evm, server: configurable tracer (#434)

* server: update server and enable configurable tracer

* config validation

* fix import cycle

* fix start

* update fields

* c++

* c++

x/evm/keeper/grpc_query.go

@@ -378,7 +378,8 @@ func (k Keeper) EthCall(c context.Context, req *types.EthCallRequest) (*types.Ms
 		return nil, status.Error(codes.Internal, err.Error())
 	}
 
-	evm := k.NewEVM(msg, ethCfg, params, coinbase)
+	evm := k.NewEVM(msg, ethCfg, params, coinbase, k.tracer)
+
 	// pass true means execute in query mode, which don't do actual gas refund.
 	res, err := k.ApplyMessage(evm, msg, ethCfg, true)
 	k.ctxStack.RevertAll()
@@ -448,7 +449,7 @@ func (k Keeper) EstimateGas(c context.Context, req *types.EthCallRequest) (*type
 		k.WithContext(ctx)
 
 		msg := args.ToMessage(req.GasCap)
-		evm := k.NewEVM(msg, ethCfg, params, coinbase)
+		evm := k.NewEVM(msg, ethCfg, params, coinbase, k.tracer)
 		// pass true means execute in query mode, which don't do actual gas refund.
 		rsp, err := k.ApplyMessage(evm, msg, ethCfg, true)
 

x/evm/keeper/keeper.go

@@ -48,6 +48,9 @@ type Keeper struct {
 
 	// chain ID number obtained from the context's chain id
 	eip155ChainID *big.Int
+
+	// Tracer used to collect execution traces from the EVM transaction execution
+	tracer string
 	// 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
@@ -58,7 +61,7 @@ func NewKeeper(
 	cdc codec.BinaryCodec,
 	storeKey, transientKey sdk.StoreKey, paramSpace paramtypes.Subspace,
 	ak types.AccountKeeper, bankKeeper types.BankKeeper, sk types.StakingKeeper,
-	debug bool,
+	tracer string, debug bool,
 ) *Keeper {
 
 	// ensure evm module account is set
@@ -80,6 +83,7 @@ func NewKeeper(
 		stakingKeeper: sk,
 		storeKey:      storeKey,
 		transientKey:  transientKey,
+		tracer:        tracer,
 		debug:         debug,
 	}
 }

x/evm/keeper/state_transition.go

@@ -2,7 +2,6 @@ package keeper
 
 import (
 	"math/big"
-	"os"
 	"time"
 
 	"github.com/palantir/stacktrace"
@@ -28,7 +27,13 @@ import (
 // (ChainConfig and module Params). It additionally sets the validator operator address as the
 // coinbase address to make it available for the COINBASE opcode, even though there is no
 // beneficiary of the coinbase transaction (since we're not mining).
-func (k *Keeper) NewEVM(msg core.Message, config *params.ChainConfig, params types.Params, coinbase common.Address) *vm.EVM {
+func (k *Keeper) NewEVM(
+	msg core.Message,
+	config *params.ChainConfig,
+	params types.Params,
+	coinbase common.Address,
+	tracer string,
+) *vm.EVM {
 	blockCtx := vm.BlockContext{
 		CanTransfer: core.CanTransfer,
 		Transfer:    core.Transfer,
@@ -41,18 +46,20 @@ func (k *Keeper) NewEVM(msg core.Message, config *params.ChainConfig, params typ
 	}
 
 	txCtx := core.NewEVMTxContext(msg)
-	vmConfig := k.VMConfig(params)
+	vmConfig := k.VMConfig(msg, params, tracer)
 
 	return vm.NewEVM(blockCtx, txCtx, k, config, vmConfig)
 }
 
 // VMConfig creates an EVM configuration from the debug setting and the extra EIPs enabled on the
 // module parameters. The config generated uses the default JumpTable from the EVM.
-func (k Keeper) VMConfig(params types.Params) vm.Config {
+func (k Keeper) VMConfig(msg core.Message, params types.Params, tracer string) vm.Config {
+	cfg := params.ChainConfig.EthereumConfig(k.eip155ChainID)
+
 	return vm.Config{
 		Debug:       k.debug,
-		Tracer:      vm.NewJSONLogger(&vm.LogConfig{Debug: k.debug}, os.Stderr), // TODO: consider using the Struct Logger too
-		NoRecursion: false,                                                      // TODO: consider disabling recursion though params
+		Tracer:      types.NewTracer(tracer, msg, cfg, k.Ctx().BlockHeight(), k.debug),
+		NoRecursion: false, // TODO: consider disabling recursion though params
 		ExtraEips:   params.EIPs(),
 	}
 }
@@ -154,7 +161,7 @@ func (k *Keeper) ApplyTransaction(tx *ethtypes.Transaction) (*types.MsgEthereumT
 	}
 
 	// create an ethereum EVM instance and run the message
-	evm := k.NewEVM(msg, ethCfg, params, coinbase)
+	evm := k.NewEVM(msg, ethCfg, params, coinbase, k.tracer)
 
 	txHash := tx.Hash()
 

x/evm/types/tracer.go

@@ -0,0 +1,40 @@
+package types
+
+import (
+	"math/big"
+	"os"
+
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+const (
+	TracerAccessList = "access_list"
+	TracerJSON       = "json"
+	TracerStruct     = "struct"
+	TracerMarkdown   = "markdown"
+)
+
+// NewTracer creates a new Logger tracer to collect execution traces from an
+// EVM transaction.
+func NewTracer(tracer string, msg core.Message, cfg *params.ChainConfig, height int64, debug bool) vm.Tracer {
+	// TODO: enable additional log configuration
+	logCfg := &vm.LogConfig{
+		Debug: debug,
+	}
+
+	switch tracer {
+	case TracerAccessList:
+		precompiles := vm.ActivePrecompiles(cfg.Rules(big.NewInt(height)))
+		return vm.NewAccessListTracer(msg.AccessList(), msg.From(), *msg.To(), precompiles)
+	case TracerJSON:
+		return vm.NewJSONLogger(logCfg, os.Stderr)
+	case TracerMarkdown:
+		return vm.NewMarkdownLogger(logCfg, os.Stdout) // TODO: Stderr ?
+	case TracerStruct:
+		return vm.NewStructLogger(logCfg)
+	default:
+		return nil
+	}
+}