1 //===-- MCJIT.h - Class definition for the MCJIT ----------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
10 #define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
12 #include "llvm/ADT/SmallPtrSet.h"
13 #include "llvm/ADT/SmallVector.h"
14 #include "llvm/ExecutionEngine/ExecutionEngine.h"
15 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
16 #include "llvm/ExecutionEngine/RuntimeDyld.h"
23 // This is a helper class that the MCJIT execution engine uses for linking
24 // functions across modules that it owns. It aggregates the memory manager
25 // that is passed in to the MCJIT constructor and defers most functionality
27 class LinkingSymbolResolver
: public LegacyJITSymbolResolver
{
29 LinkingSymbolResolver(MCJIT
&Parent
,
30 std::shared_ptr
<LegacyJITSymbolResolver
> Resolver
)
31 : ParentEngine(Parent
), ClientResolver(std::move(Resolver
)) {}
33 JITSymbol
findSymbol(const std::string
&Name
) override
;
35 // MCJIT doesn't support logical dylibs.
36 JITSymbol
findSymbolInLogicalDylib(const std::string
&Name
) override
{
42 std::shared_ptr
<LegacyJITSymbolResolver
> ClientResolver
;
43 void anchor() override
;
46 // About Module states: added->loaded->finalized.
48 // The purpose of the "added" state is having modules in standby. (added=known
49 // but not compiled). The idea is that you can add a module to provide function
50 // definitions but if nothing in that module is referenced by a module in which
51 // a function is executed (note the wording here because it's not exactly the
52 // ideal case) then the module never gets compiled. This is sort of lazy
55 // The purpose of the "loaded" state (loaded=compiled and required sections
56 // copied into local memory but not yet ready for execution) is to have an
57 // intermediate state wherein clients can remap the addresses of sections, using
58 // MCJIT::mapSectionAddress, (in preparation for later copying to a new location
59 // or an external process) before relocations and page permissions are applied.
61 // It might not be obvious at first glance, but the "remote-mcjit" case in the
62 // lli tool does this. In that case, the intermediate action is taken by the
63 // RemoteMemoryManager in response to the notifyObjectLoaded function being
66 class MCJIT
: public ExecutionEngine
{
67 MCJIT(std::unique_ptr
<Module
> M
, std::unique_ptr
<TargetMachine
> tm
,
68 std::shared_ptr
<MCJITMemoryManager
> MemMgr
,
69 std::shared_ptr
<LegacyJITSymbolResolver
> Resolver
);
71 typedef llvm::SmallPtrSet
<Module
*, 4> ModulePtrSet
;
73 class OwningModuleContainer
{
75 OwningModuleContainer() = default;
76 ~OwningModuleContainer() {
77 freeModulePtrSet(AddedModules
);
78 freeModulePtrSet(LoadedModules
);
79 freeModulePtrSet(FinalizedModules
);
82 ModulePtrSet::iterator
begin_added() { return AddedModules
.begin(); }
83 ModulePtrSet::iterator
end_added() { return AddedModules
.end(); }
84 iterator_range
<ModulePtrSet::iterator
> added() {
85 return make_range(begin_added(), end_added());
88 ModulePtrSet::iterator
begin_loaded() { return LoadedModules
.begin(); }
89 ModulePtrSet::iterator
end_loaded() { return LoadedModules
.end(); }
91 ModulePtrSet::iterator
begin_finalized() { return FinalizedModules
.begin(); }
92 ModulePtrSet::iterator
end_finalized() { return FinalizedModules
.end(); }
94 void addModule(std::unique_ptr
<Module
> M
) {
95 AddedModules
.insert(M
.release());
98 bool removeModule(Module
*M
) {
99 return AddedModules
.erase(M
) || LoadedModules
.erase(M
) ||
100 FinalizedModules
.erase(M
);
103 bool hasModuleBeenAddedButNotLoaded(Module
*M
) {
104 return AddedModules
.contains(M
);
107 bool hasModuleBeenLoaded(Module
*M
) {
108 // If the module is in either the "loaded" or "finalized" sections it
110 return LoadedModules
.contains(M
) || FinalizedModules
.contains(M
);
113 bool hasModuleBeenFinalized(Module
*M
) {
114 return FinalizedModules
.contains(M
);
117 bool ownsModule(Module
* M
) {
118 return AddedModules
.contains(M
) || LoadedModules
.contains(M
) ||
119 FinalizedModules
.contains(M
);
122 void markModuleAsLoaded(Module
*M
) {
123 // This checks against logic errors in the MCJIT implementation.
