How can I generate a list via the C preprocessor (cpp)?

Question

I would like to do something like the following:

F_BEGIN

F(f1) {some code}
F(f2) {some code}
...
F(fn) {some code}

F_END

and have it gene

Answer 1

There's this thing called X Macro which is used as:

a technique for reliable maintenance of parallel lists, of code or data, whose corresponding items must appear in the same order

This is how it works:

    #include 

//you create macro that contains your values and place them in (yet) not defined macro
#define COLORS\
    X(red, 91)\
    X(green, 92)\
    X(blue, 94)\

//you can name that macro however you like but conventional way is just an "X"

//and then you will be able to define a format for your values in that macro
#define X(name, value) name = value,
typedef enum { COLORS } Color;
#undef X //just another convention (so you don't use it accidentally, I think)

int main(void)
{
    #define X(name, value) printf("%d, ", name);
    COLORS
    #undef X
    return 0;
}

Solution for your problem would be:

#define FUNCTIONS \
F(f1, code1)\
F(f2, code2)\
F(f3, code3)

#define F(name, code) int name(void){code}
FUNCTIONS
#undef F


#define F(name, code) &name,
int (*function_table[])(void) = { FUNCTIONS };
#undef F