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      1 //===- ELFObjectFile.h - 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 declares the ELFObjectFile template class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_OBJECT_ELFOBJECTFILE_H
     15 #define LLVM_OBJECT_ELFOBJECTFILE_H
     16 
     17 #include "llvm/ADT/ArrayRef.h"
     18 #include "llvm/ADT/SmallVector.h"
     19 #include "llvm/ADT/StringRef.h"
     20 #include "llvm/ADT/Triple.h"
     21 #include "llvm/ADT/iterator_range.h"
     22 #include "llvm/MC/SubtargetFeature.h"
     23 #include "llvm/Object/Binary.h"
     24 #include "llvm/Object/ELF.h"
     25 #include "llvm/Object/ELFTypes.h"
     26 #include "llvm/Object/Error.h"
     27 #include "llvm/Object/ObjectFile.h"
     28 #include "llvm/Object/SymbolicFile.h"
     29 #include "llvm/Support/Casting.h"
     30 #include "llvm/Support/ELF.h"
     31 #include "llvm/Support/Endian.h"
     32 #include "llvm/Support/Error.h"
     33 #include "llvm/Support/ErrorHandling.h"
     34 #include "llvm/Support/ErrorOr.h"
     35 #include "llvm/Support/MemoryBuffer.h"
     36 #include <cassert>
     37 #include <cstdint>
     38 #include <system_error>
     39 
     40 namespace llvm {
     41 namespace object {
     42 
     43 class elf_symbol_iterator;
     44 class ELFSymbolRef;
     45 class ELFRelocationRef;
     46 
     47 class ELFObjectFileBase : public ObjectFile {
     48   friend class ELFSymbolRef;
     49   friend class ELFSectionRef;
     50   friend class ELFRelocationRef;
     51 
     52 protected:
     53   ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source);
     54 
     55   virtual uint16_t getEMachine() const = 0;
     56   virtual uint64_t getSymbolSize(DataRefImpl Symb) const = 0;
     57   virtual uint8_t getSymbolOther(DataRefImpl Symb) const = 0;
     58   virtual uint8_t getSymbolELFType(DataRefImpl Symb) const = 0;
     59 
     60   virtual uint32_t getSectionType(DataRefImpl Sec) const = 0;
     61   virtual uint64_t getSectionFlags(DataRefImpl Sec) const = 0;
     62 
     63   virtual ErrorOr<int64_t> getRelocationAddend(DataRefImpl Rel) const = 0;
     64 
     65 public:
     66   typedef iterator_range<elf_symbol_iterator> elf_symbol_iterator_range;
     67   virtual elf_symbol_iterator_range getDynamicSymbolIterators() const = 0;
     68 
     69   elf_symbol_iterator_range symbols() const;
     70 
     71   static inline bool classof(const Binary *v) { return v->isELF(); }
     72 
     73   SubtargetFeatures getFeatures() const override;
     74 };
     75 
     76 class ELFSectionRef : public SectionRef {
     77 public:
     78   ELFSectionRef(const SectionRef &B) : SectionRef(B) {
     79     assert(isa<ELFObjectFileBase>(SectionRef::getObject()));
     80   }
     81 
     82   const ELFObjectFileBase *getObject() const {
     83     return cast<ELFObjectFileBase>(SectionRef::getObject());
     84   }
     85 
     86   uint32_t getType() const {
     87     return getObject()->getSectionType(getRawDataRefImpl());
     88   }
     89 
     90   uint64_t getFlags() const {
     91     return getObject()->getSectionFlags(getRawDataRefImpl());
     92   }
     93 };
     94 
     95 class elf_section_iterator : public section_iterator {
     96 public:
     97   elf_section_iterator(const section_iterator &B) : section_iterator(B) {
     98     assert(isa<ELFObjectFileBase>(B->getObject()));
     99   }
    100 
    101   const ELFSectionRef *operator->() const {
    102     return static_cast<const ELFSectionRef *>(section_iterator::operator->());
    103   }
    104 
    105   const ELFSectionRef &operator*() const {
    106     return static_cast<const ELFSectionRef &>(section_iterator::operator*());
    107   }
    108 };
    109 
    110 class ELFSymbolRef : public SymbolRef {
    111 public:
    112   ELFSymbolRef(const SymbolRef &B) : SymbolRef(B) {
    113     assert(isa<ELFObjectFileBase>(SymbolRef::getObject()));
    114   }
    115 
    116   const ELFObjectFileBase *getObject() const {
    117     return cast<ELFObjectFileBase>(BasicSymbolRef::getObject());
    118   }
    119 
    120   uint64_t getSize() const {
    121     return getObject()->getSymbolSize(getRawDataRefImpl());
    122   }
    123 
    124   uint8_t getOther() const {
    125     return getObject()->getSymbolOther(getRawDataRefImpl());
    126   }
    127 
    128   uint8_t getELFType() const {
    129     return getObject()->getSymbolELFType(getRawDataRefImpl());
    130   }
    131 };
    132 
    133 class elf_symbol_iterator : public symbol_iterator {
    134 public:
    135   elf_symbol_iterator(const basic_symbol_iterator &B)
    136       : symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
    137                                   cast<ELFObjectFileBase>(B->getObject()))) {}
    138 
    139   const ELFSymbolRef *operator->() const {
    140     return static_cast<const ELFSymbolRef *>(symbol_iterator::operator->());
    141   }
    142 
    143   const ELFSymbolRef &operator*() const {
    144     return static_cast<const ELFSymbolRef &>(symbol_iterator::operator*());
    145   }
