Merge branch 'call' into eth_call

.travis.yml

@@ -33,7 +33,7 @@ env:
   global:
   # GH_TOKEN
   - secure: 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
-  - TARGETS="-p ethash -p ethcore-util -p ethcore -p ethsync -p ethcore-rpc -p parity -p ethminer"
+  - TARGETS="-p ethash -p ethcore-util -p ethcore -p ethsync -p ethcore-rpc -p parity -p ethminer -p ethjson"
   - ARCHIVE_SUFFIX="-${TRAVIS_OS_NAME}-${TRAVIS_TAG}"
   - KCOV_FEATURES=""
   - KCOV_CMD="./kcov-master/tmp/usr/local/bin/kcov --exclude-pattern /usr/,/.cargo,/root/.multirust,src/tests,util/json-tests,util/src/network/tests,sync/src/tests,ethcore/src/tests,ethcore/src/evm/tests target/kcov"
@@ -70,6 +70,7 @@ after_success: |
   $KCOV_CMD target/debug/deps/ethsync-* &&
   $KCOV_CMD target/debug/deps/ethcore_rpc-* &&
   $KCOV_CMD target/debug/deps/ethminer-* &&
+  $KCOV_CMD target/debug/deps/ethjson-* &&
   $KCOV_CMD target/debug/parity-* &&
   [ $TRAVIS_BRANCH = master ] &&
   [ $TRAVIS_PULL_REQUEST = false ] &&

ethcore/src/block.rs

@@ -24,7 +24,6 @@ use state::*;
 use verification::PreverifiedBlock;
 
 /// A block, encoded as it is on the block chain.
-// TODO: rename to Block
 #[derive(Default, Debug, Clone)]
 pub struct Block {
 	/// The header of this block.
@@ -76,8 +75,6 @@ impl Decodable for Block {
 }
 
 /// Internal type for a block's common elements.
-// TODO: rename to ExecutedBlock
-// TODO: use BareBlock
 #[derive(Debug)]
 pub struct ExecutedBlock {
 	base: Block,
@@ -85,6 +82,7 @@ pub struct ExecutedBlock {
 	receipts: Vec<Receipt>,
 	transactions_set: HashSet<H256>,
 	state: State,
+	traces: Option<Vec<Trace>>,
 }
 
 /// A set of references to `ExecutedBlock` fields that are publicly accessible.
@@ -99,11 +97,21 @@ pub struct BlockRefMut<'a> {
 	pub receipts: &'a Vec<Receipt>,
 	/// State.
 	pub state: &'a mut State,
+	/// Traces.
+	pub traces: &'a Option<Vec<Trace>>,
 }
 
 impl ExecutedBlock {
 	/// Create a new block from the given `state`.
-	fn new(state: State) -> ExecutedBlock { ExecutedBlock { base: Default::default(), receipts: Default::default(), transactions_set: Default::default(), state: state } }
+	fn new(state: State, tracing: bool) -> ExecutedBlock {
+		ExecutedBlock {
+			base: Default::default(),
+			receipts: Default::default(),
+			transactions_set: Default::default(),
+			state: state,
+			traces: if tracing {Some(Vec::new())} else {None},
+		}
+	}
 
 	/// Get a structure containing individual references to all public fields.
 	pub fn fields(&mut self) -> BlockRefMut {
@@ -113,6 +121,7 @@ impl ExecutedBlock {
 			uncles: &self.base.uncles,
 			state: &mut self.state,
 			receipts: &self.receipts,
+			traces: &self.traces,
 		}
 	}
 }
@@ -134,6 +143,9 @@ pub trait IsBlock {
 	/// Get all information on receipts in this block.
 	fn receipts(&self) -> &Vec<Receipt> { &self.block().receipts }
 
+	/// Get all information concerning transaction tracing in this block.
+	fn traces(&self) -> &Option<Vec<Trace>> { &self.block().traces }
+
 	/// Get all uncles in this block.
 	fn uncles(&self) -> &Vec<Header> { &self.block().base.uncles }
 }
@@ -171,9 +183,9 @@ pub struct SealedBlock {
 
 impl<'x> OpenBlock<'x> {
 	/// Create a new OpenBlock ready for transaction pushing.
-	pub fn new(engine: &'x Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes, author: Address, gas_floor_target: U256, extra_data: Bytes) -> Self {
+	pub fn new(engine: &'x Engine, tracing: bool, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes, author: Address, gas_floor_target: U256, extra_data: Bytes) -> Self {
 		let mut r = OpenBlock {
-			block: ExecutedBlock::new(State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce())),
+			block: ExecutedBlock::new(State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce()), tracing),
 			engine: engine,
 			last_hashes: last_hashes,
 		};
@@ -249,11 +261,13 @@ impl<'x> OpenBlock<'x> {
 	pub fn push_transaction(&mut self, t: SignedTransaction, h: Option<H256>) -> Result<&Receipt, Error> {
 		let env_info = self.env_info();
 //		info!("env_info says gas_used={}", env_info.gas_used);
-		match self.block.state.apply(&env_info, self.engine, &t) {
+		match self.block.state.apply(&env_info, self.engine, &t, self.block.traces.is_some()) {
-			Ok(receipt) => {
+			Ok(outcome) => {
 				self.block.transactions_set.insert(h.unwrap_or_else(||t.hash()));
 				self.block.base.transactions.push(t);
-				self.block.receipts.push(receipt);
+				let t = outcome.trace;
+				self.block.traces.as_mut().map(|traces| traces.push(t.expect("self.block.traces.is_some(): so we must be tracing: qed")));
+				self.block.receipts.push(outcome.receipt);
 				Ok(&self.block.receipts.last().unwrap())
 			}
 			Err(x) => Err(From::from(x))
@@ -339,7 +353,7 @@ impl IsBlock for SealedBlock {
 }
 
