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1 : //===-- MCJIT.h - Class definition for the MCJIT ----------------*- C++ -*-===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 :
10 : #ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
11 : #define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
12 :
13 : #include "llvm/ADT/SmallPtrSet.h"
14 : #include "llvm/ADT/SmallVector.h"
15 : #include "llvm/ExecutionEngine/ExecutionEngine.h"
16 : #include "llvm/ExecutionEngine/ObjectCache.h"
17 : #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
18 : #include "llvm/ExecutionEngine/RuntimeDyld.h"
19 : #include "llvm/IR/Module.h"
20 : #include "llvm/Support/SmallVectorMemoryBuffer.h"
21 :
22 : namespace llvm {
23 : class MCJIT;
24 :
25 : // This is a helper class that the MCJIT execution engine uses for linking
26 : // functions across modules that it owns. It aggregates the memory manager
27 : // that is passed in to the MCJIT constructor and defers most functionality
28 : // to that object.
29 98 : class LinkingSymbolResolver : public LegacyJITSymbolResolver {
30 : public:
31 : LinkingSymbolResolver(MCJIT &Parent,
32 : std::shared_ptr<LegacyJITSymbolResolver> Resolver)
33 121 : : ParentEngine(Parent), ClientResolver(std::move(Resolver)) {}
34 :
35 : JITSymbol findSymbol(const std::string &Name) override;
36 :
37 : // MCJIT doesn't support logical dylibs.
38 81 : JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {
39 81 : return nullptr;
40 : }
41 :
42 : private:
43 : MCJIT &ParentEngine;
44 : std::shared_ptr<LegacyJITSymbolResolver> ClientResolver;
45 : void anchor() override;
46 : };
47 :
48 : // About Module states: added->loaded->finalized.
49 : //
50 : // The purpose of the "added" state is having modules in standby. (added=known
51 : // but not compiled). The idea is that you can add a module to provide function
52 : // definitions but if nothing in that module is referenced by a module in which
53 : // a function is executed (note the wording here because it's not exactly the
54 : // ideal case) then the module never gets compiled. This is sort of lazy
55 : // compilation.
56 : //
57 : // The purpose of the "loaded" state (loaded=compiled and required sections
58 : // copied into local memory but not yet ready for execution) is to have an
59 : // intermediate state wherein clients can remap the addresses of sections, using
60 : // MCJIT::mapSectionAddress, (in preparation for later copying to a new location
61 : // or an external process) before relocations and page permissions are applied.
62 : //
63 : // It might not be obvious at first glance, but the "remote-mcjit" case in the
64 : // lli tool does this. In that case, the intermediate action is taken by the
65 : // RemoteMemoryManager in response to the notifyObjectLoaded function being
66 : // called.
67 :
68 : class MCJIT : public ExecutionEngine {
69 : MCJIT(std::unique_ptr<Module> M, std::unique_ptr<TargetMachine> tm,
70 : std::shared_ptr<MCJITMemoryManager> MemMgr,
71 : std::shared_ptr<LegacyJITSymbolResolver> Resolver);
72 :
73 : typedef llvm::SmallPtrSet<Module *, 4> ModulePtrSet;
74 :
75 : class OwningModuleContainer {
76 : public:
77 121 : OwningModuleContainer() {
78 : }
79 98 : ~OwningModuleContainer() {
80 49 : freeModulePtrSet(AddedModules);
81 49 : freeModulePtrSet(LoadedModules);
82 49 : freeModulePtrSet(FinalizedModules);
83 49 : }
84 :
85 417 : ModulePtrSet::iterator begin_added() { return AddedModules.begin(); }
86 315 : ModulePtrSet::iterator end_added() { return AddedModules.end(); }
87 102 : iterator_range<ModulePtrSet::iterator> added() {
88 102 : return make_range(begin_added(), end_added());
89 : }
90 :
91 142 : ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); }
92 142 : ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); }
93 :
94 142 : ModulePtrSet::iterator begin_finalized() { return FinalizedModules.begin(); }
95 142 : ModulePtrSet::iterator end_finalized() { return FinalizedModules.end(); }
96 :
97 : void addModule(std::unique_ptr<Module> M) {
98 304 : AddedModules.insert(M.release());
99 : }
100 :
101 0 : bool removeModule(Module *M) {
102 0 : return AddedModules.erase(M) || LoadedModules.erase(M) ||
103 0 : FinalizedModules.erase(M);
104 : }
105 :
106 : bool hasModuleBeenAddedButNotLoaded(Module *M) {
107 154 : return AddedModules.count(M) != 0;
108 : }
109 :
110 441 : bool hasModuleBeenLoaded(Module *M) {
111 : // If the module is in either the "loaded" or "finalized" sections it
112 : // has been loaded.
