| 1 | /*␊ |
| 2 | * Copyright (c) 1999-2003 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 | #ifndef _MACHO_NLIST_H_␊ |
| 24 | #define _MACHO_NLIST_H_␊ |
| 25 | /*␉$NetBSD: nlist.h,v 1.5 1994/10/26 00:56:11 cgd Exp $␉*/␊ |
| 26 | ␊ |
| 27 | /*-␊ |
| 28 | * Copyright (c) 1991, 1993␊ |
| 29 | *␉The Regents of the University of California. All rights reserved.␊ |
| 30 | * (c) UNIX System Laboratories, Inc.␊ |
| 31 | * All or some portions of this file are derived from material licensed␊ |
| 32 | * to the University of California by American Telephone and Telegraph␊ |
| 33 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with␊ |
| 34 | * the permission of UNIX System Laboratories, Inc.␊ |
| 35 | *␊ |
| 36 | * Redistribution and use in source and binary forms, with or without␊ |
| 37 | * modification, are permitted provided that the following conditions␊ |
| 38 | * are met:␊ |
| 39 | * 1. Redistributions of source code must retain the above copyright␊ |
| 40 | * notice, this list of conditions and the following disclaimer.␊ |
| 41 | * 2. Redistributions in binary form must reproduce the above copyright␊ |
| 42 | * notice, this list of conditions and the following disclaimer in the␊ |
| 43 | * documentation and/or other materials provided with the distribution.␊ |
| 44 | * 3. All advertising materials mentioning features or use of this software␊ |
| 45 | * must display the following acknowledgement:␊ |
| 46 | *␉This product includes software developed by the University of␊ |
| 47 | *␉California, Berkeley and its contributors.␊ |
| 48 | * 4. Neither the name of the University nor the names of its contributors␊ |
| 49 | * may be used to endorse or promote products derived from this software␊ |
| 50 | * without specific prior written permission.␊ |
| 51 | *␊ |
| 52 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND␊ |
| 53 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE␊ |
| 54 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE␊ |
| 55 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE␊ |
| 56 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL␊ |
| 57 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS␊ |
| 58 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)␊ |
| 59 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT␊ |
| 60 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY␊ |
| 61 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF␊ |
| 62 | * SUCH DAMAGE.␊ |
| 63 | *␊ |
| 64 | *␉@(#)nlist.h␉8.2 (Berkeley) 1/21/94␊ |
| 65 | */␊ |
| 66 | #include <stdint.h>␊ |
| 67 | ␊ |
| 68 | /*␊ |
| 69 | * Format of a symbol table entry of a Mach-O file for 32-bit architectures.␊ |
| 70 | * Modified from the BSD format. The modifications from the original format␊ |
| 71 | * were changing n_other (an unused field) to n_sect and the addition of the␊ |
| 72 | * N_SECT type. These modifications are required to support symbols in a larger␊ |
| 73 | * number of sections not just the three sections (text, data and bss) in a BSD␊ |
| 74 | * file.␊ |
| 75 | */␊ |
| 76 | struct nlist {␊ |
| 77 | ␉union {␊ |
| 78 | #ifndef __LP64__␊ |
| 79 | ␉␉char *n_name;␉/* for use when in-core */␊ |
| 80 | #endif␊ |
| 81 | ␉␉int32_t n_strx;␉/* index into the string table */␊ |
| 82 | ␉} n_un;␊ |
| 83 | ␉uint8_t n_type;␉␉/* type flag, see below */␊ |
| 84 | ␉uint8_t n_sect;␉␉/* section number or NO_SECT */␊ |
| 85 | ␉int16_t n_desc;␉␉/* see <mach-o/stab.h> */␊ |
| 86 | ␉uint32_t n_value;␉/* value of this symbol (or stab offset) */␊ |
| 87 | };␊ |
| 88 | ␊ |
| 89 | /*␊ |
| 90 | * This is the symbol table entry structure for 64-bit architectures.␊ |
| 91 | */␊ |
| 92 | struct nlist_64 {␊ |
| 93 | union {␊ |
| 94 | uint32_t n_strx; /* index into the string table */␊ |
| 95 | } n_un;␊ |
| 96 | uint8_t n_type; /* type flag, see below */␊ |
| 97 | uint8_t n_sect; /* section number or NO_SECT */␊ |
