core/vm: Refactor tracing to make Tracer the main interface

This CL makes several refactors:
 - Define a Tracer interface, implementing the `CaptureState` method
 - Add the VM environment as the first argument of
   `Tracer.CaptureState`
 - Rename existing functionality `StructLogger` an make it an
   implementation of `Tracer`
 - Delete `StructLogCollector` and make `StructLogger` collect the logs
   directly
 - Change all callers to use the new `StructLogger` where necessary and
   extract logs from that.
 - Deletes the apparently obsolete and likely nonfunctional 'TraceCall'
   from the eth API.

Callers that only wish accumulated logs can use the `StructLogger`
implementation straightforwardly. Callers that wish to efficiently
capture VM traces and operate on them without excessive copying can now
implement the `Tracer` interface to receive VM state at each step and
do with it as they wish.

This CL also removes the accumulation of logs from the vm.Environment;
this was necessary as part of the refactor, but also simplifies it by
removing a responsibility that doesn't directly belong to the
Environment.

cmd/evm/main.go

@@ -117,10 +117,13 @@ func run(ctx *cli.Context) error {
 	statedb, _ := state.New(common.Hash{}, db)
 	sender := statedb.CreateAccount(common.StringToAddress("sender"))
 
+	logger := vm.NewStructLogger(nil)
+
 	vmenv := NewEnv(statedb, common.StringToAddress("evmuser"), common.Big(ctx.GlobalString(ValueFlag.Name)), vm.Config{
 		Debug:     ctx.GlobalBool(DebugFlag.Name),
 		ForceJit:  ctx.GlobalBool(ForceJitFlag.Name),
 		EnableJit: !ctx.GlobalBool(DisableJitFlag.Name),
+		Tracer:    logger,
 	})
 
 	tstart := time.Now()
@@ -157,7 +160,7 @@ func run(ctx *cli.Context) error {
 		statedb.Commit()
 		fmt.Println(string(statedb.Dump()))
 	}
-	vm.StdErrFormat(vmenv.StructLogs())
+	vm.StdErrFormat(logger.StructLogs())
 
 	if ctx.GlobalBool(SysStatFlag.Name) {
 		var mem runtime.MemStats
@@ -209,7 +212,6 @@ func NewEnv(state *state.StateDB, transactor common.Address, value *big.Int, cfg
 		value:      value,
 		time:       big.NewInt(time.Now().Unix()),
 	}
-	cfg.Logger.Collector = env
 
 	env.evm = vm.New(env, cfg)
 	return env
@@ -242,12 +244,6 @@ func (self *VMEnv) GetHash(n uint64) common.Hash {
 	}
 	return common.Hash{}
 }
-func (self *VMEnv) AddStructLog(log vm.StructLog) {
-	self.logs = append(self.logs, log)
-}
-func (self *VMEnv) StructLogs() []vm.StructLog {
-	return self.logs
-}
 func (self *VMEnv) AddLog(log *vm.Log) {
 	self.state.AddLog(log)
 }

core/vm/environment.go

@@ -73,8 +73,6 @@ type Environment interface {
 	DelegateCall(me ContractRef, addr common.Address, data []byte, gas, price *big.Int) ([]byte, error)
 	// Create a new contract
 	Create(me ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error)
-
-	StructLogs() []StructLog
 }
 
 // Vm is the basic interface for an implementation of the EVM.

core/vm/gas.go

@@ -38,7 +38,7 @@ var (
 )
 
 // baseCheck checks for any stack error underflows
-func baseCheck(op OpCode, stack *stack, gas *big.Int) error {
+func baseCheck(op OpCode, stack *Stack, gas *big.Int) error {
 	// PUSH and DUP are a bit special. They all cost the same but we do want to have checking on stack push limit
 	// PUSH is also allowed to calculate the same price for all PUSHes
 	// DUP requirements are handled elsewhere (except for the stack limit check)

core/vm/jit.go

@@ -303,7 +303,7 @@ func RunProgram(program *Program, env Environment, contract *Contract, input []b
 	return runProgram(program, 0, NewMemory(), newstack(), env, contract, input)
 }
 
