ios-kernel-patch/data/mach-o/headers/nlist.h
2021-02-18 10:42:34 +07:00

303 lines
13 KiB
C

/*
* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#ifndef _MACHO_NLIST_H_
#define _MACHO_NLIST_H_
/* $NetBSD: nlist.h,v 1.5 1994/10/26 00:56:11 cgd Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)nlist.h 8.2 (Berkeley) 1/21/94
*/
#include <stdint.h>
/*
* Format of a symbol table entry of a Mach-O file for 32-bit architectures.
* Modified from the BSD format. The modifications from the original format
* were changing n_other (an unused field) to n_sect and the addition of the
* N_SECT type. These modifications are required to support symbols in a larger
* number of sections not just the three sections (text, data and bss) in a BSD
* file.
*/
struct nlist {
union {
#ifndef __LP64__
char *n_name; /* for use when in-core */
#endif
int32_t n_strx; /* index into the string table */
} n_un;
uint8_t n_type; /* type flag, see below */
uint8_t n_sect; /* section number or NO_SECT */
int16_t n_desc; /* see <mach-o/stab.h> */
uint32_t n_value; /* value of this symbol (or stab offset) */
};
/*
* This is the symbol table entry structure for 64-bit architectures.
*/
struct nlist_64 {
union {
uint32_t n_strx; /* index into the string table */
} n_un;
uint8_t n_type; /* type flag, see below */
uint8_t n_sect; /* section number or NO_SECT */
uint16_t n_desc; /* see <mach-o/stab.h> */
uint64_t n_value; /* value of this symbol (or stab offset) */
};
/*
* Symbols with a index into the string table of zero (n_un.n_strx == 0) are
* defined to have a null, "", name. Therefore all string indexes to non null
* names must not have a zero string index. This is bit historical information
* that has never been well documented.
*/
/*
* The n_type field really contains four fields:
* unsigned char N_STAB:3,
* N_PEXT:1,
* N_TYPE:3,
* N_EXT:1;
* which are used via the following masks.
*/
#define N_STAB 0xe0 /* if any of these bits set, a symbolic debugging entry */
#define N_PEXT 0x10 /* private external symbol bit */
#define N_TYPE 0x0e /* mask for the type bits */
#define N_EXT 0x01 /* external symbol bit, set for external symbols */
/*
* Only symbolic debugging entries have some of the N_STAB bits set and if any
* of these bits are set then it is a symbolic debugging entry (a stab). In
* which case then the values of the n_type field (the entire field) are given
* in <mach-o/stab.h>
*/
/*
* Values for N_TYPE bits of the n_type field.
*/
#define N_UNDF 0x0 /* undefined, n_sect == NO_SECT */
#define N_ABS 0x2 /* absolute, n_sect == NO_SECT */
#define N_SECT 0xe /* defined in section number n_sect */
#define N_PBUD 0xc /* prebound undefined (defined in a dylib) */
#define N_INDR 0xa /* indirect */
/*
* If the type is N_INDR then the symbol is defined to be the same as another
* symbol. In this case the n_value field is an index into the string table
* of the other symbol's name. When the other symbol is defined then they both
* take on the defined type and value.
*/
/*
* If the type is N_SECT then the n_sect field contains an ordinal of the
* section the symbol is defined in. The sections are numbered from 1 and
* refer to sections in order they appear in the load commands for the file
* they are in. This means the same ordinal may very well refer to different
* sections in different files.
*
* The n_value field for all symbol table entries (including N_STAB's) gets
* updated by the link editor based on the value of it's n_sect field and where
* the section n_sect references gets relocated. If the value of the n_sect
* field is NO_SECT then it's n_value field is not changed by the link editor.
*/
#define NO_SECT 0 /* symbol is not in any section */
#define MAX_SECT 255 /* 1 thru 255 inclusive */
/*
* Common symbols are represented by undefined (N_UNDF) external (N_EXT) types
* who's values (n_value) are non-zero. In which case the value of the n_value
* field is the size (in bytes) of the common symbol. The n_sect field is set
* to NO_SECT. The alignment of a common symbol may be set as a power of 2
* between 2^1 and 2^15 as part of the n_desc field using the macros below. If
* the alignment is not set (a value of zero) then natural alignment based on
* the size is used.
*/
#define GET_COMM_ALIGN(n_desc) (((n_desc) >> 8) & 0x0f)
#define SET_COMM_ALIGN(n_desc,align) \
(n_desc) = (((n_desc) & 0xf0ff) | (((align) & 0x0f) << 8))
/*
* To support the lazy binding of undefined symbols in the dynamic link-editor,
* the undefined symbols in the symbol table (the nlist structures) are marked
* with the indication if the undefined reference is a lazy reference or
* non-lazy reference. If both a non-lazy reference and a lazy reference is
* made to the same symbol the non-lazy reference takes precedence. A reference
* is lazy only when all references to that symbol are made through a symbol
* pointer in a lazy symbol pointer section.
*
* The implementation of marking nlist structures in the symbol table for
* undefined symbols will be to use some of the bits of the n_desc field as a
* reference type. The mask REFERENCE_TYPE will be applied to the n_desc field
* of an nlist structure for an undefined symbol to determine the type of
* undefined reference (lazy or non-lazy).
