Merge "Update aosp/master LLVM for rebase to r230699."

1 files changed, 267 insertions, 0 deletions

diff --git a/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h b/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
new file mode 100644
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+++ b/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
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+//===- ObjectLinkingLayer.h - Add object files to a JIT process -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Contains the definition for the object layer of the JIT.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H
+#define LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H
+
+#include "JITSymbol.h"
+#include "LookasideRTDyldMM.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
+#include <list>
+#include <memory>
+
+namespace llvm {
+namespace orc {
+
+class ObjectLinkingLayerBase {
+protected:
+
+  /// @brief Holds a set of objects to be allocated/linked as a unit in the JIT.
+  ///
+  /// An instance of this class will be created for each set of objects added
+  /// via JITObjectLayer::addObjectSet. Deleting the instance (via
+  /// removeObjectSet) frees its memory, removing all symbol definitions that
+  /// had been provided by this instance. Higher level layers are responsible
+  /// for taking any action required to handle the missing symbols.
+  class LinkedObjectSet {
+    LinkedObjectSet(const LinkedObjectSet&) = delete;
+    void operator=(const LinkedObjectSet&) = delete;
+  public:
+    LinkedObjectSet(std::unique_ptr<RTDyldMemoryManager> MM)
+        : MM(std::move(MM)), RTDyld(llvm::make_unique<RuntimeDyld>(&*this->MM)),
+          State(Raw) {}
+
+    // MSVC 2012 cannot infer a move constructor, so write it out longhand.
+    LinkedObjectSet(LinkedObjectSet &&O)
+        : MM(std::move(O.MM)), RTDyld(std::move(O.RTDyld)), State(O.State) {}
+
+    std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
+    addObject(const object::ObjectFile &Obj) {
+      return RTDyld->loadObject(Obj);
+    }
+
+    TargetAddress getSymbolAddress(StringRef Name, bool ExportedSymbolsOnly) {
+      if (ExportedSymbolsOnly)
+        return RTDyld->getExportedSymbolLoadAddress(Name);
+      return RTDyld->getSymbolLoadAddress(Name);
+    }
+
+    bool NeedsFinalization() const { return (State == Raw); }
+
+    void Finalize() {
+      State = Finalizing;
+      RTDyld->resolveRelocations();
+      RTDyld->registerEHFrames();
+      MM->finalizeMemory();
+      OwnedBuffers.clear();
+      State = Finalized;
+    }
+
+    void mapSectionAddress(const void *LocalAddress, TargetAddress TargetAddr) {
+      assert((State != Finalized) &&
+             "Attempting to remap sections for finalized objects.");
+      RTDyld->mapSectionAddress(LocalAddress, TargetAddr);
+    }
+
+    void takeOwnershipOfBuffer(std::unique_ptr<MemoryBuffer> B) {
+      OwnedBuffers.push_back(std::move(B));
+    }
+
+  private:
+    std::unique_ptr<RTDyldMemoryManager> MM;
+    std::unique_ptr<RuntimeDyld> RTDyld;
+    enum { Raw, Finalizing, Finalized } State;
+
+    // FIXME: This ownership hack only exists because RuntimeDyldELF still
+    //        wants to be able to inspect the original object when resolving
+    //        relocations. As soon as that can be fixed this should be removed.
+    std::vector<std::unique_ptr<MemoryBuffer>> OwnedBuffers;
+  };
+
+  typedef std::list<LinkedObjectSet> LinkedObjectSetListT;
+
+public:
+  /// @brief Handle to a set of loaded objects.
+  typedef LinkedObjectSetListT::iterator ObjSetHandleT;
+
+  // 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) {
+    for (auto &MB : MBs)
+      H->takeOwnershipOfBuffer(std::move(MB));
+  }
+
+};
+
+/// @brief Default (no-op) action to perform when loading objects.
+class DoNothingOnNotifyLoaded {
+public:
+  template <typename ObjSetT, typename LoadResult>
+  void operator()(ObjectLinkingLayerBase::ObjSetHandleT, const ObjSetT &,
+                  const LoadResult &) {}
+};
+
+/// @brief Bare bones object linking layer.
+///
+///   This class is intended to be used as the base layer for a JIT. It allows
+/// object files to be loaded into memory, linked, and the addresses of their
+/// symbols queried. All objects added to this layer can see each other's
+/// symbols.
+template <typename NotifyLoadedFtor = DoNothingOnNotifyLoaded>
+class ObjectLinkingLayer : public ObjectLinkingLayerBase {
+public:
+
+  /// @brief LoadedObjectInfo list. Contains a list of owning pointers to
+  ///        RuntimeDyld::LoadedObjectInfo instances.
+  typedef std::vector<std::unique_ptr<RuntimeDyld::LoadedObjectInfo>>
+      LoadedObjInfoList;
+
+  /// @brief Functor to create RTDyldMemoryManager instances.
