Allow evm to call native modules through logs

Closes #416

comment

add txHash parameter

review suggestions

add hooks test

x/evm/keeper/hooks.go

@@ -0,0 +1,33 @@
+package keeper
+
+import (
+	"reflect"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	ethcmn "github.com/ethereum/go-ethereum/common"
+	ethtypes "github.com/ethereum/go-ethereum/core/types"
+	"github.com/tharsis/ethermint/x/evm/types"
+)
+
+var (
+	_ types.EvmHooks = MultiEvmHooks{}
+)
+
+// MultiEvmHooks combine multiple evm hooks, all hook functions are run in array sequence
+type MultiEvmHooks []types.EvmHooks
+
+// NewMultiEvmHooks combine multiple evm hooks
+func NewMultiEvmHooks(hooks ...types.EvmHooks) MultiEvmHooks {
+	return hooks
+}
+
+// PostTxProcessing delegate the call to underlying hooks
+func (mh MultiEvmHooks) PostTxProcessing(ctx sdk.Context, txHash ethcmn.Hash, logs []*ethtypes.Log) error {
+	for i := range mh {
+		if err := mh[i].PostTxProcessing(ctx, txHash, logs); err != nil {
+			return sdkerrors.Wrapf(err, "EVM hook %s failed", reflect.TypeOf(mh[i]))
+		}
+	}
+	return nil
+}

x/evm/keeper/hooks_test.go

@@ -0,0 +1,72 @@
+package keeper_test
+
+import (
+	"errors"
+	"math/big"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/ethereum/go-ethereum/common"
+	ethtypes "github.com/ethereum/go-ethereum/core/types"
+
+	ethermint "github.com/tharsis/ethermint/types"
+	"github.com/tharsis/ethermint/x/evm/keeper"
+	"github.com/tharsis/ethermint/x/evm/types"
+)
+
+// LogRecordHook records all the logs
+type LogRecordHook struct {
+	Logs []*ethtypes.Log
+}
+
+func (dh *LogRecordHook) PostTxProcessing(ctx sdk.Context, txHash common.Hash, logs []*ethtypes.Log) error {
+	dh.Logs = logs
+	return nil
+}
+
+// FailureHook always fail
+type FailureHook struct{}
+
+func (dh FailureHook) PostTxProcessing(ctx sdk.Context, txHash common.Hash, logs []*ethtypes.Log) error {
+	return errors.New("post tx processing failed")
+}
+func (suite *KeeperTestSuite) TestEvmHooks() {
+	suite.SetupTest()
+	suite.Commit()
+
+	logRecordHook := LogRecordHook{}
+	suite.app.EvmKeeper.SetHooks(keeper.NewMultiEvmHooks(&logRecordHook))
+
+	k := suite.app.EvmKeeper
+
+	txHash := common.BigToHash(big.NewInt(1))
+
+	amt := sdk.Coins{ethermint.NewPhotonCoinInt64(100)}
+	err := suite.app.BankKeeper.MintCoins(suite.ctx, types.ModuleName, amt)
+	suite.Require().NoError(err)
+	err = suite.app.BankKeeper.SendCoinsFromModuleToAccount(suite.ctx, types.ModuleName, suite.address.Bytes(), amt)
+	suite.Require().NoError(err)
+
+	k.SetTxHashTransient(txHash)
+	k.AddLog(&ethtypes.Log{
+		Topics:  []common.Hash{},
+		Address: suite.address,
+	})
+
+	logs := k.GetTxLogs(txHash)
+	suite.Require().Equal(1, len(logs))
+
+	err = k.PostTxProcessing(txHash, logs)
+	suite.Require().NoError(err)
+
+	suite.Require().Equal(1, len(logRecordHook.Logs))
+}
+
+func (suite *KeeperTestSuite) TestHookFailure() {
+	suite.SetupTest()
+	k := suite.app.EvmKeeper
+
+	// Test failure hook
+	suite.app.EvmKeeper.SetHooks(keeper.NewMultiEvmHooks(FailureHook{}))
+	err := k.PostTxProcessing(common.Hash{}, nil)
+	suite.Require().Error(err)
+}

x/evm/keeper/keeper.go

@@ -54,6 +54,9 @@ type Keeper struct {
 	// trace EVM state transition execution. This value is obtained from the `--trace` flag.
 	// For more info check https://geth.ethereum.org/docs/dapp/tracing
 	debug bool
+
+	// EvmHooks
+	hooks types.EvmHooks
 }
 
 // NewKeeper generates new evm module keeper
@@ -416,3 +419,21 @@ func (k Keeper) ResetAccount(addr common.Address) {
 	k.DeleteCode(addr)
 	k.DeleteAccountStorage(addr)
 }
+
+// SetHooks sets the hooks for governance
+func (k *Keeper) SetHooks(eh types.EvmHooks) *Keeper {
+	if k.hooks != nil {
+		panic("cannot set evm hooks twice")
+	}
+
+	k.hooks = eh
+	return k
+}
+
+// PostTxProcessing delegate the call to the hooks
+func (k *Keeper) PostTxProcessing(txHash common.Hash, logs []*ethtypes.Log) error {
+	if k.hooks == nil {
+		return nil
+	}
+	return k.hooks.PostTxProcessing(k.Ctx(), txHash, logs)
+}

