lib/GR/Checkers/NSAutoreleasePoolChecker.cpp

   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 it's 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 "clang/GR/BugReporter/BugReporter.h"
  19 #include "clang/GR/PathSensitive/GRExprEngine.h"
  20 #include "clang/GR/PathSensitive/CheckerVisitor.h"
  21 #include "BasicObjCFoundationChecks.h"
  22 #include "clang/AST/DeclObjC.h"
  23 #include "clang/AST/Decl.h"
  24
  25 using namespace clang;
  26 using namespace GR;
  27
  28 namespace {
  29 class NSAutoreleasePoolChecker
  30   : public CheckerVisitor<NSAutoreleasePoolChecker> {
  31
  32   Selector releaseS;
  33
  34 public:
  35     NSAutoreleasePoolChecker(Selector release_s) : releaseS(release_s) {}
  36
  37   static void *getTag() {
  38     static int x = 0;
  39     return &x;
  40   }
  41
  42   void PreVisitObjCMessageExpr(CheckerContext &C, const ObjCMessageExpr *ME);
  43 };
  44
  45 } // end anonymous namespace
  46
  47
  48 void GR::RegisterNSAutoreleasePoolChecks(GRExprEngine &Eng) {
  49   ASTContext &Ctx = Eng.getContext();
  50   if (Ctx.getLangOptions().getGCMode() != LangOptions::NonGC) {
  51     Eng.registerCheck(new NSAutoreleasePoolChecker(GetNullarySelector("release",
  52                                                                       Ctx)));
  53   }
  54 }
  55
  56 void
  57 NSAutoreleasePoolChecker::PreVisitObjCMessageExpr(CheckerContext &C,
  58                                                   const ObjCMessageExpr *ME) {
  59
  60   const Expr *receiver = ME->getInstanceReceiver();
  61   if (!receiver)
  62     return;
  63
  64   // FIXME: Enhance with value-tracking information instead of consulting
  65   // the type of the expression.
  66   const ObjCObjectPointerType* PT =
  67     receiver->getType()->getAs<ObjCObjectPointerType>();
  68
  69   if (!PT)
  70     return;
  71   const ObjCInterfaceDecl* OD = PT->getInterfaceDecl();
  72   if (!OD)
  73     return;
  74   if (!OD->getIdentifier()->getName().equals("NSAutoreleasePool"))
  75     return;
  76
  77   // Sending 'release' message?
  78   if (ME->getSelector() != releaseS)
  79     return;
  80
  81   SourceRange R = ME->getSourceRange();
  82
  83   C.getBugReporter().EmitBasicReport("Use -drain instead of -release",
  84     "API Upgrade (Apple)",
  85     "Use -drain instead of -release when using NSAutoreleasePool "
  86     "and garbage collection", ME->getLocStart(), &R, 1);
  87 }