| 98 | uint16_t n_desc; /* see <mach-o/stab.h> */␊ |
| 99 | uint64_t n_value; /* value of this symbol (or stab offset) */␊ |
| 100 | };␊ |
| 101 | ␊ |
| 102 | /*␊ |
| 103 | * Symbols with a index into the string table of zero (n_un.n_strx == 0) are␊ |
| 104 | * defined to have a null, "", name. Therefore all string indexes to non null␊ |
| 105 | * names must not have a zero string index. This is bit historical information␊ |
| 106 | * that has never been well documented.␊ |
| 107 | */␊ |
| 108 | ␊ |
| 109 | /*␊ |
| 110 | * The n_type field really contains four fields:␊ |
| 111 | *␉unsigned char N_STAB:3,␊ |
| 112 | *␉␉ N_PEXT:1,␊ |
| 113 | *␉␉ N_TYPE:3,␊ |
| 114 | *␉␉ N_EXT:1;␊ |
| 115 | * which are used via the following masks.␊ |
| 116 | */␊ |
| 117 | #define␉N_STAB␉0xe0 /* if any of these bits set, a symbolic debugging entry */␊ |
| 118 | #define␉N_PEXT␉0x10 /* private external symbol bit */␊ |
| 119 | #define␉N_TYPE␉0x0e /* mask for the type bits */␊ |
| 120 | #define␉N_EXT␉0x01 /* external symbol bit, set for external symbols */␊ |
| 121 | ␊ |
| 122 | /*␊ |
| 123 | * Only symbolic debugging entries have some of the N_STAB bits set and if any␊ |
| 124 | * of these bits are set then it is a symbolic debugging entry (a stab). In␊ |
| 125 | * which case then the values of the n_type field (the entire field) are given␊ |
| 126 | * in <mach-o/stab.h>␊ |
| 127 | */␊ |
| 128 | ␊ |
| 129 | /*␊ |
| 130 | * Values for N_TYPE bits of the n_type field.␊ |
| 131 | */␊ |
| 132 | #define␉N_UNDF␉0x0␉␉/* undefined, n_sect == NO_SECT */␊ |
| 133 | #define␉N_ABS␉0x2␉␉/* absolute, n_sect == NO_SECT */␊ |
| 134 | #define␉N_SECT␉0xe␉␉/* defined in section number n_sect */␊ |
| 135 | #define␉N_PBUD␉0xc␉␉/* prebound undefined (defined in a dylib) */␊ |
| 136 | #define N_INDR␉0xa␉␉/* indirect */␊ |
| 137 | ␊ |
| 138 | /* ␊ |
| 139 | * If the type is N_INDR then the symbol is defined to be the same as another␊ |
| 140 | * symbol. In this case the n_value field is an index into the string table␊ |
| 141 | * of the other symbol's name. When the other symbol is defined then they both␊ |
| 142 | * take on the defined type and value.␊ |
| 143 | */␊ |
| 144 | ␊ |
| 145 | /*␊ |
| 146 | * If the type is N_SECT then the n_sect field contains an ordinal of the␊ |
| 147 | * section the symbol is defined in. The sections are numbered from 1 and ␊ |
| 148 | * refer to sections in order they appear in the load commands for the file␊ |
| 149 | * they are in. This means the same ordinal may very well refer to different␊ |
| 150 | * sections in different files.␊ |
| 151 | *␊ |
| 152 | * The n_value field for all symbol table entries (including N_STAB's) gets␊ |
| 153 | * updated by the link editor based on the value of it's n_sect field and where␊ |
| 154 | * the section n_sect references gets relocated. If the value of the n_sect ␊ |
| 155 | * field is NO_SECT then it's n_value field is not changed by the link editor.␊ |
| 156 | */␊ |
| 157 | #define␉NO_SECT␉␉0␉/* symbol is not in any section */␊ |
| 158 | #define MAX_SECT␉255␉/* 1 thru 255 inclusive */␊ |
| 159 | ␊ |
| 160 | /*␊ |
| 161 | * Common symbols are represented by undefined (N_UNDF) external (N_EXT) types␊ |
| 162 | * who's values (n_value) are non-zero. In which case the value of the n_value␊ |
| 163 | * field is the size (in bytes) of the common symbol. The n_sect field is set␊ |
| 164 | * to NO_SECT. The alignment of a common symbol may be set as a power of 2␊ |
| 165 | * between 2^1 and 2^15 as part of the n_desc field using the macros below. If␊ |
| 166 | * the alignment is not set (a value of zero) then natural alignment based on␊ |
| 167 | * the size is used.␊ |
| 168 | */␊ |
| 169 | #define GET_COMM_ALIGN(n_desc) (((n_desc) >> 8) & 0x0f)␊ |
| 170 | #define SET_COMM_ALIGN(n_desc,align) \␊ |