    146 };
    147 
    148 class ELFRelocationRef : public RelocationRef {
    149 public:
    150   ELFRelocationRef(const RelocationRef &B) : RelocationRef(B) {
    151     assert(isa<ELFObjectFileBase>(RelocationRef::getObject()));
    152   }
    153 
    154   const ELFObjectFileBase *getObject() const {
    155     return cast<ELFObjectFileBase>(RelocationRef::getObject());
    156   }
    157 
    158   ErrorOr<int64_t> getAddend() const {
    159     return getObject()->getRelocationAddend(getRawDataRefImpl());
    160   }
    161 };
    162 
    163 class elf_relocation_iterator : public relocation_iterator {
    164 public:
    165   elf_relocation_iterator(const relocation_iterator &B)
    166       : relocation_iterator(RelocationRef(
    167             B->getRawDataRefImpl(), cast<ELFObjectFileBase>(B->getObject()))) {}
    168 
    169   const ELFRelocationRef *operator->() const {
    170     return static_cast<const ELFRelocationRef *>(
    171         relocation_iterator::operator->());
    172   }
    173 
    174   const ELFRelocationRef &operator*() const {
    175     return static_cast<const ELFRelocationRef &>(
    176         relocation_iterator::operator*());
    177   }
    178 };
    179 
    180 inline ELFObjectFileBase::elf_symbol_iterator_range
    181 ELFObjectFileBase::symbols() const {
    182   return elf_symbol_iterator_range(symbol_begin(), symbol_end());
    183 }
    184 
    185 template <class ELFT> class ELFObjectFile : public ELFObjectFileBase {
    186   uint16_t getEMachine() const override;
    187   uint64_t getSymbolSize(DataRefImpl Sym) const override;
    188 
    189 public:
    190   LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
    191 
    192   typedef typename ELFFile<ELFT>::uintX_t uintX_t;
    193 
    194   typedef typename ELFFile<ELFT>::Elf_Sym Elf_Sym;
    195   typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
    196   typedef typename ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
    197   typedef typename ELFFile<ELFT>::Elf_Rel Elf_Rel;
    198   typedef typename ELFFile<ELFT>::Elf_Rela Elf_Rela;
    199   typedef typename ELFFile<ELFT>::Elf_Dyn Elf_Dyn;
    200 
    201 protected:
    202   ELFFile<ELFT> EF;
    203 
    204   const Elf_Shdr *DotDynSymSec = nullptr; // Dynamic symbol table section.
    205   const Elf_Shdr *DotSymtabSec = nullptr; // Symbol table section.
    206   ArrayRef<Elf_Word> ShndxTable;
    207 
    208   void moveSymbolNext(DataRefImpl &Symb) const override;
    209   Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
    210   Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
    211   uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
    212   uint32_t getSymbolAlignment(DataRefImpl Symb) const override;
    213   uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
    214   uint32_t getSymbolFlags(DataRefImpl Symb) const override;
    215   uint8_t getSymbolOther(DataRefImpl Symb) const override;
    216   uint8_t getSymbolELFType(DataRefImpl Symb) const override;
    217   Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
    218   Expected<section_iterator> getSymbolSection(const Elf_Sym *Symb,
    219                                               const Elf_Shdr *SymTab) const;
    220   Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
    221 
    222   void moveSectionNext(DataRefImpl &Sec) const override;
    223   std::error_code getSectionName(DataRefImpl Sec,
    224                                  StringRef &Res) const override;
    225   uint64_t getSectionAddress(DataRefImpl Sec) const override;
    226   uint64_t getSectionSize(DataRefImpl Sec) const override;
    227   std::error_code getSectionContents(DataRefImpl Sec,
    228                                      StringRef &Res) const override;
    229   uint64_t getSectionAlignment(DataRefImpl Sec) const override;
    230   bool isSectionCompressed(DataRefImpl Sec) const override;
    231   bool isSectionText(DataRefImpl Sec) const override;
    232   bool isSectionData(DataRefImpl Sec) const override;
    233   bool isSectionBSS(DataRefImpl Sec) const override;
    234   bool isSectionVirtual(DataRefImpl Sec) const override;
    235   relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
    236   relocation_iterator section_rel_end(DataRefImpl Sec) const override;
    237   section_iterator getRelocatedSection(DataRefImpl Sec) const override;
    238 
    239   void moveRelocationNext(DataRefImpl &Rel) const override;
    240   uint64_t getRelocationOffset(DataRefImpl Rel) const override;
    241   symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
    242   uint64_t getRelocationType(DataRefImpl Rel) const override;
    243   void getRelocationTypeName(DataRefImpl Rel,
    244                              SmallVectorImpl<char> &Result) const override;
    245 
    246   uint32_t getSectionType(DataRefImpl Sec) const override;
    247   uint64_t getSectionFlags(DataRefImpl Sec) const override;
    248   StringRef getRelocationTypeName(uint32_t Type) const;
    249 
    250   /// \brief Get the relocation section that contains \a Rel.
