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 createStringError(object_error::parse_failed,
252                             "st_name (0x%" PRIx32
253                             ") is past the end of the string table"
254                             " of size 0x%zx",
255                             Offset, StrTab.size());
256  return StringRef(StrTab.data() + Offset);
257}
258
259/// Elf_Versym: This is the structure of entries in the SHT_GNU_versym section
260/// (.gnu.version). This structure is identical for ELF32 and ELF64.
261template <class ELFT>
262struct Elf_Versym_Impl {
263  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
264  Elf_Half vs_index; // Version index with flags (e.g. VERSYM_HIDDEN)
265};
266
267/// Elf_Verdef: This is the structure of entries in the SHT_GNU_verdef section
268/// (.gnu.version_d). This structure is identical for ELF32 and ELF64.
269template <class ELFT>
270struct Elf_Verdef_Impl {
271  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
272  using Elf_Verdaux = Elf_Verdaux_Impl<ELFT>;
273  Elf_Half vd_version; // Version of this structure (e.g. VER_DEF_CURRENT)
274  Elf_Half vd_flags;   // Bitwise flags (VER_DEF_*)
275  Elf_Half vd_ndx;     // Version index, used in .gnu.version entries
276  Elf_Half vd_cnt;     // Number of Verdaux entries
277  Elf_Word vd_hash;    // Hash of name
278  Elf_Word vd_aux;     // Offset to the first Verdaux entry (in bytes)
279  Elf_Word vd_next;    // Offset to the next Verdef entry (in bytes)
280
281  /// Get the first Verdaux entry for this Verdef.
282  const Elf_Verdaux *getAux() const {
283    return reinterpret_cast<const Elf_Verdaux *>((const char *)this + vd_aux);
284  }
285};
286
287/// Elf_Verdaux: This is the structure of auxiliary data in the SHT_GNU_verdef
288/// section (.gnu.version_d). This structure is identical for ELF32 and ELF64.
289template <class ELFT>
290struct Elf_Verdaux_Impl {
291  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
292  Elf_Word vda_name; // Version name (offset in string table)
293  Elf_Word vda_next; // Offset to next Verdaux entry (in bytes)
294};
295
296/// Elf_Verneed: This is the structure of entries in the SHT_GNU_verneed
297/// section (.gnu.version_r). This structure is identical for ELF32 and ELF64.
298template <class ELFT>
299struct Elf_Verneed_Impl {
300  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
301  Elf_Half vn_version; // Version of this structure (e.g. VER_NEED_CURRENT)
302  Elf_Half vn_cnt;     // Number of associated Vernaux entries
303  Elf_Word vn_file;    // Library name (string table offset)
304  Elf_Word vn_aux;     // Offset to first Vernaux entry (in bytes)
305  Elf_Word vn_next;    // Offset to next Verneed entry (in bytes)
306};
307
308/// Elf_Vernaux: This is the structure of auxiliary data in SHT_GNU_verneed
309/// section (.gnu.version_r). This structure is identical for ELF32 and ELF64.
310template <class ELFT>
311struct Elf_Vernaux_Impl {
312  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
313  Elf_Word vna_hash;  // Hash of dependency name
314  Elf_Half vna_flags; // Bitwise Flags (VER_FLAG_*)
315  Elf_Half vna_other; // Version index, used in .gnu.version entries
316  Elf_Word vna_name;  // Dependency name
317  Elf_Word vna_next;  // Offset to next Vernaux entry (in bytes)
318};
319
320/// Elf_Dyn_Base: This structure matches the form of entries in the dynamic
321///               table section (.dynamic) look like.
322template <class ELFT> struct Elf_Dyn_Base;
323
324template <endianness TargetEndianness>
325struct Elf_Dyn_Base<ELFType<TargetEndianness, false>> {
326  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
327  Elf_Sword d_tag;
328  union {
329    Elf_Word d_val;
330    Elf_Addr d_ptr;
331  } d_un;
332};
333
334template <endianness TargetEndianness>
335struct Elf_Dyn_Base<ELFType<TargetEndianness, true>> {
336  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
337  Elf_Sxword d_tag;
338  union {
339    Elf_Xword d_val;
340    Elf_Addr d_ptr;
341  } d_un;
342};
343
344/// Elf_Dyn_Impl: This inherits from Elf_Dyn_Base, adding getters.
