[Docs] add examples of ERC contract standard checker

docs/docs.rst

@@ -7,3 +7,12 @@ Rule Engine
 -----------
 
 - `Lity rule engine v1.0 spec <_static/files/lity-rule-engine-spec-v1-0.pdf>`_
+
+ERC Contract Standard Checker
+-----------------------------
+
+- `ERC20 Checker <erc-contract-standard-checker/erc20-checker>`
+- `ERC223 Checker <erc-contract-standard-checker/erc223-checker>`
+- `ERC721 Checker <erc-contract-standard-checker/erc721-checker>`
+- `ERC827 Checker <erc-contract-standard-checker/erc827-checker>`
+- `ERC884 Checker <erc-contract-standard-checker/erc884-checker>`

docs/eni-tutorial.rst

@@ -90,7 +90,7 @@ Run with `ABCDE` as input to your contract.
   
   0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000054142434445000000000000000000000000000000000000000000000000000000
 
-Accroding to the ABI of Ethereum contracts, the output could be decode as string `EDCBA`.
+According to the ABI of Ethereum contracts, the output could be decode as string `EDCBA`.
 
 .. code:: bash
 

docs/erc-contract-standard-checker/erc20-checker.rst

@@ -0,0 +1,74 @@
+ERC20 Contract Standard Checker
+===============================
+
+Enable contract standard checker with specific ERC
+--------------------------------------------------
+
+.. code:: bash
+
+  lityc --contract-standard ERC20 <contract file>
+
+
+Examples
+--------
+
+- ERC20 Interface (erc20_interface.sol)
+
+.. code:: solidity
+
+  pragma solidity ^0.4.23;
+
+  contract ERC20Interface {
+    function totalSupply() public view returns (uint);
+    function balanceOf(address tokenOwner) public view returns (uint balance);
+    function allowance(address tokenOwner, address spender) public view returns (uint remaining);
+    function transfer(address to, uint tokens) public returns (bool success);
+    function approve(address spender, uint tokens) public returns (bool success);
+    function transferFrom(address from, address to, uint tokens) public returns (bool success);
+
+    event Transfer(address indexed from, address indexed to, uint tokens);
+    event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
+  }
+
+
+- Expect output
+
+.. code:: bash
+
+  $ lityc --contract-standard ERC20 erc20_interface.sol
+
+  erc20_standard.sol:3:1: Info: ERC20Interface is compatible to ERC20.
+  contract ERC20Interface {
+  ^ (Relevant source part starts here and spans across multiple lines).
+
+
+
+- ERC20 Interface with wrong mutability (wrong_mutability.sol)
+
+.. code:: solidity
+
+  pragma solidity ^0.4.23;
+  contract ERC20Interface {
+    function totalSupply() public pure returns (uint); // mutability should be view, not pure
+    function balanceOf(address tokenOwner) public view returns (uint balance);
+    function allowance(address tokenOwner, address spender) public view returns (uint remaining);
+    function transfer(address to, uint tokens) public returns (bool success);
+    function approve(address spender, uint tokens) public returns (bool success);
+    function transferFrom(address from, address to, uint tokens) public returns (bool success);
+
+    event Transfer(address indexed from, address indexed to, uint tokens);
+    event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
+  }
+
+
+- Expect output
+
+.. code:: bash
+
+  $ lityc --contract-standard ERC20 wrong_mutability.sol
+
+  wrong_mutability.sol:3:1: Info: Missing 'totalSupply' with type signature 'function () view external returns (uint256)'. ERC20Interface is not compatible to ERC20.
+  contract ERC20Interface {
+  ^ (Relevant source part starts here and spans across multiple lines).
+
+

