feat: minor contracts cleanup (#47)

In this PR:
* remove obsolete analytics methods in `BoundedPriceFeed`
* `BoundedPriceFeed`'s constructor now reverts if `bound` is below zero
* remove pyth dependency in favor of local interfaces
* add some missing getters here and there
* proper price feed descriptions
* minor nits

.gitmodules

@@ -14,3 +14,6 @@
 [submodule "lib/@openzeppelin"]
 	path = lib/@openzeppelin
 	url = https://github.com/OpenZeppelin/openzeppelin-contracts
+[submodule "lib/@solady"]
+	path = lib/@solady
+	url = https://github.com/Vectorized/solady

contracts/interfaces/mellow/IMellowVault.sol

@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: MIT
+// Gearbox Protocol. Generalized leverage for DeFi protocols
+// (c) Gearbox Foundation, 2024.
 pragma solidity ^0.8.23;
 
 interface IMellowVault {

contracts/interfaces/pyth/IPyth.sol

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: MIT
+// Gearbox Protocol. Generalized leverage for DeFi protocols
+// (c) Gearbox Foundation, 2024.
+pragma solidity ^0.8.23;
+
+import {PythStructs} from "./PythStructs.sol";
+
+interface IPyth {
+    function updatePriceFeeds(bytes[] calldata updateData) external payable;
+    function getPriceUnsafe(bytes32 id) external view returns (PythStructs.Price memory price);
+    function latestPriceInfoPublishTime(bytes32 priceFeedId) external view returns (uint64);
+    function getUpdateFee(bytes[] calldata updateData) external view returns (uint256 feeAmount);
+}

contracts/interfaces/pyth/PythStructs.sol

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: MIT
+// Gearbox Protocol. Generalized leverage for DeFi protocols
+// (c) Gearbox Foundation, 2024.
+pragma solidity ^0.8.23;
+
+contract PythStructs {
+    struct Price {
+        int64 price;
+        uint64 conf;
+        int32 expo;
+        uint256 publishTime;
+    }
+}

contracts/oracles/BoundedPriceFeed.sol

@@ -3,22 +3,19 @@
 // (c) Gearbox Foundation, 2024.
 pragma solidity ^0.8.23;
 
-import {AggregatorV2V3Interface} from "../interfaces/chainlink/AggregatorV2V3Interface.sol";
-
+import {LibString} from "@solady/utils/LibString.sol";
+import {IncorrectParameterException} from "@gearbox-protocol/core-v3/contracts/interfaces/IExceptions.sol";
 import {IPriceFeed} from "@gearbox-protocol/core-v3/contracts/interfaces/base/IPriceFeed.sol";
 import {SanityCheckTrait} from "@gearbox-protocol/core-v3/contracts/traits/SanityCheckTrait.sol";
 import {PriceFeedValidationTrait} from "@gearbox-protocol/core-v3/contracts/traits/PriceFeedValidationTrait.sol";
 
-interface ChainlinkReadableAggregator {
-    function aggregator() external view returns (address);
-    function phaseAggregators(uint16 idx) external view returns (AggregatorV2V3Interface);
-    function phaseId() external view returns (uint16);
-}
-
 /// @title Bounded price feed
 /// @notice Can be used to provide upper-bounded answers for assets that are
 ///         expected to have the price in a certain range, e.g. stablecoins
-contract BoundedPriceFeed is IPriceFeed, ChainlinkReadableAggregator, SanityCheckTrait, PriceFeedValidationTrait {
+contract BoundedPriceFeed is IPriceFeed, SanityCheckTrait, PriceFeedValidationTrait {
+    using LibString for string;
+    using LibString for bytes32;
+
     uint256 public constant override version = 3_10;
     bytes32 public constant override contractType = "PF_BOUNDED_ORACLE";
 
@@ -33,22 +30,28 @@ contract BoundedPriceFeed is IPriceFeed, ChainlinkReadableAggregator, SanityChec
     /// @notice Upper bound for underlying price feed answers
     int256 public immutable upperBound;
 
