eth/tracers: add withLog to callTracer (#25991)

In some cases, it is desirable to capture what is triggered by each trace, when using the `callTracer`. For example: call `USDT.transfer` will trigger a `Transfer(from, to, value)` event.

This PR adds the option to capture logs to the call tracer, by specifying `{"withLog": true}` in the tracerconfig. 
Any logs belonging to failed/reverted call-scopes are removed from the output, to prevent interpretation mistakes.

Signed-off-by: Delweng <delweng@gmail.com>
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>

eth/tracers/internal/tracetest/calltrace_test.go

@@ -46,6 +46,13 @@ type callContext struct {
 	Miner      common.Address        `json:"miner"`
 }
 
+// callLog is the result of LOG opCode
+type callLog struct {
+	Address common.Address `json:"address"`
+	Topics  []common.Hash  `json:"topics"`
+	Data    hexutil.Bytes  `json:"data"`
+}
+
 // callTrace is the result of a callTracer run.
 type callTrace struct {
 	From     common.Address  `json:"from"`
@@ -57,6 +64,7 @@ type callTrace struct {
 	Error    string          `json:"error,omitempty"`
 	Revertal string          `json:"revertReason,omitempty"`
 	Calls    []callTrace     `json:"calls,omitempty"`
+	Logs     []callLog       `json:"logs,omitempty"`
 	Value    *hexutil.Big    `json:"value,omitempty"`
 	// Gencodec adds overridden fields at the end
 	Type string `json:"type"`
@@ -81,6 +89,10 @@ func TestCallTracerNative(t *testing.T) {
 	testCallTracer("callTracer", "call_tracer", t)
 }
 
+func TestCallTracerNativeWithLog(t *testing.T) {
+	testCallTracer("callTracer", "call_tracer_withLog", t)
+}
+
 func testCallTracer(tracerName string, dirPath string, t *testing.T) {
 	isLegacy := strings.HasSuffix(dirPath, "_legacy")
 	files, err := os.ReadDir(filepath.Join("testdata", dirPath))

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/simple.json

@@ -0,0 +1,84 @@
+{
+  "genesis": {
+    "difficulty": "8430028481555",
+    "extraData": "0xd783010302844765746887676f312e352e31856c696e7578",
+    "gasLimit": "3141592",
+    "hash": "0xde66937783697293f2e529d2034887c531535d78afa8c9051511ae12ba48fbea",
+    "miner": "0x2a65aca4d5fc5b5c859090a6c34d164135398226",
+    "mixHash": "0xba28a43bfbca4a2effbb76bb70d03482a8a0c92e2883ff36cbac3d7c6dbb7df5",
+    "nonce": "0xa3827ec0a82fe823",
+    "number": "765824",
+    "stateRoot": "0x8d96cb027a29f8ca0ccd6d31f9ea0656136ec8030ecda70bb9231849ed6f41a2",
+    "timestamp": "1451389443",
+    "totalDifficulty": "4838314986494741271",
+    "alloc": {
+      "0xd1220a0cf47c7b9be7a2e6ba89f429762e7b9adb": {
+        "balance": "0x14203bee2ea6fbe8c",
+        "nonce": "34"
+      },
+      "0xe2fe6b13287f28e193333fdfe7fedf2f6df6124a": {
+        "balance": "0x2717a9c870a286f4350"
+      },
+      "0xf4eced2f682ce333f96f2d8966c613ded8fc95dd": {
+        "balance": "0x0",
+        "code": "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",
+        "storage": {
+          "0x1dae8253445d3a5edbe8200da9fc39bc4f11db9362181dc1b640d08c3c2fb4d6": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "0x8ba52aac7f255d80a49abcf003d6af4752aba5a9531cae94fde7ac8d72191d67": "0x000000000000000000000000000000000000000000000000000000000178e460"
+        }
+      }
+    },
+    "config": {
+      "chainId": 1,
+      "homesteadBlock": 1150000,
+      "daoForkBlock": 1920000,
+      "daoForkSupport": true,
+      "eip150Block": 2463000,
+      "eip150Hash": "0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0",
+      "eip155Block": 2675000,
+      "eip158Block": 2675000,
+      "byzantiumBlock": 4370000,
+      "constantinopleBlock": 7280000,
+      "petersburgBlock": 7280000,
+      "istanbulBlock": 9069000,
+      "muirGlacierBlock": 9200000,
+      "berlinBlock": 12244000,
+      "londonBlock": 12965000,
+      "arrowGlacierBlock": 13773000,
+      "grayGlacierBlock": 15050000,
+      "terminalTotalDifficultyPassed": true,
+      "ethash": {}
+    }
+  },
+  "context": {
+    "number": "765825",
+    "difficulty": "8425912256743",
+    "timestamp": "1451389488",
+    "gasLimit": "3141592",
+    "miner": "0xe2fe6b13287f28e193333fdfe7fedf2f6df6124a"
+  },
+  "input": "0xf8aa22850ba43b740083024d4594f4eced2f682ce333f96f2d8966c613ded8fc95dd80b844a9059cbb000000000000000000000000dbf03b407c01e7cd3cbea99509d93f8dddc8c6fb00000000000000000000000000000000000000000000000000000000009896801ca067da548a2e0f381a957b9b51f086073375d6bfc7312cbc9540b3647ccab7db11a042c6e5b34bc7ba821e9c25b166fa13d82ad4b0d044d16174d5587d4f04ecfcd1",
+  "tracerConfig": {
+    "withLog": true
+  },
+  "result": {
+    "from": "0xd1220a0cf47c7b9be7a2e6ba89f429762e7b9adb",
+    "gas": "0x1f36d",
+    "gasUsed": "0xc6a5",
+    "to": "0xf4eced2f682ce333f96f2d8966c613ded8fc95dd",
+    "input": "0xa9059cbb000000000000000000000000dbf03b407c01e7cd3cbea99509d93f8dddc8c6fb0000000000000000000000000000000000000000000000000000000000989680",
+    "logs": [
+      {
+        "address": "0xf4eced2f682ce333f96f2d8966c613ded8fc95dd",
+        "topics": [
+          "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
+          "0x000000000000000000000000d1220a0cf47c7b9be7a2e6ba89f429762e7b9adb",
+          "0x000000000000000000000000dbf03b407c01e7cd3cbea99509d93f8dddc8c6fb"
+        ],
+        "data": "0x0000000000000000000000000000000000000000000000000000000000989680"
+      }
+    ],
+    "value": "0x0",
+    "type": "CALL"
+  }
+}

