include/llvm/ExecutionEngine/Orc/OrcRemoteTargetClient.h

   1 //===---- OrcRemoteTargetClient.h - Orc Remote-target Client ----*- 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 // This file defines the OrcRemoteTargetClient class and helpers. This class
  11 // can be used to communicate over an RPCChannel with an OrcRemoteTargetServer
  12 // instance to support remote-JITing.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #ifndef LLVM_EXECUTIONENGINE_ORC_ORCREMOTETARGETCLIENT_H
  17 #define LLVM_EXECUTIONENGINE_ORC_ORCREMOTETARGETCLIENT_H
  18
  19 #include "IndirectionUtils.h"
  20 #include "OrcRemoteTargetRPCAPI.h"
  21 #include <system_error>
  22
  23 #define DEBUG_TYPE "orc-remote"
  24
  25 namespace llvm {
  26 namespace orc {
  27 namespace remote {
  28
  29 /// This class provides utilities (including memory manager, indirect stubs
  30 /// manager, and compile callback manager types) that support remote JITing
  31 /// in ORC.
  32 ///
  33 /// Each of the utility classes talks to a JIT server (an instance of the
  34 /// OrcRemoteTargetServer class) via an RPC system (see RPCUtils.h) to carry out
  35 /// its actions.
  36 template <typename ChannelT>
  37 class OrcRemoteTargetClient : public OrcRemoteTargetRPCAPI {
  38 public:
  39   /// Remote memory manager.
  40   class RCMemoryManager : public RuntimeDyld::MemoryManager {
  41   public:
  42     RCMemoryManager(OrcRemoteTargetClient &Client, ResourceIdMgr::ResourceId Id)
  43         : Client(Client), Id(Id) {
  44       DEBUG(dbgs() << "Created remote allocator " << Id << "\n");
  45     }
  46
  47     RCMemoryManager(RCMemoryManager &&Other)
  48         : Client(std::move(Other.Client)), Id(std::move(Other.Id)),
  49           Unmapped(std::move(Other.Unmapped)),
  50           Unfinalized(std::move(Other.Unfinalized)) {}
  51
  52     RCMemoryManager operator=(RCMemoryManager &&Other) {
  53       Client = std::move(Other.Client);
  54       Id = std::move(Other.Id);
  55       Unmapped = std::move(Other.Unmapped);
  56       Unfinalized = std::move(Other.Unfinalized);
  57       return *this;
  58     }
  59
  60     ~RCMemoryManager() {
  61       Client.destroyRemoteAllocator(Id);
  62       DEBUG(dbgs() << "Destroyed remote allocator " << Id << "\n");
  63     }
  64
  65     uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
  66                                  unsigned SectionID,
  67                                  StringRef SectionName) override {
  68       Unmapped.back().CodeAllocs.emplace_back(Size, Alignment);
  69       uint8_t *Alloc = reinterpret_cast<uint8_t *>(
  70           Unmapped.back().CodeAllocs.back().getLocalAddress());
  71       DEBUG(dbgs() << "Allocator " << Id << " allocated code for "
  72                    << SectionName << ": " << Alloc << " (" << Size
  73                    << " bytes, alignment " << Alignment << ")\n");
  74       return Alloc;
  75     }
  76
  77     uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
  78                                  unsigned SectionID, StringRef SectionName,
  79                                  bool IsReadOnly) override {
  80       if (IsReadOnly) {
  81         Unmapped.back().RODataAllocs.emplace_back(Size, Alignment);
  82         uint8_t *Alloc = reinterpret_cast<uint8_t *>(
  83             Unmapped.back().RODataAllocs.back().getLocalAddress());
  84         DEBUG(dbgs() << "Allocator " << Id << " allocated ro-data for "
  85                      << SectionName << ": " << Alloc << " (" << Size
  86                      << " bytes, alignment " << Alignment << ")\n");
  87         return Alloc;
  88       } // else...
