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_EXECUTION_ENGINE_H
16 #define LLVM_EXECUTION_ENGINE_H
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/ValueMap.h"
23 #include "llvm/Support/ValueHandle.h"
24 #include "llvm/System/Mutex.h"
25 #include "llvm/Target/TargetMachine.h"
31 class ExecutionEngine;
35 class JITEventListener;
36 class JITMemoryManager;
37 class MachineCodeInfo;
44 class ExecutionEngineState {
46 struct AddressMapConfig : public ValueMapConfig<const GlobalValue*> {
47 typedef ExecutionEngineState *ExtraData;
48 static sys::Mutex *getMutex(ExecutionEngineState *EES);
49 static void onDelete(ExecutionEngineState *EES, const GlobalValue *Old);
50 static void onRAUW(ExecutionEngineState *, const GlobalValue *,
54 typedef ValueMap<const GlobalValue *, void *, AddressMapConfig>
60 /// GlobalAddressMap - A mapping between LLVM global values and their
61 /// actualized version...
62 GlobalAddressMapTy GlobalAddressMap;
64 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
65 /// used to convert raw addresses into the LLVM global value that is emitted
66 /// at the address. This map is not computed unless getGlobalValueAtAddress
67 /// is called at some point.
68 std::map<void *, AssertingVH<const GlobalValue> > GlobalAddressReverseMap;
71 ExecutionEngineState(ExecutionEngine &EE);
74 getGlobalAddressMap(const MutexGuard &) {
75 return GlobalAddressMap;
78 std::map<void*, AssertingVH<const GlobalValue> > &
79 getGlobalAddressReverseMap(const MutexGuard &) {
80 return GlobalAddressReverseMap;
83 // Returns the address ToUnmap was mapped to.
84 void *RemoveMapping(const MutexGuard &, const GlobalValue *ToUnmap);
88 class ExecutionEngine {
90 ExecutionEngineState EEState;
92 bool GVCompilationDisabled;
93 bool SymbolSearchingDisabled;
94 bool DlsymStubsEnabled;
96 friend class EngineBuilder; // To allow access to JITCtor and InterpCtor.
99 /// Modules - This is a list of ModuleProvider's that we are JIT'ing from. We
100 /// use a smallvector to optimize for the case where there is only one module.
101 SmallVector<ModuleProvider*, 1> Modules;
103 void setTargetData(const TargetData *td) {
107 /// getMemoryforGV - Allocate memory for a global variable.
108 virtual char* getMemoryForGV(const GlobalVariable* GV);
110 // To avoid having libexecutionengine depend on the JIT and interpreter
111 // libraries, the JIT and Interpreter set these functions to ctor pointers
112 // at startup time if they are linked in.
113 static ExecutionEngine *(*JITCtor)(ModuleProvider *MP,
114 std::string *ErrorStr,
115 JITMemoryManager *JMM,
116 CodeGenOpt::Level OptLevel,
118 static ExecutionEngine *(*InterpCtor)(ModuleProvider *MP,
119 std::string *ErrorStr);
121 /// LazyFunctionCreator - If an unknown function is needed, this function
122 /// pointer is invoked to create it. If this returns null, the JIT will abort.
123 void* (*LazyFunctionCreator)(const std::string &);
125 /// ExceptionTableRegister - If Exception Handling is set, the JIT will
126 /// register dwarf tables with this function
127 typedef void (*EERegisterFn)(void*);
128 static EERegisterFn ExceptionTableRegister;
131 /// lock - This lock is protects the ExecutionEngine, JIT, JITResolver and
132 /// JITEmitter classes. It must be held while changing the internal state of
133 /// any of those classes.
134 sys::Mutex lock; // Used to make this class and subclasses thread-safe
136 //===--------------------------------------------------------------------===//
137 // ExecutionEngine Startup
138 //===--------------------------------------------------------------------===//
140 virtual ~ExecutionEngine();
142 /// create - This is the factory method for creating an execution engine which
143 /// is appropriate for the current machine. This takes ownership of the
145 static ExecutionEngine *create(ModuleProvider *MP,
146 bool ForceInterpreter = false,
147 std::string *ErrorStr = 0,
148 CodeGenOpt::Level OptLevel =
150 // Allocating globals with code breaks
151 // freeMachineCodeForFunction and is probably
152 // unsafe and bad for performance. However,
153 // we have clients who depend on this
154 // behavior, so we must support it.
