macho.rs source code [crates/object/src/macho.rs]

1	//! Mach-O definitions.
2	//!
3	//! These definitions are independent of read/write support, although we do implement
4	//! some traits useful for those.
5	//!
6	//! This module is based heavily on header files from MacOSX11.1.sdk.
7
8	#![allow(missing_docs)]
9
10	use crate::endian::{BigEndian, Endian, U64Bytes, U16, U32, U64};
11	use crate::pod::Pod;
12
13	// Definitions from "/usr/include/mach/machine.h".
14
15	/*
16	* Capability bits used in the definition of cpu_type.
17	*/
18
19	/// mask for architecture bits
20	pub const CPU_ARCH_MASK: u32 = `0xff00_0000`;
21	/// 64 bit ABI
22	pub const CPU_ARCH_ABI64: u32 = `0x0100_0000`;
23	/// ABI for 64-bit hardware with 32-bit types; LP32
24	pub const CPU_ARCH_ABI64_32: u32 = `0x0200_0000`;
25
26	/*
27	* Machine types known by all.
28	*/
29
30	pub const CPU_TYPE_ANY: u32 = !`0`;
31
32	pub const CPU_TYPE_VAX: u32 = `1`;
33	pub const CPU_TYPE_MC680X0: u32 = `6`;
34	pub const CPU_TYPE_X86: u32 = `7`;
35	pub const CPU_TYPE_X86_64: u32 = CPU_TYPE_X86 \| CPU_ARCH_ABI64;
36	pub const CPU_TYPE_MIPS: u32 = `8`;
37	pub const CPU_TYPE_MC98000: u32 = `10`;
38	pub const CPU_TYPE_HPPA: u32 = `11`;
39	pub const CPU_TYPE_ARM: u32 = `12`;
40	pub const CPU_TYPE_ARM64: u32 = CPU_TYPE_ARM \| CPU_ARCH_ABI64;
41	pub const CPU_TYPE_ARM64_32: u32 = CPU_TYPE_ARM \| CPU_ARCH_ABI64_32;
42	pub const CPU_TYPE_MC88000: u32 = `13`;
43	pub const CPU_TYPE_SPARC: u32 = `14`;
44	pub const CPU_TYPE_I860: u32 = `15`;
45	pub const CPU_TYPE_ALPHA: u32 = `16`;
46	pub const CPU_TYPE_POWERPC: u32 = `18`;
47	pub const CPU_TYPE_POWERPC64: u32 = CPU_TYPE_POWERPC \| CPU_ARCH_ABI64;
48
49	/*
50	* Capability bits used in the definition of cpu_subtype.
51	*/
52	/// mask for feature flags
53	pub const CPU_SUBTYPE_MASK: u32 = `0xff00_0000`;
54	/// 64 bit libraries
55	pub const CPU_SUBTYPE_LIB64: u32 = `0x8000_0000`;
56	/// pointer authentication with versioned ABI
57	pub const CPU_SUBTYPE_PTRAUTH_ABI: u32 = `0x8000_0000`;
58
59	/// When selecting a slice, ANY will pick the slice with the best
60	/// grading for the selected cpu_type_t, unlike the "ALL" subtypes,
61	/// which are the slices that can run on any hardware for that cpu type.
62	pub const CPU_SUBTYPE_ANY: u32 = !`0`;
63
64	/*
65	* Object files that are hand-crafted to run on any
66	* implementation of an architecture are tagged with
67	* CPU_SUBTYPE_MULTIPLE. This functions essentially the same as
68	* the "ALL" subtype of an architecture except that it allows us
69	* to easily find object files that may need to be modified
70	* whenever a new implementation of an architecture comes out.
71	*
72	* It is the responsibility of the implementor to make sure the
73	* software handles unsupported implementations elegantly.
74	*/
75	pub const CPU_SUBTYPE_MULTIPLE: u32 = !`0`;
76	pub const CPU_SUBTYPE_LITTLE_ENDIAN: u32 = `0`;
77	pub const CPU_SUBTYPE_BIG_ENDIAN: u32 = `1`;
78
79	/*
80	* VAX subtypes (these do not necessary conform to the actual cpu
81	* ID assigned by DEC available via the SID register).
82	*/
83
84	pub const CPU_SUBTYPE_VAX_ALL: u32 = `0`;
85	pub const CPU_SUBTYPE_VAX780: u32 = `1`;
86	pub const CPU_SUBTYPE_VAX785: u32 = `2`;
87	pub const CPU_SUBTYPE_VAX750: u32 = `3`;
88	pub const CPU_SUBTYPE_VAX730: u32 = `4`;
89	pub const CPU_SUBTYPE_UVAXI: u32 = `5`;
90	pub const CPU_SUBTYPE_UVAXII: u32 = `6`;
91	pub const CPU_SUBTYPE_VAX8200: u32 = `7`;
92	pub const CPU_SUBTYPE_VAX8500: u32 = `8`;
93	pub const CPU_SUBTYPE_VAX8600: u32 = `9`;
94	pub const CPU_SUBTYPE_VAX8650: u32 = `10`;
95	pub const CPU_SUBTYPE_VAX8800: u32 = `11`;
96	pub const CPU_SUBTYPE_UVAXIII: u32 = `12`;
97
98	/*
99	* 680x0 subtypes
100	*
101	* The subtype definitions here are unusual for historical reasons.
102	* NeXT used to consider 68030 code as generic 68000 code. For
103	* backwards compatibility:
104	*
105	* CPU_SUBTYPE_MC68030 symbol has been preserved for source code
106	* compatibility.
107	*
108	* CPU_SUBTYPE_MC680x0_ALL has been defined to be the same
109	* subtype as CPU_SUBTYPE_MC68030 for binary comatability.
110	*
111	* CPU_SUBTYPE_MC68030_ONLY has been added to allow new object
112	* files to be tagged as containing 68030-specific instructions.
113	*/
114
115	pub const CPU_SUBTYPE_MC680X0_ALL: u32 = `1`;
116	// compat
117	pub const CPU_SUBTYPE_MC68030: u32 = `1`;
118	pub const CPU_SUBTYPE_MC68040: u32 = `2`;
119	pub const CPU_SUBTYPE_MC68030_ONLY: u32 = `3`;
120
121	/*
122	* I386 subtypes
123	*/
124
125	#[inline]
126	pub const fn cpu_subtype_intel(f: u32, m: u32) -> u32 {
127	f + (m << `4`)
128	}
129
130	pub const CPU_SUBTYPE_I386_ALL: u32 = cpu_subtype_intel(f:`3`, m:`0`);
131	pub const CPU_SUBTYPE_386: u32 = cpu_subtype_intel(f:`3`, m:`0`);
132	pub const CPU_SUBTYPE_486: u32 = cpu_subtype_intel(f:`4`, m:`0`);
133	pub const CPU_SUBTYPE_486SX: u32 = cpu_subtype_intel(f:`4`, m:`8`);
134	pub const CPU_SUBTYPE_586: u32 = cpu_subtype_intel(f:`5`, m:`0`);
135	pub const CPU_SUBTYPE_PENT: u32 = cpu_subtype_intel(f:`5`, m:`0`);
136	pub const CPU_SUBTYPE_PENTPRO: u32 = cpu_subtype_intel(f:`6`, m:`1`);
137	pub const CPU_SUBTYPE_PENTII_M3: u32 = cpu_subtype_intel(f:`6`, m:`3`);
138	pub const CPU_SUBTYPE_PENTII_M5: u32 = cpu_subtype_intel(f:`6`, m:`5`);
139	pub const CPU_SUBTYPE_CELERON: u32 = cpu_subtype_intel(f:`7`, m:`6`);
140	pub const CPU_SUBTYPE_CELERON_MOBILE: u32 = cpu_subtype_intel(f:`7`, m:`7`);
141	pub const CPU_SUBTYPE_PENTIUM_3: u32 = cpu_subtype_intel(f:`8`, m:`0`);
142	pub const CPU_SUBTYPE_PENTIUM_3_M: u32 = cpu_subtype_intel(f:`8`, m:`1`);
143	pub const CPU_SUBTYPE_PENTIUM_3_XEON: u32 = cpu_subtype_intel(f:`8`, m:`2`);
144	pub const CPU_SUBTYPE_PENTIUM_M: u32 = cpu_subtype_intel(f:`9`, m:`0`);
145	pub const CPU_SUBTYPE_PENTIUM_4: u32 = cpu_subtype_intel(f:`10`, m:`0`);
146	pub const CPU_SUBTYPE_PENTIUM_4_M: u32 = cpu_subtype_intel(f:`10`, m:`1`);
147	pub const CPU_SUBTYPE_ITANIUM: u32 = cpu_subtype_intel(f:`11`, m:`0`);
148	pub const CPU_SUBTYPE_ITANIUM_2: u32 = cpu_subtype_intel(f:`11`, m:`1`);
149	pub const CPU_SUBTYPE_XEON: u32 = cpu_subtype_intel(f:`12`, m:`0`);
150	pub const CPU_SUBTYPE_XEON_MP: u32 = cpu_subtype_intel(f:`12`, m:`1`);
151
152	#[inline]
153	pub const fn cpu_subtype_intel_family(x: u32) -> u32 {
154	x & `15`
155	}
156	pub const CPU_SUBTYPE_INTEL_FAMILY_MAX: u32 = `15`;
157
158	#[inline]
159	pub const fn cpu_subtype_intel_model(x: u32) -> u32 {
160	x >> `4`
161	}
162	pub const CPU_SUBTYPE_INTEL_MODEL_ALL: u32 = `0`;
163
164	/*
165	* X86 subtypes.
166	*/
167
168	pub const CPU_SUBTYPE_X86_ALL: u32 = `3`;
169	pub const CPU_SUBTYPE_X86_64_ALL: u32 = `3`;
170	pub const CPU_SUBTYPE_X86_ARCH1: u32 = `4`;
171	/// Haswell feature subset
172	pub const CPU_SUBTYPE_X86_64_H: u32 = `8`;
173
174	/*
175	* Mips subtypes.
176	*/
177
178	pub const CPU_SUBTYPE_MIPS_ALL: u32 = `0`;
179	pub const CPU_SUBTYPE_MIPS_R2300: u32 = `1`;
180	pub const CPU_SUBTYPE_MIPS_R2600: u32 = `2`;
181	pub const CPU_SUBTYPE_MIPS_R2800: u32 = `3`;
182	/// pmax
183	pub const CPU_SUBTYPE_MIPS_R2000A: u32 = `4`;
184	pub const CPU_SUBTYPE_MIPS_R2000: u32 = `5`;
185	/// 3max
186	pub const CPU_SUBTYPE_MIPS_R3000A: u32 = `6`;
187	pub const CPU_SUBTYPE_MIPS_R3000: u32 = `7`;
188
189	/*
190	* MC98000 (PowerPC) subtypes
191	*/
192	pub const CPU_SUBTYPE_MC98000_ALL: u32 = `0`;
193	pub const CPU_SUBTYPE_MC98601: u32 = `1`;
194
195	/*
196	* HPPA subtypes for Hewlett-Packard HP-PA family of
197	* risc processors. Port by NeXT to 700 series.
198	*/
199
200	pub const CPU_SUBTYPE_HPPA_ALL: u32 = `0`;
201	pub const CPU_SUBTYPE_HPPA_7100LC: u32 = `1`;
202
203	/*
204	* MC88000 subtypes.
205	*/
206	pub const CPU_SUBTYPE_MC88000_ALL: u32 = `0`;
207	pub const CPU_SUBTYPE_MC88100: u32 = `1`;
208	pub const CPU_SUBTYPE_MC88110: u32 = `2`;
209
210	/*
211	* SPARC subtypes
212	*/
213	pub const CPU_SUBTYPE_SPARC_ALL: u32 = `0`;
214
215	/*
216	* I860 subtypes
217	*/
218	pub const CPU_SUBTYPE_I860_ALL: u32 = `0`;
219	pub const CPU_SUBTYPE_I860_860: u32 = `1`;
220
221	/*
222	* PowerPC subtypes
223	*/
224	pub const CPU_SUBTYPE_POWERPC_ALL: u32 = `0`;
225	pub const CPU_SUBTYPE_POWERPC_601: u32 = `1`;
226	pub const CPU_SUBTYPE_POWERPC_602: u32 = `2`;
227	pub const CPU_SUBTYPE_POWERPC_603: u32 = `3`;
228	pub const CPU_SUBTYPE_POWERPC_603E: u32 = `4`;
229	pub const CPU_SUBTYPE_POWERPC_603EV: u32 = `5`;
230	pub const CPU_SUBTYPE_POWERPC_604: u32 = `6`;
231	pub const CPU_SUBTYPE_POWERPC_604E: u32 = `7`;
232	pub const CPU_SUBTYPE_POWERPC_620: u32 = `8`;
233	pub const CPU_SUBTYPE_POWERPC_750: u32 = `9`;
234	pub const CPU_SUBTYPE_POWERPC_7400: u32 = `10`;
235	pub const CPU_SUBTYPE_POWERPC_7450: u32 = `11`;
236	pub const CPU_SUBTYPE_POWERPC_970: u32 = `100`;
237
238	/*
239	* ARM subtypes
240	*/
241	pub const CPU_SUBTYPE_ARM_ALL: u32 = `0`;
242	pub const CPU_SUBTYPE_ARM_V4T: u32 = `5`;
243	pub const CPU_SUBTYPE_ARM_V6: u32 = `6`;
244	pub const CPU_SUBTYPE_ARM_V5TEJ: u32 = `7`;
245	pub const CPU_SUBTYPE_ARM_XSCALE: u32 = `8`;
246	/// ARMv7-A and ARMv7-R
247	pub const CPU_SUBTYPE_ARM_V7: u32 = `9`;
248	/// Cortex A9
249	pub const CPU_SUBTYPE_ARM_V7F: u32 = `10`;
250	/// Swift
251	pub const CPU_SUBTYPE_ARM_V7S: u32 = `11`;
252	pub const CPU_SUBTYPE_ARM_V7K: u32 = `12`;
253	pub const CPU_SUBTYPE_ARM_V8: u32 = `13`;
254	/// Not meant to be run under xnu
255	pub const CPU_SUBTYPE_ARM_V6M: u32 = `14`;
256	/// Not meant to be run under xnu
257	pub const CPU_SUBTYPE_ARM_V7M: u32 = `15`;
258	/// Not meant to be run under xnu
259	pub const CPU_SUBTYPE_ARM_V7EM: u32 = `16`;
260	/// Not meant to be run under xnu
261	pub const CPU_SUBTYPE_ARM_V8M: u32 = `17`;
262
263	/*
264	* ARM64 subtypes
265	*/
266	pub const CPU_SUBTYPE_ARM64_ALL: u32 = `0`;
267	pub const CPU_SUBTYPE_ARM64_V8: u32 = `1`;
268	pub const CPU_SUBTYPE_ARM64E: u32 = `2`;
269
270	/*
271	* ARM64_32 subtypes
272	*/
273	pub const CPU_SUBTYPE_ARM64_32_ALL: u32 = `0`;
274	pub const CPU_SUBTYPE_ARM64_32_V8: u32 = `1`;
275
276	// Definitions from "/usr/include/mach/vm_prot.h".
277
278	/// read permission
279	pub const VM_PROT_READ: u32 = `0x01`;
280	/// write permission
281	pub const VM_PROT_WRITE: u32 = `0x02`;
282	/// execute permission
283	pub const VM_PROT_EXECUTE: u32 = `0x04`;
284
285	// Definitions from https://opensource.apple.com/source/dyld/dyld-210.2.3/launch-cache/dyld_cache_format.h.auto.html
286
287	/// The dyld cache header.
288	/// Corresponds to struct dyld_cache_header from dyld_cache_format.h.
289	/// This header has grown over time. Only the fields up to and including dyld_base_address
290	/// are guaranteed to be present. For all other fields, check the header size before
291	/// accessing the field. The header size is stored in mapping_offset; the mappings start
292	/// right after the theader.
293	#[derive(Debug, Clone, Copy)]
294	#[repr(C)]
295	pub struct DyldCacheHeader<E: Endian> {
296	/// e.g. "dyld_v0 i386"
297	pub magic: [u8; `16`],
298	/// file offset to first dyld_cache_mapping_info
299	pub mapping_offset: U32<E>, // offset: 0x10
300	/// number of dyld_cache_mapping_info entries
301	pub mapping_count: U32<E>, // offset: 0x14
302	/// file offset to first dyld_cache_image_info
303	pub images_offset: U32<E>, // offset: 0x18
304	/// number of dyld_cache_image_info entries
305	pub images_count: U32<E>, // offset: 0x1c
306	/// base address of dyld when cache was built
307	pub dyld_base_address: U64<E>, // offset: 0x20
308	reserved1: [u8; `32`], // offset: 0x28
309	/// file offset of where local symbols are stored
310	pub local_symbols_offset: U64<E>, // offset: 0x48
311	/// size of local symbols information
312	pub local_symbols_size: U64<E>, // offset: 0x50
313	/// unique value for each shared cache file
314	pub uuid: [u8; `16`], // offset: 0x58
315	reserved2: [u8; `32`], // offset: 0x68
316	reserved3: [u8; `32`], // offset: 0x88
317	reserved4: [u8; `32`], // offset: 0xa8
318	reserved5: [u8; `32`], // offset: 0xc8
319	reserved6: [u8; `32`], // offset: 0xe8
320	reserved7: [u8; `32`], // offset: 0x108
321	reserved8: [u8; `32`], // offset: 0x128
322	reserved9: [u8; `32`], // offset: 0x148
323	reserved10: [u8; `32`], // offset: 0x168
324	/// file offset to first dyld_subcache_info
325	pub subcaches_offset: U32<E>, // offset: 0x188
326	/// number of dyld_subcache_info entries
327	pub subcaches_count: U32<E>, // offset: 0x18c
328	/// the UUID of the .symbols subcache
329	pub symbols_subcache_uuid: [u8; `16`], // offset: 0x190
330	reserved11: [u8; `32`], // offset: 0x1a0
331	/// file offset to first dyld_cache_image_info
332	/// Use this instead of images_offset if mapping_offset is at least 0x1c4.
333	pub images_across_all_subcaches_offset: U32<E>, // offset: 0x1c0
334	/// number of dyld_cache_image_info entries
335	/// Use this instead of images_count if mapping_offset is at least 0x1c4.
336	pub images_across_all_subcaches_count: U32<E>, // offset: 0x1c4
337	}
338
339	/// Corresponds to struct dyld_cache_mapping_info from dyld_cache_format.h.
340	#[derive(Debug, Clone, Copy)]
341	#[repr(C)]
342	pub struct DyldCacheMappingInfo<E: Endian> {
343	pub address: U64<E>,
344	pub size: U64<E>,
345	pub file_offset: U64<E>,
346	pub max_prot: U32<E>,
347	pub init_prot: U32<E>,
348	}
349
350	/// Corresponds to struct dyld_cache_image_info from dyld_cache_format.h.
351	#[derive(Debug, Clone, Copy)]
352	#[repr(C)]
353	pub struct DyldCacheImageInfo<E: Endian> {
354	pub address: U64<E>,
355	pub mod_time: U64<E>,
356	pub inode: U64<E>,
357	pub path_file_offset: U32<E>,
358	pub pad: U32<E>,
359	}
360
361	/// Added in dyld-940, which shipped with macOS 12 / iOS 15.
362	/// Originally called `dyld_subcache_entry`, renamed to `dyld_subcache_entry_v1`
363	/// in dyld-1042.1.
