ELFTypes.h revision d111c7844ec26448764ced627e153f406d730c5f
1//===- ELFTypes.h - Endian specific types for ELF ---------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLVM_OBJECT_ELFTYPES_H
10#define LLVM_OBJECT_ELFTYPES_H
11
12#include "llvm/ADT/ArrayRef.h"
13#include "llvm/ADT/StringRef.h"
14#include "llvm/BinaryFormat/ELF.h"
15#include "llvm/Object/Error.h"
16#include "llvm/Support/Endian.h"
17#include "llvm/Support/Error.h"
18#include <cassert>
19#include <cstdint>
20#include <cstring>
21#include <type_traits>
22
23namespace llvm {
24namespace object {
25
26using support::endianness;
27
28template <class ELFT> struct Elf_Ehdr_Impl;
29template <class ELFT> struct Elf_Shdr_Impl;
30template <class ELFT> struct Elf_Sym_Impl;
31template <class ELFT> struct Elf_Dyn_Impl;
32template <class ELFT> struct Elf_Phdr_Impl;
33template <class ELFT, bool isRela> struct Elf_Rel_Impl;
34template <class ELFT> struct Elf_Verdef_Impl;
35template <class ELFT> struct Elf_Verdaux_Impl;
36template <class ELFT> struct Elf_Verneed_Impl;
37template <class ELFT> struct Elf_Vernaux_Impl;
38template <class ELFT> struct Elf_Versym_Impl;
39template <class ELFT> struct Elf_Hash_Impl;
40template <class ELFT> struct Elf_GnuHash_Impl;
41template <class ELFT> struct Elf_Chdr_Impl;
42template <class ELFT> struct Elf_Nhdr_Impl;
43template <class ELFT> class Elf_Note_Impl;
44template <class ELFT> class Elf_Note_Iterator_Impl;
45template <class ELFT> struct Elf_CGProfile_Impl;
46
47template <endianness E, bool Is64> struct ELFType {
48private:
49  template <typename Ty>
50  using packed = support::detail::packed_endian_specific_integral<Ty, E, 1>;
51
52public:
53  static const endianness TargetEndianness = E;
54  static const bool Is64Bits = Is64;
55
56  using uint = typename std::conditional<Is64, uint64_t, uint32_t>::type;
57  using Ehdr = Elf_Ehdr_Impl<ELFType<E, Is64>>;
58  using Shdr = Elf_Shdr_Impl<ELFType<E, Is64>>;
59  using Sym = Elf_Sym_Impl<ELFType<E, Is64>>;
60  using Dyn = Elf_Dyn_Impl<ELFType<E, Is64>>;
61  using Phdr = Elf_Phdr_Impl<ELFType<E, Is64>>;
62  using Rel = Elf_Rel_Impl<ELFType<E, Is64>, false>;
63  using Rela = Elf_Rel_Impl<ELFType<E, Is64>, true>;
64  using Relr = packed<uint>;
65  using Verdef = Elf_Verdef_Impl<ELFType<E, Is64>>;
66  using Verdaux = Elf_Verdaux_Impl<ELFType<E, Is64>>;
67  using Verneed = Elf_Verneed_Impl<ELFType<E, Is64>>;
68  using Vernaux = Elf_Vernaux_Impl<ELFType<E, Is64>>;
69  using Versym = Elf_Versym_Impl<ELFType<E, Is64>>;
70  using Hash = Elf_Hash_Impl<ELFType<E, Is64>>;
71  using GnuHash = Elf_GnuHash_Impl<ELFType<E, Is64>>;
72  using Chdr = Elf_Chdr_Impl<ELFType<E, Is64>>;
73  using Nhdr = Elf_Nhdr_Impl<ELFType<E, Is64>>;
74  using Note = Elf_Note_Impl<ELFType<E, Is64>>;
75  using NoteIterator = Elf_Note_Iterator_Impl<ELFType<E, Is64>>;
76  using CGProfile = Elf_CGProfile_Impl<ELFType<E, Is64>>;
77  using DynRange = ArrayRef<Dyn>;
78  using ShdrRange = ArrayRef<Shdr>;
79  using SymRange = ArrayRef<Sym>;
80  using RelRange = ArrayRef<Rel>;
81  using RelaRange = ArrayRef<Rela>;
82  using RelrRange = ArrayRef<Relr>;
83  using PhdrRange = ArrayRef<Phdr>;
84
85  using Half = packed<uint16_t>;
86  using Word = packed<uint32_t>;
87  using Sword = packed<int32_t>;
88  using Xword = packed<uint64_t>;
89  using Sxword = packed<int64_t>;
90  using Addr = packed<uint>;
91  using Off = packed<uint>;
92};
93
94using ELF32LE = ELFType<support::little, false>;
95using ELF32BE = ELFType<support::big, false>;
96using ELF64LE = ELFType<support::little, true>;
97using ELF64BE = ELFType<support::big, true>;
98
99// Use an alignment of 2 for the typedefs since that is the worst case for
100// ELF files in archives.