155 // Eventually, when we're willing to break
156 // some backwards compatability, this flag
157 // should be flipped to false, so that by
158 // default freeMachineCodeForFunction works.
159 bool GVsWithCode = true);
161 /// create - This is the factory method for creating an execution engine which
162 /// is appropriate for the current machine. This takes ownership of the
164 static ExecutionEngine *create(Module *M);
166 /// createJIT - This is the factory method for creating a JIT for the current
167 /// machine, it does not fall back to the interpreter. This takes ownership
168 /// of the ModuleProvider and JITMemoryManager if successful.
170 /// Clients should make sure to initialize targets prior to calling this
172 static ExecutionEngine *createJIT(ModuleProvider *MP,
173 std::string *ErrorStr = 0,
174 JITMemoryManager *JMM = 0,
175 CodeGenOpt::Level OptLevel =
177 bool GVsWithCode = true);
179 /// addModuleProvider - Add a ModuleProvider to the list of modules that we
180 /// can JIT from. Note that this takes ownership of the ModuleProvider: when
181 /// the ExecutionEngine is destroyed, it destroys the MP as well.
182 virtual void addModuleProvider(ModuleProvider *P) {
183 Modules.push_back(P);
186 //===----------------------------------------------------------------------===//
188 const TargetData *getTargetData() const { return TD; }
191 /// removeModuleProvider - Remove a ModuleProvider from the list of modules.
192 /// Relases the Module from the ModuleProvider, materializing it in the
193 /// process, and returns the materialized Module.
194 virtual Module* removeModuleProvider(ModuleProvider *P,
195 std::string *ErrInfo = 0);
197 /// deleteModuleProvider - Remove a ModuleProvider from the list of modules,
198 /// and deletes the ModuleProvider and owned Module. Avoids materializing
199 /// the underlying module.
200 virtual void deleteModuleProvider(ModuleProvider *P,std::string *ErrInfo = 0);
202 /// FindFunctionNamed - Search all of the active modules to find the one that
203 /// defines FnName. This is very slow operation and shouldn't be used for
205 Function *FindFunctionNamed(const char *FnName);
207 /// runFunction - Execute the specified function with the specified arguments,
208 /// and return the result.
210 virtual GenericValue runFunction(Function *F,
211 const std::vector<GenericValue> &ArgValues) = 0;
213 /// runStaticConstructorsDestructors - This method is used to execute all of
214 /// the static constructors or destructors for a program, depending on the
215 /// value of isDtors.
216 void runStaticConstructorsDestructors(bool isDtors);
217 /// runStaticConstructorsDestructors - This method is used to execute all of
218 /// the static constructors or destructors for a module, depending on the
219 /// value of isDtors.
220 void runStaticConstructorsDestructors(Module *module, bool isDtors);
223 /// runFunctionAsMain - This is a helper function which wraps runFunction to
224 /// handle the common task of starting up main with the specified argc, argv,
225 /// and envp parameters.
226 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
227 const char * const * envp);
230 /// addGlobalMapping - Tell the execution engine that the specified global is
231 /// at the specified location. This is used internally as functions are JIT'd
232 /// and as global variables are laid out in memory. It can and should also be
233 /// used by clients of the EE that want to have an LLVM global overlay
234 /// existing data in memory. Mappings are automatically removed when their
235 /// GlobalValue is destroyed.
236 void addGlobalMapping(const GlobalValue *GV, void *Addr);
238 /// clearAllGlobalMappings - Clear all global mappings and start over again
239 /// use in dynamic compilation scenarios when you want to move globals
240 void clearAllGlobalMappings();
242 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
243 /// particular module, because it has been removed from the JIT.
