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/ValueHandle.h"
22 #include "llvm/IR/ValueMap.h"
23 #include "llvm/MC/MCCodeGenInfo.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/Mutex.h"
26 #include "llvm/Target/TargetMachine.h"
27 #include "llvm/Target/TargetOptions.h"
37 class ExecutionEngine;
41 class JITEventListener;
42 class JITMemoryManager;
43 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<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 *(*MCJITCtor)(
146 std::string *ErrorStr,
147 RTDyldMemoryManager *MCJMM,
149 static ExecutionEngine *(*InterpCtor)(Module *M, std::string *ErrorStr);
151 /// LazyFunctionCreator - If an unknown function is needed, this function
152 /// pointer is invoked to create it. If this returns null, the JIT will
154 void *(*LazyFunctionCreator)(const std::string &);
157 /// lock - This lock protects the ExecutionEngine, MCJIT, JIT, JITResolver and
158 /// JITEmitter classes. It must be held while changing the internal state of
159 /// any of those classes.
162 //===--------------------------------------------------------------------===//
163 // ExecutionEngine Startup
164 //===--------------------------------------------------------------------===//
166 virtual ~ExecutionEngine();
168 /// addModule - Add a Module to the list of modules that we can JIT from.
169 /// Note that this takes ownership of the Module: when the ExecutionEngine is
170 /// destroyed, it destroys the Module as well.
171 virtual void addModule(Module *M) {
172 Modules.push_back(M);
175 /// addObjectFile - Add an ObjectFile to the execution engine.
177 /// This method is only supported by MCJIT. MCJIT will immediately load the
178 /// object into memory and adds its symbols to the list used to resolve
179 /// external symbols while preparing other objects for execution.
181 /// Objects added using this function will not be made executable until
182 /// needed by another object.
184 /// MCJIT will take ownership of the ObjectFile.
185 virtual void addObjectFile(std::unique_ptr<object::ObjectFile> O);
187 /// addArchive - Add an Archive to the execution engine.
189 /// This method is only supported by MCJIT. MCJIT will use the archive to
190 /// resolve external symbols in objects it is loading. If a symbol is found
191 /// in the Archive the contained object file will be extracted (in memory)
192 /// and loaded for possible execution.
193 virtual void addArchive(std::unique_ptr<object::Archive> A);
195 //===--------------------------------------------------------------------===//
197 const DataLayout *getDataLayout() const { return DL; }
199 /// removeModule - Remove a Module from the list of modules. Returns true if
201 virtual bool removeModule(Module *M);
203 /// FindFunctionNamed - Search all of the active modules to find the one that
204 /// defines FnName. This is very slow operation and shouldn't be used for
206 virtual Function *FindFunctionNamed(const char *FnName);
208 /// runFunction - Execute the specified function with the specified arguments,
209 /// and return the result.
210 virtual GenericValue runFunction(Function *F,
211 const std::vector<GenericValue> &ArgValues) = 0;
213 /// getPointerToNamedFunction - This method returns the address of the
214 /// specified function by using the dlsym function call. As such it is only
215 /// useful for resolving library symbols, not code generated symbols.
217 /// If AbortOnFailure is false and no function with the given name is
218 /// found, this function silently returns a null pointer. Otherwise,
219 /// it prints a message to stderr and aborts.
221 /// This function is deprecated for the MCJIT execution engine.
223 /// FIXME: the JIT and MCJIT interfaces should be disentangled or united
224 /// again, if possible.
226 virtual void *getPointerToNamedFunction(const std::string &Name,
227 bool AbortOnFailure = true) = 0;
229 /// mapSectionAddress - map a section to its target address space value.
230 /// Map the address of a JIT section as returned from the memory manager
231 /// to the address in the target process as the running code will see it.
232 /// This is the address which will be used for relocation resolution.
233 virtual void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) {
234 llvm_unreachable("Re-mapping of section addresses not supported with this "
238 /// generateCodeForModule - Run code generationen for the specified module and
239 /// load it into memory.
241 /// When this function has completed, all code and data for the specified
242 /// module, and any module on which this module depends, will be generated
243 /// and loaded into memory, but relocations will not yet have been applied
244 /// and all memory will be readable and writable but not executable.
246 /// This function is primarily useful when generating code for an external
247 /// target, allowing the client an opportunity to remap section addresses
248 /// before relocations are applied. Clients that intend to execute code
249 /// locally can use the getFunctionAddress call, which will generate code
250 /// and apply final preparations all in one step.
252 /// This method has no effect for the legacy JIT engine or the interpeter.