101
102// I really don't like doing this, but the alternative is copypasta.
103#define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)                                       \
104  using Elf_Addr = typename ELFT::Addr;                                        \
105  using Elf_Off = typename ELFT::Off;                                          \
106  using Elf_Half = typename ELFT::Half;                                        \
107  using Elf_Word = typename ELFT::Word;                                        \
108  using Elf_Sword = typename ELFT::Sword;                                      \
109  using Elf_Xword = typename ELFT::Xword;                                      \
110  using Elf_Sxword = typename ELFT::Sxword;
111
112#define LLVM_ELF_COMMA ,
113#define LLVM_ELF_IMPORT_TYPES(E, W)                                            \
114  LLVM_ELF_IMPORT_TYPES_ELFT(ELFType<E LLVM_ELF_COMMA W>)
115
116// Section header.
117template <class ELFT> struct Elf_Shdr_Base;
118
119template <endianness TargetEndianness>
120struct Elf_Shdr_Base<ELFType<TargetEndianness, false>> {
121  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
122  Elf_Word sh_name;      // Section name (index into string table)
123  Elf_Word sh_type;      // Section type (SHT_*)
124  Elf_Word sh_flags;     // Section flags (SHF_*)
125  Elf_Addr sh_addr;      // Address where section is to be loaded
126  Elf_Off sh_offset;     // File offset of section data, in bytes
127  Elf_Word sh_size;      // Size of section, in bytes
128  Elf_Word sh_link;      // Section type-specific header table index link
129  Elf_Word sh_info;      // Section type-specific extra information
130  Elf_Word sh_addralign; // Section address alignment
131  Elf_Word sh_entsize;   // Size of records contained within the section
132};
133
134template <endianness TargetEndianness>
135struct Elf_Shdr_Base<ELFType<TargetEndianness, true>> {
136  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
137  Elf_Word sh_name;       // Section name (index into string table)
138  Elf_Word sh_type;       // Section type (SHT_*)
139  Elf_Xword sh_flags;     // Section flags (SHF_*)
140  Elf_Addr sh_addr;       // Address where section is to be loaded
141  Elf_Off sh_offset;      // File offset of section data, in bytes
142  Elf_Xword sh_size;      // Size of section, in bytes
143  Elf_Word sh_link;       // Section type-specific header table index link
144  Elf_Word sh_info;       // Section type-specific extra information
145  Elf_Xword sh_addralign; // Section address alignment
146  Elf_Xword sh_entsize;   // Size of records contained within the section
147};
148
149template <class ELFT>
150struct Elf_Shdr_Impl : Elf_Shdr_Base<ELFT> {
151  using Elf_Shdr_Base<ELFT>::sh_entsize;
152  using Elf_Shdr_Base<ELFT>::sh_size;
153
154  /// Get the number of entities this section contains if it has any.
