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/Object/Binary.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/Mutex.h"
28 #include "llvm/Target/TargetMachine.h"
29 #include "llvm/Target/TargetOptions.h"
39 class ExecutionEngine;
43 class JITEventListener;
44 class JITMemoryManager;
45 class MachineCodeInfo;
48 class RTDyldMemoryManager;
57 /// \brief Helper class for helping synchronize access to the global address map
58 /// table. Access to this class should be serialized under a mutex.
59 class ExecutionEngineState {
61 struct AddressMapConfig : public ValueMapConfig<const GlobalValue*> {
62 typedef ExecutionEngineState *ExtraData;
63 static sys::Mutex *getMutex(ExecutionEngineState *EES);
64 static void onDelete(ExecutionEngineState *EES, const GlobalValue *Old);
65 static void onRAUW(ExecutionEngineState *, const GlobalValue *,
69 typedef ValueMap<const GlobalValue *, void *, AddressMapConfig>
75 /// GlobalAddressMap - A mapping between LLVM global values and their
76 /// actualized version...
77 GlobalAddressMapTy GlobalAddressMap;
79 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
80 /// used to convert raw addresses into the LLVM global value that is emitted
81 /// at the address. This map is not computed unless getGlobalValueAtAddress
82 /// is called at some point.
83 std::map<void *, AssertingVH<const GlobalValue> > GlobalAddressReverseMap;
86 ExecutionEngineState(ExecutionEngine &EE);
88 GlobalAddressMapTy &getGlobalAddressMap() {
89 return GlobalAddressMap;
92 std::map<void*, AssertingVH<const GlobalValue> > &
93 getGlobalAddressReverseMap() {
94 return GlobalAddressReverseMap;
97 /// \brief Erase an entry from the mapping table.
99 /// \returns The address that \p ToUnmap was happed to.
100 void *RemoveMapping(const GlobalValue *ToUnmap);
103 /// \brief Abstract interface for implementation execution of LLVM modules,
104 /// designed to support both interpreter and just-in-time (JIT) compiler
106 class ExecutionEngine {
107 /// The state object holding the global address mapping, which must be
108 /// accessed synchronously.
110 // FIXME: There is no particular need the entire map needs to be
111 // synchronized. Wouldn't a reader-writer design be better here?
112 ExecutionEngineState EEState;
114 /// The target data for the platform for which execution is being performed.
115 const DataLayout *DL;
117 /// Whether lazy JIT compilation is enabled.
118 bool CompilingLazily;
120 /// Whether JIT compilation of external global variables is allowed.
121 bool GVCompilationDisabled;
123 /// Whether the JIT should perform lookups of external symbols (e.g.,
125 bool SymbolSearchingDisabled;
127 /// Whether the JIT should verify IR modules during compilation.
130 friend class EngineBuilder; // To allow access to JITCtor and InterpCtor.
133 /// The list of Modules that we are JIT'ing from. We use a SmallVector to
134 /// optimize for the case where there is only one module.
135 SmallVector<std::unique_ptr<Module>, 1> Modules;
137 void setDataLayout(const DataLayout *Val) { DL = Val; }
139 /// getMemoryforGV - Allocate memory for a global variable.
140 virtual char *getMemoryForGV(const GlobalVariable *GV);
142 // To avoid having libexecutionengine depend on the JIT and interpreter
143 // libraries, the execution engine implementations set these functions to ctor
144 // pointers at startup time if they are linked in.
145 static ExecutionEngine *(*JITCtor)(
146 std::unique_ptr<Module> M,
147 std::string *ErrorStr,
148 JITMemoryManager *JMM,
151 static ExecutionEngine *(*MCJITCtor)(
152 std::unique_ptr<Module> M,
153 std::string *ErrorStr,
154 RTDyldMemoryManager *MCJMM,
156 static ExecutionEngine *(*InterpCtor)(std::unique_ptr<Module> M,
157 std::string *ErrorStr);
159 /// LazyFunctionCreator - If an unknown function is needed, this function
160 /// pointer is invoked to create it. If this returns null, the JIT will
162 void *(*LazyFunctionCreator)(const std::string &);
165 /// lock - This lock protects the ExecutionEngine, MCJIT, JIT, JITResolver and
166 /// JITEmitter classes. It must be held while changing the internal state of
167 /// any of those classes.
170 //===--------------------------------------------------------------------===//
171 // ExecutionEngine Startup
172 //===--------------------------------------------------------------------===//
174 virtual ~ExecutionEngine();
176 /// Add a Module to the list of modules that we can JIT from.