  89
  90       Unmapped.back().RWDataAllocs.emplace_back(Size, Alignment);
  91       uint8_t *Alloc = reinterpret_cast<uint8_t *>(
  92           Unmapped.back().RWDataAllocs.back().getLocalAddress());
  93       DEBUG(dbgs() << "Allocator " << Id << " allocated rw-data for "
  94                    << SectionName << ": " << Alloc << " (" << Size
  95                    << " bytes, alignment " << Alignment << "\n");
  96       return Alloc;
  97     }
  98
  99     void reserveAllocationSpace(uintptr_t CodeSize, uint32_t CodeAlign,
 100                                 uintptr_t RODataSize, uint32_t RODataAlign,
 101                                 uintptr_t RWDataSize,
 102                                 uint32_t RWDataAlign) override {
 103       Unmapped.push_back(ObjectAllocs());
 104
 105       DEBUG(dbgs() << "Allocator " << Id << " reserved:\n");
 106
 107       if (CodeSize != 0) {
 108         if (std::error_code EC = Client.reserveMem(
 109                 Unmapped.back().RemoteCodeAddr, Id, CodeSize, CodeAlign)) {
 110           (void)EC;
 111           // FIXME; Add error to poll.
 112           llvm_unreachable("Failed reserving remote memory.");
 113         }
 114         DEBUG(dbgs() << "  code: "
 115                      << format("0x%016x", Unmapped.back().RemoteCodeAddr)
 116                      << " (" << CodeSize << " bytes, alignment " << CodeAlign
 117                      << ")\n");
 118       }
 119
 120       if (RODataSize != 0) {
 121         if (auto EC = Client.reserveMem(Unmapped.back().RemoteRODataAddr, Id,
 122                                         RODataSize, RODataAlign)) {
 123           // FIXME; Add error to poll.
 124           llvm_unreachable("Failed reserving remote memory.");
 125         }
 126         DEBUG(dbgs() << "  ro-data: "
 127                      << format("0x%016x", Unmapped.back().RemoteRODataAddr)
 128                      << " (" << RODataSize << " bytes, alignment "
 129                      << RODataAlign << ")\n");
 130       }
 131
 132       if (RWDataSize != 0) {
 133         if (auto EC = Client.reserveMem(Unmapped.back().RemoteRWDataAddr, Id,
 134                                         RWDataSize, RWDataAlign)) {
 135           // FIXME; Add error to poll.
 136           llvm_unreachable("Failed reserving remote memory.");
 137         }
 138         DEBUG(dbgs() << "  rw-data: "
 139                      << format("0x%016x", Unmapped.back().RemoteRWDataAddr)
 140                      << " (" << RWDataSize << " bytes, alignment "
 141                      << RWDataAlign << ")\n");
 142       }
 143     }
 144
 145     bool needsToReserveAllocationSpace() override { return true; }
 146
 147     void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,
 148                           size_t Size) override {}
 149
 150     void deregisterEHFrames(uint8_t *addr, uint64_t LoadAddr,
 151                             size_t Size) override {}
 152
 153     void notifyObjectLoaded(RuntimeDyld &Dyld,
 154                             const object::ObjectFile &Obj) override {
 155       DEBUG(dbgs() << "Allocator " << Id << " applied mappings:\n");
 156       for (auto &ObjAllocs : Unmapped) {
 157         {
 158           TargetAddress NextCodeAddr = ObjAllocs.RemoteCodeAddr;
 159           for (auto &Alloc : ObjAllocs.CodeAllocs) {
 160             NextCodeAddr = RoundUpToAlignment(NextCodeAddr, Alloc.getAlign());
 161             Dyld.mapSectionAddress(Alloc.getLocalAddress(), NextCodeAddr);
 162             DEBUG(dbgs() << "     code: "
 163                          << static_cast<void *>(Alloc.getLocalAddress())
 164                          << " -> " << format("0x%016x", NextCodeAddr) << "\n");
 165             Alloc.setRemoteAddress(NextCodeAddr);
 166             NextCodeAddr += Alloc.getSize();
 167           }
