Build two interdependent dll

Question

I have to interdependent dll here that i would like to build without having to build them twice (force build both of them and rebuild them again to allow linking).

Here is an exemple :

**DLL A**

void fooA()
{
  fooBB();
}
void fooAA()
{
  fooB();
}

**DLL B**

void fooB()
{
  fooA();
}

void fooBB()
{
}

Is there a way to build those two DLL without mayor refactoring?

Answer 1

You could use LoadLibary and GetProcAddr to find functions' addresses and then call foo-functions by its addresses.

The following code demonstates how to do it (you should add error checking in real DLLs):

**DLL A**

typedef void fooB(void);
typedef void fooBB(void);
fooB* fooB_ptr;
fooBB* fooBB_ptr;
HMODULE hDllB;

void init()
{
  hDllB = LoadLibrary(L"DllB.dll");
  fooB_ptr = reinterpret_cast<fooB*>(GetProcAddr( hDllB, L"fooB" ));
  fooBB_ptr = reinterpret_cast<fooBB*>(GetProcAddr( hDllB, L"fooBB" ));
}

void done()
{
  FreeLibrary( hDllB );
}

void fooA()
{
  fooBB_ptr();
}
void fooAA()
{
  fooB_ptr();
}

Same in DLL B.

Answer 2

Do you actually rebuild both DLLs each time you compile ?

If not, the import libraries should be created the first time - even if the link phase fails because of unresolved externals - and allow subsequent builds to link without error...

edit: we actually have that kind of dependencies in my shop. Our build is incremental indeed, and clean builds need some projects to be built several times in order to link succesfully.