path: root/include/llvm/Object/ObjectFile.h

//===- 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/Binary.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cstring>
#include <vector>

namespace llvm {
namespace object {

class ObjectFile;

union DataRefImpl {
  struct {
    // ELF needs this for relocations. This entire union should probably be a
    // char[max(8, sizeof(uintptr_t))] and require the impl to cast.
    uint16_t a, b;
    uint32_t c;
  } w;
  struct {
    uint32_t a, b;
  } d;
  uintptr_t p;
  DataRefImpl() {
    std::memset(this, 0, sizeof(DataRefImpl));
  }
};

template<class content_type>
class content_iterator {
  content_type Current;
public:
  content_iterator(content_type symb)
    : Current(symb) {}

  const content_type* operator->() const {
    return &Current;
  }

  const content_type &operator*() const {
    return Current;
  }

  bool operator==(const content_iterator &other) const {
    return Current == other.Current;
  }

  bool operator!=(const content_iterator &other) const {
    return !(*this == other);
  }

  content_iterator& increment(error_code &err) {
    content_type next;
    if (error_code ec = Current.getNext(next))
      err = ec;
    else
      Current = next;
    return *this;
  }
};

inline bool operator==(const DataRefImpl &a, const DataRefImpl &b) {
  // Check bitwise identical. This is the only legal way to compare a union w/o
  // knowing which member is in use.
  return std::memcmp(&a, &b, sizeof(DataRefImpl)) == 0;
}

inline bool operator<(const DataRefImpl &a, const DataRefImpl &b) {
  // Check bitwise identical. This is the only legal way to compare a union w/o
  // knowing which member is in use.
  return std::memcmp(&a, &b, sizeof(DataRefImpl)) < 0;
}

class SymbolRef;

/// 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(NULL) { }

  RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);

  bool operator==(const RelocationRef &Other) const;

  error_code getNext(RelocationRef &Result) const;

  error_code getAddress(uint64_t &Result) const;
  error_code getOffset(uint64_t &Result) const;
  error_code getSymbol(SymbolRef &Result) const;
  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.
  error_code getHidden(bool &Result) const;

  /// @brief Get a string that represents the type of this relocation.
  ///
  /// This is for display purposes only.
  error_code getTypeName(SmallVectorImpl<char> &Result) const;
  error_code getAdditionalInfo(int64_t &Result) const;

  /// @brief Get a string that represents the calculation of the value of this
  ///        relocation.
  ///
  /// This is for display purposes only.
  error_code getValueString(SmallVectorImpl<char> &Result) const;

  DataRefImpl getRawDataRefImpl() 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 {
  friend class SymbolRef;
  DataRefImpl SectionPimpl;
  const ObjectFile *OwningObject;

public:
  SectionRef() : OwningObject(NULL) { }

  SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);

  bool operator==(const SectionRef &Other) const;
  bool operator<(const SectionRef &Other) const;

  error_code getNext(SectionRef &Result) const;

  error_code getName(StringRef &Result) const;
  error_code getAddress(uint64_t &Result) const;
  error_code getSize(uint64_t &Result) const;
  error_code getContents(StringRef &Result) const;

  /// @brief Get the alignment of this section as the actual value (not log 2).
  error_code getAlignment(uint64_t &Result) const;

  // FIXME: Move to the normalization layer when it's created.
  error_code isText(bool &Result) const;
  error_code isData(bool &Result) const;
  error_code isBSS(bool &Result) const;
  error_code isRequiredForExecution(bool &Result) const;
  error_code isVirtual(bool &Result) const;
  error_code isZeroInit(bool &Result) const;
  error_code isReadOnlyData(bool &Result) const;

  error_code containsSymbol(SymbolRef S, bool &Result) const;

  relocation_iterator begin_relocations() const;
  relocation_iterator end_relocations() const;

  DataRefImpl getRawDataRefImpl() const;
};
typedef content_iterator<SectionRef> section_iterator;

/// SymbolRef - This is a value type class that represents a single symbol in
/// the list of symbols in the object file.
class SymbolRef {
  friend class SectionRef;
  DataRefImpl SymbolPimpl;
  const ObjectFile *OwningObject;

public:
  SymbolRef() : OwningObject(NULL) { }

  enum Type {
    ST_Unknown, // Type not specified
    ST_Data,
    ST_Debug,
    ST_File,
    ST_Function,
    ST_Other
  };

  enum Flags {
    SF_None            = 0,
    SF_Undefined       = 1U << 0,  // Symbol is defined in another object file
    SF_Global          = 1U << 1,  // Global symbol
    SF_Weak            = 1U << 2,  // Weak symbol
    SF_Absolute        = 1U << 3,  // Absolute symbol
    SF_ThreadLocal     = 1U << 4,  // Thread local symbol
    SF_Common          = 1U << 5,  // Symbol has common linkage
    SF_FormatSpecific  = 1U << 31  // Specific to the object file format
                                   // (e.g. section symbols)
  };

  SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);

  bool operator==(const SymbolRef &Other) const;
  bool operator<(const SymbolRef &Other) const;

  error_code getNext(SymbolRef &Result) const;

  error_code getName(StringRef &Result) const;
  /// Returns the symbol virtual address (i.e. address at which it will be
  /// mapped).
  error_code getAddress(uint64_t &Result) const;
  error_code getFileOffset(uint64_t &Result) const;
  /// @brief Get the alignment of this symbol as the actual value (not log 2).
  error_code getAlignment(uint32_t &