1 //===-- MCJIT.h - Class definition for the MCJIT ----------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H 11 #define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H 12 13 #include "llvm/ADT/DenseMap.h" 14 #include "llvm/ADT/SmallPtrSet.h" 15 #include "llvm/ADT/SmallVector.h" 16 #include "llvm/ExecutionEngine/ExecutionEngine.h" 17 #include "llvm/ExecutionEngine/ObjectCache.h" 18 #include "llvm/ExecutionEngine/ObjectMemoryBuffer.h" 19 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h" 20 #include "llvm/ExecutionEngine/RuntimeDyld.h" 21 #include "llvm/IR/Module.h" 22 23 namespace llvm { 24 class MCJIT; 25 26 // This is a helper class that the MCJIT execution engine uses for linking 27 // functions across modules that it owns. It aggregates the memory manager 28 // that is passed in to the MCJIT constructor and defers most functionality 29 // to that object. 30 class LinkingSymbolResolver : public RuntimeDyld::SymbolResolver { 31 public: 32 LinkingSymbolResolver(MCJIT &Parent, 33 std::shared_ptr<RuntimeDyld::SymbolResolver> Resolver) 34 : ParentEngine(Parent), ClientResolver(std::move(Resolver)) {} 35 36 RuntimeDyld::SymbolInfo findSymbol(const std::string &Name) override; 37 38 // MCJIT doesn't support logical dylibs. 39 RuntimeDyld::SymbolInfo 40 findSymbolInLogicalDylib(const std::string &Name) override { 41 return nullptr; 42 } 43 44 private: 45 MCJIT &ParentEngine; 46 std::shared_ptr<RuntimeDyld::SymbolResolver> ClientResolver; 47 }; 48 49 // About Module states: added->loaded->finalized. 50 // 51 // The purpose of the "added" state is having modules in standby. (added=known 52 // but not compiled). The idea is that you can add a module to provide function 53 // definitions but if nothing in that module is referenced by a module in which 54 // a function is executed (note the wording here because it's not exactly the 55 // ideal case) then the module never gets compiled. This is sort of lazy 56 // compilation. 57 // 58 // The purpose of the "loaded" state (loaded=compiled and required sections 59 // copied into local memory but not yet ready for execution) is to have an 60 // intermediate state wherein clients can remap the addresses of sections, using 61 // MCJIT::mapSectionAddress, (in preparation for later copying to a new location 62 // or an external process) before relocations and page permissions are applied. 63 // 64 // It might not be obvious at first glance, but the "remote-mcjit" case in the 65 // lli tool does this. In that case, the intermediate action is taken by the 66 // RemoteMemoryManager in response to the notifyObjectLoaded function being 67 // called. 68 69 class MCJIT : public ExecutionEngine { 70 MCJIT(std::unique_ptr<Module> M, std::unique_ptr<TargetMachine> tm, 71 std::shared_ptr<MCJITMemoryManager> MemMgr, 72 std::shared_ptr<RuntimeDyld::SymbolResolver> Resolver); 73 74 typedef llvm::SmallPtrSet<Module *, 4> ModulePtrSet; 75 76 class OwningModuleContainer { 77 public: 78 OwningModuleContainer() { 79 } 80 ~OwningModuleContainer() { 81 freeModulePtrSet(AddedModules); 82 freeModulePtrSet(LoadedModules); 83 freeModulePtrSet(FinalizedModules); 84 } 85 86 ModulePtrSet::iterator begin_added() { return AddedModules.begin(); } 87 ModulePtrSet::iterator end_added() { return AddedModules.end(); } 88 iterator_range<ModulePtrSet::iterator> added() { 89 return make_range(begin_added(), end_added()); 90 } 91 92 ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); } 93 ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); } 94 95 ModulePtrSet::iterator begin_finalized() { return FinalizedModules.begin(); } 96 ModulePtrSet::iterator end_finalized() { return FinalizedModules.end(); } 97 98 void addModule(std::unique_ptr<Module> M) { 99 AddedModules.insert(M.release()); 100 } 101 102 bool removeModule(Module *M) { 103 return AddedModules.erase(M) || LoadedModules.erase(M) || 104 FinalizedModules.erase(M); 105 } 106 107 bool hasModuleBeenAddedButNotLoaded(Module *M) { 108 return AddedModules.count(M) != 0; 109 } 110 111 bool hasModuleBeenLoaded(Module *M) { 112 // If the module is in either the "loaded" or "finalized" sections it 113 // has been loaded. 