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
checkPreObjCMessage(const ObjCMethodCall & msg,CheckerContext & C) const43 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
registerNSAutoreleasePoolChecker(CheckerManager & mgr)79 void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) {
80 mgr.registerChecker<NSAutoreleasePoolChecker>();
81 }
82
shouldRegisterNSAutoreleasePoolChecker(const CheckerManager & mgr)83 bool ento::shouldRegisterNSAutoreleasePoolChecker(const CheckerManager &mgr) {
84 const LangOptions &LO = mgr.getLangOpts();
85 return LO.getGC() != LangOptions::NonGC;
86 }
87