/* * Portions Copyright (c) 1999-2010 Apple Inc. All Rights Reserved. * * 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. * */ #ifndef CPPMICROSERVICES_MACHO_LOADER_H #define CPPMICROSERVICES_MACHO_LOADER_H /* * This file describes the format of mach object files. */ #include typedef int32_t cpu_type_t; typedef int32_t cpu_subtype_t; typedef int32_t vm_prot_t; /* * Capability bits used in the definition of cpu_type. */ #define CPU_ARCH_MASK 0xff000000 /* mask for architecture bits */ #define CPU_ARCH_ABI64 0x01000000 /* 64 bit ABI */ /* * Machine types known by all. */ #define CPU_TYPE_ANY (-1) #define CPU_TYPE_VAX (1) /* skip (2) */ /* skip (3) */ /* skip (4) */ /* skip (5) */ #define CPU_TYPE_MC680x0 (6) #define CPU_TYPE_X86 (7) #define CPU_TYPE_I386 CPU_TYPE_X86 /* compatibility */ #define CPU_TYPE_X86_64 (CPU_TYPE_X86 | CPU_ARCH_ABI64) /* skip CPU_TYPE_MIPS (8) */ /* skip (9) */ #define CPU_TYPE_MC98000 (10) #define CPU_TYPE_HPPA (11) #define CPU_TYPE_ARM (12) #define CPU_TYPE_MC88000 (13) #define CPU_TYPE_SPARC (14) #define CPU_TYPE_I860 (15) /* skip CPU_TYPE_ALPHA (16) */ /* skip (17) */ #define CPU_TYPE_POWERPC (18) #define CPU_TYPE_POWERPC64 (CPU_TYPE_POWERPC | CPU_ARCH_ABI64) #ifndef _MACH_O_FAT_H_ #define _MACH_O_FAT_H_ /* * This header file describes the structures of the file format for "fat" * architecture specific file (wrapper design). At the begining of the file * there is one fat_header structure followed by a number of fat_arch * structures. For each architecture in the file, specified by a pair of * cputype and cpusubtype, the fat_header describes the file offset, file * size and alignment in the file of the architecture specific member. * The padded bytes in the file to place each member on it's specific alignment * are defined to be read as zeros and can be left as "holes" if the file system * can support them as long as they read as zeros. * * All structures defined here are always written and read to/from disk * in big-endian order. */ #define FAT_MAGIC 0xcafebabe #define FAT_CIGAM 0xbebafeca /* NXSwapLong(FAT_MAGIC) */ struct fat_header { uint32_t magic; /* FAT_MAGIC */ uint32_t nfat_arch; /* number of structs that follow */ }; struct fat_arch { cpu_type_t cputype; /* cpu specifier (int) */ cpu_subtype_t cpusubtype; /* machine specifier (int) */ uint32_t offset; /* file offset to this object file */ uint32_t size; /* size of this object file */ uint32_t align; /* alignment as a power of 2 */ }; #endif /* _MACH_O_FAT_H_ */ /* * The 32-bit mach header appears at the very beginning of the object file for * 32-bit architectures. */ struct mach_header { uint32_t magic; /* mach magic number identifier */ cpu_type_t cputype; /* cpu specifier */ cpu_subtype_t cpusubtype; /* machine specifier */ uint32_t filetype; /* type of file */ uint32_t ncmds; /* number of load commands */ uint32_t sizeofcmds; /* the size of all the load commands */ uint32_t flags; /* flags */ }; /* Constant for the magic field of the mach_header (32-bit architectures) */ #define MH_MAGIC 0xfeedface /* the mach magic number */ #define MH_CIGAM 0xcefaedfe /* NXSwapInt(MH_MAGIC) */ /* * The 64-bit mach header appears at the very beginning of object files for * 64-bit architectures. */ struct mach_header_64 { uint32_t magic; /* mach magic number identifier */ cpu_type_t cputype; /* cpu specifier */ cpu_subtype_t cpusubtype; /* machine specifier */ uint32_t filetype; /* type of file */ uint32_t ncmds; /* number of load commands */ uint32_t sizeofcmds; /* the size of all the load commands */ uint32_t flags; /* flags */ uint32_t reserved; /* reserved */ }; /* Constant for the magic field of the mach_header_64 (64-bit architectures) */ #define MH_MAGIC_64 0xfeedfacf /* the 64-bit mach magic number */ #define MH_CIGAM_64 0xcffaedfe /* NXSwapInt(MH_MAGIC_64) */ /* * The layout of the file depends on the filetype. For all but the MH_OBJECT * file type the segments are padded out and aligned on a segment alignment * boundary for efficient demand pageing. The MH_EXECUTE, MH_FVMLIB, MH_DYLIB, * MH_DYLINKER and MH_BUNDLE file types also have the headers included as part * of their first segment. * * The file type MH_OBJECT is a compact format intended as output of the * assembler and input (and possibly output) of the link editor (the .o * format). All sections are in one unnamed segment with no segment padding. * This format is used as an executable format when the file is so small the * segment padding greatly increases its size. * * The file type MH_PRELOAD is an executable format intended for things that * are not executed under the kernel (proms, stand alones, kernels, etc). The * format can be executed under the kernel but may demand paged it and not * preload it before execution. * * A