cmd/evm: add --opcode.count flag to t8n (#33800)

Adds `--opcode.count=<file>` flag to `evm t8n` that writes per-opcode
execution frequency counts to a JSON file (relative to
`--output.basedir`).

---------

Co-authored-by: MariusVanDerWijden <m.vanderwijden@live.de>
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>

cmd/evm/internal/t8ntool/execution.go

@@ -265,6 +265,9 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 			gaspool.SetGas(prevGas)
 			continue
 		}
+		if receipt.Logs == nil {
+			receipt.Logs = []*types.Log{}
+		}
 		includedTxs = append(includedTxs, tx)
 		if hashError != nil {
 			return nil, nil, nil, NewError(ErrorMissingBlockhash, hashError)

cmd/evm/internal/t8ntool/file_tracer.go

@@ -56,27 +56,35 @@ func (l *fileWritingTracer) Write(p []byte) (n int, err error) {
 	return n, nil
 }
 
-// newFileWriter creates a set of hooks which wraps inner hooks (typically a logger),
+// newFileWriter creates a tracer which wraps inner hooks (typically a logger),
 // and writes the output to a file, one file per transaction.
-func newFileWriter(baseDir string, innerFn func(out io.Writer) *tracing.Hooks) *tracing.Hooks {
+func newFileWriter(baseDir string, innerFn func(out io.Writer) *tracing.Hooks) *tracers.Tracer {
 	t := &fileWritingTracer{
 		baseDir: baseDir,
 		suffix:  "jsonl",
 	}
 	t.inner = innerFn(t) // instantiate the inner tracer
-	return t.hooks()
+	return &tracers.Tracer{
+		Hooks:     t.hooks(),
+		GetResult: func() (json.RawMessage, error) { return json.RawMessage("{}"), nil },
+		Stop:      func(err error) {},
+	}
 }
 
-// newResultWriter creates a set of hooks wraps and invokes an underlying tracer,
+// newResultWriter creates a tracer that wraps and invokes an underlying tracer,
 // and writes the result (getResult-output) to file, one per transaction.
-func newResultWriter(baseDir string, tracer *tracers.Tracer) *tracing.Hooks {
+func newResultWriter(baseDir string, tracer *tracers.Tracer) *tracers.Tracer {
 	t := &fileWritingTracer{
 		baseDir:   baseDir,
 		getResult: tracer.GetResult,
 		inner:     tracer.Hooks,
 		suffix:    "json",
 	}
-	return t.hooks()
+	return &tracers.Tracer{
+		Hooks:     t.hooks(),
+		GetResult: func() (json.RawMessage, error) { return json.RawMessage("{}"), nil },
+		Stop:      func(err error) {},
+	}
 }
 
 // OnTxStart creates a new output-file specific for this transaction, and invokes

cmd/evm/internal/t8ntool/flags.go

@@ -162,6 +162,11 @@ var (
 			strings.Join(vm.ActivateableEips(), ", ")),
 		Value: "GrayGlacier",
 	}
+	OpcodeCountFlag = &cli.StringFlag{
+		Name:  "opcode.count",
+		Usage: "If set, opcode execution counts will be written to this file (relative to output.basedir).",
+		Value: "",
+	}
 	VerbosityFlag = &cli.IntFlag{
 		Name:  "verbosity",
 		Usage: "sets the verbosity level",

cmd/evm/internal/t8ntool/transition.go

@@ -37,6 +37,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth/tracers"
 	"github.com/ethereum/go-ethereum/eth/tracers/logger"
+	"github.com/ethereum/go-ethereum/eth/tracers/native"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/tests"
@@ -167,14 +168,15 @@ func Transition(ctx *cli.Context) error {
 	}
 
