core, core/types: plain Message struct (#25977)

Here, the core.Message interface turns into a plain struct and
types.Message gets removed.

This is a breaking change to packages core and core/types. While we do
not promise API stability for package core, we do for core/types. An
exception can be made for types.Message, since it doesn't have any
purpose apart from invoking the state transition in package core.
types.Message was also marked deprecated by the same commit it
got added in, 4dca5d4 (November 2016).

The core.Message interface was added in December 2014, in commit
db49417, for the purpose of 'testing' state transitions. It's the
same change that made transaction struct fields private. Before that,
the state transition used *types.Transaction directly.

Over time, multiple implementations of the interface accrued across
different packages, since constructing a Message is required whenever
one wants to invoke the state transition. These implementations all
looked very similar, a struct with private fields exposing the fields
as accessor methods.

By changing Message into a struct with public fields we can remove all
these useless interface implementations. It will also hopefully
simplify future changes to the type with less updates to apply across
all of go-ethereum when a field is added to Message.

---------

Co-authored-by: Felix Lange <fjl@twurst.com>

accounts/abi/bind/backends/simulated.go

@@ -644,20 +644,33 @@ func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallM
 	if call.Value == nil {
 		call.Value = new(big.Int)
 	}
+
 	// Set infinite balance to the fake caller account.
 	from := stateDB.GetOrNewStateObject(call.From)
 	from.SetBalance(math.MaxBig256)
+
 	// Execute the call.
-	msg := callMsg{call}
+	msg := &core.Message{
+		From:              call.From,
+		To:                call.To,
+		Value:             call.Value,
+		GasLimit:          call.Gas,
+		GasPrice:          call.GasPrice,
+		GasFeeCap:         call.GasFeeCap,
+		GasTipCap:         call.GasTipCap,
+		Data:              call.Data,
+		AccessList:        call.AccessList,
+		SkipAccountChecks: true,
+	}
 
-	txContext := core.NewEVMTxContext(msg)
-	evmContext := core.NewEVMBlockContext(header, b.blockchain, nil)
 	// Create a new environment which holds all relevant information
 	// about the transaction and calling mechanisms.
+	txContext := core.NewEVMTxContext(msg)
+	evmContext := core.NewEVMBlockContext(header, b.blockchain, nil)
 	vmEnv := vm.NewEVM(evmContext, txContext, stateDB, b.config, vm.Config{NoBaseFee: true})
 	gasPool := new(core.GasPool).AddGas(math.MaxUint64)
 
-	return core.NewStateTransition(vmEnv, msg, gasPool).TransitionDb()
+	return core.ApplyMessage(vmEnv, msg, gasPool)
 }
 
 // SendTransaction updates the pending block to include the given transaction.
@@ -821,23 +834,6 @@ func (b *SimulatedBackend) Blockchain() *core.BlockChain {
 	return b.blockchain
 }
 
-// callMsg implements core.Message to allow passing it as a transaction simulator.
-type callMsg struct {
-	ethereum.CallMsg
-}
-
-func (m callMsg) From() common.Address         { return m.CallMsg.From }
-func (m callMsg) Nonce() uint64                { return 0 }
-func (m callMsg) IsFake() bool                 { return true }
-func (m callMsg) To() *common.Address          { return m.CallMsg.To }
-func (m callMsg) GasPrice() *big.Int           { return m.CallMsg.GasPrice }
-func (m callMsg) GasFeeCap() *big.Int          { return m.CallMsg.GasFeeCap }
-func (m callMsg) GasTipCap() *big.Int          { return m.CallMsg.GasTipCap }
-func (m callMsg) Gas() uint64                  { return m.CallMsg.Gas }
-func (m callMsg) Value() *big.Int              { return m.CallMsg.Value }
-func (m callMsg) Data() []byte                 { return m.CallMsg.Data }
-func (m callMsg) AccessList() types.AccessList { return m.CallMsg.AccessList }
-
 // filterBackend implements filters.Backend to support filtering for logs without
 // taking bloom-bits acceleration structures into account.
 type filterBackend struct {

cmd/evm/internal/t8ntool/execution.go

@@ -163,7 +163,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 	}
 
 	for i, tx := range txs {
-		msg, err := tx.AsMessage(signer, pre.Env.BaseFee)
+		msg, err := core.TransactionToMessage(tx, signer, pre.Env.BaseFee)
 		if err != nil {
 			log.Warn("rejected tx", "index", i, "hash", tx.Hash(), "error", err)
 			rejectedTxs = append(rejectedTxs, &rejectedTx{i, err.Error()})
@@ -188,7 +188,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 		msgResult, err := core.ApplyMessage(evm, msg, gaspool)
 		if err != nil {
 			statedb.RevertToSnapshot(snapshot)
-			log.Info("rejected tx", "index", i, "hash", tx.Hash(), "from", msg.From(), "error", err)
+			log.Info("rejected tx", "index", i, "hash", tx.Hash(), "from", msg.From, "error", err)
 			rejectedTxs = append(rejectedTxs, &rejectedTx{i, err.Error()})
 			gaspool.SetGas(prevGas)
 			continue
@@ -220,7 +220,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 			receipt.GasUsed = msgResult.UsedGas
 
