1 //=- NSAutoreleasePoolChecker.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 a NSAutoreleasePoolChecker, a small checker that warns 11 // about subpar uses of NSAutoreleasePool. Note that while the check itself 12 // (in it's current form) could be written as a flow-insensitive check, in 13 // can be potentially enhanced in the future with flow-sensitive information. 14 // It is also a good example of the CheckerVisitor interface. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #include "ClangSACheckers.h" 19 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 20 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 21 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 22 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerVisitor.h" 23 #include "clang/AST/DeclObjC.h" 24 #include "clang/AST/Decl.h" 25 26 using namespace clang; 27 using namespace ento; 28 29 namespace { 30 class NSAutoreleasePoolChecker 31 : public CheckerVisitor<NSAutoreleasePoolChecker> { 32 33 Selector releaseS; 34 35 public: 36 NSAutoreleasePoolChecker(Selector release_s) : releaseS(release_s) {} 37 38 static void *getTag() { 39 static int x = 0; 40 return &x; 41 } 42 43 void preVisitObjCMessage(CheckerContext &C, ObjCMessage msg); 44 }; 45 46 } // end anonymous namespace 47 48 49 static void RegisterNSAutoreleasePoolChecker(ExprEngine &Eng) { 50 ASTContext &Ctx = Eng.getContext(); 51 if (Ctx.getLangOptions().getGCMode() != LangOptions::NonGC) { 52 Eng.registerCheck(new NSAutoreleasePoolChecker(GetNullarySelector("release", 53 Ctx))); 54 } 55 } 56 57 void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) { 58 mgr.addCheckerRegisterFunction(RegisterNSAutoreleasePoolChecker); 59 } 60 61 void 62 NSAutoreleasePoolChecker::preVisitObjCMessage(CheckerContext &C, 63 ObjCMessage msg) { 64 65 const Expr *receiver = msg.getInstanceReceiver(); 66 if (!receiver) 67 return; 68 69 // FIXME: Enhance with value-tracking information instead of consulting 70 // the type of the expression. 71 const ObjCObjectPointerType* PT = 72 receiver->getType()->getAs<ObjCObjectPointerType>(); 73 74 if (!PT) 75 return; 76 const ObjCInterfaceDecl* OD = PT->getInterfaceDecl(); 77 if (!OD) 78 return; 79 if (!OD->getIdentifier()->getName().equals("NSAutoreleasePool")) 80 return; 81 82 // Sending 'release' message? 83 if (msg.getSelector() != releaseS) 84 return; 85 86 SourceRange R = msg.getSourceRange(); 87 88 C.getBugReporter().EmitBasicReport("Use -drain instead of -release", 89 "API Upgrade (Apple)", 90 "Use -drain instead of -release when using NSAutoreleasePool " 91 "and garbage collection", R.getBegin(), &R, 1); 92 } 93