+    /// @dev Price feed description ticker
+    bytes32 internal _descriptionTicker;
+
     /// @notice Constructor
     /// @param _priceFeed Underlying price feed
     /// @param _stalenessPeriod Underlying price feed staleness period, must be non-zero unless it performs own checks
     /// @param _upperBound Upper bound for underlying price feed answers
-    constructor(address _priceFeed, uint32 _stalenessPeriod, int256 _upperBound)
+    /// @param descriptionTicker Ticker to use in price feed description
+    constructor(address _priceFeed, uint32 _stalenessPeriod, int256 _upperBound, string memory descriptionTicker)
         nonZeroAddress(_priceFeed) // U:[BPF-1]
     {
+        if (_upperBound <= 0) revert IncorrectParameterException(); // U:[BPF-1]
         priceFeed = _priceFeed; // U:[BPF-1]
         stalenessPeriod = _stalenessPeriod; // U:[BPF-1]
         skipCheck = _validatePriceFeed(priceFeed, stalenessPeriod); // U:[BPF-1]
         upperBound = _upperBound; // U:[BPF-1]
+        _descriptionTicker = descriptionTicker.toSmallString();
     }
 
     /// @notice Price feed description
     function description() external view override returns (string memory) {
-        return string(abi.encodePacked(IPriceFeed(priceFeed).description(), " bounded price feed")); // U:[BPF-2]
+        return string.concat(_descriptionTicker.fromSmallString(), " bounded price feed"); // U:[BPF-2]
     }
 
     /// @notice Returns the upper-bounded USD price of the token
@@ -61,20 +64,4 @@ contract BoundedPriceFeed is IPriceFeed, ChainlinkReadableAggregator, SanityChec
     function _upperBoundValue(int256 value) internal view returns (int256) {
         return (value > upperBound) ? upperBound : value;
     }
-
-    // --------- //
-    // ANALYTICS //
-    // --------- //
-
-    function aggregator() external view override returns (address) {
-        return ChainlinkReadableAggregator(priceFeed).aggregator();
-    }
-
-    function phaseAggregators(uint16 idx) external view override returns (AggregatorV2V3Interface) {
-        return ChainlinkReadableAggregator(priceFeed).phaseAggregators(idx);
-    }
-
-    function phaseId() external view override returns (uint16) {
-        return ChainlinkReadableAggregator(priceFeed).phaseId();
-    }
 }

contracts/oracles/CompositePriceFeed.sol

@@ -3,6 +3,7 @@
 // (c) Gearbox Foundation, 2024.
 pragma solidity ^0.8.23;
 
+import {LibString} from "@solady/utils/LibString.sol";
 import {PriceFeedParams} from "./PriceFeedParams.sol";
 import {IPriceFeed} from "@gearbox-protocol/core-v3/contracts/interfaces/base/IPriceFeed.sol";
 import {PriceFeedValidationTrait} from "@gearbox-protocol/core-v3/contracts/traits/PriceFeedValidationTrait.sol";
@@ -11,6 +12,9 @@ import {SanityCheckTrait} from "@gearbox-protocol/core-v3/contracts/traits/Sanit
 /// @title Composite price feed
 /// @notice Computes target asset USD price as product of target/base price times base/USD price
 contract CompositePriceFeed is IPriceFeed, PriceFeedValidationTrait, SanityCheckTrait {
+    using LibString for string;
+    using LibString for bytes32;
+
     uint256 public constant override version = 3_10;
     bytes32 public constant override contractType = "PF_COMPOSITE_ORACLE";
 
@@ -20,6 +24,7 @@ contract CompositePriceFeed is IPriceFeed, PriceFeedValidationTrait, SanityCheck
     /// @notice Price feed that returns target asset price denominated in base asset
     address public immutable priceFeed0;
     uint32 public immutable stalenessPeriod0;
+    bool public immutable skipCheck0;
 