core file is in MH_CORE format and can be any in an arbritray legal * Mach-O file. * * Constants for the filetype field of the mach_header */ #define MH_OBJECT 0x1 /* relocatable object file */ #define MH_EXECUTE 0x2 /* demand paged executable file */ #define MH_FVMLIB 0x3 /* fixed VM shared library file */ #define MH_CORE 0x4 /* core file */ #define MH_PRELOAD 0x5 /* preloaded executable file */ #define MH_DYLIB 0x6 /* dynamically bound shared library */ #define MH_DYLINKER 0x7 /* dynamic link editor */ #define MH_BUNDLE 0x8 /* dynamically bound bundle file */ #define MH_DYLIB_STUB 0x9 /* shared library stub for static */ /* linking only, no section contents */ #define MH_DSYM 0xa /* companion file with only debug */ /* sections */ #define MH_KEXT_BUNDLE 0xb /* x86_64 kexts */ /* Constants for the flags field of the mach_header */ #define MH_NOUNDEFS 0x1 /* the object file has no undefined references */ #define MH_INCRLINK 0x2 /* the object file is the output of an incremental link against a base file and can't be link edited again */ #define MH_DYLDLINK 0x4 /* the object file is input for the dynamic linker and can't be staticly link edited again */ #define MH_BINDATLOAD 0x8 /* the object file's undefined references are bound by the dynamic linker when loaded. */ #define MH_PREBOUND 0x10 /* the file has its dynamic undefined references prebound. */ #define MH_SPLIT_SEGS 0x20 /* the file has its read-only and read-write segments split */ #define MH_LAZY_INIT 0x40 /* the shared library init routine is to be run lazily via catching memory faults to its writeable segments (obsolete) */ #define MH_TWOLEVEL 0x80 /* the image is using two-level name space bindings */ #define MH_FORCE_FLAT 0x100 /* the executable is forcing all images to use flat name space bindings */ #define MH_NOMULTIDEFS 0x200 /* this umbrella guarantees no multiple defintions of symbols in its sub-images so the two-level namespace hints can always be used. */ #define MH_NOFIXPREBINDING 0x400 /* do not have dyld notify the prebinding agent about this executable */ #define MH_PREBINDABLE 0x800 /* the binary is not prebound but can have its prebinding redone. only used when MH_PREBOUND is not set. */ #define MH_ALLMODSBOUND 0x1000 /* indicates that this binary binds to all two-level namespace modules of its dependent libraries. only used when MH_PREBINDABLE and MH_TWOLEVEL are both set. */ #define MH_SUBSECTIONS_VIA_SYMBOLS 0x2000/* safe to divide up the sections into sub-sections via symbols for dead code stripping */ #define MH_CANONICAL 0x4000 /* the binary has been canonicalized via the unprebind operation */ #define MH_WEAK_DEFINES 0x8000 /* the final linked image contains external weak symbols */ #define MH_BINDS_TO_WEAK 0x10000 /* the final linked image uses weak symbols */ #define MH_ALLOW_STACK_EXECUTION 0x20000/* When this bit is set, all stacks in the task will be given stack execution privilege. Only used in MH_EXECUTE filetypes. */ #define MH_ROOT_SAFE 0x40000 /* When this bit is set, the binary declares it is safe for use in processes with uid zero */ #define MH_SETUID_SAFE 0x80000 /* When this bit is set, the binary declares it is safe for use in processes when issetugid() is true */ #define MH_NO_REEXPORTED_DYLIBS 0x100000 /* When this bit is set on a dylib, the static linker does not need to examine dependent dylibs to see if any are re-exported */ #define MH_PIE 0x200000 /* When this bit is set, the OS will load the main executable at a random address. Only used in MH_EXECUTE filetypes. */ #define MH_DEAD_STRIPPABLE_DYLIB 0x400000 /* Only for use on dylibs. When linking against a dylib that has this bit set, the static linker will automatically not create a LC_LOAD_DYLIB load command to the dylib if no symbols are being referenced from the dylib. */ #define MH_HAS_TLV_DESCRIPTORS 0x800000 /* Contains a section of type S_THREAD_LOCAL_VARIABLES */ #define MH_NO_HEAP_EXECUTION 0x1000000 /* When this bit is set, the OS will run the main executable with a non-executable heap even on platforms (e.g. i386) that don't require it. Only used in MH_EXECUTE filetypes. */ /* * The load commands directly follow the mach_header. The total size of all * of the commands is given by the sizeofcmds field in the mach_header. All * load commands must have as their first two fields cmd and cmdsize. The cmd * field is filled in with a constant for that command type. Each command type * has a structure specifically for it. The cmdsize field is the size in bytes * of the particular load command structure plus anything that follows it that * is a part of the load command (i.e. section structures, strings, etc.). To * advance to the next load command the cmdsize can be added to the offset or * pointer of the