core/vm/runtime/runtime_test.go

@@ -333,7 +333,7 @@ func benchmarkNonModifyingCode(gas uint64, code []byte, name string, tracerCode
 	cfg.State, _ = state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
 	cfg.GasLimit = gas
 	if len(tracerCode) > 0 {
-		tracer, err := tracers.New(tracerCode, new(tracers.Context))
+		tracer, err := tracers.New(tracerCode, new(tracers.Context), nil)
 		if err != nil {
 			b.Fatal(err)
 		}
@@ -832,7 +832,7 @@ func TestRuntimeJSTracer(t *testing.T) {
 			statedb.SetCode(common.HexToAddress("0xee"), calleeCode)
 			statedb.SetCode(common.HexToAddress("0xff"), depressedCode)
 
-			tracer, err := tracers.New(jsTracer, new(tracers.Context))
+			tracer, err := tracers.New(jsTracer, new(tracers.Context), nil)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -868,7 +868,7 @@ func TestJSTracerCreateTx(t *testing.T) {
 	code := []byte{byte(vm.PUSH1), 0, byte(vm.PUSH1), 0, byte(vm.RETURN)}
 
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
-	tracer, err := tracers.New(jsTracer, new(tracers.Context))
+	tracer, err := tracers.New(jsTracer, new(tracers.Context), nil)
 	if err != nil {
 		t.Fatal(err)
 	}

eth/tracers/api.go

@@ -20,6 +20,7 @@ import (
 	"bufio"
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"os"
@@ -169,15 +170,15 @@ type TraceConfig struct {
 	Tracer  *string
 	Timeout *string
 	Reexec  *uint64
+	// Config specific to given tracer. Note struct logger
+	// config are historically embedded in main object.
+	TracerConfig json.RawMessage
 }
 
 // TraceCallConfig is the config for traceCall API. It holds one more
 // field to override the state for tracing.
 type TraceCallConfig struct {
-	*logger.Config
+	TraceConfig
-	Tracer         *string
-	Timeout        *string
-	Reexec         *uint64
 	StateOverrides *ethapi.StateOverride
 	BlockOverrides *ethapi.BlockOverrides
 }
@@ -882,7 +883,7 @@ func (api *API) traceTx(ctx context.Context, message core.Message, txctx *Contex
 	// Default tracer is the struct logger
 	tracer = logger.NewStructLogger(config.Config)
 	if config.Tracer != nil {
-		tracer, err = New(*config.Tracer, txctx)
+		tracer, err = New(*config.Tracer, txctx, config.TracerConfig)
 		if err != nil {
 			return nil, err
 		}

eth/tracers/internal/tracetest/calltrace_test.go

@@ -118,10 +118,11 @@ type callTrace struct {
 
 // callTracerTest defines a single test to check the call tracer against.
 type callTracerTest struct {
-	Genesis *core.Genesis `json:"genesis"`
+	Genesis      *core.Genesis   `json:"genesis"`
-	Context *callContext  `json:"context"`
+	Context      *callContext    `json:"context"`
-	Input   string        `json:"input"`
+	Input        string          `json:"input"`
-	Result  *callTrace    `json:"result"`
+	TracerConfig json.RawMessage `json:"tracerConfig"`
+	Result       *callTrace      `json:"result"`
 }
 
 // Iterates over all the input-output datasets in the tracer test harness and
@@ -179,7 +180,7 @@ func testCallTracer(tracerName string, dirPath string, t *testing.T) {
 				}
 				_, statedb = tests.MakePreState(rawdb.NewMemoryDatabase(), test.Genesis.Alloc, false)
 			)
-			tracer, err := tracers.New(tracerName, new(tracers.Context))
+			tracer, err := tracers.New(tracerName, new(tracers.Context), test.TracerConfig)
 			if err != nil {
 				t.Fatalf("failed to create call tracer: %v", err)
 			}
@@ -293,7 +294,7 @@ func benchTracer(tracerName string, test *callTracerTest, b *testing.B) {
 	b.ReportAllocs()
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		tracer, err := tracers.New(tracerName, new(tracers.Context))
+		tracer, err := tracers.New(tracerName, new(tracers.Context), nil)
 		if err != nil {
 			b.Fatalf("failed to create call tracer: %v", err)
 		}
@@ -359,7 +360,7 @@ func TestZeroValueToNotExitCall(t *testing.T) {
 	}
 	_, statedb := tests.MakePreState(rawdb.NewMemoryDatabase(), alloc, false)
 	// Create the tracer, the EVM environment and run it
-	tracer, err := tracers.New("callTracer", nil)
+	tracer, err := tracers.New("callTracer", nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create call tracer: %v", err)
 	}

