#include <pthread.h>
#include <execinfo.h>
#include <stdio.h>
#include <unistd.h>


static void backtracer (void) __attribute__((__noinline__));
static void backtracer (void)
{
	void *buf[512];
	puts("dummy");
	int i = backtrace (buf, 512);
	printf ("%d\n", i);
	fflush (stdout);
	backtrace_symbols_fd (buf, i, STDOUT_FILENO);
#define RAFA(level)					\
	printf("RA (%d) = %p, FA (%d) = %p\n",		\
	       level, __builtin_return_address (level),	\
	       level, __builtin_frame_address (level))
	RAFA(0);
	RAFA(1);
	RAFA(2);
	RAFA(3);
	RAFA(4);
	RAFA(5);
}

static int badone (void) __attribute__((__noinline__));
static int badone (void)
{
	backtracer ();
	return 0;
}

asm(
"	.text		\n"
"clearstack:		\n"
"	pushq	$0	\n"
"	popq	%rax	\n"
"	ret		\n"
);
extern void clearstack(void);

int main (void)
{
	clearstack ();
	badone ();
	return 0;
}