core/vm: implement opcode REVERT - eip#140

core/vm/evm.go

@@ -139,8 +139,9 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
  // above we revert to the snapshot and consume any gas remaining. Additionally
  // when we're in homestead this also counts for code storage gas errors.
  if err != nil {
- contract.UseGas(contract.Gas)
-
+ if err != errRevert {
+ contract.UseGas(contract.Gas)
+ }
  evm.StateDB.RevertToSnapshot(snapshot)
  }
  return ret, contract.Gas, err
@@ -177,7 +178,9 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 
  ret, err = evm.interpreter.Run(contract, input)
  if err != nil {
- contract.UseGas(contract.Gas)
+ if err != errRevert {
+ contract.UseGas(contract.Gas)
+ }
 
  evm.StateDB.RevertToSnapshot(snapshot)
  }
@@ -212,7 +215,9 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 
  ret, err = evm.interpreter.Run(contract, input)
  if err != nil {
- contract.UseGas(contract.Gas)
+ if err != errRevert {
+ contract.UseGas(contract.Gas)
+ }
 
  evm.StateDB.RevertToSnapshot(snapshot)
  }
@@ -275,10 +280,11 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
  // when we're in homestead this also counts for code storage gas errors.
  if maxCodeSizeExceeded ||
  (err != nil && (evm.ChainConfig().IsHomestead(evm.BlockNumber) || err != ErrCodeStoreOutOfGas)) {
- evm.StateDB.RevertToSnapshot(snapshot)
+ if err != errRevert {
+ contract.UseGas(contract.Gas)
+ }
 
- // Nothing should be returned when an error is thrown.
- return nil, contractAddr, 0, err
+ evm.StateDB.RevertToSnapshot(snapshot)
  }
  // If the vm returned with an error the return value should be set to nil.
  // This isn't consensus critical but merely to for behaviour reasons such as

core/vm/instructions.go

@@ -17,6 +17,7 @@
 package vm
 
 import (
+ "errors"
  "fmt"
  "math/big"
 
@@ -27,7 +28,10 @@ import (
  "github.com/ethereum/go-ethereum/params"
 )
 
-var bigZero = new(big.Int)
+var (
+ bigZero = new(big.Int)
+ errRevert = errors.New("standard throw")
+)
 
 func opAdd(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
  x, y := stack.pop(), stack.pop()
@@ -669,6 +673,20 @@ func opReturn(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *S
  return ret, nil
 }
 
+func opRevert(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+ // if not metropolis return an error. REVERT is not supported
+ // during pre-metropolis.
+ if !evm.ChainConfig().IsMetropolis(evm.BlockNumber) {
+ return nil, fmt.Errorf("invalid opcode %x", REVERT)
+ }
+
+ offset, size := stack.pop(), stack.pop()
+ ret := memory.GetPtr(offset.Int64(), size.Int64())
+
+ evm.interpreter.intPool.put(offset, size)
+ return ret, errRevert
+}
+
 func opStop(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
  return nil, nil
 }

core/vm/jump_table.go

@@ -390,6 +390,14 @@ func NewJumpTable() [256]operation {
  validateStack: makeStackFunc(0, 1),
  valid: true,
  },
+ // TODO:
+ // * Determine cost
+ REVERT: {
+ execute: opRevert,
+ gasCost: constGasFunc(GasFastestStep),
+ validateStack: makeStackFunc(2, 0),
+ valid: true,
+ },
  JUMPDEST: {
  execute: opJumpdest,
  gasCost: constGasFunc(params.JumpdestGas),

core/vm/opcodes.go

@@ -202,6 +202,7 @@ const (
  RETURN
  DELEGATECALL
 
+ REVERT = 0xfd
  SELFDESTRUCT = 0xff
 )
 
@@ -353,6 +354,7 @@ var opCodeToString = map[OpCode]string{
  CREATE: "CREATE",
  CALL: "CALL",
  RETURN: "RETURN",
+ REVERT: "REVERT",
  CALLCODE: "CALLCODE",
  DELEGATECALL: "DELEGATECALL",
  SELFDESTRUCT: "SELFDESTRUCT",
@@ -500,6 +502,7 @@ var stringToOp = map[string]OpCode{
  "CREATE": CREATE,
  "CALL": CALL,
  "RETURN": RETURN,
+ "REVERT": REVERT,
  "CALLCODE": CALLCODE,
  "SELFDESTRUCT": SELFDESTRUCT,
 }

params/config.go

@@ -25,26 +25,28 @@ import (
 
 // MainnetChainConfig is the chain parameters to run a node on the main network.
 var MainnetChainConfig = &ChainConfig{
- ChainId: MainNetChainID,
- HomesteadBlock: MainNetHomesteadBlock,
- DAOForkBlock: MainNetDAOForkBlock,
- DAOForkSupport: true,
- EIP150Block: MainNetHomesteadGasRepriceBlock,
- EIP150Hash: MainNetHomesteadGasRepriceHash,
- EIP155Block: MainNetSpuriousDragon,
- EIP158Block: MainNetSpuriousDragon,
+ ChainId: MainNetChainID,
+ HomesteadBlock: MainNetHomesteadBlock,
+ DAOForkBlock: MainNetDAOForkBlock,
+ DAOForkSupport: true,
+ EIP150Block: MainNetHomesteadGasRepriceBlock,
+ EIP150Hash: MainNetHomesteadGasRepriceHash,
+ EIP155Block: MainNetSpuriousDragon,
+ EIP158Block: MainNetSpuriousDragon,
+ MetropolisBlock: MainNetMetropolisBlock,
 }
 