124 // This function should never be called with either a Module that MCJIT
125 // does not own or a Module that has already been loaded and/or finalized.
126 assert(AddedModules
.count(M
) &&
127 "markModuleAsLoaded: Module not found in AddedModules");
129 // Remove the module from the "Added" set.
130 AddedModules
.erase(M
);
132 // Add the Module to the "Loaded" set.
133 LoadedModules
.insert(M
);
136 void markModuleAsFinalized(Module
*M
) {
137 // This checks against logic errors in the MCJIT implementation.
138 // This function should never be called with either a Module that MCJIT
139 // does not own, a Module that has not been loaded or a Module that has
140 // already been finalized.
141 assert(LoadedModules
.count(M
) &&
142 "markModuleAsFinalized: Module not found in LoadedModules");
144 // Remove the module from the "Loaded" section of the list.
145 LoadedModules
.erase(M
);
147 // Add the Module to the "Finalized" section of the list by inserting it
148 // before the 'end' iterator.
149 FinalizedModules
.insert(M
);
152 void markAllLoadedModulesAsFinalized() {
153 for (Module
*M
: LoadedModules
)
154 FinalizedModules
.insert(M
);
155 LoadedModules
.clear();
159 ModulePtrSet AddedModules
;
160 ModulePtrSet LoadedModules
;
161 ModulePtrSet FinalizedModules
;
163 void freeModulePtrSet(ModulePtrSet
& MPS
) {
164 // Go through the module set and delete everything.
165 for (Module
*M
: MPS
)
171 std::unique_ptr
<TargetMachine
> TM
;
173 std::shared_ptr
<MCJITMemoryManager
> MemMgr
;
174 LinkingSymbolResolver Resolver
;
176 std::vector
<JITEventListener
*> EventListeners
;
178 OwningModuleContainer OwnedModules
;
180 SmallVector
<object::OwningBinary
<object::Archive
>, 2> Archives
;
181 SmallVector
<std::unique_ptr
<MemoryBuffer
>, 2> Buffers
;
183 SmallVector
<std::unique_ptr
<object::ObjectFile
>, 2> LoadedObjects
;
185 // An optional ObjectCache to be notified of compiled objects and used to
186 // perform lookup of pre-compiled code to avoid re-compilation.
187 ObjectCache
*ObjCache
;
189 Function
*FindFunctionNamedInModulePtrSet(StringRef FnName
,
190 ModulePtrSet::iterator I
,
191 ModulePtrSet::iterator E
);
193 GlobalVariable
*FindGlobalVariableNamedInModulePtrSet(StringRef Name
,
195 ModulePtrSet::iterator I
,
196 ModulePtrSet::iterator E
);
198 void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors
,
199 ModulePtrSet::iterator I
,
200 ModulePtrSet::iterator E
);
205 /// @name ExecutionEngine interface implementation
207 void addModule(std::unique_ptr
<Module
> M
) override
;
208 void addObjectFile(std::unique_ptr
<object::ObjectFile
> O
) override
;
209 void addObjectFile(object::OwningBinary
<object::ObjectFile
> O
) override
;
210 void addArchive(object::OwningBinary
<object::Archive
> O
) override
;
211 bool removeModule(Module
*M
) override
;
213 /// FindFunctionNamed - Search all of the active modules to find the function that
214 /// defines FnName. This is very slow operation and shouldn't be used for
216 Function
*FindFunctionNamed(StringRef FnName
) override
;
218 /// FindGlobalVariableNamed - Search all of the active modules to find the
219 /// global variable that defines Name. This is very slow operation and
220 /// shouldn't be used for general code.
221 GlobalVariable
*FindGlobalVariableNamed(StringRef Name
,
222 bool AllowInternal
= false) override
;
224 /// Sets the object manager that MCJIT should use to avoid compilation.
225 void setObjectCache(ObjectCache
*manager
) override
;
227 void setProcessAllSections(bool ProcessAllSections
) override
{
228 Dyld
.setProcessAllSections(ProcessAllSections
);
231 void generateCodeForModule(Module
*M
) override
;
233 /// finalizeObject - ensure the module is fully processed and is usable.
