1 //===- ELF.h - ELF object file implementation -------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the ELFFile template class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_OBJECT_ELF_H
15 #define LLVM_OBJECT_ELF_H
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/PointerIntPair.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/StringSwitch.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/Object/ELFTypes.h"
24 #include "llvm/Object/Error.h"
25 #include "llvm/Support/Casting.h"
26 #include "llvm/Support/ELF.h"
27 #include "llvm/Support/Endian.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/ErrorOr.h"
30 #include "llvm/Support/MemoryBuffer.h"
31 #include "llvm/Support/raw_ostream.h"
39 StringRef getELFRelocationTypeName(uint32_t Machine, uint32_t Type);
41 // Subclasses of ELFFile may need this for template instantiation
42 inline std::pair<unsigned char, unsigned char>
43 getElfArchType(StringRef Object) {
44 if (Object.size() < ELF::EI_NIDENT)
45 return std::make_pair((uint8_t)ELF::ELFCLASSNONE,
46 (uint8_t)ELF::ELFDATANONE);
47 return std::make_pair((uint8_t)Object[ELF::EI_CLASS],
48 (uint8_t)Object[ELF::EI_DATA]);
54 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
55 typedef typename std::conditional<ELFT::Is64Bits,
56 uint64_t, uint32_t>::type uintX_t;
58 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
59 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
60 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
61 typedef Elf_Dyn_Impl<ELFT> Elf_Dyn;
62 typedef Elf_Phdr_Impl<ELFT> Elf_Phdr;
63 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
64 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
65 typedef Elf_Verdef_Impl<ELFT> Elf_Verdef;
66 typedef Elf_Verdaux_Impl<ELFT> Elf_Verdaux;
67 typedef Elf_Verneed_Impl<ELFT> Elf_Verneed;
68 typedef Elf_Vernaux_Impl<ELFT> Elf_Vernaux;
69 typedef Elf_Versym_Impl<ELFT> Elf_Versym;
70 typedef Elf_Hash_Impl<ELFT> Elf_Hash;
71 typedef iterator_range<const Elf_Dyn *> Elf_Dyn_Range;
72 typedef iterator_range<const Elf_Shdr *> Elf_Shdr_Range;
74 /// \brief Archive files are 2 byte aligned, so we need this for
75 /// PointerIntPair to work.
77 class ArchivePointerTypeTraits {
79 static inline const void *getAsVoidPointer(T *P) { return P; }
80 static inline T *getFromVoidPointer(const void *P) {
81 return static_cast<T *>(P);
83 enum { NumLowBitsAvailable = 1 };
86 typedef iterator_range<const Elf_Sym *> Elf_Sym_Range;
88 const uint8_t *base() const {
89 return reinterpret_cast<const uint8_t *>(Buf.data());
93 typedef SmallVector<const Elf_Shdr *, 2> Sections_t;
94 typedef DenseMap<unsigned, unsigned> IndexMap_t;
98 const Elf_Ehdr *Header;
99 const Elf_Shdr *SectionHeaderTable = nullptr;
100 StringRef DotShstrtab; // Section header string table.
101 StringRef DotStrtab; // Symbol header string table.
102 const Elf_Shdr *dot_symtab_sec = nullptr; // Symbol table section.
103 const Elf_Shdr *DotDynSymSec = nullptr; // Dynamic symbol table section.
105 const Elf_Shdr *SymbolTableSectionHeaderIndex = nullptr;
106 DenseMap<const Elf_Sym *, ELF::Elf64_Word> ExtendedSymbolTable;
108 const Elf_Shdr *dot_gnu_version_sec = nullptr; // .gnu.version
109 const Elf_Shdr *dot_gnu_version_r_sec = nullptr; // .gnu.version_r
110 const Elf_Shdr *dot_gnu_version_d_sec = nullptr; // .gnu.version_d
112 // Records for each version index the corresponding Verdef or Vernaux entry.
113 // This is filled the first time LoadVersionMap() is called.
114 class VersionMapEntry : public PointerIntPair<const void*, 1> {
116 // If the integer is 0, this is an Elf_Verdef*.
117 // If the integer is 1, this is an Elf_Vernaux*.
