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	///
309	reserved1: [u8; `32`], // offset: 0x28
310	/// file offset of where local symbols are stored
311	pub local_symbols_offset: U64<E>, // offset: 0x48
312	/// size of local symbols information
313	pub local_symbols_size: U64<E>, // offset: 0x50
314	/// unique value for each shared cache file
315	pub uuid: [u8; `16`], // offset: 0x58
316	///
317	reserved2: [u8; `32`], // offset: 0x68
318	///
319	reserved3: [u8; `32`], // offset: 0x88
320	///
321	reserved4: [u8; `32`], // offset: 0xa8
322	///
323	reserved5: [u8; `32`], // offset: 0xc8
324	///
325	reserved6: [u8; `32`], // offset: 0xe8
326	///
327	reserved7: [u8; `32`], // offset: 0x108
328	///
329	reserved8: [u8; `32`], // offset: 0x128
330	///
331	reserved9: [u8; `32`], // offset: 0x148
332	///
333	reserved10: [u8; `32`], // offset: 0x168
334	/// file offset to first dyld_subcache_info
335	pub subcaches_offset: U32<E>, // offset: 0x188
336	/// number of dyld_subcache_info entries
337	pub subcaches_count: U32<E>, // offset: 0x18c
338	/// the UUID of the .symbols subcache
339	pub symbols_subcache_uuid: [u8; `16`], // offset: 0x190
340	///
341	reserved11: [u8; `32`], // offset: 0x1a0
342	/// file offset to first dyld_cache_image_info
343	/// Use this instead of images_offset if mapping_offset is at least 0x1c4.
344	pub images_across_all_subcaches_offset: U32<E>, // offset: 0x1c0
345	/// number of dyld_cache_image_info entries
346	/// Use this instead of images_count if mapping_offset is at least 0x1c4.
347	pub images_across_all_subcaches_count: U32<E>, // offset: 0x1c4
348	}
349
350	/// Corresponds to struct dyld_cache_mapping_info from dyld_cache_format.h.
351	#[derive(Debug, Clone, Copy)]
352	#[repr(C)]
353	pub struct DyldCacheMappingInfo<E: Endian> {
354	///
355	pub address: U64<E>,
356	///
357	pub size: U64<E>,
358	///
359	pub file_offset: U64<E>,
360	///
361	pub max_prot: U32<E>,
362	///
363	pub init_prot: U32<E>,
364	}
365
366	/// Corresponds to struct dyld_cache_image_info from dyld_cache_format.h.
367	#[derive(Debug, Clone, Copy)]
368	#[repr(C)]
369	pub struct DyldCacheImageInfo<E: Endian> {
370	///
371	pub address: U64<E>,
372	///
373	pub mod_time: U64<E>,
374	///
375	pub inode: U64<E>,
376	///
377	pub path_file_offset: U32<E>,
378	///
379	pub pad: U32<E>,
380	}
381
382	/// Corresponds to a struct whose source code has not been published as of Nov 2021.
383	/// Added in the dyld cache version which shipped with macOS 12 / iOS 15.
384	#[derive(Debug, Clone, Copy)]
385	#[repr(C)]
386	pub struct DyldSubCacheInfo<E: Endian> {
387	/// The UUID of this subcache.
388	pub uuid: [u8; `16`],
389	/// The size of this subcache plus all previous subcaches.
390	pub cumulative_size: U64<E>,
391	}
392
393	// Definitions from "/usr/include/mach-o/loader.h".
394
395	/*
396	* This header file describes the structures of the file format for "fat"
397	* architecture specific file (wrapper design). At the beginning of the file
398	* there is one `FatHeader` structure followed by a number of `FatArch*`
399	* structures. For each architecture in the file, specified by a pair of
400	* cputype and cpusubtype, the `FatHeader` describes the file offset, file
401	* size and alignment in the file of the architecture specific member.
402	* The padded bytes in the file to place each member on it's specific alignment
403	* are defined to be read as zeros and can be left as "holes" if the file system
404	* can support them as long as they read as zeros.
405	*
406	* All structures defined here are always written and read to/from disk
407	* in big-endian order.
408	*/
409
410	pub const FAT_MAGIC: u32 = `0xcafe_babe`;
411	/// NXSwapLong(FAT_MAGIC)
412	pub const FAT_CIGAM: u32 = `0xbeba_feca`;
413
414	#[derive(Debug, Clone, Copy)]
415	#[repr(C)]
416	pub struct FatHeader {
417	/// FAT_MAGIC or FAT_MAGIC_64
418	pub magic: U32<BigEndian>,
419	/// number of structs that follow
420	pub nfat_arch: U32<BigEndian>,
421	}
422
423	#[derive(Debug, Clone, Copy)]
424	#[repr(C)]
425	pub struct FatArch32 {
426	/// cpu specifier (int)
427	pub cputype: U32<BigEndian>,
428	/// machine specifier (int)
429	pub cpusubtype: U32<BigEndian>,
430	/// file offset to this object file
431	pub offset: U32<BigEndian>,
432	/// size of this object file
433	pub size: U32<BigEndian>,
434	/// alignment as a power of 2
435	pub align: U32<BigEndian>,
436	}
437
438	/*
439	* The support for the 64-bit fat file format described here is a work in
440	* progress and not yet fully supported in all the Apple Developer Tools.
441	*
442	* When a slice is greater than 4mb or an offset to a slice is greater than 4mb
443	* then the 64-bit fat file format is used.
444	*/
445	pub const FAT_MAGIC_64: u32 = `0xcafe_babf`;
446	/// NXSwapLong(FAT_MAGIC_64)
447	pub const FAT_CIGAM_64: u32 = `0xbfba_feca`;
448
449	#[derive(Debug, Clone, Copy)]
450	#[repr(C)]
451	pub struct FatArch64 {
452	/// cpu specifier (int)
453	pub cputype: U32<BigEndian>,
454	/// machine specifier (int)
455	pub cpusubtype: U32<BigEndian>,
456	/// file offset to this object file
457	pub offset: U64<BigEndian>,
458	/// size of this object file
459	pub size: U64<BigEndian>,
460	/// alignment as a power of 2
461	pub align: U32<BigEndian>,
462	/// reserved
463	pub reserved: U32<BigEndian>,
464	}
465
466	// Definitions from "/usr/include/mach-o/loader.h".
467
468	/// The 32-bit mach header.
469	///
470	/// Appears at the very beginning of the object file for 32-bit architectures.
471	#[derive(Debug, Clone, Copy)]
472	#[repr(C)]
473	pub struct MachHeader32<E: Endian> {
474	/// mach magic number identifier
475	pub magic: U32<BigEndian>,
476	/// cpu specifier
477	pub cputype: U32<E>,
478	/// machine specifier
479	pub cpusubtype: U32<E>,
480	/// type of file
481	pub filetype: U32<E>,
482	/// number of load commands
483	pub ncmds: U32<E>,
484	/// the size of all the load commands
485	pub sizeofcmds: U32<E>,
486	/// flags
487	pub flags: U32<E>,
488	}
489
490	// Values for `MachHeader32::magic`.
491	/// the mach magic number
492	pub const MH_MAGIC: u32 = `0xfeed_face`;
493	/// NXSwapInt(MH_MAGIC)
494	pub const MH_CIGAM: u32 = `0xcefa_edfe`;
495
496	/// The 64-bit mach header.
497	///
498	/// Appears at the very beginning of object files for 64-bit architectures.
499	#[derive(Debug, Clone, Copy)]
500	#[repr(C)]
501	pub struct MachHeader64<E: Endian> {
502	/// mach magic number identifier
503	pub magic: U32<BigEndian>,
504	/// cpu specifier
505	pub cputype: U32<E>,
506	/// machine specifier
507	pub cpusubtype: U32<E>,
508	/// type of file
509	pub filetype: U32<E>,
510	/// number of load commands
511	pub ncmds: U32<E>,
512	/// the size of all the load commands
513	pub sizeofcmds: U32<E>,
514	/// flags
515	pub flags: U32<E>,
516	/// reserved
517	pub reserved: U32<E>,
518	}
519
520	// Values for `MachHeader64::magic`.
521	/// the 64-bit mach magic number
522	pub const MH_MAGIC_64: u32 = `0xfeed_facf`;
523	/// NXSwapInt(MH_MAGIC_64)
524	pub const MH_CIGAM_64: u32 = `0xcffa_edfe`;
525
526	/*
527	* The layout of the file depends on the filetype. For all but the MH_OBJECT
528	* file type the segments are padded out and aligned on a segment alignment
529	* boundary for efficient demand pageing. The MH_EXECUTE, MH_FVMLIB, MH_DYLIB,
530	* MH_DYLINKER and MH_BUNDLE file types also have the headers included as part
531	* of their first segment.
532	*
533	* The file type MH_OBJECT is a compact format intended as output of the
534	* assembler and input (and possibly output) of the link editor (the .o
535	* format). All sections are in one unnamed segment with no segment padding.
536	* This format is used as an executable format when the file is so small the
537	* segment padding greatly increases its size.
538	*
539	* The file type MH_PRELOAD is an executable format intended for things that
540	* are not executed under the kernel (proms, stand alones, kernels, etc). The
541	* format can be executed under the kernel but may demand paged it and not
542	* preload it before execution.
543	*
544	* A core file is in MH_CORE format and can be any in an arbritray legal
545	* Mach-O file.
546	*/
547
548	// Values for `MachHeader::filetype`.*
549	/// relocatable object file
550	pub const MH_OBJECT: u32 = `0x1`;
551	/// demand paged executable file
552	pub const MH_EXECUTE: u32 = `0x2`;
553	/// fixed VM shared library file
554	pub const MH_FVMLIB: u32 = `0x3`;
555	/// core file
556	pub const MH_CORE: u32 = `0x4`;
557	/// preloaded executable file
558	pub const MH_PRELOAD: u32 = `0x5`;
559	/// dynamically bound shared library
560	pub const MH_DYLIB: u32 = `0x6`;
561	/// dynamic link editor
562	pub const MH_DYLINKER: u32 = `0x7`;
563	/// dynamically bound bundle file
564	pub const MH_BUNDLE: u32 = `0x8`;
565	/// shared library stub for static linking only, no section contents
566	pub const MH_DYLIB_STUB: u32 = `0x9`;
567	/// companion file with only debug sections
568	pub const MH_DSYM: u32 = `0xa`;
569	/// x86_64 kexts
570	pub const MH_KEXT_BUNDLE: u32 = `0xb`;
571	/// set of mach-o's
572	pub const MH_FILESET: u32 = `0xc`;
573
574	// Values for `MachHeader::flags`.*
575	/// the object file has no undefined references
576	pub const MH_NOUNDEFS: u32 = `0x1`;
577	/// the object file is the output of an incremental link against a base file and can't be link edited again
578	pub const MH_INCRLINK: u32 = `0x2`;
579	/// the object file is input for the dynamic linker and can't be statically link edited again
580	pub const MH_DYLDLINK: u32 = `0x4`;
581	/// the object file's undefined references are bound by the dynamic linker when loaded.
582	pub const MH_BINDATLOAD: u32 = `0x8`;
583	/// the file has its dynamic undefined references prebound.
584	pub const MH_PREBOUND: u32 = `0x10`;
585	/// the file has its read-only and read-write segments split
586	pub const MH_SPLIT_SEGS: u32 = `0x20`;
587	/// the shared library init routine is to be run lazily via catching memory faults to its writeable segments (obsolete)
588	pub const MH_LAZY_INIT: u32 = `0x40`;
589	/// the image is using two-level name space bindings
590	pub const MH_TWOLEVEL: u32 = `0x80`;
591	/// the executable is forcing all images to use flat name space bindings
592	pub const MH_FORCE_FLAT: u32 = `0x100`;
593	/// this umbrella guarantees no multiple definitions of symbols in its sub-images so the two-level namespace hints can always be used.
594	pub const MH_NOMULTIDEFS: u32 = `0x200`;
595	/// do not have dyld notify the prebinding agent about this executable
596	pub const MH_NOFIXPREBINDING: u32 = `0x400`;
597	/// the binary is not prebound but can have its prebinding redone. only used when MH_PREBOUND is not set.
598	pub const MH_PREBINDABLE: u32 = `0x800`;
599	/// 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.
600	pub const MH_ALLMODSBOUND: u32 = `0x1000`;
601	/// safe to divide up the sections into sub-sections via symbols for dead code stripping
602	pub const MH_SUBSECTIONS_VIA_SYMBOLS: u32 = `0x2000`;
603	/// the binary has been canonicalized via the unprebind operation
604	pub const MH_CANONICAL: u32 = `0x4000`;
605	/// the final linked image contains external weak symbols
606	pub const MH_WEAK_DEFINES: u32 = `0x8000`;
607	/// the final linked image uses weak symbols
608	pub const MH_BINDS_TO_WEAK: u32 = `0x10000`;
609	/// When this bit is set, all stacks in the task will be given stack execution privilege. Only used in MH_EXECUTE filetypes.
610	pub const MH_ALLOW_STACK_EXECUTION: u32 = `0x20000`;
611	/// When this bit is set, the binary declares it is safe for use in processes with uid zero
612	pub const MH_ROOT_SAFE: u32 = `0x40000`;
613	/// When this bit is set, the binary declares it is safe for use in processes when issetugid() is true
614	pub const MH_SETUID_SAFE: u32 = `0x80000`;
615	/// 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
616	pub const MH_NO_REEXPORTED_DYLIBS: u32 = `0x10_0000`;
617	/// When this bit is set, the OS will load the main executable at a random address. Only used in MH_EXECUTE filetypes.
618	pub const MH_PIE: u32 = `0x20_0000`;
619	/// 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.
620	pub const MH_DEAD_STRIPPABLE_DYLIB: u32 = `0x40_0000`;
621	/// Contains a section of type S_THREAD_LOCAL_VARIABLES
622	pub const MH_HAS_TLV_DESCRIPTORS: u32 = `0x80_0000`;
623	/// 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.
624	pub const MH_NO_HEAP_EXECUTION: u32 = `0x100_0000`;
625	/// The code was linked for use in an application extension.
626	pub const MH_APP_EXTENSION_SAFE: u32 = `0x0200_0000`;
627	/// The external symbols listed in the nlist symbol table do not include all the symbols listed in the dyld info.
628	pub const MH_NLIST_OUTOFSYNC_WITH_DYLDINFO: u32 = `0x0400_0000`;
629	/// Allow LC_MIN_VERSION_MACOS and LC_BUILD_VERSION load commands with
630	/// the platforms macOS, iOSMac, iOSSimulator, tvOSSimulator and watchOSSimulator.
631	pub const MH_SIM_SUPPORT: u32 = `0x0800_0000`;
632	/// Only for use on dylibs. When this bit is set, the dylib is part of the dyld
633	/// shared cache, rather than loose in the filesystem.
634	pub const MH_DYLIB_IN_CACHE: u32 = `0x8000_0000`;
635
636	/// Common fields at the start of every load command.
637	///
638	/// The load commands directly follow the mach_header. The total size of all
639	/// of the commands is given by the sizeofcmds field in the mach_header. All
640	/// load commands must have as their first two fields `cmd` and `cmdsize`. The `cmd`
641	/// field is filled in with a constant for that command type. Each command type
642	/// has a structure specifically for it. The `cmdsize` field is the size in bytes
643	/// of the particular load command structure plus anything that follows it that
644	/// is a part of the load command (i.e. section structures, strings, etc.). To
645	/// advance to the next load command the `cmdsize` can be added to the offset or
646	/// pointer of the current load command. The `cmdsize` for 32-bit architectures
647	/// MUST be a multiple of 4 bytes and for 64-bit architectures MUST be a multiple
648	/// of 8 bytes (these are forever the maximum alignment of any load commands).
649	/// The padded bytes must be zero. All tables in the object file must also
650	/// follow these rules so the file can be memory mapped. Otherwise the pointers
651	/// to these tables will not work well or at all on some machines. With all
652	/// padding zeroed like objects will compare byte for byte.
653	#[derive(Debug, Clone, Copy)]
654	#[repr(C)]
655	pub struct LoadCommand<E: Endian> {
656	/// Type of load command.
657	///
658	/// One of the `LC_` constants.*
659	pub cmd: U32<E>,
660	/// Total size of command in bytes.
661	pub cmdsize: U32<E>,
662	}
663
664	/*
665	* After MacOS X 10.1 when a new load command is added that is required to be
666	* understood by the dynamic linker for the image to execute properly the
667	* LC_REQ_DYLD bit will be or'ed into the load command constant. If the dynamic
668	* linker sees such a load command it it does not understand will issue a
669	* "unknown load command required for execution" error and refuse to use the
670	* image. Other load commands without this bit that are not understood will
671	* simply be ignored.