    251   const Elf_Shdr *getRelSection(DataRefImpl Rel) const {
    252     return *EF.getSection(Rel.d.a);
    253   }
    254 
    255   DataRefImpl toDRI(const Elf_Shdr *SymTable, unsigned SymbolNum) const {
    256     DataRefImpl DRI;
    257     if (!SymTable) {
    258       DRI.d.a = 0;
    259       DRI.d.b = 0;
    260       return DRI;
    261     }
    262     assert(SymTable->sh_type == ELF::SHT_SYMTAB ||
    263            SymTable->sh_type == ELF::SHT_DYNSYM);
    264 
    265     uintptr_t SHT = reinterpret_cast<uintptr_t>(EF.section_begin());
    266     unsigned SymTableIndex =
    267         (reinterpret_cast<uintptr_t>(SymTable) - SHT) / sizeof(Elf_Shdr);
    268 
    269     DRI.d.a = SymTableIndex;
    270     DRI.d.b = SymbolNum;
    271     return DRI;
    272   }
    273 
    274   const Elf_Shdr *toELFShdrIter(DataRefImpl Sec) const {
    275     return reinterpret_cast<const Elf_Shdr *>(Sec.p);
    276   }
    277 
    278   DataRefImpl toDRI(const Elf_Shdr *Sec) const {
    279     DataRefImpl DRI;
    280     DRI.p = reinterpret_cast<uintptr_t>(Sec);
    281     return DRI;
    282   }
    283 
    284   DataRefImpl toDRI(const Elf_Dyn *Dyn) const {
    285     DataRefImpl DRI;
    286     DRI.p = reinterpret_cast<uintptr_t>(Dyn);
    287     return DRI;
    288   }
    289 
    290   bool isExportedToOtherDSO(const Elf_Sym *ESym) const {
    291     unsigned char Binding = ESym->getBinding();
    292     unsigned char Visibility = ESym->getVisibility();
    293 
    294     // A symbol is exported if its binding is either GLOBAL or WEAK, and its
    295     // visibility is either DEFAULT or PROTECTED. All other symbols are not
    296     // exported.
    297     return ((Binding == ELF::STB_GLOBAL || Binding == ELF::STB_WEAK) &&
    298             (Visibility == ELF::STV_DEFAULT ||
    299              Visibility == ELF::STV_PROTECTED));
    300   }
    301 
    302   // This flag is used for classof, to distinguish ELFObjectFile from
    303   // its subclass. If more subclasses will be created, this flag will
    304   // have to become an enum.
    305   bool isDyldELFObject;
    306 
    307 public:
    308   ELFObjectFile(MemoryBufferRef Object, std::error_code &EC);
    309 
    310   const Elf_Rel *getRel(DataRefImpl Rel) const;
    311   const Elf_Rela *getRela(DataRefImpl Rela) const;
    312 
    313   const Elf_Sym *getSymbol(DataRefImpl Sym) const {
    314     return EF.template getEntry<Elf_Sym>(Sym.d.a, Sym.d.b);
    315   }
    316 
    317   const Elf_Shdr *getSection(DataRefImpl Sec) const {
    318     return reinterpret_cast<const Elf_Shdr *>(Sec.p);
    319   }
    320 
    321   basic_symbol_iterator symbol_begin_impl() const override;
    322   basic_symbol_iterator symbol_end_impl() const override;
    323 
    324   elf_symbol_iterator dynamic_symbol_begin() const;
    325   elf_symbol_iterator dynamic_symbol_end() const;
    326 
    327   section_iterator section_begin() const override;
    328   section_iterator section_end() const override;
    329 
    330   ErrorOr<int64_t> getRelocationAddend(DataRefImpl Rel) const override;
    331 
    332   uint8_t getBytesInAddress() const override;
    333   StringRef getFileFormatName() const override;
    334   unsigned getArch() const override;
    335 
    336   std::error_code getPlatformFlags(unsigned &Result) const override {
    337     Result = EF.getHeader()->e_flags;
    338     return std::error_code();
    339   }
    340 
    341   const ELFFile<ELFT> *getELFFile() const { return &EF; }
    342 
    343   bool isDyldType() const { return isDyldELFObject; }
    344   static inline bool classof(const Binary *v) {
    345     return v->getType() == getELFType(ELFT::TargetEndianness == support::little,
    346                                       ELFT::Is64Bits);
    347   }
    348 
    349   elf_symbol_iterator_range getDynamicSymbolIterators() const override;
    350 
    351   bool isRelocatableObject() const override;
    352 };
    353 
    354 typedef ELFObjectFile<ELFType<support::little, false>> ELF32LEObjectFile;
    355 typedef ELFObjectFile<ELFType<support::little, true>> ELF64LEObjectFile;
    356 typedef ELFObjectFile<ELFType<support::big, false>> ELF32BEObjectFile;
    357 typedef ELFObjectFile<ELFType<support::big, true>> ELF64BEObjectFile;
    358 
    359 template <class ELFT>
    360 void ELFObjectFile<ELFT>::moveSymbolNext(DataRefImpl &Sym) const {
    361   ++Sym.d.b;
    362 }
    363 
    364 template <class ELFT>
    365 Expected<StringRef> ELFObjectFile<ELFT>::getSymbolName(DataRefImpl Sym) const {
    366   const Elf_Sym *ESym = getSymbol(Sym);
    367   const Elf_Shdr *SymTableSec = *EF.getSection(Sym.d.a);
    368   const Elf_Shdr *StringTableSec = *EF.getSection(SymTableSec->sh_link);
    369   StringRef SymTable = *EF.getStringTable(StringTableSec);
    370   return ESym->getName(SymTable);
    371 }
    372 
    373 template <class ELFT>
    374 uint64_t ELFObjectFile<ELFT>::getSectionFlags(DataRefImpl Sec) const {
    375   return getSection(Sec)->sh_flags;
    376 }
    377 
    378 template <class ELFT>
    379 uint32_t ELFObjectFile<ELFT>::getSectionType(DataRefImpl Sec) const {
    380   return getSection(Sec)->sh_type;
    381 }
    382 
    383 template <class ELFT>
    384 uint64_t ELFObjectFile<ELFT>::getSymbolValueImpl(DataRefImpl Symb) const {
    385   const Elf_Sym *ESym = getSymbol(Symb);
    386   uint64_t Ret = ESym->st_value;
    387   if (ESym->st_shndx == ELF::SHN_ABS)
    388     return Ret;
    389 
    390   const Elf_Ehdr *Header = EF.getHeader();
    391   // Clear the ARM/Thumb or microMIPS indicator flag.