364	#[derive(Debug, Clone, Copy)]
365	#[repr(C)]
366	pub struct DyldSubCacheEntryV1<E: Endian> {
367	/// The UUID of this subcache.
368	pub uuid: [u8; `16`],
369	/// The offset of this subcache from the main cache base address.
370	pub cache_vm_offset: U64<E>,
371	}
372
373	/// Added in dyld-1042.1, which shipped with macOS 13 / iOS 16.
374	/// Called `dyld_subcache_entry` as of dyld-1042.1.
375	#[derive(Debug, Clone, Copy)]
376	#[repr(C)]
377	pub struct DyldSubCacheEntryV2<E: Endian> {
378	/// The UUID of this subcache.
379	pub uuid: [u8; `16`],
380	/// The offset of this subcache from the main cache base address.
381	pub cache_vm_offset: U64<E>,
382	/// The file name suffix of the subCache file, e.g. ".25.data" or ".03.development".
383	pub file_suffix: [u8; `32`],
384	}
385
386	// Definitions from "/usr/include/mach-o/loader.h".
387
388	/*
389	* This header file describes the structures of the file format for "fat"
390	* architecture specific file (wrapper design). At the beginning of the file
391	* there is one `FatHeader` structure followed by a number of `FatArch*`
392	* structures. For each architecture in the file, specified by a pair of
393	* cputype and cpusubtype, the `FatHeader` describes the file offset, file
394	* size and alignment in the file of the architecture specific member.
395	* The padded bytes in the file to place each member on it's specific alignment
396	* are defined to be read as zeros and can be left as "holes" if the file system
397	* can support them as long as they read as zeros.
398	*
399	* All structures defined here are always written and read to/from disk
400	* in big-endian order.
401	*/
402
403	pub const FAT_MAGIC: u32 = `0xcafe_babe`;
404	/// NXSwapLong(FAT_MAGIC)
405	pub const FAT_CIGAM: u32 = `0xbeba_feca`;
406
407	#[derive(Debug, Clone, Copy)]
408	#[repr(C)]
409	pub struct FatHeader {
410	/// FAT_MAGIC or FAT_MAGIC_64
411	pub magic: U32<BigEndian>,
412	/// number of structs that follow
413	pub nfat_arch: U32<BigEndian>,
414	}
415
416	#[derive(Debug, Clone, Copy)]
417	#[repr(C)]
418	pub struct FatArch32 {
419	/// cpu specifier (int)
420	pub cputype: U32<BigEndian>,
421	/// machine specifier (int)
422	pub cpusubtype: U32<BigEndian>,
423	/// file offset to this object file
424	pub offset: U32<BigEndian>,
425	/// size of this object file
426	pub size: U32<BigEndian>,
427	/// alignment as a power of 2
428	pub align: U32<BigEndian>,
429	}
430
431	/*
432	* The support for the 64-bit fat file format described here is a work in
433	* progress and not yet fully supported in all the Apple Developer Tools.
434	*
435	* When a slice is greater than 4mb or an offset to a slice is greater than 4mb
436	* then the 64-bit fat file format is used.
437	*/
438	pub const FAT_MAGIC_64: u32 = `0xcafe_babf`;
439	/// NXSwapLong(FAT_MAGIC_64)
440	pub const FAT_CIGAM_64: u32 = `0xbfba_feca`;
441
442	#[derive(Debug, Clone, Copy)]
443	#[repr(C)]
444	pub struct FatArch64 {
445	/// cpu specifier (int)
446	pub cputype: U32<BigEndian>,
447	/// machine specifier (int)
448	pub cpusubtype: U32<BigEndian>,
449	/// file offset to this object file
450	pub offset: U64<BigEndian>,
451	/// size of this object file
452	pub size: U64<BigEndian>,
453	/// alignment as a power of 2
454	pub align: U32<BigEndian>,
455	/// reserved
456	pub reserved: U32<BigEndian>,
457	}
458
459	// Definitions from "/usr/include/mach-o/loader.h".
460
461	/// The 32-bit mach header.
462	///
463	/// Appears at the very beginning of the object file for 32-bit architectures.
464	#[derive(Debug, Clone, Copy)]
465	#[repr(C)]
466	pub struct MachHeader32<E: Endian> {
467	/// mach magic number identifier
468	pub magic: U32<BigEndian>,
469	/// cpu specifier
470	pub cputype: U32<E>,
471	/// machine specifier
472	pub cpusubtype: U32<E>,
473	/// type of file
474	pub filetype: U32<E>,
475	/// number of load commands
476	pub ncmds: U32<E>,
477	/// the size of all the load commands
478	pub sizeofcmds: U32<E>,
479	/// flags
480	pub flags: U32<E>,
481	}
482
483	// Values for `MachHeader32::magic`.
484	/// the mach magic number
485	pub const MH_MAGIC: u32 = `0xfeed_face`;
486	/// NXSwapInt(MH_MAGIC)
487	pub const MH_CIGAM: u32 = `0xcefa_edfe`;
488
489	/// The 64-bit mach header.
490	///
491	/// Appears at the very beginning of object files for 64-bit architectures.
492	#[derive(Debug, Clone, Copy)]
493	#[repr(C)]
494	pub struct MachHeader64<E: Endian> {
495	/// mach magic number identifier
496	pub magic: U32<BigEndian>,
497	/// cpu specifier
498	pub cputype: U32<E>,
499	/// machine specifier
500	pub cpusubtype: U32<E>,
501	/// type of file
502	pub filetype: U32<E>,
503	/// number of load commands
504	pub ncmds: U32<E>,
505	/// the size of all the load commands
506	pub sizeofcmds: U32<E>,
507	/// flags
508	pub flags: U32<E>,
509	/// reserved
510	pub reserved: U32<E>,
511	}
512
513	// Values for `MachHeader64::magic`.
514	/// the 64-bit mach magic number
515	pub const MH_MAGIC_64: u32 = `0xfeed_facf`;
516	/// NXSwapInt(MH_MAGIC_64)
517	pub const MH_CIGAM_64: u32 = `0xcffa_edfe`;
518
519	/*
520	* The layout of the file depends on the filetype. For all but the MH_OBJECT
521	* file type the segments are padded out and aligned on a segment alignment
522	* boundary for efficient demand pageing. The MH_EXECUTE, MH_FVMLIB, MH_DYLIB,
523	* MH_DYLINKER and MH_BUNDLE file types also have the headers included as part
524	* of their first segment.
525	*
526	* The file type MH_OBJECT is a compact format intended as output of the
527	* assembler and input (and possibly output) of the link editor (the .o
528	* format). All sections are in one unnamed segment with no segment padding.
529	* This format is used as an executable format when the file is so small the
530	* segment padding greatly increases its size.
531	*
532	* The file type MH_PRELOAD is an executable format intended for things that
533	* are not executed under the kernel (proms, stand alones, kernels, etc). The
534	* format can be executed under the kernel but may demand paged it and not
535	* preload it before execution.
536	*
537	* A core file is in MH_CORE format and can be any in an arbritray legal
538	* Mach-O file.
539	*/
540
541	// Values for `MachHeader::filetype`.*
542	/// relocatable object file
543	pub const MH_OBJECT: u32 = `0x1`;
544	/// demand paged executable file
545	pub const MH_EXECUTE: u32 = `0x2`;
546	/// fixed VM shared library file
547	pub const MH_FVMLIB: u32 = `0x3`;
548	/// core file
549	pub const MH_CORE: u32 = `0x4`;
550	/// preloaded executable file
551	pub const MH_PRELOAD: u32 = `0x5`;
552	/// dynamically bound shared library
553	pub const MH_DYLIB: u32 = `0x6`;
554	/// dynamic link editor
555	pub const MH_DYLINKER: u32 = `0x7`;
556	/// dynamically bound bundle file
557	pub const MH_BUNDLE: u32 = `0x8`;
558	/// shared library stub for static linking only, no section contents
559	pub const MH_DYLIB_STUB: u32 = `0x9`;
560	/// companion file with only debug sections
561	pub const MH_DSYM: u32 = `0xa`;
562	/// x86_64 kexts
563	pub const MH_KEXT_BUNDLE: u32 = `0xb`;
564	/// set of mach-o's
565	pub const MH_FILESET: u32 = `0xc`;
566
567	// Values for `MachHeader::flags`.*
568	/// the object file has no undefined references
569	pub const MH_NOUNDEFS: u32 = `0x1`;
570	/// the object file is the output of an incremental link against a base file and can't be link edited again
571	pub const MH_INCRLINK: u32 = `0x2`;
572	/// the object file is input for the dynamic linker and can't be statically link edited again
573	pub const MH_DYLDLINK: u32 = `0x4`;
574	/// the object file's undefined references are bound by the dynamic linker when loaded.
575	pub const MH_BINDATLOAD: u32 = `0x8`;
576	/// the file has its dynamic undefined references prebound.
577	pub const MH_PREBOUND: u32 = `0x10`;
578	/// the file has its read-only and read-write segments split
579	pub const MH_SPLIT_SEGS: u32 = `0x20`;
580	/// the shared library init routine is to be run lazily via catching memory faults to its writeable segments (obsolete)
581	pub const MH_LAZY_INIT: u32 = `0x40`;
582	/// the image is using two-level name space bindings
583	pub const MH_TWOLEVEL: u32 = `0x80`;
584	/// the executable is forcing all images to use flat name space bindings
585	pub const MH_FORCE_FLAT: u32 = `0x100`;
586	/// this umbrella guarantees no multiple definitions of symbols in its sub-images so the two-level namespace hints can always be used.
587	pub const MH_NOMULTIDEFS: u32 = `0x200`;
588	/// do not have dyld notify the prebinding agent about this executable
589	pub const MH_NOFIXPREBINDING: u32 = `0x400`;
590	/// the binary is not prebound but can have its prebinding redone. only used when MH_PREBOUND is not set.
591	pub const MH_PREBINDABLE: u32 = `0x800`;
592	/// 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.
593	pub const MH_ALLMODSBOUND: u32 = `0x1000`;
594	/// safe to divide up the sections into sub-sections via symbols for dead code stripping
595	pub const MH_SUBSECTIONS_VIA_SYMBOLS: u32 = `0x2000`;
596	/// the binary has been canonicalized via the unprebind operation
597	pub const MH_CANONICAL: u32 = `0x4000`;
598	/// the final linked image contains external weak symbols
599	pub const MH_WEAK_DEFINES: u32 = `0x8000`;
600	/// the final linked image uses weak symbols
601	pub const MH_BINDS_TO_WEAK: u32 = `0x10000`;
602	/// When this bit is set, all stacks in the task will be given stack execution privilege. Only used in MH_EXECUTE filetypes.
603	pub const MH_ALLOW_STACK_EXECUTION: u32 = `0x20000`;
604	/// When this bit is set, the binary declares it is safe for use in processes with uid zero
605	pub const MH_ROOT_SAFE: u32 = `0x40000`;
606	/// When this bit is set, the binary declares it is safe for use in processes when issetugid() is true
607	pub const MH_SETUID_SAFE: u32 = `0x80000`;
608	/// 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
609	pub const MH_NO_REEXPORTED_DYLIBS: u32 = `0x10_0000`;
610	/// When this bit is set, the OS will load the main executable at a random address. Only used in MH_EXECUTE filetypes.
611	pub const MH_PIE: u32 = `0x20_0000`;
612	/// 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.
613	pub const MH_DEAD_STRIPPABLE_DYLIB: u32 = `0x40_0000`;
614	/// Contains a section of type S_THREAD_LOCAL_VARIABLES
615	pub const MH_HAS_TLV_DESCRIPTORS: u32 = `0x80_0000`;
616	/// 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.
617	pub const MH_NO_HEAP_EXECUTION: u32 = `0x100_0000`;
618	/// The code was linked for use in an application extension.
619	pub const MH_APP_EXTENSION_SAFE: u32 = `0x0200_0000`;
620	/// The external symbols listed in the nlist symbol table do not include all the symbols listed in the dyld info.
621	pub const MH_NLIST_OUTOFSYNC_WITH_DYLDINFO: u32 = `0x0400_0000`;
622	/// Allow LC_MIN_VERSION_MACOS and LC_BUILD_VERSION load commands with
623	/// the platforms macOS, iOSMac, iOSSimulator, tvOSSimulator and watchOSSimulator.
624	pub const MH_SIM_SUPPORT: u32 = `0x0800_0000`;
625	/// Only for use on dylibs. When this bit is set, the dylib is part of the dyld
626	/// shared cache, rather than loose in the filesystem.
627	pub const MH_DYLIB_IN_CACHE: u32 = `0x8000_0000`;
628
629	/// Common fields at the start of every load command.
630	///
631	/// The load commands directly follow the mach_header. The total size of all
632	/// of the commands is given by the sizeofcmds field in the mach_header. All
633	/// load commands must have as their first two fields `cmd` and `cmdsize`. The `cmd`
634	/// field is filled in with a constant for that command type. Each command type
635	/// has a structure specifically for it. The `cmdsize` field is the size in bytes
636	/// of the particular load command structure plus anything that follows it that
637	/// is a part of the load command (i.e. section structures, strings, etc.). To
638	/// advance to the next load command the `cmdsize` can be added to the offset or
639	/// pointer of the current load command. The `cmdsize` for 32-bit architectures
640	/// MUST be a multiple of 4 bytes and for 64-bit architectures MUST be a multiple
641	/// of 8 bytes (these are forever the maximum alignment of any load commands).
642	/// The padded bytes must be zero. All tables in the object file must also
643	/// follow these rules so the file can be memory mapped. Otherwise the pointers
644	/// to these tables will not work well or at all on some machines. With all
645	/// padding zeroed like objects will compare byte for byte.
646	#[derive(Debug, Clone, Copy)]
647	#[repr(C)]
648	pub struct LoadCommand<E: Endian> {
649	/// Type of load command.
650	///
651	/// One of the `LC_` constants.*
652	pub cmd: U32<E>,
653	/// Total size of command in bytes.
654	pub cmdsize: U32<E>,
655	}
656
657	/*
658	* After MacOS X 10.1 when a new load command is added that is required to be
659	* understood by the dynamic linker for the image to execute properly the
660	* LC_REQ_DYLD bit will be or'ed into the load command constant. If the dynamic
661	* linker sees such a load command it it does not understand will issue a
662	* "unknown load command required for execution" error and refuse to use the
663	* image. Other load commands without this bit that are not understood will
664	* simply be ignored.
665	*/
666	pub const LC_REQ_DYLD: u32 = `0x8000_0000`;
667
668	/ Constants for the cmd field of all load commands, the type /
669	/// segment of this file to be mapped
670	pub const LC_SEGMENT: u32 = `0x1`;
671	/// link-edit stab symbol table info
672	pub const LC_SYMTAB: u32 = `0x2`;
673	/// link-edit gdb symbol table info (obsolete)
674	pub const LC_SYMSEG: u32 = `0x3`;
675	/// thread
676	pub const LC_THREAD: u32 = `0x4`;
677	/// unix thread (includes a stack)
678	pub const LC_UNIXTHREAD: u32 = `0x5`;
679	/// load a specified fixed VM shared library
680	pub const LC_LOADFVMLIB: u32 = `0x6`;
681	/// fixed VM shared library identification
682	pub const LC_IDFVMLIB: u32 = `0x7`;
683	/// object identification info (obsolete)
684	pub const LC_IDENT: u32 = `0x8`;
685	/// fixed VM file inclusion (internal use)
686	pub const LC_FVMFILE: u32 = `0x9`;
687	/// prepage command (internal use)
688	pub const LC_PREPAGE: u32 = `0xa`;
689	/// dynamic link-edit symbol table info
690	pub const LC_DYSYMTAB: u32 = `0xb`;
691	/// load a dynamically linked shared library
692	pub const LC_LOAD_DYLIB: u32 = `0xc`;
693	/// dynamically linked shared lib ident
694	pub const LC_ID_DYLIB: u32 = `0xd`;
695	/// load a dynamic linker
696	pub const LC_LOAD_DYLINKER: u32 = `0xe`;
697	/// dynamic linker identification
698	pub const LC_ID_DYLINKER: u32 = `0xf`;
699	/// modules prebound for a dynamically linked shared library
700	pub const LC_PREBOUND_DYLIB: u32 = `0x10`;
701	/// image routines
702	pub const LC_ROUTINES: u32 = `0x11`;
703	/// sub framework
704	pub const LC_SUB_FRAMEWORK: u32 = `0x12`;
705	/// sub umbrella
706	pub const LC_SUB_UMBRELLA: u32 = `0x13`;
707	/// sub client
708	pub const LC_SUB_CLIENT: u32 = `0x14`;
709	/// sub library
710	pub const LC_SUB_LIBRARY: u32 = `0x15`;
711	/// two-level namespace lookup hints
712	pub const LC_TWOLEVEL_HINTS: u32 = `0x16`;
713	/// prebind checksum
714	pub const LC_PREBIND_CKSUM: u32 = `0x17`;
715	/// load a dynamically linked shared library that is allowed to be missing
716	/// (all symbols are weak imported).
717	pub const LC_LOAD_WEAK_DYLIB: u32 = `0x18` \| LC_REQ_DYLD;
718	/// 64-bit segment of this file to be mapped
719	pub const LC_SEGMENT_64: u32 = `0x19`;
720	/// 64-bit image routines
721	pub const LC_ROUTINES_64: u32 = `0x1a`;
722	/// the uuid
723	pub const LC_UUID: u32 = `0x1b`;
724	/// runpath additions
725	pub const LC_RPATH: u32 = `0x1c` \| LC_REQ_DYLD;
726	/// local of code signature
727	pub const LC_CODE_SIGNATURE: u32 = `0x1d`;
728	/// local of info to split segments
729	pub const LC_SEGMENT_SPLIT_INFO: u32 = `0x1e`;
730	/// load and re-export dylib
731	pub const LC_REEXPORT_DYLIB: u32 = `0x1f` \| LC_REQ_DYLD;
732	/// delay load of dylib until first use
733	pub const LC_LAZY_LOAD_DYLIB: u32 = `0x20`;
734	/// encrypted segment information
735	pub const LC_ENCRYPTION_INFO: u32 = `0x21`;
736	/// compressed dyld information
737	pub const LC_DYLD_INFO: u32 = `0x22`;
738	/// compressed dyld information only
739	pub const LC_DYLD_INFO_ONLY: u32 = `0x22` \| LC_REQ_DYLD;
740	/// load upward dylib
741	pub const LC_LOAD_UPWARD_DYLIB: u32 = `0x23` \| LC_REQ_DYLD;
742	/// build for MacOSX min OS version
743	pub const LC_VERSION_MIN_MACOSX: u32 = `0x24`;
744	/// build for iPhoneOS min OS version
745	pub const LC_VERSION_MIN_IPHONEOS: u32 = `0x25`;
746	/// compressed table of function start addresses
747	pub const LC_FUNCTION_STARTS: u32 = `0x26`;
748	/// string for dyld to treat like environment variable
749	pub const LC_DYLD_ENVIRONMENT: u32 = `0x27`;
750	/// replacement for LC_UNIXTHREAD
751	pub const LC_MAIN: u32 = `0x28` \| LC_REQ_DYLD;
752	/// table of non-instructions in __text
753	pub const LC_DATA_IN_CODE: u32 = `0x29`;
754	/// source version used to build binary
755	pub const LC_SOURCE_VERSION: u32 = `0x2A`;
756	/// Code signing DRs copied from linked dylibs
757	pub const LC_DYLIB_CODE_SIGN_DRS: u32 = `0x2B`;
758	/// 64-bit encrypted segment information
759	pub const LC_ENCRYPTION_INFO_64: u32 = `0x2C`;
760	/// linker options in MH_OBJECT files
761	pub const LC_LINKER_OPTION: u32 = `0x2D`;
762	/// optimization hints in MH_OBJECT files
763	pub const LC_LINKER_OPTIMIZATION_HINT: u32 = `0x2E`;
764	/// build for AppleTV min OS version
765	pub const LC_VERSION_MIN_TVOS: u32 = `0x2F`;
766	/// build for Watch min OS version
767	pub const LC_VERSION_MIN_WATCHOS: u32 = `0x30`;
768	/// arbitrary data included within a Mach-O file
769	pub const LC_NOTE: u32 = `0x31`;
770	/// build for platform min OS version
771	pub const LC_BUILD_VERSION: u32 = `0x32`;
772	/// used with `LinkeditDataCommand`, payload is trie
773	pub const LC_DYLD_EXPORTS_TRIE: u32 = `0x33` \| LC_REQ_DYLD;
774	/// used with `LinkeditDataCommand`
775	pub const LC_DYLD_CHAINED_FIXUPS: u32 = `0x34` \| LC_REQ_DYLD;
776	/// used with `FilesetEntryCommand`
777	pub const LC_FILESET_ENTRY: u32 = `0x35` \| LC_REQ_DYLD;
778
779	/// A variable length string in a load command.
