update solidity version to ^0.7.0 (#122)

* update solc version to ^0.7.0

* interfaces back to solidity >0.6.0 <0.8.0

* update solc to 0.7.6

* back to 0.7.4

* upgrade to 0.7.6, fix EXTCODESIZE check

* versions >0.5.0 <0.8.0 for xdomain msgers

packages/contracts/buidler.config.ts

@@ -22,7 +22,7 @@ const config: BuidlerConfig = {
     timeout: 50000,
   },
   solc: {
-    version: '0.7.4',
+    version: '0.7.6',
     optimizer: { enabled: true, runs: 200 },
   },
   typechain: {

packages/contracts/contracts/optimistic-ethereum/OVM/bridge/OVM_BaseCrossDomainMessenger.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Interface Imports */

packages/contracts/contracts/optimistic-ethereum/OVM/bridge/OVM_L1CrossDomainMessenger.sol

 // SPDX-License-Identifier: MIT
-pragma solidity ^0.7.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */

packages/contracts/contracts/optimistic-ethereum/OVM/bridge/OVM_L2CrossDomainMessenger.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */
@@ -23,7 +23,7 @@ contract OVM_L2CrossDomainMessenger is iOVM_L2CrossDomainMessenger, OVM_BaseCros
     /***************
      * Constructor *
      ***************/
-    
+
     /**
      * @param _libAddressManager Address of the Address Manager.
      */

packages/contracts/contracts/optimistic-ethereum/OVM/precompiles/OVM_ETH.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /* Interface Imports */
 import { iOVM_ERC20 } from "../../iOVM/precompiles/iOVM_ERC20.sol";

packages/contracts/contracts/optimistic-ethereum/OVM/precompiles/OVM_L2ToL1MessagePasser.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /* Interface Imports */
 import { iOVM_L2ToL1MessagePasser } from "../../iOVM/precompiles/iOVM_L2ToL1MessagePasser.sol";

packages/contracts/contracts/optimistic-ethereum/iOVM/bridge/iOVM_BaseCrossDomainMessenger.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /**

packages/contracts/contracts/optimistic-ethereum/iOVM/bridge/iOVM_L1CrossDomainMessenger.sol

@@ -16,7 +16,7 @@ interface iOVM_L1CrossDomainMessenger is iOVM_BaseCrossDomainMessenger {
     /*******************
      * Data Structures *
      *******************/
-    
+
     struct L2MessageInclusionProof {
         bytes32 stateRoot;
         Lib_OVMCodec.ChainBatchHeader stateRootBatchHeader;
@@ -27,9 +27,9 @@ interface iOVM_L1CrossDomainMessenger is iOVM_BaseCrossDomainMessenger {
 
 
     /********************
-     * Public Functions * 
+     * Public Functions *
      ********************/
-    
+
     /**
      * Relays a cross domain message to a contract.
      * @param _target Target contract address.

packages/contracts/contracts/optimistic-ethereum/iOVM/bridge/iOVM_L2CrossDomainMessenger.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Interface Imports */
@@ -12,7 +12,7 @@ import { iOVM_BaseCrossDomainMessenger } from "./iOVM_BaseCrossDomainMessenger.s
 interface iOVM_L2CrossDomainMessenger is iOVM_BaseCrossDomainMessenger {
 
     /********************
-     * Public Functions * 
+     * Public Functions *
      ********************/
 
     /**

packages/contracts/contracts/optimistic-ethereum/iOVM/chain/iOVM_StateCommitmentChain.sol

@@ -119,7 +119,7 @@ interface iOVM_StateCommitmentChain {
         returns (
             bool _inside
         );
-    
+
     /**
      * Sets the last batch index that can be deleted.
      * @param _stateBatchHeader Proposed batch header that can be deleted.

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_StateManager.sol

@@ -31,8 +31,8 @@ interface iOVM_StateManager {
      * Public Functions: Setup *
      ***************************/
 
-    function owner() external view returns (address _owner); 
-    function ovmExecutionManager() external view returns (address _ovmExecutionManager); 
+    function owner() external view returns (address _owner);
+    function ovmExecutionManager() external view returns (address _ovmExecutionManager);
     function setExecutionManager(address _ovmExecutionManager) external;
 
 
@@ -59,7 +59,7 @@ interface iOVM_StateManager {
     function wasAccountChanged(address _address) external view returns (bool);
     function wasAccountCommitted(address _address) external view returns (bool);
 
-    
+
     /************************************
      * Public Functions: Storage Access *
      ************************************/

packages/contracts/contracts/optimistic-ethereum/iOVM/precompiles/iOVM_DeployerWhitelist.sol

