1 //===- ELFObjectFile.cpp - ELF object file implementation -------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines the ELFObjectFile class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/ADT/SmallVector.h" 15 #include "llvm/ADT/StringSwitch.h" 16 #include "llvm/ADT/Triple.h" 17 #include "llvm/Object/ObjectFile.h" 18 #include "llvm/Support/ELF.h" 19 #include "llvm/Support/Endian.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include "llvm/Support/MemoryBuffer.h" 22 #include <limits> 23 #include <utility> 24 25 using namespace llvm; 26 using namespace object; 27 28 // Templates to choose Elf_Addr and Elf_Off depending on is64Bits. 29 namespace { 30 template<support::endianness target_endianness> 31 struct ELFDataTypeTypedefHelperCommon { 32 typedef support::detail::packed_endian_specific_integral 33 <uint16_t, target_endianness, support::aligned> Elf_Half; 34 typedef support::detail::packed_endian_specific_integral 35 <uint32_t, target_endianness, support::aligned> Elf_Word; 36 typedef support::detail::packed_endian_specific_integral 37 <int32_t, target_endianness, support::aligned> Elf_Sword; 38 typedef support::detail::packed_endian_specific_integral 39 <uint64_t, target_endianness, support::aligned> Elf_Xword; 40 typedef support::detail::packed_endian_specific_integral 41 <int64_t, target_endianness, support::aligned> Elf_Sxword; 42 }; 43 } 44 45 namespace { 46 template<support::endianness target_endianness, bool is64Bits> 47 struct ELFDataTypeTypedefHelper; 48 49 /// ELF 32bit types. 50 template<support::endianness target_endianness> 51 struct ELFDataTypeTypedefHelper<target_endianness, false> 52 : ELFDataTypeTypedefHelperCommon<target_endianness> { 53 typedef support::detail::packed_endian_specific_integral 54 <uint32_t, target_endianness, support::aligned> Elf_Addr; 55 typedef support::detail::packed_endian_specific_integral 56 <uint32_t, target_endianness, support::aligned> Elf_Off; 57 }; 58 59 /// ELF 64bit types. 60 template<support::endianness target_endianness> 61 struct ELFDataTypeTypedefHelper<target_endianness, true> 62 : ELFDataTypeTypedefHelperCommon<target_endianness>{ 63 typedef support::detail::packed_endian_specific_integral 64 <uint64_t, target_endianness, support::aligned> Elf_Addr; 65 typedef support::detail::packed_endian_specific_integral 66 <uint64_t, target_endianness, support::aligned> Elf_Off; 67 }; 68 } 69 70 // I really don't like doing this, but the alternative is copypasta. 71 #define LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits) \ 72 typedef typename \ 73 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Addr Elf_Addr; \ 74 typedef typename \ 75 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Off Elf_Off; \ 76 typedef typename \ 77 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Half Elf_Half; \ 78 typedef typename \ 79 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Word Elf_Word; \ 80 typedef typename \ 81 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Sword Elf_Sword; \ 82 typedef typename \ 83 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Xword Elf_Xword; \ 84 typedef typename \ 85 ELFDataTypeTypedefHelper<target_endianness, is64Bits>::Elf_Sxword Elf_Sxword; 86 87 // Section header. 