672	*/
673	pub const LC_REQ_DYLD: u32 = `0x8000_0000`;
674
675	/ Constants for the cmd field of all load commands, the type /
676	/// segment of this file to be mapped
677	pub const LC_SEGMENT: u32 = `0x1`;
678	/// link-edit stab symbol table info
679	pub const LC_SYMTAB: u32 = `0x2`;
680	/// link-edit gdb symbol table info (obsolete)
681	pub const LC_SYMSEG: u32 = `0x3`;
682	/// thread
683	pub const LC_THREAD: u32 = `0x4`;
684	/// unix thread (includes a stack)
685	pub const LC_UNIXTHREAD: u32 = `0x5`;
686	/// load a specified fixed VM shared library
687	pub const LC_LOADFVMLIB: u32 = `0x6`;
688	/// fixed VM shared library identification
689	pub const LC_IDFVMLIB: u32 = `0x7`;
690	/// object identification info (obsolete)
691	pub const LC_IDENT: u32 = `0x8`;
692	/// fixed VM file inclusion (internal use)
693	pub const LC_FVMFILE: u32 = `0x9`;
694	/// prepage command (internal use)
695	pub const LC_PREPAGE: u32 = `0xa`;
696	/// dynamic link-edit symbol table info
697	pub const LC_DYSYMTAB: u32 = `0xb`;
698	/// load a dynamically linked shared library
699	pub const LC_LOAD_DYLIB: u32 = `0xc`;
700	/// dynamically linked shared lib ident
701	pub const LC_ID_DYLIB: u32 = `0xd`;
702	/// load a dynamic linker
703	pub const LC_LOAD_DYLINKER: u32 = `0xe`;
704	/// dynamic linker identification
705	pub const LC_ID_DYLINKER: u32 = `0xf`;
706	/// modules prebound for a dynamically linked shared library
707	pub const LC_PREBOUND_DYLIB: u32 = `0x10`;
708	/// image routines
709	pub const LC_ROUTINES: u32 = `0x11`;
710	/// sub framework
711	pub const LC_SUB_FRAMEWORK: u32 = `0x12`;
712	/// sub umbrella
713	pub const LC_SUB_UMBRELLA: u32 = `0x13`;
714	/// sub client
715	pub const LC_SUB_CLIENT: u32 = `0x14`;
716	/// sub library
717	pub const LC_SUB_LIBRARY: u32 = `0x15`;
718	/// two-level namespace lookup hints
719	pub const LC_TWOLEVEL_HINTS: u32 = `0x16`;
720	/// prebind checksum
721	pub const LC_PREBIND_CKSUM: u32 = `0x17`;
722	/// load a dynamically linked shared library that is allowed to be missing
723	/// (all symbols are weak imported).
724	pub const LC_LOAD_WEAK_DYLIB: u32 = `0x18` \| LC_REQ_DYLD;
725	/// 64-bit segment of this file to be mapped
726	pub const LC_SEGMENT_64: u32 = `0x19`;
727	/// 64-bit image routines
728	pub const LC_ROUTINES_64: u32 = `0x1a`;
729	/// the uuid
730	pub const LC_UUID: u32 = `0x1b`;
731	/// runpath additions
732	pub const LC_RPATH: u32 = `0x1c` \| LC_REQ_DYLD;
733	/// local of code signature
734	pub const LC_CODE_SIGNATURE: u32 = `0x1d`;
735	/// local of info to split segments
736	pub const LC_SEGMENT_SPLIT_INFO: u32 = `0x1e`;
737	/// load and re-export dylib
738	pub const LC_REEXPORT_DYLIB: u32 = `0x1f` \| LC_REQ_DYLD;
739	/// delay load of dylib until first use
740	pub const LC_LAZY_LOAD_DYLIB: u32 = `0x20`;
741	/// encrypted segment information
742	pub const LC_ENCRYPTION_INFO: u32 = `0x21`;
743	/// compressed dyld information
744	pub const LC_DYLD_INFO: u32 = `0x22`;
745	/// compressed dyld information only
746	pub const LC_DYLD_INFO_ONLY: u32 = `0x22` \| LC_REQ_DYLD;
747	/// load upward dylib
748	pub const LC_LOAD_UPWARD_DYLIB: u32 = `0x23` \| LC_REQ_DYLD;
749	/// build for MacOSX min OS version
750	pub const LC_VERSION_MIN_MACOSX: u32 = `0x24`;
751	/// build for iPhoneOS min OS version
752	pub const LC_VERSION_MIN_IPHONEOS: u32 = `0x25`;
753	/// compressed table of function start addresses
754	pub const LC_FUNCTION_STARTS: u32 = `0x26`;
755	/// string for dyld to treat like environment variable
756	pub const LC_DYLD_ENVIRONMENT: u32 = `0x27`;
757	/// replacement for LC_UNIXTHREAD
758	pub const LC_MAIN: u32 = `0x28` \| LC_REQ_DYLD;
759	/// table of non-instructions in __text
760	pub const LC_DATA_IN_CODE: u32 = `0x29`;
761	/// source version used to build binary
762	pub const LC_SOURCE_VERSION: u32 = `0x2A`;
763	/// Code signing DRs copied from linked dylibs
764	pub const LC_DYLIB_CODE_SIGN_DRS: u32 = `0x2B`;
765	/// 64-bit encrypted segment information
766	pub const LC_ENCRYPTION_INFO_64: u32 = `0x2C`;
767	/// linker options in MH_OBJECT files
768	pub const LC_LINKER_OPTION: u32 = `0x2D`;
769	/// optimization hints in MH_OBJECT files
770	pub const LC_LINKER_OPTIMIZATION_HINT: u32 = `0x2E`;
771	/// build for AppleTV min OS version
772	pub const LC_VERSION_MIN_TVOS: u32 = `0x2F`;
773	/// build for Watch min OS version
774	pub const LC_VERSION_MIN_WATCHOS: u32 = `0x30`;
775	/// arbitrary data included within a Mach-O file
776	pub const LC_NOTE: u32 = `0x31`;
777	/// build for platform min OS version
778	pub const LC_BUILD_VERSION: u32 = `0x32`;
779	/// used with `LinkeditDataCommand`, payload is trie
780	pub const LC_DYLD_EXPORTS_TRIE: u32 = `0x33` \| LC_REQ_DYLD;
781	/// used with `LinkeditDataCommand`
782	pub const LC_DYLD_CHAINED_FIXUPS: u32 = `0x34` \| LC_REQ_DYLD;
783	/// used with `FilesetEntryCommand`
784	pub const LC_FILESET_ENTRY: u32 = `0x35` \| LC_REQ_DYLD;
785
786	/// A variable length string in a load command.
787	///
788	/// The strings are stored just after the load command structure and
789	/// the offset is from the start of the load command structure. The size
790	/// of the string is reflected in the `cmdsize` field of the load command.
791	/// Once again any padded bytes to bring the `cmdsize` field to a multiple
792	/// of 4 bytes must be zero.
793	#[derive(Debug, Clone, Copy)]
794	#[repr(C)]
795	pub struct LcStr<E: Endian> {
796	/// offset to the string
797	pub offset: U32<E>,
798	}
799
800	/// 32-bit segment load command.
801	///
802	/// The segment load command indicates that a part of this file is to be
803	/// mapped into the task's address space. The size of this segment in memory,
804	/// vmsize, maybe equal to or larger than the amount to map from this file,
805	/// filesize. The file is mapped starting at fileoff to the beginning of
806	/// the segment in memory, vmaddr. The rest of the memory of the segment,
807	/// if any, is allocated zero fill on demand. The segment's maximum virtual
808	/// memory protection and initial virtual memory protection are specified
809	/// by the maxprot and initprot fields. If the segment has sections then the
810	/// `Section32` structures directly follow the segment command and their size is
811	/// reflected in `cmdsize`.
812	#[derive(Debug, Clone, Copy)]
813	#[repr(C)]
814	pub struct SegmentCommand32<E: Endian> {
815	/// LC_SEGMENT
816	pub cmd: U32<E>,
817	/// includes sizeof section structs
818	pub cmdsize: U32<E>,
819	/// segment name
820	pub segname: [u8; `16`],
821	/// memory address of this segment
822	pub vmaddr: U32<E>,
823	/// memory size of this segment
824	pub vmsize: U32<E>,
825	/// file offset of this segment
826	pub fileoff: U32<E>,
827	/// amount to map from the file
828	pub filesize: U32<E>,
829	/// maximum VM protection
830	pub maxprot: U32<E>,
831	/// initial VM protection
832	pub initprot: U32<E>,
833	/// number of sections in segment
834	pub nsects: U32<E>,
835	/// flags
836	pub flags: U32<E>,
837	}
838
839	/// 64-bit segment load command.
840	///
841	/// The 64-bit segment load command indicates that a part of this file is to be
842	/// mapped into a 64-bit task's address space. If the 64-bit segment has
843	/// sections then `Section64` structures directly follow the 64-bit segment
844	/// command and their size is reflected in `cmdsize`.
845	#[derive(Debug, Clone, Copy)]
846	#[repr(C)]
847	pub struct SegmentCommand64<E: Endian> {
848	/// LC_SEGMENT_64
849	pub cmd: U32<E>,
850	/// includes sizeof section_64 structs
851	pub cmdsize: U32<E>,
852	/// segment name
853	pub segname: [u8; `16`],
854	/// memory address of this segment
855	pub vmaddr: U64<E>,
856	/// memory size of this segment
857	pub vmsize: U64<E>,
858	/// file offset of this segment
859	pub fileoff: U64<E>,
860	/// amount to map from the file
861	pub filesize: U64<E>,
862	/// maximum VM protection
863	pub maxprot: U32<E>,
864	/// initial VM protection
865	pub initprot: U32<E>,
866	/// number of sections in segment
867	pub nsects: U32<E>,
868	/// flags
869	pub flags: U32<E>,
870	}
871
872	// Values for `SegmentCommand::flags`.*
873	/// 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)
874	pub const SG_HIGHVM: u32 = `0x1`;
875	/// this segment is the VM that is allocated by a fixed VM library, for overlap checking in the link editor
876	pub const SG_FVMLIB: u32 = `0x2`;
877	/// this segment has nothing that was relocated in it and nothing relocated to it, that is it maybe safely replaced without relocation
878	pub const SG_NORELOC: u32 = `0x4`;
879	/// 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.
880	pub const SG_PROTECTED_VERSION_1: u32 = `0x8`;
881	/// This segment is made read-only after fixups
882	pub const SG_READ_ONLY: u32 = `0x10`;
883
884	/*
885	* A segment is made up of zero or more sections. Non-MH_OBJECT files have
886	* all of their segments with the proper sections in each, and padded to the
887	* specified segment alignment when produced by the link editor. The first
888	* segment of a MH_EXECUTE and MH_FVMLIB format file contains the mach_header
889	* and load commands of the object file before its first section. The zero
890	* fill sections are always last in their segment (in all formats). This
891	* allows the zeroed segment padding to be mapped into memory where zero fill
892	* sections might be. The gigabyte zero fill sections, those with the section
893	* type S_GB_ZEROFILL, can only be in a segment with sections of this type.
894	* These segments are then placed after all other segments.
895	*
896	* The MH_OBJECT format has all of its sections in one segment for
897	* compactness. There is no padding to a specified segment boundary and the
898	* mach_header and load commands are not part of the segment.
899	*
900	* Sections with the same section name, sectname, going into the same segment,
901	* segname, are combined by the link editor. The resulting section is aligned
902	* to the maximum alignment of the combined sections and is the new section's
903	* alignment. The combined sections are aligned to their original alignment in
904	* the combined section. Any padded bytes to get the specified alignment are
905	* zeroed.
906	*
907	* The format of the relocation entries referenced by the reloff and nreloc
908	* fields of the section structure for mach object files is described in the
909	* header file <reloc.h>.
910	*/
911	/// 32-bit section.
912	#[derive(Debug, Clone, Copy)]
913	#[repr(C)]
914	pub struct Section32<E: Endian> {
915	/// name of this section
916	pub sectname: [u8; `16`],
917	/// segment this section goes in
918	pub segname: [u8; `16`],
919	/// memory address of this section
920	pub addr: U32<E>,
921	/// size in bytes of this section
922	pub size: U32<E>,
923	/// file offset of this section
924	pub offset: U32<E>,
925	/// section alignment (power of 2)
926	pub align: U32<E>,
927	/// file offset of relocation entries
928	pub reloff: U32<E>,
929	/// number of relocation entries
930	pub nreloc: U32<E>,
931	/// flags (section type and attributes)
932	pub flags: U32<E>,
933	/// reserved (for offset or index)
934	pub reserved1: U32<E>,
935	/// reserved (for count or sizeof)
936	pub reserved2: U32<E>,
937	}
938
939	/// 64-bit section.
940	#[derive(Debug, Clone, Copy)]
941	#[repr(C)]
942	pub struct Section64<E: Endian> {
943	/// name of this section
944	pub sectname: [u8; `16`],
945	/// segment this section goes in
946	pub segname: [u8; `16`],
947	/// memory address of this section
948	pub addr: U64<E>,
949	/// size in bytes of this section
950	pub size: U64<E>,
951	/// file offset of this section
952	pub offset: U32<E>,
953	/// section alignment (power of 2)
954	pub align: U32<E>,
955	/// file offset of relocation entries
956	pub reloff: U32<E>,
957	/// number of relocation entries
958	pub nreloc: U32<E>,
959	/// flags (section type and attributes)
960	pub flags: U32<E>,
961	/// reserved (for offset or index)
962	pub reserved1: U32<E>,
963	/// reserved (for count or sizeof)
964	pub reserved2: U32<E>,
965	/// reserved
966	pub reserved3: U32<E>,
967	}
968
969	/*
970	* The flags field of a section structure is separated into two parts a section
971	* type and section attributes. The section types are mutually exclusive (it
972	* can only have one type) but the section attributes are not (it may have more
973	* than one attribute).
974	*/
975	/// 256 section types
976	pub const SECTION_TYPE: u32 = `0x0000_00ff`;
977	/// 24 section attributes
978	pub const SECTION_ATTRIBUTES: u32 = `0xffff_ff00`;
979
980	/ Constants for the type of a section /
981	/// regular section
982	pub const S_REGULAR: u32 = `0x0`;
983	/// zero fill on demand section
984	pub const S_ZEROFILL: u32 = `0x1`;
985	/// section with only literal C strings
986	pub const S_CSTRING_LITERALS: u32 = `0x2`;
987	/// section with only 4 byte literals
988	pub const S_4BYTE_LITERALS: u32 = `0x3`;
989	/// section with only 8 byte literals
990	pub const S_8BYTE_LITERALS: u32 = `0x4`;
991	/// section with only pointers to literals
992	pub const S_LITERAL_POINTERS: u32 = `0x5`;
993	/*
994	* For the two types of symbol pointers sections and the symbol stubs section
995	* they have indirect symbol table entries. For each of the entries in the
996	* section the indirect symbol table entries, in corresponding order in the
997	* indirect symbol table, start at the index stored in the reserved1 field
998	* of the section structure. Since the indirect symbol table entries
999	* correspond to the entries in the section the number of indirect symbol table
1000	* entries is inferred from the size of the section divided by the size of the
1001	* entries in the section. For symbol pointers sections the size of the entries
1002	* in the section is 4 bytes and for symbol stubs sections the byte size of the
1003	* stubs is stored in the reserved2 field of the section structure.
1004	*/
1005	/// section with only non-lazy symbol pointers
1006	pub const S_NON_LAZY_SYMBOL_POINTERS: u32 = `0x6`;
1007	/// section with only lazy symbol pointers
1008	pub const S_LAZY_SYMBOL_POINTERS: u32 = `0x7`;
1009	/// section with only symbol stubs, byte size of stub in the reserved2 field
1010	pub const S_SYMBOL_STUBS: u32 = `0x8`;
1011	/// section with only function pointers for initialization
1012	pub const S_MOD_INIT_FUNC_POINTERS: u32 = `0x9`;
1013	/// section with only function pointers for termination
1014	pub const S_MOD_TERM_FUNC_POINTERS: u32 = `0xa`;
1015	/// section contains symbols that are to be coalesced
1016	pub const S_COALESCED: u32 = `0xb`;
1017	/// zero fill on demand section (that can be larger than 4 gigabytes)
1018	pub const S_GB_ZEROFILL: u32 = `0xc`;
1019	/// section with only pairs of function pointers for interposing
1020	pub const S_INTERPOSING: u32 = `0xd`;
1021	/// section with only 16 byte literals
1022	pub const S_16BYTE_LITERALS: u32 = `0xe`;
1023	/// section contains DTrace Object Format
1024	pub const S_DTRACE_DOF: u32 = `0xf`;
1025	/// section with only lazy symbol pointers to lazy loaded dylibs
1026	pub const S_LAZY_DYLIB_SYMBOL_POINTERS: u32 = `0x10`;
1027	/*
1028	* Section types to support thread local variables
1029	*/
1030	/// template of initial values for TLVs
1031	pub const S_THREAD_LOCAL_REGULAR: u32 = `0x11`;
1032	/// template of initial values for TLVs
1033	pub const S_THREAD_LOCAL_ZEROFILL: u32 = `0x12`;
1034	/// TLV descriptors
1035	pub const S_THREAD_LOCAL_VARIABLES: u32 = `0x13`;
1036	/// pointers to TLV descriptors
1037	pub const S_THREAD_LOCAL_VARIABLE_POINTERS: u32 = `0x14`;
1038	/// functions to call to initialize TLV values
1039	pub const S_THREAD_LOCAL_INIT_FUNCTION_POINTERS: u32 = `0x15`;
1040	/// 32-bit offsets to initializers
1041	pub const S_INIT_FUNC_OFFSETS: u32 = `0x16`;
1042
1043	/*
1044	* Constants for the section attributes part of the flags field of a section
1045	* structure.