155  unsigned getEntityCount() const {
156    if (sh_entsize == 0)
157      return 0;
158    return sh_size / sh_entsize;
159  }
160};
161
162template <class ELFT> struct Elf_Sym_Base;
163
164template <endianness TargetEndianness>
165struct Elf_Sym_Base<ELFType<TargetEndianness, false>> {
166  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
167  Elf_Word st_name;       // Symbol name (index into string table)
168  Elf_Addr st_value;      // Value or address associated with the symbol
169  Elf_Word st_size;       // Size of the symbol
170  unsigned char st_info;  // Symbol's type and binding attributes
171  unsigned char st_other; // Must be zero; reserved
172  Elf_Half st_shndx;      // Which section (header table index) it's defined in
173};
174
175template <endianness TargetEndianness>
176struct Elf_Sym_Base<ELFType<TargetEndianness, true>> {
177  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
178  Elf_Word st_name;       // Symbol name (index into string table)
179  unsigned char st_info;  // Symbol's type and binding attributes
180  unsigned char st_other; // Must be zero; reserved
181  Elf_Half st_shndx;      // Which section (header table index) it's defined in
182  Elf_Addr st_value;      // Value or address associated with the symbol
183  Elf_Xword st_size;      // Size of the symbol
184};
185
186template <class ELFT>
187struct Elf_Sym_Impl : Elf_Sym_Base<ELFT> {
188  using Elf_Sym_Base<ELFT>::st_info;
189  using Elf_Sym_Base<ELFT>::st_shndx;
190  using Elf_Sym_Base<ELFT>::st_other;
191  using Elf_Sym_Base<ELFT>::st_value;
192
193  // These accessors and mutators correspond to the ELF32_ST_BIND,
194  // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification:
195  unsigned char getBinding() const { return st_info >> 4; }
196  unsigned char getType() const { return st_info & 0x0f; }
197  uint64_t getValue() const { return st_value; }
198  void setBinding(unsigned char b) { setBindingAndType(b, getType()); }
199  void setType(unsigned char t) { setBindingAndType(getBinding(), t); }
200
201  void setBindingAndType(unsigned char b, unsigned char t) {
202    st_info = (b << 4) + (t & 0x0f);
203  }
204
205  /// Access to the STV_xxx flag stored in the first two bits of st_other.
206  /// STV_DEFAULT: 0
207  /// STV_INTERNAL: 1
208  /// STV_HIDDEN: 2
209  /// STV_PROTECTED: 3
210  unsigned char getVisibility() const { return st_other & 0x3; }
211  void setVisibility(unsigned char v) {
212    assert(v < 4 && "Invalid value for visibility");
213    st_other = (st_other & ~0x3) | v;
214  }
215
216  bool isAbsolute() const { return st_shndx == ELF::SHN_ABS; }
217
218  bool isCommon() const {
219    return getType() == ELF::STT_COMMON || st_shndx == ELF::SHN_COMMON;
220  }
221
222  bool isDefined() const { return !isUndefined(); }
223
224  bool isProcessorSpecific() const {
225    return st_shndx >= ELF::SHN_LOPROC && st_shndx <= ELF::SHN_HIPROC;
226  }
227
228  bool isOSSpecific() const {
229    return st_shndx >= ELF::SHN_LOOS && st_shndx <= ELF::SHN_HIOS;
230  }
231
232  bool isReserved() const {
233    // ELF::SHN_HIRESERVE is 0xffff so st_shndx <= ELF::SHN_HIRESERVE is always
234    // true and some compilers warn about it.
235    return st_shndx >= ELF::SHN_LORESERVE;
236  }
237
238  bool isUndefined() const { return st_shndx == ELF::SHN_UNDEF; }
239
240  bool isExternal() const {
241    return getBinding() != ELF::STB_LOCAL;
242  }
243
244  Expected<StringRef> getName(StringRef StrTab) const;
245};
246
247template <class ELFT>
248Expected<StringRef> Elf_Sym_Impl<ELFT>::getName(StringRef StrTab) const {
249  uint32_t Offset = this->st_name;
250  if (Offset >= StrTab.size())
251    return errorCodeToError(object_error::parse_failed);
252  return StringRef(StrTab.data() + Offset);
253}
254
255/// Elf_Versym: This is the structure of entries in the SHT_GNU_versym section
256/// (.gnu.version). This structure is identical for ELF32 and ELF64.
257template <class ELFT>
258struct Elf_Versym_Impl {
259  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
260  Elf_Half vs_index; // Version index with flags (e.g. VERSYM_HIDDEN)
261};
262
263/// Elf_Verdef: This is the structure of entries in the SHT_GNU_verdef section
264/// (.gnu.version_d). This structure is identical for ELF32 and ELF64.
