bsd/sys/linker_set.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*-
  24  * Copyright (c) 1999 John D. Polstra
  25  * All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46  * SUCH DAMAGE.
  47  *
  48  */
  49
  50 #ifndef _SYS_LINKER_SET_H_
  51 #define _SYS_LINKER_SET_H_
  52
  53 #include <sys/appleapiopts.h>
  54
  55 #if !defined(KERNEL) || defined(__APPLE_API_PRIVATE)
  56 /*
  57  * The following macros are used to declare global sets of objects, which
  58  * are collected by the linker into a `struct linker_set' as defined below.
  59  * For ELF, this is done by constructing a separate segment for each set.
  60  * For a.out, it is done automatically by the linker.
  61  */
  62
  63 #define __ELF__
  64 #ifdef __ELF__
  65
  66 #define MAKE_SET(seg, set, sym)                                         \
  67         static void const * const __set_##set##_sym_##sym = &sym;       \
  68         __asm(".section  seg, " #set "");       \
  69         __asm(".long " #sym);
  70
  71 /*      __asm(".previous") */
  72
  73
  74 #define TEXT_SET(set, sym) MAKE_SET(__TEXT, set, sym)
  75 #define DATA_SET(set, sym) MAKE_SET(__DATA, set, sym)
  76 #define BSS_SET(set, sym)  MAKE_SET(__BSS,  set, sym)
  77 #define ABS_SET(set, sym)  MAKE_SET(__ABS,  set, sym)
  78
  79 #else
  80
  81 /*
  82  * NB: the constants defined below must match those defined in
  83  * nlist.h.  Since their calculation requires arithmetic, we
  84  * can't name them symbolically (e.g., 7 is N_DATA | N_EXT).
  85  */
  86 #define MAKE_SET(set, sym, type) \
  87         static void const * const __set_##set##_sym_##sym = &sym; \
  88         __asm(".stabs \"_" #set "\", " #type ", 0, 0, _" #sym)
  89
  90 #define TEXT_SET(set, sym) MAKE_SET(set, sym, 5)
  91 #define DATA_SET(set, sym) MAKE_SET(set, sym, 7)
  92 #define BSS_SET(set, sym)  MAKE_SET(set, sym, 9)
  93 #define ABS_SET(set, sym)  MAKE_SET(set, sym, 3)
  94
  95 #endif
  96
  97 struct linker_set {
  98         int             ls_length;
  99         const void      *ls_items[1];           /* really ls_length of them,
 100                                                  * trailing NULL */
 101 };
 102 #endif /* !KERNEL || __APPLE_API_PRIVATE */
 103
 104 #endif /* _SYS_LINKER_SET_H_ */
 105