 /// Enact the block given by block header, transactions and uncles
-pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
+pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &Engine, tracing: bool, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	{
 		if ::log::max_log_level() >= ::log::LogLevel::Trace {
 			let s = State::from_existing(db.spawn(), parent.state_root().clone(), engine.account_start_nonce());
@@ -347,7 +361,7 @@ pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Head
 		}
 	}
 
-	let mut b = OpenBlock::new(engine, db, parent, last_hashes, header.author().clone(), x!(3141562), header.extra_data().clone());
+	let mut b = OpenBlock::new(engine, tracing, db, parent, last_hashes, header.author().clone(), x!(3141562), header.extra_data().clone());
 	b.set_difficulty(*header.difficulty());
 	b.set_gas_limit(*header.gas_limit());
 	b.set_timestamp(header.timestamp());
@@ -357,22 +371,22 @@ pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Head
 }
 
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_bytes(block_bytes: &[u8], engine: &Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
+pub fn enact_bytes(block_bytes: &[u8], engine: &Engine, tracing: bool, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	let block = BlockView::new(block_bytes);
 	let header = block.header();
-	enact(&header, &block.transactions(), &block.uncles(), engine, db, parent, last_hashes)
+	enact(&header, &block.transactions(), &block.uncles(), engine, tracing, db, parent, last_hashes)
 }
 
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_verified(block: &PreverifiedBlock, engine: &Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
+pub fn enact_verified(block: &PreverifiedBlock, engine: &Engine, tracing: bool, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	let view = BlockView::new(&block.bytes);
-	enact(&block.header, &block.transactions, &view.uncles(), engine, db, parent, last_hashes)
+	enact(&block.header, &block.transactions, &view.uncles(), engine, tracing, db, parent, last_hashes)
 }
 
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header. Seal the block aferwards
-pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<SealedBlock, Error> {
+pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, tracing: bool, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes) -> Result<SealedBlock, Error> {
 	let header = BlockView::new(block_bytes).header_view();
-	Ok(try!(try!(enact_bytes(block_bytes, engine, db, parent, last_hashes)).seal(engine, header.seal())))
+	Ok(try!(try!(enact_bytes(block_bytes, engine, tracing, db, parent, last_hashes)).seal(engine, header.seal())))
 }
 
 #[cfg(test)]
@@ -391,7 +405,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
 		let last_hashes = vec![genesis_header.hash()];
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
+		let b = OpenBlock::new(engine.deref(), false, db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
 		let b = b.close();
 		let _ = b.seal(engine.deref(), vec![]);
 	}
@@ -405,14 +419,14 @@ mod tests {
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), x!(3141562), vec![]).close().seal(engine.deref(), vec![]).unwrap();
+		let b = OpenBlock::new(engine.deref(), false, db, &genesis_header, vec![genesis_header.hash()], Address::zero(), x!(3141562), vec![]).close().seal(engine.deref(), vec![]).unwrap();
 		let orig_bytes = b.rlp_bytes();
 		let orig_db = b.drain();
 
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
-		let e = enact_and_seal(&orig_bytes, engine.deref(), db, &genesis_header, vec![genesis_header.hash()]).unwrap();
+		let e = enact_and_seal(&orig_bytes, engine.deref(), false, db, &genesis_header, vec![genesis_header.hash()]).unwrap();
 
 		assert_eq!(e.rlp_bytes(), orig_bytes);
 
@@ -430,7 +444,7 @@ mod tests {
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
-		let mut open_block = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), x!(3141562), vec![]);
+		let mut open_block = OpenBlock::new(engine.deref(), false, db, &genesis_header, vec![genesis_header.hash()], Address::zero(), x!(3141562), vec![]);
 		let mut uncle1_header = Header::new();
 		uncle1_header.extra_data = b"uncle1".to_vec();
 		let mut uncle2_header = Header::new();
@@ -445,7 +459,7 @@ mod tests {
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
-		let e = enact_and_seal(&orig_bytes, engine.deref(), db, &genesis_header, vec![genesis_header.hash()]).unwrap();
+		let e = enact_and_seal(&orig_bytes, engine.deref(), false, db, &genesis_header, vec![genesis_header.hash()]).unwrap();
 
 		let bytes = e.rlp_bytes();
 		assert_eq!(bytes, orig_bytes);

ethcore/src/blockchain/blockchain.rs

@@ -54,6 +54,9 @@ impl Default for BlockChainConfig {
 
 /// Interface for querying blocks by hash and by number.
 pub trait BlockProvider {
+	/// True if we store full tracing information for transactions.
+	fn have_tracing(&self) -> bool;
+
 	/// Returns true if the given block is known
 	/// (though not necessarily a part of the canon chain).
 	fn is_known(&self, hash: &H256) -> bool;
@@ -177,6 +180,9 @@ impl BlockProvider for BlockChain {
 		self.query_extras_exist(hash, &self.block_details)
 	}
 
+	// We do not store tracing information.
+	fn have_tracing(&self) -> bool { false }
+
 	/// Get raw block data
 	fn block(&self, hash: &H256) -> Option<Bytes> {
 		{

ethcore/src/client/client.rs

@@ -213,7 +213,7 @@ impl<V> Client<V> where V: Verifier {
 		let last_hashes = self.build_last_hashes(header.parent_hash.clone());
 		let db = self.state_db.lock().unwrap().spawn();
 
