tools/llvm-rtdyld/llvm-rtdyld.cpp

   1 //===-- llvm-rtdyld.cpp - MCJIT Testing Tool ------------------------------===//
   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 // This is a testing tool for use with the MC-JIT LLVM components.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ADT/StringMap.h"
  14 #include "llvm/DebugInfo/DIContext.h"
  15 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
  16 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
  17 #include "llvm/ExecutionEngine/RuntimeDyld.h"
  18 #include "llvm/ExecutionEngine/RuntimeDyldChecker.h"
  19 #include "llvm/MC/MCAsmInfo.h"
  20 #include "llvm/MC/MCContext.h"
  21 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
  22 #include "llvm/MC/MCInstPrinter.h"
  23 #include "llvm/MC/MCInstrInfo.h"
  24 #include "llvm/MC/MCRegisterInfo.h"
  25 #include "llvm/MC/MCSubtargetInfo.h"
  26 #include "llvm/Object/SymbolSize.h"
  27 #include "llvm/Support/CommandLine.h"
  28 #include "llvm/Support/DynamicLibrary.h"
  29 #include "llvm/Support/InitLLVM.h"
  30 #include "llvm/Support/Memory.h"
  31 #include "llvm/Support/MemoryBuffer.h"
  32 #include "llvm/Support/TargetRegistry.h"
  33 #include "llvm/Support/TargetSelect.h"
  34 #include "llvm/Support/raw_ostream.h"
  35 #include <list>
  36
  37 using namespace llvm;
  38 using namespace llvm::object;
  39
  40 static cl::list<std::string>
  41 InputFileList(cl::Positional, cl::ZeroOrMore,
  42               cl::desc("<input files>"));
  43
  44 enum ActionType {
  45   AC_Execute,
  46   AC_PrintObjectLineInfo,
  47   AC_PrintLineInfo,
  48   AC_PrintDebugLineInfo,
  49   AC_Verify
  50 };
  51
  52 static cl::opt<ActionType>
  53 Action(cl::desc("Action to perform:"),
  54        cl::init(AC_Execute),
  55        cl::values(clEnumValN(AC_Execute, "execute",
  56                              "Load, link, and execute the inputs."),
  57                   clEnumValN(AC_PrintLineInfo, "printline",
  58                              "Load, link, and print line information for each function."),
  59                   clEnumValN(AC_PrintDebugLineInfo, "printdebugline",
  60                              "Load, link, and print line information for each function using the debug object"),
  61                   clEnumValN(AC_PrintObjectLineInfo, "printobjline",
  62                              "Like -printlineinfo but does not load the object first"),
  63                   clEnumValN(AC_Verify, "verify",
  64                              "Load, link and verify the resulting memory image.")));
  65
  66 static cl::opt<std::string>
  67 EntryPoint("entry",
  68            cl::desc("Function to call as entry point."),
  69            cl::init("_main"));
  70
  71 static cl::list<std::string>
  72 Dylibs("dylib",
  73        cl::desc("Add library."),
  74        cl::ZeroOrMore);
  75
  76 static cl::opt<std::string>
  77 TripleName("triple", cl::desc("Target triple for disassembler"));
  78
  79 static cl::opt<std::string>
  80 MCPU("mcpu",
  81      cl::desc("Target a specific cpu type (-mcpu=help for details)"),
  82      cl::value_desc("cpu-name"),
  83      cl::init(""));
  84
  85 static cl::list<std::string>
  86 CheckFiles("check",
  87            cl::desc("File containing RuntimeDyld verifier checks."),
  88            cl::ZeroOrMore);
  89
  90 // Tracking BUG: 19665
  91 // http://llvm.org/bugs/show_bug.cgi?id=19665
  92 //
  93 // Do not change these options to cl::opt<uint64_t> since this silently breaks
  94 // argument parsing.
  95 static cl::opt<unsigned long long>
  96 PreallocMemory("preallocate",
  97               cl::desc("Allocate memory upfront rather than on-demand"),
  98               cl::init(0));
  99
 100 static cl::opt<unsigned long long>
 101 TargetAddrStart("target-addr-start",
 102                 cl::desc("For -verify only: start of phony target address "
 103                          "range."),
 104                 cl::init(4096), // Start at "page 1" - no allocating at "null".