1046	*/
1047	/// User setable attributes
1048	pub const SECTION_ATTRIBUTES_USR: u32 = `0xff00_0000`;
1049	/// section contains only true machine instructions
1050	pub const S_ATTR_PURE_INSTRUCTIONS: u32 = `0x8000_0000`;
1051	/// section contains coalesced symbols that are not to be in a ranlib table of contents
1052	pub const S_ATTR_NO_TOC: u32 = `0x4000_0000`;
1053	/// ok to strip static symbols in this section in files with the MH_DYLDLINK flag
1054	pub const S_ATTR_STRIP_STATIC_SYMS: u32 = `0x2000_0000`;
1055	/// no dead stripping
1056	pub const S_ATTR_NO_DEAD_STRIP: u32 = `0x1000_0000`;
1057	/// blocks are live if they reference live blocks
1058	pub const S_ATTR_LIVE_SUPPORT: u32 = `0x0800_0000`;
1059	/// Used with i386 code stubs written on by dyld
1060	pub const S_ATTR_SELF_MODIFYING_CODE: u32 = `0x0400_0000`;
1061	/*
1062	* If a segment contains any sections marked with S_ATTR_DEBUG then all
1063	* sections in that segment must have this attribute. No section other than
1064	* a section marked with this attribute may reference the contents of this
1065	* section. A section with this attribute may contain no symbols and must have
1066	* a section type S_REGULAR. The static linker will not copy section contents
1067	* from sections with this attribute into its output file. These sections
1068	* generally contain DWARF debugging info.
1069	*/
1070	/// a debug section
1071	pub const S_ATTR_DEBUG: u32 = `0x0200_0000`;
1072	/// system setable attributes
1073	pub const SECTION_ATTRIBUTES_SYS: u32 = `0x00ff_ff00`;
1074	/// section contains some machine instructions
1075	pub const S_ATTR_SOME_INSTRUCTIONS: u32 = `0x0000_0400`;
1076	/// section has external relocation entries
1077	pub const S_ATTR_EXT_RELOC: u32 = `0x0000_0200`;
1078	/// section has local relocation entries
1079	pub const S_ATTR_LOC_RELOC: u32 = `0x0000_0100`;
1080
1081	/*
1082	* The names of segments and sections in them are mostly meaningless to the
1083	* link-editor. But there are few things to support traditional UNIX
1084	* executables that require the link-editor and assembler to use some names
1085	* agreed upon by convention.
1086	*
1087	* The initial protection of the "__TEXT" segment has write protection turned
1088	* off (not writeable).
1089	*
1090	* The link-editor will allocate common symbols at the end of the "__common"
1091	* section in the "__DATA" segment. It will create the section and segment
1092	* if needed.
1093	*/
1094
1095	/ The currently known segment names and the section names in those segments /
1096
1097	/// the pagezero segment which has no protections and catches NULL references for MH_EXECUTE files
1098	pub const SEG_PAGEZERO: &str = "__PAGEZERO";
1099
1100	/// the tradition UNIX text segment
1101	pub const SEG_TEXT: &str = "__TEXT";
1102	/// the real text part of the text section no headers, and no padding
1103	pub const SECT_TEXT: &str = "__text";
1104	/// the fvmlib initialization section
1105	pub const SECT_FVMLIB_INIT0: &str = "__fvmlib_init0";
1106	/// the section following the fvmlib initialization section
1107	pub const SECT_FVMLIB_INIT1: &str = "__fvmlib_init1";
1108
1109	/// the tradition UNIX data segment
1110	pub const SEG_DATA: &str = "__DATA";
1111	/// the real initialized data section no padding, no bss overlap
1112	pub const SECT_DATA: &str = "__data";
1113	/// the real uninitialized data section no padding
1114	pub const SECT_BSS: &str = "__bss";
1115	/// the section common symbols are allocated in by the link editor
1116	pub const SECT_COMMON: &str = "__common";
1117
1118	/// objective-C runtime segment
1119	pub const SEG_OBJC: &str = "__OBJC";
1120	/// symbol table
1121	pub const SECT_OBJC_SYMBOLS: &str = "__symbol_table";
1122	/// module information
1123	pub const SECT_OBJC_MODULES: &str = "__module_info";
1124	/// string table
1125	pub const SECT_OBJC_STRINGS: &str = "__selector_strs";
1126	/// string table
1127	pub const SECT_OBJC_REFS: &str = "__selector_refs";
1128
1129	/// the icon segment
1130	pub const SEG_ICON: &str = "__ICON";
1131	/// the icon headers
1132	pub const SECT_ICON_HEADER: &str = "__header";
1133	/// the icons in tiff format
1134	pub const SECT_ICON_TIFF: &str = "__tiff";
1135
1136	/// 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
1137	pub const SEG_LINKEDIT: &str = "__LINKEDIT";
1138
1139	/// the segment overlapping with linkedit containing linking information
1140	pub const SEG_LINKINFO: &str = "__LINKINFO";
1141
1142	/// the unix stack segment
1143	pub const SEG_UNIXSTACK: &str = "__UNIXSTACK";
1144
1145	/// the segment for the self (dyld) modifying code stubs that has read, write and execute permissions
1146	pub const SEG_IMPORT: &str = "__IMPORT";
1147
1148	/*
1149	* Fixed virtual memory shared libraries are identified by two things. The
1150	* target pathname (the name of the library as found for execution), and the
1151	* minor version number. The address of where the headers are loaded is in
1152	* header_addr. (THIS IS OBSOLETE and no longer supported).
1153	*/
1154	#[derive(Debug, Clone, Copy)]
1155	#[repr(C)]
1156	pub struct Fvmlib<E: Endian> {
1157	/// library's target pathname
1158	pub name: LcStr<E>,
1159	/// library's minor version number
1160	pub minor_version: U32<E>,
1161	/// library's header address
1162	pub header_addr: U32<E>,
1163	}
1164
1165	/*
1166	* A fixed virtual shared library (filetype == MH_FVMLIB in the mach header)
1167	* contains a `FvmlibCommand` (cmd == LC_IDFVMLIB) to identify the library.
1168	* An object that uses a fixed virtual shared library also contains a
1169	* `FvmlibCommand` (cmd == LC_LOADFVMLIB) for each library it uses.
1170	* (THIS IS OBSOLETE and no longer supported).
1171	*/
1172	#[derive(Debug, Clone, Copy)]
1173	#[repr(C)]
1174	pub struct FvmlibCommand<E: Endian> {
1175	/// LC_IDFVMLIB or LC_LOADFVMLIB
1176	pub cmd: U32<E>,
1177	/// includes pathname string
1178	pub cmdsize: U32<E>,
1179	/// the library identification
1180	pub fvmlib: Fvmlib<E>,
1181	}
1182
1183	/*
1184	* Dynamically linked shared libraries are identified by two things. The
1185	* pathname (the name of the library as found for execution), and the
1186	* compatibility version number. The pathname must match and the compatibility
1187	* number in the user of the library must be greater than or equal to the
1188	* library being used. The time stamp is used to record the time a library was
1189	* built and copied into user so it can be use to determined if the library used
1190	* at runtime is exactly the same as used to built the program.
1191	*/
1192	#[derive(Debug, Clone, Copy)]
1193	#[repr(C)]
1194	pub struct Dylib<E: Endian> {
1195	/// library's path name
1196	pub name: LcStr<E>,
1197	/// library's build time stamp
1198	pub timestamp: U32<E>,
1199	/// library's current version number
1200	pub current_version: U32<E>,
1201	/// library's compatibility vers number
1202	pub compatibility_version: U32<E>,
1203	}
1204
1205	/*
1206	* A dynamically linked shared library (filetype == MH_DYLIB in the mach header)
1207	* contains a `DylibCommand` (cmd == LC_ID_DYLIB) to identify the library.
1208	* An object that uses a dynamically linked shared library also contains a
1209	* `DylibCommand` (cmd == LC_LOAD_DYLIB, LC_LOAD_WEAK_DYLIB, or
1210	* LC_REEXPORT_DYLIB) for each library it uses.
1211	*/
1212	#[derive(Debug, Clone, Copy)]
1213	#[repr(C)]
1214	pub struct DylibCommand<E: Endian> {
1215	/// LC_ID_DYLIB, LC_LOAD_{,WEAK_}DYLIB, LC_REEXPORT_DYLIB
1216	pub cmd: U32<E>,
1217	/// includes pathname string
1218	pub cmdsize: U32<E>,
1219	/// the library identification
1220	pub dylib: Dylib<E>,
1221	}
1222
1223	/*
1224	* A dynamically linked shared library may be a subframework of an umbrella
1225	* framework. If so it will be linked with "-umbrella umbrella_name" where
1226	* Where "umbrella_name" is the name of the umbrella framework. A subframework
1227	* can only be linked against by its umbrella framework or other subframeworks
1228	* that are part of the same umbrella framework. Otherwise the static link
1229	* editor produces an error and states to link against the umbrella framework.
1230	* The name of the umbrella framework for subframeworks is recorded in the
1231	* following structure.
1232	*/
1233	#[derive(Debug, Clone, Copy)]
1234	#[repr(C)]
1235	pub struct SubFrameworkCommand<E: Endian> {
1236	/// LC_SUB_FRAMEWORK
1237	pub cmd: U32<E>,
1238	/// includes umbrella string
1239	pub cmdsize: U32<E>,
1240	/// the umbrella framework name
1241	pub umbrella: LcStr<E>,
1242	}
1243
1244	/*
1245	* For dynamically linked shared libraries that are subframework of an umbrella
1246	* framework they can allow clients other than the umbrella framework or other
1247	* subframeworks in the same umbrella framework. To do this the subframework
1248	* is built with "-allowable_client client_name" and an LC_SUB_CLIENT load
1249	* command is created for each -allowable_client flag. The client_name is
1250	* usually a framework name. It can also be a name used for bundles clients
1251	* where the bundle is built with "-client_name client_name".
1252	*/
1253	#[derive(Debug, Clone, Copy)]
1254	#[repr(C)]
1255	pub struct SubClientCommand<E: Endian> {
1256	/// LC_SUB_CLIENT
1257	pub cmd: U32<E>,
1258	/// includes client string
1259	pub cmdsize: U32<E>,
1260	/// the client name
1261	pub client: LcStr<E>,
1262	}
1263
1264	/*
1265	* A dynamically linked shared library may be a sub_umbrella of an umbrella
1266	* framework. If so it will be linked with "-sub_umbrella umbrella_name" where
1267	* Where "umbrella_name" is the name of the sub_umbrella framework. When
1268	* statically linking when -twolevel_namespace is in effect a twolevel namespace
1269	* umbrella framework will only cause its subframeworks and those frameworks
1270	* listed as sub_umbrella frameworks to be implicited linked in. Any other
1271	* dependent dynamic libraries will not be linked it when -twolevel_namespace
1272	* is in effect. The primary library recorded by the static linker when
1273	* resolving a symbol in these libraries will be the umbrella framework.
1274	* Zero or more sub_umbrella frameworks may be use by an umbrella framework.
1275	* The name of a sub_umbrella framework is recorded in the following structure.
1276	*/
1277	#[derive(Debug, Clone, Copy)]
1278	#[repr(C)]
1279	pub struct SubUmbrellaCommand<E: Endian> {
1280	/// LC_SUB_UMBRELLA
1281	pub cmd: U32<E>,
1282	/// includes sub_umbrella string
1283	pub cmdsize: U32<E>,
1284	/// the sub_umbrella framework name
1285	pub sub_umbrella: LcStr<E>,
1286	}
1287
1288	/*
1289	* A dynamically linked shared library may be a sub_library of another shared
1290	* library. If so it will be linked with "-sub_library library_name" where
1291	* Where "library_name" is the name of the sub_library shared library. When
1292	* statically linking when -twolevel_namespace is in effect a twolevel namespace
1293	* shared library will only cause its subframeworks and those frameworks
1294	* listed as sub_umbrella frameworks and libraries listed as sub_libraries to
1295	* be implicited linked in. Any other dependent dynamic libraries will not be
1296	* linked it when -twolevel_namespace is in effect. The primary library
1297	* recorded by the static linker when resolving a symbol in these libraries
1298	* will be the umbrella framework (or dynamic library). Zero or more sub_library
1299	* shared libraries may be use by an umbrella framework or (or dynamic library).
1300	* The name of a sub_library framework is recorded in the following structure.
1301	* For example /usr/lib/libobjc_profile.A.dylib would be recorded as "libobjc".
1302	*/
1303	#[derive(Debug, Clone, Copy)]
1304	#[repr(C)]
1305	pub struct SubLibraryCommand<E: Endian> {
1306	/// LC_SUB_LIBRARY
1307	pub cmd: U32<E>,
1308	/// includes sub_library string
1309	pub cmdsize: U32<E>,
1310	/// the sub_library name
1311	pub sub_library: LcStr<E>,
1312	}
1313
1314	/*
1315	* A program (filetype == MH_EXECUTE) that is
1316	* prebound to its dynamic libraries has one of these for each library that
1317	* the static linker used in prebinding. It contains a bit vector for the
1318	* modules in the library. The bits indicate which modules are bound (1) and
1319	* which are not (0) from the library. The bit for module 0 is the low bit
1320	* of the first byte. So the bit for the Nth module is:
1321	* (linked_modules[N/8] >> N%8) & 1
1322	*/
1323	#[derive(Debug, Clone, Copy)]
1324	#[repr(C)]
1325	pub struct PreboundDylibCommand<E: Endian> {
1326	/// LC_PREBOUND_DYLIB
1327	pub cmd: U32<E>,
1328	/// includes strings
1329	pub cmdsize: U32<E>,
1330	/// library's path name
1331	pub name: LcStr<E>,
1332	/// number of modules in library
1333	pub nmodules: U32<E>,
1334	/// bit vector of linked modules
1335	pub linked_modules: LcStr<E>,
1336	}
1337
1338	/*
1339	* A program that uses a dynamic linker contains a `DylinkerCommand` to identify
1340	* the name of the dynamic linker (LC_LOAD_DYLINKER). And a dynamic linker
1341	* contains a `DylinkerCommand` to identify the dynamic linker (LC_ID_DYLINKER).
1342	* A file can have at most one of these.
1343	* This struct is also used for the LC_DYLD_ENVIRONMENT load command and
1344	* contains string for dyld to treat like environment variable.
1345	*/
1346	#[derive(Debug, Clone, Copy)]
1347	#[repr(C)]
1348	pub struct DylinkerCommand<E: Endian> {
1349	/// LC_ID_DYLINKER, LC_LOAD_DYLINKER or LC_DYLD_ENVIRONMENT
1350	pub cmd: U32<E>,
1351	/// includes pathname string
1352	pub cmdsize: U32<E>,
1353	/// dynamic linker's path name
1354	pub name: LcStr<E>,
1355	}
1356
1357	/*
1358	* Thread commands contain machine-specific data structures suitable for
1359	* use in the thread state primitives. The machine specific data structures
1360	* follow the struct `ThreadCommand` as follows.
1361	* Each flavor of machine specific data structure is preceded by an uint32_t
1362	* constant for the flavor of that data structure, an uint32_t that is the
1363	* count of uint32_t's of the size of the state data structure and then
1364	* the state data structure follows. This triple may be repeated for many
1365	* flavors. The constants for the flavors, counts and state data structure
1366	* definitions are expected to be in the header file <machine/thread_status.h>.
1367	* These machine specific data structures sizes must be multiples of
1368	* 4 bytes. The `cmdsize` reflects the total size of the `ThreadCommand`
1369	* and all of the sizes of the constants for the flavors, counts and state
1370	* data structures.
1371	*
1372	* For executable objects that are unix processes there will be one
1373	* `ThreadCommand` (cmd == LC_UNIXTHREAD) created for it by the link-editor.
1374	* This is the same as a LC_THREAD, except that a stack is automatically
1375	* created (based on the shell's limit for the stack size). Command arguments
1376	* and environment variables are copied onto that stack.
1377	*/
1378	#[derive(Debug, Clone, Copy)]
1379	#[repr(C)]
1380	pub struct ThreadCommand<E: Endian> {
1381	/// LC_THREAD or LC_UNIXTHREAD
1382	pub cmd: U32<E>,
1383	/// total size of this command
1384	pub cmdsize: U32<E>,
1385	/ uint32_t flavor flavor of thread state /
1386	/ uint32_t count count of uint32_t's in thread state /
1387	/ struct XXX_thread_state state thread state for this flavor /
1388	/ ... /
1389	}
1390
1391	/*
1392	* The routines command contains the address of the dynamic shared library
1393	* initialization routine and an index into the module table for the module
1394	* that defines the routine. Before any modules are used from the library the
1395	* dynamic linker fully binds the module that defines the initialization routine
1396	* and then calls it. This gets called before any module initialization
1397	* routines (used for C++ static constructors) in the library.
1398	*/
1399	#[derive(Debug, Clone, Copy)]
1400	#[repr(C)]
1401	pub struct RoutinesCommand32<E: Endian> {
1402	/ for 32-bit architectures /
1403	/// LC_ROUTINES
1404	pub cmd: U32<E>,
1405	/// total size of this command
1406	pub cmdsize: U32<E>,
1407	/// address of initialization routine
1408	pub init_address: U32<E>,
1409	/// index into the module table that the init routine is defined in
1410	pub init_module: U32<E>,
1411	pub reserved1: U32<E>,
1412	pub reserved2: U32<E>,
1413	pub reserved3: U32<E>,
1414	pub reserved4: U32<E>,
1415	pub reserved5: U32<E>,
1416	pub reserved6: U32<E>,
1417	}
1418
1419	/*
1420	* The 64-bit routines command. Same use as above.