 168         }
 169         {
 170           TargetAddress NextRODataAddr = ObjAllocs.RemoteRODataAddr;
 171           for (auto &Alloc : ObjAllocs.RODataAllocs) {
 172             NextRODataAddr =
 173                 RoundUpToAlignment(NextRODataAddr, Alloc.getAlign());
 174             Dyld.mapSectionAddress(Alloc.getLocalAddress(), NextRODataAddr);
 175             DEBUG(dbgs() << "  ro-data: "
 176                          << static_cast<void *>(Alloc.getLocalAddress())
 177                          << " -> " << format("0x%016x", NextRODataAddr)
 178                          << "\n");
 179             Alloc.setRemoteAddress(NextRODataAddr);
 180             NextRODataAddr += Alloc.getSize();
 181           }
 182         }
 183         {
 184           TargetAddress NextRWDataAddr = ObjAllocs.RemoteRWDataAddr;
 185           for (auto &Alloc : ObjAllocs.RWDataAllocs) {
 186             NextRWDataAddr =
 187                 RoundUpToAlignment(NextRWDataAddr, Alloc.getAlign());
 188             Dyld.mapSectionAddress(Alloc.getLocalAddress(), NextRWDataAddr);
 189             DEBUG(dbgs() << "  rw-data: "
 190                          << static_cast<void *>(Alloc.getLocalAddress())
 191                          << " -> " << format("0x%016x", NextRWDataAddr)
 192                          << "\n");
 193             Alloc.setRemoteAddress(NextRWDataAddr);
 194             NextRWDataAddr += Alloc.getSize();
 195           }
 196         }
 197         Unfinalized.push_back(std::move(ObjAllocs));
 198       }
 199       Unmapped.clear();
 200     }
 201
 202     bool finalizeMemory(std::string *ErrMsg = nullptr) override {
 203       DEBUG(dbgs() << "Allocator " << Id << " finalizing:\n");
 204
 205       for (auto &ObjAllocs : Unfinalized) {
 206
 207         for (auto &Alloc : ObjAllocs.CodeAllocs) {
 208           DEBUG(dbgs() << "  copying code: "
 209                        << static_cast<void *>(Alloc.getLocalAddress()) << " -> "
 210                        << format("0x%016x", Alloc.getRemoteAddress()) << " ("
 211                        << Alloc.getSize() << " bytes)\n");
 212           Client.writeMem(Alloc.getRemoteAddress(), Alloc.getLocalAddress(),
 213                           Alloc.getSize());
 214         }
 215
 216         if (ObjAllocs.RemoteCodeAddr) {
 217           DEBUG(dbgs() << "  setting R-X permissions on code block: "
 218                        << format("0x%016x", ObjAllocs.RemoteCodeAddr) << "\n");
 219           Client.setProtections(Id, ObjAllocs.RemoteCodeAddr,
 220                                 sys::Memory::MF_READ | sys::Memory::MF_EXEC);
 221         }
 222
 223         for (auto &Alloc : ObjAllocs.RODataAllocs) {
 224           DEBUG(dbgs() << "  copying ro-data: "
 225                        << static_cast<void *>(Alloc.getLocalAddress()) << " -> "
 226                        << format("0x%016x", Alloc.getRemoteAddress()) << " ("
 227                        << Alloc.getSize() << " bytes)\n");
 228           Client.writeMem(Alloc.getRemoteAddress(), Alloc.getLocalAddress(),
 229                           Alloc.getSize());
 230         }
 231
 232         if (ObjAllocs.RemoteRODataAddr) {
 233           DEBUG(dbgs() << "  setting R-- permissions on ro-data block: "
 234                        << format("0x%016x", ObjAllocs.RemoteRODataAddr)
 235                        << "\n");
 236           Client.setProtections(Id, ObjAllocs.RemoteRODataAddr,
 237                                 sys::Memory::MF_READ);
 238         }
 239
 240         for (auto &Alloc : ObjAllocs.RWDataAllocs) {
 241           DEBUG(dbgs() << "  copying rw-data: "
 242                        << static_cast<void *>(Alloc.getLocalAddress()) << " -> "
 243                        << format("0x%016x", Alloc.getRemoteAddress()) << " ("
 244                        << Alloc.getSize() << " bytes)\n");