+  typedef std::function<std::unique_ptr<RTDyldMemoryManager>()> CreateRTDyldMMFtor;
+
+  /// @brief Functor for receiving finalization notifications.
+  typedef std::function<void(ObjSetHandleT)> NotifyFinalizedFtor;
+
+  /// @brief Construct an ObjectLinkingLayer with the given NotifyLoaded,
+  ///        NotifyFinalized and CreateMemoryManager functors.
+  ObjectLinkingLayer(
+      CreateRTDyldMMFtor CreateMemoryManager = CreateRTDyldMMFtor(),
+      NotifyLoadedFtor NotifyLoaded = NotifyLoadedFtor(),
+      NotifyFinalizedFtor NotifyFinalized = NotifyFinalizedFtor())
+      : NotifyLoaded(std::move(NotifyLoaded)),
+        NotifyFinalized(std::move(NotifyFinalized)),
+        CreateMemoryManager(std::move(CreateMemoryManager)) {}
+
+  /// @brief Add a set of objects (or archives) that will be treated as a unit
+  ///        for the purposes of symbol lookup and memory management.
+  ///
+  /// @return A pair containing (1) A handle that can be used to free the memory
+  ///         allocated for the objects, and (2) a LoadedObjInfoList containing
+  ///         one LoadedObjInfo instance for each object at the corresponding
+  ///         index in the Objects list.
+  ///
+  ///   This version of this method allows the client to pass in an
+  /// RTDyldMemoryManager instance that will be used to allocate memory and look
+  /// up external symbol addresses for the given objects.
+  template <typename ObjSetT>
+  ObjSetHandleT addObjectSet(const ObjSetT &Objects,
+                             std::unique_ptr<RTDyldMemoryManager> MM) {
+
+    if (!MM) {
+      assert(CreateMemoryManager &&
+             "No memory manager or memory manager creator provided.");
+      MM = CreateMemoryManager();
+    }
+
+    ObjSetHandleT Handle = LinkedObjSetList.insert(
+        LinkedObjSetList.end(), LinkedObjectSet(std::move(MM)));
+    LinkedObjectSet &LOS = *Handle;
+    LoadedObjInfoList LoadedObjInfos;
+
+    for (auto &Obj : Objects)
+      LoadedObjInfos.push_back(LOS.addObject(*Obj));
+
+    NotifyLoaded(Handle, Objects, LoadedObjInfos);
+
+    return Handle;
+  }
+
+  /// @brief Remove the set of objects associated with handle H.
+  ///
+  ///   All memory allocated for the objects will be freed, and the sections and
+  /// symbols they provided will no longer be available. No attempt is made to
+  /// re-emit the missing symbols, and any use of these symbols (directly or
+  /// indirectly) will result in undefined behavior. If dependence tracking is
+  /// required to detect or resolve such issues it should be added at a higher
+  /// layer.
+  void removeObjectSet(ObjSetHandleT H) {
+    // How do we invalidate the symbols in H?
+    LinkedObjSetList.erase(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(StringRef Name, bool ExportedSymbolsOnly) {
+    for (auto I = LinkedObjSetList.begin(), E = LinkedObjSetList.end(); I != E;
+         ++I)
+      if (auto Symbol = findSymbolIn(I, Name, ExportedSymbolsOnly))
+        return Symbol;
+
+    return nullptr;
+  }
+
+  /// @brief Search for the given named symbol in the context of the set of
+  ///        loaded objects represented by the handle H.
+  /// @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, StringRef Name,
+                         bool ExportedSymbolsOnly) {
+    if (auto Addr = H->getSymbolAddress(Name, ExportedSymbolsOnly)) {
+      if (!H->NeedsFinalization()) {
+        // If this instance has already been finalized then we can just return
+        // the address.
+        return JITSymbol(Addr);
+      } else {
+        // If this instance needs finalization return a functor that will do it.
+        // The functor still needs to double-check whether finalization is
+        // required, in case someone else finalizes this set before the functor
+        // is called.
+        return JITSymbol(
+          [this, Addr, H]() {
+            if (H->NeedsFinalization()) {
+              H->Finalize();
+              if (NotifyFinalized)
+                NotifyFinalized(H);
+            }
+            return Addr;
+          });
+      }
+    }
+
+    return nullptr;
+  }
+
+  /// @brief Map section addresses for the objects associated with the handle H.
+  void mapSectionAddress(ObjSetHandleT H, const void *LocalAddress,
+                         TargetAddress TargetAddr) {
+    H->mapSectionAddress(LocalAddress, TargetAddr);
+  }
+
+  /// @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) {
+    H->Finalize();
+    if (NotifyFinalized)
+      NotifyFinalized(H);
+  }
+
+private:
+  LinkedObjectSetListT LinkedObjSetList;
+  NotifyLoadedFtor NotifyLoaded;
+  NotifyFinalizedFtor NotifyFinalized;
+  CreateRTDyldMMFtor CreateMemoryManager;
+};
+
+} // End namespace orc.
+} // End namespace llvm
+
+#endif // LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H