ExecutionEngine.h revision 251662
1//===- ExecutionEngine.h - Abstract Execution Engine Interface --*- 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// This file defines the abstract interface that implements execution support 11// for LLVM. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_EXECUTIONENGINE_EXECUTIONENGINE_H 16#define LLVM_EXECUTIONENGINE_EXECUTIONENGINE_H 17 18#include "llvm-c/ExecutionEngine.h" 19#include "llvm/ADT/DenseMap.h" 20#include "llvm/ADT/SmallVector.h" 21#include "llvm/ADT/StringRef.h" 22#include "llvm/ADT/ValueMap.h" 23#include "llvm/MC/MCCodeGenInfo.h" 24#include "llvm/Support/ErrorHandling.h" 25#include "llvm/Support/Mutex.h" 26#include "llvm/Support/ValueHandle.h" 27#include "llvm/Target/TargetMachine.h" 28#include "llvm/Target/TargetOptions.h" 29#include <map> 30#include <string> 31#include <vector> 32 33namespace llvm { 34 35struct GenericValue; 36class Constant; 37class ExecutionEngine; 38class Function; 39class GlobalVariable; 40class GlobalValue; 41class JITEventListener; 42class JITMemoryManager; 43class MachineCodeInfo; 44class Module; 45class MutexGuard; 46class ObjectCache; 47class DataLayout; 48class Triple; 49class Type; 50 51/// \brief Helper class for helping synchronize access to the global address map 52/// table. 53class ExecutionEngineState { 54public: 55 struct AddressMapConfig : public ValueMapConfig<const GlobalValue*> { 56 typedef ExecutionEngineState *ExtraData; 57 static sys::Mutex *getMutex(ExecutionEngineState *EES); 58 static void onDelete(ExecutionEngineState *EES, const GlobalValue *Old); 59 static void onRAUW(ExecutionEngineState *, const GlobalValue *, 60 const GlobalValue *); 61 }; 62 63 typedef ValueMap<const GlobalValue *, void *, AddressMapConfig> 64 GlobalAddressMapTy; 65 66private: 67 ExecutionEngine &EE; 68 69 /// GlobalAddressMap - A mapping between LLVM global values and their 70 /// actualized version... 71 GlobalAddressMapTy GlobalAddressMap; 72 73 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap, 74 /// used to convert raw addresses into the LLVM global value that is emitted 75 /// at the address. This map is not computed unless getGlobalValueAtAddress 76 /// is called at some point. 77 std::map<void *, AssertingVH<const GlobalValue> > GlobalAddressReverseMap; 78 79public: 80 ExecutionEngineState(ExecutionEngine &EE); 81 82 GlobalAddressMapTy &getGlobalAddressMap(const MutexGuard &) { 83 return GlobalAddressMap; 84 } 85 86 std::map<void*, AssertingVH<const GlobalValue> > & 87 getGlobalAddressReverseMap(const MutexGuard &) { 88 return GlobalAddressReverseMap; 89 } 90 91 /// \brief Erase an entry from the mapping table. 92 /// 93 /// \returns The address that \p ToUnmap was happed to. 94 void *RemoveMapping(const MutexGuard &, const GlobalValue *ToUnmap); 95}; 96 97/// \brief Abstract interface for implementation execution of LLVM modules, 98/// designed to support both interpreter and just-in-time (JIT) compiler 99/// implementations. 100class ExecutionEngine { 101 /// The state object holding the global address mapping, which must be 102 /// accessed synchronously. 103 // 104 // FIXME: There is no particular need the entire map needs to be 105 // synchronized. Wouldn't a reader-writer design be better here? 106 ExecutionEngineState EEState; 107 108 /// The target data for the platform for which execution is being performed. 109 const DataLayout *TD; 110 111 /// Whether lazy JIT compilation is enabled. 112 bool CompilingLazily; 113 114 /// Whether JIT compilation of external global variables is allowed. 115 bool GVCompilationDisabled; 116 117 /// Whether the JIT should perform lookups of external symbols (e.g., 118 /// using dlsym). 119 bool SymbolSearchingDisabled; 120 121 friend class EngineBuilder; // To allow access to JITCtor and InterpCtor. 122 123protected: 124 /// The list of Modules that we are JIT'ing from. We use a SmallVector to 125 /// optimize for the case where there is only one module. 126 SmallVector<Module*, 1> Modules; 127 128 void setDataLayout(const DataLayout *td) { TD = td; } 129 130 /// getMemoryforGV - Allocate memory for a global variable. 