244 void clearGlobalMappingsFromModule(Module *M);
246 /// updateGlobalMapping - Replace an existing mapping for GV with a new
247 /// address. This updates both maps as required. If "Addr" is null, the
248 /// entry for the global is removed from the mappings. This returns the old
249 /// value of the pointer, or null if it was not in the map.
250 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
252 /// getPointerToGlobalIfAvailable - This returns the address of the specified
253 /// global value if it is has already been codegen'd, otherwise it returns
256 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
258 /// getPointerToGlobal - This returns the address of the specified global
259 /// value. This may involve code generation if it's a function.
261 void *getPointerToGlobal(const GlobalValue *GV);
263 /// getPointerToFunction - The different EE's represent function bodies in
264 /// different ways. They should each implement this to say what a function
265 /// pointer should look like. When F is destroyed, the ExecutionEngine will
266 /// remove its global mapping and free any machine code. Be sure no threads
267 /// are running inside F when that happens.
269 virtual void *getPointerToFunction(Function *F) = 0;
271 /// getPointerToFunctionOrStub - If the specified function has been
272 /// code-gen'd, return a pointer to the function. If not, compile it, or use
273 /// a stub to implement lazy compilation if available. See
274 /// getPointerToFunction for the requirements on destroying F.
276 virtual void *getPointerToFunctionOrStub(Function *F) {
277 // Default implementation, just codegen the function.
278 return getPointerToFunction(F);
281 // The JIT overrides a version that actually does this.
282 virtual void runJITOnFunction(Function *, MachineCodeInfo * = 0) { }
284 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
285 /// at the specified address.
287 const GlobalValue *getGlobalValueAtAddress(void *Addr);
290 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
292 void InitializeMemory(const Constant *Init, void *Addr);
294 /// recompileAndRelinkFunction - This method is used to force a function
295 /// which has already been compiled to be compiled again, possibly
296 /// after it has been modified. Then the entry to the old copy is overwritten
297 /// with a branch to the new copy. If there was no old copy, this acts
298 /// just like VM::getPointerToFunction().
300 virtual void *recompileAndRelinkFunction(Function *F) = 0;
302 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
303 /// corresponding to the machine code emitted to execute this function, useful
304 /// for garbage-collecting generated code.
306 virtual void freeMachineCodeForFunction(Function *F) = 0;
308 /// getOrEmitGlobalVariable - Return the address of the specified global
309 /// variable, possibly emitting it to memory if needed. This is used by the
311 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
312 return getPointerToGlobal((GlobalValue*)GV);
315 /// Registers a listener to be called back on various events within
316 /// the JIT. See JITEventListener.h for more details. Does not
317 /// take ownership of the argument. The argument may be NULL, in
318 /// which case these functions do nothing.
319 virtual void RegisterJITEventListener(JITEventListener *) {}
320 virtual void UnregisterJITEventListener(JITEventListener *) {}
322 /// EnableLazyCompilation - When lazy compilation is off (the default), the
323 /// JIT will eagerly compile every function reachable from the argument to
324 /// getPointerToFunction. If lazy compilation is turned on, the JIT will only
325 /// compile the one function and emit stubs to compile the rest when they're
326 /// first called. If lazy compilation is turned off again while some lazy
327 /// stubs are still around, and one of those stubs is called, the program will
330 /// In order to safely compile lazily in a threaded program, the user must
331 /// ensure that 1) only one thread at a time can call any particular lazy
332 /// stub, and 2) any thread modifying LLVM IR must hold the JIT's lock
333 /// (ExecutionEngine::lock) or otherwise ensure that no other thread calls a
334 /// lazy stub. See http://llvm.org/PR5184 for details.
335 void EnableLazyCompilation(bool Enabled = true) {
336 CompilingLazily = Enabled;
338 bool isCompilingLazily() const {
339 return CompilingLazily;
342 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
343 /// allocate space and populate a GlobalVariable that is not internal to
345 void DisableGVCompilation(bool Disabled = true) {
346 GVCompilationDisabled = Disabled;
348 bool isGVCompilationDisabled() const {
349 return GVCompilationDisabled;
352 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
353 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
354 /// resolve symbols in a custom way.