1421	*/
1422	#[derive(Debug, Clone, Copy)]
1423	#[repr(C)]
1424	pub struct RoutinesCommand64<E: Endian> {
1425	/ for 64-bit architectures /
1426	/// LC_ROUTINES_64
1427	pub cmd: U32<E>,
1428	/// total size of this command
1429	pub cmdsize: U32<E>,
1430	/// address of initialization routine
1431	pub init_address: U64<E>,
1432	/// index into the module table that the init routine is defined in
1433	pub init_module: U64<E>,
1434	pub reserved1: U64<E>,
1435	pub reserved2: U64<E>,
1436	pub reserved3: U64<E>,
1437	pub reserved4: U64<E>,
1438	pub reserved5: U64<E>,
1439	pub reserved6: U64<E>,
1440	}
1441
1442	/*
1443	* The `SymtabCommand` contains the offsets and sizes of the link-edit 4.3BSD
1444	* "stab" style symbol table information as described in the header files
1445	* <nlist.h> and <stab.h>.
1446	*/
1447	#[derive(Debug, Clone, Copy)]
1448	#[repr(C)]
1449	pub struct SymtabCommand<E: Endian> {
1450	/// LC_SYMTAB
1451	pub cmd: U32<E>,
1452	/// sizeof(struct SymtabCommand)
1453	pub cmdsize: U32<E>,
1454	/// symbol table offset
1455	pub symoff: U32<E>,
1456	/// number of symbol table entries
1457	pub nsyms: U32<E>,
1458	/// string table offset
1459	pub stroff: U32<E>,
1460	/// string table size in bytes
1461	pub strsize: U32<E>,
1462	}
1463
1464	/*
1465	* This is the second set of the symbolic information which is used to support
1466	* the data structures for the dynamically link editor.
1467	*
1468	* The original set of symbolic information in the `SymtabCommand` which contains
1469	* the symbol and string tables must also be present when this load command is
1470	* present. When this load command is present the symbol table is organized
1471	* into three groups of symbols:
1472	* local symbols (static and debugging symbols) - grouped by module
1473	* defined external symbols - grouped by module (sorted by name if not lib)
1474	* undefined external symbols (sorted by name if MH_BINDATLOAD is not set,
1475	* and in order the were seen by the static
1476	* linker if MH_BINDATLOAD is set)
1477	* In this load command there are offsets and counts to each of the three groups
1478	* of symbols.
1479	*
1480	* This load command contains a the offsets and sizes of the following new
1481	* symbolic information tables:
1482	* table of contents
1483	* module table
1484	* reference symbol table
1485	* indirect symbol table
1486	* The first three tables above (the table of contents, module table and
1487	* reference symbol table) are only present if the file is a dynamically linked
1488	* shared library. For executable and object modules, which are files
1489	* containing only one module, the information that would be in these three
1490	* tables is determined as follows:
1491	* table of contents - the defined external symbols are sorted by name
1492	* module table - the file contains only one module so everything in the
1493	* file is part of the module.
1494	* reference symbol table - is the defined and undefined external symbols
1495	*
1496	* For dynamically linked shared library files this load command also contains
1497	* offsets and sizes to the pool of relocation entries for all sections
1498	* separated into two groups:
1499	* external relocation entries
1500	* local relocation entries
1501	* For executable and object modules the relocation entries continue to hang
1502	* off the section structures.
1503	*/
1504	#[derive(Debug, Clone, Copy)]
1505	#[repr(C)]
1506	pub struct DysymtabCommand<E: Endian> {
1507	/// LC_DYSYMTAB
1508	pub cmd: U32<E>,
1509	/// sizeof(struct DysymtabCommand)
1510	pub cmdsize: U32<E>,
1511
1512	/*
1513	* The symbols indicated by symoff and nsyms of the LC_SYMTAB load command
1514	* are grouped into the following three groups:
1515	* local symbols (further grouped by the module they are from)
1516	* defined external symbols (further grouped by the module they are from)
1517	* undefined symbols
1518	*
1519	* The local symbols are used only for debugging. The dynamic binding
1520	* process may have to use them to indicate to the debugger the local
1521	* symbols for a module that is being bound.
1522	*
1523	* The last two groups are used by the dynamic binding process to do the
1524	* binding (indirectly through the module table and the reference symbol
1525	* table when this is a dynamically linked shared library file).
1526	*/
1527	/// index to local symbols
1528	pub ilocalsym: U32<E>,
1529	/// number of local symbols
1530	pub nlocalsym: U32<E>,
1531
1532	/// index to externally defined symbols
1533	pub iextdefsym: U32<E>,
1534	/// number of externally defined symbols
1535	pub nextdefsym: U32<E>,
1536
1537	/// index to undefined symbols
1538	pub iundefsym: U32<E>,
1539	/// number of undefined symbols
1540	pub nundefsym: U32<E>,
1541
1542	/*
1543	* For the for the dynamic binding process to find which module a symbol
1544	* is defined in the table of contents is used (analogous to the ranlib
1545	* structure in an archive) which maps defined external symbols to modules
1546	* they are defined in. This exists only in a dynamically linked shared
1547	* library file. For executable and object modules the defined external
1548	* symbols are sorted by name and is use as the table of contents.
1549	*/
1550	/// file offset to table of contents
1551	pub tocoff: U32<E>,
1552	/// number of entries in table of contents
1553	pub ntoc: U32<E>,
1554
1555	/*
1556	* To support dynamic binding of "modules" (whole object files) the symbol
1557	* table must reflect the modules that the file was created from. This is
1558	* done by having a module table that has indexes and counts into the merged
1559	* tables for each module. The module structure that these two entries
1560	* refer to is described below. This exists only in a dynamically linked
1561	* shared library file. For executable and object modules the file only
1562	* contains one module so everything in the file belongs to the module.
1563	*/
1564	/// file offset to module table
1565	pub modtaboff: U32<E>,
1566	/// number of module table entries
1567	pub nmodtab: U32<E>,
1568
1569	/*
1570	* To support dynamic module binding the module structure for each module
1571	* indicates the external references (defined and undefined) each module
1572	* makes. For each module there is an offset and a count into the
1573	* reference symbol table for the symbols that the module references.
1574	* This exists only in a dynamically linked shared library file. For
1575	* executable and object modules the defined external symbols and the
1576	* undefined external symbols indicates the external references.
1577	*/
1578	/// offset to referenced symbol table
1579	pub extrefsymoff: U32<E>,
1580	/// number of referenced symbol table entries
1581	pub nextrefsyms: U32<E>,
1582
1583	/*
1584	* The sections that contain "symbol pointers" and "routine stubs" have
1585	* indexes and (implied counts based on the size of the section and fixed
1586	* size of the entry) into the "indirect symbol" table for each pointer
1587	* and stub. For every section of these two types the index into the
1588	* indirect symbol table is stored in the section header in the field
1589	* reserved1. An indirect symbol table entry is simply a 32bit index into
1590	* the symbol table to the symbol that the pointer or stub is referring to.
1591	* The indirect symbol table is ordered to match the entries in the section.
1592	*/
1593	/// file offset to the indirect symbol table
1594	pub indirectsymoff: U32<E>,
1595	/// number of indirect symbol table entries
1596	pub nindirectsyms: U32<E>,
1597
1598	/*
1599	* To support relocating an individual module in a library file quickly the
1600	* external relocation entries for each module in the library need to be
1601	* accessed efficiently. Since the relocation entries can't be accessed
1602	* through the section headers for a library file they are separated into
1603	* groups of local and external entries further grouped by module. In this
1604	* case the presents of this load command who's extreloff, nextrel,
1605	* locreloff and nlocrel fields are non-zero indicates that the relocation
1606	* entries of non-merged sections are not referenced through the section
1607	* structures (and the reloff and nreloc fields in the section headers are
1608	* set to zero).
1609	*
1610	* Since the relocation entries are not accessed through the section headers
1611	* this requires the r_address field to be something other than a section
1612	* offset to identify the item to be relocated. In this case r_address is
1613	* set to the offset from the vmaddr of the first LC_SEGMENT command.
1614	* For MH_SPLIT_SEGS images r_address is set to the the offset from the
1615	* vmaddr of the first read-write LC_SEGMENT command.
1616	*
1617	* The relocation entries are grouped by module and the module table
1618	* entries have indexes and counts into them for the group of external
1619	* relocation entries for that the module.
1620	*
1621	* For sections that are merged across modules there must not be any
1622	* remaining external relocation entries for them (for merged sections
1623	* remaining relocation entries must be local).
1624	*/
1625	/// offset to external relocation entries
1626	pub extreloff: U32<E>,
1627	/// number of external relocation entries
1628	pub nextrel: U32<E>,
1629
1630	/*
1631	* All the local relocation entries are grouped together (they are not
1632	* grouped by their module since they are only used if the object is moved
1633	* from it statically link edited address).
1634	*/
1635	/// offset to local relocation entries
1636	pub locreloff: U32<E>,
1637	/// number of local relocation entries
1638	pub nlocrel: U32<E>,
1639	}
1640
1641	/*
1642	* An indirect symbol table entry is simply a 32bit index into the symbol table
1643	* to the symbol that the pointer or stub is referring to. Unless it is for a
1644	* non-lazy symbol pointer section for a defined symbol which strip(1) as
1645	* removed. In which case it has the value INDIRECT_SYMBOL_LOCAL. If the
1646	* symbol was also absolute INDIRECT_SYMBOL_ABS is or'ed with that.
1647	*/
1648	pub const INDIRECT_SYMBOL_LOCAL: u32 = `0x8000_0000`;
1649	pub const INDIRECT_SYMBOL_ABS: u32 = `0x4000_0000`;
1650
1651	/ a table of contents entry /
1652	#[derive(Debug, Clone, Copy)]
1653	#[repr(C)]
1654	pub struct DylibTableOfContents<E: Endian> {
1655	/// the defined external symbol (index into the symbol table)
1656	pub symbol_index: U32<E>,
1657	/// index into the module table this symbol is defined in
1658	pub module_index: U32<E>,
1659	}
1660
1661	/ a module table entry /
1662	#[derive(Debug, Clone, Copy)]
1663	#[repr(C)]
1664	pub struct DylibModule32<E: Endian> {
1665	/// the module name (index into string table)
1666	pub module_name: U32<E>,
1667
1668	/// index into externally defined symbols
1669	pub iextdefsym: U32<E>,
1670	/// number of externally defined symbols
1671	pub nextdefsym: U32<E>,
1672	/// index into reference symbol table
1673	pub irefsym: U32<E>,
1674	/// number of reference symbol table entries
1675	pub nrefsym: U32<E>,
1676	/// index into symbols for local symbols
1677	pub ilocalsym: U32<E>,
1678	/// number of local symbols
1679	pub nlocalsym: U32<E>,
1680
1681	/// index into external relocation entries
1682	pub iextrel: U32<E>,
1683	/// number of external relocation entries
1684	pub nextrel: U32<E>,
1685
1686	/// low 16 bits are the index into the init section, high 16 bits are the index into the term section
1687	pub iinit_iterm: U32<E>,
1688	/// low 16 bits are the number of init section entries, high 16 bits are the number of term section entries
1689	pub ninit_nterm: U32<E>,
1690
1691	/// for this module address of the start of the (__OBJC,__module_info) section
1692	pub objc_module_info_addr: U32<E>,
1693	/// for this module size of the (__OBJC,__module_info) section
1694	pub objc_module_info_size: U32<E>,
1695	}
1696
1697	/ a 64-bit module table entry /
1698	#[derive(Debug, Clone, Copy)]
1699	#[repr(C)]
1700	pub struct DylibModule64<E: Endian> {
1701	/// the module name (index into string table)
1702	pub module_name: U32<E>,
1703
1704	/// index into externally defined symbols
1705	pub iextdefsym: U32<E>,
1706	/// number of externally defined symbols
1707	pub nextdefsym: U32<E>,
1708	/// index into reference symbol table
1709	pub irefsym: U32<E>,
1710	/// number of reference symbol table entries
1711	pub nrefsym: U32<E>,
1712	/// index into symbols for local symbols
1713	pub ilocalsym: U32<E>,
1714	/// number of local symbols
1715	pub nlocalsym: U32<E>,
1716
1717	/// index into external relocation entries
1718	pub iextrel: U32<E>,
1719	/// number of external relocation entries
1720	pub nextrel: U32<E>,
1721
1722	/// low 16 bits are the index into the init section, high 16 bits are the index into the term section
1723	pub iinit_iterm: U32<E>,
1724	/// low 16 bits are the number of init section entries, high 16 bits are the number of term section entries
1725	pub ninit_nterm: U32<E>,
1726
1727	/// for this module size of the (__OBJC,__module_info) section
1728	pub objc_module_info_size: U32<E>,
1729	/// for this module address of the start of the (__OBJC,__module_info) section
1730	pub objc_module_info_addr: U64<E>,
1731	}
1732
1733	/*
1734	* The entries in the reference symbol table are used when loading the module
1735	* (both by the static and dynamic link editors) and if the module is unloaded
1736	* or replaced. Therefore all external symbols (defined and undefined) are
1737	* listed in the module's reference table. The flags describe the type of
1738	* reference that is being made. The constants for the flags are defined in
1739	* <mach-o/nlist.h> as they are also used for symbol table entries.
1740	*/
1741	#[derive(Debug, Clone, Copy)]
1742	#[repr(C)]
1743	pub struct DylibReference<E: Endian> {
1744	/ TODO:*
1745	uint32_t isym:24, / index into the symbol table /
1746	flags:8; / flags to indicate the type of reference /
1747	*/
1748	pub bitfield: U32<E>,
1749	}
1750
1751	/*
1752	* The TwolevelHintsCommand contains the offset and number of hints in the
1753	* two-level namespace lookup hints table.
1754	*/
1755	#[derive(Debug, Clone, Copy)]
1756	#[repr(C)]
1757	pub struct TwolevelHintsCommand<E: Endian> {
1758	/// LC_TWOLEVEL_HINTS
1759	pub cmd: U32<E>,
1760	/// sizeof(struct TwolevelHintsCommand)
1761	pub cmdsize: U32<E>,
1762	/// offset to the hint table
1763	pub offset: U32<E>,
1764	/// number of hints in the hint table
1765	pub nhints: U32<E>,
1766	}
1767
1768	/*
1769	* The entries in the two-level namespace lookup hints table are TwolevelHint
1770	* structs. These provide hints to the dynamic link editor where to start
1771	* looking for an undefined symbol in a two-level namespace image. The
1772	* isub_image field is an index into the sub-images (sub-frameworks and
1773	* sub-umbrellas list) that made up the two-level image that the undefined
1774	* symbol was found in when it was built by the static link editor. If
1775	* isub-image is 0 the the symbol is expected to be defined in library and not
1776	* in the sub-images. If isub-image is non-zero it is an index into the array
1777	* of sub-images for the umbrella with the first index in the sub-images being
1778	* 1. The array of sub-images is the ordered list of sub-images of the umbrella
1779	* that would be searched for a symbol that has the umbrella recorded as its
1780	* primary library. The table of contents index is an index into the
1781	* library's table of contents. This is used as the starting point of the
1782	* binary search or a directed linear search.
1783	*/
1784	#[derive(Debug, Clone, Copy)]
1785	#[repr(C)]
1786	pub struct TwolevelHint<E: Endian> {
1787	/ TODO:*
1788	uint32_t
1789	isub_image:8, / index into the sub images /
1790	itoc:24; / index into the table of contents /
1791	*/
1792	pub bitfield: U32<E>,
1793	}
1794
1795	/*
1796	* The PrebindCksumCommand contains the value of the original check sum for
1797	* prebound files or zero. When a prebound file is first created or modified
1798	* for other than updating its prebinding information the value of the check sum
1799	* is set to zero. When the file has it prebinding re-done and if the value of
1800	* the check sum is zero the original check sum is calculated and stored in
1801	* cksum field of this load command in the output file. If when the prebinding
1802	* is re-done and the cksum field is non-zero it is left unchanged from the
1803	* input file.
1804	*/
1805	#[derive(Debug, Clone, Copy)]
1806	#[repr(C)]
1807	pub struct PrebindCksumCommand<E: Endian> {
1808	/// LC_PREBIND_CKSUM
1809	pub cmd: U32<E>,
1810	/// sizeof(struct PrebindCksumCommand)
1811	pub cmdsize: U32<E>,
1812	/// the check sum or zero
1813	pub cksum: U32<E>,
1814	}
1815
1816	/*
1817	* The uuid load command contains a single 128-bit unique random number that
1818	* identifies an object produced by the static link editor.
1819	*/
1820	#[derive(Debug, Clone, Copy)]
1821	#[repr(C)]
1822	pub struct UuidCommand<E: Endian> {
1823	/// LC_UUID
1824	pub cmd: U32<E>,
1825	/// sizeof(struct UuidCommand)
1826	pub cmdsize: U32<E>,
1827	/// the 128-bit uuid
1828	pub uuid: [u8; `16`],
1829	}
1830
1831	/*
1832	* The RpathCommand contains a path which at runtime should be added to
1833	* the current run path used to find @rpath prefixed dylibs.
