Post-audit fixes, more scenarios, and auxiliary improvements fixes (#63)

* Compare boolean values numerically to 1, not string 0x01 * Remove the short-circuits for market NEVER initialized (#64) These were intended to be short-circuits if not a COMP market, but in fact only take effect if *never* a COMP market. Removing the short-circuit avoids this confusion, and enables us to poke all borrowers once, instead of after every time a market becomes a COMP market for the first time. * add checkIsComped, add isComped to markets storageAt getter (#65) * Ensure updating COMP indices only takes 1 SSTORE (#66) * Set claim threshold; scen code for forks (#69) * Add events for changing comp rate and adding/dropping comped markets (#70) * Rename dripper -> reservoir; add fauceteer (#72) * Rename dripper -> reservoir * Add Fauceteer and Add Timelock Harness Features (#71) This patch adds the Fauceteer, which is a simple contract that can hold Erc20 tokens and will give away a small percentage every time you poke it. The idea is that it replaces the need for "FaucetToken" as we now just make Fauceteer own some amount of tokens and you can poke _it_ if you need test tokens. This gives us the ability to use real Dai, etc, on testnets *and* have a faucet available to users. As the Fauceteer only gives away 0.01% of what it has, it will effectively never run out, but instead just give away less and less each time you poke it. The raw number of tokens isn't that important for test-nets, so this is acceptable. We also add some functions to the TimelockTest harness. We allow it to change admin without going through timelocking, and we add the ability for it to call `_acceptAdmin` without timelocking. This significantly makes the flow of setting up a test-net easier. Co-authored-by: Max Wolff <[email protected]> Co-authored-by: Geoff Hayes <[email protected]>
compound-finance · May 27, 2020 · e0a16ae · e0a16ae
1 parent afbca63
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diff --git a/.gitignore b/.gitignore
@@ -34,6 +34,7 @@ scenario/build/webpack.js
 .solcache
 .solcachecov
 scenario/.tscache
+script/certora
 tests/scenarios/
 junit.xml
 .build

diff --git a/contracts/Comptroller.sol b/contracts/Comptroller.sol
@@ -47,6 +47,12 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
     /// @notice Emitted when an action is paused on a market
     event ActionPaused(CToken cToken, string action, bool pauseState);
 
+    /// @notice Emitted when market comped status is changed
+    event MarketComped(CToken cToken, bool isComped);
+
+    /// @notice Emitted when COMP rate is changed
+    event NewCompRate(uint oldCompRateMantissa, uint newCompRateMantissa);
+
     /// @notice Emitted when a new COMP speed is calculated for a market
     event CompSpeedUpdated(CToken indexed cToken, uint newSpeed);
 
@@ -56,8 +62,8 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
     /// @notice Emitted when COMP is distributed to a borrower
     event DistributedBorrowerComp(CToken indexed cToken, address indexed borrower, uint compDelta, uint compBorrowIndex);
 
-    /// @notice The threshold at which the flywheel starts to distribute COMP, in wei
-    uint public constant compClaimThreshold = 0.01e18;
+    /// @notice The threshold above which the flywheel transfers COMP, in wei
+    uint public constant compClaimThreshold = 0.001e18;
 
