text: //===- ObjectFile.h - File format independent object file -------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file declares a file format independent ObjectFile class.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_OBJECT_OBJECTFILE_H
  #define LLVM_OBJECT_OBJECTFILE_H
  
  #include "llvm/ADT/StringRef.h"
  #include "llvm/Object/SymbolicFile.h"
  #include "llvm/Support/DataTypes.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/FileSystem.h"
  #include "llvm/Support/MemoryBuffer.h"
  #include <cstring>
  #include <vector>
  
  namespace llvm {
  namespace object {
  
  class ObjectFile;
  class COFFObjectFile;
  class MachOObjectFile;
  
  class SymbolRef;
  class symbol_iterator;
  
  /// RelocationRef - This is a value type class that represents a single
  /// relocation in the list of relocations in the object file.
  class RelocationRef {
    DataRefImpl RelocationPimpl;
    const ObjectFile *OwningObject;
  
  public:
    RelocationRef() : OwningObject(nullptr) { }
  
    RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
  
    bool operator==(const RelocationRef &Other) const;
  
    void moveNext();
  
    std::error_code getAddress(uint64_t &Result) const;
    std::error_code getOffset(uint64_t &Result) const;
    symbol_iterator getSymbol() const;
    std::error_code getType(uint64_t &Result) const;
  
    /// @brief Indicates whether this relocation should hidden when listing
    /// relocations, usually because it is the trailing part of a multipart
    /// relocation that will be printed as part of the leading relocation.
    std::error_code getHidden(bool &Result) const;
  
    /// @brief Get a string that represents the type of this relocation.
    ///
    /// This is for display purposes only.
    std::error_code getTypeName(SmallVectorImpl<char> &Result) const;
  
    /// @brief Get a string that represents the calculation of the value of this
    ///        relocation.
    ///
    /// This is for display purposes only.
    std::error_code getValueString(SmallVectorImpl<char> &Result) const;
  
    DataRefImpl getRawDataRefImpl() const;
    const ObjectFile *getObjectFile() const;
  };
  typedef content_iterator<RelocationRef> relocation_iterator;
  
  /// SectionRef - This is a value type class that represents a single section in
  /// the list of sections in the object file.
  class SectionRef;
  typedef content_iterator<SectionRef> section_iterator;
  class SectionRef {
    friend class SymbolRef;
    DataRefImpl SectionPimpl;
    const ObjectFile *OwningObject;
  
  public:
    SectionRef() : OwningObject(nullptr) { }
  
    SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
  
    bool operator==(const SectionRef &Other) const;
    bool operator!=(const SectionRef &Other) const;
    bool operator<(const SectionRef &Other) const;
  
    void moveNext();
  
    std::error_code getName(StringRef &Result) const;
    uint64_t getAddress() const;
    uint64_t getSize() const;
    std::error_code getContents(StringRef &Result) const;
  
    /// @brief Get the alignment of this section as the actual value (not log 2).
    uint64_t getAlignment() const;
  
    bool isText() const;
    bool isData() const;
    bool isBSS() const;
    bool isVirtual() const;
  
    bool containsSymbol(SymbolRef S) const;
  
    relocation_iterator relocation_begin() const;
    relocation_iterator relocation_end() const;
    iterator_range<relocation_iterator> relocations() const {
      return iterator_range<relocation_iterator>(relocation_begin(),
                                                 relocation_end());
    }
    section_iterator getRelocatedSection() const;
  
    DataRefImpl getRawDataRefImpl() const;
    const ObjectFile *getObject() const;
  };
  
  /// SymbolRef - This is a value type class that represents a single symbol in
  /// the list of symbols in the object file.
  class SymbolRef : public BasicSymbolRef {
    friend class SectionRef;
  
  public:
    SymbolRef() : BasicSymbolRef() {}
  
    enum Type {
      ST_Unknown, // Type not specified
      ST_Data,
      ST_Debug,
      ST_File,
      ST_Function,
      ST_Other
    };
  
    SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
  
    std::error_code getName(StringRef &Result) const;
    /// Returns the symbol virtual address (i.e. address at which it will be
    /// mapped).
    std::error_code getAddress(uint64_t &Result) const;
    /// @brief Get the alignment of this symbol as the actual value (not log 2).
    std::error_code getAlignment(uint32_t &Result) const;
    std::error_code getSize(uint64_t &Result) const;
    std::error_code getType(SymbolRef::Type &Result) const;
    std::error_code getOther(uint8_t &Result) const;
  
