tools/llvm-dwp/llvm-dwp.cpp

   1 //===-- llvm-dwp.cpp - Split DWARF merging tool for llvm ------------------===//
   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 // A utility for merging DWARF 5 Split DWARF .dwo files into .dwp (DWARF
  11 // package files).
  12 //
  13 //===----------------------------------------------------------------------===//
  14 #include "DWPError.h"
  15 #include "DWPStringPool.h"
  16 #include "llvm/ADT/MapVector.h"
  17 #include "llvm/ADT/STLExtras.h"
  18 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
  19 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
  20 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
  21 #include "llvm/MC/MCAsmBackend.h"
  22 #include "llvm/MC/MCAsmInfo.h"
  23 #include "llvm/MC/MCCodeEmitter.h"
  24 #include "llvm/MC/MCContext.h"
  25 #include "llvm/MC/MCInstrInfo.h"
  26 #include "llvm/MC/MCObjectFileInfo.h"
  27 #include "llvm/MC/MCObjectWriter.h"
  28 #include "llvm/MC/MCRegisterInfo.h"
  29 #include "llvm/MC/MCStreamer.h"
  30 #include "llvm/MC/MCTargetOptionsCommandFlags.inc"
  31 #include "llvm/Object/Decompressor.h"
  32 #include "llvm/Object/ObjectFile.h"
  33 #include "llvm/Support/DataExtractor.h"
  34 #include "llvm/Support/Error.h"
  35 #include "llvm/Support/FileSystem.h"
  36 #include "llvm/Support/InitLLVM.h"
  37 #include "llvm/Support/MathExtras.h"
  38 #include "llvm/Support/MemoryBuffer.h"
  39 #include "llvm/Support/Path.h"
  40 #include "llvm/Support/TargetRegistry.h"
  41 #include "llvm/Support/TargetSelect.h"
  42 #include "llvm/Support/raw_ostream.h"
  43
  44 using namespace llvm;
  45 using namespace llvm::object;
  46
  47 cl::OptionCategory DwpCategory("Specific Options");
  48 static cl::list<std::string> InputFiles(cl::Positional, cl::ZeroOrMore,
  49                                         cl::desc("<input files>"),
  50                                         cl::cat(DwpCategory));
  51
  52 static cl::list<std::string> ExecFilenames(
  53     "e", cl::ZeroOrMore,
  54     cl::desc("Specify the executable/library files to get the list of *.dwo from"),
  55     cl::value_desc("filename"), cl::cat(DwpCategory));
  56
  57 static cl::opt<std::string> OutputFilename(cl::Required, "o",
  58                                            cl::desc("Specify the output file."),
  59                                            cl::value_desc("filename"),
  60                                            cl::cat(DwpCategory));
  61
  62 static void writeStringsAndOffsets(MCStreamer &Out, DWPStringPool &Strings,
  63                                    MCSection *StrOffsetSection,
  64                                    StringRef CurStrSection,
  65                                    StringRef CurStrOffsetSection) {
  66   // Could possibly produce an error or warning if one of these was non-null but
  67   // the other was null.
