1 //===- IndirectionUtils.h - Utilities for adding indirections ---*- 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 // Contains utilities for adding indirections and breaking up modules.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_EXECUTIONENGINE_ORC_INDIRECTIONUTILS_H
15 #define LLVM_EXECUTIONENGINE_ORC_INDIRECTIONUTILS_H
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/ExecutionEngine/JITSymbol.h"
21 #include "llvm/ExecutionEngine/Orc/Core.h"
22 #include "llvm/Support/Error.h"
23 #include "llvm/Support/Memory.h"
24 #include "llvm/Support/Process.h"
25 #include "llvm/Transforms/Utils/ValueMapper.h"
32 #include <system_error>
50 /// Base class for pools of compiler re-entry trampolines.
51 /// These trampolines are callable addresses that save all register state
52 /// before calling a supplied function to return the trampoline landing
53 /// address, then restore all state before jumping to that address. They
54 /// are used by various ORC APIs to support lazy compilation
55 class TrampolinePool {
57 virtual ~TrampolinePool() {}
59 /// Get an available trampoline address.
60 /// Returns an error if no trampoline can be created.
61 virtual Expected<JITTargetAddress> getTrampoline() = 0;
64 virtual void anchor();
67 /// A trampoline pool for trampolines within the current process.
68 template <typename ORCABI> class LocalTrampolinePool : public TrampolinePool {
70 using GetTrampolineLandingFunction =
71 std::function<JITTargetAddress(JITTargetAddress TrampolineAddr)>;
73 /// Creates a LocalTrampolinePool with the given RunCallback function.
74 /// Returns an error if this function is unable to correctly allocate, write
75 /// and protect the resolver code block.
76 static Expected<std::unique_ptr<LocalTrampolinePool>>
77 Create(GetTrampolineLandingFunction GetTrampolineLanding) {
78 Error Err = Error::success();
80 auto LTP = std::unique_ptr<LocalTrampolinePool>(
81 new LocalTrampolinePool(std::move(GetTrampolineLanding), Err));
84 return std::move(Err);
85 return std::move(LTP);
88 /// Get a free trampoline. Returns an error if one can not be provide (e.g.
89 /// because the pool is empty and can not be grown).
90 Expected<JITTargetAddress> getTrampoline() override {
91 std::lock_guard<std::mutex> Lock(LTPMutex);
92 if (AvailableTrampolines.empty()) {
93 if (auto Err = grow())
94 return std::move(Err);
96 assert(!AvailableTrampolines.empty() && "Failed to grow trampoline pool");
97 auto TrampolineAddr = AvailableTrampolines.back();
98 AvailableTrampolines.pop_back();
99 return TrampolineAddr;
102 /// Returns the given trampoline to the pool for re-use.
103 void releaseTrampoline(JITTargetAddress TrampolineAddr) {
104 std::lock_guard<std::mutex> Lock(LTPMutex);
105 AvailableTrampolines.push_back(TrampolineAddr);
109 static JITTargetAddress reenter(void *TrampolinePoolPtr, void *TrampolineId) {
110 LocalTrampolinePool<ORCABI> *TrampolinePool =
111 static_cast<LocalTrampolinePool *>(TrampolinePoolPtr);
112 return TrampolinePool->GetTrampolineLanding(static_cast<JITTargetAddress>(
113 reinterpret_cast<uintptr_t>(TrampolineId)));
116 LocalTrampolinePool(GetTrampolineLandingFunction GetTrampolineLanding,
118 : GetTrampolineLanding(std::move(GetTrampolineLanding)) {
120 ErrorAsOutParameter _(&Err);
122 /// Try to set up the resolver block.