118 VersionMapEntry() : PointerIntPair<const void*, 1>(nullptr, 0) { }
119 VersionMapEntry(const Elf_Verdef *verdef)
120 : PointerIntPair<const void*, 1>(verdef, 0) { }
121 VersionMapEntry(const Elf_Vernaux *vernaux)
122 : PointerIntPair<const void*, 1>(vernaux, 1) { }
123 bool isNull() const { return getPointer() == nullptr; }
124 bool isVerdef() const { return !isNull() && getInt() == 0; }
125 bool isVernaux() const { return !isNull() && getInt() == 1; }
126 const Elf_Verdef *getVerdef() const {
127 return isVerdef() ? (const Elf_Verdef*)getPointer() : nullptr;
129 const Elf_Vernaux *getVernaux() const {
130 return isVernaux() ? (const Elf_Vernaux*)getPointer() : nullptr;
133 mutable SmallVector<VersionMapEntry, 16> VersionMap;
134 void LoadVersionDefs(const Elf_Shdr *sec) const;
135 void LoadVersionNeeds(const Elf_Shdr *ec) const;
136 void LoadVersionMap() const;
140 const T *getEntry(uint32_t Section, uint32_t Entry) const;
141 template <typename T>
142 const T *getEntry(const Elf_Shdr *Section, uint32_t Entry) const;
144 const Elf_Shdr *getDotSymtabSec() const { return dot_symtab_sec; }
145 const Elf_Shdr *getDotDynSymSec() const { return DotDynSymSec; }
147 ErrorOr<StringRef> getStringTable(const Elf_Shdr *Section) const;
148 ErrorOr<StringRef> getStringTableForSymtab(const Elf_Shdr &Section) const;
150 ErrorOr<StringRef> getSymbolVersion(StringRef StrTab, const Elf_Sym *Symb,
151 bool &IsDefault) const;
152 void VerifyStrTab(const Elf_Shdr *sh) const;
154 StringRef getRelocationTypeName(uint32_t Type) const;
155 void getRelocationTypeName(uint32_t Type,
156 SmallVectorImpl<char> &Result) const;
158 /// \brief Get the symbol table section and symbol for a given relocation.
159 template <class RelT>
160 std::pair<const Elf_Shdr *, const Elf_Sym *>
161 getRelocationSymbol(const Elf_Shdr *RelSec, const RelT *Rel) const;
163 ELFFile(StringRef Object, std::error_code &EC);
165 bool isMipsELF64() const {
166 return Header->e_machine == ELF::EM_MIPS &&
167 Header->getFileClass() == ELF::ELFCLASS64;
170 bool isMips64EL() const {
171 return Header->e_machine == ELF::EM_MIPS &&
172 Header->getFileClass() == ELF::ELFCLASS64 &&
173 Header->getDataEncoding() == ELF::ELFDATA2LSB;
176 const Elf_Shdr *section_begin() const;
177 const Elf_Shdr *section_end() const;
178 Elf_Shdr_Range sections() const {
179 return make_range(section_begin(), section_end());
182 const Elf_Sym *symbol_begin() const;
183 const Elf_Sym *symbol_end() const;
184 Elf_Sym_Range symbols() const {
185 return make_range(symbol_begin(), symbol_end());
188 const Elf_Sym *dynamic_symbol_begin() const {
191 if (DotDynSymSec->sh_entsize != sizeof(Elf_Sym))
192 report_fatal_error("Invalid symbol size");
193 return reinterpret_cast<const Elf_Sym *>(base() + DotDynSymSec->sh_offset);
196 const Elf_Sym *dynamic_symbol_end() const {
199 return reinterpret_cast<const Elf_Sym *>(base() + DotDynSymSec->sh_offset +
200 DotDynSymSec->sh_size);
203 Elf_Sym_Range dynamic_symbols() const {
204 return make_range(dynamic_symbol_begin(), dynamic_symbol_end());
207 typedef iterator_range<const Elf_Rela *> Elf_Rela_Range;
209 const Elf_Rela *rela_begin(const Elf_Shdr *sec) const {
210 if (sec->sh_entsize != sizeof(Elf_Rela))
211 report_fatal_error("Invalid relocation entry size");
212 return reinterpret_cast<const Elf_Rela *>(base() + sec->sh_offset);
215 const Elf_Rela *rela_end(const Elf_Shdr *sec) const {
216 uint64_t Size = sec->sh_size;
