10 files changed, 1641 insertions, 0 deletions

diff --git a/include/llvm/ExecutionEngine/Orc/CloneSubModule.h b/include/llvm/ExecutionEngine/Orc/CloneSubModule.h
new file mode 100644
index 0000000..1bd3955
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/CloneSubModule.h
@@ -0,0 +1,60 @@
+//===-- CloneSubModule.h - Utilities for extracting sub-modules -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Contains utilities for extracting sub-modules. Useful for breaking up modules
+// for lazy jitting.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_CLONESUBMODULE_H
+#define LLVM_EXECUTIONENGINE_ORC_CLONESUBMODULE_H
+
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
+#include <functional>
+
+namespace llvm {
+
+class Function;
+class GlobalVariable;
+class Module;
+
+namespace orc {
+
+/// @brief Functor type for describing how CloneSubModule should mutate a
+///        GlobalVariable.
+typedef std::function<void(GlobalVariable &, const GlobalVariable &,
+                           ValueToValueMapTy &)> HandleGlobalVariableFtor;
+
+/// @brief Functor type for describing how CloneSubModule should mutate a
+///        Function.
+typedef std::function<void(Function &, const Function &, ValueToValueMapTy &)>
+    HandleFunctionFtor;
+
+/// @brief Copies the initializer from Orig to New.
+///
+///   Type is suitable for implicit conversion to a HandleGlobalVariableFtor.
+void copyGVInitializer(GlobalVariable &New, const GlobalVariable &Orig,
+                       ValueToValueMapTy &VMap);
+
+/// @brief Copies the body of Orig to New.
+///
+///   Type is suitable for implicit conversion to a HandleFunctionFtor.
+void copyFunctionBody(Function &New, const Function &Orig,
+                      ValueToValueMapTy &VMap);
+
+/// @brief Clone a subset of the module Src into Dst.
+void CloneSubModule(Module &Dst, const Module &Src,
+                    HandleGlobalVariableFtor HandleGlobalVariable,
+                    HandleFunctionFtor HandleFunction, bool KeepInlineAsm);
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_CLONESUBMODULE_H
diff --git a/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h b/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h
new file mode 100644
index 0000000..0e218e2
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h
@@ -0,0 +1,355 @@
+//===- CompileOnDemandLayer.h - Compile each function on demand -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// JIT layer for breaking up modules and inserting callbacks to allow
+// individual functions to be compiled on demand.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_COMPILEONDEMANDLAYER_H
+#define LLVM_EXECUTIONENGINE_ORC_COMPILEONDEMANDLAYER_H
+
+#include "IndirectionUtils.h"
+#include "LookasideRTDyldMM.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
+#include <list>
+
+namespace llvm {
+namespace orc {
+
+/// @brief Compile-on-demand layer.
+///
+///   Modules added to this layer have their calls indirected, and are then
+/// broken up into a set of single-function modules, each of which is added
+/// to the layer below in a singleton set. The lower layer can be any layer that
+/// accepts IR module sets.
+///
+/// It is expected that this layer will frequently be used on top of a
+/// LazyEmittingLayer. The combination of the two ensures that each function is
+/// compiled only when it is first called.
+template <typename BaseLayerT, typename CompileCallbackMgrT>
+class CompileOnDemandLayer {
+public:
+  /// @brief Lookup helper that provides compatibility with the classic
+  ///        static-compilation symbol resolution process.
+  ///
+  ///   The CompileOnDemand (COD) layer splits modules up into multiple
+  /// sub-modules, each held in its own llvm::Module instance, in order to
+  /// support lazy compilation. When a module that contains private symbols is
+  /// broken up symbol linkage changes may be required to enable access to
+  /// "private" data that now resides in a different llvm::Module instance. To
+  /// retain expected symbol resolution behavior for clients of the COD layer,
+  /// the CODScopedLookup class uses a two-tiered lookup system to resolve
+  /// symbols. Lookup first scans sibling modules that were split from the same
+  /// original module (logical-module scoped lookup), then scans all other
+  /// modules that have been added to the lookup scope (logical-dylib scoped
+  /// lookup).
+  class CODScopedLookup {
+  private:
+    typedef typename BaseLayerT::ModuleSetHandleT BaseLayerModuleSetHandleT;
+    typedef std::vector<BaseLayerModuleSetHandleT> SiblingHandlesList;
+    typedef std::list<SiblingHandlesList> PseudoDylibModuleSetHandlesList;
+
+  public:
+    /// @brief Handle for a logical module.
+    typedef typename PseudoDylibModuleSetHandlesList::iterator LMHandle;
+
+    /// @brief Construct a scoped lookup.
+    CODScopedLookup(BaseLayerT &BaseLayer) : BaseLayer(BaseLayer) {}
+
+    /// @brief Start a new context for a single logical module.
+    LMHandle createLogicalModule() {
+      Handles.push_back(SiblingHandlesList());
+      return std::prev(Handles.end());
+    }
+
+    /// @brief Add a concrete Module's handle to the given logical Module's
+    ///        lookup scope.
+    void addToLogicalModule(LMHandle LMH, BaseLayerModuleSetHandleT H) {
+      LMH->push_back(H);
+    }
+
+    /// @brief Remove a logical Module from the CODScopedLookup entirely.
+    void removeLogicalModule(LMHandle LMH) { Handles.erase(LMH); }
+
+    /// @brief Look up a symbol in this context.
+    JITSymbol findSymbol(LMHandle LMH, const std::string &Name) {
+      if (auto Symbol = findSymbolIn(LMH, Name))
+        return Symbol;
+
+      for (auto I = Handles.begin(), E = Handles.end(); I != E; ++I)
+        if (I != LMH)
+          if (auto Symbol = findSymbolIn(I, Name))
+            return Symbol;
+
+      return nullptr;
+    }
+
+  private:
+
+    JITSymbol findSymbolIn(LMHandle LMH, const std::string &Name) {
+      for (auto H : *LMH)
+        if (auto Symbol = BaseLayer.findSymbolIn(H, Name, false))
+          return Symbol;
+      return nullptr;
+    }
+
+    BaseLayerT &BaseLayer;
+    PseudoDylibModuleSetHandlesList Handles;
+  };
+
+private:
+  typedef typename BaseLayerT::ModuleSetHandleT BaseLayerModuleSetHandleT;
+  typedef std::vector<BaseLayerModuleSetHandleT> BaseLayerModuleSetHandleListT;
+
+  struct ModuleSetInfo {
+    // Symbol lookup - just one for the whole module set.
+    std::shared_ptr<CODScopedLookup> Lookup;
+
+    // Logical module handles.
