I have a macro definition in header file like this:

// header.h
ARRAY_SZ(a) = ((int) sizeof(a)/sizeof(a[0]));

This is defined in some header file, which includes some more header files.

Now, i need to use this macro in some source file that has no other reason to include header.h or any other header files included in header.h, so should i redefine the macro in my source file or simply include the header file header.h.

Will the latter approach affect the code size/compile time (I think yes), or runtime (i think no)?

Your advice on this!