Dll - Export Function - EntryPointNotFoundException

  • Thread starter Thread starter Jeffrey Walton
  • Start date Start date
J

Jeffrey Walton

Hi All,

Sorry about dropping thish on M.P.D.L.CSharp. There is no M.P.D.L.VC.
So I hope someone has come across the issue...

How does one export a function (not a class) in a managed Dll?

I'm catching a System.EntryPointNotFoundException. dumpbin confirms
that the Dll is not exporting the function.

Does not work:
* declaring method as public: error C2059: syntax error : 'public'
* __declspec( dllexport ): incompatible with /clr and /clr:pur
* .def file: fatal link error LNK1310: Exports not supported for pure
MSIL image

Thanks,
Jeff

////////////////////////
// Test Header
bool Test( array<byte>^ );

////////////////////////
// Test Implementation
bool Test( array<byte>^ a ) {...}
 
Hi All,

Sorry about dropping thish on M.P.D.L.CSharp. There is no M.P.D.L.VC.
So I hope someone has come across the issue...

How does one export a function (not a class) in a managed Dll?
Click to expand...

You cannot do it AFAIK
A managed dll export only types.
You can create a wrap and then you get a CCW (COM Callable Wrapper).
but even that is a COM DLL, not a win32 one.
The only solution I see is for you to create your .NET dll, export it
as CCW and then create a native dll that instantiate the COM and allow
a call to the method you need as a function
 
Hi Ignacio,
You cannot do it AFAIK
Click to expand...
Is that a 'you cannot' because Microsoft tools don't do it?

I asked Pavel the same. The reason I ask is that I have an
experimental linker. While developing it, I picked up a lot of PE
format knowledge. So it may be a question of finding the right tool
for the job. Naively, I'm going to say that adding a Export directory
to the PE and a thunk in the .text section is quite doable.

Jeff
 
Hi Ignacio,


Is that a 'you cannot' because Microsoft tools don't do it?

I asked Pavel the same. The reason I ask is that I have an
experimental linker. While developing it, I picked up a lot of PE
format knowledge. So it may be a question of finding the right tool
for the job. Naively, I'm going to say that adding a Export directory
to the PE and a thunk in the .text section is quite doable.
Click to expand...

You can probably do it, but that wouldn't be a pure managed assembly
anymore (similarly to what C++/CLR produces). At any rate, it wouldn't
be any different from just having a separate unmanaged assembly
redirecting calls to a managed one.
 
Hi Pavel,

{SNIP]
The reason I ask is that I have an
experimental linker. While developing it, I picked up a lot of PE
format knowledge. So it may be a question of finding the right tool
for the job. Naively, I'm going to say that adding a Export directory
to the PE and a thunk in the .text section is quite doable.
Click to expand...

You can probably do it, but that wouldn't be a pure managed assembly
anymore (similarly to what C++/CLR produces). At any rate, it wouldn't
be any different from just having a separate unmanaged assembly
redirecting calls to a managed one.
Click to expand...
I think in the end that though possible, I believe it will create more
problems then it solves. My need was to keep a consistent interface
(from an unmanaged Dll) when wrapping an AES crpyo engine. When I ran
the managed AES benchmarks, AesCryptoServiceProvider performed like a
turd.

Jeff
 
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