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24 #ifndef _MACHO_LDSYMS_H_
25 #define _MACHO_LDSYMS_H_
27 #include <mach-o/loader.h>
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
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.
54 #define _MH_EXECUTE_SYM "__mh_execute_header"
55 #define MH_EXECUTE_SYM "_mh_execute_header"
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.
71 #define _MH_BUNDLE_SYM "__mh_bundle_header"
72 #define MH_BUNDLE_SYM "_mh_bundle_header"
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.
88 #define _MH_DYLIB_SYM "__mh_dylib_header"
89 #define MH_DYLIB_SYM "_mh_dylib_header"
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.
105 #define _MH_DYLINKER_SYM "__mh_dylinker_header"
106 #define MH_DYLINKER_SYM "_mh_dylinker_header"
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
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.
133 #endif /* _MACHO_LDSYMS_H_ */