lib/ObjectYAML/COFFEmitter.cpp

   1 //===- yaml2coff - Convert YAML to a COFF object file ---------------------===//
   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 /// \file
  10 /// The COFF component of yaml2obj.
  11 ///
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ADT/STLExtras.h"
  15 #include "llvm/ADT/StringExtras.h"
  16 #include "llvm/ADT/StringMap.h"
  17 #include "llvm/ADT/StringSwitch.h"
  18 #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
  19 #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h"
  20 #include "llvm/Object/COFF.h"
  21 #include "llvm/ObjectYAML/ObjectYAML.h"
  22 #include "llvm/ObjectYAML/yaml2obj.h"
  23 #include "llvm/Support/Endian.h"
  24 #include "llvm/Support/MemoryBuffer.h"
  25 #include "llvm/Support/SourceMgr.h"
  26 #include "llvm/Support/WithColor.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include <vector>
  29
  30 using namespace llvm;
  31
  32 namespace {
  33
  34 /// This parses a yaml stream that represents a COFF object file.
  35 /// See docs/yaml2obj for the yaml scheema.
  36 struct COFFParser {
  37   COFFParser(COFFYAML::Object &Obj)
  38       : Obj(Obj), SectionTableStart(0), SectionTableSize(0) {
  39     // A COFF string table always starts with a 4 byte size field. Offsets into
  40     // it include this size, so allocate it now.
  41     StringTable.append(4, char(0));
  42   }
  43
  44   bool useBigObj() const {
  45     return static_cast<int32_t>(Obj.Sections.size()) >
  46            COFF::MaxNumberOfSections16;
  47   }
  48
  49   bool isPE() const { return Obj.OptionalHeader.hasValue(); }
  50   bool is64Bit() const {
  51     return Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64 ||
  52            Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_ARM64;
  53   }
  54
  55   uint32_t getFileAlignment() const {
  56     return Obj.OptionalHeader->Header.FileAlignment;
  57   }
  58
  59   unsigned getHeaderSize() const {
  60     return useBigObj() ? COFF::Header32Size : COFF::Header16Size;
  61   }
  62
  63   unsigned getSymbolSize() const {
  64     return useBigObj() ? COFF::Symbol32Size : COFF::Symbol16Size;
  65   }
  66
  67   bool parseSections() {
  68     for (std::vector<COFFYAML::Section>::iterator i = Obj.Sections.begin(),
  69                                                   e = Obj.Sections.end();
  70          i != e; ++i) {
  71       COFFYAML::Section &Sec = *i;
  72
  73       // If the name is less than 8 bytes, store it in place, otherwise
  74       // store it in the string table.
  75       StringRef Name = Sec.Name;
  76
  77       if (Name.size() <= COFF::NameSize) {
  78         std::copy(Name.begin(), Name.end(), Sec.Header.Name);
  79       } else {
  80         // Add string to the string table and format the index for output.
  81         unsigned Index = getStringIndex(Name);
  82         std::string str = utostr(Index);
  83         if (str.size() > 7) {
  84           errs() << "String table got too large\n";
  85           return false;
  86         }
  87         Sec.Header.Name[0] = '/';
  88         std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
  89       }
  90
  91       if (Sec.Alignment) {
  92         if (Sec.Alignment > 8192) {
  93           errs() << "Section alignment is too large\n";
  94           return false;
  95         }
  96         if (!isPowerOf2_32(Sec.Alignment)) {
  97           errs() << "Section alignment is not a power of 2\n";
  98           return false;
  99         }
 100         Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20;
 101       }
 102     }
 103     return true;
 104   }
 105
 106   bool parseSymbols() {
 107     for (std::vector<COFFYAML::Symbol>::iterator i = Obj.Symbols.begin(),
 108                                                  e = Obj.Symbols.end();
 109          i != e; ++i) {
 110       COFFYAML::Symbol &Sym = *i;
 111
 112       // If the name is less than 8 bytes, store it in place, otherwise
 113       // store it in the string table.