217 if (Size % sizeof(Elf_Rela))
218 report_fatal_error("Invalid relocation table size");
219 return rela_begin(sec) + Size / sizeof(Elf_Rela);
222 Elf_Rela_Range relas(const Elf_Shdr *Sec) const {
223 return make_range(rela_begin(Sec), rela_end(Sec));
226 const Elf_Rel *rel_begin(const Elf_Shdr *sec) const {
227 if (sec->sh_entsize != sizeof(Elf_Rel))
228 report_fatal_error("Invalid relocation entry size");
229 return reinterpret_cast<const Elf_Rel *>(base() + sec->sh_offset);
232 const Elf_Rel *rel_end(const Elf_Shdr *sec) const {
233 uint64_t Size = sec->sh_size;
234 if (Size % sizeof(Elf_Rel))
235 report_fatal_error("Invalid relocation table size");
236 return rel_begin(sec) + Size / sizeof(Elf_Rel);
239 typedef iterator_range<const Elf_Rel *> Elf_Rel_Range;
240 Elf_Rel_Range rels(const Elf_Shdr *Sec) const {
241 return make_range(rel_begin(Sec), rel_end(Sec));
244 /// \brief Iterate over program header table.
245 const Elf_Phdr *program_header_begin() const {
246 if (Header->e_phnum && Header->e_phentsize != sizeof(Elf_Phdr))
247 report_fatal_error("Invalid program header size");
248 return reinterpret_cast<const Elf_Phdr *>(base() + Header->e_phoff);
251 const Elf_Phdr *program_header_end() const {
252 return program_header_begin() + Header->e_phnum;
255 typedef iterator_range<const Elf_Phdr *> Elf_Phdr_Range;
257 const Elf_Phdr_Range program_headers() const {
258 return make_range(program_header_begin(), program_header_end());
261 uint64_t getNumSections() const;
262 uintX_t getStringTableIndex() const;
263 ELF::Elf64_Word getExtendedSymbolTableIndex(const Elf_Sym *symb) const;
264 const Elf_Ehdr *getHeader() const { return Header; }
265 ErrorOr<const Elf_Shdr *> getSection(const Elf_Sym *symb) const;
266 ErrorOr<const Elf_Shdr *> getSection(uint32_t Index) const;
267 const Elf_Sym *getSymbol(uint32_t index) const;
269 ErrorOr<StringRef> getSectionName(const Elf_Shdr *Section) const;
270 ErrorOr<ArrayRef<uint8_t> > getSectionContents(const Elf_Shdr *Sec) const;
273 typedef ELFFile<ELFType<support::little, false>> ELF32LEFile;
274 typedef ELFFile<ELFType<support::little, true>> ELF64LEFile;
275 typedef ELFFile<ELFType<support::big, false>> ELF32BEFile;
276 typedef ELFFile<ELFType<support::big, true>> ELF64BEFile;
278 // Iterate through the version definitions, and place each Elf_Verdef
279 // in the VersionMap according to its index.
280 template <class ELFT>
281 void ELFFile<ELFT>::LoadVersionDefs(const Elf_Shdr *sec) const {
282 unsigned vd_size = sec->sh_size; // Size of section in bytes
283 unsigned vd_count = sec->sh_info; // Number of Verdef entries
284 const char *sec_start = (const char*)base() + sec->sh_offset;
285 const char *sec_end = sec_start + vd_size;
286 // The first Verdef entry is at the start of the section.
287 const char *p = sec_start;
288 for (unsigned i = 0; i < vd_count; i++) {
289 if (p + sizeof(Elf_Verdef) > sec_end)
290 report_fatal_error("Section ended unexpectedly while scanning "
291 "version definitions.");
292 const Elf_Verdef *vd = reinterpret_cast<const Elf_Verdef *>(p);
293 if (vd->vd_version != ELF::VER_DEF_CURRENT)
294 report_fatal_error("Unexpected verdef version");
295 size_t index = vd->vd_ndx & ELF::VERSYM_VERSION;
296 if (index >= VersionMap.size())
297 VersionMap.resize(index + 1);
298 VersionMap[index] = VersionMapEntry(vd);
303 // Iterate through the versions needed section, and place each Elf_Vernaux
304 // in the VersionMap according to its index.
