[llvm-commits] [lld] r152269 - in /lld/trunk: ./ include/lld/Core/ include/lld/Platform/ lib/ lib/Core/ lib/Passes/ test/ tools/lld-core/

Michael Spencer bigcheesegs at gmail.com
Fri Mar 9 10:50:39 PST 2012


On Wed, Mar 7, 2012 at 4:18 PM, Nick Kledzik <kledzik at apple.com> wrote:
> Author: kledzik
> Date: Wed Mar  7 18:18:30 2012
> New Revision: 152269
>
> URL: http://llvm.org/viewvc/llvm-project?rev=152269&view=rev
> Log:
> Sources now require C++11 to build.
>
> Add first linker pass (StubsPass) which looks for calls to shared library
> symbols and replaces them with calls to a StubAtom.  On ELF system, a "stub"
> is a PLT entry.  Added a simple test case.
>
> Pass a Platform object to YAML reader and writer for converting fixup kinds
> between names and values.
>
> Change output of Resolver to be a File object instead of a vector of Atoms.
> Thus, passes operate on a File instead of just Atoms.
>
> Rework how to walk through a File's Atoms. Now iterator based instead of
> a method that visits each atom.
>
>
> Added:
>    lld/trunk/include/lld/Core/Pass.h
>    lld/trunk/lib/Passes/CMakeLists.txt
>    lld/trunk/lib/Passes/StubsPass.cpp
>    lld/trunk/test/pass-stubs-basic.objtxt
> Modified:
>    lld/trunk/CMakeLists.txt
>    lld/trunk/include/lld/Core/Atom.h
>    lld/trunk/include/lld/Core/DefinedAtom.h
>    lld/trunk/include/lld/Core/File.h
>    lld/trunk/include/lld/Core/InputFiles.h
>    lld/trunk/include/lld/Core/Resolver.h
>    lld/trunk/include/lld/Core/YamlReader.h
>    lld/trunk/include/lld/Core/YamlWriter.h
>    lld/trunk/include/lld/Platform/Platform.h
>    lld/trunk/lib/CMakeLists.txt
>    lld/trunk/lib/Core/File.cpp
>    lld/trunk/lib/Core/NativeReader.cpp
>    lld/trunk/lib/Core/NativeWriter.cpp
>    lld/trunk/lib/Core/Resolver.cpp
>    lld/trunk/lib/Core/YamlKeyValues.cpp
>    lld/trunk/lib/Core/YamlReader.cpp
>    lld/trunk/lib/Core/YamlWriter.cpp
>    lld/trunk/tools/lld-core/CMakeLists.txt
>    lld/trunk/tools/lld-core/lld-core.cpp
>
> Modified: lld/trunk/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/CMakeLists.txt?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/CMakeLists.txt (original)
> +++ lld/trunk/CMakeLists.txt Wed Mar  7 18:18:30 2012
> @@ -1,6 +1,8 @@
>  # If we are not building as a part of LLVM, build lld as a standalone project,
>  # using LLVM as an external library.
>
> +
> +
>  if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
>   project(lld)
>   cmake_minimum_required(VERSION 2.8)
> @@ -58,6 +60,20 @@
>  "`CMakeFiles'. Please delete them.")
>  endif()
>
> +#
> +# lld now requires C++11 to build
> +#
> +# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
> +include(CheckCXXCompilerFlag)
> +check_cxx_compiler_flag("-std=c++11" SUPPORTS_CXX11_FLAG)
> +if( SUPPORTS_CXX11_FLAG )
> +  message(STATUS "Building with -std=c++11")
> +  set(CMAKE_CXX_FLAGS "-std=c++11 ${CMAKE_CXX_FLAGS}")
> +else( SUPPORTS_CXX11_FLAG )
> +  message(WARNING "-std=c++11 not supported.")
> +endif()
> +
> +
>  macro(add_lld_library name)
>   llvm_process_sources(srcs ${ARGN})
>   if (MSVC_IDE OR XCODE)
>
> Modified: lld/trunk/include/lld/Core/Atom.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/Atom.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/Atom.h (original)
> +++ lld/trunk/include/lld/Core/Atom.h Wed Mar  7 18:18:30 2012
> @@ -24,7 +24,7 @@
>  class SharedLibraryAtom;
>  class AbsoluteAtom;
>
> -  ///
> +///
>  /// The linker has a Graph Theory model of linking. An object file is seen
>  /// as a set of Atoms with References to other Atoms.  Each Atom is a node
>  /// and each Reference is an edge. An Atom can be a DefinedAtom which has
>
> Modified: lld/trunk/include/lld/Core/DefinedAtom.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/DefinedAtom.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/DefinedAtom.h (original)
> +++ lld/trunk/include/lld/Core/DefinedAtom.h Wed Mar  7 18:18:30 2012
> @@ -195,13 +195,6 @@
>     uint16_t modulus;
>   };
>
> -  /// for use iterating over this Atom's References
> -  class ReferenceHandler {
> -  public:
> -    virtual ~ReferenceHandler() {}
> -    virtual void doReference(const Reference &) = 0;
> -  };
> -
>   /// ordinal - returns a value for the order of this Atom within its file.
>   /// This is used by the linker to order the layout of Atoms so that
>   /// the resulting image is stable and reproducible.
> @@ -266,10 +259,43 @@
>   /// rawContent - returns a reference to the raw (unrelocated) bytes of
>   /// this Atom's content.
>   virtual llvm::ArrayRef<uint8_t> rawContent() const = 0;
> +
> +  /// This class abstracts iterating over the sequence of References
> +  /// in an Atom.  Concrete instances of DefinedAtom must implement
> +  /// the derefIterator() and incrementIterator methods.
> +  class reference_iterator {
> +  public:
> +    reference_iterator(const DefinedAtom& a, const void* it)
> +              : _atom(a), _it(it) { }
>
> -  /// iterator over this Atom's References
> -  virtual void forEachReference(ReferenceHandler&) const = 0;
> +    const Reference* operator*() const {
> +      return _atom.derefIterator(_it);
> +    }
> +
> +    const Reference* operator->() const {
> +      return _atom.derefIterator(_it);
> +    }
> +
> +    bool operator!=(const reference_iterator& other) const {
> +      return (this->_it != other._it);
> +    }
> +
> +    reference_iterator& operator++() {
> +      _atom.incrementIterator(_it);
> +      return *this;
> +    }
> +  private:
> +    const DefinedAtom&   _atom;
> +    const void*          _it;
> +  };
> +
> +  /// Returns an iterator to the beginning of this Atom's References
> +  virtual reference_iterator referencesBegin() const = 0;
>
> +  /// Returns an iterator to the end of this Atom's References
> +  virtual reference_iterator referencesEnd() const = 0;
> +
> +
>  protected:
>   /// DefinedAtom is an abstract base class.
>   /// Only subclasses can access constructor.
> @@ -280,6 +306,15 @@
>   /// delete on an Atom.  In fact, some File objects may bulk allocate
>   /// an array of Atoms, so they cannot be individually deleted by anyone.
>   virtual ~DefinedAtom() {}
> +
> +  /// Returns a pointer to the Reference object that the abstract
> +  /// iterator "points" to.
> +  virtual const Reference* derefIterator(const void* iter) const = 0;
> +
> +  /// Adjusts the abstract iterator to "point" to the next Reference object
> +  /// for this Atom.
> +  virtual void incrementIterator(const void*& iter) const = 0;
> +
>  };
>
>  } // namespace lld
>
> Modified: lld/trunk/include/lld/Core/File.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/File.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/File.h (original)
> +++ lld/trunk/include/lld/Core/File.h Wed Mar  7 18:18:30 2012
> @@ -1,4 +1,4 @@
> -//===- Core/File.h - A Contaier of Atoms ----------------------------------===//
> +//===- Core/File.h - A Container of Atoms ---------------------------------===//
>  //
>  //                             The LLVM Linker
>  //
> @@ -10,6 +10,8 @@
>  #ifndef LLD_CORE_FILE_H_
>  #define LLD_CORE_FILE_H_
>
> +#include <vector>
> +
>  #include "llvm/ADT/StringRef.h"
>
>  #include "lld/Core/DefinedAtom.h"
> @@ -19,31 +21,190 @@
>
>  namespace lld {
>
> +
> +///
> +/// Every Atom is owned by some File. A common scenario is for a single
> +/// object file (.o) to be parsed by some reader and produce a single
> +/// File object that represents the content of that object file.
> +///
> +/// The File class has *begin() and *end() methods for use iterating through
> +/// the Atoms in a File object.
> +///
> +/// The Atom objects in a File are owned by the File object.  The Atom objects
> +/// are destroyed when the File object is destroyed.
> +///
>  class File {
>  public:
> -  File(llvm::StringRef p) : _path(p) {}
>   virtual ~File();
>
> -  class AtomHandler {
> -  public:
> -    virtual ~AtomHandler() {}
> -    virtual void doDefinedAtom(const class DefinedAtom &) = 0;
> -    virtual void doUndefinedAtom(const class UndefinedAtom &) = 0;
> -    virtual void doSharedLibraryAtom(const class SharedLibraryAtom &) = 0;
> -    virtual void doAbsoluteAtom(const class AbsoluteAtom &) = 0;
> -    virtual void doFile(const class File &) = 0;
> -  };
> -
> +  /// For error messages and debugging, this returns the path to the file
> +  /// which was used to create this object (e.g. "/tmp/foo.o").
>   llvm::StringRef path() const  {
>     return _path;
>   }
>
> -  virtual bool forEachAtom(AtomHandler &) const = 0;
> -  virtual bool justInTimeforEachAtom( llvm::StringRef name
> -                                    , AtomHandler &) const = 0;
> +  /// Returns the path of the source file used to create the object
> +  /// file which this (File) object represents.  This information is usually
> +  /// parsed out of the DWARF debug information. If the source file cannot
> +  /// be ascertained, this method returns the empty string.
> +  virtual llvm::StringRef translationUnitSource() const;
>
> -  virtual bool translationUnitSource(llvm::StringRef &path) const;
> +protected:
> +  template <typename T> class atom_iterator; // forward reference
> +public:
> +
> +  /// For use interating over DefinedAtoms in this File.
> +  typedef atom_iterator<DefinedAtom>  defined_iterator;
> +
> +  /// For use interating over UndefinedAtoms in this File.
> +  typedef atom_iterator<UndefinedAtom> undefined_iterator;
> +
> +  /// For use interating over SharedLibraryAtoms in this File.
> +  typedef atom_iterator<SharedLibraryAtom> shared_library_iterator;
> +
> +  /// For use interating over AbsoluteAtoms in this File.
> +  typedef atom_iterator<AbsoluteAtom> absolute_iterator;
> +
> +  /// Returns an iterator to the beginning of this File's DefinedAtoms
> +  defined_iterator definedAtomsBegin() const {
> +    return defined().begin();
> +  }
> +
> +  /// Returns an iterator to the end of this File's DefinedAtoms
> +  defined_iterator definedAtomsEnd() const {
> +    return defined().end();
> +  }
> +
> +  /// Returns an iterator to the beginning of this File's DefinedAtoms
> +  undefined_iterator undefinedAtomsBegin() const {
> +    return undefined().begin();
> +  }
> +
> +  /// Returns an iterator to the end of this File's UndefinedAtoms
> +  undefined_iterator undefinedAtomsEnd() const {
> +    return undefined().end();
> +  }
> +
> +  /// Returns an iterator to the beginning of this File's SharedLibraryAtoms
> +  shared_library_iterator sharedLibraryAtomsBegin() const {
> +    return sharedLibrary().begin();
> +  }
> +
> +  /// Returns an iterator to the end of this File's SharedLibraryAtoms
> +  shared_library_iterator sharedLibraryAtomsEnd() const {
> +    return sharedLibrary().end();
> +  }
> +
> +  /// Returns an iterator to the beginning of this File's AbsoluteAtoms
> +  absolute_iterator absoluteAtomsBegin() const {
> +    return absolute().begin();
> +  }
>
> +  /// Returns an iterator to the end of this File's AbsoluteAtoms
> +  absolute_iterator absoluteAtomsEnd() const {
> +    return absolute().end();
> +  }
> +
> +  /// Note: this method is not const.  All File objects instantiated by reading
> +  /// an object file from disk are "const File*" objects and cannot be
> +  /// modified.  This method can only be used with temporay File objects
> +  /// such as is seen by each Pass object when it runs.
> +  /// This method is *not* safe to call while iterating through this File's
> +  /// Atoms.  A Pass should queue up any Atoms it want to add and then
> +  /// call this method when no longer iterating over the File's Atoms.
> +  virtual void addAtom(const Atom&) = 0;
> +
> +
> +
> +protected:
> +  /// only subclasses of File can be instantiated
> +  File(llvm::StringRef p) : _path(p) {}
> +
> +
> +  /// Different object file readers may instantiate and manage atoms with
> +  /// different data structures.  This class is a collection abstraction.
