support solc 6

.solhint.json

@@ -7,6 +7,7 @@
       "no-simple-event-func-name": "off",
       "two-lines-top-level-separator": "off",
       "mark-callable-contracts": "off",
-      "reason-string": "off"
+      "reason-string": "off",
+      "compiler-version": ["error","^0.6.10"]
     }
   }

.travis.yml

@@ -3,7 +3,7 @@ dist: trusty
 language: node_js
 
 node_js:
-  - "12.16.1"
+  - "12.18.1"
 
 before_install:
 
@@ -31,4 +31,3 @@ jobs:
         name: "Solidity Test Coverage"
         if: branch = arc-factory
         script: npm run coveralls
-

buidler.config.js

@@ -124,7 +124,7 @@ module.exports = {
   }
 },
   solc: {
-    version: "0.5.17",    // Fetch exact version from solc-bin (default: truffle's version)
+    version: "0.6.10",    // Fetch exact version from solc-bin (default: truffle's version)
     optimizer: {
       enabled: true,
       runs: 200

contracts/controller/Avatar.sol

@@ -1,17 +1,17 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
 import "@daostack/infra-experimental/contracts/Reputation.sol";
 import "./DAOToken.sol";
 import "./Vault.sol";
 import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/SafeERC20.sol";
-import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
 
 /**
  * @title An Avatar holds tokens, reputation and ether for a controller
  */
-contract Avatar is Initializable, Ownable {
+contract Avatar is Initializable, OwnableUpgradeSafe {
     using SafeERC20 for IERC20;
 
     string public orgName;
@@ -29,10 +29,11 @@ contract Avatar is Initializable, Ownable {
     /**
     * @dev enables an avatar to receive ethers
     */
-    function() external payable {
-        if (msg.sender != address(vault)) {
+    /* solhint-disable */
+    receive() external payable {
+       if (msg.sender != address(vault)) {
       // solhint-disable-next-line avoid-call-value
-            (bool success, ) = address(vault).call.value(msg.value)("");
+            (bool success, ) = address(vault).call{value:msg.value}("");
             require(success, "sendEther failed.");
         }
     }
@@ -50,7 +51,8 @@ contract Avatar is Initializable, Ownable {
         orgName = _orgName;
         nativeToken = _nativeToken;
         nativeReputation = _nativeReputation;
-        Ownable.initialize(_owner);
+        __Ownable_init_unchained();
+        transferOwnership(_owner);
         vault = new Vault();
         vault.initialize(address(this));
     }
@@ -60,8 +62,8 @@ contract Avatar is Initializable, Ownable {
     * @param _contract  the contract's address to call
     * @param _data ABI-encoded contract call to call `_contract` address.
     * @param _value value (ETH) to transfer with the transaction
-    * @return bool    success or fail
-    *         bytes - the return bytes of the called contract's function.
+    * @return success  success or fail
+    *         returnValue - the return bytes of the called contract's function.
     */
     function genericCall(address _contract, bytes calldata _data, uint256 _value)
     external
@@ -71,7 +73,7 @@ contract Avatar is Initializable, Ownable {
             vault.sendEther(_value, address(this));
         }
         // solhint-disable-next-line avoid-call-value
-        (success, returnValue) = _contract.call.value(_value)(_data);
+        (success, returnValue) = _contract.call{value:_value}(_data);
         emit GenericCall(_contract, _data, _value, success);
     }
 

contracts/controller/Controller.sol

@@ -1,8 +1,8 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
 import "./Avatar.sol";
 import "../globalConstraints/GlobalConstraintInterface.sol";
-import "@openzeppelin/upgrades/contracts/Initializable.sol";
 
 
 /**
@@ -289,7 +289,7 @@ contract Controller is Initializable {
                     globalConstraintsPre[globalConstraintRegister.index] = globalConstraint;
                     globalConstraintsRegisterPre[globalConstraint].index = globalConstraintRegister.index;
                 }
-                globalConstraintsPre.length--;
+                globalConstraintsPre.pop();
                 delete globalConstraintsRegisterPre[_globalConstraint];
                 retVal = true;
             }
@@ -303,7 +303,7 @@ contract Controller is Initializable {
                     globalConstraintsPost[globalConstraintRegister.index] = globalConstraint;
                     globalConstraintsRegisterPost[globalConstraint].index = globalConstraintRegister.index;
                 }
-                globalConstraintsPost.length--;
+                globalConstraintsPost.pop();
                 delete globalConstraintsRegisterPost[_globalConstraint];
                 retVal = true;
             }

contracts/controller/DAOToken.sol

@@ -1,21 +1,17 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
 import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20Burnable.sol";
 import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/IERC20.sol";
-import "@openzeppelin/contracts-ethereum-package/contracts/ownership/Ownable.sol";
-import "@openzeppelin/upgrades/contracts/Initializable.sol";
+import "@openzeppelin/contracts-ethereum-package/contracts/access/Ownable.sol";
 
