/types"
@@ -396,7 +397,7 @@ func NewEthermintApp(
 	app.EvmKeeper = evmkeeper.NewKeeper(
 		appCodec, keys[evmtypes.StoreKey], tkeys[evmtypes.TransientKey], app.GetSubspace(evmtypes.ModuleName),
 		app.AccountKeeper, app.BankKeeper, app.StakingKeeper, app.FeeMarketKeeper,
-		tracer,
+		nil, geth.NewEVM, tracer,
 	)
 
 	// Create IBC Keeper

x/evm/keeper/keeper.go

@@ -19,6 +19,7 @@ import (
 	ethermint "github.com/evmos/ethermint/types"
 	"github.com/evmos/ethermint/x/evm/statedb"
 	"github.com/evmos/ethermint/x/evm/types"
+	evm "github.com/evmos/ethermint/x/evm/vm"
 )
 
 // Keeper grants access to the EVM module state and implements the go-ethereum StateDB interface.
@@ -54,14 +55,25 @@ type Keeper struct {
 
 	// EVM Hooks for tx post-processing
 	hooks types.EvmHooks
+
+	// custom stateless precompiled smart contracts
+	customPrecompiles evm.PrecompiledContracts
+
+	// evm constructor function
+	evmConstructor evm.Constructor
 }
 
 // NewKeeper generates new evm module keeper
 func NewKeeper(
 	cdc codec.BinaryCodec,
-	storeKey, transientKey storetypes.StoreKey, paramSpace paramtypes.Subspace,
-	ak types.AccountKeeper, bankKeeper types.BankKeeper, sk types.StakingKeeper,
+	storeKey, transientKey storetypes.StoreKey,
+	paramSpace paramtypes.Subspace,
+	ak types.AccountKeeper,
+	bankKeeper types.BankKeeper,
+	sk types.StakingKeeper,
 	fmk types.FeeMarketKeeper,
+	customPrecompiles evm.PrecompiledContracts,
+	evmConstructor evm.Constructor,
 	tracer string,
 ) *Keeper {
 	// ensure evm module account is set
@@ -76,15 +88,17 @@ func NewKeeper(
 
 	// NOTE: we pass in the parameter space to the CommitStateDB in order to use custom denominations for the EVM operations
 	return &Keeper{
-		cdc:             cdc,
-		paramSpace:      paramSpace,
-		accountKeeper:   ak,
-		bankKeeper:      bankKeeper,
-		stakingKeeper:   sk,
-		feeMarketKeeper: fmk,
-		storeKey:        storeKey,
-		transientKey:    transientKey,
-		tracer:          tracer,
+		cdc:               cdc,
+		paramSpace:        paramSpace,
+		accountKeeper:     ak,
+		bankKeeper:        bankKeeper,
+		stakingKeeper:     sk,
+		feeMarketKeeper:   fmk,
+		storeKey:          storeKey,
+		transientKey:      transientKey,
+		customPrecompiles: customPrecompiles,
+		evmConstructor:    evmConstructor,
+		tracer:            tracer,
 	}
 }
 

x/evm/keeper/state_transition.go

@@ -16,6 +16,7 @@ import (
 	ethermint "github.com/evmos/ethermint/types"
 	"github.com/evmos/ethermint/x/evm/statedb"
 	"github.com/evmos/ethermint/x/evm/types"
+	evm "github.com/evmos/ethermint/x/evm/vm"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
@@ -77,7 +78,7 @@ func (k *Keeper) NewEVM(
 	cfg *types.EVMConfig,
 	tracer vm.EVMLogger,
 	stateDB vm.StateDB,
-) *vm.EVM {
+) evm.EVM {
 	blockCtx := vm.BlockContext{
 		CanTransfer: core.CanTransfer,
 		Transfer:    core.Transfer,
@@ -95,7 +96,7 @@ func (k *Keeper) NewEVM(
 		tracer = k.Tracer(ctx, msg, cfg.ChainConfig)
 	}
 	vmConfig := k.VMConfig(ctx, msg, cfg, tracer)
-	return vm.NewEVM(blockCtx, txCtx, stateDB, cfg.ChainConfig, vmConfig)
+	return k.evmConstructor(blockCtx, txCtx, stateDB, cfg.ChainConfig, vmConfig, k.customPrecompiles)
 }
 
