[beta] Byzantium updates (#6529)

* fix modexp bug: return 0 if base=0 (#6424)

* Running state test using parity-evm (#6355)

* Initial version of state tests.

* Refactor state to support tracing.

* Unify TransactResult.

* Add test.

* Byzantium updates

ethcore/evm/src/evm.rs

@@ -69,6 +69,10 @@ pub enum Error {
 	Internal(String),
 	/// Wasm runtime error
 	Wasm(String),
+	/// Out of bounds access in RETURNDATACOPY.
+	OutOfBounds,
+	/// Execution has been reverted with REVERT.
+	Reverted,
 }
 
 impl From<Box<trie::TrieError>> for Error {
@@ -96,6 +100,8 @@ impl fmt::Display for Error {
 			Internal(ref msg) => write!(f, "Internal error: {}", msg),
 			MutableCallInStaticContext => write!(f, "Mutable call in static context"),
 			Wasm(ref msg) => write!(f, "Internal error: {}", msg),
+			OutOfBounds => write!(f, "Out of bounds"),
+			Reverted => write!(f, "Reverted"),
 		}
 	}
 }
@@ -179,7 +185,7 @@ impl Finalize for Result<GasLeft> {
 	fn finalize<E: Ext>(self, ext: E) -> Result<FinalizationResult> {
 		match self {
 			Ok(GasLeft::Known(gas_left)) => Ok(FinalizationResult { gas_left: gas_left, apply_state: true, return_data: ReturnData::empty() }),
-			Ok(GasLeft::NeedsReturn {gas_left, data, apply_state}) => ext.ret(&gas_left, &data).map(|gas_left| FinalizationResult {
+			Ok(GasLeft::NeedsReturn {gas_left, data, apply_state}) => ext.ret(&gas_left, &data, apply_state).map(|gas_left| FinalizationResult {
 				gas_left: gas_left,
 				apply_state: apply_state,
 				return_data: data,

ethcore/evm/src/ext.rs

@@ -29,7 +29,12 @@ pub enum ContractCreateResult {
 	Created(Address, U256),
 	/// Returned when contract creation failed.
 	/// VM doesn't have to know the reason.
-	Failed
+	Failed,
+	/// Returned when contract creation failed.
+	/// VM doesn't have to know the reason.
+	FailedInStaticCall,
+	/// Reverted with REVERT.
+	Reverted(U256, ReturnData),
 }
 
 /// Result of externalities call function.
@@ -39,7 +44,10 @@ pub enum MessageCallResult {
 	Success(U256, ReturnData),
 	/// Returned when message call failed.
 	/// VM doesn't have to know the reason.
-	Failed
+	Failed,
+	/// Returned when message call was reverted.
+	/// Contains gas left and output data.
+	Reverted(U256, ReturnData),
 }
 
 /// Specifies how an address is calculated for a new contract.
@@ -109,7 +117,7 @@ pub trait Ext {
 
 	/// Should be called when transaction calls `RETURN` opcode.
 	/// Returns gas_left if cost of returning the data is not too high.
-	fn ret(self, gas: &U256, data: &ReturnData) -> evm::Result<U256>;
+	fn ret(self, gas: &U256, data: &ReturnData, apply_state: bool) -> evm::Result<U256>;
 
 	/// Should be called when contract commits suicide.
 	/// Address to which funds should be refunded.
@@ -138,4 +146,7 @@ pub trait Ext {
 
 	/// Trace the finalised execution of a single instruction.
 	fn trace_executed(&mut self, _gas_used: U256, _stack_push: &[U256], _mem_diff: Option<(usize, &[u8])>, _store_diff: Option<(U256, U256)>) {}
+
+	/// Check if running in static context.
+	fn is_static(&self) -> bool;
 }

ethcore/evm/src/interpreter/mod.rs

@@ -319,6 +319,9 @@ impl<Cost: CostType> Interpreter<Cost> {
 				let contract_code = self.mem.read_slice(init_off, init_size);
 				let can_create = ext.balance(&params.address)? >= endowment && ext.depth() < ext.schedule().max_depth;
 
+				// clear return data buffer before creating new call frame.
+				self.return_data = ReturnData::empty();
+
 				if !can_create {
 					stack.push(U256::zero());
 					return Ok(InstructionResult::UnusedGas(create_gas));
@@ -330,10 +333,18 @@ impl<Cost: CostType> Interpreter<Cost> {
 						stack.push(address_to_u256(address));
 						Ok(InstructionResult::UnusedGas(Cost::from_u256(gas_left).expect("Gas left cannot be greater.")))
 					},
+					ContractCreateResult::Reverted(gas_left, return_data) => {
+						stack.push(U256::zero());
+						self.return_data = return_data;
+						Ok(InstructionResult::UnusedGas(Cost::from_u256(gas_left).expect("Gas left cannot be greater.")))
+					},
 					ContractCreateResult::Failed => {
 						stack.push(U256::zero());
 						Ok(InstructionResult::Ok)
-					}
+					},
+					ContractCreateResult::FailedInStaticCall => {
+						Err(evm::Error::MutableCallInStaticContext)
+					},
 				};
 			},
 			instructions::CALL | instructions::CALLCODE | instructions::DELEGATECALL | instructions::STATICCALL => {
@@ -344,8 +355,10 @@ impl<Cost: CostType> Interpreter<Cost> {
 				let code_address = stack.pop_back();
 				let code_address = u256_to_address(&code_address);
 
