Utilizing a 32-bit DLL in a 64-bit process via COM

Question

So some time ago I was investigating an issue that I knew would be coming up soon. We have a DLL that links to 32-bit versions of a certain library. There is no x64 version of this library available to us and we have no practical options in regards to replacing it.

When I performed this initial investigation I found an article or two describing a method by which a 64-bit process can utilize a 32-bit DLL (Windows) via a COM "server". Unfortunately I lost the links I had saved and I have now been searching for over an hour with no luck.

Is anyone here familiar with the process I am describing? I can't for the life of me remember which magical incantation I used to pull up the correct result in a search and, of course, it is now implementation time. Thanks in advance for any help you guys can offer, I will continue searching in the meantime.

Answer 1

This may not be enough, but it might get you started: Process Interoperability

On 64-bit Windows, an out-of-process 32-bit COM server can communicate with a 64-bit client, and an out-of-process 64-bit COM server can communicate with a 32-bit client. Therefore, if you have a 32-bit DLL that is not COM-aware, you can wrap it in an out-of-process COM server and use COM to marshal calls to and from a 64-bit process.

And Accessing 32-bit DLLs from 64-bit code

Migrating your 32-bit Windows application to a 64-bit machine can be problematic if you have 32-bit DLLs that you cannot re-write. Mike Becker shows you how you can access 32-bit DLLs from 64-bit code using built-in IPC mechanisms...