113 441 : return (LoadedModules.count(M) != 0 ) || (FinalizedModules.count(M) != 0);
114 : }
115 :
116 : bool hasModuleBeenFinalized(Module *M) {
117 : return FinalizedModules.count(M) != 0;
118 : }
119 :
120 : bool ownsModule(Module* M) {
121 : return (AddedModules.count(M) != 0) || (LoadedModules.count(M) != 0) ||
122 : (FinalizedModules.count(M) != 0);
123 : }
124 :
125 144 : void markModuleAsLoaded(Module *M) {
126 : // This checks against logic errors in the MCJIT implementation.
127 : // This function should never be called with either a Module that MCJIT
128 : // does not own or a Module that has already been loaded and/or finalized.
129 : assert(AddedModules.count(M) &&
130 : "markModuleAsLoaded: Module not found in AddedModules");
131 :
132 : // Remove the module from the "Added" set.
133 : AddedModules.erase(M);
134 :
135 : // Add the Module to the "Loaded" set.
136 144 : LoadedModules.insert(M);
137 144 : }
138 :
139 : void markModuleAsFinalized(Module *M) {
140 : // This checks against logic errors in the MCJIT implementation.
141 : // This function should never be called with either a Module that MCJIT
142 : // does not own, a Module that has not been loaded or a Module that has
143 : // already been finalized.
144 : assert(LoadedModules.count(M) &&
145 : "markModuleAsFinalized: Module not found in LoadedModules");
146 :
147 : // Remove the module from the "Loaded" section of the list.
148 : LoadedModules.erase(M);
149 :
150 : // Add the Module to the "Finalized" section of the list by inserting it
151 : // before the 'end' iterator.
152 : FinalizedModules.insert(M);
153 : }
154 :
155 295 : void markAllLoadedModulesAsFinalized() {
156 295 : for (ModulePtrSet::iterator I = LoadedModules.begin(),
157 295 : E = LoadedModules.end();
158 439 : I != E; ++I) {
159 : Module *M = *I;
160 144 : FinalizedModules.insert(M);
161 : }
162 295 : LoadedModules.clear();
163 295 : }
164 :
165 : private:
166 : ModulePtrSet AddedModules;
167 : ModulePtrSet LoadedModules;
168 : ModulePtrSet FinalizedModules;
169 :
170 147 : void freeModulePtrSet(ModulePtrSet& MPS) {
171 : // Go through the module set and delete everything.
172 217 : for (ModulePtrSet::iterator I = MPS.begin(), E = MPS.end(); I != E; ++I) {
173 : Module *M = *I;
174 70 : delete M;
175 : }
176 147 : MPS.clear();
177 147 : }
178 : };
179 :
180 : std::unique_ptr<TargetMachine> TM;
181 : MCContext *Ctx;
182 : std::shared_ptr<MCJITMemoryManager> MemMgr;
183 : LinkingSymbolResolver Resolver;
184 : RuntimeDyld Dyld;
185 : std::vector<JITEventListener*> EventListeners;
186 :
187 : OwningModuleContainer OwnedModules;
188 :
189 : SmallVector<object::OwningBinary<object::Archive>, 2> Archives;
190 : SmallVector<std::unique_ptr<MemoryBuffer>, 2> Buffers;
191 :
192 : SmallVector<std::unique_ptr<object::ObjectFile>, 2> LoadedObjects;
193 :
194 : // An optional ObjectCache to be notified of compiled objects and used to
195 : // perform lookup of pre-compiled code to avoid re-compilation.
196 : ObjectCache *ObjCache;
197 :
198 : Function *FindFunctionNamedInModulePtrSet(StringRef FnName,
199 : ModulePtrSet::iterator I,
200 : ModulePtrSet::iterator E);
201 :
202 : GlobalVariable *FindGlobalVariableNamedInModulePtrSet(StringRef Name,
203 : bool AllowInternal,
204 : ModulePtrSet::iterator I,
205 : ModulePtrSet::iterator E);
206 :
207 : void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors,
208 : ModulePtrSet::iterator I,
209 : ModulePtrSet::iterator E);
210 :
211 : public:
212 : ~MCJIT() override;
213 :
214 : /// @name ExecutionEngine interface implementation
215 : /// @{
216 : void addModule(std::unique_ptr<Module> M) override;
217 : void addObjectFile(std::unique_ptr<object::ObjectFile> O) override;
218 : void addObjectFile(object::OwningBinary<object::ObjectFile> O) override;
219 : void addArchive(object::OwningBinary<object::Archive> O) override;
220 : bool removeModule(Module *M) override;
221 :
222 : /// FindFunctionNamed - Search all of the active modules to find the function that
223 : /// defines FnName. This is very slow operation and shouldn't be used for
224 : /// general code.
225 : Function *FindFunctionNamed(StringRef FnName) override;
226 :
227 : /// FindGlobalVariableNamed - Search all of the active modules to find the
228 : /// global variable that defines Name. This is very slow operation and
229 : /// shouldn't be used for general code.
230 : GlobalVariable *FindGlobalVariableNamed(StringRef Name,
231 : bool AllowInternal = false) override;
232 :
233 : /// Sets the object manager that MCJIT should use to avoid compilation.
