1 //===- ExecutionEngine.h - Abstract Execution Engine Interface --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the abstract interface that implements execution support
13 //===----------------------------------------------------------------------===//
15 #ifndef EXECUTION_ENGINE_H
16 #define EXECUTION_ENGINE_H
22 #include "llvm/System/Mutex.h"
23 #include "llvm/ADT/SmallVector.h"
38 class ExecutionEngineState {
40 /// GlobalAddressMap - A mapping between LLVM global values and their
41 /// actualized version...
42 std::map<const GlobalValue*, void *> GlobalAddressMap;
44 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap,
45 /// used to convert raw addresses into the LLVM global value that is emitted
46 /// at the address. This map is not computed unless getGlobalValueAtAddress
47 /// is called at some point.
48 std::map<void *, const GlobalValue*> GlobalAddressReverseMap;
51 std::map<const GlobalValue*, void *> &
52 getGlobalAddressMap(const MutexGuard &locked) {
53 return GlobalAddressMap;
56 std::map<void*, const GlobalValue*> &
57 getGlobalAddressReverseMap(const MutexGuard& locked) {
58 return GlobalAddressReverseMap;
63 class ExecutionEngine {
65 ExecutionEngineState state;
66 bool LazyCompilationDisabled;
69 /// Modules - This is a list of ModuleProvider's that we are JIT'ing from. We
70 /// use a smallvector to optimize for the case where there is only one module.
71 SmallVector<ModuleProvider*, 1> Modules;
73 void setTargetData(const TargetData *td) {
77 // To avoid having libexecutionengine depend on the JIT and interpreter
78 // libraries, the JIT and Interpreter set these functions to ctor pointers
79 // at startup time if they are linked in.
80 typedef ExecutionEngine *(*EECtorFn)(ModuleProvider*, std::string*);
81 static EECtorFn JITCtor, InterpCtor;
83 /// LazyFunctionCreator - If an unknown function is needed, this function
84 /// pointer is invoked to create it. If this returns null, the JIT will abort.
85 void* (*LazyFunctionCreator)(const std::string &);
88 /// lock - This lock is protects the ExecutionEngine, JIT, JITResolver and
89 /// JITEmitter classes. It must be held while changing the internal state of
90 /// any of those classes.
91 sys::Mutex lock; // Used to make this class and subclasses thread-safe
93 ExecutionEngine(ModuleProvider *P);
94 ExecutionEngine(Module *M);
95 virtual ~ExecutionEngine();
97 const TargetData *getTargetData() const { return TD; }
99 /// addModuleProvider - Add a ModuleProvider to the list of modules that we
100 /// can JIT from. Note that this takes ownership of the ModuleProvider: when
101 /// the ExecutionEngine is destroyed, it destroys the MP as well.
102 void addModuleProvider(ModuleProvider *P) {
103 Modules.push_back(P);
106 /// removeModuleProvider - Remove a ModuleProvider from the list of modules.
107 /// Release module from ModuleProvider.
108 Module* removeModuleProvider(ModuleProvider *P, std::string *ErrInfo = 0);
110 /// FindFunctionNamed - Search all of the active modules to find the one that
111 /// defines FnName. This is very slow operation and shouldn't be used for
113 Function *FindFunctionNamed(const char *FnName);
115 /// create - This is the factory method for creating an execution engine which
116 /// is appropriate for the current machine. This takes ownership of the
118 static ExecutionEngine *create(ModuleProvider *MP,
119 bool ForceInterpreter = false,
120 std::string *ErrorStr = 0);
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 /// runFunction - Execute the specified function with the specified arguments,
128 /// and return the result.
130 virtual GenericValue runFunction(Function *F,
131 const std::vector<GenericValue> &ArgValues) = 0;
133 /// runStaticConstructorsDestructors - This method is used to execute all of
134 /// the static constructors or destructors for a module, depending on the
135 /// value of isDtors.
136 void runStaticConstructorsDestructors(bool isDtors);
139 /// runFunctionAsMain - This is a helper function which wraps runFunction to
140 /// handle the common task of starting up main with the specified argc, argv,
141 /// and envp parameters.
