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/System/Mutex.h"
23 #include "llvm/Target/TargetMachine.h"
37 class JITMemoryManager;
38 class MachineCodeInfo;
40 class ExecutionEngineState {
42 /// GlobalAddressMap - A mapping between LLVM global values and their
43 /// actualized version...
44 std::map<const GlobalValue*, void *> GlobalAddressMap;
46 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
47 /// used to convert raw addresses into the LLVM global value that is emitted
48 /// at the address. This map is not computed unless getGlobalValueAtAddress
49 /// is called at some point.
50 std::map<void *, const GlobalValue*> GlobalAddressReverseMap;
53 std::map<const GlobalValue*, void *> &
54 getGlobalAddressMap(const MutexGuard &) {
55 return GlobalAddressMap;
58 std::map<void*, const GlobalValue*> &
59 getGlobalAddressReverseMap(const MutexGuard &) {
60 return GlobalAddressReverseMap;
65 class ExecutionEngine {
67 ExecutionEngineState state;
68 bool LazyCompilationDisabled;
69 bool GVCompilationDisabled;
70 bool SymbolSearchingDisabled;
71 bool DlsymStubsEnabled;
74 /// Modules - This is a list of ModuleProvider's that we are JIT'ing from. We
75 /// use a smallvector to optimize for the case where there is only one module.
76 SmallVector<ModuleProvider*, 1> Modules;
78 void setTargetData(const TargetData *td) {
82 /// getMemoryforGV - Allocate memory for a global variable.
83 virtual char* getMemoryForGV(const GlobalVariable* GV);
85 // To avoid having libexecutionengine depend on the JIT and interpreter
86 // libraries, the JIT and Interpreter set these functions to ctor pointers
87 // at startup time if they are linked in.
88 typedef ExecutionEngine *(*EECtorFn)(ModuleProvider*, std::string*,
89 CodeGenOpt::Level OptLevel);
90 static EECtorFn JITCtor, InterpCtor;
92 /// LazyFunctionCreator - If an unknown function is needed, this function
93 /// pointer is invoked to create it. If this returns null, the JIT will abort.
94 void* (*LazyFunctionCreator)(const std::string &);
96 /// ExceptionTableRegister - If Exception Handling is set, the JIT will
97 /// register dwarf tables with this function
98 typedef void (*EERegisterFn)(void*);
99 static EERegisterFn ExceptionTableRegister;
102 /// lock - This lock is protects the ExecutionEngine, JIT, JITResolver and
103 /// JITEmitter classes. It must be held while changing the internal state of
104 /// any of those classes.
105 sys::Mutex lock; // Used to make this class and subclasses thread-safe
107 //===--------------------------------------------------------------------===//
108 // ExecutionEngine Startup
109 //===--------------------------------------------------------------------===//
111 virtual ~ExecutionEngine();
113 /// create - This is the factory method for creating an execution engine which
114 /// is appropriate for the current machine. This takes ownership of the
116 static ExecutionEngine *create(ModuleProvider *MP,
117 bool ForceInterpreter = false,
118 std::string *ErrorStr = 0,
119 CodeGenOpt::Level OptLevel =
120 CodeGenOpt::Default);
122 /// create - This is the factory method for creating an execution engine which
123 /// is appropriate for the current machine. This takes ownership of the
125 static ExecutionEngine *create(Module *M);
127 /// createJIT - This is the factory method for creating a JIT for the current
128 /// machine, it does not fall back to the interpreter. This takes ownership
129 /// of the ModuleProvider and JITMemoryManager if successful.
130 static ExecutionEngine *createJIT(ModuleProvider *MP,
131 std::string *ErrorStr = 0,
132 JITMemoryManager *JMM = 0,
133 CodeGenOpt::Level OptLevel =
134 CodeGenOpt::Default);
136 /// addModuleProvider - Add a ModuleProvider to the list of modules that we
137 /// can JIT from. Note that this takes ownership of the ModuleProvider: when
138 /// the ExecutionEngine is destroyed, it destroys the MP as well.
