Macro to temporarily prevent double free problems

double_free_guard.c

#include <stdio.h>
#include <stdlib.h>

/**
 * NULLs pointer after freeing.
 * Prints the pointer alerting a double free
 * in the case where that may have occurred.
 **/

#define FREE(p)                             \
do {                                        \
    if (&p) {                               \
        if (p) {                            \
            free(p);                        \
            p = NULL;                       \
        } else {                            \
            printf("Double free %p\n", &p); \
        }                                   \
    }                                       \
} while (0)

int main(void) {
    char *string = malloc(100);
    FREE(string);
    FREE(string);
    FREE(string);
    FREE(string);
    FREE(string);
    FREE(string);
    return 0;
}