/**
 * debug.c
 *
 * Debugging using the preprocessor. When DEBUG is set to 0, the LOG statements
 * are completely removed from the binary produced after compliation.
 *
 * Compile:
 *      gcc -g -Wall -o debug debug.c
 */

#include <stdio.h>

/* What happens when we set DEBUG to 0? */
#define DEBUG 0

#define LOG(fmt, ...) \
    do { if (DEBUG) fprintf(stderr, fmt, __VA_ARGS__); } while (0)

int main(void)
{
    int i = 6;

    LOG("Hello world! i = %d\n", i);

    return 0;
}