345template <class ELFT>
346struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> {
347  using Elf_Dyn_Base<ELFT>::d_tag;
348  using Elf_Dyn_Base<ELFT>::d_un;
349  using intX_t = typename std::conditional<ELFT::Is64Bits,
350                                           int64_t, int32_t>::type;
351  using uintX_t = typename std::conditional<ELFT::Is64Bits,
352                                            uint64_t, uint32_t>::type;
353  intX_t getTag() const { return d_tag; }
354  uintX_t getVal() const { return d_un.d_val; }
355  uintX_t getPtr() const { return d_un.d_ptr; }
356};
357
358template <endianness TargetEndianness>
359struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> {
360  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
361  static const bool IsRela = false;
362  Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
363  Elf_Word r_info;   // Symbol table index and type of relocation to apply
364
365  uint32_t getRInfo(bool isMips64EL) const {
366    assert(!isMips64EL);
367    return r_info;
368  }
369  void setRInfo(uint32_t R, bool IsMips64EL) {
370    assert(!IsMips64EL);
371    r_info = R;
372  }
373
374  // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
375  // and ELF32_R_INFO macros defined in the ELF specification:
376  uint32_t getSymbol(bool isMips64EL) const {
377    return this->getRInfo(isMips64EL) >> 8;
378  }
379  unsigned char getType(bool isMips64EL) const {
380    return (unsigned char)(this->getRInfo(isMips64EL) & 0x0ff);
381  }
382  void setSymbol(uint32_t s, bool IsMips64EL) {
383    setSymbolAndType(s, getType(IsMips64EL), IsMips64EL);
384  }
385  void setType(unsigned char t, bool IsMips64EL) {
386    setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL);
387  }
388  void setSymbolAndType(uint32_t s, unsigned char t, bool IsMips64EL) {
389    this->setRInfo((s << 8) + t, IsMips64EL);
390  }
391};
392
393template <endianness TargetEndianness>
394struct Elf_Rel_Impl<ELFType<TargetEndianness, false>, true>
395    : public Elf_Rel_Impl<ELFType<TargetEndianness, false>, false> {
396  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
397  static const bool IsRela = true;
398  Elf_Sword r_addend; // Compute value for relocatable field by adding this
399};
400
401template <endianness TargetEndianness>
402struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> {
403  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
404  static const bool IsRela = false;
405  Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
406  Elf_Xword r_info;  // Symbol table index and type of relocation to apply
407
408  uint64_t getRInfo(bool isMips64EL) const {
409    uint64_t t = r_info;
410    if (!isMips64EL)
411      return t;
412    // Mips64 little endian has a "special" encoding of r_info. Instead of one
413    // 64 bit little endian number, it is a little endian 32 bit number followed
414    // by a 32 bit big endian number.
415    return (t << 32) | ((t >> 8) & 0xff000000) | ((t >> 24) & 0x00ff0000) |
416           ((t >> 40) & 0x0000ff00) | ((t >> 56) & 0x000000ff);
417  }
418
419  void setRInfo(uint64_t R, bool IsMips64EL) {
420    if (IsMips64EL)
421      r_info = (R >> 32) | ((R & 0xff000000) << 8) | ((R & 0x00ff0000) << 24) |
422               ((R & 0x0000ff00) << 40) | ((R & 0x000000ff) << 56);
423    else
424      r_info = R;
425  }
426
427  // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE,
428  // and ELF64_R_INFO macros defined in the ELF specification:
429  uint32_t getSymbol(bool isMips64EL) const {
430    return (uint32_t)(this->getRInfo(isMips64EL) >> 32);
431  }
432  uint32_t getType(bool isMips64EL) const {
433    return (uint32_t)(this->getRInfo(isMips64EL) & 0xffffffffL);
434  }
435  void setSymbol(uint32_t s, bool IsMips64EL) {
436    setSymbolAndType(s, getType(IsMips64EL), IsMips64EL);
437  }
438  void setType(uint32_t t, bool IsMips64EL) {
439    setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL);
440  }
441  void setSymbolAndType(uint32_t s, uint32_t t, bool IsMips64EL) {
442    this->setRInfo(((uint64_t)s << 32) + (t & 0xffffffffL), IsMips64EL);
443  }
444};
445
446template <endianness TargetEndianness>
447struct Elf_Rel_Impl<ELFType<TargetEndianness, true>, true>
448    : public Elf_Rel_Impl<ELFType<TargetEndianness, true>, false> {
449  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
450  static const bool IsRela = true;