| 171 | (n_desc) = (((n_desc) & 0xf0ff) | (((align) & 0x0f) << 8))␊ |
| 172 | ␊ |
| 173 | /*␊ |
| 174 | * To support the lazy binding of undefined symbols in the dynamic link-editor,␊ |
| 175 | * the undefined symbols in the symbol table (the nlist structures) are marked␊ |
| 176 | * with the indication if the undefined reference is a lazy reference or␊ |
| 177 | * non-lazy reference. If both a non-lazy reference and a lazy reference is␊ |
| 178 | * made to the same symbol the non-lazy reference takes precedence. A reference␊ |
| 179 | * is lazy only when all references to that symbol are made through a symbol␊ |
| 180 | * pointer in a lazy symbol pointer section.␊ |
| 181 | *␊ |
| 182 | * The implementation of marking nlist structures in the symbol table for␊ |
| 183 | * undefined symbols will be to use some of the bits of the n_desc field as a␊ |
| 184 | * reference type. The mask REFERENCE_TYPE will be applied to the n_desc field␊ |
| 185 | * of an nlist structure for an undefined symbol to determine the type of␊ |
| 186 | * undefined reference (lazy or non-lazy).␊ |
| 187 | *␊ |
| 188 | * The constants for the REFERENCE FLAGS are propagated to the reference table␊ |
| 189 | * in a shared library file. In that case the constant for a defined symbol,␊ |
| 190 | * REFERENCE_FLAG_DEFINED, is also used.␊ |
| 191 | */␊ |
| 192 | /* Reference type bits of the n_desc field of undefined symbols */␊ |
| 193 | #define REFERENCE_TYPE␉␉␉␉0x7␊ |
| 194 | /* types of references */␊ |
| 195 | #define REFERENCE_FLAG_UNDEFINED_NON_LAZY␉␉0␊ |
| 196 | #define REFERENCE_FLAG_UNDEFINED_LAZY␉␉␉1␊ |
| 197 | #define REFERENCE_FLAG_DEFINED␉␉␉␉2␊ |
| 198 | #define REFERENCE_FLAG_PRIVATE_DEFINED␉␉␉3␊ |
| 199 | #define REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY␉4␊ |
| 200 | #define REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY␉␉5␊ |
| 201 | ␊ |
| 202 | /*␊ |
| 203 | * To simplify stripping of objects that use are used with the dynamic link␊ |
| 204 | * editor, the static link editor marks the symbols defined an object that are␊ |
| 205 | * referenced by a dynamicly bound object (dynamic shared libraries, bundles).␊ |
| 206 | * With this marking strip knows not to strip these symbols.␊ |
| 207 | */␊ |
| 208 | #define REFERENCED_DYNAMICALLY␉0x0010␊ |
| 209 | ␊ |
| 210 | /*␊ |
| 211 | * For images created by the static link editor with the -twolevel_namespace␊ |
| 212 | * option in effect the flags field of the mach header is marked with␊ |
| 213 | * MH_TWOLEVEL. And the binding of the undefined references of the image are␊ |
| 214 | * determined by the static link editor. Which library an undefined symbol is␊ |
| 215 | * bound to is recorded by the static linker in the high 8 bits of the n_desc␊ |
| 216 | * field using the SET_LIBRARY_ORDINAL macro below. The ordinal recorded␊ |
| 217 | * references the libraries listed in the Mach-O's LC_LOAD_DYLIB,␊ |
| 218 | * LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_LOAD_UPWARD_DYLIB, and␊ |
| 219 | * LC_LAZY_LOAD_DYLIB, etc. load commands in the order they appear in the␊ |
| 220 | * headers. The library ordinals start from 1.␊ |
| 221 | * For a dynamic library that is built as a two-level namespace image the␊ |
| 222 | * undefined references from module defined in another use the same nlist struct␊ |
| 223 | * an in that case SELF_LIBRARY_ORDINAL is used as the library ordinal. For␊ |
| 224 | * defined symbols in all images they also must have the library ordinal set to␊ |
| 225 | * SELF_LIBRARY_ORDINAL. The EXECUTABLE_ORDINAL refers to the executable␊ |
| 226 | * image for references from plugins that refer to the executable that loads␊ |
| 227 | * them.␊ |
| 228 | * ␊ |
| 229 | * The DYNAMIC_LOOKUP_ORDINAL is for undefined symbols in a two-level namespace␊ |
| 230 | * image that are looked up by the dynamic linker with flat namespace semantics.␊ |
