LLVM  11.0.0git
MCJIT.h
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1 //===-- MCJIT.h - Class definition for the MCJIT ----------------*- C++ -*-===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
10 #define LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
11 
12 #include "llvm/ADT/SmallPtrSet.h"
13 #include "llvm/ADT/SmallVector.h"
17 
18 namespace llvm {
19 class MCJIT;
20 class Module;
21 class ObjectCache;
22 
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
26 // to that object.
28 public:
30  std::shared_ptr<LegacyJITSymbolResolver> Resolver)
31  : ParentEngine(Parent), ClientResolver(std::move(Resolver)) {}
32 
33  JITSymbol findSymbol(const std::string &Name) override;
34 
35  // MCJIT doesn't support logical dylibs.
36  JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {
37  return nullptr;
38  }
39 
40 private:
41  MCJIT &ParentEngine;
42  std::shared_ptr<LegacyJITSymbolResolver> ClientResolver;
43  void anchor() override;
44 };
45 
46 // About Module states: added->loaded->finalized.
47 //
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
53 // compilation.
54 //
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.
60 //
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
64 // called.
65 
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);
70 
72 
73  class OwningModuleContainer {
74  public:
75  OwningModuleContainer() {
76  }
77  ~OwningModuleContainer() {
78  freeModulePtrSet(AddedModules);
79  freeModulePtrSet(LoadedModules);
80  freeModulePtrSet(FinalizedModules);
81  }
82 
83  ModulePtrSet::iterator begin_added() { return AddedModules.begin(); }
84  ModulePtrSet::iterator end_added() { return AddedModules.end(); }
86  return make_range(begin_added(), end_added());
87  }
88 
89  ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); }
90  ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); }
91 
92  ModulePtrSet::iterator begin_finalized() { return FinalizedModules.begin(); }
93  ModulePtrSet::iterator end_finalized() { return FinalizedModules.end(); }
94 
95  void addModule(std::unique_ptr<Module> M) {
96  AddedModules.insert(M.release());
97  }
98 
99  bool removeModule(Module *M) {
100  return AddedModules.erase(M) || LoadedModules.erase(M) ||
101  FinalizedModules.erase(M);
102  }
103 
104  bool hasModuleBeenAddedButNotLoaded(Module *M) {
105  return AddedModules.count(M) != 0;
106  }
107 
108  bool hasModuleBeenLoaded(Module *M) {
109  // If the module is in either the "loaded" or "finalized" sections it
110  // has been loaded.
111  return (LoadedModules.count(M) != 0 ) || (FinalizedModules.count(M) != 0);
112  }
113 
114  bool hasModuleBeenFinalized(Module *M) {
115  return FinalizedModules.count(M) != 0;
116  }
117 
118  bool ownsModule(Module* M) {
119  return (AddedModules.count(M) != 0) || (LoadedModules.count(M) != 0) ||
120  (FinalizedModules.count(M) != 0);
121  }
122 
123  void markModuleAsLoaded(Module *M) {
124  // This checks against logic errors in the MCJIT implementation.
125  // This function should never be called with either a Module that MCJIT
126  // does not own or a Module that has already been loaded and/or finalized.
127  assert(AddedModules.count(M) &&
128  "markModuleAsLoaded: Module not found in AddedModules");
129 
130  // Remove the module from the "Added" set.
131  AddedModules.erase(M);
132 
133  // Add the Module to the "Loaded" set.
134  LoadedModules.insert(M);
135  }
136 
137  void markModuleAsFinalized(Module *M) {
138  // This checks against logic errors in the MCJIT implementation.
139  // This function should never be called with either a Module that MCJIT
140  // does not own, a Module that has not been loaded or a Module that has
141  // already been finalized.
142  assert(LoadedModules.count(M) &&
143  "markModuleAsFinalized: Module not found in LoadedModules");
144 
145  // Remove the module from the "Loaded" section of the list.
146  LoadedModules.erase(M);
147 
148  // Add the Module to the "Finalized" section of the list by inserting it
149  // before the 'end' iterator.
150  FinalizedModules.insert(M);
151  }
152 
153  void markAllLoadedModulesAsFinalized() {
154  for (ModulePtrSet::iterator I = LoadedModules.begin(),
155  E = LoadedModules.end();
156  I != E; ++I) {
157  Module *M = *I;
158  FinalizedModules.insert(M);
159  }
160  LoadedModules.clear();
161  }
162 
163  private:
164  ModulePtrSet AddedModules;
165  ModulePtrSet LoadedModules;
166  ModulePtrSet FinalizedModules;
167 
168  void freeModulePtrSet(ModulePtrSet& MPS) {
169  // Go through the module set and delete everything.