265template <class ELFT>
266struct Elf_Verdef_Impl {
267  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
268  using Elf_Verdaux = Elf_Verdaux_Impl<ELFT>;
269  Elf_Half vd_version; // Version of this structure (e.g. VER_DEF_CURRENT)
270  Elf_Half vd_flags;   // Bitwise flags (VER_DEF_*)
271  Elf_Half vd_ndx;     // Version index, used in .gnu.version entries
272  Elf_Half vd_cnt;     // Number of Verdaux entries
273  Elf_Word vd_hash;    // Hash of name
274  Elf_Word vd_aux;     // Offset to the first Verdaux entry (in bytes)
275  Elf_Word vd_next;    // Offset to the next Verdef entry (in bytes)
276
277  /// Get the first Verdaux entry for this Verdef.
278  const Elf_Verdaux *getAux() const {
279    return reinterpret_cast<const Elf_Verdaux *>((const char *)this + vd_aux);
280  }
281};
282
283/// Elf_Verdaux: This is the structure of auxiliary data in the SHT_GNU_verdef
284/// section (.gnu.version_d). This structure is identical for ELF32 and ELF64.
285template <class ELFT>
286struct Elf_Verdaux_Impl {
287  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
288  Elf_Word vda_name; // Version name (offset in string table)
289  Elf_Word vda_next; // Offset to next Verdaux entry (in bytes)
290};
291
292/// Elf_Verneed: This is the structure of entries in the SHT_GNU_verneed
293/// section (.gnu.version_r). This structure is identical for ELF32 and ELF64.
294template <class ELFT>
295struct Elf_Verneed_Impl {
296  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
297  Elf_Half vn_version; // Version of this structure (e.g. VER_NEED_CURRENT)
298  Elf_Half vn_cnt;     // Number of associated Vernaux entries
299  Elf_Word vn_file;    // Library name (string table offset)
300  Elf_Word vn_aux;     // Offset to first Vernaux entry (in bytes)
301  Elf_Word vn_next;    // Offset to next Verneed entry (in bytes)
302};
303
304/// Elf_Vernaux: This is the structure of auxiliary data in SHT_GNU_verneed
305/// section (.gnu.version_r). This structure is identical for ELF32 and ELF64.
306template <class ELFT>
307struct Elf_Vernaux_Impl {
308  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
309  Elf_Word vna_hash;  // Hash of dependency name
310  Elf_Half vna_flags; // Bitwise Flags (VER_FLAG_*)
311  Elf_Half vna_other; // Version index, used in .gnu.version entries
312  Elf_Word vna_name;  // Dependency name
313  Elf_Word vna_next;  // Offset to next Vernaux entry (in bytes)
314};
315
316/// Elf_Dyn_Base: This structure matches the form of entries in the dynamic
317///               table section (.dynamic) look like.
318template <class ELFT> struct Elf_Dyn_Base;
319
320template <endianness TargetEndianness>
321struct Elf_Dyn_Base<ELFType<TargetEndianness, false>> {
322  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
323  Elf_Sword d_tag;
324  union {
325    Elf_Word d_val;
326    Elf_Addr d_ptr;
327  } d_un;
328};
329
330template <endianness TargetEndianness>
331struct Elf_Dyn_Base<ELFType<TargetEndianness, true>> {
332  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
333  Elf_Sxword d_tag;
334  union {
335    Elf_Xword d_val;
336    Elf_Addr d_ptr;
337  } d_un;
338};
339
340/// Elf_Dyn_Impl: This inherits from Elf_Dyn_Base, adding getters.
