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(Alloc &&Other)
 270           : Size(std::move(Other.Size)), Align(std::move(Other.Align)),
 271             Contents(std::move(Other.Contents)),
 272             RemoteAddr(std::move(Other.RemoteAddr)) {}
 273
 274       Alloc &operator=(Alloc &&Other) {
 275         Size = std::move(Other.Size);
 276         Align = std::move(Other.Align);
 277         Contents = std::move(Other.Contents);
 278         RemoteAddr = std::move(Other.RemoteAddr);
 279         return *this;
 280       }
 281
 282       uint64_t getSize() const { return Size; }
 283
 284       unsigned getAlign() const { return Align; }
 285
 286       char *getLocalAddress() const {
 287         uintptr_t LocalAddr = reinterpret_cast<uintptr_t>(Contents.get());
 288         LocalAddr = RoundUpToAlignment(LocalAddr, Align);
 289         return reinterpret_cast<char *>(LocalAddr);
 290       }
 291
 292       void setRemoteAddress(TargetAddress RemoteAddr) {
 293         this->RemoteAddr = RemoteAddr;
 294       }
 295
 296       TargetAddress getRemoteAddress() const { return RemoteAddr; }
 297
 298     private:
 299       uint64_t Size;
 300       unsigned Align;
 301       std::unique_ptr<char[]> Contents;
 302       TargetAddress RemoteAddr;
 303     };
 304
 305     struct ObjectAllocs {
 306       ObjectAllocs()
 307           : RemoteCodeAddr(0), RemoteRODataAddr(0), RemoteRWDataAddr(0) {}
 308       TargetAddress RemoteCodeAddr;
 309       TargetAddress RemoteRODataAddr;
 310       TargetAddress RemoteRWDataAddr;
 311       std::vector<Alloc> CodeAllocs, RODataAllocs, RWDataAllocs;
 312     };
 313
 314     OrcRemoteTargetClient &Client;
 315     ResourceIdMgr::ResourceId Id;
 316     std::vector<ObjectAllocs> Unmapped;
 317     std::vector<ObjectAllocs> Unfinalized;
 318   };
 319
 320   /// Remote indirect stubs manager.
 321   class RCIndirectStubsManager : public IndirectStubsManager {
 322   public:
 323     RCIndirectStubsManager(OrcRemoteTargetClient &Remote,
 324                            ResourceIdMgr::ResourceId Id)
 325         : Remote(Remote), Id(Id) {}
 326
 327     ~RCIndirectStubsManager() { Remote.destroyIndirectStubsManager(Id); }
 328
 329     std::error_code createStub(StringRef StubName, TargetAddress StubAddr,
 330                                JITSymbolFlags StubFlags) override {
 331       if (auto EC = reserveStubs(1))
 332         return EC;
 333
 334       return createStubInternal(StubName, StubAddr, StubFlags);
 335     }
 336
 337     std::error_code createStubs(const StubInitsMap &StubInits) override {
 338       if (auto EC = reserveStubs(StubInits.size()))
 339         return EC;
 340
 341       for (auto &Entry : StubInits)
 342         if (auto EC = createStubInternal(Entry.first(), Entry.second.first,
 343                                          Entry.second.second))
 344           return EC;
 345
 346       return std::error_code();
 347     }
 348
 349     JITSymbol findStub(StringRef Name, bool ExportedStubsOnly) override {
 350       auto I = StubIndexes.find(Name);
 351       if (I == StubIndexes.end())
 352         return nullptr;
 353       auto Key = I->second.first;
 354       auto Flags = I->second.second;
 355       auto StubSymbol = JITSymbol(getStubAddr(Key), Flags);
 356       if (ExportedStubsOnly && !StubSymbol.isExported())
 357         return nullptr;
 358       return StubSymbol;
 359     }
 360
 361     JITSymbol findPointer(StringRef Name) override {
 362       auto I = StubIndexes.find(Name);
 363       if (I == StubIndexes.end())
 364         return nullptr;
 365       auto Key = I->second.first;
 366       auto Flags = I->second.second;
 367       return JITSymbol(getPtrAddr(Key), Flags);
 368     }
 369
 370     std::error_code updatePointer(StringRef Name,
 371                                   TargetAddress NewAddr) override {
 372       auto I = StubIndexes.find(Name);