355 void DisableSymbolSearching(bool Disabled = true) {
356 SymbolSearchingDisabled = Disabled;
358 bool isSymbolSearchingDisabled() const {
359 return SymbolSearchingDisabled;
362 /// EnableDlsymStubs -
363 void EnableDlsymStubs(bool Enabled = true) {
364 DlsymStubsEnabled = Enabled;
366 bool areDlsymStubsEnabled() const {
367 return DlsymStubsEnabled;
370 /// InstallLazyFunctionCreator - If an unknown function is needed, the
371 /// specified function pointer is invoked to create it. If it returns null,
372 /// the JIT will abort.
373 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
374 LazyFunctionCreator = P;
377 /// InstallExceptionTableRegister - The JIT will use the given function
378 /// to register the exception tables it generates.
379 static void InstallExceptionTableRegister(void (*F)(void*)) {
380 ExceptionTableRegister = F;
383 /// RegisterTable - Registers the given pointer as an exception table. It uses
384 /// the ExceptionTableRegister function.
385 static void RegisterTable(void* res) {
386 if (ExceptionTableRegister)
387 ExceptionTableRegister(res);
391 explicit ExecutionEngine(ModuleProvider *P);
395 // EmitGlobalVariable - This method emits the specified global variable to the
396 // address specified in GlobalAddresses, or allocates new memory if it's not
397 // already in the map.
398 void EmitGlobalVariable(const GlobalVariable *GV);
400 GenericValue getConstantValue(const Constant *C);
401 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
405 namespace EngineKind {
406 // These are actually bitmasks that get or-ed together.
411 const static Kind Either = (Kind)(JIT | Interpreter);
414 /// EngineBuilder - Builder class for ExecutionEngines. Use this by
415 /// stack-allocating a builder, chaining the various set* methods, and
416 /// terminating it with a .create() call.
417 class EngineBuilder {
421 EngineKind::Kind WhichEngine;
422 std::string *ErrorStr;
423 CodeGenOpt::Level OptLevel;
424 JITMemoryManager *JMM;
425 bool AllocateGVsWithCode;
427 /// InitEngine - Does the common initialization of default options.
430 WhichEngine = EngineKind::Either;
432 OptLevel = CodeGenOpt::Default;
434 AllocateGVsWithCode = false;
438 /// EngineBuilder - Constructor for EngineBuilder. If create() is called and
439 /// is successful, the created engine takes ownership of the module
441 EngineBuilder(ModuleProvider *mp) : MP(mp) {
445 /// EngineBuilder - Overloaded constructor that automatically creates an
446 /// ExistingModuleProvider for an existing module.
447 EngineBuilder(Module *m);
449 /// setEngineKind - Controls whether the user wants the interpreter, the JIT,
450 /// or whichever engine works. This option defaults to EngineKind::Either.
451 EngineBuilder &setEngineKind(EngineKind::Kind w) {
456 /// setJITMemoryManager - Sets the memory manager to use. This allows
457 /// clients to customize their memory allocation policies. If create() is
458 /// called and is successful, the created engine takes ownership of the
459 /// memory manager. This option defaults to NULL.
460 EngineBuilder &setJITMemoryManager(JITMemoryManager *jmm) {
465 /// setErrorStr - Set the error string to write to on error. This option
466 /// defaults to NULL.
467 EngineBuilder &setErrorStr(std::string *e) {
472 /// setOptLevel - Set the optimization level for the JIT. This option
473 /// defaults to CodeGenOpt::Default.
474 EngineBuilder &setOptLevel(CodeGenOpt::Level l) {
479 /// setAllocateGVsWithCode - Sets whether global values should be allocated
480 /// into the same buffer as code. For most applications this should be set
481 /// to false. Allocating globals with code breaks freeMachineCodeForFunction
482 /// and is probably unsafe and bad for performance. However, we have clients
483 /// who depend on this behavior, so we must support it. This option defaults
484 /// to false so that users of the new API can safely use the new memory
485 /// manager and free machine code.
486 EngineBuilder &setAllocateGVsWithCode(bool a) {
487 AllocateGVsWithCode = a;
491 ExecutionEngine *create();
494 } // End llvm namespace