 105                 cl::Hidden);
 106
 107 static cl::opt<unsigned long long>
 108 TargetAddrEnd("target-addr-end",
 109               cl::desc("For -verify only: end of phony target address range."),
 110               cl::init(~0ULL),
 111               cl::Hidden);
 112
 113 static cl::opt<unsigned long long>
 114 TargetSectionSep("target-section-sep",
 115                  cl::desc("For -verify only: Separation between sections in "
 116                           "phony target address space."),
 117                  cl::init(0),
 118                  cl::Hidden);
 119
 120 static cl::list<std::string>
 121 SpecificSectionMappings("map-section",
 122                         cl::desc("For -verify only: Map a section to a "
 123                                  "specific address."),
 124                         cl::ZeroOrMore,
 125                         cl::Hidden);
 126
 127 static cl::list<std::string>
 128 DummySymbolMappings("dummy-extern",
 129                     cl::desc("For -verify only: Inject a symbol into the extern "
 130                              "symbol table."),
 131                     cl::ZeroOrMore,
 132                     cl::Hidden);
 133
 134 static cl::opt<bool>
 135 PrintAllocationRequests("print-alloc-requests",
 136                         cl::desc("Print allocation requests made to the memory "
 137                                  "manager by RuntimeDyld"),
 138                         cl::Hidden);
 139
 140 /* *** */
 141
 142 // A trivial memory manager that doesn't do anything fancy, just uses the
 143 // support library allocation routines directly.
 144 class TrivialMemoryManager : public RTDyldMemoryManager {
 145 public:
 146   SmallVector<sys::MemoryBlock, 16> FunctionMemory;
 147   SmallVector<sys::MemoryBlock, 16> DataMemory;
 148
 149   uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
 150                                unsigned SectionID,
 151                                StringRef SectionName) override;
 152   uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
 153                                unsigned SectionID, StringRef SectionName,
 154                                bool IsReadOnly) override;
 155
 156   void *getPointerToNamedFunction(const std::string &Name,
 157                                   bool AbortOnFailure = true) override {
 158     return nullptr;
 159   }
 160
 161   bool finalizeMemory(std::string *ErrMsg) override { return false; }
 162
 163   void addDummySymbol(const std::string &Name, uint64_t Addr) {
 164     DummyExterns[Name] = Addr;
 165   }
 166
 167   JITSymbol findSymbol(const std::string &Name) override {
 168     auto I = DummyExterns.find(Name);
 169
 170     if (I != DummyExterns.end())
 171       return JITSymbol(I->second, JITSymbolFlags::Exported);
 172
 173     return RTDyldMemoryManager::findSymbol(Name);
 174   }
 175
 176   void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr,
 177                         size_t Size) override {}
 178   void deregisterEHFrames() override {}
 179
 180   void preallocateSlab(uint64_t Size) {
 181     std::error_code EC;
 182     sys::MemoryBlock MB =
 183       sys::Memory::allocateMappedMemory(Size, nullptr,
 184                                         sys::Memory::MF_READ |
 185                                         sys::Memory::MF_WRITE,
 186                                         EC);
 187     if (!MB.base())
 188       report_fatal_error("Can't allocate enough memory: " + EC.message());
 189
 190     PreallocSlab = MB;
 191     UsePreallocation = true;
 192     SlabSize = Size;
 193   }
 194
 195   uint8_t *allocateFromSlab(uintptr_t Size, unsigned Alignment, bool isCode) {
 196     Size = alignTo(Size, Alignment);
 197     if (CurrentSlabOffset + Size > SlabSize)
 198       report_fatal_error("Can't allocate enough memory. Tune --preallocate");
 199
 200     uintptr_t OldSlabOffset = CurrentSlabOffset;