305 template <class ELFT>
306 void ELFFile<ELFT>::LoadVersionNeeds(const Elf_Shdr *sec) const {
307 unsigned vn_size = sec->sh_size; // Size of section in bytes
308 unsigned vn_count = sec->sh_info; // Number of Verneed entries
309 const char *sec_start = (const char *)base() + sec->sh_offset;
310 const char *sec_end = sec_start + vn_size;
311 // The first Verneed entry is at the start of the section.
312 const char *p = sec_start;
313 for (unsigned i = 0; i < vn_count; i++) {
314 if (p + sizeof(Elf_Verneed) > sec_end)
315 report_fatal_error("Section ended unexpectedly while scanning "
316 "version needed records.");
317 const Elf_Verneed *vn = reinterpret_cast<const Elf_Verneed *>(p);
318 if (vn->vn_version != ELF::VER_NEED_CURRENT)
319 report_fatal_error("Unexpected verneed version");
320 // Iterate through the Vernaux entries
321 const char *paux = p + vn->vn_aux;
322 for (unsigned j = 0; j < vn->vn_cnt; j++) {
323 if (paux + sizeof(Elf_Vernaux) > sec_end)
324 report_fatal_error("Section ended unexpected while scanning auxiliary "
325 "version needed records.");
326 const Elf_Vernaux *vna = reinterpret_cast<const Elf_Vernaux *>(paux);
327 size_t index = vna->vna_other & ELF::VERSYM_VERSION;
328 if (index >= VersionMap.size())
329 VersionMap.resize(index + 1);
330 VersionMap[index] = VersionMapEntry(vna);
331 paux += vna->vna_next;
337 template <class ELFT>
338 void ELFFile<ELFT>::LoadVersionMap() const {
339 // If there is no dynamic symtab or version table, there is nothing to do.
340 if (!DotDynSymSec || !dot_gnu_version_sec)
343 // Has the VersionMap already been loaded?
344 if (VersionMap.size() > 0)
347 // The first two version indexes are reserved.
348 // Index 0 is LOCAL, index 1 is GLOBAL.
349 VersionMap.push_back(VersionMapEntry());
350 VersionMap.push_back(VersionMapEntry());
352 if (dot_gnu_version_d_sec)
353 LoadVersionDefs(dot_gnu_version_d_sec);
355 if (dot_gnu_version_r_sec)
356 LoadVersionNeeds(dot_gnu_version_r_sec);
359 template <class ELFT>
361 ELFFile<ELFT>::getExtendedSymbolTableIndex(const Elf_Sym *symb) const {
362 assert(symb->st_shndx == ELF::SHN_XINDEX);
363 return ExtendedSymbolTable.lookup(symb);
366 template <class ELFT>
367 ErrorOr<const typename ELFFile<ELFT>::Elf_Shdr *>
368 ELFFile<ELFT>::getSection(const Elf_Sym *symb) const {
369 uint32_t Index = symb->st_shndx;
370 if (Index == ELF::SHN_XINDEX)
371 return getSection(ExtendedSymbolTable.lookup(symb));
372 if (Index == ELF::SHN_UNDEF || Index >= ELF::SHN_LORESERVE)
374 return getSection(symb->st_shndx);
377 template <class ELFT>
378 const typename ELFFile<ELFT>::Elf_Sym *
379 ELFFile<ELFT>::getSymbol(uint32_t Index) const {
380 return &*(symbol_begin() + Index);
383 template <class ELFT>
384 ErrorOr<ArrayRef<uint8_t> >
385 ELFFile<ELFT>::getSectionContents(const Elf_Shdr *Sec) const {
386 if (Sec->sh_offset + Sec->sh_size > Buf.size())
387 return object_error::parse_failed;
388 const uint8_t *Start = base() + Sec->sh_offset;
389 return makeArrayRef(Start, Sec->sh_size);
392 template <class ELFT>
393 StringRef ELFFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
394 return getELFRelocationTypeName(Header->e_machine, Type);
397 template <class ELFT>
398 void ELFFile<ELFT>::getRelocationTypeName(uint32_t Type,
399 SmallVectorImpl<char> &Result) const {
400 if (!isMipsELF64()) {
401 StringRef Name = getRelocationTypeName(Type);
402 Result.append(Name.begin(), Name.end());
404 // The Mips N64 ABI allows up to three operations to be specified per
405 // relocation record. Unfortunately there's no easy way to test for the
406 // presence of N64 ELFs as they have no special flag that identifies them
407 // as being N64. We can safely assume at the moment that all Mips
408 // ELFCLASS64 ELFs are N64. New Mips64 ABIs should provide enough
409 // information to disambiguate between old vs new ABIs.
