cmd/evm/internal/t8ntool: polish the code

cmd/evm/internal/t8ntool/execution.go

@@ -127,8 +127,7 @@ type rejectedTx struct {
 }
 
 // Apply applies a set of transactions to a pre-state
-func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
-	txIt txIterator, miningReward int64) (*state.StateDB, *ExecutionResult, []byte, error) {
+func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig, txIt txIterator, miningReward int64) (*state.StateDB, *ExecutionResult, []byte, error) {
 	// Capture errors for BLOCKHASH operation, if we haven't been supplied the
 	// required blockhashes
 	var hashError error

cmd/evm/internal/t8ntool/file_tracer.go

@@ -82,16 +82,16 @@ func newResultWriter(baseDir string, tracer *tracers.Tracer) *tracing.Hooks {
 // OnTxStart creates a new output-file specific for this transaction, and invokes
 // the inner OnTxStart handler.
 func (l *fileWritingTracer) OnTxStart(env *tracing.VMContext, tx *types.Transaction, from common.Address) {
-	// Open a new file,
+	// Open a new file, or print a warning log if it's failed
 	fname := filepath.Join(l.baseDir, fmt.Sprintf("trace-%d-%v.%v", l.txIndex, tx.Hash().String(), l.suffix))
 	traceFile, err := os.Create(fname)
 	if err != nil {
 		log.Warn("Failed creating trace-file", "err", err)
+	} else {
+		log.Info("Created tracing-file", "path", fname)
+		l.destination = traceFile
 	}
-	log.Info("Created tracing-file", "path", fname)
-	l.destination = traceFile
-
-	if l.inner.OnTxStart != nil {
+	if l.inner != nil && l.inner.OnTxStart != nil {
 		l.inner.OnTxStart(env, tx, from)
 	}
 }
@@ -99,7 +99,7 @@ func (l *fileWritingTracer) OnTxStart(env *tracing.VMContext, tx *types.Transact
 // OnTxEnd writes result (if getResult exist), closes any currently open output-file,
 // and invokes the inner OnTxEnd handler.
 func (l *fileWritingTracer) OnTxEnd(receipt *types.Receipt, err error) {
-	if l.inner.OnTxEnd != nil {
+	if l.inner != nil && l.inner.OnTxEnd != nil {
 		l.inner.OnTxEnd(receipt, err)
 	}
 	if l.getResult != nil && l.destination != nil {
@@ -129,7 +129,7 @@ func (l *fileWritingTracer) hooks() *tracing.Hooks {
 			}
 		},
 		OnOpcode: func(pc uint64, op byte, gas, cost uint64, scope tracing.OpContext, rData []byte, depth int, err error) {
-			if l.inner.OnOpcode != nil {
+			if l.inner != nil && l.inner.OnOpcode != nil {
 				l.inner.OnOpcode(pc, op, gas, cost, scope, rData, depth, err)
 			}
 		},

cmd/evm/internal/t8ntool/transaction.go

@@ -64,12 +64,10 @@ func (r *result) MarshalJSON() ([]byte, error) {
 }
 
 func Transaction(ctx *cli.Context) error {
-	var (
-		err error
-	)
 	// We need to load the transactions. May be either in stdin input or in files.
 	// Check if anything needs to be read from stdin
 	var (
+		err         error
 		txStr       = ctx.String(InputTxsFlag.Name)
 		inputData   = &input{}
 		chainConfig *params.ChainConfig
@@ -82,6 +80,7 @@ func Transaction(ctx *cli.Context) error {
 	}
 	// Set the chain id
 	chainConfig.ChainID = big.NewInt(ctx.Int64(ChainIDFlag.Name))
+
 	var body hexutil.Bytes
 	if txStr == stdinSelector {
 		decoder := json.NewDecoder(os.Stdin)
@@ -107,6 +106,7 @@ func Transaction(ctx *cli.Context) error {
 		}
 	}
 	signer := types.MakeSigner(chainConfig, new(big.Int), 0)
+
 	// We now have the transactions in 'body', which is supposed to be an
 	// rlp list of transactions
 	it, err := rlp.NewListIterator([]byte(body))

core/vm/evm.go

@@ -133,11 +133,6 @@ func NewEVM(blockCtx BlockContext, statedb StateDB, chainConfig *params.ChainCon
 	return evm
 }
 
-// SetTracer sets the tracer for following state transition.
-func (evm *EVM) SetTracer(tracer *tracing.Hooks) {
-	evm.Config.Tracer = tracer
-}
-
 // SetPrecompiles sets the precompiled contracts for the EVM.
 // This method is only used through RPC calls.
 // It is not thread-safe.