♻️ ERC6551 new executable interface ID (#861)

Author: Vectorized

.gas-snapshot

@@ -265,23 +265,23 @@ ERC4626Test:testWithdrawWithNoUnderlyingAmountReverts() (gas: 13102)
 ERC4626Test:testWithdrawWithNotEnoughUnderlyingAmountReverts() (gas: 144074)
 ERC4626Test:testWithdrawZero() (gas: 52807)
 ERC4626Test:test__codesize() (gas: 39940)
-ERC6551Test:testCdFallback() (gas: 894305)
-ERC6551Test:testDeployERC6551(uint256) (runs: 257, μ: 171193, ~: 168789)
+ERC6551Test:testCdFallback() (gas: 894295)
+ERC6551Test:testDeployERC6551(uint256) (runs: 257, μ: 171077, ~: 168788)
 ERC6551Test:testDeployERC6551Proxy() (gas: 80351)
-ERC6551Test:testExecute() (gas: 507899)
-ERC6551Test:testExecuteBatch() (gas: 817000)
-ERC6551Test:testExecuteBatch(uint256) (runs: 257, μ: 627737, ~: 586245)
+ERC6551Test:testExecute() (gas: 508100)
+ERC6551Test:testExecuteBatch() (gas: 817200)
+ERC6551Test:testExecuteBatch(uint256) (runs: 257, μ: 622293, ~: 483183)
 ERC6551Test:testInitializeERC6551ProxyImplementation() (gas: 189796)
 ERC6551Test:testIsValidSignature() (gas: 187642)
-ERC6551Test:testIsValidSigner(address) (runs: 257, μ: 167326, ~: 167324)
+ERC6551Test:testIsValidSigner(address) (runs: 257, μ: 167327, ~: 167324)
 ERC6551Test:testOnERC1155BatchReceived() (gas: 1526537)
 ERC6551Test:testOnERC1155Received() (gas: 1523871)
 ERC6551Test:testOnERC721Received() (gas: 1501317)
 ERC6551Test:testOnERC721ReceivedCycles() (gas: 1713680)
-ERC6551Test:testOnERC721ReceivedCyclesWithDifferentChainIds(uint256) (runs: 257, μ: 448971, ~: 454680)
+ERC6551Test:testOnERC721ReceivedCyclesWithDifferentChainIds(uint256) (runs: 257, μ: 448372, ~: 454235)
 ERC6551Test:testSupportsInterface() (gas: 169367)
-ERC6551Test:testUpgrade() (gas: 1165638)
-ERC6551Test:test__codesize() (gas: 47524)
+ERC6551Test:testUpgrade() (gas: 1164238)
+ERC6551Test:test__codesize() (gas: 47510)
 ERC6909Test:testApprove() (gas: 36771)
 ERC6909Test:testApprove(address,uint256,uint256) (runs: 257, μ: 36483, ~: 37413)
 ERC6909Test:testBurn() (gas: 40676)

src/accounts/ERC6551.sol

@@ -25,9 +25,15 @@ import {UUPSUpgradeable} from "../utils/UUPSUpgradeable.sol";
 ///    the click on "Is this a proxy?" on the clone's page on Etherscan.
 ///
 /// Note:
-/// - ERC6551 accounts are not compatible with ERC4337
-///   (at least not without crazy hacks)
-///   due to storage access limitations during ERC4337 UserOp validation.
+/// - This implementation does NOT include ERC4337 functionality.
+///   This is intentional, because the canonical ERC4337 entry point may still change and we
+///   don't want to encourage upgradeability by default for ERC6551 accounts just to handle this.
+///   We may include ERC4337 functionality once ERC4337 has been finalized.
+///   Recent updates to the account abstraction validation scope rules
+///   [ERC7562](https://eips.ethereum.org/EIPS/eip-7562) has made ERC6551 compatible with ERC4337.
+///   For an opinionated implementation, see https://github.com/tokenbound/contracts.
+///   If you want to add it yourself, you'll just need to add in the
+///   user operation validation functionality (and use ERC6551's execution functionality).
 /// - Please refer to the official [ERC6551](https://github.com/erc6551/reference) reference
 ///   for latest updates on the ERC6551 standard, as well as canonical registry information.
 abstract contract ERC6551 is UUPSUpgradeable, Receiver, ERC1271 {
@@ -172,15 +178,26 @@ abstract contract ERC6551 is UUPSUpgradeable, Receiver, ERC1271 {
     /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
 