  68   if (CurStrSection.empty() || CurStrOffsetSection.empty())
  69     return;
  70
  71   DenseMap<uint32_t, uint32_t> OffsetRemapping;
  72
  73   DataExtractor Data(CurStrSection, true, 0);
  74   uint32_t LocalOffset = 0;
  75   uint32_t PrevOffset = 0;
  76   while (const char *s = Data.getCStr(&LocalOffset)) {
  77     OffsetRemapping[PrevOffset] =
  78         Strings.getOffset(s, LocalOffset - PrevOffset);
  79     PrevOffset = LocalOffset;
  80   }
  81
  82   Data = DataExtractor(CurStrOffsetSection, true, 0);
  83
  84   Out.SwitchSection(StrOffsetSection);
  85
  86   uint32_t Offset = 0;
  87   uint64_t Size = CurStrOffsetSection.size();
  88   while (Offset < Size) {
  89     auto OldOffset = Data.getU32(&Offset);
  90     auto NewOffset = OffsetRemapping[OldOffset];
  91     Out.EmitIntValue(NewOffset, 4);
  92   }
  93 }
  94
  95 static uint32_t getCUAbbrev(StringRef Abbrev, uint64_t AbbrCode) {
  96   uint64_t CurCode;
  97   uint32_t Offset = 0;
  98   DataExtractor AbbrevData(Abbrev, true, 0);
  99   while ((CurCode = AbbrevData.getULEB128(&Offset)) != AbbrCode) {
 100     // Tag
 101     AbbrevData.getULEB128(&Offset);
 102     // DW_CHILDREN
 103     AbbrevData.getU8(&Offset);
 104     // Attributes
 105     while (AbbrevData.getULEB128(&Offset) | AbbrevData.getULEB128(&Offset))
 106       ;
 107   }
 108   return Offset;
 109 }
 110
 111 struct CompileUnitIdentifiers {
 112   uint64_t Signature = 0;
 113   const char *Name = "";
 114   const char *DWOName = "";
 115 };
 116
 117 static Expected<const char *>
 118 getIndexedString(dwarf::Form Form, DataExtractor InfoData,
 119                  uint32_t &InfoOffset, StringRef StrOffsets, StringRef Str) {
 120   if (Form == dwarf::DW_FORM_string)
 121     return InfoData.getCStr(&InfoOffset);
 122   if (Form != dwarf::DW_FORM_GNU_str_index)
 123     return make_error<DWPError>(
 124         "string field encoded without DW_FORM_string or DW_FORM_GNU_str_index");
 125   auto StrIndex = InfoData.getULEB128(&InfoOffset);
 126   DataExtractor StrOffsetsData(StrOffsets, true, 0);
 127   uint32_t StrOffsetsOffset = 4 * StrIndex;
 128   uint32_t StrOffset = StrOffsetsData.getU32(&StrOffsetsOffset);
 129   DataExtractor StrData(Str, true, 0);
 130   return StrData.getCStr(&StrOffset);
 131 }
 132
 133 static Expected<CompileUnitIdentifiers> getCUIdentifiers(StringRef Abbrev,
 134                                                          StringRef Info,
 135                                                          StringRef StrOffsets,
 136                                                          StringRef Str) {
 137   uint32_t Offset = 0;
 138   DataExtractor InfoData(Info, true, 0);
 139   dwarf::DwarfFormat Format = dwarf::DwarfFormat::DWARF32;
 140   uint64_t Length = InfoData.getU32(&Offset);
 141   // If the length is 0xffffffff, then this indictes that this is a DWARF 64
 142   // stream and the length is actually encoded into a 64 bit value that follows.
 143   if (Length == 0xffffffffU) {
 144     Format = dwarf::DwarfFormat::DWARF64;
 145     Length = InfoData.getU64(&Offset);
 146   }
 147   uint16_t Version = InfoData.getU16(&Offset);
 148   InfoData.getU32(&Offset); // Abbrev offset (should be zero)
 149   uint8_t AddrSize = InfoData.getU8(&Offset);
 150
 151   uint32_t AbbrCode = InfoData.getULEB128(&Offset);
 152
 153   DataExtractor AbbrevData(Abbrev, true, 0);
 154   uint32_t AbbrevOffset = getCUAbbrev(Abbrev, AbbrCode);
 155   auto Tag = static_cast<dwarf::Tag>(AbbrevData.getULEB128(&AbbrevOffset));
 156   if (Tag != dwarf::DW_TAG_compile_unit)
 157     return make_error<DWPError>("top level DIE is not a compile unit");
 158   // DW_CHILDREN
 159   AbbrevData.getU8(&AbbrevOffset);
 160   uint32_t Name;
 161   dwarf::Form Form;