 245           Client.writeMem(Alloc.getRemoteAddress(), Alloc.getLocalAddress(),
 246                           Alloc.getSize());
 247         }
 248
 249         if (ObjAllocs.RemoteRWDataAddr) {
 250           DEBUG(dbgs() << "  setting RW- permissions on rw-data block: "
 251                        << format("0x%016x", ObjAllocs.RemoteRWDataAddr)
 252                        << "\n");
 253           Client.setProtections(Id, ObjAllocs.RemoteRWDataAddr,
 254                                 sys::Memory::MF_READ | sys::Memory::MF_WRITE);
 255         }
 256       }
 257       Unfinalized.clear();
 258
 259       return false;
 260     }
 261
 262   private:
 263     class Alloc {
 264     public:
 265       Alloc(uint64_t Size, unsigned Align)
 266           : Size(Size), Align(Align), Contents(new char[Size + Align - 1]),
 267             RemoteAddr(0) {}
 268
 269       Alloc(const Alloc&) = delete;
 270       Alloc& operator=(const Alloc&) = delete;
 271
 272       Alloc(Alloc &&Other)
 273           : Size(std::move(Other.Size)), Align(std::move(Other.Align)),
 274             Contents(std::move(Other.Contents)),
 275             RemoteAddr(std::move(Other.RemoteAddr)) {}
 276
 277       Alloc &operator=(Alloc &&Other) {
 278         Size = std::move(Other.Size);
 279         Align = std::move(Other.Align);
 280         Contents = std::move(Other.Contents);
 281         RemoteAddr = std::move(Other.RemoteAddr);
 282         return *this;
 283       }
 284
 285       uint64_t getSize() const { return Size; }
 286
 287       unsigned getAlign() const { return Align; }
 288
 289       char *getLocalAddress() const {
 290         uintptr_t LocalAddr = reinterpret_cast<uintptr_t>(Contents.get());
 291         LocalAddr = RoundUpToAlignment(LocalAddr, Align);
 292         return reinterpret_cast<char *>(LocalAddr);
 293       }
 294
 295       void setRemoteAddress(TargetAddress RemoteAddr) {
 296         this->RemoteAddr = RemoteAddr;
 297       }
 298
 299       TargetAddress getRemoteAddress() const { return RemoteAddr; }
 300
 301     private:
 302       uint64_t Size;
 303       unsigned Align;
 304       std::unique_ptr<char[]> Contents;
 305       TargetAddress RemoteAddr;
 306     };
 307
 308     struct ObjectAllocs {
 309       ObjectAllocs()
 310           : RemoteCodeAddr(0), RemoteRODataAddr(0), RemoteRWDataAddr(0) {}
 311       TargetAddress RemoteCodeAddr;
 312       TargetAddress RemoteRODataAddr;
 313       TargetAddress RemoteRWDataAddr;
 314       std::vector<Alloc> CodeAllocs, RODataAllocs, RWDataAllocs;
 315     };
 316
 317     OrcRemoteTargetClient &Client;
 318     ResourceIdMgr::ResourceId Id;
 319     std::vector<ObjectAllocs> Unmapped;
 320     std::vector<ObjectAllocs> Unfinalized;
 321   };
 322
 323   /// Remote indirect stubs manager.
 324   class RCIndirectStubsManager : public IndirectStubsManager {
 325   public:
 326     RCIndirectStubsManager(OrcRemoteTargetClient &Remote,
 327                            ResourceIdMgr::ResourceId Id)
 328         : Remote(Remote), Id(Id) {}
 329
 330     ~RCIndirectStubsManager() { Remote.destroyIndirectStubsManager(Id); }
 331
 332     std::error_code createStub(StringRef StubName, TargetAddress StubAddr,
 333                                JITSymbolFlags StubFlags) override {
 334       if (auto EC = reserveStubs(1))
 335         return EC;
 336
 337       return createStubInternal(StubName, StubAddr, StubFlags);
 338     }
 339
 340     std::error_code createStubs(const StubInitsMap &StubInits) override {
 341       if (auto EC = reserveStubs(StubInits.size()))
 342         return EC;
 343
 344       for (auto &Entry : StubInits)
 345         if (auto EC = createStubInternal(Entry.first(), Entry.second.first,
 346                                          Entry.second.second))
 347           return EC;
