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1 //===- MachOFormat.h - Mach-O Format Structures And Constants ---*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file declares various structures and constants which are platform
11 // independent and can be shared by any client which wishes to interact with
12 // Mach object files.
13 //
14 // The definitions here are purposely chosen to match the LLVM style as opposed
15 // to following the platform specific definition of the format.
16 //
17 // On a Mach system, see the <mach-o/...> includes for more information, in
18 // particular <mach-o/loader.h>.
19 //
20 //===----------------------------------------------------------------------===//
21 
22 #ifndef LLVM_OBJECT_MACHOFORMAT_H
23 #define LLVM_OBJECT_MACHOFORMAT_H
24 
25 #include "llvm/Support/DataTypes.h"
26 
27 namespace llvm {
28 namespace object {
29 
30 /// General Mach platform information.
31 namespace mach {
32   /// @name CPU Type and Subtype Information
33   /// {
34 
35   /// \brief Capability bits used in CPU type encoding.
36   enum CPUTypeFlagsMask {
37     CTFM_ArchMask =  0xFF000000,
38     CTFM_ArchABI64 = 0x01000000
39   };
40 
41   /// \brief Machine type IDs used in CPU type encoding.
42   enum CPUTypeMachine {
43     CTM_i386      = 7,
44     CTM_x86_64    = CTM_i386 | CTFM_ArchABI64,
45     CTM_ARM       = 12,
46     CTM_SPARC     = 14,
47     CTM_PowerPC   = 18,
48     CTM_PowerPC64 = CTM_PowerPC | CTFM_ArchABI64
49   };
50 
51   /// \brief Capability bits used in CPU subtype encoding.
52   enum CPUSubtypeFlagsMask {
53     CSFM_SubtypeMask =  0xFF000000,
54     CSFM_SubtypeLib64 = 0x80000000
55   };
56 
57   /// \brief ARM Machine Subtypes.
58   enum CPUSubtypeARM {
59     CSARM_ALL    = 0,
60     CSARM_V4T    = 5,
61     CSARM_V6     = 6,
62     CSARM_V5TEJ  = 7,
63     CSARM_XSCALE = 8,
64     CSARM_V7     = 9,
65     CSARM_V7F    = 10,
66     CSARM_V7S    = 11,
67     CSARM_V7K    = 12,
68     CSARM_V6M    = 14,
69     CSARM_V7M    = 15,
70     CSARM_V7EM   = 16
71   };
72 
73   /// \brief PowerPC Machine Subtypes.
74   enum CPUSubtypePowerPC {
75     CSPPC_ALL = 0
76   };
77 
78   /// \brief SPARC Machine Subtypes.
79   enum CPUSubtypeSPARC {
80     CSSPARC_ALL = 0
81   };
82 
83   /// \brief x86 Machine Subtypes.
84   enum CPUSubtypeX86 {
85     CSX86_ALL = 3
86   };
87 
88   /// @}
89 
90 } // end namespace mach
91 
92 /// Format information for Mach object files.
93 namespace macho {
94   /// \brief Constants for structure sizes.
95   enum StructureSizes {
96     Header32Size = 28,
97     Header64Size = 32,
98     SegmentLoadCommand32Size = 56,
99     SegmentLoadCommand64Size = 72,
100     Section32Size = 68,
101     Section64Size = 80,
102     SymtabLoadCommandSize = 24,
103     DysymtabLoadCommandSize = 80,
104     Nlist32Size = 12,
105     Nlist64Size = 16,
106     RelocationInfoSize = 8,
107     LinkeditLoadCommandSize = 16
108   };
109 
110   /// \brief Constants for header magic field.
111   enum HeaderMagic {
112     HM_Object32 = 0xFEEDFACE,  ///< 32-bit mach object file
113     HM_Object64 = 0xFEEDFACF,  ///< 64-bit mach object file
114     HM_Universal = 0xCAFEBABE  ///< Universal object file
115   };
116 
117   /// \brief Header common to all Mach object files.
118   struct Header {
119     uint32_t Magic;
120     uint32_t CPUType;
121     uint32_t CPUSubtype;
122     uint32_t FileType;
123     uint32_t NumLoadCommands;
124     uint32_t SizeOfLoadCommands;
125     uint32_t Flags;
126   };
127 
128   /// \brief Extended header for 64-bit object files.
129   struct Header64Ext {
130     uint32_t Reserved;
131   };
132 
133   // See <mach-o/loader.h>.
