llvm/lib/ExecutionEngine/MCJIT/MCJIT.h - toolchain/llvm-project - Gitiles

 //===-- MCJIT.h - Class definition for the MCJIT ----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
 #define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H

 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ExecutionEngine/ExecutionEngine.h"
 #include "llvm/ExecutionEngine/ObjectCache.h"
 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
 #include "llvm/ExecutionEngine/RuntimeDyld.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/SmallVectorMemoryBuffer.h"

 namespace llvm {
 class MCJIT;

 // This is a helper class that the MCJIT execution engine uses for linking
 // functions across modules that it owns.  It aggregates the memory manager
 // that is passed in to the MCJIT constructor and defers most functionality
 // to that object.
 class LinkingSymbolResolver : public LegacyJITSymbolResolver {
 public:
   LinkingSymbolResolver(MCJIT &Parent,
                         std::shared_ptr<LegacyJITSymbolResolver> Resolver)
       : ParentEngine(Parent), ClientResolver(std::move(Resolver)) {}

   JITSymbol findSymbol(const std::string &Name) override;

   // MCJIT doesn't support logical dylibs.
   JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {
     return nullptr;
   }

 private:
   MCJIT &ParentEngine;
   std::shared_ptr<LegacyJITSymbolResolver> ClientResolver;
   void anchor() override;
 };

 // About Module states: added->loaded->finalized.
 //
 // The purpose of the "added" state is having modules in standby. (added=known
 // but not compiled). The idea is that you can add a module to provide function
 // definitions but if nothing in that module is referenced by a module in which
 // a function is executed (note the wording here because it's not exactly the
 // ideal case) then the module never gets compiled. This is sort of lazy
 // compilation.
 //
 // The purpose of the "loaded" state (loaded=compiled and required sections
 // copied into local memory but not yet ready for execution) is to have an
 // intermediate state wherein clients can remap the addresses of sections, using
 // MCJIT::mapSectionAddress, (in preparation for later copying to a new location
 // or an external process) before relocations and page permissions are applied.
 //
 // It might not be obvious at first glance, but the "remote-mcjit" case in the
 // lli tool does this.  In that case, the intermediate action is taken by the
 // RemoteMemoryManager in response to the notifyObjectLoaded function being
 // called.

 class MCJIT : public ExecutionEngine {
   MCJIT(std::unique_ptr<Module> M, std::unique_ptr<TargetMachine> tm,
         std::shared_ptr<MCJITMemoryManager> MemMgr,
         std::shared_ptr<LegacyJITSymbolResolver> Resolver);

   typedef llvm::SmallPtrSet<Module *, 4> ModulePtrSet;

   class OwningModuleContainer {
   public:
     OwningModuleContainer() {
     }
     ~OwningModuleContainer() {
       freeModulePtrSet(AddedModules);
       freeModulePtrSet(LoadedModules);
       freeModulePtrSet(FinalizedModules);
     }

     ModulePtrSet::iterator begin_added() { return AddedModules.begin(); }
     ModulePtrSet::iterator end_added() { return AddedModules.end(); }
     iterator_range<ModulePtrSet::iterator> added() {
       return make_range(begin_added(), end_added());
     }

     ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); }
     ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); }

     ModulePtrSet::iterator begin_finalized() { return FinalizedModules.begin(); }
     ModulePtrSet::iterator end_finalized() { return FinalizedModules.end(); }

     void addModule(std::unique_ptr<Module> M) {
       AddedModules.insert(M.release());
     }

     bool removeModule(Module *M) {
       return AddedModules.erase(M) || LoadedModules.erase(M) ||
              FinalizedModules.erase(M);
     }

     bool hasModuleBeenAddedButNotLoaded(Module *M) {
       return AddedModules.count(M) != 0;
     }

     bool hasModuleBeenLoaded(Module *M) {
       // If the module is in either the "loaded" or "finalized" sections it
       // has been loaded.
       return (LoadedModules.count(M) != 0 ) || (FinalizedModules.count(M) != 0);
     }

     bool hasModuleBeenFinalized(Module *M) {
       return FinalizedModules.count(M) != 0;
     }

     bool ownsModule(Module* M) {
       return (AddedModules.count(M) != 0) || (LoadedModules.count(M) != 0) ||
              (FinalizedModules.count(M) != 0);
     }

     void markModuleAsLoaded(Module *M) {
       // This checks against logic errors in the MCJIT implementation.
       // This function should never be called with either a Module that MCJIT
       // does not own or a Module that has already been loaded and/or finalized.
       assert(AddedModules.count(M) &&
              "markModuleAsLoaded: Module not found in AddedModules");