 348
 349       return std::error_code();
 350     }
 351
 352     JITSymbol findStub(StringRef Name, bool ExportedStubsOnly) override {
 353       auto I = StubIndexes.find(Name);
 354       if (I == StubIndexes.end())
 355         return nullptr;
 356       auto Key = I->second.first;
 357       auto Flags = I->second.second;
 358       auto StubSymbol = JITSymbol(getStubAddr(Key), Flags);
 359       if (ExportedStubsOnly && !StubSymbol.isExported())
 360         return nullptr;
 361       return StubSymbol;
 362     }
 363
 364     JITSymbol findPointer(StringRef Name) override {
 365       auto I = StubIndexes.find(Name);
 366       if (I == StubIndexes.end())
 367         return nullptr;
 368       auto Key = I->second.first;
 369       auto Flags = I->second.second;
 370       return JITSymbol(getPtrAddr(Key), Flags);
 371     }
 372
 373     std::error_code updatePointer(StringRef Name,
 374                                   TargetAddress NewAddr) override {
 375       auto I = StubIndexes.find(Name);
 376       assert(I != StubIndexes.end() && "No stub pointer for symbol");
 377       auto Key = I->second.first;
 378       return Remote.writePointer(getPtrAddr(Key), NewAddr);
 379     }
 380
 381   private:
 382     struct RemoteIndirectStubsInfo {
 383       RemoteIndirectStubsInfo(TargetAddress StubBase, TargetAddress PtrBase,
 384                               unsigned NumStubs)
 385           : StubBase(StubBase), PtrBase(PtrBase), NumStubs(NumStubs) {}
 386       TargetAddress StubBase;
 387       TargetAddress PtrBase;
 388       unsigned NumStubs;
 389     };
 390
 391     OrcRemoteTargetClient &Remote;
 392     ResourceIdMgr::ResourceId Id;
 393     std::vector<RemoteIndirectStubsInfo> RemoteIndirectStubsInfos;
 394     typedef std::pair<uint16_t, uint16_t> StubKey;
 395     std::vector<StubKey> FreeStubs;
 396     StringMap<std::pair<StubKey, JITSymbolFlags>> StubIndexes;
 397
 398     std::error_code reserveStubs(unsigned NumStubs) {
 399       if (NumStubs <= FreeStubs.size())
 400         return std::error_code();
 401
 402       unsigned NewStubsRequired = NumStubs - FreeStubs.size();
 403       TargetAddress StubBase;
 404       TargetAddress PtrBase;
 405       unsigned NumStubsEmitted;
 406
 407       Remote.emitIndirectStubs(StubBase, PtrBase, NumStubsEmitted, Id,
 408                                NewStubsRequired);
 409
 410       unsigned NewBlockId = RemoteIndirectStubsInfos.size();
 411       RemoteIndirectStubsInfos.push_back(
 412           RemoteIndirectStubsInfo(StubBase, PtrBase, NumStubsEmitted));
 413
 414       for (unsigned I = 0; I < NumStubsEmitted; ++I)
 415         FreeStubs.push_back(std::make_pair(NewBlockId, I));
 416
 417       return std::error_code();
 418     }
 419
 420     std::error_code createStubInternal(StringRef StubName,
 421                                        TargetAddress InitAddr,
 422                                        JITSymbolFlags StubFlags) {
 423       auto Key = FreeStubs.back();
 424       FreeStubs.pop_back();
 425       StubIndexes[StubName] = std::make_pair(Key, StubFlags);
 426       return Remote.writePointer(getPtrAddr(Key), InitAddr);
 427     }
 428
 429     TargetAddress getStubAddr(StubKey K) {
 430       assert(RemoteIndirectStubsInfos[K.first].StubBase != 0 &&
 431              "Missing stub address");
 432       return RemoteIndirectStubsInfos[K.first].StubBase +
 433              K.second * Remote.getIndirectStubSize();
 434     }
 435
 436     TargetAddress getPtrAddr(StubKey K) {
 437       assert(RemoteIndirectStubsInfos[K.first].PtrBase != 0 &&
 438              "Missing pointer address");
 439       return RemoteIndirectStubsInfos[K.first].PtrBase +
 440              K.second * Remote.getPointerSize();
 441     }
 442   };
 443
 444   /// Remote compile callback manager.