131 virtual char *getMemoryForGV(const GlobalVariable *GV); 132 133 // To avoid having libexecutionengine depend on the JIT and interpreter 134 // libraries, the execution engine implementations set these functions to ctor 135 // pointers at startup time if they are linked in. 136 static ExecutionEngine *(*JITCtor)( 137 Module *M, 138 std::string *ErrorStr, 139 JITMemoryManager *JMM, 140 bool GVsWithCode, 141 TargetMachine *TM); 142 static ExecutionEngine *(*MCJITCtor)( 143 Module *M, 144 std::string *ErrorStr, 145 JITMemoryManager *JMM, 146 bool GVsWithCode, 147 TargetMachine *TM); 148 static ExecutionEngine *(*InterpCtor)(Module *M, std::string *ErrorStr); 149 150 /// LazyFunctionCreator - If an unknown function is needed, this function 151 /// pointer is invoked to create it. If this returns null, the JIT will 152 /// abort. 153 void *(*LazyFunctionCreator)(const std::string &); 154 155 /// ExceptionTableRegister - If Exception Handling is set, the JIT will 156 /// register dwarf tables with this function. 157 typedef void (*EERegisterFn)(void*); 158 EERegisterFn ExceptionTableRegister; 159 EERegisterFn ExceptionTableDeregister; 160 /// This maps functions to their exception tables frames. 161 DenseMap<const Function*, void*> AllExceptionTables; 162 163 164public: 165 /// lock - This lock protects the ExecutionEngine, JIT, JITResolver and 166 /// JITEmitter classes. It must be held while changing the internal state of 167 /// any of those classes. 168 sys::Mutex lock; 169 170 //===--------------------------------------------------------------------===// 171 // ExecutionEngine Startup 172 //===--------------------------------------------------------------------===// 173 174 virtual ~ExecutionEngine(); 175 176 /// create - This is the factory method for creating an execution engine which 177 /// is appropriate for the current machine. This takes ownership of the 178 /// module. 179 /// 180 /// \param GVsWithCode - Allocating globals with code breaks 181 /// freeMachineCodeForFunction and is probably unsafe and bad for performance. 182 /// However, we have clients who depend on this behavior, so we must support 183 /// it. Eventually, when we're willing to break some backwards compatibility, 184 /// this flag should be flipped to false, so that by default 185 /// freeMachineCodeForFunction works. 186 static ExecutionEngine *create(Module *M, 187 bool ForceInterpreter = false, 188 std::string *ErrorStr = 0, 189 CodeGenOpt::Level OptLevel = 190 CodeGenOpt::Default, 191 bool GVsWithCode = true); 192 193 /// createJIT - This is the factory method for creating a JIT for the current 194 /// machine, it does not fall back to the interpreter. This takes ownership 195 /// of the Module and JITMemoryManager if successful. 196 /// 197 /// Clients should make sure to initialize targets prior to calling this 198 /// function. 199 static ExecutionEngine *createJIT(Module *M, 200 std::string *ErrorStr = 0, 201 JITMemoryManager *JMM = 0, 202 CodeGenOpt::Level OptLevel = 203 CodeGenOpt::Default, 204 bool GVsWithCode = true, 205 Reloc::Model RM = Reloc::Default, 206 CodeModel::Model CMM = 207 CodeModel::JITDefault); 208 209 /// addModule - Add a Module to the list of modules that we can JIT from. 210 /// Note that this takes ownership of the Module: when the ExecutionEngine is 211 /// destroyed, it destroys the Module as well. 212 virtual void addModule(Module *M) { 213 Modules.push_back(M); 214 } 215 216 //===--------------------------------------------------------------------===// 217 218 const DataLayout *getDataLayout() const { return TD; } 219 220 /// removeModule - Remove a Module from the list of modules. Returns true if 221 /// M is found. 222 virtual bool removeModule(Module *M); 223 224 /// FindFunctionNamed - Search all of the active modules to find the one that 225 /// defines FnName. This is very slow operation and shouldn't be used for 226 /// general code. 227 Function *FindFunctionNamed(const char *FnName); 228 229 /// runFunction - Execute the specified function with the specified arguments, 230 /// and return the result. 