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 *(*JITCtor)(
146 std::string *ErrorStr,
147 JITMemoryManager *JMM,
150 static ExecutionEngine *(*MCJITCtor)(
152 std::string *ErrorStr,
153 RTDyldMemoryManager *MCJMM,
155 static ExecutionEngine *(*InterpCtor)(Module *M, std::string *ErrorStr);
157 /// LazyFunctionCreator - If an unknown function is needed, this function
158 /// pointer is invoked to create it. If this returns null, the JIT will
160 void *(*LazyFunctionCreator)(const std::string &);
163 /// lock - This lock protects the ExecutionEngine, MCJIT, JIT, JITResolver and
164 /// JITEmitter classes. It must be held while changing the internal state of
165 /// any of those classes.
168 //===--------------------------------------------------------------------===//
169 // ExecutionEngine Startup
170 //===--------------------------------------------------------------------===//
172 virtual ~ExecutionEngine();
174 /// addModule - Add a Module to the list of modules that we can JIT from.
175 /// Note that this takes ownership of the Module: when the ExecutionEngine is
176 /// destroyed, it destroys the Module as well.
177 virtual void addModule(Module *M) {
178 Modules.push_back(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(std::unique_ptr<object::Archive> A) {
200 llvm_unreachable("ExecutionEngine subclass doesn't implement addArchive.");
203 //===--------------------------------------------------------------------===//
205 const DataLayout *getDataLayout() const { return DL; }
207 /// removeModule - Remove a Module from the list of modules. Returns true if
209 virtual bool removeModule(Module *M);
211 /// FindFunctionNamed - Search all of the active modules to find the one that
212 /// defines FnName. This is very slow operation and shouldn't be used for
214 virtual Function *FindFunctionNamed(const char *FnName);
216 /// runFunction - Execute the specified function with the specified arguments,
217 /// and return the result.
218 virtual GenericValue runFunction(Function *F,
219 const std::vector<GenericValue> &ArgValues) = 0;
221 /// getPointerToNamedFunction - This method returns the address of the
222 /// specified function by using the dlsym function call. As such it is only
223 /// useful for resolving library symbols, not code generated symbols.
225 /// If AbortOnFailure is false and no function with the given name is
226 /// found, this function silently returns a null pointer. Otherwise,
227 /// it prints a message to stderr and aborts.
229 /// This function is deprecated for the MCJIT execution engine.
231 /// FIXME: the JIT and MCJIT interfaces should be disentangled or united
232 /// again, if possible.
234 virtual void *getPointerToNamedFunction(const std::string &Name,
235 bool AbortOnFailure = true) = 0;
237 /// mapSectionAddress - map a section to its target address space value.
238 /// Map the address of a JIT section as returned from the memory manager
239 /// to the address in the target process as the running code will see it.
240 /// This is the address which will be used for relocation resolution.
241 virtual void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) {
242 llvm_unreachable("Re-mapping of section addresses not supported with this "
246 /// generateCodeForModule - Run code generationen for the specified module and
247 /// load it into memory.
249 /// When this function has completed, all code and data for the specified
250 /// module, and any module on which this module depends, will be generated
251 /// and loaded into memory, but relocations will not yet have been applied
252 /// and all memory will be readable and writable but not executable.
254 /// This function is primarily useful when generating code for an external
255 /// target, allowing the client an opportunity to remap section addresses
256 /// before relocations are applied. Clients that intend to execute code
257 /// locally can use the getFunctionAddress call, which will generate code
258 /// and apply final preparations all in one step.
260 /// This method has no effect for the legacy JIT engine or the interpeter.
261 virtual void generateCodeForModule(Module *M) {}
263 /// finalizeObject - ensure the module is fully processed and is usable.
265 /// It is the user-level function for completing the process of making the
266 /// object usable for execution. It should be called after sections within an
267 /// object have been relocated using mapSectionAddress. When this method is
268 /// called the MCJIT execution engine will reapply relocations for a loaded
269 /// object. This method has no effect for the legacy JIT engine or the
271 virtual void finalizeObject() {}
273 /// runStaticConstructorsDestructors - This method is used to execute all of
274 /// the static constructors or destructors for a program.
276 /// \param isDtors - Run the destructors instead of constructors.
277 virtual void runStaticConstructorsDestructors(bool isDtors);
279 /// runStaticConstructorsDestructors - This method is used to execute all of
280 /// the static constructors or destructors for a particular module.
282 /// \param isDtors - Run the destructors instead of constructors.
283 void runStaticConstructorsDestructors(Module *module, bool isDtors);
286 /// runFunctionAsMain - This is a helper function which wraps runFunction to
287 /// handle the common task of starting up main with the specified argc, argv,
288 /// and envp parameters.