170  for (ModulePtrSet::iterator I = MPS.begin(), E = MPS.end(); I != E; ++I) {
171  Module *M = *I;
172  delete M;
173  }
174  MPS.clear();
175  }
176  };
177 
178  std::unique_ptr<TargetMachine> TM;
179  MCContext *Ctx;
180  std::shared_ptr<MCJITMemoryManager> MemMgr;
181  LinkingSymbolResolver Resolver;
182  RuntimeDyld Dyld;
183  std::vector<JITEventListener*> EventListeners;
184 
185  OwningModuleContainer OwnedModules;
186 
189 
191 
192  // An optional ObjectCache to be notified of compiled objects and used to
193  // perform lookup of pre-compiled code to avoid re-compilation.
194  ObjectCache *ObjCache;
195 
196  Function *FindFunctionNamedInModulePtrSet(StringRef FnName,
197  ModulePtrSet::iterator I,
198  ModulePtrSet::iterator E);
199 
200  GlobalVariable *FindGlobalVariableNamedInModulePtrSet(StringRef Name,
201  bool AllowInternal,
202  ModulePtrSet::iterator I,
203  ModulePtrSet::iterator E);
204 
205  void runStaticConstructorsDestructorsInModulePtrSet(bool isDtors,
206  ModulePtrSet::iterator I,
207  ModulePtrSet::iterator E);
208 
209 public:
210  ~MCJIT() override;
211 
212  /// @name ExecutionEngine interface implementation
213  /// @{
214  void addModule(std::unique_ptr<Module> M) override;
215  void addObjectFile(std::unique_ptr<object::ObjectFile> O) override;
216  void addObjectFile(object::OwningBinary<object::ObjectFile> O) override;
217  void addArchive(object::OwningBinary<object::Archive> O) override;
218  bool removeModule(Module *M) override;
219 
220  /// FindFunctionNamed - Search all of the active modules to find the function that
221  /// defines FnName. This is very slow operation and shouldn't be used for
222  /// general code.
223  Function *FindFunctionNamed(StringRef FnName) override;
224 
225  /// FindGlobalVariableNamed - Search all of the active modules to find the
226  /// global variable that defines Name. This is very slow operation and
227  /// shouldn't be used for general code.
228  GlobalVariable *FindGlobalVariableNamed(StringRef Name,
229  bool AllowInternal = false) override;
230 
231  /// Sets the object manager that MCJIT should use to avoid compilation.
232  void setObjectCache(ObjectCache *manager) override;
233 
234  void setProcessAllSections(bool ProcessAllSections) override {
235  Dyld.setProcessAllSections(ProcessAllSections);
236  }
237 
238  void generateCodeForModule(Module *M) override;
239 
240  /// finalizeObject - ensure the module is fully processed and is usable.
241  ///
242  /// It is the user-level function for completing the process of making the
243  /// object usable for execution. It should be called after sections within an
244  /// object have been relocated using mapSectionAddress. When this method is
245  /// called the MCJIT execution engine will reapply relocations for a loaded
246  /// object.
247  /// Is it OK to finalize a set of modules, add modules and finalize again.
248  // FIXME: Do we really need both of these?
249  void finalizeObject() override;
250  virtual void finalizeModule(Module *);
251  void finalizeLoadedModules();
252 
253  /// runStaticConstructorsDestructors - This method is used to execute all of
254  /// the static constructors or destructors for a program.
255  ///
256  /// \param isDtors - Run the destructors instead of constructors.
257  void runStaticConstructorsDestructors(bool isDtors) override;
258 
259  void *getPointerToFunction(Function *F) override;
260 
261  GenericValue runFunction(Function *F,
262  ArrayRef<GenericValue> ArgValues) override;
263 
264  /// getPointerToNamedFunction - This method returns the address of the
265  /// specified function by using the dlsym function call. As such it is only
266  /// useful for resolving library symbols, not code generated symbols.
267  ///
268  /// If AbortOnFailure is false and no function with the given name is
269  /// found, this function silently returns a null pointer. Otherwise,
270  /// it prints a message to stderr and aborts.
271  ///
272  void *getPointerToNamedFunction(StringRef Name,
273  bool AbortOnFailure = true) override;
274 
275  /// mapSectionAddress - map a section to its target address space value.
276  /// Map the address of a JIT section as returned from the memory manager
277  /// to the address in the target process as the running code will see it.
278  /// This is the address which will be used for relocation resolution.
279  void mapSectionAddress(const void *LocalAddress,
280  uint64_t TargetAddress) override {
281  Dyld.mapSectionAddress(LocalAddress, TargetAddress);
282  }
283  void RegisterJITEventListener(JITEventListener *L) override;
284  void UnregisterJITEventListener(JITEventListener *L) override;
285 
286  // If successful, these function will implicitly finalize all loaded objects.
287  // To get a function address within MCJIT without causing a finalize, use
288  // getSymbolAddress.