231 virtual GenericValue runFunction(Function *F, 232 const std::vector<GenericValue> &ArgValues) = 0; 233 234 /// getPointerToNamedFunction - This method returns the address of the 235 /// specified function by using the dlsym function call. As such it is only 236 /// useful for resolving library symbols, not code generated symbols. 237 /// 238 /// If AbortOnFailure is false and no function with the given name is 239 /// found, this function silently returns a null pointer. Otherwise, 240 /// it prints a message to stderr and aborts. 241 /// 242 virtual void *getPointerToNamedFunction(const std::string &Name, 243 bool AbortOnFailure = true) = 0; 244 245 /// mapSectionAddress - map a section to its target address space value. 246 /// Map the address of a JIT section as returned from the memory manager 247 /// to the address in the target process as the running code will see it. 248 /// This is the address which will be used for relocation resolution. 249 virtual void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) { 250 llvm_unreachable("Re-mapping of section addresses not supported with this " 251 "EE!"); 252 } 253 254 // finalizeObject - This method should be called after sections within an 255 // object have been relocated using mapSectionAddress. When this method is 256 // called the MCJIT execution engine will reapply relocations for a loaded 257 // object. This method has no effect for the legacy JIT engine or the 258 // interpeter. 259 virtual void finalizeObject() {} 260 261 /// runStaticConstructorsDestructors - This method is used to execute all of 262 /// the static constructors or destructors for a program. 263 /// 264 /// \param isDtors - Run the destructors instead of constructors. 265 void runStaticConstructorsDestructors(bool isDtors); 266 267 /// runStaticConstructorsDestructors - This method is used to execute all of 268 /// the static constructors or destructors for a particular module. 269 /// 270 /// \param isDtors - Run the destructors instead of constructors. 271 void runStaticConstructorsDestructors(Module *module, bool isDtors); 272 273 274 /// runFunctionAsMain - This is a helper function which wraps runFunction to 275 /// handle the common task of starting up main with the specified argc, argv, 276 /// and envp parameters. 277 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv, 278 const char * const * envp); 279 280 281 /// addGlobalMapping - Tell the execution engine that the specified global is 282 /// at the specified location. This is used internally as functions are JIT'd 283 /// and as global variables are laid out in memory. It can and should also be 284 /// used by clients of the EE that want to have an LLVM global overlay 285 /// existing data in memory. Mappings are automatically removed when their 286 /// GlobalValue is destroyed. 287 void addGlobalMapping(const GlobalValue *GV, void *Addr); 288 289 /// clearAllGlobalMappings - Clear all global mappings and start over again, 290 /// for use in dynamic compilation scenarios to move globals. 291 void clearAllGlobalMappings(); 292 293 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a 294 /// particular module, because it has been removed from the JIT. 295 void clearGlobalMappingsFromModule(Module *M); 296 297 /// updateGlobalMapping - Replace an existing mapping for GV with a new 298 /// address. This updates both maps as required. If "Addr" is null, the 299 /// entry for the global is removed from the mappings. This returns the old 300 /// value of the pointer, or null if it was not in the map. 301 void *updateGlobalMapping(const GlobalValue *GV, void *Addr); 302 303 /// getPointerToGlobalIfAvailable - This returns the address of the specified 304 /// global value if it is has already been codegen'd, otherwise it returns 305 /// null. 306 void *getPointerToGlobalIfAvailable(const GlobalValue *GV); 307 308 /// getPointerToGlobal - This returns the address of the specified global 309 /// value. This may involve code generation if it's a function. 