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/BlockFrequency.h" 17 #include "llvm/Support/BranchProbability.h" 18 #include "llvm/Support/Endian.h" 19 #include "llvm/Support/Error.h" 20 #include "llvm/Support/MathExtras.h" 21 #include <cassert> 22 #include <cstdint> 23 #include <cstring> 24 #include <type_traits> 25 26 namespace llvm { 27 namespace object { 28 29 template <class ELFT> struct Elf_Ehdr_Impl; 30 template <class ELFT> struct Elf_Shdr_Impl; 31 template <class ELFT> struct Elf_Sym_Impl; 32 template <class ELFT> struct Elf_Dyn_Impl; 33 template <class ELFT> struct Elf_Phdr_Impl; 34 template <class ELFT, bool isRela> struct Elf_Rel_Impl; 35 template <bool Is64> struct Elf_Crel_Impl; 36 template <class ELFT> struct Elf_Verdef_Impl; 37 template <class ELFT> struct Elf_Verdaux_Impl; 38 template <class ELFT> struct Elf_Verneed_Impl; 39 template <class ELFT> struct Elf_Vernaux_Impl; 40 template <class ELFT> struct Elf_Versym_Impl; 41 template <class ELFT> struct Elf_Hash_Impl; 42 template <class ELFT> struct Elf_GnuHash_Impl; 43 template <class ELFT> struct Elf_Chdr_Impl; 44 template <class ELFT> struct Elf_Nhdr_Impl; 45 template <class ELFT> class Elf_Note_Impl; 46 template <class ELFT> class Elf_Note_Iterator_Impl; 47 template <class ELFT> struct Elf_CGProfile_Impl; 48 49 template <endianness E, bool Is64> struct ELFType { 50 private: 51 template <typename Ty> 52 using packed = support::detail::packed_endian_specific_integral<Ty, E, 1>; 53 54 public: 55 static const endianness Endianness = E; 56 static const bool Is64Bits = Is64; 57 58 using uint = std::conditional_t<Is64, uint64_t, uint32_t>; 59 using Ehdr = Elf_Ehdr_Impl<ELFType<E, Is64>>; 60 using Shdr = Elf_Shdr_Impl<ELFType<E, Is64>>; 61 using Sym = Elf_Sym_Impl<ELFType<E, Is64>>; 62 using Dyn = Elf_Dyn_Impl<ELFType<E, Is64>>; 63 using Phdr = Elf_Phdr_Impl<ELFType<E, Is64>>; 64 using Rel = Elf_Rel_Impl<ELFType<E, Is64>, false>; 65 using Rela = Elf_Rel_Impl<ELFType<E, Is64>, true>; 66 using Crel = Elf_Crel_Impl<Is64>; 67 using Relr = packed<uint>; 68 using Verdef = Elf_Verdef_Impl<ELFType<E, Is64>>; 69 using Verdaux = Elf_Verdaux_Impl<ELFType<E, Is64>>; 70 using Verneed = Elf_Verneed_Impl<ELFType<E, Is64>>; 71 using Vernaux = Elf_Vernaux_Impl<ELFType<E, Is64>>; 72 using Versym = Elf_Versym_Impl<ELFType<E, Is64>>; 73 using Hash = Elf_Hash_Impl<ELFType<E, Is64>>; 74 using GnuHash = Elf_GnuHash_Impl<ELFType<E, Is64>>; 75 using Chdr = Elf_Chdr_Impl<ELFType<E, Is64>>; 76 using Nhdr = Elf_Nhdr_Impl<ELFType<E, Is64>>; 77 using Note = Elf_Note_Impl<ELFType<E, Is64>>; 78 using NoteIterator = Elf_Note_Iterator_Impl<ELFType<E, Is64>>; 79 using CGProfile = Elf_CGProfile_Impl<ELFType<E, Is64>>; 80 using DynRange = ArrayRef<Dyn>; 81 using ShdrRange = ArrayRef<Shdr>; 82 using SymRange = ArrayRef<Sym>; 83 using RelRange = ArrayRef<Rel>; 84 using RelaRange = ArrayRef<Rela>; 85 using RelrRange = ArrayRef<Relr>; 86 using PhdrRange = ArrayRef<Phdr>; 87 88 using Half = packed<uint16_t>; 89 using Word = packed<uint32_t>; 90 using Sword = packed<int32_t>; 91 using Xword = packed<uint64_t>; 92 using Sxword = packed<int64_t>; 93 using Addr = packed<uint>; 94 using Off = packed<uint>; 95 }; 96 97 using ELF32LE = ELFType<llvm::endianness::little, false>; 98 using ELF32BE = ELFType<llvm::endianness::big, false>; 99 using ELF64LE = ELFType<llvm::endianness::little, true>; 100 using ELF64BE = ELFType<llvm::endianness::big, true>; 101 102 // Use an alignment of 2 for the typedefs since that is the worst case for 103 // ELF files in archives. 104 105 // I really don't like doing this, but the alternative is copypasta. 106 #define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) \ 107 using Elf_Addr = typename ELFT::Addr; \ 108 using Elf_Off = typename ELFT::Off; \ 109 using Elf_Half = typename ELFT::Half; \ 110 using Elf_Word = typename ELFT::Word; \ 111 using Elf_Sword = typename ELFT::Sword; \ 112 using Elf_Xword = typename ELFT::Xword; \ 113 using Elf_Sxword = typename ELFT::Sxword; \ 114 using uintX_t = typename ELFT::uint; \ 115 using Elf_Ehdr = typename ELFT::Ehdr; \ 116 using Elf_Shdr = typename ELFT::Shdr; \ 117 using Elf_Sym = typename ELFT::Sym; \ 118 using Elf_Dyn = typename ELFT::Dyn; \ 119 using Elf_Phdr = typename ELFT::Phdr; \ 120 using Elf_Rel = typename ELFT::Rel; \ 121 using Elf_Rela = typename ELFT::Rela; \ 122 using Elf_Crel = typename ELFT::Crel; \ 123 using Elf_Relr = typename ELFT::Relr; \ 124 using Elf_Verdef = typename ELFT::Verdef; \ 125 using Elf_Verdaux = typename ELFT::Verdaux; \ 126 using Elf_Verneed = typename ELFT::Verneed; \ 127 using Elf_Vernaux = typename ELFT::Vernaux; \ 128 using Elf_Versym = typename ELFT::Versym; \ 129 using Elf_Hash = typename ELFT::Hash; \ 130 using Elf_GnuHash = typename ELFT::GnuHash; \ 131 using Elf_Chdr = typename ELFT::Chdr; \ 132 