780	///
781	/// The strings are stored just after the load command structure and
782	/// the offset is from the start of the load command structure. The size
783	/// of the string is reflected in the `cmdsize` field of the load command.
784	/// Once again any padded bytes to bring the `cmdsize` field to a multiple
785	/// of 4 bytes must be zero.
786	#[derive(Debug, Clone, Copy)]
787	#[repr(C)]
788	pub struct LcStr<E: Endian> {
789	/// offset to the string
790	pub offset: U32<E>,
791	}
792
793	/// 32-bit segment load command.
794	///
795	/// The segment load command indicates that a part of this file is to be
796	/// mapped into the task's address space. The size of this segment in memory,
797	/// vmsize, maybe equal to or larger than the amount to map from this file,
798	/// filesize. The file is mapped starting at fileoff to the beginning of
799	/// the segment in memory, vmaddr. The rest of the memory of the segment,
800	/// if any, is allocated zero fill on demand. The segment's maximum virtual
801	/// memory protection and initial virtual memory protection are specified
802	/// by the maxprot and initprot fields. If the segment has sections then the
803	/// `Section32` structures directly follow the segment command and their size is
804	/// reflected in `cmdsize`.
805	#[derive(Debug, Clone, Copy)]
806	#[repr(C)]
807	pub struct SegmentCommand32<E: Endian> {
808	/// LC_SEGMENT
809	pub cmd: U32<E>,
810	/// includes sizeof section structs
811	pub cmdsize: U32<E>,
812	/// segment name
813	pub segname: [u8; `16`],
814	/// memory address of this segment
815	pub vmaddr: U32<E>,
816	/// memory size of this segment
817	pub vmsize: U32<E>,
818	/// file offset of this segment
819	pub fileoff: U32<E>,
820	/// amount to map from the file
821	pub filesize: U32<E>,
822	/// maximum VM protection
823	pub maxprot: U32<E>,
824	/// initial VM protection
825	pub initprot: U32<E>,
826	/// number of sections in segment
827	pub nsects: U32<E>,
828	/// flags
829	pub flags: U32<E>,
830	}
831
832	/// 64-bit segment load command.
833	///
834	/// The 64-bit segment load command indicates that a part of this file is to be
835	/// mapped into a 64-bit task's address space. If the 64-bit segment has
836	/// sections then `Section64` structures directly follow the 64-bit segment
837	/// command and their size is reflected in `cmdsize`.
838	#[derive(Debug, Clone, Copy)]
839	#[repr(C)]
840	pub struct SegmentCommand64<E: Endian> {
841	/// LC_SEGMENT_64
842	pub cmd: U32<E>,
843	/// includes sizeof section_64 structs
844	pub cmdsize: U32<E>,
845	/// segment name
846	pub segname: [u8; `16`],
847	/// memory address of this segment
848	pub vmaddr: U64<E>,
849	/// memory size of this segment
850	pub vmsize: U64<E>,
851	/// file offset of this segment
852	pub fileoff: U64<E>,
853	/// amount to map from the file
854	pub filesize: U64<E>,
855	/// maximum VM protection
856	pub maxprot: U32<E>,
857	/// initial VM protection
858	pub initprot: U32<E>,
859	/// number of sections in segment
860	pub nsects: U32<E>,
861	/// flags
862	pub flags: U32<E>,
863	}
864
865	// Values for `SegmentCommand::flags`.*
866	/// the file contents for this segment is for the high part of the VM space, the low part is zero filled (for stacks in core files)
867	pub const SG_HIGHVM: u32 = `0x1`;
868	/// this segment is the VM that is allocated by a fixed VM library, for overlap checking in the link editor
869	pub const SG_FVMLIB: u32 = `0x2`;
870	/// this segment has nothing that was relocated in it and nothing relocated to it, that is it maybe safely replaced without relocation
871	pub const SG_NORELOC: u32 = `0x4`;
872	/// This segment is protected. If the segment starts at file offset 0, the first page of the segment is not protected. All other pages of the segment are protected.
873	pub const SG_PROTECTED_VERSION_1: u32 = `0x8`;
874	/// This segment is made read-only after fixups
875	pub const SG_READ_ONLY: u32 = `0x10`;
876
877	/*
878	* A segment is made up of zero or more sections. Non-MH_OBJECT files have
879	* all of their segments with the proper sections in each, and padded to the
880	* specified segment alignment when produced by the link editor. The first
881	* segment of a MH_EXECUTE and MH_FVMLIB format file contains the mach_header
882	* and load commands of the object file before its first section. The zero
883	* fill sections are always last in their segment (in all formats). This
884	* allows the zeroed segment padding to be mapped into memory where zero fill
885	* sections might be. The gigabyte zero fill sections, those with the section
886	* type S_GB_ZEROFILL, can only be in a segment with sections of this type.
887	* These segments are then placed after all other segments.
888	*
889	* The MH_OBJECT format has all of its sections in one segment for
890	* compactness. There is no padding to a specified segment boundary and the
891	* mach_header and load commands are not part of the segment.
892	*
893	* Sections with the same section name, sectname, going into the same segment,
894	* segname, are combined by the link editor. The resulting section is aligned
895	* to the maximum alignment of the combined sections and is the new section's
896	* alignment. The combined sections are aligned to their original alignment in
897	* the combined section. Any padded bytes to get the specified alignment are
898	* zeroed.
899	*
900	* The format of the relocation entries referenced by the reloff and nreloc
901	* fields of the section structure for mach object files is described in the
902	* header file <reloc.h>.
903	*/
904	/// 32-bit section.
905	#[derive(Debug, Clone, Copy)]
906	#[repr(C)]
907	pub struct Section32<E: Endian> {
908	/// name of this section
909	pub sectname: [u8; `16`],
910	/// segment this section goes in
911	pub segname: [u8; `16`],
912	/// memory address of this section
913	pub addr: U32<E>,
914	/// size in bytes of this section
915	pub size: U32<E>,
916	/// file offset of this section
917	pub offset: U32<E>,
918	/// section alignment (power of 2)
919	pub align: U32<E>,
920	/// file offset of relocation entries
921	pub reloff: U32<E>,
922	/// number of relocation entries
923	pub nreloc: U32<E>,
924	/// flags (section type and attributes)
925	pub flags: U32<E>,
926	/// reserved (for offset or index)
927	pub reserved1: U32<E>,
928	/// reserved (for count or sizeof)
929	pub reserved2: U32<E>,
930	}
931
932	/// 64-bit section.
933	#[derive(Debug, Clone, Copy)]
934	#[repr(C)]
935	pub struct Section64<E: Endian> {
936	/// name of this section
937	pub sectname: [u8; `16`],
938	/// segment this section goes in
939	pub segname: [u8; `16`],
940	/// memory address of this section
941	pub addr: U64<E>,
942	/// size in bytes of this section
943	pub size: U64<E>,
944	/// file offset of this section
945	pub offset: U32<E>,
946	/// section alignment (power of 2)
947	pub align: U32<E>,
948	/// file offset of relocation entries
949	pub reloff: U32<E>,
950	/// number of relocation entries
951	pub nreloc: U32<E>,
952	/// flags (section type and attributes)
953	pub flags: U32<E>,
954	/// reserved (for offset or index)
955	pub reserved1: U32<E>,
956	/// reserved (for count or sizeof)
957	pub reserved2: U32<E>,
958	/// reserved
959	pub reserved3: U32<E>,
960	}
961
962	/*
963	* The flags field of a section structure is separated into two parts a section
964	* type and section attributes. The section types are mutually exclusive (it
965	* can only have one type) but the section attributes are not (it may have more
966	* than one attribute).
967	*/
968	/// 256 section types
969	pub const SECTION_TYPE: u32 = `0x0000_00ff`;
970	/// 24 section attributes
971	pub const SECTION_ATTRIBUTES: u32 = `0xffff_ff00`;
972
973	/ Constants for the type of a section /
974	/// regular section
975	pub const S_REGULAR: u32 = `0x0`;
976	/// zero fill on demand section
977	pub const S_ZEROFILL: u32 = `0x1`;
978	/// section with only literal C strings
979	pub const S_CSTRING_LITERALS: u32 = `0x2`;
980	/// section with only 4 byte literals
981	pub const S_4BYTE_LITERALS: u32 = `0x3`;
982	/// section with only 8 byte literals
983	pub const S_8BYTE_LITERALS: u32 = `0x4`;
984	/// section with only pointers to literals
985	pub const S_LITERAL_POINTERS: u32 = `0x5`;
986	/*
987	* For the two types of symbol pointers sections and the symbol stubs section
988	* they have indirect symbol table entries. For each of the entries in the
989	* section the indirect symbol table entries, in corresponding order in the
990	* indirect symbol table, start at the index stored in the reserved1 field
991	* of the section structure. Since the indirect symbol table entries
992	* correspond to the entries in the section the number of indirect symbol table
993	* entries is inferred from the size of the section divided by the size of the
994	* entries in the section. For symbol pointers sections the size of the entries
995	* in the section is 4 bytes and for symbol stubs sections the byte size of the
996	* stubs is stored in the reserved2 field of the section structure.
997	*/
998	/// section with only non-lazy symbol pointers
999	pub const S_NON_LAZY_SYMBOL_POINTERS: u32 = `0x6`;
1000	/// section with only lazy symbol pointers
1001	pub const S_LAZY_SYMBOL_POINTERS: u32 = `0x7`;
1002	/// section with only symbol stubs, byte size of stub in the reserved2 field
1003	pub const S_SYMBOL_STUBS: u32 = `0x8`;
1004	/// section with only function pointers for initialization
1005	pub const S_MOD_INIT_FUNC_POINTERS: u32 = `0x9`;
1006	/// section with only function pointers for termination
1007	pub const S_MOD_TERM_FUNC_POINTERS: u32 = `0xa`;
1008	/// section contains symbols that are to be coalesced
1009	pub const S_COALESCED: u32 = `0xb`;
1010	/// zero fill on demand section (that can be larger than 4 gigabytes)
1011	pub const S_GB_ZEROFILL: u32 = `0xc`;
1012	/// section with only pairs of function pointers for interposing
1013	pub const S_INTERPOSING: u32 = `0xd`;
1014	/// section with only 16 byte literals
1015	pub const S_16BYTE_LITERALS: u32 = `0xe`;
1016	/// section contains DTrace Object Format
1017	pub const S_DTRACE_DOF: u32 = `0xf`;
1018	/// section with only lazy symbol pointers to lazy loaded dylibs
1019	pub const S_LAZY_DYLIB_SYMBOL_POINTERS: u32 = `0x10`;
1020	/*
1021	* Section types to support thread local variables
1022	*/
1023	/// template of initial values for TLVs
1024	pub const S_THREAD_LOCAL_REGULAR: u32 = `0x11`;
1025	/// template of initial values for TLVs
1026	pub const S_THREAD_LOCAL_ZEROFILL: u32 = `0x12`;
1027	/// TLV descriptors
1028	pub const S_THREAD_LOCAL_VARIABLES: u32 = `0x13`;
1029	/// pointers to TLV descriptors
1030	pub const S_THREAD_LOCAL_VARIABLE_POINTERS: u32 = `0x14`;
1031	/// functions to call to initialize TLV values
1032	pub const S_THREAD_LOCAL_INIT_FUNCTION_POINTERS: u32 = `0x15`;
1033	/// 32-bit offsets to initializers
1034	pub const S_INIT_FUNC_OFFSETS: u32 = `0x16`;
1035
1036	/*
1037	* Constants for the section attributes part of the flags field of a section
1038	* structure.
1039	*/
1040	/// User setable attributes
1041	pub const SECTION_ATTRIBUTES_USR: u32 = `0xff00_0000`;
1042	/// section contains only true machine instructions
1043	pub const S_ATTR_PURE_INSTRUCTIONS: u32 = `0x8000_0000`;
1044	/// section contains coalesced symbols that are not to be in a ranlib table of contents
1045	pub const S_ATTR_NO_TOC: u32 = `0x4000_0000`;
1046	/// ok to strip static symbols in this section in files with the MH_DYLDLINK flag
1047	pub const S_ATTR_STRIP_STATIC_SYMS: u32 = `0x2000_0000`;
1048	/// no dead stripping
1049	pub const S_ATTR_NO_DEAD_STRIP: u32 = `0x1000_0000`;
1050	/// blocks are live if they reference live blocks
1051	pub const S_ATTR_LIVE_SUPPORT: u32 = `0x0800_0000`;
1052	/// Used with i386 code stubs written on by dyld
1053	pub const S_ATTR_SELF_MODIFYING_CODE: u32 = `0x0400_0000`;
1054	/*
1055	* If a segment contains any sections marked with S_ATTR_DEBUG then all
1056	* sections in that segment must have this attribute. No section other than
1057	* a section marked with this attribute may reference the contents of this
1058	* section. A section with this attribute may contain no symbols and must have
1059	* a section type S_REGULAR. The static linker will not copy section contents
1060	* from sections with this attribute into its output file. These sections
1061	* generally contain DWARF debugging info.
1062	*/
1063	/// a debug section
1064	pub const S_ATTR_DEBUG: u32 = `0x0200_0000`;
1065	/// system setable attributes
1066	pub const SECTION_ATTRIBUTES_SYS: u32 = `0x00ff_ff00`;
1067	/// section contains some machine instructions
1068	pub const S_ATTR_SOME_INSTRUCTIONS: u32 = `0x0000_0400`;
1069	/// section has external relocation entries
1070	pub const S_ATTR_EXT_RELOC: u32 = `0x0000_0200`;
1071	/// section has local relocation entries
1072	pub const S_ATTR_LOC_RELOC: u32 = `0x0000_0100`;
1073
1074	/*
1075	* The names of segments and sections in them are mostly meaningless to the
1076	* link-editor. But there are few things to support traditional UNIX
1077	* executables that require the link-editor and assembler to use some names
1078	* agreed upon by convention.
1079	*
1080	* The initial protection of the "__TEXT" segment has write protection turned
1081	* off (not writeable).
1082	*
1083	* The link-editor will allocate common symbols at the end of the "__common"
1084	* section in the "__DATA" segment. It will create the section and segment
1085	* if needed.
1086	*/
1087
1088	/ The currently known segment names and the section names in those segments /
1089
1090	/// the pagezero segment which has no protections and catches NULL references for MH_EXECUTE files
1091	pub const SEG_PAGEZERO: &str = "__PAGEZERO";
1092
1093	/// the tradition UNIX text segment
1094	pub const SEG_TEXT: &str = "__TEXT";
1095	/// the real text part of the text section no headers, and no padding
1096	pub const SECT_TEXT: &str = "__text";
1097	/// the fvmlib initialization section
1098	pub const SECT_FVMLIB_INIT0: &str = "__fvmlib_init0";
1099	/// the section following the fvmlib initialization section
1100	pub const SECT_FVMLIB_INIT1: &str = "__fvmlib_init1";
1101
1102	/// the tradition UNIX data segment
1103	pub const SEG_DATA: &str = "__DATA";
1104	/// the real initialized data section no padding, no bss overlap
1105	pub const SECT_DATA: &str = "__data";
1106	/// the real uninitialized data section no padding
1107	pub const SECT_BSS: &str = "__bss";
1108	/// the section common symbols are allocated in by the link editor
1109	pub const SECT_COMMON: &str = "__common";
1110
1111	/// objective-C runtime segment
1112	pub const SEG_OBJC: &str = "__OBJC";
1113	/// symbol table
1114	pub const SECT_OBJC_SYMBOLS: &str = "__symbol_table";
1115	/// module information
1116	pub const SECT_OBJC_MODULES: &str = "__module_info";
1117	/// string table
1118	pub const SECT_OBJC_STRINGS: &str = "__selector_strs";
1119	/// string table
1120	pub const SECT_OBJC_REFS: &str = "__selector_refs";
1121
1122	/// the icon segment
1123	pub const SEG_ICON: &str = "__ICON";
1124	/// the icon headers
1125	pub const SECT_ICON_HEADER: &str = "__header";
1126	/// the icons in tiff format
1127	pub const SECT_ICON_TIFF: &str = "__tiff";
1128
1129	/// the segment containing all structs created and maintained by the link editor. Created with -seglinkedit option to ld(1) for MH_EXECUTE and FVMLIB file types only
1130	pub const SEG_LINKEDIT: &str = "__LINKEDIT";
1131
1132	/// the segment overlapping with linkedit containing linking information
1133	pub const SEG_LINKINFO: &str = "__LINKINFO";
1134
1135	/// the unix stack segment
1136	pub const SEG_UNIXSTACK: &str = "__UNIXSTACK";
1137
1138	/// the segment for the self (dyld) modifying code stubs that has read, write and execute permissions
1139	pub const SEG_IMPORT: &str = "__IMPORT";
1140
1141	/*
1142	* Fixed virtual memory shared libraries are identified by two things. The
1143	* target pathname (the name of the library as found for execution), and the
1144	* minor version number. The address of where the headers are loaded is in
1145	* header_addr. (THIS IS OBSOLETE and no longer supported).
1146	*/
1147	#[derive(Debug, Clone, Copy)]
1148	#[repr(C)]
1149	pub struct Fvmlib<E: Endian> {
1150	/// library's target pathname
1151	pub name: LcStr<E>,
1152	/// library's minor version number
1153	pub minor_version: U32<E>,
1154	/// library's header address
1155	pub header_addr: U32<E>,
1156	}
1157
1158	/*
1159	* A fixed virtual shared library (filetype == MH_FVMLIB in the mach header)
1160	* contains a `FvmlibCommand` (cmd == LC_IDFVMLIB) to identify the library.
1161	* An object that uses a fixed virtual shared library also contains a
1162	* `FvmlibCommand` (cmd == LC_LOADFVMLIB) for each library it uses.
1163	* (THIS IS OBSOLETE and no longer supported).