139 virtual void addModuleProvider(ModuleProvider *P) {
140 Modules.push_back(P);
143 //===----------------------------------------------------------------------===//
145 const TargetData *getTargetData() const { return TD; }
148 /// removeModuleProvider - Remove a ModuleProvider from the list of modules.
149 /// Relases the Module from the ModuleProvider, materializing it in the
150 /// process, and returns the materialized Module.
151 virtual Module* removeModuleProvider(ModuleProvider *P,
152 std::string *ErrInfo = 0);
154 /// deleteModuleProvider - Remove a ModuleProvider from the list of modules,
155 /// and deletes the ModuleProvider and owned Module. Avoids materializing
156 /// the underlying module.
157 virtual void deleteModuleProvider(ModuleProvider *P,std::string *ErrInfo = 0);
159 /// FindFunctionNamed - Search all of the active modules to find the one that
160 /// defines FnName. This is very slow operation and shouldn't be used for
162 Function *FindFunctionNamed(const char *FnName);
164 /// runFunction - Execute the specified function with the specified arguments,
165 /// and return the result.
167 virtual GenericValue runFunction(Function *F,
168 const std::vector<GenericValue> &ArgValues) = 0;
170 /// runStaticConstructorsDestructors - This method is used to execute all of
171 /// the static constructors or destructors for a program, depending on the
172 /// value of isDtors.
173 void runStaticConstructorsDestructors(bool isDtors);
174 /// runStaticConstructorsDestructors - This method is used to execute all of
175 /// the static constructors or destructors for a module, depending on the
176 /// value of isDtors.
177 void runStaticConstructorsDestructors(Module *module, bool isDtors);
180 /// runFunctionAsMain - This is a helper function which wraps runFunction to
181 /// handle the common task of starting up main with the specified argc, argv,
182 /// and envp parameters.
183 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
184 const char * const * envp);
187 /// addGlobalMapping - Tell the execution engine that the specified global is
188 /// at the specified location. This is used internally as functions are JIT'd
189 /// and as global variables are laid out in memory. It can and should also be
190 /// used by clients of the EE that want to have an LLVM global overlay
191 /// existing data in memory. After adding a mapping for GV, you must not
192 /// destroy it until you've removed the mapping.
193 void addGlobalMapping(const GlobalValue *GV, void *Addr);
195 /// clearAllGlobalMappings - Clear all global mappings and start over again
196 /// use in dynamic compilation scenarios when you want to move globals
197 void clearAllGlobalMappings();
199 /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
200 /// particular module, because it has been removed from the JIT.
201 void clearGlobalMappingsFromModule(Module *M);
203 /// updateGlobalMapping - Replace an existing mapping for GV with a new
204 /// address. This updates both maps as required. If "Addr" is null, the
205 /// entry for the global is removed from the mappings. This returns the old
206 /// value of the pointer, or null if it was not in the map.
207 void *updateGlobalMapping(const GlobalValue *GV, void *Addr);
209 /// getPointerToGlobalIfAvailable - This returns the address of the specified
210 /// global value if it is has already been codegen'd, otherwise it returns
213 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
215 /// getPointerToGlobal - This returns the address of the specified global
216 /// value. This may involve code generation if it's a function. After
217 /// getting a pointer to GV, it and all globals it transitively refers to have
218 /// been passed to addGlobalMapping. You must clear the mapping for each
219 /// referred-to global before destroying it. If a referred-to global RTG is a
220 /// function and this ExecutionEngine is a JIT compiler, calling
221 /// updateGlobalMapping(RTG, 0) will leak the function's machine code, so you
222 /// should call freeMachineCodeForFunction(RTG) instead. Note that
223 /// optimizations can move and delete non-external GlobalValues without
224 /// notifying the ExecutionEngine.
226 void *getPointerToGlobal(const GlobalValue *GV);
228 /// getPointerToFunction - The different EE's represent function bodies in
229 /// different ways. They should each implement this to say what a function
230 /// pointer should look like. See getPointerToGlobal for the requirements on
231 /// destroying F and any GlobalValues it refers to.
