Very basic EVM binary.

ethcore/src/evm/evm.rs

@@ -95,11 +95,17 @@ impl<'a> Finalize for Result<GasLeft<'a>> {
 	}
 }
 
+/// Cost calculation type. For low-gas usage we calculate costs using usize instead of U256
 pub trait CostType: ops::Mul<Output=Self> + ops::Div<Output=Self> + ops::Add<Output=Self> + ops::Sub<Output=Self> + ops::Shr<usize, Output=Self> + ops::Shl<usize, Output=Self> + cmp::Ord + Sized + From<usize> + Copy {
+	/// Converts this cost into `U256`
 	fn as_u256(&self) -> U256;
+	/// Tries to fit `U256` into this `Cost` type
 	fn from_u256(val: U256) -> Result<Self>;
+	/// Convert to usize (may panic)
 	fn as_usize(&self) -> usize;
+	/// Add with overflow
 	fn overflow_add(self, other: Self) -> (Self, bool);
+	/// Multiple with overflow
 	fn overflow_mul(self, other: Self) -> (Self, bool);
 }
 

ethcore/src/evm/interpreter/mod.rs

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-///! Rust VM implementation
+//! Rust VM implementation
 
 #[cfg(not(feature = "evm-debug"))]
 macro_rules! evm_debug {
@@ -182,6 +182,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 				instruction: instruction
 			});
 		}
+
 		if info.tier == instructions::GasPriceTier::Invalid {
 			return Err(evm::Error::BadInstruction {
 				instruction: instruction

ethcore/src/lib.rs

@@ -117,18 +117,18 @@ pub mod pod_state;
 pub mod engine;
 pub mod migrations;
 pub mod miner;
+#[macro_use] pub mod evm;
+pub mod action_params;
 
 mod blooms;
 mod db;
 mod common;
 mod basic_types;
-#[macro_use] mod evm;
 mod env_info;
 mod pod_account;
 mod state;
 mod account;
 mod account_db;
-mod action_params;
 mod null_engine;
 mod builtin;
 mod substate;