1//=- NSAutoreleasePoolChecker.cpp --------------------------------*- C++ -*-==//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines a NSAutoreleasePoolChecker, a small checker that warns
11//  about subpar uses of NSAutoreleasePool.  Note that while the check itself
12//  (in its current form) could be written as a flow-insensitive check, in
13//  can be potentially enhanced in the future with flow-sensitive information.
14//  It is also a good example of the CheckerVisitor interface.
15//
16//===----------------------------------------------------------------------===//
17
18#include "ClangSACheckers.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/DeclObjC.h"
21#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
22#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
23#include "clang/StaticAnalyzer/Core/Checker.h"
24#include "clang/StaticAnalyzer/Core/CheckerManager.h"
25#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
26#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
27#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
28
29using namespace clang;
30using namespace ento;
31
32namespace {
33class NSAutoreleasePoolChecker
34  : public Checker<check::PreObjCMessage> {
35  mutable std::unique_ptr<BugType> BT;
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("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  if (!BT)
62    BT.reset(new BugType(this, "Use -drain instead of -release",
63                         "API Upgrade (Apple)"));
64
65  ExplodedNode *N = C.generateNonFatalErrorNode();
66  if (!N) {
67    assert(0);
68    return;
69  }
70
71  auto Report = llvm::make_unique<BugReport>(
72      *BT, "Use -drain instead of -release when using NSAutoreleasePool and "
73           "garbage collection", N);
74  Report->addRange(msg.getSourceRange());
75  C.emitReport(std::move(Report));
76}
77
78void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) {
79  if (mgr.getLangOpts().getGC() != LangOptions::NonGC)
80    mgr.registerChecker<NSAutoreleasePoolChecker>();
81}
82