@@ -5,11 +5,11 @@ pragma solidity >0.5.0 <0.8.0;
  * @title iOVM_DeployerWhitelist
  */
 interface iOVM_DeployerWhitelist {
-    
+
     /********************
      * Public Functions *
      ********************/
-    
+
     function initialize(address _owner, bool _allowArbitraryDeployment) external;
     function setWhitelistedDeployer(address _deployer, bool _isWhitelisted) external;
     function setOwner(address _newOwner) external;

packages/contracts/contracts/optimistic-ethereum/iOVM/precompiles/iOVM_ERC20.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /**
  * @title iOVM_ERC20

packages/contracts/contracts/optimistic-ethereum/iOVM/precompiles/iOVM_L1MessageSender.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /**
  * @title iOVM_L1MessageSender
  */
 interface iOVM_L1MessageSender {
-    
+
     /********************
      * Public Functions *
      ********************/
-    
+
     function getL1MessageSender() external returns (address _l1MessageSender);
 }

packages/contracts/contracts/optimistic-ethereum/iOVM/precompiles/iOVM_L2ToL1MessagePasser.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /**
  * @title iOVM_L2ToL1MessagePasser

packages/contracts/contracts/optimistic-ethereum/iOVM/verification/iOVM_BondManager.sol

@@ -64,7 +64,7 @@ interface iOVM_BondManager {
         bool canClaim;
         // Total number of `recordGasSpent` calls made
         uint256 total;
-        // The gas spent by each user to provide witness data. The sum of all 
+        // The gas spent by each user to provide witness data. The sum of all
         // values inside this map MUST be equal to the value of `total`
         mapping(address => uint256) gasSpent;
     }
@@ -73,7 +73,7 @@ interface iOVM_BondManager {
     /********************
      * Public Functions *
      ********************/
-    
+
     function recordGasSpent(
         bytes32 _preStateRoot,
         bytes32 _txHash,

packages/contracts/contracts/optimistic-ethereum/iOVM/verification/iOVM_StateTransitioner.sol

@@ -13,7 +13,7 @@ interface iOVM_StateTransitioner {
     /**********
      * Events *
      **********/
-    
+
     event AccountCommitted(
         address _address
     );
@@ -32,7 +32,7 @@ interface iOVM_StateTransitioner {
     function getPostStateRoot() external view returns (bytes32 _postStateRoot);
     function isComplete() external view returns (bool _complete);
 
-    
+
     /***********************************
      * Public Functions: Pre-Execution *
      ***********************************/

packages/contracts/contracts/optimistic-ethereum/libraries/codec/Lib_OVMCodec.sol

 // SPDX-License-Identifier: MIT
-pragma solidity ^0.7.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */

packages/contracts/contracts/optimistic-ethereum/libraries/resolver/Lib_AddressManager.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /* Contract Imports */
 import { Ownable } from "./Lib_Ownable.sol";

packages/contracts/contracts/optimistic-ethereum/libraries/resolver/Lib_AddressResolver.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /* Library Imports */
 import { Lib_AddressManager } from "./Lib_AddressManager.sol";

packages/contracts/contracts/optimistic-ethereum/libraries/resolver/Lib_Ownable.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /**
  * @title Ownable
@@ -55,7 +55,7 @@ abstract contract Ownable {
     function renounceOwnership()
         public
         virtual
-        onlyOwner 
+        onlyOwner
     {
         emit OwnershipTransferred(owner, address(0));
         owner = address(0);

packages/contracts/contracts/optimistic-ethereum/libraries/trie/Lib_SecureMerkleTrie.sol

 // SPDX-License-Identifier: MIT
-pragma solidity ^0.7.0;
+pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Library Imports */

packages/contracts/contracts/optimistic-ethereum/libraries/utils/Lib_ReentrancyGuard.sol

 // SPDX-License-Identifier: MIT
 // +build ovm
-pragma solidity >0.6.0 <0.8.0;
+pragma solidity >0.5.0 <0.8.0;
 
 /**
  * @dev Contract module that helps prevent reentrant calls to a function.

packages/contracts/test/contracts/OVM/execution/OVM_ExecutionManager/ovmCREATEEOA.spec.ts

@@ -69,7 +69,7 @@ const test_ovmCREATEEOA: TestDefinition = {
             address: '0x17ec8597ff92C3F44523bDc65BF0f1bE632917ff',
           },
           expectedReturnStatus: true,
-          expectedReturnValue: 1682,
+          expectedReturnValue: 1678,
         },
       ],
     },