     /// @notice The initial COMP index for a market
     uint224 public constant compInitialIndex = 1e36;
@@ -1152,9 +1158,12 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
         if (deltaBlocks > 0 && supplySpeed > 0) {
             uint supplyTokens = CToken(cToken).totalSupply();
             uint compAccrued = mul_(deltaBlocks, supplySpeed);
-            Double memory index = add_(Double({mantissa: supplyState.index}), fraction(compAccrued, supplyTokens));
-            supplyState.index = safe224(index.mantissa, "new index exceeds 224 bits");
-            supplyState.block = safe32(blockNumber, "block number exceeds 32 bits");
+            Double memory ratio = supplyTokens > 0 ? fraction(compAccrued, supplyTokens) : Double({mantissa: 0});
+            Double memory index = add_(Double({mantissa: supplyState.index}), ratio);
+            compSupplyState[cToken] = CompMarketState({
+                index: safe224(index.mantissa, "new index exceeds 224 bits"),
+                block: safe32(blockNumber, "block number exceeds 32 bits")
+            });
         } else if (deltaBlocks > 0) {
             supplyState.block = safe32(blockNumber, "block number exceeds 32 bits");
         }
@@ -1172,9 +1181,12 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
         if (deltaBlocks > 0 && borrowSpeed > 0) {
             uint borrowAmount = div_(CToken(cToken).totalBorrows(), marketBorrowIndex);
             uint compAccrued = mul_(deltaBlocks, borrowSpeed);
-            Double memory index = add_(Double({mantissa: borrowState.index}), fraction(compAccrued, borrowAmount));
-            borrowState.index = safe224(index.mantissa, "new index exceeds 224 bits");
-            borrowState.block = safe32(blockNumber, "block number exceeds 32 bits");
+            Double memory ratio = borrowAmount > 0 ? fraction(compAccrued, borrowAmount) : Double({mantissa: 0});
+            Double memory index = add_(Double({mantissa: borrowState.index}), ratio);
+            compBorrowState[cToken] = CompMarketState({
+                index: safe224(index.mantissa, "new index exceeds 224 bits"),
+                block: safe32(blockNumber, "block number exceeds 32 bits")
+            });
         } else if (deltaBlocks > 0) {
             borrowState.block = safe32(blockNumber, "block number exceeds 32 bits");
         }
@@ -1188,21 +1200,17 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
     function distributeSupplierComp(address cToken, address supplier) internal {
         CompMarketState storage supplyState = compSupplyState[cToken];
         Double memory supplyIndex = Double({mantissa: supplyState.index});
-
-        /* Short-circuit if this is not a COMP market */
-        if (supplyIndex.mantissa == 0) {
-            return;
-        }
-
         Double memory supplierIndex = Double({mantissa: compSupplierIndex[cToken][supplier]});
-        if (supplierIndex.mantissa == 0) {
+        compSupplierIndex[cToken][supplier] = supplyIndex.mantissa;
+
+        if (supplierIndex.mantissa == 0 && supplyIndex.mantissa > 0) {
             supplierIndex.mantissa = compInitialIndex;
         }
+
         Double memory deltaIndex = sub_(supplyIndex, supplierIndex);
         uint supplierTokens = CToken(cToken).balanceOf(supplier);
         uint supplierDelta = mul_(supplierTokens, deltaIndex);
         uint supplierAccrued = add_(compAccrued[supplier], supplierDelta);
-        compSupplierIndex[cToken][supplier] = supplyIndex.mantissa;
         compAccrued[supplier] = transferComp(supplier, supplierAccrued, compClaimThreshold);
         emit DistributedSupplierComp(CToken(cToken), supplier, supplierDelta, supplyIndex.mantissa);
     }
@@ -1216,12 +1224,6 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
     function distributeBorrowerComp(address cToken, address borrower, Exp memory marketBorrowIndex) internal {
         CompMarketState storage borrowState = compBorrowState[cToken];
         Double memory borrowIndex = Double({mantissa: borrowState.index});
-
-        /* Short-circuit if this is not a COMP market */
-        if (borrowIndex.mantissa == 0) {
-            return;
-        }
-
         Double memory borrowerIndex = Double({mantissa: compBorrowerIndex[cToken][borrower]});
         compBorrowerIndex[cToken][borrower] = borrowIndex.mantissa;
 
@@ -1281,7 +1283,9 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
     function _setCompRate(uint compRate_) public {
         require(adminOrInitializing(), "only admin can change comp rate");
 
+        uint oldRate = compRate;
         compRate = compRate_;
+        emit NewCompRate(oldRate, compRate_);
 
         refreshCompSpeeds();
     }
@@ -1306,15 +1310,20 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
         require(market.isComped == false, "comp market already added");
 
         market.isComped = true;
+        emit MarketComped(CToken(cToken), true);
 
         if (compSupplyState[cToken].index == 0 && compSupplyState[cToken].block == 0) {
-            compSupplyState[cToken].index = compInitialIndex;
-            compSupplyState[cToken].block = safe32(getBlockNumber(), "block number exceeds 32 bits");
+            compSupplyState[cToken] = CompMarketState({
+                index: compInitialIndex,
+                block: safe32(getBlockNumber(), "block number exceeds 32 bits")
+            });
         }
 
         if (compBorrowState[cToken].index == 0 && compBorrowState[cToken].block == 0) {
-            compBorrowState[cToken].index = compInitialIndex;
-            compBorrowState[cToken].block = safe32(getBlockNumber(), "block number exceeds 32 bits");
+            compBorrowState[cToken] = CompMarketState({
+                index: compInitialIndex,
+                block: safe32(getBlockNumber(), "block number exceeds 32 bits")
+            });
         }
     }
 
@@ -1329,6 +1338,7 @@ contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerE
         require(market.isComped == true, "market is not a comp market");
 
         market.isComped = false;
+        emit MarketComped(CToken(cToken), false);
 
         refreshCompSpeeds();
     }

diff --git a/contracts/Flywheel/Dripper.sol → contracts/Flywheel/Reservoir.sol b/contracts/Flywheel/Dripper.sol → contracts/Flywheel/Reservoir.sol
@@ -1,14 +1,14 @@
 pragma solidity ^0.5.16;
 