310 void *getPointerToGlobal(const GlobalValue *GV); 311 312 /// getPointerToFunction - The different EE's represent function bodies in 313 /// different ways. They should each implement this to say what a function 314 /// pointer should look like. When F is destroyed, the ExecutionEngine will 315 /// remove its global mapping and free any machine code. Be sure no threads 316 /// are running inside F when that happens. 317 virtual void *getPointerToFunction(Function *F) = 0; 318 319 /// getPointerToBasicBlock - The different EE's represent basic blocks in 320 /// different ways. Return the representation for a blockaddress of the 321 /// specified block. 322 virtual void *getPointerToBasicBlock(BasicBlock *BB) = 0; 323 324 /// getPointerToFunctionOrStub - If the specified function has been 325 /// code-gen'd, return a pointer to the function. If not, compile it, or use 326 /// a stub to implement lazy compilation if available. See 327 /// getPointerToFunction for the requirements on destroying F. 328 virtual void *getPointerToFunctionOrStub(Function *F) { 329 // Default implementation, just codegen the function. 330 return getPointerToFunction(F); 331 } 332 333 // The JIT overrides a version that actually does this. 334 virtual void runJITOnFunction(Function *, MachineCodeInfo * = 0) { } 335 336 /// getGlobalValueAtAddress - Return the LLVM global value object that starts 337 /// at the specified address. 338 /// 339 const GlobalValue *getGlobalValueAtAddress(void *Addr); 340 341 /// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr. 342 /// Ptr is the address of the memory at which to store Val, cast to 343 /// GenericValue *. It is not a pointer to a GenericValue containing the 344 /// address at which to store Val. 345 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr, 346 Type *Ty); 347 348 void InitializeMemory(const Constant *Init, void *Addr); 349 350 /// recompileAndRelinkFunction - This method is used to force a function which 351 /// has already been compiled to be compiled again, possibly after it has been 352 /// modified. Then the entry to the old copy is overwritten with a branch to 353 /// the new copy. If there was no old copy, this acts just like 354 /// VM::getPointerToFunction(). 355 virtual void *recompileAndRelinkFunction(Function *F) = 0; 356 357 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine 358 /// corresponding to the machine code emitted to execute this function, useful 359 /// for garbage-collecting generated code. 360 virtual void freeMachineCodeForFunction(Function *F) = 0; 361 362 /// getOrEmitGlobalVariable - Return the address of the specified global 363 /// variable, possibly emitting it to memory if needed. This is used by the 364 /// Emitter. 365 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) { 366 return getPointerToGlobal((const GlobalValue *)GV); 367 } 368 369 /// Registers a listener to be called back on various events within 370 /// the JIT. See JITEventListener.h for more details. Does not 371 /// take ownership of the argument. The argument may be NULL, in 372 /// which case these functions do nothing. 373 virtual void RegisterJITEventListener(JITEventListener *) {} 374 virtual void UnregisterJITEventListener(JITEventListener *) {} 375 376 /// Sets the pre-compiled object cache. The ownership of the ObjectCache is 377 /// not changed. Supported by MCJIT but not JIT. 378 virtual void setObjectCache(ObjectCache *) { 379 llvm_unreachable("No support for an object cache"); 380 } 381 382 /// DisableLazyCompilation - When lazy compilation is off (the default), the 383 /// JIT will eagerly compile every function reachable from the argument to 384 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only 385 /// compile the one function and emit stubs to compile the rest when they're 386 /// first called. If lazy compilation is turned off again while some lazy 387 /// stubs are still around, and one of those stubs is called, the program will 388 /// abort. 389 /// 390 /// In order to safely compile lazily in a threaded program, the user must 391 /// ensure that 1) only one thread at a time can call any particular lazy 392 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock 393 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a 394 /// lazy stub. See http://llvm.org/PR5184 for details. 