core/vm: use types.EmptyCodeHash (#27729)

core/vm/evm.go

@@ -21,15 +21,12 @@ import (
 	"sync/atomic"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
 )
 
-// emptyCodeHash is used by create to ensure deployment is disallowed to already
-// deployed contract addresses (relevant after the account abstraction).
-var emptyCodeHash = crypto.Keccak256Hash(nil)
-
 type (
 	// CanTransferFunc is the signature of a transfer guard function
 	CanTransferFunc func(StateDB, common.Address, *big.Int) bool
@@ -438,7 +435,7 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 	}
 	// Ensure there's no existing contract already at the designated address
 	contractHash := evm.StateDB.GetCodeHash(address)
-	if evm.StateDB.GetNonce(address) != 0 || (contractHash != (common.Hash{}) && contractHash != emptyCodeHash) {
+	if evm.StateDB.GetNonce(address) != 0 || (contractHash != (common.Hash{}) && contractHash != types.EmptyCodeHash) {
 		return nil, common.Address{}, 0, ErrContractAddressCollision
 	}
 	// Create a new account on the state

core/vm/instructions_test.go

@@ -725,7 +725,7 @@ func TestRandom(t *testing.T) {
 	for _, tt := range []testcase{
 		{name: "empty hash", random: common.Hash{}},
 		{name: "1", random: common.Hash{0}},
-		{name: "emptyCodeHash", random: emptyCodeHash},
+		{name: "emptyCodeHash", random: types.EmptyCodeHash},
 		{name: "hash(0x010203)", random: crypto.Keccak256Hash([]byte{0x01, 0x02, 0x03})},
 	} {
 		var (