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d56f5882 · POTHURI HARIKA · 1d3e456c · d56f5882
Commit d56f5882 authored 1 year ago by POTHURI HARIKA
--- a/Tools/SmartCheck/Solidity/Rules/SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN.md
+++ b/Tools/SmartCheck/Solidity/Rules/SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN.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_FUNCTION_RETURNS_TYPE_AND_NO_RETURN
+### Rule Description
+<p>Function doesn't initialize return value. As result default value will be returned.</p>
+
+### Solidity-Rules
+
+![](https://img.shields.io/badge/Pattern_ID-47acc2-gold) ![](https://img.shields.io/badge/Severity-1-brown) 
+
+```
+//functionDefinition
+                    [block]
+                    [returnsParameters/parameterList/parameter[not(identifier)]]
+                    [
+                        not(block/statement//returnStatement)
+                        and not(block//assemblyCall[matches(text()[1], "^return\(")])
+                    ]
+```
+
+![](https://img.shields.io/badge/Pattern_ID-58bdd3-gold) ![](https://img.shields.io/badge/Severity-1-brown) 
+
+```
+//functionDefinition
+                    [block]
+                    [
+                        not(block/statement//returnStatement)
+                        and not(block//assemblyCall[matches(text()[1], "^return\(")])
+                    ]
+                    [returnsParameters/parameterList/parameter/identifier
+                        [
+                            not(text()[1]
+                                = (ancestor::functionDefinition/block//expression
+                                    [matches(text()[1], "=")]/expression[1]//identifier/text()[1]))
+                            and not(text()[1]
+                                = ancestor::functionDefinition/block
+                                    //assemblyAssignment/assemblyIdentifierOrList//identifier/text()[1])
+                        ]
+                    ]
+```
+
+
+
+### Sample Code
+
+```
+pragma solidity 0.4.24;
+
+contract C {
+    // <yes> <report> SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN 47acc2
+    function remainBalanced1() public constant returns (uint256){
+        uint a =1000;
+    }
+
+    function assemblyTest1() public constant returns (uint256){
+        assembly {
+            mstore(0, 100)
+            return(0, 32)
+        }
+    }
+    // <yes> <report> SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN 47acc2
+    function remainBalanced2() public constant returns (uint a, uint256){
+        a =1000;
+    }
+    // <yes> <report> SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN 58bdd3
+    function execute(address _to, uint _value, bytes _data) returns (uint256 _r) {
+        if (_to == address(0)) {
+            revert();
+        }
+    }
+    function assemblyTest2(address _to, uint _value, bytes _data) returns (uint256 _r) {
+        assembly {
+            _r := 100
+        }
+    }
+    // <yes> <report> SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN 58bdd3
+    function execute1(address _to, uint _value, bytes _data) returns (uint256 _r) {
+        _value = _r;
+    }
+    // <yes> <report> SOLIDITY_FUNCTION_RETURNS_TYPE_AND_NO_RETURN 58bdd3
+    function execute2(address _to, uint _value, bytes _data) returns (bool flag, uint256 _r) {
+        flag = true;
+        _value = balanceOf(address(_r));
+    }
+
+    function balanceOf(address who)public view returns (uint256);
+
+    function remainBalanced() public constant returns (uint256){
+        return balanceOf(this);
+    }
+
+    function balance(address who)public view returns (uint256 _r);
+
+    function execute3(address _to, uint _value, bytes _data) returns (uint256 _r) {
+        _r = balanceOf(_to);
+    }
+
+    function execute4(address _to, uint _value, bytes _data) returns (uint256 _r) {
+        return balanceOf(_to);
+    }
+}
+```
+
+### Abstract Syntax Tree 
+
