USDC v2.2

contracts/test/UpgradedFiatTokenNewFieldsV3Test.sol → contracts/test/UpgradedFiatTokenNewFieldsV2_2Test.sol

@@ -1,8 +1,6 @@
 /**
  * SPDX-License-Identifier: MIT
  *
- * Copyright (c) 2018 zOS Global Limited.
- *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
@@ -24,13 +22,13 @@
 
 pragma solidity 0.6.12;
 
-import { FiatTokenV3 } from "../v3/FiatTokenV3.sol";
+import { FiatTokenV2_2 } from "../v2/FiatTokenV2_2.sol";
 
 /**
  * @title UpgradedFiatTokenNewFieldsTest
  * @dev ERC20 Token backed by fiat reserves
  */
-contract UpgradedFiatTokenNewFieldsV3Test is FiatTokenV3 {
+contract UpgradedFiatTokenNewFieldsV2_2Test is FiatTokenV2_2 {
     bool public newBool;
     address public newAddress;
     uint256 public newUint;

contracts/test/UpgradedFiatTokenV3.sol → contracts/test/UpgradedFiatTokenV2_2.sol

@@ -1,8 +1,6 @@
 /**
  * SPDX-License-Identifier: MIT
  *
- * Copyright (c) 2018 zOS Global Limited.
- *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
@@ -24,12 +22,12 @@
 
 pragma solidity 0.6.12;
 
-import { FiatTokenV3 } from "../v3/FiatTokenV3.sol";
+import { FiatTokenV2_2 } from "../v2/FiatTokenV2_2.sol";
 
 /**
  * @title UpgradedFiatToken
  * @dev ERC20 Token backed by fiat reserves
  */
-contract UpgradedFiatTokenV3 is FiatTokenV3 {
+contract UpgradedFiatTokenV2_2 is FiatTokenV2_2 {
 
 }

contracts/v1/FiatTokenV1.sol

@@ -111,6 +111,7 @@ contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
      * @return A boolean that indicates if the operation was successful.
      */
     function mint(address _to, uint256 _amount)
+        virtual
         external
         whenNotPaused
         onlyMinters

contracts/v3/FiatTokenV3.sol → contracts/v2/FiatTokenV2_2.sol

@@ -28,16 +28,15 @@ import { EIP712 } from "../util/EIP712.sol";
 // solhint-disable func-name-mixedcase
 
 /**
- * @title FiatTokenV3
+ * @title FiatTokenV2_2
  * @dev ERC20 Token backed by fiat reserves
  */
-contract FiatTokenV3 is FiatTokenV2_1 {
-
+contract FiatTokenV2_2 is FiatTokenV2_1 {
     /**
-     * @notice Initialize v3
+     * @notice Initialize v2.2
      */
-    function initializeV3(address[] calldata accountsToBlacklist) external {
-        require(_initializedVersion == 2, "v3 initialized out of order");
+    function initializeV2_2(address[] calldata accountsToBlacklist) external {
+        require(_initializedVersion == 2, "v2.2 initialized out of order");
 
         // re-add previously blacklisted accounts to the blacklist
         // by setting the high bit of their balance to 1
@@ -48,8 +47,6 @@ contract FiatTokenV3 is FiatTokenV2_1 {
         // additionally blacklist the contract address itself
         _blacklist(address(this));
 
-        DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(name, "3");
-
         _initializedVersion = 3;
     }
 