-func runProgram(program *Program, pcstart uint64, mem *Memory, stack *stack, env Environment, contract *Contract, input []byte) ([]byte, error) {
+func runProgram(program *Program, pcstart uint64, mem *Memory, stack *Stack, env Environment, contract *Contract, input []byte) ([]byte, error) {
 	contract.Input = input
 
 	var (
@@ -357,7 +357,7 @@ func validDest(dests map[uint64]struct{}, dest *big.Int) bool {
 
 // jitCalculateGasAndSize calculates the required given the opcode and stack items calculates the new memorysize for
 // the operation. This does not reduce gas or resizes the memory.
-func jitCalculateGasAndSize(env Environment, contract *Contract, instr instruction, statedb Database, mem *Memory, stack *stack) (*big.Int, *big.Int, error) {
+func jitCalculateGasAndSize(env Environment, contract *Contract, instr instruction, statedb Database, mem *Memory, stack *Stack) (*big.Int, *big.Int, error) {
 	var (
 		gas                 = new(big.Int)
 		newMemSize *big.Int = new(big.Int)
@@ -491,7 +491,7 @@ func jitCalculateGasAndSize(env Environment, contract *Contract, instr instructi
 
 // jitBaseCheck is the same as baseCheck except it doesn't do the look up in the
 // gas table. This is done during compilation instead.
-func jitBaseCheck(instr instruction, stack *stack, gas *big.Int) error {
+func jitBaseCheck(instr instruction, stack *Stack, gas *big.Int) error {
 	err := stack.require(instr.spop)
 	if err != nil {
 		return err

core/vm/jit_test.go

@@ -179,11 +179,6 @@ func (self *Env) RuleSet() RuleSet       { return ruleSet{new(big.Int)} }
 func (self *Env) Vm() Vm                 { return self.evm }
 func (self *Env) Origin() common.Address { return common.Address{} }
 func (self *Env) BlockNumber() *big.Int  { return big.NewInt(0) }
-func (self *Env) AddStructLog(log StructLog) {
-}
-func (self *Env) StructLogs() []StructLog {
-	return nil
-}
 
 //func (self *Env) PrevHash() []byte      { return self.parent }
 func (self *Env) Coinbase() common.Address { return common.Address{} }

core/vm/logger.go

@@ -36,19 +36,12 @@ func (self Storage) Copy() Storage {
 	return cpy
 }
 
-// StructLogCollector is the basic interface to capture emited logs by the EVM logger.
-type StructLogCollector interface {
-	// Adds the structured log to the collector.
-	AddStructLog(StructLog)
-}
-
 // LogConfig are the configuration options for structured logger the EVM
 type LogConfig struct {
-	DisableMemory  bool               // disable memory capture
-	DisableStack   bool               // disable stack capture
-	DisableStorage bool               // disable storage capture
-	FullStorage    bool               // show full storage (slow)
-	Collector      StructLogCollector // the log collector
+	DisableMemory  bool // disable memory capture
+	DisableStack   bool // disable stack capture
+	DisableStorage bool // disable storage capture
+	FullStorage    bool // show full storage (slow)
 }
 
 // StructLog is emitted to the Environment each cycle and lists information about the current internal state
@@ -65,36 +58,42 @@ type StructLog struct {
 	Err     error
 }
 
-// Logger is an EVM state logger and implements VmLogger.
+// Tracer is used to collect execution traces from an EVM transaction
+// execution. CaptureState is called for each step of the VM with the
+// current VM state.
+// Note that reference types are actual VM data structures; make copies
+// if you need to retain them beyond the current call.
+type Tracer interface {
+	CaptureState(env Environment, pc uint64, op OpCode, gas, cost *big.Int, memory *Memory, stack *Stack, contract *Contract, depth int, err error)
+}
+
+// StructLogger is an EVM state logger and implements Tracer.
 //
-// Logger can capture state based on the given Log configuration and also keeps
+// StructLogger can capture state based on the given Log configuration and also keeps
 // a track record of modified storage which is used in reporting snapshots of the
 // contract their storage.
-type Logger struct {
+type StructLogger struct {
 	cfg LogConfig
 
-	env           Environment
+	logs          []StructLog
 	changedValues map[common.Address]Storage
 }
 
