Merge pull request #105 from OffchainLabs/js-capture-arbitrum-transfers

Native and Js tracing impls for `CaptureArbitrumTransfer`

core/state/statedb.go

@@ -800,6 +800,20 @@ func (s *StateDB) GetUnexpectedBalanceDelta() *big.Int {
 	return new(big.Int).Set(s.unexpectedBalanceDelta)
 }
 
+func (s *StateDB) GetSuicides() []common.Address {
+	suicides := []common.Address{}
+	for addr := range s.journal.dirties {
+		obj, exist := s.stateObjects[addr]
+		if !exist {
+			continue
+		}
+		if obj.suicided {
+			suicides = append(suicides, addr)
+		}
+	}
+	return suicides
+}
+
 // Finalise finalises the state by removing the s destructed objects and clears
 // the journal as well as the refunds. Finalise, however, will not push any updates
 // into the tries just yet. Only IntermediateRoot or Commit will do that.

core/state_transition.go

@@ -216,6 +216,13 @@ func (st *StateTransition) buyGas() error {
 
 	st.initialGas = st.msg.Gas()
 	st.state.SubBalance(st.msg.From(), mgval)
+
+	// Arbitrum: record fee payment
+	if st.evm.Config.Debug {
+		from := st.msg.From()
+		st.evm.Config.Tracer.CaptureArbitrumTransfer(st.evm, &from, nil, mgval, true, "feePayment")
+	}
+
 	return nil
 }
 
@@ -366,8 +373,21 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 	}
 	st.state.AddBalance(st.evm.Context.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), effectiveTip))
 
+	// Arbitrum: record the tip if nonzero (this should never happen in L2)
+	if st.evm.Config.Debug && effectiveTip.Sign() != 0 {
+		st.evm.Config.Tracer.CaptureArbitrumTransfer(st.evm, nil, tipRecipient, effectiveTip, false, "tip")
+	}
+
 	st.evm.ProcessingHook.EndTxHook(st.gas, vmerr == nil)
 
+	// Arbitrum: record self destructs
+	if st.evm.Config.Debug {
+		for _, address := range st.evm.StateDB.GetSuicides() {
+			balance := st.evm.StateDB.GetBalance(address)
+			st.evm.Config.Tracer.CaptureArbitrumTransfer(st.evm, &address, nil, balance, false, "selfDestruct")
+		}
+	}
+
 	return &ExecutionResult{
 		UsedGas:       st.gasUsed(),
 		Err:           vmerr,
@@ -394,6 +414,12 @@ func (st *StateTransition) refundGas(refundQuotient uint64) {
 	remaining := new(big.Int).Mul(new(big.Int).SetUint64(st.gas), st.gasPrice)
 	st.state.AddBalance(st.msg.From(), remaining)
 
+	// Arbitrum: record the gas refund
+	if st.evm.Config.Debug {
+		from := st.msg.From()
+		st.evm.Config.Tracer.CaptureArbitrumTransfer(st.evm, nil, &from, remaining, false, "gasRefund")
+	}
+
 	// Also return remaining gas to the block gas counter so it is
 	// available for the next transaction.
 	st.gp.AddGas(st.gas)

core/vm/evm_arbitrum.go

@@ -31,7 +31,7 @@ func (evm *EVM) IncrementDepth() {
 }
 
 func (evm *EVM) DecrementDepth() {
-	evm.depth += 1
+	evm.depth -= 1
 }
 
 type TxProcessingHook interface {

core/vm/interface.go

@@ -50,6 +50,7 @@ type StateDB interface {
 
 	Suicide(common.Address) bool
 	HasSuicided(common.Address) bool
+	GetSuicides() []common.Address
 
 	// Exist reports whether the given account exists in state.
 	// Notably this should also return true for suicided accounts.

core/vm/logger.go

@@ -37,7 +37,7 @@ type EVMLogger interface {
 	CaptureEnd(output []byte, gasUsed uint64, t time.Duration, err error)
 
 	// Arbitrum: capture a transfer, mint, or burn that happens outside of EVM exectuion
-	CaptureArbitrumTransfer(env *EVM, from, to *common.Address, amount *big.Int, before bool)
+	CaptureArbitrumTransfer(env *EVM, from, to *common.Address, value *big.Int, before bool, purpose string)
 	CaptureArbitrumStorageGet(key common.Hash, depth int, before bool)
 	CaptureArbitrumStorageSet(key, value common.Hash, depth int, before bool)
 }

eth/tracers/js/tracer.go

@@ -868,6 +868,8 @@ func (jst *jsTracer) addToObj(obj int, key string, val interface{}) {
 
 func pushValue(ctx *duktape.Context, val interface{}) {
 	switch val := val.(type) {
+	case bool:
+		ctx.PushBoolean(val)
 	case uint64:
 		ctx.PushUint(uint(val))
 	case string:

eth/tracers/js/tracer_arbitrum.go

@@ -1,4 +1,4 @@
-// Copyright 2017 The go-ethereum Authors
+// Copyright 2022 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
 // The go-ethereum library is free software: you can redistribute it and/or modify
@@ -23,8 +23,42 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 )
 