+    std::vector<typename CODScopedLookup::LMHandle> LMHandles;
+
+    // List of vectors of module set handles:
+    // One vector per logical module - each vector holds the handles for the
+    // exploded modules for that logical module in the base layer.
+    BaseLayerModuleSetHandleListT BaseLayerModuleSetHandles;
+
+    ModuleSetInfo(std::shared_ptr<CODScopedLookup> Lookup)
+        : Lookup(std::move(Lookup)) {}
+
+    void releaseResources(BaseLayerT &BaseLayer) {
+      for (auto LMH : LMHandles)
+        Lookup->removeLogicalModule(LMH);
+      for (auto H : BaseLayerModuleSetHandles)
+        BaseLayer.removeModuleSet(H);
+    }
+  };
+
+  typedef std::list<ModuleSetInfo> ModuleSetInfoListT;
+
+public:
+  /// @brief Handle to a set of loaded modules.
+  typedef typename ModuleSetInfoListT::iterator ModuleSetHandleT;
+
+  // @brief Fallback lookup functor.
+  typedef std::function<uint64_t(const std::string &)> LookupFtor;
+
+  /// @brief Construct a compile-on-demand layer instance.
+  CompileOnDemandLayer(BaseLayerT &BaseLayer, LLVMContext &Context)
+    : BaseLayer(BaseLayer),
+      CompileCallbackMgr(BaseLayer, Context, 0, 64) {}
+
+  /// @brief Add a module to the compile-on-demand layer.
+  template <typename ModuleSetT>
+  ModuleSetHandleT addModuleSet(ModuleSetT Ms,
+                                LookupFtor FallbackLookup = nullptr) {
+
+    // If the user didn't supply a fallback lookup then just use
+    // getSymbolAddress.
+    if (!FallbackLookup)
+      FallbackLookup = [=](const std::string &Name) {
+                         return findSymbol(Name, true).getAddress();
+                       };
+
+    // Create a lookup context and ModuleSetInfo for this module set.
+    // For the purposes of symbol resolution the set Ms will be treated as if
+    // the modules it contained had been linked together as a dylib.
+    auto DylibLookup = std::make_shared<CODScopedLookup>(BaseLayer);
+    ModuleSetHandleT H =
+        ModuleSetInfos.insert(ModuleSetInfos.end(), ModuleSetInfo(DylibLookup));
+    ModuleSetInfo &MSI = ModuleSetInfos.back();
+
+    // Process each of the modules in this module set.
+    for (auto &M : Ms)
+      partitionAndAdd(*M, MSI, FallbackLookup);
+
+    return H;
+  }
+
+  /// @brief Remove the module represented by the given handle.
+  ///
+  ///   This will remove all modules in the layers below that were derived from
+  /// the module represented by H.
+  void removeModuleSet(ModuleSetHandleT H) {
+    H->releaseResources(BaseLayer);
+    ModuleSetInfos.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) {
+    return BaseLayer.findSymbol(Name, ExportedSymbolsOnly);
+  }
+
+  /// @brief Get the address of a symbol provided by this layer, or some layer
+  ///        below this one.
+  JITSymbol findSymbolIn(ModuleSetHandleT H, const std::string &Name,
+                         bool ExportedSymbolsOnly) {
+    BaseLayerModuleSetHandleListT &BaseLayerHandles = H->second;
+    for (auto &BH : BaseLayerHandles) {
+      if (auto Symbol = BaseLayer.findSymbolIn(BH, Name, ExportedSymbolsOnly))
+        return Symbol;
+    }
+    return nullptr;
+  }
+
+private:
+
+  void partitionAndAdd(Module &M, ModuleSetInfo &MSI,
+                       LookupFtor FallbackLookup) {
+    const char *AddrSuffix = "$orc_addr";
+    const char *BodySuffix = "$orc_body";
+
+    // We're going to break M up into a bunch of sub-modules, but we want
+    // internal linkage symbols to still resolve sensibly. CODScopedLookup
+    // provides the "logical module" concept to make this work, so create a
+    // new logical module for M.
+    auto DylibLookup = MSI.Lookup;
+    auto LogicalModule = DylibLookup->createLogicalModule();
+    MSI.LMHandles.push_back(LogicalModule);
+
+    // Partition M into a "globals and stubs" module, a "common symbols" module,
+    // and a list of single-function modules.
+    auto PartitionedModule = fullyPartition(M);
+    auto StubsModule = std::move(PartitionedModule.GlobalVars);
+    auto CommonsModule = std::move(PartitionedModule.Commons);
+    auto FunctionModules = std::move(PartitionedModule.Functions);
+
+    // Emit the commons stright away.
+    auto CommonHandle = addModule(std::move(CommonsModule), MSI, LogicalModule,
+                                  FallbackLookup);
+    BaseLayer.emitAndFinalize(CommonHandle);
+
+    // Map of definition names to callback-info data structures. We'll use
+    // this to build the compile actions for the stubs below.
+    typedef std::map<std::string,
+                     typename CompileCallbackMgrT::CompileCallbackInfo>
+      StubInfoMap;
+    StubInfoMap StubInfos;
+
+    // Now we need to take each of the extracted Modules and add them to
+    // base layer. Each Module will be added individually to make sure they
+    // can be compiled separately, and each will get its own lookaside
+    // memory manager that will resolve within this logical module first.
+    for (auto &SubM : FunctionModules) {
+
+      // Keep track of the stubs we create for this module so that we can set
+      // their compile actions.
+      std::vector<typename StubInfoMap::iterator> NewStubInfos;
+
+      // Search for function definitions and insert stubs into the stubs
+      // module.
+      for (auto &F : *SubM) {
+        if (F.isDeclaration())
+          continue;
+
+        std::string Name = F.getName();
+        Function *Proto = StubsModule->getFunction(Name);
+        assert(Proto && "Failed to clone function decl into stubs module.");
+        auto CallbackInfo =
+          CompileCallbackMgr.getCompileCallback(*Proto->getFunctionType());
+        GlobalVariable *FunctionBodyPointer =
+          createImplPointer(*Proto, Name + AddrSuffix,
+                            CallbackInfo.getAddress());
+        makeStub(*Proto, *FunctionBodyPointer);
+
+        F.setName(Name + BodySuffix);
+        F.setVisibility(GlobalValue::HiddenVisibility);
+
+        auto KV = std::make_pair(std::move(Name), std::move(CallbackInfo));
+        NewStubInfos.push_back(StubInfos.insert(StubInfos.begin(), KV));
+      }
+
+      auto H = addModule(std::move(SubM), MSI, LogicalModule, FallbackLookup);
+
+      // Set the compile actions for this module:
+      for (auto &KVPair : NewStubInfos) {
+        std::string BodyName = Mangle(KVPair->first + BodySuffix,
+                                      *M.getDataLayout());
+        auto &CCInfo = KVPair->second;
+        CCInfo.setCompileAction(
+          [=](){
+            return BaseLayer.findSymbolIn(H, BodyName, false).getAddress();
+          });
+      }
+
+    }
+
+    // Ok - we've processed all the partitioned modules. Now add the
+    // stubs/globals module and set the update actions.
