# eIP 14: Contract Upgrades
**URL:** https://forum.euler.finance/t/eip-14-contract-upgrades/305
**Category:** Protocol
**Tags:** contract-upgrade
**Created:** [July 6, 2022, 6:29pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305 "2022-07-06T18:29:16Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@doug](https://forum.euler.finance/u/doug)
#### Post date: [July 6, 2022, 6:29pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/1 "2022-07-06T18:29:16Z")
## Shared Changes
Some changes have been made to files that are shared between all/many of the modules below.
- `computeExchangeRate` has been modified to support the case where ETokens exist on the pool but no actual deposits have been made yet. The exchange rate is defined to be 1:1 in this state. This change allows an `INITIAL_RESERVES` EToken balance to be allocated to the reserves at market activation time.
- Increase the gas allocated to the `balanceOf` method to 200k.
- Some honest tokens that implement complex logic in the balanceOf method can exceed the previous 20k limit, for example stETH.
- Even if every entered market exceeded this gas limit, the total gas usage (2m) would still be below the block gas limit, so liquidations would not be prevented.
- `reentrancyLock` has been marked as `internal` to be explicit about storage visibility.
- New events and constants will show up in all diffs, even though each are only used by a subset of modules.
- Some modules haven’t been upgraded in a while, so they will have some scaling by `assetCache.underlyingDecimalsScaler` in their shared utilities. These are unused (modules that used them have already been upgraded).
## DToken
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/DToken.html)
- `flashLoan` feature: This new function support gas-efficient flash loans. The underlying tokens are transferred to the `msgSender`, and then a callback is invoked on `msgSender`. After this callback completes, the contract verifies that the loaned tokens have been transferred back.
- `approveDebt` was marked as `nonReentrant` for consistency’s sake (we don’t believe this is actually required for security).
- `transfer` was marked as `reentrantOK` (no-op). The reentrancy check is done in the `transferFrom` method.
## EToken
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/EToken.html)
- `donateToReserves` feature: This allows users to donate some of their ETokens to the reserves. This may be useful for certain wrapper contracts, and potentially could be a better way to burn “dust” in an account (for gas refund purposes).
- `approveSubAccount` was marked as `nonReentrant` for consistency’s sake (we don’t believe this is actually required for security).
- `transfer` and `transferFromMax` were marked as `reentrantOK` (no-op). The reentrancy check is done in the `transferFrom` method.
## Exec
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/Exec.html)
**The changes to this module break the external interface** : The UI already seamlessly supports both old and new versions, and we will be coordinating with bot runners to upgrade to the new interface.
- `batchDispatch` no longer returns results from a batch execution, since this was an unnecessary gas expense. Batches are typically only used by EOAs, since smart contracts can simply make multiple calls.
- `batchDispatchExtra` has been deleted.
- `batchDispatchSimulate` has been added. This method executes the items in the batch but then throws a custom `BatchDispatchSimulation` error that contains the batch item execution results. This way users can see their batch results even if the batch would subsequently have failed due to collateral violation.
## Governance
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/Governance.html)
- New `setChainlinkPriceFeed` function allows the configuration of a chainlink feed for an asset.
- `setPricingConfig` now allows the setting of a new CHAINLINK pricing type.
- `convertReserves` performs a couple additional checks:
- The reserves cannot be depleted below `INITIAL_RESERVES`
- If the account receiving the reserves has outstanding debts in this token, check the account’s liquidity to prevent an account from entering borrow isolation due to a self-collateralised loan.
- Since this module has not been upgraded recently, it also has a minor gas optimisation in `unpackTrailingParamMsgSender` and `unpackTrailingParams` that was previously deployed to the other modules, as well as some changes to constants and interfaces that don’t affect this module.
## Liquidation
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/Liquidation.html)
- No changes, other than the shared changes described above.
## Markets
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/Markets.html)
- When creating a market, start its initial reserves off at `INITIAL_RESERVES` to prevent initial deposit rounding issues.
- New view methods:
- `dTokenToUnderlying`
- `getChainlinkPriceFeedConfig`
## RiskManager
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/RiskManager.html)
- Support CHAINLINK pricing type.
- The `getPrice` and `getPriceFull` methods have been changed to use `internalLoadAssetCacheRO` so that they don’t fail when invoked by a method that has acquired the reentrancy guard (ie during a liquidation).
## Swap
[VIEW CODE DIFF](https://euler-xyz.github.io/euler-contracts-upgrade-diffs/eip14/Swap.html)
- No changes, other than the shared changes described above.
---
### Author:  [@Jib0xD](https://forum.euler.finance/u/Jib0xD)
#### Post date: [July 6, 2022, 9:32pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/2 "2022-07-06T21:32:12Z")
@doug have these code changes undergone a security review, if so by who?
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### Author:  [@doug](https://forum.euler.finance/u/doug)
#### Post date: [July 7, 2022, 1:45pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/3 "2022-07-07T13:45:29Z")
Hi, good question! Yes, the chainlink changes have been audited by Omniscia, report is here: [Omniscia Euler Finance Audit](https://omniscia.io/reports/euler-finance-chainlink-support/)
The other changes are being looked at now by Sherlock and a couple other parties. We’ll post any updates on this in the thread.
---
### Author:  [@doug](https://forum.euler.finance/u/doug)
#### Post date: [July 27, 2022, 8:18pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/4 "2022-07-27T20:18:53Z")
We have updated these diffs to reflect the changes in [this pull request](https://github.com/euler-xyz/euler-contracts/pull/148).
This change is described in “Shared Changes” section above, see description of `loadAssetCacheRO`.
EDIT: These changes are no longer part of the eIP, they were applied as a separate hotfix.
---
### Author:  [@doug](https://forum.euler.finance/u/doug)
#### Post date: [August 9, 2022, 4:04pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/5 "2022-08-09T16:04:39Z")
These changes have received another round of audits from WATCHPUG:
> **[Sherlock / Euler eIP 14](https://www.hacknote.co/17c261f7d8fWbdml/1821f966f40pJG_t)**
>
> Sherlock / Euler eIP 14 - WATCHPUG
Some of their suggestions have been incorporated, and others we have replied to separately.
---
### Author:  [@cp287](https://forum.euler.finance/u/cp287)
#### Post date: [August 13, 2022, 3:35am UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/6 "2022-08-13T03:35:47Z")
looks reasonable for me, i vote for!
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### Author:  [@doug](https://forum.euler.finance/u/doug)
#### Post date: [August 18, 2022, 4:57pm UTC](https://forum.euler.finance/t/eip-14-contract-upgrades/305/7 "2022-08-18T16:57:45Z")
The snapshot passed:
[https://snapshot.org/#/eulerdao.eth/proposal/0xaa7cf379f95466b167b8947dd5f5f41176e635fc0a083fd5c3d273c42da34097](https://snapshot.org/#/eulerdao.eth/proposal/0xaa7cf379f95466b167b8947dd5f5f41176e635fc0a083fd5c3d273c42da34097)
So these upgrades have been performed:
> **[Ethereum Transaction Hash (Txhash) Details | Etherscan](https://etherscan.io/tx/0x10adc8d4e5e95cd1a850da80f2b272534ad3fbbdbe2ccb2b8296833bc7115556)**
>
> Ethereum (ETH) detailed transaction info for txhash 0x10adc8d4e5e95cd1a850da80f2b272534ad3fbbdbe2ccb2b8296833bc7115556. The transaction status, block confirmation, gas fee, Ether (ETH), and token transfer are shown.