    392   if ((Header->e_machine == ELF::EM_ARM || Header->e_machine == ELF::EM_MIPS) &&
    393       ESym->getType() == ELF::STT_FUNC)
    394     Ret &= ~1;
    395 
    396   return Ret;
    397 }
    398 
    399 template <class ELFT>
    400 Expected<uint64_t>
    401 ELFObjectFile<ELFT>::getSymbolAddress(DataRefImpl Symb) const {
    402   uint64_t Result = getSymbolValue(Symb);
    403   const Elf_Sym *ESym = getSymbol(Symb);
    404   switch (ESym->st_shndx) {
    405   case ELF::SHN_COMMON:
    406   case ELF::SHN_UNDEF:
    407   case ELF::SHN_ABS:
    408     return Result;
    409   }
    410 
    411   const Elf_Ehdr *Header = EF.getHeader();
    412   const Elf_Shdr *SymTab = *EF.getSection(Symb.d.a);
    413 
    414   if (Header->e_type == ELF::ET_REL) {
    415     ErrorOr<const Elf_Shdr *> SectionOrErr =
    416         EF.getSection(ESym, SymTab, ShndxTable);
    417     if (std::error_code EC = SectionOrErr.getError())
    418       return errorCodeToError(EC);
    419     const Elf_Shdr *Section = *SectionOrErr;
    420     if (Section)
    421       Result += Section->sh_addr;
    422   }
    423 
    424   return Result;
    425 }
    426 
    427 template <class ELFT>
    428 uint32_t ELFObjectFile<ELFT>::getSymbolAlignment(DataRefImpl Symb) const {
    429   const Elf_Sym *Sym = getSymbol(Symb);
    430   if (Sym->st_shndx == ELF::SHN_COMMON)
    431     return Sym->st_value;
    432   return 0;
    433 }
    434 
    435 template <class ELFT>
    436 uint16_t ELFObjectFile<ELFT>::getEMachine() const {
    437   return EF.getHeader()->e_machine;
    438 }
    439 
    440 template <class ELFT>
    441 uint64_t ELFObjectFile<ELFT>::getSymbolSize(DataRefImpl Sym) const {
    442   return getSymbol(Sym)->st_size;
    443 }
    444 
    445 template <class ELFT>
    446 uint64_t ELFObjectFile<ELFT>::getCommonSymbolSizeImpl(DataRefImpl Symb) const {
    447   return getSymbol(Symb)->st_size;
    448 }
    449 
    450 template <class ELFT>
    451 uint8_t ELFObjectFile<ELFT>::getSymbolOther(DataRefImpl Symb) const {
    452   return getSymbol(Symb)->st_other;
    453 }
    454 
    455 template <class ELFT>
    456 uint8_t ELFObjectFile<ELFT>::getSymbolELFType(DataRefImpl Symb) const {
    457   return getSymbol(Symb)->getType();
    458 }
    459 
    460 template <class ELFT>
    461 Expected<SymbolRef::Type>
    462 ELFObjectFile<ELFT>::getSymbolType(DataRefImpl Symb) const {
    463   const Elf_Sym *ESym = getSymbol(Symb);
    464 
    465   switch (ESym->getType()) {
    466   case ELF::STT_NOTYPE:
    467     return SymbolRef::ST_Unknown;
    468   case ELF::STT_SECTION:
    469     return SymbolRef::ST_Debug;
    470   case ELF::STT_FILE:
    471     return SymbolRef::ST_File;
    472   case ELF::STT_FUNC:
    473     return SymbolRef::ST_Function;
    474   case ELF::STT_OBJECT:
    475   case ELF::STT_COMMON:
    476   case ELF::STT_TLS:
    477     return SymbolRef::ST_Data;
    478   default:
    479     return SymbolRef::ST_Other;
    480   }
    481 }
    482 
    483 template <class ELFT>
    484 uint32_t ELFObjectFile<ELFT>::getSymbolFlags(DataRefImpl Sym) const {
    485   const Elf_Sym *ESym = getSymbol(Sym);
    486 
    487   uint32_t Result = SymbolRef::SF_None;
    488 
    489   if (ESym->getBinding() != ELF::STB_LOCAL)
    490     Result |= SymbolRef::SF_Global;
    491 
    492   if (ESym->getBinding() == ELF::STB_WEAK)
    493     Result |= SymbolRef::SF_Weak;
    494 
    495   if (ESym->st_shndx == ELF::SHN_ABS)
    496     Result |= SymbolRef::SF_Absolute;
    497 
    498   if (ESym->getType() == ELF::STT_FILE || ESym->getType() == ELF::STT_SECTION ||
    499       ESym == EF.symbol_begin(DotSymtabSec) ||
    500       ESym == EF.symbol_begin(DotDynSymSec))
    501     Result |= SymbolRef::SF_FormatSpecific;
    502 
    503   if (EF.getHeader()->e_machine == ELF::EM_ARM) {
    504     if (Expected<StringRef> NameOrErr = getSymbolName(Sym)) {
    505       StringRef Name = *NameOrErr;
    506       if (Name.startswith("$d") || Name.startswith("$t") ||
    507           Name.startswith("$a"))
    508         Result |= SymbolRef::SF_FormatSpecific;
    509     } else {
    510       // TODO: Actually report errors helpfully.