1834	*/
1835	#[derive(Debug, Clone, Copy)]
1836	#[repr(C)]
1837	pub struct RpathCommand<E: Endian> {
1838	/// LC_RPATH
1839	pub cmd: U32<E>,
1840	/// includes string
1841	pub cmdsize: U32<E>,
1842	/// path to add to run path
1843	pub path: LcStr<E>,
1844	}
1845
1846	/*
1847	* The LinkeditDataCommand contains the offsets and sizes of a blob
1848	* of data in the __LINKEDIT segment.
1849	*/
1850	#[derive(Debug, Clone, Copy)]
1851	#[repr(C)]
1852	pub struct LinkeditDataCommand<E: Endian> {
1853	/// `LC_CODE_SIGNATURE`, `LC_SEGMENT_SPLIT_INFO`, `LC_FUNCTION_STARTS`,
1854	/// `LC_DATA_IN_CODE`, `LC_DYLIB_CODE_SIGN_DRS`, `LC_LINKER_OPTIMIZATION_HINT`,
1855	/// `LC_DYLD_EXPORTS_TRIE`, or `LC_DYLD_CHAINED_FIXUPS`.
1856	pub cmd: U32<E>,
1857	/// sizeof(struct LinkeditDataCommand)
1858	pub cmdsize: U32<E>,
1859	/// file offset of data in __LINKEDIT segment
1860	pub dataoff: U32<E>,
1861	/// file size of data in __LINKEDIT segment
1862	pub datasize: U32<E>,
1863	}
1864
1865	#[derive(Debug, Clone, Copy)]
1866	#[repr(C)]
1867	pub struct FilesetEntryCommand<E: Endian> {
1868	// LC_FILESET_ENTRY
1869	pub cmd: U32<E>,
1870	/// includes id string
1871	pub cmdsize: U32<E>,
1872	/// memory address of the dylib
1873	pub vmaddr: U64<E>,
1874	/// file offset of the dylib
1875	pub fileoff: U64<E>,
1876	/// contained entry id
1877	pub entry_id: LcStr<E>,
1878	/// entry_id is 32-bits long, so this is the reserved padding
1879	pub reserved: U32<E>,
1880	}
1881
1882	/*
1883	* The EncryptionInfoCommand32 contains the file offset and size of an
1884	* of an encrypted segment.
1885	*/
1886	#[derive(Debug, Clone, Copy)]
1887	#[repr(C)]
1888	pub struct EncryptionInfoCommand32<E: Endian> {
1889	/// LC_ENCRYPTION_INFO
1890	pub cmd: U32<E>,
1891	/// sizeof(struct EncryptionInfoCommand32)
1892	pub cmdsize: U32<E>,
1893	/// file offset of encrypted range
1894	pub cryptoff: U32<E>,
1895	/// file size of encrypted range
1896	pub cryptsize: U32<E>,
1897	/// which enryption system, 0 means not-encrypted yet
1898	pub cryptid: U32<E>,
1899	}
1900
1901	/*
1902	* The EncryptionInfoCommand64 contains the file offset and size of an
1903	* of an encrypted segment (for use in x86_64 targets).
1904	*/
1905	#[derive(Debug, Clone, Copy)]
1906	#[repr(C)]
1907	pub struct EncryptionInfoCommand64<E: Endian> {
1908	/// LC_ENCRYPTION_INFO_64
1909	pub cmd: U32<E>,
1910	/// sizeof(struct EncryptionInfoCommand64)
1911	pub cmdsize: U32<E>,
1912	/// file offset of encrypted range
1913	pub cryptoff: U32<E>,
1914	/// file size of encrypted range
1915	pub cryptsize: U32<E>,
1916	/// which enryption system, 0 means not-encrypted yet
1917	pub cryptid: U32<E>,
1918	/// padding to make this struct's size a multiple of 8 bytes
1919	pub pad: U32<E>,
1920	}
1921
1922	/*
1923	* The VersionMinCommand contains the min OS version on which this
1924	* binary was built to run.
1925	*/
1926	#[derive(Debug, Clone, Copy)]
1927	#[repr(C)]
1928	pub struct VersionMinCommand<E: Endian> {
1929	/// LC_VERSION_MIN_MACOSX or LC_VERSION_MIN_IPHONEOS or LC_VERSION_MIN_WATCHOS or LC_VERSION_MIN_TVOS
1930	pub cmd: U32<E>,
1931	/// sizeof(struct VersionMinCommand)
1932	pub cmdsize: U32<E>,
1933	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1934	pub version: U32<E>,
1935	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1936	pub sdk: U32<E>,
1937	}
1938
1939	/*
1940	* The BuildVersionCommand contains the min OS version on which this
1941	* binary was built to run for its platform. The list of known platforms and
1942	* tool values following it.
1943	*/
1944	#[derive(Debug, Clone, Copy)]
1945	#[repr(C)]
1946	pub struct BuildVersionCommand<E: Endian> {
1947	/// LC_BUILD_VERSION
1948	pub cmd: U32<E>,
1949	/// sizeof(struct BuildVersionCommand) plus ntools sizeof(struct BuildToolVersion)*
1950	pub cmdsize: U32<E>,
1951	/// platform
1952	pub platform: U32<E>,
1953	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1954	pub minos: U32<E>,
1955	/// X.Y.Z is encoded in nibbles xxxx.yy.zz
1956	pub sdk: U32<E>,
1957	/// number of tool entries following this
1958	pub ntools: U32<E>,
1959	}
1960
1961	#[derive(Debug, Clone, Copy)]
1962	#[repr(C)]
1963	pub struct BuildToolVersion<E: Endian> {
1964	/// enum for the tool
1965	pub tool: U32<E>,
1966	/// version number of the tool
1967	pub version: U32<E>,
1968	}
1969
1970	/ Known values for the platform field above. /
1971	pub const PLATFORM_MACOS: u32 = `1`;
1972	pub const PLATFORM_IOS: u32 = `2`;
1973	pub const PLATFORM_TVOS: u32 = `3`;
1974	pub const PLATFORM_WATCHOS: u32 = `4`;
1975	pub const PLATFORM_BRIDGEOS: u32 = `5`;
1976	pub const PLATFORM_MACCATALYST: u32 = `6`;
1977	pub const PLATFORM_IOSSIMULATOR: u32 = `7`;
1978	pub const PLATFORM_TVOSSIMULATOR: u32 = `8`;
1979	pub const PLATFORM_WATCHOSSIMULATOR: u32 = `9`;
1980	pub const PLATFORM_DRIVERKIT: u32 = `10`;
1981
1982	/ Known values for the tool field above. /
1983	pub const TOOL_CLANG: u32 = `1`;
1984	pub const TOOL_SWIFT: u32 = `2`;
1985	pub const TOOL_LD: u32 = `3`;
1986
1987	/*
1988	* The DyldInfoCommand contains the file offsets and sizes of
1989	* the new compressed form of the information dyld needs to
1990	* load the image. This information is used by dyld on Mac OS X
1991	* 10.6 and later. All information pointed to by this command
1992	* is encoded using byte streams, so no endian swapping is needed
1993	* to interpret it.
1994	*/
1995	#[derive(Debug, Clone, Copy)]
1996	#[repr(C)]
1997	pub struct DyldInfoCommand<E: Endian> {
1998	/// LC_DYLD_INFO or LC_DYLD_INFO_ONLY
1999	pub cmd: U32<E>,
2000	/// sizeof(struct DyldInfoCommand)
2001	pub cmdsize: U32<E>,
2002
2003	/*
2004	* Dyld rebases an image whenever dyld loads it at an address different
2005	* from its preferred address. The rebase information is a stream
2006	* of byte sized opcodes whose symbolic names start with REBASE_OPCODE_.
2007	* Conceptually the rebase information is a table of tuples:
2008	* <seg-index, seg-offset, type>
2009	* The opcodes are a compressed way to encode the table by only
2010	* encoding when a column changes. In addition simple patterns
2011	* like "every n'th offset for m times" can be encoded in a few
2012	* bytes.
2013	*/
2014	/// file offset to rebase info
2015	pub rebase_off: U32<E>,
2016	/// size of rebase info
2017	pub rebase_size: U32<E>,
2018
2019	/*
2020	* Dyld binds an image during the loading process, if the image
2021	* requires any pointers to be initialized to symbols in other images.
2022	* The bind information is a stream of byte sized
2023	* opcodes whose symbolic names start with BIND_OPCODE_.
2024	* Conceptually the bind information is a table of tuples:
2025	* <seg-index, seg-offset, type, symbol-library-ordinal, symbol-name, addend>
2026	* The opcodes are a compressed way to encode the table by only
2027	* encoding when a column changes. In addition simple patterns
2028	* like for runs of pointers initialized to the same value can be
2029	* encoded in a few bytes.
2030	*/
2031	/// file offset to binding info
2032	pub bind_off: U32<E>,
2033	/// size of binding info
2034	pub bind_size: U32<E>,
2035
2036	/*
2037	* Some C++ programs require dyld to unique symbols so that all
2038	* images in the process use the same copy of some code/data.
2039	* This step is done after binding. The content of the weak_bind
2040	* info is an opcode stream like the bind_info. But it is sorted
2041	* alphabetically by symbol name. This enable dyld to walk
2042	* all images with weak binding information in order and look
2043	* for collisions. If there are no collisions, dyld does
2044	* no updating. That means that some fixups are also encoded
2045	* in the bind_info. For instance, all calls to "operator new"
2046	* are first bound to libstdc++.dylib using the information
2047	* in bind_info. Then if some image overrides operator new
2048	* that is detected when the weak_bind information is processed
2049	* and the call to operator new is then rebound.
2050	*/
2051	/// file offset to weak binding info
2052	pub weak_bind_off: U32<E>,
2053	/// size of weak binding info
2054	pub weak_bind_size: U32<E>,
2055
2056	/*
2057	* Some uses of external symbols do not need to be bound immediately.
2058	* Instead they can be lazily bound on first use. The lazy_bind
2059	* are contains a stream of BIND opcodes to bind all lazy symbols.
2060	* Normal use is that dyld ignores the lazy_bind section when
2061	* loading an image. Instead the static linker arranged for the
2062	* lazy pointer to initially point to a helper function which
2063	* pushes the offset into the lazy_bind area for the symbol
2064	* needing to be bound, then jumps to dyld which simply adds
2065	* the offset to lazy_bind_off to get the information on what
2066	* to bind.
2067	*/
2068	/// file offset to lazy binding info
2069	pub lazy_bind_off: U32<E>,
2070	/// size of lazy binding infs
2071	pub lazy_bind_size: U32<E>,
2072
2073	/*
2074	* The symbols exported by a dylib are encoded in a trie. This
2075	* is a compact representation that factors out common prefixes.
2076	* It also reduces LINKEDIT pages in RAM because it encodes all
2077	* information (name, address, flags) in one small, contiguous range.
2078	* The export area is a stream of nodes. The first node sequentially
2079	* is the start node for the trie.
2080	*
2081	* Nodes for a symbol start with a uleb128 that is the length of
2082	* the exported symbol information for the string so far.
2083	* If there is no exported symbol, the node starts with a zero byte.
2084	* If there is exported info, it follows the length.
2085	*
2086	* First is a uleb128 containing flags. Normally, it is followed by
2087	* a uleb128 encoded offset which is location of the content named
2088	* by the symbol from the mach_header for the image. If the flags
2089	* is EXPORT_SYMBOL_FLAGS_REEXPORT, then following the flags is
2090	* a uleb128 encoded library ordinal, then a zero terminated
2091	* UTF8 string. If the string is zero length, then the symbol
2092	* is re-export from the specified dylib with the same name.
2093	* If the flags is EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER, then following
2094	* the flags is two uleb128s: the stub offset and the resolver offset.
2095	* The stub is used by non-lazy pointers. The resolver is used
2096	* by lazy pointers and must be called to get the actual address to use.
2097	*
2098	* After the optional exported symbol information is a byte of
2099	* how many edges (0-255) that this node has leaving it,
2100	* followed by each edge.
2101	* Each edge is a zero terminated UTF8 of the addition chars
2102	* in the symbol, followed by a uleb128 offset for the node that
2103	* edge points to.
2104	*
2105	*/
2106	/// file offset to lazy binding info
2107	pub export_off: U32<E>,
2108	/// size of lazy binding infs
2109	pub export_size: U32<E>,
2110	}
2111
2112	/*
2113	* The following are used to encode rebasing information
2114	*/
2115	pub const REBASE_TYPE_POINTER: u8 = `1`;
2116	pub const REBASE_TYPE_TEXT_ABSOLUTE32: u8 = `2`;
2117	pub const REBASE_TYPE_TEXT_PCREL32: u8 = `3`;
2118
2119	pub const REBASE_OPCODE_MASK: u8 = `0xF0`;
2120	pub const REBASE_IMMEDIATE_MASK: u8 = `0x0F`;
2121	pub const REBASE_OPCODE_DONE: u8 = `0x00`;
2122	pub const REBASE_OPCODE_SET_TYPE_IMM: u8 = `0x10`;
2123	pub const REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: u8 = `0x20`;
2124	pub const REBASE_OPCODE_ADD_ADDR_ULEB: u8 = `0x30`;
2125	pub const REBASE_OPCODE_ADD_ADDR_IMM_SCALED: u8 = `0x40`;
2126	pub const REBASE_OPCODE_DO_REBASE_IMM_TIMES: u8 = `0x50`;
2127	pub const REBASE_OPCODE_DO_REBASE_ULEB_TIMES: u8 = `0x60`;
2128	pub const REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB: u8 = `0x70`;
2129	pub const REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB: u8 = `0x80`;
2130
2131	/*
2132	* The following are used to encode binding information
2133	*/
2134	pub const BIND_TYPE_POINTER: u8 = `1`;
2135	pub const BIND_TYPE_TEXT_ABSOLUTE32: u8 = `2`;
2136	pub const BIND_TYPE_TEXT_PCREL32: u8 = `3`;
2137
2138	pub const BIND_SPECIAL_DYLIB_SELF: i8 = `0`;
2139	pub const BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE: i8 = `-1`;
2140	pub const BIND_SPECIAL_DYLIB_FLAT_LOOKUP: i8 = `-2`;
2141	pub const BIND_SPECIAL_DYLIB_WEAK_LOOKUP: i8 = `-3`;
2142
2143	pub const BIND_SYMBOL_FLAGS_WEAK_IMPORT: u8 = `0x1`;
2144	pub const BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION: u8 = `0x8`;
2145
2146	pub const BIND_OPCODE_MASK: u8 = `0xF0`;
2147	pub const BIND_IMMEDIATE_MASK: u8 = `0x0F`;
2148	pub const BIND_OPCODE_DONE: u8 = `0x00`;
2149	pub const BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: u8 = `0x10`;
2150	pub const BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: u8 = `0x20`;
2151	pub const BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: u8 = `0x30`;
2152	pub const BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: u8 = `0x40`;
2153	pub const BIND_OPCODE_SET_TYPE_IMM: u8 = `0x50`;
2154	pub const BIND_OPCODE_SET_ADDEND_SLEB: u8 = `0x60`;
2155	pub const BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: u8 = `0x70`;
2156	pub const BIND_OPCODE_ADD_ADDR_ULEB: u8 = `0x80`;
2157	pub const BIND_OPCODE_DO_BIND: u8 = `0x90`;
2158	pub const BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: u8 = `0xA0`;
2159	pub const BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: u8 = `0xB0`;
2160	pub const BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: u8 = `0xC0`;
2161	pub const BIND_OPCODE_THREADED: u8 = `0xD0`;
2162	pub const BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB: u8 = `0x00`;
2163	pub const BIND_SUBOPCODE_THREADED_APPLY: u8 = `0x01`;
2164
2165	/*
2166	* The following are used on the flags byte of a terminal node
2167	* in the export information.
2168	*/
2169	pub const EXPORT_SYMBOL_FLAGS_KIND_MASK: u32 = `0x03`;
2170	pub const EXPORT_SYMBOL_FLAGS_KIND_REGULAR: u32 = `0x00`;
2171	pub const EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL: u32 = `0x01`;
2172	pub const EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE: u32 = `0x02`;
2173	pub const EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION: u32 = `0x04`;
2174	pub const EXPORT_SYMBOL_FLAGS_REEXPORT: u32 = `0x08`;
2175	pub const EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER: u32 = `0x10`;
2176
2177	/*
2178	* The LinkerOptionCommand contains linker options embedded in object files.
2179	*/
2180	#[derive(Debug, Clone, Copy)]
2181	#[repr(C)]
2182	pub struct LinkerOptionCommand<E: Endian> {
2183	/// LC_LINKER_OPTION only used in MH_OBJECT filetypes
2184	pub cmd: U32<E>,
2185	pub cmdsize: U32<E>,
2186	/// number of strings
2187	pub count: U32<E>,
2188	/ concatenation of zero terminated UTF8 strings.*
2189	Zero filled at end to align /*
2190	}
2191
2192	/*
2193	* The SymsegCommand contains the offset and size of the GNU style
2194	* symbol table information as described in the header file <symseg.h>.
2195	* The symbol roots of the symbol segments must also be aligned properly
2196	* in the file. So the requirement of keeping the offsets aligned to a
2197	* multiple of a 4 bytes translates to the length field of the symbol
2198	* roots also being a multiple of a long. Also the padding must again be
2199	* zeroed. (THIS IS OBSOLETE and no longer supported).
