Compiler Warning (level 1) C4747

Calling managed 'entrypoint': Managed code may not be run under loader lock, including the DLL entrypoint and calls reached from the DLL entrypoint

The compiler found a (probable) DLL entry point compiled to MSIL. Because of potential problems with loading a DLL whose entry point has been compiled to MSIL, you are strongly discouraged from compiling a DLL entry point function to MSIL.

For more information, see Initialization of Mixed Assemblies and Linker Tools Error LNK1306.

To correct this error

  1. Do not compile the module with /clr.

  2. Mark the entry point function with #pragma unmanaged.

The following sample generates C4747.

// C4747.cpp
// compile with: /clr /c /W1
// C4747 expected
#include <windows.h>

// Uncomment the following line to resolve.
// #pragma unmanaged

BOOL WINAPI DllMain(HANDLE hInstance, ULONG Command, LPVOID Reserved) {
   return TRUE;