410 uint8_t Type1 = (Type >> 0) & 0xFF;
411 uint8_t Type2 = (Type >> 8) & 0xFF;
412 uint8_t Type3 = (Type >> 16) & 0xFF;
414 // Concat all three relocation type names.
415 StringRef Name = getRelocationTypeName(Type1);
416 Result.append(Name.begin(), Name.end());
418 Name = getRelocationTypeName(Type2);
419 Result.append(1, '/');
420 Result.append(Name.begin(), Name.end());
422 Name = getRelocationTypeName(Type3);
423 Result.append(1, '/');
424 Result.append(Name.begin(), Name.end());
428 template <class ELFT>
429 template <class RelT>
430 std::pair<const typename ELFFile<ELFT>::Elf_Shdr *,
431 const typename ELFFile<ELFT>::Elf_Sym *>
432 ELFFile<ELFT>::getRelocationSymbol(const Elf_Shdr *Sec, const RelT *Rel) const {
434 return std::make_pair(nullptr, nullptr);
435 ErrorOr<const Elf_Shdr *> SymTableOrErr = getSection(Sec->sh_link);
436 if (std::error_code EC = SymTableOrErr.getError())
437 report_fatal_error(EC.message());
438 const Elf_Shdr *SymTable = *SymTableOrErr;
439 return std::make_pair(
440 SymTable, getEntry<Elf_Sym>(SymTable, Rel->getSymbol(isMips64EL())));
443 template <class ELFT>
444 uint64_t ELFFile<ELFT>::getNumSections() const {
445 assert(Header && "Header not initialized!");
446 if (Header->e_shnum == ELF::SHN_UNDEF && Header->e_shoff > 0) {
447 assert(SectionHeaderTable && "SectionHeaderTable not initialized!");
448 return SectionHeaderTable->sh_size;
450 return Header->e_shnum;
453 template <class ELFT>
454 typename ELFFile<ELFT>::uintX_t ELFFile<ELFT>::getStringTableIndex() const {
455 if (Header->e_shnum == ELF::SHN_UNDEF) {
456 if (Header->e_shstrndx == ELF::SHN_HIRESERVE)
457 return SectionHeaderTable->sh_link;
458 if (Header->e_shstrndx >= getNumSections())
461 return Header->e_shstrndx;
464 template <class ELFT>
465 ELFFile<ELFT>::ELFFile(StringRef Object, std::error_code &EC)
467 const uint64_t FileSize = Buf.size();
469 if (sizeof(Elf_Ehdr) > FileSize) {
471 EC = object_error::parse_failed;
475 Header = reinterpret_cast<const Elf_Ehdr *>(base());
477 if (Header->e_shoff == 0)
480 const uint64_t SectionTableOffset = Header->e_shoff;
482 if (SectionTableOffset + sizeof(Elf_Shdr) > FileSize) {
483 // Section header table goes past end of file!
484 EC = object_error::parse_failed;
488 // The getNumSections() call below depends on SectionHeaderTable being set.
490 reinterpret_cast<const Elf_Shdr *>(base() + SectionTableOffset);
491 const uint64_t SectionTableSize = getNumSections() * Header->e_shentsize;
493 if (SectionTableOffset + SectionTableSize > FileSize) {
494 // Section table goes past end of file!
495 EC = object_error::parse_failed;
499 // Scan sections for special sections.
501 for (const Elf_Shdr &Sec : sections()) {
502 switch (Sec.sh_type) {
503 case ELF::SHT_SYMTAB_SHNDX:
504 if (SymbolTableSectionHeaderIndex) {
505 // More than one .symtab_shndx!