current load command. The cmdsize for 32-bit architectures * MUST be a multiple of 4 bytes and for 64-bit architectures MUST be a multiple * of 8 bytes (these are forever the maximum alignment of any load commands). * The padded bytes must be zero. All tables in the object file must also * follow these rules so the file can be memory mapped. Otherwise the pointers * to these tables will not work well or at all on some machines. With all * padding zeroed like objects will compare byte for byte. */ struct load_command { uint32_t cmd; /* type of load command */ uint32_t cmdsize; /* total size of command in bytes */ }; /* * After MacOS X 10.1 when a new load command is added that is required to be * understood by the dynamic linker for the image to execute properly the * LC_REQ_DYLD bit will be or'ed into the load command constant. If the dynamic * linker sees such a load command it it does not understand will issue a * "unknown load command required for execution" error and refuse to use the * image. Other load commands without this bit that are not understood will * simply be ignored. */ #define LC_REQ_DYLD 0x80000000 /* Constants for the cmd field of all load commands, the type */ #define LC_SEGMENT 0x1 /* segment of this file to be mapped */ #define LC_SYMTAB 0x2 /* link-edit stab symbol table info */ #define LC_SYMSEG 0x3 /* link-edit gdb symbol table info (obsolete) */ #define LC_THREAD 0x4 /* thread */ #define LC_UNIXTHREAD 0x5 /* unix thread (includes a stack) */ #define LC_LOADFVMLIB 0x6 /* load a specified fixed VM shared library */ #define LC_IDFVMLIB 0x7 /* fixed VM shared library identification */ #define LC_IDENT 0x8 /* object identification info (obsolete) */ #define LC_FVMFILE 0x9 /* fixed VM file inclusion (internal use) */ #define LC_PREPAGE 0xa /* prepage command (internal use) */ #define LC_DYSYMTAB 0xb /* dynamic link-edit symbol table info */ #define LC_LOAD_DYLIB 0xc /* load a dynamically linked shared library */ #define LC_ID_DYLIB 0xd /* dynamically linked shared lib ident */ #define LC_LOAD_DYLINKER 0xe /* load a dynamic linker */ #define LC_ID_DYLINKER 0xf /* dynamic linker identification */ #define LC_PREBOUND_DYLIB 0x10 /* modules prebound for a dynamically */ /* linked shared library */ #define LC_ROUTINES 0x11 /* image routines */ #define LC_SUB_FRAMEWORK 0x12 /* sub framework */ #define LC_SUB_UMBRELLA 0x13 /* sub umbrella */ #define LC_SUB_CLIENT 0x14 /* sub client */ #define LC_SUB_LIBRARY 0x15 /* sub library */ #define LC_TWOLEVEL_HINTS 0x16 /* two-level namespace lookup hints */ #define LC_PREBIND_CKSUM 0x17 /* prebind checksum */ /* * load a dynamically linked shared library that is allowed to be missing * (all symbols are weak imported). */ #define LC_LOAD_WEAK_DYLIB (0x18 | LC_REQ_DYLD) #define LC_SEGMENT_64 0x19 /* 64-bit segment of this file to be mapped */ #define LC_ROUTINES_64 0x1a /* 64-bit image routines */ #define LC_UUID 0x1b /* the uuid */ #define LC_RPATH (0x1c | LC_REQ_DYLD) /* runpath additions */ #define LC_CODE_SIGNATURE 0x1d /* local of code signature */ #define LC_SEGMENT_SPLIT_INFO 0x1e /* local of info to split segments */ #define LC_REEXPORT_DYLIB (0x1f | LC_REQ_DYLD) /* load and re-export dylib */ #define LC_LAZY_LOAD_DYLIB 0x20 /* delay load of dylib until first use */ #define LC_ENCRYPTION_INFO 0x21 /* encrypted segment information */ #define LC_DYLD_INFO 0x22 /* compressed dyld information */ #define LC_DYLD_INFO_ONLY (0x22|LC_REQ_DYLD) /* compressed dyld information only */ #define LC_LOAD_UPWARD_DYLIB (0x23 | LC_REQ_DYLD) /* load upward dylib */ #define LC_VERSION_MIN_MACOSX 0x24 /* build for MacOSX min OS version */ #define LC_VERSION_MIN_IPHONEOS 0x25 /* build for iPhoneOS min OS version */ #define LC_FUNCTION_STARTS 0x26 /* compressed table of function start addresses */ #define LC_DYLD_ENVIRONMENT 0x27 /* string for dyld to treat like environment variable */ /* * A variable length string in a load command is represented by an lc_str * union. The strings are stored just after the load command structure and * the offset is from the start of the load command structure. The size * of the string is reflected in the cmdsize field of the load command. * Once again any padded bytes to bring the cmdsize field to a multiple * of 4 bytes must be zero. */ union lc_str { uint32_t offset; /* offset to the string */ #ifndef __LP64__ char *ptr; /* pointer to the string */ #endif }; /* * Dynamicly linked shared libraries are identified by two things. The * pathname (the name of the library as found for execution), and the * compatibility version number. The pathname must match and the compatibility * number in the user of the library must be greater than or equal to the * library being used. The time stamp is used to record