print ascending numbers without my own state variables

asc.c

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

void countForwardTo(int x) {
    if (x > 1)
        countForwardTo(x-1); // standard recursion

    printf("%d", x);

    // get the state of the stack
    unw_context_t ctx;
    unw_getcontext(&ctx);

    // get a cursor to the previous stack frame
    unw_cursor_t cursor;
    unw_init_local(&cursor, &ctx);
    unw_step(&cursor);

    // get the name of the calling function
    unw_word_t off;
    char caller[100];
    unw_get_proc_name(&cursor, caller, 100, &off);

    if (strcmp(caller, __func__) == 0)  // if caller == this
        printf(", ");
    else                                // not a recursive stack frame
        printf("\n");
}

int main(int argc, char **argv) {
    if (argc > 1)
        countForwardTo(atoi(argv[1]));
}

Makefile

LDFLAGS=-lunwind -lunwind-x86_64

all: asc