tools/yaml2obj/yaml2coff.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 "yaml2obj.h"
  15 #include "llvm/ADT/STLExtras.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include "llvm/ADT/StringMap.h"
  18 #include "llvm/ADT/StringSwitch.h"
  19 #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
  20 #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h"
  21 #include "llvm/Object/COFF.h"
  22 #include "llvm/ObjectYAML/ObjectYAML.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 /// This parses a yaml stream that represents a COFF object file.
  33 /// See docs/yaml2obj for the yaml scheema.
  34 struct COFFParser {
  35   COFFParser(COFFYAML::Object &Obj)
  36       : Obj(Obj), SectionTableStart(0), SectionTableSize(0) {
  37     // A COFF string table always starts with a 4 byte size field. Offsets into
  38     // it include this size, so allocate it now.
  39     StringTable.append(4, char(0));
  40   }
  41
  42   bool useBigObj() const {
  43     return static_cast<int32_t>(Obj.Sections.size()) >
  44            COFF::MaxNumberOfSections16;
  45   }
  46
  47   bool isPE() const { return Obj.OptionalHeader.hasValue(); }
  48   bool is64Bit() const {
  49     return Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64 ||
  50            Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_ARM64;
  51   }
  52
  53   uint32_t getFileAlignment() const {
  54     return Obj.OptionalHeader->Header.FileAlignment;
  55   }
  56
  57   unsigned getHeaderSize() const {
  58     return useBigObj() ? COFF::Header32Size : COFF::Header16Size;
  59   }
  60
  61   unsigned getSymbolSize() const {
  62     return useBigObj() ? COFF::Symbol32Size : COFF::Symbol16Size;
  63   }
  64
  65   bool parseSections() {
  66     for (std::vector<COFFYAML::Section>::iterator i = Obj.Sections.begin(),
  67            e = Obj.Sections.end(); i != e; ++i) {
  68       COFFYAML::Section &Sec = *i;
  69
  70       // If the name is less than 8 bytes, store it in place, otherwise
  71       // store it in the string table.
  72       StringRef Name = Sec.Name;
  73
  74       if (Name.size() <= COFF::NameSize) {
  75         std::copy(Name.begin(), Name.end(), Sec.Header.Name);
  76       } else {
  77         // Add string to the string table and format the index for output.
  78         unsigned Index = getStringIndex(Name);
  79         std::string str = utostr(Index);
  80         if (str.size() > 7) {
  81           errs() << "String table got too large\n";
  82           return false;
  83         }
  84         Sec.Header.Name[0] = '/';
  85         std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
  86       }
  87
  88       if (Sec.Alignment) {
  89         if (Sec.Alignment > 8192) {
  90           errs() << "Section alignment is too large\n";
  91           return false;
  92         }
  93         if (!isPowerOf2_32(Sec.Alignment)) {
  94           errs() << "Section alignment is not a power of 2\n";
  95           return false;
  96         }
  97         Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20;
  98       }
  99     }
 100     return true;
 101   }
 102
 103   bool parseSymbols() {
 104     for (std::vector<COFFYAML::Symbol>::iterator i = Obj.Symbols.begin(),
 105            e = Obj.Symbols.end(); i != e; ++i) {
 106       COFFYAML::Symbol &Sym = *i;
 107
 108       // If the name is less than 8 bytes, store it in place, otherwise
 109       // store it in the string table.
 110       StringRef Name = Sym.Name;
 111       if (Name.size() <= COFF::NameSize) {
 112         std::copy(Name.begin(), Name.end(), Sym.Header.Name);
 113       } else {
 114         // Add string to the string table and format the index for output.
 115         unsigned Index = getStringIndex(Name);
 116         *reinterpret_cast<support::aligned_ulittle32_t*>(
 117             Sym.Header.Name + 4) = Index;
 118       }
 119
 120       Sym.Header.Type = Sym.SimpleType;
 121       Sym.Header.Type |= Sym.ComplexType << COFF::SCT_COMPLEX_TYPE_SHIFT;
 122     }
 123     return true;
 124   }
 125
 126   bool parse() {
 127     if (!parseSections())
 128       return false;
 129     if (!parseSymbols())
 130       return false;
 131     return true;
 132   }
 133
 134   unsigned getStringIndex(StringRef Str) {
 135     StringMap<unsigned>::iterator i = StringTableMap.find(Str);
 136     if (i == StringTableMap.end()) {
 137       unsigned Index = StringTable.size();
 138       StringTable.append(Str.begin(), Str.end());
 139       StringTable.push_back(0);
 140       StringTableMap[Str] = Index;
 141       return Index;
 142     }
 143     return i->second;
 144   }
 145
 146   COFFYAML::Object &Obj;
 147
 148   codeview::StringsAndChecksums StringsAndChecksums;
 149   BumpPtrAllocator Allocator;
 150   StringMap<unsigned> StringTableMap;
 151   std::string StringTable;
 152   uint32_t SectionTableStart;
 153   uint32_t SectionTableSize;
 154 };
 155
 156 // Take a CP and assign addresses and sizes to everything. Returns false if the
 157 // layout is not valid to do.