177 virtual void addModule(std::unique_ptr<Module> M) {
178 Modules.push_back(std::move(M));
181 /// addObjectFile - Add an ObjectFile to the execution engine.
183 /// This method is only supported by MCJIT. MCJIT will immediately load the
184 /// object into memory and adds its symbols to the list used to resolve
185 /// external symbols while preparing other objects for execution.
187 /// Objects added using this function will not be made executable until
188 /// needed by another object.
190 /// MCJIT will take ownership of the ObjectFile.
191 virtual void addObjectFile(std::unique_ptr<object::ObjectFile> O);
193 /// addArchive - Add an Archive to the execution engine.
195 /// This method is only supported by MCJIT. MCJIT will use the archive to
196 /// resolve external symbols in objects it is loading. If a symbol is found
197 /// in the Archive the contained object file will be extracted (in memory)
198 /// and loaded for possible execution.
199 virtual void addArchive(object::OwningBinary<object::Archive> A);
201 //===--------------------------------------------------------------------===//
203 const DataLayout *getDataLayout() const { return DL; }
205 /// removeModule - Remove a Module from the list of modules. Returns true if
207 virtual bool removeModule(Module *M);
209 /// FindFunctionNamed - Search all of the active modules to find the one that
210 /// defines FnName. This is very slow operation and shouldn't be used for
212 virtual Function *FindFunctionNamed(const char *FnName);
214 /// runFunction - Execute the specified function with the specified arguments,
215 /// and return the result.
216 virtual GenericValue runFunction(Function *F,
217 const std::vector<GenericValue> &ArgValues) = 0;
219 /// getPointerToNamedFunction - This method returns the address of the
220 /// specified function by using the dlsym function call. As such it is only
221 /// useful for resolving library symbols, not code generated symbols.
223 /// If AbortOnFailure is false and no function with the given name is
224 /// found, this function silently returns a null pointer. Otherwise,
225 /// it prints a message to stderr and aborts.
227 /// This function is deprecated for the MCJIT execution engine.
229 /// FIXME: the JIT and MCJIT interfaces should be disentangled or united
230 /// again, if possible.
232 virtual void *getPointerToNamedFunction(const std::string &Name,
233 bool AbortOnFailure = true) = 0;
235 /// mapSectionAddress - map a section to its target address space value.
236 /// Map the address of a JIT section as returned from the memory manager
237 /// to the address in the target process as the running code will see it.
238 /// This is the address which will be used for relocation resolution.
239 virtual void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) {
240 llvm_unreachable("Re-mapping of section addresses not supported with this "
244 /// generateCodeForModule - Run code generationen for the specified module and
245 /// load it into memory.
247 /// When this function has completed, all code and data for the specified
248 /// module, and any module on which this module depends, will be generated
249 /// and loaded into memory, but relocations will not yet have been applied
250 /// and all memory will be readable and writable but not executable.
252 /// This function is primarily useful when generating code for an external
253 /// target, allowing the client an opportunity to remap section addresses
254 /// before relocations are applied. Clients that intend to execute code
255 /// locally can use the getFunctionAddress call, which will generate code
256 /// and apply final preparations all in one step.
258 /// This method has no effect for the legacy JIT engine or the interpeter.
259 virtual void generateCodeForModule(Module *M) {}
261 /// finalizeObject - ensure the module is fully processed and is usable.
263 /// It is the user-level function for completing the process of making the
264 /// object usable for execution. It should be called after sections within an
265 /// object have been relocated using mapSectionAddress. When this method is
266 /// called the MCJIT execution engine will reapply relocations for a loaded
267 /// object. This method has no effect for the legacy JIT engine or the
269 virtual void finalizeObject() {}
271 /// runStaticConstructorsDestructors - This method is used to execute all of
272 /// the static constructors or destructors for a program.
274 /// \param isDtors - Run the destructors instead of constructors.
275 virtual void runStaticConstructorsDestructors(bool isDtors);
277 /// This method is used to execute all of the static constructors or
278 /// destructors for a particular module.
280 /// \param isDtors - Run the destructors instead of constructors.
281 void runStaticConstructorsDestructors(Module &module, bool isDtors);
284 /// runFunctionAsMain - This is a helper function which wraps runFunction to
285 /// handle the common task of starting up main with the specified argc, argv,
286 /// and envp parameters.
287 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
288 const char * const * envp);
291 /// addGlobalMapping - Tell the execution engine that the specified global is
292 /// at the specified location. This is used internally as functions are JIT'd
293 /// and as global variables are laid out in memory. It can and should also be
294 /// used by clients of the EE that want to have an LLVM global overlay
295 /// existing data in memory. Mappings are automatically removed when their
296 /// GlobalValue is destroyed.