    511       consumeError(NameOrErr.takeError());
    512     }
    513     if (ESym->getType() == ELF::STT_FUNC && (ESym->st_value & 1) == 1)
    514       Result |= SymbolRef::SF_Thumb;
    515   }
    516 
    517   if (ESym->st_shndx == ELF::SHN_UNDEF)
    518     Result |= SymbolRef::SF_Undefined;
    519 
    520   if (ESym->getType() == ELF::STT_COMMON || ESym->st_shndx == ELF::SHN_COMMON)
    521     Result |= SymbolRef::SF_Common;
    522 
    523   if (isExportedToOtherDSO(ESym))
    524     Result |= SymbolRef::SF_Exported;
    525 
    526   if (ESym->getVisibility() == ELF::STV_HIDDEN)
    527     Result |= SymbolRef::SF_Hidden;
    528 
    529   return Result;
    530 }
    531 
    532 template <class ELFT>
    533 Expected<section_iterator>
    534 ELFObjectFile<ELFT>::getSymbolSection(const Elf_Sym *ESym,
    535                                       const Elf_Shdr *SymTab) const {
    536   ErrorOr<const Elf_Shdr *> ESecOrErr = EF.getSection(ESym, SymTab, ShndxTable);
    537   if (std::error_code EC = ESecOrErr.getError())
    538     return errorCodeToError(EC);
    539 
    540   const Elf_Shdr *ESec = *ESecOrErr;
    541   if (!ESec)
    542     return section_end();
    543 
    544   DataRefImpl Sec;
    545   Sec.p = reinterpret_cast<intptr_t>(ESec);
    546   return section_iterator(SectionRef(Sec, this));
    547 }
    548 
    549 template <class ELFT>
    550 Expected<section_iterator>
    551 ELFObjectFile<ELFT>::getSymbolSection(DataRefImpl Symb) const {
    552   const Elf_Sym *Sym = getSymbol(Symb);
    553   const Elf_Shdr *SymTab = *EF.getSection(Symb.d.a);
    554   return getSymbolSection(Sym, SymTab);
    555 }
    556 
    557 template <class ELFT>
    558 void ELFObjectFile<ELFT>::moveSectionNext(DataRefImpl &Sec) const {
    559   const Elf_Shdr *ESec = getSection(Sec);
    560   Sec = toDRI(++ESec);
    561 }
    562 
    563 template <class ELFT>
    564 std::error_code ELFObjectFile<ELFT>::getSectionName(DataRefImpl Sec,
    565                                                     StringRef &Result) const {
    566   ErrorOr<StringRef> Name = EF.getSectionName(&*getSection(Sec));
    567   if (!Name)
    568     return Name.getError();
    569   Result = *Name;
    570   return std::error_code();
    571 }
    572 
    573 template <class ELFT>
    574 uint64_t ELFObjectFile<ELFT>::getSectionAddress(DataRefImpl Sec) const {
    575   return getSection(Sec)->sh_addr;
    576 }
    577 
    578 template <class ELFT>
    579 uint64_t ELFObjectFile<ELFT>::getSectionSize(DataRefImpl Sec) const {
    580   return getSection(Sec)->sh_size;
    581 }
    582 
    583 template <class ELFT>
    584 std::error_code
    585 ELFObjectFile<ELFT>::getSectionContents(DataRefImpl Sec,
    586                                         StringRef &Result) const {
    587   const Elf_Shdr *EShdr = getSection(Sec);
    588   Result = StringRef((const char *)base() + EShdr->sh_offset, EShdr->sh_size);
    589   return std::error_code();
    590 }
    591 
    592 template <class ELFT>
    593 uint64_t ELFObjectFile<ELFT>::getSectionAlignment(DataRefImpl Sec) const {
    594   return getSection(Sec)->sh_addralign;
    595 }
    596 
    597 template <class ELFT>
    598 bool ELFObjectFile<ELFT>::isSectionCompressed(DataRefImpl Sec) const {
    599   return getSection(Sec)->sh_flags & ELF::SHF_COMPRESSED;
    600 }
    601 
    602 template <class ELFT>
    603 bool ELFObjectFile<ELFT>::isSectionText(DataRefImpl Sec) const {
    604   return getSection(Sec)->sh_flags & ELF::SHF_EXECINSTR;
    605 }
    606 
    607 template <class ELFT>
    608 bool ELFObjectFile<ELFT>::isSectionData(DataRefImpl Sec) const {
    609   const Elf_Shdr *EShdr = getSection(Sec);
    610   return EShdr->sh_flags & (ELF::SHF_ALLOC | ELF::SHF_WRITE) &&
    611          EShdr->sh_type == ELF::SHT_PROGBITS;
    612 }
    613 
    614 template <class ELFT>
    615 bool ELFObjectFile<ELFT>::isSectionBSS(DataRefImpl Sec) const {
    616   const Elf_Shdr *EShdr = getSection(Sec);
    617   return EShdr->sh_flags & (ELF::SHF_ALLOC | ELF::SHF_WRITE) &&
    618          EShdr->sh_type == ELF::SHT_NOBITS;
    619 }
    620 
    621 template <class ELFT>
    622 bool ELFObjectFile<ELFT>::isSectionVirtual(DataRefImpl Sec) const {
    623   return getSection(Sec)->sh_type == ELF::SHT_NOBITS;
    624 }
    625 
    626 template <class ELFT>
