1/*
2 * Copyright (c) 1999 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#ifndef _MACHO_LDSYMS_H_
25#define _MACHO_LDSYMS_H_
26
27#include <mach-o/loader.h>
28
29/*
30 * This file describes the link editor defined symbols. The semantics of a
31 * link editor symbol is that it is defined by the link editor only if it is
32 * referenced and it is an error for the user to define them (see the man page
33 * ld(1)). The standard UNIX link editor symbols: __end, __etext and __edata
34 * are not not supported by the Apple Mach-O link editor. These symbols are
35 * really not meaningful in a Mach-O object file and the link editor symbols
36 * that are supported (described here) replace them. In the case of the
37 * standard UNIX link editor symbols the program can use the symbol
38 * __mh_execute_header and walk the load commands of it's program to determine
39 * the ending (or beginning) of any section or segment in the program. Note
40 * that the compiler prepends an underbar to all external symbol names coded
41 * in a high level language. Thus in 'C' names are coded without an underbar
42 * and symbol names in the symbol table have an underbar. There are two cpp
43 * macros for each link editor defined name in this file. The macro with a
44 * leading underbar is the symbol name and the one without is the name as
45 * coded in 'C'.
46 */
47
48/*
49 * The value of the link editor defined symbol _MH_EXECUTE_SYM is the address
50 * of the mach header in a Mach-O executable file type. It does not appear in
51 * any file type other than a MH_EXECUTE file type. The type of the symbol is
52 * absolute as the header is not part of any section.
53 */
54#define _MH_EXECUTE_SYM "__mh_execute_header"
55#define MH_EXECUTE_SYM "_mh_execute_header"
56extern const struct
57#ifdef __LP64__
58mach_header_64
59#else
60mach_header
61#endif
62_mh_execute_header;
63
64/*
65 * The value of the link editor defined symbol _MH_BUNDLE_SYM is the address
66 * of the mach header in a Mach-O bundle file type. It does not appear in
67 * any file type other than a MH_BUNDLE file type. The type of the symbol is
68 * an N_SECT symbol even thought the header is not part of any section. This
69 * symbol is private to the code in the bundle it is a part of.
70 */
71#define _MH_BUNDLE_SYM "__mh_bundle_header"
72#define MH_BUNDLE_SYM "_mh_bundle_header"
73extern const struct
74#ifdef __LP64__
75mach_header_64
76#else
77mach_header
78#endif
79_mh_bundle_header;
80
81/*
82 * The value of the link editor defined symbol _MH_DYLIB_SYM is the address
83 * of the mach header in a Mach-O dylib file type. It does not appear in
84 * any file type other than a MH_DYLIB file type. The type of the symbol is
85 * an N_SECT symbol even thought the header is not part of any section. This
86 * symbol is private to the code in the library it is a part of.
87 */
88#define _MH_DYLIB_SYM "__mh_dylib_header"
89#define MH_DYLIB_SYM "_mh_dylib_header"
90extern const struct
91#ifdef __LP64__
92mach_header_64
93#else
94mach_header
95#endif
96_mh_dylib_header;
97
98/*
99 * The value of the link editor defined symbol _MH_DYLINKER_SYM is the address
100 * of the mach header in a Mach-O dylinker file type. It does not appear in
101 * any file type other than a MH_DYLINKER file type. The type of the symbol is
102 * an N_SECT symbol even thought the header is not part of any section. This
103 * symbol is private to the code in the dynamic linker it is a part of.
104 */
105#define _MH_DYLINKER_SYM "__mh_dylinker_header"
106#define MH_DYLINKER_SYM "_mh_dylinker_header"
107extern const struct
108#ifdef __LP64__
109mach_header_64
110#else
111mach_header
112#endif
113_mh_dylinker_header;
114
115/*
116 * For the MH_PRELOAD file type the headers are not loaded as part of any
117 * segment so the link editor defines symbols defined for the beginning
118 * and ending of each segment and each section in each segment. The names for
119 * the symbols for a segment's beginning and end will have the form:
120 * __SEGNAME__begin and __SEGNAME__end where __SEGNAME is the name of the
121 * segment. The names for the symbols for a section's beginning and end will
122 * have the form: __SEGNAME__sectname__begin and __SEGNAME__sectname__end
123 * where __sectname is the name of the section and __SEGNAME is the segment it
124 * is in.
125 *
126 * The above symbols' types are those of the section they are referring to.
127 * This is true even for symbols who's values are end's of a section and
128 * that value is next address after that section and not really in that
129 * section. This results in these symbols having types referring to sections
130 * who's values are not in that section.
131 */
132
133#endif /* _MACHO_LDSYMS_H_ */