506 EC = object_error::parse_failed;
509 SymbolTableSectionHeaderIndex = &Sec;
511 case ELF::SHT_SYMTAB: {
512 if (dot_symtab_sec) {
513 // More than one .symtab!
514 EC = object_error::parse_failed;
517 dot_symtab_sec = &Sec;
518 ErrorOr<StringRef> SymtabOrErr = getStringTableForSymtab(Sec);
519 if ((EC = SymtabOrErr.getError()))
521 DotStrtab = *SymtabOrErr;
523 case ELF::SHT_DYNSYM: {
525 // More than one .dynsym!
526 EC = object_error::parse_failed;
532 case ELF::SHT_GNU_versym:
533 if (dot_gnu_version_sec != nullptr) {
534 // More than one .gnu.version section!
535 EC = object_error::parse_failed;
538 dot_gnu_version_sec = &Sec;
540 case ELF::SHT_GNU_verdef:
541 if (dot_gnu_version_d_sec != nullptr) {
542 // More than one .gnu.version_d section!
543 EC = object_error::parse_failed;
546 dot_gnu_version_d_sec = &Sec;
548 case ELF::SHT_GNU_verneed:
549 if (dot_gnu_version_r_sec != nullptr) {
550 // More than one .gnu.version_r section!
551 EC = object_error::parse_failed;
554 dot_gnu_version_r_sec = &Sec;
559 // Get string table sections.
560 uintX_t StringTableIndex = getStringTableIndex();
561 if (StringTableIndex) {
562 ErrorOr<const Elf_Shdr *> StrTabSecOrErr =
563 getSection(getStringTableIndex());
564 if ((EC = StrTabSecOrErr.getError()))
567 ErrorOr<StringRef> SymtabOrErr = getStringTable(*StrTabSecOrErr);
568 if ((EC = SymtabOrErr.getError()))
570 DotShstrtab = *SymtabOrErr;
573 // Build symbol name side-mapping if there is one.
574 if (SymbolTableSectionHeaderIndex) {
575 const Elf_Word *ShndxTable = reinterpret_cast<const Elf_Word*>(base() +
576 SymbolTableSectionHeaderIndex->sh_offset);
577 for (const Elf_Sym &S : symbols()) {
578 if (*ShndxTable != ELF::SHN_UNDEF)
579 ExtendedSymbolTable[&S] = *ShndxTable;
584 EC = std::error_code();
587 template <class ELFT>
588 static bool compareAddr(uint64_t VAddr, const Elf_Phdr_Impl<ELFT> *Phdr) {
589 return VAddr < Phdr->p_vaddr;
592 template <class ELFT>
593 const typename ELFFile<ELFT>::Elf_Shdr *ELFFile<ELFT>::section_begin() const {
594 if (Header->e_shentsize != sizeof(Elf_Shdr))
596 "Invalid section header entry size (e_shentsize) in ELF header");
597 return reinterpret_cast<const Elf_Shdr *>(base() + Header->e_shoff);
600 template <class ELFT>
601 const typename ELFFile<ELFT>::Elf_Shdr *ELFFile<ELFT>::section_end() const {
602 return section_begin() + getNumSections();
605 template <class ELFT>
606 const typename ELFFile<ELFT>::Elf_Sym *ELFFile<ELFT>::symbol_begin() const {
609 if (dot_symtab_sec->sh_entsize != sizeof(Elf_Sym))
610 report_fatal_error("Invalid symbol size");
611 return reinterpret_cast<const Elf_Sym *>(base() + dot_symtab_sec->sh_offset);
614 template <class ELFT>
615 const typename ELFFile<ELFT>::Elf_Sym *ELFFile<ELFT>::symbol_end() const {
618 return reinterpret_cast<const Elf_Sym *>(base() + dot_symtab_sec->sh_offset +
619 dot_symtab_sec->sh_size);
622 template <class ELFT>
623 template <typename T>
624 const T *ELFFile<ELFT>::getEntry(uint32_t Section, uint32_t Entry) const {
625 ErrorOr<const Elf_Shdr *> Sec = getSection(Section);
626 if (std::error_code EC = Sec.getError())
627 report_fatal_error(EC.message());
628 return getEntry<T>(*Sec, Entry);
631 template <class ELFT>
632 template <typename T>
633 const T *ELFFile<ELFT>::getEntry(const Elf_Shdr *Section,
634 uint32_t Entry) const {
635 return reinterpret_cast<const T *>(base() + Section->sh_offset +
636 (Entry * Section->sh_entsize));
