Preprocessor check if multiple defines are not defined

Question

I have a selection of #defines in a header that are user editable and so I subsequently wish to check that the defines exist in case a user deletes them altogether, e.g.

#if defined MANUF && defined SERIAL && defined MODEL     // All defined OK so do nothing #else     #error "User is stoopid!" #endif 

This works perfectly OK, I am wondering however if there is a better way to check if multiple defines are NOT in place... i.e. something like:

#ifn defined MANUF || defined SERIAL ||.... // note the n in #ifn 

or maybe

#if !defined MANUF || !defined SERIAL ||.... 

to remove the need for the empty #if section.

Answer 1

#if !defined(MANUF) || !defined(SERIAL) || !defined(MODEL) 

Answer 2

FWIW, @SergeyL's answer is great, but here is a slight variant for testing. Note the change in logical or to logical and.

main.c has a main wrapper like this:

#if !defined(TEST_SPI) && !defined(TEST_SERIAL) && !defined(TEST_USB) int main(int argc, char *argv[]) {   // the true main() routine. } 

spi.c, serial.c and usb.c have main wrappers for their respective test code like this:

#ifdef TEST_USB int main(int argc, char *argv[]) {   // the  main() routine for testing the usb code. } 

config.h Which is included by all the c files has an entry like this:

// Uncomment below to test the serial //#define TEST_SERIAL   // Uncomment below to test the spi code //#define TEST_SPI  // Uncomment below to test the usb code #define TEST_USB