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diff --git a/include/lld/Core/Reader.h b/include/lld/Core/Reader.h
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+//===- lld/Core/Reader.h - Abstract File Format Reading Interface ---------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_CORE_READER_H
+#define LLD_CORE_READER_H
+
+#include "lld/Core/LLVM.h"
+#include "lld/Core/Reference.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/YAMLTraits.h"
+#include <functional>
+#include <memory>
+#include <vector>
+
+using llvm::sys::fs::file_magic;
+
+namespace llvm {
+namespace yaml {
+class IO;
+}
+}
+
+namespace lld {
+class ELFLinkingContext;
+class File;
+class LinkingContext;
+class PECOFFLinkingContext;
+class TargetHandlerBase;
+class MachOLinkingContext;
+
+/// \brief An abstract class for reading object files, library files, and
+/// executable files.
+///
+/// Each file format (e.g. ELF, mach-o, PECOFF, native, etc) have a concrete
+/// subclass of Reader.
+class Reader {
+public:
+  virtual ~Reader() {}
+
+  /// Sniffs the file to determine if this Reader can parse it.
+  /// The method is called with:
+  /// 1) the file_magic enumeration returned by identify_magic()
+  /// 2) the file extension (e.g. ".obj")
+  /// 3) the whole file content buffer if the above is not enough.
+  virtual bool canParse(file_magic magic, StringRef fileExtension,
+                        const MemoryBuffer &mb) const = 0;
+
+  /// \brief Parse a supplied buffer (already filled with the contents of a
+  /// file) and create a File object.
+  /// The resulting File object takes ownership of the MemoryBuffer.
+  virtual std::error_code
+  loadFile(std::unique_ptr<MemoryBuffer> mb, const class Registry &,
+           std::vector<std::unique_ptr<File>> &result) const = 0;
+};
+
+
+/// \brief An abstract class for handling alternate yaml representations
+/// of object files.
+///
+/// The YAML syntax allows "tags" which are used to specify the type of
+/// the YAML node.  In lld, top level YAML documents can be in many YAML
+/// representations (e.g mach-o encoded as yaml, etc).  A tag is used to
+/// specify which representation is used in the following YAML document.
+/// To work, there must be a YamlIOTaggedDocumentHandler registered that
+/// handles each tag type.
+class YamlIOTaggedDocumentHandler {
+public:
+  virtual ~YamlIOTaggedDocumentHandler();
+
+  /// This method is called on each registered YamlIOTaggedDocumentHandler
+  /// until one returns true.  If the subclass handles tag type !xyz, then
+  /// this method should call io.mapTag("!xzy") to see if that is the current
+  /// document type, and if so, process the rest of the document using
+  /// YAML I/O, then convert the result into an lld::File* and return it.
+  virtual bool handledDocTag(llvm::yaml::IO &io, const lld::File *&f) const = 0;
+};
+
+
+/// A registry to hold the list of currently registered Readers and
+/// tables which map Reference kind values to strings.
+/// The linker does not directly invoke Readers.  Instead, it registers
+/// Readers based on it configuration and command line options, then calls
+/// the Registry object to parse files.
+class Registry {
+public:
+  Registry();
+
+  /// Walk the list of registered Readers and find one that can parse the
+  /// supplied file and parse it.
+  std::error_code loadFile(std::unique_ptr<MemoryBuffer> mb,
+                           std::vector<std::unique_ptr<File>> &result) const;
+
+  /// Walk the list of registered kind tables to convert a Reference Kind
+  /// name to a value.
+  bool referenceKindFromString(StringRef inputStr, Reference::KindNamespace &ns,
+                               Reference::KindArch &a,
+                               Reference::KindValue &value) const;
+
+  /// Walk the list of registered kind tables to convert a Reference Kind
+  /// value to a string.
+  bool referenceKindToString(Reference::KindNamespace ns, Reference::KindArch a,
+                             Reference::KindValue value, StringRef &) const;
+
+  /// Walk the list of registered tag handlers and have the one that handles
+  /// the current document type process the yaml into an lld::File*.
+  bool handleTaggedDoc(llvm::yaml::IO &io, const lld::File *&file) const;
+
+  // These methods are called to dynamically add support for various file
+  // formats. The methods are also implemented in the appropriate lib*.a
+  // library, so that the code for handling a format is only linked in, if this
+  // method is used.  Any options that a Reader might need must be passed
+  // as parameters to the addSupport*() method.
+  void addSupportArchives(bool logLoading);
+  void addSupportYamlFiles();
+  void addSupportNativeObjects();
+  void addSupportCOFFObjects(PECOFFLinkingContext &);
+  void addSupportCOFFImportLibraries(PECOFFLinkingContext &);
+  void addSupportMachOObjects(MachOLinkingContext &);
+  void addSupportELFObjects(ELFLinkingContext &);
+  void addSupportELFDynamicSharedObjects(ELFLinkingContext &);
+
+  /// To convert between kind values and names, the registry walks the list
+  /// of registered kind tables. Each table is a zero terminated array of
+  /// KindStrings elements.
+  struct KindStrings {
+    Reference::KindValue  value;
+    StringRef             name;
+  };
+
+  /// A Reference Kind value is a tuple of <namespace, arch, value>.  All
+  /// entries in a conversion table have the same <namespace, arch>.  The
+  /// array then contains the value/name pairs.
+  void addKindTable(Reference::KindNamespace ns, Reference::KindArch arch,
+                    const KindStrings array[]);
+
+
+private:
+  struct KindEntry {
+    Reference::KindNamespace  ns;
+    Reference::KindArch       arch;
+    const KindStrings        *array;
+  };
+
+  void add(std::unique_ptr<Reader>);
+  void add(std::unique_ptr<YamlIOTaggedDocumentHandler>);
+
+  std::vector<std::unique_ptr<Reader>>                       _readers;
+  std::vector<std::unique_ptr<YamlIOTaggedDocumentHandler>>  _yamlHandlers;
+  std::vector<KindEntry>                                     _kindEntries;
+};
+
+// Utilities for building a KindString table.  For instance:
+//   static const Registry::KindStrings table[] = {
+//      LLD_KIND_STRING_ENTRY(R_VAX_ADDR16),
+//      LLD_KIND_STRING_ENTRY(R_VAX_DATA16),
+//      LLD_KIND_STRING_END
+//   };
+#define LLD_KIND_STRING_ENTRY(name) { name, #name }
+#define LLD_KIND_STRING_END         { 0,    "" }
+
+} // end namespace lld
+
+#endif