88 namespace { 89 template<support::endianness target_endianness, bool is64Bits> 90 struct Elf_Shdr_Base; 91 92 template<support::endianness target_endianness> 93 struct Elf_Shdr_Base<target_endianness, false> { 94 LLVM_ELF_IMPORT_TYPES(target_endianness, false) 95 Elf_Word sh_name; // Section name (index into string table) 96 Elf_Word sh_type; // Section type (SHT_*) 97 Elf_Word sh_flags; // Section flags (SHF_*) 98 Elf_Addr sh_addr; // Address where section is to be loaded 99 Elf_Off sh_offset; // File offset of section data, in bytes 100 Elf_Word sh_size; // Size of section, in bytes 101 Elf_Word sh_link; // Section type-specific header table index link 102 Elf_Word sh_info; // Section type-specific extra information 103 Elf_Word sh_addralign;// Section address alignment 104 Elf_Word sh_entsize; // Size of records contained within the section 105 }; 106 107 template<support::endianness target_endianness> 108 struct Elf_Shdr_Base<target_endianness, true> { 109 LLVM_ELF_IMPORT_TYPES(target_endianness, true) 110 Elf_Word sh_name; // Section name (index into string table) 111 Elf_Word sh_type; // Section type (SHT_*) 112 Elf_Xword sh_flags; // Section flags (SHF_*) 113 Elf_Addr sh_addr; // Address where section is to be loaded 114 Elf_Off sh_offset; // File offset of section data, in bytes 115 Elf_Xword sh_size; // Size of section, in bytes 116 Elf_Word sh_link; // Section type-specific header table index link 117 Elf_Word sh_info; // Section type-specific extra information 118 Elf_Xword sh_addralign;// Section address alignment 119 Elf_Xword sh_entsize; // Size of records contained within the section 120 }; 121 122 template<support::endianness target_endianness, bool is64Bits> 123 struct Elf_Shdr_Impl : Elf_Shdr_Base<target_endianness, is64Bits> { 124 using Elf_Shdr_Base<target_endianness, is64Bits>::sh_entsize; 125 using Elf_Shdr_Base<target_endianness, is64Bits>::sh_size; 126 127 /// @brief Get the number of entities this section contains if it has any. 128 unsigned getEntityCount() const { 129 if (sh_entsize == 0) 130 return 0; 131 return sh_size / sh_entsize; 132 } 133 }; 134 } 135 136 namespace { 137 template<support::endianness target_endianness, bool is64Bits> 138 struct Elf_Sym_Base; 139 140 template<support::endianness target_endianness> 141 struct Elf_Sym_Base<target_endianness, false> { 142 LLVM_ELF_IMPORT_TYPES(target_endianness, false) 143 Elf_Word st_name; // Symbol name (index into string table) 144 Elf_Addr st_value; // Value or address associated with the symbol 145 Elf_Word st_size; // Size of the symbol 146 unsigned char st_info; // Symbol's type and binding attributes 147 unsigned char st_other; // Must be zero; reserved 148 Elf_Half st_shndx; // Which section (header table index) it's defined in 149 }; 150 151 template<support::endianness target_endianness> 152 struct Elf_Sym_Base<target_endianness, true> { 153 LLVM_ELF_IMPORT_TYPES(target_endianness, true) 154 Elf_Word st_name; // Symbol name (index into string table) 155 unsigned char st_info; // Symbol's type and binding attributes 156 unsigned char st_other; // Must be zero; reserved 157 Elf_Half st_shndx; // Which section (header table index) it's defined in 158 Elf_Addr st_value; // Value or address associated with the symbol 159 Elf_Xword st_size; // Size of the symbol 160 }; 161 162 template<support::endianness target_endianness, bool is64Bits> 163 struct Elf_Sym_Impl : Elf_Sym_Base<target_endianness, is64Bits> { 164 using Elf_Sym_Base<target_endianness, is64Bits>::st_info; 165 166 // These accessors and mutators correspond to the ELF32_ST_BIND, 167 // ELF32_ST_TYPE, and ELF32_ST_INFO macros defined in the ELF specification: 168 unsigned char getBinding() const { return st_info >> 4; } 169 unsigned char getType() const { return st_info & 0x0f; } 170 void setBinding(unsigned char b) { setBindingAndType(b, getType()); } 171 void setType(unsigned char t) { setBindingAndType(getBinding(), t); } 172 void setBindingAndType(unsigned char b, unsigned char t) { 173 st_info = (b << 4) + (t & 0x0f); 174 } 175 }; 176 } 177 178 namespace { 179 template<support::endianness target_endianness, bool is64Bits> 180 class ELFObjectFile : public ObjectFile { 181 LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits) 182 183 typedef Elf_Shdr_Impl<target_endianness, is64Bits> Elf_Shdr; 184 typedef