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/* The meat of this file is a copy of the FreeBSD sys/link_set.h */
/*
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1999 John D. Polstra
* Copyright (c) 1999,2001 Peter Wemm <peter@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <stdio.h>
#define MAKE_SET(set, sym) \
__asm__(".globl __start_set_" #set); \
__asm__(".globl __stop_set_" #set); \
static __attribute__((section("set_" #set), used)) \
void const *__set_##set##_sym_##sym = &(sym)
/*
* Initialize before referring to a given linker set.
*/
#define SET_DECLARE(set, ptype) \
extern __attribute__((weak)) ptype *__start_set_ ## set; \
extern __attribute__((weak)) ptype *__stop_set_ ## set
#define SET_BEGIN(set) (&__start_set_ ## set)
#define SET_LIMIT(set) (&__stop_set_ ## set)
/*
* Iterate over all the elements of a set.
*
* Sets always contain addresses of things, and "pvar" points to words
* containing those addresses. Thus is must be declared as "type **pvar",
* and the address of each set item is obtained inside the loop by "*pvar".
*/
#define SET_FOREACH(pvar, set) \
for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++)
#define SET_ITEM(set, i) \
((SET_BEGIN(set))[i])
/*
* Provide a count of the items in a set.
*/
#define SET_COUNT(set) \
(SET_LIMIT(set) - SET_BEGIN(set))
struct foo {
char buf[128];
};
SET_DECLARE(foo, struct foo);
struct foo a = { "foo" };
struct foo b = { "bar" };
struct foo c = { "baz" };
MAKE_SET(foo, a);
MAKE_SET(foo, b);
MAKE_SET(foo, c);
int
main(int __attribute__((unused)) argc, char __attribute__((unused)) **argv)
{
struct foo **c;
int i = 0;
printf("Set count: %d\n", SET_COUNT(foo));
printf("a: %s\n", ((struct foo *)__set_foo_sym_a)->buf);
printf("b: %s\n", ((struct foo *)__set_foo_sym_b)->buf);
printf("c: %s\n", ((struct foo *)__set_foo_sym_c)->buf);
printf("item(foo, 0): %s\n", SET_ITEM(foo, 0)->buf);
printf("item(foo, 1): %s\n", SET_ITEM(foo, 1)->buf);
printf("item(foo, 2): %s\n", SET_ITEM(foo, 2)->buf);
SET_FOREACH(c, foo) {
printf("foo[%d]: %s\n", i, (*c)->buf);
i++;
}
return (0);
}
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