 			// If the transaction created a contract, store the creation address in the receipt.
-			if msg.To() == nil {
+			if msg.To == nil {
 				receipt.ContractAddress = crypto.CreateAddress(evm.TxContext.Origin, tx.Nonce())
 			}
 

core/evm.go

@@ -70,10 +70,10 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 }
 
 // NewEVMTxContext creates a new transaction context for a single transaction.
-func NewEVMTxContext(msg Message) vm.TxContext {
+func NewEVMTxContext(msg *Message) vm.TxContext {
 	return vm.TxContext{
-		Origin:   msg.From(),
-		GasPrice: new(big.Int).Set(msg.GasPrice()),
+		Origin:   msg.From,
+		GasPrice: new(big.Int).Set(msg.GasPrice),
 	}
 }
 

core/state_prefetcher.go

@@ -63,7 +63,7 @@ func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, c
 			return
 		}
 		// Convert the transaction into an executable message and pre-cache its sender
-		msg, err := tx.AsMessage(signer, header.BaseFee)
+		msg, err := TransactionToMessage(tx, signer, header.BaseFee)
 		if err != nil {
 			return // Also invalid block, bail out
 		}
@@ -85,7 +85,7 @@ func (p *statePrefetcher) Prefetch(block *types.Block, statedb *state.StateDB, c
 // precacheTransaction attempts to apply a transaction to the given state database
 // and uses the input parameters for its environment. The goal is not to execute
 // the transaction successfully, rather to warm up touched data slots.
-func precacheTransaction(msg types.Message, config *params.ChainConfig, gaspool *GasPool, statedb *state.StateDB, header *types.Header, evm *vm.EVM) error {
+func precacheTransaction(msg *Message, config *params.ChainConfig, gaspool *GasPool, statedb *state.StateDB, header *types.Header, evm *vm.EVM) error {
 	// Update the evm with the new transaction context.
 	evm.Reset(NewEVMTxContext(msg), statedb)
 	// Add addresses to access list if applicable

core/state_processor.go

@@ -74,7 +74,7 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, p.config, cfg)
 	// Iterate over and process the individual transactions
 	for i, tx := range block.Transactions() {
-		msg, err := tx.AsMessage(types.MakeSigner(p.config, header.Number), header.BaseFee)
+		msg, err := TransactionToMessage(tx, types.MakeSigner(p.config, header.Number), header.BaseFee)
 		if err != nil {
 			return nil, nil, 0, fmt.Errorf("could not apply tx %d [%v]: %w", i, tx.Hash().Hex(), err)
 		}
@@ -97,7 +97,7 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	return receipts, allLogs, *usedGas, nil
 }
 
-func applyTransaction(msg types.Message, config *params.ChainConfig, gp *GasPool, statedb *state.StateDB, blockNumber *big.Int, blockHash common.Hash, tx *types.Transaction, usedGas *uint64, evm *vm.EVM) (*types.Receipt, error) {
+func applyTransaction(msg *Message, config *params.ChainConfig, gp *GasPool, statedb *state.StateDB, blockNumber *big.Int, blockHash common.Hash, tx *types.Transaction, usedGas *uint64, evm *vm.EVM) (*types.Receipt, error) {
 	// Create a new context to be used in the EVM environment.
 	txContext := NewEVMTxContext(msg)
 	evm.Reset(txContext, statedb)
@@ -129,7 +129,7 @@ func applyTransaction(msg types.Message, config *params.ChainConfig, gp *GasPool
 	receipt.GasUsed = result.UsedGas
 
 	// If the transaction created a contract, store the creation address in the receipt.
-	if msg.To() == nil {
+	if msg.To == nil {
 		receipt.ContractAddress = crypto.CreateAddress(evm.TxContext.Origin, tx.Nonce())
 	}
 
@@ -147,7 +147,7 @@ func applyTransaction(msg types.Message, config *params.ChainConfig, gp *GasPool
 // for the transaction, gas used and an error if the transaction failed,
 // indicating the block was invalid.
 func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config) (*types.Receipt, error) {
-	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number), header.BaseFee)
+	msg, err := TransactionToMessage(tx, types.MakeSigner(config, header.Number), header.BaseFee)
 	if err != nil {
 		return nil, err
 	}