 445   class RCCompileCallbackManager : public JITCompileCallbackManager {
 446   public:
 447     RCCompileCallbackManager(TargetAddress ErrorHandlerAddress,
 448                              OrcRemoteTargetClient &Remote)
 449         : JITCompileCallbackManager(ErrorHandlerAddress), Remote(Remote) {
 450       assert(!Remote.CompileCallback && "Compile callback already set");
 451       Remote.CompileCallback = [this](TargetAddress TrampolineAddr) {
 452         return executeCompileCallback(TrampolineAddr);
 453       };
 454       Remote.emitResolverBlock();
 455     }
 456
 457   private:
 458     void grow() {
 459       TargetAddress BlockAddr = 0;
 460       uint32_t NumTrampolines = 0;
 461       auto EC = Remote.emitTrampolineBlock(BlockAddr, NumTrampolines);
 462       assert(!EC && "Failed to create trampolines");
 463
 464       uint32_t TrampolineSize = Remote.getTrampolineSize();
 465       for (unsigned I = 0; I < NumTrampolines; ++I)
 466         this->AvailableTrampolines.push_back(BlockAddr + (I * TrampolineSize));
 467     }
 468
 469     OrcRemoteTargetClient &Remote;
 470   };
 471
 472   /// Create an OrcRemoteTargetClient.
 473   /// Channel is the ChannelT instance to communicate on. It is assumed that
 474   /// the channel is ready to be read from and written to.
 475   static ErrorOr<OrcRemoteTargetClient> Create(ChannelT &Channel) {
 476     std::error_code EC;
 477     OrcRemoteTargetClient H(Channel, EC);
 478     if (EC)
 479       return EC;
 480     return H;
 481   }
 482
 483   /// Call the int(void) function at the given address in the target and return
 484   /// its result.
 485   std::error_code callIntVoid(int &Result, TargetAddress Addr) {
 486     DEBUG(dbgs() << "Calling int(*)(void) " << format("0x%016x", Addr) << "\n");
 487
 488     if (auto EC = call<CallIntVoid>(Channel, Addr))
 489       return EC;
 490
 491     unsigned NextProcId;
 492     if (auto EC = listenForCompileRequests(NextProcId))
 493       return EC;
 494
 495     if (NextProcId != CallIntVoidResponseId)
 496       return orcError(OrcErrorCode::UnexpectedRPCCall);
 497
 498     return handle<CallIntVoidResponse>(Channel, [&](int R) {
 499       Result = R;
 500       DEBUG(dbgs() << "Result: " << R << "\n");
 501       return std::error_code();
 502     });
 503   }
 504
 505   /// Call the int(int, char*[]) function at the given address in the target and
 506   /// return its result.
 507   std::error_code callMain(int &Result, TargetAddress Addr,
 508                            const std::vector<std::string> &Args) {
 509     DEBUG(dbgs() << "Calling int(*)(int, char*[]) " << format("0x%016x", Addr)
 510                  << "\n");
 511
 512     if (auto EC = call<CallMain>(Channel, Addr, Args))
 513       return EC;
 514
 515     unsigned NextProcId;
 516     if (auto EC = listenForCompileRequests(NextProcId))
 517       return EC;
 518
 519     if (NextProcId != CallMainResponseId)
 520       return orcError(OrcErrorCode::UnexpectedRPCCall);
 521
 522     return handle<CallMainResponse>(Channel, [&](int R) {
 523       Result = R;
 524       DEBUG(dbgs() << "Result: " << R << "\n");
 525       return std::error_code();
 526     });
 527   }
 528
 529   /// Call the void() function at the given address in the target and wait for
 530   /// it to finish.
 531   std::error_code callVoidVoid(TargetAddress Addr) {
 532     DEBUG(dbgs() << "Calling void(*)(void) " << format("0x%016x", Addr)
 533                  << "\n");
 534
 535     if (auto EC = call<CallVoidVoid>(Channel, Addr))
 536       return EC;
 537
 538     unsigned NextProcId;
 539     if (auto EC = listenForCompileRequests(NextProcId))
 540       return EC;
 541
 542     if (NextProcId != CallVoidVoidResponseId)
 543       return orcError(OrcErrorCode::UnexpectedRPCCall);
 544
 545     return handle<CallVoidVoidResponse>(Channel, doNothing);
 546   }
 547
 548   /// Create an RCMemoryManager which will allocate its memory on the remote
 549   /// target.
 550   std::error_code
 551   createRemoteMemoryManager(std::unique_ptr<RCMemoryManager> &MM) {
 552     assert(!MM && "MemoryManager should be null before creation.");
 553
 554     auto Id = AllocatorIds.getNext();
 555     if (auto EC = call<CreateRemoteAllocator>(Channel, Id))
 556       return EC;
 557     MM = llvm::make_unique<RCMemoryManager>(*this, Id);
 558     return std::error_code();
 559   }
 560
 561   /// Create an RCIndirectStubsManager that will allocate stubs on the remote
 562   /// target.