       // Remove the module from the "Added" set.
       AddedModules.erase(M);

       // Add the Module to the "Loaded" set.
       LoadedModules.insert(M);
     }

     void markModuleAsFinalized(Module *M) {
       // This checks against logic errors in the MCJIT implementation.
       // This function should never be called with either a Module that MCJIT
       // does not own, a Module that has not been loaded or a Module that has
       // already been finalized.
       assert(LoadedModules.count(M) &&
              "markModuleAsFinalized: Module not found in LoadedModules");

       // Remove the module from the "Loaded" section of the list.
       LoadedModules.erase(M);

       // Add the Module to the "Finalized" section of the list by inserting it
       // before the 'end' iterator.
       FinalizedModules.insert(M);
     }

     void markAllLoadedModulesAsFinalized() {
       for (ModulePtrSet::iterator I = LoadedModules.begin(),
                                   E = LoadedModules.end();
            I != E; ++I) {
         Module *M = *I;
         FinalizedModules.insert(M);
       }
       LoadedModules.clear();
     }

   private:
     ModulePtrSet AddedModules;
     ModulePtrSet LoadedModules;
     ModulePtrSet FinalizedModules;

     void freeModulePtrSet(ModulePtrSet& MPS) {
       // Go through the module set and delete everything.
       for (ModulePtrSet::iterator I = MPS.begin(), E = MPS.end(); I != E; ++I) {
         Module *M = *I;
         delete M;
       }
       MPS.clear();
     }
   };

   std::unique_ptr<TargetMachine> TM;
   MCContext *Ctx;
   std::shared_ptr<MCJITMemoryManager> MemMgr;
   LinkingSymbolResolver Resolver;
   RuntimeDyld Dyld;
   std::vector<JITEventListener*> EventListeners;

   OwningModuleContainer OwnedModules;

   SmallVector<object::OwningBinary<object::Archive>, 2> Archives;
   SmallVector<std::unique_ptr<MemoryBuffer>, 2> Buffers;

   SmallVector<std::unique_ptr<object::ObjectFile>, 2> LoadedObjects;

   // An optional ObjectCache to be notified of compiled objects and used to
   // perform lookup of pre-compiled code to avoid re-compilation.
   ObjectCache *ObjCache;

   Function *FindFunctionNamedInModulePtrSet(StringRef FnName,
                                             ModulePtrSet::iterator I,
                                             ModulePtrSet::iterator E);

   GlobalVariable *FindGlobalVariableNamedInModulePtrSet(StringRef Name,
                                                         bool AllowInternal,
                                                         ModulePtrSet::iterator I,
                                                         ModulePtrSet::iterator E);

   void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors,
                                                       ModulePtrSet::iterator I,
                                                       ModulePtrSet::iterator E);

 public:
   ~MCJIT() override;

   /// @name ExecutionEngine interface implementation
   /// @{
   void addModule(std::unique_ptr<Module> M) override;
   void addObjectFile(std::unique_ptr<object::ObjectFile> O) override;
   void addObjectFile(object::OwningBinary<object::ObjectFile> O) override;
   void addArchive(object::OwningBinary<object::Archive> O) override;
   bool removeModule(Module *M) override;

   /// FindFunctionNamed - Search all of the active modules to find the function that
   /// defines FnName.  This is very slow operation and shouldn't be used for
   /// general code.
   Function *FindFunctionNamed(StringRef FnName) override;

   /// FindGlobalVariableNamed - Search all of the active modules to find the
   /// global variable that defines Name.  This is very slow operation and
   /// shouldn't be used for general code.
   GlobalVariable *FindGlobalVariableNamed(StringRef Name,
                                           bool AllowInternal = false) override;

   /// Sets the object manager that MCJIT should use to avoid compilation.
   void setObjectCache(ObjectCache *manager) override;

   void setProcessAllSections(bool ProcessAllSections) override {
     Dyld.setProcessAllSections(ProcessAllSections);
   }

   void generateCodeForModule(Module *M) override;

