How do you compile just a .h file in a makefile?

Question

I have a makefile that creates object files for two classes (and main) and one of those classes is just defined in a .h file. In my makefile I have a line that says

FileName.o: FileName.h
  g++ -c FileName.h

but when I try to compile it says it can't find FileName.o

Do I have to create FileName.cpp in order to get this to compile?

Answer 1

You are using your class from FileName.h somewhere, aren't you? So at least one of your .cpp files should contain #include "FileName.h", and .h's code will be compiled with this .cpp and you needn't compile .h's code separately.