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I have a very simple DLL written in unmanaged C++ that I access from my application. I recently switch to Visual Studio 2010, and the DLL went from 55k down to 35k with no code changes, and now it will no longer load in Windows 2000. I didn't change any code or compiler settings. I have my defines setup for 0x0500, which should include Windows 2000 support. Has anyone else run into this, or have any ideas of what I can do?

Jon Tackabury
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  • possible duplicate of [Can I use Visual Studio 2010's C++ compiler with Visual Studio 2008's C++ Runtime Library?](http://stackoverflow.com/questions/2484511/can-i-use-visual-studio-2010s-c-compiler-with-visual-studio-2008s-c-runtime) – Suma Aug 17 '10 at 12:08

2 Answers2

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Visual Studio 2010 cannot build binaries that run on Windows 2000. It's actually even worse than that, they won't run on Windows XP RTM or Windows XP Service Pack 1 either. This is because VS2010's C runtime library requires the EncodePointer API which is not available until SP2.

It appears you're stuck building with installing VS2008 if you want to support earlier versions of Windows. You can either move your entire project to Visual Studio 2008 or you can target the vc90 (Visual Studio 2008) toolset from within your Visual Studio 2010 projects. For more details on the latter method, see this anwser to my related question here.

Community
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Billy ONeal
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  • Thanks for the link, that is some unfortunate news. :( – Jon Tackabury Apr 19 '10 at 00:59
  • @Jon Tackabury: I know -- I really really would like to use `auto` :( – Billy ONeal Apr 19 '10 at 01:01
  • I just don't want to have VS 2008 and 2010 both installed. :( – Jon Tackabury Apr 19 '10 at 01:11
  • @Paul: True, it just seems a waste to have both installed just to build 1 DLL. – Jon Tackabury Apr 19 '10 at 02:52
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    @Jon: you don't need the entire VS2008 IDE. If you have the compiler, linker, headers and libs, you can target the VS2008 C++ toolchain from within VS2010. see http://blogs.msdn.com/vcblog/archive/2009/12/08/c-native-multi-targeting.aspx and http://blogs.msdn.com/vcblog/archive/2010/03/02/visual-studio-2010-c-project-upgrade-guide.aspx – sean e Apr 19 '10 at 02:57
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The solution is probably to provide EncodePointer (and DecodePointer, obviously) in a seperate lib, and link that preferentially to KERNEL32.LIB. This is a perfectly supported scenario. In the past, libs like "LIBCTINY" and "UNICOWS" have used this preferential link mechanism to add/replace selected but not all functions from another lib.

MSalters
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  • Exactly. Unfortunatelly I did not see your answer before writing my own in the linked topic, otherwise I would not spent that much time experimenting with it. Still, as my answer contains ready to use and tested code, I hope it may be of some use - see http://stackoverflow.com/questions/2484511/can-i-use-visual-studio-2010s-c-compiler-with-visual-studio-2008s-c-runtime/3502056#3502056 – Suma Aug 17 '10 at 12:07
  • One important implementation note: you do not provide the EncodePointer / DecodePointer (the functions from DLL) directly. You need to replace their import vectors, which is what is resolved when liking to .lib. They are called like _imp__FunctionName. – Suma Aug 17 '10 at 19:39