 114       StringRef Name = Sym.Name;
 115       if (Name.size() <= COFF::NameSize) {
 116         std::copy(Name.begin(), Name.end(), Sym.Header.Name);
 117       } else {
 118         // Add string to the string table and format the index for output.
 119         unsigned Index = getStringIndex(Name);
 120         *reinterpret_cast<support::aligned_ulittle32_t *>(Sym.Header.Name + 4) =
 121             Index;
 122       }
 123
 124       Sym.Header.Type = Sym.SimpleType;
 125       Sym.Header.Type |= Sym.ComplexType << COFF::SCT_COMPLEX_TYPE_SHIFT;
 126     }
 127     return true;
 128   }
 129
 130   bool parse() {
 131     if (!parseSections())
 132       return false;
 133     if (!parseSymbols())
 134       return false;
 135     return true;
 136   }
 137
 138   unsigned getStringIndex(StringRef Str) {
 139     StringMap<unsigned>::iterator i = StringTableMap.find(Str);
 140     if (i == StringTableMap.end()) {
 141       unsigned Index = StringTable.size();
 142       StringTable.append(Str.begin(), Str.end());
 143       StringTable.push_back(0);
 144       StringTableMap[Str] = Index;
 145       return Index;
 146     }
 147     return i->second;
 148   }
 149
 150   COFFYAML::Object &Obj;
 151
 152   codeview::StringsAndChecksums StringsAndChecksums;
 153   BumpPtrAllocator Allocator;
 154   StringMap<unsigned> StringTableMap;
 155   std::string StringTable;
 156   uint32_t SectionTableStart;
 157   uint32_t SectionTableSize;
 158 };
 159
 160 enum { DOSStubSize = 128 };
 161
 162 } // end anonymous namespace
 163
 164 // Take a CP and assign addresses and sizes to everything. Returns false if the
 165 // layout is not valid to do.
 166 static bool layoutOptionalHeader(COFFParser &CP) {
 167   if (!CP.isPE())
 168     return true;
 169   unsigned PEHeaderSize = CP.is64Bit() ? sizeof(object::pe32plus_header)
 170                                        : sizeof(object::pe32_header);
 171   CP.Obj.Header.SizeOfOptionalHeader =
 172       PEHeaderSize +
 173       sizeof(object::data_directory) * (COFF::NUM_DATA_DIRECTORIES + 1);
 174   return true;
 175 }
 176
 177 static yaml::BinaryRef
 178 toDebugS(ArrayRef<CodeViewYAML::YAMLDebugSubsection> Subsections,
 179          const codeview::StringsAndChecksums &SC, BumpPtrAllocator &Allocator) {
 180   using namespace codeview;
 181   ExitOnError Err("Error occurred writing .debug$S section");
 182   auto CVSS =
 183       Err(CodeViewYAML::toCodeViewSubsectionList(Allocator, Subsections, SC));
 184
 185   std::vector<DebugSubsectionRecordBuilder> Builders;
 186   uint32_t Size = sizeof(uint32_t);
 187   for (auto &SS : CVSS) {
 188     DebugSubsectionRecordBuilder B(SS, CodeViewContainer::ObjectFile);
 189     Size += B.calculateSerializedLength();
 190     Builders.push_back(std::move(B));
 191   }
 192   uint8_t *Buffer = Allocator.Allocate<uint8_t>(Size);
 193   MutableArrayRef<uint8_t> Output(Buffer, Size);
 194   BinaryStreamWriter Writer(Output, support::little);
 195
 196   Err(Writer.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC));
 197   for (const auto &B : Builders) {
 198     Err(B.commit(Writer));
 199   }
 200   return {Output};
 201 }
 202
 203 // Take a CP and assign addresses and sizes to everything. Returns false if the
 204 // layout is not valid to do.
 205 static bool layoutCOFF(COFFParser &CP) {
 206   // The section table starts immediately after the header, including the
 207   // optional header.