114 return (LoadedModules.count(M) != 0 ) || (FinalizedModules.count(M) != 0); 115 } 116 117 bool hasModuleBeenFinalized(Module *M) { 118 return FinalizedModules.count(M) != 0; 119 } 120 121 bool ownsModule(Module* M) { 122 return (AddedModules.count(M) != 0) || (LoadedModules.count(M) != 0) || 123 (FinalizedModules.count(M) != 0); 124 } 125 126 void markModuleAsLoaded(Module *M) { 127 // This checks against logic errors in the MCJIT implementation. 128 // This function should never be called with either a Module that MCJIT 129 // does not own or a Module that has already been loaded and/or finalized. 130 assert(AddedModules.count(M) && 131 "markModuleAsLoaded: Module not found in AddedModules"); 132 133 // Remove the module from the "Added" set. 134 AddedModules.erase(M); 135 136 // Add the Module to the "Loaded" set. 137 LoadedModules.insert(M); 138 } 139 140 void markModuleAsFinalized(Module *M) { 141 // This checks against logic errors in the MCJIT implementation. 142 // This function should never be called with either a Module that MCJIT 143 // does not own, a Module that has not been loaded or a Module that has 144 // already been finalized. 145 assert(LoadedModules.count(M) && 146 "markModuleAsFinalized: Module not found in LoadedModules"); 147 148 // Remove the module from the "Loaded" section of the list. 149 LoadedModules.erase(M); 150 151 // Add the Module to the "Finalized" section of the list by inserting it 152 // before the 'end' iterator. 153 FinalizedModules.insert(M); 154 } 155 156 void markAllLoadedModulesAsFinalized() { 157 for (ModulePtrSet::iterator I = LoadedModules.begin(), 158 E = LoadedModules.end(); 159 I != E; ++I) { 160 Module *M = *I; 161 FinalizedModules.insert(M); 162 } 163 LoadedModules.clear(); 164 } 165 166 private: 167 ModulePtrSet AddedModules; 168 ModulePtrSet LoadedModules; 169 ModulePtrSet FinalizedModules; 170 171 void freeModulePtrSet(ModulePtrSet& MPS) { 172 // Go through the module set and delete everything. 173 for (ModulePtrSet::iterator I = MPS.begin(), E = MPS.end(); I != E; ++I) { 174 Module *M = *I; 175 delete M; 176 } 177 MPS.clear(); 178 } 179 }; 180 181 std::unique_ptr<TargetMachine> TM; 182 MCContext *Ctx; 183 std::shared_ptr<MCJITMemoryManager> MemMgr; 184 LinkingSymbolResolver Resolver; 185 RuntimeDyld Dyld; 186 std::vector<JITEventListener*> EventListeners; 187 188 OwningModuleContainer OwnedModules; 189 190 SmallVector<object::OwningBinary<object::Archive>, 2> Archives; 191 SmallVector<std::unique_ptr<MemoryBuffer>, 2> Buffers; 192 193 SmallVector<std::unique_ptr<object::ObjectFile>, 2> LoadedObjects; 194 195 // An optional ObjectCache to be notified of compiled objects and used to 196 // perform lookup of pre-compiled code to avoid re-compilation. 197 ObjectCache *ObjCache; 198 199 Function *FindFunctionNamedInModulePtrSet(const char *FnName, 200 ModulePtrSet::iterator I, 201 ModulePtrSet::iterator E); 202 203 GlobalVariable *FindGlobalVariableNamedInModulePtrSet(const char *Name, 204 bool AllowInternal, 205 ModulePtrSet::iterator I, 206 ModulePtrSet::iterator E); 207 208 void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors, 209 ModulePtrSet::iterator I, 210 ModulePtrSet::iterator E); 211 212 public: 213 ~MCJIT() override; 214 215 /// @name ExecutionEngine interface implementation 216 /// @{ 217 void addModule(std::unique_ptr<Module> M) override; 218 void addObjectFile(std::unique_ptr<object::ObjectFile> O) override; 219 void addObjectFile(object::OwningBinary<object::ObjectFile> O) override; 220 void addArchive(object::OwningBinary<object::Archive> O) override; 221 bool removeModule(Module *M) override; 222 223 /// FindFunctionNamed - Search all of the active modules to find the function that 224 /// defines FnName. This is very slow operation and shouldn't be used for 225 /// general code. 226 Function *FindFunctionNamed(const char *FnName) override; 227 228 /// FindGlobalVariableNamed - Search all of the active modules to find the 229 /// global variable that defines Name. This is very slow operation and 230 /// shouldn't be used for general code. 231 GlobalVariable *FindGlobalVariableNamed(const char *Name, 232 bool AllowInternal = false) override; 233 234 /// Sets the object manager that MCJIT should use to avoid compilation. 235 void setObjectCache(ObjectCache *manager) override; 236 237 void setProcessAllSections(bool ProcessAllSections) override { 238 Dyld.setProcessAllSections(ProcessAllSections); 239 } 240 241 void generateCodeForModule(Module *M) override; 242 243 /// finalizeObject - ensure the module is fully processed and is usable. 