124 ResolverBlock = sys::OwningMemoryBlock(sys::Memory::allocateMappedMemory(
125 ORCABI::ResolverCodeSize, nullptr,
126 sys::Memory::MF_READ | sys::Memory::MF_WRITE, EC));
128 Err = errorCodeToError(EC);
132 ORCABI::writeResolverCode(static_cast<uint8_t *>(ResolverBlock.base()),
135 EC = sys::Memory::protectMappedMemory(ResolverBlock.getMemoryBlock(),
136 sys::Memory::MF_READ |
137 sys::Memory::MF_EXEC);
139 Err = errorCodeToError(EC);
145 assert(this->AvailableTrampolines.empty() && "Growing prematurely?");
148 auto TrampolineBlock =
149 sys::OwningMemoryBlock(sys::Memory::allocateMappedMemory(
150 sys::Process::getPageSize(), nullptr,
151 sys::Memory::MF_READ | sys::Memory::MF_WRITE, EC));
153 return errorCodeToError(EC);
155 unsigned NumTrampolines =
156 (sys::Process::getPageSize() - ORCABI::PointerSize) /
157 ORCABI::TrampolineSize;
159 uint8_t *TrampolineMem = static_cast<uint8_t *>(TrampolineBlock.base());
160 ORCABI::writeTrampolines(TrampolineMem, ResolverBlock.base(),
163 for (unsigned I = 0; I < NumTrampolines; ++I)
164 this->AvailableTrampolines.push_back(
165 static_cast<JITTargetAddress>(reinterpret_cast<uintptr_t>(
166 TrampolineMem + (I * ORCABI::TrampolineSize))));
168 if (auto EC = sys::Memory::protectMappedMemory(
169 TrampolineBlock.getMemoryBlock(),
170 sys::Memory::MF_READ | sys::Memory::MF_EXEC))
171 return errorCodeToError(EC);
173 TrampolineBlocks.push_back(std::move(TrampolineBlock));
174 return Error::success();
177 GetTrampolineLandingFunction GetTrampolineLanding;
180 sys::OwningMemoryBlock ResolverBlock;
181 std::vector<sys::OwningMemoryBlock> TrampolineBlocks;
182 std::vector<JITTargetAddress> AvailableTrampolines;
185 /// Target-independent base class for compile callback management.
186 class JITCompileCallbackManager {
188 using CompileFunction = std::function<JITTargetAddress()>;
190 virtual ~JITCompileCallbackManager() = default;
192 /// Reserve a compile callback.
193 Expected<JITTargetAddress> getCompileCallback(CompileFunction Compile);
195 /// Execute the callback for the given trampoline id. Called by the JIT
196 /// to compile functions on demand.
197 JITTargetAddress executeCompileCallback(JITTargetAddress TrampolineAddr);
200 /// Construct a JITCompileCallbackManager.
201 JITCompileCallbackManager(std::unique_ptr<TrampolinePool> TP,
202 ExecutionSession &ES,
203 JITTargetAddress ErrorHandlerAddress)
204 : TP(std::move(TP)), ES(ES),
205 CallbacksJD(ES.createJITDylib("<Callbacks>")),
206 ErrorHandlerAddress(ErrorHandlerAddress) {}
208 void setTrampolinePool(std::unique_ptr<TrampolinePool> TP) {
209 this->TP = std::move(TP);
213 std::mutex CCMgrMutex;
214 std::unique_ptr<TrampolinePool> TP;
215 ExecutionSession &ES;
216 JITDylib &CallbacksJD;
217 JITTargetAddress ErrorHandlerAddress;
218 std::map<JITTargetAddress, SymbolStringPtr> AddrToSymbol;
219 size_t NextCallbackId = 0;
222 /// Manage compile callbacks for in-process JITs.
223 template <typename ORCABI>
224 class LocalJITCompileCallbackManager : public JITCompileCallbackManager {
226 /// Create a new LocalJITCompileCallbackManager.
227 static Expected<std::unique_ptr<LocalJITCompileCallbackManager>>
228 Create(ExecutionSession &ES, JITTargetAddress ErrorHandlerAddress) {
229 Error Err = Error::success();
230 auto CCMgr = std::unique_ptr<LocalJITCompileCallbackManager>(
231 new LocalJITCompileCallbackManager(ES, ErrorHandlerAddress, Err));
233 return std::move(Err);
234 return std::move(CCMgr);
238 /// Construct a InProcessJITCompileCallbackManager.
239 /// @param ErrorHandlerAddress The address of an error handler in the target
240 /// process to be used if a compile callback fails.
241 LocalJITCompileCallbackManager(ExecutionSession &ES,
242 JITTargetAddress ErrorHandlerAddress,
244 : JITCompileCallbackManager(nullptr, ES, ErrorHandlerAddress) {
245 ErrorAsOutParameter _(&Err);
246 auto TP = LocalTrampolinePool<ORCABI>::Create(
247 [this](JITTargetAddress TrampolineAddr) {
248 return executeCompileCallback(TrampolineAddr);
252 Err = TP.takeError();
256 setTrampolinePool(std::move(*TP));
260 /// Base class for managing collections of named indirect stubs.
261 class IndirectStubsManager {
263 /// Map type for initializing the manager. See init.
264 using StubInitsMap = StringMap<std::pair<JITTargetAddress, JITSymbolFlags>>;
266 virtual ~IndirectStubsManager() = default;
268 /// Create a single stub with the given name, target address and flags.
