core/state, core/vm: implement createcontract journal event

Author: holiman

core/state/journal.go

@@ -105,6 +105,11 @@ type (
 	createObjectChange struct {
 		account *common.Address
 	}
+
+	createContractChange struct {
+		account common.Address
+	}
+
 	selfDestructChange struct {
 		account     *common.Address
 		prev        bool // whether account had already self-destructed
@@ -173,6 +178,20 @@ func (ch createObjectChange) copy() journalEntry {
 	}
 }
 
+func (ch createContractChange) revert(s *StateDB) {
+	s.stateObjects[ch.account].created = false
+}
+
+func (ch createContractChange) dirtied() *common.Address {
+	return &ch.account
+}
+
+func (ch createContractChange) copy() journalEntry {
+	return createContractChange{
+		account: ch.account,
+	}
+}
+
 func (ch selfDestructChange) revert(s *StateDB) {
 	obj := s.getStateObject(*ch.account)
 	if obj != nil {

core/state/statedb.go

@@ -662,6 +662,19 @@ func (s *StateDB) CreateAccount(addr common.Address) {
 	s.createObject(addr)
 }
 
+// CreateContract is used whenever a contract is created. This may be preceded
+// by CreateAccount, but that is not required if it already existed
+// in the state due to funds sent beforehand.
+// This operation sets the 'created'-flag, which is required in order to
+// correctly handle EIP-6780 'delete-in-same-transaction' logic.
+func (s *StateDB) CreateContract(addr common.Address) {
+	obj := s.getStateObject(addr)
+	if !obj.created {
+		obj.created = true
+		s.journal.append(createContractChange{account: addr})
+	}
+}
+
 // Copy creates a deep, independent copy of the state.
 // Snapshots of the copied state cannot be applied to the copy.
 func (s *StateDB) Copy() *StateDB {

core/vm/evm.go

@@ -462,6 +462,12 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 	if !evm.StateDB.Exist(address) {
 		evm.StateDB.CreateAccount(address)
 	}
+	// CreateContract means that regardless of whether the acccount existed
+	// in the state trie or not, previously, it _now_ becomes created as a
+	// _contract_ account. This is performed _prior_ to executing the initcode,
+	// since the initcode acts inside that account.
+	evm.StateDB.CreateContract(address)
+
 	if evm.chainRules.IsEIP158 {
 		evm.StateDB.SetNonce(address, 1)
 	}

core/vm/interface.go

@@ -29,6 +29,7 @@ import (
 // StateDB is an EVM database for full state querying.
 type StateDB interface {
 	CreateAccount(common.Address)
+	CreateContract(common.Address)
 
 	SubBalance(common.Address, *uint256.Int, tracing.BalanceChangeReason)
 	AddBalance(common.Address, *uint256.Int, tracing.BalanceChangeReason)