1164	*/
1165	#[derive(Debug, Clone, Copy)]
1166	#[repr(C)]
1167	pub struct FvmlibCommand<E: Endian> {
1168	/// LC_IDFVMLIB or LC_LOADFVMLIB
1169	pub cmd: U32<E>,
1170	/// includes pathname string
1171	pub cmdsize: U32<E>,
1172	/// the library identification
1173	pub fvmlib: Fvmlib<E>,
1174	}
1175
1176	/*
1177	* Dynamically linked shared libraries are identified by two things. The
1178	* pathname (the name of the library as found for execution), and the
1179	* compatibility version number. The pathname must match and the compatibility
1180	* number in the user of the library must be greater than or equal to the
1181	* library being used. The time stamp is used to record the time a library was
1182	* built and copied into user so it can be use to determined if the library used
1183	* at runtime is exactly the same as used to built the program.
1184	*/
1185	#[derive(Debug, Clone, Copy)]
1186	#[repr(C)]
1187	pub struct Dylib<E: Endian> {
1188	/// library's path name
1189	pub name: LcStr<E>,
1190	/// library's build time stamp
1191	pub timestamp: U32<E>,
1192	/// library's current version number
1193	pub current_version: U32<E>,
1194	/// library's compatibility vers number
1195	pub compatibility_version: U32<E>,
1196	}
1197
1198	/*
1199	* A dynamically linked shared library (filetype == MH_DYLIB in the mach header)
1200	* contains a `DylibCommand` (cmd == LC_ID_DYLIB) to identify the library.
1201	* An object that uses a dynamically linked shared library also contains a
1202	* `DylibCommand` (cmd == LC_LOAD_DYLIB, LC_LOAD_WEAK_DYLIB, or
1203	* LC_REEXPORT_DYLIB) for each library it uses.
1204	*/
1205	#[derive(Debug, Clone, Copy)]
1206	#[repr(C)]
1207	pub struct DylibCommand<E: Endian> {
1208	/// LC_ID_DYLIB, LC_LOAD_{,WEAK_}DYLIB, LC_REEXPORT_DYLIB
1209	pub cmd: U32<E>,
1210	/// includes pathname string
1211	pub cmdsize: U32<E>,
1212	/// the library identification
1213	pub dylib: Dylib<E>,
1214	}
1215
1216	/*
1217	* A dynamically linked shared library may be a subframework of an umbrella
1218	* framework. If so it will be linked with "-umbrella umbrella_name" where
1219	* Where "umbrella_name" is the name of the umbrella framework. A subframework
1220	* can only be linked against by its umbrella framework or other subframeworks
1221	* that are part of the same umbrella framework. Otherwise the static link
1222	* editor produces an error and states to link against the umbrella framework.
1223	* The name of the umbrella framework for subframeworks is recorded in the
1224	* following structure.
1225	*/
1226	#[derive(Debug, Clone, Copy)]
1227	#[repr(C)]
1228	pub struct SubFrameworkCommand<E: Endian> {
1229	/// LC_SUB_FRAMEWORK
1230	pub cmd: U32<E>,
1231	/// includes umbrella string
1232	pub cmdsize: U32<E>,
1233	/// the umbrella framework name
1234	pub umbrella: LcStr<E>,
1235	}
1236
1237	/*
1238	* For dynamically linked shared libraries that are subframework of an umbrella
1239	* framework they can allow clients other than the umbrella framework or other
1240	* subframeworks in the same umbrella framework. To do this the subframework
1241	* is built with "-allowable_client client_name" and an LC_SUB_CLIENT load
1242	* command is created for each -allowable_client flag. The client_name is
1243	* usually a framework name. It can also be a name used for bundles clients
1244	* where the bundle is built with "-client_name client_name".
1245	*/
1246	#[derive(Debug, Clone, Copy)]
1247	#[repr(C)]
1248	pub struct SubClientCommand<E: Endian> {
1249	/// LC_SUB_CLIENT
1250	pub cmd: U32<E>,
1251	/// includes client string
1252	pub cmdsize: U32<E>,
1253	/// the client name
1254	pub client: LcStr<E>,
1255	}
1256
1257	/*
1258	* A dynamically linked shared library may be a sub_umbrella of an umbrella
1259	* framework. If so it will be linked with "-sub_umbrella umbrella_name" where
1260	* Where "umbrella_name" is the name of the sub_umbrella framework. When
1261	* statically linking when -twolevel_namespace is in effect a twolevel namespace
1262	* umbrella framework will only cause its subframeworks and those frameworks
1263	* listed as sub_umbrella frameworks to be implicited linked in. Any other
1264	* dependent dynamic libraries will not be linked it when -twolevel_namespace
1265	* is in effect. The primary library recorded by the static linker when
1266	* resolving a symbol in these libraries will be the umbrella framework.
1267	* Zero or more sub_umbrella frameworks may be use by an umbrella framework.
1268	* The name of a sub_umbrella framework is recorded in the following structure.
1269	*/
1270	#[derive(Debug, Clone, Copy)]
1271	#[repr(C)]
1272	pub struct SubUmbrellaCommand<E: Endian> {
1273	/// LC_SUB_UMBRELLA
1274	pub cmd: U32<E>,
1275	/// includes sub_umbrella string
1276	pub cmdsize: U32<E>,
1277	/// the sub_umbrella framework name
1278	pub sub_umbrella: LcStr<E>,
1279	}
1280
1281	/*
1282	* A dynamically linked shared library may be a sub_library of another shared
1283	* library. If so it will be linked with "-sub_library library_name" where
1284	* Where "library_name" is the name of the sub_library shared library. When
1285	* statically linking when -twolevel_namespace is in effect a twolevel namespace
1286	* shared library will only cause its subframeworks and those frameworks
1287	* listed as sub_umbrella frameworks and libraries listed as sub_libraries to
1288	* be implicited linked in. Any other dependent dynamic libraries will not be
1289	* linked it when -twolevel_namespace is in effect. The primary library
1290	* recorded by the static linker when resolving a symbol in these libraries
1291	* will be the umbrella framework (or dynamic library). Zero or more sub_library
1292	* shared libraries may be use by an umbrella framework or (or dynamic library).
1293	* The name of a sub_library framework is recorded in the following structure.
1294	* For example /usr/lib/libobjc_profile.A.dylib would be recorded as "libobjc".
1295	*/
1296	#[derive(Debug, Clone, Copy)]
1297	#[repr(C)]
1298	pub struct SubLibraryCommand<E: Endian> {
1299	/// LC_SUB_LIBRARY
1300	pub cmd: U32<E>,
1301	/// includes sub_library string
1302	pub cmdsize: U32<E>,
1303	/// the sub_library name
1304	pub sub_library: LcStr<E>,
1305	}
1306
1307	/*
1308	* A program (filetype == MH_EXECUTE) that is
1309	* prebound to its dynamic libraries has one of these for each library that
1310	* the static linker used in prebinding. It contains a bit vector for the
1311	* modules in the library. The bits indicate which modules are bound (1) and
1312	* which are not (0) from the library. The bit for module 0 is the low bit
1313	* of the first byte. So the bit for the Nth module is:
1314	* (linked_modules[N/8] >> N%8) & 1
1315	*/
1316	#[derive(Debug, Clone, Copy)]
1317	#[repr(C)]
1318	pub struct PreboundDylibCommand<E: Endian> {
1319	/// LC_PREBOUND_DYLIB
1320	pub cmd: U32<E>,
1321	/// includes strings
1322	pub cmdsize: U32<E>,
1323	/// library's path name
1324	pub name: LcStr<E>,
1325	/// number of modules in library
1326	pub nmodules: U32<E>,
1327	/// bit vector of linked modules
1328	pub linked_modules: LcStr<E>,
1329	}
1330
1331	/*
1332	* A program that uses a dynamic linker contains a `DylinkerCommand` to identify
1333	* the name of the dynamic linker (LC_LOAD_DYLINKER). And a dynamic linker
1334	* contains a `DylinkerCommand` to identify the dynamic linker (LC_ID_DYLINKER).
1335	* A file can have at most one of these.
1336	* This struct is also used for the LC_DYLD_ENVIRONMENT load command and
1337	* contains string for dyld to treat like environment variable.
1338	*/
1339	#[derive(Debug, Clone, Copy)]
1340	#[repr(C)]
1341	pub struct DylinkerCommand<E: Endian> {
1342	/// LC_ID_DYLINKER, LC_LOAD_DYLINKER or LC_DYLD_ENVIRONMENT
1343	pub cmd: U32<E>,
1344	/// includes pathname string
1345	pub cmdsize: U32<E>,
1346	/// dynamic linker's path name
1347	pub name: LcStr<E>,
1348	}
1349
1350	/*
1351	* Thread commands contain machine-specific data structures suitable for
1352	* use in the thread state primitives. The machine specific data structures
1353	* follow the struct `ThreadCommand` as follows.
1354	* Each flavor of machine specific data structure is preceded by an uint32_t
1355	* constant for the flavor of that data structure, an uint32_t that is the
1356	* count of uint32_t's of the size of the state data structure and then
1357	* the state data structure follows. This triple may be repeated for many
1358	* flavors. The constants for the flavors, counts and state data structure
1359	* definitions are expected to be in the header file <machine/thread_status.h>.
1360	* These machine specific data structures sizes must be multiples of
1361	* 4 bytes. The `cmdsize` reflects the total size of the `ThreadCommand`
1362	* and all of the sizes of the constants for the flavors, counts and state
1363	* data structures.
1364	*
1365	* For executable objects that are unix processes there will be one
1366	* `ThreadCommand` (cmd == LC_UNIXTHREAD) created for it by the link-editor.
1367	* This is the same as a LC_THREAD, except that a stack is automatically
1368	* created (based on the shell's limit for the stack size). Command arguments
1369	* and environment variables are copied onto that stack.
1370	*/
1371	#[derive(Debug, Clone, Copy)]
1372	#[repr(C)]
1373	pub struct ThreadCommand<E: Endian> {
1374	/// LC_THREAD or LC_UNIXTHREAD
1375	pub cmd: U32<E>,
1376	/// total size of this command
1377	pub cmdsize: U32<E>,
1378	/ uint32_t flavor flavor of thread state /
1379	/ uint32_t count count of uint32_t's in thread state /
1380	/ struct XXX_thread_state state thread state for this flavor /
1381	/ ... /
1382	}
1383
1384	/*
1385	* The routines command contains the address of the dynamic shared library
1386	* initialization routine and an index into the module table for the module
1387	* that defines the routine. Before any modules are used from the library the
1388	* dynamic linker fully binds the module that defines the initialization routine
1389	* and then calls it. This gets called before any module initialization
1390	* routines (used for C++ static constructors) in the library.
1391	*/
1392	#[derive(Debug, Clone, Copy)]
1393	#[repr(C)]
1394	pub struct RoutinesCommand32<E: Endian> {
1395	/ for 32-bit architectures /
1396	/// LC_ROUTINES
1397	pub cmd: U32<E>,
1398	/// total size of this command
1399	pub cmdsize: U32<E>,
1400	/// address of initialization routine
1401	pub init_address: U32<E>,
1402	/// index into the module table that the init routine is defined in
1403	pub init_module: U32<E>,
1404	pub reserved1: U32<E>,
1405	pub reserved2: U32<E>,
1406	pub reserved3: U32<E>,
1407	pub reserved4: U32<E>,
1408	pub reserved5: U32<E>,
1409	pub reserved6: U32<E>,
1410	}
1411
1412	/*
1413	* The 64-bit routines command. Same use as above.
1414	*/
1415	#[derive(Debug, Clone, Copy)]
1416	#[repr(C)]
1417	pub struct RoutinesCommand64<E: Endian> {
1418	/ for 64-bit architectures /
1419	/// LC_ROUTINES_64
1420	pub cmd: U32<E>,
1421	/// total size of this command
1422	pub cmdsize: U32<E>,
1423	/// address of initialization routine
1424	pub init_address: U64<E>,
1425	/// index into the module table that the init routine is defined in
1426	pub init_module: U64<E>,
1427	pub reserved1: U64<E>,
1428	pub reserved2: U64<E>,
1429	pub reserved3: U64<E>,
1430	pub reserved4: U64<E>,
1431	pub reserved5: U64<E>,
1432	pub reserved6: U64<E>,
1433	}
1434
1435	/*
1436	* The `SymtabCommand` contains the offsets and sizes of the link-edit 4.3BSD
1437	* "stab" style symbol table information as described in the header files
1438	* <nlist.h> and <stab.h>.
1439	*/
1440	#[derive(Debug, Clone, Copy)]
1441	#[repr(C)]
1442	pub struct SymtabCommand<E: Endian> {
1443	/// LC_SYMTAB
1444	pub cmd: U32<E>,
1445	/// sizeof(struct SymtabCommand)
1446	pub cmdsize: U32<E>,
1447	/// symbol table offset
1448	pub symoff: U32<E>,
1449	/// number of symbol table entries
1450	pub nsyms: U32<E>,
1451	/// string table offset
1452	pub stroff: U32<E>,
1453	/// string table size in bytes
1454	pub strsize: U32<E>,
1455	}
1456
1457	/*
1458	* This is the second set of the symbolic information which is used to support
1459	* the data structures for the dynamically link editor.
1460	*
1461	* The original set of symbolic information in the `SymtabCommand` which contains
1462	* the symbol and string tables must also be present when this load command is
1463	* present. When this load command is present the symbol table is organized
1464	* into three groups of symbols:
1465	* local symbols (static and debugging symbols) - grouped by module
1466	* defined external symbols - grouped by module (sorted by name if not lib)
1467	* undefined external symbols (sorted by name if MH_BINDATLOAD is not set,
1468	* and in order the were seen by the static
1469	* linker if MH_BINDATLOAD is set)
1470	* In this load command there are offsets and counts to each of the three groups
1471	* of symbols.
1472	*
1473	* This load command contains a the offsets and sizes of the following new
1474	* symbolic information tables:
1475	* table of contents
1476	* module table
1477	* reference symbol table
1478	* indirect symbol table
1479	* The first three tables above (the table of contents, module table and
1480	* reference symbol table) are only present if the file is a dynamically linked
1481	* shared library. For executable and object modules, which are files
1482	* containing only one module, the information that would be in these three
1483	* tables is determined as follows:
1484	* table of contents - the defined external symbols are sorted by name
1485	* module table - the file contains only one module so everything in the
1486	* file is part of the module.
1487	* reference symbol table - is the defined and undefined external symbols
1488	*
1489	* For dynamically linked shared library files this load command also contains
1490	* offsets and sizes to the pool of relocation entries for all sections
1491	* separated into two groups:
1492	* external relocation entries
1493	* local relocation entries
1494	* For executable and object modules the relocation entries continue to hang
1495	* off the section structures.
1496	*/
1497	#[derive(Debug, Clone, Copy)]
1498	#[repr(C)]
1499	pub struct DysymtabCommand<E: Endian> {
1500	/// LC_DYSYMTAB
1501	pub cmd: U32<E>,
1502	/// sizeof(struct DysymtabCommand)
1503	pub cmdsize: U32<E>,
1504
1505	/*
1506	* The symbols indicated by symoff and nsyms of the LC_SYMTAB load command
1507	* are grouped into the following three groups:
1508	* local symbols (further grouped by the module they are from)
1509	* defined external symbols (further grouped by the module they are from)
1510	* undefined symbols
1511	*
1512	* The local symbols are used only for debugging. The dynamic binding
1513	* process may have to use them to indicate to the debugger the local
1514	* symbols for a module that is being bound.
1515	*
1516	* The last two groups are used by the dynamic binding process to do the
1517	* binding (indirectly through the module table and the reference symbol
1518	* table when this is a dynamically linked shared library file).
1519	*/
1520	/// index to local symbols
1521	pub ilocalsym: U32<E>,
1522	/// number of local symbols
1523	pub nlocalsym: U32<E>,
1524
1525	/// index to externally defined symbols
1526	pub iextdefsym: U32<E>,
1527	/// number of externally defined symbols
1528	pub nextdefsym: U32<E>,
1529
1530	/// index to undefined symbols
1531	pub iundefsym: U32<E>,
1532	/// number of undefined symbols
1533	pub nundefsym: U32<E>,
1534
1535	/*
1536	* For the for the dynamic binding process to find which module a symbol
1537	* is defined in the table of contents is used (analogous to the ranlib
1538	* structure in an archive) which maps defined external symbols to modules
1539	* they are defined in. This exists only in a dynamically linked shared
1540	* library file. For executable and object modules the defined external
1541	* symbols are sorted by name and is use as the table of contents.
1542	*/
1543	/// file offset to table of contents
1544	pub tocoff: U32<E>,
1545	/// number of entries in table of contents
1546	pub ntoc: U32<E>,
1547
1548	/*
1549	* To support dynamic binding of "modules" (whole object files) the symbol
1550	* table must reflect the modules that the file was created from. This is
1551	* done by having a module table that has indexes and counts into the merged
1552	* tables for each module. The module structure that these two entries
1553	* refer to is described below. This exists only in a dynamically linked
1554	* shared library file. For executable and object modules the file only
1555	* contains one module so everything in the file belongs to the module.
1556	*/
1557	/// file offset to module table
1558	pub modtaboff: U32<E>,
1559	/// number of module table entries
1560	pub nmodtab: U32<E>,
1561
1562	/*
1563	* To support dynamic module binding the module structure for each module
1564	* indicates the external references (defined and undefined) each module
1565	* makes. For each module there is an offset and a count into the
1566	* reference symbol table for the symbols that the module references.
1567	* This exists only in a dynamically linked shared library file. For
1568	* executable and object modules the defined external symbols and the
1569	* undefined external symbols indicates the external references.
1570	*/
1571	/// offset to referenced symbol table
1572	pub extrefsymoff: U32<E>,
1573	/// number of referenced symbol table entries
1574	pub nextrefsyms: U32<E>,
1575
1576	/*
1577	* The sections that contain "symbol pointers" and "routine stubs" have
1578	* indexes and (implied counts based on the size of the section and fixed
1579	* size of the entry) into the "indirect symbol" table for each pointer
1580	* and stub. For every section of these two types the index into the
1581	* indirect symbol table is stored in the section header in the field
1582	* reserved1. An indirect symbol table entry is simply a 32bit index into
1583	* the symbol table to the symbol that the pointer or stub is referring to.
1584	* The indirect symbol table is ordered to match the entries in the section.
1585	*/
1586	/// file offset to the indirect symbol table
1587	pub indirectsymoff: U32<E>,
1588	/// number of indirect symbol table entries
1589	pub nindirectsyms: U32<E>,
1590
1591	/*
1592	* To support relocating an individual module in a library file quickly the
1593	* external relocation entries for each module in the library need to be
1594	* accessed efficiently. Since the relocation entries can't be accessed
1595	* through the section headers for a library file they are separated into
1596	* groups of local and external entries further grouped by module. In this
1597	* case the presents of this load command who's extreloff, nextrel,
1598	* locreloff and nlocrel fields are non-zero indicates that the relocation
1599	* entries of non-merged sections are not referenced through the section
1600	* structures (and the reloff and nreloc fields in the section headers are
1601	* set to zero).
1602	*
1603	* Since the relocation entries are not accessed through the section headers
1604	* this requires the r_address field to be something other than a section
1605	* offset to identify the item to be relocated. In this case r_address is
1606	* set to the offset from the vmaddr of the first LC_SEGMENT command.
1607	* For MH_SPLIT_SEGS images r_address is set to the the offset from the
1608	* vmaddr of the first read-write LC_SEGMENT command.
1609	*
1610	* The relocation entries are grouped by module and the module table
1611	* entries have indexes and counts into them for the group of external
1612	* relocation entries for that the module.
1613	*
1614	* For sections that are merged across modules there must not be any
1615	* remaining external relocation entries for them (for merged sections
1616	* remaining relocation entries must be local).