     /// @notice Price feed that returns base price denominated in USD
     address public immutable priceFeed1;
@@ -29,10 +34,14 @@ contract CompositePriceFeed is IPriceFeed, PriceFeedValidationTrait, SanityCheck
     /// @notice Scale of answers in target/base price feed
     int256 public immutable targetFeedScale;
 
+    /// @dev Price feed description ticker
+    bytes32 internal _descriptionTicker;
+
     /// @notice Constructor
     /// @param priceFeeds Array with two price feeds, where the first one returns target asset price
     ///        denominated in base asset, and the second one returns base price denominated in USD
-    constructor(PriceFeedParams[2] memory priceFeeds)
+    /// @param descriptionTicker Ticker to use in price feed description
+    constructor(PriceFeedParams[2] memory priceFeeds, string memory descriptionTicker)
         nonZeroAddress(priceFeeds[0].priceFeed) // U:[CPF-1]
         nonZeroAddress(priceFeeds[1].priceFeed) // U:[CPF-1]
     {
@@ -44,24 +53,20 @@ contract CompositePriceFeed is IPriceFeed, PriceFeedValidationTrait, SanityCheck
 
         targetFeedScale = int256(10 ** IPriceFeed(priceFeed0).decimals()); // U:[CPF-1]
         // target/base price feed validation is omitted because it will fail if feed has other than 8 decimals
+        skipCheck0 = false; // U:[CPF-1]
         skipCheck1 = _validatePriceFeed(priceFeed1, stalenessPeriod1); // U:[CPF-1]
+
+        _descriptionTicker = descriptionTicker.toSmallString();
     }
 
     /// @notice Price feed description
     function description() external view override returns (string memory) {
-        return string(
-            abi.encodePacked(
-                IPriceFeed(priceFeed0).description(),
-                " * ",
-                IPriceFeed(priceFeed1).description(),
-                " composite price feed"
-            )
-        ); // U:[CPF-2]
+        return string.concat(_descriptionTicker.fromSmallString(), " composite price feed"); // U:[CPF-2]
     }
 
     /// @notice Returns the USD price of the target asset, computed as target/base price times base/USD price
     function latestRoundData() external view override returns (uint80, int256 answer, uint256, uint256, uint80) {
-        answer = _getValidatedPrice(priceFeed0, stalenessPeriod0, false); // U:[CPF-3]
+        answer = _getValidatedPrice(priceFeed0, stalenessPeriod0, skipCheck0); // U:[CPF-3]
         int256 answer2 = _getValidatedPrice(priceFeed1, stalenessPeriod1, skipCheck1); // U:[CPF-3]
         answer = (answer * answer2) / targetFeedScale; // U:[CPF-3]
         return (0, answer, 0, 0, 0);

contracts/oracles/LPPriceFeed.sol

@@ -58,7 +58,7 @@ abstract contract LPPriceFeed is ILPPriceFeed, ControlledTrait, SanityCheckTrait
 
     /// @notice Price feed description
     function description() external view override returns (string memory) {
-        return string(abi.encodePacked(ERC20(lpToken).symbol(), " / USD price feed")); // U:[LPPF-2]
+        return string.concat(ERC20(lpToken).symbol(), " / USD LP price feed"); // U:[LPPF-2]
     }
 
     /// @notice Returns USD price of the LP token with 8 decimals

contracts/oracles/balancer/BPTWeightedPriceFeed.sol

@@ -176,7 +176,7 @@ contract BPTWeightedPriceFeed is LPPriceFeed {
 
         uint256 weightedPrice = FixedPoint.ONE;
         uint256 currentBase = FixedPoint.ONE;
-        for (uint256 i = 0; i < numAssets;) {
+        for (uint256 i = 0; i < numAssets; ++i) {
             (address priceFeed, uint32 stalenessPeriod, bool skipCheck) = _getPriceFeedParams(i);
             answer = _getValidatedPrice(priceFeed, stalenessPeriod, skipCheck);
             answer = answer * int256(WAD_OVER_USD_FEED_SCALE);
@@ -186,10 +186,6 @@ contract BPTWeightedPriceFeed is LPPriceFeed {
                 weightedPrice = weightedPrice.mulDown(currentBase.powDown(weights[i]));
                 currentBase = FixedPoint.ONE;
             }
-
-            unchecked {
-                ++i;
-            }
         }
 
