core/vm: return delegation designator prefix for code reading ops

Author: lightclient

core/vm/eips.go

@@ -23,6 +23,8 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/tracing"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
 )
@@ -718,8 +720,10 @@ func opExtCodeCopyEIP7702(pc *uint64, interpreter *EVMInterpreter, scope *ScopeC
 	if overflow {
 		uint64CodeOffset = math.MaxUint64
 	}
-	addr := common.Address(a.Bytes20())
-	code := interpreter.evm.resolveCode(addr)
+	code := interpreter.evm.StateDB.GetCode(common.Address(a.Bytes20()))
+	if _, ok := types.ParseDelegation(code); ok {
+		code = types.DelegationPrefix[:2]
+	}
 	codeCopy := getData(code, uint64CodeOffset, length.Uint64())
 	scope.Memory.Set(memOffset.Uint64(), length.Uint64(), codeCopy)
 
@@ -729,18 +733,29 @@ func opExtCodeCopyEIP7702(pc *uint64, interpreter *EVMInterpreter, scope *ScopeC
 // opExtCodeSizeEIP7702 implements the EIP-7702 variation of opExtCodeSize.
 func opExtCodeSizeEIP7702(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
 	slot := scope.Stack.peek()
-	slot.SetUint64(uint64(len(interpreter.evm.resolveCode(slot.Bytes20()))))
+	code := interpreter.evm.StateDB.GetCode(common.Address(slot.Bytes20()))
+	if _, ok := types.ParseDelegation(code); ok {
+		code = types.DelegationPrefix[:2]
+	}
+	slot.SetUint64(uint64(len(code)))
 	return nil, nil
 }
 
 // opExtCodeHashEIP7702 implements the EIP-7702 variation of opExtCodeHash.
 func opExtCodeHashEIP7702(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
 	slot := scope.Stack.peek()
-	address := common.Address(slot.Bytes20())
-	if interpreter.evm.StateDB.Empty(address) {
+	addr := common.Address(slot.Bytes20())
+	if interpreter.evm.StateDB.Empty(addr) {
 		slot.Clear()
+		return nil, nil
+	}
+	code := interpreter.evm.StateDB.GetCode(addr)
+	if _, ok := types.ParseDelegation(code); ok {
+		// If the code is a delegation, return the prefix without version.
+		slot.SetBytes(crypto.Keccak256(types.DelegationPrefix[:2]))
 	} else {
-		slot.SetBytes(interpreter.evm.resolveCodeHash(address).Bytes())
+		// Otherwise, return normal code hash.
+		slot.SetBytes(interpreter.evm.StateDB.GetCodeHash(addr).Bytes())
 	}
 	return nil, nil
 }

core/vm/evm.go

@@ -583,7 +583,8 @@ func (evm *EVM) resolveCode(addr common.Address) []byte {
 
 // resolveCodeHash returns the code hash associated with the provided address.
 // After Prague, it can also resolve code hash of the account pointed to by a
-// delegation designator.
+// delegation designator. Although this is not accessible in the EVM it is used
+// internally to associate jumpdest analysis to code.
 func (evm *EVM) resolveCodeHash(addr common.Address) common.Hash {
 	if evm.chainRules.IsPrague {
 		code := evm.StateDB.GetCode(addr)