using Elf_Nhdr = typename ELFT::Nhdr; \ 133 using Elf_Note = typename ELFT::Note; \ 134 using Elf_Note_Iterator = typename ELFT::NoteIterator; \ 135 using Elf_CGProfile = typename ELFT::CGProfile; \ 136 using Elf_Dyn_Range = typename ELFT::DynRange; \ 137 using Elf_Shdr_Range = typename ELFT::ShdrRange; \ 138 using Elf_Sym_Range = typename ELFT::SymRange; \ 139 using Elf_Rel_Range = typename ELFT::RelRange; \ 140 using Elf_Rela_Range = typename ELFT::RelaRange; \ 141 using Elf_Relr_Range = typename ELFT::RelrRange; \ 142 using Elf_Phdr_Range = typename ELFT::PhdrRange; 143 144 #define LLVM_ELF_COMMA , 145 #define LLVM_ELF_IMPORT_TYPES(E, W) \ 146 LLVM_ELF_IMPORT_TYPES_ELFT(ELFType<E LLVM_ELF_COMMA W>) 147 148 // Section header. 149 template <class ELFT> struct Elf_Shdr_Base; 150 151 template <endianness Endianness> 152 struct Elf_Shdr_Base<ELFType<Endianness, false>> { 153 LLVM_ELF_IMPORT_TYPES(Endianness, false) 154 Elf_Word sh_name; // Section name (index into string table) 155 Elf_Word sh_type; // Section type (SHT_*) 156 Elf_Word sh_flags; // Section flags (SHF_*) 157 Elf_Addr sh_addr; // Address where section is to be loaded 158 Elf_Off sh_offset; // File offset of section data, in bytes 159 Elf_Word sh_size; // Size of section, in bytes 160 Elf_Word sh_link; // Section type-specific header table index link 161 Elf_Word sh_info; // Section type-specific extra information 162 Elf_Word sh_addralign; // Section address alignment 163 Elf_Word sh_entsize; // Size of records contained within the section 164 }; 165 166 template <endianness Endianness> 167 struct Elf_Shdr_Base<ELFType<Endianness, true>> { 168 LLVM_ELF_IMPORT_TYPES(Endianness, true) 169 Elf_Word sh_name; // Section name (index into string table) 170 Elf_Word sh_type; // Section type (SHT_*) 171 Elf_Xword sh_flags; // Section flags (SHF_*) 172 Elf_Addr sh_addr; // Address where section is to be loaded 173 Elf_Off sh_offset; // File offset of section data, in bytes 174 Elf_Xword sh_size; // Size of section, in bytes 175 Elf_Word sh_link; // Section type-specific header table index link 176 Elf_Word sh_info; // Section type-specific extra information 177 Elf_Xword sh_addralign; // Section address alignment 178 Elf_Xword sh_entsize; // Size of records contained within the section 179 }; 180 181 template <class ELFT> 182 struct Elf_Shdr_Impl : Elf_Shdr_Base<ELFT> { 183 using Elf_Shdr_Base<ELFT>::sh_entsize; 184 using Elf_Shdr_Base<ELFT>::sh_size; 185 186 /// Get the number of entities this section contains if it has any. 187 unsigned getEntityCount() const { 188 if (sh_entsize == 0) 189 return 0; 190 return sh_size / sh_entsize; 191 } 192 }; 193 194 template <class ELFT> struct Elf_Sym_Base; 195 196 template <endianness Endianness> 197 struct Elf_Sym_Base<ELFType<Endianness, false>> { 198 LLVM_ELF_IMPORT_TYPES(Endianness, false) 199 Elf_Word st_name; // Symbol name (index into string table) 200 Elf_Addr st_value; // Value or address associated with the symbol 201 Elf_Word st_size; // Size of the symbol 202 unsigned char st_info; // Symbol's type and binding attributes 203 unsigned char st_other; // Must be zero; reserved 204 Elf_Half st_shndx; // Which section (header table index) it's defined in 205 }; 206 207 template <endianness Endianness> 208 struct Elf_Sym_Base<ELFType<Endianness, true>> { 209 LLVM_ELF_IMPORT_TYPES(Endianness, true) 210 Elf_Word st_name; // Symbol name (index into string table) 211 unsigned char st_info; // Symbol's type and binding attributes 212 unsigned char st_other; // Must be zero; reserved 213 Elf_Half st_shndx; // Which section (header table index) it's defined in 214 Elf_Addr st_value; // Value or address associated with the symbol 215 Elf_Xword st_size; // Size of the symbol 216 }; 217 218 template <class ELFT> 219 struct Elf_Sym_Impl : Elf_Sym_Base<ELFT> { 220 using Elf_Sym_Base<ELFT>::st_info; 221 using Elf_Sym_Base<ELFT>::st_shndx; 222 using Elf_Sym_Base<ELFT>::st_other; 223 using Elf_Sym_Base<ELFT>::st_value; 224 225 // These accessors and mutators correspond to the ELF32_ST_BIND, 226 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification: 227 unsigned char getBinding() const { return st_info >> 4; } 228 unsigned char getType() const { return st_info & 0x0f; } 229 uint64_t getValue() const { return st_value; } 230 void setBinding(unsigned char b) { setBindingAndType(b, getType()); } 231 void setType(unsigned char t) { setBindingAndType(getBinding(), t); } 232 233 void setBindingAndType(unsigned char b, unsigned char t) { 234 st_info = (b << 4) + (t & 0x0f); 235 } 236 237 /// Access to the STV_xxx flag stored in the first two bits of st_other. 