1 //===- ExecutionEngine.h - Abstract Execution Engine Interface --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the abstract interface that implements execution support
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_EXECUTIONENGINE_EXECUTIONENGINE_H
16 #define LLVM_EXECUTIONENGINE_EXECUTIONENGINE_H
18 #include "llvm-c/ExecutionEngine.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/IR/ValueHandle.h"
23 #include "llvm/IR/ValueMap.h"
24 #include "llvm/MC/MCCodeGenInfo.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/Mutex.h"
27 #include "llvm/Target/TargetMachine.h"
28 #include "llvm/Target/TargetOptions.h"
38 class ExecutionEngine;
42 class JITEventListener;
43 class JITMemoryManager;
44 class MachineCodeInfo;
47 class RTDyldMemoryManager;
56 /// \brief Helper class for helping synchronize access to the global address map
57 /// table. Access to this class should be serialized under a mutex.
58 class ExecutionEngineState {
60 struct AddressMapConfig : public ValueMapConfig<const GlobalValue*> {
61 typedef ExecutionEngineState *ExtraData;
62 static sys::Mutex *getMutex(ExecutionEngineState *EES);
63 static void onDelete(ExecutionEngineState *EES, const GlobalValue *Old);
64 static void onRAUW(ExecutionEngineState *, const GlobalValue *,
68 typedef ValueMap<const GlobalValue *, void *, AddressMapConfig>
74 /// GlobalAddressMap - A mapping between LLVM global values and their
75 /// actualized version...
76 GlobalAddressMapTy GlobalAddressMap;
78 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
79 /// used to convert raw addresses into the LLVM global value that is emitted
80 /// at the address. This map is not computed unless getGlobalValueAtAddress
81 /// is called at some point.
82 std::map<void *, AssertingVH<const GlobalValue> > GlobalAddressReverseMap;
85 ExecutionEngineState(ExecutionEngine &EE);
87 GlobalAddressMapTy &getGlobalAddressMap() {
88 return GlobalAddressMap;
91 std::map<void*, AssertingVH<const GlobalValue> > &
92 getGlobalAddressReverseMap() {
93 return GlobalAddressReverseMap;
96 /// \brief Erase an entry from the mapping table.
98 /// \returns The address that \p ToUnmap was happed to.
99 void *RemoveMapping(const GlobalValue *ToUnmap);
102 /// \brief Abstract interface for implementation execution of LLVM modules,
103 /// designed to support both interpreter and just-in-time (JIT) compiler
105 class ExecutionEngine {
106 /// The state object holding the global address mapping, which must be
107 /// accessed synchronously.
109 // FIXME: There is no particular need the entire map needs to be
110 // synchronized. Wouldn't a reader-writer design be better here?
111 ExecutionEngineState EEState;
113 /// The target data for the platform for which execution is being performed.
114 const DataLayout *DL;
116 /// Whether lazy JIT compilation is enabled.
117 bool CompilingLazily;
119 /// Whether JIT compilation of external global variables is allowed.
120 bool GVCompilationDisabled;
122 /// Whether the JIT should perform lookups of external symbols (e.g.,
124 bool SymbolSearchingDisabled;
126 /// Whether the JIT should verify IR modules during compilation.
129 friend class EngineBuilder; // To allow access to JITCtor and InterpCtor.
132 /// The list of Modules that we are JIT'ing from. We use a SmallVector to
133 /// optimize for the case where there is only one module.
134 SmallVector<std::unique_ptr<Module>, 1> Modules;
136 void setDataLayout(const DataLayout *Val) { DL = Val; }
138 /// getMemoryforGV - Allocate memory for a global variable.
139 virtual char *getMemoryForGV(const GlobalVariable *GV);
141 // To avoid having libexecutionengine depend on the JIT and interpreter
142 // libraries, the execution engine implementations set these functions to ctor
143 // pointers at startup time if they are linked in.
