C++ ObjCMethodCall::getNumArgs方法代码示例

/// Returns the released value if M is a call a setter that releases
/// and nils out its underlying instance variable.
SymbolRef
ObjCDeallocChecker::getValueReleasedByNillingOut(const ObjCMethodCall &M,
                                                 CheckerContext &C) const {
  SVal ReceiverVal = M.getReceiverSVal();
  if (!ReceiverVal.isValid())
    return nullptr;

  if (M.getNumArgs() == 0)
    return nullptr;

  if (!M.getArgExpr(0)->getType()->isObjCRetainableType())
    return nullptr;

  // Is the first argument nil?
  SVal Arg = M.getArgSVal(0);
  ProgramStateRef notNilState, nilState;
  std::tie(notNilState, nilState) =
      M.getState()->assume(Arg.castAs<DefinedOrUnknownSVal>());
  if (!(nilState && !notNilState))
    return nullptr;

  const ObjCPropertyDecl *Prop = M.getAccessedProperty();
  if (!Prop)
    return nullptr;

  ObjCIvarDecl *PropIvarDecl = Prop->getPropertyIvarDecl();
  if (!PropIvarDecl)
    return nullptr;

  ProgramStateRef State = C.getState();

  SVal LVal = State->getLValue(PropIvarDecl, ReceiverVal);
  Optional<Loc> LValLoc = LVal.getAs<Loc>();
  if (!LValLoc)
    return nullptr;

  SVal CurrentValInIvar = State->getSVal(LValLoc.getValue());
  return CurrentValInIvar.getAsSymbol();
}

void VariadicMethodTypeChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
                                                    CheckerContext &C) const {
  if (!BT) {
    BT.reset(new APIMisuse(this,
                           "Arguments passed to variadic method aren't all "
                           "Objective-C pointer types"));

    ASTContext &Ctx = C.getASTContext();
    arrayWithObjectsS = GetUnarySelector("arrayWithObjects", Ctx);
    dictionaryWithObjectsAndKeysS =
      GetUnarySelector("dictionaryWithObjectsAndKeys", Ctx);
    setWithObjectsS = GetUnarySelector("setWithObjects", Ctx);
    orderedSetWithObjectsS = GetUnarySelector("orderedSetWithObjects", Ctx);

    initWithObjectsS = GetUnarySelector("initWithObjects", Ctx);
    initWithObjectsAndKeysS = GetUnarySelector("initWithObjectsAndKeys", Ctx);
  }

  if (!isVariadicMessage(msg))
      return;

  // We are not interested in the selector arguments since they have
  // well-defined types, so the compiler will issue a warning for them.
  unsigned variadicArgsBegin = msg.getSelector().getNumArgs();

  // We're not interested in the last argument since it has to be nil or the
  // compiler would have issued a warning for it elsewhere.
  unsigned variadicArgsEnd = msg.getNumArgs() - 1;

  if (variadicArgsEnd <= variadicArgsBegin)
    return;

  // Verify that all arguments have Objective-C types.
  Optional<ExplodedNode*> errorNode;

  for (unsigned I = variadicArgsBegin; I != variadicArgsEnd; ++I) {
    QualType ArgTy = msg.getArgExpr(I)->getType();
    if (ArgTy->isObjCObjectPointerType())
      continue;

    // Block pointers are treaded as Objective-C pointers.
    if (ArgTy->isBlockPointerType())
      continue;

    // Ignore pointer constants.
    if (msg.getArgSVal(I).getAs<loc::ConcreteInt>())
      continue;

    // Ignore pointer types annotated with 'NSObject' attribute.
    if (C.getASTContext().isObjCNSObjectType(ArgTy))
      continue;

    // Ignore CF references, which can be toll-free bridged.
    if (coreFoundation::isCFObjectRef(ArgTy))
      continue;

    // Generate only one error node to use for all bug reports.
    if (!errorNode.hasValue())
      errorNode = C.generateNonFatalErrorNode();

    if (!errorNode.getValue())
      continue;

    SmallString<128> sbuf;
    llvm::raw_svector_ostream os(sbuf);

    StringRef TypeName = GetReceiverInterfaceName(msg);
    if (!TypeName.empty())
      os << "Argument to '" << TypeName << "' method '";
    else
      os << "Argument to method '";

    msg.getSelector().print(os);
    os << "' should be an Objective-C pointer type, not '";
    ArgTy.print(os, C.getLangOpts());
    os << "'";

    auto R = llvm::make_unique<BugReport>(*BT, os.str(), errorNode.getValue());
    R->addRange(msg.getArgSourceRange(I));
    C.emitReport(std::move(R));
  }
}