docs/erc-contract-standard-checker/erc223-checker.rst

@@ -0,0 +1,181 @@
+ERC223 Contract Standard Checker
+===============================
+
+Enable contract standard checker with specific ERC
+--------------------------------------------------
+
+.. code:: bash
+
+  lityc --contract-standard ERC223 <contract file>
+
+
+Examples
+--------
+
+- ERC223 Interface (erc223_interface.sol)
+
+.. code:: solidity
+
+  pragma solidity ^0.4.23;
+
+  contract ERC223Interface {
+    function totalSupply() public view returns (uint);
+    function balanceOf(address tokenOwner) public view returns (uint balance);
+    function transfer(address to, uint tokens) public returns (bool success);
+    function transfer(address to, uint tokens, bytes data) public returns (bool success);
+    event Transfer(address indexed from, address indexed to, uint tokens, bytes data);
+  }
+
+
+- Expect output
+
+.. code:: bash
+
+  $ lityc --contract-standard ERC223 erc223_interface.sol
+
+  erc223_standard.sol:3:1: Info: ERC223Interface is compatible to ERC223.
+  contract ERC223Interface {
+  ^ (Relevant source part starts here and spans across multiple lines).
+
+
+
+- ERC223 Token example (erc223_token.sol)
+
+.. code:: solidity
+
+  pragma solidity ^0.4.11;
+
+  library SafeMath {
+    function mul(uint a, uint b) internal pure returns (uint) {
+    uint c = a * b;
+    _assert(a == 0 || c / a == b);
+    return c;
+  }
+
+  function div(uint a, uint b) internal pure returns (uint) {
+    // _assert(b > 0); // Solidity automatically throws when dividing by 0
+    uint c = a / b;
+    // _assert(a == b * c + a % b); // There is no case in which this doesn't hold
+    return c;
+  }
+
+  function sub(uint a, uint b) internal pure returns (uint) {
+    _assert(b <= a);
+    return a - b;
+  }
+
+  function add(uint a, uint b) internal pure returns (uint) {
+    uint c = a + b;
+    _assert(c >= a);
+    return c;
+  }
+
+  function max64(uint64 a, uint64 b) internal pure returns (uint64) {
+    return a >= b ? a : b;
+  }
+
+  function min64(uint64 a, uint64 b) internal pure returns (uint64) {
+    return a < b ? a : b;
+  }
+
+  function max256(uint256 a, uint256 b) internal pure returns (uint256) {
+    return a >= b ? a : b;
+  }
+
+  function min256(uint256 a, uint256 b) internal pure returns (uint256) {
+    return a < b ? a : b;
+  }
+
+  function _assert(bool assertion) internal pure {
+    if (!assertion) {
+      revert();
+    }
+  }
+  }
+
+  contract ERC223Interface {
+    function totalSupply() public view returns (uint);
+    function balanceOf(address tokenOwner) public view returns (uint balance);
+    function transfer(address to, uint tokens, bytes data) public returns (bool success);
+    function transfer(address to, uint tokens) public returns (bool success);
+    event Transfer(address indexed from, address indexed to, uint tokens, bytes data);
+  }
+
+  contract ERC223ReceivingContract {
+    function tokenFallback(address _from, uint _value, bytes _data) public;
+  }
+
+  contract ERC223Token is ERC223Interface {
+    using SafeMath for uint;
+
+    mapping(address => uint) balances; // List of user balances.
+
+    function totalSupply() public view returns (uint) {
+      return 2**18;
+    }
+
+    function transfer(address _to, uint _value, bytes _data) public returns (bool) {
+      // Standard function transfer similar to ERC20 transfer with no _data .
+      // Added due to backwards compatibility reasons .
+      uint codeLength;
+
+      assembly {
+        // Retrieve the size of the code on target address, this needs assembly .
+        codeLength := extcodesize(_to)
+      }
+
+      balances[msg.sender] = balances[msg.sender].sub(_value);
+      balances[_to] = balances[_to].add(_value);
+      if(codeLength>0) {
+        ERC223ReceivingContract receiver = ERC223ReceivingContract(_to);
+        receiver.tokenFallback(msg.sender, _value, _data);
+        return true;
+      }
+      emit Transfer(msg.sender, _to, _value, _data);
+      return true;
+    }
+
+    function transfer(address _to, uint _value) public returns (bool) {
+      uint codeLength;
+      bytes memory empty;
+
+      assembly {
+        // Retrieve the size of the code on target address, this needs assembly .
+        codeLength := extcodesize(_to)
+      }
+
+      balances[msg.sender] = balances[msg.sender].sub(_value);
+      balances[_to] = balances[_to].add(_value);
+      if(codeLength>0) {
+        ERC223ReceivingContract receiver = ERC223ReceivingContract(_to);
+        receiver.tokenFallback(msg.sender, _value, empty);
+        return true;
+      }
+      emit Transfer(msg.sender, _to, _value, empty);
+      return true;
+    }
+
+    function balanceOf(address _owner) public view returns (uint balance) {
+      return balances[_owner];
+    }
+  }
+
+
+- Expect output
+
+.. code:: bash
+
+  $ lityc --contract-standard ERC223 erc223_token.sol
+
+  erc223_token.sol:6:1: Info: Missing 'totalSupply' with type signature 'function () view external returns (uint256)'. SafeMath is not compatible to ERC223.
+  library SafeMath {
+  ^ (Relevant source part starts here and spans across multiple lines).
+  erc223_token.sol:54:1: Info: ERC223Interface is compatible to ERC223.
+  contract ERC223Interface {
+  ^ (Relevant source part starts here and spans across multiple lines).
+  erc223_token.sol:65:1: Info: Missing 'totalSupply' with type signature 'function () view external returns (uint256)'. ERC223ReceivingContract is not compatible to ERC223.
+  contract ERC223ReceivingContract {
+  ^ (Relevant source part starts here and spans across multiple lines).
+  erc223_token.sol:78:1: Info: ERC223Token is compatible to ERC223.
+  contract ERC223Token is ERC223Interface {
+  ^ (Relevant source part starts here and spans across multiple lines).