144 static ExecutionEngine *(*JITCtor)(
145 std::unique_ptr<Module> M,
146 std::string *ErrorStr,
147 JITMemoryManager *JMM,
150 static ExecutionEngine *(*MCJITCtor)(
151 std::unique_ptr<Module> M,
152 std::string *ErrorStr,
153 RTDyldMemoryManager *MCJMM,
155 static ExecutionEngine *(*InterpCtor)(std::unique_ptr<Module> M,
156 std::string *ErrorStr);
158 /// LazyFunctionCreator - If an unknown function is needed, this function
159 /// pointer is invoked to create it. If this returns null, the JIT will
161 void *(*LazyFunctionCreator)(const std::string &);
164 /// lock - This lock protects the ExecutionEngine, MCJIT, JIT, JITResolver and
165 /// JITEmitter classes. It must be held while changing the internal state of
166 /// any of those classes.
169 //===--------------------------------------------------------------------===//
170 // ExecutionEngine Startup
171 //===--------------------------------------------------------------------===//
173 virtual ~ExecutionEngine();
175 /// Add a Module to the list of modules that we can JIT from.
176 virtual void addModule(std::unique_ptr<Module> M) {
177 Modules.push_back(std::move(M));
180 /// addObjectFile - Add an ObjectFile to the execution engine.
182 /// This method is only supported by MCJIT. MCJIT will immediately load the
183 /// object into memory and adds its symbols to the list used to resolve
184 /// external symbols while preparing other objects for execution.
186 /// Objects added using this function will not be made executable until
187 /// needed by another object.
189 /// MCJIT will take ownership of the ObjectFile.
190 virtual void addObjectFile(std::unique_ptr<object::ObjectFile> O);
192 /// addArchive - Add an Archive to the execution engine.
194 /// This method is only supported by MCJIT. MCJIT will use the archive to
195 /// resolve external symbols in objects it is loading. If a symbol is found
196 /// in the Archive the contained object file will be extracted (in memory)
197 /// and loaded for possible execution.
198 virtual void addArchive(std::unique_ptr<object::Archive> A);
200 //===--------------------------------------------------------------------===//
202 const DataLayout *getDataLayout() const { return DL; }
204 /// removeModule - Remove a Module from the list of modules. Returns true if
206 virtual bool removeModule(Module *M);
208 /// FindFunctionNamed - Search all of the active modules to find the one that
209 /// defines FnName. This is very slow operation and shouldn't be used for
211 virtual Function *FindFunctionNamed(const char *FnName);
213 /// runFunction - Execute the specified function with the specified arguments,
214 /// and return the result.
215 virtual GenericValue runFunction(Function *F,
216 const std::vector<GenericValue> &ArgValues) = 0;
218 /// getPointerToNamedFunction - This method returns the address of the
219 /// specified function by using the dlsym function call. As such it is only
220 /// useful for resolving library symbols, not code generated symbols.
222 /// If AbortOnFailure is false and no function with the given name is
223 /// found, this function silently returns a null pointer. Otherwise,
224 /// it prints a message to stderr and aborts.
226 /// This function is deprecated for the MCJIT execution engine.
228 /// FIXME: the JIT and MCJIT interfaces should be disentangled or united
229 /// again, if possible.
231 virtual void *getPointerToNamedFunction(const std::string &Name,
232 bool AbortOnFailure = true) = 0;
234 /// mapSectionAddress - map a section to its target address space value.
235 /// Map the address of a JIT section as returned from the memory manager
236 /// to the address in the target process as the running code will see it.
237 /// This is the address which will be used for relocation resolution.
238 virtual void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) {
239 llvm_unreachable("Re-mapping of section addresses not supported with this "
243 /// generateCodeForModule - Run code generationen for the specified module and
244 /// load it into memory.
246 /// When this function has completed, all code and data for the specified
247 /// module, and any module on which this module depends, will be generated
248 /// and loaded into memory, but relocations will not yet have been applied
249 /// and all memory will be readable and writable but not executable.