 158 static bool layoutOptionalHeader(COFFParser &CP) {
 159   if (!CP.isPE())
 160     return true;
 161   unsigned PEHeaderSize = CP.is64Bit() ? sizeof(object::pe32plus_header)
 162                                        : sizeof(object::pe32_header);
 163   CP.Obj.Header.SizeOfOptionalHeader =
 164       PEHeaderSize +
 165       sizeof(object::data_directory) * (COFF::NUM_DATA_DIRECTORIES + 1);
 166   return true;
 167 }
 168
 169 namespace {
 170 enum { DOSStubSize = 128 };
 171 }
 172
 173 static yaml::BinaryRef
 174 toDebugS(ArrayRef<CodeViewYAML::YAMLDebugSubsection> Subsections,
 175          const codeview::StringsAndChecksums &SC, BumpPtrAllocator &Allocator) {
 176   using namespace codeview;
 177   ExitOnError Err("Error occurred writing .debug$S section");
 178   auto CVSS =
 179       Err(CodeViewYAML::toCodeViewSubsectionList(Allocator, Subsections, SC));
 180
 181   std::vector<DebugSubsectionRecordBuilder> Builders;
 182   uint32_t Size = sizeof(uint32_t);
 183   for (auto &SS : CVSS) {
 184     DebugSubsectionRecordBuilder B(SS, CodeViewContainer::ObjectFile);
 185     Size += B.calculateSerializedLength();
 186     Builders.push_back(std::move(B));
 187   }
 188   uint8_t *Buffer = Allocator.Allocate<uint8_t>(Size);
 189   MutableArrayRef<uint8_t> Output(Buffer, Size);
 190   BinaryStreamWriter Writer(Output, support::little);
 191
 192   Err(Writer.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC));
 193   for (const auto &B : Builders) {
 194     Err(B.commit(Writer));
 195   }
 196   return {Output};
 197 }
 198
 199 // Take a CP and assign addresses and sizes to everything. Returns false if the
 200 // layout is not valid to do.
 201 static bool layoutCOFF(COFFParser &CP) {
 202   // The section table starts immediately after the header, including the
 203   // optional header.
 204   CP.SectionTableStart =
 205       CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader;
 206   if (CP.isPE())
 207     CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic);
 208   CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size();
 209
 210   uint32_t CurrentSectionDataOffset =
 211       CP.SectionTableStart + CP.SectionTableSize;
 212
 213   for (COFFYAML::Section &S : CP.Obj.Sections) {
 214     // We support specifying exactly one of SectionData or Subsections.  So if
 215     // there is already some SectionData, then we don't need to do any of this.
 216     if (S.Name == ".debug$S" && S.SectionData.binary_size() == 0) {
 217       CodeViewYAML::initializeStringsAndChecksums(S.DebugS,
 218                                                   CP.StringsAndChecksums);
 219       if (CP.StringsAndChecksums.hasChecksums() &&
 220           CP.StringsAndChecksums.hasStrings())
 221         break;
 222     }
 223   }
 224
 225   // Assign each section data address consecutively.