+    auto StubsH =
+      addModule(std::move(StubsModule), MSI, LogicalModule, FallbackLookup);
+
+    for (auto &KVPair : StubInfos) {
+      std::string AddrName = Mangle(KVPair.first + AddrSuffix,
+                                    *M.getDataLayout());
+      auto &CCInfo = KVPair.second;
+      CCInfo.setUpdateAction(
+        CompileCallbackMgr.getLocalFPUpdater(StubsH, AddrName));
+    }
+  }
+
+  // Add the given Module to the base layer using a memory manager that will
+  // perform the appropriate scoped lookup (i.e. will look first with in the
+  // module from which it was extracted, then into the set to which that module
+  // belonged, and finally externally).
+  BaseLayerModuleSetHandleT addModule(
+                               std::unique_ptr<Module> M,
+                               ModuleSetInfo &MSI,
+                               typename CODScopedLookup::LMHandle LogicalModule,
+                               LookupFtor FallbackLookup) {
+
+    // Add this module to the JIT with a memory manager that uses the
+    // DylibLookup to resolve symbols.
+    std::vector<std::unique_ptr<Module>> MSet;
+    MSet.push_back(std::move(M));
+
+    auto DylibLookup = MSI.Lookup;
+    auto MM =
+      createLookasideRTDyldMM<SectionMemoryManager>(
+        [=](const std::string &Name) {
+          if (auto Symbol = DylibLookup->findSymbol(LogicalModule, Name))
+            return Symbol.getAddress();
+          return FallbackLookup(Name);
+        },
+        [=](const std::string &Name) {
+          return DylibLookup->findSymbol(LogicalModule, Name).getAddress();
+        });
+
+    BaseLayerModuleSetHandleT H =
+      BaseLayer.addModuleSet(std::move(MSet), std::move(MM));
+    // Add this module to the logical module lookup.
+    DylibLookup->addToLogicalModule(LogicalModule, H);
+    MSI.BaseLayerModuleSetHandles.push_back(H);
+
+    return H;
+  }
+
+  static std::string Mangle(StringRef Name, const DataLayout &DL) {
+    Mangler M(&DL);
+    std::string MangledName;
+    {
+      raw_string_ostream MangledNameStream(MangledName);
+      M.getNameWithPrefix(MangledNameStream, Name);
+    }
+    return MangledName;
+  }
+
+  BaseLayerT &BaseLayer;
+  CompileCallbackMgrT CompileCallbackMgr;
+  ModuleSetInfoListT ModuleSetInfos;
+};
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_COMPILEONDEMANDLAYER_H
diff --git a/include/llvm/ExecutionEngine/Orc/CompileUtils.h b/include/llvm/ExecutionEngine/Orc/CompileUtils.h
new file mode 100644
index 0000000..49a1fba
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/CompileUtils.h
@@ -0,0 +1,62 @@
+//===-- CompileUtils.h - Utilities for compiling IR in the JIT --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Contains utilities for compiling IR to object files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_COMPILEUTILS_H
+#define LLVM_EXECUTIONENGINE_ORC_COMPILEUTILS_H
+
+#include "llvm/ExecutionEngine/ObjectMemoryBuffer.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Target/TargetMachine.h"
+
+namespace llvm {
+namespace orc {
+
+/// @brief Simple compile functor: Takes a single IR module and returns an
+///        ObjectFile.
+class SimpleCompiler {
+public:
+  /// @brief Construct a simple compile functor with the given target.
+  SimpleCompiler(TargetMachine &TM) : TM(TM) {}
+
+  /// @brief Compile a Module to an ObjectFile.
+  object::OwningBinary<object::ObjectFile> operator()(Module &M) const {
+    SmallVector<char, 0> ObjBufferSV;
+    raw_svector_ostream ObjStream(ObjBufferSV);
+
+    legacy::PassManager PM;
+    MCContext *Ctx;
+    if (TM.addPassesToEmitMC(PM, Ctx, ObjStream))
+      llvm_unreachable("Target does not support MC emission.");
+    PM.run(M);
+    ObjStream.flush();
+    std::unique_ptr<MemoryBuffer> ObjBuffer(
+        new ObjectMemoryBuffer(std::move(ObjBufferSV)));
+    ErrorOr<std::unique_ptr<object::ObjectFile>> Obj =
+        object::ObjectFile::createObjectFile(ObjBuffer->getMemBufferRef());
+    // TODO: Actually report errors helpfully.
+    typedef object::OwningBinary<object::ObjectFile> OwningObj;
+    if (Obj)
+      return OwningObj(std::move(*Obj), std::move(ObjBuffer));
+    return OwningObj(nullptr, nullptr);
+  }
+
+private:
+  TargetMachine &TM;
+};
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_COMPILEUTILS_H
diff --git a/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h b/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h
new file mode 100644
index 0000000..6a47622
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/IRCompileLayer.h
@@ -0,0 +1,146 @@
+//===------ IRCompileLayer.h -- Eagerly compile IR for JIT ------*- 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 a basic, eagerly compiling layer of the JIT.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_IRCOMPILELAYER_H
+#define LLVM_EXECUTIONENGINE_ORC_IRCOMPILELAYER_H
+
+#include "JITSymbol.h"
+#include "llvm/ExecutionEngine/ObjectCache.h"
+#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
+#include "llvm/Object/ObjectFile.h"
+#include <memory>
+
+namespace llvm {
+namespace orc {
+
+/// @brief Eager IR compiling layer.
+///
+///   This layer accepts sets of LLVM IR Modules (via addModuleSet). It
+/// immediately compiles each IR module to an object file (each IR Module is
+/// compiled separately). The resulting set of object files is then added to
+/// the layer below, which must implement the object layer concept.
+template <typename BaseLayerT> class IRCompileLayer {
+public:
+  typedef std::function<object::OwningBinary<object::ObjectFile>(Module &)>
+      CompileFtor;
+
+private:
+  typedef typename BaseLayerT::ObjSetHandleT ObjSetHandleT;
+
+  typedef std::vector<std::unique_ptr<object::ObjectFile>> OwningObjectVec;
+  typedef std::vector<std::unique_ptr<MemoryBuffer>> OwningBufferVec;
+
+public:
+  /// @brief Handle to a set of compiled modules.
