Merge pull request #826 from 0xProject/refactor/contracts/todos

Address TODOs and small fixes

30 files changed, 49 insertions, 65 deletions

diff --git a/packages/contracts/package.json b/packages/contracts/package.json
index 5c23d210e..c0beac0cb 100644
--- a/packages/contracts/package.json
+++ b/packages/contracts/package.json
@@ -24,7 +24,7 @@
         "compile": "sol-compiler --contracts-dir src",
         "clean": "shx rm -rf lib generated_contract_wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../contract_templates/contract.handlebars --partials '../contract_templates/partials/**/*.handlebars' --output generated_contract_wrappers --backend ethers",
-        "lint": "tslint --project . --exclude **/src/generated_contract_wrappers/**/* --exclude **/lib/**/*",
+        "lint": "tslint --project . --exclude **/src/generated_contract_wrappers/**/* --exclude **/lib/**/* && yarn lint-contracts",
         "coverage:report:text": "istanbul report text",
         "coverage:report:html": "istanbul report html && open coverage/index.html",
         "profiler:report:html": "istanbul report html && open coverage/index.html",
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol b/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol
index 387c3de6b..23c130d69 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 
 contract MixinERC20 {
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol b/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
index 92e2cebe8..12392be79 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import { WETH9 as EtherToken } from "../tokens/WETH9/WETH9.sol";
 import "../protocol/Exchange/libs/LibMath.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
index 295974f97..b5cec6b64 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../utils/LibBytes/LibBytes.sol";
 import "./MixinAuthorizable.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
index 43777d374..1f9958b43 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../utils/LibBytes/LibBytes.sol";
 import "./MixinAuthorizable.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
index d21eac618..ff4660a31 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../utils/Ownable/Ownable.sol";
 import "./mixins/MAuthorizable.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
index 71491f7bb..3651dd694 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "./IAuthorizable.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
index dd4c5fc65..8fac43a47 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../../utils/Ownable/IOwnable.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
index 312e1bde9..8afc8c8d8 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../interfaces/IAuthorizable.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
index cf53c3176..ec84b1e19 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
@@ -374,21 +374,19 @@ contract MixinExchangeCore is
         returns (FillResults memory fillResults)
     {
         // Compute proportional transfer amounts
-        // TODO: All three are multiplied by the same fraction. This can
-        // potentially be optimized.
         fillResults.takerAssetFilledAmount = takerAssetFilledAmount;
         fillResults.makerAssetFilledAmount = getPartialAmount(
-            fillResults.takerAssetFilledAmount,
+            takerAssetFilledAmount,
             order.takerAssetAmount,
             order.makerAssetAmount
         );
         fillResults.makerFeePaid = getPartialAmount(
-            fillResults.takerAssetFilledAmount,
+            takerAssetFilledAmount,
             order.takerAssetAmount,
             order.makerFee
         );
         fillResults.takerFeePaid = getPartialAmount(
-            fillResults.takerAssetFilledAmount,
+            takerAssetFilledAmount,
             order.takerAssetAmount,
             order.takerFee
         );
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
index ba687543a..56b309a1b 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
@@ -41,7 +41,6 @@ contract MixinMatchOrders is
     /// @param leftSignature Proof that order was created by the left maker.
     /// @param rightSignature Proof that order was created by the right maker.
     /// @return matchedFillResults Amounts filled and fees paid by maker and taker of matched orders.
-    /// TODO: Make this function external once supported by Solidity (See Solidity Issues #3199, #1603)
     function matchOrders(
         LibOrder.Order memory leftOrder,
         LibOrder.Order memory rightOrder,
@@ -184,7 +183,6 @@ contract MixinMatchOrders is
             leftTakerAssetFilledAmount = leftTakerAssetAmountRemaining;
 
             // The right order receives an amount proportional to how much was spent.
-            // TODO: Can we ensure rounding error is in the correct direction?
             rightTakerAssetFilledAmount = getPartialAmount(
                 rightOrder.takerAssetAmount,
                 rightOrder.makerAssetAmount,
@@ -195,7 +193,6 @@ contract MixinMatchOrders is
             rightTakerAssetFilledAmount = rightTakerAssetAmountRemaining;
 
