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1//===-- MCJIT.h - Class definition for the MCJIT ----------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H10#define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H11 12#include "llvm/ADT/SmallPtrSet.h"13#include "llvm/ADT/SmallVector.h"14#include "llvm/ExecutionEngine/ExecutionEngine.h"15#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"16#include "llvm/ExecutionEngine/RuntimeDyld.h"17 18namespace llvm {19class MCJIT;20class Module;21class ObjectCache;22 23// This is a helper class that the MCJIT execution engine uses for linking24// functions across modules that it owns. It aggregates the memory manager25// that is passed in to the MCJIT constructor and defers most functionality26// to that object.27class LinkingSymbolResolver : public LegacyJITSymbolResolver {28public:29 LinkingSymbolResolver(MCJIT &Parent,30 std::shared_ptr<LegacyJITSymbolResolver> Resolver)31 : ParentEngine(Parent), ClientResolver(std::move(Resolver)) {}32 33 JITSymbol findSymbol(const std::string &Name) override;34 35 // MCJIT doesn't support logical dylibs.36 JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {37 return nullptr;38 }39 40private:41 MCJIT &ParentEngine;42 std::shared_ptr<LegacyJITSymbolResolver> ClientResolver;43 void anchor() override;44};45 46// About Module states: added->loaded->finalized.47//48// The purpose of the "added" state is having modules in standby. (added=known49// but not compiled). The idea is that you can add a module to provide function50// definitions but if nothing in that module is referenced by a module in which51// a function is executed (note the wording here because it's not exactly the52// ideal case) then the module never gets compiled. This is sort of lazy53// compilation.54//55// The purpose of the "loaded" state (loaded=compiled and required sections56// copied into local memory but not yet ready for execution) is to have an57// intermediate state wherein clients can remap the addresses of sections, using58// MCJIT::mapSectionAddress, (in preparation for later copying to a new location59// or an external process) before relocations and page permissions are applied.60//61// It might not be obvious at first glance, but the "remote-mcjit" case in the62// lli tool does this. In that case, the intermediate action is taken by the63// RemoteMemoryManager in response to the notifyObjectLoaded function being64// called.65 66class MCJIT : public ExecutionEngine {67 MCJIT(std::unique_ptr<Module> M, std::unique_ptr<TargetMachine> tm,68 std::shared_ptr<MCJITMemoryManager> MemMgr,69 std::shared_ptr<LegacyJITSymbolResolver> Resolver);70 71 typedef llvm::SmallPtrSet<Module *, 4> ModulePtrSet;72 73 class OwningModuleContainer {74 public:75 OwningModuleContainer() = default;76 ~OwningModuleContainer() {77 freeModulePtrSet(AddedModules);78 freeModulePtrSet(LoadedModules);79 freeModulePtrSet(FinalizedModules);80 }81 82 ModulePtrSet::iterator begin_added() { return AddedModules.begin(); }83 ModulePtrSet::iterator end_added() { return AddedModules.end(); }84 iterator_range<ModulePtrSet::iterator> added() {85 return make_range(begin_added(), end_added());86 }87 88 ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); }89 ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); }90 91 ModulePtrSet::iterator begin_finalized() { return FinalizedModules.begin(); }92 ModulePtrSet::iterator end_finalized() { return FinalizedModules.end(); }93 94 void addModule(std::unique_ptr<Module> M) {95 AddedModules.insert(M.release());96 }97 98 bool removeModule(Module *M) {99 return AddedModules.erase(M) || LoadedModules.erase(M) ||100 FinalizedModules.erase(M);101 }102 103 bool hasModuleBeenAddedButNotLoaded(Module *M) {104 return AddedModules.contains(M);105 }106 107 bool hasModuleBeenLoaded(Module *M) {108 // If the module is in either the "loaded" or "finalized" sections it109 // has been loaded.110 return LoadedModules.contains(M) || FinalizedModules.contains(M);111 }112 113 bool hasModuleBeenFinalized(Module *M) {114 return FinalizedModules.contains(M);115 }116 117 bool ownsModule(Module* M) {118 return AddedModules.contains(M) || LoadedModules.contains(M) ||119 