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c++windowsvisual-studiodllvtable

How to use delay loading with a DLL that exports C++ classes

I have a DLL one.dll that uses a class TwoClass exported from two.dll via class __declspec(dllexport). I'd like one.dll to use /delayload for two.dll, but I get a link error:

LINK : fatal error LNK1194: cannot delay-load 'two.dll' due to import
of data symbol '"__declspec(dllimport) const TwoClass::`vftable'"
(__imp_??_7TwoClass@@6B@)'; link without /DELAYLOAD:two.dll

That's in a Release build; in a Debug build it works. (I don't know what the difference is between Release and Debug in terms of vtable exports, nor can I find any compiler switches or pragmas to control it.)

How can I use /delayload with a DLL that exports classes like this in a Release build?

Solution

  • Have a look here, seems that the person had exactly the same problem and found a workaround

    I managed to get the delay loading to work in release build by disabling the optimizations on the translation unit that was using SomeClass class - somehow it took away the dependency on exported vtable.