   /// finalizeObject - ensure the module is fully processed and is usable.
   ///
   /// It is the user-level function for completing the process of making the
   /// object usable for execution. It should be called after sections within an
   /// object have been relocated using mapSectionAddress.  When this method is
   /// called the MCJIT execution engine will reapply relocations for a loaded
   /// object.
   /// Is it OK to finalize a set of modules, add modules and finalize again.
   // FIXME: Do we really need both of these?
   void finalizeObject() override;
   virtual void finalizeModule(Module *);
   void finalizeLoadedModules();

   /// runStaticConstructorsDestructors - This method is used to execute all of
   /// the static constructors or destructors for a program.
   ///
   /// \param isDtors - Run the destructors instead of constructors.
   void runStaticConstructorsDestructors(bool isDtors) override;

   void *getPointerToFunction(Function *F) override;

   GenericValue runFunction(Function *F,
                            ArrayRef<GenericValue> ArgValues) override;

   /// getPointerToNamedFunction - This method returns the address of the
   /// specified function by using the dlsym function call.  As such it is only
   /// useful for resolving library symbols, not code generated symbols.
   ///
   /// If AbortOnFailure is false and no function with the given name is
   /// found, this function silently returns a null pointer. Otherwise,
   /// it prints a message to stderr and aborts.
   ///
   void *getPointerToNamedFunction(StringRef Name,
                                   bool AbortOnFailure = true) override;

   /// mapSectionAddress - map a section to its target address space value.
   /// Map the address of a JIT section as returned from the memory manager
   /// to the address in the target process as the running code will see it.
   /// This is the address which will be used for relocation resolution.
   void mapSectionAddress(const void *LocalAddress,
                          uint64_t TargetAddress) override {
     Dyld.mapSectionAddress(LocalAddress, TargetAddress);
   }
   void RegisterJITEventListener(JITEventListener *L) override;
   void UnregisterJITEventListener(JITEventListener *L) override;

   // If successful, these function will implicitly finalize all loaded objects.
   // To get a function address within MCJIT without causing a finalize, use
   // getSymbolAddress.
   uint64_t getGlobalValueAddress(const std::string &Name) override;
   uint64_t getFunctionAddress(const std::string &Name) override;

   TargetMachine *getTargetMachine() override { return TM.get(); }

   /// @}
   /// @name (Private) Registration Interfaces
   /// @{

   static void Register() {
     MCJITCtor = createJIT;
   }

   static ExecutionEngine *
   createJIT(std::unique_ptr<Module> M, std::string *ErrorStr,
             std::shared_ptr<MCJITMemoryManager> MemMgr,
             std::shared_ptr<LegacyJITSymbolResolver> Resolver,
             std::unique_ptr<TargetMachine> TM);

   // @}

   // Takes a mangled name and returns the corresponding JITSymbol (if a
   // definition of that mangled name has been added to the JIT).
   JITSymbol findSymbol(const std::string &Name, bool CheckFunctionsOnly);

   // DEPRECATED - Please use findSymbol instead.
   //
   // This is not directly exposed via the ExecutionEngine API, but it is
   // used by the LinkingMemoryManager.
   //
   // getSymbolAddress takes an unmangled name and returns the corresponding
   // JITSymbol if a definition of the name has been added to the JIT.
   uint64_t getSymbolAddress(const std::string &Name,
                             bool CheckFunctionsOnly);

 protected:
   /// emitObject -- Generate a JITed object in memory from the specified module
   /// Currently, MCJIT only supports a single module and the module passed to
   /// this function call is expected to be the contained module.  The module
   /// is passed as a parameter here to prepare for multiple module support in
   /// the future.
   std::unique_ptr<MemoryBuffer> emitObject(Module *M);

   void notifyObjectLoaded(const object::ObjectFile &Obj,
                           const RuntimeDyld::LoadedObjectInfo &L);
   void notifyFreeingObject(const object::ObjectFile &Obj);

   JITSymbol findExistingSymbol(const std::string &Name);
   Module *findModuleForSymbol(const std::string &Name, bool CheckFunctionsOnly);
 };