@@ -291,10 +288,43 @@ contract FiatTokenV3 is FiatTokenV2_1 {
     }
 
     /**
-     * @notice Version string for the EIP712 domain separator
-     * @return Version string
+     * @dev Function to mint tokens
+     * @param _to The address that will receive the minted tokens.
+     * @param _amount The amount of tokens to mint. Must be less than or equal
+     * to the minterAllowance of the caller.
+     * @return A boolean that indicates if the operation was successful.
      */
-    function version() external override view returns (string memory) {
-        return "3";
+    function mint(address _to, uint256 _amount)
+        override
+        external
+        whenNotPaused
+        onlyMinters
+        notBlacklisted(msg.sender)
+        notBlacklisted(_to)
+        returns (bool)
+    {
+        require(_to != address(0), "FiatToken: mint to the zero address");
+        require(_amount > 0, "FiatToken: mint amount not greater than 0");
+
+        uint256 mintingAllowedAmount = minterAllowed[msg.sender];
+        require(
+            _amount <= mintingAllowedAmount,
+            "FiatToken: mint amount exceeds minterAllowance"
+        );
+
+        uint256 newTotalSupply = totalSupply_.add(_amount);
+        // The supply cap ensures that no account can be unintentionally blacklisted
+        // with a high balance
+        // Hardcoding the value here as opposed to setting it in storage since it's
+        // expected to be static and this avoids an SLOAD
+        require(newTotalSupply <= (uint256(1) << 255) - 1, "mint causes total supply to supply cap");
+
+        totalSupply_ = newTotalSupply;
+
+        balances[_to] = balances[_to].add(_amount);
+        minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
+        emit Mint(msg.sender, _to, _amount);
+        emit Transfer(address(0), _to, _amount);
+        return true;
     }
 }

contracts/v3/upgrader/V3Upgrader.sol → contracts/v2/upgrader/V2_2Upgrader.sol

@@ -25,20 +25,20 @@ pragma solidity 0.6.12;
 import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { Ownable } from "../../v1/Ownable.sol";
-import { FiatTokenV3 } from "../FiatTokenV3.sol";
+import { FiatTokenV2_2 } from "../FiatTokenV2_2.sol";
 import { FiatTokenProxy } from "../../v1/FiatTokenProxy.sol";
 import { V2UpgraderHelper } from "../../v2/upgrader/V2UpgraderHelper.sol";
 
 /**
- * @title V3 Upgrader
- * @notice Performs USDC v3 upgrade
- * @dev Read docs/v3_upgrade.md
+ * @title v2.2 Upgrader
+ * @notice Performs USDC v2.2 upgrade
+ * @dev docs TBD
  */
-contract V3Upgrader is Ownable {
+contract V2_2Upgrader is Ownable {
     using SafeMath for uint256;
 
     FiatTokenProxy private _proxy;
-    FiatTokenV3 private _implementation;
+    FiatTokenV2_2 private _implementation;
     address private _newProxyAdmin;
     string private _newName;
     V2UpgraderHelper private _helper;
@@ -47,13 +47,13 @@ contract V3Upgrader is Ownable {
     /**
      * @notice Constructor
      * @param proxy                 FiatTokenProxy contract
-     * @param implementation        FiatTokenV3 implementation contract
+     * @param implementation        FiatTokenV2_2 implementation contract
      * @param newProxyAdmin         Grantee of proxy admin role after upgrade
      * @param accountsToBlacklist   Accounts to re-add to the blacklist
      */
     constructor(
         FiatTokenProxy proxy,
-        FiatTokenV3 implementation,
+        FiatTokenV2_2 implementation,
         address newProxyAdmin,
         address[] memory accountsToBlacklist
     ) public Ownable() {
@@ -73,7 +73,7 @@ contract V3Upgrader is Ownable {
     }
 
     /**
-     * @notice The address of the FiatTokenV3 implementation contract
+     * @notice The address of the FiatTokenV2_2 implementation contract
      * @return Contract address
      */
     function implementation() external view returns (address) {
@@ -117,7 +117,7 @@ contract V3Upgrader is Ownable {
 
         // Check that this contract sufficient funds to run the tests
         uint256 contractBal = _helper.balanceOf(address(this));
-        require(contractBal >= 2e5, "V3Upgrader: 0.2 USDC needed");
+        require(contractBal >= 2e5, "V2_2Upgrader: 0.2 USDC needed");
 
         uint256 callerBal = _helper.balanceOf(msg.sender);
 
@@ -137,52 +137,52 @@ contract V3Upgrader is Ownable {
         // Transfer proxy admin role
         _proxy.changeAdmin(_newProxyAdmin);
 
-        // Initialize V3 contract
-        FiatTokenV3 v3 = FiatTokenV3(address(_proxy));
-        v3.initializeV3(_accountsToBlacklist);
+        // Initialize V2_2 contract
+        FiatTokenV2_2 v2_2 = FiatTokenV2_2(address(_proxy));
+        v2_2.initializeV2_2(_accountsToBlacklist);
 