Elf_Sym_Impl<target_endianness, is64Bits> Elf_Sym; 185 186 struct Elf_Ehdr { 187 unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes 188 Elf_Half e_type; // Type of file (see ET_*) 189 Elf_Half e_machine; // Required architecture for this file (see EM_*) 190 Elf_Word e_version; // Must be equal to 1 191 Elf_Addr e_entry; // Address to jump to in order to start program 192 Elf_Off e_phoff; // Program header table's file offset, in bytes 193 Elf_Off e_shoff; // Section header table's file offset, in bytes 194 Elf_Word e_flags; // Processor-specific flags 195 Elf_Half e_ehsize; // Size of ELF header, in bytes 196 Elf_Half e_phentsize;// Size of an entry in the program header table 197 Elf_Half e_phnum; // Number of entries in the program header table 198 Elf_Half e_shentsize;// Size of an entry in the section header table 199 Elf_Half e_shnum; // Number of entries in the section header table 200 Elf_Half e_shstrndx; // Section header table index of section name 201 // string table 202 bool checkMagic() const { 203 return (memcmp(e_ident, ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; 204 } 205 unsigned char getFileClass() const { return e_ident[ELF::EI_CLASS]; } 206 unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; } 207 }; 208 209 typedef SmallVector<const Elf_Shdr*, 1> SymbolTableSections_t; 210 211 const Elf_Ehdr *Header; 212 const Elf_Shdr *SectionHeaderTable; 213 const Elf_Shdr *dot_shstrtab_sec; // Section header string table. 214 const Elf_Shdr *dot_strtab_sec; // Symbol header string table. 215 SymbolTableSections_t SymbolTableSections; 216 217 void validateSymbol(DataRefImpl Symb) const; 218 const Elf_Sym *getSymbol(DataRefImpl Symb) const; 219 const Elf_Shdr *getSection(DataRefImpl index) const; 220 const Elf_Shdr *getSection(uint16_t index) const; 221 const char *getString(uint16_t section, uint32_t offset) const; 222 const char *getString(const Elf_Shdr *section, uint32_t offset) const; 223 224 protected: 225 virtual SymbolRef getSymbolNext(DataRefImpl Symb) const; 226 virtual StringRef getSymbolName(DataRefImpl Symb) const; 227 virtual uint64_t getSymbolAddress(DataRefImpl Symb) const; 228 virtual uint64_t getSymbolSize(DataRefImpl Symb) const; 229 virtual char getSymbolNMTypeChar(DataRefImpl Symb) const; 230 virtual bool isSymbolInternal(DataRefImpl Symb) const; 231 232 virtual SectionRef getSectionNext(DataRefImpl Sec) const; 233 virtual StringRef getSectionName(DataRefImpl Sec) const; 234 virtual uint64_t getSectionAddress(DataRefImpl Sec) const; 235 virtual uint64_t getSectionSize(DataRefImpl Sec) const; 236 virtual StringRef getSectionContents(DataRefImpl Sec) const; 237 virtual bool isSectionText(DataRefImpl Sec) const; 238 239 public: 240 ELFObjectFile(MemoryBuffer *Object, error_code &ec); 241 virtual symbol_iterator begin_symbols() const; 242 virtual symbol_iterator end_symbols() const; 243 virtual section_iterator begin_sections() const; 244 virtual section_iterator end_sections() const; 245 246 virtual uint8_t getBytesInAddress() const; 247 virtual StringRef getFileFormatName() const; 248 virtual unsigned getArch() const; 249 }; 250 } // end namespace 251 252 template<support::endianness target_endianness, bool is64Bits> 253 void ELFObjectFile<target_endianness, is64Bits> 254 ::validateSymbol(DataRefImpl Symb) const { 255 const Elf_Sym *symb = getSymbol(Symb); 256 const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b]; 257 // FIXME: We really need to do proper error handling in the case of an invalid 258 // input file. Because we don't use exceptions, I think we'll just pass 259 // an error object around. 260 if (!( symb 261 && SymbolTableSection 262 && symb >= (const Elf_Sym*)(base() 263 + SymbolTableSection->sh_offset) 264 && symb < (const Elf_Sym*)(base() 265 + SymbolTableSection->sh_offset 266 + SymbolTableSection->sh_size))) 267 // FIXME: Proper error handling. 