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
22 #include "llvm/System/Mutex.h"
23 #include "llvm/ADT/SmallVector.h"
37 class JITMemoryManager;
39 class ExecutionEngineState {
41 /// GlobalAddressMap - A mapping between LLVM global values and their
42 /// actualized version...
43 std::map<const GlobalValue*, void *> GlobalAddressMap;
45 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
46 /// used to convert raw addresses into the LLVM global value that is emitted
47 /// at the address. This map is not computed unless getGlobalValueAtAddress
48 /// is called at some point.
49 std::map<void *, const GlobalValue*> GlobalAddressReverseMap;
52 std::map<const GlobalValue*, void *> &
53 getGlobalAddressMap(const MutexGuard &) {
54 return GlobalAddressMap;
57 std::map<void*, const GlobalValue*> &
58 getGlobalAddressReverseMap(const MutexGuard &) {
59 return GlobalAddressReverseMap;
64 class ExecutionEngine {
66 ExecutionEngineState state;
67 bool LazyCompilationDisabled;
68 bool GVCompilationDisabled;
69 bool SymbolSearchingDisabled;
72 /// Modules - This is a list of ModuleProvider's that we are JIT'ing from. We
73 /// use a smallvector to optimize for the case where there is only one module.
74 SmallVector<ModuleProvider*, 1> Modules;
76 void setTargetData(const TargetData *td) {
80 /// getMemoryforGV - Allocate memory for a global variable.
81 virtual char* getMemoryForGV(const GlobalVariable* GV);
83 // To avoid having libexecutionengine depend on the JIT and interpreter
84 // libraries, the JIT and Interpreter set these functions to ctor pointers
85 // at startup time if they are linked in.
86 typedef ExecutionEngine *(*EECtorFn)(ModuleProvider*, std::string*,
88 static EECtorFn JITCtor, InterpCtor;
90 /// LazyFunctionCreator - If an unknown function is needed, this function
91 /// pointer is invoked to create it. If this returns null, the JIT will abort.
92 void* (*LazyFunctionCreator)(const std::string &);
94 /// ExceptionTableRegister - If Exception Handling is set, the JIT will
95 /// register dwarf tables with this function
96 typedef void (*EERegisterFn)(void*);
97 static EERegisterFn ExceptionTableRegister;
100 /// lock - This lock is protects the ExecutionEngine, JIT, JITResolver and
101 /// JITEmitter classes. It must be held while changing the internal state of
102 /// any of those classes.
103 sys::Mutex lock; // Used to make this class and subclasses thread-safe
105 //===--------------------------------------------------------------------===//
106 // ExecutionEngine Startup
107 //===--------------------------------------------------------------------===//
109 virtual ~ExecutionEngine();
111 /// create - This is the factory method for creating an execution engine which
112 /// is appropriate for the current machine. This takes ownership of the
114 static ExecutionEngine *create(ModuleProvider *MP,
115 bool ForceInterpreter = false,
116 std::string *ErrorStr = 0,
119 /// create - This is the factory method for creating an execution engine which
120 /// is appropriate for the current machine. This takes ownership of the
122 static ExecutionEngine *create(Module *M);
124 /// createJIT - This is the factory method for creating a JIT for the current
125 /// machine, it does not fall back to the interpreter. This takes ownership
126 /// of the ModuleProvider and JITMemoryManager if successful.
127 static ExecutionEngine *createJIT(ModuleProvider *MP,
128 std::string *ErrorStr = 0,
129 JITMemoryManager *JMM = 0,
134 /// addModuleProvider - Add a ModuleProvider to the list of modules that we
135 /// can JIT from. Note that this takes ownership of the ModuleProvider: when
136 /// the ExecutionEngine is destroyed, it destroys the MP as well.
137 virtual void addModuleProvider(ModuleProvider *P) {
138 Modules.push_back(P);
141 //===----------------------------------------------------------------------===//
143 const TargetData *getTargetData() const { return TD; }
146 /// removeModuleProvider - Remove a ModuleProvider from the list of modules.
147 /// Release module from ModuleProvider.
148 virtual Module* removeModuleProvider(ModuleProvider *P,
149 std::string *ErrInfo = 0);
151 /// FindFunctionNamed - Search all of the active modules to find the one that
152 /// defines FnName. This is very slow operation and shouldn't be used for
154 Function *FindFunctionNamed(const char *FnName);
156 /// runFunction - Execute the specified function with the specified arguments,
157 /// and return the result.
159 virtual GenericValue runFunction(Function *F,
160 const std::vector<GenericValue> &ArgValues) = 0;
162 /// runStaticConstructorsDestructors - This method is used to execute all of
163 /// the static constructors or destructors for a program, depending on the
164 /// value of isDtors.
165 void runStaticConstructorsDestructors(bool isDtors);
166 /// runStaticConstructorsDestructors - This method is used to execute all of
167 /// the static constructors or destructors for a module, depending on the
168 /// value of isDtors.