244 /// 245 /// It is the user-level function for completing the process of making the 246 /// object usable for execution. It should be called after sections within an 247 /// object have been relocated using mapSectionAddress. When this method is 248 /// called the MCJIT execution engine will reapply relocations for a loaded 249 /// object. 250 /// Is it OK to finalize a set of modules, add modules and finalize again. 251 // FIXME: Do we really need both of these? 252 void finalizeObject() override; 253 virtual void finalizeModule(Module *); 254 void finalizeLoadedModules(); 255 256 /// runStaticConstructorsDestructors - This method is used to execute all of 257 /// the static constructors or destructors for a program. 258 /// 259 /// \param isDtors - Run the destructors instead of constructors. 260 void runStaticConstructorsDestructors(bool isDtors) override; 261 262 void *getPointerToFunction(Function *F) override; 263 264 GenericValue runFunction(Function *F, 265 ArrayRef<GenericValue> ArgValues) override; 266 267 /// getPointerToNamedFunction - This method returns the address of the 268 /// specified function by using the dlsym function call. As such it is only 269 /// useful for resolving library symbols, not code generated symbols. 270 /// 271 /// If AbortOnFailure is false and no function with the given name is 272 /// found, this function silently returns a null pointer. Otherwise, 273 /// it prints a message to stderr and aborts. 274 /// 275 void *getPointerToNamedFunction(StringRef Name, 276 bool AbortOnFailure = true) override; 277 278 /// mapSectionAddress - map a section to its target address space value. 279 /// Map the address of a JIT section as returned from the memory manager 280 /// to the address in the target process as the running code will see it. 281 /// This is the address which will be used for relocation resolution. 282 void mapSectionAddress(const void *LocalAddress, 283 uint64_t TargetAddress) override { 284 Dyld.mapSectionAddress(LocalAddress, TargetAddress); 285 } 286 void RegisterJITEventListener(JITEventListener *L) override; 287 void UnregisterJITEventListener(JITEventListener *L) override; 288 289 // If successful, these function will implicitly finalize all loaded objects. 290 // To get a function address within MCJIT without causing a finalize, use 291 // getSymbolAddress. 292 uint64_t getGlobalValueAddress(const std::string &Name) override; 293 uint64_t getFunctionAddress(const std::string &Name) override; 294 295 TargetMachine *getTargetMachine() override { return TM.get(); } 296 297 /// @} 298 /// @name (Private) Registration Interfaces 299 /// @{ 300 301 static void Register() { 302 MCJITCtor = createJIT; 303 } 304 305 static ExecutionEngine* 306 createJIT(std::unique_ptr<Module> M, 307 std::string *ErrorStr, 308 std::shared_ptr<MCJITMemoryManager> MemMgr, 309 std::shared_ptr<RuntimeDyld::SymbolResolver> Resolver, 310 std::unique_ptr<TargetMachine> TM); 311 312 // @} 313 314 RuntimeDyld::SymbolInfo findSymbol(const std::string &Name, 315 bool CheckFunctionsOnly); 316 // DEPRECATED - Please use findSymbol instead. 317 // This is not directly exposed via the ExecutionEngine API, but it is 318 // used by the LinkingMemoryManager. 319 uint64_t getSymbolAddress(const std::string &Name, 320 bool CheckFunctionsOnly); 321 322 protected: 323 /// emitObject -- Generate a JITed object in memory from the specified module 324 /// Currently, MCJIT only supports a single module and the module passed to 325 /// this function call is expected to be the contained module. The module 326 /// is passed as a parameter here to prepare for multiple module support in 327 /// the future. 328 std::unique_ptr<MemoryBuffer> emitObject(Module *M); 329 330 void NotifyObjectEmitted(const object::ObjectFile& Obj, 331 const RuntimeDyld::LoadedObjectInfo &L); 332 void NotifyFreeingObject(const object::ObjectFile& Obj); 333 334 RuntimeDyld::SymbolInfo findExistingSymbol(const std::string &Name); 335 Module *findModuleForSymbol(const std::string &Name, 336 bool CheckFunctionsOnly); 337 }; 338 339 } // end llvm namespace 340 341 #endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H 342