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/* Copyright (C) 2022 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <execinfo.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "sframe-backtrace-api.h"
#ifdef __has_attribute
# if !__has_attribute (noclone)
# define ATTRIBUTE_NOCLONE
# endif
#endif
#ifndef ATTRIBUTE_NOCLONE
# define ATTRIBUTE_NOCLONE __attribute__((noclone))
#endif
#define BT_BUF_SIZE 16
/* funclist for running tailcall. */
const char *const func_list[] =
{
"show_bt",
"dec",
"dec",
"main"
};
void show_bt ()
{
void *buffer[BT_BUF_SIZE];
int j, nptrs, err;
char **strings;
/* Call the unwinder to get an array of return addresses. */
nptrs = sframe_backtrace (buffer, BT_BUF_SIZE, &err);
if (nptrs == -1 || nptrs != 4)
{
printf ("SFrame error: %s (%d)\n", sframe_bt_errmsg (err), nptrs);
return;
}
/* Get these addresses symbolically. */
strings = backtrace_symbols (buffer, nptrs);
if (strings == NULL) {
printf ("Error in backtrace_symbols");
return;
}
/* Verify the results. */
for (j = 0; j < nptrs; j++)
if (!strstr (strings[j], func_list[j]))
break;
free(strings);
printf ("%s: tailcall test\n", j == nptrs ? "PASS" : "FAIL");
}
/* An example of tail recursive function. */
void __attribute__((__noinline__)) ATTRIBUTE_NOCLONE
dec (int n)
{
void *buffer[BT_BUF_SIZE];
int nptrs, err;
/* Call the unwinder to get an array of return addresses. */
nptrs = sframe_backtrace (buffer, BT_BUF_SIZE, &err);
if (nptrs == -1)
{
printf ("SFrame error: %s (%d)\n", sframe_bt_errmsg (err), nptrs);
return;
}
if (n < 0)
return;
if (n == 2)
show_bt ();
/* The last executed statement is recursive call. */
dec (n-1);
}
int
main (void)
{
dec (3);
}
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