268 report_fatal_error("Symb must point to a valid symbol!"); 269 } 270 271 template<support::endianness target_endianness, bool is64Bits> 272 SymbolRef ELFObjectFile<target_endianness, is64Bits> 273 ::getSymbolNext(DataRefImpl Symb) const { 274 validateSymbol(Symb); 275 const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b]; 276 277 ++Symb.d.a; 278 // Check to see if we are at the end of this symbol table. 279 if (Symb.d.a >= SymbolTableSection->getEntityCount()) { 280 // We are at the end. If there are other symbol tables, jump to them. 281 ++Symb.d.b; 282 Symb.d.a = 1; // The 0th symbol in ELF is fake. 283 // Otherwise return the terminator. 284 if (Symb.d.b >= SymbolTableSections.size()) { 285 Symb.d.a = std::numeric_limits<uint32_t>::max(); 286 Symb.d.b = std::numeric_limits<uint32_t>::max(); 287 } 288 } 289 290 return SymbolRef(Symb, this); 291 } 292 293 template<support::endianness target_endianness, bool is64Bits> 294 StringRef ELFObjectFile<target_endianness, is64Bits> 295 ::getSymbolName(DataRefImpl Symb) const { 296 validateSymbol(Symb); 297 const Elf_Sym *symb = getSymbol(Symb); 298 if (symb->st_name == 0) { 299 const Elf_Shdr *section = getSection(symb->st_shndx); 300 if (!section) 301 return ""; 302 return getString(dot_shstrtab_sec, section->sh_name); 303 } 304 305 // Use the default symbol table name section. 306 return getString(dot_strtab_sec, symb->st_name); 307 } 308 309 template<support::endianness target_endianness, bool is64Bits> 310 uint64_t ELFObjectFile<target_endianness, is64Bits> 311 ::getSymbolAddress(DataRefImpl Symb) const { 312 validateSymbol(Symb); 313 const Elf_Sym *symb = getSymbol(Symb); 314 const Elf_Shdr *Section; 315 switch (symb->st_shndx) { 316 case ELF::SHN_COMMON: 317 // Undefined symbols have no address yet. 318 case ELF::SHN_UNDEF: return UnknownAddressOrSize; 319 case ELF::SHN_ABS: return symb->st_value; 320 default: Section = getSection(symb->st_shndx); 321 } 322 323 switch (symb->getType()) { 324 case ELF::STT_SECTION: return Section ? Section->sh_addr 325 : UnknownAddressOrSize; 326 case ELF::STT_FUNC: 327 case ELF::STT_OBJECT: 328 case ELF::STT_NOTYPE: 329 return symb->st_value; 330 default: return UnknownAddressOrSize; 331 } 332 } 333 334 template<support::endianness target_endianness, bool is64Bits> 335 uint64_t ELFObjectFile<target_endianness, is64Bits> 336 ::getSymbolSize(DataRefImpl Symb) const { 337 validateSymbol(Symb); 338 const Elf_Sym *symb = getSymbol(Symb); 339 if (symb->st_size == 0) 340 return UnknownAddressOrSize; 341 return symb->st_size; 342 } 343 344 template<support::endianness target_endianness, bool is64Bits> 345 char ELFObjectFile<target_endianness, is64Bits> 346 ::getSymbolNMTypeChar(DataRefImpl Symb) const { 347 validateSymbol(Symb); 348 const Elf_Sym *symb = getSymbol(Symb); 349 const Elf_Shdr *Section = getSection(symb->st_shndx); 350 351 char ret = '?'; 352 353 if (Section) { 354 switch (Section->sh_type) { 355 case ELF::SHT_PROGBITS: 356 case ELF::SHT_DYNAMIC: 357 switch (Section->sh_flags) { 358 case (ELF::SHF_ALLOC | ELF::SHF_EXECINSTR): 359 ret = 't'; break; 360 case (ELF::SHF_ALLOC | ELF::SHF_WRITE): 361 ret = 'd'; break; 362 case ELF::SHF_ALLOC: 363 case (ELF::SHF_ALLOC | ELF::SHF_MERGE): 364 case (ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::SHF_STRINGS): 365 ret = 'r'; break; 366 } 367 break; 368 case ELF::SHT_NOBITS: ret = 'b'; 369 } 370 } 371 372 switch (symb->st_shndx) { 373 case ELF::SHN_UNDEF: 374 if (ret == '?') 