341template <class ELFT>
342struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> {
343  using Elf_Dyn_Base<ELFT>::d_tag;
344  using Elf_Dyn_Base<ELFT>::d_un;
345  using intX_t = typename std::conditional<ELFT::Is64Bits,
346                                           int64_t, int32_t>::type;
347  using uintX_t = typename std::conditional<ELFT::Is64Bits,
348                                            uint64_t, uint32_t>::type;
349  intX_t getTag() const { return d_tag; }
350  uintX_t getVal() const { return d_un.d_val; }
351  uintX_t getPtr() const { return d_un.d_ptr; }
352};
353
354template <endianness TargetEndianness>
355struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> {
356  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
357  static const bool IsRela = false;
358  Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
359  Elf_Word r_info;   // Symbol table index and type of relocation to apply
360
361  uint32_t getRInfo(bool isMips64EL) const {
362    assert(!isMips64EL);
363    return r_info;
364  }
365  void setRInfo(uint32_t R, bool IsMips64EL) {
366    assert(!IsMips64EL);
367    r_info = R;
368  }
369
370  // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
371  // and ELF32_R_INFO macros defined in the ELF specification:
372  uint32_t getSymbol(bool isMips64EL) const {
373    return this->getRInfo(isMips64EL) >> 8;
374  }
375  unsigned char getType(bool isMips64EL) const {
376    return (unsigned char)(this->getRInfo(isMips64EL) & 0x0ff);
377  }
378  void setSymbol(uint32_t s, bool IsMips64EL) {
379    setSymbolAndType(s, getType(IsMips64EL), IsMips64EL);
380  }
381  void setType(unsigned char t, bool IsMips64EL) {
382    setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL);
383  }
384  void setSymbolAndType(uint32_t s, unsigned char t, bool IsMips64EL) {
385    this->setRInfo((s << 8) + t, IsMips64EL);
386  }
387};
388
389template <endianness TargetEndianness>
390struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, true>
391    : public Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> {
392  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
393  static const bool IsRela = true;
394  Elf_Sword r_addend; // Compute value for relocatable field by adding this
395};
396
397template <endianness TargetEndianness>
398struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> {
399  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
400  static const bool IsRela = false;
401  Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
402  Elf_Xword r_info;  // Symbol table index and type of relocation to apply
403
404  uint64_t getRInfo(bool isMips64EL) const {
405    uint64_t t = r_info;
406    if (!isMips64EL)
407      return t;
408    // Mips64 little endian has a "special" encoding of r_info. Instead of one
409    // 64 bit little endian number, it is a little endian 32 bit number followed
410    // by a 32 bit big endian number.
411    return (t << 32) | ((t >> 8) & 0xff000000) | ((t >> 24) & 0x00ff0000) |
412           ((t >> 40) & 0x0000ff00) | ((t >> 56) & 0x000000ff);
413  }
414
415  void setRInfo(uint64_t R, bool IsMips64EL) {
416    if (IsMips64EL)
417      r_info = (R >> 32) | ((R & 0xff000000) << 8) | ((R & 0x00ff0000) << 24) |
418               ((R & 0x0000ff00) << 40) | ((R & 0x000000ff) << 56);
419    else
420      r_info = R;
421  }
422
423  // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE,
424  // and ELF64_R_INFO macros defined in the ELF specification:
425  uint32_t getSymbol(bool isMips64EL) const {
426    return (uint32_t)(this->getRInfo(isMips64EL) >> 32);
427  }
428  uint32_t getType(bool isMips64EL) const {
429    return (uint32_t)(this->getRInfo(isMips64EL) & 0xffffffffL);
430  }
431  void setSymbol(uint32_t s, bool IsMips64EL) {
432    setSymbolAndType(s, getType(IsMips64EL), IsMips64EL);
433  }
434  void setType(uint32_t t, bool IsMips64EL) {
435    setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL);
436  }
437  void setSymbolAndType(uint32_t s, uint32_t t, bool IsMips64EL) {
438    this->setRInfo(((uint64_t)s << 32) + (t & 0xffffffffL), IsMips64EL);
439  }
440};
441
442template <endianness TargetEndianness>
443struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, true>
444    : public Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> {
445  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
446  static const bool IsRela = true;