238 /// STV_DEFAULT: 0 239 /// STV_INTERNAL: 1 240 /// STV_HIDDEN: 2 241 /// STV_PROTECTED: 3 242 unsigned char getVisibility() const { return st_other & 0x3; } 243 void setVisibility(unsigned char v) { 244 assert(v < 4 && "Invalid value for visibility"); 245 st_other = (st_other & ~0x3) | v; 246 } 247 248 bool isAbsolute() const { return st_shndx == ELF::SHN_ABS; } 249 250 bool isCommon() const { 251 return getType() == ELF::STT_COMMON || st_shndx == ELF::SHN_COMMON; 252 } 253 254 bool isDefined() const { return !isUndefined(); } 255 256 bool isProcessorSpecific() const { 257 return st_shndx >= ELF::SHN_LOPROC && st_shndx <= ELF::SHN_HIPROC; 258 } 259 260 bool isOSSpecific() const { 261 return st_shndx >= ELF::SHN_LOOS && st_shndx <= ELF::SHN_HIOS; 262 } 263 264 bool isReserved() const { 265 // ELF::SHN_HIRESERVE is 0xffff so st_shndx <= ELF::SHN_HIRESERVE is always 266 // true and some compilers warn about it. 267 return st_shndx >= ELF::SHN_LORESERVE; 268 } 269 270 bool isUndefined() const { return st_shndx == ELF::SHN_UNDEF; } 271 272 bool isExternal() const { 273 return getBinding() != ELF::STB_LOCAL; 274 } 275 276 Expected<StringRef> getName(StringRef StrTab) const; 277 }; 278 279 template <class ELFT> 280 Expected<StringRef> Elf_Sym_Impl<ELFT>::getName(StringRef StrTab) const { 281 uint32_t Offset = this->st_name; 282 if (Offset >= StrTab.size()) 283 return createStringError(object_error::parse_failed, 284 "st_name (0x%" PRIx32 285 ") is past the end of the string table" 286 " of size 0x%zx", 287 Offset, StrTab.size()); 288 return StringRef(StrTab.data() + Offset); 289 } 290 291 /// Elf_Versym: This is the structure of entries in the SHT_GNU_versym section 292 /// (.gnu.version). This structure is identical for ELF32 and ELF64. 293 template <class ELFT> 294 struct Elf_Versym_Impl { 295 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 296 Elf_Half vs_index; // Version index with flags (e.g. VERSYM_HIDDEN) 297 }; 298 299 /// Elf_Verdef: This is the structure of entries in the SHT_GNU_verdef section 300 /// (.gnu.version_d). This structure is identical for ELF32 and ELF64. 301 template <class ELFT> 302 struct Elf_Verdef_Impl { 303 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 304 Elf_Half vd_version; // Version of this structure (e.g. VER_DEF_CURRENT) 305 Elf_Half vd_flags; // Bitwise flags (VER_DEF_*) 306 Elf_Half vd_ndx; // Version index, used in .gnu.version entries 307 Elf_Half vd_cnt; // Number of Verdaux entries 308 Elf_Word vd_hash; // Hash of name 309 Elf_Word vd_aux; // Offset to the first Verdaux entry (in bytes) 310 Elf_Word vd_next; // Offset to the next Verdef entry (in bytes) 311 312 /// Get the first Verdaux entry for this Verdef. 313 const Elf_Verdaux *getAux() const { 314 return reinterpret_cast<const Elf_Verdaux *>((const char *)this + vd_aux); 315 } 316 }; 317 318 /// Elf_Verdaux: This is the structure of auxiliary data in the SHT_GNU_verdef 319 /// section (.gnu.version_d). This structure is identical for ELF32 and ELF64. 320 template <class ELFT> 321 struct Elf_Verdaux_Impl { 322 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 323 Elf_Word vda_name; // Version name (offset in string table) 324 Elf_Word vda_next; // Offset to next Verdaux entry (in bytes) 325 }; 326 327 /// Elf_Verneed: This is the structure of entries in the SHT_GNU_verneed 328 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 329 template <class ELFT> 330 struct Elf_Verneed_Impl { 331 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 332 Elf_Half vn_version; // Version of this structure (e.g. VER_NEED_CURRENT) 333 Elf_Half vn_cnt; // Number of associated Vernaux entries 334 Elf_Word vn_file; // Library name (string table offset) 335 Elf_Word vn_aux; // Offset to first Vernaux entry (in bytes) 336 Elf_Word vn_next; // Offset to next Verneed entry (in bytes) 337 }; 338 339 /// Elf_Vernaux: This is the structure of auxiliary data in SHT_GNU_verneed 340 /// section (.gnu.version_r). This structure is identical for ELF32 and ELF64. 341 template <class ELFT> 342 struct Elf_Vernaux_Impl { 343 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 344 Elf_Word vna_hash; // Hash of dependency name 345 Elf_Half vna_flags; // Bitwise Flags (VER_FLAG_*) 346 Elf_Half vna_other; // Version index, used in .gnu.version entries 347 Elf_Word vna_name; // Dependency name 348 Elf_Word vna_next; // Offset to next Vernaux entry (in bytes) 349 }; 350 351 /// Elf_Dyn_Base: This structure matches the form of entries in the dynamic 352 /// table section (.dynamic) look like. 353 template <class ELFT> struct Elf_Dyn_Base; 354 355 template <endianness Endianness> 356 struct Elf_Dyn_Base<ELFType<Endianness, false>> { 357 LLVM_ELF_IMPORT_TYPES(Endianness, false) 358 Elf_Sword d_tag; 359 union { 360 Elf_Word d_val; 361 Elf_Addr d_ptr; 362 } d_un; 363 }; 364 365 template <endianness Endianness> 366 struct Elf_Dyn_Base<ELFType<Endianness, true>> { 367 LLVM_ELF_IMPORT_TYPES(Endianness, true) 368 Elf_Sxword d_tag; 369 union { 370 Elf_Xword d_val; 371 Elf_Addr d_ptr; 372 } d_un; 373 }; 374 375 /// Elf_Dyn_Impl: This inherits from Elf_Dyn_Base, adding getters. 