+  typedef ObjSetHandleT ModuleSetHandleT;
+
+  /// @brief Construct an IRCompileLayer with the given BaseLayer, which must
+  ///        implement the ObjectLayer concept.
+  IRCompileLayer(BaseLayerT &BaseLayer, CompileFtor Compile)
+      : BaseLayer(BaseLayer), Compile(std::move(Compile)), ObjCache(nullptr) {}
+
+  /// @brief Set an ObjectCache to query before compiling.
+  void setObjectCache(ObjectCache *NewCache) { ObjCache = NewCache; }
+
+  /// @brief Compile each module in the given module set, then then add the
+  ///        resulting set of objects to the base layer, along with the memory
+  //         manager MM.
+  ///
+  /// @return A handle for the added modules.
+  template <typename ModuleSetT>
+  ModuleSetHandleT addModuleSet(ModuleSetT Ms,
+                                std::unique_ptr<RTDyldMemoryManager> MM) {
+    OwningObjectVec Objects;
+    OwningBufferVec Buffers;
+
+    for (const auto &M : Ms) {
+      std::unique_ptr<object::ObjectFile> Object;
+      std::unique_ptr<MemoryBuffer> Buffer;
+
+      if (ObjCache)
+        std::tie(Object, Buffer) = tryToLoadFromObjectCache(*M).takeBinary();
+
+      if (!Object) {
+        std::tie(Object, Buffer) = Compile(*M).takeBinary();
+        if (ObjCache)
+          ObjCache->notifyObjectCompiled(&*M, Buffer->getMemBufferRef());
+      }
+
+      Objects.push_back(std::move(Object));
+      Buffers.push_back(std::move(Buffer));
+    }
+
+    ModuleSetHandleT H =
+      BaseLayer.addObjectSet(Objects, std::move(MM));
+
+    BaseLayer.takeOwnershipOfBuffers(H, std::move(Buffers));
+
+    return H;
+  }
+
+  /// @brief Remove the module set associated with the handle H.
+  void removeModuleSet(ModuleSetHandleT 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
+  ///        compiled modules represented by the handle H. This call is
+  ///        forwarded to the base layer's implementation.
+  /// @param H The handle for the module 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 module set.
+  JITSymbol findSymbolIn(ModuleSetHandleT H, const std::string &Name,
+                         bool ExportedSymbolsOnly) {
+    return BaseLayer.findSymbolIn(H, Name, ExportedSymbolsOnly);
+  }
+
+  /// @brief Immediately emit and finalize the moduleOB set represented by the
+  ///        given handle.
+  /// @param H Handle for module set to emit/finalize.
+  void emitAndFinalize(ModuleSetHandleT H) {
+    BaseLayer.emitAndFinalize(H);
+  }
+
+private:
+  object::OwningBinary<object::ObjectFile>
+  tryToLoadFromObjectCache(const Module &M) {
+    std::unique_ptr<MemoryBuffer> ObjBuffer = ObjCache->getObject(&M);
+    if (!ObjBuffer)
+      return object::OwningBinary<object::ObjectFile>();
+
+    ErrorOr<std::unique_ptr<object::ObjectFile>> Obj =
+        object::ObjectFile::createObjectFile(ObjBuffer->getMemBufferRef());
+    if (!Obj)
+      return object::OwningBinary<object::ObjectFile>();
+
+    return object::OwningBinary<object::ObjectFile>(std::move(*Obj),
+                                                    std::move(ObjBuffer));
+  }
+
+  BaseLayerT &BaseLayer;
+  CompileFtor Compile;
+  ObjectCache *ObjCache;
+};
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_IRCOMPILINGLAYER_H
diff --git a/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h b/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h
new file mode 100644
index 0000000..e9d3d34
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h
@@ -0,0 +1,246 @@
+//===-- IndirectionUtils.h - Utilities for adding indirections --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Contains utilities for adding indirections and breaking up modules.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_INDIRECTIONUTILS_H
+#define LLVM_EXECUTIONENGINE_ORC_INDIRECTIONUTILS_H
+
+#include "JITSymbol.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/IR/Module.h"
+#include <sstream>
+
+namespace llvm {
+namespace orc {
+
+/// @brief Base class for JITLayer independent aspects of
+///        JITCompileCallbackManager.
+template <typename TargetT>
+class JITCompileCallbackManagerBase {
+public:
+
+  /// @brief Construct a JITCompileCallbackManagerBase.
+  /// @param ErrorHandlerAddress The address of an error handler in the target
+  ///                            process to be used if a compile callback fails.
+  /// @param NumTrampolinesPerBlock Number of trampolines to emit if there is no
+  ///                             available trampoline when getCompileCallback is
+  ///                             called.
+  JITCompileCallbackManagerBase(TargetAddress ErrorHandlerAddress,
+                                unsigned NumTrampolinesPerBlock)
+    : ErrorHandlerAddress(ErrorHandlerAddress),
+      NumTrampolinesPerBlock(NumTrampolinesPerBlock) {}
+
+  /// @brief Execute the callback for the given trampoline id. Called by the JIT
+  ///        to compile functions on demand.
+  TargetAddress executeCompileCallback(TargetAddress TrampolineID) {
+    typename TrampolineMapT::iterator I = ActiveTrampolines.find(TrampolineID);
+    // FIXME: Also raise an error in the Orc error-handler when we finally have
+    //        one.
+    if (I == ActiveTrampolines.end())
+      return ErrorHandlerAddress;
+
+    // Found a callback handler. Yank this trampoline out of the active list and
+    // put it back in the available trampolines list, then try to run the
+    // handler's compile and update actions.
+    // Moving the trampoline ID back to the available list first means there's at
+    // least one available trampoline if the compile action triggers a request for
+    // a new one.
+    AvailableTrampolines.push_back(I->first - TargetT::CallSize);
+    auto CallbackHandler = std::move(I->second);
+    ActiveTrampolines.erase(I);
+
+    if (auto Addr = CallbackHandler.Compile()) {
+      CallbackHandler.Update(Addr);
+      return Addr;
+    }
+    return ErrorHandlerAddress;
+  }
+
+protected:
+
+  typedef std::function<TargetAddress()> CompileFtorT;
+  typedef std::function<void(TargetAddress)> UpdateFtorT;
+
+  struct CallbackHandler {
+    CompileFtorT Compile;
+    UpdateFtorT Update;
+  };
+
+  TargetAddress ErrorHandlerAddress;
+  unsigned NumTrampolinesPerBlock;
+
+  typedef std::map<TargetAddress, CallbackHandler> TrampolineMapT;
+  TrampolineMapT ActiveTrampolines;
+  std::vector<TargetAddress> AvailableTrampolines;
+};
+
+/// @brief Manage compile callbacks.