 201     sys::MemoryBlock MB((void *)OldSlabOffset, Size);
 202     if (isCode)
 203       FunctionMemory.push_back(MB);
 204     else
 205       DataMemory.push_back(MB);
 206     CurrentSlabOffset += Size;
 207     return (uint8_t*)OldSlabOffset;
 208   }
 209
 210 private:
 211   std::map<std::string, uint64_t> DummyExterns;
 212   sys::MemoryBlock PreallocSlab;
 213   bool UsePreallocation = false;
 214   uintptr_t SlabSize = 0;
 215   uintptr_t CurrentSlabOffset = 0;
 216 };
 217
 218 uint8_t *TrivialMemoryManager::allocateCodeSection(uintptr_t Size,
 219                                                    unsigned Alignment,
 220                                                    unsigned SectionID,
 221                                                    StringRef SectionName) {
 222   if (PrintAllocationRequests)
 223     outs() << "allocateCodeSection(Size = " << Size << ", Alignment = "
 224            << Alignment << ", SectionName = " << SectionName << ")\n";
 225
 226   if (UsePreallocation)
 227     return allocateFromSlab(Size, Alignment, true /* isCode */);
 228
 229   std::error_code EC;
 230   sys::MemoryBlock MB =
 231     sys::Memory::allocateMappedMemory(Size, nullptr,
 232                                       sys::Memory::MF_READ |
 233                                       sys::Memory::MF_WRITE,
 234                                       EC);
 235   if (!MB.base())
 236     report_fatal_error("MemoryManager allocation failed: " + EC.message());
 237   FunctionMemory.push_back(MB);
 238   return (uint8_t*)MB.base();
 239 }
 240
 241 uint8_t *TrivialMemoryManager::allocateDataSection(uintptr_t Size,
 242                                                    unsigned Alignment,
 243                                                    unsigned SectionID,
 244                                                    StringRef SectionName,
 245                                                    bool IsReadOnly) {
 246   if (PrintAllocationRequests)
 247     outs() << "allocateDataSection(Size = " << Size << ", Alignment = "
 248            << Alignment << ", SectionName = " << SectionName << ")\n";
 249
 250   if (UsePreallocation)
 251     return allocateFromSlab(Size, Alignment, false /* isCode */);
 252
 253   std::error_code EC;
 254   sys::MemoryBlock MB =
 255     sys::Memory::allocateMappedMemory(Size, nullptr,
 256                                       sys::Memory::MF_READ |
 257                                       sys::Memory::MF_WRITE,
 258                                       EC);
 259   if (!MB.base())
 260     report_fatal_error("MemoryManager allocation failed: " + EC.message());
 261   DataMemory.push_back(MB);
 262   return (uint8_t*)MB.base();
 263 }
 264
 265 static const char *ProgramName;
 266
 267 static void ErrorAndExit(const Twine &Msg) {
 268   errs() << ProgramName << ": error: " << Msg << "\n";
 269   exit(1);
 270 }
 271
 272 static void loadDylibs() {
 273   for (const std::string &Dylib : Dylibs) {
 274     if (!sys::fs::is_regular_file(Dylib))
 275       report_fatal_error("Dylib not found: '" + Dylib + "'.");
 276     std::string ErrMsg;
 277     if (sys::DynamicLibrary::LoadLibraryPermanently(Dylib.c_str(), &ErrMsg))
 278       report_fatal_error("Error loading '" + Dylib + "': " + ErrMsg);
 279   }
 280 }
 281
 282 /* *** */
 283
 284 static int printLineInfoForInput(bool LoadObjects, bool UseDebugObj) {
 285   assert(LoadObjects || !UseDebugObj);
 286
 287   // Load any dylibs requested on the command line.
 288   loadDylibs();
 289
 290   // If we don't have any input files, read from stdin.
 291   if (!InputFileList.size())
 292     InputFileList.push_back("-");
 293   for (auto &File : InputFileList) {
 294     // Instantiate a dynamic linker.
 295     TrivialMemoryManager MemMgr;
 296     RuntimeDyld Dyld(MemMgr, MemMgr);
 297
 298     // Load the input memory buffer.
