feat: make Solidity V8 migration non breaking

contracts/facets/IexecERC20Core.sol

@@ -12,7 +12,13 @@ contract IexecERC20Core is IexecERC20Common, FacetBase {
         require(sender != address(0), "ERC20: transfer from the zero address");
         require(recipient != address(0), "ERC20: transfer to the zero address");
         PocoStorageLib.PocoStorage storage $ = PocoStorageLib.getPocoStorage();
-        $.m_balances[sender] = $.m_balances[sender] - amount;
+        uint256 senderBalance = $.m_balances[sender];
+        // TEMPORARY MIGRATION FIX: Check balance to prevent underflow and revert without reason for backward compatibility
+        // TODO: Remove this in the next major version
+        if (senderBalance < amount) {
+            revert();
+        }
+        $.m_balances[sender] = senderBalance - amount;
         $.m_balances[recipient] = $.m_balances[recipient] + amount;
         emit Transfer(sender, recipient, amount);
     }
@@ -32,8 +38,14 @@ contract IexecERC20Core is IexecERC20Common, FacetBase {
     function _burn(address account, uint256 amount) internal {
         require(account != address(0), "ERC20: burn from the zero address");
         PocoStorageLib.PocoStorage storage $ = PocoStorageLib.getPocoStorage();
+        uint256 accountBalance = $.m_balances[account];
+        // TEMPORARY MIGRATION FIX: Check balance to prevent underflow and revert without reason for backward compatibility
+        // TODO: Remove this in the next major version
+        if (accountBalance < amount) {
+            revert();
+        }
         $.m_totalSupply = $.m_totalSupply - amount;
-        $.m_balances[account] = $.m_balances[account] - amount;
+        $.m_balances[account] = accountBalance - amount;
         emit Transfer(account, address(0), amount);
     }
 

contracts/facets/IexecERC20Facet.sol

@@ -45,7 +45,13 @@ contract IexecERC20Facet is IexecERC20, FacetBase, IexecERC20Core {
     ) external override returns (bool) {
         PocoStorageLib.PocoStorage storage $ = PocoStorageLib.getPocoStorage();
         _transfer(sender, recipient, amount);
-        _approve(sender, _msgSender(), $.m_allowances[sender][_msgSender()] - amount);
+        // TEMPORARY MIGRATION FIX: Check allowance to prevent underflow and revert without reason for backward compatibility
+        // TODO: Remove this in the next major version
+        uint256 currentAllowance = $.m_allowances[sender][_msgSender()];
+        if (currentAllowance < amount) {
+            revert();
+        }
+        _approve(sender, _msgSender(), currentAllowance - amount);
         return true;
     }
 
@@ -63,7 +69,13 @@ contract IexecERC20Facet is IexecERC20, FacetBase, IexecERC20Core {
         uint256 subtractedValue
     ) external override returns (bool) {
         PocoStorageLib.PocoStorage storage $ = PocoStorageLib.getPocoStorage();
-        _approve(_msgSender(), spender, $.m_allowances[_msgSender()][spender] - subtractedValue);
+        // TEMPORARY MIGRATION FIX: Check allowance to prevent underflow and revert without reason for backward compatibility
+        // TODO: Remove this in the next major version
+        uint256 currentAllowance = $.m_allowances[_msgSender()][spender];
+        if (currentAllowance < subtractedValue) {
+            revert();
+        }
+        _approve(_msgSender(), spender, currentAllowance - subtractedValue);
         return true;
     }
 }

contracts/facets/IexecEscrowTokenFacet.sol

@@ -10,7 +10,6 @@ import {IexecTokenSpender} from "../interfaces/IexecTokenSpender.sol";
 import {PocoStorageLib} from "../libs/PocoStorageLib.sol";
 
 contract IexecEscrowTokenFacet is IexecEscrowToken, IexecTokenSpender, FacetBase, IexecERC20Core {
-
     /***************************************************************************
      *                         Escrow methods: public                          *
      ***************************************************************************/

contracts/interfaces/IOwnable.sol

@@ -1,8 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 interface IOwnable {
     event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

contracts/interfaces/IexecAccessorsABILegacy.sol

@@ -1,8 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 import "../libs/IexecLibCore_v5.sol";
 

contracts/interfaces/IexecCategoryManager.sol

@@ -1,8 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 interface IexecCategoryManager {
     event CreateCategory(uint256 catid, string name, string description, uint256 workClockTimeRef);

contracts/interfaces/IexecConfiguration.sol

@@ -1,9 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
-
+pragma solidity ^0.8.0;
 import "../libs/IexecLibOrders_v5.sol";
 