 } // end llvm namespace

 #endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
	//===-- MCJIT.h - Class definition for the MCJIT ----------------- C++ --===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
	#define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H

	#include "llvm/ADT/SmallPtrSet.h"
	#include "llvm/ADT/SmallVector.h"
	#include "llvm/ExecutionEngine/ExecutionEngine.h"
	#include "llvm/ExecutionEngine/ObjectCache.h"
	#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
	#include "llvm/ExecutionEngine/RuntimeDyld.h"
	#include "llvm/IR/Module.h"
	#include "llvm/Support/SmallVectorMemoryBuffer.h"

	namespace llvm {
	class MCJIT;

	// This is a helper class that the MCJIT execution engine uses for linking
	// functions across modules that it owns. It aggregates the memory manager
	// that is passed in to the MCJIT constructor and defers most functionality
	// to that object.
	class LinkingSymbolResolver : public LegacyJITSymbolResolver {
	public:
	LinkingSymbolResolver(MCJIT &Parent,
	std::shared_ptr<LegacyJITSymbolResolver> Resolver)
	: ParentEngine(Parent), ClientResolver(std::move(Resolver)) {}

	JITSymbol findSymbol(const std::string &Name) override;

	// MCJIT doesn't support logical dylibs.
	JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {
	return nullptr;
	}

	private:
	MCJIT &ParentEngine;
	std::shared_ptr<LegacyJITSymbolResolver> ClientResolver;
	void anchor() override;
	};

	// About Module states: added->loaded->finalized.
	//
	// The purpose of the "added" state is having modules in standby. (added=known
	// but not compiled). The idea is that you can add a module to provide function
	// definitions but if nothing in that module is referenced by a module in which
	// a function is executed (note the wording here because it's not exactly the
	// ideal case) then the module never gets compiled. This is sort of lazy
	// compilation.
	//
	// The purpose of the "loaded" state (loaded=compiled and required sections
	// copied into local memory but not yet ready for execution) is to have an
	// intermediate state wherein clients can remap the addresses of sections, using
	// MCJIT::mapSectionAddress, (in preparation for later copying to a new location
	// or an external process) before relocations and page permissions are applied.
	//
	// It might not be obvious at first glance, but the "remote-mcjit" case in the
	// lli tool does this. In that case, the intermediate action is taken by the
	// RemoteMemoryManager in response to the notifyObjectLoaded function being
	// called.

	class MCJIT : public ExecutionEngine {
	MCJIT(std::unique_ptr<Module> M, std::unique_ptr<TargetMachine> tm,
	std::shared_ptr<MCJITMemoryManager> MemMgr,
	std::shared_ptr<LegacyJITSymbolResolver> Resolver);

	typedef llvm::SmallPtrSet<Module *, 4> ModulePtrSet;

	class OwningModuleContainer {
	public:
	OwningModuleContainer() {
	}
	~OwningModuleContainer() {
	freeModulePtrSet(AddedModules);
	freeModulePtrSet(LoadedModules);
	freeModulePtrSet(FinalizedModules);
	}

	ModulePtrSet::iterator begin_added() { return AddedModules.begin(); }
	ModulePtrSet::iterator end_added() { return AddedModules.end(); }
	iterator_range<ModulePtrSet::iterator> added() {
	return make_range(begin_added(), end_added());
	}

	ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); }
	ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); }

	ModulePtrSet::iterator begin_finalized() { return FinalizedModules.begin(); }
	ModulePtrSet::iterator end_finalized() { return FinalizedModules.end(); }

	void addModule(std::unique_ptr<Module> M) {
	AddedModules.insert(M.release());
	}

	bool removeModule(Module *M) {
	return AddedModules.erase(M) \|\| LoadedModules.erase(M) \|\|
	FinalizedModules.erase(M);
	}

	bool hasModuleBeenAddedButNotLoaded(Module *M) {
	return AddedModules.count(M) != 0;
	}

	bool hasModuleBeenLoaded(Module *M) {
	// If the module is in either the "loaded" or "finalized" sections it
	// has been loaded.
	return (LoadedModules.count(M) != 0 ) \|\| (FinalizedModules.count(M) != 0);
	}

	bool hasModuleBeenFinalized(Module *M) {
	return FinalizedModules.count(M) != 0;
	}

	bool ownsModule(Module* M) {
	return (AddedModules.count(M) != 0) \|\| (LoadedModules.count(M) != 0) \|\|
	(FinalizedModules.count(M) != 0);
	}

	void markModuleAsLoaded(Module *M) {
	// This checks against logic errors in the MCJIT implementation.
	// This function should never be called with either a Module that MCJIT
	// does not own or a Module that has already been loaded and/or finalized.
	assert(AddedModules.count(M) &&
	"markModuleAsLoaded: Module not found in AddedModules");

