//

#define UNW_LOCAL_ONLY
#include <libunwind.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <execinfo.h>
#include <setjmp.h>

__attribute__((noinline)) void unw(void)
{
    printf("Unwinding.\n");
    unw_context_t context;
    memset(&context, 0, sizeof(context));
    unw_getcontext(&context);
    unw_cursor_t cursor;
    if (unw_init_local(&cursor, &context) != 0) {
        printf("Init failed\n");
        return;
    }
    while (1) {
        unw_word_t reg;
        if (unw_get_reg(&cursor, UNW_REG_IP, &reg) < 0) {
            printf("Can't get RIP\n");
            return;
        }
        // printf("  RIP: %p\n", (void*)(uintptr_t)reg);
        /* reg--; */
        backtrace_symbols_fd((void *const*)&reg, 1, 1);
        /* if (unw_get_reg(&cursor, UNW_REG_SP, &reg) < 0) { */
        /*     printf("Can't get RSP\n"); */
        /*     return; */
        /* } */
        /* printf("RSP: %p\n", (void*)(uintptr_t)reg); */
        if (unw_step(&cursor) <= 0) {
            printf("Done\n");
            return;
        }
    }
}

jmp_buf start;

__attribute__((noinline,noreturn)) void throw(void *p, void *p2, void *p3, void *p4, int a)
{
    unw();
    asm volatile ("" :: "r"(p), "r"(p2), "r"(p3), "r"(p4) : "memory");
    if (a) {
        longjmp(start, 1);
    }
    else {
        _exit(0);
    }
}

__attribute__((noinline)) void not_throw(void *p)
{
    /* unw(); */
    asm volatile ("" :: "r"(p) : "memory");
}

__attribute__((noinline)) void f(int a, int b)
{
    if (a) {
        uint32_t p = a;
        not_throw(&p);
        throw(&p, &a, &b, &p, a);
    }
    else {
        not_throw(&a);
        int p = 2;
        throw(&b, &p, &a, &b, a);
    }
}

__attribute__((noinline)) void g(int a, int b)
{
    f(a, b - a);
}

__attribute__((noinline)) void h(int a, int b)
{
    g(a + b, -a);
}

volatile int flag = 1;
volatile int flag2 = 0;

int main()
{
    if (setjmp(start) == 0) {
        h(flag, flag2);
    }
    else {
        h(0, flag2);
    }
    return 0;
}