375 ret = 'U'; 376 break; 377 case ELF::SHN_ABS: ret = 'a'; break; 378 case ELF::SHN_COMMON: ret = 'c'; break; 379 } 380 381 switch (symb->getBinding()) { 382 case ELF::STB_GLOBAL: ret = ::toupper(ret); break; 383 case ELF::STB_WEAK: 384 if (symb->st_shndx == ELF::SHN_UNDEF) 385 ret = 'w'; 386 else 387 if (symb->getType() == ELF::STT_OBJECT) 388 ret = 'V'; 389 else 390 ret = 'W'; 391 } 392 393 if (ret == '?' && symb->getType() == ELF::STT_SECTION) 394 return StringSwitch<char>(getSymbolName(Symb)) 395 .StartsWith(".debug", 'N') 396 .StartsWith(".note", 'n'); 397 398 return ret; 399 } 400 401 template<support::endianness target_endianness, bool is64Bits> 402 bool ELFObjectFile<target_endianness, is64Bits> 403 ::isSymbolInternal(DataRefImpl Symb) const { 404 validateSymbol(Symb); 405 const Elf_Sym *symb = getSymbol(Symb); 406 407 if ( symb->getType() == ELF::STT_FILE 408 || symb->getType() == ELF::STT_SECTION) 409 return true; 410 return false; 411 } 412 413 template<support::endianness target_endianness, bool is64Bits> 414 SectionRef ELFObjectFile<target_endianness, is64Bits> 415 ::getSectionNext(DataRefImpl Sec) const { 416 const uint8_t *sec = reinterpret_cast<const uint8_t *>(Sec.p); 417 sec += Header->e_shentsize; 418 Sec.p = reinterpret_cast<intptr_t>(sec); 419 return SectionRef(Sec, this); 420 } 421 422 template<support::endianness target_endianness, bool is64Bits> 423 StringRef ELFObjectFile<target_endianness, is64Bits> 424 ::getSectionName(DataRefImpl Sec) const { 425 const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p); 426 return StringRef(getString(dot_shstrtab_sec, sec->sh_name)); 427 } 428 429 template<support::endianness target_endianness, bool is64Bits> 430 uint64_t ELFObjectFile<target_endianness, is64Bits> 431 ::getSectionAddress(DataRefImpl Sec) const { 432 const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p); 433 return sec->sh_addr; 434 } 435 436 template<support::endianness target_endianness, bool is64Bits> 437 uint64_t ELFObjectFile<target_endianness, is64Bits> 438 ::getSectionSize(DataRefImpl Sec) const { 439 const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p); 440 return sec->sh_size; 441 } 442 443 template<support::endianness target_endianness, bool is64Bits> 444 StringRef ELFObjectFile<target_endianness, is64Bits> 445 ::getSectionContents(DataRefImpl Sec) const { 446 const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p); 447 const char *start = (char*)base() + sec->sh_offset; 448 return StringRef(start, sec->sh_size); 449 } 450 451 template<support::endianness target_endianness, bool is64Bits> 452 bool ELFObjectFile<target_endianness, is64Bits> 453 ::isSectionText(DataRefImpl Sec) const { 454 const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p); 455 if (sec->sh_flags & ELF::SHF_EXECINSTR) 456 return true; 457 return false; 458 } 459 460 template<support::endianness target_endianness, bool is64Bits> 461 ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object 462 , error_code &ec) 463 : ObjectFile(Binary::isELF, Object, ec) 464 , SectionHeaderTable(0) 465 , dot_shstrtab_sec(0) 466 , dot_strtab_sec(0) { 467 Header = reinterpret_cast<const Elf_Ehdr *>(base()); 468 469 if (Header->e_shoff == 0) 470 return; 471 472 SectionHeaderTable = 473 reinterpret_cast<const Elf_Shdr *>(base() + Header->e_shoff); 474 uint32_t SectionTableSize = Header->e_shnum * Header->e_shentsize; 475 if (!( (const uint8_t *)SectionHeaderTable + SectionTableSize 476 <= base() + Data->getBufferSize())) 477 // FIXME: Proper error handling. 478 report_fatal_error("Section table goes past end of file!"); 479 480 481 // To find the symbol tables we walk the section table to find SHT_STMTAB. 482 for (const char *i = reinterpret_cast<const char *>(SectionHeaderTable), 483 *e = i + Header->e_shnum * Header->e_shentsize; 484 i != e; i += Header->e_shentsize) { 485 const Elf_Shdr *sh = reinterpret_cast<const Elf_Shdr*>(i); 486 if (sh->sh_type == ELF::SHT_SYMTAB) { 487 SymbolTableSections.push_back(sh); 488 } 489 } 490 491 // Get string table sections. 