253 virtual void generateCodeForModule(Module *M) {}
255 /// finalizeObject - ensure the module is fully processed and is usable.
257 /// It is the user-level function for completing the process of making the
258 /// object usable for execution. It should be called after sections within an
259 /// object have been relocated using mapSectionAddress. When this method is
260 /// called the MCJIT execution engine will reapply relocations for a loaded
261 /// object. This method has no effect for the legacy JIT engine or the
263 virtual void finalizeObject() {}
265 /// runStaticConstructorsDestructors - This method is used to execute all of
266 /// the static constructors or destructors for a program.
268 /// \param isDtors - Run the destructors instead of constructors.
269 virtual void runStaticConstructorsDestructors(bool isDtors);
271 /// runStaticConstructorsDestructors - This method is used to execute all of
272 /// the static constructors or destructors for a particular module.
274 /// \param isDtors - Run the destructors instead of constructors.
275 void runStaticConstructorsDestructors(Module *module, bool isDtors);
278 /// runFunctionAsMain - This is a helper function which wraps runFunction to
279 /// handle the common task of starting up main with the specified argc, argv,
280 /// and envp parameters.
281 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
282 const char * const * envp);
285 /// addGlobalMapping - Tell the execution engine that the specified global is
286 /// at the specified location. This is used internally as functions are JIT'd
287 /// and as global variables are laid out in memory. It can and should also be
288 /// used by clients of the EE that want to have an LLVM global overlay
289 /// existing data in memory. Mappings are automatically removed when their
290 /// GlobalValue is destroyed.
291 void addGlobalMapping(const GlobalValue *GV, void *Addr);
293 /// clearAllGlobalMappings - Clear all global mappings and start over again,
294 /// for use in dynamic compilation scenarios to move globals.
295 void clearAllGlobalMappings();
297 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
298 /// particular module, because it has been removed from the JIT.
299 void clearGlobalMappingsFromModule(Module *M);
301 /// updateGlobalMapping - Replace an existing mapping for GV with a new
302 /// address. This updates both maps as required. If "Addr" is null, the
303 /// entry for the global is removed from the mappings. This returns the old
304 /// value of the pointer, or null if it was not in the map.
305 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
307 /// getPointerToGlobalIfAvailable - This returns the address of the specified
308 /// global value if it is has already been codegen'd, otherwise it returns
311 /// This function is deprecated for the MCJIT execution engine. It doesn't
312 /// seem to be needed in that case, but an equivalent can be added if it is.
313 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
315 /// getPointerToGlobal - This returns the address of the specified global
316 /// value. This may involve code generation if it's a function.
318 /// This function is deprecated for the MCJIT execution engine. Use
319 /// getGlobalValueAddress instead.
320 void *getPointerToGlobal(const GlobalValue *GV);
322 /// getPointerToFunction - The different EE's represent function bodies in
323 /// different ways. They should each implement this to say what a function
324 /// pointer should look like. When F is destroyed, the ExecutionEngine will
325 /// remove its global mapping and free any machine code. Be sure no threads
326 /// are running inside F when that happens.
328 /// This function is deprecated for the MCJIT execution engine. Use
329 /// getFunctionAddress instead.
330 virtual void *getPointerToFunction(Function *F) = 0;
332 /// getPointerToFunctionOrStub - If the specified function has been
333 /// code-gen'd, return a pointer to the function. If not, compile it, or use
334 /// a stub to implement lazy compilation if available. See
335 /// getPointerToFunction for the requirements on destroying F.
337 /// This function is deprecated for the MCJIT execution engine. Use
338 /// getFunctionAddress instead.
339 virtual void *getPointerToFunctionOrStub(Function *F) {
340 // Default implementation, just codegen the function.
341 return getPointerToFunction(F);
344 /// getGlobalValueAddress - Return the address of the specified global
345 /// value. This may involve code generation.
347 /// This function should not be called with the JIT or interpreter engines.
348 virtual uint64_t getGlobalValueAddress(const std::string &Name) {
349 // Default implementation for JIT and interpreter. MCJIT will override this.
350 // JIT and interpreter clients should use getPointerToGlobal instead.
354 /// getFunctionAddress - Return the address of the specified function.
355 /// This may involve code generation.
356 virtual uint64_t getFunctionAddress(const std::string &Name) {
357 // Default implementation for JIT and interpreter. MCJIT will override this.
358 // JIT and interpreter clients should use getPointerToFunction instead.
362 // The JIT overrides a version that actually does this.
