Merge pull request #2454 from karalabe/trace-fix

eth: fix single transaction tracing (run prev mutations)

2 files changed, 65 insertions, 53 deletions

diff --git a/eth/api.go b/eth/api.go
index 105886752..f0fbef1ef 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -1594,7 +1594,7 @@ type BlockTraceResult struct {
 
 // TraceBlock processes the given block's RLP but does not import the block in to
 // the chain.
-func (api *PrivateDebugAPI) TraceBlock(blockRlp []byte, config vm.Config) BlockTraceResult {
+func (api *PrivateDebugAPI) TraceBlock(blockRlp []byte, config *vm.Config) BlockTraceResult {
 	var block types.Block
 	err := rlp.Decode(bytes.NewReader(blockRlp), &block)
 	if err != nil {
@@ -1611,7 +1611,7 @@ func (api *PrivateDebugAPI) TraceBlock(blockRlp []byte, config vm.Config) BlockT
 
 // TraceBlockFromFile loads the block's RLP from the given file name and attempts to
 // process it but does not import the block in to the chain.
-func (api *PrivateDebugAPI) TraceBlockFromFile(file string, config vm.Config) BlockTraceResult {
+func (api *PrivateDebugAPI) TraceBlockFromFile(file string, config *vm.Config) BlockTraceResult {
 	blockRlp, err := ioutil.ReadFile(file)
 	if err != nil {
 		return BlockTraceResult{Error: fmt.Sprintf("could not read file: %v", err)}
@@ -1620,7 +1620,7 @@ func (api *PrivateDebugAPI) TraceBlockFromFile(file string, config vm.Config) Bl
 }
 
 // TraceProcessBlock processes the block by canonical block number.
-func (api *PrivateDebugAPI) TraceBlockByNumber(number uint64, config vm.Config) BlockTraceResult {
+func (api *PrivateDebugAPI) TraceBlockByNumber(number uint64, config *vm.Config) BlockTraceResult {
 	// Fetch the block that we aim to reprocess
 	block := api.eth.BlockChain().GetBlockByNumber(number)
 	if block == nil {
@@ -1636,7 +1636,7 @@ func (api *PrivateDebugAPI) TraceBlockByNumber(number uint64, config vm.Config)
 }
 
 // TraceBlockByHash processes the block by hash.
-func (api *PrivateDebugAPI) TraceBlockByHash(hash common.Hash, config vm.Config) BlockTraceResult {
+func (api *PrivateDebugAPI) TraceBlockByHash(hash common.Hash, config *vm.Config) BlockTraceResult {
 	// Fetch the block that we aim to reprocess
 	block := api.eth.BlockChain().GetBlock(hash)
 	if block == nil {
@@ -1664,7 +1664,7 @@ func (t *TraceCollector) AddStructLog(slog vm.StructLog) {
 }
 
 // traceBlock processes the given block but does not save the state.
-func (api *PrivateDebugAPI) traceBlock(block *types.Block, config vm.Config) (bool, []vm.StructLog, error) {
+func (api *PrivateDebugAPI) traceBlock(block *types.Block, config *vm.Config) (bool, []vm.StructLog, error) {
 	// Validate and reprocess the block
 	var (
 		blockchain = api.eth.BlockChain()
@@ -1672,6 +1672,9 @@ func (api *PrivateDebugAPI) traceBlock(block *types.Block, config vm.Config) (bo
 		processor  = blockchain.Processor()
 		collector  = &TraceCollector{}
 	)
+	if config == nil {
+		config = new(vm.Config)
+	}
 	config.Debug = true // make sure debug is set.
 	config.Logger.Collector = collector
 
@@ -1683,7 +1686,7 @@ func (api *PrivateDebugAPI) traceBlock(block *types.Block, config vm.Config) (bo
 		return false, collector.traces, err
 	}
 
-	receipts, _, usedGas, err := processor.Process(block, statedb, config)
+	receipts, _, usedGas, err := processor.Process(block, statedb, *config)
 	if err != nil {
 		return false, collector.traces, err
 	}
@@ -1771,56 +1774,65 @@ func formatError(err error) string {
 