 // TestnetChainConfig is the chain parameters to run a node on the test network.
 var TestnetChainConfig = &ChainConfig{
- ChainId: big.NewInt(3),
- HomesteadBlock: big.NewInt(0),
- DAOForkBlock: nil,
- DAOForkSupport: true,
- EIP150Block: big.NewInt(0),
- EIP150Hash: common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
- EIP155Block: big.NewInt(10),
- EIP158Block: big.NewInt(10),
+ ChainId: big.NewInt(3),
+ HomesteadBlock: big.NewInt(0),
+ DAOForkBlock: nil,
+ DAOForkSupport: true,
+ EIP150Block: big.NewInt(0),
+ EIP150Hash: common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
+ EIP155Block: big.NewInt(10),
+ EIP158Block: big.NewInt(10),
+ MetropolisBlock: big.NewInt(0),
 }
 
 // AllProtocolChanges contains every protocol change (EIPs)
@@ -55,7 +57,7 @@ var TestnetChainConfig = &ChainConfig{
 // means that all fields must be set at all times. This forces
 // anyone adding flags to the config to also have to set these
 // fields.
-var AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0)}
+var AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0)}
 
 // ChainConfig is the core config which determines the blockchain settings.
 //
@@ -75,23 +77,26 @@ type ChainConfig struct {
 
  EIP155Block *big.Int `json:"eip155Block"` // EIP155 HF block
  EIP158Block *big.Int `json:"eip158Block"` // EIP158 HF block
+
+ MetropolisBlock *big.Int `json:"metropolisBlock"` // Metropolis switch block (nil = no fork, 0 = alraedy on homestead)
 }
 
 // String implements the Stringer interface.
 func (c *ChainConfig) String() string {
- return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v}",
+ return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Metropolis: %v}",
  c.ChainId,
  c.HomesteadBlock,
  c.DAOForkBlock,
  c.DAOForkSupport,
  c.EIP150Block,
  c.EIP155Block,
  c.EIP158Block,
+ c.MetropolisBlock,
  )
 }
 
 var (
- TestChainConfig = &ChainConfig{big.NewInt(1), new(big.Int), new(big.Int), true, new(big.Int), common.Hash{}, new(big.Int), new(big.Int)}
+ TestChainConfig = &ChainConfig{big.NewInt(1), new(big.Int), new(big.Int), true, new(big.Int), common.Hash{}, new(big.Int), new(big.Int), new(big.Int)}
  TestRules = TestChainConfig.Rules(new(big.Int))
 )
 
@@ -145,6 +150,14 @@ func (c *ChainConfig) IsEIP158(num *big.Int) bool {
 
 }
 
+func (c *ChainConfig) IsMetropolis(num *big.Int) bool {
+ if c.MetropolisBlock == nil || num == nil {
+ return false
+ }
+ return num.Cmp(c.MetropolisBlock) >= 0
+
+}
+
 // Rules wraps ChainConfig and is merely syntatic sugar or can be used for functions
 // that do not have or require information about the block.
 //
@@ -153,8 +166,9 @@ func (c *ChainConfig) IsEIP158(num *big.Int) bool {
 type Rules struct {
  ChainId *big.Int
  IsHomestead, IsEIP150, IsEIP155, IsEIP158 bool
+ IsMetropolis bool
 }
 
 func (c *ChainConfig) Rules(num *big.Int) Rules {
- return Rules{ChainId: new(big.Int).Set(c.ChainId), IsHomestead: c.IsHomestead(num), IsEIP150: c.IsEIP150(num), IsEIP155: c.IsEIP155(num), IsEIP158: c.IsEIP158(num)}
+ return Rules{ChainId: new(big.Int).Set(c.ChainId), IsHomestead: c.IsHomestead(num), IsEIP150: c.IsEIP150(num), IsEIP155: c.IsEIP155(num), IsEIP158: c.IsEIP158(num), IsMetropolis: c.IsMetropolis(num)}
 }

params/util.go

@@ -38,6 +38,8 @@ var (
  TestNetSpuriousDragon = big.NewInt(10)
  MainNetSpuriousDragon = big.NewInt(2675000)
 
+ MainNetMetropolisBlock = big.NewInt(5000000)
+
  TestNetChainID = big.NewInt(3) // Test net default chain ID
  MainNetChainID = big.NewInt(1) // main net default chain ID
 )