internal/ethapi: support for beacon root and withdrawals in simulate api (#31304)

Adds block override fields for beacon block root and withdrawals to the eth_simulateV1.
Addresses https://github.com/ethereum/go-ethereum/issues/31264

eth/gasestimator/gasestimator.go

@@ -223,7 +223,9 @@ func run(ctx context.Context, call *core.Message, opts *Options) (*core.Executio
 		dirtyState = opts.State.Copy()
 	)
 	if opts.BlockOverrides != nil {
-		opts.BlockOverrides.Apply(&evmContext)
+		if err := opts.BlockOverrides.Apply(&evmContext); err != nil {
+			return nil, err
+		}
 	}
 	// Lower the basefee to 0 to avoid breaking EVM
 	// invariants (basefee < feecap).

eth/tracers/api.go

@@ -950,7 +950,9 @@ func (api *API) TraceCall(ctx context.Context, args ethapi.TransactionArgs, bloc
 	vmctx := core.NewEVMBlockContext(block.Header(), api.chainContext(ctx), nil)
 	// Apply the customization rules if required.
 	if config != nil {
-		config.BlockOverrides.Apply(&vmctx)
+		if overrideErr := config.BlockOverrides.Apply(&vmctx); overrideErr != nil {
+			return nil, overrideErr
+		}
 		rules := api.backend.ChainConfig().Rules(vmctx.BlockNumber, vmctx.Random != nil, vmctx.Time)
 
 		precompiles = vm.ActivePrecompiledContracts(rules)

internal/ethapi/api.go

@@ -660,7 +660,9 @@ func (context *ChainContext) Config() *params.ChainConfig {
 func doCall(ctx context.Context, b Backend, args TransactionArgs, state *state.StateDB, header *types.Header, overrides *override.StateOverride, blockOverrides *override.BlockOverrides, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
 	blockCtx := core.NewEVMBlockContext(header, NewChainContext(ctx, b), nil)
 	if blockOverrides != nil {
-		blockOverrides.Apply(&blockCtx)
+		if err := blockOverrides.Apply(&blockCtx); err != nil {
+			return nil, err
+		}
 	}
 	rules := b.ChainConfig().Rules(blockCtx.BlockNumber, blockCtx.Random != nil, blockCtx.Time)
 	precompiles := vm.ActivePrecompiledContracts(rules)

internal/ethapi/api_test.go

@@ -1134,6 +1134,24 @@ func TestCall(t *testing.T) {
 			},
 			want: "0x0000000000000000000000000000000000000000000000000000000000000000",
 		},
+		{
+			name:        "unsupported block override beaconRoot",
+			blockNumber: rpc.LatestBlockNumber,
+			call:        TransactionArgs{},
+			blockOverrides: override.BlockOverrides{
+				BeaconRoot: &common.Hash{0, 1, 2},
+			},
+			expectErr: errors.New(`block override "beaconRoot" is not supported for this RPC method`),
+		},
+		{
+			name:        "unsupported block override withdrawals",
+			blockNumber: rpc.LatestBlockNumber,
+			call:        TransactionArgs{},
+			blockOverrides: override.BlockOverrides{
+				Withdrawals: &types.Withdrawals{},
+			},
+			expectErr: errors.New(`block override "withdrawals" is not supported for this RPC method`),
+		},
 	}
 	for _, tc := range testSuite {
 		result, err := api.Call(context.Background(), tc.call, &rpc.BlockNumberOrHash{BlockNumber: &tc.blockNumber}, &tc.overrides, &tc.blockOverrides)

internal/ethapi/override/override.go

@@ -17,6 +17,7 @@
 package override
 
 import (
+	"errors"
 	"fmt"
 	"math/big"
 
@@ -128,12 +129,20 @@ type BlockOverrides struct {
 	PrevRandao    *common.Hash
 	BaseFeePerGas *hexutil.Big
 	BlobBaseFee   *hexutil.Big
+	BeaconRoot    *common.Hash
+	Withdrawals   *types.Withdrawals
 }
 
 // Apply overrides the given header fields into the given block context.
-func (o *BlockOverrides) Apply(blockCtx *vm.BlockContext) {
+func (o *BlockOverrides) Apply(blockCtx *vm.BlockContext) error {
 	if o == nil {
-		return
+		return nil
+	}
+	if o.BeaconRoot != nil {
+		return errors.New(`block override "beaconRoot" is not supported for this RPC method`)
+	}
+	if o.Withdrawals != nil {
+		return errors.New(`block override "withdrawals" is not supported for this RPC method`)
 	}
 	if o.Number != nil {
 		blockCtx.BlockNumber = o.Number.ToInt()
@@ -159,6 +168,7 @@ func (o *BlockOverrides) Apply(blockCtx *vm.BlockContext) {
 	if o.BlobBaseFee != nil {
 		blockCtx.BlobBaseFee = o.BlobBaseFee.ToInt()
 	}
+	return nil
 }
 
 // MakeHeader returns a new header object with the overridden

internal/ethapi/simulate.go

@@ -36,7 +36,6 @@ import (
 	"github.com/ethereum/go-ethereum/internal/ethapi/override"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
-	"github.com/ethereum/go-ethereum/trie"
 )
 
 const (
@@ -95,6 +94,47 @@ type simOpts struct {
 	ReturnFullTransactions bool
 }
 
