Convert to use rich reverts

contracts/exchange/contracts/src/MixinAssetProxyDispatcher.sol

@@ -25,7 +25,8 @@ import "./interfaces/IAssetProxy.sol";
 
 contract MixinAssetProxyDispatcher is
     Ownable,
-    MAssetProxyDispatcher
+    MAssetProxyDispatcher,
+    MRichErrors
 {
     // Mapping from Asset Proxy Id's to their respective Asset Proxy
     mapping (bytes4 => address) public assetProxies;
@@ -64,17 +65,17 @@ contract MixinAssetProxyDispatcher is
     }
 
     /// @dev Forwards arguments to assetProxy and calls `transferFrom`. Either succeeds or throws.
+    /// @param orderHash Hash of the order associated with this transfer.
     /// @param assetData Byte array encoded for the asset.
     /// @param from Address to transfer token from.
     /// @param to Address to transfer token to.
     /// @param amount Amount of token to transfer.
-    /// @param orderHash Order hash, used for rich reverts.
     function dispatchTransferFrom(
+        bytes32 orderHash,
         bytes memory assetData,
         address from,
         address to,
-        uint256 amount,
+        uint256 amount
-        bytes32 orderHash
     )
         internal
     {
@@ -82,14 +83,13 @@ contract MixinAssetProxyDispatcher is
         if (amount > 0 && from != to) {
             // Ensure assetData length is valid
             if (assetData.length <= 3) {
-                rrevert(AssetProxyDispatchError(AssetProxyDispatchErrorCodes.INVALID_ASSET_DATA_LENGTH));
+                rrevert(AssetProxyDispatchError(
+                    orderHash,
+                    assetData,
+                    AssetProxyDispatchErrorCodes.INVALID_ASSET_DATA_LENGTH
+                ));
             }
 
-            require(
-                assetData.length > 3,
-                "LENGTH_GREATER_THAN_3_REQUIRED"
-            );
-
             // Lookup assetProxy. We do not use `LibBytes.readBytes4` for gas efficiency reasons.
             bytes4 assetProxyId;
             assembly {
@@ -102,13 +102,17 @@ contract MixinAssetProxyDispatcher is
 
             // Ensure that assetProxy exists
             if (assetProxy == address(0)) {
-                rrevert(AssetProxyDispatchError(AssetProxyDispatchErrorCodes.UNKNOWN_ASSET_PROXY));
+                rrevert(AssetProxyDispatchError(
+                    orderHash,
+                    assetData,
+                    AssetProxyDispatchErrorCodes.UNKNOWN_ASSET_PROXY
+                ));
             }
 
             // Whether the AssetProxy transfer succeeded.
             bool didSucceed;
             // On failure, the revert message returned by the asset proxy.
-            bytes revertMessage = new bytes(0);
+            bytes revertMessage;
 
             // We construct calldata for the `assetProxy.transferFrom` ABI.
             // The layout of this calldata is in the table below.
@@ -129,8 +133,8 @@ contract MixinAssetProxyDispatcher is
                 /////// Setup State ///////
                 // `cdStart` is the start of the calldata for `assetProxy.transferFrom` (equal to free memory ptr).
                 let cdStart := mload(64)
-                // We reserve 256 bytes from `cdStart` because we'll reuse it later for return data.
+                // We reserve 288 bytes from `cdStart` because we'll reuse it later for return data.
-                mstore(64, add(cdStart, 256))
+                mstore(64, add(cdStart, 288))
                 // `dataAreaLength` is the total number of words needed to store `assetData`
                 //  As-per the ABI spec, this value is padded up to the nearest multiple of 32,
                 //  and includes 32-bytes for length.
@@ -172,7 +176,7 @@ contract MixinAssetProxyDispatcher is
                     cdStart,                // pointer to start of input
                     sub(cdEnd, cdStart),    // length of input
                     cdStart,                // write output over input
-                    256                     // reserve 256 bytes for output
+                    288                     // reserve 288 bytes for output
                 )
 