> +  /// Each concrete File instance must implement these atom_collection
> +  /// methods to enable clients to interate the File's atoms.
> +  template <typename T>
> +  class atom_collection {
> +  public:
> +    virtual atom_iterator<T> begin() const = 0;
> +    virtual atom_iterator<T> end() const = 0;
> +    virtual const T* deref(const void* it) const = 0;
> +    virtual void next(const void*& it) const = 0;
> +  };
> +
> +
> +  /// The class is the iterator type used to iterate through a File's Atoms.
> +  /// This iterator delegates the work to the associated atom_collection object.
> +  /// There are four kinds of Atoms, so this iterator is templated on
> +  /// the four base Atom kinds.
> +  template <typename T>
> +  class atom_iterator {
> +  public:
> +    atom_iterator(const atom_collection<T>& c, const void* it)
> +              : _collection(c), _it(it) { }
> +
> +    const T* operator*() const {
> +      return _collection.deref(_it);
> +    }
> +
> +    const T* operator->() const {
> +      return _collection.deref(_it);
> +    }
> +
> +    bool operator!=(const atom_iterator<T>& other) const {
> +      return (this->_it != other._it);
> +    }
> +
> +    atom_iterator<T>& operator++() {
> +      _collection.next(_it);
> +      return *this;
> +    }
> +  private:
> +    const atom_collection<T>&   _collection;
> +    const void*                 _it;
> +  };
> +
> +  /// Must be implemented to return the atom_collection object for
> +  /// all DefinedAtoms in this File.
> +  virtual const atom_collection<DefinedAtom>& defined() const = 0;
> +
> +  /// Must be implemented to return the atom_collection object for
> +  /// all UndefinedAtomw in this File.
> +  virtual const atom_collection<UndefinedAtom>& undefined() const = 0;
> +
> +  /// Must be implemented to return the atom_collection object for
> +  /// all SharedLibraryAtoms in this File.
> +  virtual const atom_collection<SharedLibraryAtom>& sharedLibrary() const = 0;
> +
> +  /// Must be implemented to return the atom_collection object for
> +  /// all AbsoluteAtoms in this File.
> +  virtual const atom_collection<AbsoluteAtom>& absolute() const = 0;
> +
> +  /// This is a convenience class for File subclasses which manage their
> +  /// atoms as a simple std::vector<>.
> +  template <typename T>
> +  class atom_collection_vector : public atom_collection<T> {
> +  public:
> +    virtual atom_iterator<T> begin() const {
> +      return atom_iterator<T>(*this, reinterpret_cast<const void*>(&_atoms[0]));
> +    }
> +    virtual atom_iterator<T> end() const{
> +      return atom_iterator<T>(*this, reinterpret_cast<const void*>
> +                              (&_atoms[_atoms.size()]));
> +    }
> +    virtual const T* deref(const void* it) const {
> +      return *reinterpret_cast<const T* const*>(it);
> +    }
> +    virtual void next(const void*& it) const {
> +      const T * const * p = reinterpret_cast<const T * const *>(it);
> +      ++p;
> +      it = reinterpret_cast<const void*>(p);
> +    }
> +    std::vector<const T*>   _atoms;
> +  };
> +

I find the use of void* and reinterpret_cast in the above concerning.
We could simply use LLVM's rtti and cast<T>. This has no runtime cost
in -asserts builds, and with assert builds we get runtime type
checking.

- Michael Spencer

>  private:
>   llvm::StringRef _path;
>
> Modified: lld/trunk/include/lld/Core/InputFiles.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/InputFiles.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/InputFiles.h (original)
> +++ lld/trunk/include/lld/Core/InputFiles.h Wed Mar  7 18:18:30 2012
> @@ -24,15 +24,26 @@
>  /// The searchLibraries() method is used to lazily search libraries.
>  class InputFiles {
>  public:
> +  class Handler {
> +  public:
> +    virtual ~Handler() {}
> +    virtual void doFile(const class File &) = 0;
> +    virtual void doDefinedAtom(const class DefinedAtom &) = 0;
> +    virtual void doUndefinedAtom(const class UndefinedAtom &) = 0;
> +    virtual void doSharedLibraryAtom(const class SharedLibraryAtom &) = 0;
> +    virtual void doAbsoluteAtom(const class AbsoluteAtom &) = 0;
> +  };
> +
> +
>   /// @brief iterates all atoms in initial files
> -  virtual void forEachInitialAtom(File::AtomHandler &) const = 0;
> +  virtual void forEachInitialAtom(Handler &) const = 0;
>
>   /// @brief searches libraries for name
>   virtual bool searchLibraries(  llvm::StringRef name
>                                , bool searchDylibs
>                                , bool searchArchives
>                                , bool dataSymbolOnly
> -                               , File::AtomHandler &) const = 0;
> +                               , Handler &) const = 0;
>  };
>
>  } // namespace lld
>
> Added: lld/trunk/include/lld/Core/Pass.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/Pass.h?rev=152269&view=auto
> ==============================================================================
> --- lld/trunk/include/lld/Core/Pass.h (added)
> +++ lld/trunk/include/lld/Core/Pass.h Wed Mar  7 18:18:30 2012
> @@ -0,0 +1,65 @@
> +//===------ Core/Pass.h - Base class for linker passes --------------------===//
> +//
> +//                             The LLVM Linker
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLD_CORE_PASS_H_
> +#define LLD_CORE_PASS_H_
> +
> +#include <vector>
> +
> +#include "lld/Core/Atom.h"
> +#include "lld/Platform/Platform.h"
> +
> +namespace lld {
> +
> +
> +///
> +/// Once the core linking is done (which resolves references, coalesces atoms
> +/// and produces a complete Atom graph), the linker runs a series of passes
> +/// on the Atom graph. The graph is modeled as a File, which means the pass
> +/// has access to all the atoms and to File level attributes. Each pass does
> +/// a particular transformation to the Atom graph or to the File attributes.
> +///
> +/// This is the abstract base class for all passes.  A Pass does its
> +/// actual work in it perform() method.  It can iterator over Atoms in the
> +/// graph using the *begin()/*end() atom iterator of the File.  It can add
> +/// new Atoms to the graph using the File's addAtom() method.
> +///
> +///
> +class Pass {
> +public:
> +    /// Do the actual work of the Pass.
> +    virtual void perform() = 0;
> +
> +protected:
> +  // Only subclassess can be instantiated.
> +  Pass(File& f, Platform& p) : _file(f), _platform(p) {}
> +
> +
> +  File&       _file;
> +  Platform&   _platform;
> +};
> +
> +
> +///
> +/// Pass for adding stubs (PLT entries) for calls to functions
> +/// outside the linkage unit.
> +///
> +class StubsPass : public Pass {
> +public:
> +  StubsPass(File& f, Platform& p) : Pass(f, p) {}
> +
> +  /// Scans all Atoms looking for call-site uses of SharedLibraryAtoms
> +  /// and transfroms the call-site to call a stub instead.
> +  virtual void perform();
> +};
> +
> +
> +} // namespace lld
> +
> +#endif // LLD_CORE_PASS_H_
>
> Modified: lld/trunk/include/lld/Core/Resolver.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/Resolver.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/Resolver.h (original)
> +++ lld/trunk/include/lld/Core/Resolver.h Wed Mar  7 18:18:30 2012
> @@ -11,6 +11,7 @@
>  #define LLD_CORE_RESOLVER_H_
>
>  #include "lld/Core/File.h"
> +#include "lld/Core/InputFiles.h"
>  #include "lld/Core/SymbolTable.h"
>
>  #include "llvm/ADT/DenseSet.h"
> @@ -30,7 +31,7 @@
>  ///
>  /// All platform specific resolving is done by delegating to the
>  /// Platform object specified.
> -class Resolver : public File::AtomHandler {
> +class Resolver : public InputFiles::Handler {
>  public:
>   Resolver(Platform &plat, const InputFiles &inputs)
>     : _platform(plat)
> @@ -40,7 +41,7 @@
>     , _addToFinalSection(false)
>     , _completedInitialObjectFiles(false) {}
>
> -  // AtomHandler methods
> +  // InputFiles::Handler methods
>   virtual void doDefinedAtom(const class DefinedAtom&);
>   virtual void doUndefinedAtom(const class UndefinedAtom&);
>   virtual void doSharedLibraryAtom(const class SharedLibraryAtom &);
> @@ -48,7 +49,11 @@
>   virtual void doFile(const File&);
>
>   /// @brief do work of merging and resolving and return list
> -  std::vector<const Atom *> &resolve();
> +  void resolve();
> +
> +  File& resultFile() {
> +    return _result;
> +  }
>
>  private:
>   struct WhyLiveBackChain {
> @@ -73,31 +78,49 @@
>   void addAtoms(const std::vector<const DefinedAtom *>&);
>
>
> -  // helper to update targets for use with forEachReference()
> -  class MarkLiveReferences : public DefinedAtom::ReferenceHandler {
> +  class MergedFile : public File {
>   public:
> -             MarkLiveReferences(Resolver& resolver, WhyLiveBackChain* chain)
> -                  : _resolver(resolver), _chain(chain) { }
> +    MergedFile() : File("<linker-internal>") { }
>
> -    virtual void doReference(const Reference& ref) {
> -    _resolver.markLive(*ref.target(), _chain);
> -    }
> +
> +
> +  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;
> +  }
> +
> +  void addAtoms(std::vector<const Atom*>& atoms);
> +
> +  virtual void addAtom(const Atom& atom);
>
>   private:
> -    Resolver&          _resolver;
> -    WhyLiveBackChain*  _chain;
> +    atom_collection_vector<DefinedAtom>         _definedAtoms;
> +    atom_collection_vector<UndefinedAtom>       _undefinedAtoms;
> +    atom_collection_vector<SharedLibraryAtom>   _sharedLibraryAtoms;
> +    atom_collection_vector<AbsoluteAtom>        _absoluteAtoms;
>   };
> -
> -  Platform &_platform;
> -  const InputFiles &_inputFiles;
> -  SymbolTable _symbolTable;
> -  std::vector<const Atom *> _atoms;
> -  std::set<const Atom *> _deadStripRoots;
> -  std::vector<const Atom *> _atomsWithUnresolvedReferences;
> -  llvm::DenseSet<const Atom *> _liveAtoms;
> -  bool _haveLLVMObjs;
> -  bool _addToFinalSection;
> -  bool _completedInitialObjectFiles;
> +
> +
> +
> +  Platform&                     _platform;
> +  const InputFiles&             _inputFiles;
> +  SymbolTable                   _symbolTable;
> +  std::vector<const Atom *>     _atoms;
> +  std::set<const Atom *>        _deadStripRoots;
> +  std::vector<const Atom *>     _atomsWithUnresolvedReferences;
> +  llvm::DenseSet<const Atom *>  _liveAtoms;
> +  MergedFile                    _result;
> +  bool                          _haveLLVMObjs;
> +  bool                          _addToFinalSection;
> +  bool                          _completedInitialObjectFiles;
>  };
>
>  } // namespace lld
>
> Modified: lld/trunk/include/lld/Core/YamlReader.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/YamlReader.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/YamlReader.h (original)
> +++ lld/trunk/include/lld/Core/YamlReader.h Wed Mar  7 18:18:30 2012
> @@ -10,8 +10,6 @@
>  #ifndef LLD_CORE_YAML_READER_H_
>  #define LLD_CORE_YAML_READER_H_
>
> -#include "lld/Core/File.h"
> -
>  #include "llvm/Support/system_error.h"
>
>  #include <vector>
> @@ -19,19 +17,25 @@
>  namespace llvm { class MemoryBuffer; }
>
>  namespace lld {
> +
> +class Platform;
> +class File;
> +
>  namespace yaml {
>
>   /// parseObjectTextFileOrSTDIN - Open the specified YAML file (use stdin if
>   /// the path is "-") and parse into lld::File object(s) and append each to
>   /// the specified vector<File*>.
>   llvm::error_code parseObjectTextFileOrSTDIN(llvm::StringRef path
> -                                 , std::vector<File *>&);
> +                                              , Platform&
> +                                              , std::vector<const File *>&);
>
>
>   /// parseObjectText - Parse the specified YAML formatted MemoryBuffer
>   /// into lld::File object(s) and append each to the specified vector<File*>.
>   llvm::error_code parseObjectText(llvm::MemoryBuffer *mb
> -                                 , std::vector<File *>&);
> +                                , Platform&
> +                                , std::vector<const File *>&);
>
>  } // namespace yaml
>  } // namespace lld
>
> Modified: lld/trunk/include/lld/Core/YamlWriter.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Core/YamlWriter.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Core/YamlWriter.h (original)
> +++ lld/trunk/include/lld/Core/YamlWriter.h Wed Mar  7 18:18:30 2012
> @@ -10,15 +10,18 @@
>  #ifndef LLD_CORE_YAML_WRITER_H_
>  #define LLD_CORE_YAML_WRITER_H_
>
> -#include "lld/Core/File.h"
>  #include "llvm/Support/raw_ostream.h"
>
>  namespace lld {
> +
> +class Platform;
> +class File;
> +
>  namespace yaml {
>
>   /// writeObjectText - writes the lld::File object as in YAML
>   /// format to the specified stream.