447  Elf_Sxword r_addend; // Compute value for relocatable field by adding this.
448};
449
450template <class ELFT>
451struct Elf_Ehdr_Impl {
452  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
453  unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes
454  Elf_Half e_type;                       // Type of file (see ET_*)
455  Elf_Half e_machine;   // Required architecture for this file (see EM_*)
456  Elf_Word e_version;   // Must be equal to 1
457  Elf_Addr e_entry;     // Address to jump to in order to start program
458  Elf_Off e_phoff;      // Program header table's file offset, in bytes
459  Elf_Off e_shoff;      // Section header table's file offset, in bytes
460  Elf_Word e_flags;     // Processor-specific flags
461  Elf_Half e_ehsize;    // Size of ELF header, in bytes
462  Elf_Half e_phentsize; // Size of an entry in the program header table
463  Elf_Half e_phnum;     // Number of entries in the program header table
464  Elf_Half e_shentsize; // Size of an entry in the section header table
465  Elf_Half e_shnum;     // Number of entries in the section header table
466  Elf_Half e_shstrndx;  // Section header table index of section name
467                        // string table
468
469  bool checkMagic() const {
470    return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
471  }
472
473  unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; }
474  unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; }
475};
476
477template <endianness TargetEndianness>
478struct Elf_Phdr_Impl<ELFType<TargetEndianness, false>> {
479  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
480  Elf_Word p_type;   // Type of segment
481  Elf_Off p_offset;  // FileOffset where segment is located, in bytes
482  Elf_Addr p_vaddr;  // Virtual Address of beginning of segment
483  Elf_Addr p_paddr;  // Physical address of beginning of segment (OS-specific)
484  Elf_Word p_filesz; // Num. of bytes in file image of segment (may be zero)
485  Elf_Word p_memsz;  // Num. of bytes in mem image of segment (may be zero)
486  Elf_Word p_flags;  // Segment flags
487  Elf_Word p_align;  // Segment alignment constraint
488};
489
490template <endianness TargetEndianness>
491struct Elf_Phdr_Impl<ELFType<TargetEndianness, true>> {
492  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
493  Elf_Word p_type;    // Type of segment
494  Elf_Word p_flags;   // Segment flags
495  Elf_Off p_offset;   // FileOffset where segment is located, in bytes
496  Elf_Addr p_vaddr;   // Virtual Address of beginning of segment
497  Elf_Addr p_paddr;   // Physical address of beginning of segment (OS-specific)
498  Elf_Xword p_filesz; // Num. of bytes in file image of segment (may be zero)
499  Elf_Xword p_memsz;  // Num. of bytes in mem image of segment (may be zero)
500  Elf_Xword p_align;  // Segment alignment constraint
501};
502
503// ELFT needed for endianness.
504template <class ELFT>
505struct Elf_Hash_Impl {
506  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
507  Elf_Word nbucket;
508  Elf_Word nchain;
509
510  ArrayRef<Elf_Word> buckets() const {
511    return ArrayRef<Elf_Word>(&nbucket + 2, &nbucket + 2 + nbucket);
512  }
513
514  ArrayRef<Elf_Word> chains() const {
515    return ArrayRef<Elf_Word>(&nbucket + 2 + nbucket,
516                              &nbucket + 2 + nbucket + nchain);
517  }
518};
519
520// .gnu.hash section
521template <class ELFT>
522struct Elf_GnuHash_Impl {
523  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
524  Elf_Word nbuckets;
525  Elf_Word symndx;
526  Elf_Word maskwords;
527  Elf_Word shift2;
528
529  ArrayRef<Elf_Off> filter() const {
530    return ArrayRef<Elf_Off>(reinterpret_cast<const Elf_Off *>(&shift2 + 1),
531                             maskwords);
532  }
533
534  ArrayRef<Elf_Word> buckets() const {
535    return ArrayRef<Elf_Word>(
536        reinterpret_cast<const Elf_Word *>(filter().end()), nbuckets);
537  }
538
539  ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const {
540    return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx);
541  }
542};
543
544// Compressed section headers.
545// http://www.sco.com/developers/gabi/latest/ch4.sheader.html#compression_header
546template <endianness TargetEndianness>
547struct Elf_Chdr_Impl<ELFType<TargetEndianness, false>> {
548  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
549  Elf_Word ch_type;
550  Elf_Word ch_size;
551  Elf_Word ch_addralign;
552};
553
554template <endianness TargetEndianness>
555struct Elf_Chdr_Impl<ELFType<TargetEndianness, true>> {
556  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
557  Elf_Word ch_type;
558  Elf_Word ch_reserved;
559  Elf_Xword ch_size;
560  Elf_Xword ch_addralign;
561};
562
563/// Note header
564template <class ELFT>
565struct Elf_Nhdr_Impl {
566  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
567  Elf_Word n_namesz;
568  Elf_Word n_descsz;
569  Elf_Word n_type;
570
571  /// The alignment of the name and descriptor.