2200	*/
2201	#[derive(Debug, Clone, Copy)]
2202	#[repr(C)]
2203	pub struct SymsegCommand<E: Endian> {
2204	/// LC_SYMSEG
2205	pub cmd: U32<E>,
2206	/// sizeof(struct SymsegCommand)
2207	pub cmdsize: U32<E>,
2208	/// symbol segment offset
2209	pub offset: U32<E>,
2210	/// symbol segment size in bytes
2211	pub size: U32<E>,
2212	}
2213
2214	/*
2215	* The IdentCommand contains a free format string table following the
2216	* IdentCommand structure. The strings are null terminated and the size of
2217	* the command is padded out with zero bytes to a multiple of 4 bytes/
2218	* (THIS IS OBSOLETE and no longer supported).
2219	*/
2220	#[derive(Debug, Clone, Copy)]
2221	#[repr(C)]
2222	pub struct IdentCommand<E: Endian> {
2223	/// LC_IDENT
2224	pub cmd: U32<E>,
2225	/// strings that follow this command
2226	pub cmdsize: U32<E>,
2227	}
2228
2229	/*
2230	* The FvmfileCommand contains a reference to a file to be loaded at the
2231	* specified virtual address. (Presently, this command is reserved for
2232	* internal use. The kernel ignores this command when loading a program into
2233	* memory).
2234	*/
2235	#[derive(Debug, Clone, Copy)]
2236	#[repr(C)]
2237	pub struct FvmfileCommand<E: Endian> {
2238	/// LC_FVMFILE
2239	pub cmd: U32<E>,
2240	/// includes pathname string
2241	pub cmdsize: U32<E>,
2242	/// files pathname
2243	pub name: LcStr<E>,
2244	/// files virtual address
2245	pub header_addr: U32<E>,
2246	}
2247
2248	/*
2249	* The EntryPointCommand is a replacement for thread_command.
2250	* It is used for main executables to specify the location (file offset)
2251	* of main(). If -stack_size was used at link time, the stacksize
2252	* field will contain the stack size need for the main thread.
2253	*/
2254	#[derive(Debug, Clone, Copy)]
2255	#[repr(C)]
2256	pub struct EntryPointCommand<E: Endian> {
2257	/// LC_MAIN only used in MH_EXECUTE filetypes
2258	pub cmd: U32<E>,
2259	/// 24
2260	pub cmdsize: U32<E>,
2261	/// file (__TEXT) offset of main()
2262	pub entryoff: U64<E>,
2263	/// if not zero, initial stack size
2264	pub stacksize: U64<E>,
2265	}
2266
2267	/*
2268	* The SourceVersionCommand is an optional load command containing
2269	* the version of the sources used to build the binary.
2270	*/
2271	#[derive(Debug, Clone, Copy)]
2272	#[repr(C)]
2273	pub struct SourceVersionCommand<E: Endian> {
2274	/// LC_SOURCE_VERSION
2275	pub cmd: U32<E>,
2276	/// 16
2277	pub cmdsize: U32<E>,
2278	/// A.B.C.D.E packed as a24.b10.c10.d10.e10
2279	pub version: U64<E>,
2280	}
2281
2282	/*
2283	* The LC_DATA_IN_CODE load commands uses a LinkeditDataCommand
2284	* to point to an array of DataInCodeEntry entries. Each entry
2285	* describes a range of data in a code section.
2286	*/
2287	#[derive(Debug, Clone, Copy)]
2288	#[repr(C)]
2289	pub struct DataInCodeEntry<E: Endian> {
2290	/// from mach_header to start of data range
2291	pub offset: U32<E>,
2292	/// number of bytes in data range
2293	pub length: U16<E>,
2294	/// a DICE_KIND_ value*
2295	pub kind: U16<E>,
2296	}
2297	pub const DICE_KIND_DATA: u32 = `0x0001`;
2298	pub const DICE_KIND_JUMP_TABLE8: u32 = `0x0002`;
2299	pub const DICE_KIND_JUMP_TABLE16: u32 = `0x0003`;
2300	pub const DICE_KIND_JUMP_TABLE32: u32 = `0x0004`;
2301	pub const DICE_KIND_ABS_JUMP_TABLE32: u32 = `0x0005`;
2302
2303	/*
2304	* Sections of type S_THREAD_LOCAL_VARIABLES contain an array
2305	* of TlvDescriptor structures.
2306	*/
2307	/ TODO:*
2308	#[derive(Debug, Clone, Copy)]
2309	#[repr(C)]
2310	pub struct TlvDescriptor<E: Endian>
2311	{
2312	void (thunk)(struct TlvDescriptor);*
2313	unsigned long key;
2314	unsigned long offset;
2315	}
2316	*/
2317
2318	/*
2319	* LC_NOTE commands describe a region of arbitrary data included in a Mach-O
2320	* file. Its initial use is to record extra data in MH_CORE files.
2321	*/
2322	#[derive(Debug, Clone, Copy)]
2323	#[repr(C)]
2324	pub struct NoteCommand<E: Endian> {
2325	/// LC_NOTE
2326	pub cmd: U32<E>,
2327	/// sizeof(struct NoteCommand)
2328	pub cmdsize: U32<E>,
2329	/// owner name for this LC_NOTE
2330	pub data_owner: [u8; `16`],
2331	/// file offset of this data
2332	pub offset: U64<E>,
2333	/// length of data region
2334	pub size: U64<E>,
2335	}
2336
2337	// Definitions from "/usr/include/mach-o/nlist.h".
2338
2339	#[derive(Debug, Clone, Copy)]
2340	#[repr(C)]
2341	pub struct Nlist32<E: Endian> {
2342	/// index into the string table
2343	pub n_strx: U32<E>,
2344	/// type flag, see below
2345	pub n_type: u8,
2346	/// section number or NO_SECT
2347	pub n_sect: u8,
2348	/// see <mach-o/stab.h>
2349	pub n_desc: U16<E>,
2350	/// value of this symbol (or stab offset)
2351	pub n_value: U32<E>,
2352	}
2353
2354	/*
2355	* This is the symbol table entry structure for 64-bit architectures.
2356	*/
2357	#[derive(Debug, Clone, Copy)]
2358	#[repr(C)]
2359	pub struct Nlist64<E: Endian> {
2360	/// index into the string table
2361	pub n_strx: U32<E>,
2362	/// type flag, see below
2363	pub n_type: u8,
2364	/// section number or NO_SECT
2365	pub n_sect: u8,
2366	/// see <mach-o/stab.h>
2367	pub n_desc: U16<E>,
2368	/// value of this symbol (or stab offset)
2369	// Note: 4 byte alignment has been observed in practice.
2370	pub n_value: U64Bytes<E>,
2371	}
2372
2373	/*
2374	* Symbols with a index into the string table of zero (n_un.n_strx == 0) are
2375	* defined to have a null, "", name. Therefore all string indexes to non null
2376	* names must not have a zero string index. This is bit historical information
2377	* that has never been well documented.
2378	*/
2379
2380	/*
2381	* The n_type field really contains four fields:
2382	* unsigned char N_STAB:3,
2383	* N_PEXT:1,
2384	* N_TYPE:3,
2385	* N_EXT:1;
2386	* which are used via the following masks.
2387	*/
2388	/// if any of these bits set, a symbolic debugging entry
2389	pub const N_STAB: u8 = `0xe0`;
2390	/// private external symbol bit
2391	pub const N_PEXT: u8 = `0x10`;
2392	/// mask for the type bits
2393	pub const N_TYPE: u8 = `0x0e`;
2394	/// external symbol bit, set for external symbols
2395	pub const N_EXT: u8 = `0x01`;
2396
2397	/*
2398	* Only symbolic debugging entries have some of the N_STAB bits set and if any
2399	* of these bits are set then it is a symbolic debugging entry (a stab). In
2400	* which case then the values of the n_type field (the entire field) are given
2401	* in <mach-o/stab.h>
2402	*/
2403
2404	/*
2405	* Values for N_TYPE bits of the n_type field.
2406	*/
2407	/// undefined, n_sect == NO_SECT
2408	pub const N_UNDF: u8 = `0x0`;
2409	/// absolute, n_sect == NO_SECT
2410	pub const N_ABS: u8 = `0x2`;
2411	/// defined in section number n_sect
2412	pub const N_SECT: u8 = `0xe`;
2413	/// prebound undefined (defined in a dylib)
2414	pub const N_PBUD: u8 = `0xc`;
2415	/// indirect
2416	pub const N_INDR: u8 = `0xa`;
2417
2418	/*
2419	* If the type is N_INDR then the symbol is defined to be the same as another
2420	* symbol. In this case the n_value field is an index into the string table
2421	* of the other symbol's name. When the other symbol is defined then they both
2422	* take on the defined type and value.
2423	*/
2424
2425	/*
2426	* If the type is N_SECT then the n_sect field contains an ordinal of the
2427	* section the symbol is defined in. The sections are numbered from 1 and
2428	* refer to sections in order they appear in the load commands for the file
2429	* they are in. This means the same ordinal may very well refer to different
2430	* sections in different files.
2431	*
2432	* The n_value field for all symbol table entries (including N_STAB's) gets
2433	* updated by the link editor based on the value of it's n_sect field and where
2434	* the section n_sect references gets relocated. If the value of the n_sect
2435	* field is NO_SECT then it's n_value field is not changed by the link editor.
2436	*/
2437	/// symbol is not in any section
2438	pub const NO_SECT: u8 = `0`;
2439	/// 1 thru 255 inclusive
2440	pub const MAX_SECT: u8 = `255`;
2441
2442	/*
2443	* Common symbols are represented by undefined (N_UNDF) external (N_EXT) types
2444	* who's values (n_value) are non-zero. In which case the value of the n_value
2445	* field is the size (in bytes) of the common symbol. The n_sect field is set
2446	* to NO_SECT. The alignment of a common symbol may be set as a power of 2
2447	* between 2^1 and 2^15 as part of the n_desc field using the macros below. If
2448	* the alignment is not set (a value of zero) then natural alignment based on
2449	* the size is used.
2450	*/
2451	/ TODO:*
2452	#define GET_COMM_ALIGN(n_desc) (((n_desc) >> 8) & 0x0f)
2453	#define SET_COMM_ALIGN(n_desc,align) \
2454	(n_desc) = (((n_desc) & 0xf0ff) \| (((align) & 0x0f) << 8))
2455	*/
2456
2457	/*
2458	* To support the lazy binding of undefined symbols in the dynamic link-editor,
2459	* the undefined symbols in the symbol table (the nlist structures) are marked
2460	* with the indication if the undefined reference is a lazy reference or
2461	* non-lazy reference. If both a non-lazy reference and a lazy reference is
2462	* made to the same symbol the non-lazy reference takes precedence. A reference
2463	* is lazy only when all references to that symbol are made through a symbol
2464	* pointer in a lazy symbol pointer section.
2465	*
2466	* The implementation of marking nlist structures in the symbol table for
2467	* undefined symbols will be to use some of the bits of the n_desc field as a
2468	* reference type. The mask REFERENCE_TYPE will be applied to the n_desc field
2469	* of an nlist structure for an undefined symbol to determine the type of
2470	* undefined reference (lazy or non-lazy).
2471	*
2472	* The constants for the REFERENCE FLAGS are propagated to the reference table
2473	* in a shared library file. In that case the constant for a defined symbol,
2474	* REFERENCE_FLAG_DEFINED, is also used.
2475	*/
2476	/ Reference type bits of the n_desc field of undefined symbols /
2477	pub const REFERENCE_TYPE: u16 = `0x7`;
2478	/ types of references /
2479	pub const REFERENCE_FLAG_UNDEFINED_NON_LAZY: u16 = `0`;
2480	pub const REFERENCE_FLAG_UNDEFINED_LAZY: u16 = `1`;
2481	pub const REFERENCE_FLAG_DEFINED: u16 = `2`;
2482	pub const REFERENCE_FLAG_PRIVATE_DEFINED: u16 = `3`;
2483	pub const REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY: u16 = `4`;
2484	pub const REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY: u16 = `5`;
2485
2486	/*
2487	* To simplify stripping of objects that use are used with the dynamic link
2488	* editor, the static link editor marks the symbols defined an object that are
2489	* referenced by a dynamically bound object (dynamic shared libraries, bundles).
2490	* With this marking strip knows not to strip these symbols.
2491	*/
2492	pub const REFERENCED_DYNAMICALLY: u16 = `0x0010`;
2493
2494	/*
2495	* For images created by the static link editor with the -twolevel_namespace
2496	* option in effect the flags field of the mach header is marked with
2497	* MH_TWOLEVEL. And the binding of the undefined references of the image are
2498	* determined by the static link editor. Which library an undefined symbol is
2499	* bound to is recorded by the static linker in the high 8 bits of the n_desc
2500	* field using the SET_LIBRARY_ORDINAL macro below. The ordinal recorded
2501	* references the libraries listed in the Mach-O's LC_LOAD_DYLIB,
2502	* LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_LOAD_UPWARD_DYLIB, and
2503	* LC_LAZY_LOAD_DYLIB, etc. load commands in the order they appear in the
2504	* headers. The library ordinals start from 1.
2505	* For a dynamic library that is built as a two-level namespace image the
2506	* undefined references from module defined in another use the same nlist struct
2507	* an in that case SELF_LIBRARY_ORDINAL is used as the library ordinal. For
2508	* defined symbols in all images they also must have the library ordinal set to
2509	* SELF_LIBRARY_ORDINAL. The EXECUTABLE_ORDINAL refers to the executable
2510	* image for references from plugins that refer to the executable that loads
2511	* them.
2512	*
2513	* The DYNAMIC_LOOKUP_ORDINAL is for undefined symbols in a two-level namespace
2514	* image that are looked up by the dynamic linker with flat namespace semantics.
2515	* This ordinal was added as a feature in Mac OS X 10.3 by reducing the
2516	* value of MAX_LIBRARY_ORDINAL by one. So it is legal for existing binaries
2517	* or binaries built with older tools to have 0xfe (254) dynamic libraries. In
2518	* this case the ordinal value 0xfe (254) must be treated as a library ordinal
2519	* for compatibility.
2520	*/
2521	/ TODO:*
2522	#define GET_LIBRARY_ORDINAL(n_desc) (((n_desc) >> 8) & 0xff)
2523	#define SET_LIBRARY_ORDINAL(n_desc,ordinal) \
2524	(n_desc) = (((n_desc) & 0x00ff) \| (((ordinal) & 0xff) << 8))
2525	*/
2526	pub const SELF_LIBRARY_ORDINAL: u8 = `0x0`;
2527	pub const MAX_LIBRARY_ORDINAL: u8 = `0xfd`;
2528	pub const DYNAMIC_LOOKUP_ORDINAL: u8 = `0xfe`;
2529	pub const EXECUTABLE_ORDINAL: u8 = `0xff`;
2530
2531	/*
2532	* The bit 0x0020 of the n_desc field is used for two non-overlapping purposes
2533	* and has two different symbolic names, N_NO_DEAD_STRIP and N_DESC_DISCARDED.
2534	*/
2535
2536	/*
2537	* The N_NO_DEAD_STRIP bit of the n_desc field only ever appears in a
2538	* relocatable .o file (MH_OBJECT filetype). And is used to indicate to the
2539	* static link editor it is never to dead strip the symbol.
2540	*/
2541	/// symbol is not to be dead stripped
2542	pub const N_NO_DEAD_STRIP: u16 = `0x0020`;
2543
2544	/*
2545	* The N_DESC_DISCARDED bit of the n_desc field never appears in linked image.
2546	* But is used in very rare cases by the dynamic link editor to mark an in
2547	* memory symbol as discared and longer used for linking.
2548	*/
2549	/// symbol is discarded
2550	pub const N_DESC_DISCARDED: u16 = `0x0020`;
2551
2552	/*
2553	* The N_WEAK_REF bit of the n_desc field indicates to the dynamic linker that
2554	* the undefined symbol is allowed to be missing and is to have the address of
2555	* zero when missing.
2556	*/
2557	/// symbol is weak referenced
2558	pub const N_WEAK_REF: u16 = `0x0040`;
2559
2560	/*
2561	* The N_WEAK_DEF bit of the n_desc field indicates to the static and dynamic
2562	* linkers that the symbol definition is weak, allowing a non-weak symbol to
2563	* also be used which causes the weak definition to be discared. Currently this
2564	* is only supported for symbols in coalesced sections.
2565	*/
2566	/// coalesced symbol is a weak definition
2567	pub const N_WEAK_DEF: u16 = `0x0080`;
2568
2569	/*
2570	* The N_REF_TO_WEAK bit of the n_desc field indicates to the dynamic linker
2571	* that the undefined symbol should be resolved using flat namespace searching.
2572	*/
2573	/// reference to a weak symbol
2574	pub const N_REF_TO_WEAK: u16 = `0x0080`;
2575
2576	/*
2577	* The N_ARM_THUMB_DEF bit of the n_desc field indicates that the symbol is
2578	* a definition of a Thumb function.
2579	*/
2580	/// symbol is a Thumb function (ARM)
2581	pub const N_ARM_THUMB_DEF: u16 = `0x0008`;
2582
2583	/*
2584	* The N_SYMBOL_RESOLVER bit of the n_desc field indicates that the
2585	* that the function is actually a resolver function and should
2586	* be called to get the address of the real function to use.
2587	* This bit is only available in .o files (MH_OBJECT filetype)
2588	*/
2589	pub const N_SYMBOL_RESOLVER: u16 = `0x0100`;
2590
2591	/*
2592	* The N_ALT_ENTRY bit of the n_desc field indicates that the
2593	* symbol is pinned to the previous content.