 563   std::error_code
 564   createIndirectStubsManager(std::unique_ptr<RCIndirectStubsManager> &I) {
 565     assert(!I && "Indirect stubs manager should be null before creation.");
 566     auto Id = IndirectStubOwnerIds.getNext();
 567     if (auto EC = call<CreateIndirectStubsOwner>(Channel, Id))
 568       return EC;
 569     I = llvm::make_unique<RCIndirectStubsManager>(*this, Id);
 570     return std::error_code();
 571   }
 572
 573   /// Search for symbols in the remote process. Note: This should be used by
 574   /// symbol resolvers *after* they've searched the local symbol table in the
 575   /// JIT stack.
 576   std::error_code getSymbolAddress(TargetAddress &Addr, StringRef Name) {
 577     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 578     if (ExistingError)
 579       return ExistingError;
 580
 581     // Request remote symbol address.
 582     if (auto EC = call<GetSymbolAddress>(Channel, Name))
 583       return EC;
 584
 585     return expect<GetSymbolAddressResponse>(Channel, [&](TargetAddress &A) {
 586       Addr = A;
 587       DEBUG(dbgs() << "Remote address lookup " << Name << " = "
 588                    << format("0x%016x", Addr) << "\n");
 589       return std::error_code();
 590     });
 591   }
 592
 593   /// Get the triple for the remote target.
 594   const std::string &getTargetTriple() const { return RemoteTargetTriple; }
 595
 596   std::error_code terminateSession() { return call<TerminateSession>(Channel); }
 597
 598 private:
 599   OrcRemoteTargetClient(ChannelT &Channel, std::error_code &EC)
 600       : Channel(Channel), RemotePointerSize(0), RemotePageSize(0),
 601         RemoteTrampolineSize(0), RemoteIndirectStubSize(0) {
 602     if ((EC = call<GetRemoteInfo>(Channel)))
 603       return;
 604
 605     EC = expect<GetRemoteInfoResponse>(
 606         Channel, readArgs(RemoteTargetTriple, RemotePointerSize, RemotePageSize,
 607                           RemoteTrampolineSize, RemoteIndirectStubSize));
 608   }
 609
 610   void destroyRemoteAllocator(ResourceIdMgr::ResourceId Id) {
 611     if (auto EC = call<DestroyRemoteAllocator>(Channel, Id)) {
 612       // FIXME: This will be triggered by a removeModuleSet call: Propagate
 613       //        error return up through that.
 614       llvm_unreachable("Failed to destroy remote allocator.");
 615       AllocatorIds.release(Id);
 616     }
 617   }
 618
 619   std::error_code destroyIndirectStubsManager(ResourceIdMgr::ResourceId Id) {
 620     IndirectStubOwnerIds.release(Id);
 621     return call<DestroyIndirectStubsOwner>(Channel, Id);
 622   }
 623
 624   std::error_code emitIndirectStubs(TargetAddress &StubBase,
 625                                     TargetAddress &PtrBase,
 626                                     uint32_t &NumStubsEmitted,
 627                                     ResourceIdMgr::ResourceId Id,
 628                                     uint32_t NumStubsRequired) {
 629     if (auto EC = call<EmitIndirectStubs>(Channel, Id, NumStubsRequired))
 630       return EC;
 631
 632     return expect<EmitIndirectStubsResponse>(
 633         Channel, readArgs(StubBase, PtrBase, NumStubsEmitted));
 634   }
 635
 636   std::error_code emitResolverBlock() {
 637     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 638     if (ExistingError)
 639       return ExistingError;
 640
 641     return call<EmitResolverBlock>(Channel);
 642   }
 643
 644   std::error_code emitTrampolineBlock(TargetAddress &BlockAddr,
 645                                       uint32_t &NumTrampolines) {
 646     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 647     if (ExistingError)
 648       return ExistingError;
 649
 650     if (auto EC = call<EmitTrampolineBlock>(Channel))
 651       return EC;
 652
 653     return expect<EmitTrampolineBlockResponse>(
 654         Channel, [&](TargetAddress BAddr, uint32_t NTrampolines) {
 655           BlockAddr = BAddr;
 656           NumTrampolines = NTrampolines;
 657           return std::error_code();
