Append items to an array with a macro, in C

Question

I have an array (C language) that should be initialized at compile time.

For example:

DECLARE_CMD(f1, arg);
DECLARE_CMD(f2, arg);
         


        

Answer 1

Yes, it is possible. The usual trick is to have all the DECLARE_CMD(func, args) lines in one (or more) include files, and to include those in various places with an appropriate definition for the macro.

For example:

In file 'commands.inc':

DECLARE_CMD(f1, args)
DECLARE_CMD(f2, args)

In some source file:

/* function declarations */
#define DECLARE_CMD(func, args) my_func_type func;
#include "commands.inc"
#undef DECLARE_CMD

/* array with poiners */
#define DECLARE_CMD(func, args) &func,
my_func_type* my_funcs[] = {
    #include "commands.inc"
    NULL
};