the time a library was * built and copied into user so it can be use to determined if the library used * at runtime is exactly the same as used to built the program. */ struct dylib { union lc_str name; /* library's path name */ uint32_t timestamp; /* library's build time stamp */ uint32_t current_version; /* library's current version number */ uint32_t compatibility_version; /* library's compatibility vers number*/ }; /* * A dynamically linked shared library (filetype == MH_DYLIB in the mach header) * contains a dylib_command (cmd == LC_ID_DYLIB) to identify the library. * An object that uses a dynamically linked shared library also contains a * dylib_command (cmd == LC_LOAD_DYLIB, LC_LOAD_WEAK_DYLIB, or * LC_REEXPORT_DYLIB) for each library it uses. */ struct dylib_command { uint32_t cmd; /* LC_ID_DYLIB, LC_LOAD_{,WEAK_}DYLIB, LC_REEXPORT_DYLIB */ uint32_t cmdsize; /* includes pathname string */ struct dylib dylib; /* the library identification */ }; /* * The symtab_command contains the offsets and sizes of the link-edit 4.3BSD * "stab" style symbol table information as described in the header files * and . */ struct symtab_command { uint32_t cmd; /* LC_SYMTAB */ uint32_t cmdsize; /* sizeof(struct symtab_command) */ uint32_t symoff; /* symbol table offset */ uint32_t nsyms; /* number of symbol table entries */ uint32_t stroff; /* string table offset */ uint32_t strsize; /* string table size in bytes */ }; /* * This is the second set of the symbolic information which is used to support * the data structures for the dynamically link editor. * * The original set of symbolic information in the symtab_command which contains * the symbol and string tables must also be present when this load command is * present. When this load command is present the symbol table is organized * into three groups of symbols: * local symbols (static and debugging symbols) - grouped by module * defined external symbols - grouped by module (sorted by name if not lib) * undefined external symbols (sorted by name if MH_BINDATLOAD is not set, * and in order the were seen by the static * linker if MH_BINDATLOAD is set) * In this load command there are offsets and counts to each of the three groups * of symbols. * * This load command contains a the offsets and sizes of the following new * symbolic information tables: * table of contents * module table * reference symbol table * indirect symbol table * The first three tables above (the table of contents, module table and * reference symbol table) are only present if the file is a dynamically linked * shared library. For executable and object modules, which are files * containing only one module, the information that would be in these three * tables is determined as follows: * table of contents - the defined external symbols are sorted by name * module table - the file contains only one module so everything in the * file is part of the module. * reference symbol table - is the defined and undefined external symbols * * For dynamically linked shared library files this load command also contains * offsets and sizes to the pool of relocation entries for all sections * separated into two groups: * external relocation entries * local relocation entries * For executable and object modules the relocation entries continue to hang * off the section structures. */ struct dysymtab_command { uint32_t cmd; /* LC_DYSYMTAB */ uint32_t cmdsize; /* sizeof(struct dysymtab_command) */ /* * The symbols indicated by symoff and nsyms of the LC_SYMTAB load command * are grouped into the following three groups: * local symbols (further grouped by the module they are from) * defined external symbols (further grouped by the module they are from) * undefined symbols * * The local symbols are used only for debugging. The dynamic binding * process may have to use them to indicate to the debugger the local * symbols for a module that is being bound. * * The last two groups are used by the dynamic binding process to do the * binding (indirectly through the module table and the reference symbol * table when this is a dynamically linked shared library file). */ uint32_t ilocalsym; /* index to local symbols */ uint32_t nlocalsym; /* number of local symbols */ uint32_t iextdefsym;/* index to externally defined symbols */ uint32_t nextdefsym;/* number of externally defined symbols */ uint32_t iundefsym; /* index to undefined symbols */ uint32_t nundefsym; /* number of undefined symbols */ /* * For the for the dynamic binding process to find which module a symbol * is defined in the table of contents is used (analogous to the ranlib * structure in an archive) which maps defined external symbols to modules * they are defined in. This exists only in a dynamically linked shared * library