	// Remove the module from the "Added" set.
	AddedModules.erase(M);

	// Add the Module to the "Loaded" set.
	LoadedModules.insert(M);
	}

	void markModuleAsFinalized(Module *M) {
	// This checks against logic errors in the MCJIT implementation.
	// This function should never be called with either a Module that MCJIT
	// does not own, a Module that has not been loaded or a Module that has
	// already been finalized.
	assert(LoadedModules.count(M) &&
	"markModuleAsFinalized: Module not found in LoadedModules");

	// Remove the module from the "Loaded" section of the list.
	LoadedModules.erase(M);

	// Add the Module to the "Finalized" section of the list by inserting it
	// before the 'end' iterator.
	FinalizedModules.insert(M);
	}

	void markAllLoadedModulesAsFinalized() {
	for (ModulePtrSet::iterator I = LoadedModules.begin(),
	E = LoadedModules.end();
	I != E; ++I) {
	Module M = I;
	FinalizedModules.insert(M);
	}
	LoadedModules.clear();
	}

	private:
	ModulePtrSet AddedModules;
	ModulePtrSet LoadedModules;
	ModulePtrSet FinalizedModules;

	void freeModulePtrSet(ModulePtrSet& MPS) {
	// Go through the module set and delete everything.
	for (ModulePtrSet::iterator I = MPS.begin(), E = MPS.end(); I != E; ++I) {
	Module M = I;
	delete M;
	}
	MPS.clear();
	}
	};

	std::unique_ptr<TargetMachine> TM;
	MCContext *Ctx;
	std::shared_ptr<MCJITMemoryManager> MemMgr;
	LinkingSymbolResolver Resolver;
	RuntimeDyld Dyld;
	std::vector<JITEventListener*> EventListeners;

	OwningModuleContainer OwnedModules;

	SmallVector<object::OwningBinary<object::Archive>, 2> Archives;
	SmallVector<std::unique_ptr<MemoryBuffer>, 2> Buffers;

	SmallVector<std::unique_ptr<object::ObjectFile>, 2> LoadedObjects;

	// An optional ObjectCache to be notified of compiled objects and used to
	// perform lookup of pre-compiled code to avoid re-compilation.
	ObjectCache *ObjCache;

	Function *FindFunctionNamedInModulePtrSet(StringRef FnName,
	ModulePtrSet::iterator I,
	ModulePtrSet::iterator E);

	GlobalVariable *FindGlobalVariableNamedInModulePtrSet(StringRef Name,
	bool AllowInternal,
	ModulePtrSet::iterator I,
	ModulePtrSet::iterator E);

	void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors,
	ModulePtrSet::iterator I,
	ModulePtrSet::iterator E);

	public:
	~MCJIT() override;

	/// @name ExecutionEngine interface implementation
	/// @{
	void addModule(std::unique_ptr<Module> M) override;
	void addObjectFile(std::unique_ptr<object::ObjectFile> O) override;
	void addObjectFile(object::OwningBinary<object::ObjectFile> O) override;
	void addArchive(object::OwningBinary<object::Archive> O) override;
	bool removeModule(Module *M) override;

	/// FindFunctionNamed - Search all of the active modules to find the function that
	/// defines FnName. This is very slow operation and shouldn't be used for
	/// general code.
	Function *FindFunctionNamed(StringRef FnName) override;

	/// FindGlobalVariableNamed - Search all of the active modules to find the
	/// global variable that defines Name. This is very slow operation and
	/// shouldn't be used for general code.
	GlobalVariable *FindGlobalVariableNamed(StringRef Name,
	bool AllowInternal = false) override;