+template <typename JITLayerT, typename TargetT>
+class JITCompileCallbackManager :
+    public JITCompileCallbackManagerBase<TargetT> {
+public:
+
+  typedef typename JITCompileCallbackManagerBase<TargetT>::CompileFtorT
+    CompileFtorT;
+  typedef typename JITCompileCallbackManagerBase<TargetT>::UpdateFtorT
+    UpdateFtorT;
+
+  /// @brief Construct a JITCompileCallbackManager.
+  /// @param JIT JIT layer to emit callback trampolines, etc. into.
+  /// @param Context LLVMContext to use for trampoline & resolve block modules.
+  /// @param ErrorHandlerAddress The address of an error handler in the target
+  ///                            process to be used if a compile callback fails.
+  /// @param NumTrampolinesPerBlock Number of trampolines to allocate whenever
+  ///                               there is no existing callback trampoline.
+  ///                               (Trampolines are allocated in blocks for
+  ///                               efficiency.)
+  JITCompileCallbackManager(JITLayerT &JIT, LLVMContext &Context,
+                            TargetAddress ErrorHandlerAddress,
+                            unsigned NumTrampolinesPerBlock)
+    : JITCompileCallbackManagerBase<TargetT>(ErrorHandlerAddress,
+                                             NumTrampolinesPerBlock),
+      JIT(JIT) {
+    emitResolverBlock(Context);
+  }
+
+  /// @brief Handle to a newly created compile callback. Can be used to get an
+  ///        IR constant representing the address of the trampoline, and to set
+  ///        the compile and update actions for the callback.
+  class CompileCallbackInfo {
+  public:
+    CompileCallbackInfo(Constant *Addr, CompileFtorT &Compile,
+                        UpdateFtorT &Update)
+      : Addr(Addr), Compile(Compile), Update(Update) {}
+
+    Constant* getAddress() const { return Addr; }
+    void setCompileAction(CompileFtorT Compile) {
+      this->Compile = std::move(Compile);
+    }
+    void setUpdateAction(UpdateFtorT Update) {
+      this->Update = std::move(Update);
+    }
+  private:
+    Constant *Addr;
+    CompileFtorT &Compile;
+    UpdateFtorT &Update;
+  };
+
+  /// @brief Get/create a compile callback with the given signature.
+  CompileCallbackInfo getCompileCallback(FunctionType &FT) {
+    TargetAddress TrampolineAddr = getAvailableTrampolineAddr(FT.getContext());
+    auto &CallbackHandler =
+      this->ActiveTrampolines[TrampolineAddr + TargetT::CallSize];
+    Constant *AddrIntVal =
+      ConstantInt::get(Type::getInt64Ty(FT.getContext()), TrampolineAddr);
+    Constant *AddrPtrVal =
+      ConstantExpr::getCast(Instruction::IntToPtr, AddrIntVal,
+                            PointerType::get(&FT, 0));
+
+    return CompileCallbackInfo(AddrPtrVal, CallbackHandler.Compile,
+                               CallbackHandler.Update);
+  }
+
+  /// @brief Get a functor for updating the value of a named function pointer.
+  UpdateFtorT getLocalFPUpdater(typename JITLayerT::ModuleSetHandleT H,
+                                std::string Name) {
+    // FIXME: Move-capture Name once we can use C++14.
+    return [=](TargetAddress Addr) {
+      auto FPSym = JIT.findSymbolIn(H, Name, true);
+      assert(FPSym && "Cannot find function pointer to update.");
+      void *FPAddr = reinterpret_cast<void*>(
+                       static_cast<uintptr_t>(FPSym.getAddress()));
+      memcpy(FPAddr, &Addr, sizeof(uintptr_t));
+    };
+  }
+
+private:
+
+  std::vector<std::unique_ptr<Module>>
+  SingletonSet(std::unique_ptr<Module> M) {
+    std::vector<std::unique_ptr<Module>> Ms;
+    Ms.push_back(std::move(M));
+    return Ms;
+  }
+
+  void emitResolverBlock(LLVMContext &Context) {
+    std::unique_ptr<Module> M(new Module("resolver_block_module",
+                                         Context));
+    TargetT::insertResolverBlock(*M, *this);
+    auto H = JIT.addModuleSet(SingletonSet(std::move(M)), nullptr);
+    JIT.emitAndFinalize(H);
+    auto ResolverBlockSymbol =
+      JIT.findSymbolIn(H, TargetT::ResolverBlockName, false);
+    assert(ResolverBlockSymbol && "Failed to insert resolver block");
+    ResolverBlockAddr = ResolverBlockSymbol.getAddress();
+  }
+
+  TargetAddress getAvailableTrampolineAddr(LLVMContext &Context) {
+    if (this->AvailableTrampolines.empty())
+      grow(Context);
+    assert(!this->AvailableTrampolines.empty() &&
+           "Failed to grow available trampolines.");
+    TargetAddress TrampolineAddr = this->AvailableTrampolines.back();
+    this->AvailableTrampolines.pop_back();
+    return TrampolineAddr;
+  }
+
+  void grow(LLVMContext &Context) {
+    assert(this->AvailableTrampolines.empty() && "Growing prematurely?");
+    std::unique_ptr<Module> M(new Module("trampoline_block", Context));
+    auto GetLabelName =
+      TargetT::insertCompileCallbackTrampolines(*M, ResolverBlockAddr,
+                                                this->NumTrampolinesPerBlock,
+                                                this->ActiveTrampolines.size());
+    auto H = JIT.addModuleSet(SingletonSet(std::move(M)), nullptr);
+    JIT.emitAndFinalize(H);
+    for (unsigned I = 0; I < this->NumTrampolinesPerBlock; ++I) {
+      std::string Name = GetLabelName(I);
+      auto TrampolineSymbol = JIT.findSymbolIn(H, Name, false);
+      assert(TrampolineSymbol && "Failed to emit trampoline.");
+      this->AvailableTrampolines.push_back(TrampolineSymbol.getAddress());
+    }
+  }
+
+  JITLayerT &JIT;
+  TargetAddress ResolverBlockAddr;
+};
+
+GlobalVariable* createImplPointer(Function &F, const Twine &Name,
+                                  Constant *Initializer);
+
+void makeStub(Function &F, GlobalVariable &ImplPointer);
+
+typedef std::map<Module*, DenseSet<const GlobalValue*>> ModulePartitionMap;
+
+void partition(Module &M, const ModulePartitionMap &PMap);
+
+/// @brief Struct for trivial "complete" partitioning of a module.