eth/tracers/native/call.go

@@ -36,6 +36,12 @@ func init() {
 	register("callTracer", newCallTracer)
 }
 
+type callLog struct {
+	Address common.Address `json:"address"`
+	Topics  []common.Hash  `json:"topics"`
+	Data    hexutil.Bytes  `json:"data"`
+}
+
 type callFrame struct {
 	Type     vm.OpCode      `json:"-"`
 	From     common.Address `json:"from"`
@@ -47,6 +53,7 @@ type callFrame struct {
 	Error    string         `json:"error,omitempty" rlp:"optional"`
 	Revertal string         `json:"revertReason,omitempty"`
 	Calls    []callFrame    `json:"calls,omitempty" rlp:"optional"`
+	Logs     []callLog      `json:"logs,omitempty" rlp:"optional"`
 	// Placed at end on purpose. The RLP will be decoded to 0 instead of
 	// nil if there are non-empty elements after in the struct.
 	Value *big.Int `json:"value,omitempty" rlp:"optional"`
@@ -56,6 +63,10 @@ func (f callFrame) TypeString() string {
 	return f.Type.String()
 }
 
+func (f callFrame) failed() bool {
+	return len(f.Error) > 0
+}
+
 func (f *callFrame) capture(output []byte, err error) {
 	output = common.CopyBytes(output)
 	if err == nil {
@@ -98,6 +109,7 @@ type callTracer struct {
 
 type callTracerConfig struct {
 	OnlyTopCall bool `json:"onlyTopCall"` // If true, call tracer won't collect any subcalls
+	WithLog     bool `json:"withLog"`     // If true, call tracer will collect event logs
 }
 
 // newCallTracer returns a native go tracer which tracks
@@ -137,10 +149,38 @@ func (t *callTracer) CaptureEnd(output []byte, gasUsed uint64, _ time.Duration,
 