234 : void setObjectCache(ObjectCache *manager) override;
235 :
236 0 : void setProcessAllSections(bool ProcessAllSections) override {
237 : Dyld.setProcessAllSections(ProcessAllSections);
238 0 : }
239 :
240 : void generateCodeForModule(Module *M) override;
241 :
242 : /// finalizeObject - ensure the module is fully processed and is usable.
243 : ///
244 : /// It is the user-level function for completing the process of making the
245 : /// object usable for execution. It should be called after sections within an
246 : /// object have been relocated using mapSectionAddress. When this method is
247 : /// called the MCJIT execution engine will reapply relocations for a loaded
248 : /// object.
249 : /// Is it OK to finalize a set of modules, add modules and finalize again.
250 : // FIXME: Do we really need both of these?
251 : void finalizeObject() override;
252 : virtual void finalizeModule(Module *);
253 : void finalizeLoadedModules();
254 :
255 : /// runStaticConstructorsDestructors - This method is used to execute all of
256 : /// the static constructors or destructors for a program.
257 : ///
258 : /// \param isDtors - Run the destructors instead of constructors.
259 : void runStaticConstructorsDestructors(bool isDtors) override;
260 :
261 : void *getPointerToFunction(Function *F) override;
262 :
263 : GenericValue runFunction(Function *F,
264 : ArrayRef<GenericValue> ArgValues) override;
265 :
266 : /// getPointerToNamedFunction - This method returns the address of the
267 : /// specified function by using the dlsym function call. As such it is only
268 : /// useful for resolving library symbols, not code generated symbols.
269 : ///
270 : /// If AbortOnFailure is false and no function with the given name is
271 : /// found, this function silently returns a null pointer. Otherwise,
272 : /// it prints a message to stderr and aborts.
273 : ///
274 : void *getPointerToNamedFunction(StringRef Name,
275 : bool AbortOnFailure = true) override;
276 :
277 : /// mapSectionAddress - map a section to its target address space value.
278 : /// Map the address of a JIT section as returned from the memory manager
279 : /// to the address in the target process as the running code will see it.
280 : /// This is the address which will be used for relocation resolution.
281 0 : void mapSectionAddress(const void *LocalAddress,
282 : uint64_t TargetAddress) override {
283 0 : Dyld.mapSectionAddress(LocalAddress, TargetAddress);
284 0 : }
285 : void RegisterJITEventListener(JITEventListener *L) override;
286 : void UnregisterJITEventListener(JITEventListener *L) override;
287 :
288 : // If successful, these function will implicitly finalize all loaded objects.
289 : // To get a function address within MCJIT without causing a finalize, use
290 : // getSymbolAddress.
291 : uint64_t getGlobalValueAddress(const std::string &Name) override;
292 : uint64_t getFunctionAddress(const std::string &Name) override;
293 :
294 0 : TargetMachine *getTargetMachine() override { return TM.get(); }
295 :
296 : /// @}
297 : /// @name (Private) Registration Interfaces
298 : /// @{
299 :
300 : static void Register() {
301 0 : MCJITCtor = createJIT;
302 : }
303 :
304 : static ExecutionEngine *
305 : createJIT(std::unique_ptr<Module> M, std::string *ErrorStr,
306 : std::shared_ptr<MCJITMemoryManager> MemMgr,
307 : std::shared_ptr<LegacyJITSymbolResolver> Resolver,
308 : std::unique_ptr<TargetMachine> TM);
309 :
310 : // @}
311 :
312 : // Takes a mangled name and returns the corresponding JITSymbol (if a
313 : // definition of that mangled name has been added to the JIT).
314 : JITSymbol findSymbol(const std::string &Name, bool CheckFunctionsOnly);
315 :
316 : // DEPRECATED - Please use findSymbol instead.
317 : //
318 : // This is not directly exposed via the ExecutionEngine API, but it is
319 : // used by the LinkingMemoryManager.
320 : //
321 : // getSymbolAddress takes an unmangled name and returns the corresponding
322 : // JITSymbol if a definition of the name has been added to the JIT.
323 : uint64_t getSymbolAddress(const std::string &Name,
324 : bool CheckFunctionsOnly);
325 :
326 : protected:
327 : /// emitObject -- Generate a JITed object in memory from the specified module
328 : /// Currently, MCJIT only supports a single module and the module passed to
329 : /// this function call is expected to be the contained module. The module
330 : /// is passed as a parameter here to prepare for multiple module support in
331 : /// the future.
332 : std::unique_ptr<MemoryBuffer> emitObject(Module *M);
333 :
334 : void NotifyObjectEmitted(const object::ObjectFile& Obj,
335 : const RuntimeDyld::LoadedObjectInfo &L);
336 : void NotifyFreeingObject(const object::ObjectFile& Obj);
337 :
338 : JITSymbol findExistingSymbol(const std::string &Name);
339 : Module *findModuleForSymbol(const std::string &Name, bool CheckFunctionsOnly);
340 : };
341 :
342 : } // end llvm namespace
343 :
344 : #endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
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