    /// @brief Get section this symbol is defined in reference to. Result is
    /// end_sections() if it is undefined or is an absolute symbol.
    std::error_code getSection(section_iterator &Result) const;
  
    const ObjectFile *getObject() const;
  };
  
  class symbol_iterator : public basic_symbol_iterator {
  public:
    symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
    symbol_iterator(const basic_symbol_iterator &B)
        : basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
                                          cast<ObjectFile>(B->getObject()))) {}
  
    const SymbolRef *operator->() const {
      const BasicSymbolRef &P = basic_symbol_iterator::operator *();
      return static_cast<const SymbolRef*>(&P);
    }
  
    const SymbolRef &operator*() const {
      const BasicSymbolRef &P = basic_symbol_iterator::operator *();
      return static_cast<const SymbolRef&>(P);
    }
  };
  
  /// ObjectFile - This class is the base class for all object file types.
  /// Concrete instances of this object are created by createObjectFile, which
  /// figures out which type to create.
  class ObjectFile : public SymbolicFile {
    virtual void anchor();
    ObjectFile() = delete;
    ObjectFile(const ObjectFile &other) = delete;
  
  protected:
    ObjectFile(unsigned int Type, MemoryBufferRef Source);
  
    const uint8_t *base() const {
      return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
    }
  
    // These functions are for SymbolRef to call internally. The main goal of
    // this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
    // entry in the memory mapped object file. SymbolPimpl cannot contain any
    // virtual functions because then it could not point into the memory mapped
    // file.
    //
    // Implementations assume that the DataRefImpl is valid and has not been
    // modified externally. It's UB otherwise.
    friend class SymbolRef;
    virtual std::error_code getSymbolName(DataRefImpl Symb,
                                          StringRef &Res) const = 0;
    std::error_code printSymbolName(raw_ostream &OS,
                                    DataRefImpl Symb) const override;
    virtual std::error_code getSymbolAddress(DataRefImpl Symb,
                                             uint64_t &Res) const = 0;
    virtual std::error_code getSymbolAlignment(DataRefImpl Symb,
                                               uint32_t &Res) const;
    virtual std::error_code getSymbolSize(DataRefImpl Symb,
                                          uint64_t &Res) const = 0;
    virtual std::error_code getSymbolType(DataRefImpl Symb,
                                          SymbolRef::Type &Res) const = 0;
    virtual std::error_code getSymbolSection(DataRefImpl Symb,
                                             section_iterator &Res) const = 0;
    virtual std::error_code getSymbolOther(DataRefImpl Symb,
                                           uint8_t &Res) const {
      return object_error::invalid_file_type;
    }
  
    // Same as above for SectionRef.
    friend class SectionRef;
    virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
    virtual std::error_code getSectionName(DataRefImpl Sec,
                                           StringRef &Res) const = 0;
    virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
    virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
    virtual std::error_code getSectionContents(DataRefImpl Sec,
                                               StringRef &Res) const = 0;
    virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
    virtual bool isSectionText(DataRefImpl Sec) const = 0;
    virtual bool isSectionData(DataRefImpl Sec) const = 0;
    virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
    // A section is 'virtual' if its contents aren't present in the object image.
    virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
    virtual bool sectionContainsSymbol(DataRefImpl Sec,
                                       DataRefImpl Symb) const = 0;
    virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
    virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
    virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
  
