llvm-project/lld/lib/ReaderWriter/MachO/SimpleAtoms.hpp

//===- lib/ReaderWriter/MachO/SimpleAtoms.hpp -----------------------------===//
//
//                             The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef LLD_READER_WRITER_MACHO_SIMPLE_ATOM_H_
#define LLD_READER_WRITER_MACHO_SIMPLE_ATOM_H_

#include <vector>

#include "lld/Core/DefinedAtom.h"
#include "lld/Core/UndefinedAtom.h"
#include "lld/Core/File.h"
#include "lld/Core/Reference.h"

namespace lld {
namespace mach_o {


//
// Simple File
//
class SimpleFile : public File {
public:
      SimpleFile(StringRef path) 
        : File(path) {
      }
      
  virtual void addAtom(const Atom &atom) {
    if (const DefinedAtom* defAtom = dyn_cast<DefinedAtom>(&atom)) {
      _definedAtoms._atoms.push_back(defAtom);
    } 
    else if (const UndefinedAtom* undefAtom = dyn_cast<UndefinedAtom>(&atom)) {
      _undefinedAtoms._atoms.push_back(undefAtom);
    } 
    else if (const SharedLibraryAtom* slAtom =
                 dyn_cast<SharedLibraryAtom>(&atom)) {
      _sharedLibraryAtoms._atoms.push_back(slAtom);
    } 
    else if (const AbsoluteAtom* abAtom = dyn_cast<AbsoluteAtom>(&atom)) {
      _absoluteAtoms._atoms.push_back(abAtom);
    } 
    else {
      assert(0 && "atom has unknown definition kind");
    }
  }

  virtual const atom_collection<DefinedAtom>& defined() const {
    return _definedAtoms;
  }
  virtual const atom_collection<UndefinedAtom>& undefined() const {
      return _undefinedAtoms;
  }
  virtual const atom_collection<SharedLibraryAtom>& sharedLibrary() const {
      return _sharedLibraryAtoms;
  }
  virtual const atom_collection<AbsoluteAtom>& absolute() const {
      return _absoluteAtoms;
  }
      
private:
  atom_collection_vector<DefinedAtom>         _definedAtoms;
  atom_collection_vector<UndefinedAtom>       _undefinedAtoms;
  atom_collection_vector<SharedLibraryAtom>   _sharedLibraryAtoms;
  atom_collection_vector<AbsoluteAtom>        _absoluteAtoms;
};



//
// Simple Reference
//
class SimpleReference : public Reference {
public:
                SimpleReference(Reference::Kind k, uint64_t off, 
                                const Atom *t, Reference::Addend a) 
                      : _target(t), _offsetInAtom(off), _addend(a), _kind(k) { }

  virtual uint64_t offsetInAtom() const {
    return _offsetInAtom;
  }

  virtual Kind kind() const {
    return _kind;
  }

  virtual void setKind(Kind k) {
    _kind = k;
  }

  virtual const Atom* target() const {
    return _target;
  }

  virtual Addend addend() const {
    return _addend;
  }

  virtual void setAddend(Addend a) {
    _addend = a;
  }

  virtual void setTarget(const Atom* newAtom) {
    _target = newAtom;
  }
private:
  const Atom*  _target;
  uint64_t     _offsetInAtom;
  Addend       _addend;
  Kind         _kind;
};


//
// Generic Atom base class
//
class SimpleDefinedAtom : public DefinedAtom {
public:
        SimpleDefinedAtom(const File &f) : _file(f) {
          static uint32_t lastOrdinal = 0;
          _ordinal = lastOrdinal++; 
        }

  virtual const File& file() const {
    return _file;
  }

  virtual StringRef name() const {
    return StringRef();
  }
  
  virtual uint64_t ordinal() const {
    return _ordinal;
  }

  virtual Scope scope() const {
    return DefinedAtom::scopeLinkageUnit;
  }
  
  virtual Interposable interposable() const {
    return DefinedAtom::interposeNo;
  }
  
  virtual Merge merge() const {
    return DefinedAtom::mergeNo;
  }
  
  virtual Alignment alignment() const {
    return Alignment(0,0);
  }
  
  virtual SectionChoice sectionChoice() const {
    return DefinedAtom::sectionBasedOnContent;
  }
    
  virtual StringRef customSectionName() const {
    return StringRef();
  }
  virtual DeadStripKind deadStrip() const {
    return DefinedAtom::deadStripNormal;
  }
    
  virtual bool isThumb() const {
    return false;
  }
    
  virtual bool isAlias() const {
    return false;
  }
  
  virtual DefinedAtom::reference_iterator begin() const {
    uintptr_t index = 0;
    const void* it = reinterpret_cast<const void*>(index);
    return reference_iterator(*this, it);
  }

  virtual DefinedAtom::reference_iterator end() const {
    uintptr_t index = _references.size();
    const void* it = reinterpret_cast<const void*>(index);
    return reference_iterator(*this, it);
  }

  virtual const Reference* derefIterator(const void* it) const {
    uintptr_t index = reinterpret_cast<uintptr_t>(it);
    assert(index < _references.size());
    return &_references[index];
  }

  virtual void incrementIterator(const void*& it) const {
    uintptr_t index = reinterpret_cast<uintptr_t>(it);
    ++index;
    it = reinterpret_cast<const void*>(index);
  }
  
  void addReference(Reference::Kind kind, uint64_t offset, const Atom *target, 
                   Reference::Addend addend) {
    _references.push_back(SimpleReference(kind, offset, target, addend));
  }
  
private:
  const File&                   _file;
  uint32_t                      _ordinal;
  std::vector<SimpleReference>  _references;
};



//
// Generic UndefinedAtom base class
//
class SimpleUndefinedAtom : public UndefinedAtom {
public:
        SimpleUndefinedAtom(const File &f, StringRef name) 
            : _file(f), _name(name) {
        }

  /// file - returns the File that produced/owns this Atom
  virtual const class File& file() const {
    return _file;
  }

  /// name - The name of the atom. For a function atom, it is the (mangled)
  /// name of the function.
  virtual StringRef name() const {
    return _name;
  }
 
  virtual CanBeNull canBeNull() const {
    return UndefinedAtom::canBeNullNever;
  }
 
private:
  const File&                   _file;
  StringRef                     _name;
};



} // namespace mach_o 
} // namespace lld 


#endif // LLD_READER_WRITER_MACHO_SIMPLE_ATOM_H_