FinalizedModules.contains(M);120 }121 122 void markModuleAsLoaded(Module *M) {123 // This checks against logic errors in the MCJIT implementation.124 // This function should never be called with either a Module that MCJIT125 // does not own or a Module that has already been loaded and/or finalized.126 assert(AddedModules.count(M) &&127 "markModuleAsLoaded: Module not found in AddedModules");128 129 // Remove the module from the "Added" set.130 AddedModules.erase(M);131 132 // Add the Module to the "Loaded" set.133 LoadedModules.insert(M);134 }135 136 void markModuleAsFinalized(Module *M) {137 // This checks against logic errors in the MCJIT implementation.138 // This function should never be called with either a Module that MCJIT139 // does not own, a Module that has not been loaded or a Module that has140 // already been finalized.141 assert(LoadedModules.count(M) &&142 "markModuleAsFinalized: Module not found in LoadedModules");143 144 // Remove the module from the "Loaded" section of the list.145 LoadedModules.erase(M);146 147 // Add the Module to the "Finalized" section of the list by inserting it148 // before the 'end' iterator.149 FinalizedModules.insert(M);150 }151 152 void markAllLoadedModulesAsFinalized() {153 FinalizedModules.insert_range(LoadedModules);154 LoadedModules.clear();155 }156 157 private:158 ModulePtrSet AddedModules;159 ModulePtrSet LoadedModules;160 ModulePtrSet FinalizedModules;161 162 void freeModulePtrSet(ModulePtrSet& MPS) {163 // Go through the module set and delete everything.164 for (Module *M : MPS)165 delete M;166 MPS.clear();167 }168 };169 170 std::unique_ptr<TargetMachine> TM;171 MCContext *Ctx;172 std::shared_ptr<MCJITMemoryManager> MemMgr;173 LinkingSymbolResolver Resolver;174 RuntimeDyld Dyld;175 std::vector<JITEventListener*> EventListeners;176 177 OwningModuleContainer OwnedModules;178 179 SmallVector<object::OwningBinary<object::Archive>, 2> Archives;180 SmallVector<std::unique_ptr<MemoryBuffer>, 2> Buffers;181 182 SmallVector<std::unique_ptr<object::ObjectFile>, 2> LoadedObjects;183 184 // An optional ObjectCache to be notified of compiled objects and used to185 // perform lookup of pre-compiled code to avoid re-compilation.186 ObjectCache *ObjCache;187 188 Function *FindFunctionNamedInModulePtrSet(StringRef FnName,189 ModulePtrSet::iterator I,190 ModulePtrSet::iterator E);191 192 GlobalVariable *FindGlobalVariableNamedInModulePtrSet(StringRef Name,193 bool AllowInternal,194 ModulePtrSet::iterator I,195 ModulePtrSet::iterator E);196 197 void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors,198 ModulePtrSet::iterator I,199 ModulePtrSet::iterator E);200 201public:202 ~MCJIT() override;203 204 /// @name ExecutionEngine interface implementation205 /// @{206 void addModule(std::unique_ptr<Module> M) override;207 void addObjectFile(std::unique_ptr<object::ObjectFile> O) override;208 void addObjectFile(object::OwningBinary<object::ObjectFile> O) override;209 void addArchive(object::OwningBinary<object::Archive> O) override;210 bool removeModule(Module *M) override;211 212 /// FindFunctionNamed - Search all of the active modules to find the function that213 /// defines FnName. This is very slow operation and shouldn't be used for214 /// general code.215 Function *FindFunctionNamed(StringRef FnName) override;216 217 /// FindGlobalVariableNamed - Search all of the active modules to find the218 /// global variable that defines Name. This is very slow operation and219 /// shouldn't be used for general code.220 GlobalVariable *FindGlobalVariableNamed(StringRef Name,221 bool AllowInternal = false) override;222 223 /// Sets the object manager that MCJIT should use to avoid compilation.224 void setObjectCache(ObjectCache *manager) override;225 226 void setProcessAllSections(bool ProcessAllSections) override {227 Dyld.setProcessAllSections(ProcessAllSections);228 }229 230 void generateCodeForModule(Module *M) override;231 232 /// finalizeObject - ensure the module is fully processed and is usable.233 ///234 /// It is the user-level function for completing the process of making the235 /// object usable for execution. It should be called after sections within