 299
 300     ErrorOr<std::unique_ptr<MemoryBuffer>> InputBuffer =
 301         MemoryBuffer::getFileOrSTDIN(File);
 302     if (std::error_code EC = InputBuffer.getError())
 303       ErrorAndExit("unable to read input: '" + EC.message() + "'");
 304
 305     Expected<std::unique_ptr<ObjectFile>> MaybeObj(
 306       ObjectFile::createObjectFile((*InputBuffer)->getMemBufferRef()));
 307
 308     if (!MaybeObj) {
 309       std::string Buf;
 310       raw_string_ostream OS(Buf);
 311       logAllUnhandledErrors(MaybeObj.takeError(), OS);
 312       OS.flush();
 313       ErrorAndExit("unable to create object file: '" + Buf + "'");
 314     }
 315
 316     ObjectFile &Obj = **MaybeObj;
 317
 318     OwningBinary<ObjectFile> DebugObj;
 319     std::unique_ptr<RuntimeDyld::LoadedObjectInfo> LoadedObjInfo = nullptr;
 320     ObjectFile *SymbolObj = &Obj;
 321     if (LoadObjects) {
 322       // Load the object file
 323       LoadedObjInfo =
 324         Dyld.loadObject(Obj);
 325
 326       if (Dyld.hasError())
 327         ErrorAndExit(Dyld.getErrorString());
 328
 329       // Resolve all the relocations we can.
 330       Dyld.resolveRelocations();
 331
 332       if (UseDebugObj) {
 333         DebugObj = LoadedObjInfo->getObjectForDebug(Obj);
 334         SymbolObj = DebugObj.getBinary();
 335         LoadedObjInfo.reset();
 336       }
 337     }
 338
 339     std::unique_ptr<DIContext> Context =
 340         DWARFContext::create(*SymbolObj, LoadedObjInfo.get());
 341
 342     std::vector<std::pair<SymbolRef, uint64_t>> SymAddr =
 343         object::computeSymbolSizes(*SymbolObj);
 344
 345     // Use symbol info to iterate functions in the object.
 346     for (const auto &P : SymAddr) {
 347       object::SymbolRef Sym = P.first;
 348       Expected<SymbolRef::Type> TypeOrErr = Sym.getType();
 349       if (!TypeOrErr) {
 350         // TODO: Actually report errors helpfully.
 351         consumeError(TypeOrErr.takeError());
 352         continue;
 353       }
 354       SymbolRef::Type Type = *TypeOrErr;
 355       if (Type == object::SymbolRef::ST_Function) {
 356         Expected<StringRef> Name = Sym.getName();
 357         if (!Name) {
 358           // TODO: Actually report errors helpfully.
 359           consumeError(Name.takeError());
 360           continue;
 361         }
 362         Expected<uint64_t> AddrOrErr = Sym.getAddress();
 363         if (!AddrOrErr) {
 364           // TODO: Actually report errors helpfully.
 365           consumeError(AddrOrErr.takeError());
 366           continue;
 367         }
 368         uint64_t Addr = *AddrOrErr;
 369
 370         uint64_t Size = P.second;
 371         // If we're not using the debug object, compute the address of the
 372         // symbol in memory (rather than that in the unrelocated object file)
 373         // and use that to query the DWARFContext.
 374         if (!UseDebugObj && LoadObjects) {
 375           auto SecOrErr = Sym.getSection();
 376           if (!SecOrErr) {
 377             // TODO: Actually report errors helpfully.
 378             consumeError(SecOrErr.takeError());
 379             continue;
 380           }
 381           object::section_iterator Sec = *SecOrErr;
 382           StringRef SecName;
 383           Sec->getName(SecName);
 384           uint64_t SectionLoadAddress =
 385             LoadedObjInfo->getSectionLoadAddress(*Sec);
 386           if (SectionLoadAddress != 0)
 387             Addr += SectionLoadAddress - Sec->getAddress();
 388         }
 389
 390         outs() << "Function: " << *Name << ", Size = " << Size
 391                << ", Addr = " << Addr << "\n";
 392
 393         DILineInfoTable Lines = Context->getLineInfoForAddressRange(Addr, Size);
 394         for (auto &D : Lines) {
 395           outs() << "  Line info @ " << D.first - Addr << ": "
 396                  << D.second.FileName << ", line:" << D.second.Line << "\n";
 397         }
 398       }
 399     }
 400   }
 401
 402   return 0;
 403 }
 404
 405 static void doPreallocation(TrivialMemoryManager &MemMgr) {
 406   // Allocate a slab of memory upfront, if required. This is used if
 407   // we want to test small code models.
