1 //===--- CloneChecker.cpp - Clone detection checker -------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 /// 10 /// \file 11 /// CloneChecker is a checker that reports clones in the current translation 12 /// unit. 13 /// 14 //===----------------------------------------------------------------------===// 15 16 #include "ClangSACheckers.h" 17 #include "clang/Analysis/CloneDetection.h" 18 #include "clang/Basic/Diagnostic.h" 19 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 20 #include "clang/StaticAnalyzer/Core/Checker.h" 21 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 22 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 23 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 24 25 using namespace clang; 26 using namespace ento; 27 28 namespace { 29 class CloneChecker 30 : public Checker<check::ASTCodeBody, check::EndOfTranslationUnit> { 31 mutable CloneDetector Detector; 32 mutable std::unique_ptr<BugType> BT_Exact, BT_Suspicious; 33 34 public: 35 void checkASTCodeBody(const Decl *D, AnalysisManager &Mgr, 36 BugReporter &BR) const; 37 38 void checkEndOfTranslationUnit(const TranslationUnitDecl *TU, 39 AnalysisManager &Mgr, BugReporter &BR) const; 40 41 /// \brief Reports all clones to the user. 42 void reportClones(BugReporter &BR, AnalysisManager &Mgr, 43 int MinComplexity) const; 44 45 /// \brief Reports only suspicious clones to the user along with informaton 46 /// that explain why they are suspicious. 47 void reportSuspiciousClones(BugReporter &BR, AnalysisManager &Mgr, 48 int MinComplexity) const; 49 }; 50 } // end anonymous namespace 51 52 void CloneChecker::checkASTCodeBody(const Decl *D, AnalysisManager &Mgr, 53 BugReporter &BR) const { 54 // Every statement that should be included in the search for clones needs to 55 // be passed to the CloneDetector. 56 Detector.analyzeCodeBody(D); 57 } 58 59 void CloneChecker::checkEndOfTranslationUnit(const TranslationUnitDecl *TU, 60 AnalysisManager &Mgr, 61 BugReporter &BR) const { 62 // At this point, every statement in the translation unit has been analyzed by 63 // the CloneDetector. The only thing left to do is to report the found clones. 64 65 int MinComplexity = Mgr.getAnalyzerOptions().getOptionAsInteger( 66 "MinimumCloneComplexity", 10, this); 67 assert(MinComplexity >= 0); 68 69 bool ReportSuspiciousClones = Mgr.getAnalyzerOptions().getBooleanOption( 70 "ReportSuspiciousClones", true, this); 71 72 bool ReportNormalClones = Mgr.getAnalyzerOptions().getBooleanOption( 73 "ReportNormalClones", true, this); 74 75 if (ReportSuspiciousClones) 76 reportSuspiciousClones(BR, Mgr, MinComplexity); 77 78 if (ReportNormalClones) 79 reportClones(BR, Mgr, MinComplexity); 80 } 81 82 static PathDiagnosticLocation makeLocation(const StmtSequence &S, 83 AnalysisManager &Mgr) { 84 ASTContext &ACtx = Mgr.getASTContext(); 85 return PathDiagnosticLocation::createBegin( 86 S.front(), ACtx.getSourceManager(), 87 Mgr.getAnalysisDeclContext(ACtx.getTranslationUnitDecl())); 88 } 89 90 void CloneChecker::reportClones(BugReporter &BR, AnalysisManager &Mgr, 91 int MinComplexity) const { 92 93 std::vector<CloneDetector::CloneGroup> CloneGroups; 94 Detector.findClones(CloneGroups, MinComplexity); 95 96 if (!BT_Exact) 97 BT_Exact.reset(new BugType(this, "Exact code clone", "Code clone")); 98 99 for (CloneDetector::CloneGroup &Group : CloneGroups) { 100 // We group the clones by printing the first as a warning and all others 101 // as a note. 102 auto R = llvm::make_unique<BugReport>( 103 *BT_Exact, "Duplicate code detected", 104 makeLocation(Group.Sequences.front(), Mgr)); 105 R->addRange(Group.Sequences.front().getSourceRange()); 106 107 for (unsigned i = 1; i < Group.Sequences.size(); ++i) 108 R->addNote("Similar code here", 109 makeLocation(Group.Sequences[i], Mgr), 110 Group.Sequences[i].getSourceRange()); 111 BR.emitReport(std::move(R)); 112 } 113 } 114 115 void CloneChecker::reportSuspiciousClones(BugReporter &BR, 116 AnalysisManager &Mgr, 117 int MinComplexity) const { 118 119 std::vector<CloneDetector::SuspiciousClonePair> Clones; 120 Detector.findSuspiciousClones(Clones, MinComplexity); 121 122 if (!BT_Suspicious) 123 BT_Suspicious.reset( 124 new BugType(this, "Suspicious code clone", "Code clone")); 125 126 ASTContext &ACtx = BR.getContext(); 127 SourceManager &SM = ACtx.getSourceManager(); 128 AnalysisDeclContext *ADC = 129 Mgr.getAnalysisDeclContext(ACtx.getTranslationUnitDecl()); 130 131 for (CloneDetector::SuspiciousClonePair &Pair : Clones) { 132 // FIXME: We are ignoring the suggestions currently, because they are 133 // only 50% accurate (even if the second suggestion is unavailable), 134 // which may confuse the user. 135 // Think how to perform more accurate suggestions? 136 137 auto R = llvm::make_unique<BugReport>( 138 *BT_Suspicious, 139 "Potential copy-paste error; did you really mean to use '" + 140 Pair.FirstCloneInfo.Variable->getNameAsString() + "' here?", 141 PathDiagnosticLocation::createBegin(Pair.FirstCloneInfo.Mention, SM, 142 ADC)); 143 R->addRange(Pair.FirstCloneInfo.Mention->getSourceRange()); 144 145 R->addNote("Similar code using '" + 146 Pair.SecondCloneInfo.Variable->getNameAsString() + "' here", 147 PathDiagnosticLocation::createBegin(Pair.SecondCloneInfo.Mention, 148 SM, ADC), 149 Pair.SecondCloneInfo.Mention->getSourceRange()); 150 151 BR.emitReport(std::move(R)); 152 } 153 } 154 155 //===----------------------------------------------------------------------===// 156 // Register CloneChecker 157 //===----------------------------------------------------------------------===// 158 159 void ento::registerCloneChecker(CheckerManager &Mgr) { 160 Mgr.registerChecker<CloneChecker>(); 161 } 162