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  mutable std::unique_ptr<BugType> BT;
35  mutable Selector releaseS;
36
37public:
38  void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
39};
40
41} // end anonymous namespace
42
43void 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
79void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) {
80  mgr.registerChecker<NSAutoreleasePoolChecker>();
81}
82
83bool ento::shouldRegisterNSAutoreleasePoolChecker(const CheckerManager &mgr) {
84  const LangOptions &LO = mgr.getLangOpts();
85  return LO.getGC() != LangOptions::NonGC;
86}
87