 373       assert(I != StubIndexes.end() && "No stub pointer for symbol");
 374       auto Key = I->second.first;
 375       return Remote.writePointer(getPtrAddr(Key), NewAddr);
 376     }
 377
 378   private:
 379     struct RemoteIndirectStubsInfo {
 380       RemoteIndirectStubsInfo(TargetAddress StubBase, TargetAddress PtrBase,
 381                               unsigned NumStubs)
 382           : StubBase(StubBase), PtrBase(PtrBase), NumStubs(NumStubs) {}
 383       TargetAddress StubBase;
 384       TargetAddress PtrBase;
 385       unsigned NumStubs;
 386     };
 387
 388     OrcRemoteTargetClient &Remote;
 389     ResourceIdMgr::ResourceId Id;
 390     std::vector<RemoteIndirectStubsInfo> RemoteIndirectStubsInfos;
 391     typedef std::pair<uint16_t, uint16_t> StubKey;
 392     std::vector<StubKey> FreeStubs;
 393     StringMap<std::pair<StubKey, JITSymbolFlags>> StubIndexes;
 394
 395     std::error_code reserveStubs(unsigned NumStubs) {
 396       if (NumStubs <= FreeStubs.size())
 397         return std::error_code();
 398
 399       unsigned NewStubsRequired = NumStubs - FreeStubs.size();
 400       TargetAddress StubBase;
 401       TargetAddress PtrBase;
 402       unsigned NumStubsEmitted;
 403
 404       Remote.emitIndirectStubs(StubBase, PtrBase, NumStubsEmitted, Id,
 405                                NewStubsRequired);
 406
 407       unsigned NewBlockId = RemoteIndirectStubsInfos.size();
 408       RemoteIndirectStubsInfos.push_back(
 409           RemoteIndirectStubsInfo(StubBase, PtrBase, NumStubsEmitted));
 410
 411       for (unsigned I = 0; I < NumStubsEmitted; ++I)
 412         FreeStubs.push_back(std::make_pair(NewBlockId, I));
 413
 414       return std::error_code();
 415     }
 416
 417     std::error_code createStubInternal(StringRef StubName,
 418                                        TargetAddress InitAddr,
 419                                        JITSymbolFlags StubFlags) {
 420       auto Key = FreeStubs.back();
 421       FreeStubs.pop_back();
 422       StubIndexes[StubName] = std::make_pair(Key, StubFlags);
 423       return Remote.writePointer(getPtrAddr(Key), InitAddr);
 424     }
 425
 426     TargetAddress getStubAddr(StubKey K) {
 427       assert(RemoteIndirectStubsInfos[K.first].StubBase != 0 &&
 428              "Missing stub address");
 429       return RemoteIndirectStubsInfos[K.first].StubBase +
 430              K.second * Remote.getIndirectStubSize();
 431     }
 432
 433     TargetAddress getPtrAddr(StubKey K) {
 434       assert(RemoteIndirectStubsInfos[K.first].PtrBase != 0 &&
 435              "Missing pointer address");
 436       return RemoteIndirectStubsInfos[K.first].PtrBase +
 437              K.second * Remote.getPointerSize();
 438     }
 439   };
 440
 441   /// Remote compile callback manager.
 442   class RCCompileCallbackManager : public JITCompileCallbackManager {
 443   public:
 444     RCCompileCallbackManager(TargetAddress ErrorHandlerAddress,
 445                              OrcRemoteTargetClient &Remote)
 446         : JITCompileCallbackManager(ErrorHandlerAddress), Remote(Remote) {
 447       assert(!Remote.CompileCallback && "Compile callback already set");
 448       Remote.CompileCallback = [this](TargetAddress TrampolineAddr) {
 449         return executeCompileCallback(TrampolineAddr);
 450       };
 451       Remote.emitResolverBlock();
 452     }
 453
 454   private:
 455     void grow() {
 456       TargetAddress BlockAddr = 0;
 457       uint32_t NumTrampolines = 0;
 458       auto EC = Remote.emitTrampolineBlock(BlockAddr, NumTrampolines);
 459       assert(!EC && "Failed to create trampolines");
 460
 461       uint32_t TrampolineSize = Remote.getTrampolineSize();
 462       for (unsigned I = 0; I < NumTrampolines; ++I)
 463         this->AvailableTrampolines.push_back(BlockAddr + (I * TrampolineSize));
 464     }
 465
 466     OrcRemoteTargetClient &Remote;
 467   };
 468
 469   /// Create an OrcRemoteTargetClient.