 // VMConfig creates an EVM configuration from the debug setting and the extra EIPs enabled on the
@@ -366,17 +367,19 @@ func (k *Keeper) ApplyMessageWithConfig(ctx sdk.Context,
 	evm := k.NewEVM(ctx, msg, cfg, tracer, stateDB)
 
 	leftoverGas := msg.Gas()
+
 	// Allow the tracer captures the tx level events, mainly the gas consumption.
-	if evm.Config.Debug {
-		evm.Config.Tracer.CaptureTxStart(leftoverGas)
+	vmCfg := evm.Config()
+	if vmCfg.Debug {
+		vmCfg.Tracer.CaptureTxStart(leftoverGas)
 		defer func() {
-			evm.Config.Tracer.CaptureTxEnd(leftoverGas)
+			vmCfg.Tracer.CaptureTxEnd(leftoverGas)
 		}()
 	}
 
 	sender := vm.AccountRef(msg.From())
 	contractCreation := msg.To() == nil
-	isLondon := cfg.ChainConfig.IsLondon(evm.Context.BlockNumber)
+	isLondon := cfg.ChainConfig.IsLondon(evm.Context().BlockNumber)
 
 	intrinsicGas, err := k.GetEthIntrinsicGas(ctx, msg, cfg.ChainConfig, contractCreation)
 	if err != nil {
@@ -394,7 +397,7 @@ func (k *Keeper) ApplyMessageWithConfig(ctx sdk.Context,
 	// access list preparation is moved from ante handler to here, because it's needed when `ApplyMessage` is called
 	// under contexts where ante handlers are not run, for example `eth_call` and `eth_estimateGas`.
 	if rules := cfg.ChainConfig.Rules(big.NewInt(ctx.BlockHeight()), cfg.ChainConfig.MergeNetsplitBlock != nil); rules.IsBerlin {
-		stateDB.PrepareAccessList(msg.From(), msg.To(), vm.ActivePrecompiles(rules), msg.AccessList())
+		stateDB.PrepareAccessList(msg.From(), msg.To(), evm.ActivePrecompiles(rules), msg.AccessList())
 	}
 
 	if contractCreation {

x/evm/statedb/interfaces.go

@@ -3,8 +3,19 @@ package statedb
 import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/vm"
 )
 
+// ExtStateDB defines an extension to the interface provided by the go-ethereum
+// codebase to support additional state transition functionalities. In particular
+// it supports appending a new entry to the state journal through
+// AppendJournalEntry so that the state can be reverted after running
+// stateful precompiled contracts.
+type ExtStateDB interface {
+	vm.StateDB
+	AppendJournalEntry(JournalEntry)
+}
+
 // Keeper provide underlying storage of StateDB
 type Keeper interface {
 	// Read methods

x/evm/statedb/journal.go

@@ -24,21 +24,21 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 )
 
-// journalEntry is a modification entry in the state change journal that can be
-// reverted on demand.
-type journalEntry interface {
-	// revert undoes the changes introduced by this journal entry.
-	revert(*StateDB)
+// JournalEntry is a modification entry in the state change journal that can be
+// Reverted on demand.
+type JournalEntry interface {
+	// Revert undoes the changes introduced by this journal entry.
+	Revert(*StateDB)
 
-	// dirtied returns the Ethereum address modified by this journal entry.
-	dirtied() *common.Address
+	// Dirtied returns the Ethereum address modified by this journal entry.
+	Dirtied() *common.Address
 }
 
 // journal contains the list of state modifications applied since the last state
 // commit. These are tracked to be able to be reverted in the case of an execution
 // exception or request for reversal.
 type journal struct {
-	entries []journalEntry         // Current changes tracked by the journal
+	entries []JournalEntry         // Current changes tracked by the journal
 	dirties map[common.Address]int // Dirty accounts and the number of changes
 }
 
@@ -64,22 +64,22 @@ func (j *journal) sortedDirties() []common.Address {
 }
 
 // append inserts a new modification entry to the end of the change journal.
-func (j *journal) append(entry journalEntry) {
+func (j *journal) append(entry JournalEntry) {
 	j.entries = append(j.entries, entry)
-	if addr := entry.dirtied(); addr != nil {
+	if addr := entry.Dirtied(); addr != nil {
 		j.dirties[*addr]++
 	}
 }
 
-// revert undoes a batch of journalled modifications along with any reverted
+// Revert undoes a batch of journalled modifications along with any Reverted
 // dirty handling too.
-func (j *journal) revert(statedb *StateDB, snapshot int) {
+func (j *journal) Revert(statedb *StateDB, snapshot int) {
 	for i := len(j.entries) - 1; i >= snapshot; i-- {
 		// Undo the changes made by the operation
-		j.entries[i].revert(statedb)
+		j.entries[i].Revert(statedb)
 
 		// Drop any dirty tracking induced by the change
-		if addr := j.entries[i].dirtied(); addr != nil {
+		if addr := j.entries[i].Dirtied(); addr != nil {
 			if j.dirties[*addr]--; j.dirties[*addr] == 0 {
 				delete(j.dirties, *addr)
 			}
@@ -141,83 +141,83 @@ type (
 	}
 )
 