289 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
290 const char * const * envp);
293 /// addGlobalMapping - Tell the execution engine that the specified global is
294 /// at the specified location. This is used internally as functions are JIT'd
295 /// and as global variables are laid out in memory. It can and should also be
296 /// used by clients of the EE that want to have an LLVM global overlay
297 /// existing data in memory. Mappings are automatically removed when their
298 /// GlobalValue is destroyed.
299 void addGlobalMapping(const GlobalValue *GV, void *Addr);
301 /// clearAllGlobalMappings - Clear all global mappings and start over again,
302 /// for use in dynamic compilation scenarios to move globals.
303 void clearAllGlobalMappings();
305 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
306 /// particular module, because it has been removed from the JIT.
307 void clearGlobalMappingsFromModule(Module *M);
309 /// updateGlobalMapping - Replace an existing mapping for GV with a new
310 /// address. This updates both maps as required. If "Addr" is null, the
311 /// entry for the global is removed from the mappings. This returns the old
312 /// value of the pointer, or null if it was not in the map.
313 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
315 /// getPointerToGlobalIfAvailable - This returns the address of the specified
316 /// global value if it is has already been codegen'd, otherwise it returns
319 /// This function is deprecated for the MCJIT execution engine. It doesn't
320 /// seem to be needed in that case, but an equivalent can be added if it is.
321 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
323 /// getPointerToGlobal - This returns the address of the specified global
324 /// value. This may involve code generation if it's a function.
326 /// This function is deprecated for the MCJIT execution engine. Use
327 /// getGlobalValueAddress instead.
328 void *getPointerToGlobal(const GlobalValue *GV);
330 /// getPointerToFunction - The different EE's represent function bodies in
331 /// different ways. They should each implement this to say what a function
332 /// pointer should look like. When F is destroyed, the ExecutionEngine will
333 /// remove its global mapping and free any machine code. Be sure no threads
334 /// are running inside F when that happens.
336 /// This function is deprecated for the MCJIT execution engine. Use
337 /// getFunctionAddress instead.
338 virtual void *getPointerToFunction(Function *F) = 0;
340 /// getPointerToBasicBlock - The different EE's represent basic blocks in
341 /// different ways. Return the representation for a blockaddress of the
344 /// This function will not be implemented for the MCJIT execution engine.
345 virtual void *getPointerToBasicBlock(BasicBlock *BB) = 0;
347 /// getPointerToFunctionOrStub - If the specified function has been
348 /// code-gen'd, return a pointer to the function. If not, compile it, or use
349 /// a stub to implement lazy compilation if available. See
350 /// getPointerToFunction for the requirements on destroying F.
352 /// This function is deprecated for the MCJIT execution engine. Use
353 /// getFunctionAddress instead.
354 virtual void *getPointerToFunctionOrStub(Function *F) {
355 // Default implementation, just codegen the function.
356 return getPointerToFunction(F);
359 /// getGlobalValueAddress - Return the address of the specified global
360 /// value. This may involve code generation.
362 /// This function should not be called with the JIT or interpreter engines.
363 virtual uint64_t getGlobalValueAddress(const std::string &Name) {
364 // Default implementation for JIT and interpreter. MCJIT will override this.
365 // JIT and interpreter clients should use getPointerToGlobal instead.
369 /// getFunctionAddress - Return the address of the specified function.
370 /// This may involve code generation.
371 virtual uint64_t getFunctionAddress(const std::string &Name) {
372 // Default implementation for JIT and interpreter. MCJIT will override this.
373 // JIT and interpreter clients should use getPointerToFunction instead.
377 // The JIT overrides a version that actually does this.
378 virtual void runJITOnFunction(Function *, MachineCodeInfo * = nullptr) { }
380 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
381 /// at the specified address.
383 const GlobalValue *getGlobalValueAtAddress(void *Addr);
385 /// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr.
386 /// Ptr is the address of the memory at which to store Val, cast to
387 /// GenericValue *. It is not a pointer to a GenericValue containing the
388 /// address at which to store Val.
389 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
392 void InitializeMemory(const Constant *Init, void *Addr);
394 /// recompileAndRelinkFunction - This method is used to force a function which
395 /// has already been compiled to be compiled again, possibly after it has been
396 /// modified. Then the entry to the old copy is overwritten with a branch to
397 /// the new copy. If there was no old copy, this acts just like
398 /// VM::getPointerToFunction().
399 virtual void *recompileAndRelinkFunction(Function *F) = 0;
401 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
402 /// corresponding to the machine code emitted to execute this function, useful
403 /// for garbage-collecting generated code.