 208   CP.SectionTableStart =
 209       CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader;
 210   if (CP.isPE())
 211     CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic);
 212   CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size();
 213
 214   uint32_t CurrentSectionDataOffset =
 215       CP.SectionTableStart + CP.SectionTableSize;
 216
 217   for (COFFYAML::Section &S : CP.Obj.Sections) {
 218     // We support specifying exactly one of SectionData or Subsections.  So if
 219     // there is already some SectionData, then we don't need to do any of this.
 220     if (S.Name == ".debug$S" && S.SectionData.binary_size() == 0) {
 221       CodeViewYAML::initializeStringsAndChecksums(S.DebugS,
 222                                                   CP.StringsAndChecksums);
 223       if (CP.StringsAndChecksums.hasChecksums() &&
 224           CP.StringsAndChecksums.hasStrings())
 225         break;
 226     }
 227   }
 228
 229   // Assign each section data address consecutively.
 230   for (COFFYAML::Section &S : CP.Obj.Sections) {
 231     if (S.Name == ".debug$S") {
 232       if (S.SectionData.binary_size() == 0) {
 233         assert(CP.StringsAndChecksums.hasStrings() &&
 234                "Object file does not have debug string table!");
 235
 236         S.SectionData =
 237             toDebugS(S.DebugS, CP.StringsAndChecksums, CP.Allocator);
 238       }
 239     } else if (S.Name == ".debug$T") {
 240       if (S.SectionData.binary_size() == 0)
 241         S.SectionData = CodeViewYAML::toDebugT(S.DebugT, CP.Allocator, S.Name);
 242     } else if (S.Name == ".debug$P") {
 243       if (S.SectionData.binary_size() == 0)
 244         S.SectionData = CodeViewYAML::toDebugT(S.DebugP, CP.Allocator, S.Name);
 245     } else if (S.Name == ".debug$H") {
 246       if (S.DebugH.hasValue() && S.SectionData.binary_size() == 0)
 247         S.SectionData = CodeViewYAML::toDebugH(*S.DebugH, CP.Allocator);
 248     }
 249
 250     if (S.SectionData.binary_size() > 0) {
 251       CurrentSectionDataOffset = alignTo(CurrentSectionDataOffset,
 252                                          CP.isPE() ? CP.getFileAlignment() : 4);
 253       S.Header.SizeOfRawData = S.SectionData.binary_size();
 254       if (CP.isPE())
 255         S.Header.SizeOfRawData =
 256             alignTo(S.Header.SizeOfRawData, CP.getFileAlignment());
 257       S.Header.PointerToRawData = CurrentSectionDataOffset;
 258       CurrentSectionDataOffset += S.Header.SizeOfRawData;
 259       if (!S.Relocations.empty()) {
 260         S.Header.PointerToRelocations = CurrentSectionDataOffset;
 261         S.Header.NumberOfRelocations = S.Relocations.size();
 262         CurrentSectionDataOffset +=
 263             S.Header.NumberOfRelocations * COFF::RelocationSize;
 264       }
 265     } else {
 266       // Leave SizeOfRawData unaltered. For .bss sections in object files, it
 267       // carries the section size.
 268       S.Header.PointerToRawData = 0;
 269     }
 270   }
 271
 272   uint32_t SymbolTableStart = CurrentSectionDataOffset;
 273
 274   // Calculate number of symbols.
 275   uint32_t NumberOfSymbols = 0;
 276   for (std::vector<COFFYAML::Symbol>::iterator i = CP.Obj.Symbols.begin(),
 277                                                e = CP.Obj.Symbols.end();
 278        i != e; ++i) {
 279     uint32_t NumberOfAuxSymbols = 0;
 280     if (i->FunctionDefinition)
 281       NumberOfAuxSymbols += 1;
 282     if (i->bfAndefSymbol)
 283       NumberOfAuxSymbols += 1;
 284     if (i->WeakExternal)
 285       NumberOfAuxSymbols += 1;
 286     if (!i->File.empty())
 287       NumberOfAuxSymbols +=
 288           (i->File.size() + CP.getSymbolSize() - 1) / CP.getSymbolSize();
 289     if (i->SectionDefinition)
 290       NumberOfAuxSymbols += 1;
 291     if (i->CLRToken)
 292       NumberOfAuxSymbols += 1;
 293     i->Header.NumberOfAuxSymbols = NumberOfAuxSymbols;
 294     NumberOfSymbols += 1 + NumberOfAuxSymbols;
 295   }
 296
 297   // Store all the allocated start addresses in the header.