    627 relocation_iterator
    628 ELFObjectFile<ELFT>::section_rel_begin(DataRefImpl Sec) const {
    629   DataRefImpl RelData;
    630   uintptr_t SHT = reinterpret_cast<uintptr_t>(EF.section_begin());
    631   RelData.d.a = (Sec.p - SHT) / EF.getHeader()->e_shentsize;
    632   RelData.d.b = 0;
    633   return relocation_iterator(RelocationRef(RelData, this));
    634 }
    635 
    636 template <class ELFT>
    637 relocation_iterator
    638 ELFObjectFile<ELFT>::section_rel_end(DataRefImpl Sec) const {
    639   const Elf_Shdr *S = reinterpret_cast<const Elf_Shdr *>(Sec.p);
    640   relocation_iterator Begin = section_rel_begin(Sec);
    641   if (S->sh_type != ELF::SHT_RELA && S->sh_type != ELF::SHT_REL)
    642     return Begin;
    643   DataRefImpl RelData = Begin->getRawDataRefImpl();
    644   const Elf_Shdr *RelSec = getRelSection(RelData);
    645 
    646   // Error check sh_link here so that getRelocationSymbol can just use it.
    647   ErrorOr<const Elf_Shdr *> SymSecOrErr = EF.getSection(RelSec->sh_link);
    648   if (std::error_code EC = SymSecOrErr.getError())
    649     report_fatal_error(EC.message());
    650 
    651   RelData.d.b += S->sh_size / S->sh_entsize;
    652   return relocation_iterator(RelocationRef(RelData, this));
    653 }
    654 
    655 template <class ELFT>
    656 section_iterator
    657 ELFObjectFile<ELFT>::getRelocatedSection(DataRefImpl Sec) const {
    658   if (EF.getHeader()->e_type != ELF::ET_REL)
    659     return section_end();
    660 
    661   const Elf_Shdr *EShdr = getSection(Sec);
    662   uintX_t Type = EShdr->sh_type;
    663   if (Type != ELF::SHT_REL && Type != ELF::SHT_RELA)
    664     return section_end();
    665 
    666   ErrorOr<const Elf_Shdr *> R = EF.getSection(EShdr->sh_info);
    667   if (std::error_code EC = R.getError())
    668     report_fatal_error(EC.message());
    669   return section_iterator(SectionRef(toDRI(*R), this));
    670 }
    671 
    672 // Relocations
    673 template <class ELFT>
    674 void ELFObjectFile<ELFT>::moveRelocationNext(DataRefImpl &Rel) const {
    675   ++Rel.d.b;
    676 }
    677 
    678 template <class ELFT>
    679 symbol_iterator
    680 ELFObjectFile<ELFT>::getRelocationSymbol(DataRefImpl Rel) const {
    681   uint32_t symbolIdx;
    682   const Elf_Shdr *sec = getRelSection(Rel);
    683   if (sec->sh_type == ELF::SHT_REL)
    684     symbolIdx = getRel(Rel)->getSymbol(EF.isMips64EL());
    685   else
    686     symbolIdx = getRela(Rel)->getSymbol(EF.isMips64EL());
    687   if (!symbolIdx)
    688     return symbol_end();
    689 
    690   // FIXME: error check symbolIdx
    691   DataRefImpl SymbolData;
    692   SymbolData.d.a = sec->sh_link;
    693   SymbolData.d.b = symbolIdx;
    694   return symbol_iterator(SymbolRef(SymbolData, this));
    695 }
    696 
    697 template <class ELFT>
    698 uint64_t ELFObjectFile<ELFT>::getRelocationOffset(DataRefImpl Rel) const {
    699   assert(EF.getHeader()->e_type == ELF::ET_REL &&
    700          "Only relocatable object files have relocation offsets");
    701   const Elf_Shdr *sec = getRelSection(Rel);
    702   if (sec->sh_type == ELF::SHT_REL)
    703     return getRel(Rel)->r_offset;
    704 
    705   return getRela(Rel)->r_offset;
    706 }
    707 
    708 template <class ELFT>
    709 uint64_t ELFObjectFile<ELFT>::getRelocationType(DataRefImpl Rel) const {
    710   const Elf_Shdr *sec = getRelSection(Rel);
    711   if (sec->sh_type == ELF::SHT_REL)
    712     return getRel(Rel)->getType(EF.isMips64EL());
    713   else
    714     return getRela(Rel)->getType(EF.isMips64EL());
    715 }
    716 
    717 template <class ELFT>
    718 StringRef ELFObjectFile<ELFT>::getRelocationTypeName(uint32_t Type) const {
    719   return getELFRelocationTypeName(EF.getHeader()->e_machine, Type);
    720 }
    721 
    722 template <class ELFT>
    723 void ELFObjectFile<ELFT>::getRelocationTypeName(
    724     DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
    725   uint32_t type = getRelocationType(Rel);
    726   EF.getRelocationTypeName(type, Result);
    727 }
    728 
    729 template <class ELFT>
    730 ErrorOr<int64_t>
    731 ELFObjectFile<ELFT>::getRelocationAddend(DataRefImpl Rel) const {
    732   if (getRelSection(Rel)->sh_type != ELF::SHT_RELA)
    733     return object_error::parse_failed;