376 template <class ELFT> 377 struct Elf_Dyn_Impl : Elf_Dyn_Base<ELFT> { 378 using Elf_Dyn_Base<ELFT>::d_tag; 379 using Elf_Dyn_Base<ELFT>::d_un; 380 using intX_t = std::conditional_t<ELFT::Is64Bits, int64_t, int32_t>; 381 using uintX_t = std::conditional_t<ELFT::Is64Bits, uint64_t, uint32_t>; 382 intX_t getTag() const { return d_tag; } 383 uintX_t getVal() const { return d_un.d_val; } 384 uintX_t getPtr() const { return d_un.d_ptr; } 385 }; 386 387 template <endianness Endianness> 388 struct Elf_Rel_Impl<ELFType<Endianness, false>, false> { 389 LLVM_ELF_IMPORT_TYPES(Endianness, false) 390 static const bool HasAddend = false; 391 static const bool IsCrel = false; 392 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 393 Elf_Word r_info; // Symbol table index and type of relocation to apply 394 395 uint32_t getRInfo(bool isMips64EL) const { 396 assert(!isMips64EL); 397 return r_info; 398 } 399 void setRInfo(uint32_t R, bool IsMips64EL) { 400 assert(!IsMips64EL); 401 r_info = R; 402 } 403 404 // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE, 405 // and ELF32_R_INFO macros defined in the ELF specification: 406 uint32_t getSymbol(bool isMips64EL) const { 407 return this->getRInfo(isMips64EL) >> 8; 408 } 409 unsigned char getType(bool isMips64EL) const { 410 return (unsigned char)(this->getRInfo(isMips64EL) & 0x0ff); 411 } 412 void setSymbol(uint32_t s, bool IsMips64EL) { 413 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 414 } 415 void setType(unsigned char t, bool IsMips64EL) { 416 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 417 } 418 void setSymbolAndType(uint32_t s, unsigned char t, bool IsMips64EL) { 419 this->setRInfo((s << 8) + t, IsMips64EL); 420 } 421 }; 422 423 template <endianness Endianness> 424 struct Elf_Rel_Impl<ELFType<Endianness, false>, true> 425 : public Elf_Rel_Impl<ELFType<Endianness, false>, false> { 426 LLVM_ELF_IMPORT_TYPES(Endianness, false) 427 static const bool HasAddend = true; 428 static const bool IsCrel = false; 429 Elf_Sword r_addend; // Compute value for relocatable field by adding this 430 }; 431 432 template <endianness Endianness> 433 struct Elf_Rel_Impl<ELFType<Endianness, true>, false> { 434 LLVM_ELF_IMPORT_TYPES(Endianness, true) 435 static const bool HasAddend = false; 436 static const bool IsCrel = false; 437 Elf_Addr r_offset; // Location (file byte offset, or program virtual addr) 438 Elf_Xword r_info; // Symbol table index and type of relocation to apply 439 440 uint64_t getRInfo(bool isMips64EL) const { 441 uint64_t t = r_info; 442 if (!isMips64EL) 443 return t; 444 // Mips64 little endian has a "special" encoding of r_info. Instead of one 445 // 64 bit little endian number, it is a little endian 32 bit number followed 446 // by a 32 bit big endian number. 447 return (t << 32) | ((t >> 8) & 0xff000000) | ((t >> 24) & 0x00ff0000) | 448 ((t >> 40) & 0x0000ff00) | ((t >> 56) & 0x000000ff); 449 } 450 451 void setRInfo(uint64_t R, bool IsMips64EL) { 452 if (IsMips64EL) 453 r_info = (R >> 32) | ((R & 0xff000000) << 8) | ((R & 0x00ff0000) << 24) | 454 ((R & 0x0000ff00) << 40) | ((R & 0x000000ff) << 56); 455 else 456 r_info = R; 457 } 458 459 // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE, 460 // and ELF64_R_INFO macros defined in the ELF specification: 461 uint32_t getSymbol(bool isMips64EL) const { 462 return (uint32_t)(this->getRInfo(isMips64EL) >> 32); 463 } 464 uint32_t getType(bool isMips64EL) const { 465 return (uint32_t)(this->getRInfo(isMips64EL) & 0xffffffffL); 466 } 467 void setSymbol(uint32_t s, bool IsMips64EL) { 468 setSymbolAndType(s, getType(IsMips64EL), IsMips64EL); 469 } 470 void setType(uint32_t t, bool IsMips64EL) { 471 setSymbolAndType(getSymbol(IsMips64EL), t, IsMips64EL); 472 } 473 void setSymbolAndType(uint32_t s, uint32_t t, bool IsMips64EL) { 474 this->setRInfo(((uint64_t)s << 32) + (t & 0xffffffffL), IsMips64EL); 475 } 476 }; 477 478 template <endianness Endianness> 479 struct Elf_Rel_Impl<ELFType<Endianness, true>, true> 480 : public Elf_Rel_Impl<ELFType<Endianness, true>, false> { 481 LLVM_ELF_IMPORT_TYPES(Endianness, true) 482 static const bool HasAddend = true; 483 static const bool IsCrel = false; 484 Elf_Sxword r_addend; // Compute value for relocatable field by adding this. 485 }; 486 487 // In-memory representation. The serialized representation uses LEB128. 