 /**
- * @title Dripper Contract
+ * @title Reservoir Contract
  * @notice Distributes a token to a different contract at a fixed rate.
  * @dev This contract must be poked via the `drip()` function every so often.
  * @author Compound
  */
-contract Dripper {
+contract Reservoir {
 
-  /// @notice The block number when the Dripper started (immutable)
+  /// @notice The block number when the Reservoir started (immutable)
   uint public dripStart;
 
   /// @notice Tokens per block that to drip to target (immutable)
@@ -24,7 +24,7 @@ contract Dripper {
   uint public dripped;
 
   /**
-    * @notice Constructs a Dripper
+    * @notice Constructs a Reservoir
     * @param dripRate_ Numer of tokens per block to drip
     * @param token_ The token to drip
     * @param target_ The recipient of dripped tokens
@@ -45,7 +45,7 @@ contract Dripper {
   function drip() public returns (uint) {
     // First, read storage into memory
     EIP20Interface token_ = token;
-    uint dripperBalance_ = token_.balanceOf(address(this)); // TODO: Verify this is a static call
+    uint reservoirBalance_ = token_.balanceOf(address(this)); // TODO: Verify this is a static call
     uint dripRate_ = dripRate;
     uint dripStart_ = dripStart;
     uint dripped_ = dripped;
@@ -55,7 +55,7 @@ contract Dripper {
     // Next, calculate intermediate values
     uint dripTotal_ = mul(dripRate_, blockNumber_ - dripStart_, "dripTotal overflow");
     uint deltaDrip_ = sub(dripTotal_, dripped_, "deltaDrip underflow");
-    uint toDrip_ = min(dripperBalance_, deltaDrip_);
+    uint toDrip_ = min(reservoirBalance_, deltaDrip_);
     uint drippedNext_ = add(dripped_, toDrip_, "tautological");
 
     // Finally, write new `dripped` value and transfer tokens to target

diff --git a/package.json b/package.json
@@ -29,6 +29,6 @@
   },
   "resolutions": {
     "scrypt.js": "https://registry.npmjs.org/@compound-finance/ethereumjs-wallet/-/ethereumjs-wallet-0.6.3.tgz",
-    "**/ganache-core": "https://github.com/compound-finance/ganache-core.git#compound"
+    "**/ganache-core": "https://github.com/compound-finance/ganache-core.git#jflatow/unbreak-fork"
   }
 }
diff --git a/scenario/package.json b/scenario/package.json
@@ -1,5 +1,5 @@
 {
-  "name": "compound-money-market",
+  "name": "compound-protocol-alpha",
   "version": "0.2.1",
   "description": "The Compound Money Market",
   "main": "index.js",
@@ -29,6 +29,6 @@
   },
   "resolutions": {
     "scrypt.js": "https://registry.npmjs.org/@compound-finance/ethereumjs-wallet/-/ethereumjs-wallet-0.6.3.tgz",
-    "**/ganache-core": "https://github.com/compound-finance/ganache-core.git#compound"
+    "**/ganache-core": "https://github.com/compound-finance/ganache-core.git#jflatow/unbreak-fork"
   }
 }
diff --git a/scenario/src/Command.ts b/scenario/src/Command.ts
@@ -4,7 +4,7 @@ import {mustArray} from './Utils';
 import {NothingV} from './Value';
 
 interface ArgOpts<T> {
-  default?: T
+  default?: T | T[]
   implicit?: boolean
   variadic?: boolean
   mapped?: boolean
@@ -16,7 +16,7 @@ export class Arg<T> {
   name: string
   type: any
   getter: (World, Event?) => Promise<T>
-  defaultValue: T | undefined
+  defaultValue: T | T[] | undefined
   implicit: boolean
   variadic: boolean
   mapped: boolean

diff --git a/scenario/src/Contract/Comptroller.ts b/scenario/src/Contract/Comptroller.ts
@@ -15,7 +15,7 @@ interface ComptrollerMethods {
   closeFactorMantissa(): Callable<number>
   blockNumber(): Callable<number>
   collateralFactor(string): Callable<string>
-  markets(string): Callable<{0: boolean, 1: number}>
+  markets(string): Callable<{0: boolean, 1: number, 2?: boolean}>
   _setMintPaused(bool): Sendable<number>
   _setMaxAssets(encodedNumber): Sendable<number>
   _setLiquidationIncentive(encodedNumber): Sendable<number>
@@ -49,6 +49,7 @@ interface ComptrollerMethods {
   _dropCompMarket(market: string): Sendable<void>
   getCompMarkets(): Callable<string[]>
   refreshCompSpeeds(): Sendable<void>
+  compRate(): Callable<number>
   compSupplyState(string): Callable<string>
   compBorrowState(string): Callable<string>
   compAccrued(string): Callable<string>

diff --git a/scenario/src/Contract/Dripper.ts → scenario/src/Contract/Reservoir.ts b/scenario/src/Contract/Dripper.ts → scenario/src/Contract/Reservoir.ts
@@ -2,7 +2,7 @@ import { Contract } from '../Contract';
 import { encodedNumber } from '../Encoding';
 import { Callable, Sendable } from '../Invokation';
 