134   enum HeaderFileType {
135     HFT_Object = 0x1
136   };
137 
138   enum HeaderFlags {
139     HF_SubsectionsViaSymbols = 0x2000
140   };
141 
142   enum LoadCommandType {
143     LCT_Segment = 0x1,
144     LCT_Symtab = 0x2,
145     LCT_Dysymtab = 0xb,
146     LCT_Segment64 = 0x19,
147     LCT_UUID = 0x1b,
148     LCT_CodeSignature = 0x1d,
149     LCT_SegmentSplitInfo = 0x1e,
150     LCT_FunctionStarts = 0x26,
151     LCT_DataInCode = 0x29,
152     LCT_LinkerOptions = 0x2D
153   };
154 
155   /// \brief Load command structure.
156   struct LoadCommand {
157     uint32_t Type;
158     uint32_t Size;
159   };
160 
161   /// @name Load Command Structures
162   /// @{
163 
164   struct SegmentLoadCommand {
165     uint32_t Type;
166     uint32_t Size;
167     char Name[16];
168     uint32_t VMAddress;
169     uint32_t VMSize;
170     uint32_t FileOffset;
171     uint32_t FileSize;
172     uint32_t MaxVMProtection;
173     uint32_t InitialVMProtection;
174     uint32_t NumSections;
175     uint32_t Flags;
176   };
177 
178   struct Segment64LoadCommand {
179     uint32_t Type;
180     uint32_t Size;
181     char Name[16];
182     uint64_t VMAddress;
183     uint64_t VMSize;
184     uint64_t FileOffset;
185     uint64_t FileSize;
186     uint32_t MaxVMProtection;
187     uint32_t InitialVMProtection;
188     uint32_t NumSections;
189     uint32_t Flags;
190   };
191 
192   struct SymtabLoadCommand {
193     uint32_t Type;
194     uint32_t Size;
195     uint32_t SymbolTableOffset;
196     uint32_t NumSymbolTableEntries;
197     uint32_t StringTableOffset;
198     uint32_t StringTableSize;
199   };
200 
201   struct DysymtabLoadCommand {
202     uint32_t Type;
203     uint32_t Size;
204 
205     uint32_t LocalSymbolsIndex;
206     uint32_t NumLocalSymbols;
207 
208     uint32_t ExternalSymbolsIndex;
209     uint32_t NumExternalSymbols;
210 
211     uint32_t UndefinedSymbolsIndex;
212     uint32_t NumUndefinedSymbols;
213 
214     uint32_t TOCOffset;
215     uint32_t NumTOCEntries;
216 
217     uint32_t ModuleTableOffset;
218     uint32_t NumModuleTableEntries;
219 
220     uint32_t ReferenceSymbolTableOffset;
221     uint32_t NumReferencedSymbolTableEntries;
222 
223     uint32_t IndirectSymbolTableOffset;
224     uint32_t NumIndirectSymbolTableEntries;
225 
226     uint32_t ExternalRelocationTableOffset;
227     uint32_t NumExternalRelocationTableEntries;
228 
229     uint32_t LocalRelocationTableOffset;
230     uint32_t NumLocalRelocationTableEntries;
231   };
232 
233   struct LinkeditDataLoadCommand {
234     uint32_t Type;
235     uint32_t Size;
236     uint32_t DataOffset;
237     uint32_t DataSize;
238   };
239 
240   struct LinkerOptionsLoadCommand {
241     uint32_t Type;
242     uint32_t Size;
243     uint32_t Count;
244     // Load command is followed by Count number of zero-terminated UTF8 strings,
245     // and then zero-filled to be 4-byte aligned.
246   };
247 
248   /// @}
249   /// @name Section Data
250   /// @{
251 
252   enum SectionFlags {
253     SF_PureInstructions = 0x80000000
254   };
255 
256   struct Section {
257     char Name[16];
258     char SegmentName[16];
259     uint32_t Address;
260     uint32_t Size;
261     uint32_t Offset;
262     uint32_t Align;
263     uint32_t RelocationTableOffset;
264     uint32_t NumRelocationTableEntries;
265     uint32_t Flags;
266     uint32_t Reserved1;
267     uint32_t Reserved2;
268   };
269   struct Section64 {
270     char Name[16];
271     char SegmentName[16];
272     uint64_t Address;
273     uint64_t Size;
274     uint32_t Offset;
275     uint32_t Align;
276     uint32_t RelocationTableOffset;
277     uint32_t NumRelocationTableEntries;
278     uint32_t Flags;
279     uint32_t Reserved1;
280     uint32_t Reserved2;
281     uint32_t Reserved3;
282   };
283 
284   /// @}
285   /// @name Symbol Table Entries
286   /// @{
287 
288   struct SymbolTableEntry {
289     uint32_t StringIndex;
290     uint8_t Type;
291     uint8_t SectionIndex;
292     uint16_t Flags;
293     uint32_t Value;
294   };
295   // Despite containing a uint64_t, this structure is only 4-byte aligned within
296   // a MachO file.