488 template <bool Is64> struct Elf_Crel_Impl { 489 using uint = std::conditional_t<Is64, uint64_t, uint32_t>; 490 static const bool HasAddend = true; 491 static const bool IsCrel = true; 492 uint r_offset; 493 uint32_t r_symidx; 494 uint32_t r_type; 495 std::conditional_t<Is64, int64_t, int32_t> r_addend; 496 497 // Dummy bool parameter is for compatibility with Elf_Rel_Impl. 498 uint32_t getType(bool) const { return r_type; } 499 uint32_t getSymbol(bool) const { return r_symidx; } 500 void setSymbolAndType(uint32_t s, unsigned char t, bool) { 501 r_symidx = s; 502 r_type = t; 503 } 504 }; 505 506 template <class ELFT> 507 struct Elf_Ehdr_Impl { 508 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 509 unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes 510 Elf_Half e_type; // Type of file (see ET_*) 511 Elf_Half e_machine; // Required architecture for this file (see EM_*) 512 Elf_Word e_version; // Must be equal to 1 513 Elf_Addr e_entry; // Address to jump to in order to start program 514 Elf_Off e_phoff; // Program header table's file offset, in bytes 515 Elf_Off e_shoff; // Section header table's file offset, in bytes 516 Elf_Word e_flags; // Processor-specific flags 517 Elf_Half e_ehsize; // Size of ELF header, in bytes 518 Elf_Half e_phentsize; // Size of an entry in the program header table 519 Elf_Half e_phnum; // Number of entries in the program header table 520 Elf_Half e_shentsize; // Size of an entry in the section header table 521 Elf_Half e_shnum; // Number of entries in the section header table 522 Elf_Half e_shstrndx; // Section header table index of section name 523 // string table 524 525 bool checkMagic() const { 526 return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; 527 } 528 529 unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; } 530 unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; } 531 }; 532 533 template <endianness Endianness> 534 struct Elf_Phdr_Impl<ELFType<Endianness, false>> { 535 LLVM_ELF_IMPORT_TYPES(Endianness, false) 536 Elf_Word p_type; // Type of segment 537 Elf_Off p_offset; // FileOffset where segment is located, in bytes 538 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 539 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 540 Elf_Word p_filesz; // Num. of bytes in file image of segment (may be zero) 541 Elf_Word p_memsz; // Num. of bytes in mem image of segment (may be zero) 542 Elf_Word p_flags; // Segment flags 543 Elf_Word p_align; // Segment alignment constraint 544 }; 545 546 template <endianness Endianness> 547 struct Elf_Phdr_Impl<ELFType<Endianness, true>> { 548 LLVM_ELF_IMPORT_TYPES(Endianness, true) 549 Elf_Word p_type; // Type of segment 550 Elf_Word p_flags; // Segment flags 551 Elf_Off p_offset; // FileOffset where segment is located, in bytes 552 Elf_Addr p_vaddr; // Virtual Address of beginning of segment 553 Elf_Addr p_paddr; // Physical address of beginning of segment (OS-specific) 554 Elf_Xword p_filesz; // Num. of bytes in file image of segment (may be zero) 555 Elf_Xword p_memsz; // Num. of bytes in mem image of segment (may be zero) 556 Elf_Xword p_align; // Segment alignment constraint 557 }; 558 559 // ELFT needed for endianness. 560 template <class ELFT> 561 struct Elf_Hash_Impl { 562 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 563 Elf_Word nbucket; 564 Elf_Word nchain; 565 566 ArrayRef<Elf_Word> buckets() const { 567 return ArrayRef<Elf_Word>(&nbucket + 2, &nbucket + 2 + nbucket); 568 } 569 570 ArrayRef<Elf_Word> chains() const { 571 return ArrayRef<Elf_Word>(&nbucket + 2 + nbucket, 572 &nbucket + 2 + nbucket + nchain); 573 } 574 }; 575 576 // .gnu.hash section 577 template <class ELFT> 578 struct Elf_GnuHash_Impl { 579 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 580 Elf_Word nbuckets; 581 Elf_Word symndx; 582 Elf_Word maskwords; 583 Elf_Word shift2; 584 585 ArrayRef<Elf_Off> filter() const { 586 return ArrayRef<Elf_Off>(reinterpret_cast<const Elf_Off *>(&shift2 + 1), 587 maskwords); 588 } 589 590 ArrayRef<Elf_Word> buckets() const { 591 return ArrayRef<Elf_Word>( 592 reinterpret_cast<const Elf_Word *>(filter().end()), nbuckets); 593 } 594 595 ArrayRef<Elf_Word> values(unsigned DynamicSymCount) const { 596 assert(DynamicSymCount >= symndx); 597 return ArrayRef<Elf_Word>(buckets().end(), DynamicSymCount - symndx); 598 } 599 }; 600 601 // Compressed section headers. 602 // http://www.sco.com/developers/gabi/latest/ch4.sheader.html#compression_header 603 template <endianness Endianness> 604 struct Elf_Chdr_Impl<ELFType<Endianness, false>> { 605 LLVM_ELF_IMPORT_TYPES(Endianness, false) 606 Elf_Word ch_type; 607 Elf_Word ch_size; 608 Elf_Word ch_addralign; 609 }; 610 611 template <endianness Endianness> 612 struct Elf_Chdr_Impl<ELFType<Endianness, true>> { 613 LLVM_ELF_IMPORT_TYPES(Endianness, true) 614 Elf_Word ch_type; 615 Elf_Word ch_reserved; 616 Elf_Xword ch_size; 617 Elf_Xword ch_addralign; 618 }; 619 620 /// Note header 621 template <class ELFT> 622 struct Elf_Nhdr_Impl { 623 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 624 Elf_Word n_namesz; 625 Elf_Word n_descsz; 626 Elf_Word n_type; 627 628 /// Get the size of the note, including name, descriptor, and padding. Both 629 /// the start and the end of the descriptor are aligned by the section 630 /// alignment. In practice many 64-bit systems deviate from the generic ABI by 631 /// using sh_addralign=4. 