297 void addGlobalMapping(const GlobalValue *GV, void *Addr);
299 /// clearAllGlobalMappings - Clear all global mappings and start over again,
300 /// for use in dynamic compilation scenarios to move globals.
301 void clearAllGlobalMappings();
303 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
304 /// particular module, because it has been removed from the JIT.
305 void clearGlobalMappingsFromModule(Module *M);
307 /// updateGlobalMapping - Replace an existing mapping for GV with a new
308 /// address. This updates both maps as required. If "Addr" is null, the
309 /// entry for the global is removed from the mappings. This returns the old
310 /// value of the pointer, or null if it was not in the map.
311 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
313 /// getPointerToGlobalIfAvailable - This returns the address of the specified
314 /// global value if it is has already been codegen'd, otherwise it returns
317 /// This function is deprecated for the MCJIT execution engine. It doesn't
318 /// seem to be needed in that case, but an equivalent can be added if it is.
319 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
321 /// getPointerToGlobal - This returns the address of the specified global
322 /// value. This may involve code generation if it's a function.
324 /// This function is deprecated for the MCJIT execution engine. Use
325 /// getGlobalValueAddress instead.
326 void *getPointerToGlobal(const GlobalValue *GV);
328 /// getPointerToFunction - The different EE's represent function bodies in
329 /// different ways. They should each implement this to say what a function
330 /// pointer should look like. When F is destroyed, the ExecutionEngine will
331 /// remove its global mapping and free any machine code. Be sure no threads
332 /// are running inside F when that happens.
334 /// This function is deprecated for the MCJIT execution engine. Use
335 /// getFunctionAddress instead.
336 virtual void *getPointerToFunction(Function *F) = 0;
338 /// getPointerToBasicBlock - The different EE's represent basic blocks in
339 /// different ways. Return the representation for a blockaddress of the
342 /// This function will not be implemented for the MCJIT execution engine.
343 virtual void *getPointerToBasicBlock(BasicBlock *BB) = 0;
345 /// getPointerToFunctionOrStub - If the specified function has been
346 /// code-gen'd, return a pointer to the function. If not, compile it, or use
347 /// a stub to implement lazy compilation if available. See
348 /// getPointerToFunction for the requirements on destroying F.
350 /// This function is deprecated for the MCJIT execution engine. Use
351 /// getFunctionAddress instead.
352 virtual void *getPointerToFunctionOrStub(Function *F) {
353 // Default implementation, just codegen the function.
354 return getPointerToFunction(F);
357 /// getGlobalValueAddress - Return the address of the specified global
358 /// value. This may involve code generation.
360 /// This function should not be called with the JIT or interpreter engines.
361 virtual uint64_t getGlobalValueAddress(const std::string &Name) {
362 // Default implementation for JIT and interpreter. MCJIT will override this.
363 // JIT and interpreter clients should use getPointerToGlobal instead.
367 /// getFunctionAddress - Return the address of the specified function.
368 /// This may involve code generation.
369 virtual uint64_t getFunctionAddress(const std::string &Name) {
370 // Default implementation for JIT and interpreter. MCJIT will override this.
371 // JIT and interpreter clients should use getPointerToFunction instead.
375 // The JIT overrides a version that actually does this.
376 virtual void runJITOnFunction(Function *, MachineCodeInfo * = nullptr) { }
378 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
379 /// at the specified address.
381 const GlobalValue *getGlobalValueAtAddress(void *Addr);
383 /// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr.
384 /// Ptr is the address of the memory at which to store Val, cast to
385 /// GenericValue *. It is not a pointer to a GenericValue containing the
386 /// address at which to store Val.
387 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
390 void InitializeMemory(const Constant *Init, void *Addr);
392 /// recompileAndRelinkFunction - This method is used to force a function which
393 /// has already been compiled to be compiled again, possibly after it has been
394 /// modified. Then the entry to the old copy is overwritten with a branch to
395 /// the new copy. If there was no old copy, this acts just like
396 /// VM::getPointerToFunction().
397 virtual void *recompileAndRelinkFunction(Function *F) = 0;
399 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
400 /// corresponding to the machine code emitted to execute this function, useful
401 /// for garbage-collecting generated code.
402 virtual void freeMachineCodeForFunction(Function *F) = 0;
404 /// getOrEmitGlobalVariable - Return the address of the specified global
405 /// variable, possibly emitting it to memory if needed. This is used by the
408 /// This function is deprecated for the MCJIT execution engine. Use
409 /// getGlobalValueAddress instead.