 298   CP.Obj.Header.NumberOfSections = CP.Obj.Sections.size();
 299   CP.Obj.Header.NumberOfSymbols = NumberOfSymbols;
 300   if (NumberOfSymbols > 0 || CP.StringTable.size() > 4)
 301     CP.Obj.Header.PointerToSymbolTable = SymbolTableStart;
 302   else
 303     CP.Obj.Header.PointerToSymbolTable = 0;
 304
 305   *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0]) =
 306       CP.StringTable.size();
 307
 308   return true;
 309 }
 310
 311 template <typename value_type> struct binary_le_impl {
 312   value_type Value;
 313   binary_le_impl(value_type V) : Value(V) {}
 314 };
 315
 316 template <typename value_type>
 317 raw_ostream &operator<<(raw_ostream &OS,
 318                         const binary_le_impl<value_type> &BLE) {
 319   char Buffer[sizeof(BLE.Value)];
 320   support::endian::write<value_type, support::little, support::unaligned>(
 321       Buffer, BLE.Value);
 322   OS.write(Buffer, sizeof(BLE.Value));
 323   return OS;
 324 }
 325
 326 template <typename value_type>
 327 binary_le_impl<value_type> binary_le(value_type V) {
 328   return binary_le_impl<value_type>(V);
 329 }
 330
 331 template <size_t NumBytes> struct zeros_impl {};
 332
 333 template <size_t NumBytes>
 334 raw_ostream &operator<<(raw_ostream &OS, const zeros_impl<NumBytes> &) {
 335   char Buffer[NumBytes];
 336   memset(Buffer, 0, sizeof(Buffer));
 337   OS.write(Buffer, sizeof(Buffer));
 338   return OS;
 339 }
 340
 341 template <typename T> zeros_impl<sizeof(T)> zeros(const T &) {
 342   return zeros_impl<sizeof(T)>();
 343 }
 344
 345 template <typename T>
 346 static uint32_t initializeOptionalHeader(COFFParser &CP, uint16_t Magic,
 347                                          T Header) {
 348   memset(Header, 0, sizeof(*Header));
 349   Header->Magic = Magic;
 350   Header->SectionAlignment = CP.Obj.OptionalHeader->Header.SectionAlignment;
 351   Header->FileAlignment = CP.Obj.OptionalHeader->Header.FileAlignment;
 352   uint32_t SizeOfCode = 0, SizeOfInitializedData = 0,
 353            SizeOfUninitializedData = 0;
 354   uint32_t SizeOfHeaders = alignTo(CP.SectionTableStart + CP.SectionTableSize,
 355                                    Header->FileAlignment);
 356   uint32_t SizeOfImage = alignTo(SizeOfHeaders, Header->SectionAlignment);
 357   uint32_t BaseOfData = 0;
 358   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 359     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_CODE)
 360       SizeOfCode += S.Header.SizeOfRawData;
 361     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
 362       SizeOfInitializedData += S.Header.SizeOfRawData;
 363     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
 364       SizeOfUninitializedData += S.Header.SizeOfRawData;
 365     if (S.Name.equals(".text"))
 366       Header->BaseOfCode = S.Header.VirtualAddress; // RVA