x/evm/keeper/keeper_test.go

@@ -14,11 +14,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/crypto/keyring"
-	"github.com/cosmos/cosmos-sdk/simapp"
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	authkeeper "github.com/cosmos/cosmos-sdk/x/auth/keeper"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
-	bankkeeper "github.com/cosmos/cosmos-sdk/x/bank/keeper"
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 
 	"github.com/tharsis/ethermint/app"
@@ -150,13 +147,6 @@ func (suite *KeeperTestSuite) DoSetupTest(t require.TestingT) {
 	suite.clientCtx = client.Context{}.WithTxConfig(encodingConfig.TxConfig)
 	suite.ethSigner = ethtypes.LatestSignerForChainID(suite.app.EvmKeeper.ChainID())
 	suite.appCodec = encodingConfig.Marshaler
-
-	// mint some tokens to coinbase address
-	_, bankKeeper := suite.initKeepersWithmAccPerms()
-	require.NoError(t, err)
-	initCoin := sdk.NewCoins(sdk.NewCoin(suite.EvmDenom(), testTokens))
-	err = simapp.FundAccount(bankKeeper, suite.ctx, acc.GetAddress(), initCoin)
-	require.NoError(t, err)
 }
 
 func (suite *KeeperTestSuite) SetupTest() {
@@ -187,24 +177,6 @@ func (suite *KeeperTestSuite) Commit() {
 	suite.queryClient = types.NewQueryClient(queryHelper)
 }
 
-// initKeepersWithmAccPerms construct a bank keeper that can mint tokens out of thin air
-func (suite *KeeperTestSuite) initKeepersWithmAccPerms() (authkeeper.AccountKeeper, bankkeeper.BaseKeeper) {
-	maccPerms := app.GetMaccPerms()
-
-	maccPerms[authtypes.Burner] = []string{authtypes.Burner}
-	maccPerms[authtypes.Minter] = []string{authtypes.Minter}
-	authKeeper := authkeeper.NewAccountKeeper(
-		suite.appCodec, suite.app.GetKey(types.StoreKey), suite.app.GetSubspace(types.ModuleName),
-		authtypes.ProtoBaseAccount, maccPerms,
-	)
-	keeper := bankkeeper.NewBaseKeeper(
-		suite.appCodec, suite.app.GetKey(types.StoreKey), authKeeper,
-		suite.app.GetSubspace(types.ModuleName), map[string]bool{},
-	)
-
-	return authKeeper, keeper
-}
-
 // DeployTestContract deploy a test erc20 contract and returns the contract address
 func (suite *KeeperTestSuite) DeployTestContract(t require.TestingT, owner common.Address, supply *big.Int) common.Address {
 	ctx := sdk.WrapSDKContext(suite.ctx)

x/evm/keeper/state_transition.go

@@ -175,6 +175,9 @@ func (k *Keeper) ApplyTransaction(tx *ethtypes.Transaction) (*types.MsgEthereumT
 		panic("context stack shouldn't be dirty before apply message")
 	}
 
+	// Contains the tx processing and post processing in same scope
+	revision := k.Snapshot()
+
 	// pass false to execute in real mode, which do actual gas refunding
 	res, err := k.ApplyMessage(evm, msg, ethCfg, false)
 	if err != nil {
@@ -183,6 +186,17 @@ func (k *Keeper) ApplyTransaction(tx *ethtypes.Transaction) (*types.MsgEthereumT
 
 	res.Hash = txHash.Hex()
 	logs := k.GetTxLogs(txHash)
+
+	if !res.Failed() {
+		// Only call hooks if tx executed successfully.
+		if err = k.PostTxProcessing(txHash, logs); err != nil {
+			// If hooks return error, revert the whole tx.
+			k.RevertToSnapshot(revision)
+			res.VmError = types.ErrPostTxProcessing.Error()
+			k.Logger(ctx).Error("tx post processing failed", "error", err)
+		}
+	}
+
 	if len(logs) > 0 {
 		res.Logs = types.NewLogsFromEth(logs)
 		// Update transient block bloom filter

x/evm/types/errors.go

@@ -32,6 +32,10 @@ const (
 	codeErrInvalidBaseFee
 )
 
+var (
+	ErrPostTxProcessing = errors.New("failed to execute post processing")
+)
+
 var (
 	// ErrInvalidState returns an error resulting from an invalid Storage State.
 	ErrInvalidState = sdkerrors.Register(ModuleName, codeErrInvalidState, "invalid storage state")

x/evm/types/interfaces.go

@@ -4,6 +4,8 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
+	ethcmn "github.com/ethereum/go-ethereum/common"
+	ethtypes "github.com/ethereum/go-ethereum/core/types"
 )
 
 // AccountKeeper defines the expected account keeper interface
@@ -33,3 +35,12 @@ type StakingKeeper interface {
 	GetHistoricalInfo(ctx sdk.Context, height int64) (stakingtypes.HistoricalInfo, bool)
 	GetValidatorByConsAddr(ctx sdk.Context, consAddr sdk.ConsAddress) (validator stakingtypes.Validator, found bool)
 }
+
+// Event Hooks
+// These can be utilized to customize evm transaction processing.
+
+// EvmHooks event hooks for evm tx processing
+type EvmHooks interface {
+	// Must be called after tx is processed, if failed, the whole evm transaction is reverted.
+	PostTxProcessing(ctx sdk.Context, txHash ethcmn.Hash, logs []*ethtypes.Log) error
+}