FIX: MIDL Gives Warning MIDL2039 When Decimal Used as Parameter Type in IDL (232778)


The information in this article applies to:

  • Microsoft Visual C++, 32-bit Enterprise Edition 5.0
  • Microsoft Visual C++, 32-bit Enterprise Edition 6.0
  • Microsoft Visual C++, 32-bit Professional Edition 5.0
  • Microsoft Visual C++, 32-bit Professional Edition 6.0
  • Microsoft Visual C++, 32-bit Learning Edition 6.0
This article was previously published under Q232778

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 that this is a bug in the Microsoft products that are 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' ) ]
Modification Type:MajorLast Reviewed:12/2/2003
Keywords:kbBug kbCompiler kbfix kbNoUpdate KB232778
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