Creating a Win32-Based Thunk DLL

After you compile the thunk script to create the 32-bit side of the thunk, you must create the Win32-based thunk DLL. To implement the Win32-based thunk DLL, use the following steps:

To implement the Win32-based thunk DLL

1. Add the entry-point function to your 32-bit DLL's entry-point function (named DllMain by default). This function must call the following function created by the thunk compiler:

   BOOL WINAPI XXX_ThunkConnect32(LPSTR pszDll16, LPSTR pszDll32, 
       DWORD hInst, DWORD dwReason);

   Here is an example of a DLL entry-point function calling XXX_ThunkConnect32:

   BOOL WINAPI DllMain(DWORD hInst, DWORD dwReason, 
       DWORD dwReserved) 
   {
       if( !(XXX_ThunkConnect32( "DLL16.DLL",  // name of 16-bit DLL 
           "DLL32.DLL",                        // name of 32-bit DLL 
           hInst, dwReason)) ) 
       {
           return FALSE; 
       } 
       // Process dwReason. 
    
       Return TRUE;
   } 

2. Add the following export statement to your 32-bit DLL's .DEF file.

   EXPORTS
   XXX_ThunkData32

3. Export the function to which you are thunking.
4. Build the DLL. Be sure to link with the 32-bit .OBJ file created from the thunk script and THUNK32.LIB. The 32-bit .OBJ file contains the code for XXX_ThunkData32, which is a table of function calls that the thunk compiler uses to implement the thunks.