    // Same as above for RelocationRef.
    friend class RelocationRef;
    virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
    virtual std::error_code getRelocationAddress(DataRefImpl Rel,
                                                 uint64_t &Res) const = 0;
    virtual std::error_code getRelocationOffset(DataRefImpl Rel,
                                                uint64_t &Res) const = 0;
    virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
    virtual std::error_code getRelocationType(DataRefImpl Rel,
                                              uint64_t &Res) const = 0;
    virtual std::error_code
    getRelocationTypeName(DataRefImpl Rel,
                          SmallVectorImpl<char> &Result) const = 0;
    virtual std::error_code
    getRelocationValueString(DataRefImpl Rel,
                             SmallVectorImpl<char> &Result) const = 0;
    virtual std::error_code getRelocationHidden(DataRefImpl Rel,
                                                bool &Result) const {
      Result = false;
      return object_error::success;
    }
  
  public:
    typedef iterator_range<symbol_iterator> symbol_iterator_range;
    symbol_iterator_range symbols() const {
      return symbol_iterator_range(symbol_begin(), symbol_end());
    }
  
    virtual section_iterator section_begin() const = 0;
    virtual section_iterator section_end() const = 0;
  
    typedef iterator_range<section_iterator> section_iterator_range;
    section_iterator_range sections() const {
      return section_iterator_range(section_begin(), section_end());
    }
  
    /// @brief The number of bytes used to represent an address in this object
    ///        file format.
    virtual uint8_t getBytesInAddress() const = 0;
  
    virtual StringRef getFileFormatName() const = 0;
    virtual /* Triple::ArchType */ unsigned getArch() const = 0;
  
    /// Returns platform-specific object flags, if any.
    virtual std::error_code getPlatformFlags(unsigned &Result) const {
      Result = 0;
      return object_error::invalid_file_type;
    }
  
    /// True if this is a relocatable object (.o/.obj).
    virtual bool isRelocatableObject() const = 0;
  
    /// @returns Pointer to ObjectFile subclass to handle this type of object.
    /// @param ObjectPath The path to the object file. ObjectPath.isObject must
    ///        return true.
    /// @brief Create ObjectFile from path.
    static ErrorOr<OwningBinary<ObjectFile>>
    createObjectFile(StringRef ObjectPath);
  
    static ErrorOr<std::unique_ptr<ObjectFile>>
    createObjectFile(MemoryBufferRef Object, sys::fs::file_magic Type);
    static ErrorOr<std::unique_ptr<ObjectFile>>
    createObjectFile(MemoryBufferRef Object) {
      return createObjectFile(Object, sys::fs::file_magic::unknown);
    }
  
  
    static inline bool classof(const Binary *v) {
      return v->isObject();
    }
  
    static ErrorOr<std::unique_ptr<COFFObjectFile>>
    createCOFFObjectFile(MemoryBufferRef Object);
  
    static ErrorOr<std::unique_ptr<ObjectFile>>
    createELFObjectFile(MemoryBufferRef Object);
  
    static ErrorOr<std::unique_ptr<MachOObjectFile>>
    createMachOObjectFile(MemoryBufferRef Object);
  };
  
  // Inline function definitions.
  inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
      : BasicSymbolRef(SymbolP, Owner) {}
  
  inline std::error_code SymbolRef::getName(StringRef &Result) const {
    return getObject()->getSymbolName(getRawDataRefImpl(), Result);
  }
  
  inline std::error_code SymbolRef::getAddress(uint64_t &Result) const {
    return getObject()->getSymbolAddress(getRawDataRefImpl(), Result);
  }
  
  inline std::error_code SymbolRef::getAlignment(uint32_t &Result) const {
    return getObject()->getSymbolAlignment(getRawDataRefImpl(), Result);
  }
  
  inline std::error_code SymbolRef::getSize(uint64_t &Result) const {
    return getObject()->getSymbolSize(getRawDataRefImpl(), Result);
  }
  
  inline std::error_code SymbolRef::getSection(section_iterator &Result) const {
    return getObject()->getSymbolSection(getRawDataRefImpl(), Result);
  }
  
  inline std::error_code SymbolRef::getType(SymbolRef::Type &Result) const {
    return getObject()->getSymbolType(getRawDataRefImpl(), Result);
  }
  
  inline std::error_code SymbolRef::getOther(uint8_t &Result) const {
    return getObject()->getSymbolOther(getRawDataRefImpl(), Result);
  }
  
  inline const ObjectFile *SymbolRef::getObject() const {
    const SymbolicFile *O = BasicSymbolRef::getObject();
    return cast<ObjectFile>(O);
  }
  