eth/tracers/internal/tracetest/testdata/call_tracer/simple_onlytop.json

@@ -0,0 +1,72 @@
+{
+  "context": {
+    "difficulty": "3502894804",
+    "gasLimit": "4722976",
+    "miner": "0x1585936b53834b021f68cc13eeefdec2efc8e724",
+    "number": "2289806",
+    "timestamp": "1513601314"
+  },
+  "genesis": {
+    "alloc": {
+      "0x0024f658a46fbb89d8ac105e98d7ac7cbbaf27c5": {
+        "balance": "0x0",
+        "code": "0x",
+        "nonce": "22",
+        "storage": {}
+      },
+      "0x3b873a919aa0512d5a0f09e6dcceaa4a6727fafe": {
+        "balance": "0x4d87094125a369d9bd5",
+        "code": "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",
+        "nonce": "1",
+        "storage": {
+          "0x0000000000000000000000000000000000000000000000000000000000000000": "0x000000000000000000000001b436ba50d378d4bbc8660d312a13df6af6e89dfb",
+          "0x0000000000000000000000000000000000000000000000000000000000000001": "0x00000000000000000000000000000000000000000000000006f05b59d3b20000",
+          "0x0000000000000000000000000000000000000000000000000000000000000002": "0x000000000000000000000000000000000000000000000000000000000000003c",
+          "0x0000000000000000000000000000000000000000000000000000000000000003": "0x000000000000000000000000000000000000000000000000000000005a37b834"
+        }
+      },
+      "0xb436ba50d378d4bbc8660d312a13df6af6e89dfb": {
+        "balance": "0x1780d77678137ac1b775",
+        "code": "0x",
+        "nonce": "29072",
+        "storage": {}
+      }
+    },
+    "config": {
+      "byzantiumBlock": 1700000,
+      "chainId": 3,
+      "daoForkSupport": true,
+      "eip150Block": 0,
+      "eip150Hash": "0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d",
+      "eip155Block": 10,
+      "eip158Block": 10,
+      "ethash": {},
+      "homesteadBlock": 0
+    },
+    "difficulty": "3509749784",
+    "extraData": "0x4554482e45544846414e532e4f52472d4641313738394444",
+    "gasLimit": "4727564",
+    "hash": "0x609948ac3bd3c00b7736b933248891d6c901ee28f066241bddb28f4e00a9f440",
+    "miner": "0xbbf5029fd710d227630c8b7d338051b8e76d50b3",
+    "mixHash": "0xb131e4507c93c7377de00e7c271bf409ec7492767142ff0f45c882f8068c2ada",
+    "nonce": "0x4eb12e19c16d43da",
+    "number": "2289805",
+    "stateRoot": "0xc7f10f352bff82fac3c2999d3085093d12652e19c7fd32591de49dc5d91b4f1f",
+    "timestamp": "1513601261",
+    "totalDifficulty": "7143276353481064"
+  },
+  "input": "0xf88b8271908506fc23ac0083015f90943b873a919aa0512d5a0f09e6dcceaa4a6727fafe80a463e4bff40000000000000000000000000024f658a46fbb89d8ac105e98d7ac7cbbaf27c52aa0bdce0b59e8761854e857fe64015f06dd08a4fbb7624f6094893a79a72e6ad6bea01d9dde033cff7bb235a3163f348a6d7ab8d6b52bc0963a95b91612e40ca766a4",
+  "tracerConfig": {
+      "onlyTopCall": true
+  },
+  "result": {
+    "from": "0xb436ba50d378d4bbc8660d312a13df6af6e89dfb",
+    "gas": "0x10738",
+    "gasUsed": "0x3ef9",
+    "input": "0x63e4bff40000000000000000000000000024f658a46fbb89d8ac105e98d7ac7cbbaf27c5",
+    "output": "0x0000000000000000000000000000000000000000000000000000000000000001",
+    "to": "0x3b873a919aa0512d5a0f09e6dcceaa4a6727fafe",
+    "type": "CALL",
+    "value": "0x0"
+  }
+}