 interface IexecConfiguration {

contracts/interfaces/IexecConfigurationExtra.sol

@@ -1,9 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
-
+pragma solidity ^0.8.0;
 interface IexecConfigurationExtra {
     function changeRegistries(address, address, address) external;
 }

contracts/interfaces/IexecERC20.sol

@@ -1,13 +1,11 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 import {IexecERC20Common} from "./IexecERC20Common.sol";
 
 interface IexecERC20 is IexecERC20Common {
-
     function transfer(address, uint256) external returns (bool);
     function approve(address, uint256) external returns (bool);
     function transferFrom(address, address, uint256) external returns (bool);

contracts/interfaces/IexecERC20Common.sol

@@ -1,9 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
-
+pragma solidity ^0.8.0;
 // TODO merge with IexecERC20 interface.
 interface IexecERC20Common {
     event Transfer(address indexed from, address indexed to, uint256 value);

contracts/interfaces/IexecEscrowNative.sol

@@ -1,9 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
-
+pragma solidity ^0.8.0;
 interface IexecEscrowNative {
     receive() external payable;
     fallback() external payable;

contracts/interfaces/IexecEscrowToken.sol

@@ -1,8 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 interface IexecEscrowToken {
     receive() external payable;

contracts/interfaces/IexecPoco1.sol

@@ -1,9 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
-
+pragma solidity ^0.8.0;
 import {IexecLibOrders_v5} from "../libs/IexecLibOrders_v5.sol";
 
 interface IexecPoco1 {

contracts/interfaces/IexecRelay.sol

@@ -1,8 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 import "../libs/IexecLibOrders_v5.sol";
 

contracts/interfaces/IexecTokenSpender.sol

@@ -1,8 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
+pragma solidity ^0.8.0;
 
 interface IexecTokenSpender {
     function receiveApproval(address, uint256, address, bytes calldata) external returns (bool);

contracts/libs/IexecLibCore_v5.sol

@@ -1,7 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2024 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
+pragma solidity ^0.8.0;
 
 library IexecLibCore_v5 {
     /**

contracts/libs/IexecLibOrders_v5.sol

@@ -1,9 +1,7 @@
 // SPDX-FileCopyrightText: 2020-2025 IEXEC BLOCKCHAIN TECH <[email protected]>
 // SPDX-License-Identifier: Apache-2.0
 
-pragma solidity >=0.6.0;
-pragma experimental ABIEncoderV2;
-
+pragma solidity ^0.8.0;
 library IexecLibOrders_v5 {
     // bytes32 public constant EIP712DOMAIN_TYPEHASH = keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)');
     // bytes32 public constant APPORDER_TYPEHASH = keccak256('AppOrder(address app,uint256 appprice,uint256 volume,bytes32 tag,address datasetrestrict,address workerpoolrestrict,address requesterrestrict,bytes32 salt)');

contracts/registries/Registry.sol

@@ -28,6 +28,14 @@ abstract contract Registry is IRegistry, ERC721Enumerable, Ownable {
         proxyCodeHash = keccak256(proxyCode);
     }
 
+    // TEMPORARY MIGRATION FIX: Override _checkOwner to catch custom errors and throw string errors for backward compatibility
+    // TODO: Remove this override in the next major version
+    function _checkOwner() internal view override {
+        if (owner() != _msgSender()) {
+            revert("Ownable: caller is not the owner");
+        }
+    }
+
     function initialize(address _previous) external onlyOwner {
         require(!initialized);
         initialized = true;
@@ -69,8 +77,14 @@ abstract contract Registry is IRegistry, ERC721Enumerable, Ownable {
 
     /* Factory */
     function _mintCreate(address _owner, bytes memory _args) internal returns (address) {
+        // TEMPORARY MIGRATION FIX: Check if contract already exists to revert without custom error for backward compatibility
+        // TODO: Remove this in the next major version
+        address entry = _mintPredict(_owner, _args);
+        if (entry.code.length > 0) {
+            revert("Create2: Failed on deploy");
+        }
         // Create entry (proxy)
-        address entry = Create2.deploy(0, keccak256(abi.encodePacked(_args, _owner)), proxyCode);
+        entry = Create2.deploy(0, keccak256(abi.encodePacked(_args, _owner)), proxyCode);
         InitializableUpgradeabilityProxy(payable(entry)).initialize(master, _args);
         // Mint corresponding token
         _mint(_owner, uint256(uint160(entry)));