 408   if (static_cast<intptr_t>(PreallocMemory) < 0)
 409     report_fatal_error("Pre-allocated bytes of memory must be a positive integer.");
 410
 411   // FIXME: Limit the amount of memory that can be preallocated?
 412   if (PreallocMemory != 0)
 413     MemMgr.preallocateSlab(PreallocMemory);
 414 }
 415
 416 static int executeInput() {
 417   // Load any dylibs requested on the command line.
 418   loadDylibs();
 419
 420   // Instantiate a dynamic linker.
 421   TrivialMemoryManager MemMgr;
 422   doPreallocation(MemMgr);
 423   RuntimeDyld Dyld(MemMgr, MemMgr);
 424
 425   // If we don't have any input files, read from stdin.
 426   if (!InputFileList.size())
 427     InputFileList.push_back("-");
 428   for (auto &File : InputFileList) {
 429     // Load the input memory buffer.
 430     ErrorOr<std::unique_ptr<MemoryBuffer>> InputBuffer =
 431         MemoryBuffer::getFileOrSTDIN(File);
 432     if (std::error_code EC = InputBuffer.getError())
 433       ErrorAndExit("unable to read input: '" + EC.message() + "'");
 434     Expected<std::unique_ptr<ObjectFile>> MaybeObj(
 435       ObjectFile::createObjectFile((*InputBuffer)->getMemBufferRef()));
 436
 437     if (!MaybeObj) {
 438       std::string Buf;
 439       raw_string_ostream OS(Buf);
 440       logAllUnhandledErrors(MaybeObj.takeError(), OS);
 441       OS.flush();
 442       ErrorAndExit("unable to create object file: '" + Buf + "'");
 443     }
 444
 445     ObjectFile &Obj = **MaybeObj;
 446
 447     // Load the object file
 448     Dyld.loadObject(Obj);
 449     if (Dyld.hasError()) {
 450       ErrorAndExit(Dyld.getErrorString());
 451     }
 452   }
 453
 454   // Resove all the relocations we can.
 455   // FIXME: Error out if there are unresolved relocations.
 456   Dyld.resolveRelocations();
 457
 458   // Get the address of the entry point (_main by default).
 459   void *MainAddress = Dyld.getSymbolLocalAddress(EntryPoint);
 460   if (!MainAddress)
 461     ErrorAndExit("no definition for '" + EntryPoint + "'");
 462
 463   // Invalidate the instruction cache for each loaded function.
 464   for (auto &FM : MemMgr.FunctionMemory) {
 465
 466     // Make sure the memory is executable.
 467     // setExecutable will call InvalidateInstructionCache.
 468     if (auto EC = sys::Memory::protectMappedMemory(FM,
 469                                                    sys::Memory::MF_READ |
 470                                                    sys::Memory::MF_EXEC))
 471       ErrorAndExit("unable to mark function executable: '" + EC.message() +
 472                    "'");
 473   }
 474
 475   // Dispatch to _main().
 476   errs() << "loaded '" << EntryPoint << "' at: " << (void*)MainAddress << "\n";
 477
 478   int (*Main)(int, const char**) =
 479     (int(*)(int,const char**)) uintptr_t(MainAddress);
 480   const char **Argv = new const char*[2];
 481   // Use the name of the first input object module as argv[0] for the target.