-func (*jsTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+func (jst *jsTracer) CaptureArbitrumTransfer(
+	env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string,
+) {
+	traceTransfers := jst.vm.GetPropString(jst.tracerObject, "captureArbitrumTransfer")
+	jst.vm.Pop()
+	if !traceTransfers {
+		return
+	}
+
+	obj := jst.vm.PushObject()
+	if from != nil {
+		jst.addToObj(obj, "from", from.String())
+	} else {
+		jst.addNull(obj, "from")
+	}
+	if to != nil {
+		jst.addToObj(obj, "to", to.String())
+	} else {
+		jst.addNull(obj, "to")
+	}
+
+	jst.addToObj(obj, "value", value)
+	jst.addToObj(obj, "before", before)
+	jst.addToObj(obj, "purpose", purpose)
+	jst.vm.PutPropString(jst.stateObject, "transfer")
+
+	if _, err := jst.call(true, "captureArbitrumTransfer", "transfer"); err != nil {
+		jst.err = wrapError("captureArbitrumTransfer", err)
+	}
 }
 
 func (*jsTracer) CaptureArbitrumStorageGet(key common.Hash, depth int, before bool)        {}
 func (*jsTracer) CaptureArbitrumStorageSet(key, value common.Hash, depth int, before bool) {}
+
+// addNull pushes a null field to a JS object.
+func (jst *jsTracer) addNull(obj int, key string) {
+	jst.vm.PushNull()
+	jst.vm.PutPropString(obj, key)
+}

eth/tracers/logger/logger_arbitrum.go

@@ -23,11 +23,11 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 )
 
-func (*AccessListTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+func (*AccessListTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string) {
 }
-func (*JSONLogger) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+func (*JSONLogger) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string) {
 }
-func (*StructLogger) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+func (*StructLogger) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string) {
 }
 
 func (*AccessListTracer) CaptureArbitrumStorageGet(key common.Hash, depth int, before bool) {}

eth/tracers/native/call.go

@@ -35,6 +35,10 @@ func init() {
 }
 
 type callFrame struct {
+	// Arbitrum: we add these here due to the tracer returning the top frame
+	BeforeEVMTransfers *[]arbitrumTransfer `json:"beforeEVMTransfers,omitempty"`
+	AfterEVMTransfers  *[]arbitrumTransfer `json:"afterEVMTransfers,omitempty"`
+
 	Type    string      `json:"type"`
 	From    string      `json:"from"`
 	To      string      `json:"to,omitempty"`
@@ -48,6 +52,10 @@ type callFrame struct {
 }
 
 type callTracer struct {
+	// Arbitrum: capture transfers occuring outside of evm execution
+	beforeEVMTransfers []arbitrumTransfer
+	afterEVMTransfers  []arbitrumTransfer
+
 	env       *vm.EVM
 	callstack []callFrame
 	interrupt uint32 // Atomic flag to signal execution interruption
@@ -59,7 +67,11 @@ type callTracer struct {
 func newCallTracer() tracers.Tracer {
 	// First callframe contains tx context info
 	// and is populated on start and end.
-	return &callTracer{callstack: make([]callFrame, 1)}
+	return &callTracer{
+		callstack:          make([]callFrame, 1),
+		beforeEVMTransfers: []arbitrumTransfer{},
+		afterEVMTransfers:  []arbitrumTransfer{},
+	}
 }
 
 // CaptureStart implements the EVMLogger interface to initialize the tracing operation.
@@ -148,7 +160,13 @@ func (t *callTracer) GetResult() (json.RawMessage, error) {
 	if len(t.callstack) != 1 {
 		return nil, errors.New("incorrect number of top-level calls")
 	}
-	res, err := json.Marshal(t.callstack[0])
+
+	// Arbitrum: populate the top-level call with additional info
+	call := t.callstack[0]
+	call.BeforeEVMTransfers = &t.beforeEVMTransfers
+	call.AfterEVMTransfers = &t.afterEVMTransfers
+
+	res, err := json.Marshal(call)
 	if err != nil {
 		return nil, err
 	}

eth/tracers/native/tracer_arbitrum.go

@@ -23,13 +23,40 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 )
 
-func (*callTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+type arbitrumTransfer struct {
+	Purpose string  `json:"purpose"`
+	From    *string `json:"from"`
+	To      *string `json:"to"`
+	Value   string  `json:"value"`
 }
-func (*fourByteTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+
+func (t *callTracer) CaptureArbitrumTransfer(
+	env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string,
+) {
+	transfer := arbitrumTransfer{
+		Purpose: purpose,
+		Value:   bigToHex(value),
+	}
+	if from != nil {
+		from := from.String()
+		transfer.From = &from
+	}
+	if to != nil {
+		to := to.String()
+		transfer.To = &to
+	}
+	if before {
+		t.beforeEVMTransfers = append(t.beforeEVMTransfers, transfer)
+	} else {
+		t.afterEVMTransfers = append(t.afterEVMTransfers, transfer)
+	}
+}
+
+func (*fourByteTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string) {
 }
-func (*noopTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+func (*noopTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string) {
 }
-func (*prestateTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, amount *big.Int, before bool) {
+func (*prestateTracer) CaptureArbitrumTransfer(env *vm.EVM, from, to *common.Address, value *big.Int, before bool, purpose string) {
 }
 
 func (*callTracer) CaptureArbitrumStorageGet(key common.Hash, depth int, before bool)     {}