251 /// This function is primarily useful when generating code for an external
252 /// target, allowing the client an opportunity to remap section addresses
253 /// before relocations are applied. Clients that intend to execute code
254 /// locally can use the getFunctionAddress call, which will generate code
255 /// and apply final preparations all in one step.
257 /// This method has no effect for the legacy JIT engine or the interpeter.
258 virtual void generateCodeForModule(Module *M) {}
260 /// finalizeObject - ensure the module is fully processed and is usable.
262 /// It is the user-level function for completing the process of making the
263 /// object usable for execution. It should be called after sections within an
264 /// object have been relocated using mapSectionAddress. When this method is
265 /// called the MCJIT execution engine will reapply relocations for a loaded
266 /// object. This method has no effect for the legacy JIT engine or the
268 virtual void finalizeObject() {}
270 /// runStaticConstructorsDestructors - This method is used to execute all of
271 /// the static constructors or destructors for a program.
273 /// \param isDtors - Run the destructors instead of constructors.
274 virtual void runStaticConstructorsDestructors(bool isDtors);
276 /// This method is used to execute all of the static constructors or
277 /// destructors for a particular module.
279 /// \param isDtors - Run the destructors instead of constructors.
280 void runStaticConstructorsDestructors(Module &module, bool isDtors);
283 /// runFunctionAsMain - This is a helper function which wraps runFunction to
284 /// handle the common task of starting up main with the specified argc, argv,
285 /// and envp parameters.
286 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
287 const char * const * envp);
290 /// addGlobalMapping - Tell the execution engine that the specified global is
291 /// at the specified location. This is used internally as functions are JIT'd
292 /// and as global variables are laid out in memory. It can and should also be
293 /// used by clients of the EE that want to have an LLVM global overlay
294 /// existing data in memory. Mappings are automatically removed when their
295 /// GlobalValue is destroyed.
296 void addGlobalMapping(const GlobalValue *GV, void *Addr);
298 /// clearAllGlobalMappings - Clear all global mappings and start over again,
299 /// for use in dynamic compilation scenarios to move globals.
300 void clearAllGlobalMappings();
302 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
303 /// particular module, because it has been removed from the JIT.
304 void clearGlobalMappingsFromModule(Module *M);
306 /// updateGlobalMapping - Replace an existing mapping for GV with a new
307 /// address. This updates both maps as required. If "Addr" is null, the
308 /// entry for the global is removed from the mappings. This returns the old
309 /// value of the pointer, or null if it was not in the map.
310 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
312 /// getPointerToGlobalIfAvailable - This returns the address of the specified
313 /// global value if it is has already been codegen'd, otherwise it returns
316 /// This function is deprecated for the MCJIT execution engine. It doesn't
317 /// seem to be needed in that case, but an equivalent can be added if it is.
318 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
320 /// getPointerToGlobal - This returns the address of the specified global
321 /// value. This may involve code generation if it's a function.
323 /// This function is deprecated for the MCJIT execution engine. Use
324 /// getGlobalValueAddress instead.
325 void *getPointerToGlobal(const GlobalValue *GV);
327 /// getPointerToFunction - The different EE's represent function bodies in
328 /// different ways. They should each implement this to say what a function
329 /// pointer should look like. When F is destroyed, the ExecutionEngine will
330 /// remove its global mapping and free any machine code. Be sure no threads
331 /// are running inside F when that happens.
333 /// This function is deprecated for the MCJIT execution engine. Use
334 /// getFunctionAddress instead.
335 virtual void *getPointerToFunction(Function *F) = 0;
337 /// getPointerToBasicBlock - The different EE's represent basic blocks in
338 /// different ways. Return the representation for a blockaddress of the
341 /// This function will not be implemented for the MCJIT execution engine.
