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 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 static ExecutionEngine *(*MCJITCtor)(std::unique_ptr<Module> M,
142 std::string *ErrorStr,
143 RTDyldMemoryManager *MCJMM,
144 std::unique_ptr<TargetMachine> TM);
145 static ExecutionEngine *(*InterpCtor)(std::unique_ptr<Module> M,
146 std::string *ErrorStr);
148 /// LazyFunctionCreator - If an unknown function is needed, this function
149 /// pointer is invoked to create it. If this returns null, the JIT will
151 void *(*LazyFunctionCreator)(const std::string &);
154 /// lock - This lock protects the ExecutionEngine and MCJIT classes. It must
155 /// be held while changing the internal state of any of those classes.
158 //===--------------------------------------------------------------------===//
159 // ExecutionEngine Startup
160 //===--------------------------------------------------------------------===//
162 virtual ~ExecutionEngine();
164 /// Add a Module to the list of modules that we can JIT from.
165 virtual void addModule(std::unique_ptr<Module> M) {
166 Modules.push_back(std::move(M));
169 /// addObjectFile - Add an ObjectFile to the execution engine.
171 /// This method is only supported by MCJIT. MCJIT will immediately load the
172 /// object into memory and adds its symbols to the list used to resolve
173 /// external symbols while preparing other objects for execution.
175 /// Objects added using this function will not be made executable until
176 /// needed by another object.
178 /// MCJIT will take ownership of the ObjectFile.
179 virtual void addObjectFile(std::unique_ptr<object::ObjectFile> O);
180 virtual void addObjectFile(object::OwningBinary<object::ObjectFile> O);
182 /// addArchive - Add an Archive to the execution engine.
184 /// This method is only supported by MCJIT. MCJIT will use the archive to
185 /// resolve external symbols in objects it is loading. If a symbol is found
186 /// in the Archive the contained object file will be extracted (in memory)
187 /// and loaded for possible execution.
188 virtual void addArchive(object::OwningBinary<object::Archive> A);
190 //===--------------------------------------------------------------------===//
192 const DataLayout *getDataLayout() const { return DL; }
194 /// removeModule - Remove a Module from the list of modules. Returns true if
196 virtual bool removeModule(Module *M);
198 /// FindFunctionNamed - Search all of the active modules to find the one that
199 /// defines FnName. This is very slow operation and shouldn't be used for
201 virtual Function *FindFunctionNamed(const char *FnName);
203 /// runFunction - Execute the specified function with the specified arguments,
204 /// and return the result.
205 virtual GenericValue runFunction(Function *F,
206 const std::vector<GenericValue> &ArgValues) = 0;
208 /// getPointerToNamedFunction - This method returns the address of the
209 /// specified function by using the dlsym function call. As such it is only
210 /// useful for resolving library symbols, not code generated symbols.
212 /// If AbortOnFailure is false and no function with the given name is
213 /// found, this function silently returns a null pointer. Otherwise,
214 /// it prints a message to stderr and aborts.
216 /// This function is deprecated for the MCJIT execution engine.
217 virtual void *getPointerToNamedFunction(StringRef Name,
218 bool AbortOnFailure = true) = 0;
220 /// mapSectionAddress - map a section to its target address space value.
221 /// Map the address of a JIT section as returned from the memory manager
222 /// to the address in the target process as the running code will see it.
223 /// This is the address which will be used for relocation resolution.
224 virtual void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) {
225 llvm_unreachable("Re-mapping of section addresses not supported with this "
229 /// generateCodeForModule - Run code generation for the specified module and
230 /// load it into memory.
232 /// When this function has completed, all code and data for the specified
233 /// module, and any module on which this module depends, will be generated
234 /// and loaded into memory, but relocations will not yet have been applied
235 /// and all memory will be readable and writable but not executable.
237 /// This function is primarily useful when generating code for an external
238 /// target, allowing the client an opportunity to remap section addresses
239 /// before relocations are applied. Clients that intend to execute code
240 /// locally can use the getFunctionAddress call, which will generate code
241 /// and apply final preparations all in one step.
243 /// This method has no effect for the interpeter.