> -  void writeObjectText(const lld::File &, llvm::raw_ostream &);
> +  void writeObjectText(const lld::File &, Platform &, llvm::raw_ostream &);
>
>  } // namespace yaml
>  } // namespace lld
>
> Modified: lld/trunk/include/lld/Platform/Platform.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/Platform/Platform.h?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/include/lld/Platform/Platform.h (original)
> +++ lld/trunk/include/lld/Platform/Platform.h Wed Mar  7 18:18:30 2012
> @@ -12,10 +12,13 @@
>
>  #include <vector>
>
> +#include "lld/Core/Reference.h"
> +
>  namespace lld {
>  class Atom;
>  class DefinedAtom;
>
> +
>  /// The Platform class encapsulated plaform specific linking knowledge.
>  ///
>  /// Much of what it does is driving by platform specific linker options.
> @@ -98,6 +101,26 @@
>
>   /// @brief last chance for platform to tweak atoms
>   virtual void postResolveTweaks(std::vector<const Atom *>& all) = 0;
> +
> +  /// If the output being generated uses needs stubs for external calls
> +  virtual bool outputUsesStubs() = 0;
> +
> +  /// Converts a reference kind string to a in-memory numeric value.
> +  /// For use with parsing YAML encoded object files.
> +  virtual Reference::Kind kindFromString(llvm::StringRef) = 0;
> +
> +  /// Converts an in-memory reference kind value to a string.
> +  /// For use with writing YAML encoded object files.
> +  virtual llvm::StringRef kindToString(Reference::Kind) = 0;
> +
> +  /// If Reference is a branch instruction that might need to be changed
> +  /// to target a stub (PLT entry).
> +  virtual bool isBranch(const Reference*) = 0;
> +
> +  /// Create a platform specific atom which contains a stub/PLT entry
> +  /// targeting the specified shared library atom.
> +  virtual const Atom* makeStub(const SharedLibraryAtom&, File&) = 0;
> +
>  };
>
>  } // namespace lld
>
> Modified: lld/trunk/lib/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/CMakeLists.txt?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/CMakeLists.txt (original)
> +++ lld/trunk/lib/CMakeLists.txt Wed Mar  7 18:18:30 2012
> @@ -1 +1,2 @@
>  add_subdirectory(Core)
> +add_subdirectory(Passes)
>
> Modified: lld/trunk/lib/Core/File.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/File.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/File.cpp (original)
> +++ lld/trunk/lib/Core/File.cpp Wed Mar  7 18:18:30 2012
> @@ -13,8 +13,8 @@
>
>  File::~File() {}
>
> -bool File::translationUnitSource(llvm::StringRef &path) const {
> -  return false;
> +llvm::StringRef File::translationUnitSource() const {
> +  return llvm::StringRef();
>  }
>
>
>
> Modified: lld/trunk/lib/Core/NativeReader.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/NativeReader.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/NativeReader.cpp (original)
> +++ lld/trunk/lib/Core/NativeReader.cpp Wed Mar  7 18:18:30 2012
> @@ -92,9 +92,15 @@
>   }
>
>   virtual llvm::ArrayRef<uint8_t> rawContent() const;
> -
> -  virtual void forEachReference(ReferenceHandler&) const;
> -
> +
> +  virtual reference_iterator referencesBegin() const;
> +
> +  virtual reference_iterator referencesEnd() const;
> +
> +  virtual const Reference* derefIterator(const void*) const;
> +
> +  virtual void incrementIterator(const void*& it) const;
> +
>  private:
>   const NativeAtomAttributesV1& attributes() const;
>
> @@ -299,53 +305,29 @@
>     // the _definedAtoms array which was allocated to contain an array
>     // of Atom objects.  The atoms have empty destructors, so it is ok
>     // to just delete the memory.
> -    delete _definedAtoms.arrayStart;
> -    delete _undefinedAtoms.arrayStart;
> -    delete _sharedLibraryAtoms.arrayStart;
> -    delete _absoluteAtoms.arrayStart;
> +    delete _definedAtoms._arrayStart;
> +    delete _undefinedAtoms._arrayStart;
> +    delete _sharedLibraryAtoms._arrayStart;
> +    delete _absoluteAtoms._arrayStart;
>     delete _references.arrayStart;
>     delete _targetsTable;
>   }
>
> -  // visits each atom in the file
> -  virtual bool forEachAtom(AtomHandler& handler) const {
> -    bool didSomething = false;
> -    for(const uint8_t* p=_definedAtoms.arrayStart; p != _definedAtoms.arrayEnd;
> -          p += _definedAtoms.elementSize) {
> -      const DefinedAtom* atom = reinterpret_cast<const DefinedAtom*>(p);
> -      handler.doDefinedAtom(*atom);
> -      didSomething = true;
> -    }
> -    for(const uint8_t* p=_undefinedAtoms.arrayStart;
> -                      p != _undefinedAtoms.arrayEnd;
> -                      p += _undefinedAtoms.elementSize) {
> -      const UndefinedAtom* atom = reinterpret_cast<const UndefinedAtom*>(p);
> -      handler.doUndefinedAtom(*atom);
> -      didSomething = true;
> -    }
> -    for(const uint8_t* p=_sharedLibraryAtoms.arrayStart;
> -                  p != _sharedLibraryAtoms.arrayEnd;
> -                  p += _sharedLibraryAtoms.elementSize) {
> -      const SharedLibraryAtom* atom
> -                          = reinterpret_cast<const SharedLibraryAtom*>(p);
> -      handler.doSharedLibraryAtom(*atom);
> -      didSomething = true;
> -    }
> -    for(const uint8_t* p=_absoluteAtoms.arrayStart;
> -                  p != _absoluteAtoms.arrayEnd;
> -                  p += _absoluteAtoms.elementSize) {
> -      const AbsoluteAtom* atom
> -                          = reinterpret_cast<const AbsoluteAtom*>(p);
> -      handler.doAbsoluteAtom(*atom);
> -      didSomething = true;
> -    }
> -    return didSomething;
> -  }
> -
> -  // not used
> -  virtual bool justInTimeforEachAtom(llvm::StringRef name,
> -                                              AtomHandler &) const {
> -    return false;
> +  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;
> +  }
> +
> +  virtual void addAtom(const Atom&) {
> +    assert(0 && "cannot add atoms to native .o files");
>   }
>
>  private:
> @@ -378,10 +360,10 @@
>       new (atomAllocSpace) NativeDefinedAtomV1(*this, ivarData);
>       ++ivarData;
>     }
> -    this->_definedAtoms.arrayStart = atomsStart;
> -    this->_definedAtoms.arrayEnd = atomsEnd;
> -    this->_definedAtoms.elementSize = atomSize;
> -    this->_definedAtoms.elementCount = chunk->elementCount;
> +    this->_definedAtoms._arrayStart = atomsStart;
> +    this->_definedAtoms._arrayEnd = atomsEnd;
> +    this->_definedAtoms._elementSize = atomSize;
> +    this->_definedAtoms._elementCount = chunk->elementCount;
>     return make_error_code(native_reader_error::success);
>   }
>
> @@ -416,10 +398,10 @@
>       new (atomAllocSpace) NativeUndefinedAtomV1(*this, ivarData);
>       ++ivarData;
>     }
> -    this->_undefinedAtoms.arrayStart = atomsStart;
> -    this->_undefinedAtoms.arrayEnd = atomsEnd;
> -    this->_undefinedAtoms.elementSize = atomSize;
> -    this->_undefinedAtoms.elementCount = chunk->elementCount;
> +    this->_undefinedAtoms._arrayStart = atomsStart;
> +    this->_undefinedAtoms._arrayEnd = atomsEnd;
> +    this->_undefinedAtoms._elementSize = atomSize;
> +    this->_undefinedAtoms._elementCount = chunk->elementCount;
>     return make_error_code(native_reader_error::success);
>   }
>
> @@ -447,10 +429,10 @@
>       new (atomAllocSpace) NativeSharedLibraryAtomV1(*this, ivarData);
>       ++ivarData;
>     }
> -    this->_sharedLibraryAtoms.arrayStart = atomsStart;
> -    this->_sharedLibraryAtoms.arrayEnd = atomsEnd;
> -    this->_sharedLibraryAtoms.elementSize = atomSize;
> -    this->_sharedLibraryAtoms.elementCount = chunk->elementCount;
> +    this->_sharedLibraryAtoms._arrayStart = atomsStart;
> +    this->_sharedLibraryAtoms._arrayEnd = atomsEnd;
> +    this->_sharedLibraryAtoms._elementSize = atomSize;
> +    this->_sharedLibraryAtoms._elementCount = chunk->elementCount;
>     return make_error_code(native_reader_error::success);
>   }
>
> @@ -478,10 +460,10 @@
>       new (atomAllocSpace) NativeAbsoluteAtomV1(*this, ivarData);
>       ++ivarData;
>     }
> -    this->_absoluteAtoms.arrayStart = atomsStart;
> -    this->_absoluteAtoms.arrayEnd = atomsEnd;
> -    this->_absoluteAtoms.elementSize = atomSize;
> -    this->_absoluteAtoms.elementCount = chunk->elementCount;
> +    this->_absoluteAtoms._arrayStart = atomsStart;
> +    this->_absoluteAtoms._arrayEnd = atomsEnd;
> +    this->_absoluteAtoms._elementSize = atomSize;
> +    this->_absoluteAtoms._elementCount = chunk->elementCount;
>     return make_error_code(native_reader_error::success);
>   }
>
> @@ -529,33 +511,33 @@
>     this->_targetsTable = new const Atom*[chunk->elementCount];
>     for (uint32_t i=0; i < chunk->elementCount; ++i) {
>       const uint32_t index = targetIndexes[i];
> -      if ( index < _definedAtoms.elementCount ) {
> -        const uint8_t* p = _definedAtoms.arrayStart
> -                                    + index * _definedAtoms.elementSize;
> +      if ( index < _definedAtoms._elementCount ) {
> +        const uint8_t* p = _definedAtoms._arrayStart
> +                                    + index * _definedAtoms._elementSize;
>         this->_targetsTable[i] = reinterpret_cast<const DefinedAtom*>(p);
>         continue;
>       }
> -      const uint32_t undefIndex = index - _definedAtoms.elementCount;
> -      if ( undefIndex < _undefinedAtoms.elementCount ) {
> -        const uint8_t* p = _undefinedAtoms.arrayStart
> -                                    + undefIndex * _undefinedAtoms.elementSize;
> +      const uint32_t undefIndex = index - _definedAtoms._elementCount;
> +      if ( undefIndex < _undefinedAtoms._elementCount ) {
> +        const uint8_t* p = _undefinedAtoms._arrayStart
> +                                    + undefIndex * _undefinedAtoms._elementSize;
>         this->_targetsTable[i] = reinterpret_cast<const UndefinedAtom*>(p);
>         continue;
>       }
> -      const uint32_t slIndex = index - _definedAtoms.elementCount
> -                                     - _undefinedAtoms.elementCount;
> -      if ( slIndex < _sharedLibraryAtoms.elementCount ) {
> -        const uint8_t* p = _sharedLibraryAtoms.arrayStart
> -                                  + slIndex * _sharedLibraryAtoms.elementSize;
> +      const uint32_t slIndex = index - _definedAtoms._elementCount
> +                                     - _undefinedAtoms._elementCount;
> +      if ( slIndex < _sharedLibraryAtoms._elementCount ) {
> +        const uint8_t* p = _sharedLibraryAtoms._arrayStart
> +                                  + slIndex * _sharedLibraryAtoms._elementSize;
>         this->_targetsTable[i] = reinterpret_cast<const SharedLibraryAtom*>(p);
>         continue;
>       }
> -      const uint32_t abIndex = index - _definedAtoms.elementCount
> -                                     - _undefinedAtoms.elementCount
> -                                     - _sharedLibraryAtoms.elementCount;
> -      if ( abIndex < _absoluteAtoms.elementCount ) {
> -        const uint8_t* p = _absoluteAtoms.arrayStart
> -                                  + slIndex * _absoluteAtoms.elementSize;
> +      const uint32_t abIndex = index - _definedAtoms._elementCount
> +                                     - _undefinedAtoms._elementCount
> +                                     - _sharedLibraryAtoms._elementCount;
> +      if ( abIndex < _absoluteAtoms._elementCount ) {
> +        const uint8_t* p = _absoluteAtoms._arrayStart
> +                                  + slIndex * _absoluteAtoms._elementSize;