632 size_t getSize(size_t Align) const { 633 return alignToPowerOf2(sizeof(*this) + n_namesz, Align) + 634 alignToPowerOf2(n_descsz, Align); 635 } 636 }; 637 638 /// An ELF note. 639 /// 640 /// Wraps a note header, providing methods for accessing the name and 641 /// descriptor safely. 642 template <class ELFT> 643 class Elf_Note_Impl { 644 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 645 646 const Elf_Nhdr_Impl<ELFT> &Nhdr; 647 648 template <class NoteIteratorELFT> friend class Elf_Note_Iterator_Impl; 649 650 public: 651 Elf_Note_Impl(const Elf_Nhdr_Impl<ELFT> &Nhdr) : Nhdr(Nhdr) {} 652 653 /// Get the note's name, excluding the terminating null byte. 654 StringRef getName() const { 655 if (!Nhdr.n_namesz) 656 return StringRef(); 657 return StringRef(reinterpret_cast<const char *>(&Nhdr) + sizeof(Nhdr), 658 Nhdr.n_namesz - 1); 659 } 660 661 /// Get the note's descriptor. 662 ArrayRef<uint8_t> getDesc(size_t Align) const { 663 if (!Nhdr.n_descsz) 664 return ArrayRef<uint8_t>(); 665 return ArrayRef<uint8_t>( 666 reinterpret_cast<const uint8_t *>(&Nhdr) + 667 alignToPowerOf2(sizeof(Nhdr) + Nhdr.n_namesz, Align), 668 Nhdr.n_descsz); 669 } 670 671 /// Get the note's descriptor as StringRef 672 StringRef getDescAsStringRef(size_t Align) const { 673 ArrayRef<uint8_t> Desc = getDesc(Align); 674 return StringRef(reinterpret_cast<const char *>(Desc.data()), Desc.size()); 675 } 676 677 /// Get the note's type. 678 Elf_Word getType() const { return Nhdr.n_type; } 679 }; 680 681 template <class ELFT> class Elf_Note_Iterator_Impl { 682 public: 683 using iterator_category = std::forward_iterator_tag; 684 using value_type = Elf_Note_Impl<ELFT>; 685 using difference_type = std::ptrdiff_t; 686 using pointer = value_type *; 687 using reference = value_type &; 688 689 private: 690 // Nhdr being a nullptr marks the end of iteration. 691 const Elf_Nhdr_Impl<ELFT> *Nhdr = nullptr; 692 size_t RemainingSize = 0u; 693 size_t Align = 0; 694 Error *Err = nullptr; 695 696 template <class ELFFileELFT> friend class ELFFile; 697 698 // Stop iteration and indicate an overflow. 699 void stopWithOverflowError() { 700 Nhdr = nullptr; 701 *Err = make_error<StringError>("ELF note overflows container", 702 object_error::parse_failed); 703 } 704 705 // Advance Nhdr by NoteSize bytes, starting from NhdrPos. 706 // 707 // Assumes NoteSize <= RemainingSize. Ensures Nhdr->getSize() <= RemainingSize 708 // upon returning. Handles stopping iteration when reaching the end of the 709 // container, either cleanly or with an overflow error. 710 void advanceNhdr(const uint8_t *NhdrPos, size_t NoteSize) { 711 RemainingSize -= NoteSize; 712 if (RemainingSize == 0u) { 713 // Ensure that if the iterator walks to the end, the error is checked 714 // afterwards. 715 *Err = Error::success(); 716 Nhdr = nullptr; 717 } else if (sizeof(*Nhdr) > RemainingSize) 718 stopWithOverflowError(); 719 else { 720 Nhdr = reinterpret_cast<const Elf_Nhdr_Impl<ELFT> *>(NhdrPos + NoteSize); 721 if (Nhdr->getSize(Align) > RemainingSize) 722 stopWithOverflowError(); 723 else 724 *Err = Error::success(); 725 } 726 } 727 728 Elf_Note_Iterator_Impl() = default; 729 explicit Elf_Note_Iterator_Impl(Error &Err) : Err(&Err) {} 730 Elf_Note_Iterator_Impl(const uint8_t *Start, size_t Size, size_t Align, 731 Error &Err) 732 : RemainingSize(Size), Align(Align), Err(&Err) { 733 consumeError(std::move(Err)); 734 assert(Start && "ELF note iterator starting at NULL"); 735 advanceNhdr(Start, 0u); 736 } 737 738 public: 739 Elf_Note_Iterator_Impl &operator++() { 740 assert(Nhdr && "incremented ELF note end iterator"); 741 const uint8_t *NhdrPos = reinterpret_cast<const uint8_t *>(Nhdr); 742 size_t NoteSize = Nhdr->getSize(Align); 743 advanceNhdr(NhdrPos, NoteSize); 744 return *this; 745 } 746 bool operator==(Elf_Note_Iterator_Impl Other) const { 747 if (!Nhdr && Other.Err) 748 (void)(bool)(*Other.Err); 749 if (!Other.Nhdr && Err) 750 (void)(bool)(*Err); 751 return Nhdr == Other.Nhdr; 752 } 753 bool operator!=(Elf_Note_Iterator_Impl Other) const { 754 return !