289  uint64_t getGlobalValueAddress(const std::string &Name) override;
290  uint64_t getFunctionAddress(const std::string &Name) override;
291 
292  TargetMachine *getTargetMachine() override { return TM.get(); }
293 
294  /// @}
295  /// @name (Private) Registration Interfaces
296  /// @{
297 
298  static void Register() {
299  MCJITCtor = createJIT;
300  }
301 
302  static ExecutionEngine *
303  createJIT(std::unique_ptr<Module> M, std::string *ErrorStr,
304  std::shared_ptr<MCJITMemoryManager> MemMgr,
305  std::shared_ptr<LegacyJITSymbolResolver> Resolver,
306  std::unique_ptr<TargetMachine> TM);
307 
308  // @}
309 
310  // Takes a mangled name and returns the corresponding JITSymbol (if a
311  // definition of that mangled name has been added to the JIT).
312  JITSymbol findSymbol(const std::string &Name, bool CheckFunctionsOnly);
313 
314  // DEPRECATED - Please use findSymbol instead.
315  //
316  // This is not directly exposed via the ExecutionEngine API, but it is
317  // used by the LinkingMemoryManager.
318  //
319  // getSymbolAddress takes an unmangled name and returns the corresponding
320  // JITSymbol if a definition of the name has been added to the JIT.
321  uint64_t getSymbolAddress(const std::string &Name,
322  bool CheckFunctionsOnly);
323 
324 protected:
325  /// emitObject -- Generate a JITed object in memory from the specified module
326  /// Currently, MCJIT only supports a single module and the module passed to
327  /// this function call is expected to be the contained module. The module
328  /// is passed as a parameter here to prepare for multiple module support in
329  /// the future.
330  std::unique_ptr<MemoryBuffer> emitObject(Module *M);
331 
332  void notifyObjectLoaded(const object::ObjectFile &Obj,
334  void notifyFreeingObject(const object::ObjectFile &Obj);
335 
336  JITSymbol findExistingSymbol(const std::string &Name);
337  Module *findModuleForSymbol(const std::string &Name, bool CheckFunctionsOnly);
338 };
339 
340 } // end llvm namespace
341 
342 #endif // LLVM_LIB_EXECUTIONENGINE_MCJIT_MCJIT_H
Information about the loaded object.
Definition: RuntimeDyld.h:70
Represents a symbol in the JIT.
Definition: JITSymbol.h:265
This class represents lattice values for constants.
Definition: AllocatorList.h:23
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:66
Machine Debugify Module
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
JITEventListener - Abstract interface for use by the JIT to notify clients about significant events d...
Legacy symbol resolution interface.
Definition: JITSymbol.h:398
This class is the base class for all object file types.
Definition: ObjectFile.h:225
F(f)
static void Register()
Definition: MCJIT.h:298
Definition: BitVector.h:959
Context object for machine code objects.
Definition: MCContext.h:66
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
JITSymbol findSymbol(const std::string &Name) override
This method returns the address of the specified function or variable.
Definition: MCJIT.cpp:676
void setProcessAllSections(bool ProcessAllSections)
By default, only sections that are "required for execution" are passed to the RTDyldMemoryManager, and other sections are discarded.
Definition: RuntimeDyld.h:245
void setProcessAllSections(bool ProcessAllSections) override
setProcessAllSections (MCJIT Only): By default, only sections that are "required for execution" are p...
Definition: MCJIT.h:234
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
Interface for looking up the initializer for a variable name, used by Init::resolveReferences.
Definition: Record.h:1870
LinkingSymbolResolver(MCJIT &Parent, std::shared_ptr< LegacyJITSymbolResolver > Resolver)
Definition: MCJIT.h:29
JITSymbol findSymbolInLogicalDylib(const std::string &Name) override
This method returns the address of the specified symbol if it exists within the logical dynamic libra...
Definition: MCJIT.h:36
TargetMachine * getTargetMachine() override
Return the target machine (if available).
Definition: MCJIT.h:292
Abstract interface for implementation execution of LLVM modules, designed to support both interpreter...
void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress) override
mapSectionAddress - map a section to its target address space value.
Definition: MCJIT.h:279
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:883
A range adaptor for a pair of iterators.
iterator begin() const
Definition: SmallPtrSet.h:390
#define I(x, y, z)
Definition: MD5.cpp:59
This is the base ObjectCache type which can be provided to an ExecutionEngine for the purpose of avoi...
Definition: ObjectCache.h:23
iterator end() const
Definition: SmallPtrSet.h:395
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Primary interface to the complete machine description for the target machine.
Definition: TargetMachine.h:65
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:57
void mapSectionAddress(const void *LocalAddress, uint64_t TargetAddress)
Map a section to its target address space value.