404 virtual void freeMachineCodeForFunction(Function *F) = 0;
406 /// getOrEmitGlobalVariable - Return the address of the specified global
407 /// variable, possibly emitting it to memory if needed. This is used by the
410 /// This function is deprecated for the MCJIT execution engine. Use
411 /// getGlobalValueAddress instead.
412 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
413 return getPointerToGlobal((const GlobalValue *)GV);
416 /// Registers a listener to be called back on various events within
417 /// the JIT. See JITEventListener.h for more details. Does not
418 /// take ownership of the argument. The argument may be NULL, in
419 /// which case these functions do nothing.
420 virtual void RegisterJITEventListener(JITEventListener *) {}
421 virtual void UnregisterJITEventListener(JITEventListener *) {}
423 /// Sets the pre-compiled object cache. The ownership of the ObjectCache is
424 /// not changed. Supported by MCJIT but not JIT.
425 virtual void setObjectCache(ObjectCache *) {
426 llvm_unreachable("No support for an object cache");
429 /// setProcessAllSections (MCJIT Only): By default, only sections that are
430 /// "required for execution" are passed to the RTDyldMemoryManager, and other
431 /// sections are discarded. Passing 'true' to this method will cause
432 /// RuntimeDyld to pass all sections to its RTDyldMemoryManager regardless
433 /// of whether they are "required to execute" in the usual sense.
435 /// Rationale: Some MCJIT clients want to be able to inspect metadata
436 /// sections (e.g. Dwarf, Stack-maps) to enable functionality or analyze
437 /// performance. Passing these sections to the memory manager allows the
438 /// client to make policy about the relevant sections, rather than having
440 virtual void setProcessAllSections(bool ProcessAllSections) {
441 llvm_unreachable("No support for ProcessAllSections option");
444 /// Return the target machine (if available).
445 virtual TargetMachine *getTargetMachine() { return nullptr; }
447 /// DisableLazyCompilation - When lazy compilation is off (the default), the
448 /// JIT will eagerly compile every function reachable from the argument to
449 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only
450 /// compile the one function and emit stubs to compile the rest when they're
451 /// first called. If lazy compilation is turned off again while some lazy
452 /// stubs are still around, and one of those stubs is called, the program will
455 /// In order to safely compile lazily in a threaded program, the user must
456 /// ensure that 1) only one thread at a time can call any particular lazy
457 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
458 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
459 /// lazy stub. See http://llvm.org/PR5184 for details.
460 void DisableLazyCompilation(bool Disabled = true) {
461 CompilingLazily = !Disabled;
463 bool isCompilingLazily() const {
464 return CompilingLazily;
466 // Deprecated in favor of isCompilingLazily (to reduce double-negatives).
467 // Remove this in LLVM 2.8.
468 bool isLazyCompilationDisabled() const {
469 return !CompilingLazily;
472 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
473 /// allocate space and populate a GlobalVariable that is not internal to
475 void DisableGVCompilation(bool Disabled = true) {
476 GVCompilationDisabled = Disabled;
478 bool isGVCompilationDisabled() const {
479 return GVCompilationDisabled;
482 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
483 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
484 /// resolve symbols in a custom way.
485 void DisableSymbolSearching(bool Disabled = true) {
486 SymbolSearchingDisabled = Disabled;
488 bool isSymbolSearchingDisabled() const {
489 return SymbolSearchingDisabled;
492 /// Enable/Disable IR module verification.
494 /// Note: Module verification is enabled by default in Debug builds, and
495 /// disabled by default in Release. Use this method to override the default.
496 void setVerifyModules(bool Verify) {
497 VerifyModules = Verify;
499 bool getVerifyModules() const {
500 return VerifyModules;
503 /// InstallLazyFunctionCreator - If an unknown function is needed, the
504 /// specified function pointer is invoked to create it. If it returns null,
505 /// the JIT will abort.
506 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
507 LazyFunctionCreator = P;
511 explicit ExecutionEngine(Module *M);
515 void EmitGlobalVariable(const GlobalVariable *GV);
517 GenericValue getConstantValue(const Constant *C);
518 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
522 namespace EngineKind {
523 // These are actually bitmasks that get or-ed together.
528 const static Kind Either = (Kind)(JIT | Interpreter);
531 /// EngineBuilder - Builder class for ExecutionEngines. Use this by
532 /// stack-allocating a builder, chaining the various set* methods, and
533 /// terminating it with a .create() call.
534 class EngineBuilder {
537 EngineKind::Kind WhichEngine;
538 std::string *ErrorStr;
539 CodeGenOpt::Level OptLevel;
540 RTDyldMemoryManager *MCJMM;
541 JITMemoryManager *JMM;
542 bool AllocateGVsWithCode;
543 TargetOptions Options;
544 Reloc::Model RelocModel;
545 CodeModel::Model CMModel;
548 SmallVector<std::string, 4> MAttrs;
552 /// InitEngine - Does the common initialization of default options.
