Where are macros stored?

Question

If I use macros in my C code, such as

#define var 10

then where exactly are the stored in the space allocated to the process by the kernel? In heap or BSS or global data? Or is it just a text replacement for var in one of the compiler passes?

Answer 1

Yes.
the last one

just a text replacement

It is performed by a preprocessing pass. Some good details can be found here

Answer 2

Preprocessor directives like #define are replaced with the corresponding text during the preprocessing phase of compilation, and are (almost) never represented in the final executable.

Answer 3

"Macros" are a "compile time thing".

It just "replaces the text" that the compiler sees - before it compiles.

The result (in the compiled code) can be a set of operations ... a data declaration ... or nothing at all.

But the "macro" itself is Ancient History after the preprocessor finishes, and before compilation actually begins.