 470   /// Channel is the ChannelT instance to communicate on. It is assumed that
 471   /// the channel is ready to be read from and written to.
 472   static ErrorOr<OrcRemoteTargetClient> Create(ChannelT &Channel) {
 473     std::error_code EC;
 474     OrcRemoteTargetClient H(Channel, EC);
 475     if (EC)
 476       return EC;
 477     return H;
 478   }
 479
 480   /// Call the int(void) function at the given address in the target and return
 481   /// its result.
 482   std::error_code callIntVoid(int &Result, TargetAddress Addr) {
 483     DEBUG(dbgs() << "Calling int(*)(void) " << format("0x%016x", Addr) << "\n");
 484
 485     if (auto EC = call<CallIntVoid>(Channel, Addr))
 486       return EC;
 487
 488     unsigned NextProcId;
 489     if (auto EC = listenForCompileRequests(NextProcId))
 490       return EC;
 491
 492     if (NextProcId != CallIntVoidResponseId)
 493       return orcError(OrcErrorCode::UnexpectedRPCCall);
 494
 495     return handle<CallIntVoidResponse>(Channel, [&](int R) {
 496       Result = R;
 497       DEBUG(dbgs() << "Result: " << R << "\n");
 498       return std::error_code();
 499     });
 500   }
 501
 502   /// Call the int(int, char*[]) function at the given address in the target and
 503   /// return its result.
 504   std::error_code callMain(int &Result, TargetAddress Addr,
 505                            const std::vector<std::string> &Args) {
 506     DEBUG(dbgs() << "Calling int(*)(int, char*[]) " << format("0x%016x", Addr)
 507                  << "\n");
 508
 509     if (auto EC = call<CallMain>(Channel, Addr, Args))
 510       return EC;
 511
 512     unsigned NextProcId;
 513     if (auto EC = listenForCompileRequests(NextProcId))
 514       return EC;
 515
 516     if (NextProcId != CallMainResponseId)
 517       return orcError(OrcErrorCode::UnexpectedRPCCall);
 518
 519     return handle<CallMainResponse>(Channel, [&](int R) {
 520       Result = R;
 521       DEBUG(dbgs() << "Result: " << R << "\n");
 522       return std::error_code();
 523     });
 524   }
 525
 526   /// Call the void() function at the given address in the target and wait for
 527   /// it to finish.
 528   std::error_code callVoidVoid(TargetAddress Addr) {
 529     DEBUG(dbgs() << "Calling void(*)(void) " << format("0x%016x", Addr)
 530                  << "\n");
 531
 532     if (auto EC = call<CallVoidVoid>(Channel, Addr))
 533       return EC;
 534
 535     unsigned NextProcId;
 536     if (auto EC = listenForCompileRequests(NextProcId))
 537       return EC;
 538
 539     if (NextProcId != CallVoidVoidResponseId)
 540       return orcError(OrcErrorCode::UnexpectedRPCCall);
 541
 542     return handle<CallVoidVoidResponse>(Channel, doNothing);
 543   }
 544
 545   /// Create an RCMemoryManager which will allocate its memory on the remote
 546   /// target.
 547   std::error_code
 548   createRemoteMemoryManager(std::unique_ptr<RCMemoryManager> &MM) {
 549     assert(!MM && "MemoryManager should be null before creation.");
 550
 551     auto Id = AllocatorIds.getNext();
 552     if (auto EC = call<CreateRemoteAllocator>(Channel, Id))
 553       return EC;
 554     MM = llvm::make_unique<RCMemoryManager>(*this, Id);
 555     return std::error_code();
 556   }
 557
 558   /// Create an RCIndirectStubsManager that will allocate stubs on the remote
 559   /// target.
