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Tools/SmartCheck/Solidity/Rules/SOLIDITY_SAFEMATH.md

+# Analysis of Smart Contract Security Vulnerabilities and Tools ![](https://img.shields.io/badge/-Live-brightgreen)
+![](https://img.shields.io/badge/Batch-UG21CYS-lightgreen) ![](https://img.shields.io/badge/Batch-PG21CYS-green) ![](https://img.shields.io/badge/Batch-UG22CYS-lightgreen) ![](https://img.shields.io/badge/Batch-PG21CYS-green) ![](https://img.shields.io/badge/Batch-PhD-darkgreen) ![](https://img.shields.io/badge/-B_RIG-darkgreen)<br/>   ![](https://img.shields.io/badge/BlockchainCourse-21CY712-green)  ![](https://img.shields.io/badge/-M.Tech_Dissertation-blue) ![](https://img.shields.io/badge/Focus-Smart_Contract_Security-yellow) <br/>
+![](https://img.shields.io/badge/Blockchain-Ethereum-blue)   <br/> 
+![](https://img.shields.io/badge/Language-Solidity-blue)
+
+## SOLIDITY_SAFEMATH
+### Rule Description
+<p>
+    <code>SafeMath</code> library is used.
+</p>
+
+### Solidity-Rules
+
+![](https://img.shields.io/badge/Pattern_ID-837cac-gold) ![](https://img.shields.io/badge/Severity-1-brown) 
+
+```
+usingForDeclaration[identifier[matches(text()[1], "^SafeMath$", "i")]]
+```
+
+### Sample Code
+
+```
+pragma solidity 0.4.24;
+
+library SafeMath {
+  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
+    assert(b <= a);
+    return a - b;
+  }
+}
+
+contract MyToken {
+    // <yes> <report> SOLIDITY_SAFEMATH 837cac
+    using SafeMath for uint256;
+
+    function sub(uint a, uint b) public returns(uint) {
+        return(a.sub(b));
+    }
+}
+```
+
+### Abstract Syntax Tree 
+
+[Click Here](https://astexplorer.net/#/gist/6d119342ef1d67adbea057d4787442cd/3e3ec2fdbe24bb0b1ae2d58e1a9a3b7465dd0f69) to view the AST for the above code. Code generated from AST Explorer using _solidity-parser-antlr-0.4.11_
+
+
+### Code Result
+
+```
+SOLIDITY_SAFEMATH
+patternId: 837cac
+severity: 1
+line: 12
+column: 4
+content: usingSafeMathforuint256;
+
+SOLIDITY_SAFEMATH :1
+
+
+```