410 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
411 return getPointerToGlobal((const GlobalValue *)GV);
414 /// Registers a listener to be called back on various events within
415 /// the JIT. See JITEventListener.h for more details. Does not
416 /// take ownership of the argument. The argument may be NULL, in
417 /// which case these functions do nothing.
418 virtual void RegisterJITEventListener(JITEventListener *) {}
419 virtual void UnregisterJITEventListener(JITEventListener *) {}
421 /// Sets the pre-compiled object cache. The ownership of the ObjectCache is
422 /// not changed. Supported by MCJIT but not JIT.
423 virtual void setObjectCache(ObjectCache *) {
424 llvm_unreachable("No support for an object cache");
427 /// setProcessAllSections (MCJIT Only): By default, only sections that are
428 /// "required for execution" are passed to the RTDyldMemoryManager, and other
429 /// sections are discarded. Passing 'true' to this method will cause
430 /// RuntimeDyld to pass all sections to its RTDyldMemoryManager regardless
431 /// of whether they are "required to execute" in the usual sense.
433 /// Rationale: Some MCJIT clients want to be able to inspect metadata
434 /// sections (e.g. Dwarf, Stack-maps) to enable functionality or analyze
435 /// performance. Passing these sections to the memory manager allows the
436 /// client to make policy about the relevant sections, rather than having
438 virtual void setProcessAllSections(bool ProcessAllSections) {
439 llvm_unreachable("No support for ProcessAllSections option");
442 /// Return the target machine (if available).
443 virtual TargetMachine *getTargetMachine() { return nullptr; }
445 /// DisableLazyCompilation - When lazy compilation is off (the default), the
446 /// JIT will eagerly compile every function reachable from the argument to
447 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only
448 /// compile the one function and emit stubs to compile the rest when they're
449 /// first called. If lazy compilation is turned off again while some lazy
450 /// stubs are still around, and one of those stubs is called, the program will
453 /// In order to safely compile lazily in a threaded program, the user must
454 /// ensure that 1) only one thread at a time can call any particular lazy
455 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
456 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
457 /// lazy stub. See http://llvm.org/PR5184 for details.
458 void DisableLazyCompilation(bool Disabled = true) {
459 CompilingLazily = !Disabled;
461 bool isCompilingLazily() const {
462 return CompilingLazily;
464 // Deprecated in favor of isCompilingLazily (to reduce double-negatives).
465 // Remove this in LLVM 2.8.
466 bool isLazyCompilationDisabled() const {
467 return !CompilingLazily;
470 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
471 /// allocate space and populate a GlobalVariable that is not internal to
473 void DisableGVCompilation(bool Disabled = true) {
474 GVCompilationDisabled = Disabled;
476 bool isGVCompilationDisabled() const {
477 return GVCompilationDisabled;
480 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
481 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
482 /// resolve symbols in a custom way.
483 void DisableSymbolSearching(bool Disabled = true) {
484 SymbolSearchingDisabled = Disabled;
486 bool isSymbolSearchingDisabled() const {
487 return SymbolSearchingDisabled;
490 /// Enable/Disable IR module verification.
492 /// Note: Module verification is enabled by default in Debug builds, and
493 /// disabled by default in Release. Use this method to override the default.
494 void setVerifyModules(bool Verify) {
495 VerifyModules = Verify;
497 bool getVerifyModules() const {
498 return VerifyModules;
501 /// InstallLazyFunctionCreator - If an unknown function is needed, the
502 /// specified function pointer is invoked to create it. If it returns null,
503 /// the JIT will abort.
504 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
505 LazyFunctionCreator = P;
509 explicit ExecutionEngine(std::unique_ptr<Module> M);
513 void EmitGlobalVariable(const GlobalVariable *GV);
515 GenericValue getConstantValue(const Constant *C);
516 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
520 namespace EngineKind {
521 // These are actually bitmasks that get or-ed together.
526 const static Kind Either = (Kind)(JIT | Interpreter);
529 /// Builder class for ExecutionEngines. Use this by stack-allocating a builder,
530 /// chaining the various set* methods, and terminating it with a .create()
532 class EngineBuilder {
534 std::unique_ptr<Module> M;
535 EngineKind::Kind WhichEngine;
536 std::string *ErrorStr;
537 CodeGenOpt::Level OptLevel;
538 RTDyldMemoryManager *MCJMM;
539 JITMemoryManager *JMM;
540 bool AllocateGVsWithCode;
541 TargetOptions Options;
542 Reloc::Model RelocModel;
543 CodeModel::Model CMModel;
546 SmallVector<std::string, 4> MAttrs;
550 /// InitEngine - Does the common initialization of default options.