 658         });
 659   }
 660
 661   uint32_t getIndirectStubSize() const { return RemoteIndirectStubSize; }
 662   uint32_t getPageSize() const { return RemotePageSize; }
 663   uint32_t getPointerSize() const { return RemotePointerSize; }
 664
 665   uint32_t getTrampolineSize() const { return RemoteTrampolineSize; }
 666
 667   std::error_code listenForCompileRequests(uint32_t &NextId) {
 668     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 669     if (ExistingError)
 670       return ExistingError;
 671
 672     if (auto EC = getNextProcId(Channel, NextId))
 673       return EC;
 674
 675     while (NextId == RequestCompileId) {
 676       TargetAddress TrampolineAddr = 0;
 677       if (auto EC = handle<RequestCompile>(Channel, readArgs(TrampolineAddr)))
 678         return EC;
 679
 680       TargetAddress ImplAddr = CompileCallback(TrampolineAddr);
 681       if (auto EC = call<RequestCompileResponse>(Channel, ImplAddr))
 682         return EC;
 683
 684       if (auto EC = getNextProcId(Channel, NextId))
 685         return EC;
 686     }
 687
 688     return std::error_code();
 689   }
 690
 691   std::error_code readMem(char *Dst, TargetAddress Src, uint64_t Size) {
 692     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 693     if (ExistingError)
 694       return ExistingError;
 695
 696     if (auto EC = call<ReadMem>(Channel, Src, Size))
 697       return EC;
 698
 699     if (auto EC = expect<ReadMemResponse>(
 700             Channel, [&]() { return Channel.readBytes(Dst, Size); }))
 701       return EC;
 702
 703     return std::error_code();
 704   }
 705
 706   std::error_code reserveMem(TargetAddress &RemoteAddr,
 707                              ResourceIdMgr::ResourceId Id, uint64_t Size,
 708                              uint32_t Align) {
 709
 710     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 711     if (ExistingError)
 712       return ExistingError;
 713
 714     if (auto EC = call<ReserveMem>(Channel, Id, Size, Align))
 715       return EC;
 716
 717     if (std::error_code EC =
 718             expect<ReserveMemResponse>(Channel, [&](TargetAddress Addr) {
 719               RemoteAddr = Addr;
 720               return std::error_code();
 721             }))
 722       return EC;
 723
 724     return std::error_code();
 725   }
 726
 727   std::error_code setProtections(ResourceIdMgr::ResourceId Id,
 728                                  TargetAddress RemoteSegAddr,
 729                                  unsigned ProtFlags) {
 730     return call<SetProtections>(Channel, Id, RemoteSegAddr, ProtFlags);
 731   }
 732
 733   std::error_code writeMem(TargetAddress Addr, const char *Src, uint64_t Size) {
 734     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 735     if (ExistingError)
 736       return ExistingError;
 737
 738     // Make the send call.
 739     if (auto EC = call<WriteMem>(Channel, Addr, Size))
 740       return EC;
 741
 742     // Follow this up with the section contents.
 743     if (auto EC = Channel.appendBytes(Src, Size))
 744       return EC;
 745
 746     return Channel.send();
 747   }
 748
 749   std::error_code writePointer(TargetAddress Addr, TargetAddress PtrVal) {
 750     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 751     if (ExistingError)
 752       return ExistingError;
 753
 754     return call<WritePtr>(Channel, Addr, PtrVal);
 755   }
 756
 757   static std::error_code doNothing() { return std::error_code(); }
 758
 759   ChannelT &Channel;
 760   std::error_code ExistingError;
 761   std::string RemoteTargetTriple;
 762   uint32_t RemotePointerSize;
 763   uint32_t RemotePageSize;
 764   uint32_t RemoteTrampolineSize;
 765   uint32_t RemoteIndirectStubSize;
 766   ResourceIdMgr AllocatorIds, IndirectStubOwnerIds;
 767   std::function<TargetAddress(TargetAddress)> CompileCallback;
 768 };
 769
 770 } // end namespace remote
 771 } // end namespace orc
 772 } // end namespace llvm
 773
 774 #undef DEBUG_TYPE
 775
 776 #endif