file. For executable and object modules the defined external * symbols are sorted by name and is use as the table of contents. */ uint32_t tocoff; /* file offset to table of contents */ uint32_t ntoc; /* number of entries in table of contents */ /* * To support dynamic binding of "modules" (whole object files) the symbol * table must reflect the modules that the file was created from. This is * done by having a module table that has indexes and counts into the merged * tables for each module. The module structure that these two entries * refer to is described below. This exists only in a dynamically linked * shared library file. For executable and object modules the file only * contains one module so everything in the file belongs to the module. */ uint32_t modtaboff; /* file offset to module table */ uint32_t nmodtab; /* number of module table entries */ /* * To support dynamic module binding the module structure for each module * indicates the external references (defined and undefined) each module * makes. For each module there is an offset and a count into the * reference symbol table for the symbols that the module references. * This exists only in a dynamically linked shared library file. For * executable and object modules the defined external symbols and the * undefined external symbols indicates the external references. */ uint32_t extrefsymoff; /* offset to referenced symbol table */ uint32_t nextrefsyms; /* number of referenced symbol table entries */ /* * The sections that contain "symbol pointers" and "routine stubs" have * indexes and (implied counts based on the size of the section and fixed * size of the entry) into the "indirect symbol" table for each pointer * and stub. For every section of these two types the index into the * indirect symbol table is stored in the section header in the field * reserved1. An indirect symbol table entry is simply a 32bit index into * the symbol table to the symbol that the pointer or stub is referring to. * The indirect symbol table is ordered to match the entries in the section. */ uint32_t indirectsymoff; /* file offset to the indirect symbol table */ uint32_t nindirectsyms; /* number of indirect symbol table entries */ /* * To support relocating an individual module in a library file quickly the * external relocation entries for each module in the library need to be * accessed efficiently. Since the relocation entries can't be accessed * through the section headers for a library file they are separated into * groups of local and external entries further grouped by module. In this * case the presents of this load command who's extreloff, nextrel, * locreloff and nlocrel fields are non-zero indicates that the relocation * entries of non-merged sections are not referenced through the section * structures (and the reloff and nreloc fields in the section headers are * set to zero). * * Since the relocation entries are not accessed through the section headers * this requires the r_address field to be something other than a section * offset to identify the item to be relocated. In this case r_address is * set to the offset from the vmaddr of the first LC_SEGMENT command. * For MH_SPLIT_SEGS images r_address is set to the the offset from the * vmaddr of the first read-write LC_SEGMENT command. * * The relocation entries are grouped by module and the module table * entries have indexes and counts into them for the group of external * relocation entries for that the module. * * For sections that are merged across modules there must not be any * remaining external relocation entries for them (for merged sections * remaining relocation entries must be local). */ uint32_t extreloff; /* offset to external relocation entries */ uint32_t nextrel; /* number of external relocation entries */ /* * All the local relocation entries are grouped together (they are not * grouped by their module since they are only used if the object is moved * from it staticly link edited address). */ uint32_t locreloff; /* offset to local relocation entries */ uint32_t nlocrel; /* number of local relocation entries */ }; /* * The rpath_command contains a path which at runtime should be added to * the current run path used to find @rpath prefixed dylibs. */ struct rpath_command { uint32_t cmd; /* LC_RPATH */ uint32_t cmdsize; /* includes string */ union lc_str path; /* path to add to run path */ }; #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 */ /* * 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 */ 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 */ 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 */ /* * 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 */ #endif /* _MACHO_LIST_H_ */ #endif /* CPPMICROSERVICES_MACHO_LOADER_H */