554 /// Constructor for EngineBuilder.
555 EngineBuilder(std::unique_ptr<Module> M) : M(std::move(M)) {
559 /// setEngineKind - Controls whether the user wants the interpreter, the JIT,
560 /// or whichever engine works. This option defaults to EngineKind::Either.
561 EngineBuilder &setEngineKind(EngineKind::Kind w) {
566 /// setMCJITMemoryManager - Sets the MCJIT memory manager to use. This allows
567 /// clients to customize their memory allocation policies for the MCJIT. This
568 /// is only appropriate for the MCJIT; setting this and configuring the builder
569 /// to create anything other than MCJIT will cause a runtime error. If create()
570 /// is called and is successful, the created engine takes ownership of the
571 /// memory manager. This option defaults to NULL. Using this option nullifies
572 /// the setJITMemoryManager() option.
573 EngineBuilder &setMCJITMemoryManager(RTDyldMemoryManager *mcjmm) {
579 /// setJITMemoryManager - Sets the JIT memory manager to use. This allows
580 /// clients to customize their memory allocation policies. This is only
581 /// appropriate for either JIT or MCJIT; setting this and configuring the
582 /// builder to create an interpreter will cause a runtime error. If create()
583 /// is called and is successful, the created engine takes ownership of the
584 /// memory manager. This option defaults to NULL. This option overrides
585 /// setMCJITMemoryManager() as well.
586 EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) {
592 /// setErrorStr - Set the error string to write to on error. This option
593 /// defaults to NULL.
594 EngineBuilder &setErrorStr(std::string *e) {
599 /// setOptLevel - Set the optimization level for the JIT. This option
600 /// defaults to CodeGenOpt::Default.
601 EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
606 /// setTargetOptions - Set the target options that the ExecutionEngine
607 /// target is using. Defaults to TargetOptions().
608 EngineBuilder &setTargetOptions(const TargetOptions &Opts) {
613 /// setRelocationModel - Set the relocation model that the ExecutionEngine
614 /// target is using. Defaults to target specific default "Reloc::Default".
615 EngineBuilder &setRelocationModel(Reloc::Model RM) {
620 /// setCodeModel - Set the CodeModel that the ExecutionEngine target
621 /// data is using. Defaults to target specific default
622 /// "CodeModel::JITDefault".
623 EngineBuilder &setCodeModel(CodeModel::Model M) {
628 /// setAllocateGVsWithCode - Sets whether global values should be allocated
629 /// into the same buffer as code. For most applications this should be set
630 /// to false. Allocating globals with code breaks freeMachineCodeForFunction
631 /// and is probably unsafe and bad for performance. However, we have clients
632 /// who depend on this behavior, so we must support it. This option defaults
633 /// to false so that users of the new API can safely use the new memory
634 /// manager and free machine code.
635 EngineBuilder &setAllocateGVsWithCode(bool a) {
636 AllocateGVsWithCode = a;
640 /// setMArch - Override the architecture set by the Module's triple.
641 EngineBuilder &setMArch(StringRef march) {
642 MArch.assign(march.begin(), march.end());
646 /// setMCPU - Target a specific cpu type.
647 EngineBuilder &setMCPU(StringRef mcpu) {
648 MCPU.assign(mcpu.begin(), mcpu.end());
652 /// setUseMCJIT - Set whether the MC-JIT implementation should be used
654 EngineBuilder &setUseMCJIT(bool Value) {
659 /// setVerifyModules - Set whether the JIT implementation should verify
660 /// IR modules during compilation.
661 EngineBuilder &setVerifyModules(bool Verify) {
662 VerifyModules = Verify;
666 /// setMAttrs - Set cpu-specific attributes.
667 template<typename StringSequence>
668 EngineBuilder &setMAttrs(const StringSequence &mattrs) {
670 MAttrs.append(mattrs.begin(), mattrs.end());
674 TargetMachine *selectTarget();
676 /// selectTarget - Pick a target either via -march or by guessing the native
677 /// arch. Add any CPU features specified via -mcpu or -mattr.
678 TargetMachine *selectTarget(const Triple &TargetTriple,
681 const SmallVectorImpl<std::string>& MAttrs);
683 ExecutionEngine *create() {
684 return create(selectTarget());
687 ExecutionEngine *create(TargetMachine *TM);
690 // Create wrappers for C Binding types (see CBindingWrapping.h).
691 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ExecutionEngine, LLVMExecutionEngineRef)
693 } // End llvm namespace