1617	*/
1618	/// offset to external relocation entries
1619	pub extreloff: U32<E>,
1620	/// number of external relocation entries
1621	pub nextrel: U32<E>,
1622
1623	/*
1624	* All the local relocation entries are grouped together (they are not
1625	* grouped by their module since they are only used if the object is moved
1626	* from it statically link edited address).
1627	*/
1628	/// offset to local relocation entries
1629	pub locreloff: U32<E>,
1630	/// number of local relocation entries
1631	pub nlocrel: U32<E>,
1632	}
1633
1634	/*
1635	* An indirect symbol table entry is simply a 32bit index into the symbol table
1636	* to the symbol that the pointer or stub is referring to. Unless it is for a
1637	* non-lazy symbol pointer section for a defined symbol which strip(1) as
1638	* removed. In which case it has the value INDIRECT_SYMBOL_LOCAL. If the
1639	* symbol was also absolute INDIRECT_SYMBOL_ABS is or'ed with that.
1640	*/
1641	pub const INDIRECT_SYMBOL_LOCAL: u32 = `0x8000_0000`;
1642	pub const INDIRECT_SYMBOL_ABS: u32 = `0x4000_0000`;
1643
1644	/ a table of contents entry /
1645	#[derive(Debug, Clone, Copy)]
1646	#[repr(C)]
1647	pub struct DylibTableOfContents<E: Endian> {
1648	/// the defined external symbol (index into the symbol table)
1649	pub symbol_index: U32<E>,
1650	/// index into the module table this symbol is defined in
1651	pub module_index: U32<E>,
1652	}
1653
1654	/ a module table entry /
1655	#[derive(Debug, Clone, Copy)]
1656	#[repr(C)]
1657	pub struct DylibModule32<E: Endian> {
1658	/// the module name (index into string table)
1659	pub module_name: U32<E>,
1660
1661	/// index into externally defined symbols
1662	pub iextdefsym: U32<E>,
1663	/// number of externally defined symbols
1664	pub nextdefsym: U32<E>,
1665	/// index into reference symbol table
1666	pub irefsym: U32<E>,
1667	/// number of reference symbol table entries
1668	pub nrefsym: U32<E>,
1669	/// index into symbols for local symbols
1670	pub ilocalsym: U32<E>,
1671	/// number of local symbols
1672	pub nlocalsym: U32<E>,
1673
1674	/// index into external relocation entries
1675	pub iextrel: U32<E>,
1676	/// number of external relocation entries
1677	pub nextrel: U32<E>,
1678
1679	/// low 16 bits are the index into the init section, high 16 bits are the index into the term section
1680	pub iinit_iterm: U32<E>,
1681	/// low 16 bits are the number of init section entries, high 16 bits are the number of term section entries
1682	pub ninit_nterm: U32<E>,
1683
1684	/// for this module address of the start of the (__OBJC,__module_info) section
1685	pub objc_module_info_addr: U32<E>,
1686	/// for this module size of the (__OBJC,__module_info) section
1687	pub objc_module_info_size: U32<E>,
1688	}
1689
1690	/ a 64-bit module table entry /
1691	#[derive(Debug, Clone, Copy)]
1692	#[repr(C)]
1693	pub struct DylibModule64<E: Endian> {
1694	/// the module name (index into string table)
1695	pub module_name: U32<E>,
1696
1697	/// index into externally defined symbols
1698	pub iextdefsym: U32<E>,
1699	/// number of externally defined symbols
1700	pub nextdefsym: U32<E>,
1701	/// index into reference symbol table
1702	pub irefsym: U32<E>,
1703	/// number of reference symbol table entries
1704	pub nrefsym: U32<E>,
1705	/// index into symbols for local symbols
1706	pub ilocalsym: U32<E>,
1707	/// number of local symbols
1708	pub nlocalsym: U32<E>,
1709
1710	/// index into external relocation entries
1711	pub iextrel: U32<E>,
1712	/// number of external relocation entries
1713	pub nextrel: U32<E>,
1714
1715	/// low 16 bits are the index into the init section, high 16 bits are the index into the term section
1716	pub iinit_iterm: U32<E>,
1717	/// low 16 bits are the number of init section entries, high 16 bits are the number of term section entries
1718	pub ninit_nterm: U32<E>,
1719
1720	/// for this module size of the (__OBJC,__module_info) section
1721	pub objc_module_info_size: U32<E>,
1722	/// for this module address of the start of the (__OBJC,__module_info) section
1723	pub objc_module_info_addr: U64<E>,
1724	}
1725
1726	/*
1727	* The entries in the reference symbol table are used when loading the module
1728	* (both by the static and dynamic link editors) and if the module is unloaded
1729	* or replaced. Therefore all external symbols (defined and undefined) are
1730	* listed in the module's reference table. The flags describe the type of
1731	* reference that is being made. The constants for the flags are defined in
1732	* <mach-o/nlist.h> as they are also used for symbol table entries.
1733	*/
1734	#[derive(Debug, Clone, Copy)]
1735	#[repr(C)]
1736	pub struct DylibReference<E: Endian> {
1737	/ TODO:*
1738	uint32_t isym:24, / index into the symbol table /
1739	flags:8; / flags to indicate the type of reference /
1740	*/
1741	pub bitfield: U32<E>,
1742	}
1743
1744	/*
1745	* The TwolevelHintsCommand contains the offset and number of hints in the
1746	* two-level namespace lookup hints table.
1747	*/
1748	#[derive(Debug, Clone, Copy)]
1749	#[repr(C)]
1750	pub struct TwolevelHintsCommand<E: Endian> {
1751	/// LC_TWOLEVEL_HINTS
1752	pub cmd: U32<E>,
1753	/// sizeof(struct TwolevelHintsCommand)
1754	pub cmdsize: U32<E>,
1755	/// offset to the hint table
1756	pub offset: U32<E>,
1757	/// number of hints in the hint table
1758	pub nhints: U32<E>,
1759	}
1760
1761	/*
1762	* The entries in the two-level namespace lookup hints table are TwolevelHint
1763	* structs. These provide hints to the dynamic link editor where to start
1764	* looking for an undefined symbol in a two-level namespace image. The
1765	* isub_image field is an index into the sub-images (sub-frameworks and
1766	* sub-umbrellas list) that made up the two-level image that the undefined
1767	* symbol was found in when it was built by the static link editor. If
1768	* isub-image is 0 the the symbol is expected to be defined in library and not
1769	* in the sub-images. If isub-image is non-zero it is an index into the array
1770	* of sub-images for the umbrella with the first index in the sub-images being
1771	* 1. The array of sub-images is the ordered list of sub-images of the umbrella
1772	* that would be searched for a symbol that has the umbrella recorded as its
1773	* primary library. The table of contents index is an index into the
1774	* library's table of contents. This is used as the starting point of the
1775	* binary search or a directed linear search.
1776	*/
1777	#[derive(Debug, Clone, Copy)]
1778	#[repr(C)]
1779	pub struct TwolevelHint<E: Endian> {
1780	/ TODO:*
1781	uint32_t
1782	isub_image:8, / index into the sub images /
1783	itoc:24; / index into the table of contents /
1784	*/
1785	pub bitfield: U32<E>,
1786	}
1787
1788	/*
1789	* The PrebindCksumCommand contains the value of the original check sum for
1790	* prebound files or zero. When a prebound file is first created or modified
1791	* for other than updating its prebinding information the value of the check sum
1792	* is set to zero. When the file has it prebinding re-done and if the value of
1793	* the check sum is zero the original check sum is calculated and stored in
1794	* cksum field of this load command in the output file. If when the prebinding
1795	* is re-done and the cksum field is non-zero it is left unchanged from the
1796	* input file.
1797	*/
1798	#[derive(Debug, Clone, Copy)]
1799	#[repr(C)]
1800	pub struct PrebindCksumCommand<E: Endian> {
1801	/// LC_PREBIND_CKSUM
1802	pub cmd: U32<E>,
1803	/// sizeof(struct PrebindCksumCommand)
1804	pub cmdsize: U32<E>,
1805	/// the check sum or zero
1806	pub cksum: U32<E>,
1807	}
1808
1809	/*
1810	* The uuid load command contains a single 128-bit unique random number that
1811	* identifies an object produced by the static link editor.
1812	*/
1813	#[derive(Debug, Clone, Copy)]
1814	#[repr(C)]
1815	pub struct UuidCommand<E: Endian> {
1816	/// LC_UUID
1817	pub cmd: U32<E>,
1818	/// sizeof(struct UuidCommand)
1819	pub cmdsize: U32<E>,
1820	/// the 128-bit uuid
1821	pub uuid: [u8; `16`],
1822	}
1823
1824	/*
1825	* The RpathCommand contains a path which at runtime should be added to
1826	* the current run path used to find @rpath prefixed dylibs.
1827	*/
1828	#[derive(Debug, Clone, Copy)]
1829	#[repr(C)]
1830	pub struct RpathCommand<E: Endian> {
1831	/// LC_RPATH
1832	pub cmd: U32<E>,
1833	/// includes string
1834	pub cmdsize: U32<E>,
1835	/// path to add to run path
1836	pub path: LcStr<E>,
1837	}
1838
1839	/*
1840	* The LinkeditDataCommand contains the offsets and sizes of a blob
1841	* of data in the __LINKEDIT segment.
1842	*/
1843	#[derive(Debug, Clone, Copy)]
1844	#[repr(C)]
1845	pub struct LinkeditDataCommand<E: Endian> {
1846	/// `LC_CODE_SIGNATURE`, `LC_SEGMENT_SPLIT_INFO`, `LC_FUNCTION_STARTS`,
1847	/// `LC_DATA_IN_CODE`, `LC_DYLIB_CODE_SIGN_DRS`, `LC_LINKER_OPTIMIZATION_HINT`,
1848	/// `LC_DYLD_EXPORTS_TRIE`, or `LC_DYLD_CHAINED_FIXUPS`.
1849	pub cmd: U32<E>,
1850	/// sizeof(struct LinkeditDataCommand)
1851	pub cmdsize: U32<E>,
1852	/// file offset of data in __LINKEDIT segment
1853	pub dataoff: U32<E>,
1854	/// file size of data in __LINKEDIT segment
1855	pub datasize: U32<E>,
1856	}
1857
1858	#[derive(Debug, Clone, Copy)]
1859	#[repr(C)]
1860	pub struct FilesetEntryCommand<E: Endian> {
1861	// LC_FILESET_ENTRY
1862	pub cmd: U32<E>,
1863	/// includes id string
1864	pub cmdsize: U32<E>,
1865	/// memory address of the dylib
1866	pub vmaddr: U64<E>,
1867	/// file offset of the dylib
1868	pub fileoff: U64<E>,
1869	/// contained entry id
1870	pub entry_id: LcStr<E>,
1871	/// entry_id is 32-bits long, so this is the reserved padding
1872	pub reserved: U32<E>,
1873	}
1874
1875	/*
1876	* The EncryptionInfoCommand32 contains the file offset and size of an
1877	* of an encrypted segment.
1878	*/
1879	#[derive(Debug, Clone, Copy)]
1880	#[repr(C)]
1881	pub struct EncryptionInfoCommand32<E: Endian> {
1882	/// LC_ENCRYPTION_INFO
1883	pub cmd: U32<E>,
1884	/// sizeof(struct EncryptionInfoCommand32)
1885	pub cmdsize: U32<E>,
1886	/// file offset of encrypted range
1887	pub cryptoff: U32<E>,
1888	/// file size of encrypted range
1889	pub cryptsize: U32<E>,
1890	/// which enryption system, 0 means not-encrypted yet
1891	pub cryptid: U32<E>,
1892	}
1893
1894	/*
1895	* The EncryptionInfoCommand64 contains the file offset and size of an
1896	* of an encrypted segment (for use in x86_64 targets).
1897	*/
1898	#[derive(Debug, Clone, Copy)]
1899	#[repr(C)]
1900	pub struct EncryptionInfoCommand64<E: Endian> {
1901	/// LC_ENCRYPTION_INFO_64
1902	pub cmd: U32<E>,
1903	/// sizeof(struct EncryptionInfoCommand64)
1904	pub cmdsize: U32<E>,
1905	/// file offset of encrypted range
1906	pub cryptoff: U32<E>,
1907	/// file size of encrypted range
1908	pub cryptsize: U32<E>,
1909	/// which enryption system, 0 means not-encrypted yet
1910	pub cryptid: U32<E>,
1911	/// padding to make this struct's size a multiple of 8 bytes
1912	pub pad: U32<E>,
1913	}
1914
1915	/*
1916	* The VersionMinCommand contains the min OS version on which this
1917	* binary was built to run.
1918	*/
1919	#[derive(Debug, Clone, Copy)]
1920	#[repr(C)]
1921	pub struct VersionMinCommand<E: Endian> {
1922	/// LC_VERSION_MIN_MACOSX or LC_VERSION_MIN_IPHONEOS or LC_VERSION_MIN_WATCHOS or LC_VERSION_MIN_TVOS
1923	pub cmd: U32<E>,
1924	/// sizeof(struct VersionMinCommand)
1925	pub cmdsize: U32<E>,
1926	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1927	pub version: U32<E>,
1928	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1929	pub sdk: U32<E>,
1930	}
1931
1932	/*
1933	* The BuildVersionCommand contains the min OS version on which this
1934	* binary was built to run for its platform. The list of known platforms and
1935	* tool values following it.
1936	*/
1937	#[derive(Debug, Clone, Copy)]
1938	#[repr(C)]
1939	pub struct BuildVersionCommand<E: Endian> {
1940	/// LC_BUILD_VERSION
1941	pub cmd: U32<E>,
1942	/// sizeof(struct BuildVersionCommand) plus ntools sizeof(struct BuildToolVersion)*
1943	pub cmdsize: U32<E>,
1944	/// platform
1945	pub platform: U32<E>,
1946	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1947	pub minos: U32<E>,
1948	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1949	pub sdk: U32<E>,
1950	/// number of tool entries following this
1951	pub ntools: U32<E>,
1952	}
1953
1954	#[derive(Debug, Clone, Copy)]
1955	#[repr(C)]
1956	pub struct BuildToolVersion<E: Endian> {
1957	/// enum for the tool
1958	pub tool: U32<E>,
1959	/// version number of the tool
1960	pub version: U32<E>,
1961	}
1962
1963	/ Known values for the platform field above. /
1964	pub const PLATFORM_MACOS: u32 = `1`;
1965	pub const PLATFORM_IOS: u32 = `2`;
1966	pub const PLATFORM_TVOS: u32 = `3`;
1967	pub const PLATFORM_WATCHOS: u32 = `4`;
1968	pub const PLATFORM_BRIDGEOS: u32 = `5`;
1969	pub const PLATFORM_MACCATALYST: u32 = `6`;
1970	pub const PLATFORM_IOSSIMULATOR: u32 = `7`;
1971	pub const PLATFORM_TVOSSIMULATOR: u32 = `8`;
1972	pub const PLATFORM_WATCHOSSIMULATOR: u32 = `9`;
1973	pub const PLATFORM_DRIVERKIT: u32 = `10`;
1974	pub const PLATFORM_XROS: u32 = `11`;
1975	pub const PLATFORM_XROSSIMULATOR: u32 = `12`;
1976
1977	/ Known values for the tool field above. /
1978	pub const TOOL_CLANG: u32 = `1`;
1979	pub const TOOL_SWIFT: u32 = `2`;
1980	pub const TOOL_LD: u32 = `3`;
1981
1982	/*
1983	* The DyldInfoCommand contains the file offsets and sizes of
1984	* the new compressed form of the information dyld needs to
1985	* load the image. This information is used by dyld on Mac OS X
1986	* 10.6 and later. All information pointed to by this command
1987	* is encoded using byte streams, so no endian swapping is needed
1988	* to interpret it.
1989	*/
1990	#[derive(Debug, Clone, Copy)]
1991	#[repr(C)]
1992	pub struct DyldInfoCommand<E: Endian> {
1993	/// LC_DYLD_INFO or LC_DYLD_INFO_ONLY
1994	pub cmd: U32<E>,
1995	/// sizeof(struct DyldInfoCommand)
1996	pub cmdsize: U32<E>,
1997
1998	/*
1999	* Dyld rebases an image whenever dyld loads it at an address different
2000	* from its preferred address. The rebase information is a stream
2001	* of byte sized opcodes whose symbolic names start with REBASE_OPCODE_.
2002	* Conceptually the rebase information is a table of tuples:
2003	* <seg-index, seg-offset, type>
2004	* The opcodes are a compressed way to encode the table by only
2005	* encoding when a column changes. In addition simple patterns
2006	* like "every n'th offset for m times" can be encoded in a few
2007	* bytes.
2008	*/
2009	/// file offset to rebase info
2010	pub rebase_off: U32<E>,
2011	/// size of rebase info
2012	pub rebase_size: U32<E>,
2013
2014	/*
2015	* Dyld binds an image during the loading process, if the image
2016	* requires any pointers to be initialized to symbols in other images.
2017	* The bind information is a stream of byte sized
2018	* opcodes whose symbolic names start with BIND_OPCODE_.
2019	* Conceptually the bind information is a table of tuples:
2020	* <seg-index, seg-offset, type, symbol-library-ordinal, symbol-name, addend>
2021	* The opcodes are a compressed way to encode the table by only
2022	* encoding when a column changes. In addition simple patterns
2023	* like for runs of pointers initialized to the same value can be
2024	* encoded in a few bytes.
2025	*/
2026	/// file offset to binding info
2027	pub bind_off: U32<E>,
2028	/// size of binding info
2029	pub bind_size: U32<E>,
2030
2031	/*
2032	* Some C++ programs require dyld to unique symbols so that all
2033	* images in the process use the same copy of some code/data.
2034	* This step is done after binding. The content of the weak_bind
2035	* info is an opcode stream like the bind_info. But it is sorted
2036	* alphabetically by symbol name. This enable dyld to walk
2037	* all images with weak binding information in order and look
2038	* for collisions. If there are no collisions, dyld does
2039	* no updating. That means that some fixups are also encoded
2040	* in the bind_info. For instance, all calls to "operator new"
2041	* are first bound to libstdc++.dylib using the information
2042	* in bind_info. Then if some image overrides operator new
2043	* that is detected when the weak_bind information is processed
2044	* and the call to operator new is then rebound.
2045	*/
2046	/// file offset to weak binding info
2047	pub weak_bind_off: U32<E>,
2048	/// size of weak binding info
2049	pub weak_bind_size: U32<E>,
2050
2051	/*
2052	* Some uses of external symbols do not need to be bound immediately.
2053	* Instead they can be lazily bound on first use. The lazy_bind
2054	* are contains a stream of BIND opcodes to bind all lazy symbols.
2055	* Normal use is that dyld ignores the lazy_bind section when
2056	* loading an image. Instead the static linker arranged for the
2057	* lazy pointer to initially point to a helper function which
2058	* pushes the offset into the lazy_bind area for the symbol
2059	* needing to be bound, then jumps to dyld which simply adds
2060	* the offset to lazy_bind_off to get the information on what
2061	* to bind.
2062	*/
2063	/// file offset to lazy binding info
2064	pub lazy_bind_off: U32<E>,
2065	/// size of lazy binding infs
2066	pub lazy_bind_size: U32<E>,
2067
2068	/*
2069	* The symbols exported by a dylib are encoded in a trie. This
2070	* is a compact representation that factors out common prefixes.
2071	* It also reduces LINKEDIT pages in RAM because it encodes all
2072	* information (name, address, flags) in one small, contiguous range.
2073	* The export area is a stream of nodes. The first node sequentially
2074	* is the start node for the trie.