 	// Configure tracer
+	var tracer *tracers.Tracer
 	if ctx.IsSet(TraceTracerFlag.Name) { // Custom tracing
 		config := json.RawMessage(ctx.String(TraceTracerConfigFlag.Name))
-		tracer, err := tracers.DefaultDirectory.New(ctx.String(TraceTracerFlag.Name),
+		innerTracer, err := tracers.DefaultDirectory.New(ctx.String(TraceTracerFlag.Name),
 			nil, config, chainConfig)
 		if err != nil {
 			return NewError(ErrorConfig, fmt.Errorf("failed instantiating tracer: %v", err))
 		}
-		vmConfig.Tracer = newResultWriter(baseDir, tracer)
+		tracer = newResultWriter(baseDir, innerTracer)
 	} else if ctx.Bool(TraceFlag.Name) { // JSON opcode tracing
 		logConfig := &logger.Config{
 			DisableStack:     ctx.Bool(TraceDisableStackFlag.Name),
@@ -182,20 +184,45 @@ func Transition(ctx *cli.Context) error {
 			EnableReturnData: ctx.Bool(TraceEnableReturnDataFlag.Name),
 		}
 		if ctx.Bool(TraceEnableCallFramesFlag.Name) {
-			vmConfig.Tracer = newFileWriter(baseDir, func(out io.Writer) *tracing.Hooks {
+			tracer = newFileWriter(baseDir, func(out io.Writer) *tracing.Hooks {
 				return logger.NewJSONLoggerWithCallFrames(logConfig, out)
 			})
 		} else {
-			vmConfig.Tracer = newFileWriter(baseDir, func(out io.Writer) *tracing.Hooks {
+			tracer = newFileWriter(baseDir, func(out io.Writer) *tracing.Hooks {
 				return logger.NewJSONLogger(logConfig, out)
 			})
 		}
 	}
+	// Configure opcode counter
+	var opcodeTracer *tracers.Tracer
+	if ctx.IsSet(OpcodeCountFlag.Name) && ctx.String(OpcodeCountFlag.Name) != "" {
+		opcodeTracer = native.NewOpcodeCounter()
+		if tracer != nil {
+			// If we have an existing tracer, multiplex with the opcode tracer
+			mux, _ := native.NewMuxTracer([]string{"trace", "opcode"}, []*tracers.Tracer{tracer, opcodeTracer})
+			vmConfig.Tracer = mux.Hooks
+		} else {
+			vmConfig.Tracer = opcodeTracer.Hooks
+		}
+	} else if tracer != nil {
+		vmConfig.Tracer = tracer.Hooks
+	}
 	// Run the test and aggregate the result
 	s, result, body, err := prestate.Apply(vmConfig, chainConfig, txIt, ctx.Int64(RewardFlag.Name))
 	if err != nil {
 		return err
 	}
+	// Write opcode counts if enabled
+	if opcodeTracer != nil {
+		fname := ctx.String(OpcodeCountFlag.Name)
+		result, err := opcodeTracer.GetResult()
+		if err != nil {
+			return NewError(ErrorJson, fmt.Errorf("failed getting opcode counts: %v", err))
+		}
+		if err := saveFile(baseDir, fname, result); err != nil {
+			return err
+		}
+	}
 	// Dump the execution result
 	var (
 		collector = make(Alloc)

cmd/evm/main.go

@@ -161,6 +161,7 @@ var (
 			t8ntool.ForknameFlag,
 			t8ntool.ChainIDFlag,
 			t8ntool.RewardFlag,
+			t8ntool.OpcodeCountFlag,
 		},
 	}
 

cmd/evm/testdata/1/exp.json

@@ -24,7 +24,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x5208",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x0557bacce3375c98d806609b8d5043072f0b6a8bae45ae5a67a00d3a1a18d673",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x5208",

cmd/evm/testdata/13/exp2.json

@@ -12,7 +12,7 @@
         "status": "0x0",
         "cumulativeGasUsed": "0x84d0",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0xa98a24882ea90916c6a86da650fbc6b14238e46f0af04a131ce92be897507476",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x84d0",
@@ -27,7 +27,7 @@
         "status": "0x0",
         "cumulativeGasUsed": "0x109a0",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x36bad80acce7040c45fd32764b5c2b2d2e6f778669fb41791f73f546d56e739a",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x84d0",

cmd/evm/testdata/23/exp.json

@@ -11,7 +11,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x520b",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x72fadbef39cd251a437eea619cfeda752271a5faaaa2147df012e112159ffb81",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x520b",

cmd/evm/testdata/24/exp.json

@@ -27,7 +27,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0xa861",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x92ea4a28224d033afb20e0cc2b290d4c7c2d61f6a4800a680e4e19ac962ee941",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0xa861",
@@ -41,7 +41,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x10306",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x16b1d912f1d664f3f60f4e1b5f296f3c82a64a1a253117b4851d18bc03c4f1da",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x5aa5",

cmd/evm/testdata/25/exp.json

@@ -23,7 +23,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x5208",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x92ea4a28224d033afb20e0cc2b290d4c7c2d61f6a4800a680e4e19ac962ee941",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x5208",

cmd/evm/testdata/28/exp.json

@@ -28,7 +28,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0xa865",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x7508d7139d002a4b3a26a4f12dec0d87cb46075c78bf77a38b569a133b509262",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0xa865",

cmd/evm/testdata/29/exp.json

@@ -26,7 +26,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x5208",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x84f70aba406a55628a0620f26d260f90aeb6ccc55fed6ec2ac13dd4f727032ed",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x5208",