-				let value = if instruction == instructions::DELEGATECALL || instruction == instructions::STATICCALL {
+				let value = if instruction == instructions::DELEGATECALL {
 					None
+				} else if instruction == instructions::STATICCALL {
+					Some(U256::zero())
 				} else {
 					Some(stack.pop_back())
 				};
@@ -364,6 +377,9 @@ impl<Cost: CostType> Interpreter<Cost> {
 				// Get sender & receive addresses, check if we have balance
 				let (sender_address, receive_address, has_balance, call_type) = match instruction {
 					instructions::CALL => {
+						if ext.is_static() && value.map_or(false, |v| !v.is_zero()) {
+							return Err(evm::Error::MutableCallInStaticContext);
+						}
 						let has_balance = ext.balance(&params.address)? >= value.expect("value set for all but delegate call; qed");
 						(&params.address, &code_address, has_balance, CallType::Call)
 					},
@@ -372,10 +388,13 @@ impl<Cost: CostType> Interpreter<Cost> {
 						(&params.address, &params.address, has_balance, CallType::CallCode)
 					},
 					instructions::DELEGATECALL => (&params.sender, &params.address, true, CallType::DelegateCall),
-					instructions::STATICCALL => (&params.sender, &params.address, true, CallType::StaticCall),
+					instructions::STATICCALL => (&params.address, &code_address, true, CallType::StaticCall),
 					_ => panic!(format!("Unexpected instruction {} in CALL branch.", instruction))
 				};
 
+				// clear return data buffer before creating new call frame.
+				self.return_data = ReturnData::empty();
+
 				let can_call = has_balance && ext.depth() < ext.schedule().max_depth;
 				if !can_call {
 					stack.push(U256::zero());
@@ -394,12 +413,17 @@ impl<Cost: CostType> Interpreter<Cost> {
 					MessageCallResult::Success(gas_left, data) => {
 						stack.push(U256::one());
 						self.return_data = data;
-						Ok(InstructionResult::UnusedGas(Cost::from_u256(gas_left).expect("Gas left cannot be greater then current one")))
+						Ok(InstructionResult::UnusedGas(Cost::from_u256(gas_left).expect("Gas left cannot be greater than current one")))
+					},
+					MessageCallResult::Reverted(gas_left, data) => {
+						stack.push(U256::zero());
+						self.return_data = data;
+						Ok(InstructionResult::UnusedGas(Cost::from_u256(gas_left).expect("Gas left cannot be greater than current one")))
 					},
 					MessageCallResult::Failed  => {
 						stack.push(U256::zero());
 						Ok(InstructionResult::Ok)
-					}
+					},
 				};
 			},
 			instructions::RETURN => {
@@ -537,6 +561,14 @@ impl<Cost: CostType> Interpreter<Cost> {
 				Self::copy_data_to_memory(&mut self.mem, stack, params.data.as_ref().map_or_else(|| &[] as &[u8], |d| &*d as &[u8]));
 			},
 			instructions::RETURNDATACOPY => {
+				{
+					let source_offset = stack.peek(1);
+					let size = stack.peek(2);
+					let return_data_len = U256::from(self.return_data.len());
+					if source_offset.overflow_add(*size).0 > return_data_len {
+						return Err(evm::Error::OutOfBounds);
+					}
+				}
 				Self::copy_data_to_memory(&mut self.mem, stack, &*self.return_data);
 			},
 			instructions::CODECOPY => {

ethcore/evm/src/schedule.rs

@@ -111,6 +111,8 @@ pub struct Schedule {
 	pub have_return_data: bool,
 	/// Kill basic accounts below this balance if touched.
 	pub kill_dust: CleanDustMode,
+	/// Enable EIP-86 rules
+	pub eip86: bool,
 }
 
 /// Dust accounts cleanup mode.
@@ -184,17 +186,17 @@ impl Schedule {
 			blockhash_gas: 20,
 			have_static_call: false,
 			kill_dust: CleanDustMode::Off,
+			eip86: false,
 		}
 	}
 
-	/// Schedule for the Metropolis of the Ethereum main net.
-	pub fn new_metropolis() -> Schedule {
+	/// Schedule for the Byzantium fork of the Ethereum main net.
+	pub fn new_byzantium() -> Schedule {
 		let mut schedule = Self::new_post_eip150(24576, true, true, true);
 		schedule.have_create2 = true;
 		schedule.have_revert = true;
 		schedule.have_static_call = true;
 		schedule.have_return_data = true;
-		schedule.blockhash_gas = 350;
 		schedule
 	}
 
@@ -246,6 +248,7 @@ impl Schedule {
 			blockhash_gas: 20,
 			have_static_call: false,
 			kill_dust: CleanDustMode::Off,
+			eip86: false,
 		}
 	}
 }

ethcore/evm/src/wasm/runtime.rs

@@ -163,7 +163,16 @@ impl<'a> Runtime<'a> {
 			ext::ContractCreateResult::Failed => {
 				trace!(target: "wasm", "runtime: create contract fail");
 				Ok(Some((-1i32).into()))
-			}
+			},
+			ext::ContractCreateResult::Reverted(gas_left, _) => {
+				trace!(target: "wasm", "runtime: create contract reverted");
+				self.gas_counter = self.gas_limit - gas_left.low_u64();
+				Ok(Some((-1i32).into()))
+			},
+			ext::ContractCreateResult::FailedInStaticCall => {
+				trace!(target: "wasm", "runtime: create contract called in static context");
+				Err(interpreter::Error::Trap("CREATE in static context".to_owned()))
+			},
 		}
 	}