1 // Copyright Brian Schott (Hackerpilot) 2014. 2 // Distributed under the Boost Software License, Version 1.0. 3 // (See accompanying file LICENSE_1_0.txt or copy at 4 // http://www.boost.org/LICENSE_1_0.txt) 5 6 module analysis.logic_precedence; 7 8 import std.stdio; 9 import dparse.ast; 10 import dparse.lexer; 11 import analysis.base; 12 import analysis.helpers; 13 import dsymbol.scope_; 14 15 /** 16 * Checks for code with confusing && and || operator precedence 17 * --- 18 * if (a && b || c) // bad 19 * if (a && (b || c)) // good 20 * --- 21 */ 22 class LogicPrecedenceCheck : BaseAnalyzer 23 { 24 alias visit = BaseAnalyzer.visit; 25 26 enum string KEY = "dscanner.confusing.logical_precedence"; 27 28 this(string fileName, const(Scope)* sc) 29 { 30 super(fileName, sc); 31 } 32 33 override void visit(const OrOrExpression orOr) 34 { 35 if (orOr.left is null || orOr.right is null) return; 36 const AndAndExpression left = cast(AndAndExpression) orOr.left; 37 const AndAndExpression right = cast(AndAndExpression) orOr.right; 38 if (left is null && right is null) return; 39 if ((left !is null && left.right is null) && (right !is null && right.right is null)) return; 40 addErrorMessage(orOr.line, orOr.column, KEY, 41 "Use parenthesis to clarify this expression."); 42 orOr.accept(this); 43 } 44 } 45 46 unittest 47 { 48 import analysis.config : StaticAnalysisConfig; 49 50 StaticAnalysisConfig sac; 51 sac.logical_precedence_check = true; 52 assertAnalyzerWarnings(q{ 53 void testFish() 54 { 55 if (a && b || c) {} // [warn]: Use parenthesis to clarify this expression. 56 if ((a && b) || c) {} // Good 57 if (b || c && d) {} // [warn]: Use parenthesis to clarify this expression. 58 if (b || (c && d)) {} // Good 59 } 60 }}, sac); 61 stderr.writeln("Unittest for LogicPrecedenceCheck passed."); 62 } 63