235 /// It is the user-level function for completing the process of making the
236 /// object usable for execution. It should be called after sections within an
237 /// object have been relocated using mapSectionAddress. When this method is
238 /// called the MCJIT execution engine will reapply relocations for a loaded
240 /// Is it OK to finalize a set of modules, add modules and finalize again.
241 // FIXME: Do we really need both of these?
242 void finalizeObject() override
;
243 virtual void finalizeModule(Module
*);
244 void finalizeLoadedModules();
246 /// runStaticConstructorsDestructors - This method is used to execute all of
247 /// the static constructors or destructors for a program.
249 /// \param isDtors - Run the destructors instead of constructors.
250 void runStaticConstructorsDestructors(bool isDtors
) override
;
252 void *getPointerToFunction(Function
*F
) override
;
254 GenericValue
runFunction(Function
*F
,
255 ArrayRef
<GenericValue
> ArgValues
) override
;
257 /// getPointerToNamedFunction - This method returns the address of the
258 /// specified function by using the dlsym function call. As such it is only
259 /// useful for resolving library symbols, not code generated symbols.
261 /// If AbortOnFailure is false and no function with the given name is
262 /// found, this function silently returns a null pointer. Otherwise,
263 /// it prints a message to stderr and aborts.
265 void *getPointerToNamedFunction(StringRef Name
,
266 bool AbortOnFailure
= true) override
;
268 /// mapSectionAddress - map a section to its target address space value.
269 /// Map the address of a JIT section as returned from the memory manager
270 /// to the address in the target process as the running code will see it.
271 /// This is the address which will be used for relocation resolution.
272 void mapSectionAddress(const void *LocalAddress
,
273 uint64_t TargetAddress
) override
{
274 Dyld
.mapSectionAddress(LocalAddress
, TargetAddress
);
276 void RegisterJITEventListener(JITEventListener
*L
) override
;
277 void UnregisterJITEventListener(JITEventListener
*L
) override
;
279 // If successful, these function will implicitly finalize all loaded objects.
280 // To get a function address within MCJIT without causing a finalize, use
282 uint64_t getGlobalValueAddress(const std::string
&Name
) override
;
283 uint64_t getFunctionAddress(const std::string
&Name
) override
;
285 TargetMachine
*getTargetMachine() override
{ return TM
.get(); }
288 /// @name (Private) Registration Interfaces
291 static void Register() {
292 MCJITCtor
= createJIT
;
295 static ExecutionEngine
*
296 createJIT(std::unique_ptr
<Module
> M
, std::string
*ErrorStr
,
297 std::shared_ptr
<MCJITMemoryManager
> MemMgr
,
298 std::shared_ptr
<LegacyJITSymbolResolver
> Resolver
,
299 std::unique_ptr
<TargetMachine
> TM
);
303 // Takes a mangled name and returns the corresponding JITSymbol (if a
304 // definition of that mangled name has been added to the JIT).
305 JITSymbol
findSymbol(const std::string
&Name
, bool CheckFunctionsOnly
);
307 // DEPRECATED - Please use findSymbol instead.
309 // This is not directly exposed via the ExecutionEngine API, but it is
310 // used by the LinkingMemoryManager.
312 // getSymbolAddress takes an unmangled name and returns the corresponding
313 // JITSymbol if a definition of the name has been added to the JIT.
314 uint64_t getSymbolAddress(const std::string
&Name
,
315 bool CheckFunctionsOnly
);
318 /// emitObject -- Generate a JITed object in memory from the specified module
319 /// Currently, MCJIT only supports a single module and the module passed to
320 /// this function call is expected to be the contained module. The module
321 /// is passed as a parameter here to prepare for multiple module support in
323 std::unique_ptr
<MemoryBuffer
> emitObject(Module
*M
);
325 void notifyObjectLoaded(const object::ObjectFile
&Obj
,
326 const RuntimeDyld::LoadedObjectInfo
&L
);
327 void notifyFreeingObject(const object::ObjectFile
&Obj
);
329 JITSymbol
findExistingSymbol(const std::string
&Name
);
330 Module
*findModuleForSymbol(const std::string
&Name
, bool CheckFunctionsOnly
);
333 } // end llvm namespace
335 #endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H