1 /*- 2 * Copyright (c) 1999 John D. Polstra 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/sys/sys/linker_set.h,v 1.4.2.1 2000/08/02 21:52:20 peter Exp $ 27 */ 28 29 #ifndef _SYS_LINKER_SET_H_ 30 #define _SYS_LINKER_SET_H_ 31 32 #ifndef _SYS_CDEFS_H_ 33 #include <sys/cdefs.h> 34 #endif 35 36 /* 37 * The following macros are used to declare global sets of objects, which 38 * are collected by the linker into a `struct linker_set' as defined below. 39 * For ELF, this is done by constructing a separate segment for each set. 40 * 41 * In the __MAKE_SET macros below, the lines: 42 * 43 * static void const * const __set_##set##_sym_##sym = &sym; 44 * 45 * are present only to prevent the compiler from producing bogus 46 * warnings about unused symbols. 47 */ 48 #ifndef __ELF__ 49 #error only ELF is supported 50 #endif 51 52 #if 0 53 54 #define __MAKE_SET(set, sym) \ 55 static void const * const __set_##set##_sym_##sym = &sym; \ 56 __asm(".section set_" #set ",\"aw\""); \ 57 __asm(".long " #sym); \ 58 __asm(".previous") 59 60 #endif 61 62 #define __MAKE_SET(set, sym) \ 63 __GLOBL(__CONCAT(__start_set_,set)); \ 64 __GLOBL(__CONCAT(__stop_set_,set)); \ 65 static void const * const __set_##set##_sym_##sym \ 66 __section("set_" #set) __used = &(sym) 67 68 #define TEXT_SET(set, sym) __MAKE_SET(set, sym) 69 #define DATA_SET(set, sym) __MAKE_SET(set, sym) 70 #define BSS_SET(set, sym) __MAKE_SET(set, sym) 71 #define ABS_SET(set, sym) __MAKE_SET(set, sym) 72 #define SET_ENTRY(set, sym) __MAKE_SET(set, sym) 73 74 #define SET_DECLARE(set, ptype) \ 75 extern ptype *__CONCAT(__start_set_,set); \ 76 extern ptype *__CONCAT(__stop_set_,set) 77 #define SET_DECLARE_WEAK(set, ptype) \ 78 extern ptype __weak_symbol *__CONCAT(__start_set_,set); \ 79 extern ptype __weak_symbol *__CONCAT(__stop_set_,set) 80 81 #define SET_BEGIN(set) (&__CONCAT(__start_set_,set)) 82 #define SET_LIMIT(set) (&__CONCAT(__stop_set_,set)) 83 84 /* 85 * Iterate over all the elements of a set. 86 * 87 * Sets always contain addresses of things, and "pvar" points to words 88 * containing those addresses. Thus is must be declared as "type **pvar", 89 * and the address of each set item is obtained inside the loop by "*pvar". 90 */ 91 #define SET_FOREACH(pvar, set) \ 92 for (pvar = SET_BEGIN(set); pvar < SET_LIMIT(set); pvar++) 93 94 #define SET_ITEM(set, i) \ 95 ((SET_BEGIN(set))[i]) 96 97 /* 98 * Provide a count of the items in a set. 99 */ 100 #define SET_COUNT(set) \ 101 (SET_LIMIT(set) - SET_BEGIN(set)) 102 103 #endif /* _SYS_LINKER_SET_H_ */ 104