244 virtual void generateCodeForModule(Module *M) {}
246 /// finalizeObject - ensure the module is fully processed and is usable.
248 /// It is the user-level function for completing the process of making the
249 /// object usable for execution. It should be called after sections within an
250 /// object have been relocated using mapSectionAddress. When this method is
251 /// called the MCJIT execution engine will reapply relocations for a loaded
252 /// object. This method has no effect for the interpeter.
253 virtual void finalizeObject() {}
255 /// runStaticConstructorsDestructors - This method is used to execute all of
256 /// the static constructors or destructors for a program.
258 /// \param isDtors - Run the destructors instead of constructors.
259 virtual void runStaticConstructorsDestructors(bool isDtors);
261 /// This method is used to execute all of the static constructors or
262 /// destructors for a particular module.
264 /// \param isDtors - Run the destructors instead of constructors.
265 void runStaticConstructorsDestructors(Module &module, bool isDtors);
268 /// runFunctionAsMain - This is a helper function which wraps runFunction to
269 /// handle the common task of starting up main with the specified argc, argv,
270 /// and envp parameters.
271 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
272 const char * const * envp);
275 /// addGlobalMapping - Tell the execution engine that the specified global is
276 /// at the specified location. This is used internally as functions are JIT'd
277 /// and as global variables are laid out in memory. It can and should also be
278 /// used by clients of the EE that want to have an LLVM global overlay
279 /// existing data in memory. Mappings are automatically removed when their
280 /// GlobalValue is destroyed.
281 void addGlobalMapping(const GlobalValue *GV, void *Addr);
283 /// clearAllGlobalMappings - Clear all global mappings and start over again,
284 /// for use in dynamic compilation scenarios to move globals.
285 void clearAllGlobalMappings();
287 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
288 /// particular module, because it has been removed from the JIT.
289 void clearGlobalMappingsFromModule(Module *M);
291 /// updateGlobalMapping - Replace an existing mapping for GV with a new
292 /// address. This updates both maps as required. If "Addr" is null, the
293 /// entry for the global is removed from the mappings. This returns the old
294 /// value of the pointer, or null if it was not in the map.
295 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
297 /// getPointerToGlobalIfAvailable - This returns the address of the specified
298 /// global value if it is has already been codegen'd, otherwise it returns
301 /// This function is deprecated for the MCJIT execution engine. It doesn't
302 /// seem to be needed in that case, but an equivalent can be added if it is.
303 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
305 /// getPointerToGlobal - This returns the address of the specified global
306 /// value. This may involve code generation if it's a function.
308 /// This function is deprecated for the MCJIT execution engine. Use
309 /// getGlobalValueAddress instead.
310 void *getPointerToGlobal(const GlobalValue *GV);
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.
318 /// This function is deprecated for the MCJIT execution engine. Use
319 /// getFunctionAddress instead.
320 virtual void *getPointerToFunction(Function *F) = 0;
322 /// getPointerToFunctionOrStub - If the specified function has been
323 /// code-gen'd, return a pointer to the function. If not, compile it, or use
324 /// a stub to implement lazy compilation if available. See
325 /// getPointerToFunction for the requirements on destroying F.
327 /// This function is deprecated for the MCJIT execution engine. Use
328 /// getFunctionAddress instead.
329 virtual void *getPointerToFunctionOrStub(Function *F) {
330 // Default implementation, just codegen the function.
331 return getPointerToFunction(F);
334 /// getGlobalValueAddress - Return the address of the specified global
335 /// value. This may involve code generation.
337 /// This function should not be called with the interpreter engine.
338 virtual uint64_t getGlobalValueAddress(const std::string &Name) {
339 // Default implementation for the interpreter. MCJIT will override this.
340 // JIT and interpreter clients should use getPointerToGlobal instead.
344 /// getFunctionAddress - Return the address of the specified function.
345 /// This may involve code generation.
346 virtual uint64_t getFunctionAddress(const std::string &Name) {
347 // Default implementation for the interpreter. MCJIT will override this.
348 // Interpreter clients should use getPointerToFunction instead.
352 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
353 /// at the specified address.