-// newLogger returns a new logger
-func newLogger(cfg LogConfig, env Environment) *Logger {
-	return &Logger{
-		cfg:           cfg,
-		env:           env,
+// NewLogger returns a new logger
+func NewStructLogger(cfg *LogConfig) *StructLogger {
+	logger := &StructLogger{
 		changedValues: make(map[common.Address]Storage),
 	}
+	if cfg != nil {
+		logger.cfg = *cfg
+	}
+	return logger
 }
 
 // captureState logs a new structured log message and pushes it out to the environment
 //
 // captureState also tracks SSTORE ops to track dirty values.
-func (l *Logger) captureState(pc uint64, op OpCode, gas, cost *big.Int, memory *Memory, stack *stack, contract *Contract, depth int, err error) {
-	// short circuit if no log collector is present
-	if l.cfg.Collector == nil {
-		return
-	}
-
+func (l *StructLogger) CaptureState(env Environment, pc uint64, op OpCode, gas, cost *big.Int, memory *Memory, stack *Stack, contract *Contract, depth int, err error) {
 	// initialise new changed values storage container for this contract
 	// if not present.
 	if l.changedValues[contract.Address()] == nil {
@@ -139,7 +138,7 @@ func (l *Logger) captureState(pc uint64, op OpCode, gas, cost *big.Int, memory *
 			storage = make(Storage)
 			// Get the contract account and loop over each storage entry. This may involve looping over
 			// the trie and is a very expensive process.
-			l.env.Db().GetAccount(contract.Address()).ForEachStorage(func(key, value common.Hash) bool {
+			env.Db().GetAccount(contract.Address()).ForEachStorage(func(key, value common.Hash) bool {
 				storage[key] = value
 				// Return true, indicating we'd like to continue.
 				return true
@@ -150,9 +149,14 @@ func (l *Logger) captureState(pc uint64, op OpCode, gas, cost *big.Int, memory *
 		}
 	}
 	// create a new snaptshot of the EVM.
-	log := StructLog{pc, op, new(big.Int).Set(gas), cost, mem, stck, storage, l.env.Depth(), err}
-	// Add the log to the collector
-	l.cfg.Collector.AddStructLog(log)
+	log := StructLog{pc, op, new(big.Int).Set(gas), cost, mem, stck, storage, env.Depth(), err}
+
+	l.logs = append(l.logs, log)
+}
+
+// StructLogs returns a list of captured log entries
+func (l *StructLogger) StructLogs() []StructLog {
+	return l.logs
 }
 
 // StdErrFormat formats a slice of StructLogs to human readable format

core/vm/logger_test.go

@@ -54,12 +54,11 @@ func newDummyEnv(ref *dummyContractRef) *dummyEnv {
 func (d dummyEnv) GetAccount(common.Address) Account {
 	return d.ref
 }
-func (d dummyEnv) AddStructLog(StructLog) {}
 
 func TestStoreCapture(t *testing.T) {
 	var (
 		env      = NewEnv(true, false)
-		logger   = newLogger(LogConfig{Collector: env}, env)
+		logger   = NewStructLogger(nil)
 		mem      = NewMemory()
 		stack    = newstack()
 		contract = NewContract(&dummyContractRef{}, &dummyContractRef{}, new(big.Int), new(big.Int), new(big.Int))
@@ -69,7 +68,7 @@ func TestStoreCapture(t *testing.T) {
 
 	var index common.Hash
 
-	logger.captureState(0, SSTORE, new(big.Int), new(big.Int), mem, stack, contract, 0, nil)
+	logger.CaptureState(env, 0, SSTORE, new(big.Int), new(big.Int), mem, stack, contract, 0, nil)
 	if len(logger.changedValues[contract.Address()]) == 0 {
 		t.Fatalf("expected exactly 1 changed value on address %x, got %d", contract.Address(), len(logger.changedValues[contract.Address()]))
 	}
@@ -86,18 +85,18 @@ func TestStorageCapture(t *testing.T) {
 		ref      = &dummyContractRef{}
 		contract = NewContract(ref, ref, new(big.Int), new(big.Int), new(big.Int))
 		env      = newDummyEnv(ref)
-		logger   = newLogger(LogConfig{Collector: env}, env)
+		logger   = NewStructLogger(nil)
 		mem      = NewMemory()
 		stack    = newstack()
 	)
 