(*this == Other); 755 } 756 Elf_Note_Impl<ELFT> operator*() const { 757 assert(Nhdr && "dereferenced ELF note end iterator"); 758 return Elf_Note_Impl<ELFT>(*Nhdr); 759 } 760 }; 761 762 template <class ELFT> struct Elf_CGProfile_Impl { 763 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 764 Elf_Xword cgp_weight; 765 }; 766 767 // MIPS .reginfo section 768 template <class ELFT> 769 struct Elf_Mips_RegInfo; 770 771 template <llvm::endianness Endianness> 772 struct Elf_Mips_RegInfo<ELFType<Endianness, false>> { 773 LLVM_ELF_IMPORT_TYPES(Endianness, false) 774 Elf_Word ri_gprmask; // bit-mask of used general registers 775 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 776 Elf_Addr ri_gp_value; // gp register value 777 }; 778 779 template <llvm::endianness Endianness> 780 struct Elf_Mips_RegInfo<ELFType<Endianness, true>> { 781 LLVM_ELF_IMPORT_TYPES(Endianness, true) 782 Elf_Word ri_gprmask; // bit-mask of used general registers 783 Elf_Word ri_pad; // unused padding field 784 Elf_Word ri_cprmask[4]; // bit-mask of used co-processor registers 785 Elf_Addr ri_gp_value; // gp register value 786 }; 787 788 // .MIPS.options section 789 template <class ELFT> struct Elf_Mips_Options { 790 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 791 uint8_t kind; // Determines interpretation of variable part of descriptor 792 uint8_t size; // Byte size of descriptor, including this header 793 Elf_Half section; // Section header index of section affected, 794 // or 0 for global options 795 Elf_Word info; // Kind-specific information 796 797 Elf_Mips_RegInfo<ELFT> &getRegInfo() { 798 assert(kind == ELF::ODK_REGINFO); 799 return *reinterpret_cast<Elf_Mips_RegInfo<ELFT> *>( 800 (uint8_t *)this + sizeof(Elf_Mips_Options)); 801 } 802 const Elf_Mips_RegInfo<ELFT> &getRegInfo() const { 803 return const_cast<Elf_Mips_Options *>(this)->getRegInfo(); 804 } 805 }; 806 807 // .MIPS.abiflags section content 808 template <class ELFT> struct Elf_Mips_ABIFlags { 809 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 810 Elf_Half version; // Version of the structure 811 uint8_t isa_level; // ISA level: 1-5, 32, and 64 812 uint8_t isa_rev; // ISA revision (0 for MIPS I - MIPS V) 813 uint8_t gpr_size; // General purpose registers size 814 uint8_t cpr1_size; // Co-processor 1 registers size 815 uint8_t cpr2_size; // Co-processor 2 registers size 816 uint8_t fp_abi; // Floating-point ABI flag 817 Elf_Word isa_ext; // Processor-specific extension 818 Elf_Word ases; // ASEs flags 819 Elf_Word flags1; // General flags 820 Elf_Word flags2; // General flags 821 }; 822 823 // Struct representing the BBAddrMap for one function. 824 struct BBAddrMap { 825 826 // Bitfield of optional features to control the extra information 827 // emitted/encoded in the the section. 828 struct Features { 829 bool FuncEntryCount : 1; 830 bool BBFreq : 1; 831 bool BrProb : 1; 832 bool MultiBBRange : 1; 833 834 bool hasPGOAnalysis() const { return FuncEntryCount || BBFreq || BrProb; } 835 836 bool hasPGOAnalysisBBData() const { return BBFreq || BrProb; } 837 838 // Encodes to minimum bit width representation. 839 uint8_t encode() const { 840 return (static_cast<uint8_t>(FuncEntryCount) << 0) | 841 (static_cast<uint8_t>(BBFreq) << 1) | 842 (static_cast<uint8_t>(BrProb) << 2) | 843 (static_cast<uint8_t>(MultiBBRange) << 3); 844 } 845 846 // Decodes from minimum bit width representation and validates no 847 // unnecessary bits are used. 848 static Expected<Features> decode(uint8_t Val) { 849 Features Feat{ 850 static_cast<bool>(Val & (1 << 0)), static_cast<bool>(Val & (1 << 1)), 851 static_cast<bool>(Val & (1 << 2)), static_cast<bool>(Val & (1 << 3))}; 852 if (Feat.encode() != Val) 853 return createStringError( 854 std::error_code(), "invalid encoding for BBAddrMap::Features: 0x%x", 855 Val); 856 return Feat; 857 } 858 859 bool operator==(const Features &Other) const { 860 return std::tie(FuncEntryCount, BBFreq, BrProb, MultiBBRange) == 861 std::tie(Other.FuncEntryCount, Other.BBFreq, Other.BrProb, 862 Other.MultiBBRange); 863 } 864 }; 865 866 // Struct representing the BBAddrMap information for one basic block. 867 struct BBEntry { 868 struct Metadata { 869 bool HasReturn : 1; // If this block ends with a return (or tail 870 // call). 871 bool HasTailCall : 1; // If this block ends with a tail call. 872 bool IsEHPad : 1; // If this is an exception handling block. 873 bool CanFallThrough : 1; // If this block can fall through to its next. 874 bool HasIndirectBranch : 1; // If this block ends with an indirect branch 875 // (branch via a register). 876 877 bool operator==(const Metadata &Other) const { 878 return HasReturn == Other.HasReturn && 879 HasTailCall == Other.HasTailCall && IsEHPad == Other.IsEHPad && 880 CanFallThrough == Other.CanFallThrough && 881 HasIndirectBranch == Other.HasIndirectBranch; 882 } 883 884 // Encodes this struct as a uint32_t value. 885 uint32_t encode() const { 886 return static_cast<uint32_t>(HasReturn) | 887 (static_cast<uint32_t>(HasTailCall) << 1) | 888 (static_cast<uint32_t>(IsEHPad) << 2) | 889 (static_cast<uint32_t>(CanFallThrough) << 3) | 890 (static_cast<uint32_t>(HasIndirectBranch) << 4); 891 } 892 893 // Decodes and returns a Metadata struct from a uint32_t value. 