an236 /// object have been relocated using mapSectionAddress. When this method is237 /// called the MCJIT execution engine will reapply relocations for a loaded238 /// object.239 /// Is it OK to finalize a set of modules, add modules and finalize again.240 // FIXME: Do we really need both of these?241 void finalizeObject() override;242 virtual void finalizeModule(Module *);243 void finalizeLoadedModules();244 245 /// runStaticConstructorsDestructors - This method is used to execute all of246 /// the static constructors or destructors for a program.247 ///248 /// \param isDtors - Run the destructors instead of constructors.249 void runStaticConstructorsDestructors(bool isDtors) override;250 251 void *getPointerToFunction(Function *F) override;252 253 GenericValue runFunction(Function *F,254 ArrayRef<GenericValue> ArgValues) override;255 256 /// getPointerToNamedFunction - This method returns the address of the257 /// specified function by using the dlsym function call. As such it is only258 /// useful for resolving library symbols, not code generated symbols.259 ///260 /// If AbortOnFailure is false and no function with the given name is261 /// found, this function silently returns a null pointer. Otherwise,262 /// it prints a message to stderr and aborts.263 ///264 void *getPointerToNamedFunction(StringRef Name,265 bool AbortOnFailure = true) override;266 267 /// mapSectionAddress - map a section to its target address space value.268 /// Map the address of a JIT section as returned from the memory manager269 /// to the address in the target process as the running code will see it.270 /// This is the address which will be used for relocation resolution.271 void mapSectionAddress(const void *LocalAddress,272 uint64_t TargetAddress) override {273 Dyld.mapSectionAddress(LocalAddress, TargetAddress);274 }275 void RegisterJITEventListener(JITEventListener *L) override;276 void UnregisterJITEventListener(JITEventListener *L) override;277 278 // If successful, these function will implicitly finalize all loaded objects.279 // To get a function address within MCJIT without causing a finalize, use280 // getSymbolAddress.281 uint64_t getGlobalValueAddress(const std::string &Name) override;282 uint64_t getFunctionAddress(const std::string &Name) override;283 284 TargetMachine *getTargetMachine() override { return TM.get(); }285 286 /// @}287 /// @name (Private) Registration Interfaces288 /// @{289 290 static void Register() {291 MCJITCtor = createJIT;292 }293 294 static ExecutionEngine *295 createJIT(std::unique_ptr<Module> M, std::string *ErrorStr,296 std::shared_ptr<MCJITMemoryManager> MemMgr,297 std::shared_ptr<LegacyJITSymbolResolver> Resolver,298 std::unique_ptr<TargetMachine> TM);299 300 // @}301 302 // Takes a mangled name and returns the corresponding JITSymbol (if a303 // definition of that mangled name has been added to the JIT).304 JITSymbol findSymbol(const std::string &Name, bool CheckFunctionsOnly);305 306 // DEPRECATED - Please use findSymbol instead.307 //308 // This is not directly exposed via the ExecutionEngine API, but it is309 // used by the LinkingMemoryManager.310 //311 // getSymbolAddress takes an unmangled name and returns the corresponding312 // JITSymbol if a definition of the name has been added to the JIT.313 uint64_t getSymbolAddress(const std::string &Name,314 bool CheckFunctionsOnly);315 316protected:317 /// emitObject -- Generate a JITed object in memory from the specified module318 /// Currently, MCJIT only supports a single module and the module passed to319 /// this function call is expected to be the contained module. The module320 /// is passed as a parameter here to prepare for multiple module support in321 /// the future.322 std::unique_ptr<MemoryBuffer> emitObject(Module *M);323 324 void notifyObjectLoaded(const object::ObjectFile &Obj,325 const RuntimeDyld::LoadedObjectInfo &L);326 void notifyFreeingObject(const object::ObjectFile &Obj);327 328 JITSymbol findExistingSymbol(const std::string &Name);329 Module *findModuleForSymbol(const std::string &Name, bool CheckFunctionsOnly);330};331 332} // end llvm namespace333 334#endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H335