Merge development

15 files changed, 138 insertions, 161 deletions

diff --git a/packages/contracts/src/2.0.0/forwarder/MixinAssets.sol b/packages/contracts/src/2.0.0/forwarder/MixinAssets.sol
index 5cf5f831b..e06f9a8e3 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinAssets.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinAssets.sol
@@ -36,28 +36,25 @@ contract MixinAssets is
 
     bytes4 constant internal ERC20_TRANSFER_SELECTOR = bytes4(keccak256("transfer(address,uint256)"));
 
-    /// @dev Withdraws ERC20 tokens from this contract. The contract requires a ZRX balance in order to 
+    /// @dev Withdraws assets from this contract. The contract requires a ZRX balance in order to 
     ///      function optimally, and this function allows the ZRX to be withdrawn by owner. It may also be
-    ///      used to withdraw tokens that were accidentally sent to this contract.
-    /// @param token Address of ERC20 token to withdraw.
+    ///      used to withdraw assets that were accidentally sent to this contract.
+    /// @param assetData Byte array encoded for the respective asset proxy.
     /// @param amount Amount of ERC20 token to withdraw.
-    function withdrawERC20(
-        address token,
+    function withdrawAsset(
+        bytes assetData,
         uint256 amount
     )
         external
         onlyOwner
     {
-        require(
-            IERC20Token(token).transfer(msg.sender, amount),
-            "WITHDRAWAL_FAILED"
-        );
+        transferAssetToSender(assetData, amount);
     }
 
     /// @dev Transfers given amount of asset to sender.
     /// @param assetData Byte array encoded for the respective asset proxy.
     /// @param amount Amount of asset to transfer to sender.
-    function transferPurchasedAssetToSender(
+    function transferAssetToSender(
         bytes memory assetData,
         uint256 amount
     )
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinExchangeWrapper.sol b/packages/contracts/src/2.0.0/forwarder/MixinExchangeWrapper.sol
index f3aa483c5..4584bb840 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinExchangeWrapper.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinExchangeWrapper.sol
@@ -139,7 +139,7 @@ contract MixinExchangeWrapper is
     /// @param makerAssetFillAmount Desired amount of makerAsset to buy.
     /// @param signatures Proofs that orders have been signed by makers.
     /// @return Amounts filled and fees paid by makers and taker.
-    function marketBuyWithWeth(
+    function marketBuyExactAmountWithWeth(
         LibOrder.Order[] memory orders,
         uint256 makerAssetFillAmount,
         bytes[] memory signatures
@@ -180,10 +180,16 @@ contract MixinExchangeWrapper is
             addFillResults(totalFillResults, singleFillResults);
 
             // Stop execution if the entire amount of makerAsset has been bought
-            if (totalFillResults.makerAssetFilledAmount >= makerAssetFillAmount) {
+            uint256 makerAssetFilledAmount = totalFillResults.makerAssetFilledAmount;
+            if (makerAssetFilledAmount >= makerAssetFillAmount) {
                 break;
             }
         }
+
+        require(
+            makerAssetFilledAmount >= makerAssetFillAmount,
+            "COMPLETE_FILL_FAILED"
+        );
         return totalFillResults;
     }
 
@@ -196,7 +202,7 @@ contract MixinExchangeWrapper is
     /// @param zrxBuyAmount Desired amount of ZRX to buy.
     /// @param signatures Proofs that orders have been created by makers.
     /// @return totalFillResults Amounts filled and fees paid by maker and taker.
-    function marketBuyZrxWithWeth(
+    function marketBuyExactZrxWithWeth(
         LibOrder.Order[] memory orders,
         uint256 zrxBuyAmount,
         bytes[] memory signatures
@@ -248,6 +254,10 @@ contract MixinExchangeWrapper is
             }
         }
 