*
* The constants for the REFERENCE FLAGS are propagated to the reference table
* in a shared library file. In that case the constant for a defined symbol,
* REFERENCE_FLAG_DEFINED, is also used.
*/
/* Reference type bits of the n_desc field of undefined symbols */
#define REFERENCE_TYPE 0x7
/* types of references */
#define REFERENCE_FLAG_UNDEFINED_NON_LAZY 0
#define REFERENCE_FLAG_UNDEFINED_LAZY 1
#define REFERENCE_FLAG_DEFINED 2
#define REFERENCE_FLAG_PRIVATE_DEFINED 3
#define REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY 4
#define REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY 5
/*
* To simplify stripping of objects that use are used with the dynamic link
* editor, the static link editor marks the symbols defined an object that are
* referenced by a dynamicly bound object (dynamic shared libraries, bundles).
* With this marking strip knows not to strip these symbols.
*/
#define REFERENCED_DYNAMICALLY 0x0010
/*
* For images created by the static link editor with the -twolevel_namespace
* option in effect the flags field of the mach header is marked with
* MH_TWOLEVEL. And the binding of the undefined references of the image are
* determined by the static link editor. Which library an undefined symbol is
* bound to is recorded by the static linker in the high 8 bits of the n_desc
* field using the SET_LIBRARY_ORDINAL macro below. The ordinal recorded
* references the libraries listed in the Mach-O's LC_LOAD_DYLIB load commands
* in the order they appear in the headers. The library ordinals start from 1.
* For a dynamic library that is built as a two-level namespace image the
* undefined references from module defined in another use the same nlist struct
* an in that case SELF_LIBRARY_ORDINAL is used as the library ordinal. For
* defined symbols in all images they also must have the library ordinal set to
* SELF_LIBRARY_ORDINAL. The EXECUTABLE_ORDINAL refers to the executable
* image for references from plugins that refer to the executable that loads
* them.
*
* The DYNAMIC_LOOKUP_ORDINAL is for undefined symbols in a two-level namespace
* image that are looked up by the dynamic linker with flat namespace semantics.
* This ordinal was added as a feature in Mac OS X 10.3 by reducing the
* value of MAX_LIBRARY_ORDINAL by one. So it is legal for existing binaries
* or binaries built with older tools to have 0xfe (254) dynamic libraries. In
* this case the ordinal value 0xfe (254) must be treated as a library ordinal
* for compatibility.
*/
#define GET_LIBRARY_ORDINAL(n_desc) (((n_desc) >> 8) & 0xff)
#define SET_LIBRARY_ORDINAL(n_desc,ordinal) \
(n_desc) = (((n_desc) & 0x00ff) | (((ordinal) & 0xff) << 8))
#define SELF_LIBRARY_ORDINAL 0x0
#define MAX_LIBRARY_ORDINAL 0xfd
#define DYNAMIC_LOOKUP_ORDINAL 0xfe
#define EXECUTABLE_ORDINAL 0xff
/*
* The bit 0x0020 of the n_desc field is used for two non-overlapping purposes
* and has two different symbolic names, N_NO_DEAD_STRIP and N_DESC_DISCARDED.
*/
/*
* The N_NO_DEAD_STRIP bit of the n_desc field only ever appears in a
* relocatable .o file (MH_OBJECT filetype). And is used to indicate to the
* static link editor it is never to dead strip the symbol.
*/
#define N_NO_DEAD_STRIP 0x0020 /* symbol is not to be dead stripped */
/*
* The N_DESC_DISCARDED bit of the n_desc field never appears in linked image.
* But is used in very rare cases by the dynamic link editor to mark an in
* memory symbol as discared and longer used for linking.
*/
#define N_DESC_DISCARDED 0x0020 /* symbol is discarded */
/*
* The N_WEAK_REF bit of the n_desc field indicates to the dynamic linker that
* the undefined symbol is allowed to be missing and is to have the address of
* zero when missing.
*/
#define N_WEAK_REF 0x0040 /* symbol is weak referenced */
/*
* The N_WEAK_DEF bit of the n_desc field indicates to the static and dynamic
* linkers that the symbol definition is weak, allowing a non-weak symbol to
* also be used which causes the weak definition to be discared. Currently this
* is only supported for symbols in coalesed sections.
*/
#define N_WEAK_DEF 0x0080 /* coalesed symbol is a weak definition */
/*
* The N_REF_TO_WEAK bit of the n_desc field indicates to the dynamic linker
* that the undefined symbol should be resolved using flat namespace searching.
*/
#define N_REF_TO_WEAK 0x0080 /* reference to a weak symbol */
/*
* The N_ARM_THUMB_DEF bit of the n_desc field indicates that the symbol is
* a defintion of a Thumb function.
*/
#define N_ARM_THUMB_DEF 0x0008 /* symbol is a Thumb function (ARM) */
#ifndef __STRICT_BSD__
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
/*
* The function nlist(3) from the C library.
*/
extern int nlist (const char *filename, struct nlist *list);
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __STRICT_BSD__ */
#endif /* _MACHO_LIST_H_ */