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      1 //===- ObjectFile.h - File format independent object file -------*- 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 a file format independent ObjectFile class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_OBJECT_OBJECTFILE_H
     15 #define LLVM_OBJECT_OBJECTFILE_H
     16 
     17 #include "llvm/ADT/StringRef.h"
     18 #include "llvm/Object/SymbolicFile.h"
     19 #include "llvm/Support/DataTypes.h"
     20 #include "llvm/Support/ErrorHandling.h"
     21 #include "llvm/Support/FileSystem.h"
     22 #include "llvm/Support/MemoryBuffer.h"
     23 #include <cstring>
     24 #include <vector>
     25 
     26 namespace llvm {
     27 namespace object {
     28 
     29 class ObjectFile;
     30 
     31 class SymbolRef;
     32 class symbol_iterator;
     33 
     34 /// RelocationRef - This is a value type class that represents a single
     35 /// relocation in the list of relocations in the object file.
     36 class RelocationRef {
     37   DataRefImpl RelocationPimpl;
     38   const ObjectFile *OwningObject;
     39 
     40 public:
     41   RelocationRef() : OwningObject(nullptr) { }
     42 
     43   RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
     44 
     45   bool operator==(const RelocationRef &Other) const;
     46 
     47   void moveNext();
     48 
     49   std::error_code getAddress(uint64_t &Result) const;
     50   std::error_code getOffset(uint64_t &Result) const;
     51   symbol_iterator getSymbol() const;
     52   std::error_code getType(uint64_t &Result) const;
     53 
     54   /// @brief Indicates whether this relocation should hidden when listing
     55   /// relocations, usually because it is the trailing part of a multipart
     56   /// relocation that will be printed as part of the leading relocation.
     57   std::error_code getHidden(bool &Result) const;
     58 
     59   /// @brief Get a string that represents the type of this relocation.
     60   ///
     61   /// This is for display purposes only.
     62   std::error_code getTypeName(SmallVectorImpl<char> &Result) const;
     63 
     64   /// @brief Get a string that represents the calculation of the value of this
     65   ///        relocation.
     66   ///
     67   /// This is for display purposes only.
     68   std::error_code getValueString(SmallVectorImpl<char> &Result) const;
     69 
     70   DataRefImpl getRawDataRefImpl() const;
     71   const ObjectFile *getObjectFile() const;
     72 };
     73 typedef content_iterator<RelocationRef> relocation_iterator;
     74 
     75 /// SectionRef - This is a value type class that represents a single section in
     76 /// the list of sections in the object file.
     77 class SectionRef;
     78 typedef content_iterator<SectionRef> section_iterator;
     79 class SectionRef {
     80   friend class SymbolRef;
     81   DataRefImpl SectionPimpl;
     82   const ObjectFile *OwningObject;
     83 
     84 public:
     85   SectionRef() : OwningObject(nullptr) { }
     86 
     87   SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
     88 
     89   bool operator==(const SectionRef &Other) const;
     90   bool operator!=(const SectionRef &Other) const;
     91   bool operator<(const SectionRef &Other) const;
     92 
     93   void moveNext();
     94 
     95   std::error_code getName(StringRef &Result) const;
     96   std::error_code getAddress(uint64_t &Result) const;
     97   std::error_code getSize(uint64_t &Result) const;
     98   std::error_code getContents(StringRef &Result) const;
     99 
    100   /// @brief Get the alignment of this section as the actual value (not log 2).
    101   std::error_code getAlignment(uint64_t &Result) const;
    102 
    103   // FIXME: Move to the normalization layer when it's created.