+        require(
+            zrxPurchased >= zrxBuyAmount,
+            "COMPLETE_FILL_FAILED"
+        );
         return totalFillResults;
     }
 }
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol b/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
index 1164ae919..93cbf79be 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
@@ -23,7 +23,7 @@ import "./libs/LibConstants.sol";
 import "./mixins/MWeth.sol";
 import "./mixins/MAssets.sol";
 import "./mixins/MExchangeWrapper.sol";
-import "./mixins/MForwarderCore.sol";
+import "./interfaces/IForwarderCore.sol";
 import "../utils/LibBytes/LibBytes.sol";
 import "../protocol/Exchange/libs/LibOrder.sol";
 import "../protocol/Exchange/libs/LibFillResults.sol";
@@ -37,7 +37,7 @@ contract MixinForwarderCore is
     MWeth,
     MAssets,
     MExchangeWrapper,
-    MForwarderCore
+    IForwarderCore
 {
 
     using LibBytes for bytes;
@@ -117,7 +117,7 @@ contract MixinForwarderCore is
             );
             // Buy back all ZRX spent on fees.
             zrxBuyAmount = orderFillResults.takerFeePaid;
-            feeOrderFillResults = marketBuyZrxWithWeth(
+            feeOrderFillResults = marketBuyExactZrxWithWeth(
                 feeOrders,
                 zrxBuyAmount,
                 feeSignatures
@@ -125,13 +125,6 @@ contract MixinForwarderCore is
             makerAssetAmountPurchased = orderFillResults.makerAssetFilledAmount;
         }
 
-        // Ensure that all ZRX fees have been repurchased and no extra WETH owned by this contract has been sold.
-        assertValidFillResults(
-            orderFillResults,
-            feeOrderFillResults,
-            zrxBuyAmount
-        );
-
         // Transfer feePercentage of total ETH spent on primary orders to feeRecipient.
         // Refund remaining ETH to msg.sender.
         transferEthFeeAndRefund(
@@ -142,7 +135,7 @@ contract MixinForwarderCore is
         );
 
         // Transfer purchased assets to msg.sender.
-        transferPurchasedAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased);
+        transferAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased);
     }
 
     /// @dev Attempt to purchase makerAssetFillAmount of makerAsset by selling ETH provided with transaction.
@@ -180,7 +173,7 @@ contract MixinForwarderCore is
         if (orders[0].makerAssetData.equals(ZRX_ASSET_DATA)) {
             // If the makerAsset is ZRX, it is not necessary to pay fees out of this
             // contracts's ZRX balance because fees are factored into the price of the order.
-            orderFillResults = marketBuyZrxWithWeth(
+            orderFillResults = marketBuyExactZrxWithWeth(
                 orders,
                 makerAssetFillAmount,
                 signatures
@@ -190,14 +183,14 @@ contract MixinForwarderCore is
         } else {
             // Attemp to purchase desired amount of makerAsset.
             // ZRX fees are payed with this contract's balance.
-            orderFillResults = marketBuyWithWeth(
+            orderFillResults = marketBuyExactAmountWithWeth(
                 orders,
                 makerAssetFillAmount,
                 signatures
             );
             // Buy back all ZRX spent on fees.
             zrxBuyAmount = orderFillResults.takerFeePaid;
-            feeOrderFillResults = marketBuyZrxWithWeth(
+            feeOrderFillResults = marketBuyExactZrxWithWeth(
                 feeOrders,
                 zrxBuyAmount,
                 feeSignatures
@@ -205,13 +198,6 @@ contract MixinForwarderCore is
             makerAssetAmountPurchased = orderFillResults.makerAssetFilledAmount;
         }
 
-        // Ensure that all ZRX fees have been repurchased and no extra WETH owned by this contract has been sold.
-        assertValidFillResults(
-            orderFillResults,
-            feeOrderFillResults,
-            zrxBuyAmount
-        );
-
         // Transfer feePercentage of total ETH spent on primary orders to feeRecipient.
         // Refund remaining ETH to msg.sender.
         transferEthFeeAndRefund(
@@ -222,33 +208,6 @@ contract MixinForwarderCore is
         );
 