-		let enact_result = enact_verified(&block, engine, db, &parent, last_hashes);
+		let enact_result = enact_verified(&block, engine, self.chain.have_tracing(), db, &parent, last_hashes);
 		if let Err(e) = enact_result {
 			warn!(target: "client", "Block import failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
 			return Err(());
@@ -423,6 +423,7 @@ impl<V> BlockChainClient for Client<V> where V: Verifier {
 
 		let mut b = OpenBlock::new(
 			engine,
+			false,	// TODO: this will need to be parameterised once we want to do immediate mining insertion.
 			self.state_db.lock().unwrap().spawn(),
 			match self.chain.block_header(&h) { Some(ref x) => x, None => {return None} },
 			self.build_last_hashes(h.clone()),

ethcore/src/common.rs

@@ -26,3 +26,4 @@ pub use transaction::*;
 pub use log_entry::*;
 pub use receipt::*;
 pub use action_params::*;
+pub use trace::*;

ethcore/src/ethereum/ethash.rs

@@ -299,7 +299,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
 		let last_hashes = vec![genesis_header.hash()];
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
+		let b = OpenBlock::new(engine.deref(), false, db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
 		let b = b.close();
 		assert_eq!(b.state().balance(&Address::zero()), U256::from_str("4563918244f40000").unwrap());
 	}
@@ -312,7 +312,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
 		let last_hashes = vec![genesis_header.hash()];
-		let mut b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
+		let mut b = OpenBlock::new(engine.deref(), false, db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
 		let mut uncle = Header::new();
 		let uncle_author = address_from_hex("ef2d6d194084c2de36e0dabfce45d046b37d1106");
 		uncle.author = uncle_author.clone();

ethcore/src/evm/evm.rs

@@ -65,7 +65,7 @@ pub enum Error {
 
 /// Evm result.
 /// 
-/// Returns gas_left if execution is successfull, otherwise error.
+/// Returns gas_left if execution is successful, otherwise error.
 pub type Result = result::Result<U256, Error>;
 
 /// Evm interface.

ethcore/src/executive.rs

@@ -41,19 +41,24 @@ pub fn contract_address(address: &Address, nonce: &U256) -> Address {
 pub struct Executed {
 	/// Gas paid up front for execution of transaction.
 	pub gas: U256,
+
 	/// Gas used during execution of transaction.
 	pub gas_used: U256,
+
 	/// Gas refunded after the execution of transaction.
 	/// To get gas that was required up front, add `refunded` and `gas_used`.
 	pub refunded: U256,
+
 	/// Cumulative gas used in current block so far.
 	///
 	/// `cumulative_gas_used = gas_used(t0) + gas_used(t1) + ... gas_used(tn)`
 	///
 	/// where `tn` is current transaction.
 	pub cumulative_gas_used: U256,
+
 	/// Vector of logs generated by transaction.
 	pub logs: Vec<LogEntry>,
+
 	/// Addresses of contracts created during execution of transaction.
 	/// Ordered from earliest creation.
 	///
@@ -63,6 +68,8 @@ pub struct Executed {
 	pub contracts_created: Vec<Address>,
 	/// Transaction output.
 	pub output: Bytes,
+	/// The trace of this transaction.
+	pub trace: Option<Trace>,
 }
 
 /// Transaction execution result.
@@ -73,38 +80,37 @@ pub struct Executive<'a> {
 	state: &'a mut State,
 	info: &'a EnvInfo,
 	engine: &'a Engine,
-	depth: usize
+	depth: usize,
 }
 
 impl<'a> Executive<'a> {
 	/// Basic constructor.
 	pub fn new(state: &'a mut State, info: &'a EnvInfo, engine: &'a Engine) -> Self {
-		Executive::new_with_depth(state, info, engine, 0)
-	}
-
-	/// Populates executive from parent properties. Increments executive depth.
-	pub fn from_parent(state: &'a mut State, info: &'a EnvInfo, engine: &'a Engine, depth: usize) -> Self {
-		Executive::new_with_depth(state, info, engine, depth + 1)
-	}
-
-	/// Helper constructor. Should be used to create `Executive` with desired depth.
-	/// Private.
-	fn new_with_depth(state: &'a mut State, info: &'a EnvInfo, engine: &'a Engine, depth: usize) -> Self {
 		Executive {
 			state: state,
 			info: info,
 			engine: engine,
-			depth: depth
+			depth: 0,
+		}
+	}
+
+	/// Populates executive from parent properties. Increments executive depth.
+	pub fn from_parent(state: &'a mut State, info: &'a EnvInfo, engine: &'a Engine, parent_depth: usize) -> Self {
+		Executive {
+			state: state,
+			info: info,
+			engine: engine,
+			depth: parent_depth + 1,
 		}
 	}
 
 	/// Creates `Externalities` from `Executive`.
-	pub fn as_externalities<'_>(&'_ mut self, origin_info: OriginInfo, substate: &'_ mut Substate, output: OutputPolicy<'_>) -> Externalities {
+	pub fn as_externalities<'_>(&'_ mut self, origin_info: OriginInfo, substate: &'_ mut Substate, output: OutputPolicy<'_, '_>) -> Externalities {
 		Externalities::new(self.state, self.info, self.engine, self.depth, origin_info, substate, output)
 	}
 
 	/// This funtion should be used to execute transaction.
-	pub fn transact(&'a mut self, t: &SignedTransaction) -> Result<Executed, Error> {
+	pub fn transact(&'a mut self, t: &SignedTransaction, tracing: bool) -> Result<Executed, Error> {
 		let sender = try!(t.sender());
 		let nonce = self.state.nonce(&sender);
 
@@ -145,7 +151,7 @@ impl<'a> Executive<'a> {
 		self.state.inc_nonce(&sender);
 		self.state.sub_balance(&sender, &U256::from(gas_cost));
 
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(tracing);
 
 		let (gas_left, output) = match t.action {
 			Action::Create => {
@@ -243,15 +249,27 @@ impl<'a> Executive<'a> {
 			// if destination is a contract, do normal message call
 
 			// part of substate that may be reverted
-			let mut unconfirmed_substate = Substate::new();
+			let mut unconfirmed_substate = Substate::new(substate.subtraces.is_some());
+
+			// transaction tracing stuff. None if there's no tracing.
+			let mut trace_info = substate.subtraces.as_ref().map(|_| (TraceAction::from_call(&params), self.depth));
+			let mut trace_output = trace_info.as_ref().map(|_| vec![]);
 
 			let res = {
-				self.exec_vm(params, &mut unconfirmed_substate, OutputPolicy::Return(output))
+				self.exec_vm(params, &mut unconfirmed_substate, OutputPolicy::Return(output, trace_output.as_mut()))
 			};
 