 560   std::error_code
 561   createIndirectStubsManager(std::unique_ptr<RCIndirectStubsManager> &I) {
 562     assert(!I && "Indirect stubs manager should be null before creation.");
 563     auto Id = IndirectStubOwnerIds.getNext();
 564     if (auto EC = call<CreateIndirectStubsOwner>(Channel, Id))
 565       return EC;
 566     I = llvm::make_unique<RCIndirectStubsManager>(*this, Id);
 567     return std::error_code();
 568   }
 569
 570   /// Search for symbols in the remote process. Note: This should be used by
 571   /// symbol resolvers *after* they've searched the local symbol table in the
 572   /// JIT stack.
 573   std::error_code getSymbolAddress(TargetAddress &Addr, StringRef Name) {
 574     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 575     if (ExistingError)
 576       return ExistingError;
 577
 578     // Request remote symbol address.
 579     if (auto EC = call<GetSymbolAddress>(Channel, Name))
 580       return EC;
 581
 582     return expect<GetSymbolAddressResponse>(Channel, [&](TargetAddress &A) {
 583       Addr = A;
 584       DEBUG(dbgs() << "Remote address lookup " << Name << " = "
 585                    << format("0x%016x", Addr) << "\n");
 586       return std::error_code();
 587     });
 588   }
 589
 590   /// Get the triple for the remote target.
 591   const std::string &getTargetTriple() const { return RemoteTargetTriple; }
 592
 593   std::error_code terminateSession() { return call<TerminateSession>(Channel); }
 594
 595 private:
 596   OrcRemoteTargetClient(ChannelT &Channel, std::error_code &EC)
 597       : Channel(Channel), RemotePointerSize(0), RemotePageSize(0),
 598         RemoteTrampolineSize(0), RemoteIndirectStubSize(0) {
 599     if ((EC = call<GetRemoteInfo>(Channel)))
 600       return;
 601
 602     EC = expect<GetRemoteInfoResponse>(
 603         Channel, readArgs(RemoteTargetTriple, RemotePointerSize, RemotePageSize,
 604                           RemoteTrampolineSize, RemoteIndirectStubSize));
 605   }
 606
 607   void destroyRemoteAllocator(ResourceIdMgr::ResourceId Id) {
 608     if (auto EC = call<DestroyRemoteAllocator>(Channel, Id)) {
 609       // FIXME: This will be triggered by a removeModuleSet call: Propagate
 610       //        error return up through that.
 611       llvm_unreachable("Failed to destroy remote allocator.");
 612       AllocatorIds.release(Id);
 613     }
 614   }
 615
 616   std::error_code destroyIndirectStubsManager(ResourceIdMgr::ResourceId Id) {
 617     IndirectStubOwnerIds.release(Id);
 618     return call<DestroyIndirectStubsOwner>(Channel, Id);
 619   }
 620
 621   std::error_code emitIndirectStubs(TargetAddress &StubBase,
 622                                     TargetAddress &PtrBase,
 623                                     uint32_t &NumStubsEmitted,
 624                                     ResourceIdMgr::ResourceId Id,
 625                                     uint32_t NumStubsRequired) {
 626     if (auto EC = call<EmitIndirectStubs>(Channel, Id, NumStubsRequired))
 627       return EC;
 628
 629     return expect<EmitIndirectStubsResponse>(
 630         Channel, readArgs(StubBase, PtrBase, NumStubsEmitted));
 631   }
 632
 633   std::error_code emitResolverBlock() {
 634     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 635     if (ExistingError)
 636       return ExistingError;
 637
 638     return call<EmitResolverBlock>(Channel);
 639   }
 640
 641   std::error_code emitTrampolineBlock(TargetAddress &BlockAddr,
 642                                       uint32_t &NumTrampolines) {
 643     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 644     if (ExistingError)
 645       return ExistingError;
 646
 647     if (auto EC = call<EmitTrampolineBlock>(Channel))
 648       return EC;
 649
 650     return expect<EmitTrampolineBlockResponse>(
 651         Channel, [&](TargetAddress BAddr, uint32_t NTrampolines) {
 652           BlockAddr = BAddr;
 653           NumTrampolines = NTrampolines;
 654           return std::error_code();