269 virtual Error createStub(StringRef StubName, JITTargetAddress StubAddr,
270 JITSymbolFlags StubFlags) = 0;
272 /// Create StubInits.size() stubs with the given names, target
273 /// addresses, and flags.
274 virtual Error createStubs(const StubInitsMap &StubInits) = 0;
276 /// Find the stub with the given name. If ExportedStubsOnly is true,
277 /// this will only return a result if the stub's flags indicate that it
279 virtual JITEvaluatedSymbol findStub(StringRef Name, bool ExportedStubsOnly) = 0;
281 /// Find the implementation-pointer for the stub.
282 virtual JITEvaluatedSymbol findPointer(StringRef Name) = 0;
284 /// Change the value of the implementation pointer for the stub.
285 virtual Error updatePointer(StringRef Name, JITTargetAddress NewAddr) = 0;
288 virtual void anchor();
291 /// IndirectStubsManager implementation for the host architecture, e.g.
292 /// OrcX86_64. (See OrcArchitectureSupport.h).
293 template <typename TargetT>
294 class LocalIndirectStubsManager : public IndirectStubsManager {
296 Error createStub(StringRef StubName, JITTargetAddress StubAddr,
297 JITSymbolFlags StubFlags) override {
298 std::lock_guard<std::mutex> Lock(StubsMutex);
299 if (auto Err = reserveStubs(1))
302 createStubInternal(StubName, StubAddr, StubFlags);
304 return Error::success();
307 Error createStubs(const StubInitsMap &StubInits) override {
308 std::lock_guard<std::mutex> Lock(StubsMutex);
309 if (auto Err = reserveStubs(StubInits.size()))
312 for (auto &Entry : StubInits)
313 createStubInternal(Entry.first(), Entry.second.first,
314 Entry.second.second);
316 return Error::success();
319 JITEvaluatedSymbol findStub(StringRef Name, bool ExportedStubsOnly) override {
320 std::lock_guard<std::mutex> Lock(StubsMutex);
321 auto I = StubIndexes.find(Name);
322 if (I == StubIndexes.end())
324 auto Key = I->second.first;
325 void *StubAddr = IndirectStubsInfos[Key.first].getStub(Key.second);
326 assert(StubAddr && "Missing stub address");
327 auto StubTargetAddr =
328 static_cast<JITTargetAddress>(reinterpret_cast<uintptr_t>(StubAddr));
329 auto StubSymbol = JITEvaluatedSymbol(StubTargetAddr, I->second.second);
330 if (ExportedStubsOnly && !StubSymbol.getFlags().isExported())
335 JITEvaluatedSymbol findPointer(StringRef Name) override {
336 std::lock_guard<std::mutex> Lock(StubsMutex);
337 auto I = StubIndexes.find(Name);
338 if (I == StubIndexes.end())
340 auto Key = I->second.first;
341 void *PtrAddr = IndirectStubsInfos[Key.first].getPtr(Key.second);
342 assert(PtrAddr && "Missing pointer address");
344 static_cast<JITTargetAddress>(reinterpret_cast<uintptr_t>(PtrAddr));
345 return JITEvaluatedSymbol(PtrTargetAddr, I->second.second);
348 Error updatePointer(StringRef Name, JITTargetAddress NewAddr) override {
349 using AtomicIntPtr = std::atomic<uintptr_t>;
351 std::lock_guard<std::mutex> Lock(StubsMutex);
352 auto I = StubIndexes.find(Name);
353 assert(I != StubIndexes.end() && "No stub pointer for symbol");
354 auto Key = I->second.first;
355 AtomicIntPtr *AtomicStubPtr = reinterpret_cast<AtomicIntPtr *>(
356 IndirectStubsInfos[Key.first].getPtr(Key.second));
357 *AtomicStubPtr = static_cast<uintptr_t>(NewAddr);
358 return Error::success();
362 Error reserveStubs(unsigned NumStubs) {
363 if (NumStubs <= FreeStubs.size())
364 return Error::success();
366 unsigned NewStubsRequired = NumStubs - FreeStubs.size();
367 unsigned NewBlockId = IndirectStubsInfos.size();
368 typename TargetT::IndirectStubsInfo ISI;
370 TargetT::emitIndirectStubsBlock(ISI, NewStubsRequired, nullptr))
372 for (unsigned I = 0; I < ISI.getNumStubs(); ++I)
373 FreeStubs.push_back(std::make_pair(NewBlockId, I));
374 IndirectStubsInfos.push_back(std::move(ISI));
375 return Error::success();
378 void createStubInternal(StringRef StubName, JITTargetAddress InitAddr,
379 JITSymbolFlags StubFlags) {
380 auto Key = FreeStubs.back();
381 FreeStubs.pop_back();
382 *IndirectStubsInfos[Key.first].getPtr(Key.second) =
383 reinterpret_cast<void *>(static_cast<uintptr_t>(InitAddr));
384 StubIndexes[StubName] = std::make_pair(Key, StubFlags);
387 std::mutex StubsMutex;
388 std::vector<typename TargetT::IndirectStubsInfo> IndirectStubsInfos;
389 using StubKey = std::pair<uint16_t, uint16_t>;
390 std::vector<StubKey> FreeStubs;
391 StringMap<std::pair<StubKey, JITSymbolFlags>> StubIndexes;
394 /// Create a local compile callback manager.
