cmd/evm, core, tests: review changes

accounts/abi/bind/backends/simulated.go

@@ -226,7 +226,7 @@ func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallM
 	// Execute the call.
 	msg := callmsg{call}
 
-	evmContext := core.ToEVMContext(msg, block.Header(), b.blockchain)
+	evmContext := core.NewEVMContext(msg, block.Header(), b.blockchain)
 	// Create a new environment which holds all relevant information
 	// about the transaction and calling mechanisms.
 	vmenv := vm.NewEnvironment(evmContext, statedb, chainConfig, vm.Config{})

cmd/evm/main.go

@@ -162,6 +162,7 @@ func run(ctx *cli.Context) error {
 			Origin:   sender.Address(),
 			State:    statedb,
 			GasLimit: common.Big(ctx.GlobalString(GasFlag.Name)),
+			GasPrice: common.Big(ctx.GlobalString(PriceFlag.Name)),
 			Value:    common.Big(ctx.GlobalString(ValueFlag.Name)),
 			EVMConfig: vm.Config{
 				Tracer: logger,
@@ -175,6 +176,7 @@ func run(ctx *cli.Context) error {
 			Origin:   sender.Address(),
 			State:    statedb,
 			GasLimit: common.Big(ctx.GlobalString(GasFlag.Name)),
+			GasPrice: common.Big(ctx.GlobalString(PriceFlag.Name)),
 			Value:    common.Big(ctx.GlobalString(ValueFlag.Name)),
 			EVMConfig: vm.Config{
 				Tracer: logger,

core/evm.go

@@ -1,5 +1,4 @@
 // Copyright 2014 The go-ethereum Authors
-
 // This file is part of the go-ethereum library.
 //
 // The go-ethereum library is free software: you can redistribute it and/or modify
@@ -26,13 +25,13 @@ import (
 )
 
 // BlockFetcher retrieves headers by their hash
-type BlockFetcher interface {
+type HeaderFetcher interface {
 	// GetHeader returns the hash corresponding to their hash
 	GetHeader(common.Hash, uint64) *types.Header
 }
 
-// ToEVMContext creates a new context for use in the EVM.
+// NewEVMContext creates a new context for use in the EVM.
-func ToEVMContext(msg Message, header *types.Header, chain BlockFetcher) vm.Context {
+func NewEVMContext(msg Message, header *types.Header, chain HeaderFetcher) vm.Context {
 	return vm.Context{
 		CanTransfer: CanTransfer,
 		Transfer:    Transfer,
@@ -48,10 +47,8 @@ func ToEVMContext(msg Message, header *types.Header, chain BlockFetcher) vm.Cont
 	}
 }
 
-// GetHashFn returns a function for which the VM env can query block hashes through
+// GetHashFn returns a GetHashFunc which retrieves header hashes by number
-// up to the limit defined by the Yellow Paper and uses the given block chain
+func GetHashFn(ref *types.Header, chain HeaderFetcher) func(n uint64) common.Hash {
-// to query for information.
-func GetHashFn(ref *types.Header, chain BlockFetcher) func(n uint64) common.Hash {
 	return func(n uint64) common.Hash {
 		for header := chain.GetHeader(ref.ParentHash, ref.Number.Uint64()-1); header != nil; header = chain.GetHeader(header.ParentHash, header.Number.Uint64()-1) {
 			if header.Number.Uint64() == n {
@@ -64,6 +61,7 @@ func GetHashFn(ref *types.Header, chain BlockFetcher) func(n uint64) common.Hash
 }
 
 // CanTransfer checks wether there are enough funds in the address' account to make a transfer.
+// This does not take the necessary gas in to account to make the transfer valid.
 func CanTransfer(db vm.StateDB, addr common.Address, amount *big.Int) bool {
 	return db.GetBalance(addr).Cmp(amount) >= 0
 }

core/state/statedb.go

@@ -293,6 +293,7 @@ func (self *StateDB) HasSuicided(addr common.Address) bool {
  * SETTERS
  */
 
+// AddBalance adds amount to the account associated with addr
 func (self *StateDB) AddBalance(addr common.Address, amount *big.Int) {
 	stateObject := self.GetOrNewStateObject(addr)
 	if stateObject != nil {
@@ -300,6 +301,7 @@ func (self *StateDB) AddBalance(addr common.Address, amount *big.Int) {
 	}
 }
 