>         this->_targetsTable[i] = reinterpret_cast<const AbsoluteAtom*>(p);
>         continue;
>       }
> @@ -612,21 +594,13 @@
>     assert((result+size) <= _contentEnd);
>     return result;
>   }
> -
> -  void forEachReference(DefinedAtom::ReferenceHandler& handler,
> -                                        uint32_t start, uint32_t count) const {
> -    assert(start < _references.elementCount);
> -    assert(start+count <= _references.elementCount);
> -    const uint8_t* arrStart = _references.arrayStart
> -                                   + start * _references.elementSize;
> -    const uint8_t* arrEnd = arrStart + count * _references.elementSize;
> -    for(const uint8_t* p=arrStart; p != arrEnd; p += _references.elementSize) {
> -      const NativeReferenceV1* ref
> -                              = reinterpret_cast<const NativeReferenceV1*>(p);
> -      handler.doReference(*ref);
> -    }
> -  }
>
> +  const Reference* referenceByIndex(uintptr_t index) const {
> +    assert(index < _references.elementCount);
> +    const uint8_t* p = _references.arrayStart + index * _references.elementSize;
> +    return reinterpret_cast<const NativeReferenceV1*>(p);
> +  }
> +
>   const Atom* target(uint32_t index) const {
>     assert(index < _targetsTableCount);
>     return _targetsTable[index];
> @@ -656,21 +630,52 @@
>                                                   (_buffer->getBufferStart());
>   }
>
> +  template <typename T>
> +  class AtomArray : public File::atom_collection<T> {
> +  public:
> +     AtomArray() : _arrayStart(NULL), _arrayEnd(NULL),
> +                   _elementSize(0), _elementCount(0) { }
> +
> +    virtual atom_iterator<T> begin() const {
> +      return atom_iterator<T>(*this, reinterpret_cast<const void*>(_arrayStart));
> +    }
> +    virtual atom_iterator<T> end() const{
> +      return atom_iterator<T>(*this, reinterpret_cast<const void*>(_arrayEnd));
> +    }
> +    virtual const T* deref(const void* it) const {
> +      return reinterpret_cast<const T*>(it);
> +    }
> +    virtual void next(const void*& it) const {
> +      const uint8_t* p = reinterpret_cast<const uint8_t*>(it);
> +      p += _elementSize;
> +      it = reinterpret_cast<const void*>(p);
> +    }
> +    const uint8_t*     _arrayStart;
> +    const uint8_t*     _arrayEnd;
> +    uint32_t           _elementSize;
> +    uint32_t           _elementCount;
> +  };
> +
>   struct IvarArray {
> -                      IvarArray() : arrayStart(NULL), arrayEnd(NULL),
> -                                    elementSize(0), elementCount(0) { }
> +                      IvarArray() :
> +                        arrayStart(NULL),
> +                        arrayEnd(NULL),
> +                        elementSize(0),
> +                        elementCount(0) { }
> +
>     const uint8_t*     arrayStart;
>     const uint8_t*     arrayEnd;
>     uint32_t           elementSize;
>     uint32_t           elementCount;
> - };
> +  };
> +
>
>   llvm::OwningPtr<llvm::MemoryBuffer>  _buffer;
>   const NativeFileHeader*         _header;
> -  IvarArray                       _definedAtoms;
> -  IvarArray                       _undefinedAtoms;
> -  IvarArray                       _sharedLibraryAtoms;
> -  IvarArray                       _absoluteAtoms;
> +  AtomArray<DefinedAtom>          _definedAtoms;
> +  AtomArray<UndefinedAtom>        _undefinedAtoms;
> +  AtomArray<SharedLibraryAtom>    _sharedLibraryAtoms;
> +  AtomArray<AbsoluteAtom>         _absoluteAtoms;
>   const uint8_t*                  _attributes;
>   uint32_t                        _attributesMaxOffset;
>   IvarArray                       _references;
> @@ -684,14 +689,14 @@
>   const uint8_t*                  _contentEnd;
>  };
>
> -
> +
>  inline const class File& NativeDefinedAtomV1::file() const {
>   return *_file;
>  }
>
>  inline uint64_t NativeDefinedAtomV1:: ordinal() const {
>   const uint8_t* p = reinterpret_cast<const uint8_t*>(_ivarData);
> -  return p - _file->_definedAtoms.arrayStart;
> +  return p - _file->_definedAtoms._arrayStart;
>  }
>
>  inline llvm::StringRef NativeDefinedAtomV1::name() const {
> @@ -715,11 +720,27 @@
>   return _file->string(offset);
>  }
>
> -inline void NativeDefinedAtomV1::forEachReference(ReferenceHandler& hnd) const {
> -  if ( _ivarData->referencesCount == 0 )
> -    return;
> -  _file->forEachReference(hnd, _ivarData->referencesStartIndex,
> -                               _ivarData->referencesCount);
> +DefinedAtom::reference_iterator NativeDefinedAtomV1::referencesBegin() const {
> +  uintptr_t index = _ivarData->referencesStartIndex;
> +  const void* it = reinterpret_cast<const void*>(index);
> +  return reference_iterator(*this, it);
> +}
> +
> +DefinedAtom::reference_iterator NativeDefinedAtomV1::referencesEnd() const {
> +  uintptr_t index = _ivarData->referencesStartIndex+_ivarData->referencesCount;
> +  const void* it = reinterpret_cast<const void*>(index);
> +  return reference_iterator(*this, it);
> +}
> +
> +const Reference* NativeDefinedAtomV1::derefIterator(const void* it) const {
> +  uintptr_t index = reinterpret_cast<uintptr_t>(it);
> +  return _file->referenceByIndex(index);
> +}
> +
> +void NativeDefinedAtomV1::incrementIterator(const void*& it) const {
> +  uintptr_t index = reinterpret_cast<uintptr_t>(it);
> +  ++index;
> +  it = reinterpret_cast<const void*>(index);
>  }
>
>  inline const class File& NativeUndefinedAtomV1::file() const {
>
> Modified: lld/trunk/lib/Core/NativeWriter.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/NativeWriter.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/NativeWriter.cpp (original)
> +++ lld/trunk/lib/Core/NativeWriter.cpp Wed Mar  7 18:18:30 2012
> @@ -8,7 +8,6 @@
>  //===----------------------------------------------------------------------===//
>
>  #include <vector>
> -#include <map>
>
>  #include "llvm/ADT/StringRef.h"
>  #include "llvm/ADT/ArrayRef.h"
> @@ -26,15 +25,36 @@
>  ///
>  /// Class for writing native object files.
>  ///
> -class NativeWriter : public File::AtomHandler,
> -                     public DefinedAtom::ReferenceHandler {
> +class NativeWriter {
>  public:
>   /// construct writer for an lld::File object
>   NativeWriter(const lld::File& file) : _file(file) {
>     // reserve first byte for unnamed atoms
>     _stringPool.push_back('\0');
>     // visit all atoms
> -    _file.forEachAtom(*this);
> +    for(File::defined_iterator it=file.definedAtomsBegin(),
> +                              end=file.definedAtomsEnd();
> +                               it != end; ++it) {
> +      this->addIVarsForDefinedAtom(**it);
> +    }
> +    for(File::undefined_iterator it=file.undefinedAtomsBegin(),
> +                              end=file.undefinedAtomsEnd();
> +                               it != end; ++it) {
> +      this->addIVarsForUndefinedAtom(**it);
> +    }
> +    for(File::shared_library_iterator it=file.sharedLibraryAtomsBegin(),
> +                              end=file.sharedLibraryAtomsEnd();
> +                               it != end; ++it) {
> +      this->addIVarsForSharedLibraryAtom(**it);
> +    }
> +    for(File::absolute_iterator it=file.absoluteAtomsBegin(),
> +                              end=file.absoluteAtomsEnd();
> +                               it != end; ++it) {
> +      this->addIVarsForAbsoluteAtom(**it);
> +    }
> +
> +
> +
>     // construct file header based on atom information accumulated
>     makeHeader();
>   }
> @@ -105,8 +125,7 @@
>
>  private:
>
> -  // visitor routine called by forEachAtom()
> -  virtual void doDefinedAtom(const DefinedAtom& atom) {
> +  void addIVarsForDefinedAtom(const DefinedAtom& atom) {
>     _definedAtomIndex[&atom] = _definedAtomIvars.size();
>     NativeDefinedAtomIvarsV1 ivar;
>     unsigned refsCount;
> @@ -119,8 +138,7 @@
>     _definedAtomIvars.push_back(ivar);
>   }
>
> -  // visitor routine called by forEachAtom()
> -  virtual void doUndefinedAtom(const UndefinedAtom& atom) {
> +  void addIVarsForUndefinedAtom(const UndefinedAtom& atom) {
>     _undefinedAtomIndex[&atom] = _undefinedAtomIvars.size();
>     NativeUndefinedAtomIvarsV1 ivar;
>     ivar.nameOffset = getNameOffset(atom);
> @@ -128,8 +146,7 @@
>     _undefinedAtomIvars.push_back(ivar);
>   }
>
> -  // visitor routine called by forEachAtom()
> -  virtual void doSharedLibraryAtom(const SharedLibraryAtom& atom) {
> +  void addIVarsForSharedLibraryAtom(const SharedLibraryAtom& atom) {
>     _sharedLibraryAtomIndex[&atom] = _sharedLibraryAtomIvars.size();
>     NativeSharedLibraryAtomIvarsV1 ivar;
>     ivar.nameOffset = getNameOffset(atom);
> @@ -138,8 +155,7 @@
>     _sharedLibraryAtomIvars.push_back(ivar);
>   }
>
> -  // visitor routine called by forEachAtom()
> -  virtual void doAbsoluteAtom(const AbsoluteAtom& atom) {
> +  void addIVarsForAbsoluteAtom(const AbsoluteAtom& atom) {
>     _absoluteAtomIndex[&atom] = _absoluteAtomIvars.size();
>     NativeAbsoluteAtomIvarsV1 ivar;
>     ivar.nameOffset = getNameOffset(atom);
> @@ -148,10 +164,6 @@
>     _absoluteAtomIvars.push_back(ivar);
>   }
>
> -  // visitor routine called by forEachAtom()
> -  virtual void doFile(const File &) {
> -  }
> -
>   // fill out native file header and chunk directory
>   void makeHeader() {
>     const bool hasDefines = !_definedAtomIvars.empty();
> @@ -304,6 +316,7 @@
>         return chunks[i];
>     }
>     assert(0 && "findChunk() signature not found");
> +    static NativeChunk x; return x; // suppress warning
>   }
>
>   // append atom name to string pool and return offset
> @@ -403,23 +416,23 @@
>     count = 0;
>     size_t startRefSize = _references.size();
>     uint32_t result = startRefSize;
> -    atom.forEachReference(*this);
> +    for (auto it=atom.referencesBegin(), end=atom.referencesEnd();
> +                                                    it != end; ++it) {
> +      const Reference* ref = *it;
> +      NativeReferenceIvarsV1 nref;
> +      nref.offsetInAtom = ref->offsetInAtom();
> +      nref.kind = ref->kind();
> +      nref.targetIndex = this->getTargetIndex(ref->target());
> +      nref.addendIndex = this->getAddendIndex(ref->addend());
> +      _references.push_back(nref);
> +    }
>     count = _references.size() - startRefSize;
>     if ( count == 0 )
>       return 0;
>     else
>       return result;
>   }
> -
> -  void doReference(const Reference& ref) {
> -    NativeReferenceIvarsV1 nref;
> -    nref.offsetInAtom = ref.offsetInAtom();
> -    nref.kind = ref.kind();
> -    nref.targetIndex = this->getTargetIndex(ref.target());
> -    nref.addendIndex = this->getAddendIndex(ref.addend());
> -    _references.push_back(nref);
> -  }
> -
> +
>   uint32_t getTargetIndex(const Atom* target) {
>     TargetToIndex::const_iterator pos = _targetsTableIndex.find(target);
>     if ( pos != _targetsTableIndex.end() ) {
>
> Modified: lld/trunk/lib/Core/Resolver.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/Resolver.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/Resolver.cpp (original)
> +++ lld/trunk/lib/Core/Resolver.cpp Wed Mar  7 18:18:30 2012
> @@ -217,29 +217,18 @@
>   }
>  }
>
> -// helper to update targets for use with forEachReference()
> -class ReferenceUpdater : public DefinedAtom::ReferenceHandler {
> -public:
> -                          ReferenceUpdater(SymbolTable& sym) : _symbolTable(sym) { }
> -
> -       virtual void doReference(const Reference& ref) {