+			// if there's tracing, make up trace_info's result with trace_output and some arithmetic.
+			if let Some((TraceAction::Call(ref mut c), _)) = trace_info {
+				if let Some(output) = trace_output {
+					c.result = res.as_ref().ok().map(|gas_left| (c.gas - *gas_left, output));
+				}
+			}
+
 			trace!("exec: sstore-clears={}\n", unconfirmed_substate.sstore_clears_count);
 			trace!("exec: substate={:?}; unconfirmed_substate={:?}\n", substate, unconfirmed_substate);
-			self.enact_result(&res, substate, unconfirmed_substate);
+
+			self.enact_result(&res, substate, unconfirmed_substate, trace_info);
 			trace!("exec: new substate={:?}\n", substate);
 			res
 		} else {
@@ -269,7 +287,7 @@ impl<'a> Executive<'a> {
 		self.state.snapshot();
 
 		// part of substate that may be reverted
-		let mut unconfirmed_substate = Substate::new();
+		let mut unconfirmed_substate = Substate::new(substate.subtraces.is_some());
 
 		// create contract and transfer value to it if necessary
 		let prev_bal = self.state.balance(&params.address);
@@ -280,10 +298,21 @@ impl<'a> Executive<'a> {
 			self.state.new_contract(&params.address, prev_bal);
 		}
 
+		let mut trace_info = substate.subtraces.as_ref().map(|_| (TraceAction::from_create(&params), self.depth));
+		let mut trace_output = trace_info.as_ref().map(|_| vec![]);
+		let created = params.address.clone();
+
 		let res = {
-			self.exec_vm(params, &mut unconfirmed_substate, OutputPolicy::InitContract)
+			self.exec_vm(params, &mut unconfirmed_substate, OutputPolicy::InitContract(trace_output.as_mut()))
 		};
-		self.enact_result(&res, substate, unconfirmed_substate);
+
+		if let Some((TraceAction::Create(ref mut c), _)) = trace_info {
+			if let Some(output) = trace_output {
+				c.result = res.as_ref().ok().map(|gas_left| (c.gas - *gas_left, created, output));
+			}
+		}
+
+		self.enact_result(&res, substate, unconfirmed_substate, trace_info);
 		res
 	}
 
@@ -330,6 +359,7 @@ impl<'a> Executive<'a> {
 					logs: vec![],
 					contracts_created: vec![],
 					output: output,
+					trace: None,
 				})
 			},
 			_ => {
@@ -341,12 +371,13 @@ impl<'a> Executive<'a> {
 					logs: substate.logs,
 					contracts_created: substate.contracts_created,
 					output: output,
+					trace: substate.subtraces.and_then(|mut v| v.pop()),
 				})
 			},
 		}
 	}
 
-	fn enact_result(&mut self, result: &evm::Result, substate: &mut Substate, un_substate: Substate) {
+	fn enact_result(&mut self, result: &evm::Result, substate: &mut Substate, un_substate: Substate, maybe_info: Option<(TraceAction, usize)>) {
 		match *result {
 			Err(evm::Error::OutOfGas)
 				| Err(evm::Error::BadJumpDestination {..})
@@ -357,7 +388,7 @@ impl<'a> Executive<'a> {
 			},
 			Ok(_) | Err(evm::Error::Internal) => {
 				self.state.clear_snapshot();
-				substate.accrue(un_substate)
+				substate.accrue(un_substate, maybe_info)
 			}
 		}
 	}
@@ -395,7 +426,7 @@ mod tests {
 		state.add_balance(&sender, &U256::from(0x100u64));
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(0, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		let gas_left = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
@@ -412,8 +443,8 @@ mod tests {
 		// TODO: just test state root.
 	}
 
-	evm_test!{test_create_contract: test_create_contract_jit, test_create_contract_int}
+	evm_test!{test_create_contract_out_of_depth: test_create_contract_out_of_depth_jit, test_create_contract_out_of_depth_int}
-	fn test_create_contract(factory: Factory) {
+	fn test_create_contract_out_of_depth(factory: Factory) {
 		// code:
 		//
 		// 7c 601080600c6000396000f3006000355415600957005b60203560003555 - push 29 bytes?
@@ -454,7 +485,7 @@ mod tests {
 		state.add_balance(&sender, &U256::from(100));
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(0, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		let gas_left = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
@@ -466,6 +497,135 @@ mod tests {
 		assert_eq!(substate.contracts_created.len(), 0);
 	}
 