639 template <class ELFT>
640 ErrorOr<const typename ELFFile<ELFT>::Elf_Shdr *>
641 ELFFile<ELFT>::getSection(uint32_t Index) const {
642 assert(SectionHeaderTable && "SectionHeaderTable not initialized!");
643 if (Index >= getNumSections())
644 return object_error::invalid_section_index;
646 return reinterpret_cast<const Elf_Shdr *>(
647 reinterpret_cast<const char *>(SectionHeaderTable) +
648 (Index * Header->e_shentsize));
651 template <class ELFT>
653 ELFFile<ELFT>::getStringTable(const Elf_Shdr *Section) const {
654 if (Section->sh_type != ELF::SHT_STRTAB)
655 return object_error::parse_failed;
656 uint64_t Offset = Section->sh_offset;
657 uint64_t Size = Section->sh_size;
658 if (Offset + Size > Buf.size())
659 return object_error::parse_failed;
660 StringRef Data((const char *)base() + Section->sh_offset, Size);
661 if (Data[Size - 1] != '\0')
662 return object_error::string_table_non_null_end;
666 template <class ELFT>
668 ELFFile<ELFT>::getStringTableForSymtab(const Elf_Shdr &Sec) const {
669 if (Sec.sh_type != ELF::SHT_SYMTAB && Sec.sh_type != ELF::SHT_DYNSYM)
670 return object_error::parse_failed;
671 ErrorOr<const Elf_Shdr *> SectionOrErr = getSection(Sec.sh_link);
672 if (std::error_code EC = SectionOrErr.getError())
674 return getStringTable(*SectionOrErr);
677 template <class ELFT>
679 ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section) const {
680 uint32_t Offset = Section->sh_name;
683 if (Offset >= DotShstrtab.size())
684 return object_error::parse_failed;
685 return StringRef(DotShstrtab.data() + Offset);
688 template <class ELFT>
689 ErrorOr<StringRef> ELFFile<ELFT>::getSymbolVersion(StringRef StrTab,
691 bool &IsDefault) const {
692 // This is a dynamic symbol. Look in the GNU symbol version table.
693 if (!dot_gnu_version_sec) {
696 return StringRef("");
699 // Determine the position in the symbol table of this entry.
701 (reinterpret_cast<uintptr_t>(symb) - DotDynSymSec->sh_offset -
702 reinterpret_cast<uintptr_t>(base())) /
705 // Get the corresponding version index entry
706 const Elf_Versym *vs = getEntry<Elf_Versym>(dot_gnu_version_sec, entry_index);
707 size_t version_index = vs->vs_index & ELF::VERSYM_VERSION;
709 // Special markers for unversioned symbols.
710 if (version_index == ELF::VER_NDX_LOCAL ||
711 version_index == ELF::VER_NDX_GLOBAL) {
713 return StringRef("");
716 // Lookup this symbol in the version table
718 if (version_index >= VersionMap.size() || VersionMap[version_index].isNull())
719 return object_error::parse_failed;
720 const VersionMapEntry &entry = VersionMap[version_index];
722 // Get the version name string
724 if (entry.isVerdef()) {
725 // The first Verdaux entry holds the name.
726 name_offset = entry.getVerdef()->getAux()->vda_name;
728 name_offset = entry.getVernaux()->vna_name;
732 if (entry.isVerdef()) {
733 IsDefault = !(vs->vs_index & ELF::VERSYM_HIDDEN);
738 if (name_offset >= StrTab.size())
739 return object_error::parse_failed;
740 return StringRef(StrTab.data() + name_offset);
743 /// This function returns the hash value for a symbol in the .dynsym section
744 /// Name of the API remains consistent as specified in the libelf
745 /// REF : http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#hash
746 static inline unsigned elf_hash(StringRef &symbolName) {
748 for (unsigned i = 0, j = symbolName.size(); i < j; i++) {
749 h = (h << 4) + symbolName[i];
757 } // end namespace object
758 } // end namespace llvm