 162   CompileUnitIdentifiers ID;
 163   while ((Name = AbbrevData.getULEB128(&AbbrevOffset)) |
 164          (Form = static_cast<dwarf::Form>(AbbrevData.getULEB128(&AbbrevOffset))) &&
 165          (Name != 0 || Form != 0)) {
 166     switch (Name) {
 167     case dwarf::DW_AT_name: {
 168       Expected<const char *> EName =
 169           getIndexedString(Form, InfoData, Offset, StrOffsets, Str);
 170       if (!EName)
 171         return EName.takeError();
 172       ID.Name = *EName;
 173       break;
 174     }
 175     case dwarf::DW_AT_GNU_dwo_name: {
 176       Expected<const char *> EName =
 177           getIndexedString(Form, InfoData, Offset, StrOffsets, Str);
 178       if (!EName)
 179         return EName.takeError();
 180       ID.DWOName = *EName;
 181       break;
 182     }
 183     case dwarf::DW_AT_GNU_dwo_id:
 184       ID.Signature = InfoData.getU64(&Offset);
 185       break;
 186     default:
 187       DWARFFormValue::skipValue(Form, InfoData, &Offset,
 188                                 dwarf::FormParams({Version, AddrSize, Format}));
 189     }
 190   }
 191   return ID;
 192 }
 193
 194 struct UnitIndexEntry {
 195   DWARFUnitIndex::Entry::SectionContribution Contributions[8];
 196   std::string Name;
 197   std::string DWOName;
 198   StringRef DWPName;
 199 };
 200
 201 static StringRef getSubsection(StringRef Section,
 202                                const DWARFUnitIndex::Entry &Entry,
 203                                DWARFSectionKind Kind) {
 204   const auto *Off = Entry.getOffset(Kind);
 205   if (!Off)
 206     return StringRef();
 207   return Section.substr(Off->Offset, Off->Length);
 208 }
 209
 210 static void addAllTypesFromDWP(
 211     MCStreamer &Out, MapVector<uint64_t, UnitIndexEntry> &TypeIndexEntries,
 212     const DWARFUnitIndex &TUIndex, MCSection *OutputTypes, StringRef Types,
 213     const UnitIndexEntry &TUEntry, uint32_t &TypesOffset) {
 214   Out.SwitchSection(OutputTypes);
 215   for (const DWARFUnitIndex::Entry &E : TUIndex.getRows()) {
 216     auto *I = E.getOffsets();
 217     if (!I)
 218       continue;
 219     auto P = TypeIndexEntries.insert(std::make_pair(E.getSignature(), TUEntry));
 220     if (!P.second)
 221       continue;
 222     auto &Entry = P.first->second;
 223     // Zero out the debug_info contribution
 224     Entry.Contributions[0] = {};
 225     for (auto Kind : TUIndex.getColumnKinds()) {
 226       auto &C = Entry.Contributions[Kind - DW_SECT_INFO];
 227       C.Offset += I->Offset;
 228       C.Length = I->Length;
 229       ++I;
 230     }
 231     auto &C = Entry.Contributions[DW_SECT_TYPES - DW_SECT_INFO];
 232     Out.EmitBytes(Types.substr(
 233         C.Offset - TUEntry.Contributions[DW_SECT_TYPES - DW_SECT_INFO].Offset,
 234         C.Length));
 235     C.Offset = TypesOffset;
 236     TypesOffset += C.Length;
 237   }
 238 }
 239
 240 static void addAllTypes(MCStreamer &Out,
 241                         MapVector<uint64_t, UnitIndexEntry> &TypeIndexEntries,
 242                         MCSection *OutputTypes,
 243                         const std::vector<StringRef> &TypesSections,
 244                         const UnitIndexEntry &CUEntry, uint32_t &TypesOffset) {
 245   for (StringRef Types : TypesSections) {
 246     Out.SwitchSection(OutputTypes);
 247     uint32_t Offset = 0;
 248     DataExtractor Data(Types, true, 0);
 249     while (Data.isValidOffset(Offset)) {
 250       UnitIndexEntry Entry = CUEntry;
 251       // Zero out the debug_info contribution
 252       Entry.Contributions[0] = {};
 253       auto &C = Entry.Contributions[DW_SECT_TYPES - DW_SECT_INFO];
 254       C.Offset = TypesOffset;
 255       auto PrevOffset = Offset;
 256       // Length of the unit, including the 4 byte length field.