396 /// The given target triple will determine the ABI, and the given
397 /// ErrorHandlerAddress will be used by the resulting compile callback
398 /// manager if a compile callback fails.
399 Expected<std::unique_ptr<JITCompileCallbackManager>>
400 createLocalCompileCallbackManager(const Triple &T, ExecutionSession &ES,
401 JITTargetAddress ErrorHandlerAddress);
403 /// Create a local indriect stubs manager builder.
405 /// The given target triple will determine the ABI.
406 std::function<std::unique_ptr<IndirectStubsManager>()>
407 createLocalIndirectStubsManagerBuilder(const Triple &T);
409 /// Build a function pointer of FunctionType with the given constant
412 /// Usage example: Turn a trampoline address into a function pointer constant
413 /// for use in a stub.
414 Constant *createIRTypedAddress(FunctionType &FT, JITTargetAddress Addr);
416 /// Create a function pointer with the given type, name, and initializer
417 /// in the given Module.
418 GlobalVariable *createImplPointer(PointerType &PT, Module &M, const Twine &Name,
419 Constant *Initializer);
421 /// Turn a function declaration into a stub function that makes an
422 /// indirect call using the given function pointer.
423 void makeStub(Function &F, Value &ImplPointer);
425 /// Promotes private symbols to global hidden, and renames to prevent clashes
426 /// with other promoted symbols. The same SymbolPromoter instance should be
427 /// used for all symbols to be added to a single JITDylib.
428 class SymbolLinkagePromoter {
430 /// Promote symbols in the given module. Returns the set of global values
431 /// that have been renamed/promoted.
432 std::vector<GlobalValue *> operator()(Module &M);
438 /// Clone a function declaration into a new module.
440 /// This function can be used as the first step towards creating a callback
441 /// stub (see makeStub), or moving a function body (see moveFunctionBody).
443 /// If the VMap argument is non-null, a mapping will be added between F and
444 /// the new declaration, and between each of F's arguments and the new
445 /// declaration's arguments. This map can then be passed in to moveFunction to
446 /// move the function body if required. Note: When moving functions between
447 /// modules with these utilities, all decls should be cloned (and added to a
448 /// single VMap) before any bodies are moved. This will ensure that references
449 /// between functions all refer to the versions in the new module.
450 Function *cloneFunctionDecl(Module &Dst, const Function &F,
451 ValueToValueMapTy *VMap = nullptr);
453 /// Move the body of function 'F' to a cloned function declaration in a
454 /// different module (See related cloneFunctionDecl).
456 /// If the target function declaration is not supplied via the NewF parameter
457 /// then it will be looked up via the VMap.
459 /// This will delete the body of function 'F' from its original parent module,
460 /// but leave its declaration.
461 void moveFunctionBody(Function &OrigF, ValueToValueMapTy &VMap,
462 ValueMaterializer *Materializer = nullptr,
463 Function *NewF = nullptr);
465 /// Clone a global variable declaration into a new module.
466 GlobalVariable *cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
467 ValueToValueMapTy *VMap = nullptr);
469 /// Move global variable GV from its parent module to cloned global
470 /// declaration in a different module.
472 /// If the target global declaration is not supplied via the NewGV parameter
473 /// then it will be looked up via the VMap.
475 /// This will delete the initializer of GV from its original parent module,
476 /// but leave its declaration.
477 void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
478 ValueToValueMapTy &VMap,
479 ValueMaterializer *Materializer = nullptr,
480 GlobalVariable *NewGV = nullptr);
482 /// Clone a global alias declaration into a new module.
483 GlobalAlias *cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
484 ValueToValueMapTy &VMap);
486 /// Clone module flags metadata into the destination module.
487 void cloneModuleFlagsMetadata(Module &Dst, const Module &Src,
488 ValueToValueMapTy &VMap);
490 } // end namespace orc
492 } // end namespace llvm
494 #endif // LLVM_EXECUTIONENGINE_ORC_INDIRECTIONUTILS_H