+class FullyPartitionedModule {
+public:
+  std::unique_ptr<Module> GlobalVars;
+  std::unique_ptr<Module> Commons;
+  std::vector<std::unique_ptr<Module>> Functions;
+
+  FullyPartitionedModule() = default;
+  FullyPartitionedModule(FullyPartitionedModule &&S)
+      : GlobalVars(std::move(S.GlobalVars)), Commons(std::move(S.Commons)),
+        Functions(std::move(S.Functions)) {}
+};
+
+FullyPartitionedModule fullyPartition(Module &M);
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_INDIRECTIONUTILS_H
diff --git a/include/llvm/ExecutionEngine/Orc/JITSymbol.h b/include/llvm/ExecutionEngine/Orc/JITSymbol.h
new file mode 100644
index 0000000..a670222
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/JITSymbol.h
@@ -0,0 +1,74 @@
+//===----------- JITSymbol.h - JIT symbol abstraction -----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Abstraction for target process addresses.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H
+#define LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H
+
+#include "llvm/Support/DataTypes.h"
+#include <cassert>
+#include <functional>
+
+namespace llvm {
+namespace orc {
+
+/// @brief Represents an address in the target process's address space.
+typedef uint64_t TargetAddress;
+
+/// @brief Represents a symbol in the JIT.
+class JITSymbol {
+public:
+  typedef std::function<TargetAddress()> GetAddressFtor;
+
+  /// @brief Create a 'null' symbol that represents failure to find a symbol
+  ///        definition.
+  JITSymbol(std::nullptr_t) : CachedAddr(0) {}
+
+  /// @brief Create a symbol for a definition with a known address.
+  JITSymbol(TargetAddress Addr)
+    : CachedAddr(Addr) {}
+
+  /// @brief Create a symbol for a definition that doesn't have a known address
+  ///        yet.
+  /// @param GetAddress A functor to materialize a definition (fixing the
+  ///        address) on demand.
+  ///
+  ///   This constructor allows a JIT layer to provide a reference to a symbol
+  /// definition without actually materializing the definition up front. The
+  /// user can materialize the definition at any time by calling the getAddress
+  /// method.
+  JITSymbol(GetAddressFtor GetAddress)
+    : CachedAddr(0), GetAddress(std::move(GetAddress)) {}
+
+  /// @brief Returns true if the symbol exists, false otherwise.
+  explicit operator bool() const { return CachedAddr || GetAddress; }
+
+  /// @brief Get the address of the symbol in the target address space. Returns
+  ///        '0' if the symbol does not exist.
+  TargetAddress getAddress() {
+    if (GetAddress) {
+      CachedAddr = GetAddress();
+      assert(CachedAddr && "Symbol could not be materialized.");
+      GetAddress = nullptr;
+    }
+    return CachedAddr;
+  }
+
+private:
+  TargetAddress CachedAddr;
+  GetAddressFtor GetAddress;
+};
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H
diff --git a/include/llvm/ExecutionEngine/Orc/LazyEmittingLayer.h b/include/llvm/ExecutionEngine/Orc/LazyEmittingLayer.h
new file mode 100644
index 0000000..2a94abe
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/LazyEmittingLayer.h
@@ -0,0 +1,283 @@
+//===- LazyEmittingLayer.h - Lazily emit IR to lower JIT layers -*- 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 a lazy-emitting layer for the JIT.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_LAZYEMITTINGLAYER_H
+#define LLVM_EXECUTIONENGINE_ORC_LAZYEMITTINGLAYER_H
+
+#include "JITSymbol.h"
+#include "LookasideRTDyldMM.h"
+#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/IR/Module.h"
+#include "llvm/ADT/StringMap.h"
+#include <list>
+
+namespace llvm {
+namespace orc {
+
+/// @brief Lazy-emitting IR layer.
+///
+///   This layer accepts sets of LLVM IR Modules (via addModuleSet), but does
+/// not immediately emit them the layer below. Instead, emissing to the base
+/// layer is deferred until the first time the client requests the address
+/// (via JITSymbol::getAddress) for a symbol contained in this layer.
+template <typename BaseLayerT> class LazyEmittingLayer {
+public:
+  typedef typename BaseLayerT::ModuleSetHandleT BaseLayerHandleT;
+
+private:
+  class EmissionDeferredSet {
+  public:
+    EmissionDeferredSet() : EmitState(NotEmitted) {}
+    virtual ~EmissionDeferredSet() {}
+
+    JITSymbol find(StringRef Name, bool ExportedSymbolsOnly, BaseLayerT &B) {
+      switch (EmitState) {
+      case NotEmitted:
+        if (provides(Name, ExportedSymbolsOnly)) {
+          // Create a std::string version of Name to capture here - the argument
+          // (a StringRef) may go away before the lambda is executed.
+          // FIXME: Use capture-init when we move to C++14. 
+          std::string PName = Name;
+          return JITSymbol(
+              [this, ExportedSymbolsOnly, PName, &B]() -> TargetAddress {
+                if (this->EmitState == Emitting)
+                  return 0;
+                else if (this->EmitState == NotEmitted) {
+                  this->EmitState = Emitting;
+                  Handle = this->emitToBaseLayer(B);
+                  this->EmitState = Emitted;
+                }
+                return B.findSymbolIn(Handle, PName, ExportedSymbolsOnly)
+                          .getAddress();
+              });
+        } else
+          return nullptr;
+      case Emitting:
+        // Calling "emit" can trigger external symbol lookup (e.g. to check for
+        // pre-existing definitions of common-symbol), but it will never find in
+        // this module that it would not have found already, so return null from
+        // here.
+        return nullptr;
+      case Emitted:
+        return B.findSymbolIn(Handle, Name, ExportedSymbolsOnly);
+      }
+      llvm_unreachable("Invalid emit-state.");
+    }
+
+    void removeModulesFromBaseLayer(BaseLayerT &BaseLayer) {
+      if (EmitState != NotEmitted)
+        BaseLayer.removeModuleSet(Handle);
+    }
+
+    void emitAndFinalize(BaseLayerT &BaseLayer) {
+      assert(EmitState != Emitting &&
+             "Cannot emitAndFinalize while already emitting");
+      if (EmitState == NotEmitted) {
+        EmitState = Emitting;
+        Handle = emitToBaseLayer(BaseLayer);
+        EmitState = Emitted;
+      }
+      BaseLayer.emitAndFinalize(Handle);
+    }
+
+    template <typename ModuleSetT>
+    static std::unique_ptr<EmissionDeferredSet>
+    create(BaseLayerT &B, ModuleSetT Ms,
+           std::unique_ptr<RTDyldMemoryManager> MM);
+
+  protected:
+    virtual bool provides(StringRef Name, bool ExportedSymbolsOnly) const = 0;
+    virtual BaseLayerHandleT emitToBaseLayer(BaseLayerT &BaseLayer) = 0;
+
+  private:
+    enum { NotEmitted, Emitting, Emitted } EmitState;
+    BaseLayerHandleT Handle;
+  };
+
+  template <typename ModuleSetT>
+  class EmissionDeferredSetImpl : public EmissionDeferredSet {
+  public:
+    EmissionDeferredSetImpl(ModuleSetT Ms,
+                            std::unique_ptr<RTDyldMemoryManager> MM)
+        : Ms(std::move(Ms)), MM(std::move(MM)) {}
+
+  protected:
+
+    BaseLayerHandleT emitToBaseLayer(BaseLayerT &BaseLayer) override {
+      // We don't need the mangled names set any more: Once we've emitted this
+      // to the base layer we'll just look for symbols there.