             // The left order receives an amount proportional to how much was spent.
-            // TODO: Can we ensure rounding error is in the correct direction?
             leftTakerAssetFilledAmount = getPartialAmount(
                 rightOrder.makerAssetAmount,
                 rightOrder.takerAssetAmount,
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 822701459..ac7382715 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
@@ -91,7 +91,6 @@ contract MixinSignatureValidator is
         view
         returns (bool isValid)
     {
-        // TODO: Domain separation: make hash depend on role. (Taker sig should not be valid as maker sig, etc.)
         require(
             signature.length > 0,
             "LENGTH_GREATER_THAN_0_REQUIRED"
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 823e14316..88d2da7d7 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
@@ -99,9 +99,10 @@ contract MixinTransactions is
             "FAILED_EXECUTION"
         );
 
-        // Reset current transaction signer
-        // TODO: Check if gas is paid when currentContextAddress is already 0.
-        currentContextAddress = address(0);
+        // Reset current transaction signer if it was previously updated
+        if (signerAddress != msg.sender) {
+            currentContextAddress = address(0);
+        }
     }
 
     /// @dev Calculates EIP712 hash of the Transaction.
@@ -120,13 +121,15 @@ contract MixinTransactions is
     {
         bytes32 schemaHash = EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH;
         bytes32 dataHash = keccak256(data);
+
         // Assembly for more efficiently computing:
         // keccak256(abi.encode(
-        //   EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
-        //   salt,
-        //   signerAddress,
-        //   keccak256(data)
-        //  ));
+        //     EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
+        //     salt,
+        //     signerAddress,
+        //     keccak256(data)
+        // ));
+
         assembly {
             let memPtr := mload(64)
             mstore(memPtr, schemaHash)
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
index cea5adbbb..73447f3ae 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
@@ -33,7 +33,6 @@ contract IMatchOrders {
     /// @param leftSignature Proof that order was created by the left maker.
     /// @param rightSignature Proof that order was created by the right maker.
     /// @return matchedFillResults Amounts filled and fees paid by maker and taker of matched orders.
-    /// TODO: Make this function external once supported by Solidity (See Solidity Issues #3199, #1603)
     function matchOrders(
         LibOrder.Order memory leftOrder,
         LibOrder.Order memory rightOrder,
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
index 7c8b12724..ad7a56a06 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
@@ -24,6 +24,7 @@ import "../libs/LibFillResults.sol";
 
 
 contract IWrapperFunctions {
+
     /// @dev Fills the input order. Reverts if exact takerAssetFillAmount not filled.
     /// @param order LibOrder.Order struct containing order specifications.
     /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
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 2ea864a5a..68f2c8aed 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
@@ -101,21 +101,23 @@ contract LibOrder is
         bytes32 schemaHash = EIP712_ORDER_SCHEMA_HASH;
         bytes32 makerAssetDataHash = keccak256(order.makerAssetData);
         bytes32 takerAssetDataHash = keccak256(order.takerAssetData);
+
         // Assembly for more efficiently computing:
-        //   keccak256(abi.encode(
-        //       order.makerAddress,
-        //       order.takerAddress,
-        //       order.feeRecipientAddress,
-        //       order.senderAddress,
-        //       order.makerAssetAmount,
-        //       order.takerAssetAmount,
-        //       order.makerFee,
-        //       order.takerFee,
-        //       order.expirationTimeSeconds,
-        //       order.salt,
-        //       keccak256(order.makerAssetData),
-        //       keccak256(order.takerAssetData)
-        //   ));
+        //    keccak256(abi.encode(
+        //        order.makerAddress,
+        //        order.takerAddress,
+        //        order.feeRecipientAddress,
+        //        order.senderAddress,
+        //        order.makerAssetAmount,
+        //        order.takerAssetAmount,
+        //        order.makerFee,
+        //        order.takerFee,
+        //        order.expirationTimeSeconds,
+        //        order.salt,
+        //        keccak256(order.makerAssetData),
+        //        keccak256(order.takerAssetData)
+        //    ));
+
         assembly {
             // Backup
             // solhint-disable-next-line space-after-comma
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
index 9207dfdc2..c6904300a 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../interfaces/IAssetProxyDispatcher.sol";
 