492 dot_shstrtab_sec = getSection(Header->e_shstrndx); 493 if (dot_shstrtab_sec) { 494 // Verify that the last byte in the string table in a null. 495 if (((const char*)base() + dot_shstrtab_sec->sh_offset) 496 [dot_shstrtab_sec->sh_size - 1] != 0) 497 // FIXME: Proper error handling. 498 report_fatal_error("String table must end with a null terminator!"); 499 } 500 501 // Merge this into the above loop. 502 for (const char *i = reinterpret_cast<const char *>(SectionHeaderTable), 503 *e = i + Header->e_shnum * Header->e_shentsize; 504 i != e; i += Header->e_shentsize) { 505 const Elf_Shdr *sh = reinterpret_cast<const Elf_Shdr*>(i); 506 if (sh->sh_type == ELF::SHT_STRTAB) { 507 StringRef SectionName(getString(dot_shstrtab_sec, sh->sh_name)); 508 if (SectionName == ".strtab") { 509 if (dot_strtab_sec != 0) 510 // FIXME: Proper error handling. 511 report_fatal_error("Already found section named .strtab!"); 512 dot_strtab_sec = sh; 513 const char *dot_strtab = (const char*)base() + sh->sh_offset; 514 if (dot_strtab[sh->sh_size - 1] != 0) 515 // FIXME: Proper error handling. 516 report_fatal_error("String table must end with a null terminator!"); 517 } 518 } 519 } 520 } 521 522 template<support::endianness target_endianness, bool is64Bits> 523 ObjectFile::symbol_iterator ELFObjectFile<target_endianness, is64Bits> 524 ::begin_symbols() const { 525 DataRefImpl SymbolData; 526 memset(&SymbolData, 0, sizeof(SymbolData)); 527 if (SymbolTableSections.size() == 0) { 528 SymbolData.d.a = std::numeric_limits<uint32_t>::max(); 529 SymbolData.d.b = std::numeric_limits<uint32_t>::max(); 530 } else { 531 SymbolData.d.a = 1; // The 0th symbol in ELF is fake. 532 SymbolData.d.b = 0; 533 } 534 return symbol_iterator(SymbolRef(SymbolData, this)); 535 } 536 537 template<support::endianness target_endianness, bool is64Bits> 538 ObjectFile::symbol_iterator ELFObjectFile<target_endianness, is64Bits> 539 ::end_symbols() const { 540 DataRefImpl SymbolData; 541 memset(&SymbolData, 0, sizeof(SymbolData)); 542 SymbolData.d.a = std::numeric_limits<uint32_t>::max(); 543 SymbolData.d.b = std::numeric_limits<uint32_t>::max(); 544 return symbol_iterator(SymbolRef(SymbolData, this)); 545 } 546 547 template<support::endianness target_endianness, bool is64Bits> 548 ObjectFile::section_iterator ELFObjectFile<target_endianness, is64Bits> 549 ::begin_sections() const { 550 DataRefImpl ret; 551 memset(&ret, 0, sizeof(DataRefImpl)); 552 ret.p = reinterpret_cast<intptr_t>(base() + Header->e_shoff); 553 return section_iterator(SectionRef(ret, this)); 554 } 555 556 template<support::endianness target_endianness, bool is64Bits> 557 ObjectFile::section_iterator ELFObjectFile<target_endianness, is64Bits> 558 ::end_sections() const { 559 DataRefImpl ret; 560 memset(&ret, 0, sizeof(DataRefImpl)); 561 ret.p = reinterpret_cast<intptr_t>(base() 562 + Header->e_shoff 563 + (Header->e_shentsize * Header->e_shnum)); 564 return section_iterator(SectionRef(ret, this)); 565 } 566 567 template<support::endianness target_endianness, bool is64Bits> 568 uint8_t ELFObjectFile<target_endianness, is64Bits>::getBytesInAddress() const { 569 return is64Bits ? 8 : 4; 570 } 571 572 template<support::endianness target_endianness, bool is64Bits> 573 StringRef ELFObjectFile<target_endianness, is64Bits> 574 ::getFileFormatName() const { 575 switch(Header->e_ident[ELF::EI_CLASS]) { 576 case ELF::ELFCLASS32: 577 switch(Header->e_machine) { 578 case ELF::EM_386: 579 return "ELF32-i386"; 580 case ELF::EM_X86_64: 581 return "ELF32-x86-64"; 582 default: 583 return "ELF32-unknown"; 584 } 585 case ELF::ELFCLASS64: 586 switch(Header->e_machine) { 587 case ELF::EM_386: 588 return "ELF64-i386"; 589 case ELF::EM_X86_64: 590 return "ELF64-x86-64"; 591 default: 592 return "ELF64-unknown"; 593 } 594 default: 595 // FIXME: Proper error handling. 