363 virtual void runJITOnFunction(Function *, MachineCodeInfo * = nullptr) { }
365 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
366 /// at the specified address.
368 const GlobalValue *getGlobalValueAtAddress(void *Addr);
370 /// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr.
371 /// Ptr is the address of the memory at which to store Val, cast to
372 /// GenericValue *. It is not a pointer to a GenericValue containing the
373 /// address at which to store Val.
374 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
377 void InitializeMemory(const Constant *Init, void *Addr);
379 /// getOrEmitGlobalVariable - Return the address of the specified global
380 /// variable, possibly emitting it to memory if needed. This is used by the
383 /// This function is deprecated for the MCJIT execution engine. Use
384 /// getGlobalValueAddress instead.
385 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
386 return getPointerToGlobal((const GlobalValue *)GV);
389 /// Registers a listener to be called back on various events within
390 /// the JIT. See JITEventListener.h for more details. Does not
391 /// take ownership of the argument. The argument may be NULL, in
392 /// which case these functions do nothing.
393 virtual void RegisterJITEventListener(JITEventListener *) {}
394 virtual void UnregisterJITEventListener(JITEventListener *) {}
396 /// Sets the pre-compiled object cache. The ownership of the ObjectCache is
397 /// not changed. Supported by MCJIT but not JIT.
398 virtual void setObjectCache(ObjectCache *) {
399 llvm_unreachable("No support for an object cache");
402 /// setProcessAllSections (MCJIT Only): By default, only sections that are
403 /// "required for execution" are passed to the RTDyldMemoryManager, and other
404 /// sections are discarded. Passing 'true' to this method will cause
405 /// RuntimeDyld to pass all sections to its RTDyldMemoryManager regardless
406 /// of whether they are "required to execute" in the usual sense.
408 /// Rationale: Some MCJIT clients want to be able to inspect metadata
409 /// sections (e.g. Dwarf, Stack-maps) to enable functionality or analyze
410 /// performance. Passing these sections to the memory manager allows the
411 /// client to make policy about the relevant sections, rather than having
413 virtual void setProcessAllSections(bool ProcessAllSections) {
414 llvm_unreachable("No support for ProcessAllSections option");
417 /// Return the target machine (if available).
418 virtual TargetMachine *getTargetMachine() { return nullptr; }
420 /// DisableLazyCompilation - When lazy compilation is off (the default), the
421 /// JIT will eagerly compile every function reachable from the argument to
422 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only
423 /// compile the one function and emit stubs to compile the rest when they're
424 /// first called. If lazy compilation is turned off again while some lazy
425 /// stubs are still around, and one of those stubs is called, the program will
428 /// In order to safely compile lazily in a threaded program, the user must
429 /// ensure that 1) only one thread at a time can call any particular lazy
430 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
431 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
432 /// lazy stub. See http://llvm.org/PR5184 for details.
433 void DisableLazyCompilation(bool Disabled = true) {
434 CompilingLazily = !Disabled;
436 bool isCompilingLazily() const {
437 return CompilingLazily;
439 // Deprecated in favor of isCompilingLazily (to reduce double-negatives).
440 // Remove this in LLVM 2.8.
441 bool isLazyCompilationDisabled() const {
442 return !CompilingLazily;
445 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
446 /// allocate space and populate a GlobalVariable that is not internal to
448 void DisableGVCompilation(bool Disabled = true) {
449 GVCompilationDisabled = Disabled;
451 bool isGVCompilationDisabled() const {
452 return GVCompilationDisabled;
455 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
456 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
457 /// resolve symbols in a custom way.
458 void DisableSymbolSearching(bool Disabled = true) {
459 SymbolSearchingDisabled = Disabled;
461 bool isSymbolSearchingDisabled() const {
462 return SymbolSearchingDisabled;
465 /// Enable/Disable IR module verification.
467 /// Note: Module verification is enabled by default in Debug builds, and
468 /// disabled by default in Release. Use this method to override the default.
469 void setVerifyModules(bool Verify) {
470 VerifyModules = Verify;
472 bool getVerifyModules() const {
473 return VerifyModules;
476 /// InstallLazyFunctionCreator - If an unknown function is needed, the
477 /// specified function pointer is invoked to create it. If it returns null,
478 /// the JIT will abort.
479 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
480 LazyFunctionCreator = P;
484 explicit ExecutionEngine(Module *M);
488 void EmitGlobalVariable(const GlobalVariable *GV);
490 GenericValue getConstantValue(const Constant *C);
491 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
495 namespace EngineKind {
496 // These are actually bitmasks that get or-ed together.