2594	*/
2595	pub const N_ALT_ENTRY: u16 = `0x0200`;
2596
2597	// Definitions from "/usr/include/mach-o/stab.h".
2598
2599	/*
2600	* This file gives definitions supplementing <nlist.h> for permanent symbol
2601	* table entries of Mach-O files. Modified from the BSD definitions. The
2602	* modifications from the original definitions were changing what the values of
2603	* what was the n_other field (an unused field) which is now the n_sect field.
2604	* These modifications are required to support symbols in an arbitrary number of
2605	* sections not just the three sections (text, data and bss) in a BSD file.
2606	* The values of the defined constants have NOT been changed.
2607	*
2608	* These must have one of the N_STAB bits on. The n_value fields are subject
2609	* to relocation according to the value of their n_sect field. So for types
2610	* that refer to things in sections the n_sect field must be filled in with the
2611	* proper section ordinal. For types that are not to have their n_value field
2612	* relocatated the n_sect field must be NO_SECT.
2613	*/
2614
2615	/*
2616	* Symbolic debugger symbols. The comments give the conventional use for
2617	*
2618	* .stabs "n_name", n_type, n_sect, n_desc, n_value
2619	*
2620	* where n_type is the defined constant and not listed in the comment. Other
2621	* fields not listed are zero. n_sect is the section ordinal the entry is
2622	* referring to.
2623	*/
2624	/// global symbol: name,,NO_SECT,type,0
2625	pub const N_GSYM: u8 = `0x20`;
2626	/// procedure name (f77 kludge): name,,NO_SECT,0,0
2627	pub const N_FNAME: u8 = `0x22`;
2628	/// procedure: name,,n_sect,linenumber,address
2629	pub const N_FUN: u8 = `0x24`;
2630	/// static symbol: name,,n_sect,type,address
2631	pub const N_STSYM: u8 = `0x26`;
2632	/// .lcomm symbol: name,,n_sect,type,address
2633	pub const N_LCSYM: u8 = `0x28`;
2634	/// begin nsect sym: 0,,n_sect,0,address
2635	pub const N_BNSYM: u8 = `0x2e`;
2636	/// AST file path: name,,NO_SECT,0,0
2637	pub const N_AST: u8 = `0x32`;
2638	/// emitted with gcc2_compiled and in gcc source
2639	pub const N_OPT: u8 = `0x3c`;
2640	/// register sym: name,,NO_SECT,type,register
2641	pub const N_RSYM: u8 = `0x40`;
2642	/// src line: 0,,n_sect,linenumber,address
2643	pub const N_SLINE: u8 = `0x44`;
2644	/// end nsect sym: 0,,n_sect,0,address
2645	pub const N_ENSYM: u8 = `0x4e`;
2646	/// structure elt: name,,NO_SECT,type,struct_offset
2647	pub const N_SSYM: u8 = `0x60`;
2648	/// source file name: name,,n_sect,0,address
2649	pub const N_SO: u8 = `0x64`;
2650	/// object file name: name,,0,0,st_mtime
2651	pub const N_OSO: u8 = `0x66`;
2652	/// local sym: name,,NO_SECT,type,offset
2653	pub const N_LSYM: u8 = `0x80`;
2654	/// include file beginning: name,,NO_SECT,0,sum
2655	pub const N_BINCL: u8 = `0x82`;
2656	/// #included file name: name,,n_sect,0,address
2657	pub const N_SOL: u8 = `0x84`;
2658	/// compiler parameters: name,,NO_SECT,0,0
2659	pub const N_PARAMS: u8 = `0x86`;
2660	/// compiler version: name,,NO_SECT,0,0
2661	pub const N_VERSION: u8 = `0x88`;
2662	/// compiler -O level: name,,NO_SECT,0,0
2663	pub const N_OLEVEL: u8 = `0x8A`;
2664	/// parameter: name,,NO_SECT,type,offset
2665	pub const N_PSYM: u8 = `0xa0`;
2666	/// include file end: name,,NO_SECT,0,0
2667	pub const N_EINCL: u8 = `0xa2`;
2668	/// alternate entry: name,,n_sect,linenumber,address
2669	pub const N_ENTRY: u8 = `0xa4`;
2670	/// left bracket: 0,,NO_SECT,nesting level,address
2671	pub const N_LBRAC: u8 = `0xc0`;
2672	/// deleted include file: name,,NO_SECT,0,sum
2673	pub const N_EXCL: u8 = `0xc2`;
2674	/// right bracket: 0,,NO_SECT,nesting level,address
2675	pub const N_RBRAC: u8 = `0xe0`;
2676	/// begin common: name,,NO_SECT,0,0
2677	pub const N_BCOMM: u8 = `0xe2`;
2678	/// end common: name,,n_sect,0,0
2679	pub const N_ECOMM: u8 = `0xe4`;
2680	/// end common (local name): 0,,n_sect,0,address
2681	pub const N_ECOML: u8 = `0xe8`;
2682	/// second stab entry with length information
2683	pub const N_LENG: u8 = `0xfe`;
2684
2685	/*
2686	* for the berkeley pascal compiler, pc(1):
2687	*/
2688	/// global pascal symbol: name,,NO_SECT,subtype,line
2689	pub const N_PC: u8 = `0x30`;
2690
2691	// Definitions from "/usr/include/mach-o/reloc.h".
2692
2693	/// A relocation entry.
2694	///
2695	/// Mach-O relocations have plain and scattered variants, with the
2696	/// meaning of the fields depending on the variant.
2697	///
2698	/// This type provides functions for determining whether the relocation
2699	/// is scattered, and for accessing the fields of each variant.
2700	#[derive(Debug, Clone, Copy)]
2701	#[repr(C)]
2702	pub struct Relocation<E: Endian> {
2703	pub r_word0: U32<E>,
2704	pub r_word1: U32<E>,
2705	}
2706
2707	impl<E: Endian> Relocation<E> {
2708	/// Determine whether this is a scattered relocation.
2709	#[inline]
2710	pub fn r_scattered(self, endian: E, cputype: u32) -> bool {
2711	if cputype == CPU_TYPE_X86_64 {
2712	`false`
2713	} else {
2714	self.r_word0.get(endian) & R_SCATTERED != `0`
2715	}
2716	}
2717
2718	/// Return the fields of a plain relocation.
2719	pub fn info(self, endian: E) -> RelocationInfo {
2720	let r_address = self.r_word0.get(endian);
2721	let r_word1 = self.r_word1.get(endian);
2722	if endian.is_little_endian() {
2723	RelocationInfo {
2724	r_address,
2725	r_symbolnum: r_word1 & `0x00ff_ffff`,
2726	r_pcrel: ((r_word1 >> `24`) & `0x1`) != `0`,
2727	r_length: ((r_word1 >> `25`) & `0x3`) as u8,
2728	r_extern: ((r_word1 >> `27`) & `0x1`) != `0`,
2729	r_type: (r_word1 >> `28`) as u8,
2730	}
2731	} else {
2732	RelocationInfo {
2733	r_address,
2734	r_symbolnum: r_word1 >> `8`,
2735	r_pcrel: ((r_word1 >> `7`) & `0x1`) != `0`,
2736	r_length: ((r_word1 >> `5`) & `0x3`) as u8,
2737	r_extern: ((r_word1 >> `4`) & `0x1`) != `0`,
2738	r_type: (r_word1 & `0xf`) as u8,
2739	}
2740	}
2741	}
2742
2743	/// Return the fields of a scattered relocation.
2744	pub fn scattered_info(self, endian: E) -> ScatteredRelocationInfo {
2745	let r_word0 = self.r_word0.get(endian);
2746	let r_value = self.r_word1.get(endian);
2747	ScatteredRelocationInfo {
2748	r_address: r_word0 & `0x00ff_ffff`,
2749	r_type: ((r_word0 >> `24`) & `0xf`) as u8,
2750	r_length: ((r_word0 >> `28`) & `0x3`) as u8,
2751	r_pcrel: ((r_word0 >> `30`) & `0x1`) != `0`,
2752	r_value,
2753	}
2754	}
2755	}
2756
2757	/*
2758	* Format of a relocation entry of a Mach-O file. Modified from the 4.3BSD
2759	* format. The modifications from the original format were changing the value
2760	* of the r_symbolnum field for "local" (r_extern == 0) relocation entries.
2761	* This modification is required to support symbols in an arbitrary number of
2762	* sections not just the three sections (text, data and bss) in a 4.3BSD file.
2763	* Also the last 4 bits have had the r_type tag added to them.
2764	*/
2765
2766	#[derive(Debug, Clone, Copy)]
2767	pub struct RelocationInfo {
2768	/// offset in the section to what is being relocated
2769	pub r_address: u32,
2770	/// symbol index if r_extern == 1 or section ordinal if r_extern == 0
2771	pub r_symbolnum: u32,
2772	/// was relocated pc relative already
2773	pub r_pcrel: bool,
2774	/// 0=byte, 1=word, 2=long, 3=quad
2775	pub r_length: u8,
2776	/// does not include value of sym referenced
2777	pub r_extern: bool,
2778	/// if not 0, machine specific relocation type
2779	pub r_type: u8,
2780	}
2781
2782	impl RelocationInfo {
2783	/// Combine the fields into a `Relocation`.
2784	pub fn relocation<E: Endian>(self, endian: E) -> Relocation<E> {
2785	let r_word0: U32Bytes = U32::new(e:endian, self.r_address);
2786	let r_word1: U32Bytes = U32::new(
2787	e:endian,
2788	n:if endian.is_little_endian() {
2789	self.r_symbolnum & `0x00ff_ffff`
2790	\| u32::from(self.r_pcrel) << `24`
2791	\| u32::from(self.r_length & `0x3`) << `25`
2792	\| u32::from(self.r_extern) << `27`
2793	\| u32::from(self.r_type) << `28`
2794	} else {
2795	self.r_symbolnum >> `8`
2796	\| u32::from(self.r_pcrel) << `7`
2797	\| u32::from(self.r_length & `0x3`) << `5`
2798	\| u32::from(self.r_extern) << `4`
2799	\| u32::from(self.r_type) & `0xf`
2800	},
2801	);
2802	Relocation { r_word0, r_word1 }
2803	}
2804	}
2805
2806	/// absolute relocation type for Mach-O files
2807	pub const R_ABS: u8 = `0`;
2808
2809	/*
2810	* The r_address is not really the address as it's name indicates but an offset.
2811	* In 4.3BSD a.out objects this offset is from the start of the "segment" for
2812	* which relocation entry is for (text or data). For Mach-O object files it is
2813	* also an offset but from the start of the "section" for which the relocation
2814	* entry is for. See comments in <mach-o/loader.h> about the r_address feild
2815	* in images for used with the dynamic linker.
2816	*
2817	* In 4.3BSD a.out objects if r_extern is zero then r_symbolnum is an ordinal
2818	* for the segment the symbol being relocated is in. These ordinals are the
2819	* symbol types N_TEXT, N_DATA, N_BSS or N_ABS. In Mach-O object files these
2820	* ordinals refer to the sections in the object file in the order their section
2821	* structures appear in the headers of the object file they are in. The first
2822	* section has the ordinal 1, the second 2, and so on. This means that the
2823	* same ordinal in two different object files could refer to two different
2824	* sections. And further could have still different ordinals when combined
2825	* by the link-editor. The value R_ABS is used for relocation entries for
2826	* absolute symbols which need no further relocation.
2827	*/
2828
2829	/*
2830	* For RISC machines some of the references are split across two instructions
2831	* and the instruction does not contain the complete value of the reference.
2832	* In these cases a second, or paired relocation entry, follows each of these
2833	* relocation entries, using a PAIR r_type, which contains the other part of the
2834	* reference not contained in the instruction. This other part is stored in the
2835	* pair's r_address field. The exact number of bits of the other part of the
2836	* reference store in the r_address field is dependent on the particular
2837	* relocation type for the particular architecture.
2838	*/
2839
2840	/*
2841	* To make scattered loading by the link editor work correctly "local"
2842	* relocation entries can't be used when the item to be relocated is the value
2843	* of a symbol plus an offset (where the resulting expression is outside the
2844	* block the link editor is moving, a blocks are divided at symbol addresses).
2845	* In this case. where the item is a symbol value plus offset, the link editor
2846	* needs to know more than just the section the symbol was defined. What is
2847	* needed is the actual value of the symbol without the offset so it can do the
2848	* relocation correctly based on where the value of the symbol got relocated to
2849	* not the value of the expression (with the offset added to the symbol value).
2850	* So for the NeXT 2.0 release no "local" relocation entries are ever used when
2851	* there is a non-zero offset added to a symbol. The "external" and "local"
2852	* relocation entries remain unchanged.
2853	*
2854	* The implementation is quite messy given the compatibility with the existing
2855	* relocation entry format. The ASSUMPTION is that a section will never be
2856	* bigger than 2**24 - 1 (0x00ffffff or 16,777,215) bytes. This assumption
2857	* allows the r_address (which is really an offset) to fit in 24 bits and high
2858	* bit of the r_address field in the relocation_info structure to indicate
2859	* it is really a scattered_relocation_info structure. Since these are only
2860	* used in places where "local" relocation entries are used and not where
2861	* "external" relocation entries are used the r_extern field has been removed.
2862	*
2863	* For scattered loading to work on a RISC machine where some of the references
2864	* are split across two instructions the link editor needs to be assured that
2865	* each reference has a unique 32 bit reference (that more than one reference is
2866	* NOT sharing the same high 16 bits for example) so it move each referenced
2867	* item independent of each other. Some compilers guarantees this but the
2868	* compilers don't so scattered loading can be done on those that do guarantee
2869	* this.
2870	*/
2871
2872	/// Bit set in `Relocation::r_word0` for scattered relocations.
2873	pub const R_SCATTERED: u32 = `0x8000_0000`;
2874
2875	#[derive(Debug, Clone, Copy)]
2876	pub struct ScatteredRelocationInfo {
2877	/// offset in the section to what is being relocated
2878	pub r_address: u32,
2879	/// if not 0, machine specific relocation type
2880	pub r_type: u8,
2881	/// 0=byte, 1=word, 2=long, 3=quad
2882	pub r_length: u8,
2883	/// was relocated pc relative already
2884	pub r_pcrel: bool,
2885	/// the value the item to be relocated is referring to (without any offset added)
2886	pub r_value: u32,
2887	}
2888
2889	impl ScatteredRelocationInfo {
2890	/// Combine the fields into a `Relocation`.
2891	pub fn relocation<E: Endian>(self, endian: E) -> Relocation<E> {
2892	let r_word0: U32Bytes = U32::new(
2893	e:endian,
2894	self.r_address & `0x00ff_ffff`
2895	\| u32::from(self.r_type & `0xf`) << `24`
2896	\| u32::from(self.r_length & `0x3`) << `28`
2897	\| u32::from(self.r_pcrel) << `30`
2898	\| R_SCATTERED,
2899	);
2900	let r_word1: U32Bytes = U32::new(e:endian, self.r_value);
2901	Relocation { r_word0, r_word1 }
2902	}
2903	}
2904
2905	/*
2906	* Relocation types used in a generic implementation. Relocation entries for
2907	* normal things use the generic relocation as described above and their r_type
2908	* is GENERIC_RELOC_VANILLA (a value of zero).
2909	*
2910	* Another type of generic relocation, GENERIC_RELOC_SECTDIFF, is to support
2911	* the difference of two symbols defined in different sections. That is the
2912	* expression "symbol1 - symbol2 + constant" is a relocatable expression when
2913	* both symbols are defined in some section. For this type of relocation the
2914	* both relocations entries are scattered relocation entries. The value of
2915	* symbol1 is stored in the first relocation entry's r_value field and the
2916	* value of symbol2 is stored in the pair's r_value field.
2917	*
2918	* A special case for a prebound lazy pointer is needed to beable to set the
2919	* value of the lazy pointer back to its non-prebound state. This is done
2920	* using the GENERIC_RELOC_PB_LA_PTR r_type. This is a scattered relocation
2921	* entry where the r_value feild is the value of the lazy pointer not prebound.
2922	*/
2923	/// generic relocation as described above
2924	pub const GENERIC_RELOC_VANILLA: u8 = `0`;
2925	/// Only follows a GENERIC_RELOC_SECTDIFF
2926	pub const GENERIC_RELOC_PAIR: u8 = `1`;
2927	pub const GENERIC_RELOC_SECTDIFF: u8 = `2`;
2928	/// prebound lazy pointer
2929	pub const GENERIC_RELOC_PB_LA_PTR: u8 = `3`;
2930	pub const GENERIC_RELOC_LOCAL_SECTDIFF: u8 = `4`;
2931	/// thread local variables
2932	pub const GENERIC_RELOC_TLV: u8 = `5`;
2933
2934	// Definitions from "/usr/include/mach-o/arm/reloc.h".
2935
2936	/*
2937	* Relocation types used in the arm implementation. Relocation entries for
2938	* things other than instructions use the same generic relocation as described
2939	* in <mach-o/reloc.h> and their r_type is ARM_RELOC_VANILLA, one of the
2940	* _SECTDIFF or the _PB_LA_PTR types. The rest of the relocation types are
2941	* for instructions. Since they are for instructions the r_address field
2942	* indicates the 32 bit instruction that the relocation is to be performed on.