451  Elf_Sxword r_addend; // Compute value for relocatable field by adding this.
452};
453
454template <class ELFT>
455struct Elf_Ehdr_Impl {
456  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
457  unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes
458  Elf_Half e_type;                       // Type of file (see ET_*)
459  Elf_Half e_machine;   // Required architecture for this file (see EM_*)
460  Elf_Word e_version;   // Must be equal to 1
461  Elf_Addr e_entry;     // Address to jump to in order to start program
462  Elf_Off e_phoff;      // Program header table's file offset, in bytes
463  Elf_Off e_shoff;      // Section header table's file offset, in bytes
464  Elf_Word e_flags;     // Processor-specific flags
465  Elf_Half e_ehsize;    // Size of ELF header, in bytes
466  Elf_Half e_phentsize; // Size of an entry in the program header table
467  Elf_Half e_phnum;     // Number of entries in the program header table
468  Elf_Half e_shentsize; // Size of an entry in the section header table
469  Elf_Half e_shnum;     // Number of entries in the section header table
470  Elf_Half e_shstrndx;  // Section header table index of section name
471                        // string table
472
473  bool checkMagic() const {
474    return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
475  }
476
477  unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; }
478  unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; }
479};
480
481template <endianness TargetEndianness>
482struct Elf_Phdr_Impl<ELFType<TargetEndianness, false>> {
483  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
484  Elf_Word p_type;   // Type of segment
485  Elf_Off p_offset;  // FileOffset where segment is located, in bytes
486  Elf_Addr p_vaddr;  // Virtual Address of beginning of segment
487  Elf_Addr p_paddr;  // Physical address of beginning of segment (OS-specific)
488  Elf_Word p_filesz; // Num. of bytes in file image of segment (may be zero)
489  Elf_Word p_memsz;  // Num. of bytes in mem image of segment (may be zero)
490  Elf_Word p_flags;  // Segment flags
491  Elf_Word p_align;  // Segment alignment constraint
492};
493
494template <endianness TargetEndianness>
495struct Elf_Phdr_Impl<ELFType<TargetEndianness, true>> {
496  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
497  Elf_Word p_type;    // Type of segment
498  Elf_Word p_flags;   // Segment flags
499  Elf_Off p_offset;   // FileOffset where segment is located, in bytes
500  Elf_Addr p_vaddr;   // Virtual Address of beginning of segment
501  Elf_Addr p_paddr;   // Physical address of beginning of segment (OS-specific)
502  Elf_Xword p_filesz; // Num. of bytes in file image of segment (may be zero)
503  Elf_Xword p_memsz;  // Num. of bytes in mem image of segment (may be zero)
504  Elf_Xword p_align;  // Segment alignment constraint
505};
506
507// ELFT needed for endianness.
508template <class ELFT>
509struct Elf_Hash_Impl {
510  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
511  Elf_Word nbucket;
512  Elf_Word nchain;
513
514  ArrayRef<Elf_Word> buckets() const {
515    return ArrayRef<Elf_Word>(&nbucket + 2, &nbucket + 2 + nbucket);
516  }
517
518  ArrayRef<Elf_Word> chains() const {
519    return ArrayRef<Elf_Word>(&nbucket + 2 + nbucket,
520                              &nbucket + 2 + nbucket + nchain);
521  }
522};
523
524// .gnu.hash section
525template <class ELFT>
526struct Elf_GnuHash_Impl {
527  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
528  Elf_Word nbuckets;
529  Elf_Word symndx;
530  Elf_Word maskwords;
531  Elf_Word shift2;
532
533  ArrayRef<Elf_Off> filter() const {
534    return ArrayRef<Elf_Off>(reinterpret_cast<const Elf_Off *>(&shift2 + 1),
535                             maskwords);
536  }
537
538  ArrayRef<Elf_Word> buckets() const {
539    return ArrayRef<Elf_Word>(
540        reinterpret_cast<const Elf_Word *>(filter().end()), nbuckets);
541  }
542
543  ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const {
544    return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx);
545  }
546};
547
548// Compressed section headers.