-	logger.captureState(0, STOP, new(big.Int), new(big.Int), mem, stack, contract, 0, nil)
+	logger.CaptureState(env, 0, STOP, new(big.Int), new(big.Int), mem, stack, contract, 0, nil)
 	if ref.calledForEach {
 		t.Error("didn't expect for each to be called")
 	}
 
-	logger = newLogger(LogConfig{Collector: env, FullStorage: true}, env)
-	logger.captureState(0, STOP, new(big.Int), new(big.Int), mem, stack, contract, 0, nil)
+	logger = NewStructLogger(&LogConfig{FullStorage: true})
+	logger.CaptureState(env, 0, STOP, new(big.Int), new(big.Int), mem, stack, contract, 0, nil)
 	if !ref.calledForEach {
 		t.Error("expected for each to be called")
 	}

core/vm/runtime/env.go

@@ -39,8 +39,6 @@ type Env struct {
 	difficulty *big.Int
 	gasLimit   *big.Int
 
-	logs []vm.StructLog
-
 	getHashFn func(uint64) common.Hash
 
 	evm *vm.EVM
@@ -62,23 +60,11 @@ func NewEnv(cfg *Config, state *state.StateDB) vm.Environment {
 		Debug:     cfg.Debug,
 		EnableJit: !cfg.DisableJit,
 		ForceJit:  !cfg.DisableJit,
-
-		Logger: vm.LogConfig{
-			Collector: env,
-		},
 	})
 
 	return env
 }
 
-func (self *Env) StructLogs() []vm.StructLog {
-	return self.logs
-}
-
-func (self *Env) AddStructLog(log vm.StructLog) {
-	self.logs = append(self.logs, log)
-}
-
 func (self *Env) RuleSet() vm.RuleSet      { return self.ruleSet }
 func (self *Env) Vm() vm.Vm                { return self.evm }
 func (self *Env) Origin() common.Address   { return self.origin }

core/vm/segments.go

@@ -24,7 +24,7 @@ type jumpSeg struct {
 	gas *big.Int
 }
 
-func (j jumpSeg) do(program *Program, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *stack) ([]byte, error) {
+func (j jumpSeg) do(program *Program, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	if !contract.UseGas(j.gas) {
 		return nil, OutOfGasError
 	}
@@ -42,7 +42,7 @@ type pushSeg struct {
 	gas  *big.Int
 }
 
-func (s pushSeg) do(program *Program, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *stack) ([]byte, error) {
+func (s pushSeg) do(program *Program, pc *uint64, env Environment, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	// Use the calculated gas. When insufficient gas is present, use all gas and return an
 	// Out Of Gas error
 	if !contract.UseGas(s.gas) {

core/vm/stack.go

@@ -24,58 +24,58 @@ import (
 // stack is an object for basic stack operations. Items popped to the stack are
 // expected to be changed and modified. stack does not take care of adding newly
 // initialised objects.
-type stack struct {
+type Stack struct {
 	data []*big.Int
 }
 
-func newstack() *stack {
-	return &stack{}
+func newstack() *Stack {
+	return &Stack{}
 }
 
-func (st *stack) Data() []*big.Int {
+func (st *Stack) Data() []*big.Int {
 	return st.data
 }
 
-func (st *stack) push(d *big.Int) {
+func (st *Stack) push(d *big.Int) {
 	// NOTE push limit (1024) is checked in baseCheck
 	//stackItem := new(big.Int).Set(d)
 	//st.data = append(st.data, stackItem)
 	st.data = append(st.data, d)
 }
-func (st *stack) pushN(ds ...*big.Int) {
+func (st *Stack) pushN(ds ...*big.Int) {
 	st.data = append(st.data, ds...)
 }
 
-func (st *stack) pop() (ret *big.Int) {
+func (st *Stack) pop() (ret *big.Int) {
 	ret = st.data[len(st.data)-1]
 	st.data = st.data[:len(st.data)-1]
 	return
 }
 
-func (st *stack) len() int {
+func (st *Stack) len() int {
 	return len(st.data)
 }
 
-func (st *stack) swap(n int) {
+func (st *Stack) swap(n int) {
 	st.data[st.len()-n], st.data[st.len()-1] = st.data[st.len()-1], st.data[st.len()-n]
 }
 