+	evm_test!{test_call_to_create: test_call_to_create_jit, test_call_to_create_int}
+	fn test_call_to_create(factory: Factory) {
+		// code:
+		//
+		// 7c 601080600c6000396000f3006000355415600957005b60203560003555 - push 29 bytes?
+		// 60 00 - push 0
+		// 52
+		// 60 1d - push 29
+		// 60 03 - push 3
+		// 60 17 - push 17
+		// f0 - create
+		// 60 00 - push 0
+		// 55 sstore
+		//
+		// other code:
+		//
+		// 60 10 - push 16
+		// 80 - duplicate first stack item
+		// 60 0c - push 12
+		// 60 00 - push 0
+		// 39 - copy current code to memory
+		// 60 00 - push 0
+		// f3 - return
+
+		let code = "7c601080600c6000396000f3006000355415600957005b60203560003555600052601d60036017f0600055".from_hex().unwrap();
+
+		let sender = Address::from_str("cd1722f3947def4cf144679da39c4c32bdc35681").unwrap();
+		let address = contract_address(&sender, &U256::zero());
+		// TODO: add tests for 'callcreate'
+		//let next_address = contract_address(&address, &U256::zero());
+		let mut params = ActionParams::default();
+		params.address = address.clone();
+		params.sender = sender.clone();
+		params.origin = sender.clone();
+		params.gas = U256::from(100_000);
+		params.code = Some(code.clone());
+		params.value = ActionValue::Transfer(U256::from(100));
+		let mut state_result = get_temp_state();
+		let mut state = state_result.reference_mut();
+		state.add_balance(&sender, &U256::from(100));
+		let info = EnvInfo::default();
+		let engine = TestEngine::new(5, factory);
+		let mut substate = Substate::new(true);
+
+		let gas_left = {
+			let mut ex = Executive::new(&mut state, &info, &engine);
+			let output = BytesRef::Fixed(&mut[0u8;0]);
+			ex.call(params, &mut substate, output).unwrap()
+		};
+
+		println!("trace: {:?}", substate.subtraces);
+		let expected_trace = Some(vec![ Trace {
+			depth: 0,
+			action: TraceAction::Call(TraceCall {
+				from: x!("cd1722f3947def4cf144679da39c4c32bdc35681"),
+				to: x!("b010143a42d5980c7e5ef0e4a4416dc098a4fed3"),
+				value: x!(100),
+				gas: x!(100000),
+				input: vec![],
+				result: Some((x!(55248), vec![]))
+			}),
+			subs: vec![Trace {
+				depth: 1,
+				action: TraceAction::Create(TraceCreate {
+					from: x!("b010143a42d5980c7e5ef0e4a4416dc098a4fed3"),
+					value: x!(23),
+					gas: x!(67979),
+					init: vec![96, 16, 128, 96, 12, 96, 0, 57, 96, 0, 243, 0, 96, 0, 53, 84, 21, 96, 9, 87, 0, 91, 96, 32, 53, 96, 0, 53, 85],
+					result: Some((x!(3224), x!("c6d80f262ae5e0f164e5fde365044d7ada2bfa34"), vec![96, 0, 53, 84, 21, 96, 9, 87, 0, 91, 96, 32, 53, 96, 0, 53])),
+				}),
+				subs: vec![]
+			}]
+		} ]);
+		assert_eq!(substate.subtraces, expected_trace);
+		assert_eq!(gas_left, U256::from(44_752));
+	}
+
+	evm_test!{test_create_contract: test_create_contract_jit, test_create_contract_int}
+	fn test_create_contract(factory: Factory) {
+		// code:
+		//
+		// 60 10 - push 16
+		// 80 - duplicate first stack item
+		// 60 0c - push 12
+		// 60 00 - push 0
+		// 39 - copy current code to memory
+		// 60 00 - push 0
+		// f3 - return
+
+		let code = "601080600c6000396000f3006000355415600957005b60203560003555".from_hex().unwrap();
+
+		let sender = Address::from_str("cd1722f3947def4cf144679da39c4c32bdc35681").unwrap();
+		let address = contract_address(&sender, &U256::zero());
+		// TODO: add tests for 'callcreate'
+		//let next_address = contract_address(&address, &U256::zero());
+		let mut params = ActionParams::default();
+		params.address = address.clone();
+		params.sender = sender.clone();
+		params.origin = sender.clone();
+		params.gas = U256::from(100_000);
+		params.code = Some(code.clone());
+		params.value = ActionValue::Transfer(x!(100));
+		let mut state_result = get_temp_state();
+		let mut state = state_result.reference_mut();
+		state.add_balance(&sender, &U256::from(100));
+		let info = EnvInfo::default();
+		let engine = TestEngine::new(5, factory);
+		let mut substate = Substate::new(true);
+
+		let gas_left = {
+			let mut ex = Executive::new(&mut state, &info, &engine);
+			ex.create(params.clone(), &mut substate).unwrap()
+		};
+
+		println!("trace: {:?}", substate.subtraces);
+		let expected_trace = Some(vec![Trace {
+			depth: 0,
+			action: TraceAction::Create(TraceCreate {
+				from: params.sender,
+				value: x!(100),
+				gas: params.gas,
+				init: vec![96, 16, 128, 96, 12, 96, 0, 57, 96, 0, 243, 0, 96, 0, 53, 84, 21, 96, 9, 87, 0, 91, 96, 32, 53, 96, 0, 53, 85],
+				result: Some((x!(3224), params.address, vec![96, 0, 53, 84, 21, 96, 9, 87, 0, 91, 96, 32, 53, 96, 0, 53])),
+			}),
+			subs: vec![]
+		} ]);
+		assert_eq!(substate.subtraces, expected_trace);
+		assert_eq!(gas_left, U256::from(96_776));
+	}
 	evm_test!{test_create_contract_value_too_high: test_create_contract_value_too_high_jit, test_create_contract_value_too_high_int}
 	fn test_create_contract_value_too_high(factory: Factory) {
 		// code:
@@ -508,7 +668,7 @@ mod tests {
 		state.add_balance(&sender, &U256::from(100));
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(0, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		let gas_left = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
@@ -560,7 +720,7 @@ mod tests {
 		state.add_balance(&sender, &U256::from(100));
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(1024, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		{
 			let mut ex = Executive::new(&mut state, &info, &engine);
@@ -621,7 +781,7 @@ mod tests {
 
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(0, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		let gas_left = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
@@ -666,7 +826,7 @@ mod tests {
 		state.init_code(&address, code.clone());
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(0, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		let gas_left = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
@@ -703,7 +863,7 @@ mod tests {
 
 		let executed = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
-			ex.transact(&t).unwrap()
+			ex.transact(&t, false).unwrap()
 		};
 
 		assert_eq!(executed.gas, U256::from(100_000));
@@ -736,7 +896,7 @@ mod tests {
 
 		let res = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
-			ex.transact(&t)
+			ex.transact(&t, false)
 		};
 
 		match res {
@@ -767,7 +927,7 @@ mod tests {
 
 		let res = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
-			ex.transact(&t)
+			ex.transact(&t, false)
 		};
 
 		match res {
@@ -800,7 +960,7 @@ mod tests {
 
 		let res = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
-			ex.transact(&t)
+			ex.transact(&t, false)
 		};
 
 		match res {
@@ -833,7 +993,7 @@ mod tests {
 
 		let res = {
 			let mut ex = Executive::new(&mut state, &info, &engine);
-			ex.transact(&t)
+			ex.transact(&t, false)
 		};
 
 		match res {
@@ -863,7 +1023,7 @@ mod tests {
 		state.add_balance(&sender, &U256::from_str("152d02c7e14af6800000").unwrap());
 		let info = EnvInfo::default();
 		let engine = TestEngine::new(0, factory);
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 
 		let result = {
 			let mut ex = Executive::new(&mut state, &info, &engine);

ethcore/src/externalities.rs

@@ -23,12 +23,12 @@ use evm::{self, Schedule, Ext, ContractCreateResult, MessageCallResult};
 use substate::*;
 