+// simChainHeadReader implements ChainHeaderReader which is needed as input for FinalizeAndAssemble.
+type simChainHeadReader struct {
+	context.Context
+	Backend
+}
+
+func (m *simChainHeadReader) Config() *params.ChainConfig {
+	return m.Backend.ChainConfig()
+}
+
+func (m *simChainHeadReader) CurrentHeader() *types.Header {
+	return m.Backend.CurrentHeader()
+}
+
+func (m *simChainHeadReader) GetHeader(hash common.Hash, number uint64) *types.Header {
+	header, err := m.Backend.HeaderByNumber(m.Context, rpc.BlockNumber(number))
+	if err != nil || header == nil {
+		return nil
+	}
+	if header.Hash() != hash {
+		return nil
+	}
+	return header
+}
+
+func (m *simChainHeadReader) GetHeaderByNumber(number uint64) *types.Header {
+	header, err := m.Backend.HeaderByNumber(m.Context, rpc.BlockNumber(number))
+	if err != nil {
+		return nil
+	}
+	return header
+}
+
+func (m *simChainHeadReader) GetHeaderByHash(hash common.Hash) *types.Header {
+	header, err := m.Backend.HeaderByHash(m.Context, hash)
+	if err != nil {
+		return nil
+	}
+	return header
+}
+
 // simulator is a stateful object that simulates a series of blocks.
 // it is not safe for concurrent use.
 type simulator struct {
@@ -209,6 +249,9 @@ func (sim *simulator) processBlock(ctx context.Context, block *simBlock, header,
 	if sim.chainConfig.IsPrague(header.Number, header.Time) || sim.chainConfig.IsVerkle(header.Number, header.Time) {
 		core.ProcessParentBlockHash(header.ParentHash, evm)
 	}
+	if header.ParentBeaconRoot != nil {
+		core.ProcessBeaconBlockRoot(*header.ParentBeaconRoot, evm)
+	}
 	var allLogs []*types.Log
 	for i, call := range block.Calls {
 		if err := ctx.Err(); err != nil {
@@ -258,6 +301,10 @@ func (sim *simulator) processBlock(ctx context.Context, block *simBlock, header,
 		}
 		callResults[i] = callRes
 	}
+	header.GasUsed = gasUsed
+	if sim.chainConfig.IsCancun(header.Number, header.Time) {
+		header.BlobGasUsed = &blobGasUsed
+	}
 	var requests [][]byte
 	// Process EIP-7685 requests
 	if sim.chainConfig.IsPrague(header.Number, header.Time) {
@@ -271,20 +318,16 @@ func (sim *simulator) processBlock(ctx context.Context, block *simBlock, header,
 		// EIP-7251
 		core.ProcessConsolidationQueue(&requests, evm)
 	}
-	header.Root = sim.state.IntermediateRoot(true)
-	header.GasUsed = gasUsed
-	if sim.chainConfig.IsCancun(header.Number, header.Time) {
-		header.BlobGasUsed = &blobGasUsed
-	}
-	var withdrawals types.Withdrawals
-	if sim.chainConfig.IsShanghai(header.Number, header.Time) {
-		withdrawals = make([]*types.Withdrawal, 0)
-	}
 	if requests != nil {
 		reqHash := types.CalcRequestsHash(requests)
 		header.RequestsHash = &reqHash
 	}
-	b := types.NewBlock(header, &types.Body{Transactions: txes, Withdrawals: withdrawals}, receipts, trie.NewStackTrie(nil))
+	blockBody := &types.Body{Transactions: txes, Withdrawals: *block.BlockOverrides.Withdrawals}
+	chainHeadReader := &simChainHeadReader{ctx, sim.b}
+	b, err := sim.b.Engine().FinalizeAndAssemble(chainHeadReader, header, sim.state, blockBody, receipts)
+	if err != nil {
+		return nil, nil, err
+	}
 	repairLogs(callResults, b.Hash())
 	return b, callResults, nil
 }
@@ -346,6 +389,9 @@ func (sim *simulator) sanitizeChain(blocks []simBlock) ([]simBlock, error) {
 			n := new(big.Int).Add(prevNumber, big.NewInt(1))
 			block.BlockOverrides.Number = (*hexutil.Big)(n)
 		}
+		if block.BlockOverrides.Withdrawals == nil {
+			block.BlockOverrides.Withdrawals = &types.Withdrawals{}
+		}
 		diff := new(big.Int).Sub(block.BlockOverrides.Number.ToInt(), prevNumber)
 		if diff.Cmp(common.Big0) <= 0 {
 			return nil, &invalidBlockNumberError{fmt.Sprintf("block numbers must be in order: %d <= %d", block.BlockOverrides.Number.ToInt().Uint64(), prevNumber)}
@@ -360,7 +406,13 @@ func (sim *simulator) sanitizeChain(blocks []simBlock) ([]simBlock, error) {
 			for i := uint64(0); i < gap.Uint64(); i++ {
 				n := new(big.Int).Add(prevNumber, big.NewInt(int64(i+1)))
 				t := prevTimestamp + timestampIncrement
-				b := simBlock{BlockOverrides: &override.BlockOverrides{Number: (*hexutil.Big)(n), Time: (*hexutil.Uint64)(&t)}}
+				b := simBlock{
+					BlockOverrides: &override.BlockOverrides{
+						Number:      (*hexutil.Big)(n),
+						Time:        (*hexutil.Uint64)(&t),
+						Withdrawals: &types.Withdrawals{},
+					},
+				}
 				prevTimestamp = t
 				res = append(res, b)
 			}
@@ -405,6 +457,9 @@ func (sim *simulator) makeHeaders(blocks []simBlock) ([]*types.Header, error) {
 		var parentBeaconRoot *common.Hash
 		if sim.chainConfig.IsCancun(overrides.Number.ToInt(), (uint64)(*overrides.Time)) {
 			parentBeaconRoot = &common.Hash{}
+			if overrides.BeaconRoot != nil {
+				parentBeaconRoot = overrides.BeaconRoot
+			}
 		}
 		header = overrides.MakeHeader(&types.Header{
 			UncleHash:        types.EmptyUncleHash,