internal/ethapi: add block overrides to eth_call (#26414)

Adds an optional config parameter to eth_call which allows users to override block context fields (same functionality that was added to traceCall in #24871)

---------

Co-authored-by: Martin Holst Swende <martin@swende.se>

internal/ethapi/api.go

@@ -33,6 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core"
@@ -955,7 +956,39 @@ func (diff *BlockOverrides) Apply(blockCtx *vm.BlockContext) {
 	}
 }
 
-func DoCall(ctx context.Context, b Backend, args TransactionArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *StateOverride, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
+// ChainContextBackend provides methods required to implement ChainContext.
+type ChainContextBackend interface {
+	Engine() consensus.Engine
+	HeaderByNumber(context.Context, rpc.BlockNumber) (*types.Header, error)
+}
+
+// ChainContext is an implementation of core.ChainContext. It's main use-case
+// is instantiating a vm.BlockContext without having access to the BlockChain object.
+type ChainContext struct {
+	b   ChainContextBackend
+	ctx context.Context
+}
+
+// NewChainContext creates a new ChainContext object.
+func NewChainContext(ctx context.Context, backend ChainContextBackend) *ChainContext {
+	return &ChainContext{ctx: ctx, b: backend}
+}
+
+func (context *ChainContext) Engine() consensus.Engine {
+	return context.b.Engine()
+}
+
+func (context *ChainContext) GetHeader(hash common.Hash, number uint64) *types.Header {
+	// This method is called to get the hash for a block number when executing the BLOCKHASH
+	// opcode. Hence no need to search for non-canonical blocks.
+	header, err := context.b.HeaderByNumber(context.ctx, rpc.BlockNumber(number))
+	if err != nil || header.Hash() != hash {
+		return nil
+	}
+	return header
+}
+
+func DoCall(ctx context.Context, b Backend, args TransactionArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *StateOverride, blockOverrides *BlockOverrides, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
 	defer func(start time.Time) { log.Debug("Executing EVM call finished", "runtime", time.Since(start)) }(time.Now())
 
 	state, header, err := b.StateAndHeaderByNumberOrHash(ctx, blockNrOrHash)
@@ -982,7 +1015,11 @@ func DoCall(ctx context.Context, b Backend, args TransactionArgs, blockNrOrHash
 	if err != nil {
 		return nil, err
 	}
-	evm, vmError, err := b.GetEVM(ctx, msg, state, header, &vm.Config{NoBaseFee: true})
+	blockCtx := core.NewEVMBlockContext(header, NewChainContext(ctx, b), nil)
+	if blockOverrides != nil {
+		blockOverrides.Apply(&blockCtx)
+	}
+	evm, vmError, err := b.GetEVM(ctx, msg, state, header, &vm.Config{NoBaseFee: true}, &blockCtx)
 	if err != nil {
 		return nil, err
 	}
@@ -1046,8 +1083,8 @@ func (e *revertError) ErrorData() interface{} {
 //
 // Note, this function doesn't make and changes in the state/blockchain and is
 // useful to execute and retrieve values.
-func (s *BlockChainAPI) Call(ctx context.Context, args TransactionArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *StateOverride) (hexutil.Bytes, error) {
-	result, err := DoCall(ctx, s.b, args, blockNrOrHash, overrides, s.b.RPCEVMTimeout(), s.b.RPCGasCap())
+func (s *BlockChainAPI) Call(ctx context.Context, args TransactionArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *StateOverride, blockOverrides *BlockOverrides) (hexutil.Bytes, error) {
+	result, err := DoCall(ctx, s.b, args, blockNrOrHash, overrides, blockOverrides, s.b.RPCEVMTimeout(), s.b.RPCGasCap())
 	if err != nil {
 		return nil, err
 	}
@@ -1132,7 +1169,7 @@ func DoEstimateGas(ctx context.Context, b Backend, args TransactionArgs, blockNr
 	executable := func(gas uint64) (bool, *core.ExecutionResult, error) {
 		args.Gas = (*hexutil.Uint64)(&gas)
 
-		result, err := DoCall(ctx, b, args, blockNrOrHash, nil, 0, gasCap)
+		result, err := DoCall(ctx, b, args, blockNrOrHash, nil, nil, 0, gasCap)
 		if err != nil {
 			if errors.Is(err, core.ErrIntrinsicGas) {
 				return true, nil, nil // Special case, raise gas limit
@@ -1478,7 +1515,7 @@ func AccessList(ctx context.Context, b Backend, blockNrOrHash rpc.BlockNumberOrH
 		// Apply the transaction with the access list tracer
 		tracer := logger.NewAccessListTracer(accessList, args.from(), to, precompiles)
 		config := vm.Config{Tracer: tracer, NoBaseFee: true}
-		vmenv, _, err := b.GetEVM(ctx, msg, statedb, header, &config)
+		vmenv, _, err := b.GetEVM(ctx, msg, statedb, header, &config, nil)
 		if err != nil {
 			return nil, 0, nil, err
 		}