297 #pragma pack(push)
298 #pragma pack(4)
299   struct Symbol64TableEntry {
300     uint32_t StringIndex;
301     uint8_t Type;
302     uint8_t SectionIndex;
303     uint16_t Flags;
304     uint64_t Value;
305   };
306 #pragma pack(pop)
307 
308   /// @}
309   /// @name Data-in-code Table Entry
310   /// @{
311 
312   // See <mach-o/loader.h>.
313   enum DataRegionType { Data = 1, JumpTable8, JumpTable16, JumpTable32 };
314   struct DataInCodeTableEntry {
315     uint32_t Offset;  /* from mach_header to start of data region */
316     uint16_t Length;  /* number of bytes in data region */
317     uint16_t Kind;    /* a DataRegionType value  */
318   };
319 
320   /// @}
321   /// @name Indirect Symbol Table
322   /// @{
323 
324   struct IndirectSymbolTableEntry {
325     uint32_t Index;
326   };
327 
328   /// @}
329   /// @name Relocation Data
330   /// @{
331 
332   struct RelocationEntry {
333     uint32_t Word0;
334     uint32_t Word1;
335   };
336 
337   /// @}
338 
339   // See <mach-o/nlist.h>.
340   enum SymbolTypeType {
341     STT_Undefined = 0x00,
342     STT_Absolute  = 0x02,
343     STT_Section   = 0x0e
344   };
345 
346   enum SymbolTypeFlags {
347     // If any of these bits are set, then the entry is a stab entry number (see
348     // <mach-o/stab.h>. Otherwise the other masks apply.
349     STF_StabsEntryMask = 0xe0,
350 
351     STF_TypeMask       = 0x0e,
352     STF_External       = 0x01,
353     STF_PrivateExtern  = 0x10
354   };
355 
356   /// IndirectSymbolFlags - Flags for encoding special values in the indirect
357   /// symbol entry.
358   enum IndirectSymbolFlags {
359     ISF_Local    = 0x80000000,
360     ISF_Absolute = 0x40000000
361   };
362 
363   /// RelocationFlags - Special flags for addresses.
364   enum RelocationFlags {
365     RF_Scattered = 0x80000000
366   };
367 
368   /// Common relocation info types.
369   enum RelocationInfoType {
370     RIT_Vanilla             = 0,
371     RIT_Pair                = 1,
372     RIT_Difference          = 2
373   };
374 
375   /// Generic relocation info types, which are shared by some (but not all)
376   /// platforms.
377   enum RelocationInfoType_Generic {
378     RIT_Generic_PreboundLazyPointer = 3,
379     RIT_Generic_LocalDifference     = 4,
380     RIT_Generic_TLV                 = 5
381   };
382 
383   /// X86_64 uses its own relocation types.
384   enum RelocationInfoTypeX86_64 {
385     // Note that x86_64 doesn't even share the common relocation types.
386     RIT_X86_64_Unsigned   = 0,
387     RIT_X86_64_Signed     = 1,
388     RIT_X86_64_Branch     = 2,
389     RIT_X86_64_GOTLoad    = 3,
390     RIT_X86_64_GOT        = 4,
391     RIT_X86_64_Subtractor = 5,
392     RIT_X86_64_Signed1    = 6,
393     RIT_X86_64_Signed2    = 7,
394     RIT_X86_64_Signed4    = 8,
395     RIT_X86_64_TLV        = 9
396   };
397 
398   /// ARM uses its own relocation types.
399   enum RelocationInfoTypeARM {
400     RIT_ARM_LocalDifference = 3,
401     RIT_ARM_PreboundLazyPointer = 4,
402     RIT_ARM_Branch24Bit = 5,
403     RIT_ARM_ThumbBranch22Bit = 6,
404     RIT_ARM_ThumbBranch32Bit = 7,
405     RIT_ARM_Half = 8,
406     RIT_ARM_HalfDifference = 9
407 
408   };
409 
410 } // end namespace macho
411 
412 } // end namespace object
413 } // end namespace llvm
414 
415 #endif
416