C++ ObjCMessage::getNumArgs方法代码示例

void VariadicMethodTypeChecker::checkPreObjCMessage(ObjCMessage msg,
                                                    CheckerContext &C) const {
  if (!BT) {
    BT.reset(new APIMisuse("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.
  llvm::Optional<ExplodedNode*> errorNode;
  ProgramStateRef state = C.getState();
  
  for (unsigned I = variadicArgsBegin; I != variadicArgsEnd; ++I) {
    QualType ArgTy = msg.getArgType(I);
    if (ArgTy->isObjCObjectPointerType())
      continue;

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

    // Ignore pointer constants.
    if (isa<loc::ConcreteInt>(msg.getArgSVal(I, C.getLocationContext(),
                                             state)))
      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.addTransition();
    }

    if (!errorNode.getValue())
      continue;

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

    if (const char *TypeName = GetReceiverNameType(msg))
      os << "Argument to '" << TypeName << "' method '";
    else
      os << "Argument to method '";

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

    BugReport *R = new BugReport(*BT, os.str(),
                                             errorNode.getValue());
    R->addRange(msg.getArgSourceRange(I));
    C.EmitReport(R);
  }
}