 482   Argv[0] = InputFileList[0].c_str();
 483   Argv[1] = nullptr;
 484   return Main(1, Argv);
 485 }
 486
 487 static int checkAllExpressions(RuntimeDyldChecker &Checker) {
 488   for (const auto& CheckerFileName : CheckFiles) {
 489     ErrorOr<std::unique_ptr<MemoryBuffer>> CheckerFileBuf =
 490         MemoryBuffer::getFileOrSTDIN(CheckerFileName);
 491     if (std::error_code EC = CheckerFileBuf.getError())
 492       ErrorAndExit("unable to read input '" + CheckerFileName + "': " +
 493                    EC.message());
 494
 495     if (!Checker.checkAllRulesInBuffer("# rtdyld-check:",
 496                                        CheckerFileBuf.get().get()))
 497       ErrorAndExit("some checks in '" + CheckerFileName + "' failed");
 498   }
 499   return 0;
 500 }
 501
 502 void applySpecificSectionMappings(RuntimeDyldChecker &Checker) {
 503
 504   for (StringRef Mapping : SpecificSectionMappings) {
 505
 506     size_t EqualsIdx = Mapping.find_first_of("=");
 507     std::string SectionIDStr = Mapping.substr(0, EqualsIdx);
 508     size_t ComaIdx = Mapping.find_first_of(",");
 509
 510     if (ComaIdx == StringRef::npos)
 511       report_fatal_error("Invalid section specification '" + Mapping +
 512                          "'. Should be '<file name>,<section name>=<addr>'");
 513
 514     std::string FileName = SectionIDStr.substr(0, ComaIdx);
 515     std::string SectionName = SectionIDStr.substr(ComaIdx + 1);
 516
 517     uint64_t OldAddrInt;
 518     std::string ErrorMsg;
 519     std::tie(OldAddrInt, ErrorMsg) =
 520       Checker.getSectionAddr(FileName, SectionName, true);
 521
 522     if (ErrorMsg != "")
 523       report_fatal_error(ErrorMsg);
 524
 525     void* OldAddr = reinterpret_cast<void*>(static_cast<uintptr_t>(OldAddrInt));
 526
 527     std::string NewAddrStr = Mapping.substr(EqualsIdx + 1);
 528     uint64_t NewAddr;
 529
 530     if (StringRef(NewAddrStr).getAsInteger(0, NewAddr))
 531       report_fatal_error("Invalid section address in mapping '" + Mapping +
 532                          "'.");
 533
 534     Checker.getRTDyld().mapSectionAddress(OldAddr, NewAddr);
 535   }
 536 }
 537
 538 // Scatter sections in all directions!
 539 // Remaps section addresses for -verify mode. The following command line options
 540 // can be used to customize the layout of the memory within the phony target's
 541 // address space:
 542 // -target-addr-start <s> -- Specify where the phony target address range starts.
 543 // -target-addr-end   <e> -- Specify where the phony target address range ends.
 544 // -target-section-sep <d> -- Specify how big a gap should be left between the
 545 //                            end of one section and the start of the next.
 546 //                            Defaults to zero. Set to something big
 547 //                            (e.g. 1 << 32) to stress-test stubs, GOTs, etc.
 548 //
 549 static void remapSectionsAndSymbols(const llvm::Triple &TargetTriple,
 550                                     TrivialMemoryManager &MemMgr,
 551                                     RuntimeDyldChecker &Checker) {
 552
 553   // Set up a work list (section addr/size pairs).
 554   typedef std::list<std::pair<void*, uint64_t>> WorklistT;
 555   WorklistT Worklist;
 556
 557   for (const auto& CodeSection : MemMgr.FunctionMemory)
 558     Worklist.push_back(std::make_pair(CodeSection.base(), CodeSection.size()));
 559   for (const auto& DataSection : MemMgr.DataMemory)
 560     Worklist.push_back(std::make_pair(DataSection.base(), DataSection.size()));
 561
 562   // Apply any section-specific mappings that were requested on the command
 563   // line.
 564   applySpecificSectionMappings(Checker);
 565
 566   // Keep an "already allocated" mapping of section target addresses to sizes.
 567   // Sections whose address mappings aren't specified on the command line will
 568   // allocated around the explicitly mapped sections while maintaining the
 569   // minimum separation.
 570   std::map<uint64_t, uint64_t> AlreadyAllocated;
 571
 572   // Move the previously applied mappings (whether explicitly specified on the
 573   // command line, or implicitly set by RuntimeDyld) into the already-allocated
 574   // map.