docs/erc-contract-standard-checker/erc721-checker.rst

@@ -0,0 +1,80 @@
+ERC721 Contract Standard Checker
+===============================
+
+Enable contract standard checker with specific ERC
+--------------------------------------------------
+
+.. code:: bash
+
+  lityc --contract-standard ERC721 <contract file>
+
+
+Examples
+--------
+
+- ERC721 Interface (erc721_interface.sol)
+
+.. code:: solidity
+
+  pragma solidity ^0.4.23;
+
+  contract ERC721Interface {
+    event Transfer(address indexed _from, address indexed _to, uint256 _tokenId);
+    event Approval(address indexed _owner, address indexed _approved, uint256 _tokenId);
+    event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);
+    function balanceOf(address _owner) external view returns (uint256);
+    function ownerOf(uint256 _tokenId) external view returns (address);
+    function safeTransferFrom(address _from, address _to, uint256 _tokenId, bytes data) external payable;
+    function safeTransferFrom(address _from, address _to, uint256 _tokenId) external payable;
+    function transferFrom(address _from, address _to, uint256 _tokenId) external payable;
+    function approve(address _approved, uint256 _tokenId) external payable;
+    function setApprovalForAll(address _operator, bool _approved) external;
+    function getApproved(uint256 _tokenId) external view returns (address);
+    function isApprovedForAll(address _owner, address _operator) external view returns (bool);
+    function supportsInterface(bytes4 interfaceID) external view returns (bool);
+  }
+
+
+- Expect output
+
+.. code:: bash
+
+  $ lityc --contract-standard ERC721 erc721_interface.sol
+
+
+
+
+- ERC721 Interface with wrong modification level (wrong_modification_level.sol)
+
+.. code:: solidity
+
+  pragma solidity ^0.4.23;
+
+  contract ERC721Interface {
+    event Transfer(address indexed _from, address indexed _to, uint256 _tokenId);
+    event Approval(address indexed _owner, address indexed _approved, uint256 _tokenId);
+    event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);
+    function balanceOf(address _owner) external view returns (uint256);
+    function ownerOf(uint256 _tokenId) external view returns (address);
+    function safeTransferFrom(address _from, address _to, uint256 _tokenId, bytes data) external payable;
+    function safeTransferFrom(address _from, address _to, uint256 _tokenId) external payable;
+    function transferFrom(address _from, address _to, uint256 _tokenId) external; // missing payable
+    function approve(address _approved, uint256 _tokenId) external payable;
+    function setApprovalForAll(address _operator, bool _approved) external;
+    function getApproved(uint256 _tokenId) external view returns (address);
+    function isApprovedForAll(address _owner, address _operator) external view returns (bool);
+    function supportsInterface(bytes4 interfaceID) external view returns (bool);
+  }
+
+
+- Expect output
+
+.. code:: bash
+
+  $ lityc --contract-standard ERC721 wrong_modification_level.sol
+
+  wrong_modification_level.sol:3:1: Info: Missing 'transferFrom' with type signature 'function (address,address,uint256) payable external'. ERC721Interface is not compatible to ERC721.
+  contract ERC721Interface {
+  ^ (Relevant source part starts here and spans across multiple lines).
+
+