> -    const Atom* newTarget = _symbolTable.replacement(ref.target());
> -    (const_cast<Reference*>(&ref))->setTarget(newTarget);
> -  }
> -
> -private:
> -       SymbolTable&  _symbolTable;
> -};
> -
>
>  // switch all references to undefined or coalesced away atoms
>  // to the new defined atom
>  void Resolver::updateReferences() {
> -  ReferenceUpdater updater(_symbolTable);
> -  for (std::vector<const Atom *>::iterator it = _atoms.begin();
> -       it != _atoms.end(); ++it) {
> -    if ( const DefinedAtom* defAtom = (*it)->definedAtom() ) {
> -      defAtom->forEachReference(updater);
> +  for (auto ait = _atoms.begin(); ait != _atoms.end(); ++ait) {
> +    if ( const DefinedAtom* defAtom = (*ait)->definedAtom() ) {
> +      for (auto rit=defAtom->referencesBegin(), end=defAtom->referencesEnd();
> +                                                        rit != end; ++rit) {
> +        const Reference* ref = *rit;
> +        const Atom* newTarget = _symbolTable.replacement(ref->target());
> +        (const_cast<Reference*>(ref))->setTarget(newTarget);
> +      }
>     }
>   }
>  }
> @@ -272,8 +261,11 @@
>   thisChain.previous = previous;
>   thisChain.referer = &atom;
>   if ( const DefinedAtom* defAtom = atom.definedAtom() ) {
> -    MarkLiveReferences markRefs(*this, &thisChain);
> -    defAtom->forEachReference(markRefs);
> +    for (auto rit=defAtom->referencesBegin(), end=defAtom->referencesEnd();
> +                                                        rit != end; ++rit) {
> +      const Reference* ref = *rit;
> +      this->markLive(*ref->target(), &thisChain);
> +    }
>   }
>  }
>
> @@ -382,7 +374,7 @@
>   // FIX ME
>  }
>
> -std::vector<const Atom *> &Resolver::resolve() {
> +void Resolver::resolve() {
>   this->initializeState();
>   this->addInitialUndefines();
>   this->buildInitialAtomList();
> @@ -394,7 +386,32 @@
>   this->checkDylibSymbolCollisions();
>   this->linkTimeOptimize();
>   this->tweakAtoms();
> -  return _atoms;
> +  this->_result.addAtoms(_atoms);
>  }
>
> +void Resolver::MergedFile::addAtom(const Atom& atom) {
> +  if ( const DefinedAtom* defAtom = atom.definedAtom() ) {
> +    _definedAtoms._atoms.push_back(defAtom);
> +  }
> +  else if ( const UndefinedAtom* undefAtom = atom.undefinedAtom() ) {
> +    _undefinedAtoms._atoms.push_back(undefAtom);
> +  }
> +  else if ( const SharedLibraryAtom* slAtom = atom.sharedLibraryAtom() ) {
> +    _sharedLibraryAtoms._atoms.push_back(slAtom);
> +  }
> +  else if ( const AbsoluteAtom* abAtom = atom.absoluteAtom() ) {
> +    _absoluteAtoms._atoms.push_back(abAtom);
> +  }
> +  else {
> +    assert(0 && "atom has unknown definition kind");
> +  }
> +}
> +
> +void Resolver::MergedFile::addAtoms(std::vector<const Atom*>& all) {
> +  for(std::vector<const Atom*>::iterator it=all.begin(); it != all.end(); ++it) {
> +    this->addAtom(**it);
> +  }
> +}
> +
> +
>  } // namespace lld
>
> Modified: lld/trunk/lib/Core/YamlKeyValues.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/YamlKeyValues.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/YamlKeyValues.cpp (original)
> +++ lld/trunk/lib/Core/YamlKeyValues.cpp Wed Mar  7 18:18:30 2012
> @@ -137,6 +137,7 @@
>  static const ContentTypeMapping typeMappings[] = {
>   { "unknown",        DefinedAtom::typeUnknown },
>   { "code",           DefinedAtom::typeCode },
> +  { "stub",           DefinedAtom::typeStub },
>   { "resolver",       DefinedAtom::typeResolver },
>   { "constant",       DefinedAtom::typeConstant },
>   { "c-string",       DefinedAtom::typeCString },
>
> Modified: lld/trunk/lib/Core/YamlReader.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/YamlReader.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/YamlReader.cpp (original)
> +++ lld/trunk/lib/Core/YamlReader.cpp Wed Mar  7 18:18:30 2012
> @@ -20,6 +20,8 @@
>  #include "lld/Core/File.h"
>  #include "lld/Core/Reference.h"
>
> +#include "lld/Platform/Platform.h"
> +
>  #include "llvm/ADT/OwningPtr.h"
>  #include "llvm/ADT/StringRef.h"
>  #include "llvm/ADT/ArrayRef.h"
> @@ -297,10 +299,23 @@
>     : File("path")
>     , _lastRefIndex(0) {}
>
> -  virtual bool forEachAtom(File::AtomHandler &) const;
> -  virtual bool justInTimeforEachAtom(llvm::StringRef name,
> -                                     File::AtomHandler &) const;
> +  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;
> +  }
>
> +  virtual void addAtom(const Atom&) {
> +    assert(0 && "cannot add atoms to YAML files");
> +  }
> +
>   void bindTargetReferences();
>   void addDefinedAtom(YAMLDefinedAtom* atom, const char* refName);
>   void addUndefinedAtom(UndefinedAtom* atom);
> @@ -314,13 +329,13 @@
>     Atom*        atom;
>   };
>
> -  std::vector<YAMLDefinedAtom*>   _definedAtoms;
> -  std::vector<UndefinedAtom*>     _undefinedAtoms;
> -  std::vector<SharedLibraryAtom*> _sharedLibraryAtoms;
> -  std::vector<AbsoluteAtom*>      _absoluteAtoms;
> -  std::vector<YAMLReference>      _references;
> -  std::vector<NameAtomPair>       _nameToAtomMapping;
> -  unsigned int                    _lastRefIndex;
> +  atom_collection_vector<DefinedAtom>         _definedAtoms;
> +  atom_collection_vector<UndefinedAtom>       _undefinedAtoms;
> +  atom_collection_vector<SharedLibraryAtom>   _sharedLibraryAtoms;
> +  atom_collection_vector<AbsoluteAtom>        _absoluteAtoms;
> +  std::vector<YAMLReference>                  _references;
> +  std::vector<NameAtomPair>                   _nameToAtomMapping;
> +  unsigned int                                _lastRefIndex;
>  };
>
>
> @@ -434,14 +449,35 @@
>     return _ord;
>   }
>
> -
> -  virtual void forEachReference(ReferenceHandler& handler) const {
> -    for (uint32_t i=_refStartIndex; i < _refEndIndex; ++i) {
> -      handler.doReference(_file._references[i]);
> -    }
> +  DefinedAtom::reference_iterator referencesBegin() const {
> +    uintptr_t index = _refStartIndex;
> +    const void* it = reinterpret_cast<const void*>(index);
> +    return reference_iterator(*this, it);
>   }
>
> -  void bindTargetReferences() {
> +  DefinedAtom::reference_iterator referencesEnd() const {
> +    uintptr_t index = _refEndIndex;
> +    const void* it = reinterpret_cast<const void*>(index);
> +    return reference_iterator(*this, it);
> +  }
> +
> +  const Reference* derefIterator(const void* it) const {
> +    uintptr_t index = reinterpret_cast<uintptr_t>(it);
> +    assert(index >= _refStartIndex);
> +    assert(index < _refEndIndex);
> +    assert(index < _file._references.size());
> +    return &_file._references[index];
> +  }
> +
> +  void incrementIterator(const void*& it) const {
> +    uintptr_t index = reinterpret_cast<uintptr_t>(it);
> +    ++index;
> +    it = reinterpret_cast<const void*>(index);
> +  }
> +
> +
> +
> +  void bindTargetReferences() const {
>     for (unsigned int i=_refStartIndex; i < _refEndIndex; ++i) {
>       const char* targetName = _file._references[i]._targetName;
>       Atom* targetAtom = _file.findAtom(targetName);
> @@ -559,40 +595,9 @@
>
>
>
> -
> -bool YAMLFile::forEachAtom(File::AtomHandler &handler) const {
> -  handler.doFile(*this);
> -  for (std::vector<YAMLDefinedAtom *>::const_iterator it = _definedAtoms.begin();
> -       it != _definedAtoms.end(); ++it) {
> -    handler.doDefinedAtom(**it);
> -  }
> -  for (std::vector<UndefinedAtom *>::const_iterator it = _undefinedAtoms.begin();
> -       it != _undefinedAtoms.end(); ++it) {
> -    handler.doUndefinedAtom(**it);
> -  }
> -  for (std::vector<SharedLibraryAtom *>::const_iterator
> -        it = _sharedLibraryAtoms.begin();
> -        it != _sharedLibraryAtoms.end(); ++it) {
> -    handler.doSharedLibraryAtom(**it);
> -  }
> -  for (std::vector<AbsoluteAtom *>::const_iterator
> -        it = _absoluteAtoms.begin();
> -        it != _absoluteAtoms.end(); ++it) {
> -    handler.doAbsoluteAtom(**it);
> -  }
> -
> -  return true;
> -}
> -
> -bool YAMLFile::justInTimeforEachAtom(llvm::StringRef name,
> -                                     File::AtomHandler &handler) const {
> -  return false;
> -}
> -
>  void YAMLFile::bindTargetReferences() {
> -    for (std::vector<YAMLDefinedAtom *>::const_iterator
> -         it = _definedAtoms.begin(); it != _definedAtoms.end(); ++it) {
> -      YAMLDefinedAtom* atom = *it;
> +    for (defined_iterator it = definedAtomsBegin(); it != definedAtomsEnd(); ++it) {
> +      const YAMLDefinedAtom* atom = reinterpret_cast<const YAMLDefinedAtom*>(*it);
>       atom->bindTargetReferences();
>     }
>  }
> @@ -607,31 +612,31 @@
>  }
>
>  void YAMLFile::addDefinedAtom(YAMLDefinedAtom* atom, const char* refName) {
> -  _definedAtoms.push_back(atom);
> +  _definedAtoms._atoms.push_back(atom);
>   assert(refName != NULL);
>   _nameToAtomMapping.push_back(NameAtomPair(refName, atom));
>  }
>
>  void YAMLFile::addUndefinedAtom(UndefinedAtom* atom) {
> -  _undefinedAtoms.push_back(atom);
> +  _undefinedAtoms._atoms.push_back(atom);
>   _nameToAtomMapping.push_back(NameAtomPair(atom->name().data(), atom));
>  }
>
>  void YAMLFile::addSharedLibraryAtom(SharedLibraryAtom* atom) {
> -  _sharedLibraryAtoms.push_back(atom);
> +  _sharedLibraryAtoms._atoms.push_back(atom);
>   _nameToAtomMapping.push_back(NameAtomPair(atom->name().data(), atom));
>  }
>
>  void YAMLFile::addAbsoluteAtom(AbsoluteAtom* atom) {
> -  _absoluteAtoms.push_back(atom);
> +  _absoluteAtoms._atoms.push_back(atom);
>   _nameToAtomMapping.push_back(NameAtomPair(atom->name().data(), atom));
>  }
>
>
>  class YAMLAtomState {
>  public:
> -  YAMLAtomState();
> -
> +  YAMLAtomState(Platform& platform);
> +
>   void setName(const char *n);
>   void setRefName(const char *n);
>   void setAlign2(const char *n);
> @@ -642,6 +647,7 @@
>
>   void makeAtom(YAMLFile&);
>
> +  Platform&                   _platform;
>   const char *                _name;
>   const char *                _refName;
>   const char *                _sectionName;
> @@ -666,8 +672,9 @@
>  };
>
>
> -YAMLAtomState::YAMLAtomState()
> -  : _name(NULL)
> +YAMLAtomState::YAMLAtomState(Platform& platform)
> +  : _platform(platform)
> +  , _name(NULL)
>   , _refName(NULL)
>   , _sectionName(NULL)
>   , _loadName(NULL)
> @@ -764,15 +771,7 @@
>
>
>  void YAMLAtomState::setFixupKind(const char *s) {
> -  if (strcmp(s, "pcrel32") == 0)
> -    _ref._kind = 1;
> -  else if (strcmp(s, "call32") == 0)
> -    _ref._kind = 2;
> -  else {
> -    int k;
> -    llvm::StringRef(s).getAsInteger(10, k);
> -    _ref._kind = k;
> -  }
> +  _ref._kind = _platform.kindFromString(llvm::StringRef(s));
>  }
>
>  void YAMLAtomState::setFixupTarget(const char *s) {
> @@ -800,12 +799,13 @@
>  /// parseObjectText - Parse the specified YAML formatted MemoryBuffer
>  /// into lld::File object(s) and append each to the specified vector<File*>.
>  llvm::error_code parseObjectText( llvm::MemoryBuffer *mb
> -                                , std::vector<File *> &result) {
> +                                , Platform& platform
> +                                , std::vector<const File *> &result) {
>   std::vector<const YAML::Entry *> entries;
>   YAML::parse(mb, entries);
>
>   YAMLFile *file = NULL;
> -  YAMLAtomState atomState;
> +  YAMLAtomState atomState(platform);
>   bool inAtoms       = false;
>   bool inFixups      = false;
>   int depthForAtoms  = -1;
> @@ -985,13 +985,14 @@
>  // Fill in vector<File*> from path to input text file.