 575   for (WorklistT::iterator I = Worklist.begin(), E = Worklist.end();
 576        I != E;) {
 577     WorklistT::iterator Tmp = I;
 578     ++I;
 579     auto LoadAddr = Checker.getSectionLoadAddress(Tmp->first);
 580
 581     if (LoadAddr &&
 582         *LoadAddr != static_cast<uint64_t>(
 583                        reinterpret_cast<uintptr_t>(Tmp->first))) {
 584       // A section will have a LoadAddr of 0 if it wasn't loaded for whatever
 585       // reason (e.g. zero byte COFF sections). Don't include those sections in
 586       // the allocation map.
 587       if (*LoadAddr != 0)
 588         AlreadyAllocated[*LoadAddr] = Tmp->second;
 589       Worklist.erase(Tmp);
 590     }
 591   }
 592
 593   // If the -target-addr-end option wasn't explicitly passed, then set it to a
 594   // sensible default based on the target triple.
 595   if (TargetAddrEnd.getNumOccurrences() == 0) {
 596     if (TargetTriple.isArch16Bit())
 597       TargetAddrEnd = (1ULL << 16) - 1;
 598     else if (TargetTriple.isArch32Bit())
 599       TargetAddrEnd = (1ULL << 32) - 1;
 600     // TargetAddrEnd already has a sensible default for 64-bit systems, so
 601     // there's nothing to do in the 64-bit case.
 602   }
 603
 604   // Process any elements remaining in the worklist.
 605   while (!Worklist.empty()) {
 606     std::pair<void*, uint64_t> CurEntry = Worklist.front();
 607     Worklist.pop_front();
 608
 609     uint64_t NextSectionAddr = TargetAddrStart;
 610
 611     for (const auto &Alloc : AlreadyAllocated)
 612       if (NextSectionAddr + CurEntry.second + TargetSectionSep <= Alloc.first)
 613         break;
 614       else
 615         NextSectionAddr = Alloc.first + Alloc.second + TargetSectionSep;
 616
 617     AlreadyAllocated[NextSectionAddr] = CurEntry.second;
 618     Checker.getRTDyld().mapSectionAddress(CurEntry.first, NextSectionAddr);
 619   }
 620
 621   // Add dummy symbols to the memory manager.
 622   for (const auto &Mapping : DummySymbolMappings) {
 623     size_t EqualsIdx = Mapping.find_first_of('=');
 624
 625     if (EqualsIdx == StringRef::npos)
 626       report_fatal_error("Invalid dummy symbol specification '" + Mapping +
 627                          "'. Should be '<symbol name>=<addr>'");
 628
 629     std::string Symbol = Mapping.substr(0, EqualsIdx);
 630     std::string AddrStr = Mapping.substr(EqualsIdx + 1);
 631
 632     uint64_t Addr;
 633     if (StringRef(AddrStr).getAsInteger(0, Addr))
 634       report_fatal_error("Invalid symbol mapping '" + Mapping + "'.");
 635
 636     MemMgr.addDummySymbol(Symbol, Addr);
 637   }
 638 }
 639
 640 // Load and link the objects specified on the command line, but do not execute
 641 // anything. Instead, attach a RuntimeDyldChecker instance and call it to
 642 // verify the correctness of the linked memory.
 643 static int linkAndVerify() {
 644
 645   // Check for missing triple.
 646   if (TripleName == "")
 647     ErrorAndExit("-triple required when running in -verify mode.");
 648
 649   // Look up the target and build the disassembler.
 650   Triple TheTriple(Triple::normalize(TripleName));
 651   std::string ErrorStr;
 652   const Target *TheTarget =
 653     TargetRegistry::lookupTarget("", TheTriple, ErrorStr);
 654   if (!TheTarget)
 655     ErrorAndExit("Error accessing target '" + TripleName + "': " + ErrorStr);
 656
 657   TripleName = TheTriple.getTriple();
 658
 659   std::unique_ptr<MCSubtargetInfo> STI(
 660     TheTarget->createMCSubtargetInfo(TripleName, MCPU, ""));
 661   if (!STI)
 662     ErrorAndExit("Unable to create subtarget info!");
 663
 664   std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
 665   if (!MRI)
 666     ErrorAndExit("Unable to create target register info!");
 667
 668   std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TripleName));
 669   if (!MAI)
 670     ErrorAndExit("Unable to create target asm info!");
 671
 672   MCContext Ctx(MAI.get(), MRI.get(), nullptr);
 673
 674   std::unique_ptr<MCDisassembler> Disassembler(
 675     TheTarget->createMCDisassembler(*STI, Ctx));
 676   if (!Disassembler)
 677     ErrorAndExit("Unable to create disassembler!");
 678
 679   std::unique_ptr<MCInstrInfo> MII(TheTarget->createMCInstrInfo());
 680
 681   std::unique_ptr<MCInstPrinter> InstPrinter(
 682       TheTarget->createMCInstPrinter(Triple(TripleName), 0, *MAI, *MII, *MRI));
 683
 684   // Load any dylibs requested on the command line.