 257       C.Length = Data.getU32(&Offset) + 4;
 258
 259       Data.getU16(&Offset); // Version
 260       Data.getU32(&Offset); // Abbrev offset
 261       Data.getU8(&Offset);  // Address size
 262       auto Signature = Data.getU64(&Offset);
 263       Offset = PrevOffset + C.Length;
 264
 265       auto P = TypeIndexEntries.insert(std::make_pair(Signature, Entry));
 266       if (!P.second)
 267         continue;
 268
 269       Out.EmitBytes(Types.substr(PrevOffset, C.Length));
 270       TypesOffset += C.Length;
 271     }
 272   }
 273 }
 274
 275 static void
 276 writeIndexTable(MCStreamer &Out, ArrayRef<unsigned> ContributionOffsets,
 277                 const MapVector<uint64_t, UnitIndexEntry> &IndexEntries,
 278                 uint32_t DWARFUnitIndex::Entry::SectionContribution::*Field) {
 279   for (const auto &E : IndexEntries)
 280     for (size_t i = 0; i != array_lengthof(E.second.Contributions); ++i)
 281       if (ContributionOffsets[i])
 282         Out.EmitIntValue(E.second.Contributions[i].*Field, 4);
 283 }
 284
 285 static void
 286 writeIndex(MCStreamer &Out, MCSection *Section,
 287            ArrayRef<unsigned> ContributionOffsets,
 288            const MapVector<uint64_t, UnitIndexEntry> &IndexEntries) {
 289   if (IndexEntries.empty())
 290     return;
 291
 292   unsigned Columns = 0;
 293   for (auto &C : ContributionOffsets)
 294     if (C)
 295       ++Columns;
 296
 297   std::vector<unsigned> Buckets(NextPowerOf2(3 * IndexEntries.size() / 2));
 298   uint64_t Mask = Buckets.size() - 1;
 299   size_t i = 0;
 300   for (const auto &P : IndexEntries) {
 301     auto S = P.first;
 302     auto H = S & Mask;
 303     auto HP = ((S >> 32) & Mask) | 1;
 304     while (Buckets[H]) {
 305       assert(S != IndexEntries.begin()[Buckets[H] - 1].first &&
 306              "Duplicate unit");
 307       H = (H + HP) & Mask;
 308     }
 309     Buckets[H] = i + 1;
 310     ++i;
 311   }
 312
 313   Out.SwitchSection(Section);
 314   Out.EmitIntValue(2, 4);                   // Version
 315   Out.EmitIntValue(Columns, 4);             // Columns
 316   Out.EmitIntValue(IndexEntries.size(), 4); // Num Units
 317   Out.EmitIntValue(Buckets.size(), 4);      // Num Buckets
 318
 319   // Write the signatures.
 320   for (const auto &I : Buckets)
 321     Out.EmitIntValue(I ? IndexEntries.begin()[I - 1].first : 0, 8);
 322
 323   // Write the indexes.
 324   for (const auto &I : Buckets)
 325     Out.EmitIntValue(I, 4);
 326
 327   // Write the column headers (which sections will appear in the table)
 328   for (size_t i = 0; i != ContributionOffsets.size(); ++i)
 329     if (ContributionOffsets[i])
 330       Out.EmitIntValue(i + DW_SECT_INFO, 4);
 331
 332   // Write the offsets.
 333   writeIndexTable(Out, ContributionOffsets, IndexEntries,
 334                   &DWARFUnitIndex::Entry::SectionContribution::Offset);
 335
 336   // Write the lengths.
 337   writeIndexTable(Out, ContributionOffsets, IndexEntries,
 338                   &DWARFUnitIndex::Entry::SectionContribution::Length);
 339 }
 340
 341 std::string buildDWODescription(StringRef Name, StringRef DWPName, StringRef DWOName) {
 342   std::string Text = "\'";
 343   Text += Name;
 344   Text += '\'';
 345   if (!DWPName.empty()) {
 346     Text += " (from ";
 347     if (!DWOName.empty()) {
 348       Text += '\'';
 349       Text += DWOName;
 350       Text += "' in ";
 351     }
 352     Text += '\'';
 353     Text += DWPName;
 354     Text += "')";
 355   }
 356   return Text;
 357 }
 358
 359 static Error createError(StringRef Name, Error E) {
 360   return make_error<DWPError>(
 361       ("failure while decompressing compressed section: '" + Name + "', " +
 362        llvm::toString(std::move(E)))
 363           .str());
 364 }
 365
 366 static Error
 367 handleCompressedSection(std::deque<SmallString<32>> &UncompressedSections,
 368                         StringRef &Name, StringRef &Contents) {
 369   if (!Decompressor::isGnuStyle(Name))
