Utilizing Compiler supported cleanup attribute as Defer in C.

compiler_defer.c

#include <stdio.h>
#include <string.h>

#define DEFER(func) __attribute__((__cleanup__(func)))

static void free_char(char **p) {
    if (p == NULL) return;
    if (*p == NULL) return;
    free(*p);
    *p = NULL;
}

int main(void) {
    DEFER(free_char) char *test = malloc((sizeof(char)*14));
    strncpy(test, "Hello, World!", 13);
    test[14] = '\0';
    printf("test string = \"%s\"\n", test);
    // free_char is called when this function exits
    return 0;
}