395 void DisableLazyCompilation(bool Disabled = true) { 396 CompilingLazily = !Disabled; 397 } 398 bool isCompilingLazily() const { 399 return CompilingLazily; 400 } 401 // Deprecated in favor of isCompilingLazily (to reduce double-negatives). 402 // Remove this in LLVM 2.8. 403 bool isLazyCompilationDisabled() const { 404 return !CompilingLazily; 405 } 406 407 /// DisableGVCompilation - If called, the JIT will abort if it's asked to 408 /// allocate space and populate a GlobalVariable that is not internal to 409 /// the module. 410 void DisableGVCompilation(bool Disabled = true) { 411 GVCompilationDisabled = Disabled; 412 } 413 bool isGVCompilationDisabled() const { 414 return GVCompilationDisabled; 415 } 416 417 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown 418 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to 419 /// resolve symbols in a custom way. 420 void DisableSymbolSearching(bool Disabled = true) { 421 SymbolSearchingDisabled = Disabled; 422 } 423 bool isSymbolSearchingDisabled() const { 424 return SymbolSearchingDisabled; 425 } 426 427 /// InstallLazyFunctionCreator - If an unknown function is needed, the 428 /// specified function pointer is invoked to create it. If it returns null, 429 /// the JIT will abort. 430 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) { 431 LazyFunctionCreator = P; 432 } 433 434 /// InstallExceptionTableRegister - The JIT will use the given function 435 /// to register the exception tables it generates. 436 void InstallExceptionTableRegister(EERegisterFn F) { 437 ExceptionTableRegister = F; 438 } 439 void InstallExceptionTableDeregister(EERegisterFn F) { 440 ExceptionTableDeregister = F; 441 } 442 443 /// RegisterTable - Registers the given pointer as an exception table. It 444 /// uses the ExceptionTableRegister function. 445 void RegisterTable(const Function *fn, void* res) { 446 if (ExceptionTableRegister) { 447 ExceptionTableRegister(res); 448 AllExceptionTables[fn] = res; 449 } 450 } 451 452 /// DeregisterTable - Deregisters the exception frame previously registered 453 /// for the given function. 454 void DeregisterTable(const Function *Fn) { 455 if (ExceptionTableDeregister) { 456 DenseMap<const Function*, void*>::iterator frame = 457 AllExceptionTables.find(Fn); 458 if(frame != AllExceptionTables.end()) { 459 ExceptionTableDeregister(frame->second); 460 AllExceptionTables.erase(frame); 461 } 462 } 463 } 464 465 /// DeregisterAllTables - Deregisters all previously registered pointers to an 466 /// exception tables. It uses the ExceptionTableoDeregister function. 467 void DeregisterAllTables(); 468 469protected: 470 explicit ExecutionEngine(Module *M); 471 472 void emitGlobals(); 473 474 void EmitGlobalVariable(const GlobalVariable *GV); 475 476 GenericValue getConstantValue(const Constant *C); 477 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr, 478 Type *Ty); 479}; 480 481namespace EngineKind { 482 // These are actually bitmasks that get or-ed together. 483 enum Kind { 484 JIT = 0x1, 485 Interpreter = 0x2 486 }; 487 const static Kind Either = (Kind)(JIT | Interpreter); 488} 489 490/// EngineBuilder - Builder class for ExecutionEngines. Use this by 491/// stack-allocating a builder, chaining the various set* methods, and 492/// terminating it with a .create() call. 493class EngineBuilder { 494private: 495 Module *M; 496 EngineKind::Kind WhichEngine; 497 std::string *ErrorStr; 498 CodeGenOpt::Level OptLevel; 499 JITMemoryManager *JMM; 500 bool AllocateGVsWithCode; 501 TargetOptions Options; 502 Reloc::Model RelocModel; 503 CodeModel::Model CMModel; 504 std::string MArch; 505 std::string MCPU; 506 SmallVector<std::string, 4> MAttrs; 507 bool UseMCJIT; 508 509 /// InitEngine - Does the common initialization of default options. 510 void InitEngine() { 511 WhichEngine = EngineKind::Either; 512 ErrorStr = NULL; 513 OptLevel = CodeGenOpt::Default; 514 JMM = NULL; 515 Options = TargetOptions(); 516 AllocateGVsWithCode = false; 517 RelocModel = Reloc::Default; 518 CMModel = CodeModel::JITDefault; 519 UseMCJIT = false; 520 } 521 522public: 523 /// EngineBuilder - Constructor for EngineBuilder. If create() is called and 524 /// is successful, the created engine takes ownership of the module. 