>  //
>  llvm::error_code parseObjectTextFileOrSTDIN(llvm::StringRef path
> -                                 , std::vector<File*>& result) {
> +                                          , Platform&  platform
> +                                          , std::vector<const File*>& result) {
>   llvm::OwningPtr<llvm::MemoryBuffer> mb;
>   llvm::error_code ec = llvm::MemoryBuffer::getFileOrSTDIN(path, mb);
>   if ( ec )
>       return ec;
>
> -  return parseObjectText(mb.get(), result);
> +  return parseObjectText(mb.get(), platform, result);
>  }
>
>
>
> Modified: lld/trunk/lib/Core/YamlWriter.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Core/YamlWriter.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/lib/Core/YamlWriter.cpp (original)
> +++ lld/trunk/lib/Core/YamlWriter.cpp Wed Mar  7 18:18:30 2012
> @@ -14,6 +14,8 @@
>  #include "lld/Core/File.h"
>  #include "lld/Core/Reference.h"
>
> +#include "lld/Platform/Platform.h"
> +
>  #include "llvm/ADT/OwningPtr.h"
>  #include "llvm/ADT/DenseMap.h"
>  #include "llvm/ADT/StringExtras.h"
> @@ -41,44 +43,50 @@
>  /// In that case referencing the function by name is ambiguous, so a unique
>  /// ref-name is added.
>  ///
> -class RefNameBuilder : public File::AtomHandler,
> -                       public DefinedAtom::ReferenceHandler {
> +class RefNameBuilder {
>  public:
> -  RefNameBuilder() { }
> -
> -  virtual void doReference(const Reference& ref) {
> -    // create refname for any unnamed reference target
> -    if ( ref.target()->name().empty() ) {
> -      char* buffer;
> -      asprintf(&buffer, "L%03d", _unnamedCounter++);
> -      _refNames[ref.target()] = buffer;
> +  RefNameBuilder(const File& file)
> +                : _collisionCount(0), _unnamedCounter(0) {
> +    // visit all atoms
> +    for(File::defined_iterator it=file.definedAtomsBegin(),
> +                              end=file.definedAtomsEnd();
> +                               it != end; ++it) {
> +      const DefinedAtom* atom = *it;
> +      // Build map of atoms names to detect duplicates
> +      if ( ! atom->name().empty() )
> +        buildDuplicateNameMap(*atom);
> +
> +      // Find references to unnamed atoms and create ref-names for them.
> +      for (auto rit=atom->referencesBegin(), rend=atom->referencesEnd();
> +                                                        rit != rend; ++rit) {
> +        const Reference* ref = *rit;
> +        // create refname for any unnamed reference target
> +        if ( ref->target()->name().empty() ) {
> +          char* buffer;
> +          asprintf(&buffer, "L%03d", _unnamedCounter++);
> +          _refNames[ref->target()] = buffer;
> +        }
> +      }
> +    }
> +    for(File::undefined_iterator it=file.undefinedAtomsBegin(),
> +                              end=file.undefinedAtomsEnd();
> +                               it != end; ++it) {
> +      buildDuplicateNameMap(**it);
> +    }
> +    for(File::shared_library_iterator it=file.sharedLibraryAtomsBegin(),
> +                              end=file.sharedLibraryAtomsEnd();
> +                               it != end; ++it) {
> +      buildDuplicateNameMap(**it);
> +    }
> +    for(File::absolute_iterator it=file.absoluteAtomsBegin(),
> +                              end=file.absoluteAtomsEnd();
> +                               it != end; ++it) {
> +      buildDuplicateNameMap(**it);
>     }
> -  }
>
> -  virtual void doFile(const File &) { }
> -
> -  virtual void doDefinedAtom(const DefinedAtom& atom) {
> -    // Build map of atoms names to detect duplicates
> -    if ( ! atom.name().empty() )
> -      buildDuplicateNameMap(atom);
> -
> -    // Find references to unnamed atoms and create ref-names for them.
> -    _unnamedCounter = 0;
> -    atom.forEachReference(*this);
> -  }
> -
> -  virtual void doUndefinedAtom(const UndefinedAtom& atom) {
> -    buildDuplicateNameMap(atom);
> -  }
>
> -  virtual void doSharedLibraryAtom(const SharedLibraryAtom& atom) {
> -    buildDuplicateNameMap(atom);
> -  }
> -
> -  virtual void doAbsoluteAtom(const AbsoluteAtom& atom) {
> -    buildDuplicateNameMap(atom);
>   }
> -
> +
>   void buildDuplicateNameMap(const Atom& atom) {
>     assert(!atom.name().empty());
>     NameToAtom::iterator pos = _nameMap.find(atom.name());
> @@ -131,27 +139,55 @@
>  ///
>  /// Helper class for writeObjectText() to write out atoms in yaml format.
>  ///
> -class AtomWriter : public File::AtomHandler,
> -                   public DefinedAtom::ReferenceHandler {
> +class AtomWriter {
>  public:
> -  AtomWriter(RefNameBuilder& rnb, llvm::raw_ostream &out)
> -    : _out(out), _rnb(rnb), _firstAtom(true) { }
> +  AtomWriter(const File& file, Platform& platform, RefNameBuilder& rnb)
> +    : _file(file), _platform(platform), _rnb(rnb), _firstAtom(true) { }
> +
> +
> +  void write(llvm::raw_ostream& out) {
> +    // write header
> +    out << "---\n";
> +
> +    // visit all atoms
> +    for(File::defined_iterator it=_file.definedAtomsBegin(),
> +                              end=_file.definedAtomsEnd();
> +                               it != end; ++it) {
> +      writeDefinedAtom(**it, out);
> +    }
> +    for(File::undefined_iterator it=_file.undefinedAtomsBegin(),
> +                              end=_file.undefinedAtomsEnd();
> +                               it != end; ++it) {
> +      writeUndefinedAtom(**it, out);
> +    }
> +    for(File::shared_library_iterator it=_file.sharedLibraryAtomsBegin(),
> +                              end=_file.sharedLibraryAtomsEnd();
> +                               it != end; ++it) {
> +      writeSharedLibraryAtom(**it, out);
> +    }
> +    for(File::absolute_iterator it=_file.absoluteAtomsBegin(),
> +                              end=_file.absoluteAtomsEnd();
> +                               it != end; ++it) {
> +      writeAbsoluteAtom(**it, out);
> +    }
> +
> +    out << "...\n";
> +  }
>
> -  virtual void doFile(const class File &) { _firstAtom = true; }
>
> -  virtual void doDefinedAtom(const class DefinedAtom &atom) {
> +  void writeDefinedAtom(const DefinedAtom &atom, llvm::raw_ostream& out) {
>     if ( _firstAtom ) {
> -      _out << "atoms:\n";
> +      out << "atoms:\n";
>       _firstAtom = false;
>     }
>     else {
>       // add blank line between atoms for readability
> -      _out << "\n";
> +      out << "\n";
>     }
>
>     bool hasDash = false;
>     if ( !atom.name().empty() ) {
> -      _out  << "    - "
> +      out   << "    - "
>             << KeyValues::nameKeyword
>             << ":"
>             << spacePadding(KeyValues::nameKeyword)
> @@ -161,7 +197,7 @@
>     }
>
>     if ( _rnb.hasRefName(&atom) ) {
> -      _out  << (hasDash ? "      " : "    - ")
> +      out   << (hasDash ? "      " : "    - ")
>             << KeyValues::refNameKeyword
>             << ":"
>             << spacePadding(KeyValues::refNameKeyword)
> @@ -171,7 +207,7 @@
>     }
>
>     if ( atom.definition() != KeyValues::definitionDefault ) {
> -      _out  << (hasDash ? "      " : "    - ")
> +      out   << (hasDash ? "      " : "    - ")
>             << KeyValues::definitionKeyword
>             << ":"
>             << spacePadding(KeyValues::definitionKeyword)
> @@ -181,7 +217,7 @@
>     }
>
>     if ( atom.scope() != KeyValues::scopeDefault ) {
> -      _out  << (hasDash ? "      " : "    - ")
> +      out   << (hasDash ? "      " : "    - ")
>             << KeyValues::scopeKeyword
>             << ":"
>             << spacePadding(KeyValues::scopeKeyword)
> @@ -191,7 +227,7 @@
>     }
>
>      if ( atom.interposable() != KeyValues::interposableDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::interposableKeyword
>             << ":"
>             << spacePadding(KeyValues::interposableKeyword)
> @@ -200,7 +236,7 @@
>     }
>
>     if ( atom.merge() != KeyValues::mergeDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::mergeKeyword
>             << ":"
>             << spacePadding(KeyValues::mergeKeyword)
> @@ -209,7 +245,7 @@
>     }
>
>     if ( atom.contentType() != KeyValues::contentTypeDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::contentTypeKeyword
>             << ":"
>             << spacePadding(KeyValues::contentTypeKeyword)
> @@ -218,7 +254,7 @@
>     }
>
>     if ( atom.deadStrip() != KeyValues::deadStripKindDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::deadStripKindKeyword
>             << ":"
>             << spacePadding(KeyValues::deadStripKindKeyword)
> @@ -227,14 +263,14 @@
>     }
>
>     if ( atom.sectionChoice() != KeyValues::sectionChoiceDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::sectionChoiceKeyword
>             << ":"
>             << spacePadding(KeyValues::sectionChoiceKeyword)
>             << KeyValues::sectionChoice(atom.sectionChoice())
>             << "\n";
>       assert( ! atom.customSectionName().empty() );
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::sectionNameKeyword
>             << ":"
>             << spacePadding(KeyValues::sectionNameKeyword)
> @@ -243,7 +279,7 @@
>     }
>
>     if ( atom.isThumb() != KeyValues::isThumbDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::isThumbKeyword
>             << ":"
>             << spacePadding(KeyValues::isThumbKeyword)
> @@ -252,7 +288,7 @@
>     }
>
>     if ( atom.isAlias() != KeyValues::isAliasDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::isAliasKeyword
>             << ":"
>             << spacePadding(KeyValues::isAliasKeyword)
> @@ -262,7 +298,7 @@
>
>     if ( (atom.contentType() != DefinedAtom::typeZeroFill)
>                                    && (atom.size() != 0) ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::contentKeyword
>             << ":"
>             << spacePadding(KeyValues::contentKeyword)
> @@ -271,77 +307,77 @@
>       bool needComma = false;
>       for (unsigned int i=0; i < arr.size(); ++i) {
>         if ( needComma )
> -          _out << ", ";
> -        _out << hexdigit(arr[i] >> 4);
> -        _out << hexdigit(arr[i] & 0x0F);
> +          out  << ", ";
> +        out  << hexdigit(arr[i] >> 4);
> +        out  << hexdigit(arr[i] & 0x0F);
>         needComma = true;
>       }
> -      _out << " ]\n";
> +      out  << " ]\n";
>     }
>
> -    _wroteFirstFixup = false;
> -    atom.forEachReference(*this);
> -  }
> -
> -  virtual void doReference(const Reference& ref) {
> -    if ( !_wroteFirstFixup ) {
> -      _out << "      fixups:\n";
> -      _wroteFirstFixup = true;
> -    }
> -    _out  << "      - "
> -          << KeyValues::fixupsOffsetKeyword
> -          << ":"
> -          << spacePadding(KeyValues::fixupsOffsetKeyword)
> -          << ref.offsetInAtom()
> -          << "\n";
> -    _out  << "        "
> -          << KeyValues::fixupsKindKeyword
> -          << ":"
> -          << spacePadding(KeyValues::fixupsKindKeyword)
> -          << ref.kind()
> -          << "\n";
> -    const Atom* target = ref.target();
> -    if ( target != NULL ) {
> -      llvm::StringRef refName = target->name();
> -      if ( _rnb.hasRefName(target) )
> -        refName = _rnb.refName(target);
> -      assert(!refName.empty());
> -      _out  << "        "
> -            << KeyValues::fixupsTargetKeyword
> -            << ":"
> -            << spacePadding(KeyValues::fixupsTargetKeyword)
> -            << refName
> -            << "\n";
> -    }
> -    if ( ref.addend() != 0 ) {
> -      _out  << "        "
> -            << KeyValues::fixupsAddendKeyword
> +    bool wroteFirstFixup = false;
> +    for (auto it=atom.referencesBegin(), end=atom.referencesEnd();
> +                                                    it != end; ++it) {
> +      const Reference* ref = *it;
> +      if ( !wroteFirstFixup ) {
> +        out  << "      fixups:\n";
> +        wroteFirstFixup = true;
> +      }
> +      out   << "      - "
> +            << KeyValues::fixupsOffsetKeyword
>             << ":"
> -            << spacePadding(KeyValues::fixupsAddendKeyword)
> -            << ref.addend()
> +            << spacePadding(KeyValues::fixupsOffsetKeyword)
> +            << ref->offsetInAtom()
>             << "\n";
> +      out   << "        "