 367     else if (S.Name.equals(".data"))
 368       BaseOfData = S.Header.VirtualAddress; // RVA
 369     if (S.Header.VirtualAddress)
 370       SizeOfImage += alignTo(S.Header.VirtualSize, Header->SectionAlignment);
 371   }
 372   Header->SizeOfCode = SizeOfCode;
 373   Header->SizeOfInitializedData = SizeOfInitializedData;
 374   Header->SizeOfUninitializedData = SizeOfUninitializedData;
 375   Header->AddressOfEntryPoint =
 376       CP.Obj.OptionalHeader->Header.AddressOfEntryPoint; // RVA
 377   Header->ImageBase = CP.Obj.OptionalHeader->Header.ImageBase;
 378   Header->MajorOperatingSystemVersion =
 379       CP.Obj.OptionalHeader->Header.MajorOperatingSystemVersion;
 380   Header->MinorOperatingSystemVersion =
 381       CP.Obj.OptionalHeader->Header.MinorOperatingSystemVersion;
 382   Header->MajorImageVersion = CP.Obj.OptionalHeader->Header.MajorImageVersion;
 383   Header->MinorImageVersion = CP.Obj.OptionalHeader->Header.MinorImageVersion;
 384   Header->MajorSubsystemVersion =
 385       CP.Obj.OptionalHeader->Header.MajorSubsystemVersion;
 386   Header->MinorSubsystemVersion =
 387       CP.Obj.OptionalHeader->Header.MinorSubsystemVersion;
 388   Header->SizeOfImage = SizeOfImage;
 389   Header->SizeOfHeaders = SizeOfHeaders;
 390   Header->Subsystem = CP.Obj.OptionalHeader->Header.Subsystem;
 391   Header->DLLCharacteristics = CP.Obj.OptionalHeader->Header.DLLCharacteristics;
 392   Header->SizeOfStackReserve = CP.Obj.OptionalHeader->Header.SizeOfStackReserve;
 393   Header->SizeOfStackCommit = CP.Obj.OptionalHeader->Header.SizeOfStackCommit;
 394   Header->SizeOfHeapReserve = CP.Obj.OptionalHeader->Header.SizeOfHeapReserve;
 395   Header->SizeOfHeapCommit = CP.Obj.OptionalHeader->Header.SizeOfHeapCommit;
 396   Header->NumberOfRvaAndSize = COFF::NUM_DATA_DIRECTORIES + 1;
 397   return BaseOfData;
 398 }
 399
 400 static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
 401   if (CP.isPE()) {
 402     // PE files start with a DOS stub.
 403     object::dos_header DH;
 404     memset(&DH, 0, sizeof(DH));
 405
 406     // DOS EXEs start with "MZ" magic.
 407     DH.Magic[0] = 'M';
 408     DH.Magic[1] = 'Z';
 409     // Initializing the AddressOfRelocationTable is strictly optional but
 410     // mollifies certain tools which expect it to have a value greater than
 411     // 0x40.
 412     DH.AddressOfRelocationTable = sizeof(DH);
 413     // This is the address of the PE signature.
 414     DH.AddressOfNewExeHeader = DOSStubSize;
 415
 416     // Write out our DOS stub.
 417     OS.write(reinterpret_cast<char *>(&DH), sizeof(DH));
 418     // Write padding until we reach the position of where our PE signature
 419     // should live.
 420     OS.write_zeros(DOSStubSize - sizeof(DH));
 421     // Write out the PE signature.