 655         });
 656   }
 657
 658   uint32_t getIndirectStubSize() const { return RemoteIndirectStubSize; }
 659   uint32_t getPageSize() const { return RemotePageSize; }
 660   uint32_t getPointerSize() const { return RemotePointerSize; }
 661
 662   uint32_t getTrampolineSize() const { return RemoteTrampolineSize; }
 663
 664   std::error_code listenForCompileRequests(uint32_t &NextId) {
 665     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 666     if (ExistingError)
 667       return ExistingError;
 668
 669     if (auto EC = getNextProcId(Channel, NextId))
 670       return EC;
 671
 672     while (NextId == RequestCompileId) {
 673       TargetAddress TrampolineAddr = 0;
 674       if (auto EC = handle<RequestCompile>(Channel, readArgs(TrampolineAddr)))
 675         return EC;
 676
 677       TargetAddress ImplAddr = CompileCallback(TrampolineAddr);
 678       if (auto EC = call<RequestCompileResponse>(Channel, ImplAddr))
 679         return EC;
 680
 681       if (auto EC = getNextProcId(Channel, NextId))
 682         return EC;
 683     }
 684
 685     return std::error_code();
 686   }
 687
 688   std::error_code readMem(char *Dst, TargetAddress Src, uint64_t Size) {
 689     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 690     if (ExistingError)
 691       return ExistingError;
 692
 693     if (auto EC = call<ReadMem>(Channel, Src, Size))
 694       return EC;
 695
 696     if (auto EC = expect<ReadMemResponse>(
 697             Channel, [&]() { return Channel.readBytes(Dst, Size); }))
 698       return EC;
 699
 700     return std::error_code();
 701   }
 702
 703   std::error_code reserveMem(TargetAddress &RemoteAddr,
 704                              ResourceIdMgr::ResourceId Id, uint64_t Size,
 705                              uint32_t Align) {
 706
 707     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 708     if (ExistingError)
 709       return ExistingError;
 710
 711     if (auto EC = call<ReserveMem>(Channel, Id, Size, Align))
 712       return EC;
 713
 714     if (std::error_code EC =
 715             expect<ReserveMemResponse>(Channel, [&](TargetAddress Addr) {
 716               RemoteAddr = Addr;
 717               return std::error_code();
 718             }))
 719       return EC;
 720
 721     return std::error_code();
 722   }
 723
 724   std::error_code setProtections(ResourceIdMgr::ResourceId Id,
 725                                  TargetAddress RemoteSegAddr,
 726                                  unsigned ProtFlags) {
 727     return call<SetProtections>(Channel, Id, RemoteSegAddr, ProtFlags);
 728   }
 729
 730   std::error_code writeMem(TargetAddress Addr, const char *Src, uint64_t Size) {
 731     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 732     if (ExistingError)
 733       return ExistingError;
 734
 735     // Make the send call.
 736     if (auto EC = call<WriteMem>(Channel, Addr, Size))
 737       return EC;
 738
 739     // Follow this up with the section contents.
 740     if (auto EC = Channel.appendBytes(Src, Size))
 741       return EC;
 742
 743     return Channel.send();
 744   }
 745
 746   std::error_code writePointer(TargetAddress Addr, TargetAddress PtrVal) {
 747     // Check for an 'out-of-band' error, e.g. from an MM destructor.
 748     if (ExistingError)
 749       return ExistingError;
 750
 751     return call<WritePtr>(Channel, Addr, PtrVal);
 752   }
 753
 754   static std::error_code doNothing() { return std::error_code(); }
 755
 756   ChannelT &Channel;
 757   std::error_code ExistingError;
 758   std::string RemoteTargetTriple;
 759   uint32_t RemotePointerSize;
 760   uint32_t RemotePageSize;
 761   uint32_t RemoteTrampolineSize;
 762   uint32_t RemoteIndirectStubSize;
 763   ResourceIdMgr AllocatorIds, IndirectStubOwnerIds;
 764   std::function<TargetAddress(TargetAddress)> CompileCallback;
 765 };
 766
 767 } // end namespace remote
 768 } // end namespace orc
 769 } // end namespace llvm
 770
 771 #undef DEBUG_TYPE
 772
 773 #endif