-func (ch createObjectChange) revert(s *StateDB) {
+func (ch createObjectChange) Revert(s *StateDB) {
 	delete(s.stateObjects, *ch.account)
 }
 
-func (ch createObjectChange) dirtied() *common.Address {
+func (ch createObjectChange) Dirtied() *common.Address {
 	return ch.account
 }
 
-func (ch resetObjectChange) revert(s *StateDB) {
+func (ch resetObjectChange) Revert(s *StateDB) {
 	s.setStateObject(ch.prev)
 }
 
-func (ch resetObjectChange) dirtied() *common.Address {
+func (ch resetObjectChange) Dirtied() *common.Address {
 	return nil
 }
 
-func (ch suicideChange) revert(s *StateDB) {
+func (ch suicideChange) Revert(s *StateDB) {
 	obj := s.getStateObject(*ch.account)
 	if obj != nil {
 		obj.suicided = ch.prev
 		obj.setBalance(ch.prevbalance)
 	}
 }
 
-func (ch suicideChange) dirtied() *common.Address {
+func (ch suicideChange) Dirtied() *common.Address {
 	return ch.account
 }
 
-func (ch balanceChange) revert(s *StateDB) {
+func (ch balanceChange) Revert(s *StateDB) {
 	s.getStateObject(*ch.account).setBalance(ch.prev)
 }
 
-func (ch balanceChange) dirtied() *common.Address {
+func (ch balanceChange) Dirtied() *common.Address {
 	return ch.account
 }
 
-func (ch nonceChange) revert(s *StateDB) {
+func (ch nonceChange) Revert(s *StateDB) {
 	s.getStateObject(*ch.account).setNonce(ch.prev)
 }
 
-func (ch nonceChange) dirtied() *common.Address {
+func (ch nonceChange) Dirtied() *common.Address {
 	return ch.account
 }
 
-func (ch codeChange) revert(s *StateDB) {
+func (ch codeChange) Revert(s *StateDB) {
 	s.getStateObject(*ch.account).setCode(common.BytesToHash(ch.prevhash), ch.prevcode)
 }
 
-func (ch codeChange) dirtied() *common.Address {
+func (ch codeChange) Dirtied() *common.Address {
 	return ch.account
 }
 
-func (ch storageChange) revert(s *StateDB) {
+func (ch storageChange) Revert(s *StateDB) {
 	s.getStateObject(*ch.account).setState(ch.key, ch.prevalue)
 }
 
-func (ch storageChange) dirtied() *common.Address {
+func (ch storageChange) Dirtied() *common.Address {
 	return ch.account
 }
 
-func (ch refundChange) revert(s *StateDB) {
+func (ch refundChange) Revert(s *StateDB) {
 	s.refund = ch.prev
 }
 
-func (ch refundChange) dirtied() *common.Address {
+func (ch refundChange) Dirtied() *common.Address {
 	return nil
 }
 
-func (ch addLogChange) revert(s *StateDB) {
+func (ch addLogChange) Revert(s *StateDB) {
 	s.logs = s.logs[:len(s.logs)-1]
 }
 
-func (ch addLogChange) dirtied() *common.Address {
+func (ch addLogChange) Dirtied() *common.Address {
 	return nil
 }
 
-func (ch accessListAddAccountChange) revert(s *StateDB) {
+func (ch accessListAddAccountChange) Revert(s *StateDB) {
 	/*
 		One important invariant here, is that whenever a (addr, slot) is added, if the
 		addr is not already present, the add causes two journal entries:
@@ -230,14 +230,14 @@ func (ch accessListAddAccountChange) revert(s *StateDB) {
 	s.accessList.DeleteAddress(*ch.address)
 }
 
-func (ch accessListAddAccountChange) dirtied() *common.Address {
+func (ch accessListAddAccountChange) Dirtied() *common.Address {
 	return nil
 }
 
-func (ch accessListAddSlotChange) revert(s *StateDB) {
+func (ch accessListAddSlotChange) Revert(s *StateDB) {
 	s.accessList.DeleteSlot(*ch.address, *ch.slot)
 }
 
-func (ch accessListAddSlotChange) dirtied() *common.Address {
+func (ch accessListAddSlotChange) Dirtied() *common.Address {
 	return nil
 }

x/evm/statedb/statedb.go

@@ -429,7 +429,7 @@ func (s *StateDB) RevertToSnapshot(revid int) {
 	snapshot := s.validRevisions[idx].journalIndex
 
 	// Replay the journal to undo changes and remove invalidated snapshots
-	s.journal.revert(s, snapshot)
+	s.journal.Revert(s, snapshot)
 	s.validRevisions = s.validRevisions[:idx]
 }