+      MangledNames.reset();
+      return BaseLayer.addModuleSet(std::move(Ms), std::move(MM));
+    }
+
+    bool provides(StringRef Name, bool ExportedSymbolsOnly) const override {
+      // FIXME: We could clean all this up if we had a way to reliably demangle
+      //        names: We could just demangle name and search, rather than
+      //        mangling everything else.
+
+      // If we have already built the mangled name set then just search it.
+      if (MangledNames) {
+        auto VI = MangledNames->find(Name);
+        if (VI == MangledNames->end())
+          return false;
+        return !ExportedSymbolsOnly || VI->second;
+      }
+
+      // If we haven't built the mangled name set yet, try to build it. As an
+      // optimization this will leave MangledNames set to nullptr if we find
+      // Name in the process of building the set.
+      buildMangledNames(Name, ExportedSymbolsOnly);
+      if (!MangledNames)
+        return true;
+      return false;
+    }
+
+  private:
+    // If the mangled name of the given GlobalValue matches the given search
+    // name (and its visibility conforms to the ExportedSymbolsOnly flag) then
+    // just return 'true'. Otherwise, add the mangled name to the Names map and
+    // return 'false'.
+    bool addGlobalValue(StringMap<bool> &Names, const GlobalValue &GV,
+                        const Mangler &Mang, StringRef SearchName,
+                        bool ExportedSymbolsOnly) const {
+      // Modules don't "provide" decls or common symbols.
+      if (GV.isDeclaration() || GV.hasCommonLinkage())
+        return false;
+
+      // Mangle the GV name.
+      std::string MangledName;
+      {
+        raw_string_ostream MangledNameStream(MangledName);
+        Mang.getNameWithPrefix(MangledNameStream, &GV, false);
+      }
+
+      // Check whether this is the name we were searching for, and if it is then
+      // bail out early.
+      if (MangledName == SearchName)
+        if (!ExportedSymbolsOnly || GV.hasDefaultVisibility())
+          return true;
+
+      // Otherwise add this to the map for later.
+      Names[MangledName] = GV.hasDefaultVisibility();
+      return false;
+    }
+
+    // Build the MangledNames map. Bails out early (with MangledNames left set
+    // to nullptr) if the given SearchName is found while building the map.
+    void buildMangledNames(StringRef SearchName,
+                           bool ExportedSymbolsOnly) const {
+      assert(!MangledNames && "Mangled names map already exists?");
+
+      auto Names = llvm::make_unique<StringMap<bool>>();
+
+      for (const auto &M : Ms) {
+        Mangler Mang(M->getDataLayout());
+
+        for (const auto &GV : M->globals())
+          if (addGlobalValue(*Names, GV, Mang, SearchName, ExportedSymbolsOnly))
+            return;
+
+        for (const auto &F : *M)
+          if (addGlobalValue(*Names, F, Mang, SearchName, ExportedSymbolsOnly))
+            return;
+      }
+
+      MangledNames = std::move(Names);
+    }
+
+    ModuleSetT Ms;
+    std::unique_ptr<RTDyldMemoryManager> MM;
+    mutable std::unique_ptr<StringMap<bool>> MangledNames;
+  };
+
+  typedef std::list<std::unique_ptr<EmissionDeferredSet>> ModuleSetListT;
+
+  BaseLayerT &BaseLayer;
+  ModuleSetListT ModuleSetList;
+
+public:
+  /// @brief Handle to a set of loaded modules.
+  typedef typename ModuleSetListT::iterator ModuleSetHandleT;
+
+  /// @brief Construct a lazy emitting layer.
+  LazyEmittingLayer(BaseLayerT &BaseLayer) : BaseLayer(BaseLayer) {}
+
+  /// @brief Add the given set of modules to the lazy emitting layer.
+  template <typename ModuleSetT>
+  ModuleSetHandleT addModuleSet(ModuleSetT Ms,
+                                std::unique_ptr<RTDyldMemoryManager> MM) {
+    return ModuleSetList.insert(
+        ModuleSetList.end(),
+        EmissionDeferredSet::create(BaseLayer, std::move(Ms), std::move(MM)));
+  }
+
+  /// @brief Remove the module set represented by the given handle.
+  ///
+  ///   This method will free the memory associated with the given module set,
+  /// both in this layer, and the base layer.
+  void removeModuleSet(ModuleSetHandleT H) {
+    (*H)->removeModulesFromBaseLayer(BaseLayer);
+    ModuleSetList.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(const std::string &Name, bool ExportedSymbolsOnly) {
+    // Look for the symbol among existing definitions.
+    if (auto Symbol = BaseLayer.findSymbol(Name, ExportedSymbolsOnly))
+      return Symbol;
+
+    // If not found then search the deferred sets. If any of these contain a
+    // definition of 'Name' then they will return a JITSymbol that will emit
+    // the corresponding module when the symbol address is requested.
+    for (auto &DeferredSet : ModuleSetList)
+      if (auto Symbol = DeferredSet->find(Name, ExportedSymbolsOnly, BaseLayer))
+        return Symbol;
+
+    // If no definition found anywhere return a null symbol.
+    return nullptr;
+  }
+
+  /// @brief Get the address of the given symbol in the context of the set of
+  ///        compiled modules represented by the handle H.
+  JITSymbol findSymbolIn(ModuleSetHandleT H, const std::string &Name,
+                         bool ExportedSymbolsOnly) {
+    return (*H)->find(Name, ExportedSymbolsOnly, BaseLayer);
+  }
+
+  /// @brief Immediately emit and finalize the moduleOB set represented by the
+  ///        given handle.
+  /// @param H Handle for module set to emit/finalize.