 370     return Error::success();
 371
 372   Expected<Decompressor> Dec =
 373       Decompressor::create(Name, Contents, false /*IsLE*/, false /*Is64Bit*/);
 374   if (!Dec)
 375     return createError(Name, Dec.takeError());
 376
 377   UncompressedSections.emplace_back();
 378   if (Error E = Dec->resizeAndDecompress(UncompressedSections.back()))
 379     return createError(Name, std::move(E));
 380
 381   Name = Name.substr(2); // Drop ".z"
 382   Contents = UncompressedSections.back();
 383   return Error::success();
 384 }
 385
 386 static Error handleSection(
 387     const StringMap<std::pair<MCSection *, DWARFSectionKind>> &KnownSections,
 388     const MCSection *StrSection, const MCSection *StrOffsetSection,
 389     const MCSection *TypesSection, const MCSection *CUIndexSection,
 390     const MCSection *TUIndexSection, const SectionRef &Section, MCStreamer &Out,
 391     std::deque<SmallString<32>> &UncompressedSections,
 392     uint32_t (&ContributionOffsets)[8], UnitIndexEntry &CurEntry,
 393     StringRef &CurStrSection, StringRef &CurStrOffsetSection,
 394     std::vector<StringRef> &CurTypesSection, StringRef &InfoSection,
 395     StringRef &AbbrevSection, StringRef &CurCUIndexSection,
 396     StringRef &CurTUIndexSection) {
 397   if (Section.isBSS())
 398     return Error::success();
 399
 400   if (Section.isVirtual())
 401     return Error::success();
 402
 403   StringRef Name;
 404   if (std::error_code Err = Section.getName(Name))
 405     return errorCodeToError(Err);
 406
 407   StringRef Contents;
 408   if (auto Err = Section.getContents(Contents))
 409     return errorCodeToError(Err);
 410
 411   if (auto Err = handleCompressedSection(UncompressedSections, Name, Contents))
 412     return Err;
 413
 414   Name = Name.substr(Name.find_first_not_of("._"));
 415
 416   auto SectionPair = KnownSections.find(Name);
 417   if (SectionPair == KnownSections.end())
 418     return Error::success();
 419
 420   if (DWARFSectionKind Kind = SectionPair->second.second) {
 421     auto Index = Kind - DW_SECT_INFO;
 422     if (Kind != DW_SECT_TYPES) {
 423       CurEntry.Contributions[Index].Offset = ContributionOffsets[Index];
 424       ContributionOffsets[Index] +=
 425           (CurEntry.Contributions[Index].Length = Contents.size());
 426     }
 427
 428     switch (Kind) {
 429     case DW_SECT_INFO:
 430       InfoSection = Contents;
 431       break;
 432     case DW_SECT_ABBREV:
 433       AbbrevSection = Contents;
 434       break;
 435     default:
 436       break;
 437     }
 438   }
 439
 440   MCSection *OutSection = SectionPair->second.first;
 441   if (OutSection == StrOffsetSection)
 442     CurStrOffsetSection = Contents;
 443   else if (OutSection == StrSection)
 444     CurStrSection = Contents;
 445   else if (OutSection == TypesSection)
 446     CurTypesSection.push_back(Contents);
 447   else if (OutSection == CUIndexSection)
 448     CurCUIndexSection = Contents;
 449   else if (OutSection == TUIndexSection)
 450     CurTUIndexSection = Contents;
 451   else {
 452     Out.SwitchSection(OutSection);
 453     Out.EmitBytes(Contents);
 454   }
 455   return Error::success();
 456 }
 457
 458 static Error
 459 buildDuplicateError(const std::pair<uint64_t, UnitIndexEntry> &PrevE,
 460                     const CompileUnitIdentifiers &ID, StringRef DWPName) {
 461   return make_error<DWPError>(
 462       std::string("Duplicate DWO ID (") + utohexstr(PrevE.first) + ") in " +
 463       buildDWODescription(PrevE.second.Name, PrevE.second.DWPName,
 464                           PrevE.second.DWOName) +
 465       " and " + buildDWODescription(ID.Name, DWPName, ID.DWOName));
 466 }
 467
 468 static Expected<SmallVector<std::string, 16>>
 469 getDWOFilenames(StringRef ExecFilename) {
 470   auto ErrOrObj = object::ObjectFile::createObjectFile(ExecFilename);
 471   if (!ErrOrObj)
 472     return ErrOrObj.takeError();
 473
