eth/tracers: add diffMode to prestateTracer

eth/tracers/internal/tracetest/calltrace_test.go

@@ -21,10 +21,8 @@ import (
 	"math/big"
 	"os"
 	"path/filepath"
-	"reflect"
 	"strings"
 	"testing"
-	"unicode"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -38,62 +36,8 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/tests"
-
-	// Force-load native and js packages, to trigger registration
-	_ "github.com/ethereum/go-ethereum/eth/tracers/js"
-	_ "github.com/ethereum/go-ethereum/eth/tracers/native"
 )
 
-// To generate a new callTracer test, copy paste the makeTest method below into
-// a Geth console and call it with a transaction hash you which to export.
-
-/*
-// makeTest generates a callTracer test by running a prestate reassembled and a
-// call trace run, assembling all the gathered information into a test case.
-var makeTest = function(tx, rewind) {
-  // Generate the genesis block from the block, transaction and prestate data
-  var block   = eth.getBlock(eth.getTransaction(tx).blockHash);
-  var genesis = eth.getBlock(block.parentHash);
-
-  delete genesis.gasUsed;
-  delete genesis.logsBloom;
-  delete genesis.parentHash;
-  delete genesis.receiptsRoot;
-  delete genesis.sha3Uncles;
-  delete genesis.size;
-  delete genesis.transactions;
-  delete genesis.transactionsRoot;
-  delete genesis.uncles;
-
-  genesis.gasLimit  = genesis.gasLimit.toString();
-  genesis.number    = genesis.number.toString();
-  genesis.timestamp = genesis.timestamp.toString();
-
-  genesis.alloc = debug.traceTransaction(tx, {tracer: "prestateTracer", rewind: rewind});
-  for (var key in genesis.alloc) {
-    genesis.alloc[key].nonce = genesis.alloc[key].nonce.toString();
-  }
-  genesis.config = admin.nodeInfo.protocols.eth.config;
-
-  // Generate the call trace and produce the test input
-  var result = debug.traceTransaction(tx, {tracer: "callTracer", rewind: rewind});
-  delete result.time;
-
-  console.log(JSON.stringify({
-    genesis: genesis,
-    context: {
-      number:     block.number.toString(),
-      difficulty: block.difficulty,
-      timestamp:  block.timestamp.toString(),
-      gasLimit:   block.gasLimit.toString(),
-      miner:      block.miner,
-    },
-    input:  eth.getRawTransaction(tx),
-    result: result,
-  }, null, 2));
-}
-*/
-
 type callContext struct {
 	Number     math.HexOrDecimal64   `json:"number"`
 	Difficulty *math.HexOrDecimal256 `json:"difficulty"`
@@ -203,7 +147,7 @@ func testCallTracer(tracerName string, dirPath string, t *testing.T) {
 				t.Fatalf("failed to unmarshal trace result: %v", err)
 			}
 
-			if !jsonEqual(ret, test.Result) {
+			if !jsonEqual(ret, test.Result, new(callTrace), new(callTrace)) {
 				// uncomment this for easier debugging
 				//have, _ := json.MarshalIndent(ret, "", " ")
 				//want, _ := json.MarshalIndent(test.Result, "", " ")
@@ -214,32 +158,6 @@ func testCallTracer(tracerName string, dirPath string, t *testing.T) {
 	}
 }
 
-// jsonEqual is similar to reflect.DeepEqual, but does a 'bounce' via json prior to
-// comparison
-func jsonEqual(x, y interface{}) bool {
-	xTrace := new(callTrace)
-	yTrace := new(callTrace)
-	if xj, err := json.Marshal(x); err == nil {
-		json.Unmarshal(xj, xTrace)
-	} else {
-		return false
-	}
-	if yj, err := json.Marshal(y); err == nil {
-		json.Unmarshal(yj, yTrace)
-	} else {
-		return false
-	}
-	return reflect.DeepEqual(xTrace, yTrace)
-}
-
-// camel converts a snake cased input string into a camel cased output.
-func camel(str string) string {
-	pieces := strings.Split(str, "_")
-	for i := 1; i < len(pieces); i++ {
-		pieces[i] = string(unicode.ToUpper(rune(pieces[i][0]))) + pieces[i][1:]
-	}
-	return strings.Join(pieces, "")
-}
 func BenchmarkTracers(b *testing.B) {
 	files, err := os.ReadDir(filepath.Join("testdata", "call_tracer"))
 	if err != nil {
@@ -385,7 +303,7 @@ func TestZeroValueToNotExitCall(t *testing.T) {
 	wantStr := `{"type":"CALL","from":"0x682a80a6f560eec50d54e63cbeda1c324c5f8d1b","to":"0x00000000000000000000000000000000deadbeef","value":"0x0","gas":"0x7148","gasUsed":"0x2d0","input":"0x","output":"0x","calls":[{"type":"CALL","from":"0x00000000000000000000000000000000deadbeef","to":"0x00000000000000000000000000000000000000ff","value":"0x0","gas":"0x6cbf","gasUsed":"0x0","input":"0x","output":"0x"}]}`
 	want := new(callTrace)
 	json.Unmarshal([]byte(wantStr), want)
-	if !jsonEqual(have, want) {
+	if !jsonEqual(have, want, new(callTrace), new(callTrace)) {
 		t.Error("have != want")
 	}
 }