 // TraceTransaction returns the structured logs created during the execution of EVM
 // and returns them as a JSON object.
-func (s *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger vm.LogConfig) (*ExecutionResult, error) {
-	// Retrieve the tx from the chain
-	tx, _, blockIndex, _ := core.GetTransaction(s.eth.ChainDb(), txHash)
-
+func (s *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogConfig) (*ExecutionResult, error) {
+	if logger == nil {
+		logger = new(vm.LogConfig)
+	}
+	// Retrieve the tx from the chain and the containing block
+	tx, blockHash, _, txIndex := core.GetTransaction(s.eth.ChainDb(), txHash)
 	if tx == nil {
-		return nil, fmt.Errorf("Transaction not found")
+		return nil, fmt.Errorf("transaction %x not found", txHash)
 	}
-
-	block := s.eth.BlockChain().GetBlockByNumber(blockIndex - 1)
+	block := s.eth.BlockChain().GetBlock(blockHash)
 	if block == nil {
-		return nil, fmt.Errorf("Unable to retrieve prior block")
+		return nil, fmt.Errorf("block %x not found", blockHash)
 	}
-
-	// Create the state database
-	stateDb, err := state.New(block.Root(), s.eth.ChainDb())
-	if err != nil {
-		return nil, err
+	// Create the state database to mutate and eventually trace
+	parent := s.eth.BlockChain().GetBlock(block.ParentHash())
+	if parent == nil {
+		return nil, fmt.Errorf("block parent %x not found", block.ParentHash())
 	}
-
-	txFrom, err := tx.FromFrontier()
-
+	stateDb, err := state.New(parent.Root(), s.eth.ChainDb())
 	if err != nil {
-		return nil, fmt.Errorf("Unable to create transaction sender")
-	}
-	from := stateDb.GetOrNewStateObject(txFrom)
-	msg := callmsg{
-		from:     from,
-		to:       tx.To(),
-		gas:      tx.Gas(),
-		gasPrice: tx.GasPrice(),
-		value:    tx.Value(),
-		data:     tx.Data(),
+		return nil, err
 	}
-
-	vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, block.Header(), vm.Config{
-		Debug:  true,
-		Logger: logger,
-	})
-	gp := new(core.GasPool).AddGas(block.GasLimit())
-
-	ret, gas, err := core.ApplyMessage(vmenv, msg, gp)
-	if err != nil {
-		return nil, fmt.Errorf("Error executing transaction %v", err)
+	// Mutate the state and trace the selected transaction
+	for idx, tx := range block.Transactions() {
+		// Assemble the transaction call message
+		from, err := tx.FromFrontier()
+		if err != nil {
+			return nil, fmt.Errorf("sender retrieval failed: %v", err)
+		}
+		msg := callmsg{
+			from:     stateDb.GetOrNewStateObject(from),
+			to:       tx.To(),
+			gas:      tx.Gas(),
+			gasPrice: tx.GasPrice(),
+			value:    tx.Value(),
+			data:     tx.Data(),
+		}
+		// Mutate the state if we haven't reached the tracing transaction yet
+		if uint64(idx) < txIndex {
+			vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, parent.Header(), vm.Config{})
+			_, _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
+			if err != nil {
+				return nil, fmt.Errorf("mutation failed: %v", err)
+			}
+			continue
+		}
+		// Otherwise trace the transaction and return
+		vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, parent.Header(), vm.Config{Debug: true, Logger: *logger})
+		ret, gas, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
+		if err != nil {
+			return nil, fmt.Errorf("tracing failed: %v", err)
+		}
+		return &ExecutionResult{
+			Gas:         gas,
+			ReturnValue: fmt.Sprintf("%x", ret),
+			StructLogs:  formatLogs(vmenv.StructLogs()),
+		}, nil
 	}
-
-	return &ExecutionResult{
-		Gas:         gas,
-		ReturnValue: fmt.Sprintf("%x", ret),
-		StructLogs:  formatLogs(vmenv.StructLogs()),
-	}, nil
+	return nil, errors.New("database inconsistency")
 }
 
 func (s *PublicBlockChainAPI) TraceCall(args CallArgs, blockNr rpc.BlockNumber) (*ExecutionResult, error) {
diff --git a/rpc/javascript.go b/rpc/javascript.go
index 475691a87..4d2bd1cde 100644
--- a/rpc/javascript.go
+++ b/rpc/javascript.go
@@ -268,22 +268,22 @@ web3._extend({
 		new web3._extend.Method({
 			name: 'traceBlock',
 			call: 'debug_traceBlock',
-			params: 2
+			params: 1
 		}),
 		new web3._extend.Method({
 			name: 'traceBlockByFile',
 			call: 'debug_traceBlockByFile',
-			params: 2
+			params: 1
 		}),
 		new web3._extend.Method({
 			name: 'traceBlockByNumber',
 			call: 'debug_traceBlockByNumber',
-			params: 2
+			params: 1
 		}),
 		new web3._extend.Method({
 			name: 'traceBlockByHash',
 			call: 'debug_traceBlockByHash',
-			params: 2
+			params: 1
 		}),
 		new web3._extend.Method({
 			name: 'seedHash',
@@ -390,7 +390,7 @@ web3._extend({
 		new web3._extend.Method({
 			name: 'traceTransaction',
 			call: 'debug_traceTransaction',
-			params: 2
+			params: 1
 		})
 	],
 	properties: []