How to set entry point of a process created from CreateProcess

Question

I am using CreateProcess to invoke cl to compile and link another C++ program ( TestProg.cxx ) into a DLL. I invoke cl with the following compilation options:

/Od /nologo /Fo /RTC /w /Zc /EHsc /I\INCLUDE /I\LIB /I\PATH TestProg.cxx /DLL

the call:

if ( CreateProcess(full path to cl.exe, compilation options, NULL,NULL,FALSE,0,       NULL,NULL,&si,&pi) ) 
{
 //....
}

Running the application from VS tools prompt, I got the following linkage error:

LINK : fatal error LNK1561: entry point must be defined

What am I doing wrong? I searched the answer for the last 1/2 day at the web, but didn't find it. Using windows API is new to me.

Thanks

Answer 1

That's not an error in using CreateProcess() to run the compiler, it's an error from the compiler telling you that your TestProg.cxx has no main() function. (Or DllMain() , since you seem to be building a DLL.)

Answer 2

You have a linker error, so linker was unable to build you a binary. The entry point can be provided via /ENTRY command line parameter, see MSDN for details:

/ENTRY (Entry-Point Symbol)

You will have something like: cl.exe /ENTRY:DllMain ... where DllMain will be your entry point function in source code.