  
  /// SectionRef
  inline SectionRef::SectionRef(DataRefImpl SectionP,
                                const ObjectFile *Owner)
    : SectionPimpl(SectionP)
    , OwningObject(Owner) {}
  
  inline bool SectionRef::operator==(const SectionRef &Other) const {
    return SectionPimpl == Other.SectionPimpl;
  }
  
  inline bool SectionRef::operator!=(const SectionRef &Other) const {
    return SectionPimpl != Other.SectionPimpl;
  }
  
  inline bool SectionRef::operator<(const SectionRef &Other) const {
    return SectionPimpl < Other.SectionPimpl;
  }
  
  inline void SectionRef::moveNext() {
    return OwningObject->moveSectionNext(SectionPimpl);
  }
  
  inline std::error_code SectionRef::getName(StringRef &Result) const {
    return OwningObject->getSectionName(SectionPimpl, Result);
  }
  
  inline uint64_t SectionRef::getAddress() const {
    return OwningObject->getSectionAddress(SectionPimpl);
  }
  
  inline uint64_t SectionRef::getSize() const {
    return OwningObject->getSectionSize(SectionPimpl);
  }
  
  inline std::error_code SectionRef::getContents(StringRef &Result) const {
    return OwningObject->getSectionContents(SectionPimpl, Result);
  }
  
  inline uint64_t SectionRef::getAlignment() const {
    return OwningObject->getSectionAlignment(SectionPimpl);
  }
  
  inline bool SectionRef::isText() const {
    return OwningObject->isSectionText(SectionPimpl);
  }
  
  inline bool SectionRef::isData() const {
    return OwningObject->isSectionData(SectionPimpl);
  }
  
  inline bool SectionRef::isBSS() const {
    return OwningObject->isSectionBSS(SectionPimpl);
  }
  
  inline bool SectionRef::isVirtual() const {
    return OwningObject->isSectionVirtual(SectionPimpl);
  }
  
  inline bool SectionRef::containsSymbol(SymbolRef S) const {
    return OwningObject->sectionContainsSymbol(SectionPimpl,
                                               S.getRawDataRefImpl());
  }
  
  inline relocation_iterator SectionRef::relocation_begin() const {
    return OwningObject->section_rel_begin(SectionPimpl);
  }
  
  inline relocation_iterator SectionRef::relocation_end() const {
    return OwningObject->section_rel_end(SectionPimpl);
  }
  
  inline section_iterator SectionRef::getRelocatedSection() const {
    return OwningObject->getRelocatedSection(SectionPimpl);
  }
  
  inline DataRefImpl SectionRef::getRawDataRefImpl() const {
    return SectionPimpl;
  }
  
  inline const ObjectFile *SectionRef::getObject() const {
    return OwningObject;
  }
  
  /// RelocationRef
  inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
                                const ObjectFile *Owner)
    : RelocationPimpl(RelocationP)
    , OwningObject(Owner) {}
  
  inline bool RelocationRef::operator==(const RelocationRef &Other) const {
    return RelocationPimpl == Other.RelocationPimpl;
  }
  
  inline void RelocationRef::moveNext() {
    return OwningObject->moveRelocationNext(RelocationPimpl);
  }
  
  inline std::error_code RelocationRef::getAddress(uint64_t &Result) const {
    return OwningObject->getRelocationAddress(RelocationPimpl, Result);
  }
  
  inline std::error_code RelocationRef::getOffset(uint64_t &Result) const {
    return OwningObject->getRelocationOffset(RelocationPimpl, Result);
  }
  
  inline symbol_iterator RelocationRef::getSymbol() const {
    return OwningObject->getRelocationSymbol(RelocationPimpl);
  }
  
  inline std::error_code RelocationRef::getType(uint64_t &Result) const {
    return OwningObject->getRelocationType(RelocationPimpl, Result);
  }
  
  inline std::error_code
  RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
    return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
  }
  
  inline std::error_code
  RelocationRef::getValueString(SmallVectorImpl<char> &Result) const {
    return OwningObject->getRelocationValueString(RelocationPimpl, Result);
  }
  
  inline std::error_code RelocationRef::getHidden(bool &Result) const {
    return OwningObject->getRelocationHidden(RelocationPimpl, Result);
  }
  
  inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
    return RelocationPimpl;
  }
  
  inline const ObjectFile *RelocationRef::getObjectFile() const {
    return OwningObject;
  }
  
  
  } // end namespace object
  } // end namespace llvm
  
  #endif
  