eth/tracers/js/goja.go

@@ -125,7 +125,7 @@ type jsTracer struct {
 // The methods `result` and `fault` are required to be present.
 // The methods `step`, `enter`, and `exit` are optional, but note that
 // `enter` and `exit` always go together.
-func newJsTracer(code string, ctx *tracers.Context) (tracers.Tracer, error) {
+func newJsTracer(code string, ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
 	if c, ok := assetTracers[code]; ok {
 		code = c
 	}
@@ -177,6 +177,17 @@ func newJsTracer(code string, ctx *tracers.Context) (tracers.Tracer, error) {
 	t.exit = exit
 	t.result = result
 	t.fault = fault
+
+	// Pass in config
+	if setup, ok := goja.AssertFunction(obj.Get("setup")); ok {
+		cfgStr := "{}"
+		if cfg != nil {
+			cfgStr = string(cfg)
+		}
+		if _, err := setup(obj, vm.ToValue(cfgStr)); err != nil {
+			return nil, err
+		}
+	}
 	// Setup objects carrying data to JS. These are created once and re-used.
 	t.log = &steplog{
 		vm:       vm,

eth/tracers/js/tracer_test.go

@@ -85,7 +85,7 @@ func runTrace(tracer tracers.Tracer, vmctx *vmContext, chaincfg *params.ChainCon
 func TestTracer(t *testing.T) {
 	execTracer := func(code string) ([]byte, string) {
 		t.Helper()
-		tracer, err := newJsTracer(code, nil)
+		tracer, err := newJsTracer(code, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -149,7 +149,7 @@ func TestTracer(t *testing.T) {
 
 func TestHalt(t *testing.T) {
 	timeout := errors.New("stahp")
-	tracer, err := newJsTracer("{step: function() { while(1); }, result: function() { return null; }, fault: function(){}}", nil)
+	tracer, err := newJsTracer("{step: function() { while(1); }, result: function() { return null; }, fault: function(){}}", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -163,7 +163,7 @@ func TestHalt(t *testing.T) {
 }
 
 func TestHaltBetweenSteps(t *testing.T) {
-	tracer, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }}", nil)
+	tracer, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }}", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -187,7 +187,7 @@ func TestHaltBetweenSteps(t *testing.T) {
 func TestNoStepExec(t *testing.T) {
 	execTracer := func(code string) []byte {
 		t.Helper()
-		tracer, err := newJsTracer(code, nil)
+		tracer, err := newJsTracer(code, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -221,7 +221,7 @@ func TestIsPrecompile(t *testing.T) {
 	chaincfg.IstanbulBlock = big.NewInt(200)
 	chaincfg.BerlinBlock = big.NewInt(300)
 	txCtx := vm.TxContext{GasPrice: big.NewInt(100000)}
-	tracer, err := newJsTracer("{addr: toAddress('0000000000000000000000000000000000000009'), res: null, step: function() { this.res = isPrecompiled(this.addr); }, fault: function() {}, result: function() { return this.res; }}", nil)
+	tracer, err := newJsTracer("{addr: toAddress('0000000000000000000000000000000000000009'), res: null, step: function() { this.res = isPrecompiled(this.addr); }, fault: function() {}, result: function() { return this.res; }}", nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -235,7 +235,7 @@ func TestIsPrecompile(t *testing.T) {
 		t.Errorf("tracer should not consider blake2f as precompile in byzantium")
 	}
 
-	tracer, _ = newJsTracer("{addr: toAddress('0000000000000000000000000000000000000009'), res: null, step: function() { this.res = isPrecompiled(this.addr); }, fault: function() {}, result: function() { return this.res; }}", nil)
+	tracer, _ = newJsTracer("{addr: toAddress('0000000000000000000000000000000000000009'), res: null, step: function() { this.res = isPrecompiled(this.addr); }, fault: function() {}, result: function() { return this.res; }}", nil, nil)
 	blockCtx = vm.BlockContext{BlockNumber: big.NewInt(250)}
 	res, err = runTrace(tracer, &vmContext{blockCtx, txCtx}, chaincfg)
 	if err != nil {
@@ -248,14 +248,14 @@ func TestIsPrecompile(t *testing.T) {
 