 422     OS.write(COFF::PEMagic, sizeof(COFF::PEMagic));
 423   }
 424   if (CP.useBigObj()) {
 425     OS << binary_le(static_cast<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN))
 426        << binary_le(static_cast<uint16_t>(0xffff))
 427        << binary_le(
 428               static_cast<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion))
 429        << binary_le(CP.Obj.Header.Machine)
 430        << binary_le(CP.Obj.Header.TimeDateStamp);
 431     OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
 432     OS << zeros(uint32_t(0)) << zeros(uint32_t(0)) << zeros(uint32_t(0))
 433        << zeros(uint32_t(0)) << binary_le(CP.Obj.Header.NumberOfSections)
 434        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 435        << binary_le(CP.Obj.Header.NumberOfSymbols);
 436   } else {
 437     OS << binary_le(CP.Obj.Header.Machine)
 438        << binary_le(static_cast<int16_t>(CP.Obj.Header.NumberOfSections))
 439        << binary_le(CP.Obj.Header.TimeDateStamp)
 440        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 441        << binary_le(CP.Obj.Header.NumberOfSymbols)
 442        << binary_le(CP.Obj.Header.SizeOfOptionalHeader)
 443        << binary_le(CP.Obj.Header.Characteristics);
 444   }
 445   if (CP.isPE()) {
 446     if (CP.is64Bit()) {
 447       object::pe32plus_header PEH;
 448       initializeOptionalHeader(CP, COFF::PE32Header::PE32_PLUS, &PEH);
 449       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 450     } else {
 451       object::pe32_header PEH;
 452       uint32_t BaseOfData =
 453           initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH);
 454       PEH.BaseOfData = BaseOfData;
 455       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 456     }
 457     for (const Optional<COFF::DataDirectory> &DD :
 458          CP.Obj.OptionalHeader->DataDirectories) {
 459       if (!DD.hasValue()) {
 460         OS << zeros(uint32_t(0));
 461         OS << zeros(uint32_t(0));
 462       } else {
 463         OS << binary_le(DD->RelativeVirtualAddress);
 464         OS << binary_le(DD->Size);
 465       }
 466     }
 467     OS << zeros(uint32_t(0));
 468     OS << zeros(uint32_t(0));
 469   }
 470
 471   assert(OS.tell() == CP.SectionTableStart);
 472   // Output section table.
 473   for (std::vector<COFFYAML::Section>::iterator i = CP.Obj.Sections.begin(),
 474                                                 e = CP.Obj.Sections.end();
 475        i != e; ++i) {
 476     OS.write(i->Header.Name, COFF::NameSize);
 477     OS << binary_le(i->Header.VirtualSize)
 478        << binary_le(i->Header.VirtualAddress)
 479        << binary_le(i->Header.SizeOfRawData)
 480        << binary_le(i->Header.PointerToRawData)
 481        << binary_le(i->Header.PointerToRelocations)
 482        << binary_le(i->Header.PointerToLineNumbers)
 483        << binary_le(i->Header.NumberOfRelocations)
 484        << binary_le(i->Header.NumberOfLineNumbers)
 485        << binary_le(i->Header.Characteristics);
 486   }
 487   assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize);
 488
 489   unsigned CurSymbol = 0;
 490   StringMap<unsigned> SymbolTableIndexMap;
 491   for (std::vector<COFFYAML::Symbol>::iterator I = CP.Obj.Symbols.begin(),
 492                                                E = CP.Obj.Symbols.end();
 493        I != E; ++I) {
 494     SymbolTableIndexMap[I->Name] = CurSymbol;
 495     CurSymbol += 1 + I->Header.NumberOfAuxSymbols;
 496   }
 497
 498   // Output section data.
 499   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 500     if (S.Header.SizeOfRawData == 0 || S.Header.PointerToRawData == 0)
 501       continue;
 502     assert(S.Header.PointerToRawData >= OS.tell());
 503     OS.write_zeros(S.Header.PointerToRawData - OS.tell());
 504     S.SectionData.writeAsBinary(OS);
 505     assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
 506     OS.write_zeros(S.Header.SizeOfRawData - S.SectionData.binary_size());
 507     for (const COFFYAML::Relocation &R : S.Relocations) {
 508       uint32_t SymbolTableIndex;
 509       if (R.SymbolTableIndex) {
 510         if (!R.SymbolName.empty())
 511           WithColor::error()
 512               << "Both SymbolName and SymbolTableIndex specified\n";
 513         SymbolTableIndex = *R.SymbolTableIndex;
 514       } else {
 515         SymbolTableIndex = SymbolTableIndexMap[R.SymbolName];
 516       }
 517       OS << binary_le(R.VirtualAddress) << binary_le(SymbolTableIndex)
 518          << binary_le(R.Type);
 519     }
 520   }
 521
 522   // Output symbol table.
