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
28using namespace clang;
29using namespace ento;
30
31namespace {
32class 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
38public:
39 void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
40};
41
42} // end anonymous namespace
43
44void 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(Str: "NSAutoreleasePool"))
53 return;
54
55 if (releaseS.isNull())
56 releaseS = GetNullarySelector(name: "release", Ctx&: 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 args: BT,
69 args: "Use -drain instead of -release when using NSAutoreleasePool and "
70 "garbage collection",
71 args&: N);
72 Report->addRange(R: msg.getSourceRange());
73 C.emitReport(R: std::move(Report));
74}
75
76void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) {
77 mgr.registerChecker<NSAutoreleasePoolChecker>();
78}
79
80bool ento::shouldRegisterNSAutoreleasePoolChecker(const CheckerManager &mgr) {
81 const LangOptions &LO = mgr.getLangOpts();
82 return LO.getGC() != LangOptions::NonGC;
83}
84