> +            << KeyValues::fixupsKindKeyword
> +            << ":"
> +            << spacePadding(KeyValues::fixupsKindKeyword)
> +            << _platform.kindToString(ref->kind())
> +            << "\n";
> +      const Atom* target = ref->target();
> +      if ( target != NULL ) {
> +        llvm::StringRef refName = target->name();
> +        if ( _rnb.hasRefName(target) )
> +          refName = _rnb.refName(target);
> +        assert(!refName.empty());
> +        out   << "        "
> +              << KeyValues::fixupsTargetKeyword
> +              << ":"
> +              << spacePadding(KeyValues::fixupsTargetKeyword)
> +              << refName
> +              << "\n";
> +      }
> +      if ( ref->addend() != 0 ) {
> +        out   << "        "
> +              << KeyValues::fixupsAddendKeyword
> +              << ":"
> +              << spacePadding(KeyValues::fixupsAddendKeyword)
> +              << ref->addend()
> +              << "\n";
> +      }
>     }
>   }
> +
>
> -
> -  virtual void doUndefinedAtom(const class UndefinedAtom &atom) {
> +  void writeUndefinedAtom(const UndefinedAtom &atom, llvm::raw_ostream& out) {
>     if ( _firstAtom ) {
> -      _out << "atoms:\n";
> +      out  << "atoms:\n";
>       _firstAtom = false;
>     }
>     else {
>       // add blank line between atoms for readability
> -      _out << "\n";
> +      out  << "\n";
>     }
>
> -    _out  << "    - "
> +    out   << "    - "
>           << KeyValues::nameKeyword
>           << ":"
>           << spacePadding(KeyValues::nameKeyword)
>           << atom.name()
>           << "\n";
>
> -    _out  << "      "
> +    out   << "      "
>           << KeyValues::definitionKeyword
>           << ":"
>           << spacePadding(KeyValues::definitionKeyword)
> @@ -349,7 +385,7 @@
>           << "\n";
>
>     if ( atom.canBeNull() != KeyValues::canBeNullDefault ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::canBeNullKeyword
>             << ":"
>             << spacePadding(KeyValues::canBeNullKeyword)
> @@ -358,24 +394,24 @@
>     }
>   }
>
> -   virtual void doSharedLibraryAtom(const SharedLibraryAtom& atom) {
> +  void writeSharedLibraryAtom(const SharedLibraryAtom& atom, llvm::raw_ostream& out) {
>     if ( _firstAtom ) {
> -      _out << "atoms:\n";
> +      out  << "atoms:\n";
>       _firstAtom = false;
>     }
>     else {
>       // add blank line between atoms for readability
> -      _out << "\n";
> +      out  << "\n";
>     }
>
> -    _out  << "    - "
> +    out   << "    - "
>           << KeyValues::nameKeyword
>           << ":"
>           << spacePadding(KeyValues::nameKeyword)
>           << atom.name()
>           << "\n";
>
> -    _out  << "      "
> +    out   << "      "
>           << KeyValues::definitionKeyword
>           << ":"
>           << spacePadding(KeyValues::definitionKeyword)
> @@ -383,7 +419,7 @@
>           << "\n";
>
>     if ( !atom.loadName().empty() ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::loadNameKeyword
>             << ":"
>             << spacePadding(KeyValues::loadNameKeyword)
> @@ -392,7 +428,7 @@
>     }
>
>     if ( atom.canBeNullAtRuntime() ) {
> -      _out  << "      "
> +      out   << "      "
>             << KeyValues::canBeNullKeyword
>             << ":"
>             << spacePadding(KeyValues::canBeNullKeyword)
> @@ -401,37 +437,37 @@
>     }
>    }
>
> -   virtual void doAbsoluteAtom(const AbsoluteAtom& atom) {
> +  void writeAbsoluteAtom(const AbsoluteAtom& atom, llvm::raw_ostream& out) {
>      if ( _firstAtom ) {
> -      _out << "atoms:\n";
> +      out << "atoms:\n";
>       _firstAtom = false;
>     }
>     else {
>       // add blank line between atoms for readability
> -      _out << "\n";
> +      out << "\n";
>     }
>
> -    _out  << "    - "
> +    out   << "    - "
>           << KeyValues::nameKeyword
>           << ":"
>           << spacePadding(KeyValues::nameKeyword)
>           << atom.name()
>           << "\n";
>
> -    _out  << "      "
> +    out   << "      "
>           << KeyValues::definitionKeyword
>           << ":"
>           << spacePadding(KeyValues::definitionKeyword)
>           << KeyValues::definition(atom.definition())
>           << "\n";
>
> -    _out  << "      "
> +    out   << "      "
>           << KeyValues::valueKeyword
>           << ":"
>           << spacePadding(KeyValues::valueKeyword)
>           << "0x";
> -     _out.write_hex(atom.value());
> -     _out << "\n";
> +     out.write_hex(atom.value());
> +     out << "\n";
>    }
>
>
> @@ -450,10 +486,10 @@
>       return 'A' + nibble - 0x0A;
>   }
>
> -  llvm::raw_ostream&  _out;
> -  RefNameBuilder      _rnb;
> +  const File&         _file;
> +  Platform&           _platform;
> +  RefNameBuilder&     _rnb;
>   bool                _firstAtom;
> -  bool                _wroteFirstFixup;
>  };
>
>  } // anonymous namespace
> @@ -464,16 +500,14 @@
>  /// writeObjectText - writes the lld::File object as in YAML
>  /// format to the specified stream.
>  ///
> -void writeObjectText(const File &file, llvm::raw_ostream &out) {
> +void writeObjectText(const File& file, Platform& platform,
> +                      llvm::raw_ostream &out) {
>   // Figure what ref-name labels are needed
> -  RefNameBuilder rnb;
> -  file.forEachAtom(rnb);
> +  RefNameBuilder rnb(file);
>
>   // Write out all atoms
> -  AtomWriter h(rnb, out);
> -  out << "---\n";
> -  file.forEachAtom(h);
> -  out << "...\n";
> +  AtomWriter writer(file, platform, rnb);
> +  writer.write(out);
>  }
>
>  } // namespace yaml
>
> Added: lld/trunk/lib/Passes/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Passes/CMakeLists.txt?rev=152269&view=auto
> ==============================================================================
> --- lld/trunk/lib/Passes/CMakeLists.txt (added)
> +++ lld/trunk/lib/Passes/CMakeLists.txt Wed Mar  7 18:18:30 2012
> @@ -0,0 +1,3 @@
> +add_lld_library(lldPasses
> +  StubsPass.cpp
> +  )
>
> Added: lld/trunk/lib/Passes/StubsPass.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Passes/StubsPass.cpp?rev=152269&view=auto
> ==============================================================================
> --- lld/trunk/lib/Passes/StubsPass.cpp (added)
> +++ lld/trunk/lib/Passes/StubsPass.cpp Wed Mar  7 18:18:30 2012
> @@ -0,0 +1,79 @@
> +//===- Passes/StubsPass.cpp - Adds stubs ----------------------------------===//
> +//
> +//                             The LLVM Linker
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +
> +//
> +// This linker pass is
> +//
> +//
> +//
> +//
> +
> +
> +#include "llvm/ADT/DenseMap.h"
> +
> +#include "lld/Core/Pass.h"
> +#include "lld/Core/File.h"
> +#include "lld/Core/Reference.h"
> +#include "lld/Platform/Platform.h"
> +
> +
> +namespace lld {
> +
> +void StubsPass::perform() {
> +  // Skip this pass if output format does not need stubs.
> +  if ( !_platform.outputUsesStubs() )
> +    return;
> +
> +  // Use map so all call sites to same shlib symbol use same stub
> +  llvm::DenseMap<const SharedLibraryAtom*, const Atom*> shlibToStub;
> +
> +  // Scan all references in all atoms.
> +  for(auto ait=_file.definedAtomsBegin(), aend=_file.definedAtomsEnd();
> +                                                      ait != aend; ++ait) {
> +    const DefinedAtom* atom = *ait;
> +    for (auto rit=atom->referencesBegin(), rend=atom->referencesEnd();
> +                                                      rit != rend; ++rit) {
> +      const Reference* ref = *rit;
> +      const Atom* target = ref->target();
> +      assert(target != NULL);
> +      // If the target of this reference is in a shared library
> +      if ( const SharedLibraryAtom* shlbTarget = target->sharedLibraryAtom() ) {
> +        // and this is a call to that shared library symbol.
> +        if ( _platform.isBranch(ref) ) {
> +          const Atom* stub;
> +          // Replace the target with a reference to a stub
> +          auto pos = shlibToStub.find(shlbTarget);
> +          if ( pos == shlibToStub.end() ) {
> +            // This is no existing stub.  Create a new one.
> +            stub = _platform.makeStub(*shlbTarget, _file);
> +            shlibToStub[shlbTarget] = stub;
> +          }
> +          else {
> +            // Reuse and existing stub
> +            stub = pos->second;
> +          }
> +          assert(stub != NULL);
> +          // Switch call site in atom to refrence stub instead of shlib atom.
> +          (const_cast<Reference*>(ref))->setTarget(stub);
> +        }
> +      }
> +    }
> +  }
> +
> +  // add all created stubs to file
> +  for (auto it=shlibToStub.begin(), end=shlibToStub.end(); it != end; ++it) {
> +    _file.addAtom(*it->second);
> +  }
> +
> +
> +}
> +
> +
> +
> +}
>
> Added: lld/trunk/test/pass-stubs-basic.objtxt
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/pass-stubs-basic.objtxt?rev=152269&view=auto
> ==============================================================================
> --- lld/trunk/test/pass-stubs-basic.objtxt (added)
> +++ lld/trunk/test/pass-stubs-basic.objtxt Wed Mar  7 18:18:30 2012
> @@ -0,0 +1,50 @@
> +# RUN: lld-core %s -stubs_pass  | FileCheck %s
> +
> +#
> +# Test that stubs pass adds stubs and rebinds call sites to the stub
> +#
> +
> +---
> +atoms:
> +    - name:              foo
> +      type:              code
> +      content:           [ E8, 00, 00, 00, 00, E8, 00, 00, 00,
> +                           00, 48 ,8B, 05, 00, 00, 00, 00 ]
> +      fixups:
> +      - offset:          1
> +        kind:            call32
> +        target:          malloc
> +      - offset:          6
> +        kind:            call32
> +        target:          free
> +      - offset:          13
> +        kind:            gotLoad32
> +        target:          malloc
> +
> +    - name:              malloc
> +      definition:        shared-library
> +      load-name:         libc.so
> +
> +    - name:              free
> +      definition:        shared-library
> +      load-name:         libc.so
> +
> +...
> +
> +# CHECK:       name:         foo
> +# CHECK:       fixups:
> +# CHECK:       kind:         call32
> +# CHECK:       target:       L
> +# CHECK:       kind:         call32
> +# CHECK:       target:       L
> +# CHECK:       kind:         gotLoad32
> +# CHECK:       target:       malloc
> +# CHECK:       name:         L
> +# CHECK:       type:         stub
> +# CHECK:       name:         L
> +# CHECK:       type:         stub
> +# CHECK:       name:         malloc
> +# CHECK:       definition:   shared-library
> +# CHECK:       name:         free
> +# CHECK:       definition:   shared-library
> +# CHECK:       ...
>
> Modified: lld/trunk/tools/lld-core/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/tools/lld-core/CMakeLists.txt?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/tools/lld-core/CMakeLists.txt (original)
> +++ lld/trunk/tools/lld-core/CMakeLists.txt Wed Mar  7 18:18:30 2012
> @@ -1,5 +1,6 @@
>  set(LLVM_USED_LIBS
>   lldCore
> +  lldPasses
>   )
>
>  set(LLVM_LINK_COMPONENTS
>
> Modified: lld/trunk/tools/lld-core/lld-core.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/tools/lld-core/lld-core.cpp?rev=152269&r1=152268&r2=152269&view=diff
> ==============================================================================
> --- lld/trunk/tools/lld-core/lld-core.cpp (original)
> +++ lld/trunk/tools/lld-core/lld-core.cpp Wed Mar  7 18:18:30 2012
> @@ -11,6 +11,7 @@
>  #include "lld/Core/Atom.h"
>  #include "lld/Core/DefinedAtom.h"
>  #include "lld/Core/UndefinedAtom.h"
> +#include "lld/Core/Pass.h"
>  #include "lld/Core/Resolver.h"
>  #include "lld/Core/YamlReader.h"
>  #include "lld/Core/YamlWriter.h"
> @@ -22,6 +23,7 @@
>  #include "llvm/ADT/StringRef.h"
>  #include "llvm/ADT/SmallString.h"
>  #include "llvm/ADT/Twine.h"
> +#include "llvm/Support/CommandLine.h"
>  #include "llvm/Support/DataTypes.h"
>  #include "llvm/Support/ManagedStatic.h"
>  #include "llvm/Support/MemoryBuffer.h"
> @@ -49,15 +51,110 @@
>  }
>
>  namespace {
> -class LdCore : public InputFiles, public Platform {
> +
> +
> +//
> +// Simple atoms created by the stubs pass.