    734   return (int64_t)getRela(Rel)->r_addend;
    735 }
    736 
    737 template <class ELFT>
    738 const typename ELFObjectFile<ELFT>::Elf_Rel *
    739 ELFObjectFile<ELFT>::getRel(DataRefImpl Rel) const {
    740   assert(getRelSection(Rel)->sh_type == ELF::SHT_REL);
    741   return EF.template getEntry<Elf_Rel>(Rel.d.a, Rel.d.b);
    742 }
    743 
    744 template <class ELFT>
    745 const typename ELFObjectFile<ELFT>::Elf_Rela *
    746 ELFObjectFile<ELFT>::getRela(DataRefImpl Rela) const {
    747   assert(getRelSection(Rela)->sh_type == ELF::SHT_RELA);
    748   return EF.template getEntry<Elf_Rela>(Rela.d.a, Rela.d.b);
    749 }
    750 
    751 template <class ELFT>
    752 ELFObjectFile<ELFT>::ELFObjectFile(MemoryBufferRef Object, std::error_code &EC)
    753     : ELFObjectFileBase(
    754           getELFType(ELFT::TargetEndianness == support::little, ELFT::Is64Bits),
    755           Object),
    756       EF(Data.getBuffer(), EC) {
    757   if (EC)
    758     return;
    759   for (const Elf_Shdr &Sec : EF.sections()) {
    760     switch (Sec.sh_type) {
    761     case ELF::SHT_DYNSYM: {
    762       if (DotDynSymSec) {
    763         // More than one .dynsym!
    764         EC = object_error::parse_failed;
    765         return;
    766       }
    767       DotDynSymSec = &Sec;
    768       break;
    769     }
    770     case ELF::SHT_SYMTAB: {
    771       if (DotSymtabSec) {
    772         // More than one .dynsym!
    773         EC = object_error::parse_failed;
    774         return;
    775       }
    776       DotSymtabSec = &Sec;
    777       break;
    778     }
    779     case ELF::SHT_SYMTAB_SHNDX: {
    780       ErrorOr<ArrayRef<Elf_Word>> TableOrErr = EF.getSHNDXTable(Sec);
    781       if ((EC = TableOrErr.getError()))
    782         return;
    783       ShndxTable = *TableOrErr;
    784       break;
    785     }
    786     }
    787   }
    788 }
    789 
    790 template <class ELFT>
    791 basic_symbol_iterator ELFObjectFile<ELFT>::symbol_begin_impl() const {
    792   DataRefImpl Sym = toDRI(DotSymtabSec, 0);
    793   return basic_symbol_iterator(SymbolRef(Sym, this));
    794 }
    795 
    796 template <class ELFT>
    797 basic_symbol_iterator ELFObjectFile<ELFT>::symbol_end_impl() const {
    798   const Elf_Shdr *SymTab = DotSymtabSec;
    799   if (!SymTab)
    800     return symbol_begin_impl();
    801   DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
    802   return basic_symbol_iterator(SymbolRef(Sym, this));
    803 }
    804 
    805 template <class ELFT>
    806 elf_symbol_iterator ELFObjectFile<ELFT>::dynamic_symbol_begin() const {
    807   DataRefImpl Sym = toDRI(DotDynSymSec, 0);
    808   return symbol_iterator(SymbolRef(Sym, this));
    809 }
    810 
    811 template <class ELFT>
    812 elf_symbol_iterator ELFObjectFile<ELFT>::dynamic_symbol_end() const {
    813   const Elf_Shdr *SymTab = DotDynSymSec;
    814   DataRefImpl Sym = toDRI(SymTab, SymTab->sh_size / sizeof(Elf_Sym));
    815   return basic_symbol_iterator(SymbolRef(Sym, this));
    816 }
    817 
    818 template <class ELFT>
    819 section_iterator ELFObjectFile<ELFT>::section_begin() const {
    820   return section_iterator(SectionRef(toDRI(EF.section_begin()), this));
    821 }
    822 
    823 template <class ELFT>
    824 section_iterator ELFObjectFile<ELFT>::section_end() const {
    825   return section_iterator(SectionRef(toDRI(EF.section_end()), this));
    826 }
    827 
    828 template <class ELFT>
    829 uint8_t ELFObjectFile<ELFT>::getBytesInAddress() const {
    830   return ELFT::Is64Bits ? 8 : 4;
    831 }
    832 
    833 template <class ELFT>
    834 StringRef ELFObjectFile<ELFT>::getFileFormatName() const {
    835   bool IsLittleEndian = ELFT::TargetEndianness == support::little;
    836   switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
    837   case ELF::ELFCLASS32:
    838     switch (EF.getHeader()->e_machine) {
    839     case ELF::EM_386:
    840       return "ELF32-i386";
    841     case ELF::EM_IAMCU:
    842       return "ELF32-iamcu";
    843     case ELF::EM_X86_64:
    844       return "ELF32-x86-64";
    845     case ELF::EM_ARM:
    846       return (IsLittleEndian ? "ELF32-arm-little" : "ELF32-arm-big");
    847     case ELF::EM_AVR:
    848       return "ELF32-avr";
    849     case ELF::EM_HEXAGON:
    850       return "ELF32-hexagon";
    851     case ELF::EM_LANAI:
    852       return "ELF32-lanai";
    853     case ELF::EM_MIPS:
    854       return "ELF32-mips";
    855     case ELF::EM_PPC:
    856       return "ELF32-ppc";
    857     case ELF::EM_SPARC:
    858     case ELF::EM_SPARC32PLUS:
    859       return "ELF32-sparc";
    860     case ELF::EM_WEBASSEMBLY:
    861       return "ELF32-wasm";
    862     case ELF::EM_AMDGPU:
    863       return "ELF32-amdgpu";
    864     default:
    865       return "ELF32-unknown";
    866     }
    867   case ELF::ELFCLASS64:
    868     switch (EF.getHeader()->e_machine) {
    869     case ELF::EM_386:
    870       return "ELF64-i386";
    871     case ELF::EM_X86_64:
    872       return "ELF64-x86-64";
    873     case ELF::EM_AARCH64:
    874       return (IsLittleEndian ? "ELF64-aarch64-little" : "ELF64-aarch64-big");
    875     case ELF::EM_PPC64:
    876       return "ELF64-ppc64";
    877     case ELF::EM_S390:
    878       return "ELF64-s390";
    879     case ELF::EM_SPARCV9:
    880       return "ELF64-sparc";
    881     case ELF::EM_MIPS:
    882       return "ELF64-mips";
    883     case ELF::EM_WEBASSEMBLY:
    884       return "ELF64-wasm";
    885     case ELF::EM_AMDGPU:
    886       return (EF.getHeader()->e_ident[ELF::EI_OSABI] == ELF::ELFOSABI_AMDGPU_HSA
    887               && IsLittleEndian) ?
    888              "ELF64-amdgpu-hsacobj" : "ELF64-amdgpu";
    889     default:
    890       return "ELF64-unknown";
    891     }
    892   default:
    893     // FIXME: Proper error handling.
    894     report_fatal_error("Invalid ELFCLASS!");
    895   }
    896 }
    897 
    898 template <class ELFT>
    899 unsigned ELFObjectFile<ELFT>::getArch() const {
    900   bool IsLittleEndian = ELFT::TargetEndianness == support::little;
    901   switch (EF.getHeader()->e_machine) {
    902   case ELF::EM_386:
    903   case ELF::EM_IAMCU:
    904     return Triple::x86;
    905   case ELF::EM_X86_64:
    906     return Triple::x86_64;
    907   case ELF::EM_AARCH64:
    908     return Triple::aarch64;
    909   case ELF::EM_ARM:
    910     return Triple::arm;
    911   case ELF::EM_AVR:
    912     return Triple::avr;
    913   case ELF::EM_HEXAGON:
    914     return Triple::hexagon;
    915   case ELF::EM_LANAI:
    916     return Triple::lanai;
    917   case ELF::EM_MIPS:
    918     switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
    919     case ELF::ELFCLASS32:
    920       return IsLittleEndian ? Triple::mipsel : Triple::mips;
    921     case ELF::ELFCLASS64:
    922       return IsLittleEndian ? Triple::mips64el : Triple::mips64;
    923     default:
    924       report_fatal_error("Invalid ELFCLASS!");
    925     }
    926   case ELF::EM_PPC:
    927     return Triple::ppc;
    928   case ELF::EM_PPC64:
    929     return IsLittleEndian ? Triple::ppc64le : Triple::ppc64;
    930   case ELF::EM_S390:
    931     return Triple::systemz;
    932 
    933   case ELF::EM_SPARC:
    934   case ELF::EM_SPARC32PLUS:
    935     return IsLittleEndian ? Triple::sparcel : Triple::sparc;
    936   case ELF::EM_SPARCV9:
    937     return Triple::sparcv9;
    938   case ELF::EM_WEBASSEMBLY:
    939     switch (EF.getHeader()->e_ident[ELF::EI_CLASS]) {
    940     case ELF::ELFCLASS32: return Triple::wasm32;
    941     case ELF::ELFCLASS64: return Triple::wasm64;
    942     default: return Triple::UnknownArch;
    943     }
    944 
    945   case ELF::EM_AMDGPU:
    946     return (EF.getHeader()->e_ident[ELF::EI_CLASS] == ELF::ELFCLASS64
    947          && EF.getHeader()->e_ident[ELF::EI_OSABI] == ELF::ELFOSABI_AMDGPU_HSA
    948          && IsLittleEndian) ?
    949       Triple::amdgcn : Triple::UnknownArch;
    950 
    951   default:
    952     return Triple::UnknownArch;
    953   }
    954 }
    955 
    956 template <class ELFT>
    957 ELFObjectFileBase::elf_symbol_iterator_range
    958 ELFObjectFile<ELFT>::getDynamicSymbolIterators() const {
    959   return make_range(dynamic_symbol_begin(), dynamic_symbol_end());
    960 }
    961 
    962 template <class ELFT> bool ELFObjectFile<ELFT>::isRelocatableObject() const {
    963   return EF.getHeader()->e_type == ELF::ET_REL;
    964 }
    965 
    966 } // end namespace object
    967 } // end namespace llvm
    968 
    969 #endif // LLVM_OBJECT_ELFOBJECTFILE_H
    970