    104   std::error_code isText(bool &Result) const;
    105   std::error_code isData(bool &Result) const;
    106   std::error_code isBSS(bool &Result) const;
    107   std::error_code isRequiredForExecution(bool &Result) const;
    108   std::error_code isVirtual(bool &Result) const;
    109   std::error_code isZeroInit(bool &Result) const;
    110   std::error_code isReadOnlyData(bool &Result) const;
    111 
    112   std::error_code containsSymbol(SymbolRef S, bool &Result) const;
    113 
    114   relocation_iterator relocation_begin() const;
    115   relocation_iterator relocation_end() const;
    116   iterator_range<relocation_iterator> relocations() const {
    117     return iterator_range<relocation_iterator>(relocation_begin(),
    118                                                relocation_end());
    119   }
    120   section_iterator getRelocatedSection() const;
    121 
    122   DataRefImpl getRawDataRefImpl() const;
    123 };
    124 
    125 /// SymbolRef - This is a value type class that represents a single symbol in
    126 /// the list of symbols in the object file.
    127 class SymbolRef : public BasicSymbolRef {
    128   friend class SectionRef;
    129 
    130 public:
    131   SymbolRef() : BasicSymbolRef() {}
    132 
    133   enum Type {
    134     ST_Unknown, // Type not specified
    135     ST_Data,
    136     ST_Debug,
    137     ST_File,
    138     ST_Function,
    139     ST_Other
    140   };
    141 
    142   SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
    143 
    144   std::error_code getName(StringRef &Result) const;
    145   /// Returns the symbol virtual address (i.e. address at which it will be
    146   /// mapped).
    147   std::error_code getAddress(uint64_t &Result) const;
    148   /// @brief Get the alignment of this symbol as the actual value (not log 2).
    149   std::error_code getAlignment(uint32_t &Result) const;
    150   std::error_code getSize(uint64_t &Result) const;
    151   std::error_code getType(SymbolRef::Type &Result) const;
    152 
    153   /// @brief Get section this symbol is defined in reference to. Result is
    154   /// end_sections() if it is undefined or is an absolute symbol.
    155   std::error_code getSection(section_iterator &Result) const;
    156 
    157   const ObjectFile *getObject() const;
    158 };
    159 
    160 class symbol_iterator : public basic_symbol_iterator {
    161 public:
    162   symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
    163   symbol_iterator(const basic_symbol_iterator &B)
    164       : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
    165                                         cast<ObjectFile>(B->getObject()))) {}
    166 
    167   const SymbolRef *operator->() const {
    168     const BasicSymbolRef &P = basic_symbol_iterator::operator *();
    169     return static_cast<const SymbolRef*>(&P);
    170   }
    171 
    172   const SymbolRef &operator*() const {
    173     const BasicSymbolRef &P = basic_symbol_iterator::operator *();
    174     return static_cast<const SymbolRef&>(P);
    175   }
    176 };
    177 
    178 /// LibraryRef - This is a value type class that represents a single library in
    179 /// the list of libraries needed by a shared or dynamic object.
    180 class LibraryRef {
    181   friend class SectionRef;
    182   DataRefImpl LibraryPimpl;
    183   const ObjectFile *OwningObject;
    184 
    185 public:
    186   LibraryRef() : OwningObject(nullptr) { }
    187 
    188   LibraryRef(DataRefImpl LibraryP, const ObjectFile *Owner);
    189 
    190   bool operator==(const LibraryRef &Other) const;
    191   bool operator<(const LibraryRef &Other) const;
    192 
    193   std::error_code getNext(LibraryRef &Result) const;
    194 
    195   // Get the path to this library, as stored in the object file.
    196   std::error_code getPath(StringRef &Result) const;
    197 
    198   DataRefImpl getRawDataRefImpl() const;
    199 };
    200 typedef content_iterator<LibraryRef> library_iterator;
    201 
    202 /// ObjectFile - This class is the base class for all object file types.
    203 /// Concrete instances of this object are created by createObjectFile, which
    204 /// figures out which type to create.