2075	*
2076	* Nodes for a symbol start with a uleb128 that is the length of
2077	* the exported symbol information for the string so far.
2078	* If there is no exported symbol, the node starts with a zero byte.
2079	* If there is exported info, it follows the length.
2080	*
2081	* First is a uleb128 containing flags. Normally, it is followed by
2082	* a uleb128 encoded offset which is location of the content named
2083	* by the symbol from the mach_header for the image. If the flags
2084	* is EXPORT_SYMBOL_FLAGS_REEXPORT, then following the flags is
2085	* a uleb128 encoded library ordinal, then a zero terminated
2086	* UTF8 string. If the string is zero length, then the symbol
2087	* is re-export from the specified dylib with the same name.
2088	* If the flags is EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER, then following
2089	* the flags is two uleb128s: the stub offset and the resolver offset.
2090	* The stub is used by non-lazy pointers. The resolver is used
2091	* by lazy pointers and must be called to get the actual address to use.
2092	*
2093	* After the optional exported symbol information is a byte of
2094	* how many edges (0-255) that this node has leaving it,
2095	* followed by each edge.
2096	* Each edge is a zero terminated UTF8 of the addition chars
2097	* in the symbol, followed by a uleb128 offset for the node that
2098	* edge points to.
2099	*
2100	*/
2101	/// file offset to lazy binding info
2102	pub export_off: U32<E>,
2103	/// size of lazy binding infs
2104	pub export_size: U32<E>,
2105	}
2106
2107	/*
2108	* The following are used to encode rebasing information
2109	*/
2110	pub const REBASE_TYPE_POINTER: u8 = `1`;
2111	pub const REBASE_TYPE_TEXT_ABSOLUTE32: u8 = `2`;
2112	pub const REBASE_TYPE_TEXT_PCREL32: u8 = `3`;
2113
2114	pub const REBASE_OPCODE_MASK: u8 = `0xF0`;
2115	pub const REBASE_IMMEDIATE_MASK: u8 = `0x0F`;
2116	pub const REBASE_OPCODE_DONE: u8 = `0x00`;
2117	pub const REBASE_OPCODE_SET_TYPE_IMM: u8 = `0x10`;
2118	pub const REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: u8 = `0x20`;
2119	pub const REBASE_OPCODE_ADD_ADDR_ULEB: u8 = `0x30`;
2120	pub const REBASE_OPCODE_ADD_ADDR_IMM_SCALED: u8 = `0x40`;
2121	pub const REBASE_OPCODE_DO_REBASE_IMM_TIMES: u8 = `0x50`;
2122	pub const REBASE_OPCODE_DO_REBASE_ULEB_TIMES: u8 = `0x60`;
2123	pub const REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB: u8 = `0x70`;
2124	pub const REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB: u8 = `0x80`;
2125
2126	/*
2127	* The following are used to encode binding information
2128	*/
2129	pub const BIND_TYPE_POINTER: u8 = `1`;
2130	pub const BIND_TYPE_TEXT_ABSOLUTE32: u8 = `2`;
2131	pub const BIND_TYPE_TEXT_PCREL32: u8 = `3`;
2132
2133	pub const BIND_SPECIAL_DYLIB_SELF: i8 = `0`;
2134	pub const BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE: i8 = `-1`;
2135	pub const BIND_SPECIAL_DYLIB_FLAT_LOOKUP: i8 = `-2`;
2136	pub const BIND_SPECIAL_DYLIB_WEAK_LOOKUP: i8 = `-3`;
2137
2138	pub const BIND_SYMBOL_FLAGS_WEAK_IMPORT: u8 = `0x1`;
2139	pub const BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION: u8 = `0x8`;
2140
2141	pub const BIND_OPCODE_MASK: u8 = `0xF0`;
2142	pub const BIND_IMMEDIATE_MASK: u8 = `0x0F`;
2143	pub const BIND_OPCODE_DONE: u8 = `0x00`;
2144	pub const BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: u8 = `0x10`;
2145	pub const BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: u8 = `0x20`;
2146	pub const BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: u8 = `0x30`;
2147	pub const BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: u8 = `0x40`;
2148	pub const BIND_OPCODE_SET_TYPE_IMM: u8 = `0x50`;
2149	pub const BIND_OPCODE_SET_ADDEND_SLEB: u8 = `0x60`;
2150	pub const BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: u8 = `0x70`;
2151	pub const BIND_OPCODE_ADD_ADDR_ULEB: u8 = `0x80`;
2152	pub const BIND_OPCODE_DO_BIND: u8 = `0x90`;
2153	pub const BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: u8 = `0xA0`;
2154	pub const BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: u8 = `0xB0`;
2155	pub const BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: u8 = `0xC0`;
2156	pub const BIND_OPCODE_THREADED: u8 = `0xD0`;
2157	pub const BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB: u8 = `0x00`;
2158	pub const BIND_SUBOPCODE_THREADED_APPLY: u8 = `0x01`;
2159
2160	/*
2161	* The following are used on the flags byte of a terminal node
2162	* in the export information.
2163	*/
2164	pub const EXPORT_SYMBOL_FLAGS_KIND_MASK: u32 = `0x03`;
2165	pub const EXPORT_SYMBOL_FLAGS_KIND_REGULAR: u32 = `0x00`;
2166	pub const EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL: u32 = `0x01`;
2167	pub const EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE: u32 = `0x02`;
2168	pub const EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION: u32 = `0x04`;
2169	pub const EXPORT_SYMBOL_FLAGS_REEXPORT: u32 = `0x08`;
2170	pub const EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER: u32 = `0x10`;
2171
2172	/*
2173	* The LinkerOptionCommand contains linker options embedded in object files.
2174	*/
2175	#[derive(Debug, Clone, Copy)]
2176	#[repr(C)]
2177	pub struct LinkerOptionCommand<E: Endian> {
2178	/// LC_LINKER_OPTION only used in MH_OBJECT filetypes
2179	pub cmd: U32<E>,
2180	pub cmdsize: U32<E>,
2181	/// number of strings
2182	pub count: U32<E>,
2183	/ concatenation of zero terminated UTF8 strings.*
2184	Zero filled at end to align /*
2185	}
2186
2187	/*
2188	* The SymsegCommand contains the offset and size of the GNU style
2189	* symbol table information as described in the header file <symseg.h>.
2190	* The symbol roots of the symbol segments must also be aligned properly
2191	* in the file. So the requirement of keeping the offsets aligned to a
2192	* multiple of a 4 bytes translates to the length field of the symbol
2193	* roots also being a multiple of a long. Also the padding must again be
2194	* zeroed. (THIS IS OBSOLETE and no longer supported).
2195	*/
2196	#[derive(Debug, Clone, Copy)]
2197	#[repr(C)]
2198	pub struct SymsegCommand<E: Endian> {
2199	/// LC_SYMSEG
2200	pub cmd: U32<E>,
2201	/// sizeof(struct SymsegCommand)
2202	pub cmdsize: U32<E>,
2203	/// symbol segment offset
2204	pub offset: U32<E>,
2205	/// symbol segment size in bytes
2206	pub size: U32<E>,
2207	}
2208
2209	/*
2210	* The IdentCommand contains a free format string table following the
2211	* IdentCommand structure. The strings are null terminated and the size of
2212	* the command is padded out with zero bytes to a multiple of 4 bytes/
2213	* (THIS IS OBSOLETE and no longer supported).
2214	*/
2215	#[derive(Debug, Clone, Copy)]
2216	#[repr(C)]
2217	pub struct IdentCommand<E: Endian> {
2218	/// LC_IDENT
2219	pub cmd: U32<E>,
2220	/// strings that follow this command
2221	pub cmdsize: U32<E>,
2222	}
2223
2224	/*
2225	* The FvmfileCommand contains a reference to a file to be loaded at the
2226	* specified virtual address. (Presently, this command is reserved for
2227	* internal use. The kernel ignores this command when loading a program into
2228	* memory).
2229	*/
2230	#[derive(Debug, Clone, Copy)]
2231	#[repr(C)]
2232	pub struct FvmfileCommand<E: Endian> {
2233	/// LC_FVMFILE
2234	pub cmd: U32<E>,
2235	/// includes pathname string
2236	pub cmdsize: U32<E>,
2237	/// files pathname
2238	pub name: LcStr<E>,
2239	/// files virtual address
2240	pub header_addr: U32<E>,
2241	}
2242
2243	/*
2244	* The EntryPointCommand is a replacement for thread_command.
2245	* It is used for main executables to specify the location (file offset)
2246	* of main(). If -stack_size was used at link time, the stacksize
2247	* field will contain the stack size need for the main thread.
2248	*/
2249	#[derive(Debug, Clone, Copy)]
2250	#[repr(C)]
2251	pub struct EntryPointCommand<E: Endian> {
2252	/// LC_MAIN only used in MH_EXECUTE filetypes
2253	pub cmd: U32<E>,
2254	/// 24
2255	pub cmdsize: U32<E>,
2256	/// file (__TEXT) offset of main()
2257	pub entryoff: U64<E>,
2258	/// if not zero, initial stack size
2259	pub stacksize: U64<E>,
2260	}
2261
2262	/*
2263	* The SourceVersionCommand is an optional load command containing
2264	* the version of the sources used to build the binary.
2265	*/
2266	#[derive(Debug, Clone, Copy)]
2267	#[repr(C)]
2268	pub struct SourceVersionCommand<E: Endian> {
2269	/// LC_SOURCE_VERSION
2270	pub cmd: U32<E>,
2271	/// 16
2272	pub cmdsize: U32<E>,
2273	/// A.B.C.D.E packed as a24.b10.c10.d10.e10
2274	pub version: U64<E>,
2275	}
2276
2277	/*
2278	* The LC_DATA_IN_CODE load commands uses a LinkeditDataCommand
2279	* to point to an array of DataInCodeEntry entries. Each entry
2280	* describes a range of data in a code section.
2281	*/
2282	#[derive(Debug, Clone, Copy)]
2283	#[repr(C)]
2284	pub struct DataInCodeEntry<E: Endian> {
2285	/// from mach_header to start of data range
2286	pub offset: U32<E>,
2287	/// number of bytes in data range
2288	pub length: U16<E>,
2289	/// a DICE_KIND_ value*
2290	pub kind: U16<E>,
2291	}
2292	pub const DICE_KIND_DATA: u32 = `0x0001`;
2293	pub const DICE_KIND_JUMP_TABLE8: u32 = `0x0002`;
2294	pub const DICE_KIND_JUMP_TABLE16: u32 = `0x0003`;
2295	pub const DICE_KIND_JUMP_TABLE32: u32 = `0x0004`;
2296	pub const DICE_KIND_ABS_JUMP_TABLE32: u32 = `0x0005`;
2297
2298	/*
2299	* Sections of type S_THREAD_LOCAL_VARIABLES contain an array
2300	* of TlvDescriptor structures.
2301	*/
2302	/ TODO:*
2303	#[derive(Debug, Clone, Copy)]
2304	#[repr(C)]
2305	pub struct TlvDescriptor<E: Endian>
2306	{
2307	void (thunk)(struct TlvDescriptor);*
2308	unsigned long key;
2309	unsigned long offset;
2310	}
2311	*/
2312
2313	/*
2314	* LC_NOTE commands describe a region of arbitrary data included in a Mach-O
2315	* file. Its initial use is to record extra data in MH_CORE files.
2316	*/
2317	#[derive(Debug, Clone, Copy)]
2318	#[repr(C)]
2319	pub struct NoteCommand<E: Endian> {
2320	/// LC_NOTE
2321	pub cmd: U32<E>,
2322	/// sizeof(struct NoteCommand)
2323	pub cmdsize: U32<E>,
2324	/// owner name for this LC_NOTE
2325	pub data_owner: [u8; `16`],
2326	/// file offset of this data
2327	pub offset: U64<E>,
2328	/// length of data region
2329	pub size: U64<E>,
2330	}
2331
2332	// Definitions from "/usr/include/mach-o/nlist.h".
2333
2334	#[derive(Debug, Clone, Copy)]
2335	#[repr(C)]
2336	pub struct Nlist32<E: Endian> {
2337	/// index into the string table
2338	pub n_strx: U32<E>,
2339	/// type flag, see below
2340	pub n_type: u8,
2341	/// section number or NO_SECT
2342	pub n_sect: u8,
2343	/// see <mach-o/stab.h>
2344	pub n_desc: U16<E>,
2345	/// value of this symbol (or stab offset)
2346	pub n_value: U32<E>,
2347	}
2348
2349	/*
2350	* This is the symbol table entry structure for 64-bit architectures.
2351	*/
2352	#[derive(Debug, Clone, Copy)]
2353	#[repr(C)]
2354	pub struct Nlist64<E: Endian> {
2355	/// index into the string table
2356	pub n_strx: U32<E>,
2357	/// type flag, see below
2358	pub n_type: u8,
2359	/// section number or NO_SECT
2360	pub n_sect: u8,
2361	/// see <mach-o/stab.h>
2362	pub n_desc: U16<E>,
2363	/// value of this symbol (or stab offset)
2364	// Note: 4 byte alignment has been observed in practice.
2365	pub n_value: U64Bytes<E>,
2366	}
2367
2368	/*
2369	* Symbols with a index into the string table of zero (n_un.n_strx == 0) are
2370	* defined to have a null, "", name. Therefore all string indexes to non null
2371	* names must not have a zero string index. This is bit historical information
2372	* that has never been well documented.
2373	*/
2374
2375	/*
2376	* The n_type field really contains four fields:
2377	* unsigned char N_STAB:3,
2378	* N_PEXT:1,
2379	* N_TYPE:3,
2380	* N_EXT:1;
2381	* which are used via the following masks.
2382	*/
2383	/// if any of these bits set, a symbolic debugging entry
2384	pub const N_STAB: u8 = `0xe0`;
2385	/// private external symbol bit
2386	pub const N_PEXT: u8 = `0x10`;
2387	/// mask for the type bits
2388	pub const N_TYPE: u8 = `0x0e`;
2389	/// external symbol bit, set for external symbols
2390	pub const N_EXT: u8 = `0x01`;
2391
2392	/*
2393	* Only symbolic debugging entries have some of the N_STAB bits set and if any
2394	* of these bits are set then it is a symbolic debugging entry (a stab). In
2395	* which case then the values of the n_type field (the entire field) are given
2396	* in <mach-o/stab.h>
2397	*/
2398
2399	/*
2400	* Values for N_TYPE bits of the n_type field.
2401	*/
2402	/// undefined, n_sect == NO_SECT
2403	pub const N_UNDF: u8 = `0x0`;
2404	/// absolute, n_sect == NO_SECT
2405	pub const N_ABS: u8 = `0x2`;
2406	/// defined in section number n_sect
2407	pub const N_SECT: u8 = `0xe`;
2408	/// prebound undefined (defined in a dylib)
2409	pub const N_PBUD: u8 = `0xc`;
2410	/// indirect
2411	pub const N_INDR: u8 = `0xa`;
2412
2413	/*
2414	* If the type is N_INDR then the symbol is defined to be the same as another
2415	* symbol. In this case the n_value field is an index into the string table
2416	* of the other symbol's name. When the other symbol is defined then they both
2417	* take on the defined type and value.
2418	*/
2419
2420	/*
2421	* If the type is N_SECT then the n_sect field contains an ordinal of the
2422	* section the symbol is defined in. The sections are numbered from 1 and
2423	* refer to sections in order they appear in the load commands for the file
2424	* they are in. This means the same ordinal may very well refer to different
2425	* sections in different files.
2426	*
2427	* The n_value field for all symbol table entries (including N_STAB's) gets
2428	* updated by the link editor based on the value of it's n_sect field and where
2429	* the section n_sect references gets relocated. If the value of the n_sect
2430	* field is NO_SECT then it's n_value field is not changed by the link editor.
2431	*/
2432	/// symbol is not in any section
2433	pub const NO_SECT: u8 = `0`;
2434	/// 1 thru 255 inclusive
2435	pub const MAX_SECT: u8 = `255`;
2436
2437	/*
2438	* Common symbols are represented by undefined (N_UNDF) external (N_EXT) types
2439	* who's values (n_value) are non-zero. In which case the value of the n_value
2440	* field is the size (in bytes) of the common symbol. The n_sect field is set
2441	* to NO_SECT. The alignment of a common symbol may be set as a power of 2
2442	* between 2^1 and 2^15 as part of the n_desc field using the macros below. If
2443	* the alignment is not set (a value of zero) then natural alignment based on
2444	* the size is used.
2445	*/
2446	/ TODO:*
2447	#define GET_COMM_ALIGN(n_desc) (((n_desc) >> 8) & 0x0f)
2448	#define SET_COMM_ALIGN(n_desc,align) \
2449	(n_desc) = (((n_desc) & 0xf0ff) \| (((align) & 0x0f) << 8))
2450	*/
2451
2452	/*
2453	* To support the lazy binding of undefined symbols in the dynamic link-editor,
2454	* the undefined symbols in the symbol table (the nlist structures) are marked
2455	* with the indication if the undefined reference is a lazy reference or
2456	* non-lazy reference. If both a non-lazy reference and a lazy reference is
2457	* made to the same symbol the non-lazy reference takes precedence. A reference
2458	* is lazy only when all references to that symbol are made through a symbol
2459	* pointer in a lazy symbol pointer section.
2460	*
2461	* The implementation of marking nlist structures in the symbol table for
2462	* undefined symbols will be to use some of the bits of the n_desc field as a
2463	* reference type. The mask REFERENCE_TYPE will be applied to the n_desc field
2464	* of an nlist structure for an undefined symbol to determine the type of
2465	* undefined reference (lazy or non-lazy).
2466	*
2467	* The constants for the REFERENCE FLAGS are propagated to the reference table
2468	* in a shared library file. In that case the constant for a defined symbol,
2469	* REFERENCE_FLAG_DEFINED, is also used.
2470	*/
2471	/ Reference type bits of the n_desc field of undefined symbols /
2472	pub const REFERENCE_TYPE: u16 = `0x7`;
2473	/ types of references /
2474	pub const REFERENCE_FLAG_UNDEFINED_NON_LAZY: u16 = `0`;
2475	pub const REFERENCE_FLAG_UNDEFINED_LAZY: u16 = `1`;
2476	pub const REFERENCE_FLAG_DEFINED: u16 = `2`;
2477	pub const REFERENCE_FLAG_PRIVATE_DEFINED: u16 = `3`;
2478	pub const REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY: u16 = `4`;
2479	pub const REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY: u16 = `5`;
2480
2481	/*
2482	* To simplify stripping of objects that use are used with the dynamic link
2483	* editor, the static link editor marks the symbols defined an object that are
2484	* referenced by a dynamically bound object (dynamic shared libraries, bundles).
2485	* With this marking strip knows not to strip these symbols.
2486	*/
2487	pub const REFERENCED_DYNAMICALLY: u16 = `0x0010`;
2488
2489	/*
2490	* For images created by the static link editor with the -twolevel_namespace
2491	* option in effect the flags field of the mach header is marked with
2492	* MH_TWOLEVEL. And the binding of the undefined references of the image are
2493	* determined by the static link editor. Which library an undefined symbol is
2494	* bound to is recorded by the static linker in the high 8 bits of the n_desc
2495	* field using the SET_LIBRARY_ORDINAL macro below. The ordinal recorded
2496	* references the libraries listed in the Mach-O's LC_LOAD_DYLIB,
2497	* LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_LOAD_UPWARD_DYLIB, and
2498	* LC_LAZY_LOAD_DYLIB, etc. load commands in the order they appear in the
2499	* headers. The library ordinals start from 1.