355 const GlobalValue *getGlobalValueAtAddress(void *Addr);
357 /// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr.
358 /// Ptr is the address of the memory at which to store Val, cast to
359 /// GenericValue *. It is not a pointer to a GenericValue containing the
360 /// address at which to store Val.
361 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
364 void InitializeMemory(const Constant *Init, void *Addr);
366 /// getOrEmitGlobalVariable - Return the address of the specified global
367 /// variable, possibly emitting it to memory if needed. This is used by the
370 /// This function is deprecated for the MCJIT execution engine. Use
371 /// getGlobalValueAddress instead.
372 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
373 return getPointerToGlobal((const GlobalValue *)GV);
376 /// Registers a listener to be called back on various events within
377 /// the JIT. See JITEventListener.h for more details. Does not
378 /// take ownership of the argument. The argument may be NULL, in
379 /// which case these functions do nothing.
380 virtual void RegisterJITEventListener(JITEventListener *) {}
381 virtual void UnregisterJITEventListener(JITEventListener *) {}
383 /// Sets the pre-compiled object cache. The ownership of the ObjectCache is
384 /// not changed. Supported by MCJIT but not the interpreter.
385 virtual void setObjectCache(ObjectCache *) {
386 llvm_unreachable("No support for an object cache");
389 /// setProcessAllSections (MCJIT Only): By default, only sections that are
390 /// "required for execution" are passed to the RTDyldMemoryManager, and other
391 /// sections are discarded. Passing 'true' to this method will cause
392 /// RuntimeDyld to pass all sections to its RTDyldMemoryManager regardless
393 /// of whether they are "required to execute" in the usual sense.
395 /// Rationale: Some MCJIT clients want to be able to inspect metadata
396 /// sections (e.g. Dwarf, Stack-maps) to enable functionality or analyze
397 /// performance. Passing these sections to the memory manager allows the
398 /// client to make policy about the relevant sections, rather than having
400 virtual void setProcessAllSections(bool ProcessAllSections) {
401 llvm_unreachable("No support for ProcessAllSections option");
404 /// Return the target machine (if available).
405 virtual TargetMachine *getTargetMachine() { return nullptr; }
407 /// DisableLazyCompilation - When lazy compilation is off (the default), the
408 /// JIT will eagerly compile every function reachable from the argument to
409 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only
410 /// compile the one function and emit stubs to compile the rest when they're
411 /// first called. If lazy compilation is turned off again while some lazy
412 /// stubs are still around, and one of those stubs is called, the program will
415 /// In order to safely compile lazily in a threaded program, the user must
416 /// ensure that 1) only one thread at a time can call any particular lazy
417 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
418 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
419 /// lazy stub. See http://llvm.org/PR5184 for details.
420 void DisableLazyCompilation(bool Disabled = true) {
421 CompilingLazily = !Disabled;
423 bool isCompilingLazily() const {
424 return CompilingLazily;
427 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
428 /// allocate space and populate a GlobalVariable that is not internal to
430 void DisableGVCompilation(bool Disabled = true) {
431 GVCompilationDisabled = Disabled;
433 bool isGVCompilationDisabled() const {
434 return GVCompilationDisabled;
437 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
438 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
439 /// resolve symbols in a custom way.
440 void DisableSymbolSearching(bool Disabled = true) {
441 SymbolSearchingDisabled = Disabled;
443 bool isSymbolSearchingDisabled() const {
444 return SymbolSearchingDisabled;
447 /// Enable/Disable IR module verification.
449 /// Note: Module verification is enabled by default in Debug builds, and
450 /// disabled by default in Release. Use this method to override the default.
451 void setVerifyModules(bool Verify) {
452 VerifyModules = Verify;
454 bool getVerifyModules() const {
455 return VerifyModules;
458 /// InstallLazyFunctionCreator - If an unknown function is needed, the
459 /// specified function pointer is invoked to create it. If it returns null,
460 /// the JIT will abort.
461 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
462 LazyFunctionCreator = P;
466 explicit ExecutionEngine(std::unique_ptr<Module> M);
470 void EmitGlobalVariable(const GlobalVariable *GV);
472 GenericValue getConstantValue(const Constant *C);
473 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
477 namespace EngineKind {
478 // These are actually bitmasks that get or-ed together.
