//===- ObjectTransformLayer.h - Run all objects through functor -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Run all objects passed in through a user supplied functor.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_EXECUTIONENGINE_ORC_OBJECTTRANSFORMLAYER_H
#define LLVM_EXECUTIONENGINE_ORC_OBJECTTRANSFORMLAYER_H

#include "JITSymbol.h"

namespace llvm {
namespace orc {

/// @brief Object mutating layer.
///
///   This layer accepts sets of ObjectFiles (via addObjectSet). It
/// immediately applies the user supplied functor to each object, then adds
/// the set of transformed objects to the layer below.
template <typename BaseLayerT, typename TransformFtor>
class ObjectTransformLayer {
public:
  /// @brief Handle to a set of added objects.
  typedef typename BaseLayerT::ObjSetHandleT ObjSetHandleT;

  /// @brief Construct an ObjectTransformLayer with the given BaseLayer
  ObjectTransformLayer(BaseLayerT &BaseLayer,
                       TransformFtor Transform = TransformFtor())
      : BaseLayer(BaseLayer), Transform(std::move(Transform)) {}

  /// @brief Apply the transform functor to each object in the object set, then
  ///        add the resulting set of objects to the base layer, along with the
  ///        memory manager and symbol resolver.
  ///
  /// @return A handle for the added objects.
  template <typename ObjSetT, typename MemoryManagerPtrT,
            typename SymbolResolverPtrT>
  ObjSetHandleT addObjectSet(ObjSetT &Objects, MemoryManagerPtrT MemMgr,
                             SymbolResolverPtrT Resolver) {

    for (auto I = Objects.begin(), E = Objects.end(); I != E; ++I)
      *I = Transform(std::move(*I));

    return BaseLayer.addObjectSet(Objects, std::move(MemMgr),
                                  std::move(Resolver));
  }

  /// @brief Remove the object set associated with the handle H.
  void removeObjectSet(ObjSetHandleT H) { BaseLayer.removeObjectSet(H); }

  /// @brief Search for the given named symbol.
  /// @param Name The name of the symbol to search for.
  /// @param ExportedSymbolsOnly If true, search only for exported symbols.
  /// @return A handle for the given named symbol, if it exists.
  JITSymbol findSymbol(const std::string &Name, bool ExportedSymbolsOnly) {
    return BaseLayer.findSymbol(Name, ExportedSymbolsOnly);
  }

  /// @brief Get the address of the given symbol in the context of the set of
  ///        objects represented by the handle H. This call is forwarded to the
  ///        base layer's implementation.
  /// @param H The handle for the object set to search in.
  /// @param Name The name of the symbol to search for.
  /// @param ExportedSymbolsOnly If true, search only for exported symbols.
  /// @return A handle for the given named symbol, if it is found in the
  ///         given object set.
  JITSymbol findSymbolIn(ObjSetHandleT H, const std::string &Name,
                         bool ExportedSymbolsOnly) {
    return BaseLayer.findSymbolIn(H, Name, ExportedSymbolsOnly);
  }

  /// @brief Immediately emit and finalize the object set represented by the
  ///        given handle.
  /// @param H Handle for object set to emit/finalize.
  void emitAndFinalize(ObjSetHandleT H) { BaseLayer.emitAndFinalize(H); }

  /// @brief Map section addresses for the objects associated with the handle H.
  void mapSectionAddress(ObjSetHandleT H, const void *LocalAddress,
                         TargetAddress TargetAddr) {
    BaseLayer.mapSectionAddress(H, LocalAddress, TargetAddr);
  }

  // Ownership hack.
  // FIXME: Remove this as soon as RuntimeDyldELF can apply relocations without
  //        referencing the original object.
  template <typename OwningMBSet>
  void takeOwnershipOfBuffers(ObjSetHandleT H, OwningMBSet MBs) {
    BaseLayer.takeOwnershipOfBuffers(H, std::move(MBs));
  }

  /// @brief Access the transform functor directly.
  TransformFtor &getTransform() { return Transform; }

  /// @brief Access the mumate functor directly.
  const TransformFtor &getTransform() const { return Transform; }

private:
  BaseLayerT &BaseLayer;
  TransformFtor Transform;
};

} // End namespace orc.
} // End namespace llvm.

#endif // LLVM_EXECUTIONENGINE_ORC_OBJECTTRANSFORMLAYER_H