 func TestEnterExit(t *testing.T) {
 	// test that either both or none of enter() and exit() are defined
-	if _, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }, enter: function() {}}", new(tracers.Context)); err == nil {
+	if _, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }, enter: function() {}}", new(tracers.Context), nil); err == nil {
 		t.Fatal("tracer creation should've failed without exit() definition")
 	}
-	if _, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }, enter: function() {}, exit: function() {}}", new(tracers.Context)); err != nil {
+	if _, err := newJsTracer("{step: function() {}, fault: function() {}, result: function() { return null; }, enter: function() {}, exit: function() {}}", new(tracers.Context), nil); err != nil {
 		t.Fatal(err)
 	}
 	// test that the enter and exit method are correctly invoked and the values passed
-	tracer, err := newJsTracer("{enters: 0, exits: 0, enterGas: 0, gasUsed: 0, step: function() {}, fault: function() {}, result: function() { return {enters: this.enters, exits: this.exits, enterGas: this.enterGas, gasUsed: this.gasUsed} }, enter: function(frame) { this.enters++; this.enterGas = frame.getGas(); }, exit: function(res) { this.exits++; this.gasUsed = res.getGasUsed(); }}", new(tracers.Context))
+	tracer, err := newJsTracer("{enters: 0, exits: 0, enterGas: 0, gasUsed: 0, step: function() {}, fault: function() {}, result: function() { return {enters: this.enters, exits: this.exits, enterGas: this.enterGas, gasUsed: this.gasUsed} }, enter: function(frame) { this.enters++; this.enterGas = frame.getGas(); }, exit: function(res) { this.exits++; this.gasUsed = res.getGasUsed(); }}", new(tracers.Context), nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -274,3 +274,33 @@ func TestEnterExit(t *testing.T) {
 		t.Errorf("Number of invocations of enter() and exit() is wrong. Have %s, want %s\n", have, want)
 	}
 }
+
+func TestSetup(t *testing.T) {
+	// Test empty config
+	_, err := newJsTracer(`{setup: function(cfg) { if (cfg !== "{}") { throw("invalid empty config") } }, fault: function() {}, result: function() {}}`, new(tracers.Context), nil)
+	if err != nil {
+		t.Error(err)
+	}
+
+	cfg, err := json.Marshal(map[string]string{"foo": "bar"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Test no setup func
+	_, err = newJsTracer(`{fault: function() {}, result: function() {}}`, new(tracers.Context), cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Test config value
+	tracer, err := newJsTracer("{config: null, setup: function(cfg) { this.config = JSON.parse(cfg) }, step: function() {}, fault: function() {}, result: function() { return this.config.foo }}", new(tracers.Context), cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	have, err := tracer.GetResult()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(have) != `"bar"` {
+		t.Errorf("tracer returned wrong result. have: %s, want: \"bar\"\n", string(have))
+	}
+}

eth/tracers/native/4byte.go

@@ -55,11 +55,11 @@ type fourByteTracer struct {
 
 // newFourByteTracer returns a native go tracer which collects
 // 4 byte-identifiers of a tx, and implements vm.EVMLogger.
-func newFourByteTracer(ctx *tracers.Context) tracers.Tracer {
+func newFourByteTracer(ctx *tracers.Context, _ json.RawMessage) (tracers.Tracer, error) {
 	t := &fourByteTracer{
 		ids: make(map[string]int),
 	}
-	return t
+	return t, nil
 }
 
 // isPrecompiled returns whether the addr is a precompile. Logic borrowed from newJsTracer in eth/tracers/js/tracer.go

eth/tracers/native/call.go

@@ -50,16 +50,27 @@ type callFrame struct {
 type callTracer struct {
 	env       *vm.EVM
 	callstack []callFrame
+	config    callTracerConfig
 	interrupt uint32 // Atomic flag to signal execution interruption
 	reason    error  // Textual reason for the interruption
 }
 
+type callTracerConfig struct {
+	OnlyTopCall bool `json:"onlyTopCall"` // If true, call tracer won't collect any subcalls
+}
+
 // newCallTracer returns a native go tracer which tracks
 // call frames of a tx, and implements vm.EVMLogger.
-func newCallTracer(ctx *tracers.Context) tracers.Tracer {
+func newCallTracer(ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
+	var config callTracerConfig
+	if cfg != nil {
+		if err := json.Unmarshal(cfg, &config); err != nil {
+			return nil, err
+		}
+	}
 	// 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), config: config}, nil
 }
 
 // CaptureStart implements the EVMLogger interface to initialize the tracing operation.
@@ -101,6 +112,9 @@ func (t *callTracer) CaptureFault(pc uint64, op vm.OpCode, gas, cost uint64, _ *
 