         // Sanity test
         // Check metadata
         require(
-            keccak256(bytes(name)) == keccak256(bytes(v3.name())) &&
-                keccak256(bytes(symbol)) == keccak256(bytes(v3.symbol())) &&
-                decimals == v3.decimals() &&
-                keccak256(bytes(currency)) == keccak256(bytes(v3.currency())) &&
-                masterMinter == v3.masterMinter() &&
-                owner == v3.owner() &&
-                pauser == v3.pauser() &&
-                blacklister == v3.blacklister(),
-            "V3Upgrader: metadata test failed"
+            keccak256(bytes(name)) == keccak256(bytes(v2_2.name())) &&
+                keccak256(bytes(symbol)) == keccak256(bytes(v2_2.symbol())) &&
+                decimals == v2_2.decimals() &&
+                keccak256(bytes(currency)) == keccak256(bytes(v2_2.currency())) &&
+                masterMinter == v2_2.masterMinter() &&
+                owner == v2_2.owner() &&
+                pauser == v2_2.pauser() &&
+                blacklister == v2_2.blacklister(),
+            "V2_2Upgrader: metadata test failed"
         );
 
         // Test balanceOf
         require(
-            v3.balanceOf(address(this)) == contractBal,
-            "V3Upgrader: balanceOf test failed"
+            v2_2.balanceOf(address(this)) == contractBal,
+            "V2_2Upgrader: balanceOf test failed"
         );
 
         // Test transfer
         require(
-            v3.transfer(msg.sender, 1e5) &&
-                v3.balanceOf(msg.sender) == callerBal.add(1e5) &&
-                v3.balanceOf(address(this)) == contractBal.sub(1e5),
-            "V3Upgrader: transfer test failed"
+            v2_2.transfer(msg.sender, 1e5) &&
+                v2_2.balanceOf(msg.sender) == callerBal.add(1e5) &&
+                v2_2.balanceOf(address(this)) == contractBal.sub(1e5),
+            "V2_2Upgrader: transfer test failed"
         );
 
         // Test approve/transferFrom
         require(
-            v3.approve(address(_helper), 1e5) &&
-                v3.allowance(address(this), address(_helper)) == 1e5 &&
+            v2_2.approve(address(_helper), 1e5) &&
+                v2_2.allowance(address(this), address(_helper)) == 1e5 &&
                 _helper.transferFrom(address(this), msg.sender, 1e5) &&
-                v3.allowance(address(this), msg.sender) == 0 &&
-                v3.balanceOf(msg.sender) == callerBal.add(2e5) &&
-                v3.balanceOf(address(this)) == contractBal.sub(2e5),
-            "V3Upgrader: approve/transferFrom test failed"
+                v2_2.allowance(address(this), msg.sender) == 0 &&
+                v2_2.balanceOf(msg.sender) == callerBal.add(2e5) &&
+                v2_2.balanceOf(address(this)) == contractBal.sub(2e5),
+            "V2_2Upgrader: approve/transferFrom test failed"
         );
 
         // Check that addresses that should be blacklisted are
         for (uint256 i = 0; i < _accountsToBlacklist.length; i++) {
-            require(v3.isBlacklisted(_accountsToBlacklist[i]), "V3Upgrader: blacklist test failed");
+            require(v2_2.isBlacklisted(_accountsToBlacklist[i]), "V2_2Upgrader: blacklist test failed");
         }
 
         // Transfer any remaining USDC to the caller
@@ -202,7 +202,7 @@ contract V3Upgrader is Ownable {
         if (balance > 0) {
             require(
                 usdc.transfer(msg.sender, balance),
-                "V3Upgrader: failed to withdraw USDC"
+                "V2_2Upgrader: failed to withdraw USDC"
             );
         }
     }

scripts/gas_usage_v2_vs_v3.js → gas_usage_v2_1_vs_v2_2.js

@@ -1,22 +1,22 @@
-// run with `yarn truffle exec scripts/gas_usage_v2_vs_v3.js`
+// run with `yarn truffle exec scripts/gas_usage_v2_1_vs_v2_2.js`
 
 const FiatTokenV2_1 = artifacts.require("FiatTokenV2_1");
-const FiatTokenV3 = artifacts.require("FiatTokenV3");
+const FiatTokenV2_2 = artifacts.require("FiatTokenV2_2");
 
 module.exports = async function (callback) {
   try {
     const [fiatTokenOwner, alice, bob] = await web3.eth.getAccounts();
     const mintAmount = 50e6;
     const transferAmount = 10e6;
 
