KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q232778: FIX: MIDL Gives Warning MIDL2039 When Decimal Parameter Is Used

Article: Q232778
Product(s): Microsoft C Compiler
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbCompiler kbCOMt kbVC500bug kbVC600bug kbNoUpdate
Last Modified: 11-FEB-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 
- Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 
- Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you compile an .idl file with decimal as the type of parameter for a
method, you get an MIDL2039 warning. But it is documented that the decimal is a
valid type for a parameter (for example, search the MSDN Library Index for
"oleautomation").

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.

MORE INFORMATION
================

Steps to Reproduce the Behavior
-------------------------------

1. Copy the following code into a new file and save it as an .idl file.

  import "oaidl.idl";
  import "ocidl.idl";
  [
  	object,
  	uuid(DE4C1D8D-C007-11D2-B978-00AA00C0018D),
  	dual,
  	helpstring("IFoo1 Interface"),
  	pointer_default(unique)
  ]
  interface IFoo1 : IDispatch
  {
  };

  [
  	uuid(DE4C1D80-C007-11D2-B978-00AA00C0018D),
  	version(1.0),
  	helpstring("huh 1.0 Type Library")
  ]
  library HUHLib
  {
  	importlib("stdole2.tlb");

  	[
  		uuid(DE4C1D8F-C007-11D2-B978-00AA00C0018D),
  		hidden,
  		helpstring("_IFoo1Events Interface")
  	]
  	dispinterface _IFoo1Events
  	{
  		properties:
  		methods:
  		[id(1), helpstring("method MIDL2039")] HRESULT MIDL2039([in] Decimal d);
  	};

  	[
  		uuid(DE4C1D8E-C007-11D2-B978-00AA00C0018D),
  		helpstring("Foo1 Class")
  	]
  	coclass Foo1 {

  		[default] interface IFoo1;
  		[default, source] dispinterface _IFoo1Events;
  	};
  };

2. Now compile it with Microsoft Interface Definition Language (MIDL) and see
  the warning:

  huh.idl(38) : warning MIDL2039 : interface does not conform to 
  [oleautomation] attribute :   [ Parameter 'd' of Procedure 'MIDL2039' ( 
  Dispinterface '_IFoo1Events' ) ]

Additional query words:

======================================================================
Keywords          : kbCompiler kbCOMt kbVC500bug kbVC600bug kbNoUpdate 
Technology        : kbVCsearch kbAudDeveloper kbVC500 kbVC600 kbVC32bitSearch kbVC500Search
Version           : :5.0,6.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.