	/// Sets the object manager that MCJIT should use to avoid compilation.
	void setObjectCache(ObjectCache *manager) override;

	void setProcessAllSections(bool ProcessAllSections) override {
	Dyld.setProcessAllSections(ProcessAllSections);
	}

	void generateCodeForModule(Module *M) override;

	/// finalizeObject - ensure the module is fully processed and is usable.
	///
	/// It is the user-level function for completing the process of making the
	/// object usable for execution. It should be called after sections within an
	/// object have been relocated using mapSectionAddress. When this method is
	/// called the MCJIT execution engine will reapply relocations for a loaded
	/// object.
	/// Is it OK to finalize a set of modules, add modules and finalize again.
	// FIXME: Do we really need both of these?
	void finalizeObject() override;
	virtual void finalizeModule(Module *);
	void finalizeLoadedModules();

	/// runStaticConstructorsDestructors - This method is used to execute all of
	/// the static constructors or destructors for a program.
	///
	/// \param isDtors - Run the destructors instead of constructors.
	void runStaticConstructorsDestructors(bool isDtors) override;

	void getPointerToFunction(Function F) override;

	GenericValue runFunction(Function *F,
	ArrayRef<GenericValue> ArgValues) override;

	/// getPointerToNamedFunction - This method returns the address of the
	/// specified function by using the dlsym function call. As such it is only
	/// useful for resolving library symbols, not code generated symbols.
	///
	/// If AbortOnFailure is false and no function with the given name is
	/// found, this function silently returns a null pointer. Otherwise,
	/// it prints a message to stderr and aborts.
	///
	void *getPointerToNamedFunction(StringRef Name,
	bool AbortOnFailure = true) override;

	/// mapSectionAddress - map a section to its target address space value.
	/// Map the address of a JIT section as returned from the memory manager
	/// to the address in the target process as the running code will see it.
	/// This is the address which will be used for relocation resolution.
	void mapSectionAddress(const void *LocalAddress,
	uint64_t TargetAddress) override {
	Dyld.mapSectionAddress(LocalAddress, TargetAddress);
	}
	void RegisterJITEventListener(JITEventListener *L) override;
	void UnregisterJITEventListener(JITEventListener *L) override;

	// If successful, these function will implicitly finalize all loaded objects.
	// To get a function address within MCJIT without causing a finalize, use
	// getSymbolAddress.
	uint64_t getGlobalValueAddress(const std::string &Name) override;
	uint64_t getFunctionAddress(const std::string &Name) override;

	TargetMachine *getTargetMachine() override { return TM.get(); }

	/// @}
	/// @name (Private) Registration Interfaces
	/// @{

	static void Register() {
	MCJITCtor = createJIT;
	}

	static ExecutionEngine *
	createJIT(std::unique_ptr<Module> M, std::string *ErrorStr,
	std::shared_ptr<MCJITMemoryManager> MemMgr,
	std::shared_ptr<LegacyJITSymbolResolver> Resolver,
	std::unique_ptr<TargetMachine> TM);

	// @}

	// Takes a mangled name and returns the corresponding JITSymbol (if a
	// definition of that mangled name has been added to the JIT).
	JITSymbol findSymbol(const std::string &Name, bool CheckFunctionsOnly);

	// DEPRECATED - Please use findSymbol instead.
	//
	// This is not directly exposed via the ExecutionEngine API, but it is
	// used by the LinkingMemoryManager.
	//
	// getSymbolAddress takes an unmangled name and returns the corresponding
	// JITSymbol if a definition of the name has been added to the JIT.
	uint64_t getSymbolAddress(const std::string &Name,
	bool CheckFunctionsOnly);

	protected:
	/// emitObject -- Generate a JITed object in memory from the specified module
	/// Currently, MCJIT only supports a single module and the module passed to
	/// this function call is expected to be the contained module. The module
	/// is passed as a parameter here to prepare for multiple module support in
	/// the future.
	std::unique_ptr<MemoryBuffer> emitObject(Module *M);

	void notifyObjectLoaded(const object::ObjectFile &Obj,
	const RuntimeDyld::LoadedObjectInfo &L);
	void notifyFreeingObject(const object::ObjectFile &Obj);

	JITSymbol findExistingSymbol(const std::string &Name);
	Module *findModuleForSymbol(const std::string &Name, bool CheckFunctionsOnly);
	};

	} // end llvm namespace

	#endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H