Use transient storage slot to pass the request

foundry.toml

@@ -10,14 +10,14 @@ auto_detect_solc = false
 optimizer = true
 optimizer_runs = 1_000
 gas_limit = 100_000_000 # ETH is 30M, but we use a higher value.
-skip = ["*/*Transient*", "*/ext/ithaca/*", "*/ext/zksync/*"]
+skip = ["*/*7702*", "*/*Transient*", "*/ext/ithaca/*", "*/ext/zksync/*"]
 fs_permissions = [{ access = "read", path = "./test/data"}]
 remappings = [
   "forge-std=test/utils/forge-std/"
 ]
 
 [profile.pre_global_structs]
-skip = ["*/g/*", "*/*Transient*", "*/ext/ithaca/*", "*/ext/zksync/*"]
+skip = ["*/g/*", "*/*7702*", "*/*Transient*", "*/ext/ithaca/*", "*/ext/zksync/*"]
 
 [profile.post_cancun]
 evm_version = "cancun"

src/Milady.sol

@@ -1,14 +1,12 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.4;
 
-import "./accounts/EIP7702Proxy.sol";
 import "./accounts/ERC1271.sol";
 import "./accounts/ERC4337.sol";
 import "./accounts/ERC4337Factory.sol";
 import "./accounts/ERC6551.sol";
 import "./accounts/ERC6551Proxy.sol";
 import "./accounts/ERC7821.sol";
-import "./accounts/LibEIP7702.sol";
 import "./accounts/LibERC6551.sol";
 import "./accounts/LibERC7579.sol";
 import "./accounts/Receiver.sol";

src/accounts/EIP7702Proxy.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.4;
+pragma solidity ^0.8.24;
 
 /// @notice Relay proxy for EIP7702 delegations.
 /// @author Solady (https://github.com/vectorized/solady/blob/main/src/accounts/EIP7702Proxy.sol)
@@ -33,10 +33,10 @@ contract EIP7702Proxy {
     bytes32 internal constant _ERC1967_ADMIN_SLOT =
         0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
 
-    /// @dev The prefix for the ERC-1967 storage slot value if it should
-    /// be initialized with the latest implementation.
-    /// `uint32(bytes4(keccak256("eip7702.proxy.delegation.initialization")))`
-    uint32 internal constant _EIP7702_PROXY_DELEGATION_INITIALIZATION_PREFIX = 0x17723f10;
+    /// @dev The transient storage slot for requesting the proxy to initialize the implementation.
+    /// `uint256(keccak256("eip7702.proxy.delegation.initialization.request")) - 1`.
+    bytes32 internal constant _EIP7702_PROXY_DELEGATION_INITIALIZATION_REQUEST_SLOT =
+        0x94e11c6e41e7fb92cb8bb65e13fdfbd4eba8b831292a1a220f7915c78c7c078f;
 
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
     /*                        CONSTRUCTOR                         */
@@ -124,10 +124,12 @@ contract EIP7702Proxy {
                 // to signal that we should replace it with the actual implementation.
                 // This also gives the flexibility on whether to let the proxy auto-upgrade,
                 // or let the authority manually upgrade.
-                let implSlot := _ERC1967_IMPLEMENTATION_SLOT
-                if eq(_EIP7702_PROXY_DELEGATION_INITIALIZATION_PREFIX, shr(224, sload(implSlot))) {
+                // A non-zero value in transient storage denotes a initialization request.
+                if tload(_EIP7702_PROXY_DELEGATION_INITIALIZATION_REQUEST_SLOT) {
+                    let implSlot := _ERC1967_IMPLEMENTATION_SLOT
                     // The `implementation` is still at `calldatasize()` in memory.
-                    sstore(implSlot, or(shl(160, shr(160, impl)), mload(calldatasize())))
+                    sstore(implSlot, or(shl(160, shr(160, sload(implSlot))), mload(calldatasize())))
+                    tstore(_EIP7702_PROXY_DELEGATION_INITIALIZATION_REQUEST_SLOT, 0) // Clear.
                 }
                 returndatacopy(0x00, 0x00, returndatasize())
                 return(0x00, returndatasize())

src/accounts/LibEIP7702.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.4;
+pragma solidity ^0.8.24;
 
 /// @notice Library for EIP7702 operations.
 /// @author Solady (https://github.com/vectorized/solady/blob/main/src/accounts/LibEIP7702.sol)
@@ -26,10 +26,10 @@ library LibEIP7702 {
     bytes32 internal constant ERC1967_IMPLEMENTATION_SLOT =
         0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 
-    /// @dev The prefix for the ERC-1967 storage slot value if it should
-    /// be initialized with the latest implementation.
-    /// `uint32(bytes4(keccak256("eip7702.proxy.delegation.initialization")))`
-    uint32 internal constant EIP7702_PROXY_DELEGATION_INITIALIZATION_PREFIX = 0x17723f10;
+    /// @dev The transient storage slot for requesting the proxy to initialize the implementation.
+    /// `uint256(keccak256("eip7702.proxy.delegation.initialization.request")) - 1`.
+    bytes32 internal constant _EIP7702_PROXY_DELEGATION_INITIALIZATION_REQUEST_SLOT =
+        0x94e11c6e41e7fb92cb8bb65e13fdfbd4eba8b831292a1a220f7915c78c7c078f;
 
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
     /*                    AUTHORITY OPERATIONS                    */
@@ -138,12 +138,8 @@ library LibEIP7702 {
     function requestProxyDelegationInitialization() internal {
         /// @solidity memory-safe-assembly
         assembly {
-            let s := ERC1967_IMPLEMENTATION_SLOT
-            let v := sload(s)
-            if iszero(shl(96, v)) {
-                mstore(0x20, v)
-                mstore(0x04, EIP7702_PROXY_DELEGATION_INITIALIZATION_PREFIX)
-                sstore(s, mload(0x20))
+            if iszero(shl(96, sload(ERC1967_IMPLEMENTATION_SLOT))) {
+                tstore(_EIP7702_PROXY_DELEGATION_INITIALIZATION_REQUEST_SLOT, address())
             }
         }
     }