From 64067fbdc46237df3b862db3ac7ae4c9158618d5 Mon Sep 17 00:00:00 2001
From: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>
Date: Thu, 17 Nov 2022 09:27:48 +0100
Subject: [PATCH] eth/tracers: small refactor for native tracers (#26196)

Use noopTracer as a base for other native tracers to avoid extra boilerplate for unimplemented hooks.
---
 eth/tracers/native/4byte.go    | 23 +----------------------
 eth/tracers/native/call.go     |  5 +----
 eth/tracers/native/prestate.go | 14 +-------------
 3 files changed, 3 insertions(+), 39 deletions(-)

diff --git a/eth/tracers/native/4byte.go b/eth/tracers/native/4byte.go
index d9b52b184..00cd5fe77 100644
--- a/eth/tracers/native/4byte.go
+++ b/eth/tracers/native/4byte.go
@@ -21,7 +21,6 @@ import (
 	"math/big"
 	"strconv"
 	"sync/atomic"
-	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -47,6 +46,7 @@ func init() {
 //	  0xc281d19e-0: 1
 //	}
 type fourByteTracer struct {
+	noopTracer
 	ids               map[string]int   // ids aggregates the 4byte ids found
 	interrupt         uint32           // Atomic flag to signal execution interruption
 	reason            error            // Textual reason for the interruption
@@ -90,10 +90,6 @@ func (t *fourByteTracer) CaptureStart(env *vm.EVM, from common.Address, to commo
 	}
 }
 
-// CaptureState implements the EVMLogger interface to trace a single step of VM execution.
-func (t *fourByteTracer) CaptureState(pc uint64, op vm.OpCode, gas, cost uint64, scope *vm.ScopeContext, rData []byte, depth int, err error) {
-}
-
 // CaptureEnter is called when EVM enters a new scope (via call, create or selfdestruct).
 func (t *fourByteTracer) CaptureEnter(op vm.OpCode, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
 	// Skip if tracing was interrupted
@@ -115,23 +111,6 @@ func (t *fourByteTracer) CaptureEnter(op vm.OpCode, from common.Address, to comm
 	t.store(input[0:4], len(input)-4)
 }
 
-// CaptureExit is called when EVM exits a scope, even if the scope didn't
-// execute any code.
-func (t *fourByteTracer) CaptureExit(output []byte, gasUsed uint64, err error) {
-}
-
-// CaptureFault implements the EVMLogger interface to trace an execution fault.
-func (t *fourByteTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64, scope *vm.ScopeContext, depth int, err error) {
-}
-
-// CaptureEnd is called after the call finishes to finalize the tracing.
-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) {
diff --git a/eth/tracers/native/call.go b/eth/tracers/native/call.go
index 2d19c6fdb..4be242c8b 100644
--- a/eth/tracers/native/call.go
+++ b/eth/tracers/native/call.go
@@ -99,6 +99,7 @@ type callFrameMarshaling struct {
 }
 
 type callTracer struct {
+	noopTracer
 	callstack []callFrame
 	config    callTracerConfig
 	gasLimit  uint64
@@ -181,10 +182,6 @@ func (t *callTracer) CaptureState(pc uint64, op vm.OpCode, gas, cost uint64, sco
 	}
 }
 
-// CaptureFault implements the EVMLogger interface to trace an execution fault.
-func (t *callTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64, scope *vm.ScopeContext, depth int, err error) {
-}
-
 // CaptureEnter is called when EVM enters a new scope (via call, create or selfdestruct).
 func (t *callTracer) CaptureEnter(typ vm.OpCode, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
 	if t.config.OnlyTopCall {
diff --git a/eth/tracers/native/prestate.go b/eth/tracers/native/prestate.go
index 9562bb01c..b965c50df 100644
--- a/eth/tracers/native/prestate.go
+++ b/eth/tracers/native/prestate.go
@@ -55,6 +55,7 @@ type accountMarshaling struct {
 }
 
 type prestateTracer struct {
+	noopTracer
 	env       *vm.EVM
 	pre       state
 	post      state
@@ -167,19 +168,6 @@ func (t *prestateTracer) CaptureState(pc uint64, op vm.OpCode, gas, cost uint64,
 	}
 }
 
-// CaptureFault implements the EVMLogger interface to trace an execution fault.
-func (t *prestateTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64, _ *vm.ScopeContext, depth int, err error) {
-}
-
-// CaptureEnter is called when EVM enters a new scope (via call, create or selfdestruct).
-func (t *prestateTracer) CaptureEnter(typ vm.OpCode, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
-}
-
-// CaptureExit is called when EVM exits a scope, even if the scope didn't
-// execute any code.
-func (t *prestateTracer) CaptureExit(output []byte, gasUsed uint64, err error) {
-}
-
 func (t *prestateTracer) CaptureTxStart(gasLimit uint64) {
 	t.gasLimit = gasLimit
 }