2500	* For a dynamic library that is built as a two-level namespace image the
2501	* undefined references from module defined in another use the same nlist struct
2502	* an in that case SELF_LIBRARY_ORDINAL is used as the library ordinal. For
2503	* defined symbols in all images they also must have the library ordinal set to
2504	* SELF_LIBRARY_ORDINAL. The EXECUTABLE_ORDINAL refers to the executable
2505	* image for references from plugins that refer to the executable that loads
2506	* them.
2507	*
2508	* The DYNAMIC_LOOKUP_ORDINAL is for undefined symbols in a two-level namespace
2509	* image that are looked up by the dynamic linker with flat namespace semantics.
2510	* This ordinal was added as a feature in Mac OS X 10.3 by reducing the
2511	* value of MAX_LIBRARY_ORDINAL by one. So it is legal for existing binaries
2512	* or binaries built with older tools to have 0xfe (254) dynamic libraries. In
2513	* this case the ordinal value 0xfe (254) must be treated as a library ordinal
2514	* for compatibility.
2515	*/
2516	/ TODO:*
2517	#define GET_LIBRARY_ORDINAL(n_desc) (((n_desc) >> 8) & 0xff)
2518	#define SET_LIBRARY_ORDINAL(n_desc,ordinal) \
2519	(n_desc) = (((n_desc) & 0x00ff) \| (((ordinal) & 0xff) << 8))
2520	*/
2521	pub const SELF_LIBRARY_ORDINAL: u8 = `0x0`;
2522	pub const MAX_LIBRARY_ORDINAL: u8 = `0xfd`;
2523	pub const DYNAMIC_LOOKUP_ORDINAL: u8 = `0xfe`;
2524	pub const EXECUTABLE_ORDINAL: u8 = `0xff`;
2525
2526	/*
2527	* The bit 0x0020 of the n_desc field is used for two non-overlapping purposes
2528	* and has two different symbolic names, N_NO_DEAD_STRIP and N_DESC_DISCARDED.
2529	*/
2530
2531	/*
2532	* The N_NO_DEAD_STRIP bit of the n_desc field only ever appears in a
2533	* relocatable .o file (MH_OBJECT filetype). And is used to indicate to the
2534	* static link editor it is never to dead strip the symbol.
2535	*/
2536	/// symbol is not to be dead stripped
2537	pub const N_NO_DEAD_STRIP: u16 = `0x0020`;
2538
2539	/*
2540	* The N_DESC_DISCARDED bit of the n_desc field never appears in linked image.
2541	* But is used in very rare cases by the dynamic link editor to mark an in
2542	* memory symbol as discared and longer used for linking.
2543	*/
2544	/// symbol is discarded
2545	pub const N_DESC_DISCARDED: u16 = `0x0020`;
2546
2547	/*
2548	* The N_WEAK_REF bit of the n_desc field indicates to the dynamic linker that
2549	* the undefined symbol is allowed to be missing and is to have the address of
2550	* zero when missing.
2551	*/
2552	/// symbol is weak referenced
2553	pub const N_WEAK_REF: u16 = `0x0040`;
2554
2555	/*
2556	* The N_WEAK_DEF bit of the n_desc field indicates to the static and dynamic
2557	* linkers that the symbol definition is weak, allowing a non-weak symbol to
2558	* also be used which causes the weak definition to be discared. Currently this
2559	* is only supported for symbols in coalesced sections.
2560	*/
2561	/// coalesced symbol is a weak definition
2562	pub const N_WEAK_DEF: u16 = `0x0080`;
2563
2564	/*
2565	* The N_REF_TO_WEAK bit of the n_desc field indicates to the dynamic linker
2566	* that the undefined symbol should be resolved using flat namespace searching.
2567	*/
2568	/// reference to a weak symbol
2569	pub const N_REF_TO_WEAK: u16 = `0x0080`;
2570
2571	/*
2572	* The N_ARM_THUMB_DEF bit of the n_desc field indicates that the symbol is
2573	* a definition of a Thumb function.
2574	*/
2575	/// symbol is a Thumb function (ARM)
2576	pub const N_ARM_THUMB_DEF: u16 = `0x0008`;
2577
2578	/*
2579	* The N_SYMBOL_RESOLVER bit of the n_desc field indicates that the
2580	* that the function is actually a resolver function and should
2581	* be called to get the address of the real function to use.
2582	* This bit is only available in .o files (MH_OBJECT filetype)
2583	*/
2584	pub const N_SYMBOL_RESOLVER: u16 = `0x0100`;
2585
2586	/*
2587	* The N_ALT_ENTRY bit of the n_desc field indicates that the
2588	* symbol is pinned to the previous content.
2589	*/
2590	pub const N_ALT_ENTRY: u16 = `0x0200`;
2591
2592	// Definitions from "/usr/include/mach-o/stab.h".
2593
2594	/*
2595	* This file gives definitions supplementing <nlist.h> for permanent symbol
2596	* table entries of Mach-O files. Modified from the BSD definitions. The
2597	* modifications from the original definitions were changing what the values of
2598	* what was the n_other field (an unused field) which is now the n_sect field.
2599	* These modifications are required to support symbols in an arbitrary number of
2600	* sections not just the three sections (text, data and bss) in a BSD file.
2601	* The values of the defined constants have NOT been changed.
2602	*
2603	* These must have one of the N_STAB bits on. The n_value fields are subject
2604	* to relocation according to the value of their n_sect field. So for types
2605	* that refer to things in sections the n_sect field must be filled in with the
2606	* proper section ordinal. For types that are not to have their n_value field
2607	* relocatated the n_sect field must be NO_SECT.
2608	*/
2609
2610	/*
2611	* Symbolic debugger symbols. The comments give the conventional use for
2612	*
2613	* .stabs "n_name", n_type, n_sect, n_desc, n_value
2614	*
2615	* where n_type is the defined constant and not listed in the comment. Other
2616	* fields not listed are zero. n_sect is the section ordinal the entry is
2617	* referring to.
2618	*/
2619	/// global symbol: name,,NO_SECT,type,0
2620	pub const N_GSYM: u8 = `0x20`;
2621	/// procedure name (f77 kludge): name,,NO_SECT,0,0
2622	pub const N_FNAME: u8 = `0x22`;
2623	/// procedure: name,,n_sect,linenumber,address
2624	pub const N_FUN: u8 = `0x24`;
2625	/// static symbol: name,,n_sect,type,address
2626	pub const N_STSYM: u8 = `0x26`;
2627	/// .lcomm symbol: name,,n_sect,type,address
2628	pub const N_LCSYM: u8 = `0x28`;
2629	/// begin nsect sym: 0,,n_sect,0,address
2630	pub const N_BNSYM: u8 = `0x2e`;
2631	/// AST file path: name,,NO_SECT,0,0
2632	pub const N_AST: u8 = `0x32`;
2633	/// emitted with gcc2_compiled and in gcc source
2634	pub const N_OPT: u8 = `0x3c`;
2635	/// register sym: name,,NO_SECT,type,register
2636	pub const N_RSYM: u8 = `0x40`;
2637	/// src line: 0,,n_sect,linenumber,address
2638	pub const N_SLINE: u8 = `0x44`;
2639	/// end nsect sym: 0,,n_sect,0,address
2640	pub const N_ENSYM: u8 = `0x4e`;
2641	/// structure elt: name,,NO_SECT,type,struct_offset
2642	pub const N_SSYM: u8 = `0x60`;
2643	/// source file name: name,,n_sect,0,address
2644	pub const N_SO: u8 = `0x64`;
2645	/// object file name: name,,0,0,st_mtime
2646	pub const N_OSO: u8 = `0x66`;
2647	/// local sym: name,,NO_SECT,type,offset
2648	pub const N_LSYM: u8 = `0x80`;
2649	/// include file beginning: name,,NO_SECT,0,sum
2650	pub const N_BINCL: u8 = `0x82`;
2651	/// #included file name: name,,n_sect,0,address
2652	pub const N_SOL: u8 = `0x84`;
2653	/// compiler parameters: name,,NO_SECT,0,0
2654	pub const N_PARAMS: u8 = `0x86`;
2655	/// compiler version: name,,NO_SECT,0,0
2656	pub const N_VERSION: u8 = `0x88`;
2657	/// compiler -O level: name,,NO_SECT,0,0
2658	pub const N_OLEVEL: u8 = `0x8A`;
2659	/// parameter: name,,NO_SECT,type,offset
2660	pub const N_PSYM: u8 = `0xa0`;
2661	/// include file end: name,,NO_SECT,0,0
2662	pub const N_EINCL: u8 = `0xa2`;
2663	/// alternate entry: name,,n_sect,linenumber,address
2664	pub const N_ENTRY: u8 = `0xa4`;
2665	/// left bracket: 0,,NO_SECT,nesting level,address
2666	pub const N_LBRAC: u8 = `0xc0`;
2667	/// deleted include file: name,,NO_SECT,0,sum
2668	pub const N_EXCL: u8 = `0xc2`;
2669	/// right bracket: 0,,NO_SECT,nesting level,address
2670	pub const N_RBRAC: u8 = `0xe0`;
2671	/// begin common: name,,NO_SECT,0,0
2672	pub const N_BCOMM: u8 = `0xe2`;
2673	/// end common: name,,n_sect,0,0
2674	pub const N_ECOMM: u8 = `0xe4`;
2675	/// end common (local name): 0,,n_sect,0,address
2676	pub const N_ECOML: u8 = `0xe8`;
2677	/// second stab entry with length information
2678	pub const N_LENG: u8 = `0xfe`;
2679
2680	/*
2681	* for the berkeley pascal compiler, pc(1):
2682	*/
2683	/// global pascal symbol: name,,NO_SECT,subtype,line
2684	pub const N_PC: u8 = `0x30`;
2685
2686	// Definitions from "/usr/include/mach-o/reloc.h".
2687
2688	/// A relocation entry.
2689	///
2690	/// Mach-O relocations have plain and scattered variants, with the
2691	/// meaning of the fields depending on the variant.
2692	///
2693	/// This type provides functions for determining whether the relocation
2694	/// is scattered, and for accessing the fields of each variant.
2695	#[derive(Debug, Clone, Copy)]
2696	#[repr(C)]
2697	pub struct Relocation<E: Endian> {
2698	pub r_word0: U32<E>,
2699	pub r_word1: U32<E>,
2700	}
2701
2702	impl<E: Endian> Relocation<E> {
2703	/// Determine whether this is a scattered relocation.
2704	#[inline]
2705	pub fn r_scattered(self, endian: E, cputype: u32) -> bool {
2706	if cputype == CPU_TYPE_X86_64 {
2707	`false`
2708	} else {
2709	self.r_word0.get(endian) & R_SCATTERED != `0`
2710	}
2711	}
2712
2713	/// Return the fields of a plain relocation.
2714	pub fn info(self, endian: E) -> RelocationInfo {
2715	let r_address = self.r_word0.get(endian);
2716	let r_word1 = self.r_word1.get(endian);
2717	if endian.is_little_endian() {
2718	RelocationInfo {
2719	r_address,
2720	r_symbolnum: r_word1 & `0x00ff_ffff`,
2721	r_pcrel: ((r_word1 >> `24`) & `0x1`) != `0`,
2722	r_length: ((r_word1 >> `25`) & `0x3`) as u8,
2723	r_extern: ((r_word1 >> `27`) & `0x1`) != `0`,
2724	r_type: (r_word1 >> `28`) as u8,
2725	}
2726	} else {
2727	RelocationInfo {
2728	r_address,
2729	r_symbolnum: r_word1 >> `8`,
2730	r_pcrel: ((r_word1 >> `7`) & `0x1`) != `0`,
2731	r_length: ((r_word1 >> `5`) & `0x3`) as u8,
2732	r_extern: ((r_word1 >> `4`) & `0x1`) != `0`,
2733	r_type: (r_word1 & `0xf`) as u8,
2734	}
2735	}
2736	}
2737
2738	/// Return the fields of a scattered relocation.
2739	pub fn scattered_info(self, endian: E) -> ScatteredRelocationInfo {
2740	let r_word0 = self.r_word0.get(endian);
2741	let r_value = self.r_word1.get(endian);
2742	ScatteredRelocationInfo {
2743	r_address: r_word0 & `0x00ff_ffff`,
2744	r_type: ((r_word0 >> `24`) & `0xf`) as u8,
2745	r_length: ((r_word0 >> `28`) & `0x3`) as u8,
2746	r_pcrel: ((r_word0 >> `30`) & `0x1`) != `0`,
2747	r_value,
2748	}
2749	}
2750	}
2751
2752	/*
2753	* Format of a relocation entry of a Mach-O file. Modified from the 4.3BSD
2754	* format. The modifications from the original format were changing the value
2755	* of the r_symbolnum field for "local" (r_extern == 0) relocation entries.
2756	* This modification is required to support symbols in an arbitrary number of
2757	* sections not just the three sections (text, data and bss) in a 4.3BSD file.
2758	* Also the last 4 bits have had the r_type tag added to them.
2759	*/
2760
2761	#[derive(Debug, Clone, Copy)]
2762	pub struct RelocationInfo {
2763	/// offset in the section to what is being relocated
2764	pub r_address: u32,
2765	/// symbol index if r_extern == 1 or section ordinal if r_extern == 0
2766	pub r_symbolnum: u32,
2767	/// was relocated pc relative already
2768	pub r_pcrel: bool,
2769	/// 0=byte, 1=word, 2=long, 3=quad
2770	pub r_length: u8,
2771	/// does not include value of sym referenced
2772	pub r_extern: bool,
2773	/// if not 0, machine specific relocation type
2774	pub r_type: u8,
2775	}
2776
2777	impl RelocationInfo {
2778	/// Combine the fields into a `Relocation`.
2779	pub fn relocation<E: Endian>(self, endian: E) -> Relocation<E> {
2780	let r_word0: U32Bytes = U32::new(e:endian, self.r_address);
2781	let r_word1: U32Bytes = U32::new(
2782	e:endian,
2783	n:if endian.is_little_endian() {
2784	self.r_symbolnum & `0x00ff_ffff`
2785	\| u32::from(self.r_pcrel) << `24`
2786	\| u32::from(self.r_length & `0x3`) << `25`
2787	\| u32::from(self.r_extern) << `27`
2788	\| u32::from(self.r_type) << `28`
2789	} else {
2790	self.r_symbolnum >> `8`
2791	\| u32::from(self.r_pcrel) << `7`
2792	\| u32::from(self.r_length & `0x3`) << `5`
2793	\| u32::from(self.r_extern) << `4`
2794	\| u32::from(self.r_type) & `0xf`
2795	},
2796	);
2797	Relocation { r_word0, r_word1 }
2798	}
2799	}
2800
2801	/// absolute relocation type for Mach-O files
2802	pub const R_ABS: u8 = `0`;
2803
2804	/*
2805	* The r_address is not really the address as it's name indicates but an offset.
2806	* In 4.3BSD a.out objects this offset is from the start of the "segment" for
2807	* which relocation entry is for (text or data). For Mach-O object files it is
2808	* also an offset but from the start of the "section" for which the relocation
2809	* entry is for. See comments in <mach-o/loader.h> about the r_address feild
2810	* in images for used with the dynamic linker.
2811	*
2812	* In 4.3BSD a.out objects if r_extern is zero then r_symbolnum is an ordinal
2813	* for the segment the symbol being relocated is in. These ordinals are the
2814	* symbol types N_TEXT, N_DATA, N_BSS or N_ABS. In Mach-O object files these
2815	* ordinals refer to the sections in the object file in the order their section
2816	* structures appear in the headers of the object file they are in. The first
2817	* section has the ordinal 1, the second 2, and so on. This means that the
2818	* same ordinal in two different object files could refer to two different
2819	* sections. And further could have still different ordinals when combined
2820	* by the link-editor. The value R_ABS is used for relocation entries for
2821	* absolute symbols which need no further relocation.
2822	*/
2823
2824	/*
2825	* For RISC machines some of the references are split across two instructions
2826	* and the instruction does not contain the complete value of the reference.
2827	* In these cases a second, or paired relocation entry, follows each of these
2828	* relocation entries, using a PAIR r_type, which contains the other part of the
2829	* reference not contained in the instruction. This other part is stored in the
2830	* pair's r_address field. The exact number of bits of the other part of the
2831	* reference store in the r_address field is dependent on the particular
2832	* relocation type for the particular architecture.
2833	*/
2834
2835	/*
2836	* To make scattered loading by the link editor work correctly "local"
2837	* relocation entries can't be used when the item to be relocated is the value
2838	* of a symbol plus an offset (where the resulting expression is outside the
2839	* block the link editor is moving, a blocks are divided at symbol addresses).
2840	* In this case. where the item is a symbol value plus offset, the link editor
2841	* needs to know more than just the section the symbol was defined. What is
2842	* needed is the actual value of the symbol without the offset so it can do the
2843	* relocation correctly based on where the value of the symbol got relocated to
2844	* not the value of the expression (with the offset added to the symbol value).
2845	* So for the NeXT 2.0 release no "local" relocation entries are ever used when
2846	* there is a non-zero offset added to a symbol. The "external" and "local"
2847	* relocation entries remain unchanged.
2848	*
2849	* The implementation is quite messy given the compatibility with the existing
2850	* relocation entry format. The ASSUMPTION is that a section will never be
2851	* bigger than 2**24 - 1 (0x00ffffff or 16,777,215) bytes. This assumption
2852	* allows the r_address (which is really an offset) to fit in 24 bits and high
2853	* bit of the r_address field in the relocation_info structure to indicate
2854	* it is really a scattered_relocation_info structure. Since these are only
2855	* used in places where "local" relocation entries are used and not where
2856	* "external" relocation entries are used the r_extern field has been removed.
2857	*
2858	* For scattered loading to work on a RISC machine where some of the references
2859	* are split across two instructions the link editor needs to be assured that
2860	* each reference has a unique 32 bit reference (that more than one reference is
2861	* NOT sharing the same high 16 bits for example) so it move each referenced
2862	* item independent of each other. Some compilers guarantees this but the
2863	* compilers don't so scattered loading can be done on those that do guarantee
2864	* this.
2865	*/
2866
2867	/// Bit set in `Relocation::r_word0` for scattered relocations.
2868	pub const R_SCATTERED: u32 = `0x8000_0000`;
2869
2870	#[derive(Debug, Clone, Copy)]
2871	pub struct ScatteredRelocationInfo {
2872	/// offset in the section to what is being relocated
2873	pub r_address: u32,
2874	/// if not 0, machine specific relocation type
2875	pub r_type: u8,
2876	/// 0=byte, 1=word, 2=long, 3=quad
2877	pub r_length: u8,
2878	/// was relocated pc relative already
2879	pub r_pcrel: bool,
2880	/// the value the item to be relocated is referring to (without any offset added)
2881	pub r_value: u32,
2882	}
2883
2884	impl ScatteredRelocationInfo {
2885	/// Combine the fields into a `Relocation`.
2886	pub fn relocation<E: Endian>(self, endian: E) -> Relocation<E> {
2887	let r_word0: U32Bytes = U32::new(
2888	e:endian,
2889	self.r_address & `0x00ff_ffff`
2890	\| u32::from(self.r_type & `0xf`) << `24`
2891	\| u32::from(self.r_length & `0x3`) << `28`
2892	\| u32::from(self.r_pcrel) << `30`
2893	\| R_SCATTERED,
2894	);
2895	let r_word1: U32Bytes = U32::new(e:endian, self.r_value);
2896	Relocation { r_word0, r_word1 }
2897	}
2898	}
2899
2900	/*
2901	* Relocation types used in a generic implementation. Relocation entries for
2902	* normal things use the generic relocation as described above and their r_type
2903	* is GENERIC_RELOC_VANILLA (a value of zero).