342 virtual void *getPointerToBasicBlock(BasicBlock *BB) = 0;
344 /// getPointerToFunctionOrStub - If the specified function has been
345 /// code-gen'd, return a pointer to the function. If not, compile it, or use
346 /// a stub to implement lazy compilation if available. See
347 /// getPointerToFunction for the requirements on destroying F.
349 /// This function is deprecated for the MCJIT execution engine. Use
350 /// getFunctionAddress instead.
351 virtual void *getPointerToFunctionOrStub(Function *F) {
352 // Default implementation, just codegen the function.
353 return getPointerToFunction(F);
356 /// getGlobalValueAddress - Return the address of the specified global
357 /// value. This may involve code generation.
359 /// This function should not be called with the JIT or interpreter engines.
360 virtual uint64_t getGlobalValueAddress(const std::string &Name) {
361 // Default implementation for JIT and interpreter. MCJIT will override this.
362 // JIT and interpreter clients should use getPointerToGlobal instead.
366 /// getFunctionAddress - Return the address of the specified function.
367 /// This may involve code generation.
368 virtual uint64_t getFunctionAddress(const std::string &Name) {
369 // Default implementation for JIT and interpreter. MCJIT will override this.
370 // JIT and interpreter clients should use getPointerToFunction instead.
374 // The JIT overrides a version that actually does this.
375 virtual void runJITOnFunction(Function *, MachineCodeInfo * = nullptr) { }
377 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
378 /// at the specified address.
380 const GlobalValue *getGlobalValueAtAddress(void *Addr);
382 /// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr.
383 /// Ptr is the address of the memory at which to store Val, cast to
384 /// GenericValue *. It is not a pointer to a GenericValue containing the
385 /// address at which to store Val.
386 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
389 void InitializeMemory(const Constant *Init, void *Addr);
391 /// recompileAndRelinkFunction - This method is used to force a function which
392 /// has already been compiled to be compiled again, possibly after it has been
393 /// modified. Then the entry to the old copy is overwritten with a branch to
394 /// the new copy. If there was no old copy, this acts just like
395 /// VM::getPointerToFunction().
396 virtual void *recompileAndRelinkFunction(Function *F) = 0;
398 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
399 /// corresponding to the machine code emitted to execute this function, useful
400 /// for garbage-collecting generated code.
401 virtual void freeMachineCodeForFunction(Function *F) = 0;
403 /// getOrEmitGlobalVariable - Return the address of the specified global
404 /// variable, possibly emitting it to memory if needed. This is used by the
407 /// This function is deprecated for the MCJIT execution engine. Use
408 /// getGlobalValueAddress instead.
409 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
410 return getPointerToGlobal((const GlobalValue *)GV);
413 /// Registers a listener to be called back on various events within
414 /// the JIT. See JITEventListener.h for more details. Does not
415 /// take ownership of the argument. The argument may be NULL, in
416 /// which case these functions do nothing.
417 virtual void RegisterJITEventListener(JITEventListener *) {}
418 virtual void UnregisterJITEventListener(JITEventListener *) {}
420 /// Sets the pre-compiled object cache. The ownership of the ObjectCache is
421 /// not changed. Supported by MCJIT but not JIT.
422 virtual void setObjectCache(ObjectCache *) {
423 llvm_unreachable("No support for an object cache");
426 /// setProcessAllSections (MCJIT Only): By default, only sections that are
427 /// "required for execution" are passed to the RTDyldMemoryManager, and other
428 /// sections are discarded. Passing 'true' to this method will cause
429 /// RuntimeDyld to pass all sections to its RTDyldMemoryManager regardless
430 /// of whether they are "required to execute" in the usual sense.
432 /// Rationale: Some MCJIT clients want to be able to inspect metadata
433 /// sections (e.g. Dwarf, Stack-maps) to enable functionality or analyze
434 /// performance. Passing these sections to the memory manager allows the
435 /// client to make policy about the relevant sections, rather than having
437 virtual void setProcessAllSections(bool ProcessAllSections) {
438 llvm_unreachable("No support for ProcessAllSections option");
441 /// Return the target machine (if available).