556 /// EngineBuilder - Constructor for EngineBuilder. If create() is called and
557 /// is successful, the created engine takes ownership of the module.
558 EngineBuilder(Module *m) : M(m) {
562 /// setEngineKind - Controls whether the user wants the interpreter, the JIT,
563 /// or whichever engine works. This option defaults to EngineKind::Either.
564 EngineBuilder &setEngineKind(EngineKind::Kind w) {
569 /// setMCJITMemoryManager - Sets the MCJIT memory manager to use. This allows
570 /// clients to customize their memory allocation policies for the MCJIT. This
571 /// is only appropriate for the MCJIT; setting this and configuring the builder
572 /// to create anything other than MCJIT will cause a runtime error. If create()
573 /// is called and is successful, the created engine takes ownership of the
574 /// memory manager. This option defaults to NULL. Using this option nullifies
575 /// the setJITMemoryManager() option.
576 EngineBuilder &setMCJITMemoryManager(RTDyldMemoryManager *mcjmm) {
582 /// setJITMemoryManager - Sets the JIT memory manager to use. This allows
583 /// clients to customize their memory allocation policies. This is only
584 /// appropriate for either JIT or MCJIT; setting this and configuring the
585 /// builder to create an interpreter will cause a runtime error. If create()
586 /// is called and is successful, the created engine takes ownership of the
587 /// memory manager. This option defaults to NULL. This option overrides
588 /// setMCJITMemoryManager() as well.
589 EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) {
595 /// setErrorStr - Set the error string to write to on error. This option
596 /// defaults to NULL.
597 EngineBuilder &setErrorStr(std::string *e) {
602 /// setOptLevel - Set the optimization level for the JIT. This option
603 /// defaults to CodeGenOpt::Default.
604 EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
609 /// setTargetOptions - Set the target options that the ExecutionEngine
610 /// target is using. Defaults to TargetOptions().
611 EngineBuilder &setTargetOptions(const TargetOptions &Opts) {
616 /// setRelocationModel - Set the relocation model that the ExecutionEngine
617 /// target is using. Defaults to target specific default "Reloc::Default".
618 EngineBuilder &setRelocationModel(Reloc::Model RM) {
623 /// setCodeModel - Set the CodeModel that the ExecutionEngine target
624 /// data is using. Defaults to target specific default
625 /// "CodeModel::JITDefault".
626 EngineBuilder &setCodeModel(CodeModel::Model M) {
631 /// setAllocateGVsWithCode - Sets whether global values should be allocated
632 /// into the same buffer as code. For most applications this should be set
633 /// to false. Allocating globals with code breaks freeMachineCodeForFunction
634 /// and is probably unsafe and bad for performance. However, we have clients
635 /// who depend on this behavior, so we must support it. This option defaults
636 /// to false so that users of the new API can safely use the new memory
637 /// manager and free machine code.
638 EngineBuilder &setAllocateGVsWithCode(bool a) {
639 AllocateGVsWithCode = a;
643 /// setMArch - Override the architecture set by the Module's triple.
644 EngineBuilder &setMArch(StringRef march) {
645 MArch.assign(march.begin(), march.end());
649 /// setMCPU - Target a specific cpu type.
650 EngineBuilder &setMCPU(StringRef mcpu) {
651 MCPU.assign(mcpu.begin(), mcpu.end());
655 /// setUseMCJIT - Set whether the MC-JIT implementation should be used
657 EngineBuilder &setUseMCJIT(bool Value) {
662 /// setVerifyModules - Set whether the JIT implementation should verify
663 /// IR modules during compilation.
664 EngineBuilder &setVerifyModules(bool Verify) {
665 VerifyModules = Verify;
669 /// setMAttrs - Set cpu-specific attributes.
670 template<typename StringSequence>
671 EngineBuilder &setMAttrs(const StringSequence &mattrs) {
673 MAttrs.append(mattrs.begin(), mattrs.end());
677 TargetMachine *selectTarget();
679 /// selectTarget - Pick a target either via -march or by guessing the native
680 /// arch. Add any CPU features specified via -mcpu or -mattr.
681 TargetMachine *selectTarget(const Triple &TargetTriple,
684 const SmallVectorImpl<std::string>& MAttrs);
686 ExecutionEngine *create() {
687 return create(selectTarget());
690 ExecutionEngine *create(TargetMachine *TM);
693 // Create wrappers for C Binding types (see CBindingWrapping.h).
694 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ExecutionEngine, LLVMExecutionEngineRef)
696 } // End llvm namespace