diff --git a/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol b/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
index 44b0777b8..97801166a 100644
--- a/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../Mintable/Mintable.sol";
 import "../../utils/Ownable/Ownable.sol";
diff --git a/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol b/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
index ba647fea4..627746a52 100644
--- a/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../tokens/ERC721Token/ERC721Token.sol";
 import "../../utils/Ownable/Ownable.sol";
diff --git a/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol b/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
index 747ac7a86..767cc8d25 100644
--- a/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
+++ b/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol";
 import "../../utils/SafeMath/SafeMath.sol";
@@ -27,7 +26,10 @@ import "../../utils/SafeMath/SafeMath.sol";
  * Mintable
  * Base contract that creates a mintable UnlimitedAllowanceToken
  */
-contract Mintable is UnlimitedAllowanceToken, SafeMath {
+contract Mintable is 
+    UnlimitedAllowanceToken,
+    SafeMath
+{
     function mint(uint256 _value)
         public
     {
diff --git a/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
index 76f1c6290..07986f4bb 100644
--- a/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../protocol/Exchange/MixinAssetProxyDispatcher.sol";
 
@@ -27,7 +26,8 @@ contract TestAssetProxyDispatcher is MixinAssetProxyDispatcher {
         bytes memory assetData,
         address from,
         address to,
-        uint256 amount)
+        uint256 amount
+    )
         public
     {
         dispatchTransferFrom(assetData, from, to, amount);
diff --git a/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol b/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
index 8b9c00590..00d861e61 100644
--- a/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../utils/LibBytes/LibBytes.sol";
 
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 40e2c84dc..5a349527b 100644
--- a/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
@@ -32,7 +32,8 @@ contract TestLibs is
     function publicGetPartialAmount(
         uint256 numerator,
         uint256 denominator,
-        uint256 target)
+        uint256 target
+    )
         public
         pure
         returns (uint256 partialAmount)
@@ -48,7 +49,8 @@ contract TestLibs is
     function publicIsRoundingError(
         uint256 numerator,
         uint256 denominator,
-        uint256 target)
+        uint256 target
+    )
         public
         pure
         returns (bool isError)
diff --git a/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol b/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
index 235c77d17..e1a610469 100644
--- a/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../../protocol/Exchange/MixinSignatureValidator.sol";
 import "../../protocol/Exchange/MixinTransactions.sol";
diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
index 58ffdfcb6..d9950145d 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "./IERC20Token.sol";
 
diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
index e3e193666..5ee5e1011 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 
 contract IERC20Token {
diff --git a/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
index a974503ca..9feb5c914 100644
--- a/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
+++ b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
@@ -17,7 +17,6 @@
 */
 
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 import "../ERC20Token/ERC20Token.sol";
 
diff --git a/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol b/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
index 36563d837..116b8dc89 100644
--- a/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
+++ b/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
@@ -1,5 +1,4 @@
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 /*
  * Ownable
diff --git a/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol b/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
index 81a14a447..aca65aad2 100644
--- a/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
+++ b/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
@@ -1,5 +1,4 @@
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 /*
  * Ownable
diff --git a/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol b/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
index 8cbb8e526..4413244db 100644
--- a/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
+++ b/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
@@ -1,28 +1,27 @@
 pragma solidity 0.4.24;
-pragma experimental ABIEncoderV2;
 
 
 contract SafeMath {
-    function safeMul(uint a, uint b)
+    function safeMul(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
     {
-        uint c = a * b;
+        uint256 c = a * b;
         assert(a == 0 || c / a == b);
         return c;
     }
 
-    function safeDiv(uint a, uint b)
+    function safeDiv(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
     {
-        uint c = a / b;
+        uint256 c = a / b;
         return c;
     }
 
-    function safeSub(uint a, uint b)
+    function safeSub(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
@@ -31,12 +30,12 @@ contract SafeMath {
         return a - b;
     }
 
-    function safeAdd(uint a, uint b)
+    function safeAdd(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
     {
-        uint c = a + b;
+        uint256 c = a + b;
         assert(c >= a);
         return c;
     }