-    const fiatTokenV3 = await initializeV3(fiatTokenOwner);
+    const fiatTokenV2_2 = await initializeV2_2(fiatTokenOwner);
     const fiatTokenV2_1 = await initializeV2_1(fiatTokenOwner);
 
-    await fiatTokenV3.mint(alice, mintAmount, { from: fiatTokenOwner });
-    const transferTxV3 = await fiatTokenV3.transfer(bob, transferAmount, {
+    await FiatTokenV2_2.mint(alice, mintAmount, { from: fiatTokenOwner });
+    const transferTxV2_2 = await FiatTokenV2_2.transfer(bob, transferAmount, {
       from: alice,
     });
-    console.log("V3 transfer gas usage:", transferTxV3.receipt.gasUsed);
+    console.log("V2.2 transfer gas usage:", transferTxV2_2.receipt.gasUsed);
 
     await fiatTokenV2_1.mint(alice, mintAmount, {
       from: fiatTokenOwner,
@@ -26,25 +26,28 @@ module.exports = async function (callback) {
     });
     console.log("V2.1 transfer gas usage:", transferTxV2_1.receipt.gasUsed);
 
-    const approvalTxV3 = await fiatTokenV3.approve(bob, transferAmount, {
+    const approvalTxV2_2 = await fiatTokenV2_2.approve(bob, transferAmount, {
       from: alice,
     });
-    console.log("V3 approve gas usage:", approvalTxV3.receipt.gasUsed);
+    console.log("V2.2 approve gas usage:", approvalTxV2_2.receipt.gasUsed);
 
     const approvalTxV2_1 = await fiatTokenV2_1.approve(bob, transferAmount, {
       from: alice,
     });
     console.log("V2.1 approve gas usage:", approvalTxV2_1.receipt.gasUsed);
 
-    const transferFromTxV3 = await fiatTokenV3.transferFrom(
+    const transferFromTxV2_2 = await fiatTokenV2_2.transferFrom(
       alice,
       bob,
       transferAmount,
       {
         from: bob,
       }
     );
-    console.log("V3 transferFrom gas usage:", transferFromTxV3.receipt.gasUsed);
+    console.log(
+      "V2.2 transferFrom gas usage:",
+      transferFromTxV2_2.receipt.gasUsed
+    );
 
     const transferFromTxV2_1 = await fiatTokenV2_1.transferFrom(
       alice,
@@ -65,10 +68,10 @@ module.exports = async function (callback) {
   callback();
 };
 
-async function initializeV3(fiatTokenOwner) {
-  const fiatTokenV3 = await FiatTokenV3.new();
+async function initializeV2_2(fiatTokenOwner) {
+  const fiatTokenV2_2 = await FiatTokenV2_2.new();
 
-  await fiatTokenV3.initialize(
+  await fiatTokenV2_2.initialize(
     "USD Coin",
     "USDC",
     "USD",
@@ -78,15 +81,15 @@ async function initializeV3(fiatTokenOwner) {
     fiatTokenOwner,
     fiatTokenOwner
   );
-  await fiatTokenV3.initializeV2("USD Coin", { from: fiatTokenOwner });
-  await fiatTokenV3.initializeV2_1(fiatTokenOwner, { from: fiatTokenOwner });
-  await fiatTokenV3.initializeV3([], { from: fiatTokenOwner });
+  await fiatTokenV2_2.initializeV2("USD Coin", { from: fiatTokenOwner });
+  await fiatTokenV2_2.initializeV2_1(fiatTokenOwner, { from: fiatTokenOwner });
+  await fiatTokenV2_2.initializeV2_2([], { from: fiatTokenOwner });
 
-  await fiatTokenV3.configureMinter(fiatTokenOwner, 1000000e6, {
+  await fiatTokenV2_2.configureMinter(fiatTokenOwner, 1000000e6, {
     from: fiatTokenOwner,
   });
 
-  return fiatTokenV3;
+  return fiatTokenV2_2;
 }
 
 async function initializeV2_1(fiatTokenOwner) {