233 virtual void *getPointerToFunction(Function *F) = 0;
235 /// getPointerToFunctionOrStub - If the specified function has been
236 /// code-gen'd, return a pointer to the function. If not, compile it, or use
237 /// a stub to implement lazy compilation if available. See getPointerToGlobal
238 /// for the requirements on destroying F and any GlobalValues it refers to.
240 virtual void *getPointerToFunctionOrStub(Function *F) {
241 // Default implementation, just codegen the function.
242 return getPointerToFunction(F);
245 // The JIT overrides a version that actually does this.
246 virtual void runJITOnFunction(Function *, MachineCodeInfo * = 0) { }
248 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
249 /// at the specified address.
251 const GlobalValue *getGlobalValueAtAddress(void *Addr);
254 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr,
256 void InitializeMemory(const Constant *Init, void *Addr);
258 /// recompileAndRelinkFunction - This method is used to force a function
259 /// which has already been compiled to be compiled again, possibly
260 /// after it has been modified. Then the entry to the old copy is overwritten
261 /// with a branch to the new copy. If there was no old copy, this acts
262 /// just like VM::getPointerToFunction().
264 virtual void *recompileAndRelinkFunction(Function *F) = 0;
266 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
267 /// corresponding to the machine code emitted to execute this function, useful
268 /// for garbage-collecting generated code.
270 virtual void freeMachineCodeForFunction(Function *F) = 0;
272 /// getOrEmitGlobalVariable - Return the address of the specified global
273 /// variable, possibly emitting it to memory if needed. This is used by the
274 /// Emitter. See getPointerToGlobal for the requirements on destroying GV and
275 /// any GlobalValues it refers to.
276 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
277 return getPointerToGlobal((GlobalValue*)GV);
280 /// DisableLazyCompilation - If called, the JIT will abort if lazy compilation
281 /// is ever attempted.
282 void DisableLazyCompilation(bool Disabled = true) {
283 LazyCompilationDisabled = Disabled;
285 bool isLazyCompilationDisabled() const {
286 return LazyCompilationDisabled;
289 /// DisableGVCompilation - If called, the JIT will abort if it's asked to
290 /// allocate space and populate a GlobalVariable that is not internal to
292 void DisableGVCompilation(bool Disabled = true) {
293 GVCompilationDisabled = Disabled;
295 bool isGVCompilationDisabled() const {
296 return GVCompilationDisabled;
299 /// DisableSymbolSearching - If called, the JIT will not try to lookup unknown
300 /// symbols with dlsym. A client can still use InstallLazyFunctionCreator to
301 /// resolve symbols in a custom way.
302 void DisableSymbolSearching(bool Disabled = true) {
303 SymbolSearchingDisabled = Disabled;
305 bool isSymbolSearchingDisabled() const {
306 return SymbolSearchingDisabled;
309 /// EnableDlsymStubs -
310 void EnableDlsymStubs(bool Enabled = true) {
311 DlsymStubsEnabled = Enabled;
313 bool areDlsymStubsEnabled() const {
314 return DlsymStubsEnabled;
317 /// InstallLazyFunctionCreator - If an unknown function is needed, the
318 /// specified function pointer is invoked to create it. If it returns null,
319 /// the JIT will abort.
320 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
321 LazyFunctionCreator = P;
324 /// InstallExceptionTableRegister - The JIT will use the given function
325 /// to register the exception tables it generates.
326 static void InstallExceptionTableRegister(void (*F)(void*)) {
327 ExceptionTableRegister = F;
330 /// RegisterTable - Registers the given pointer as an exception table. It uses
331 /// the ExceptionTableRegister function.
332 static void RegisterTable(void* res) {
333 if (ExceptionTableRegister)
334 ExceptionTableRegister(res);
338 explicit ExecutionEngine(ModuleProvider *P);
342 // EmitGlobalVariable - This method emits the specified global variable to the
343 // address specified in GlobalAddresses, or allocates new memory if it's not
344 // already in the map.
345 void EmitGlobalVariable(const GlobalVariable *GV);
347 GenericValue getConstantValue(const Constant *C);
348 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
352 } // End llvm namespace