 523
 524   for (std::vector<COFFYAML::Symbol>::const_iterator i = CP.Obj.Symbols.begin(),
 525                                                      e = CP.Obj.Symbols.end();
 526        i != e; ++i) {
 527     OS.write(i->Header.Name, COFF::NameSize);
 528     OS << binary_le(i->Header.Value);
 529     if (CP.useBigObj())
 530       OS << binary_le(i->Header.SectionNumber);
 531     else
 532       OS << binary_le(static_cast<int16_t>(i->Header.SectionNumber));
 533     OS << binary_le(i->Header.Type) << binary_le(i->Header.StorageClass)
 534        << binary_le(i->Header.NumberOfAuxSymbols);
 535
 536     if (i->FunctionDefinition) {
 537       OS << binary_le(i->FunctionDefinition->TagIndex)
 538          << binary_le(i->FunctionDefinition->TotalSize)
 539          << binary_le(i->FunctionDefinition->PointerToLinenumber)
 540          << binary_le(i->FunctionDefinition->PointerToNextFunction)
 541          << zeros(i->FunctionDefinition->unused);
 542       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 543     }
 544     if (i->bfAndefSymbol) {
 545       OS << zeros(i->bfAndefSymbol->unused1)
 546          << binary_le(i->bfAndefSymbol->Linenumber)
 547          << zeros(i->bfAndefSymbol->unused2)
 548          << binary_le(i->bfAndefSymbol->PointerToNextFunction)
 549          << zeros(i->bfAndefSymbol->unused3);
 550       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 551     }
 552     if (i->WeakExternal) {
 553       OS << binary_le(i->WeakExternal->TagIndex)
 554          << binary_le(i->WeakExternal->Characteristics)
 555          << zeros(i->WeakExternal->unused);
 556       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 557     }
 558     if (!i->File.empty()) {
 559       unsigned SymbolSize = CP.getSymbolSize();
 560       uint32_t NumberOfAuxRecords =
 561           (i->File.size() + SymbolSize - 1) / SymbolSize;
 562       uint32_t NumberOfAuxBytes = NumberOfAuxRecords * SymbolSize;
 563       uint32_t NumZeros = NumberOfAuxBytes - i->File.size();
 564       OS.write(i->File.data(), i->File.size());
 565       OS.write_zeros(NumZeros);
 566     }
 567     if (i->SectionDefinition) {
 568       OS << binary_le(i->SectionDefinition->Length)
 569          << binary_le(i->SectionDefinition->NumberOfRelocations)
 570          << binary_le(i->SectionDefinition->NumberOfLinenumbers)
 571          << binary_le(i->SectionDefinition->CheckSum)
 572          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number))
 573          << binary_le(i->SectionDefinition->Selection)
 574          << zeros(i->SectionDefinition->unused)
 575          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number >> 16));
 576       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 577     }
 578     if (i->CLRToken) {
 579       OS << binary_le(i->CLRToken->AuxType) << zeros(i->CLRToken->unused1)
 580          << binary_le(i->CLRToken->SymbolTableIndex)
 581          << zeros(i->CLRToken->unused2);
 582       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 583     }
 584   }
 585
 586   // Output string table.
 587   if (CP.Obj.Header.PointerToSymbolTable)
 588     OS.write(&CP.StringTable[0], CP.StringTable.size());
 589   return true;
 590 }
 591
 592 namespace llvm {
 593 namespace yaml {
 594
 595 int yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out) {
 596   COFFParser CP(Doc);
 597   if (!CP.parse()) {
 598     errs() << "yaml2obj: Failed to parse YAML file!\n";
 599     return 1;
 600   }
 601
 602   if (!layoutOptionalHeader(CP)) {
 603     errs() << "yaml2obj: Failed to layout optional header for COFF file!\n";
 604     return 1;
 605   }
 606
 607   if (!layoutCOFF(CP)) {
 608     errs() << "yaml2obj: Failed to layout COFF file!\n";
 609     return 1;
 610   }
 611   if (!writeCOFF(CP, Out)) {
 612     errs() << "yaml2obj: Failed to write COFF file!\n";
 613     return 1;
 614   }
 615   return 0;
 616 }
 617
 618 } // namespace yaml
 619 } // namespace llvm