 /// Policy for handling output data on `RETURN` opcode.
-pub enum OutputPolicy<'a> {
+pub enum OutputPolicy<'a, 'b> {
 	/// Return reference to fixed sized output.
 	/// Used for message calls.
-	Return(BytesRef<'a>),
+	Return(BytesRef<'a>, Option<&'b mut Bytes>),
 	/// Init new contract as soon as `RETURN` is called.
-	InitContract
+	InitContract(Option<&'b mut Bytes>),
 }
 
 /// Transaction properties that externalities need to know about.
@@ -62,7 +62,7 @@ pub struct Externalities<'a> {
 	origin_info: OriginInfo,
 	substate: &'a mut Substate,
 	schedule: Schedule,
-	output: OutputPolicy<'a>
+	output: OutputPolicy<'a, 'a>
 }
 
 impl<'a> Externalities<'a> {
@@ -73,7 +73,8 @@ impl<'a> Externalities<'a> {
 		depth: usize,
 		origin_info: OriginInfo,
 		substate: &'a mut Substate,
-			   output: OutputPolicy<'a>) -> Self {
+		output: OutputPolicy<'a, 'a>
+	) -> Self {
 		Externalities {
 			state: state,
 			env_info: env_info,
@@ -190,20 +191,31 @@ impl<'a> Ext for Externalities<'a> {
 
 	#[cfg_attr(feature="dev", allow(match_ref_pats))]
 	fn ret(&mut self, gas: &U256, data: &[u8]) -> Result<U256, evm::Error> {
-		match &mut self.output {
+		let handle_copy = |to: &mut Option<&mut Bytes>| {
-			&mut OutputPolicy::Return(BytesRef::Fixed(ref mut slice)) => unsafe {
+			to.as_mut().map(|b| **b = data.to_owned());
+		};
+		match self.output {
+			OutputPolicy::Return(BytesRef::Fixed(ref mut slice), ref mut copy) => {
+				handle_copy(copy);
+
 				let len = cmp::min(slice.len(), data.len());
+				unsafe {
 					ptr::copy(data.as_ptr(), slice.as_mut_ptr(), len);
+				}
 				Ok(*gas)
 			},
-			&mut OutputPolicy::Return(BytesRef::Flexible(ref mut vec)) => unsafe {
+			OutputPolicy::Return(BytesRef::Flexible(ref mut vec), ref mut copy) => {
+				handle_copy(copy);
+				
 				vec.clear();
 				vec.reserve(data.len());
+				unsafe {
 					ptr::copy(data.as_ptr(), vec.as_mut_ptr(), data.len());
 					vec.set_len(data.len());
+				}
 				Ok(*gas)
 			},
-			&mut OutputPolicy::InitContract => {
+			OutputPolicy::InitContract(ref mut copy) => {
 				let return_cost = U256::from(data.len()) * U256::from(self.schedule.create_data_gas);
 				if return_cost > *gas {
 					return match self.schedule.exceptional_failed_code_deposit {
@@ -211,14 +223,16 @@ impl<'a> Ext for Externalities<'a> {
 						false => Ok(*gas)
 					}
 				}
+				
+				handle_copy(copy);
+
 				let mut code = vec![];
 				code.reserve(data.len());
 				unsafe {
 					ptr::copy(data.as_ptr(), code.as_mut_ptr(), data.len());
 					code.set_len(data.len());
 				}
-				let address = &self.origin_info.address;
+				self.state.init_code(&self.origin_info.address, code);
-				self.state.init_code(address, code);
 				Ok(*gas - return_cost)
 			}
 		}
@@ -312,7 +326,7 @@ mod tests {
 			TestSetup {
 				state: get_temp_state(),
 				engine: get_test_spec().to_engine().unwrap(),
-				sub_state: Substate::new(),
+				sub_state: Substate::new(false),
 				env_info: get_test_env_info()
 			}
 		}
@@ -323,7 +337,7 @@ mod tests {
 		let mut setup = TestSetup::new();
 		let state = setup.state.reference_mut();
 
-		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract);
+		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None));
 
 		assert_eq!(ext.env_info().number, 100);
 	}
@@ -332,7 +346,7 @@ mod tests {
 	fn can_return_block_hash_no_env() {
 		let mut setup = TestSetup::new();
 		let state = setup.state.reference_mut();
-		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract);
+		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None));
 
 		let hash = ext.blockhash(&U256::from_str("0000000000000000000000000000000000000000000000000000000000120000").unwrap());
 
@@ -351,7 +365,7 @@ mod tests {
 			env_info.last_hashes.push(test_hash.clone());
 		}
 		let state = setup.state.reference_mut();
-		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract);
+		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None));
 
 		let hash = ext.blockhash(&U256::from_str("0000000000000000000000000000000000000000000000000000000000120000").unwrap());
 
@@ -363,7 +377,7 @@ mod tests {
 	fn can_call_fail_empty() {
 		let mut setup = TestSetup::new();
 		let state = setup.state.reference_mut();
-		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract);
+		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None));
 
 		let mut output = vec![];
 
@@ -387,7 +401,7 @@ mod tests {
 		let state = setup.state.reference_mut();
 
 		{
-			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract);
+			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None));
 			ext.log(log_topics, &log_data);
 		}
 
@@ -402,7 +416,7 @@ mod tests {
 		let state = setup.state.reference_mut();
 