442 virtual TargetMachine *getTargetMachine() { return nullptr; }
444 /// DisableLazyCompilation - When lazy compilation is off (the default), the
445 /// JIT will eagerly compile every function reachable from the argument to
446 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only
447 /// compile the one function and emit stubs to compile the rest when they're
448 /// first called. If lazy compilation is turned off again while some lazy
449 /// stubs are still around, and one of those stubs is called, the program will
452 /// In order to safely compile lazily in a threaded program, the user must
453 /// ensure that 1) only one thread at a time can call any particular lazy
454 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
455 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
456 /// lazy stub. See http://llvm.org/PR5184 for details.
457 void DisableLazyCompilation(bool Disabled = true) {
458 CompilingLazily = !Disabled;
460 bool isCompilingLazily() const {
461 return CompilingLazily;
463 // Deprecated in favor of isCompilingLazily (to reduce double-negatives).
464 // Remove this in LLVM 2.8.
465 bool isLazyCompilationDisabled() const {
466 return !CompilingLazily;
469 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
470 /// allocate space and populate a GlobalVariable that is not internal to
472 void DisableGVCompilation(bool Disabled = true) {
473 GVCompilationDisabled = Disabled;
475 bool isGVCompilationDisabled() const {
476 return GVCompilationDisabled;
479 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
480 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
481 /// resolve symbols in a custom way.
482 void DisableSymbolSearching(bool Disabled = true) {
483 SymbolSearchingDisabled = Disabled;
485 bool isSymbolSearchingDisabled() const {
486 return SymbolSearchingDisabled;
489 /// Enable/Disable IR module verification.
491 /// Note: Module verification is enabled by default in Debug builds, and
492 /// disabled by default in Release. Use this method to override the default.
493 void setVerifyModules(bool Verify) {
494 VerifyModules = Verify;
496 bool getVerifyModules() const {
497 return VerifyModules;
500 /// InstallLazyFunctionCreator - If an unknown function is needed, the
501 /// specified function pointer is invoked to create it. If it returns null,
502 /// the JIT will abort.
503 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
504 LazyFunctionCreator = P;
508 explicit ExecutionEngine(std::unique_ptr<Module> M);
512 void EmitGlobalVariable(const GlobalVariable *GV);
514 GenericValue getConstantValue(const Constant *C);
515 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
519 namespace EngineKind {
520 // These are actually bitmasks that get or-ed together.
525 const static Kind Either = (Kind)(JIT | Interpreter);
528 /// Builder class for ExecutionEngines. Use this by stack-allocating a builder,
529 /// chaining the various set* methods, and terminating it with a .create()
531 class EngineBuilder {
533 std::unique_ptr<Module> M;
534 EngineKind::Kind WhichEngine;
535 std::string *ErrorStr;
536 CodeGenOpt::Level OptLevel;
537 RTDyldMemoryManager *MCJMM;
538 JITMemoryManager *JMM;
539 bool AllocateGVsWithCode;
540 TargetOptions Options;
541 Reloc::Model RelocModel;
542 CodeModel::Model CMModel;
545 SmallVector<std::string, 4> MAttrs;
549 /// InitEngine - Does the common initialization of default options.
553 /// Constructor for EngineBuilder.
554 EngineBuilder(std::unique_ptr<Module> M) : M(std::move(M)) {
558 /// setEngineKind - Controls whether the user wants the interpreter, the JIT,
559 /// or whichever engine works. This option defaults to EngineKind::Either.
560 EngineBuilder &setEngineKind(EngineKind::Kind w) {
565 /// setMCJITMemoryManager - Sets the MCJIT memory manager to use. This allows
566 /// clients to customize their memory allocation policies for the MCJIT. This
567 /// is only appropriate for the MCJIT; setting this and configuring the builder
568 /// to create anything other than MCJIT will cause a runtime error. If create()
569 /// is called and is successful, the created engine takes ownership of the
570 /// memory manager. This option defaults to NULL. Using this option nullifies
571 /// the setJITMemoryManager() option.
