core,eth: implement tx-level hooks for tracers

core/state_transition.go

@@ -287,15 +287,23 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 	if err := st.preCheck(); err != nil {
 		return nil, err
 	}
-	msg := st.msg
-	sender := vm.AccountRef(msg.From())
-	homestead := st.evm.ChainConfig().IsHomestead(st.evm.Context.BlockNumber)
-	istanbul := st.evm.ChainConfig().IsIstanbul(st.evm.Context.BlockNumber)
-	london := st.evm.ChainConfig().IsLondon(st.evm.Context.BlockNumber)
-	contractCreation := msg.To() == nil
+
+	if st.evm.Config.Debug {
+		st.evm.Config.Tracer.CaptureTxStart(st.initialGas)
+		defer func() {
+			st.evm.Config.Tracer.CaptureTxEnd(st.gas)
+		}()
+	}
+
+	var (
+		msg              = st.msg
+		sender           = vm.AccountRef(msg.From())
+		rules            = st.evm.ChainConfig().Rules(st.evm.Context.BlockNumber, st.evm.Context.Random != nil)
+		contractCreation = msg.To() == nil
+	)
 
 	// Check clauses 4-5, subtract intrinsic gas if everything is correct
-	gas, err := IntrinsicGas(st.data, st.msg.AccessList(), contractCreation, homestead, istanbul)
+	gas, err := IntrinsicGas(st.data, st.msg.AccessList(), contractCreation, rules.IsHomestead, rules.IsIstanbul)
 	if err != nil {
 		return nil, err
 	}
@@ -310,7 +318,7 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 	}
 
 	// Set up the initial access list.
-	if rules := st.evm.ChainConfig().Rules(st.evm.Context.BlockNumber, st.evm.Context.Random != nil); rules.IsBerlin {
+	if rules.IsBerlin {
 		st.state.PrepareAccessList(msg.From(), msg.To(), vm.ActivePrecompiles(rules), msg.AccessList())
 	}
 	var (
@@ -325,15 +333,15 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 		ret, st.gas, vmerr = st.evm.Call(sender, st.to(), st.data, st.gas, st.value)
 	}
 
-	if !london {
+	if !rules.IsLondon {
 		// Before EIP-3529: refunds were capped to gasUsed / 2
 		st.refundGas(params.RefundQuotient)
 	} else {
 		// After EIP-3529: refunds are capped to gasUsed / 5
 		st.refundGas(params.RefundQuotientEIP3529)
 	}
 	effectiveTip := st.gasPrice
-	if london {
+	if rules.IsLondon {
 		effectiveTip = cmath.BigMin(st.gasTipCap, new(big.Int).Sub(st.gasFeeCap, st.evm.Context.BaseFee))
 	}
 	st.state.AddBalance(st.evm.Context.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), effectiveTip))

core/vm/logger.go

@@ -29,10 +29,16 @@ import (
 // Note that reference types are actual VM data structures; make copies
 // if you need to retain them beyond the current call.
 type EVMLogger interface {
+	// Transaction level
+	CaptureTxStart(gasLimit uint64)
+	CaptureTxEnd(restGas uint64)
+	// Top call frame
 	CaptureStart(env *EVM, from common.Address, to common.Address, create bool, input []byte, gas uint64, value *big.Int)
-	CaptureState(pc uint64, op OpCode, gas, cost uint64, scope *ScopeContext, rData []byte, depth int, err error)
+	CaptureEnd(output []byte, gasUsed uint64, t time.Duration, err error)
+	// Rest of call frames
 	CaptureEnter(typ OpCode, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int)
 	CaptureExit(output []byte, gasUsed uint64, err error)
+	// Opcode level
+	CaptureState(pc uint64, op OpCode, gas, cost uint64, scope *ScopeContext, rData []byte, depth int, err error)
 	CaptureFault(pc uint64, op OpCode, gas, cost uint64, scope *ScopeContext, depth int, err error)
-	CaptureEnd(output []byte, gasUsed uint64, t time.Duration, err error)
 }

eth/tracers/js/tracer.go

@@ -30,7 +30,6 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	tracers2 "github.com/ethereum/go-ethereum/eth/tracers"
@@ -419,6 +418,7 @@ type jsTracer struct {
 	activePrecompiles []common.Address // Updated on CaptureStart based on given rules
 	traceSteps        bool             // When true, will invoke step() on each opcode
 	traceCallFrames   bool             // When true, will invoke enter() and exit() js funcs
+	gasLimit          uint64           // Amount of gas bought for the whole tx
 }
 
 // New instantiates a new tracer instance. code specifies a Javascript snippet,
@@ -679,7 +679,18 @@ func wrapError(context string, err error) error {
 	return fmt.Errorf("%v    in server-side tracer function '%v'", err, context)
 }
 