 		{
-			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract);
+			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None));
 			ext.suicide(&refund_account);
 		}
 

ethcore/src/json_tests/executive.rs

@@ -75,7 +75,7 @@ impl<'a> TestExt<'a> {
 			   depth: usize,
 			   origin_info: OriginInfo,
 			   substate: &'a mut Substate,
-			   output: OutputPolicy<'a>,
+			   output: OutputPolicy<'a, 'a>,
 			   address: Address) -> Self {
 		TestExt {
 			contract_address: contract_address(&address, &state.nonce(&address)),
@@ -227,19 +227,21 @@ fn do_json_test_for(vm: &VMType, json_data: &[u8]) -> Vec<String> {
 		let out_of_gas = test.find("callcreates").map(|_calls| {
 		}).is_none();
 
-		let mut substate = Substate::new();
+		let mut substate = Substate::new(false);
 		let mut output = vec![];
 
 		// execute
 		let (res, callcreates) = {
-			let mut ex = TestExt::new(&mut state,
+			let mut ex = TestExt::new(
+				&mut state,
 				&info,
 				&engine,
 				0,
 				OriginInfo::from(&params),
 				&mut substate,
-									  OutputPolicy::Return(BytesRef::Flexible(&mut output)),
+				OutputPolicy::Return(BytesRef::Flexible(&mut output), None),
-									  params.address.clone());
+				params.address.clone()
+			);
 			let evm = engine.vm_factory().create();
 			let res = evm.exec(params, &mut ex);
 			(res, ex.callcreates)

ethcore/src/json_tests/state.rs

@@ -69,7 +69,7 @@ pub fn json_chain_test(json_data: &[u8], era: ChainEra) -> Vec<String> {
 				let mut state = state_result.reference_mut();
 				state.populate_from(pre);
 				state.commit();
-				let res = state.apply(&env, engine.deref(), &t);
+				let res = state.apply(&env, engine.deref(), &t, false);
 
 				if fail_unless(state.root() == &post_state_root) {
 					println!("!!! {}: State mismatch (got: {}, expect: {}):", name, state.root(), post_state_root);
@@ -80,9 +80,9 @@ pub fn json_chain_test(json_data: &[u8], era: ChainEra) -> Vec<String> {
 				}
 
 				if let Ok(r) = res {
-					if fail_unless(logs == r.logs) {
+					if fail_unless(logs == r.receipt.logs) {
 						println!("!!! {}: Logs mismatch:", name);
-						println!("Got:\n{:?}", r.logs);
+						println!("Got:\n{:?}", r.receipt.logs);
 						println!("Expect:\n{:?}", logs);
 					}
 				}

ethcore/src/lib.rs

@@ -97,6 +97,7 @@ pub mod filter;
 pub mod header;
 pub mod service;
 pub mod log_entry;
+pub mod trace;
 pub mod spec;
 pub mod transaction;
 pub mod views;

ethcore/src/state.rs

@@ -26,8 +26,16 @@ use pod_account::*;
 use pod_state::PodState;
 //use state_diff::*;	// TODO: uncomment once to_pod() works correctly.
 
+/// Used to return information about an `State::apply` operation.
+pub struct ApplyOutcome {
+	/// The receipt for the applied transaction.
+	pub receipt: Receipt,
+	/// The trace for the applied transaction, if None if tracing is disabled.
+	pub trace: Option<Trace>,
+}
+
 /// Result type for the execution ("application") of a transaction.
-pub type ApplyResult = Result<Receipt, Error>;
+pub type ApplyResult = Result<ApplyOutcome, Error>;
 
 /// Representation of the entire state of all accounts in the system.
 pub struct State {
@@ -209,17 +217,17 @@ impl State {
 
 	/// Execute a given transaction.
 	/// This will change the state accordingly.
-	pub fn apply(&mut self, env_info: &EnvInfo, engine: &Engine, t: &SignedTransaction) -> ApplyResult {
+	pub fn apply(&mut self, env_info: &EnvInfo, engine: &Engine, t: &SignedTransaction, tracing: bool) -> ApplyResult {
 //		let old = self.to_pod();
 
-		let e = try!(Executive::new(self, env_info, engine).transact(t));
+		let e = try!(Executive::new(self, env_info, engine).transact(t, tracing));
 
 		// TODO uncomment once to_pod() works correctly.
 //		trace!("Applied transaction. Diff:\n{}\n", StateDiff::diff_pod(&old, &self.to_pod()));
 		self.commit();
 		let receipt = Receipt::new(self.root().clone(), e.cumulative_gas_used, e.logs);
 //		trace!("Transaction receipt: {:?}", receipt);
-		Ok(receipt)
+		Ok(ApplyOutcome{receipt: receipt, trace: e.trace})
 	}
 
 	/// Commit accounts to SecTrieDBMut. This is similar to cpp-ethereum's dev::eth::commit.

ethcore/src/substate.rs

@@ -23,37 +23,45 @@ use common::*;
 pub struct Substate {
 	/// Any accounts that have suicided.
 	pub suicides: HashSet<Address>,
+
 	/// Any logs.
 	pub logs: Vec<LogEntry>,
+
 	/// Refund counter of SSTORE nonzero -> zero.
 	pub sstore_clears_count: U256,
-	/// Created contracts.
-	pub contracts_created: Vec<Address>
-}
 
-impl Default for Substate {
+	/// Created contracts.
-	fn default() -> Self {
+	pub contracts_created: Vec<Address>,
-		Substate::new()
+
-	}
+	/// The trace during this execution or `None` if we're not tracing.
+	pub subtraces: Option<Vec<Trace>>,
 }
 
 impl Substate {
 	/// Creates new substate.
-	pub fn new() -> Self {
+	pub fn new(tracing: bool) -> Self {
 		Substate {
-			suicides: HashSet::new(),
+			suicides: Default::default(),
-			logs: vec![],
+			logs: Default::default(),
-			sstore_clears_count: U256::zero(),
+			sstore_clears_count: Default::default(),
-			contracts_created: vec![]
+			contracts_created: Default::default(),
+			subtraces: if tracing {Some(vec![])} else {None},
 		}
 	}
 