572  ///
573  /// Implementations differ from the specification here: in practice all
574  /// variants align both the name and descriptor to 4-bytes.
575  static const unsigned int Align = 4;
576
577  /// Get the size of the note, including name, descriptor, and padding.
578  size_t getSize() const {
579    return sizeof(*this) + alignTo<Align>(n_namesz) + alignTo<Align>(n_descsz);
580  }
581};
582
583/// An ELF note.
584///
585/// Wraps a note header, providing methods for accessing the name and
586/// descriptor safely.
587template <class ELFT>
588class Elf_Note_Impl {
589  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
590
591  const Elf_Nhdr_Impl<ELFT> &Nhdr;
592
593  template <class NoteIteratorELFT> friend class Elf_Note_Iterator_Impl;
594
595public:
596  Elf_Note_Impl(const Elf_Nhdr_Impl<ELFT> &Nhdr) : Nhdr(Nhdr) {}
597
598  /// Get the note's name, excluding the terminating null byte.
599  StringRef getName() const {
600    if (!Nhdr.n_namesz)
601      return StringRef();
602    return StringRef(reinterpret_cast<const char *>(&Nhdr) + sizeof(Nhdr),
603                     Nhdr.n_namesz - 1);
604  }
605
606  /// Get the note's descriptor.
607  ArrayRef<uint8_t> getDesc() const {
608    if (!Nhdr.n_descsz)
609      return ArrayRef<uint8_t>();
610    return ArrayRef<uint8_t>(
611        reinterpret_cast<const uint8_t *>(&Nhdr) + sizeof(Nhdr) +
612          alignTo<Elf_Nhdr_Impl<ELFT>::Align>(Nhdr.n_namesz),
613        Nhdr.n_descsz);
614  }
615
616  /// Get the note's type.
617  Elf_Word getType() const { return Nhdr.n_type; }
618};
619
620template <class ELFT>
621class Elf_Note_Iterator_Impl
622    : std::iterator<std::forward_iterator_tag, Elf_Note_Impl<ELFT>> {
623  // Nhdr being a nullptr marks the end of iteration.
624  const Elf_Nhdr_Impl<ELFT> *Nhdr = nullptr;
625  size_t RemainingSize = 0u;
626  Error *Err = nullptr;
627
628  template <class ELFFileELFT> friend class ELFFile;
629
630  // Stop iteration and indicate an overflow.
631  void stopWithOverflowError() {
632    Nhdr = nullptr;
633    *Err = make_error<StringError>("ELF note overflows container",
634                                   object_error::parse_failed);
635  }
636
637  // Advance Nhdr by NoteSize bytes, starting from NhdrPos.
638  //
639  // Assumes NoteSize <= RemainingSize. Ensures Nhdr->getSize() <= RemainingSize
640  // upon returning. Handles stopping iteration when reaching the end of the
641  // container, either cleanly or with an overflow error.
642  void advanceNhdr(const uint8_t *NhdrPos, size_t NoteSize) {
643    RemainingSize -= NoteSize;
644    if (RemainingSize == 0u) {
645      // Ensure that if the iterator walks to the end, the error is checked
646      // afterwards.
