diff options
Diffstat (limited to 'core/vm/evm.go')
| -rw-r--r-- | core/vm/evm.go | 49 |
1 files changed, 33 insertions, 16 deletions
diff --git a/core/vm/evm.go b/core/vm/evm.go index 71efcfa45..9296cc7ca 100644 --- a/core/vm/evm.go +++ b/core/vm/evm.go @@ -33,7 +33,20 @@ type ( GetHashFunc func(uint64) common.Hash ) -// Context provides the EVM with auxiliary information. Once provided it shouldn't be modified. +// run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter. +func run(evm *EVM, snapshot int, contract *Contract, input []byte) ([]byte, error) { + if contract.CodeAddr != nil { + precompiledContracts := PrecompiledContracts + if p := precompiledContracts[*contract.CodeAddr]; p != nil { + return RunPrecompiledContract(p, input, contract) + } + } + + return evm.interpreter.Run(snapshot, contract, input) +} + +// Context provides the EVM with auxiliary information. Once provided +// it shouldn't be modified. type Context struct { // CanTransfer returns whether the account contains // sufficient ether to transfer the value @@ -55,7 +68,13 @@ type Context struct { Difficulty *big.Int // Provides information for DIFFICULTY } -// EVM provides information about external sources for the EVM +// EVM is the Ethereum Virtual Machine base object and provides +// the necessary tools to run a contract on the given state with +// the provided context. It should be noted that any error +// generated through any of the calls should be considered a +// revert-state-and-consume-all-gas operation, no checks on +// specific errors should ever be performed. The interpreter makes +// sure that any errors generated are to be considered faulty code. // // The EVM should never be reused and is not thread safe. type EVM struct { @@ -68,6 +87,8 @@ type EVM struct { // chainConfig contains information about the current chain chainConfig *params.ChainConfig + // chain rules contains the chain rules for the current epoch + chainRules params.Rules // virtual machine configuration options used to initialise the // evm. vmConfig Config @@ -79,21 +100,23 @@ type EVM struct { abort int32 } -// NewEVM retutrns a new EVM evmironment. +// NewEVM retutrns a new EVM evmironment. The returned EVM is not thread safe +// and should only ever be used *once*. func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM { evm := &EVM{ Context: ctx, StateDB: statedb, vmConfig: vmConfig, chainConfig: chainConfig, + chainRules: chainConfig.Rules(ctx.BlockNumber), } evm.interpreter = NewInterpreter(evm, vmConfig) return evm } -// Cancel cancels any running EVM operation. This may be called concurrently and it's safe to be -// called multiple times. +// Cancel cancels any running EVM operation. This may be called concurrently and +// it's safe to be called multiple times. func (evm *EVM) Cancel() { atomic.StoreInt32(&evm.abort, 1) } @@ -134,13 +157,12 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas contract := NewContract(caller, to, value, gas) contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) - ret, err = evm.interpreter.Run(contract, input) + ret, err = run(evm, snapshot, contract, input) // When an error was returned by the EVM or when setting the creation code // 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) - evm.StateDB.RevertToSnapshot(snapshot) } return ret, contract.Gas, err @@ -175,10 +197,9 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, contract := NewContract(caller, to, value, gas) contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) - ret, err = evm.interpreter.Run(contract, input) + ret, err = run(evm, snapshot, contract, input) if err != nil { contract.UseGas(contract.Gas) - evm.StateDB.RevertToSnapshot(snapshot) } @@ -210,10 +231,9 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by contract := NewContract(caller, to, nil, gas).AsDelegate() contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) - ret, err = evm.interpreter.Run(contract, input) + ret, err = run(evm, snapshot, contract, input) if err != nil { contract.UseGas(contract.Gas) - evm.StateDB.RevertToSnapshot(snapshot) } @@ -253,8 +273,7 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I contract := NewContract(caller, AccountRef(contractAddr), value, gas) contract.SetCallCode(&contractAddr, crypto.Keccak256Hash(code), code) - ret, err = evm.interpreter.Run(contract, nil) - + ret, err = run(evm, snapshot, contract, nil) // check whether the max code size has been exceeded maxCodeSizeExceeded := len(ret) > params.MaxCodeSize // if the contract creation ran successfully and no errors were returned @@ -275,10 +294,8 @@ 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)) { + contract.UseGas(contract.Gas) evm.StateDB.RevertToSnapshot(snapshot) - - // Nothing should be returned when an error is thrown. - return nil, contractAddr, 0, err } // 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 |