    205 class ObjectFile : public SymbolicFile {
    206   virtual void anchor();
    207   ObjectFile() LLVM_DELETED_FUNCTION;
    208   ObjectFile(const ObjectFile &other) LLVM_DELETED_FUNCTION;
    209 
    210 protected:
    211   ObjectFile(unsigned int Type, std::unique_ptr<MemoryBuffer> Source);
    212 
    213   const uint8_t *base() const {
    214     return reinterpret_cast<const uint8_t *>(Data->getBufferStart());
    215   }
    216 
    217   // These functions are for SymbolRef to call internally. The main goal of
    218   // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
    219   // entry in the memory mapped object file. SymbolPimpl cannot contain any
    220   // virtual functions because then it could not point into the memory mapped
    221   // file.
    222   //
    223   // Implementations assume that the DataRefImpl is valid and has not been
    224   // modified externally. It's UB otherwise.
    225   friend class SymbolRef;
    226   virtual std::error_code getSymbolName(DataRefImpl Symb,
    227                                         StringRef &Res) const = 0;
    228   std::error_code printSymbolName(raw_ostream &OS,
    229                                   DataRefImpl Symb) const override;
    230   virtual std::error_code getSymbolAddress(DataRefImpl Symb,
    231                                            uint64_t &Res) const = 0;
    232   virtual std::error_code getSymbolAlignment(DataRefImpl Symb,
    233                                              uint32_t &Res) const;
    234   virtual std::error_code getSymbolSize(DataRefImpl Symb,
    235                                         uint64_t &Res) const = 0;
    236   virtual std::error_code getSymbolType(DataRefImpl Symb,
    237                                         SymbolRef::Type &Res) const = 0;
    238   virtual std::error_code getSymbolSection(DataRefImpl Symb,
    239                                            section_iterator &Res) const = 0;
    240 
    241   // Same as above for SectionRef.
    242   friend class SectionRef;
    243   virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
    244   virtual std::error_code getSectionName(DataRefImpl Sec,
    245                                          StringRef &Res) const = 0;
    246   virtual std::error_code getSectionAddress(DataRefImpl Sec,
    247                                             uint64_t &Res) const = 0;
    248   virtual std::error_code getSectionSize(DataRefImpl Sec,
    249                                          uint64_t &Res) const = 0;
    250   virtual std::error_code getSectionContents(DataRefImpl Sec,
    251                                              StringRef &Res) const = 0;
    252   virtual std::error_code getSectionAlignment(DataRefImpl Sec,
    253                                               uint64_t &Res) const = 0;
    254   virtual std::error_code isSectionText(DataRefImpl Sec, bool &Res) const = 0;
    255   virtual std::error_code isSectionData(DataRefImpl Sec, bool &Res) const = 0;
    256   virtual std::error_code isSectionBSS(DataRefImpl Sec, bool &Res) const = 0;
    257   virtual std::error_code isSectionRequiredForExecution(DataRefImpl Sec,
    258                                                         bool &Res) const = 0;
    259   // A section is 'virtual' if its contents aren't present in the object image.
    260   virtual std::error_code isSectionVirtual(DataRefImpl Sec,
    261                                            bool &Res) const = 0;
    262   virtual std::error_code isSectionZeroInit(DataRefImpl Sec,
    263                                             bool &Res) const = 0;
    264   virtual std::error_code isSectionReadOnlyData(DataRefImpl Sec,
    265                                                 bool &Res) const = 0;
    266   virtual std::error_code sectionContainsSymbol(DataRefImpl Sec,
    267                                                 DataRefImpl Symb,
    268                                                 bool &Result) const = 0;
    269   virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
    270   virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
    271   virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
    272 
    273   // Same as above for RelocationRef.