-// CaptureStart implements the Tracer interface to initialize the tracing operation.
+// CaptureTxStart implements the Tracer interface and is invoked at the beginning of
+// transaction processing.
+func (jst *jsTracer) CaptureTxStart(gasLimit uint64) {
+	jst.gasLimit = gasLimit
+}
+
+// CaptureTxStart implements the Tracer interface and is invoked at the end of
+// transaction processing.
+func (*jsTracer) CaptureTxEnd(restGas uint64) {}
+
+// CaptureStart implements the Tracer interface and is invoked before executing the
+// top-level call frame of a transaction.
 func (jst *jsTracer) CaptureStart(env *vm.EVM, from common.Address, to common.Address, create bool, input []byte, gas uint64, value *big.Int) {
 	jst.env = env
 	jst.ctx["type"] = "CALL"
@@ -700,14 +711,8 @@ func (jst *jsTracer) CaptureStart(env *vm.EVM, from common.Address, to common.Ad
 	rules := env.ChainConfig().Rules(env.Context.BlockNumber, env.Context.Random != nil)
 	jst.activePrecompiles = vm.ActivePrecompiles(rules)
 
-	// Compute intrinsic gas
-	isHomestead := env.ChainConfig().IsHomestead(env.Context.BlockNumber)
-	isIstanbul := env.ChainConfig().IsIstanbul(env.Context.BlockNumber)
-	intrinsicGas, err := core.IntrinsicGas(input, nil, jst.ctx["type"] == "CREATE", isHomestead, isIstanbul)
-	if err != nil {
-		return
-	}
-	jst.ctx["intrinsicGas"] = intrinsicGas
+	// Intrinsic costs are the only things reduced from initial gas to this point
+	jst.ctx["intrinsicGas"] = jst.gasLimit - gas
 }
 
 // CaptureState implements the Tracer interface to trace a single step of VM execution.
@@ -760,7 +765,7 @@ func (jst *jsTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64, sco
 	}
 }
 
-// CaptureEnd is called after the call finishes to finalize the tracing.
+// CaptureEnd is called after the top-level call finishes.
 func (jst *jsTracer) CaptureEnd(output []byte, gasUsed uint64, t time.Duration, err error) {
 	jst.ctx["output"] = output
 	jst.ctx["time"] = t.String()

eth/tracers/js/tracer_test.go

@@ -62,15 +62,19 @@ func testCtx() *vmContext {
 func runTrace(tracer tracers.Tracer, vmctx *vmContext, chaincfg *params.ChainConfig) (json.RawMessage, error) {
 	var (
 		env             = vm.NewEVM(vmctx.blockCtx, vmctx.txCtx, &dummyStatedb{}, chaincfg, vm.Config{Debug: true, Tracer: tracer})
+		gasLimit uint64 = 31000
 		startGas uint64 = 10000
 		value           = big.NewInt(0)
 		contract        = vm.NewContract(account{}, account{}, value, startGas)
 	)
 	contract.Code = []byte{byte(vm.PUSH1), 0x1, byte(vm.PUSH1), 0x1, 0x0}
 
+	tracer.CaptureTxStart(gasLimit)
 	tracer.CaptureStart(env, contract.Caller(), contract.Address(), false, []byte{}, startGas, value)
 	ret, err := env.Interpreter().Run(contract, []byte{}, false)
 	tracer.CaptureEnd(ret, startGas-contract.Gas, 1, err)
+	// Rest gas assumes no refund
+	tracer.CaptureTxEnd(startGas - contract.Gas)
 	if err != nil {
 		return nil, err
 	}

eth/tracers/logger/access_list_tracer.go

@@ -174,6 +174,10 @@ func (*AccessListTracer) CaptureEnter(typ vm.OpCode, from common.Address, to com
 
 func (*AccessListTracer) CaptureExit(output []byte, gasUsed uint64, err error) {}
 
+func (*AccessListTracer) CaptureTxStart(gasLimit uint64) {}
+
+func (*AccessListTracer) CaptureTxEnd(restGas uint64) {}
+
 // AccessList returns the current accesslist maintained by the tracer.
 func (a *AccessListTracer) AccessList() types.AccessList {
 	return a.list.accessList()

eth/tracers/logger/logger.go

@@ -223,6 +223,10 @@ func (l *StructLogger) CaptureEnter(typ vm.OpCode, from common.Address, to commo
 
 func (l *StructLogger) CaptureExit(output []byte, gasUsed uint64, err error) {}
 
+func (*StructLogger) CaptureTxStart(gasLimit uint64) {}
+
+func (*StructLogger) CaptureTxEnd(restGas uint64) {}
+
 // StructLogs returns the captured log entries.
 func (l *StructLogger) StructLogs() []StructLog { return l.logs }
 