| 231 | * This ordinal was added as a feature in Mac OS X 10.3 by reducing the␊ |
| 232 | * value of MAX_LIBRARY_ORDINAL by one. So it is legal for existing binaries␊ |
| 233 | * or binaries built with older tools to have 0xfe (254) dynamic libraries. In␊ |
| 234 | * this case the ordinal value 0xfe (254) must be treated as a library ordinal␊ |
| 235 | * for compatibility. ␊ |
| 236 | */␊ |
| 237 | #define GET_LIBRARY_ORDINAL(n_desc) (((n_desc) >> 8) & 0xff)␊ |
| 238 | #define SET_LIBRARY_ORDINAL(n_desc,ordinal) \␊ |
| 239 | ␉(n_desc) = (((n_desc) & 0x00ff) | (((ordinal) & 0xff) << 8))␊ |
| 240 | #define SELF_LIBRARY_ORDINAL 0x0␊ |
| 241 | #define MAX_LIBRARY_ORDINAL 0xfd␊ |
| 242 | #define DYNAMIC_LOOKUP_ORDINAL 0xfe␊ |
| 243 | #define EXECUTABLE_ORDINAL 0xff␊ |
| 244 | ␊ |
| 245 | /*␊ |
| 246 | * The bit 0x0020 of the n_desc field is used for two non-overlapping purposes␊ |
| 247 | * and has two different symbolic names, N_NO_DEAD_STRIP and N_DESC_DISCARDED.␊ |
| 248 | */␊ |
| 249 | ␊ |
| 250 | /*␊ |
| 251 | * The N_NO_DEAD_STRIP bit of the n_desc field only ever appears in a ␊ |
| 252 | * relocatable .o file (MH_OBJECT filetype). And is used to indicate to the␊ |
| 253 | * static link editor it is never to dead strip the symbol.␊ |
| 254 | */␊ |
| 255 | #define N_NO_DEAD_STRIP 0x0020 /* symbol is not to be dead stripped */␊ |
| 256 | ␊ |
| 257 | /*␊ |
| 258 | * The N_DESC_DISCARDED bit of the n_desc field never appears in linked image.␊ |
| 259 | * But is used in very rare cases by the dynamic link editor to mark an in␊ |
| 260 | * memory symbol as discared and longer used for linking.␊ |
| 261 | */␊ |
| 262 | #define N_DESC_DISCARDED 0x0020␉/* symbol is discarded */␊ |
| 263 | ␊ |
| 264 | /*␊ |
| 265 | * The N_WEAK_REF bit of the n_desc field indicates to the dynamic linker that␊ |
| 266 | * the undefined symbol is allowed to be missing and is to have the address of␊ |
| 267 | * zero when missing.␊ |
| 268 | */␊ |
| 269 | #define N_WEAK_REF␉0x0040 /* symbol is weak referenced */␊ |
| 270 | ␊ |
| 271 | /*␊ |
| 272 | * The N_WEAK_DEF bit of the n_desc field indicates to the static and dynamic␊ |
| 273 | * linkers that the symbol definition is weak, allowing a non-weak symbol to␊ |
| 274 | * also be used which causes the weak definition to be discared. Currently this␊ |
| 275 | * is only supported for symbols in coalesed sections.␊ |
| 276 | */␊ |
| 277 | #define N_WEAK_DEF␉0x0080 /* coalesed symbol is a weak definition */␊ |
| 278 | ␊ |
| 279 | /*␊ |
| 280 | * The N_REF_TO_WEAK bit of the n_desc field indicates to the dynamic linker␊ |
| 281 | * that the undefined symbol should be resolved using flat namespace searching.␊ |
| 282 | */␊ |
| 283 | #define␉N_REF_TO_WEAK␉0x0080 /* reference to a weak symbol */␊ |
| 284 | ␊ |
| 285 | /*␊ |
| 286 | * The N_ARM_THUMB_DEF bit of the n_desc field indicates that the symbol is␊ |
| 287 | * a defintion of a Thumb function.␊ |
| 288 | */␊ |
| 289 | #define N_ARM_THUMB_DEF␉0x0008 /* symbol is a Thumb function (ARM) */␊ |
| 290 | ␊ |
| 291 | /*␊ |
| 292 | * The N_SYMBOL_RESOLVER bit of the n_desc field indicates that the␊ |
| 293 | * that the function is actually a resolver function and should␊ |
| 294 | * be called to get the address of the real function to use.␊ |
| 295 | * This bit is only available in .o files (MH_OBJECT filetype)␊ |
| 296 | */␊ |
| 297 | #define N_SYMBOL_RESOLVER 0x0100 ␊ |
| 298 | ␊ |
| 299 | #ifndef __STRICT_BSD__␊ |
| 300 | #if __cplusplus␊ |
| 301 | extern "C" {␊ |
| 302 | #endif /* __cplusplus */␊ |
| 303 | /*␊ |
| 304 | * The function nlist(3) from the C library.␊ |
| 305 | */␊ |
| 306 | extern int nlist (const char *filename, struct nlist *list);␊ |
| 307 | #if __cplusplus␊ |
| 308 | }␊ |
| 309 | #endif /* __cplusplus */␊ |
| 310 | #endif /* __STRICT_BSD__ */␊ |
| 311 | ␊ |
| 312 | #endif /* _MACHO_LIST_H_ */␊ |
| 313 | |