         answer = int256(weightedPrice / (numAssets * WAD_OVER_USD_FEED_SCALE)); // U:[BAL-W-2]
@@ -212,16 +208,12 @@ contract BPTWeightedPriceFeed is LPPriceFeed {
 
         k = FixedPoint.ONE;
         uint256 currentBase = FixedPoint.ONE;
-        for (uint256 i = 0; i < len;) {
+        for (uint256 i = 0; i < len; ++i) {
             currentBase = currentBase.mulDown(balances[i]);
             if (i == len - 1 || weights[i] != weights[i + 1]) {
                 k = k.mulDown(currentBase.powDown(weights[i]));
                 currentBase = FixedPoint.ONE;
             }
-
-            unchecked {
-                ++i;
-            }
         }
     }
 
@@ -295,10 +287,8 @@ contract BPTWeightedPriceFeed is LPPriceFeed {
     function _sort(uint256[] memory data) internal pure returns (uint256[] memory indices) {
         uint256 len = data.length;
         indices = new uint256[](len);
-        unchecked {
-            for (uint256 i; i < len; ++i) {
-                indices[i] = i;
-            }
+        for (uint256 i; i < len; ++i) {
+            indices[i] = i;
         }
         _quickSort(data, indices, 0, len - 1);
     }

contracts/oracles/curve/CurveCryptoLPPriceFeed.sol

@@ -18,7 +18,7 @@ contract CurveCryptoLPPriceFeed is LPPriceFeed {
     using FixedPoint for uint256;
 
     uint256 public constant override version = 3_10;
-    bytes32 public constant contractType = "PF_CURVE_CRYPTO_ORACLE";
+    bytes32 public constant contractType = "PF_CURVE_CRYPTO_LP_ORACLE";
 
     uint16 public immutable nCoins;
 

contracts/oracles/curve/CurveStableLPPriceFeed.sol

@@ -13,7 +13,7 @@ import {WAD} from "@gearbox-protocol/core-v3/contracts/libraries/Constants.sol";
 /// @dev Older pools may be decoupled from their LP token, so constructor accepts both token and pool
 contract CurveStableLPPriceFeed is LPPriceFeed {
     uint256 public constant override version = 3_10;
-    bytes32 public immutable override contractType;
+    bytes32 public constant override contractType = "PF_CURVE_STABLE_LP_ORACLE";
 
     uint16 public immutable nCoins;
 
@@ -55,10 +55,6 @@ contract CurveStableLPPriceFeed is LPPriceFeed {
         skipCheck2 = nCoins > 2 ? _validatePriceFeed(priceFeed2, stalenessPeriod2) : false;
         skipCheck3 = nCoins > 3 ? _validatePriceFeed(priceFeed3, stalenessPeriod3) : false;
 
-        contractType = nCoins == 2
-            ? bytes32("PF_CURVE_2LP_ORACLE")
-            : (nCoins == 3 ? bytes32("PF_CURVE_3LP_ORACLE") : bytes32("PF_CURVE_4LP_ORACLE"));
-
         _setLimiter(lowerBound); // U:[CRV-S-1]
     }
 

contracts/oracles/mellow/MellowLRTPriceFeed.sol

@@ -4,7 +4,6 @@
 pragma solidity ^0.8.23;
 
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
-import {IStateSerializer} from "../../interfaces/IStateSerializer.sol";
 import {IMellowVault} from "../../interfaces/mellow/IMellowVault.sol";
 import {SingleAssetLPPriceFeed} from "../SingleAssetLPPriceFeed.sol";
 import {WAD} from "@gearbox-protocol/core-v3/contracts/libraries/Constants.sol";