501 const static Kind Either = (Kind)(JIT | Interpreter);
504 /// EngineBuilder - Builder class for ExecutionEngines. Use this by
505 /// stack-allocating a builder, chaining the various set* methods, and
506 /// terminating it with a .create() call.
507 class EngineBuilder {
510 EngineKind::Kind WhichEngine;
511 std::string *ErrorStr;
512 CodeGenOpt::Level OptLevel;
513 RTDyldMemoryManager *MCJMM;
514 JITMemoryManager *JMM;
515 TargetOptions Options;
516 Reloc::Model RelocModel;
517 CodeModel::Model CMModel;
520 SmallVector<std::string, 4> MAttrs;
523 /// InitEngine - Does the common initialization of default options.
527 /// EngineBuilder - Constructor for EngineBuilder. If create() is called and
528 /// is successful, the created engine takes ownership of the module.
529 EngineBuilder(Module *m) : M(m) {
533 /// setEngineKind - Controls whether the user wants the interpreter, the JIT,
534 /// or whichever engine works. This option defaults to EngineKind::Either.
535 EngineBuilder &setEngineKind(EngineKind::Kind w) {
540 /// setMCJITMemoryManager - Sets the MCJIT memory manager to use. This allows
541 /// clients to customize their memory allocation policies for the MCJIT. This
542 /// is only appropriate for the MCJIT; setting this and configuring the builder
543 /// to create anything other than MCJIT will cause a runtime error. If create()
544 /// is called and is successful, the created engine takes ownership of the
545 /// memory manager. This option defaults to NULL. Using this option nullifies
546 /// the setJITMemoryManager() option.
547 EngineBuilder &setMCJITMemoryManager(RTDyldMemoryManager *mcjmm) {
553 /// setJITMemoryManager - Sets the JIT memory manager to use. This allows
554 /// clients to customize their memory allocation policies. This is only
555 /// appropriate for either JIT or MCJIT; setting this and configuring the
556 /// builder to create an interpreter will cause a runtime error. If create()
557 /// is called and is successful, the created engine takes ownership of the
558 /// memory manager. This option defaults to NULL. This option overrides
559 /// setMCJITMemoryManager() as well.
560 EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) {
566 /// setErrorStr - Set the error string to write to on error. This option
567 /// defaults to NULL.
568 EngineBuilder &setErrorStr(std::string *e) {
573 /// setOptLevel - Set the optimization level for the JIT. This option
574 /// defaults to CodeGenOpt::Default.
575 EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
580 /// setTargetOptions - Set the target options that the ExecutionEngine
581 /// target is using. Defaults to TargetOptions().
582 EngineBuilder &setTargetOptions(const TargetOptions &Opts) {
587 /// setRelocationModel - Set the relocation model that the ExecutionEngine
588 /// target is using. Defaults to target specific default "Reloc::Default".
589 EngineBuilder &setRelocationModel(Reloc::Model RM) {
594 /// setCodeModel - Set the CodeModel that the ExecutionEngine target
595 /// data is using. Defaults to target specific default
596 /// "CodeModel::JITDefault".
597 EngineBuilder &setCodeModel(CodeModel::Model M) {
602 /// setMArch - Override the architecture set by the Module's triple.
603 EngineBuilder &setMArch(StringRef march) {
604 MArch.assign(march.begin(), march.end());
608 /// setMCPU - Target a specific cpu type.
609 EngineBuilder &setMCPU(StringRef mcpu) {
610 MCPU.assign(mcpu.begin(), mcpu.end());
614 /// setVerifyModules - Set whether the JIT implementation should verify
615 /// IR modules during compilation.
616 EngineBuilder &setVerifyModules(bool Verify) {
617 VerifyModules = Verify;
621 /// setMAttrs - Set cpu-specific attributes.
622 template<typename StringSequence>
623 EngineBuilder &setMAttrs(const StringSequence &mattrs) {
625 MAttrs.append(mattrs.begin(), mattrs.end());
629 TargetMachine *selectTarget();
631 /// selectTarget - Pick a target either via -march or by guessing the native
632 /// arch. Add any CPU features specified via -mcpu or -mattr.
633 TargetMachine *selectTarget(const Triple &TargetTriple,
636 const SmallVectorImpl<std::string>& MAttrs);
638 ExecutionEngine *create() {
639 return create(selectTarget());
642 ExecutionEngine *create(TargetMachine *TM);
645 // Create wrappers for C Binding types (see CBindingWrapping.h).
646 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ExecutionEngine, LLVMExecutionEngineRef)
648 } // End llvm namespace