894 static Expected<Metadata> decode(uint32_t V) { 895 Metadata MD{/*HasReturn=*/static_cast<bool>(V & 1), 896 /*HasTailCall=*/static_cast<bool>(V & (1 << 1)), 897 /*IsEHPad=*/static_cast<bool>(V & (1 << 2)), 898 /*CanFallThrough=*/static_cast<bool>(V & (1 << 3)), 899 /*HasIndirectBranch=*/static_cast<bool>(V & (1 << 4))}; 900 if (MD.encode() != V) 901 return createStringError( 902 std::error_code(), "invalid encoding for BBEntry::Metadata: 0x%x", 903 V); 904 return MD; 905 } 906 }; 907 908 uint32_t ID = 0; // Unique ID of this basic block. 909 uint32_t Offset = 0; // Offset of basic block relative to the base address. 910 uint32_t Size = 0; // Size of the basic block. 911 Metadata MD = {false, false, false, false, 912 false}; // Metdata for this basic block. 913 914 BBEntry(uint32_t ID, uint32_t Offset, uint32_t Size, Metadata MD) 915 : ID(ID), Offset(Offset), Size(Size), MD(MD){}; 916 917 bool operator==(const BBEntry &Other) const { 918 return ID == Other.ID && Offset == Other.Offset && Size == Other.Size && 919 MD == Other.MD; 920 } 921 922 bool hasReturn() const { return MD.HasReturn; } 923 bool hasTailCall() const { return MD.HasTailCall; } 924 bool isEHPad() const { return MD.IsEHPad; } 925 bool canFallThrough() const { return MD.CanFallThrough; } 926 bool hasIndirectBranch() const { return MD.HasIndirectBranch; } 927 }; 928 929 // Struct representing the BBAddrMap information for a contiguous range of 930 // basic blocks (a function or a basic block section). 931 struct BBRangeEntry { 932 uint64_t BaseAddress = 0; // Base address of the range. 933 std::vector<BBEntry> BBEntries; // Basic block entries for this range. 934 935 // Equality operator for unit testing. 936 bool operator==(const BBRangeEntry &Other) const { 937 return BaseAddress == Other.BaseAddress && 938 std::equal(BBEntries.begin(), BBEntries.end(), 939 Other.BBEntries.begin()); 940 } 941 }; 942 943 // All ranges for this function. Cannot be empty. The first range always 944 // corresponds to the function entry. 945 std::vector<BBRangeEntry> BBRanges; 946 947 // Returns the function address associated with this BBAddrMap, which is 948 // stored as the `BaseAddress` of its first BBRangeEntry. 949 uint64_t getFunctionAddress() const { 950 assert(!BBRanges.empty()); 951 return BBRanges.front().BaseAddress; 952 } 953 954 // Returns the total number of bb entries in all bb ranges. 955 size_t getNumBBEntries() const { 956 size_t NumBBEntries = 0; 957 for (const auto &BBR : BBRanges) 958 NumBBEntries += BBR.BBEntries.size(); 959 return NumBBEntries; 960 } 961 962 // Returns the index of the bb range with the given base address, or 963 // `std::nullopt` if no such range exists. 964 std::optional<size_t> 965 getBBRangeIndexForBaseAddress(uint64_t BaseAddress) const { 966 for (size_t I = 0; I < BBRanges.size(); ++I) 967 if (BBRanges[I].BaseAddress == BaseAddress) 968 return I; 969 return {}; 970 } 971 972 // Returns bb entries in the first range. 973 const std::vector<BBEntry> &getBBEntries() const { 974 return BBRanges.front().BBEntries; 975 } 976 977 const std::vector<BBRangeEntry> &getBBRanges() const { return BBRanges; } 978 979 // Equality operator for unit testing. 980 bool operator==(const BBAddrMap &Other) const { 981 return std::equal(BBRanges.begin(), BBRanges.end(), Other.BBRanges.begin()); 982 } 983 }; 984 985 /// A feature extension of BBAddrMap that holds information relevant to PGO. 986 struct PGOAnalysisMap { 987 /// Extra basic block data with fields for block frequency and branch 988 /// probability. 989 struct PGOBBEntry { 990 /// Single successor of a given basic block that contains the tag and branch 991 /// probability associated with it. 992 struct SuccessorEntry { 993 /// Unique ID of this successor basic block. 994 uint32_t ID; 995 /// Branch Probability of the edge to this successor taken from MBPI. 996 BranchProbability Prob; 997 998 bool operator==(const SuccessorEntry &Other) const { 999 return std::tie(ID, Prob) == std::tie(Other.ID, Other.Prob); 1000 } 1001 }; 1002 1003 /// Block frequency taken from MBFI 1004 BlockFrequency BlockFreq; 1005 /// List of successors of the current block 1006 llvm::SmallVector<SuccessorEntry, 2> Successors; 1007 1008 bool operator==(const PGOBBEntry &Other) const { 1009 return std::tie(BlockFreq, Successors) == 1010 std::tie(Other.BlockFreq, Other.Successors); 1011 } 1012 }; 1013 1014 uint64_t FuncEntryCount; // Prof count from IR function 1015 std::vector<PGOBBEntry> BBEntries; // Extended basic block entries 1016 1017 // Flags to indicate if each PGO related info was enabled in this function 1018 BBAddrMap::Features FeatEnable; 1019 1020 bool operator==(const PGOAnalysisMap &Other) const { 1021 return std::tie(FuncEntryCount, BBEntries, FeatEnable) == 1022 std::tie(Other.FuncEntryCount, Other.BBEntries, Other.FeatEnable); 1023 } 1024 }; 1025 1026 } // end namespace object. 1027 } // end namespace llvm. 1028 1029 #endif // LLVM_OBJECT_ELFTYPES_H 1030