5 files changed, 235 insertions, 0 deletions
diff --git a/include/clang/Index/Entity.h b/include/clang/Index/Entity.h
new file mode 100644
index 0000000000..8caaeb870f
--- /dev/null
+++ b/include/clang/Index/Entity.h
@@ -0,0 +1,70 @@
+//===--- Entity.h - Cross-translation-unit "token" for decls ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Entity is a ASTContext-independent way to refer to declarations that are
+//  visible across translation units.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INDEX_ENTITY_H
+#define LLVM_CLANG_INDEX_ENTITY_H
+
+#include "llvm/ADT/FoldingSet.h"
+
+namespace clang {
+  class ASTContext;
+  class Decl;
+
+namespace idx {
+  class Program;
+
+/// \brief A ASTContext-independent way to refer to declarations that are
+/// visible across translation units.
+///
+/// Entity is basically the link for declarations that are semantically the same
+/// in multiple ASTContexts. A client will convert a Decl into an Entity and
+/// later use that Entity to find the "same" Decl into another ASTContext.
+///
+/// An Entity may only refer to declarations that can be visible by multiple
+/// translation units, e.g. a static function cannot have an Entity associated
+/// with it.
+///
+/// Entities are uniqued so pointer equality can be used (note that the same
+/// Program object should be used when getting Entities).
+///
+class Entity : public llvm::FoldingSetNode {
+public:
+  /// \brief Find the Decl that can be referred to by this entity.
+  Decl *getDecl(ASTContext &AST);
+
+  /// \brief Get an Entity associated with the given Decl.
+  /// \returns Null if an Entity cannot refer to this Decl.
+  static Entity *get(Decl *D, Program &Prog);
+
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    Profile(ID, Parent, Id);
+  }
+  static void Profile(llvm::FoldingSetNodeID &ID, Entity *Parent, void *Id) {
+    ID.AddPointer(Parent);
+    ID.AddPointer(Id);
+  }
+  
+private:
+  Entity *Parent;
+  void *Id;
+  
+  Entity(Entity *parent, void *id) : Parent(parent), Id(id) { }
+  friend class EntityGetter;
+};
+  
+} // namespace idx
+
+} // namespace clang
+
+#endif
diff --git a/include/clang/Index/EntityHandler.h b/include/clang/Index/EntityHandler.h
new file mode 100644
index 0000000000..b5c2cee881
--- /dev/null
+++ b/include/clang/Index/EntityHandler.h
@@ -0,0 +1,33 @@
+//===--- EntityHandler.h - Interface for receiving entities -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Abstract interface for receiving Entities.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INDEX_ENTITYHANDLER_H
+#define LLVM_CLANG_INDEX_ENTITYHANDLER_H
+
+namespace clang {
+
+namespace idx {
+  class Entity;
+
+/// \brief Abstract interface for receiving Entities.
+class EntityHandler {
+public:
+  virtual ~EntityHandler();
+  virtual void HandleEntity(Entity *Ent) { }
+};
+  
+} // namespace idx
+
+} // namespace clang
+
+#endif
diff --git a/include/clang/Index/IndexProvider.h b/include/clang/Index/IndexProvider.h
new file mode 100644
index 0000000000..abd436cc82
--- /dev/null
+++ b/include/clang/Index/IndexProvider.h
@@ -0,0 +1,56 @@
+//===--- IndexProvider.h - Map of entities to translation units -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSaE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Maps Entities to TranslationUnits
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INDEX_INDEXPROVIDER_H
+#define LLVM_CLANG_INDEX_INDEXPROVIDER_H
+
+#include "llvm/ADT/SmallPtrSet.h"
+#include <map>
+
+namespace clang {
+
+namespace idx {
+  class Program;
+  class Entity;
+  class TranslationUnit;
+
+/// \brief Maps Entities to TranslationUnits.
+class IndexProvider {
+  typedef llvm::SmallPtrSet<TranslationUnit *, 4> TUSetTy;
+  typedef std::map<Entity *, TUSetTy> MapTy;
+  class Indexer;
+
+public:
+  explicit IndexProvider(Program &prog) : Prog(prog) { }
+
+  Program &getProgram() const { return Prog; }
+
+  /// \brief Find all Entities and map them to the given translation unit.
+  void IndexAST(TranslationUnit *TU);
+
+  typedef TUSetTy::iterator translation_unit_iterator;
+
+  translation_unit_iterator translation_units_begin(Entity *Ent) const;
+  translation_unit_iterator translation_units_end(Entity *Ent) const;
+  bool translation_units_empty(Entity *Ent) const;
+  
+private:
+  Program &Prog;
+  mutable MapTy Map;
+};
+
+} // namespace idx
+
+} // namespace clang
+
+#endif
diff --git a/include/clang/Index/Program.h b/include/clang/Index/Program.h
new file mode 100644
index 0000000000..30afa0be46
--- /dev/null
+++ b/include/clang/Index/Program.h
@@ -0,0 +1,43 @@
+//===--- Program.h - Entity originator and misc -----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Storage for Entities and utility functions
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INDEX_PROGRAM_H
+#define LLVM_CLANG_INDEX_PROGRAM_H
+
+namespace clang {
+  class ASTContext;
+
+namespace idx {
+  class EntityHandler;
+
+/// \brief Repository for Entities.
+class Program {
+  void *Impl;
+
+  Program(const Program&); // do not implement
+  Program &operator=(const Program &); // do not implement
+  friend class Entity;
+  
+public:
+  Program();
+  ~Program();
+
+  /// \brief Traverses the AST and passes all the entities to the Handler.
+  void FindEntities(ASTContext &Ctx, EntityHandler *Handler);
+};
+
+} // namespace idx
+
+} // namespace clang
+
+#endif
diff --git a/include/clang/Index/TranslationUnit.h b/include/clang/Index/TranslationUnit.h
new file mode 100644
index 0000000000..d0171422de
--- /dev/null
+++ b/include/clang/Index/TranslationUnit.h
@@ -0,0 +1,33 @@
+//===--- TranslationUnit.h - Interface for a translation unit ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSaE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Abstract interface for a translation unit
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INDEX_TRANSLATIONUNIT_H
+#define LLVM_CLANG_INDEX_TRANSLATIONUNIT_H
+
+namespace clang {
+  class ASTContext;
+
+namespace idx {
+
+/// \brief Abstract interface for a translation unit.
+class TranslationUnit {
+public:
+  virtual ~TranslationUnit();
+  virtual ASTContext &getASTContext() = 0;
+};
+
+} // namespace idx
+
+} // namespace clang
+
+#endif