-func (st *stack) dup(n int) {
+func (st *Stack) dup(n int) {
 	st.push(new(big.Int).Set(st.data[st.len()-n]))
 }
 
-func (st *stack) peek() *big.Int {
+func (st *Stack) peek() *big.Int {
 	return st.data[st.len()-1]
 }
 
-func (st *stack) require(n int) error {
+func (st *Stack) require(n int) error {
 	if st.len() < n {
 		return fmt.Errorf("stack underflow (%d <=> %d)", len(st.data), n)
 	}
 	return nil
 }
 
-func (st *stack) Print() {
+func (st *Stack) Print() {
 	fmt.Println("### stack ###")
 	if len(st.data) > 0 {
 		for i, val := range st.data {

core/vm/vm.go

@@ -33,7 +33,7 @@ type Config struct {
 	Debug     bool
 	EnableJit bool
 	ForceJit  bool
-	Logger    LogConfig
+	Tracer    Tracer
 }
 
 // EVM is used to run Ethereum based contracts and will utilise the
@@ -44,22 +44,14 @@ type EVM struct {
 	env       Environment
 	jumpTable vmJumpTable
 	cfg       Config
-
-	logger *Logger
 }
 
 // New returns a new instance of the EVM.
 func New(env Environment, cfg Config) *EVM {
-	var logger *Logger
-	if cfg.Debug {
-		logger = newLogger(cfg.Logger, env)
-	}
-
 	return &EVM{
 		env:       env,
 		jumpTable: newJumpTable(env.RuleSet(), env.BlockNumber()),
 		cfg:       cfg,
-		logger:    logger,
 	}
 }
 
@@ -149,7 +141,7 @@ func (evm *EVM) Run(contract *Contract, input []byte) (ret []byte, err error) {
 	// User defer pattern to check for an error and, based on the error being nil or not, use all gas and return.
 	defer func() {
 		if err != nil && evm.cfg.Debug {
-			evm.logger.captureState(pc, op, contract.Gas, cost, mem, stack, contract, evm.env.Depth(), err)
+			evm.cfg.Tracer.CaptureState(evm.env, pc, op, contract.Gas, cost, mem, stack, contract, evm.env.Depth(), err)
 		}
 	}()
 
@@ -191,7 +183,7 @@ func (evm *EVM) Run(contract *Contract, input []byte) (ret []byte, err error) {
 		mem.Resize(newMemSize.Uint64())
 		// Add a log message
 		if evm.cfg.Debug {
-			evm.logger.captureState(pc, op, contract.Gas, cost, mem, stack, contract, evm.env.Depth(), nil)
+			evm.cfg.Tracer.CaptureState(evm.env, pc, op, contract.Gas, cost, mem, stack, contract, evm.env.Depth(), nil)
 		}
 
 		if opPtr := evm.jumpTable[op]; opPtr.valid {
@@ -241,7 +233,7 @@ func (evm *EVM) Run(contract *Contract, input []byte) (ret []byte, err error) {
 
 // calculateGasAndSize calculates the required given the opcode and stack items calculates the new memorysize for
 // the operation. This does not reduce gas or resizes the memory.
-func calculateGasAndSize(env Environment, contract *Contract, caller ContractRef, op OpCode, statedb Database, mem *Memory, stack *stack) (*big.Int, *big.Int, error) {
+func calculateGasAndSize(env Environment, contract *Contract, caller ContractRef, op OpCode, statedb Database, mem *Memory, stack *Stack) (*big.Int, *big.Int, error) {
 	var (
 		gas                 = new(big.Int)
 		newMemSize *big.Int = new(big.Int)

core/vm_env.go

@@ -49,7 +49,6 @@ type VMEnv struct {
 
 	header    *types.Header            // Header information
 	chain     *BlockChain              // Blockchain handle
-	logs      []vm.StructLog           // Logs for the custom structured logger
 	getHashFn func(uint64) common.Hash // getHashFn callback is used to retrieve block hashes
 }
 
@@ -63,11 +62,6 @@ func NewEnv(state *state.StateDB, chainConfig *ChainConfig, chain *BlockChain, m
 		getHashFn:   GetHashFn(header.ParentHash, chain),
 	}
 