169 void runStaticConstructorsDestructors(Module *module, bool isDtors);
172 /// runFunctionAsMain - This is a helper function which wraps runFunction to
173 /// handle the common task of starting up main with the specified argc, argv,
174 /// and envp parameters.
175 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
176 const char * const * envp);
179 /// addGlobalMapping - Tell the execution engine that the specified global is
180 /// at the specified location. This is used internally as functions are JIT'd
181 /// and as global variables are laid out in memory. It can and should also be
182 /// used by clients of the EE that want to have an LLVM global overlay
183 /// existing data in memory.
184 void addGlobalMapping(const GlobalValue *GV, void *Addr);
186 /// clearAllGlobalMappings - Clear all global mappings and start over again
187 /// use in dynamic compilation scenarios when you want to move globals
188 void clearAllGlobalMappings();
190 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
191 /// particular module, because it has been removed from the JIT.
192 void clearGlobalMappingsFromModule(Module *M);
194 /// updateGlobalMapping - Replace an existing mapping for GV with a new
195 /// address. This updates both maps as required. If "Addr" is null, the
196 /// entry for the global is removed from the mappings. This returns the old
197 /// value of the pointer, or null if it was not in the map.
198 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
200 /// getPointerToGlobalIfAvailable - This returns the address of the specified
201 /// global value if it is has already been codegen'd, otherwise it returns
204 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
206 /// getPointerToGlobal - This returns the address of the specified global
207 /// value. This may involve code generation if it's a function.
209 void *getPointerToGlobal(const GlobalValue *GV);
211 /// getPointerToFunction - The different EE's represent function bodies in
212 /// different ways. They should each implement this to say what a function
213 /// pointer should look like.
215 virtual void *getPointerToFunction(Function *F) = 0;
217 /// getPointerToFunctionOrStub - If the specified function has been
218 /// code-gen'd, return a pointer to the function. If not, compile it, or use
219 /// a stub to implement lazy compilation if available.
221 virtual void *getPointerToFunctionOrStub(Function *F) {
222 // Default implementation, just codegen the function.
223 return getPointerToFunction(F);
226 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
227 /// at the specified address.
229 const GlobalValue *getGlobalValueAtAddress(void *Addr);
232 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
234 void InitializeMemory(const Constant *Init, void *Addr);
236 /// recompileAndRelinkFunction - This method is used to force a function
237 /// which has already been compiled to be compiled again, possibly
238 /// after it has been modified. Then the entry to the old copy is overwritten
239 /// with a branch to the new copy. If there was no old copy, this acts
240 /// just like VM::getPointerToFunction().
242 virtual void *recompileAndRelinkFunction(Function *F) = 0;
244 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
245 /// corresponding to the machine code emitted to execute this function, useful
246 /// for garbage-collecting generated code.
248 virtual void freeMachineCodeForFunction(Function *F) = 0;
250 /// getOrEmitGlobalVariable - Return the address of the specified global
251 /// variable, possibly emitting it to memory if needed. This is used by the
253 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
254 return getPointerToGlobal((GlobalValue*)GV);
257 /// DisableLazyCompilation - If called, the JIT will abort if lazy compilation
258 /// is ever attempted.
259 void DisableLazyCompilation(bool Disabled = true) {
260 LazyCompilationDisabled = Disabled;
262 bool isLazyCompilationDisabled() const {
263 return LazyCompilationDisabled;
266 /// DisableGVCompilation - If called, the JIT will abort if it's asked to allocate
267 /// space and populate a GlobalVariable.
268 void DisableGVCompilation(bool Disabled = true) {
269 GVCompilationDisabled = Disabled;
271 bool isGVCompilationDisabled() const {
272 return GVCompilationDisabled;
275 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
276 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
277 /// resolve symbols in a custom way.
278 void DisableSymbolSearching(bool Disabled = true) {
279 SymbolSearchingDisabled = Disabled;
281 bool isSymbolSearchingDisabled() const {
282 return SymbolSearchingDisabled;
286 /// InstallLazyFunctionCreator - If an unknown function is needed, the
287 /// specified function pointer is invoked to create it. If it returns null,
288 /// the JIT will abort.
289 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
290 LazyFunctionCreator = P;
293 /// InstallExceptionTableRegister - The JIT will use the given function
294 /// to register the exception tables it generates.
295 static void InstallExceptionTableRegister(void (*F)(void*)) {
296 ExceptionTableRegister = F;
299 /// RegisterTable - Registers the given pointer as an exception table. It uses
300 /// the ExceptionTableRegister function.
301 static void RegisterTable(void* res) {
302 if (ExceptionTableRegister)
303 ExceptionTableRegister(res);
307 explicit ExecutionEngine(ModuleProvider *P);
311 // EmitGlobalVariable - This method emits the specified global variable to the
312 // address specified in GlobalAddresses, or allocates new memory if it's not
313 // already in the map.
314 void EmitGlobalVariable(const GlobalVariable *GV);
316 GenericValue getConstantValue(const Constant *C);
317 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
321 } // End llvm namespace