+[Click Here](https://astexplorer.net/#/gist/97b0733c802223834cf2ca2603d94139/cf6c626549d7281ee5f6b00a8b2a8ddd23ee8644) to view the AST for the above code. Code generated from AST Explorer using _solidity-parser-antlr-0.4.11_
+
+### Code Result
+```
+SOLIDITY_DEPRECATED_CONSTRUCTIONS
+patternId: 28fa69
+severity: 1
+line: 5
+column: 4
+content: functionremainBalanced1()publicconstantreturns(uint256){uinta=1000;}
+
+ruleId: SOLIDITY_DEPRECATED_CONSTRUCTIONS
+patternId: 28fa69
+severity: 1
+line: 9
+column: 4
+content: functionassemblyTest1()publicconstantreturns(uint256){assembly{mstore(0,100)return(0,32)}}
+
+ruleId: SOLIDITY_DEPRECATED_CONSTRUCTIONS
+patternId: 28fa69
+severity: 1
+line: 16
+column: 4
+content: functionremainBalanced2()publicconstantreturns(uinta,uint256){a=1000;}
+
+ruleId: SOLIDITY_DEPRECATED_CONSTRUCTIONS
+patternId: 28fa69
+severity: 1
+line: 42
+column: 4
+content: functionremainBalanced()publicconstantreturns(uint256){returnbalanceOf(this);}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 47acc2
+severity: 1
+line: 5
+column: 4
+content: functionremainBalanced1()publicconstantreturns(uint256){uinta=1000;}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 47acc2
+severity: 1
+line: 9
+column: 4
+content: functionassemblyTest1()publicconstantreturns(uint256){assembly{mstore(0,100)return(0,32)}}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 47acc2
+severity: 1
+line: 16
+column: 4
+content: functionremainBalanced2()publicconstantreturns(uinta,uint256){a=1000;}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 58bdd3
+severity: 1
+line: 20
+column: 4
+content: functionexecute(address_to,uint_value,bytes_data)returns(uint256_r){if(_to==address(0)){revert();}}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 58bdd3
+severity: 1
+line: 25
+column: 4
+content: functionassemblyTest2(address_to,uint_value,bytes_data)returns(uint256_r){assembly{_r:=100}}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 58bdd3
+severity: 1
+line: 31
+column: 4
+content: functionexecute1(address_to,uint_value,bytes_data)returns(uint256_r){_value=_r;}
+
+ruleId: SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN
+patternId: 58bdd3
+severity: 1
+line: 35
+column: 4
+content: functionexecute2(address_to,uint_value,bytes_data)returns(boolflag,uint256_r){flag=true;_value=balanceOf(address(_r));}
+
+ruleId: SOLIDITY_REVERT_REQUIRE
+patternId: c56b12
+severity: 1
+line: 21
+column: 8
+content: if(_to==address(0)){revert();}
+
+ruleId: SOLIDITY_USING_INLINE_ASSEMBLY
+patternId: 109cd5
+severity: 1
+line: 10
+column: 8
+content: assembly{mstore(0,100)return(0,32)}
+
+ruleId: SOLIDITY_USING_INLINE_ASSEMBLY
+patternId: 109cd5
+severity: 1
+line: 26
+column: 8
+content: assembly{_r:=100}
+
+ruleId: SOLIDITY_VISIBILITY
+patternId: 910067
+severity: 1
+line: 20
+column: 4
+content: functionexecute(address_to,uint_value,bytes_data)returns(uint256_r){if(_to==address(0)){revert();}}
+
+ruleId: SOLIDITY_VISIBILITY
+patternId: 910067
+severity: 1
+line: 25
+column: 4
+content: functionassemblyTest2(address_to,uint_value,bytes_data)returns(uint256_r){assembly{_r:=100}}
+
+ruleId: SOLIDITY_VISIBILITY
+patternId: 910067
+severity: 1
+line: 31
+column: 4
+content: functionexecute1(address_to,uint_value,bytes_data)returns(uint256_r){_value=_r;}
+
+ruleId: SOLIDITY_VISIBILITY
+patternId: 910067
+severity: 1
+line: 35
+column: 4
+content: functionexecute2(address_to,uint_value,bytes_data)returns(boolflag,uint256_r){flag=true;_value=balanceOf(address(_r));}
+
+ruleId: SOLIDITY_VISIBILITY
+patternId: 910067
+severity: 1
+line: 48
+column: 4
+content: functionexecute3(address_to,uint_value,bytes_data)returns(uint256_r){_r=balanceOf(_to);}
+
+ruleId: SOLIDITY_VISIBILITY
+patternId: 910067
+severity: 1
+line: 52
+column: 4
+content: functionexecute4(address_to,uint_value,bytes_data)returns(uint256_r){returnbalanceOf(_to);}
+
+SOLIDITY_VISIBILITY :6
+SOLIDITY_DEPRECATED_CONSTRUCTIONS :4
+SOLIDITY_REVERT_REQUIRE :1
+SOLIDITY_FUNCTIONS_RETURNS_TYPE_AND_NO_RETURN :7
+SOLIDITY_USING_INLINE_ASSEMBLY :2
+
+```