549// http://www.sco.com/developers/gabi/latest/ch4.sheader.html#compression_header
550template <endianness TargetEndianness>
551struct Elf_Chdr_Impl<ELFType<TargetEndianness, false>> {
552  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
553  Elf_Word ch_type;
554  Elf_Word ch_size;
555  Elf_Word ch_addralign;
556};
557
558template <endianness TargetEndianness>
559struct Elf_Chdr_Impl<ELFType<TargetEndianness, true>> {
560  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
561  Elf_Word ch_type;
562  Elf_Word ch_reserved;
563  Elf_Xword ch_size;
564  Elf_Xword ch_addralign;
565};
566
567/// Note header
568template <class ELFT>
569struct Elf_Nhdr_Impl {
570  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
571  Elf_Word n_namesz;
572  Elf_Word n_descsz;
573  Elf_Word n_type;
574
575  /// The alignment of the name and descriptor.
576  ///
577  /// Implementations differ from the specification here: in practice all
578  /// variants align both the name and descriptor to 4-bytes.
579  static const unsigned int Align = 4;
580
581  /// Get the size of the note, including name, descriptor, and padding.
582  size_t getSize() const {
583    return sizeof(*this) + alignTo<Align>(n_namesz) + alignTo<Align>(n_descsz);
584  }
585};
586
587/// An ELF note.
588///
589/// Wraps a note header, providing methods for accessing the name and
590/// descriptor safely.
591template <class ELFT>
592class Elf_Note_Impl {
593  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
594
595  const Elf_Nhdr_Impl<ELFT> &Nhdr;
596
597  template <class NoteIteratorELFT> friend class Elf_Note_Iterator_Impl;
598
599public:
600  Elf_Note_Impl(const Elf_Nhdr_Impl<ELFT> &Nhdr) : Nhdr(Nhdr) {}
601
602  /// Get the note's name, excluding the terminating null byte.
603  StringRef getName() const {
604    if (!Nhdr.n_namesz)
605      return StringRef();
606    return StringRef(reinterpret_cast<const char *>(&Nhdr) + sizeof(Nhdr),
607                     Nhdr.n_namesz - 1);
608  }
609
610  /// Get the note's descriptor.
611  ArrayRef<uint8_t> getDesc() const {
612    if (!Nhdr.n_descsz)
613      return ArrayRef<uint8_t>();
614    return ArrayRef<uint8_t>(
615        reinterpret_cast<const uint8_t *>(&Nhdr) + sizeof(Nhdr) +
616          alignTo<Elf_Nhdr_Impl<ELFT>::Align>(Nhdr.n_namesz),
617        Nhdr.n_descsz);
618  }
619
620  /// Get the note's type.
621  Elf_Word getType() const { return Nhdr.n_type; }
622};
623
624template <class ELFT>
625class Elf_Note_Iterator_Impl
626    : std::iterator<std::forward_iterator_tag, Elf_Note_Impl<ELFT>> {
627  // Nhdr being a nullptr marks the end of iteration.
628  const Elf_Nhdr_Impl<ELFT> *Nhdr = nullptr;
629  size_t RemainingSize = 0u;
630  Error *Err = nullptr;
631
632  template <class ELFFileELFT> friend class ELFFile;
633
634  // Stop iteration and indicate an overflow.
635  void stopWithOverflowError() {
636    Nhdr = nullptr;
637    *Err = make_error<StringError>("ELF note overflows container",
638                                   object_error::parse_failed);
639  }
640
641  // Advance Nhdr by NoteSize bytes, starting from NhdrPos.
642  //
643  // Assumes NoteSize <= RemainingSize. Ensures Nhdr->getSize() <= RemainingSize
644  // upon returning. Handles stopping iteration when reaching the end of the
645  // container, either cleanly or with an overflow error.
646  void advanceNhdr(const uint8_t *NhdrPos, size_t NoteSize) {
647    RemainingSize -= NoteSize;
648    if (RemainingSize == 0u) {
649      // Ensure that if the iterator walks to the end, the error is checked
650      // afterwards.