@@ -347,3 +351,7 @@ func (t *mdLogger) CaptureEnter(typ vm.OpCode, from common.Address, to common.Ad
 }
 
 func (t *mdLogger) CaptureExit(output []byte, gasUsed uint64, err error) {}
+
+func (*mdLogger) CaptureTxStart(gasLimit uint64) {}
+
+func (*mdLogger) CaptureTxEnd(restGas uint64) {}

eth/tracers/logger/logger_json.go

@@ -98,3 +98,7 @@ func (l *JSONLogger) CaptureEnter(typ vm.OpCode, from common.Address, to common.
 }
 
 func (l *JSONLogger) CaptureExit(output []byte, gasUsed uint64, err error) {}
+
+func (l *JSONLogger) CaptureTxStart(gasLimit uint64) {}
+
+func (l *JSONLogger) CaptureTxEnd(restGas uint64) {}

eth/tracers/native/4byte.go

@@ -131,6 +131,10 @@ func (t *fourByteTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64,
 func (t *fourByteTracer) CaptureEnd(output []byte, gasUsed uint64, _ time.Duration, err error) {
 }
 
+func (*fourByteTracer) CaptureTxStart(gasLimit uint64) {}
+
+func (*fourByteTracer) CaptureTxEnd(restGas uint64) {}
+
 // GetResult returns the json-encoded nested list of call traces, and any
 // error arising from the encoding or forceful termination (via `Stop`).
 func (t *fourByteTracer) GetResult() (json.RawMessage, error) {

eth/tracers/native/call.go

@@ -142,6 +142,10 @@ func (t *callTracer) CaptureExit(output []byte, gasUsed uint64, err error) {
 	t.callstack[size-1].Calls = append(t.callstack[size-1].Calls, call)
 }
 
+func (*callTracer) CaptureTxStart(gasLimit uint64) {}
+
+func (*callTracer) CaptureTxEnd(restGas uint64) {}
+
 // GetResult returns the json-encoded nested list of call traces, and any
 // error arising from the encoding or forceful termination (via `Stop`).
 func (t *callTracer) GetResult() (json.RawMessage, error) {

eth/tracers/native/noop.go

@@ -64,6 +64,10 @@ func (t *noopTracer) CaptureEnter(typ vm.OpCode, from common.Address, to common.
 func (t *noopTracer) CaptureExit(output []byte, gasUsed uint64, err error) {
 }
 
+func (*noopTracer) CaptureTxStart(gasLimit uint64) {}
+
+func (*noopTracer) CaptureTxEnd(restGas uint64) {}
+
 // GetResult returns an empty json object.
 func (t *noopTracer) GetResult() (json.RawMessage, error) {
 	return json.RawMessage(`{}`), nil

eth/tracers/native/prestate.go

@@ -24,7 +24,6 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth/tracers"
@@ -47,6 +46,7 @@ type prestateTracer struct {
 	prestate  prestate
 	create    bool
 	to        common.Address
+	gasLimit  uint64 // Amount of gas bought for the whole tx
 	interrupt uint32 // Atomic flag to signal execution interruption
 	reason    error  // Textual reason for the interruption
 }
@@ -63,14 +63,6 @@ func (t *prestateTracer) CaptureStart(env *vm.EVM, from common.Address, to commo
 	t.create = create
 	t.to = to
 
-	// Compute intrinsic gas
-	isHomestead := env.ChainConfig().IsHomestead(env.Context.BlockNumber)
-	isIstanbul := env.ChainConfig().IsIstanbul(env.Context.BlockNumber)
-	intrinsicGas, err := core.IntrinsicGas(input, nil, create, isHomestead, isIstanbul)
-	if err != nil {
-		return
-	}
-
 	t.lookupAccount(from)
 	t.lookupAccount(to)
 
@@ -82,6 +74,7 @@ func (t *prestateTracer) CaptureStart(env *vm.EVM, from common.Address, to commo
 	// The sender balance is after reducing: value, gasLimit, intrinsicGas.
 	// We need to re-add them to get the pre-tx balance.
 	fromBal := hexutil.MustDecodeBig(t.prestate[from].Balance)
+	intrinsicGas := t.gasLimit - gas
 	gasPrice := env.TxContext.GasPrice
 	consumedGas := new(big.Int).Mul(
 		gasPrice,
@@ -145,6 +138,12 @@ func (t *prestateTracer) CaptureEnter(typ vm.OpCode, from common.Address, to com
 func (t *prestateTracer) CaptureExit(output []byte, gasUsed uint64, err error) {
 }
 
+func (t *prestateTracer) CaptureTxStart(gasLimit uint64) {
+	t.gasLimit = gasLimit
+}
+
+func (t *prestateTracer) CaptureTxEnd(restGas uint64) {}
+
 // GetResult returns the json-encoded nested list of call traces, and any
 // error arising from the encoding or forceful termination (via `Stop`).
 func (t *prestateTracer) GetResult() (json.RawMessage, error) {