1/*-
2 * Copyright (c) 1999 John D. Polstra
3 * Copyright (c) 1999,2001 Peter Wemm <peter@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#ifndef _SYS_LINKER_SET_H_
31#define _SYS_LINKER_SET_H_
32
33#ifndef _SYS_CDEFS_H_
34#error this file needs sys/cdefs.h as a prerequisite
35#endif
36
37/*
38 * The following macros are used to declare global sets of objects, which
39 * are collected by the linker into a `linker_set' as defined below.
40 * For ELF, this is done by constructing a separate segment for each set.
41 */
42
43#if defined(__powerpc64__)
44/*
45 * Move the symbol pointer from ".text" to ".data" segment, to make
46 * the GCC compiler happy:
47 */
48#define	__MAKE_SET_CONST
49#else
50#define	__MAKE_SET_CONST const
51#endif
52
53/*
54 * Private macros, not to be used outside this header file.
55 */
56#ifdef __GNUCLIKE___SECTION
57#define __MAKE_SET(set, sym)				\
58	__GLOBL(__CONCAT(__start_set_,set));		\
59	__GLOBL(__CONCAT(__stop_set_,set));		\
60	static void const * __MAKE_SET_CONST		\
61	__set_##set##_sym_##sym __section("set_" #set)	\
62	__used = &(sym)
63#else /* !__GNUCLIKE___SECTION */
64#ifndef lint
65#error this file needs to be ported to your compiler
66#endif /* lint */
67#define __MAKE_SET(set, sym)	extern void const * const (__set_##set##_sym_##sym)
68#endif /* __GNUCLIKE___SECTION */
69
70/*
71 * Public macros.
72 */
73#define TEXT_SET(set, sym)	__MAKE_SET(set, sym)
74#define DATA_SET(set, sym)	__MAKE_SET(set, sym)
75#define BSS_SET(set, sym)	__MAKE_SET(set, sym)
76#define ABS_SET(set, sym)	__MAKE_SET(set, sym)
77#define SET_ENTRY(set, sym)	__MAKE_SET(set, sym)
78
79/*
80 * Initialize before referring to a given linker set.
81 */
82#define SET_DECLARE(set, ptype)					\
83	extern ptype __weak_symbol *__CONCAT(__start_set_,set);	\
84	extern ptype __weak_symbol *__CONCAT(__stop_set_,set)
85
86#define SET_BEGIN(set)							\
87	(&__CONCAT(__start_set_,set))
88#define SET_LIMIT(set)							\
89	(&__CONCAT(__stop_set_,set))
90
91/*
92 * Iterate over all the elements of a set.
93 *
94 * Sets always contain addresses of things, and "pvar" points to words
95 * containing those addresses.  Thus is must be declared as "type **pvar",
96 * and the address of each set item is obtained inside the loop by "*pvar".
97 */
98#define SET_FOREACH(pvar, set)						\
99	for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++)
100
101#define SET_ITEM(set, i)						\
102	((SET_BEGIN(set))[i])
103
104/*
105 * Provide a count of the items in a set.
106 */
107#define SET_COUNT(set)							\
108	(SET_LIMIT(set) - SET_BEGIN(set))
109
110#endif	/* _SYS_LINKER_SET_H_ */
111