2904	*
2905	* Another type of generic relocation, GENERIC_RELOC_SECTDIFF, is to support
2906	* the difference of two symbols defined in different sections. That is the
2907	* expression "symbol1 - symbol2 + constant" is a relocatable expression when
2908	* both symbols are defined in some section. For this type of relocation the
2909	* both relocations entries are scattered relocation entries. The value of
2910	* symbol1 is stored in the first relocation entry's r_value field and the
2911	* value of symbol2 is stored in the pair's r_value field.
2912	*
2913	* A special case for a prebound lazy pointer is needed to beable to set the
2914	* value of the lazy pointer back to its non-prebound state. This is done
2915	* using the GENERIC_RELOC_PB_LA_PTR r_type. This is a scattered relocation
2916	* entry where the r_value feild is the value of the lazy pointer not prebound.
2917	*/
2918	/// generic relocation as described above
2919	pub const GENERIC_RELOC_VANILLA: u8 = `0`;
2920	/// Only follows a GENERIC_RELOC_SECTDIFF
2921	pub const GENERIC_RELOC_PAIR: u8 = `1`;
2922	pub const GENERIC_RELOC_SECTDIFF: u8 = `2`;
2923	/// prebound lazy pointer
2924	pub const GENERIC_RELOC_PB_LA_PTR: u8 = `3`;
2925	pub const GENERIC_RELOC_LOCAL_SECTDIFF: u8 = `4`;
2926	/// thread local variables
2927	pub const GENERIC_RELOC_TLV: u8 = `5`;
2928
2929	// Definitions from "/usr/include/mach-o/arm/reloc.h".
2930
2931	/*
2932	* Relocation types used in the arm implementation. Relocation entries for
2933	* things other than instructions use the same generic relocation as described
2934	* in <mach-o/reloc.h> and their r_type is ARM_RELOC_VANILLA, one of the
2935	* _SECTDIFF or the _PB_LA_PTR types. The rest of the relocation types are
2936	* for instructions. Since they are for instructions the r_address field
2937	* indicates the 32 bit instruction that the relocation is to be performed on.
2938	*/
2939	/// generic relocation as described above
2940	pub const ARM_RELOC_VANILLA: u8 = `0`;
2941	/// the second relocation entry of a pair
2942	pub const ARM_RELOC_PAIR: u8 = `1`;
2943	/// a PAIR follows with subtract symbol value
2944	pub const ARM_RELOC_SECTDIFF: u8 = `2`;
2945	/// like ARM_RELOC_SECTDIFF, but the symbol referenced was local.
2946	pub const ARM_RELOC_LOCAL_SECTDIFF: u8 = `3`;
2947	/// prebound lazy pointer
2948	pub const ARM_RELOC_PB_LA_PTR: u8 = `4`;
2949	/// 24 bit branch displacement (to a word address)
2950	pub const ARM_RELOC_BR24: u8 = `5`;
2951	/// 22 bit branch displacement (to a half-word address)
2952	pub const ARM_THUMB_RELOC_BR22: u8 = `6`;
2953	/// obsolete - a thumb 32-bit branch instruction possibly needing page-spanning branch workaround
2954	pub const ARM_THUMB_32BIT_BRANCH: u8 = `7`;
2955
2956	/*
2957	* For these two r_type relocations they always have a pair following them
2958	* and the r_length bits are used differently. The encoding of the
2959	* r_length is as follows:
2960	* low bit of r_length:
2961	* 0 - :lower16: for movw instructions
2962	* 1 - :upper16: for movt instructions
2963	* high bit of r_length:
2964	* 0 - arm instructions
2965	* 1 - thumb instructions
2966	* the other half of the relocated expression is in the following pair
2967	* relocation entry in the the low 16 bits of r_address field.
2968	*/
2969	pub const ARM_RELOC_HALF: u8 = `8`;
2970	pub const ARM_RELOC_HALF_SECTDIFF: u8 = `9`;
2971
2972	// Definitions from "/usr/include/mach-o/arm64/reloc.h".
2973
2974	/*
2975	* Relocation types used in the arm64 implementation.
2976	*/
2977	/// for pointers
2978	pub const ARM64_RELOC_UNSIGNED: u8 = `0`;
2979	/// must be followed by a ARM64_RELOC_UNSIGNED
2980	pub const ARM64_RELOC_SUBTRACTOR: u8 = `1`;
2981	/// a B/BL instruction with 26-bit displacement
2982	pub const ARM64_RELOC_BRANCH26: u8 = `2`;
2983	/// pc-rel distance to page of target
2984	pub const ARM64_RELOC_PAGE21: u8 = `3`;
2985	/// offset within page, scaled by r_length
2986	pub const ARM64_RELOC_PAGEOFF12: u8 = `4`;
2987	/// pc-rel distance to page of GOT slot
2988	pub const ARM64_RELOC_GOT_LOAD_PAGE21: u8 = `5`;
2989	/// offset within page of GOT slot, scaled by r_length
2990	pub const ARM64_RELOC_GOT_LOAD_PAGEOFF12: u8 = `6`;
2991	/// for pointers to GOT slots
2992	pub const ARM64_RELOC_POINTER_TO_GOT: u8 = `7`;
2993	/// pc-rel distance to page of TLVP slot
2994	pub const ARM64_RELOC_TLVP_LOAD_PAGE21: u8 = `8`;
2995	/// offset within page of TLVP slot, scaled by r_length
2996	pub const ARM64_RELOC_TLVP_LOAD_PAGEOFF12: u8 = `9`;
2997	/// must be followed by PAGE21 or PAGEOFF12
2998	pub const ARM64_RELOC_ADDEND: u8 = `10`;
2999
3000	// An arm64e authenticated pointer.
3001	//
3002	// Represents a pointer to a symbol (like ARM64_RELOC_UNSIGNED).
3003	// Additionally, the resulting pointer is signed. The signature is
3004	// specified in the target location: the addend is restricted to the lower
3005	// 32 bits (instead of the full 64 bits for ARM64_RELOC_UNSIGNED):
3006	//
3007	// \|63\|62\|61-51\|50-49\| 48 \|47 - 32\|31 - 0\|
3008	// \| 1\| 0\| 0 \| key \| addr \| discriminator \| addend \|
3009	//
3010	// The key is one of:
3011	// IA: 00 IB: 01
3012	// DA: 10 DB: 11
3013	//
3014	// The discriminator field is used as extra signature diversification.
3015	//
3016	// The addr field indicates whether the target address should be blended
3017	// into the discriminator.
3018	//
3019	pub const ARM64_RELOC_AUTHENTICATED_POINTER: u8 = `11`;
3020
3021	// Definitions from "/usr/include/mach-o/ppc/reloc.h".
3022
3023	/*
3024	* Relocation types used in the ppc implementation. Relocation entries for
3025	* things other than instructions use the same generic relocation as described
3026	* above and their r_type is RELOC_VANILLA. The rest of the relocation types
3027	* are for instructions. Since they are for instructions the r_address field
3028	* indicates the 32 bit instruction that the relocation is to be performed on.
3029	* The fields r_pcrel and r_length are ignored for non-RELOC_VANILLA r_types
3030	* except for PPC_RELOC_BR14.
3031	*
3032	* For PPC_RELOC_BR14 if the r_length is the unused value 3, then the branch was
3033	* statically predicted setting or clearing the Y-bit based on the sign of the
3034	* displacement or the opcode. If this is the case the static linker must flip
3035	* the value of the Y-bit if the sign of the displacement changes for non-branch
3036	* always conditions.
3037	*/
3038	/// generic relocation as described above
3039	pub const PPC_RELOC_VANILLA: u8 = `0`;
3040	/// the second relocation entry of a pair
3041	pub const PPC_RELOC_PAIR: u8 = `1`;
3042	/// 14 bit branch displacement (to a word address)
3043	pub const PPC_RELOC_BR14: u8 = `2`;
3044	/// 24 bit branch displacement (to a word address)
3045	pub const PPC_RELOC_BR24: u8 = `3`;
3046	/// a PAIR follows with the low half
3047	pub const PPC_RELOC_HI16: u8 = `4`;
3048	/// a PAIR follows with the high half
3049	pub const PPC_RELOC_LO16: u8 = `5`;
3050	/// Same as the RELOC_HI16 except the low 16 bits and the high 16 bits are added together
3051	/// with the low 16 bits sign extended first. This means if bit 15 of the low 16 bits is
3052	/// set the high 16 bits stored in the instruction will be adjusted.
3053	pub const PPC_RELOC_HA16: u8 = `6`;
3054	/// Same as the LO16 except that the low 2 bits are not stored in the instruction and are
3055	/// always zero. This is used in double word load/store instructions.
3056	pub const PPC_RELOC_LO14: u8 = `7`;
3057	/// a PAIR follows with subtract symbol value
3058	pub const PPC_RELOC_SECTDIFF: u8 = `8`;
3059	/// prebound lazy pointer
3060	pub const PPC_RELOC_PB_LA_PTR: u8 = `9`;
3061	/// section difference forms of above. a PAIR
3062	pub const PPC_RELOC_HI16_SECTDIFF: u8 = `10`;
3063	/// follows these with subtract symbol value
3064	pub const PPC_RELOC_LO16_SECTDIFF: u8 = `11`;
3065	pub const PPC_RELOC_HA16_SECTDIFF: u8 = `12`;
3066	pub const PPC_RELOC_JBSR: u8 = `13`;
3067	pub const PPC_RELOC_LO14_SECTDIFF: u8 = `14`;
3068	/// like PPC_RELOC_SECTDIFF, but the symbol referenced was local.
3069	pub const PPC_RELOC_LOCAL_SECTDIFF: u8 = `15`;
3070
3071	// Definitions from "/usr/include/mach-o/x86_64/reloc.h".
3072
3073	/*
3074	* Relocations for x86_64 are a bit different than for other architectures in
3075	* Mach-O: Scattered relocations are not used. Almost all relocations produced
3076	* by the compiler are external relocations. An external relocation has the
3077	* r_extern bit set to 1 and the r_symbolnum field contains the symbol table
3078	* index of the target label.
3079	*
3080	* When the assembler is generating relocations, if the target label is a local
3081	* label (begins with 'L'), then the previous non-local label in the same
3082	* section is used as the target of the external relocation. An addend is used
3083	* with the distance from that non-local label to the target label. Only when
3084	* there is no previous non-local label in the section is an internal
3085	* relocation used.
3086	*
3087	* The addend (i.e. the 4 in _foo+4) is encoded in the instruction (Mach-O does
3088	* not have RELA relocations). For PC-relative relocations, the addend is
3089	* stored directly in the instruction. This is different from other Mach-O
3090	* architectures, which encode the addend minus the current section offset.
3091	*
3092	* The relocation types are:
3093	*
3094	* X86_64_RELOC_UNSIGNED // for absolute addresses
3095	* X86_64_RELOC_SIGNED // for signed 32-bit displacement
3096	* X86_64_RELOC_BRANCH // a CALL/JMP instruction with 32-bit displacement
3097	* X86_64_RELOC_GOT_LOAD // a MOVQ load of a GOT entry
3098	* X86_64_RELOC_GOT // other GOT references
3099	* X86_64_RELOC_SUBTRACTOR // must be followed by a X86_64_RELOC_UNSIGNED
3100	*
3101	* The following are sample assembly instructions, followed by the relocation
3102	* and section content they generate in an object file:
3103	*
3104	* call _foo
3105	* r_type=X86_64_RELOC_BRANCH, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3106	* E8 00 00 00 00
3107	*
3108	* call _foo+4
3109	* r_type=X86_64_RELOC_BRANCH, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3110	* E8 04 00 00 00
3111	*
3112	* movq _foo@GOTPCREL(%rip), %rax
3113	* r_type=X86_64_RELOC_GOT_LOAD, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3114	* 48 8B 05 00 00 00 00
3115	*
3116	* pushq _foo@GOTPCREL(%rip)
3117	* r_type=X86_64_RELOC_GOT, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3118	* FF 35 00 00 00 00
3119	*
3120	* movl _foo(%rip), %eax
3121	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3122	* 8B 05 00 00 00 00
3123	*
3124	* movl _foo+4(%rip), %eax
3125	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3126	* 8B 05 04 00 00 00
3127	*
3128	* movb $0x12, _foo(%rip)
3129	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3130	* C6 05 FF FF FF FF 12
3131	*
3132	* movl $0x12345678, _foo(%rip)
3133	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3134	* C7 05 FC FF FF FF 78 56 34 12
3135	*
3136	* .quad _foo
3137	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3138	* 00 00 00 00 00 00 00 00
3139	*
3140	* .quad _foo+4
3141	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3142	* 04 00 00 00 00 00 00 00
3143	*
3144	* .quad _foo - _bar
3145	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_bar
3146	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3147	* 00 00 00 00 00 00 00 00
3148	*
3149	* .quad _foo - _bar + 4
3150	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_bar
3151	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3152	* 04 00 00 00 00 00 00 00
3153	*
3154	* .long _foo - _bar
3155	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=2, r_extern=1, r_pcrel=0, r_symbolnum=_bar
3156	* r_type=X86_64_RELOC_UNSIGNED, r_length=2, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3157	* 00 00 00 00
3158	*
3159	* lea L1(%rip), %rax
3160	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_prev
3161	* 48 8d 05 12 00 00 00
3162	* // assumes _prev is the first non-local label 0x12 bytes before L1
3163	*
3164	* lea L0(%rip), %rax
3165	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=0, r_pcrel=1, r_symbolnum=3
3166	* 48 8d 05 56 00 00 00
3167	* // assumes L0 is in third section and there is no previous non-local label.
3168	* // The rip-relative-offset of 0x00000056 is L0-address_of_next_instruction.
3169	* // address_of_next_instruction is the address of the relocation + 4.
3170	*
3171	* add $6,L0(%rip)
3172	* r_type=X86_64_RELOC_SIGNED_1, r_length=2, r_extern=0, r_pcrel=1, r_symbolnum=3
3173	* 83 05 18 00 00 00 06
3174	* // assumes L0 is in third section and there is no previous non-local label.
3175	* // The rip-relative-offset of 0x00000018 is L0-address_of_next_instruction.
3176	* // address_of_next_instruction is the address of the relocation + 4 + 1.
3177	* // The +1 comes from SIGNED_1. This is used because the relocation is not
3178	* // at the end of the instruction.
3179	*
3180	* .quad L1
3181	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_prev
3182	* 12 00 00 00 00 00 00 00
3183	* // assumes _prev is the first non-local label 0x12 bytes before L1
3184	*
3185	* .quad L0
3186	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=0, r_pcrel=0, r_symbolnum=3
3187	* 56 00 00 00 00 00 00 00
3188	* // assumes L0 is in third section, has an address of 0x00000056 in .o
3189	* // file, and there is no previous non-local label
3190	*
3191	* .quad _foo - .
3192	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_prev
3193	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3194	* EE FF FF FF FF FF FF FF
3195	* // assumes _prev is the first non-local label 0x12 bytes before this
3196	* // .quad
3197	*
3198	* .quad _foo - L1
3199	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_prev
3200	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3201	* EE FF FF FF FF FF FF FF
3202	* // assumes _prev is the first non-local label 0x12 bytes before L1
3203	*
3204	* .quad L1 - _prev
3205	* // No relocations. This is an assembly time constant.
3206	* 12 00 00 00 00 00 00 00
3207	* // assumes _prev is the first non-local label 0x12 bytes before L1
3208	*
3209	*
3210	*
3211	* In final linked images, there are only two valid relocation kinds:
3212	*
3213	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_pcrel=0, r_extern=1, r_symbolnum=sym_index
3214	* This tells dyld to add the address of a symbol to a pointer sized (8-byte)
3215	* piece of data (i.e on disk the 8-byte piece of data contains the addend). The
3216	* r_symbolnum contains the index into the symbol table of the target symbol.
3217	*
3218	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_pcrel=0, r_extern=0, r_symbolnum=0
3219	* This tells dyld to adjust the pointer sized (8-byte) piece of data by the amount
3220	* the containing image was loaded from its base address (e.g. slide).
3221	*
3222	*/
3223	/// for absolute addresses
3224	pub const X86_64_RELOC_UNSIGNED: u8 = `0`;
3225	/// for signed 32-bit displacement
3226	pub const X86_64_RELOC_SIGNED: u8 = `1`;
3227	/// a CALL/JMP instruction with 32-bit displacement
3228	pub const X86_64_RELOC_BRANCH: u8 = `2`;
3229	/// a MOVQ load of a GOT entry
3230	pub const X86_64_RELOC_GOT_LOAD: u8 = `3`;
3231	/// other GOT references
3232	pub const X86_64_RELOC_GOT: u8 = `4`;
3233	/// must be followed by a X86_64_RELOC_UNSIGNED
3234	pub const X86_64_RELOC_SUBTRACTOR: u8 = `5`;
3235	/// for signed 32-bit displacement with a -1 addend
3236	pub const X86_64_RELOC_SIGNED_1: u8 = `6`;
3237	/// for signed 32-bit displacement with a -2 addend
3238	pub const X86_64_RELOC_SIGNED_2: u8 = `7`;
3239	/// for signed 32-bit displacement with a -4 addend
3240	pub const X86_64_RELOC_SIGNED_4: u8 = `8`;
3241	/// for thread local variables
3242	pub const X86_64_RELOC_TLV: u8 = `9`;
3243
3244	unsafe_impl_pod!(FatHeader, FatArch32, FatArch64,);
3245	unsafe_impl_endian_pod!(
3246	DyldCacheHeader,
3247	DyldCacheMappingInfo,
3248	DyldCacheImageInfo,
3249	DyldSubCacheEntryV1,
3250	DyldSubCacheEntryV2,
3251	MachHeader32,
3252	MachHeader64,
3253	LoadCommand,
3254	LcStr,
3255	SegmentCommand32,
3256	SegmentCommand64,
3257	Section32,
3258	Section64,
3259	Fvmlib,
3260	FvmlibCommand,
3261	Dylib,
3262	DylibCommand,
3263	SubFrameworkCommand,
3264	SubClientCommand,
3265	SubUmbrellaCommand,
3266	SubLibraryCommand,
3267	PreboundDylibCommand,
3268	DylinkerCommand,
3269	ThreadCommand,
3270	RoutinesCommand32,
3271	RoutinesCommand64,
3272	SymtabCommand,
3273	DysymtabCommand,
3274	DylibTableOfContents,
3275	DylibModule32,
3276	DylibModule64,
3277	DylibReference,
3278	TwolevelHintsCommand,
3279	TwolevelHint,
3280	PrebindCksumCommand,
3281	UuidCommand,
3282	RpathCommand,
3283	LinkeditDataCommand,
3284	FilesetEntryCommand,
3285	EncryptionInfoCommand32,
3286	EncryptionInfoCommand64,
3287	VersionMinCommand,
3288	BuildVersionCommand,
3289	BuildToolVersion,
3290	DyldInfoCommand,
3291	LinkerOptionCommand,
3292	SymsegCommand,
3293	IdentCommand,
3294	FvmfileCommand,
3295	EntryPointCommand,
3296	SourceVersionCommand,
3297	DataInCodeEntry,
3298	//TlvDescriptor,
3299	NoteCommand,
3300	Nlist32,
3301	Nlist64,
3302	Relocation,
3303	);
3304