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 /* 33 * The following macros are used to declare global sets of objects, which 34 * are collected by the linker into a `struct linker_set' as defined below. 35 * For ELF, this is done by constructing a separate segment for each set. 36 * For a.out, it is done automatically by the linker. 37 * 38 * In the MAKE_SET macros below, the lines: 39 * 40 * static void const * const __set_##set##_sym_##sym = &sym; 41 * 42 * are present only to prevent the compiler from producing bogus 43 * warnings about unused symbols. 44 */ 45 #ifdef __ELF__ 46 47 /* 48 * Alpha GAS needs an align before the section change. It seems to assume 49 * that after the .previous, it is aligned, so the following .align 3 is 50 * ignored. Since the previous instructions often contain strings, this is 51 * a problem. 52 */ 53 54 #ifdef __alpha__ 55 #define MAKE_SET(set, sym) \ 56 static void const * const __set_##set##_sym_##sym = &sym; \ 57 __asm(".align 3"); \ 58 __asm(".section .set." #set ",\"aw\""); \ 59 __asm(".quad " #sym); \ 60 __asm(".previous") 61 #else 62 #define MAKE_SET(set, sym) \ 63 static void const * const __set_##set##_sym_##sym = &sym; \ 64 __asm(".section .set." #set ",\"aw\""); \ 65 __asm(".long " #sym); \ 66 __asm(".previous") 67 #endif 68 #define TEXT_SET(set, sym) MAKE_SET(set, sym) 69 #define DATA_SET(set, sym) MAKE_SET(set, sym) 70 71 #else 72 73 /* 74 * NB: the constants defined below must match those defined in 75 * ld/ld.h. Since their calculation requires arithmetic, we 76 * can't name them symbolically (e.g., 23 is N_SETT | N_EXT). 77 */ 78 #define MAKE_SET(set, sym, type) \ 79 static void const * const __set_##set##_sym_##sym = &sym; \ 80 __asm(".stabs \"_" #set "\", " #type ", 0, 0, _" #sym) 81 #define TEXT_SET(set, sym) MAKE_SET(set, sym, 23) 82 #define DATA_SET(set, sym) MAKE_SET(set, sym, 25) 83 84 #endif 85 86 struct linker_set { 87 int ls_length; 88 void *ls_items[1]; /* really ls_length of them, 89 * trailing NULL */ 90 }; 91 92 #endif /* _SYS_LINKER_SET_H_ */ 93