 474   const ObjectFile &Obj = *ErrOrObj.get().getBinary();
 475   std::unique_ptr<DWARFContext> DWARFCtx = DWARFContext::create(Obj);
 476
 477   SmallVector<std::string, 16> DWOPaths;
 478   for (const auto &CU : DWARFCtx->compile_units()) {
 479     const DWARFDie &Die = CU->getUnitDIE();
 480     std::string DWOName = dwarf::toString(
 481         Die.find({dwarf::DW_AT_dwo_name, dwarf::DW_AT_GNU_dwo_name}), "");
 482     if (DWOName.empty())
 483       continue;
 484     std::string DWOCompDir =
 485         dwarf::toString(Die.find(dwarf::DW_AT_comp_dir), "");
 486     if (!DWOCompDir.empty()) {
 487       SmallString<16> DWOPath;
 488       sys::path::append(DWOPath, DWOCompDir, DWOName);
 489       DWOPaths.emplace_back(DWOPath.data(), DWOPath.size());
 490     } else {
 491       DWOPaths.push_back(std::move(DWOName));
 492     }
 493   }
 494   return std::move(DWOPaths);
 495 }
 496
 497 static Error write(MCStreamer &Out, ArrayRef<std::string> Inputs) {
 498   const auto &MCOFI = *Out.getContext().getObjectFileInfo();
 499   MCSection *const StrSection = MCOFI.getDwarfStrDWOSection();
 500   MCSection *const StrOffsetSection = MCOFI.getDwarfStrOffDWOSection();
 501   MCSection *const TypesSection = MCOFI.getDwarfTypesDWOSection();
 502   MCSection *const CUIndexSection = MCOFI.getDwarfCUIndexSection();
 503   MCSection *const TUIndexSection = MCOFI.getDwarfTUIndexSection();
 504   const StringMap<std::pair<MCSection *, DWARFSectionKind>> KnownSections = {
 505       {"debug_info.dwo", {MCOFI.getDwarfInfoDWOSection(), DW_SECT_INFO}},
 506       {"debug_types.dwo", {MCOFI.getDwarfTypesDWOSection(), DW_SECT_TYPES}},
 507       {"debug_str_offsets.dwo", {StrOffsetSection, DW_SECT_STR_OFFSETS}},
 508       {"debug_str.dwo", {StrSection, static_cast<DWARFSectionKind>(0)}},
 509       {"debug_loc.dwo", {MCOFI.getDwarfLocDWOSection(), DW_SECT_LOC}},
 510       {"debug_line.dwo", {MCOFI.getDwarfLineDWOSection(), DW_SECT_LINE}},
 511       {"debug_abbrev.dwo", {MCOFI.getDwarfAbbrevDWOSection(), DW_SECT_ABBREV}},
 512       {"debug_cu_index", {CUIndexSection, static_cast<DWARFSectionKind>(0)}},
 513       {"debug_tu_index", {TUIndexSection, static_cast<DWARFSectionKind>(0)}}};
 514
 515   MapVector<uint64_t, UnitIndexEntry> IndexEntries;
 516   MapVector<uint64_t, UnitIndexEntry> TypeIndexEntries;
 517
 518   uint32_t ContributionOffsets[8] = {};
 519
 520   DWPStringPool Strings(Out, StrSection);
 521
 522   SmallVector<OwningBinary<object::ObjectFile>, 128> Objects;
 523   Objects.reserve(Inputs.size());
 524
 525   std::deque<SmallString<32>> UncompressedSections;
 526
 527   for (const auto &Input : Inputs) {
 528     auto ErrOrObj = object::ObjectFile::createObjectFile(Input);
 529     if (!ErrOrObj)
 530       return ErrOrObj.takeError();
 531
 532     auto &Obj = *ErrOrObj->getBinary();
 533     Objects.push_back(std::move(*ErrOrObj));
 534
 535     UnitIndexEntry CurEntry = {};
 536
 537     StringRef CurStrSection;
 538     StringRef CurStrOffsetSection;
 539     std::vector<StringRef> CurTypesSection;
 540     StringRef InfoSection;
 541     StringRef AbbrevSection;
 542     StringRef CurCUIndexSection;
 543     StringRef CurTUIndexSection;
 544
 545     for (const auto &Section : Obj.sections())
 546       if (auto Err = handleSection(
 547               KnownSections, StrSection, StrOffsetSection, TypesSection,
 548               CUIndexSection, TUIndexSection, Section, Out,
 549               UncompressedSections, ContributionOffsets, CurEntry,
 550               CurStrSection, CurStrOffsetSection, CurTypesSection, InfoSection,
 551               AbbrevSection, CurCUIndexSection, CurTUIndexSection))
 552         return Err;
 553
 554     if (InfoSection.empty())
 555       continue;
 556
 557     writeStringsAndOffsets(Out, Strings, StrOffsetSection, CurStrSection,
 558                            CurStrOffsetSection);
 559
 560     if (CurCUIndexSection.empty()) {
 561       Expected<CompileUnitIdentifiers> EID = getCUIdentifiers(