                 if iszero(didSucceed) { // Call reverted.
@@ -196,12 +200,12 @@ contract MixinAssetProxyDispatcher is
                         let selector := and(mload(sub(cdStart, 28), 0xffffffff)
                         cdStart := add(cdStart, 4)
                         if eq(selector, 0x08c379a) {
-                            let dataLength := mload(cdStart);
+                            // Set revertMessage to the start of Data.
                             revertMessage := add(cdStart, mload(cdStart))
                             // Truncate the data length if it's larger than our buffer
-                            // size (256 - 32 = 224)
+                            // size (288 - 32 = 256)
-                            if gt(dataLength, 224) {
+                            if gt(mload(revertMessage), 256) {
-                                mstore(revertMessage, 224)
+                                mstore(revertMessage, 256)
                             }
                         }
                     }

contracts/exchange/contracts/src/MixinRichErrors.sol

@@ -135,7 +135,7 @@ contract MixinRichErrors is
     }
 
     function AssetProxyExistsError(
-        address proxy
+        address proxyAddress
     )
         internal
         pure
@@ -143,11 +143,12 @@ contract MixinRichErrors is
     {
         return abi.encodeWithSelector(
             ASSET_PROXY_EXISTS_ERROR_SELECTOR,
-            proxy
+            proxyAddress
         );
     }
 
     function AssetProxyDispatchError(
+        bytes32 orderHash,
         bytes memory assetData,
         AssetProxyDispatchErrorCodes error
     )
@@ -157,6 +158,7 @@ contract MixinRichErrors is
     {
         return abi.encodeWithSelector(
             ASSET_PROXY_DISPATCH_ERROR_SELECTOR,
+            orderHash,
             assetData,
             uint8(error)
         );

contracts/exchange/contracts/src/mixins/MRichErrors.sol

@@ -18,9 +18,12 @@
 
 pragma solidity ^0.5.5;
 
+import "@0x/contracts-utils/contracs/src/mixins/MLibRichErrors.sol";
 
-contract MRichErrors {
 
+contract MRichErrors is
+    MLibRichErrors
+{
     enum FillErrorCodes {
         INVALID_TAKER_AMOUNT,
         TAKER_OVERPAY,
@@ -139,9 +142,10 @@ contract MRichErrors {
         returns (bytes memory);
 
     bytes4 internal constant ASSET_PROXY_DISPATCH_ERROR_SELECTOR =
-        bytes4(keccak256("AssetProxyDispatchError(bytes,uint8)"));
+        bytes4(keccak256("AssetProxyDispatchError(bytes32,bytes,uint8)"));
 
     function AssetProxyDispatchError(
+        bytes32 orderHash,
         bytes memory assetData,
         AssetProxyDispatchErrorCodes error
     )

contracts/utils/contracts/src/LibRichErrors.sol

@@ -18,12 +18,13 @@
 
 pragma solidity ^0.5.5;
 
-contract LibRichErrors {
+import "./mixins/MLibRichErrors.sol";
+
+
+contract LibRichErrors is
+    MLibRichErrors
+{
     // solhint-disable func-name-mixedcase
-
-    bytes4 private constant STANDARD_ERROR_SELECTOR =
-        bytes4(keccak256("Error(string)"));
-
     function StandardError(
         string memory message
     )

contracts/utils/contracts/src/mixins/MLibRichErrors.sol

@@ -0,0 +1,41 @@
+/*
+
+  Copyright 2019 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 ^0.5.5;
+
+contract MRichErrors {
+    // solhint-disable func-name-mixedcase
+
+    bytes4 internal constant STANDARD_ERROR_SELECTOR =
+        bytes4(keccak256("Error(string)"));
+
+    function StandardError(
+        string memory message
+    )
+        internal
+        pure
+        returns (bytes memory);
+
+    // solhint-enable func-name-mixedcase
+
+    /// @dev Reverts an encoded rich revert reason `errorData`.
+    /// @param errorData ABI encoded error data.
+    function rrevert(bytes memory errorData)
+        internal
+        pure;
+}