2943	*/
2944	/// generic relocation as described above
2945	pub const ARM_RELOC_VANILLA: u8 = `0`;
2946	/// the second relocation entry of a pair
2947	pub const ARM_RELOC_PAIR: u8 = `1`;
2948	/// a PAIR follows with subtract symbol value
2949	pub const ARM_RELOC_SECTDIFF: u8 = `2`;
2950	/// like ARM_RELOC_SECTDIFF, but the symbol referenced was local.
2951	pub const ARM_RELOC_LOCAL_SECTDIFF: u8 = `3`;
2952	/// prebound lazy pointer
2953	pub const ARM_RELOC_PB_LA_PTR: u8 = `4`;
2954	/// 24 bit branch displacement (to a word address)
2955	pub const ARM_RELOC_BR24: u8 = `5`;
2956	/// 22 bit branch displacement (to a half-word address)
2957	pub const ARM_THUMB_RELOC_BR22: u8 = `6`;
2958	/// obsolete - a thumb 32-bit branch instruction possibly needing page-spanning branch workaround
2959	pub const ARM_THUMB_32BIT_BRANCH: u8 = `7`;
2960
2961	/*
2962	* For these two r_type relocations they always have a pair following them
2963	* and the r_length bits are used differently. The encoding of the
2964	* r_length is as follows:
2965	* low bit of r_length:
2966	* 0 - :lower16: for movw instructions
2967	* 1 - :upper16: for movt instructions
2968	* high bit of r_length:
2969	* 0 - arm instructions
2970	* 1 - thumb instructions
2971	* the other half of the relocated expression is in the following pair
2972	* relocation entry in the the low 16 bits of r_address field.
2973	*/
2974	pub const ARM_RELOC_HALF: u8 = `8`;
2975	pub const ARM_RELOC_HALF_SECTDIFF: u8 = `9`;
2976
2977	// Definitions from "/usr/include/mach-o/arm64/reloc.h".
2978
2979	/*
2980	* Relocation types used in the arm64 implementation.
2981	*/
2982	/// for pointers
2983	pub const ARM64_RELOC_UNSIGNED: u8 = `0`;
2984	/// must be followed by a ARM64_RELOC_UNSIGNED
2985	pub const ARM64_RELOC_SUBTRACTOR: u8 = `1`;
2986	/// a B/BL instruction with 26-bit displacement
2987	pub const ARM64_RELOC_BRANCH26: u8 = `2`;
2988	/// pc-rel distance to page of target
2989	pub const ARM64_RELOC_PAGE21: u8 = `3`;
2990	/// offset within page, scaled by r_length
2991	pub const ARM64_RELOC_PAGEOFF12: u8 = `4`;
2992	/// pc-rel distance to page of GOT slot
2993	pub const ARM64_RELOC_GOT_LOAD_PAGE21: u8 = `5`;
2994	/// offset within page of GOT slot, scaled by r_length
2995	pub const ARM64_RELOC_GOT_LOAD_PAGEOFF12: u8 = `6`;
2996	/// for pointers to GOT slots
2997	pub const ARM64_RELOC_POINTER_TO_GOT: u8 = `7`;
2998	/// pc-rel distance to page of TLVP slot
2999	pub const ARM64_RELOC_TLVP_LOAD_PAGE21: u8 = `8`;
3000	/// offset within page of TLVP slot, scaled by r_length
3001	pub const ARM64_RELOC_TLVP_LOAD_PAGEOFF12: u8 = `9`;
3002	/// must be followed by PAGE21 or PAGEOFF12
3003	pub const ARM64_RELOC_ADDEND: u8 = `10`;
3004
3005	// An arm64e authenticated pointer.
3006	//
3007	// Represents a pointer to a symbol (like ARM64_RELOC_UNSIGNED).
3008	// Additionally, the resulting pointer is signed. The signature is
3009	// specified in the target location: the addend is restricted to the lower
3010	// 32 bits (instead of the full 64 bits for ARM64_RELOC_UNSIGNED):
3011	//
3012	// \|63\|62\|61-51\|50-49\| 48 \|47 - 32\|31 - 0\|
3013	// \| 1\| 0\| 0 \| key \| addr \| discriminator \| addend \|
3014	//
3015	// The key is one of:
3016	// IA: 00 IB: 01
3017	// DA: 10 DB: 11
3018	//
3019	// The discriminator field is used as extra signature diversification.
3020	//
3021	// The addr field indicates whether the target address should be blended
3022	// into the discriminator.
3023	//
3024	pub const ARM64_RELOC_AUTHENTICATED_POINTER: u8 = `11`;
3025
3026	// Definitions from "/usr/include/mach-o/ppc/reloc.h".
3027
3028	/*
3029	* Relocation types used in the ppc implementation. Relocation entries for
3030	* things other than instructions use the same generic relocation as described
3031	* above and their r_type is RELOC_VANILLA. The rest of the relocation types
3032	* are for instructions. Since they are for instructions the r_address field
3033	* indicates the 32 bit instruction that the relocation is to be performed on.
3034	* The fields r_pcrel and r_length are ignored for non-RELOC_VANILLA r_types
3035	* except for PPC_RELOC_BR14.
3036	*
3037	* For PPC_RELOC_BR14 if the r_length is the unused value 3, then the branch was
3038	* statically predicted setting or clearing the Y-bit based on the sign of the
3039	* displacement or the opcode. If this is the case the static linker must flip
3040	* the value of the Y-bit if the sign of the displacement changes for non-branch
3041	* always conditions.
3042	*/
3043	/// generic relocation as described above
3044	pub const PPC_RELOC_VANILLA: u8 = `0`;
3045	/// the second relocation entry of a pair
3046	pub const PPC_RELOC_PAIR: u8 = `1`;
3047	/// 14 bit branch displacement (to a word address)
3048	pub const PPC_RELOC_BR14: u8 = `2`;
3049	/// 24 bit branch displacement (to a word address)
3050	pub const PPC_RELOC_BR24: u8 = `3`;
3051	/// a PAIR follows with the low half
3052	pub const PPC_RELOC_HI16: u8 = `4`;
3053	/// a PAIR follows with the high half
3054	pub const PPC_RELOC_LO16: u8 = `5`;
3055	/// Same as the RELOC_HI16 except the low 16 bits and the high 16 bits are added together
3056	/// with the low 16 bits sign extended first. This means if bit 15 of the low 16 bits is
3057	/// set the high 16 bits stored in the instruction will be adjusted.
3058	pub const PPC_RELOC_HA16: u8 = `6`;
3059	/// Same as the LO16 except that the low 2 bits are not stored in the instruction and are
3060	/// always zero. This is used in double word load/store instructions.
3061	pub const PPC_RELOC_LO14: u8 = `7`;
3062	/// a PAIR follows with subtract symbol value
3063	pub const PPC_RELOC_SECTDIFF: u8 = `8`;
3064	/// prebound lazy pointer
3065	pub const PPC_RELOC_PB_LA_PTR: u8 = `9`;
3066	/// section difference forms of above. a PAIR
3067	pub const PPC_RELOC_HI16_SECTDIFF: u8 = `10`;
3068	/// follows these with subtract symbol value
3069	pub const PPC_RELOC_LO16_SECTDIFF: u8 = `11`;
3070	pub const PPC_RELOC_HA16_SECTDIFF: u8 = `12`;
3071	pub const PPC_RELOC_JBSR: u8 = `13`;
3072	pub const PPC_RELOC_LO14_SECTDIFF: u8 = `14`;
3073	/// like PPC_RELOC_SECTDIFF, but the symbol referenced was local.
3074	pub const PPC_RELOC_LOCAL_SECTDIFF: u8 = `15`;
3075
3076	// Definitions from "/usr/include/mach-o/x86_64/reloc.h".
3077
3078	/*
3079	* Relocations for x86_64 are a bit different than for other architectures in
3080	* Mach-O: Scattered relocations are not used. Almost all relocations produced
3081	* by the compiler are external relocations. An external relocation has the
3082	* r_extern bit set to 1 and the r_symbolnum field contains the symbol table
3083	* index of the target label.
3084	*
3085	* When the assembler is generating relocations, if the target label is a local
3086	* label (begins with 'L'), then the previous non-local label in the same
3087	* section is used as the target of the external relocation. An addend is used
3088	* with the distance from that non-local label to the target label. Only when
3089	* there is no previous non-local label in the section is an internal
3090	* relocation used.
3091	*
3092	* The addend (i.e. the 4 in _foo+4) is encoded in the instruction (Mach-O does
3093	* not have RELA relocations). For PC-relative relocations, the addend is
3094	* stored directly in the instruction. This is different from other Mach-O
3095	* architectures, which encode the addend minus the current section offset.
3096	*
3097	* The relocation types are:
3098	*
3099	* X86_64_RELOC_UNSIGNED // for absolute addresses
3100	* X86_64_RELOC_SIGNED // for signed 32-bit displacement
3101	* X86_64_RELOC_BRANCH // a CALL/JMP instruction with 32-bit displacement
3102	* X86_64_RELOC_GOT_LOAD // a MOVQ load of a GOT entry
3103	* X86_64_RELOC_GOT // other GOT references
3104	* X86_64_RELOC_SUBTRACTOR // must be followed by a X86_64_RELOC_UNSIGNED
3105	*
3106	* The following are sample assembly instructions, followed by the relocation
3107	* and section content they generate in an object file:
3108	*
3109	* call _foo
3110	* r_type=X86_64_RELOC_BRANCH, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3111	* E8 00 00 00 00
3112	*
3113	* call _foo+4
3114	* r_type=X86_64_RELOC_BRANCH, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3115	* E8 04 00 00 00
3116	*
3117	* movq _foo@GOTPCREL(%rip), %rax
3118	* r_type=X86_64_RELOC_GOT_LOAD, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3119	* 48 8B 05 00 00 00 00
3120	*
3121	* pushq _foo@GOTPCREL(%rip)
3122	* r_type=X86_64_RELOC_GOT, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3123	* FF 35 00 00 00 00
3124	*
3125	* movl _foo(%rip), %eax
3126	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3127	* 8B 05 00 00 00 00
3128	*
3129	* movl _foo+4(%rip), %eax
3130	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3131	* 8B 05 04 00 00 00
3132	*
3133	* movb $0x12, _foo(%rip)
3134	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3135	* C6 05 FF FF FF FF 12
3136	*
3137	* movl $0x12345678, _foo(%rip)
3138	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_foo
3139	* C7 05 FC FF FF FF 78 56 34 12
3140	*
3141	* .quad _foo
3142	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3143	* 00 00 00 00 00 00 00 00
3144	*
3145	* .quad _foo+4
3146	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3147	* 04 00 00 00 00 00 00 00
3148	*
3149	* .quad _foo - _bar
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	* 00 00 00 00 00 00 00 00
3153	*
3154	* .quad _foo - _bar + 4
3155	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_bar
3156	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3157	* 04 00 00 00 00 00 00 00
3158	*
3159	* .long _foo - _bar
3160	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=2, r_extern=1, r_pcrel=0, r_symbolnum=_bar
3161	* r_type=X86_64_RELOC_UNSIGNED, r_length=2, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3162	* 00 00 00 00
3163	*
3164	* lea L1(%rip), %rax
3165	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=1, r_pcrel=1, r_symbolnum=_prev
3166	* 48 8d 05 12 00 00 00
3167	* // assumes _prev is the first non-local label 0x12 bytes before L1
3168	*
3169	* lea L0(%rip), %rax
3170	* r_type=X86_64_RELOC_SIGNED, r_length=2, r_extern=0, r_pcrel=1, r_symbolnum=3
3171	* 48 8d 05 56 00 00 00
3172	* // assumes L0 is in third section and there is no previous non-local label.
3173	* // The rip-relative-offset of 0x00000056 is L0-address_of_next_instruction.
3174	* // address_of_next_instruction is the address of the relocation + 4.
3175	*
3176	* add $6,L0(%rip)
3177	* r_type=X86_64_RELOC_SIGNED_1, r_length=2, r_extern=0, r_pcrel=1, r_symbolnum=3
3178	* 83 05 18 00 00 00 06
3179	* // assumes L0 is in third section and there is no previous non-local label.
3180	* // The rip-relative-offset of 0x00000018 is L0-address_of_next_instruction.
3181	* // address_of_next_instruction is the address of the relocation + 4 + 1.
3182	* // The +1 comes from SIGNED_1. This is used because the relocation is not
3183	* // at the end of the instruction.
3184	*
3185	* .quad L1
3186	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_prev
3187	* 12 00 00 00 00 00 00 00
3188	* // assumes _prev is the first non-local label 0x12 bytes before L1
3189	*
3190	* .quad L0
3191	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=0, r_pcrel=0, r_symbolnum=3
3192	* 56 00 00 00 00 00 00 00
3193	* // assumes L0 is in third section, has an address of 0x00000056 in .o
3194	* // file, and there is no previous non-local label
3195	*
3196	* .quad _foo - .
3197	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_prev
3198	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3199	* EE FF FF FF FF FF FF FF
3200	* // assumes _prev is the first non-local label 0x12 bytes before this
3201	* // .quad
3202	*
3203	* .quad _foo - L1
3204	* r_type=X86_64_RELOC_SUBTRACTOR, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_prev
3205	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_extern=1, r_pcrel=0, r_symbolnum=_foo
3206	* EE FF FF FF FF FF FF FF
3207	* // assumes _prev is the first non-local label 0x12 bytes before L1
3208	*
3209	* .quad L1 - _prev
3210	* // No relocations. This is an assembly time constant.
3211	* 12 00 00 00 00 00 00 00
3212	* // assumes _prev is the first non-local label 0x12 bytes before L1
3213	*
3214	*
3215	*
3216	* In final linked images, there are only two valid relocation kinds:
3217	*
3218	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_pcrel=0, r_extern=1, r_symbolnum=sym_index
3219	* This tells dyld to add the address of a symbol to a pointer sized (8-byte)
3220	* piece of data (i.e on disk the 8-byte piece of data contains the addend). The
3221	* r_symbolnum contains the index into the symbol table of the target symbol.
3222	*
3223	* r_type=X86_64_RELOC_UNSIGNED, r_length=3, r_pcrel=0, r_extern=0, r_symbolnum=0
3224	* This tells dyld to adjust the pointer sized (8-byte) piece of data by the amount
3225	* the containing image was loaded from its base address (e.g. slide).
3226	*
3227	*/
3228	/// for absolute addresses
3229	pub const X86_64_RELOC_UNSIGNED: u8 = `0`;
3230	/// for signed 32-bit displacement
3231	pub const X86_64_RELOC_SIGNED: u8 = `1`;
3232	/// a CALL/JMP instruction with 32-bit displacement
3233	pub const X86_64_RELOC_BRANCH: u8 = `2`;
3234	/// a MOVQ load of a GOT entry
3235	pub const X86_64_RELOC_GOT_LOAD: u8 = `3`;
3236	/// other GOT references
3237	pub const X86_64_RELOC_GOT: u8 = `4`;
3238	/// must be followed by a X86_64_RELOC_UNSIGNED
3239	pub const X86_64_RELOC_SUBTRACTOR: u8 = `5`;
3240	/// for signed 32-bit displacement with a -1 addend
3241	pub const X86_64_RELOC_SIGNED_1: u8 = `6`;
3242	/// for signed 32-bit displacement with a -2 addend
3243	pub const X86_64_RELOC_SIGNED_2: u8 = `7`;
3244	/// for signed 32-bit displacement with a -4 addend
3245	pub const X86_64_RELOC_SIGNED_4: u8 = `8`;
3246	/// for thread local variables
3247	pub const X86_64_RELOC_TLV: u8 = `9`;
3248
3249	unsafe_impl_pod!(FatHeader, FatArch32, FatArch64,);
3250	unsafe_impl_endian_pod!(
3251	DyldCacheHeader,
3252	DyldCacheMappingInfo,
3253	DyldCacheImageInfo,
3254	DyldSubCacheInfo,
3255	MachHeader32,
3256	MachHeader64,
3257	LoadCommand,
3258	LcStr,
3259	SegmentCommand32,
3260	SegmentCommand64,
3261	Section32,
3262	Section64,
3263	Fvmlib,
3264	FvmlibCommand,
3265	Dylib,
3266	DylibCommand,
3267	SubFrameworkCommand,
3268	SubClientCommand,
3269	SubUmbrellaCommand,
3270	SubLibraryCommand,
3271	PreboundDylibCommand,
3272	DylinkerCommand,
3273	ThreadCommand,
3274	RoutinesCommand32,
3275	RoutinesCommand64,
3276	SymtabCommand,
3277	DysymtabCommand,
3278	DylibTableOfContents,
3279	DylibModule32,
3280	DylibModule64,
3281	DylibReference,
3282	TwolevelHintsCommand,
3283	TwolevelHint,
3284	PrebindCksumCommand,
3285	UuidCommand,
3286	RpathCommand,
3287	LinkeditDataCommand,
3288	FilesetEntryCommand,
3289	EncryptionInfoCommand32,
3290	EncryptionInfoCommand64,
3291	VersionMinCommand,
3292	BuildVersionCommand,
3293	BuildToolVersion,
3294	DyldInfoCommand,
3295	LinkerOptionCommand,
3296	SymsegCommand,
3297	IdentCommand,
3298	FvmfileCommand,
3299	EntryPointCommand,
3300	SourceVersionCommand,
3301	DataInCodeEntry,
3302	//TlvDescriptor,
3303	NoteCommand,
3304	Nlist32,
3305	Nlist64,
3306	Relocation,
3307	);
3308