1 //=- NSAutoreleasePoolChecker.cpp --------------------------------*- C++ -*-==// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines a NSAutoreleasePoolChecker, a small checker that warns 10 // about subpar uses of NSAutoreleasePool. Note that while the check itself 11 // (in its current form) could be written as a flow-insensitive check, in 12 // can be potentially enhanced in the future with flow-sensitive information. 13 // It is also a good example of the CheckerVisitor interface. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 18 #include "clang/AST/Decl.h" 19 #include "clang/AST/DeclObjC.h" 20 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 21 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 22 #include "clang/StaticAnalyzer/Core/Checker.h" 23 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 24 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 25 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 26 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 27 28 using namespace clang; 29 using namespace ento; 30 31 namespace { 32 class NSAutoreleasePoolChecker 33 : public Checker<check::PreObjCMessage> { 34 mutable std::unique_ptr<BugType> BT; 35 mutable Selector releaseS; 36 37 public: 38 void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const; 39 }; 40 41 } // end anonymous namespace 42 43 void NSAutoreleasePoolChecker::checkPreObjCMessage(const ObjCMethodCall &msg, 44 CheckerContext &C) const { 45 if (!msg.isInstanceMessage()) 46 return; 47 48 const ObjCInterfaceDecl *OD = msg.getReceiverInterface(); 49 if (!OD) 50 return; 51 if (!OD->getIdentifier()->isStr("NSAutoreleasePool")) 52 return; 53 54 if (releaseS.isNull()) 55 releaseS = GetNullarySelector("release", C.getASTContext()); 56 // Sending 'release' message? 57 if (msg.getSelector() != releaseS) 58 return; 59 60 if (!BT) 61 BT.reset(new BugType(this, "Use -drain instead of -release", 62 "API Upgrade (Apple)")); 63 64 ExplodedNode *N = C.generateNonFatalErrorNode(); 65 if (!N) { 66 assert(0); 67 return; 68 } 69 70 auto Report = std::make_unique<PathSensitiveBugReport>( 71 *BT, 72 "Use -drain instead of -release when using NSAutoreleasePool and " 73 "garbage collection", 74 N); 75 Report->addRange(msg.getSourceRange()); 76 C.emitReport(std::move(Report)); 77 } 78 79 void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) { 80 mgr.registerChecker<NSAutoreleasePoolChecker>(); 81 } 82 83 bool ento::shouldRegisterNSAutoreleasePoolChecker(const CheckerManager &mgr) { 84 const LangOptions &LO = mgr.getLangOpts(); 85 return LO.getGC() != LangOptions::NonGC; 86 } 87