NSAutoreleasePoolChecker.cpp revision c23482b5ded0c032a5959d54109d26f38d00edd2 
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/StaticAnalyzer/Core/Checker.h"
20#include "clang/StaticAnalyzer/Core/CheckerManager.h"
21#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
22#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
23#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
24#include "clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h"
25#include "clang/AST/DeclObjC.h"
26#include "clang/AST/Decl.h"
27
28using namespace clang;
29using namespace ento;
30
31namespace {
32class NSAutoreleasePoolChecker
33  : public Checker<check::PreObjCMessage> {
34
35  mutable Selector releaseS;
36
37public:
38  void checkPreObjCMessage(ObjCMessage msg, CheckerContext &C) const;
39};
40
41} // end anonymous namespace
42
43void NSAutoreleasePoolChecker::checkPreObjCMessage(ObjCMessage msg,
44                                                   CheckerContext &C) const {
45
46  const Expr *receiver = msg.getInstanceReceiver();
47  if (!receiver)
48    return;
49
50  // FIXME: Enhance with value-tracking information instead of consulting
51  // the type of the expression.
52  const ObjCObjectPointerType* PT =
53    receiver->getType()->getAs<ObjCObjectPointerType>();
54
55  if (!PT)
56    return;
57  const ObjCInterfaceDecl *OD = PT->getInterfaceDecl();
58  if (!OD)
59    return;
60  if (!OD->getIdentifier()->getName().equals("NSAutoreleasePool"))
61    return;
62
63  if (releaseS.isNull())
64    releaseS = GetNullarySelector("release", C.getASTContext());
65  // Sending 'release' message?
66  if (msg.getSelector() != releaseS)
67    return;
68
69  SourceRange R = msg.getSourceRange();
70  const LocationContext *LC = C.getPredecessor()->getLocationContext();
71  const SourceManager &SM = C.getSourceManager();
72  const Expr *E = msg.getMsgOrPropExpr();
73  PathDiagnosticLocation L = PathDiagnosticLocation::createBegin(E, SM, LC);
74  C.EmitBasicReport("Use -drain instead of -release",
75    "API Upgrade (Apple)",
76    "Use -drain instead of -release when using NSAutoreleasePool "
77    "and garbage collection", L, &R, 1);
78}
79
80void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) {
81  if (mgr.getLangOptions().getGC() != LangOptions::NonGC)
82    mgr.registerChecker<NSAutoreleasePoolChecker>();
83}
84