+  void emitAndFinalize(ModuleSetHandleT H) {
+    (*H)->emitAndFinalize(BaseLayer);
+  }
+
+};
+
+template <typename BaseLayerT>
+template <typename ModuleSetT>
+std::unique_ptr<typename LazyEmittingLayer<BaseLayerT>::EmissionDeferredSet>
+LazyEmittingLayer<BaseLayerT>::EmissionDeferredSet::create(
+    BaseLayerT &B, ModuleSetT Ms, std::unique_ptr<RTDyldMemoryManager> MM) {
+  return llvm::make_unique<EmissionDeferredSetImpl<ModuleSetT>>(std::move(Ms),
+                                                                std::move(MM));
+}
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_LAZYEMITTINGLAYER_H
diff --git a/include/llvm/ExecutionEngine/Orc/LookasideRTDyldMM.h b/include/llvm/ExecutionEngine/Orc/LookasideRTDyldMM.h
new file mode 100644
index 0000000..4456404
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/LookasideRTDyldMM.h
@@ -0,0 +1,92 @@
+//===- LookasideRTDyldMM - Redirect symbol lookup via a functor -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//   Defines an adapter for RuntimeDyldMM that allows lookups for external
+// symbols to go via a functor.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_LOOKASIDERTDYLDMM_H
+#define LLVM_EXECUTIONENGINE_ORC_LOOKASIDERTDYLDMM_H
+
+#include "llvm/ADT/STLExtras.h"
+#include <memory>
+#include <vector>
+
+namespace llvm {
+namespace orc {
+
+/// @brief Defines an adapter for RuntimeDyldMM that allows lookups for external
+///        symbols to go via a functor, before falling back to the lookup logic
+///        provided by the underlying RuntimeDyldMM instance.
+///
+///   This class is useful for redirecting symbol lookup back to various layers
+/// of a JIT component stack, e.g. to enable lazy module emission.
+///
+template <typename BaseRTDyldMM, typename ExternalLookupFtor,
+          typename DylibLookupFtor>
+class LookasideRTDyldMM : public BaseRTDyldMM {
+public:
+  /// @brief Create a LookasideRTDyldMM intance.
+  LookasideRTDyldMM(ExternalLookupFtor ExternalLookup,
+                    DylibLookupFtor DylibLookup)
+      : ExternalLookup(std::move(ExternalLookup)),
+        DylibLookup(std::move(DylibLookup)) {}
+
+  /// @brief Look up the given symbol address, first via the functor this
+  ///        instance was created with, then (if the symbol isn't found)
+  ///        via the underlying RuntimeDyldMM.
+  uint64_t getSymbolAddress(const std::string &Name) override {
+    if (uint64_t Addr = ExternalLookup(Name))
+      return Addr;
+    return BaseRTDyldMM::getSymbolAddress(Name);
+  }
+
+  uint64_t getSymbolAddressInLogicalDylib(const std::string &Name) override {
+    if (uint64_t Addr = DylibLookup(Name))
+      return Addr;
+    return BaseRTDyldMM::getSymbolAddressInLogicalDylib(Name);
+  };
+
+  /// @brief Get a reference to the ExternalLookup functor.
+  ExternalLookupFtor &getExternalLookup() { return ExternalLookup; }
+
+  /// @brief Get a const-reference to the ExternalLookup functor.
+  const ExternalLookupFtor &getExternalLookup() const { return ExternalLookup; }
+
+  /// @brief Get a reference to the DylibLookup functor.
+  DylibLookupFtor &getDylibLookup() { return DylibLookup; }
+
+  /// @brief Get a const-reference to the DylibLookup functor.
+  const DylibLookupFtor &getDylibLookup() const { return DylibLookup; }
+
+private:
+  ExternalLookupFtor ExternalLookup;
+  DylibLookupFtor DylibLookup;
+};
+
+/// @brief Create a LookasideRTDyldMM from a base memory manager type, an
+///        external lookup functor, and a dylib lookup functor.
+template <typename BaseRTDyldMM, typename ExternalLookupFtor,
+          typename DylibLookupFtor>
+std::unique_ptr<
+    LookasideRTDyldMM<BaseRTDyldMM, ExternalLookupFtor, DylibLookupFtor>>
+createLookasideRTDyldMM(ExternalLookupFtor &&ExternalLookup,
+                        DylibLookupFtor &&DylibLookup) {
+  typedef LookasideRTDyldMM<BaseRTDyldMM, ExternalLookupFtor, DylibLookupFtor>
+      ThisLookasideMM;
+  return llvm::make_unique<ThisLookasideMM>(
+      std::forward<ExternalLookupFtor>(ExternalLookup),
+      std::forward<DylibLookupFtor>(DylibLookup));
+}
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_LOOKASIDERTDYLDMM_H
diff --git a/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h b/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
new file mode 100644
index 0000000..36af0fe
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h
@@ -0,0 +1,267 @@
+//===- 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
diff --git a/include/llvm/ExecutionEngine/Orc/OrcTargetSupport.h b/include/llvm/ExecutionEngine/Orc/OrcTargetSupport.h
new file mode 100644
index 0000000..c6f866a
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/OrcTargetSupport.h
@@ -0,0 +1,56 @@
+//===-- OrcTargetSupport.h - Code to support specific targets  --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Target specific code for Orc, e.g. callback assembly.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_ORCTARGETSUPPORT_H
+#define LLVM_EXECUTIONENGINE_ORC_ORCTARGETSUPPORT_H
+
+#include "IndirectionUtils.h"
+
+namespace llvm {
+namespace orc {
+
+class OrcX86_64 {
+public:
+  static const char *ResolverBlockName;
+
+  /// @brief Insert module-level inline callback asm into module M for the
+  /// symbols managed by JITResolveCallbackHandler J.
+  static void insertResolverBlock(
+                                 Module &M,
+                                 JITCompileCallbackManagerBase<OrcX86_64> &JCBM);
+
+  /// @brief Get a label name from the given index.
+  typedef std::function<std::string(unsigned)> LabelNameFtor;
+
+  static const unsigned CallSize = 6;
+
+  /// @brief Insert the requested number of trampolines into the given module.
+  /// @param M Module to insert the call block into.
+  /// @param NumCalls Number of calls to create in the call block.
+  /// @param StartIndex Optional argument specifying the index suffix to start
+  ///                   with.
+  /// @return A functor that provides the symbol name for each entry in the call
+  ///         block.
+  ///
+  static LabelNameFtor insertCompileCallbackTrampolines(
+                                                    Module &M,
+                                                    TargetAddress TrampolineAddr,
+                                                    unsigned NumCalls,
+                                                    unsigned StartIndex = 0);
+
+};
+
+} // End namespace orc.
+} // End namespace llvm.
+
+#endif // LLVM_EXECUTIONENGINE_ORC_ORCTARGETSUPPORT_H