 
 /**
  * @title DAOToken, base on zeppelin contract.
  * @dev ERC20 compatible token. It is a mintable, burnable token.
  */
-contract DAOToken is Initializable, Ownable, ERC20, ERC20Burnable {
+contract DAOToken is ERC20BurnableUpgradeSafe, OwnableUpgradeSafe {
 
-    string public name;
-    string public symbol;
-    // solhint-disable-next-line const-name-snakecase
-    uint8 public constant decimals = 18;
     uint256 public cap;
 
     /**
@@ -27,10 +23,10 @@ contract DAOToken is Initializable, Ownable, ERC20, ERC20Burnable {
     function initialize(string calldata _name, string calldata _symbol, uint256 _cap, address _owner)
     external
     initializer {
-        name = _name;
-        symbol = _symbol;
         cap = _cap;
-        Ownable.initialize(_owner);
+        __ERC20_init_unchained(_name, _symbol);
+        __Ownable_init_unchained();
+        transferOwnership(_owner);
     }
 
     /**

contracts/controller/Vault.sol

@@ -1,24 +1,37 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
-import "@openzeppelin/contracts-ethereum-package/contracts/ownership/Ownable.sol";
+import "@openzeppelin/contracts-ethereum-package/contracts/access/Ownable.sol";
 
 
 //Proxy contracts cannot recive eth via fallback function.
 //For now , we will use this vault to overcome that
-contract Vault is Ownable {
+contract Vault is OwnableUpgradeSafe {
     event ReceiveEther(address indexed _sender, uint256 _value);
     event SendEther(address indexed _to, uint256 _value);
 
+    /**
+    * @dev initialize
+    * @param _owner vault owner
+    */
+    function initialize(address _owner)
+    external
+    initializer {
+        __Ownable_init_unchained();
+        transferOwnership(_owner);
+    }
+
     /**
     * @dev enables this contract to receive ethers
     */
-    function() external payable {
+    /* solhint-disable */
+    receive() external payable {
         emit ReceiveEther(msg.sender, msg.value);
     }
 
     function sendEther(uint256 _amountInWei, address payable _to) external onlyOwner returns(bool) {
         // solhint-disable-next-line avoid-call-value
-        (bool success, ) = _to.call.value(_amountInWei)("");
+        (bool success, ) = _to.call{value:_amountInWei}("");
         require(success, "sendEther failed.");
         emit SendEther(_to, _amountInWei);
     }

contracts/globalConstraints/GlobalConstraintInterface.sol

@@ -1,15 +1,16 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
-
-contract GlobalConstraintInterface {
+// solhint-disable-next-line indent
+abstract contract GlobalConstraintInterface {
 
     enum CallPhase { Pre, Post, PreAndPost }
 
-    function pre( address _scheme, bytes32 _method ) public returns(bool);
-    function post( address _scheme, bytes32 _method ) public returns(bool);
+    function pre( address _scheme, bytes32 _method ) public virtual returns(bool);
+    function post( address _scheme, bytes32 _method ) public virtual returns(bool);
     /**
      * @dev when return if this globalConstraints is pre, post or both.
      * @return CallPhase enum indication  Pre, Post or PreAndPost.
      */
-    function when() public returns(CallPhase);
+    function when() public virtual returns(CallPhase);
 }

contracts/globalConstraints/TokenCapGC.sol

@@ -1,8 +1,10 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
 import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/IERC20.sol";
 import "./GlobalConstraintInterface.sol";
-import "@openzeppelin/upgrades/contracts/Initializable.sol";
+import "@openzeppelin/contracts-ethereum-package/contracts/Initializable.sol";
+
 
 /**
  * @title Token Cap Global Constraint

contracts/libs/Bytes32ToStr.sol

@@ -1,4 +1,5 @@
-pragma solidity ^0.5.17;
+pragma solidity ^0.6.10;
+// SPDX-License-Identifier: GPL-3.0
 
 library Bytes32ToStr {
     function toStr(bytes32 x) internal pure returns (string memory) {