eth/tracers/internal/tracetest/prestate_test.go

@@ -0,0 +1,144 @@
+// Copyright 2021 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package tracetest
+
+import (
+	"encoding/json"
+	"math/big"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth/tracers"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/tests"
+)
+
+// prestateTrace is the result of a prestateTrace run.
+type prestateTrace = map[common.Address]*account
+type account struct {
+	Balance string                      `json:"balance,omitempty"`
+	Nonce   uint64                      `json:"nonce,omitempty"`
+	Code    string                      `json:"code,omitempty"`
+	Storage map[common.Hash]common.Hash `json:"storage,omitempty"`
+}
+type prePostStateTrace struct {
+	Pre  prestateTrace `json:"pre"`
+	Post prestateTrace `json:"post"`
+}
+
+// prestateTraceTest defines a single test to check the stateDiff tracer against.
+type prestateTraceTest struct {
+	Genesis      *core.Genesis   `json:"genesis"`
+	Context      *callContext    `json:"context"`
+	Input        string          `json:"input"`
+	TracerConfig json.RawMessage `json:"tracerConfig"`
+	Result       interface{}     `json:"result"`
+}
+
+func TestPrestateTracer(t *testing.T) {
+	testPrestateDiffTracer("prestateTracer", "prestate_tracer", t, func() interface{} { return new(prestateTrace) })
+}
+
+func TestPrestateWithDiffModeTracer(t *testing.T) {
+	testPrestateDiffTracer("prestateTracer", "prestate_tracer_with_diff_mode", t, func() interface{} { return new(prePostStateTrace) })
+}
+
+func testPrestateDiffTracer(tracerName string, dirPath string, t *testing.T, typeBuilder func() interface{}) {
+	files, err := os.ReadDir(filepath.Join("testdata", dirPath))
+	if err != nil {
+		t.Fatalf("failed to retrieve tracer test suite: %v", err)
+	}
+	for _, file := range files {
+		if !strings.HasSuffix(file.Name(), ".json") {
+			continue
+		}
+		file := file // capture range variable
+		t.Run(camel(strings.TrimSuffix(file.Name(), ".json")), func(t *testing.T) {
+			t.Parallel()
+
+			var (
+				test = new(prestateTraceTest)
+				tx   = new(types.Transaction)
+			)
+			// Call tracer test found, read if from disk
+			if blob, err := os.ReadFile(filepath.Join("testdata", dirPath, file.Name())); err != nil {
+				t.Fatalf("failed to read testcase: %v", err)
+			} else if err := json.Unmarshal(blob, test); err != nil {
+				t.Fatalf("failed to parse testcase: %v", err)
+			}
+			if err := rlp.DecodeBytes(common.FromHex(test.Input), tx); err != nil {
+				t.Fatalf("failed to parse testcase input: %v", err)
+			}
+			// Configure a blockchain with the given prestate
+			var (
+				signer    = types.MakeSigner(test.Genesis.Config, new(big.Int).SetUint64(uint64(test.Context.Number)))
+				origin, _ = signer.Sender(tx)
+				txContext = vm.TxContext{
+					Origin:   origin,
+					GasPrice: tx.GasPrice(),
+				}
+				context = vm.BlockContext{
+					CanTransfer: core.CanTransfer,
+					Transfer:    core.Transfer,
+					Coinbase:    test.Context.Miner,
+					BlockNumber: new(big.Int).SetUint64(uint64(test.Context.Number)),
+					Time:        new(big.Int).SetUint64(uint64(test.Context.Time)),
+					Difficulty:  (*big.Int)(test.Context.Difficulty),
+					GasLimit:    uint64(test.Context.GasLimit),
+				}
+				_, statedb = tests.MakePreState(rawdb.NewMemoryDatabase(), test.Genesis.Alloc, false)
+			)
+			tracer, err := tracers.New(tracerName, new(tracers.Context), test.TracerConfig)
+			if err != nil {
+				t.Fatalf("failed to create call tracer: %v", err)
+			}
+			evm := vm.NewEVM(context, txContext, statedb, test.Genesis.Config, vm.Config{Debug: true, Tracer: tracer})
+			msg, err := tx.AsMessage(signer, nil)
+			if err != nil {
+				t.Fatalf("failed to prepare transaction for tracing: %v", err)
+			}
+			st := core.NewStateTransition(evm, msg, new(core.GasPool).AddGas(tx.Gas()))
+			if _, err = st.TransitionDb(); err != nil {
+				t.Fatalf("failed to execute transaction: %v", err)
+			}
+			// Retrieve the trace result and compare against the etalon
+			res, err := tracer.GetResult()
+			if err != nil {
+				t.Fatalf("failed to retrieve trace result: %v", err)
+			}
+			ret := typeBuilder()
+			if err := json.Unmarshal(res, ret); err != nil {
+				t.Fatalf("failed to unmarshal trace result: %v", err)
+			}
+
+			if !jsonEqual(ret, test.Result, typeBuilder(), typeBuilder()) {
+				// uncomment this for easier debugging
+				// have, _ := json.MarshalIndent(ret, "", " ")
+				// want, _ := json.MarshalIndent(test.Result, "", " ")
+				// t.Fatalf("trace mismatch: \nhave %+v\nwant %+v", string(have), string(want))
+				t.Fatalf("trace mismatch: \nhave %+v\nwant %+v", ret, test.Result)
+			}
+		})
+	}
+}