    274   friend class RelocationRef;
    275   virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
    276   virtual std::error_code getRelocationAddress(DataRefImpl Rel,
    277                                                uint64_t &Res) const = 0;
    278   virtual std::error_code getRelocationOffset(DataRefImpl Rel,
    279                                               uint64_t &Res) const = 0;
    280   virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
    281   virtual std::error_code getRelocationType(DataRefImpl Rel,
    282                                             uint64_t &Res) const = 0;
    283   virtual std::error_code
    284   getRelocationTypeName(DataRefImpl Rel,
    285                         SmallVectorImpl<char> &Result) const = 0;
    286   virtual std::error_code
    287   getRelocationValueString(DataRefImpl Rel,
    288                            SmallVectorImpl<char> &Result) const = 0;
    289   virtual std::error_code getRelocationHidden(DataRefImpl Rel,
    290                                               bool &Result) const {
    291     Result = false;
    292     return object_error::success;
    293   }
    294 
    295   // Same for LibraryRef
    296   friend class LibraryRef;
    297   virtual std::error_code getLibraryNext(DataRefImpl Lib,
    298                                          LibraryRef &Res) const = 0;
    299   virtual std::error_code getLibraryPath(DataRefImpl Lib,
    300                                          StringRef &Res) const = 0;
    301 
    302 public:
    303   typedef iterator_range<symbol_iterator> symbol_iterator_range;
    304   symbol_iterator_range symbols() const {
    305     return symbol_iterator_range(symbol_begin(), symbol_end());
    306   }
    307 
    308   virtual section_iterator section_begin() const = 0;
    309   virtual section_iterator section_end() const = 0;
    310 
    311   typedef iterator_range<section_iterator> section_iterator_range;
    312   section_iterator_range sections() const {
    313     return section_iterator_range(section_begin(), section_end());
    314   }
    315 
    316   virtual library_iterator needed_library_begin() const = 0;
    317   virtual library_iterator needed_library_end() const = 0;
    318 
    319   /// @brief The number of bytes used to represent an address in this object
    320   ///        file format.
    321   virtual uint8_t getBytesInAddress() const = 0;
    322 
    323   virtual StringRef getFileFormatName() const = 0;
    324   virtual /* Triple::ArchType */ unsigned getArch() const = 0;
    325 
    326   /// For shared objects, returns the name which this object should be
    327   /// loaded from at runtime. This corresponds to DT_SONAME on ELF and
    328   /// LC_ID_DYLIB (install name) on MachO.
    329   virtual StringRef getLoadName() const = 0;
    330 
    331   /// @returns Pointer to ObjectFile subclass to handle this type of object.
    332   /// @param ObjectPath The path to the object file. ObjectPath.isObject must
    333   ///        return true.
    334   /// @brief Create ObjectFile from path.
    335   static ErrorOr<ObjectFile *> createObjectFile(StringRef ObjectPath);
    336   static ErrorOr<ObjectFile *>
    337   createObjectFile(std::unique_ptr<MemoryBuffer> &Object,
    338                    sys::fs::file_magic Type);
    339   static ErrorOr<ObjectFile *>
    340   createObjectFile(std::unique_ptr<MemoryBuffer> &Object) {
    341     return createObjectFile(Object, sys::fs::file_magic::unknown);
    342   }
    343 
    344 
    345   static inline bool classof(const Binary *v) {
    346     return v->isObject();
    347   }
    348 
    349 public:
    350   static ErrorOr<ObjectFile *>
    351   createCOFFObjectFile(std::unique_ptr<MemoryBuffer> Object);
    352   static ErrorOr<ObjectFile *>
    353   createELFObjectFile(std::unique_ptr<MemoryBuffer> &Object);
    354   static ErrorOr<ObjectFile *>
    355   createMachOObjectFile(std::unique_ptr<MemoryBuffer> &Object);
    356 };
    357 
    358 // Inline function definitions.