 562           AbbrevSection, InfoSection, CurStrOffsetSection, CurStrSection);
 563       if (!EID)
 564         return EID.takeError();
 565       const auto &ID = *EID;
 566       auto P = IndexEntries.insert(std::make_pair(ID.Signature, CurEntry));
 567       if (!P.second)
 568         return buildDuplicateError(*P.first, ID, "");
 569       P.first->second.Name = ID.Name;
 570       P.first->second.DWOName = ID.DWOName;
 571       addAllTypes(Out, TypeIndexEntries, TypesSection, CurTypesSection,
 572                   CurEntry, ContributionOffsets[DW_SECT_TYPES - DW_SECT_INFO]);
 573       continue;
 574     }
 575
 576     DWARFUnitIndex CUIndex(DW_SECT_INFO);
 577     DataExtractor CUIndexData(CurCUIndexSection, Obj.isLittleEndian(), 0);
 578     if (!CUIndex.parse(CUIndexData))
 579       return make_error<DWPError>("Failed to parse cu_index");
 580
 581     for (const DWARFUnitIndex::Entry &E : CUIndex.getRows()) {
 582       auto *I = E.getOffsets();
 583       if (!I)
 584         continue;
 585       auto P = IndexEntries.insert(std::make_pair(E.getSignature(), CurEntry));
 586       Expected<CompileUnitIdentifiers> EID = getCUIdentifiers(
 587           getSubsection(AbbrevSection, E, DW_SECT_ABBREV),
 588           getSubsection(InfoSection, E, DW_SECT_INFO),
 589           getSubsection(CurStrOffsetSection, E, DW_SECT_STR_OFFSETS),
 590           CurStrSection);
 591       if (!EID)
 592         return EID.takeError();
 593       const auto &ID = *EID;
 594       if (!P.second)
 595         return buildDuplicateError(*P.first, ID, Input);
 596       auto &NewEntry = P.first->second;
 597       NewEntry.Name = ID.Name;
 598       NewEntry.DWOName = ID.DWOName;
 599       NewEntry.DWPName = Input;
 600       for (auto Kind : CUIndex.getColumnKinds()) {
 601         auto &C = NewEntry.Contributions[Kind - DW_SECT_INFO];
 602         C.Offset += I->Offset;
 603         C.Length = I->Length;
 604         ++I;
 605       }
 606     }
 607
 608     if (!CurTypesSection.empty()) {
 609       if (CurTypesSection.size() != 1)
 610         return make_error<DWPError>("multiple type unit sections in .dwp file");
 611       DWARFUnitIndex TUIndex(DW_SECT_TYPES);
 612       DataExtractor TUIndexData(CurTUIndexSection, Obj.isLittleEndian(), 0);
 613       if (!TUIndex.parse(TUIndexData))
 614         return make_error<DWPError>("Failed to parse tu_index");
 615       addAllTypesFromDWP(Out, TypeIndexEntries, TUIndex, TypesSection,
 616                          CurTypesSection.front(), CurEntry,
 617                          ContributionOffsets[DW_SECT_TYPES - DW_SECT_INFO]);
 618     }
 619   }
 620
 621   // Lie about there being no info contributions so the TU index only includes
 622   // the type unit contribution
 623   ContributionOffsets[0] = 0;
 624   writeIndex(Out, MCOFI.getDwarfTUIndexSection(), ContributionOffsets,
 625              TypeIndexEntries);
 626
 627   // Lie about the type contribution
 628   ContributionOffsets[DW_SECT_TYPES - DW_SECT_INFO] = 0;
 629   // Unlie about the info contribution
 630   ContributionOffsets[0] = 1;
 631
 632   writeIndex(Out, MCOFI.getDwarfCUIndexSection(), ContributionOffsets,
 633              IndexEntries);
 634
 635   return Error::success();
 636 }
 637
 638 static int error(const Twine &Error, const Twine &Context) {
 639   errs() << Twine("while processing ") + Context + ":\n";
 640   errs() << Twine("error: ") + Error + "\n";
 641   return 1;
 642 }
 643
 644 int main(int argc, char **argv) {
 645   InitLLVM X(argc, argv);
 646
 647   cl::ParseCommandLineOptions(argc, argv, "merge split dwarf (.dwo) files\n");
 648
 649   llvm::InitializeAllTargetInfos();
 650   llvm::InitializeAllTargetMCs();
 651   llvm::InitializeAllTargets();
 652   llvm::InitializeAllAsmPrinters();
 653
 654   std::string ErrorStr;
 655   StringRef Context = "dwarf streamer init";
 656
 657   Triple TheTriple("x86_64-linux-gnu");
 658
 659   // Get the target.