 	/// Merge secondary substate `s` into self, accruing each element correspondingly.
-	pub fn accrue(&mut self, s: Substate) {
+	pub fn accrue(&mut self, s: Substate, maybe_info: Option<(TraceAction, usize)>) {
 		self.suicides.extend(s.suicides.into_iter());
 		self.logs.extend(s.logs.into_iter());
 		self.sstore_clears_count = self.sstore_clears_count + s.sstore_clears_count;
 		self.contracts_created.extend(s.contracts_created.into_iter());
+		if let Some(info) = maybe_info {
+			self.subtraces.as_mut().expect("maybe_action is Some: so we must be tracing: qed").push(Trace {
+				action: info.0,
+				depth: info.1,
+				subs: s.subtraces.expect("maybe_action is Some: so we must be tracing: qed"),
+			});
+		}
 	}
 }
 
@@ -64,13 +72,13 @@ mod tests {
 
 	#[test]
 	fn created() {
-		let sub_state = Substate::new();
+		let sub_state = Substate::new(false);
 		assert_eq!(sub_state.suicides.len(), 0);
 	}
 
 	#[test]
 	fn accrue() {
-		let mut sub_state = Substate::new();
+		let mut sub_state = Substate::new(false);
 		sub_state.contracts_created.push(address_from_u64(1u64));
 		sub_state.logs.push(LogEntry {
 			address: address_from_u64(1u64),
@@ -80,7 +88,7 @@ mod tests {
 		sub_state.sstore_clears_count = x!(5);
 		sub_state.suicides.insert(address_from_u64(10u64));
 
-		let mut sub_state_2 = Substate::new();
+		let mut sub_state_2 = Substate::new(false);
 		sub_state_2.contracts_created.push(address_from_u64(2u64));
 		sub_state_2.logs.push(LogEntry {
 			address: address_from_u64(1u64),
@@ -89,7 +97,7 @@ mod tests {
 		});
 		sub_state_2.sstore_clears_count = x!(7);
 
-		sub_state.accrue(sub_state_2);
+		sub_state.accrue(sub_state_2, None);
 		assert_eq!(sub_state.contracts_created.len(), 2);
 		assert_eq!(sub_state.sstore_clears_count, x!(12));
 		assert_eq!(sub_state.suicides.len(), 1);

ethcore/src/trace.rs

@@ -0,0 +1,111 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Tracing datatypes.
+use common::*;
+
+/// Description of a _call_ action, either a `CALL` operation or a message transction.
+#[derive(Debug, Clone, PartialEq)]
+pub struct TraceCall {
+	/// The sending account.
+	pub from: Address,
+	/// The destination account.
+	pub to: Address,
+	/// The value transferred to the destination account.
+	pub value: U256,
+	/// The gas available for executing the call.
+	pub gas: U256,
+	/// The input data provided to the call.
+	pub input: Bytes,
+	/// The result of the operation; the gas used and the output data of the call.
+	pub result: Option<(U256, Bytes)>,
+}
+
+/// Description of a _create_ action, either a `CREATE` operation or a create transction.
+#[derive(Debug, Clone, PartialEq)]
+pub struct TraceCreate {
+	/// The address of the creator.
+	pub from: Address,
+	/// The value with which the new account is endowed.
+	pub value: U256,
+	/// The gas available for the creation init code.
+	pub gas: U256,
+	/// The init code.
+	pub init: Bytes,
+	/// The result of the operation; tuple of the gas used, the address of the newly created account and its code.
+	/// NOTE: Presently failed operations are not reported so this will always be `Some`.
+	pub result: Option<(U256, Address, Bytes)>,
+//	pub output: Bytes,
+}
+
+/// Description of an action that we trace; will be either a call or a create.
+#[derive(Debug, Clone, PartialEq)]
+pub enum TraceAction {
+	/// Action isn't yet known.
+	Unknown,
+	/// It's a call action.
+	Call(TraceCall),
+	/// It's a create action.
+	Create(TraceCreate),
+}
+
+#[derive(Debug, Clone, PartialEq)]
+/// A trace; includes a description of the action being traced and sub traces of each interior action.
+pub struct Trace {
+	/// The number of EVM execution environments active when this action happened; 0 if it's
+	/// the outer action of the transaction.
+	pub depth: usize,
+	/// The action being performed.
+	pub action: TraceAction,
+	/// The sub traces for each interior action performed as part of this call.
+	pub subs: Vec<Trace>,
+}
+
+impl Default for Trace {
+	fn default() -> Trace {
+		Trace {
+			depth: 0,
+			action: TraceAction::Unknown,
+			subs: vec![],
+		}
+	}
+}
+
+impl TraceAction {
+	/// Compose a `TraceAction` from an `ActionParams`, knowing that the action is a call.
+	pub fn from_call(p: &ActionParams) -> TraceAction {
+		TraceAction::Call(TraceCall {
+			from: p.sender.clone(),
+			to: p.address.clone(),
+			value: match p.value { ActionValue::Transfer(ref x) | ActionValue::Apparent(ref x) => x.clone() },
+			gas: p.gas.clone(),
+			input: p.data.clone().unwrap_or(vec![]),
+			result: None,
+		})
+	}
+
+	/// Compose a `TraceAction` from an `ActionParams`, knowing that the action is a create.
+	pub fn from_create(p: &ActionParams) -> TraceAction {
+		TraceAction::Create(TraceCreate {
+			from: p.sender.clone(),
+			value: match p.value { ActionValue::Transfer(ref x) | ActionValue::Apparent(ref x) => x.clone() },
+			gas: p.gas.clone(),
+			init: p.code.clone().unwrap_or(vec![]),
+			result: None,
+		})
+	}
+}
+

ethcore/src/verification/verification.rs

@@ -278,6 +278,8 @@ mod tests {
 	}
 
 	impl BlockProvider for TestBlockChain {
+		fn have_tracing(&self) -> bool { false }
+		
 		fn is_known(&self, hash: &H256) -> bool {
 			self.blocks.contains_key(hash)
 		}