Merge pull request #5542 from onflow/ramtin/5509-populate-receipt-root

[Flow EVM] populate receipt root hash in blocks

fvm/evm/handler/handler.go

@@ -191,7 +191,8 @@ func (h *ContractHandler) run(
 
 	bp.AppendTxHash(res.TxHash)
 
-	// TODO: in the future we might update the receipt hash here
+	// Populate receipt root
+	bp.PopulateReceiptRoot([]types.Result{*res})
 
 	blockHash, err := bp.Hash()
 	if err != nil {
@@ -307,7 +308,9 @@ func (h *ContractHandler) executeAndHandleCall(
 	}
 
 	bp.AppendTxHash(res.TxHash)
-	// TODO: in the future we might update the receipt hash here
+
+	// Populate receipt root
+	bp.PopulateReceiptRoot([]types.Result{*res})
 
 	if totalSupplyDiff != nil {
 		if deductSupplyDiff {

fvm/evm/types/block.go

@@ -6,7 +6,8 @@ import (
 	gethCommon "github.com/ethereum/go-ethereum/common"
 	gethTypes "github.com/ethereum/go-ethereum/core/types"
 	gethCrypto "github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/rlp"
+	gethRLP "github.com/ethereum/go-ethereum/rlp"
+	gethTrie "github.com/ethereum/go-ethereum/trie"
 )
 
 // Block represents a evm block.
@@ -22,6 +23,9 @@ type Block struct {
 	TotalSupply *big.Int
 
 	// ReceiptRoot returns the root hash of the receipts emitted in this block
+	// Note that this value won't be unique to each block, for example for the
+	// case of empty trie of receipts or a single receipt with no logs and failed state
+	// the same receipt root would be reported for block.
 	ReceiptRoot gethCommon.Hash
 
 	// transaction hashes
@@ -30,7 +34,7 @@ type Block struct {
 
 // ToBytes encodes the block into bytes
 func (b *Block) ToBytes() ([]byte, error) {
-	return rlp.EncodeToBytes(b)
+	return gethRLP.EncodeToBytes(b)
 }
 
 // Hash returns the hash of the block
@@ -39,6 +43,20 @@ func (b *Block) Hash() (gethCommon.Hash, error) {
 	return gethCrypto.Keccak256Hash(data), err
 }
 
+// PopulateReceiptRoot populates receipt root with the given results
+func (b *Block) PopulateReceiptRoot(results []Result) {
+	if len(results) == 0 {
+		b.ReceiptRoot = gethTypes.EmptyReceiptsHash
+		return
+	}
+
+	receipts := make(gethTypes.Receipts, len(results))
+	for i, res := range results {
+		receipts[i] = res.Receipt()
+	}
+	b.ReceiptRoot = gethTypes.DeriveSha(receipts, gethTrie.NewStackTrie(nil))
+}
+
 // AppendTxHash appends a transaction hash to the list of transaction hashes of the block
 func (b *Block) AppendTxHash(txHash gethCommon.Hash) {
 	b.TransactionHashes = append(b.TransactionHashes, txHash)
@@ -64,7 +82,7 @@ func NewBlock(
 // NewBlockFromBytes constructs a new block from encoded data
 func NewBlockFromBytes(encoded []byte) (*Block, error) {
 	res := &Block{}
-	err := rlp.DecodeBytes(encoded, res)
+	err := gethRLP.DecodeBytes(encoded, res)
 	return res, err
 }
 

fvm/evm/types/block_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	gethCommon "github.com/ethereum/go-ethereum/common"
+	gethTypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -30,4 +31,13 @@ func Test_BlockHash(t *testing.T) {
 
 	// hashes should not equal if any data is changed
 	assert.NotEqual(t, h1, h2)
+
+	b.PopulateReceiptRoot(nil)
+	require.Equal(t, gethTypes.EmptyReceiptsHash, b.ReceiptRoot)
+
+	res := Result{
+		GasConsumed: 10,
+	}
+	b.PopulateReceiptRoot([]Result{res})
+	require.NotEqual(t, gethTypes.EmptyReceiptsHash, b.ReceiptRoot)
 }

fvm/evm/types/result.go

@@ -42,7 +42,13 @@ func (res *Result) VMErrorString() string {
 
 // Receipt constructs an EVM-style receipt
 // can be used by json-rpc and other integration to be returned.
-func (res *Result) Receipt() *gethTypes.ReceiptForStorage {
+//
+// This is method is also used to construct block receipt root hash
+// which requires the return receipt satisfy RLP encoding and cover these feilds
+// Type (txType), PostState or Status, CumulativeGasUsed, Logs and Logs Bloom
+// and for each log, Address, Topics, Data (consensus fields)
+// During execution we also do fill in BlockNumber, TxIndex, Index (event index)
+func (res *Result) Receipt() *gethTypes.Receipt {
 	receipt := &gethTypes.Receipt{
 		Type:              res.TxType,
 		CumulativeGasUsed: res.GasConsumed, // TODO: update to capture cumulative
@@ -56,7 +62,7 @@ func (res *Result) Receipt() *gethTypes.ReceiptForStorage {
 	}
 
 	receipt.Bloom = gethTypes.CreateBloom(gethTypes.Receipts{receipt})
-	return (*gethTypes.ReceiptForStorage)(receipt)
+	return receipt
 }
 
 // Status captures the status of an interaction to the emulator