Question

Using VC2005, I have 3 projects to build:

• libA (contains a typelib, results in libA.dll): IDL has a line library libA { ...
• libB (contains a typelib importing libA, results in libB.dll): IDL has a line importlib( 'libA ' );
• libC (imports libB): one of the source files contains #import <libB.dll>

the #import <libB.dll> is handled by the compiler in the following way (according to documentation):

1. search directories of %PATH%
2. search directories of %LIB%
3. search the ‘additional include paths’ (/I compiler option)

When compiling libC, I can see that cl.exe clearly is able to find the libA.dll on the executable path (using Filemon.exe)

VC error C4772: #import of typelib with another dependency

However, still the libA namespace is not found and all references to libA types are replaced by __missing_type__

(edit) Meanwhile, I found out the problem only appears when using the debug dlls.

Anyone seen this problem before? And solved it?

Answer 1

Finally Found It!

In the Visual Studio project, the A.idl file in LibA had the MkTypeLib Compatible setting ON. This overruled the behaviour inherited from the A project. To make things worse, it was only ON in the Debug configuration.

The consequence was that for every

typedef [public] tagE enum { cE1, cE2 } eE; 

This resulted in the tagE not being defined in the resulting typelib. When LibB did it’s import( 'A.dll' ), all references to tagE were replaced with __missing_type__…