         // Transfer purchased assets to msg.sender.
-        transferPurchasedAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased);
-    }
-
-    /// @dev Ensures that all ZRX fees have been repurchased and no extra WETH owned by this contract has been sold.
-    /// @param orderFillResults Amounts filled and fees paid for primary orders.
-    /// @param feeOrderFillResults Amounts filled and fees paid for fee orders.
-    /// @param zrxBuyAmount The amount of ZRX that needed to be repurchased after filling primary orders.
-    function assertValidFillResults(
-        FillResults memory orderFillResults,
-        FillResults memory feeOrderFillResults,
-        uint256 zrxBuyAmount
-    )
-        internal
-        view
-    {
-        // Ensure that all ZRX spent while filling primary orders has been repurchased.
-        uint256 zrxPurchased = safeSub(feeOrderFillResults.makerAssetFilledAmount, feeOrderFillResults.takerFeePaid);
-        require(
-            zrxPurchased >= zrxBuyAmount,
-            "COMPLETE_FILL_FAILED"
-        );
-
-        // Ensure that no extra WETH owned by this contract has been sold.
-        uint256 wethSold = safeAdd(orderFillResults.takerAssetFilledAmount, feeOrderFillResults.takerAssetFilledAmount);
-        require(
-            wethSold <= msg.value,
-            "OVERSOLD_WETH"
-        );
+        transferAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased);
     }
 }
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinWeth.sol b/packages/contracts/src/2.0.0/forwarder/MixinWeth.sol
index 8ba236e7f..e07940776 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinWeth.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinWeth.sol
@@ -71,12 +71,16 @@ contract MixinWeth is
             "FEE_PERCENTAGE_TOO_LARGE"
         );
 
-        // Calculate amount of WETH that hasn't been sold.
-        uint256 wethRemaining = safeSub(
-            msg.value,
-            safeAdd(wethSoldExcludingFeeOrders, wethSoldForZrx)
+        // Ensure that no extra WETH owned by this contract has been sold.
+        uint256 wethSold = safeAdd(wethSoldExcludingFeeOrders, wethSoldForZrx);
+        require(
+            wethSold <= msg.value,
+            "OVERSOLD_WETH"
         );
 
+        // Calculate amount of WETH that hasn't been sold.
+        uint256 wethRemaining = safeSub(msg.value, wethSold);
+
         // Calculate ETH fee to pay to feeRecipient.
         uint256 ethFee = getPartialAmount(
             feePercentage,
diff --git a/packages/contracts/src/2.0.0/forwarder/interfaces/IAssets.sol b/packages/contracts/src/2.0.0/forwarder/interfaces/IAssets.sol
index 9b0d995eb..1e034c003 100644
--- a/packages/contracts/src/2.0.0/forwarder/interfaces/IAssets.sol
+++ b/packages/contracts/src/2.0.0/forwarder/interfaces/IAssets.sol
@@ -21,13 +21,13 @@ pragma solidity 0.4.24;
 