> +//
> +class TestingStubAtom : public DefinedAtom {
>  public:
> -  LdCore(std::vector<File *> &f) : _files(f) { }
> +        TestingStubAtom(const File& f, const SharedLibraryAtom& shlib) :
> +                        _file(f), _shlib(shlib) {
> +          static uint32_t lastOrdinal = 0;
> +          _ordinal = lastOrdinal++;
> +        }
>
> -  // InputFiles interface
> -  virtual void forEachInitialAtom(File::AtomHandler &) const;
> -  virtual bool searchLibraries(llvm::StringRef name, bool searchDylibs,
> -                               bool searchArchives, bool dataSymbolOnly,
> -                               File::AtomHandler &) const;
> +  virtual const File& file() const {
> +    return _file;
> +  }
> +
> +  virtual llvm::StringRef name() const {
> +    return llvm::StringRef();
> +  }
> +
> +  virtual uint64_t ordinal() const {
> +    return _ordinal;
> +  }
> +
> +  virtual uint64_t size() const {
> +    return 0;
> +  }
> +
> +  virtual Scope scope() const {
> +    return DefinedAtom::scopeLinkageUnit;
> +  }
> +
> +  virtual Interposable interposable() const {
> +    return DefinedAtom::interposeNo;
> +  }
> +
> +  virtual Merge merge() const {
> +    return DefinedAtom::mergeNo;
> +  }
> +
> +  virtual ContentType contentType() const  {
> +    return DefinedAtom::typeStub;
> +  }
> +
> +  virtual Alignment alignment() const {
> +    return Alignment(0,0);
> +  }
> +
> +  virtual SectionChoice sectionChoice() const {
> +    return DefinedAtom::sectionBasedOnContent;
> +  }
> +
> +  virtual llvm::StringRef customSectionName() const {
> +    return llvm::StringRef();
> +  }
> +  virtual DeadStripKind deadStrip() const {
> +    return DefinedAtom::deadStripNormal;
> +  }
> +
> +  virtual ContentPermissions permissions() const  {
> +    return DefinedAtom::permR_X;
> +  }
> +
> +  virtual bool isThumb() const {
> +    return false;
> +  }
> +
> +  virtual bool isAlias() const {
> +    return false;
> +  }
> +
> +  virtual llvm::ArrayRef<uint8_t> rawContent() const {
> +    return llvm::ArrayRef<uint8_t>();
> +  }
> +
> +  virtual reference_iterator referencesBegin() const {
> +    return reference_iterator(*this, NULL);
> +  }
> +
> +  virtual reference_iterator referencesEnd() const {
> +    return reference_iterator(*this, NULL);
> +  }
> +
> +  virtual const Reference* derefIterator(const void* iter) const {
> +    return NULL;
> +  }
> +
> +  virtual void incrementIterator(const void*& iter) const {
> +
> +  }
> +
> +private:
> +  const File&               _file;
> +  const SharedLibraryAtom&  _shlib;
> +  uint32_t                  _ordinal;
> +};
> +
> +
> +//
> +// A simple platform for testing.
> +//
> +class TestingPlatform : public Platform {
> +public:
>
>   virtual void initialize() { }
>
> @@ -155,97 +252,163 @@
>   // last chance for platform to tweak atoms
>   virtual void postResolveTweaks(std::vector<const Atom *> &all) {}
>
> -private:
> -  std::vector<File *> &_files;
> -};
> -}
> +  virtual bool outputUsesStubs() { return true; };
> +
> +
> +  struct KindMapping {
> +    const char*           string;
> +    Reference::Kind       value;
> +    bool                  isBranch;
> +  };
>
> -void LdCore::forEachInitialAtom(File::AtomHandler &handler) const {
> -  for (std::vector<File *>::iterator it = _files.begin();
> -       it != _files.end(); ++it) {
> -    const File *file = *it;
> -    handler.doFile(*file);
> -    file->forEachAtom(handler);
> +  static const KindMapping _s_kindMappings[];
> +
> +  virtual Reference::Kind kindFromString(llvm::StringRef kindName) {
> +    for (const KindMapping* p = _s_kindMappings; p->string != NULL; ++p) {
> +      if ( kindName.equals(p->string) )
> +        return p->value;
> +    }
> +    int k;
> +    kindName.getAsInteger(0, k);
> +    return k;
> +  }
> +
> +  virtual llvm::StringRef kindToString(Reference::Kind value) {
> +    for (const KindMapping* p = _s_kindMappings; p->string != NULL; ++p) {
> +      if ( value == p->value)
> +        return p->string;
> +    }
> +    return llvm::StringRef("???");
>   }
> -}
>
> -bool LdCore::searchLibraries(llvm::StringRef name, bool searchDylibs,
> -                             bool searchArchives, bool dataSymbolOnly,
> -                             File::AtomHandler &) const {
> -  return false;
> -}
>
> -namespace {
> -class MergedFile : public File {
> +  virtual bool isBranch(const Reference* ref) {
> +    Reference::Kind value = ref->kind();
> +    for (const KindMapping* p = _s_kindMappings; p->string != NULL; ++p) {
> +      if ( value == p->value )
> +        return p->isBranch;
> +    }
> +    return false;
> +  }
> +
> +  virtual const Atom* makeStub(const SharedLibraryAtom& shlibAtom, File& file) {
> +    return new TestingStubAtom(file, shlibAtom);
> +  }
> +};
> +
> +
> +//
> +// Table of fixup kinds in YAML documents used for testing
> +//
> +const TestingPlatform::KindMapping TestingPlatform::_s_kindMappings[] = {
> +    { "call32",         1,    true },
> +    { "pcrel32",        2,    false },
> +    { "gotLoad32",      3,    false },
> +    { NULL,             0,    false }
> +  };
> +
> +
> +//
> +// A simple input files wrapper for testing.
> +//
> +class TestingInputFiles : public InputFiles {
>  public:
> -  MergedFile(std::vector<const Atom *> &a)
> -    : File("path"), _atoms(a) { }
> +  TestingInputFiles(std::vector<const File*>& f) : _files(f) { }
>
> -  virtual bool forEachAtom(File::AtomHandler &handler) const {
> -    handler.doFile(*this);
> -    // visit defined atoms
> -    for (std::vector<const Atom *>::iterator it = _atoms.begin();
> -         it != _atoms.end(); ++it) {
> -      const DefinedAtom* atom = (*it)->definedAtom();
> -      if ( atom )
> -          handler.doDefinedAtom(*atom);
> -    }
> -    // visit undefined atoms
> -    for (std::vector<const Atom *>::iterator it = _atoms.begin();
> -         it != _atoms.end(); ++it) {
> -      const UndefinedAtom* atom = (*it)->undefinedAtom();
> -      if ( atom )
> -          handler.doUndefinedAtom(*atom);
> -    }
> -    // visit shared library atoms
> -    for (std::vector<const Atom *>::iterator it = _atoms.begin();
> -         it != _atoms.end(); ++it) {
> -      const SharedLibraryAtom* atom = (*it)->sharedLibraryAtom();
> -      if ( atom )
> -          handler.doSharedLibraryAtom(*atom);
> -    }
> -    // visit absolute atoms
> -    for (std::vector<const Atom *>::iterator it = _atoms.begin();
> -         it != _atoms.end(); ++it) {
> -      const AbsoluteAtom* atom = (*it)->absoluteAtom();
> -      if ( atom )
> -          handler.doAbsoluteAtom(*atom);
> +  // InputFiles interface
> +  virtual void forEachInitialAtom(InputFiles::Handler& handler) const {
> +    for (std::vector<const File *>::iterator fit = _files.begin();
> +                                       fit != _files.end(); ++fit) {
> +      const File* file = *fit;
> +      handler.doFile(*file);
> +      for(auto it=file->definedAtomsBegin(),end=file->definedAtomsEnd();
> +                                 it != end; ++it) {
> +        handler.doDefinedAtom(**it);
> +      }
> +      for(auto it=file->undefinedAtomsBegin(), end=file->undefinedAtomsEnd();
> +                                 it != end; ++it) {
> +        handler.doUndefinedAtom(**it);
> +      }
> +      for(auto it=file->sharedLibraryAtomsBegin(), end=file->sharedLibraryAtomsEnd();
> +                                 it != end; ++it) {
> +        handler.doSharedLibraryAtom(**it);
> +      }
> +      for(auto it=file->absoluteAtomsBegin(),end=file->absoluteAtomsEnd();
> +                                 it != end; ++it) {
> +        handler.doAbsoluteAtom(**it);
> +      }
>     }
> -    return true;
>   }
>
> -  virtual bool justInTimeforEachAtom(llvm::StringRef name,
> -                                     File::AtomHandler &) const {
> +  virtual bool searchLibraries(llvm::StringRef name, bool searchDylibs,
> +                               bool searchArchives, bool dataSymbolOnly,
> +                               InputFiles::Handler &) const {
>     return false;
>   }
>
> +
>  private:
> -  std::vector<const Atom *> &_atoms;
> +  std::vector<const File*>&        _files;
>  };
> -} //anonymous namespace
> +}
> +
> +
> +
>
>
> -int main(int argc, const char *argv[]) {
> +
> +llvm::cl::opt<std::string>
> +gInputFilePath(llvm::cl::Positional,
> +              llvm::cl::desc("<input file>"),
> +              llvm::cl::init("-"));
> +
> +llvm::cl::opt<std::string>
> +gOutputFilePath("o",
> +              llvm::cl::desc("Specify output filename"),
> +              llvm::cl::value_desc("filename"));
> +
> +llvm::cl::opt<bool>
> +gDoStubsPass("stubs_pass",
> +          llvm::cl::desc("Run pass to create stub atoms"));
> +
> +
> +int main(int argc, char *argv[]) {
>   // Print a stack trace if we signal out.
>   llvm::sys::PrintStackTraceOnErrorSignal();
>   llvm::PrettyStackTraceProgram X(argc, argv);
>   llvm::llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
>
> +  // parse options
> +  llvm::cl::ParseCommandLineOptions(argc, argv);
> +
> +  // create platform for testing
> +  TestingPlatform testingPlatform;
> +
>   // read input YAML doc into object file(s)
> -  std::vector<File *> files;
> -  if (error(yaml::parseObjectTextFileOrSTDIN(llvm::StringRef(argv[1]), files)))
> +  std::vector<const File *> files;
> +  if (error(yaml::parseObjectTextFileOrSTDIN(gInputFilePath,
> +                                            testingPlatform, files))) {
>     return 1;
> -
> +  }
> +
> +  // create object to mange input files
> +  TestingInputFiles inputFiles(files);
> +
>   // merge all atom graphs
> -  LdCore core(files);
> -  Resolver resolver(core, core);
> -  std::vector<const Atom *> &mergedAtoms = resolver.resolve();
> -  MergedFile outFile(mergedAtoms);
> +  Resolver resolver(testingPlatform, inputFiles);
> +  resolver.resolve();
>
> +  // run passes
> +  if ( gDoStubsPass ) {
> +    StubsPass  addStubs(resolver.resultFile(), testingPlatform);
> +    addStubs.perform();
> +  }
> +
>   // write new atom graph out as YAML doc
>   std::string errorInfo;
> -  llvm::raw_fd_ostream out("-", errorInfo);
> -//  yaml::writeObjectText(outFile, out);
> +  const char* outPath = gOutputFilePath.empty() ? "-" : gOutputFilePath.c_str();
> +  llvm::raw_fd_ostream out(outPath, errorInfo);
> +//  yaml::writeObjectText(resolver.resultFile(), out);
>
>   // make unique temp .o file to put generated object file
>   int fd;
> @@ -254,7 +417,7 @@
>   llvm::raw_fd_ostream  binaryOut(fd, /*shouldClose=*/true);
>
>   // write native file
> -  writeNativeObjectFile(outFile, binaryOut);
> +  writeNativeObjectFile(resolver.resultFile(), binaryOut);
>   binaryOut.close();  // manually close so that file can be read next
>
>  //  out << "native file: " << tempPath.str() << "\n";
> @@ -265,7 +428,7 @@
>        return 1;
>
>   // write new atom graph out as YAML doc
> -  yaml::writeObjectText(*natFile, out);
> +  yaml::writeObjectText(*natFile, testingPlatform, out);
>
>   // delete temp .o file
>   bool existed;
>
>
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