cmd/evm/testdata/3/exp.json

@@ -24,7 +24,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x521f",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x72fadbef39cd251a437eea619cfeda752271a5faaaa2147df012e112159ffb81",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x521f",

cmd/evm/testdata/30/exp.json

@@ -25,7 +25,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0x5208",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0xa98a24882ea90916c6a86da650fbc6b14238e46f0af04a131ce92be897507476",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x5208",
@@ -40,7 +40,7 @@
         "status": "0x1",
         "cumulativeGasUsed": "0xa410",
         "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-        "logs": null,
+        "logs": [],
         "transactionHash": "0x36bad80acce7040c45fd32764b5c2b2d2e6f778669fb41791f73f546d56e739a",
         "contractAddress": "0x0000000000000000000000000000000000000000",
         "gasUsed": "0x5208",

cmd/evm/testdata/33/exp.json

@@ -44,7 +44,7 @@
       "root": "0x",
       "status": "0x1",
       "cumulativeGasUsed": "0x15fa9",
-      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","logs": null,"transactionHash": "0x0417aab7c1d8a3989190c3167c132876ce9b8afd99262c5a0f9d06802de3d7ef",
+      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","logs": [],"transactionHash": "0x0417aab7c1d8a3989190c3167c132876ce9b8afd99262c5a0f9d06802de3d7ef",
       "contractAddress": "0x0000000000000000000000000000000000000000",
       "gasUsed": "0x15fa9",
       "effectiveGasPrice": null,

eth/tracers/native/mux.go

@@ -28,7 +28,7 @@ import (
 )
 
 func init() {
-	tracers.DefaultDirectory.Register("muxTracer", newMuxTracer, false)
+	tracers.DefaultDirectory.Register("muxTracer", newMuxTracerFromConfig, false)
 }
 
 // muxTracer is a go implementation of the Tracer interface which
@@ -38,8 +38,8 @@ type muxTracer struct {
 	tracers []*tracers.Tracer
 }
 
-// newMuxTracer returns a new mux tracer.
+// newMuxTracerFromConfig returns a new mux tracer.
-func newMuxTracer(ctx *tracers.Context, cfg json.RawMessage, chainConfig *params.ChainConfig) (*tracers.Tracer, error) {
+func newMuxTracerFromConfig(ctx *tracers.Context, cfg json.RawMessage, chainConfig *params.ChainConfig) (*tracers.Tracer, error) {
 	var config map[string]json.RawMessage
 	if err := json.Unmarshal(cfg, &config); err != nil {
 		return nil, err
@@ -54,7 +54,16 @@ func newMuxTracer(ctx *tracers.Context, cfg json.RawMessage, chainConfig *params
 		objects = append(objects, t)
 		names = append(names, k)
 	}
+	return NewMuxTracer(names, objects)
+}
 
+// NewMuxTracer creates a multiplexing tracer that fans out tracing hooks to
+// multiple child tracers. Each hook invocation is forwarded to all children,
+// in the order they are provided.
+//
+// The names parameter associates a label with each tracer, used as keys in
+// the aggregated JSON result returned by GetResult.
+func NewMuxTracer(names []string, objects []*tracers.Tracer) (*tracers.Tracer, error) {
 	t := &muxTracer{names: names, tracers: objects}
 	return &tracers.Tracer{
 		Hooks: &tracing.Hooks{

eth/tracers/native/opcode_counter.go

@@ -0,0 +1,55 @@
+// Copyright 2025 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package native
+
+import (
+	"encoding/json"
+
+	"github.com/ethereum/go-ethereum/core/tracing"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth/tracers"
+)
+
+// opcodeCounter is a simple tracer that counts how many times each opcode is executed.
+type opcodeCounter struct {
+	counts [256]uint64
+}
+
+// NewOpcodeCounter returns a new opcodeCounter tracer.
+func NewOpcodeCounter() *tracers.Tracer {
+	c := &opcodeCounter{}
+	return &tracers.Tracer{
+		Hooks: &tracing.Hooks{
+			OnOpcode: func(pc uint64, op byte, gas, cost uint64, scope tracing.OpContext, rData []byte, depth int, err error) {
+				c.counts[op]++
+			},
+		},
+		GetResult: c.getResult,
+		Stop:      func(err error) {},
+	}
+}
+
+// getResult returns the opcode counts keyed by opcode name.
+func (c *opcodeCounter) getResult() (json.RawMessage, error) {
+	out := make(map[string]uint64)
+	for op, count := range c.counts {
+		if count != 0 {
+			out[vm.OpCode(op).String()] = count
+		}
+	}
+	return json.Marshal(out)
+}