142 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv,
143 const char * const * envp);
146 /// addGlobalMapping - Tell the execution engine that the specified global is
147 /// at the specified location. This is used internally as functions are JIT'd
148 /// and as global variables are laid out in memory. It can and should also be
149 /// used by clients of the EE that want to have an LLVM global overlay
150 /// existing data in memory.
151 void addGlobalMapping(const GlobalValue *GV, void *Addr);
153 /// clearAllGlobalMappings - Clear all global mappings and start over again
154 /// use in dynamic compilation scenarios when you want to move globals
155 void clearAllGlobalMappings();
157 /// updateGlobalMapping - Replace an existing mapping for GV with a new
158 /// address. This updates both maps as required. If "Addr" is null, the
159 /// entry for the global is removed from the mappings.
160 void updateGlobalMapping(const GlobalValue *GV, void *Addr);
162 /// getPointerToGlobalIfAvailable - This returns the address of the specified
163 /// global value if it is has already been codegen'd, otherwise it returns
166 void *getPointerToGlobalIfAvailable(const GlobalValue *GV);
168 /// getPointerToGlobal - This returns the address of the specified global
169 /// value. This may involve code generation if it's a function.
171 void *getPointerToGlobal(const GlobalValue *GV);
173 /// getPointerToFunction - The different EE's represent function bodies in
174 /// different ways. They should each implement this to say what a function
175 /// pointer should look like.
177 virtual void *getPointerToFunction(Function *F) = 0;
179 /// getPointerToFunctionOrStub - If the specified function has been
180 /// code-gen'd, return a pointer to the function. If not, compile it, or use
181 /// a stub to implement lazy compilation if available.
183 virtual void *getPointerToFunctionOrStub(Function *F) {
184 // Default implementation, just codegen the function.
185 return getPointerToFunction(F);
188 /// getGlobalValueAtAddress - Return the LLVM global value object that starts
189 /// at the specified address.
191 const GlobalValue *getGlobalValueAtAddress(void *Addr);
194 void StoreValueToMemory(const GenericValue &Val, GenericValue *Ptr, const Type *Ty);
195 void InitializeMemory(const Constant *Init, void *Addr);
197 /// recompileAndRelinkFunction - This method is used to force a function
198 /// which has already been compiled to be compiled again, possibly
199 /// after it has been modified. Then the entry to the old copy is overwritten
200 /// with a branch to the new copy. If there was no old copy, this acts
201 /// just like VM::getPointerToFunction().
203 virtual void *recompileAndRelinkFunction(Function *F) = 0;
205 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine
206 /// corresponding to the machine code emitted to execute this function, useful
207 /// for garbage-collecting generated code.
209 virtual void freeMachineCodeForFunction(Function *F) = 0;
211 /// getOrEmitGlobalVariable - Return the address of the specified global
212 /// variable, possibly emitting it to memory if needed. This is used by the
214 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) {
215 return getPointerToGlobal((GlobalValue*)GV);
218 /// DisableLazyCompilation - If called, the JIT will abort if lazy compilation
219 // is ever attempted.
220 void DisableLazyCompilation() {
221 LazyCompilationDisabled = true;
223 bool isLazyCompilationDisabled() const {
224 return LazyCompilationDisabled;
228 /// InstallLazyFunctionCreator - If an unknown function is needed, the
229 /// specified function pointer is invoked to create it. If it returns null,
230 /// the JIT will abort.
231 void InstallLazyFunctionCreator(void* (*P)(const std::string &)) {
232 LazyFunctionCreator = P;
238 // EmitGlobalVariable - This method emits the specified global variable to the
239 // address specified in GlobalAddresses, or allocates new memory if it's not
240 // already in the map.
241 void EmitGlobalVariable(const GlobalVariable *GV);
243 GenericValue getConstantValue(const Constant *C);
244 void LoadValueFromMemory(GenericValue &Result, GenericValue *Ptr,
248 } // End llvm namespace