-	// if no log collector is present set self as the collector
-	if cfg.Logger.Collector == nil {
-		cfg.Logger.Collector = env
-	}
-
 	env.evm = vm.New(env, cfg)
 	return env
 }
@@ -121,11 +115,3 @@ func (self *VMEnv) DelegateCall(me vm.ContractRef, addr common.Address, data []b
 func (self *VMEnv) Create(me vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
 	return Create(self, me, data, gas, price, value)
 }
-
-func (self *VMEnv) StructLogs() []vm.StructLog {
-	return self.logs
-}
-
-func (self *VMEnv) AddStructLog(log vm.StructLog) {
-	self.logs = append(self.logs, log)
-}

eth/api.go

@@ -319,7 +319,7 @@ 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.LogConfig) BlockTraceResult {
 	var block types.Block
 	err := rlp.Decode(bytes.NewReader(blockRlp), &block)
 	if err != nil {
@@ -336,7 +336,7 @@ func (api *PrivateDebugAPI) TraceBlock(blockRlp []byte, config *vm.Config) Block
 
 // 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.LogConfig) BlockTraceResult {
 	blockRlp, err := ioutil.ReadFile(file)
 	if err != nil {
 		return BlockTraceResult{Error: fmt.Sprintf("could not read file: %v", err)}
@@ -345,7 +345,7 @@ func (api *PrivateDebugAPI) TraceBlockFromFile(file string, config *vm.Config) B
 }
 
 // TraceBlockByNumber 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.LogConfig) BlockTraceResult {
 	// Fetch the block that we aim to reprocess
 	block := api.eth.BlockChain().GetBlockByNumber(number)
 	if block == nil {
@@ -361,7 +361,7 @@ 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.LogConfig) BlockTraceResult {
 	// Fetch the block that we aim to reprocess
 	block := api.eth.BlockChain().GetBlockByHash(hash)
 	if block == nil {
@@ -376,49 +376,38 @@ func (api *PrivateDebugAPI) TraceBlockByHash(hash common.Hash, config *vm.Config
 	}
 }
 
-// TraceCollector collects EVM structered logs.
-//
-// TraceCollector implements vm.Collector
-type TraceCollector struct {
-	traces []vm.StructLog
-}
-
-// AddStructLog adds a structered log.
-func (t *TraceCollector) AddStructLog(slog vm.StructLog) {
-	t.traces = append(t.traces, slog)
-}
-
 // 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, logConfig *vm.LogConfig) (bool, []vm.StructLog, error) {
 	// Validate and reprocess the block
 	var (
 		blockchain = api.eth.BlockChain()
 		validator  = blockchain.Validator()
 		processor  = blockchain.Processor()
-		collector  = &TraceCollector{}
 	)
-	if config == nil {
-		config = new(vm.Config)
+
+	structLogger := vm.NewStructLogger(logConfig)
+
+	config := vm.Config{
+		Debug:  true,
+		Tracer: structLogger,
 	}
-	config.Debug = true // make sure debug is set.
-	config.Logger.Collector = collector
 
 	if err := core.ValidateHeader(api.config, blockchain.AuxValidator(), block.Header(), blockchain.GetHeader(block.ParentHash(), block.NumberU64()-1), true, false); err != nil {
-		return false, collector.traces, err
+		return false, structLogger.StructLogs(), err
 	}
 	statedb, err := state.New(blockchain.GetBlock(block.ParentHash(), block.NumberU64()-1).Root(), api.eth.ChainDb())
 	if err != nil {
-		return false, collector.traces, err
+		return false, structLogger.StructLogs(), 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
+		return false, structLogger.StructLogs(), err
 	}
 	if err := validator.ValidateState(block, blockchain.GetBlock(block.ParentHash(), block.NumberU64()-1), statedb, receipts, usedGas); err != nil {
-		return false, collector.traces, err
+		return false, structLogger.StructLogs(), err
 	}
-	return true, collector.traces, nil
+	return true, structLogger.StructLogs(), nil
 }
 
 // callmsg is the message type used for call transations.
@@ -452,10 +441,9 @@ func formatError(err error) string {
 