+// SubBalance subtracts amount from the account associated with addr
 func (self *StateDB) SubBalance(addr common.Address, amount *big.Int) {
 	stateObject := self.GetOrNewStateObject(addr)
 	if stateObject != nil {

core/state_processor.go

@@ -97,7 +97,7 @@ func ApplyTransaction(config *params.ChainConfig, bc *BlockChain, gp *GasPool, s
 		return nil, nil, nil, err
 	}
 	// Create a new context to be used in the EVM environment
-	context := ToEVMContext(msg, header, bc)
+	context := NewEVMContext(msg, header, bc)
 	// Create a new environment which holds all relevant information
 	// about the transaction and calling mechanisms.
 	vmenv := vm.NewEnvironment(context, statedb, config, vm.Config{})

core/vm/environment.go

@@ -74,17 +74,20 @@ type Environment struct {
 }
 
 // NewEnvironment retutrns a new EVM environment.
-func NewEnvironment(context Context, statedb StateDB, chainConfig *params.ChainConfig, vmCfg Config) *Environment {
+func NewEnvironment(context Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *Environment {
 	env := &Environment{
 		Context:     context,
 		StateDB:     statedb,
-		vmConfig:    vmCfg,
+		vmConfig:    vmConfig,
 		chainConfig: chainConfig,
 	}
-	env.evm = New(env, vmCfg)
+	env.evm = New(env, vmConfig)
 	return env
 }
 
+// Call executes the contract associated with the addr with the given input as paramaters. It also handles any
+// necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
+// case of an execution error or failed value transfer.
 func (env *Environment) Call(caller ContractRef, addr common.Address, input []byte, gas, value *big.Int) ([]byte, error) {
 	if env.vmConfig.NoRecursion && env.Depth > 0 {
 		caller.ReturnGas(gas)
@@ -140,7 +143,11 @@ func (env *Environment) Call(caller ContractRef, addr common.Address, input []by
 	return ret, err
 }
 
-// Take another's contract code and execute within our own context
+// CallCode executes the contract associated with the addr with the given input as paramaters. It also handles any
+// necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
+// case of an execution error or failed value transfer.
+//
+// CallCode differs from Call in the sense that it executes the given address' code with the caller as context.
 func (env *Environment) CallCode(caller ContractRef, addr common.Address, input []byte, gas, value *big.Int) ([]byte, error) {
 	if env.vmConfig.NoRecursion && env.Depth > 0 {
 		caller.ReturnGas(gas)
@@ -182,7 +189,11 @@ func (env *Environment) CallCode(caller ContractRef, addr common.Address, input
 	return ret, err
 }
 
-// Same as CallCode except sender and value is propagated from parent to child scope
+// DelegateCall executes the contract associated with the addr with the given input as paramaters.
+// It reverses the state in case of an execution error.
+//
+// DelegateCall differs from CallCode in the sense that it executes the given address' code with the caller as context
+// and the caller is set to the caller of the caller.
 func (env *Environment) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas *big.Int) ([]byte, error) {
 	if env.vmConfig.NoRecursion && env.Depth > 0 {
 		caller.ReturnGas(gas)
@@ -217,7 +228,7 @@ func (env *Environment) DelegateCall(caller ContractRef, addr common.Address, in
 	return ret, err
 }
 
-// Create a new contract
+// Create creates a new contract using code as deployment code.
 func (env *Environment) Create(caller ContractRef, code []byte, gas, value *big.Int) ([]byte, common.Address, error) {
 	if env.vmConfig.NoRecursion && env.Depth > 0 {
 		caller.ReturnGas(gas)

eth/api.go

@@ -515,7 +515,7 @@ func (api *PrivateDebugAPI) TraceTransaction(ctx context.Context, txHash common.
 		if err != nil {
 			return nil, fmt.Errorf("sender retrieval failed: %v", err)
 		}
-		context := core.ToEVMContext(msg, block.Header(), api.eth.BlockChain())
+		context := core.NewEVMContext(msg, block.Header(), api.eth.BlockChain())
 
 		// Mutate the state if we haven't reached the tracing transaction yet
 		if uint64(idx) < txIndex {

eth/api_backend.go

@@ -112,7 +112,7 @@ func (b *EthApiBackend) GetVMEnv(ctx context.Context, msg core.Message, state et
 	from.SetBalance(common.MaxBig)
 	vmError := func() error { return nil }
 
