usr/src/boot/sys/sys/linker_set.h

   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_ */