-export interface DripperMethods {
+export interface ReservoirMethods {
   drip(): Sendable<void>;
   dripped(): Callable<number>;
   dripStart(): Callable<number>;
@@ -11,7 +11,7 @@ export interface DripperMethods {
   target(): Callable<string>;
 }
 
-export interface Dripper extends Contract {
-  methods: DripperMethods;
+export interface Reservoir extends Contract {
+  methods: ReservoirMethods;
   name: string;
 }
diff --git a/scenario/src/CoreEvent.ts b/scenario/src/CoreEvent.ts
@@ -41,7 +41,7 @@ import { fork } from './Hypothetical';
 import { buildContractEvent } from './EventBuilder';
 import { Counter } from './Contract/Counter';
 import { CompoundLens } from './Contract/CompoundLens';
-import { Dripper } from './Contract/Dripper';
+import { Reservoir } from './Contract/Reservoir';
 import Web3 from 'web3';
 
 export class EventProcessingError extends Error {
@@ -270,7 +270,7 @@ export const commands: (View<any> | ((world: World) => Promise<View<any>>))[] =
     'Web3Fork',
     [
       new Arg('url', getStringV),
-      new Arg('unlockedAccounts', getAddressV, { mapped: true })
+      new Arg('unlockedAccounts', getAddressV, { default: [], mapped: true })
     ],
     async (world, { url, unlockedAccounts }) => fork(world, url.val, unlockedAccounts.map(v => v.val))
   ),
@@ -812,7 +812,7 @@ export const commands: (View<any> | ((world: World) => Promise<View<any>>))[] =
 
   buildContractEvent<Counter>("Counter", false),
   buildContractEvent<CompoundLens>("CompoundLens", false),
-  buildContractEvent<Dripper>("Dripper", true),
+  buildContractEvent<Reservoir>("Reservoir", true),
 
   new View<{ event: EventV }>(
     `

diff --git a/scenario/src/CoreValue.ts b/scenario/src/CoreValue.ts
@@ -453,27 +453,32 @@ const fetchers = [
       new Arg('valType', getStringV)
     ],
     async (world, { addr, slot, key, nestedKey, valType }) => {
+      const areEqual = (v, x) => toBN(v).eq(toBN(x));
       let paddedSlot = slot.toNumber().toString(16).padStart(64, '0');
       let paddedKey = padLeft(key.val, 64);
       let newKey = sha3(paddedKey + paddedSlot);
       let val = await world.web3.eth.getStorageAt(addr.val, newKey);
 
       switch (valType.val) {
         case 'marketStruct':
-          let isListed = val == '0x01';
+          let isListed = areEqual(val, 1);
           let collateralFactorKey = '0x' + toBN(newKey).add(toBN(1)).toString(16);
           let collateralFactorStr = await world.web3.eth.getStorageAt(addr.val, collateralFactorKey);
           let collateralFactor = toBN(collateralFactorStr);
           let userMarketBaseKey = padLeft(toBN(newKey).add(toBN(2)).toString(16), 64);
           let paddedSlot = padLeft(userMarketBaseKey, 64);
           let paddedKey = padLeft(nestedKey.val, 64);
-          let newKeyToo = sha3(paddedKey + paddedSlot);
-          let userInMarket = await world.web3.eth.getStorageAt(addr.val, newKeyToo);
+          let newKeyTwo = sha3(paddedKey + paddedSlot);
+          let userInMarket = await world.web3.eth.getStorageAt(addr.val, newKeyTwo);
+
+          let isCompKey = '0x' + toBN(newKey).add(toBN(3)).toString(16);
+          let isCompStr = await world.web3.eth.getStorageAt(addr.val, isCompKey);
 
           return new ListV([
             new BoolV(isListed),
             new ExpNumberV(collateralFactor.toString(), 1e18),
-            new BoolV(userInMarket == '0x01')
+            new BoolV(areEqual(userInMarket, 1)),
+            new BoolV(areEqual(isCompStr, 1))
           ]);
         default:
           return new NothingV();
@@ -965,7 +970,7 @@ const fetchers = [
 let contractFetchers = [
   { contract: "Counter", implicit: false },
   { contract: "CompoundLens", implicit: false },
-  { contract: "Dripper", implicit: true }
+  { contract: "Reservoir", implicit: true }
 ];
 
 export async function getFetchers(world: World) {