596 report_fatal_error("Invalid ELFCLASS!"); 597 } 598 } 599 600 template<support::endianness target_endianness, bool is64Bits> 601 unsigned ELFObjectFile<target_endianness, is64Bits>::getArch() const { 602 switch(Header->e_machine) { 603 case ELF::EM_386: 604 return Triple::x86; 605 case ELF::EM_X86_64: 606 return Triple::x86_64; 607 default: 608 return Triple::UnknownArch; 609 } 610 } 611 612 template<support::endianness target_endianness, bool is64Bits> 613 const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Sym * 614 ELFObjectFile<target_endianness, is64Bits>::getSymbol(DataRefImpl Symb) const { 615 const Elf_Shdr *sec = SymbolTableSections[Symb.d.b]; 616 return reinterpret_cast<const Elf_Sym *>( 617 base() 618 + sec->sh_offset 619 + (Symb.d.a * sec->sh_entsize)); 620 } 621 622 template<support::endianness target_endianness, bool is64Bits> 623 const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Shdr * 624 ELFObjectFile<target_endianness, is64Bits>::getSection(DataRefImpl Symb) const { 625 const Elf_Shdr *sec = getSection(Symb.d.b); 626 if (sec->sh_type != ELF::SHT_SYMTAB) 627 // FIXME: Proper error handling. 628 report_fatal_error("Invalid symbol table section!"); 629 return sec; 630 } 631 632 template<support::endianness target_endianness, bool is64Bits> 633 const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Shdr * 634 ELFObjectFile<target_endianness, is64Bits>::getSection(uint16_t index) const { 635 if (index == 0 || index >= ELF::SHN_LORESERVE) 636 return 0; 637 if (!SectionHeaderTable || index >= Header->e_shnum) 638 // FIXME: Proper error handling. 639 report_fatal_error("Invalid section index!"); 640 641 return reinterpret_cast<const Elf_Shdr *>( 642 reinterpret_cast<const char *>(SectionHeaderTable) 643 + (index * Header->e_shentsize)); 644 } 645 646 template<support::endianness target_endianness, bool is64Bits> 647 const char *ELFObjectFile<target_endianness, is64Bits> 648 ::getString(uint16_t section, 649 ELF::Elf32_Word offset) const { 650 return getString(getSection(section), offset); 651 } 652 653 template<support::endianness target_endianness, bool is64Bits> 654 const char *ELFObjectFile<target_endianness, is64Bits> 655 ::getString(const Elf_Shdr *section, 656 ELF::Elf32_Word offset) const { 657 assert(section && section->sh_type == ELF::SHT_STRTAB && "Invalid section!"); 658 if (offset >= section->sh_size) 659 // FIXME: Proper error handling. 660 report_fatal_error("Symbol name offset outside of string table!"); 661 return (const char *)base() + section->sh_offset + offset; 662 } 663 664 // EI_CLASS, EI_DATA. 665 static std::pair<unsigned char, unsigned char> 666 getElfArchType(MemoryBuffer *Object) { 667 if (Object->getBufferSize() < ELF::EI_NIDENT) 668 return std::make_pair((uint8_t)ELF::ELFCLASSNONE,(uint8_t)ELF::ELFDATANONE); 669 return std::make_pair( (uint8_t)Object->getBufferStart()[ELF::EI_CLASS] 670 , (uint8_t)Object->getBufferStart()[ELF::EI_DATA]); 671 } 672 673 namespace llvm { 674 675 ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) { 676 std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object); 677 error_code ec; 678 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) 679 return new ELFObjectFile<support::little, false>(Object, ec); 680 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) 681 return new ELFObjectFile<support::big, false>(Object, ec); 682 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) 683 return new ELFObjectFile<support::little, true>(Object, ec); 684 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) 685 return new ELFObjectFile<support::big, true>(Object, ec); 686 // FIXME: Proper error handling. 687 report_fatal_error("Not an ELF object file!"); 688 } 689 690 } // end namespace llvm 691