 660   const Target *TheTarget =
 661       TargetRegistry::lookupTarget("", TheTriple, ErrorStr);
 662   if (!TheTarget)
 663     return error(ErrorStr, Context);
 664   std::string TripleName = TheTriple.getTriple();
 665
 666   // Create all the MC Objects.
 667   std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
 668   if (!MRI)
 669     return error(Twine("no register info for target ") + TripleName, Context);
 670
 671   std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TripleName));
 672   if (!MAI)
 673     return error("no asm info for target " + TripleName, Context);
 674
 675   MCObjectFileInfo MOFI;
 676   MCContext MC(MAI.get(), MRI.get(), &MOFI);
 677   MOFI.InitMCObjectFileInfo(TheTriple, /*PIC*/ false, MC);
 678
 679   std::unique_ptr<MCSubtargetInfo> MSTI(
 680       TheTarget->createMCSubtargetInfo(TripleName, "", ""));
 681   if (!MSTI)
 682     return error("no subtarget info for target " + TripleName, Context);
 683
 684   MCTargetOptions Options;
 685   auto MAB = TheTarget->createMCAsmBackend(*MSTI, *MRI, Options);
 686   if (!MAB)
 687     return error("no asm backend for target " + TripleName, Context);
 688
 689   std::unique_ptr<MCInstrInfo> MII(TheTarget->createMCInstrInfo());
 690   if (!MII)
 691     return error("no instr info info for target " + TripleName, Context);
 692
 693   MCCodeEmitter *MCE = TheTarget->createMCCodeEmitter(*MII, *MRI, MC);
 694   if (!MCE)
 695     return error("no code emitter for target " + TripleName, Context);
 696
 697   // Create the output file.
 698   std::error_code EC;
 699   raw_fd_ostream OutFile(OutputFilename, EC, sys::fs::F_None);
 700   Optional<buffer_ostream> BOS;
 701   raw_pwrite_stream *OS;
 702   if (EC)
 703     return error(Twine(OutputFilename) + ": " + EC.message(), Context);
 704   if (OutFile.supportsSeeking()) {
 705     OS = &OutFile;
 706   } else {
 707     BOS.emplace(OutFile);
 708     OS = BOS.getPointer();
 709   }
 710
 711   MCTargetOptions MCOptions = InitMCTargetOptionsFromFlags();
 712   std::unique_ptr<MCStreamer> MS(TheTarget->createMCObjectStreamer(
 713       TheTriple, MC, std::unique_ptr<MCAsmBackend>(MAB),
 714       MAB->createObjectWriter(*OS), std::unique_ptr<MCCodeEmitter>(MCE),
 715       *MSTI, MCOptions.MCRelaxAll, MCOptions.MCIncrementalLinkerCompatible,
 716       /*DWARFMustBeAtTheEnd*/ false));
 717   if (!MS)
 718     return error("no object streamer for target " + TripleName, Context);
 719
 720   std::vector<std::string> DWOFilenames = InputFiles;
 721   for (const auto &ExecFilename : ExecFilenames) {
 722     auto DWOs = getDWOFilenames(ExecFilename);
 723     if (!DWOs) {
 724       logAllUnhandledErrors(DWOs.takeError(), errs(), "error: ");
 725       return 1;
 726     }
 727     DWOFilenames.insert(DWOFilenames.end(),
 728                         std::make_move_iterator(DWOs->begin()),
 729                         std::make_move_iterator(DWOs->end()));
 730   }
 731
 732   if (auto Err = write(*MS, DWOFilenames)) {
 733     logAllUnhandledErrors(std::move(Err), errs(), "error: ");
 734     return 1;
 735   }
 736
 737   MS->Finish();
 738 }