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/BugReporter/BugReporter.h" 20 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 21 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerVisitor.h" 22 #include "clang/AST/DeclObjC.h" 23 #include "clang/AST/Decl.h" 24 25 using namespace clang; 26 using namespace ento; 27 28 namespace { 29 class NSAutoreleasePoolChecker 30 : public CheckerVisitor<NSAutoreleasePoolChecker> { 31 32 Selector releaseS; 33 34 public: 35 NSAutoreleasePoolChecker(Selector release_s) : releaseS(release_s) {} 36 37 static void *getTag() { 38 static int x = 0; 39 return &x; 40 } 41 42 void preVisitObjCMessage(CheckerContext &C, ObjCMessage msg); 43 }; 44 45 } // end anonymous namespace 46 47 48 void ento::registerNSAutoreleasePoolChecker(ExprEngine &Eng) { 49 ASTContext &Ctx = Eng.getContext(); 50 if (Ctx.getLangOptions().getGCMode() != LangOptions::NonGC) { 51 Eng.registerCheck(new NSAutoreleasePoolChecker(GetNullarySelector("release", 52 Ctx))); 53 } 54 } 55 56 void 57 NSAutoreleasePoolChecker::preVisitObjCMessage(CheckerContext &C, 58 ObjCMessage msg) { 59 60 const Expr *receiver = msg.getInstanceReceiver(); 61 if (!receiver) 62 return; 63 64 // FIXME: Enhance with value-tracking information instead of consulting 65 // the type of the expression. 66 const ObjCObjectPointerType* PT = 67 receiver->getType()->getAs<ObjCObjectPointerType>(); 68 69 if (!PT) 70 return; 71 const ObjCInterfaceDecl* OD = PT->getInterfaceDecl(); 72 if (!OD) 73 return; 74 if (!OD->getIdentifier()->getName().equals("NSAutoreleasePool")) 75 return; 76 77 // Sending 'release' message? 78 if (msg.getSelector() != releaseS) 79 return; 80 81 SourceRange R = msg.getSourceRange(); 82 83 C.getBugReporter().EmitBasicReport("Use -drain instead of -release", 84 "API Upgrade (Apple)", 85 "Use -drain instead of -release when using NSAutoreleasePool " 86 "and garbage collection", R.getBegin(), &R, 1); 87 } 88