-	context := core.ToEVMContext(msg, header, b.eth.BlockChain())
+	context := core.NewEVMContext(msg, header, b.eth.BlockChain())
 	return vm.NewEnvironment(context, statedb, b.eth.chainConfig, vm.Config{}), vmError, nil
 }
 

les/api_backend.go

@@ -98,7 +98,7 @@ func (b *LesApiBackend) GetVMEnv(ctx context.Context, msg core.Message, state et
 	from.SetBalance(common.MaxBig)
 
 	vmstate := light.NewVMState(ctx, stateDb)
-	context := core.ToEVMContext(msg, header, b.eth.blockchain)
+	context := core.NewEVMContext(msg, header, b.eth.blockchain)
 	return vm.NewEnvironment(context, vmstate, b.eth.chainConfig, vm.Config{}), vmstate.Error, nil
 }
 

les/odr_test.go

@@ -122,7 +122,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, config *params.Chai
 
 				msg := callmsg{types.NewMessage(from.Address(), &testContractAddr, 0, new(big.Int), big.NewInt(100000), new(big.Int), data, false)}
 
-				context := core.ToEVMContext(msg, header, bc)
+				context := core.NewEVMContext(msg, header, bc)
 				vmenv := vm.NewEnvironment(context, statedb, config, vm.Config{})
 
 				//vmenv := core.NewEnv(statedb, config, bc, msg, header, vm.Config{})
@@ -140,7 +140,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, config *params.Chai
 
 				msg := callmsg{types.NewMessage(from.Address(), &testContractAddr, 0, new(big.Int), big.NewInt(100000), new(big.Int), data, false)}
 
-				context := core.ToEVMContext(msg, header, lc)
+				context := core.NewEVMContext(msg, header, lc)
 				vmenv := vm.NewEnvironment(context, vmstate, config, vm.Config{})
 
 				//vmenv := light.NewEnv(ctx, state, config, lc, msg, header, vm.Config{})

light/odr_test.go

@@ -171,7 +171,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, bc *core.BlockChain
 
 				msg := callmsg{types.NewMessage(from.Address(), &testContractAddr, 0, new(big.Int), big.NewInt(1000000), new(big.Int), data, false)}
 
-				context := core.ToEVMContext(msg, header, bc)
+				context := core.NewEVMContext(msg, header, bc)
 				vmenv := vm.NewEnvironment(context, statedb, config, vm.Config{})
 
 				gp := new(core.GasPool).AddGas(common.MaxBig)
@@ -187,7 +187,7 @@ func odrContractCall(ctx context.Context, db ethdb.Database, bc *core.BlockChain
 				from.SetBalance(common.MaxBig)
 
 				msg := callmsg{types.NewMessage(from.Address(), &testContractAddr, 0, new(big.Int), big.NewInt(1000000), new(big.Int), data, false)}
-				context := core.ToEVMContext(msg, header, lc)
+				context := core.NewEVMContext(msg, header, lc)
 				vmenv := vm.NewEnvironment(context, vmstate, config, vm.Config{})
 				gp := new(core.GasPool).AddGas(common.MaxBig)
 				ret, _, _ := core.ApplyMessage(vmenv, msg, gp)

tests/state_test_util.go

@@ -221,43 +221,4 @@ func RunState(chainConfig *params.ChainConfig, statedb *state.StateDB, env, tx m
 	statedb.Commit(chainConfig.IsEIP158(environment.Context.BlockNumber))
 
 	return ret, statedb.Logs(), gasUsed, err
-	/*
-
-		var (
-			data  = common.FromHex(tx["data"])
-			gas   = common.Big(tx["gasLimit"])
-			price = common.Big(tx["gasPrice"])
-			value = common.Big(tx["value"])
-			nonce = common.Big(tx["nonce"]).Uint64()
-		)
-
-		var to *common.Address
-		if len(tx["to"]) > 2 {
-			t := common.HexToAddress(tx["to"])
-			to = &t
-		}
-		// Set pre compiled contracts
-		vm.Precompiled = vm.PrecompiledContracts()
-		gaspool := new(core.GasPool).AddGas(common.Big(env["currentGasLimit"]))
-
-		key, _ := hex.DecodeString(tx["secretKey"])
-		addr := crypto.PubkeyToAddress(crypto.ToECDSA(key).PublicKey)
-
-		message := types.NewMessage(addr, to, nonce, value, gas, price, data, true)
-		vmenv := NewEnvFromMap(chainConfig, statedb, env, tx)
-		vmenv.origin = addr
-
-		root, _ := statedb.Commit(false)
-		statedb.Reset(root)
-
-		snapshot := statedb.Snapshot()
-
-		ret, _, err := core.ApplyMessage(vmenv, message, gaspool)
-		if core.IsNonceErr(err) || core.IsInvalidTxErr(err) || core.IsGasLimitErr(err) {
-			statedb.RevertToSnapshot(snapshot)
-		}
-		statedb.Commit(chainConfig.IsEIP158(vmenv.BlockNumber()))
-
-		return ret, vmenv.state.Logs(), vmenv.Gas, err
-	*/
 }