525 EngineBuilder(Module *m) : M(m) { 526 InitEngine(); 527 } 528 529 /// setEngineKind - Controls whether the user wants the interpreter, the JIT, 530 /// or whichever engine works. This option defaults to EngineKind::Either. 531 EngineBuilder &setEngineKind(EngineKind::Kind w) { 532 WhichEngine = w; 533 return *this; 534 } 535 536 /// setJITMemoryManager - Sets the memory manager to use. This allows 537 /// clients to customize their memory allocation policies. If create() is 538 /// called and is successful, the created engine takes ownership of the 539 /// memory manager. This option defaults to NULL. 540 EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) { 541 JMM = jmm; 542 return *this; 543 } 544 545 /// setErrorStr - Set the error string to write to on error. This option 546 /// defaults to NULL. 547 EngineBuilder &setErrorStr(std::string *e) { 548 ErrorStr = e; 549 return *this; 550 } 551 552 /// setOptLevel - Set the optimization level for the JIT. This option 553 /// defaults to CodeGenOpt::Default. 554 EngineBuilder &setOptLevel(CodeGenOpt::Level l) { 555 OptLevel = l; 556 return *this; 557 } 558 559 /// setTargetOptions - Set the target options that the ExecutionEngine 560 /// target is using. Defaults to TargetOptions(). 561 EngineBuilder &setTargetOptions(const TargetOptions &Opts) { 562 Options = Opts; 563 return *this; 564 } 565 566 /// setRelocationModel - Set the relocation model that the ExecutionEngine 567 /// target is using. Defaults to target specific default "Reloc::Default". 568 EngineBuilder &setRelocationModel(Reloc::Model RM) { 569 RelocModel = RM; 570 return *this; 571 } 572 573 /// setCodeModel - Set the CodeModel that the ExecutionEngine target 574 /// data is using. Defaults to target specific default 575 /// "CodeModel::JITDefault". 576 EngineBuilder &setCodeModel(CodeModel::Model M) { 577 CMModel = M; 578 return *this; 579 } 580 581 /// setAllocateGVsWithCode - Sets whether global values should be allocated 582 /// into the same buffer as code. For most applications this should be set 583 /// to false. Allocating globals with code breaks freeMachineCodeForFunction 584 /// and is probably unsafe and bad for performance. However, we have clients 585 /// who depend on this behavior, so we must support it. This option defaults 586 /// to false so that users of the new API can safely use the new memory 587 /// manager and free machine code. 588 EngineBuilder &setAllocateGVsWithCode(bool a) { 589 AllocateGVsWithCode = a; 590 return *this; 591 } 592 593 /// setMArch - Override the architecture set by the Module's triple. 594 EngineBuilder &setMArch(StringRef march) { 595 MArch.assign(march.begin(), march.end()); 596 return *this; 597 } 598 599 /// setMCPU - Target a specific cpu type. 600 EngineBuilder &setMCPU(StringRef mcpu) { 601 MCPU.assign(mcpu.begin(), mcpu.end()); 602 return *this; 603 } 604 605 /// setUseMCJIT - Set whether the MC-JIT implementation should be used 606 /// (experimental). 607 EngineBuilder &setUseMCJIT(bool Value) { 608 UseMCJIT = Value; 609 return *this; 610 } 611 612 /// setMAttrs - Set cpu-specific attributes. 613 template<typename StringSequence> 614 EngineBuilder &setMAttrs(const StringSequence &mattrs) { 615 MAttrs.clear(); 616 MAttrs.append(mattrs.begin(), mattrs.end()); 617 return *this; 618 } 619 620 TargetMachine *selectTarget(); 621 622 /// selectTarget - Pick a target either via -march or by guessing the native 623 /// arch. Add any CPU features specified via -mcpu or -mattr. 624 TargetMachine *selectTarget(const Triple &TargetTriple, 625 StringRef MArch, 626 StringRef MCPU, 627 const SmallVectorImpl<std::string>& MAttrs); 628 629 ExecutionEngine *create() { 630 return create(selectTarget()); 631 } 632 633 ExecutionEngine *create(TargetMachine *TM); 634}; 635 636// Create wrappers for C Binding types (see CBindingWrapping.h). 637DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ExecutionEngine, LLVMExecutionEngineRef) 638 639} // End llvm namespace 640 641#endif 642