 // TraceTransaction returns the structured logs created during the execution of EVM
 // and returns them as a JSON object.
-func (api *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogConfig) (*ethapi.ExecutionResult, error) {
-	if logger == nil {
-		logger = new(vm.LogConfig)
-	}
+func (api *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logConfig *vm.LogConfig) (*ethapi.ExecutionResult, error) {
+	logger := vm.NewStructLogger(logConfig)
+
 	// Retrieve the tx from the chain and the containing block
 	tx, blockHash, _, txIndex := core.GetTransaction(api.eth.ChainDb(), txHash)
 	if tx == nil {
@@ -500,7 +488,7 @@ func (api *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogC
 			continue
 		}
 		// Otherwise trace the transaction and return
-		vmenv := core.NewEnv(stateDb, api.config, api.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Logger: *logger})
+		vmenv := core.NewEnv(stateDb, api.config, api.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Tracer: 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)
@@ -508,7 +496,7 @@ func (api *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogC
 		return &ethapi.ExecutionResult{
 			Gas:         gas,
 			ReturnValue: fmt.Sprintf("%x", ret),
-			StructLogs:  ethapi.FormatLogs(vmenv.StructLogs()),
+			StructLogs:  ethapi.FormatLogs(logger.StructLogs()),
 		}, nil
 	}
 	return nil, errors.New("database inconsistency")

internal/ethapi/api.go

@@ -584,60 +584,6 @@ func FormatLogs(structLogs []vm.StructLog) []StructLogRes {
 	return formattedStructLogs
 }
 
-// TraceCall executes a call and returns the amount of gas, created logs and optionally returned values.
-func (s *PublicBlockChainAPI) TraceCall(ctx context.Context, args CallArgs, blockNr rpc.BlockNumber) (*ExecutionResult, error) {
-	state, header, err := s.b.StateAndHeaderByNumber(blockNr)
-	if state == nil || err != nil {
-		return nil, err
-	}
-
-	var addr common.Address
-	if args.From == (common.Address{}) {
-		accounts := s.b.AccountManager().Accounts()
-		if len(accounts) == 0 {
-			addr = common.Address{}
-		} else {
-			addr = accounts[0].Address
-		}
-	} else {
-		addr = args.From
-	}
-
-	// Assemble the CALL invocation
-	msg := callmsg{
-		addr:     addr,
-		to:       args.To,
-		gas:      args.Gas.BigInt(),
-		gasPrice: args.GasPrice.BigInt(),
-		value:    args.Value.BigInt(),
-		data:     common.FromHex(args.Data),
-	}
-
-	if msg.gas.Cmp(common.Big0) == 0 {
-		msg.gas = big.NewInt(50000000)
-	}
-
-	if msg.gasPrice.Cmp(common.Big0) == 0 {
-		msg.gasPrice = new(big.Int).Mul(big.NewInt(50), common.Shannon)
-	}
-
-	// Execute the call and return
-	vmenv, vmError, err := s.b.GetVMEnv(ctx, msg, state, header)
-	if err != nil {
-		return nil, err
-	}
-	gp := new(core.GasPool).AddGas(common.MaxBig)
-	ret, gas, err := core.ApplyMessage(vmenv, msg, gp)
-	if err := vmError(); err != nil {
-		return nil, err
-	}
-	return &ExecutionResult{
-		Gas:         gas,
-		ReturnValue: fmt.Sprintf("%x", ret),
-		StructLogs:  FormatLogs(vmenv.StructLogs()),
-	}, nil
-}
-
 // rpcOutputBlock converts the given block to the RPC output which depends on fullTx. If inclTx is true transactions are
 // returned. When fullTx is true the returned block contains full transaction details, otherwise it will only contain
 // transaction hashes.

tests/util.go

@@ -166,8 +166,6 @@ type Env struct {
 	difficulty *big.Int
 	gasLimit   *big.Int
 
-	logs []vm.StructLog
-
 	vmTest bool
 
 	evm *vm.EVM
@@ -181,14 +179,6 @@ func NewEnv(ruleSet RuleSet, state *state.StateDB) *Env {
 	return env
 }
 
-func (self *Env) StructLogs() []vm.StructLog {
-	return self.logs
-}
-
-func (self *Env) AddStructLog(log vm.StructLog) {
-	self.logs = append(self.logs, log)
-}
-
 func NewEnvFromMap(ruleSet RuleSet, state *state.StateDB, envValues map[string]string, exeValues map[string]string) *Env {
 	env := NewEnv(ruleSet, state)