 contract IAssets {
 
-    /// @dev Withdraws ERC20 tokens from this contract. The contract requires a ZRX balance in order to 
+    /// @dev Withdraws assets from this contract. The contract requires a ZRX balance in order to 
     ///      function optimally, and this function allows the ZRX to be withdrawn by owner. It may also be
-    ///      used to withdraw tokens that were accidentally sent to this contract.
-    /// @param token Address of ERC20 token to withdraw.
+    ///      used to withdraw assets that were accidentally sent to this contract.
+    /// @param assetData Byte array encoded for the respective asset proxy.
     /// @param amount Amount of ERC20 token to withdraw.
-    function withdrawERC20(
-        address token,
+    function withdrawAsset(
+        bytes assetData,
         uint256 amount
     )
         external;
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MAssets.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MAssets.sol
index 340ee0bcb..83636432a 100644
--- a/packages/contracts/src/2.0.0/forwarder/mixins/MAssets.sol
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MAssets.sol
@@ -28,7 +28,7 @@ contract MAssets is
     /// @dev Transfers given amount of asset to sender.
     /// @param assetData Byte array encoded for the respective asset proxy.
     /// @param amount Amount of asset to transfer to sender.
-    function transferPurchasedAssetToSender(
+    function transferAssetToSender(
         bytes memory assetData,
         uint256 amount
     )
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MExchangeWrapper.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MExchangeWrapper.sol
index 5a2def7e5..360dea0e4 100644
--- a/packages/contracts/src/2.0.0/forwarder/mixins/MExchangeWrapper.sol
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MExchangeWrapper.sol
@@ -60,7 +60,7 @@ contract MExchangeWrapper {
     /// @param makerAssetFillAmount Desired amount of makerAsset to buy.
     /// @param signatures Proofs that orders have been signed by makers.
     /// @return Amounts filled and fees paid by makers and taker.
-    function marketBuyWithWeth(
+    function marketBuyExactAmountWithWeth(
         LibOrder.Order[] memory orders,
         uint256 makerAssetFillAmount,
         bytes[] memory signatures
@@ -77,7 +77,7 @@ contract MExchangeWrapper {
     /// @param zrxBuyAmount Desired amount of ZRX to buy.
     /// @param signatures Proofs that orders have been created by makers.
     /// @return totalFillResults Amounts filled and fees paid by maker and taker.
-    function marketBuyZrxWithWeth(
+    function marketBuyExactZrxWithWeth(
         LibOrder.Order[] memory orders,
         uint256 zrxBuyAmount,
         bytes[] memory signatures
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MForwarderCore.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MForwarderCore.sol
deleted file mode 100644
index 0f5cd9c66..000000000
--- a/packages/contracts/src/2.0.0/forwarder/mixins/MForwarderCore.sol
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
-
-import "../../protocol/Exchange/libs/LibOrder.sol";
-import "../../protocol/Exchange/libs/LibFillResults.sol";
-import "../interfaces/IForwarderCore.sol";
-
-
-contract MForwarderCore is
-    IForwarderCore
-{
-
-    /// @dev Ensures that all ZRX fees have been repurchased and no extra WETH owned by this contract has been sold.
-    /// @param orderFillResults Amounts filled and fees paid for primary orders.
-    /// @param feeOrderFillResults Amounts filled and fees paid for fee orders.
-    /// @param zrxBuyAmount The amount of ZRX that needed to be repurchased after filling primary orders.
-    function assertValidFillResults(
-        LibFillResults.FillResults memory orderFillResults,
-        LibFillResults.FillResults memory feeOrderFillResults,
-        uint256 zrxBuyAmount
-    )
-        internal
-        view;
-}
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
index ac7382715..44de54817 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
@@ -96,14 +96,15 @@ contract MixinSignatureValidator is
             "LENGTH_GREATER_THAN_0_REQUIRED"
         );
 
-        // Ensure signature is supported
+        // Pop last byte off of signature byte array.
         uint8 signatureTypeRaw = uint8(signature.popLastByte());
+
+        // Ensure signature is supported
         require(
             signatureTypeRaw < uint8(SignatureType.NSignatureTypes),
             "SIGNATURE_UNSUPPORTED"
         );
 
-        // Pop last byte off of signature byte array.
         SignatureType signatureType = SignatureType(signatureTypeRaw);
 
         // Variables are not scoped in Solidity.
@@ -141,7 +142,12 @@ contract MixinSignatureValidator is
             v = uint8(signature[0]);
             r = signature.readBytes32(1);
             s = signature.readBytes32(33);
-            recovered = ecrecover(hash, v, r, s);
+            recovered = ecrecover(
+                hash,
+                v,
+                r,
+                s
+            );
             isValid = signerAddress == recovered;
             return isValid;
 
@@ -197,7 +203,6 @@ contract MixinSignatureValidator is
         // | 0x14 + x | 1      | Signature type is always "\x06" |
         } else if (signatureType == SignatureType.Validator) {
             // Pop last 20 bytes off of signature byte array.
-
             address validatorAddress = signature.popLast20Bytes();
             
             // Ensure signer has approved validator.
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
index 88d2da7d7..821d30279 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
@@ -123,22 +123,25 @@ contract MixinTransactions is
         bytes32 dataHash = keccak256(data);
 
         // Assembly for more efficiently computing:
-        // keccak256(abi.encode(
+        // keccak256(abi.encodePacked(
         //     EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
         //     salt,
-        //     signerAddress,
+        //     bytes32(signerAddress),
         //     keccak256(data)
         // ));
 
         assembly {
+            // Load free memory pointer
             let memPtr := mload(64)
-            mstore(memPtr, schemaHash)
-            mstore(add(memPtr, 32), salt)
-            mstore(add(memPtr, 64), and(signerAddress, 0xffffffffffffffffffffffffffffffffffffffff))
-            mstore(add(memPtr, 96), dataHash)
+
+            mstore(memPtr, schemaHash)                                                               // hash of schema
+            mstore(add(memPtr, 32), salt)                                                            // salt
+            mstore(add(memPtr, 64), and(signerAddress, 0xffffffffffffffffffffffffffffffffffffffff))  // signerAddress
+            mstore(add(memPtr, 96), dataHash)                                                        // hash of data
+
+            // Compute hash
             result := keccak256(memPtr, 128)
         }
-
         return result;
     }
 