     /// @dev Execute a call from this account.
+    /// Reverts and bubbles up error if operation fails.
+    /// Returns the result of the operation.
+    ///
+    /// Accounts MUST accept the following operation parameter values:
+    /// - 0 = CALL
+    /// - 1 = DELEGATECALL
+    /// - 2 = CREATE
+    /// - 3 = CREATE2
+    ///
+    /// Accounts MAY support additional operations or restrict a signer's
+    /// ability to execute certain operations.
     function execute(address target, uint256 value, bytes calldata data, uint8 operation)
         public
         payable
         virtual
         onlyValidSigner
-        onlyValidExecuteOperation(operation)
         incrementState
         returns (bytes memory result)
     {
+        if (operation != 0) revert OperationNotSupported();
         /// @solidity memory-safe-assembly
         assembly {
             result := mload(0x40)
@@ -198,15 +215,19 @@ abstract contract ERC6551 is UUPSUpgradeable, Receiver, ERC1271 {
     }
 
     /// @dev Execute a sequence of calls from this account.
+    /// Reverts and bubbles up error if an operation fails.
+    /// Returns the results of the operations.
+    ///
+    /// This is a batch variant of `execute` and is not required for `IERC6551Executable`.
     function executeBatch(Call[] calldata calls, uint8 operation)
         public
         payable
         virtual
         onlyValidSigner
-        onlyValidExecuteOperation(operation)
         incrementState
         returns (bytes[] memory results)
     {
+        if (operation != 0) revert OperationNotSupported();
         /// @solidity memory-safe-assembly
         assembly {
             results := mload(0x40)
@@ -235,12 +256,6 @@ abstract contract ERC6551 is UUPSUpgradeable, Receiver, ERC1271 {
         }
     }
 
-    /// @dev Requires that the execute `operation` is supported.
-    modifier onlyValidExecuteOperation(uint8 operation) virtual {
-        if (operation != 0) revert OperationNotSupported();
-        _;
-    }
-
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
     /*                           ERC165                           */
     /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
@@ -252,8 +267,8 @@ abstract contract ERC6551 is UUPSUpgradeable, Receiver, ERC1271 {
         /// @solidity memory-safe-assembly
         assembly {
             let s := shr(224, interfaceId)
-            // ERC165: 0x01ffc9a7, ERC6551: 0x6faff5f1, ERC6551Executable: 0x74420f4c.
-            result := or(or(eq(s, 0x01ffc9a7), eq(s, 0x6faff5f1)), eq(s, 0x74420f4c))
+            // ERC165: 0x01ffc9a7, ERC6551: 0x6faff5f1, ERC6551Executable: 0x51945447.
+            result := or(or(eq(s, 0x01ffc9a7), eq(s, 0x6faff5f1)), eq(s, 0x51945447))
         }
     }
 

test/ERC6551.t.sol

@@ -333,7 +333,7 @@ contract ERC6551Test is SoladyTest {
         _TestTemps memory t = _testTemps();
         assertTrue(t.account.supportsInterface(0x01ffc9a7));
         assertTrue(t.account.supportsInterface(0x6faff5f1));
-        assertTrue(t.account.supportsInterface(0x74420f4c));
+        assertTrue(t.account.supportsInterface(0x51945447));
         assertFalse(t.account.supportsInterface(0x00000001));
     }