572 EngineBuilder &setMCJITMemoryManager(RTDyldMemoryManager *mcjmm) {
578 /// setJITMemoryManager - Sets the JIT memory manager to use. This allows
579 /// clients to customize their memory allocation policies. This is only
580 /// appropriate for either JIT or MCJIT; setting this and configuring the
581 /// builder to create an interpreter will cause a runtime error. If create()
582 /// is called and is successful, the created engine takes ownership of the
583 /// memory manager. This option defaults to NULL. This option overrides
584 /// setMCJITMemoryManager() as well.
585 EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) {
591 /// setErrorStr - Set the error string to write to on error. This option
592 /// defaults to NULL.
593 EngineBuilder &setErrorStr(std::string *e) {
598 /// setOptLevel - Set the optimization level for the JIT. This option
599 /// defaults to CodeGenOpt::Default.
600 EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
605 /// setTargetOptions - Set the target options that the ExecutionEngine
606 /// target is using. Defaults to TargetOptions().
607 EngineBuilder &setTargetOptions(const TargetOptions &Opts) {
612 /// setRelocationModel - Set the relocation model that the ExecutionEngine
613 /// target is using. Defaults to target specific default "Reloc::Default".
614 EngineBuilder &setRelocationModel(Reloc::Model RM) {
619 /// setCodeModel - Set the CodeModel that the ExecutionEngine target
620 /// data is using. Defaults to target specific default
621 /// "CodeModel::JITDefault".
622 EngineBuilder &setCodeModel(CodeModel::Model M) {
627 /// setAllocateGVsWithCode - Sets whether global values should be allocated
628 /// into the same buffer as code. For most applications this should be set
629 /// to false. Allocating globals with code breaks freeMachineCodeForFunction
630 /// and is probably unsafe and bad for performance. However, we have clients
631 /// who depend on this behavior, so we must support it. This option defaults
632 /// to false so that users of the new API can safely use the new memory
633 /// manager and free machine code.
634 EngineBuilder &setAllocateGVsWithCode(bool a) {
635 AllocateGVsWithCode = a;
639 /// setMArch - Override the architecture set by the Module's triple.
640 EngineBuilder &setMArch(StringRef march) {
641 MArch.assign(march.begin(), march.end());
645 /// setMCPU - Target a specific cpu type.
646 EngineBuilder &setMCPU(StringRef mcpu) {
647 MCPU.assign(mcpu.begin(), mcpu.end());
651 /// setUseMCJIT - Set whether the MC-JIT implementation should be used
653 EngineBuilder &setUseMCJIT(bool Value) {
658 /// setVerifyModules - Set whether the JIT implementation should verify
659 /// IR modules during compilation.
660 EngineBuilder &setVerifyModules(bool Verify) {
661 VerifyModules = Verify;
665 /// setMAttrs - Set cpu-specific attributes.
666 template<typename StringSequence>
667 EngineBuilder &setMAttrs(const StringSequence &mattrs) {
669 MAttrs.append(mattrs.begin(), mattrs.end());
673 TargetMachine *selectTarget();
675 /// selectTarget - Pick a target either via -march or by guessing the native
676 /// arch. Add any CPU features specified via -mcpu or -mattr.
677 TargetMachine *selectTarget(const Triple &TargetTriple,
680 const SmallVectorImpl<std::string>& MAttrs);
682 ExecutionEngine *create() {
683 return create(selectTarget());
686 ExecutionEngine *create(TargetMachine *TM);
689 // Create wrappers for C Binding types (see CBindingWrapping.h).
690 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ExecutionEngine, LLVMExecutionEngineRef)
692 } // End llvm namespace