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibAbiEncoder.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibAbiEncoder.sol
index 704c7061c..4aad37709 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibAbiEncoder.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibAbiEncoder.sol
@@ -24,20 +24,17 @@ import "./LibOrder.sol";
 
 contract LibAbiEncoder {
 
-    /// @dev ABI encodes calldata for `fillOrder` in memory and returns the address range.
-    ///      This range can be passed into `call` or `delegatecall` to invoke an external
-    ///      call to `fillOrder`.
+    /// @dev ABI encodes calldata for `fillOrder`.
     /// @param order Order struct containing order specifications.
     /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
     /// @param signature Proof that order has been created by maker.
-    /// @return calldataBegin Memory address of ABI encoded calldata.
-    /// @return calldataLength Lenfgth of ABI encoded calldata.
+    /// @return ABI encoded calldata for `fillOrder`.
     function abiEncodeFillOrder(
         LibOrder.Order memory order,
         uint256 takerAssetFillAmount,
         bytes memory signature
     )
-        public
+        internal
         pure
         returns (bytes memory fillOrderCalldata)
     {
@@ -207,10 +204,10 @@ contract LibAbiEncoder {
             }
 
             // Set length of calldata
-            mstore(
-                fillOrderCalldata,
-                sub(dataAreaEnd, add(fillOrderCalldata, 0x20))
-            )
+            mstore(fillOrderCalldata, sub(dataAreaEnd, add(fillOrderCalldata, 0x20)))
+
+            // Increment free memory pointer
+            mstore(0x40, dataAreaEnd)
         }
 
         return fillOrderCalldata;
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
index 1fc41dafd..b02f7632e 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
@@ -30,7 +30,7 @@ contract LibEIP712 {
     string constant internal EIP712_DOMAIN_VERSION = "2";
 
     // Hash of the EIP712 Domain Separator Schema
-    bytes32 public constant EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH = keccak256(abi.encodePacked(
+    bytes32 constant internal EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH = keccak256(abi.encodePacked(
         "EIP712Domain(",
         "string name,",
         "string version,",
@@ -45,11 +45,11 @@ contract LibEIP712 {
     constructor ()
         public
     {
-        EIP712_DOMAIN_HASH = keccak256(abi.encode(
+        EIP712_DOMAIN_HASH = keccak256(abi.encodePacked(
             EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
             keccak256(bytes(EIP712_DOMAIN_NAME)),
             keccak256(bytes(EIP712_DOMAIN_VERSION)),
-            address(this)
+            bytes32(address(this))
         ));
     }
 
@@ -59,8 +59,28 @@ contract LibEIP712 {
     function hashEIP712Message(bytes32 hashStruct)
         internal
         view
-        returns (bytes32)
+        returns (bytes32 result)
     {
-        return keccak256(abi.encodePacked(EIP191_HEADER, EIP712_DOMAIN_HASH, hashStruct));
+        bytes32 eip712DomainHash = EIP712_DOMAIN_HASH;
+
+        // Assembly for more efficient computing:
+        // keccak256(abi.encodePacked(
+        //     EIP191_HEADER,
+        //     EIP712_DOMAIN_HASH,
+        //     hashStruct    
+        // ));
+
+        assembly {
+            // Load free memory pointer
+            let memPtr := mload(64)
+
+            mstore(memPtr, 0x1901000000000000000000000000000000000000000000000000000000000000)  // EIP191 header
+            mstore(add(memPtr, 2), eip712DomainHash)                                            // EIP712 domain hash
+            mstore(add(memPtr, 34), hashStruct)                                                 // Hash of struct
+
+            // Compute hash
+            result := keccak256(memPtr, 66)
+        }
+        return result;
     }
 }
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
index 4031ff26b..68f4f5f1b 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
@@ -103,11 +103,12 @@ contract LibOrder is
         bytes32 takerAssetDataHash = keccak256(order.takerAssetData);
 