 // 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 {
+		return
+	}
 	// Skip if tracing was interrupted
 	if atomic.LoadUint32(&t.interrupt) > 0 {
 		t.env.Cancel()
@@ -121,6 +135,9 @@ func (t *callTracer) CaptureEnter(typ vm.OpCode, from common.Address, to common.
 // CaptureExit is called when EVM exits a scope, even if the scope didn't
 // execute any code.
 func (t *callTracer) CaptureExit(output []byte, gasUsed uint64, err error) {
+	if t.config.OnlyTopCall {
+		return
+	}
 	size := len(t.callstack)
 	if size <= 1 {
 		return

eth/tracers/native/noop.go

@@ -35,8 +35,8 @@ func init() {
 type noopTracer struct{}
 
 // newNoopTracer returns a new noop tracer.
-func newNoopTracer(ctx *tracers.Context) tracers.Tracer {
+func newNoopTracer(ctx *tracers.Context, _ json.RawMessage) (tracers.Tracer, error) {
-	return &noopTracer{}
+	return &noopTracer{}, nil
 }
 
 // CaptureStart implements the EVMLogger interface to initialize the tracing operation.

eth/tracers/native/prestate.go

@@ -51,10 +51,10 @@ type prestateTracer struct {
 	reason    error  // Textual reason for the interruption
 }
 
-func newPrestateTracer(ctx *tracers.Context) tracers.Tracer {
+func newPrestateTracer(ctx *tracers.Context, _ json.RawMessage) (tracers.Tracer, error) {
 	// First callframe contains tx context info
 	// and is populated on start and end.
-	return &prestateTracer{prestate: prestate{}}
+	return &prestateTracer{prestate: prestate{}}, nil
 }
 
 // CaptureStart implements the EVMLogger interface to initialize the tracing operation.

eth/tracers/native/revertreason.go

@@ -46,8 +46,8 @@ type revertReasonTracer struct {
 }
 
 // newRevertReasonTracer returns a new revert reason tracer.
-func newRevertReasonTracer(_ *tracers.Context) tracers.Tracer {
+func newRevertReasonTracer(_ *tracers.Context, _ json.RawMessage) (tracers.Tracer, error) {
-	return &revertReasonTracer{}
+	return &revertReasonTracer{}, nil
 }
 
 // CaptureStart implements the EVMLogger interface to initialize the tracing operation.

eth/tracers/native/tracer.go

@@ -35,6 +35,7 @@ func init() {
 package native
 
 import (
+	"encoding/json"
 	"errors"
 
 	"github.com/ethereum/go-ethereum/eth/tracers"
@@ -46,7 +47,7 @@ func init() {
 }
 
 // ctorFn is the constructor signature of a native tracer.
-type ctorFn = func(*tracers.Context) tracers.Tracer
+type ctorFn = func(*tracers.Context, json.RawMessage) (tracers.Tracer, error)
 
 /*
 ctors is a map of package-local tracer constructors.
@@ -71,12 +72,12 @@ func register(name string, ctor ctorFn) {
 }
 
 // lookup returns a tracer, if one can be matched to the given name.
-func lookup(name string, ctx *tracers.Context) (tracers.Tracer, error) {
+func lookup(name string, ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
 	if ctors == nil {
 		ctors = make(map[string]ctorFn)
 	}
 	if ctor, ok := ctors[name]; ok {
-		return ctor(ctx), nil
+		return ctor(ctx, cfg)
 	}
 	return nil, errors.New("no tracer found")
 }

eth/tracers/tracers.go

@@ -42,7 +42,7 @@ type Tracer interface {
 	Stop(err error)
 }
 
-type lookupFunc func(string, *Context) (Tracer, error)
+type lookupFunc func(string, *Context, json.RawMessage) (Tracer, error)
 
 var (
 	lookups []lookupFunc
@@ -62,9 +62,9 @@ func RegisterLookup(wildcard bool, lookup lookupFunc) {
 
 // New returns a new instance of a tracer, by iterating through the
 // registered lookups.
-func New(code string, ctx *Context) (Tracer, error) {
+func New(code string, ctx *Context, cfg json.RawMessage) (Tracer, error) {
 	for _, lookup := range lookups {
-		if tracer, err := lookup(code, ctx); err == nil {
+		if tracer, err := lookup(code, ctx, cfg); err == nil {
 			return tracer, nil
 		}
 	}