 685   loadDylibs();
 686
 687   // Instantiate a dynamic linker.
 688   TrivialMemoryManager MemMgr;
 689   doPreallocation(MemMgr);
 690   RuntimeDyld Dyld(MemMgr, MemMgr);
 691   Dyld.setProcessAllSections(true);
 692   RuntimeDyldChecker Checker(Dyld, Disassembler.get(), InstPrinter.get(),
 693                              llvm::dbgs());
 694
 695   // If we don't have any input files, read from stdin.
 696   if (!InputFileList.size())
 697     InputFileList.push_back("-");
 698   for (auto &Filename : InputFileList) {
 699     // Load the input memory buffer.
 700     ErrorOr<std::unique_ptr<MemoryBuffer>> InputBuffer =
 701         MemoryBuffer::getFileOrSTDIN(Filename);
 702
 703     if (std::error_code EC = InputBuffer.getError())
 704       ErrorAndExit("unable to read input: '" + EC.message() + "'");
 705
 706     Expected<std::unique_ptr<ObjectFile>> MaybeObj(
 707       ObjectFile::createObjectFile((*InputBuffer)->getMemBufferRef()));
 708
 709     if (!MaybeObj) {
 710       std::string Buf;
 711       raw_string_ostream OS(Buf);
 712       logAllUnhandledErrors(MaybeObj.takeError(), OS);
 713       OS.flush();
 714       ErrorAndExit("unable to create object file: '" + Buf + "'");
 715     }
 716
 717     ObjectFile &Obj = **MaybeObj;
 718
 719     // Load the object file
 720     Dyld.loadObject(Obj);
 721     if (Dyld.hasError()) {
 722       ErrorAndExit(Dyld.getErrorString());
 723     }
 724   }
 725
 726   // Re-map the section addresses into the phony target address space and add
 727   // dummy symbols.
 728   remapSectionsAndSymbols(TheTriple, MemMgr, Checker);
 729
 730   // Resolve all the relocations we can.
 731   Dyld.resolveRelocations();
 732
 733   // Register EH frames.
 734   Dyld.registerEHFrames();
 735
 736   int ErrorCode = checkAllExpressions(Checker);
 737   if (Dyld.hasError())
 738     ErrorAndExit("RTDyld reported an error applying relocations:\n  " +
 739                  Dyld.getErrorString());
 740
 741   return ErrorCode;
 742 }
 743
 744 int main(int argc, char **argv) {
 745   InitLLVM X(argc, argv);
 746   ProgramName = argv[0];
 747
 748   llvm::InitializeAllTargetInfos();
 749   llvm::InitializeAllTargetMCs();
 750   llvm::InitializeAllDisassemblers();
 751
 752   cl::ParseCommandLineOptions(argc, argv, "llvm MC-JIT tool\n");
 753
 754   switch (Action) {
 755   case AC_Execute:
 756     return executeInput();
 757   case AC_PrintDebugLineInfo:
 758     return printLineInfoForInput(/* LoadObjects */ true,/* UseDebugObj */ true);
 759   case AC_PrintLineInfo:
 760     return printLineInfoForInput(/* LoadObjects */ true,/* UseDebugObj */false);
 761   case AC_PrintObjectLineInfo:
 762     return printLineInfoForInput(/* LoadObjects */false,/* UseDebugObj */false);
 763   case AC_Verify:
 764     return linkAndVerify();
 765   }
 766 }