         // Assembly for more efficiently computing:
-        // keccak256(abi.encode(
-        //     order.makerAddress,
-        //     order.takerAddress,
-        //     order.feeRecipientAddress,
-        //     order.senderAddress,
+        // keccak256(abi.encodePacked(
+        //     EIP712_ORDER_SCHEMA_HASH,
+        //     bytes32(order.makerAddress),
+        //     bytes32(order.takerAddress),
+        //     bytes32(order.feeRecipientAddress),
+        //     bytes32(order.senderAddress),
         //     order.makerAssetAmount,
         //     order.takerAssetAmount,
         //     order.makerFee,
@@ -119,24 +120,26 @@ contract LibOrder is
         // ));
 
         assembly {
+            // Calculate memory addresses that will be swapped out before hashing
+            let pos1 := sub(order, 32)
+            let pos2 := add(order, 320)
+            let pos3 := add(order, 352)
+
             // Backup
-            // solhint-disable-next-line space-after-comma
-            let temp1 := mload(sub(order,  32))
-            let temp2 := mload(add(order, 320))
-            let temp3 := mload(add(order, 352))
+            let temp1 := mload(pos1)
+            let temp2 := mload(pos2)
+            let temp3 := mload(pos3)
             
             // Hash in place
-            // solhint-disable-next-line space-after-comma
-            mstore(sub(order,  32), schemaHash)
-            mstore(add(order, 320), makerAssetDataHash)
-            mstore(add(order, 352), takerAssetDataHash)
-            result := keccak256(sub(order, 32), 416)
+            mstore(pos1, schemaHash)
+            mstore(pos2, makerAssetDataHash)
+            mstore(pos3, takerAssetDataHash)
+            result := keccak256(pos1, 416)
             
             // Restore
-            // solhint-disable-next-line space-after-comma
-            mstore(sub(order,  32), temp1)
-            mstore(add(order, 320), temp2)
-            mstore(add(order, 352), temp3)
+            mstore(pos1, temp1)
+            mstore(pos2, temp2)
+            mstore(pos3, temp3)
         }
         return result;
     }
diff --git a/packages/contracts/src/2.0.0/test/TestExchangeInternals/TestExchangeInternals.sol b/packages/contracts/src/2.0.0/test/TestExchangeInternals/TestExchangeInternals.sol
index 923bac97d..d9cec9edc 100644
--- a/packages/contracts/src/2.0.0/test/TestExchangeInternals/TestExchangeInternals.sol
+++ b/packages/contracts/src/2.0.0/test/TestExchangeInternals/TestExchangeInternals.sol
@@ -22,6 +22,7 @@ pragma experimental ABIEncoderV2;
 import "../../protocol/Exchange/Exchange.sol";
 
 
+// solhint-disable no-empty-blocks
 contract TestExchangeInternals is
     Exchange
 {
diff --git a/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
index 5a349527b..4a99dd9c1 100644
--- a/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
@@ -22,13 +22,33 @@ pragma experimental ABIEncoderV2;
 import "../../protocol/Exchange/libs/LibMath.sol";
 import "../../protocol/Exchange/libs/LibOrder.sol";
 import "../../protocol/Exchange/libs/LibFillResults.sol";
+import "../../protocol/Exchange/libs/LibAbiEncoder.sol";
 
 
 contract TestLibs is 
     LibMath,
     LibOrder,
-    LibFillResults
+    LibFillResults,
+    LibAbiEncoder
 {
+
+    function publicAbiEncodeFillOrder(
+        Order memory order,
+        uint256 takerAssetFillAmount,
+        bytes memory signature
+    )
+        public
+        pure
+        returns (bytes memory fillOrderCalldata)
+    {
+        fillOrderCalldata = abiEncodeFillOrder(
+            order,
+            takerAssetFillAmount,
+            signature
+        );
+        return fillOrderCalldata;
+    }
+
     function publicGetPartialAmount(
         uint256 numerator,
         uint256 denominator,