    359 inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
    360     : BasicSymbolRef(SymbolP, Owner) {}
    361 
    362 inline std::error_code SymbolRef::getName(StringRef &Result) const {
    363   return getObject()->getSymbolName(getRawDataRefImpl(), Result);
    364 }
    365 
    366 inline std::error_code SymbolRef::getAddress(uint64_t &Result) const {
    367   return getObject()->getSymbolAddress(getRawDataRefImpl(), Result);
    368 }
    369 
    370 inline std::error_code SymbolRef::getAlignment(uint32_t &Result) const {
    371   return getObject()->getSymbolAlignment(getRawDataRefImpl(), Result);
    372 }
    373 
    374 inline std::error_code SymbolRef::getSize(uint64_t &Result) const {
    375   return getObject()->getSymbolSize(getRawDataRefImpl(), Result);
    376 }
    377 
    378 inline std::error_code SymbolRef::getSection(section_iterator &Result) const {
    379   return getObject()->getSymbolSection(getRawDataRefImpl(), Result);
    380 }
    381 
    382 inline std::error_code SymbolRef::getType(SymbolRef::Type &Result) const {
    383   return getObject()->getSymbolType(getRawDataRefImpl(), Result);
    384 }
    385 
    386 inline const ObjectFile *SymbolRef::getObject() const {
    387   const SymbolicFile *O = BasicSymbolRef::getObject();
    388   return cast<ObjectFile>(O);
    389 }
    390 
    391 
    392 /// SectionRef
    393 inline SectionRef::SectionRef(DataRefImpl SectionP,
    394                               const ObjectFile *Owner)
    395   : SectionPimpl(SectionP)
    396   , OwningObject(Owner) {}
    397 
    398 inline bool SectionRef::operator==(const SectionRef &Other) const {
    399   return SectionPimpl == Other.SectionPimpl;
    400 }
    401 
    402 inline bool SectionRef::operator!=(const SectionRef &Other) const {
    403   return SectionPimpl != Other.SectionPimpl;
    404 }
    405 
    406 inline bool SectionRef::operator<(const SectionRef &Other) const {
    407   return SectionPimpl < Other.SectionPimpl;
    408 }
    409 
    410 inline void SectionRef::moveNext() {
    411   return OwningObject->moveSectionNext(SectionPimpl);
    412 }
    413 
    414 inline std::error_code SectionRef::getName(StringRef &Result) const {
    415   return OwningObject->getSectionName(SectionPimpl, Result);
    416 }
    417 
    418 inline std::error_code SectionRef::getAddress(uint64_t &Result) const {
    419   return OwningObject->getSectionAddress(SectionPimpl, Result);
    420 }
    421 
    422 inline std::error_code SectionRef::getSize(uint64_t &Result) const {
    423   return OwningObject->getSectionSize(SectionPimpl, Result);
    424 }
    425 
    426 inline std::error_code SectionRef::getContents(StringRef &Result) const {
    427   return OwningObject->getSectionContents(SectionPimpl, Result);
    428 }
    429 
    430 inline std::error_code SectionRef::getAlignment(uint64_t &Result) const {
    431   return OwningObject->getSectionAlignment(SectionPimpl, Result);
    432 }
    433 
    434 inline std::error_code SectionRef::isText(bool &Result) const {
    435   return OwningObject->isSectionText(SectionPimpl, Result);
    436 }
    437 
    438 inline std::error_code SectionRef::isData(bool &Result) const {
    439   return OwningObject->isSectionData(SectionPimpl, Result);
    440 }
    441 
    442 inline std::error_code SectionRef::isBSS(bool &Result) const {
    443   return OwningObject->isSectionBSS(SectionPimpl, Result);
    444 }
    445 
    446 inline std::error_code SectionRef::isRequiredForExecution(bool &Result) const {
    447   return OwningObject->isSectionRequiredForExecution(SectionPimpl, Result);
    448 }
    449 
    450 inline std::error_code SectionRef::isVirtual(bool &Result) const {
    451   return OwningObject->isSectionVirtual(SectionPimpl, Result);
    452 }
    453 
    454 inline std::error_code SectionRef::isZeroInit(bool &Result) const {
    455   return OwningObject->isSectionZeroInit(SectionPimpl, Result);
    456 }
    457 