651      *Err = Error::success();
652      Nhdr = nullptr;
653    } else if (sizeof(*Nhdr) > RemainingSize)
654      stopWithOverflowError();
655    else {
656      Nhdr = reinterpret_cast<const Elf_Nhdr_Impl<ELFT> *>(NhdrPos + NoteSize);
657      if (Nhdr->getSize() > RemainingSize)
658        stopWithOverflowError();
659      else
660        *Err = Error::success();
661    }
662  }
663
664  Elf_Note_Iterator_Impl() {}
665  explicit Elf_Note_Iterator_Impl(Error &Err) : Err(&Err) {}
666  Elf_Note_Iterator_Impl(const uint8_t *Start, size_t Size, Error &Err)
667      : RemainingSize(Size), Err(&Err) {
668    consumeError(std::move(Err));
669    assert(Start && "ELF note iterator starting at NULL");
670    advanceNhdr(Start, 0u);
671  }
672
673public:
674  Elf_Note_Iterator_Impl &operator++() {
675    assert(Nhdr && "incremented ELF note end iterator");
676    const uint8_t *NhdrPos = reinterpret_cast<const uint8_t *>(Nhdr);
677    size_t NoteSize = Nhdr->getSize();
678    advanceNhdr(NhdrPos, NoteSize);
679    return *this;
680  }
681  bool operator==(Elf_Note_Iterator_Impl Other) const {
682    if (!Nhdr && Other.Err)
683      (void)(bool)(*Other.Err);
684    if (!Other.Nhdr && Err)
685      (void)(bool)(*Err);
686    return Nhdr == Other.Nhdr;
687  }
688  bool operator!=(Elf_Note_Iterator_Impl Other) const {
689    return !(*this == Other);
690  }
691  Elf_Note_Impl<ELFT> operator*() const {
692    assert(Nhdr && "dereferenced ELF note end iterator");
693    return Elf_Note_Impl<ELFT>(*Nhdr);
694  }
695};
696
697template <class ELFT> struct Elf_CGProfile_Impl {
698  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
699  Elf_Word cgp_from;
700  Elf_Word cgp_to;
701  Elf_Xword cgp_weight;
702};
703
704// MIPS .reginfo section
705template <class ELFT>
706struct Elf_Mips_RegInfo;
707
708template <support::endianness TargetEndianness>
709struct Elf_Mips_RegInfo<ELFType<TargetEndianness, false>> {
710  LLVM_ELF_IMPORT_TYPES(TargetEndianness, false)
711  Elf_Word ri_gprmask;     // bit-mask of used general registers
712  Elf_Word ri_cprmask[4];  // bit-mask of used co-processor registers
713  Elf_Addr ri_gp_value;    // gp register value
714};
715
716template <support::endianness TargetEndianness>
717struct Elf_Mips_RegInfo<ELFType<TargetEndianness, true>> {
718  LLVM_ELF_IMPORT_TYPES(TargetEndianness, true)
719  Elf_Word ri_gprmask;     // bit-mask of used general registers
720  Elf_Word ri_pad;         // unused padding field
721  Elf_Word ri_cprmask[4];  // bit-mask of used co-processor registers
722  Elf_Addr ri_gp_value;    // gp register value
723};
724
725// .MIPS.options section
726template <class ELFT> struct Elf_Mips_Options {
727  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
728  uint8_t kind;     // Determines interpretation of variable part of descriptor
729  uint8_t size;     // Byte size of descriptor, including this header
730  Elf_Half section; // Section header index of section affected,
731                    // or 0 for global options
732  Elf_Word info;    // Kind-specific information
733
734  Elf_Mips_RegInfo<ELFT> &getRegInfo() {
735    assert(kind == ELF::ODK_REGINFO);
736    return *reinterpret_cast<Elf_Mips_RegInfo<ELFT> *>(
737        (uint8_t *)this + sizeof(Elf_Mips_Options));
738  }
739  const Elf_Mips_RegInfo<ELFT> &getRegInfo() const {
740    return const_cast<Elf_Mips_Options *>(this)->getRegInfo();
741  }
742};
743
744// .MIPS.abiflags section content
745template <class ELFT> struct Elf_Mips_ABIFlags {
746  LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
747  Elf_Half version;  // Version of the structure
748  uint8_t isa_level; // ISA level: 1-5, 32, and 64
749  uint8_t isa_rev;   // ISA revision (0 for MIPS I - MIPS V)
750  uint8_t gpr_size;  // General purpose registers size
751  uint8_t cpr1_size; // Co-processor 1 registers size
752  uint8_t cpr2_size; // Co-processor 2 registers size
753  uint8_t fp_abi;    // Floating-point ABI flag
754  Elf_Word isa_ext;  // Processor-specific extension
755  Elf_Word ases;     // ASEs flags
756  Elf_Word flags1;   // General flags
757  Elf_Word flags2;   // General flags
758};
759
760} // end namespace object.
761} // end namespace llvm.
762
763#endif // LLVM_OBJECT_ELFTYPES_H
764