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 const BugType BT{this, "Use -drain instead of -release", 35 "API Upgrade (Apple)"}; 36 mutable Selector releaseS; 37 38 public: 39 void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const; 40 }; 41 42 } // end anonymous namespace 43 44 void NSAutoreleasePoolChecker::checkPreObjCMessage(const ObjCMethodCall &msg, 45 CheckerContext &C) const { 46 if (!msg.isInstanceMessage()) 47 return; 48 49 const ObjCInterfaceDecl *OD = msg.getReceiverInterface(); 50 if (!OD) 51 return; 52 if (!OD->getIdentifier()->isStr("NSAutoreleasePool")) 53 return; 54 55 if (releaseS.isNull()) 56 releaseS = GetNullarySelector("release", C.getASTContext()); 57 // Sending 'release' message? 58 if (msg.getSelector() != releaseS) 59 return; 60 61 ExplodedNode *N = C.generateNonFatalErrorNode(); 62 if (!N) { 63 assert(0); 64 return; 65 } 66 67 auto Report = std::make_unique<PathSensitiveBugReport>( 68 BT, 69 "Use -drain instead of -release when using NSAutoreleasePool and " 70 "garbage collection", 71 N); 72 Report->addRange(msg.getSourceRange()); 73 C.emitReport(std::move(Report)); 74 } 75 76 void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) { 77 mgr.registerChecker<NSAutoreleasePoolChecker>(); 78 } 79 80 bool ento::shouldRegisterNSAutoreleasePoolChecker(const CheckerManager &mgr) { 81 const LangOptions &LO = mgr.getLangOpts(); 82 return LO.getGC() != LangOptions::NonGC; 83 } 84