647      *Err = Error::success();
648      Nhdr = nullptr;
649    } else if (sizeof(*Nhdr) > RemainingSize)
650      stopWithOverflowError();
651    else {
652      Nhdr = reinterpret_cast<const Elf_Nhdr_Impl<ELFT> *>(NhdrPos + NoteSize);
653      if (Nhdr->getSize() > RemainingSize)
654        stopWithOverflowError();
655      else
656        *Err = Error::success();
657    }
658  }
659
660  Elf_Note_Iterator_Impl() {}
661  explicit Elf_Note_Iterator_Impl(Error &Err) : Err(&Err) {}
662  Elf_Note_Iterator_Impl(const uint8_t *Start, size_t Size, Error &Err)
663      : RemainingSize(Size), Err(&Err) {
664    consumeError(std::move(Err));
665    assert(Start && "ELF note iterator starting at NULL");
666    advanceNhdr(Start, 0u);
667  }
668
669public:
670  Elf_Note_Iterator_Impl &operator++() {
671    assert(Nhdr && "incremented ELF note end iterator");
672    const uint8_t *NhdrPos = reinterpret_cast<const uint8_t *>(Nhdr);
673    size_t NoteSize = Nhdr->getSize();
674    advanceNhdr(NhdrPos, NoteSize);
675    return *this;
676  }
677  bool operator==(Elf_Note_Iterator_Impl Other) const {
678    if (!Nhdr && Other.Err)
679      (void)(bool)(*Other.Err);
680    if (!Other.Nhdr && Err)
681      (void)(bool)(*Err);
682    return Nhdr == Other.Nhdr;
683  }
684  bool operator!=(Elf_Note_Iterator_Impl Other) const {
685    return !(*this == Other);
686  }
687  Elf_Note_Impl<ELFT> operator*() const {
688    assert(Nhdr && "dereferenced ELF note end iterator");
689    return Elf_Note_Impl<ELFT>(*Nhdr);
690  }
691};
692
693template <class ELFT> struct Elf_CGProfile_Impl {
694  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
695  Elf_Word cgp_from;
696  Elf_Word cgp_to;
697  Elf_Xword cgp_weight;
698};
699
700// MIPS .reginfo section
701template <class ELFT>
702struct Elf_Mips_RegInfo;
703
704template <support::endianness TargetEndianness>
705struct Elf_Mips_RegInfo<ELFType<TargetEndianness, false>> {
706  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
707  Elf_Word ri_gprmask;     // bit-mask of used general registers
708  Elf_Word ri_cprmask[4];  // bit-mask of used co-processor registers
709  Elf_Addr ri_gp_value;    // gp register value
710};
711
712template <support::endianness TargetEndianness>
713struct Elf_Mips_RegInfo<ELFType<TargetEndianness, true>> {
714  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
715  Elf_Word ri_gprmask;     // bit-mask of used general registers
716  Elf_Word ri_pad;         // unused padding field
717  Elf_Word ri_cprmask[4];  // bit-mask of used co-processor registers
718  Elf_Addr ri_gp_value;    // gp register value
719};
720
721// .MIPS.options section
722template <class ELFT> struct Elf_Mips_Options {
723  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
724  uint8_t kind;     // Determines interpretation of variable part of descriptor
725  uint8_t size;     // Byte size of descriptor, including this header
726  Elf_Half section; // Section header index of section affected,
727                    // or 0 for global options
728  Elf_Word info;    // Kind-specific information
729
730  Elf_Mips_RegInfo<ELFT> &getRegInfo() {
731    assert(kind == ELF::ODK_REGINFO);
732    return *reinterpret_cast<Elf_Mips_RegInfo<ELFT> *>(
733        (uint8_t *)this + sizeof(Elf_Mips_Options));
734  }
735  const Elf_Mips_RegInfo<ELFT> &getRegInfo() const {
736    return const_cast<Elf_Mips_Options *>(this)->getRegInfo();
737  }
738};
739
740// .MIPS.abiflags section content
741template <class ELFT> struct Elf_Mips_ABIFlags {
742  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
743  Elf_Half version;  // Version of the structure
744  uint8_t isa_level; // ISA level: 1-5, 32, and 64
745  uint8_t isa_rev;   // ISA revision (0 for MIPS I - MIPS V)
746  uint8_t gpr_size;  // General purpose registers size
747  uint8_t cpr1_size; // Co-processor 1 registers size
748  uint8_t cpr2_size; // Co-processor 2 registers size
749  uint8_t fp_abi;    // Floating-point ABI flag
750  Elf_Word isa_ext;  // Processor-specific extension
751  Elf_Word ases;     // ASEs flags
752  Elf_Word flags1;   // General flags
753  Elf_Word flags2;   // General flags
754};
755
756} // end namespace object.
757} // end namespace llvm.
758
759#endif // LLVM_OBJECT_ELFTYPES_H
760