 // CaptureState implements the EVMLogger interface to trace a single step of VM execution.
 func (t *callTracer) CaptureState(pc uint64, op vm.OpCode, gas, cost uint64, scope *vm.ScopeContext, rData []byte, depth int, err error) {
+	// Only logs need to be captured via opcode processing
+	if !t.config.WithLog {
+		return
+	}
+	// Avoid processing nested calls when only caring about top call
+	if t.config.OnlyTopCall && depth > 0 {
+		return
+	}
+	switch op {
+	case vm.LOG0, vm.LOG1, vm.LOG2, vm.LOG3, vm.LOG4:
+		size := int(op - vm.LOG0)
+
+		stack := scope.Stack
+		stackData := stack.Data()
+
+		// Don't modify the stack
+		mStart := stackData[len(stackData)-1]
+		mSize := stackData[len(stackData)-2]
+		topics := make([]common.Hash, size)
+		for i := 0; i < size; i++ {
+			topic := stackData[len(stackData)-2-(i+1)]
+			topics[i] = common.Hash(topic.Bytes32())
+		}
+
+		data := scope.Memory.GetCopy(int64(mStart.Uint64()), int64(mSize.Uint64()))
+		log := callLog{Address: scope.Contract.Address(), Topics: topics, Data: hexutil.Bytes(data)}
+		t.callstack[len(t.callstack)-1].Logs = append(t.callstack[len(t.callstack)-1].Logs, log)
+	}
 }
 
 // CaptureFault implements the EVMLogger interface to trace an execution fault.
-func (t *callTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64, _ *vm.ScopeContext, depth int, err error) {
+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).
@@ -191,6 +231,10 @@ func (t *callTracer) CaptureTxStart(gasLimit uint64) {
 
 func (t *callTracer) CaptureTxEnd(restGas uint64) {
 	t.callstack[0].GasUsed = t.gasLimit - restGas
+	if t.config.WithLog {
+		// Logs are not emitted when the call fails
+		clearFailedLogs(&t.callstack[0], false)
+	}
 }
 
 // GetResult returns the json-encoded nested list of call traces, and any
@@ -211,3 +255,16 @@ func (t *callTracer) Stop(err error) {
 	t.reason = err
 	atomic.StoreUint32(&t.interrupt, 1)
 }
+
+// clearFailedLogs clears the logs of a callframe and all its children
+// in case of execution failure.
+func clearFailedLogs(cf *callFrame, parentFailed bool) {
+	failed := cf.failed() || parentFailed
+	// Clear own logs
+	if failed {
+		cf.Logs = nil
+	}
+	for i := range cf.Calls {
+		clearFailedLogs(&cf.Calls[i], failed)
+	}
+}

eth/tracers/native/gen_callframe_json.go

@@ -26,6 +26,7 @@ func (c callFrame) MarshalJSON() ([]byte, error) {
 		Error      string         `json:"error,omitempty" rlp:"optional"`
 		Revertal   string         `json:"revertReason,omitempty"`
 		Calls      []callFrame    `json:"calls,omitempty" rlp:"optional"`
+		Logs       []callLog      `json:"logs,omitempty" rlp:"optional"`
 		Value      *hexutil.Big   `json:"value,omitempty" rlp:"optional"`
 		TypeString string         `json:"type"`
 	}
@@ -40,6 +41,7 @@ func (c callFrame) MarshalJSON() ([]byte, error) {
 	enc.Error = c.Error
 	enc.Revertal = c.Revertal
 	enc.Calls = c.Calls
+	enc.Logs = c.Logs
 	enc.Value = (*hexutil.Big)(c.Value)
 	enc.TypeString = c.TypeString()
 	return json.Marshal(&enc)
@@ -58,6 +60,7 @@ func (c *callFrame) UnmarshalJSON(input []byte) error {
 		Error    *string         `json:"error,omitempty" rlp:"optional"`
 		Revertal *string         `json:"revertReason,omitempty"`
 		Calls    []callFrame     `json:"calls,omitempty" rlp:"optional"`
+		Logs     []callLog       `json:"logs,omitempty" rlp:"optional"`
 		Value    *hexutil.Big    `json:"value,omitempty" rlp:"optional"`
 	}
 	var dec callFrame0
@@ -94,6 +97,9 @@ func (c *callFrame) UnmarshalJSON(input []byte) error {
 	if dec.Calls != nil {
 		c.Calls = dec.Calls
 	}
+	if dec.Logs != nil {
+		c.Logs = dec.Logs
+	}
 	if dec.Value != nil {
 		c.Value = (*big.Int)(dec.Value)
 	}