483 const static Kind Either = (Kind)(JIT | Interpreter);
486 /// Builder class for ExecutionEngines. Use this by stack-allocating a builder,
487 /// chaining the various set* methods, and terminating it with a .create()
489 class EngineBuilder {
491 std::unique_ptr<Module> M;
492 EngineKind::Kind WhichEngine;
493 std::string *ErrorStr;
494 CodeGenOpt::Level OptLevel;
495 RTDyldMemoryManager *MCJMM;
496 TargetOptions Options;
497 Reloc::Model RelocModel;
498 CodeModel::Model CMModel;
501 SmallVector<std::string, 4> MAttrs;
504 /// InitEngine - Does the common initialization of default options.
508 /// Constructor for EngineBuilder.
509 EngineBuilder(std::unique_ptr<Module> M) : M(std::move(M)) {
513 /// setEngineKind - Controls whether the user wants the interpreter, the JIT,
514 /// or whichever engine works. This option defaults to EngineKind::Either.
515 EngineBuilder &setEngineKind(EngineKind::Kind w) {
520 /// setMCJITMemoryManager - Sets the MCJIT memory manager to use. This allows
521 /// clients to customize their memory allocation policies for the MCJIT. This
522 /// is only appropriate for the MCJIT; setting this and configuring the builder
523 /// to create anything other than MCJIT will cause a runtime error. If create()
524 /// is called and is successful, the created engine takes ownership of the
525 /// memory manager. This option defaults to NULL.
526 EngineBuilder &setMCJITMemoryManager(RTDyldMemoryManager *mcjmm) {
531 /// setErrorStr - Set the error string to write to on error. This option
532 /// defaults to NULL.
533 EngineBuilder &setErrorStr(std::string *e) {
538 /// setOptLevel - Set the optimization level for the JIT. This option
539 /// defaults to CodeGenOpt::Default.
540 EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
545 /// setTargetOptions - Set the target options that the ExecutionEngine
546 /// target is using. Defaults to TargetOptions().
547 EngineBuilder &setTargetOptions(const TargetOptions &Opts) {
552 /// setRelocationModel - Set the relocation model that the ExecutionEngine
553 /// target is using. Defaults to target specific default "Reloc::Default".
554 EngineBuilder &setRelocationModel(Reloc::Model RM) {
559 /// setCodeModel - Set the CodeModel that the ExecutionEngine target
560 /// data is using. Defaults to target specific default
561 /// "CodeModel::JITDefault".
562 EngineBuilder &setCodeModel(CodeModel::Model M) {
567 /// setMArch - Override the architecture set by the Module's triple.
568 EngineBuilder &setMArch(StringRef march) {
569 MArch.assign(march.begin(), march.end());
573 /// setMCPU - Target a specific cpu type.
574 EngineBuilder &setMCPU(StringRef mcpu) {
575 MCPU.assign(mcpu.begin(), mcpu.end());
579 /// setVerifyModules - Set whether the JIT implementation should verify
580 /// IR modules during compilation.
581 EngineBuilder &setVerifyModules(bool Verify) {
582 VerifyModules = Verify;
586 /// setMAttrs - Set cpu-specific attributes.
587 template<typename StringSequence>
588 EngineBuilder &setMAttrs(const StringSequence &mattrs) {
590 MAttrs.append(mattrs.begin(), mattrs.end());
594 TargetMachine *selectTarget();
596 /// selectTarget - Pick a target either via -march or by guessing the native
597 /// arch. Add any CPU features specified via -mcpu or -mattr.
598 TargetMachine *selectTarget(const Triple &TargetTriple,
601 const SmallVectorImpl<std::string>& MAttrs);
603 ExecutionEngine *create() {
604 return create(selectTarget());
607 ExecutionEngine *create(TargetMachine *TM);
610 // Create wrappers for C Binding types (see CBindingWrapping.h).
611 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ExecutionEngine, LLVMExecutionEngineRef)
613 } // End llvm namespace