1 //== ReturnUndefChecker.cpp -------------------------------------*- 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 // This file defines ReturnUndefChecker, which is a path-sensitive 11 // check which looks for undefined or garbage values being returned to the 12 // caller. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #include "ClangSACheckers.h" 17 #include "clang/StaticAnalyzer/Core/Checker.h" 18 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 19 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 20 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 21 22 using namespace clang; 23 using namespace ento; 24 25 namespace { 26 class ReturnUndefChecker : 27 public Checker< check::PreStmt<ReturnStmt> > { 28 mutable OwningPtr<BuiltinBug> BT; 29 public: 30 void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const; 31 }; 32 } 33 34 void ReturnUndefChecker::checkPreStmt(const ReturnStmt *RS, 35 CheckerContext &C) const { 36 37 const Expr *RetE = RS->getRetValue(); 38 if (!RetE) 39 return; 40 41 if (!C.getState()->getSVal(RetE, C.getLocationContext()).isUndef()) 42 return; 43 44 ExplodedNode *N = C.generateSink(); 45 46 if (!N) 47 return; 48 49 if (!BT) 50 BT.reset(new BuiltinBug("Garbage return value", 51 "Undefined or garbage value returned to caller")); 52 53 BugReport *report = 54 new BugReport(*BT, BT->getDescription(), N); 55 56 report->addRange(RetE->getSourceRange()); 57 report->addVisitor(bugreporter::getTrackNullOrUndefValueVisitor(N, RetE, 58 report)); 59 60 C.EmitReport(report); 61 } 62 63 void ento::registerReturnUndefChecker(CheckerManager &mgr) { 64 mgr.registerChecker<ReturnUndefChecker>(); 65 } 66