    458 inline std::error_code SectionRef::isReadOnlyData(bool &Result) const {
    459   return OwningObject->isSectionReadOnlyData(SectionPimpl, Result);
    460 }
    461 
    462 inline std::error_code SectionRef::containsSymbol(SymbolRef S,
    463                                                   bool &Result) const {
    464   return OwningObject->sectionContainsSymbol(SectionPimpl,
    465                                              S.getRawDataRefImpl(), Result);
    466 }
    467 
    468 inline relocation_iterator SectionRef::relocation_begin() const {
    469   return OwningObject->section_rel_begin(SectionPimpl);
    470 }
    471 
    472 inline relocation_iterator SectionRef::relocation_end() const {
    473   return OwningObject->section_rel_end(SectionPimpl);
    474 }
    475 
    476 inline section_iterator SectionRef::getRelocatedSection() const {
    477   return OwningObject->getRelocatedSection(SectionPimpl);
    478 }
    479 
    480 inline DataRefImpl SectionRef::getRawDataRefImpl() const {
    481   return SectionPimpl;
    482 }
    483 
    484 /// RelocationRef
    485 inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
    486                               const ObjectFile *Owner)
    487   : RelocationPimpl(RelocationP)
    488   , OwningObject(Owner) {}
    489 
    490 inline bool RelocationRef::operator==(const RelocationRef &Other) const {
    491   return RelocationPimpl == Other.RelocationPimpl;
    492 }
    493 
    494 inline void RelocationRef::moveNext() {
    495   return OwningObject->moveRelocationNext(RelocationPimpl);
    496 }
    497 
    498 inline std::error_code RelocationRef::getAddress(uint64_t &Result) const {
    499   return OwningObject->getRelocationAddress(RelocationPimpl, Result);
    500 }
    501 
    502 inline std::error_code RelocationRef::getOffset(uint64_t &Result) const {
    503   return OwningObject->getRelocationOffset(RelocationPimpl, Result);
    504 }
    505 
    506 inline symbol_iterator RelocationRef::getSymbol() const {
    507   return OwningObject->getRelocationSymbol(RelocationPimpl);
    508 }
    509 
    510 inline std::error_code RelocationRef::getType(uint64_t &Result) const {
    511   return OwningObject->getRelocationType(RelocationPimpl, Result);
    512 }
    513 
    514 inline std::error_code
    515 RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
    516   return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
    517 }
    518 
    519 inline std::error_code
    520 RelocationRef::getValueString(SmallVectorImpl<char> &Result) const {
    521   return OwningObject->getRelocationValueString(RelocationPimpl, Result);
    522 }
    523 
    524 inline std::error_code RelocationRef::getHidden(bool &Result) const {
    525   return OwningObject->getRelocationHidden(RelocationPimpl, Result);
    526 }
    527 
    528 inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
    529   return RelocationPimpl;
    530 }
    531 
    532 inline const ObjectFile *RelocationRef::getObjectFile() const {
    533   return OwningObject;
    534 }
    535 
    536 // Inline function definitions.
    537 inline LibraryRef::LibraryRef(DataRefImpl LibraryP, const ObjectFile *Owner)
    538   : LibraryPimpl(LibraryP)
    539   , OwningObject(Owner) {}
    540 
    541 inline bool LibraryRef::operator==(const LibraryRef &Other) const {
    542   return LibraryPimpl == Other.LibraryPimpl;
    543 }
    544 
    545 inline bool LibraryRef::operator<(const LibraryRef &Other) const {
    546   return LibraryPimpl < Other.LibraryPimpl;
    547 }
    548 
    549 inline std::error_code LibraryRef::getNext(LibraryRef &Result) const {
    550   return OwningObject->getLibraryNext(LibraryPimpl, Result);
    551 }
    552 
    553 inline std::error_code LibraryRef::getPath(StringRef &Result) const {
    554   return OwningObject->getLibraryPath(LibraryPimpl, Result);
    555 }
    556 
    557 } // end namespace object
    558 } // end namespace llvm
    559 
    560 #endif
    561