 226   for (COFFYAML::Section &S : CP.Obj.Sections) {
 227     if (S.Name == ".debug$S") {
 228       if (S.SectionData.binary_size() == 0) {
 229         assert(CP.StringsAndChecksums.hasStrings() &&
 230                "Object file does not have debug string table!");
 231
 232         S.SectionData =
 233             toDebugS(S.DebugS, CP.StringsAndChecksums, CP.Allocator);
 234       }
 235     } else if (S.Name == ".debug$T") {
 236       if (S.SectionData.binary_size() == 0)
 237         S.SectionData = CodeViewYAML::toDebugT(S.DebugT, CP.Allocator, S.Name);
 238     } else if (S.Name == ".debug$P") {
 239       if (S.SectionData.binary_size() == 0)
 240         S.SectionData = CodeViewYAML::toDebugT(S.DebugP, CP.Allocator, S.Name);
 241     } else if (S.Name == ".debug$H") {
 242       if (S.DebugH.hasValue() && S.SectionData.binary_size() == 0)
 243         S.SectionData = CodeViewYAML::toDebugH(*S.DebugH, CP.Allocator);
 244     }
 245
 246     if (S.SectionData.binary_size() > 0) {
 247       CurrentSectionDataOffset = alignTo(CurrentSectionDataOffset,
 248                                          CP.isPE() ? CP.getFileAlignment() : 4);
 249       S.Header.SizeOfRawData = S.SectionData.binary_size();
 250       if (CP.isPE())
 251         S.Header.SizeOfRawData =
 252             alignTo(S.Header.SizeOfRawData, CP.getFileAlignment());
 253       S.Header.PointerToRawData = CurrentSectionDataOffset;
 254       CurrentSectionDataOffset += S.Header.SizeOfRawData;
 255       if (!S.Relocations.empty()) {
 256         S.Header.PointerToRelocations = CurrentSectionDataOffset;
 257         S.Header.NumberOfRelocations = S.Relocations.size();
 258         CurrentSectionDataOffset +=
 259             S.Header.NumberOfRelocations * COFF::RelocationSize;
 260       }
 261     } else {
 262       S.Header.SizeOfRawData = 0;
 263       S.Header.PointerToRawData = 0;
 264     }
 265   }
 266
 267   uint32_t SymbolTableStart = CurrentSectionDataOffset;
 268
 269   // Calculate number of symbols.
 270   uint32_t NumberOfSymbols = 0;
 271   for (std::vector<COFFYAML::Symbol>::iterator i = CP.Obj.Symbols.begin(),
 272                                                e = CP.Obj.Symbols.end();
 273                                                i != e; ++i) {
 274     uint32_t NumberOfAuxSymbols = 0;
 275     if (i->FunctionDefinition)
 276       NumberOfAuxSymbols += 1;
 277     if (i->bfAndefSymbol)
 278       NumberOfAuxSymbols += 1;
 279     if (i->WeakExternal)
 280       NumberOfAuxSymbols += 1;
 281     if (!i->File.empty())
 282       NumberOfAuxSymbols +=
 283           (i->File.size() + CP.getSymbolSize() - 1) / CP.getSymbolSize();
 284     if (i->SectionDefinition)
 285       NumberOfAuxSymbols += 1;
 286     if (i->CLRToken)
 287       NumberOfAuxSymbols += 1;
 288     i->Header.NumberOfAuxSymbols = NumberOfAuxSymbols;
 289     NumberOfSymbols += 1 + NumberOfAuxSymbols;
 290   }
 291
 292   // Store all the allocated start addresses in the header.
 293   CP.Obj.Header.NumberOfSections = CP.Obj.Sections.size();
 294   CP.Obj.Header.NumberOfSymbols = NumberOfSymbols;
 295   if (NumberOfSymbols > 0 || CP.StringTable.size() > 4)
 296     CP.Obj.Header.PointerToSymbolTable = SymbolTableStart;
 297   else
 298     CP.Obj.Header.PointerToSymbolTable = 0;
 299
 300   *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0])
 301     = CP.StringTable.size();
 302
 303   return true;
 304 }
 305
 306 template <typename value_type>
 307 struct binary_le_impl {
 308   value_type Value;
 309   binary_le_impl(value_type V) : Value(V) {}
 310 };
 311
 312 template <typename value_type>
 313 raw_ostream &operator <<( raw_ostream &OS
 314                         , const binary_le_impl<value_type> &BLE) {
 315   char Buffer[sizeof(BLE.Value)];
 316   support::endian::write<value_type, support::little, support::unaligned>(
 317     Buffer, BLE.Value);
 318   OS.write(Buffer, sizeof(BLE.Value));
 319   return OS;
 320 }
 321
 322 template <typename value_type>
 323 binary_le_impl<value_type> binary_le(value_type V) {
 324   return binary_le_impl<value_type>(V);
 325 }
 326
 327 template <size_t NumBytes> struct zeros_impl {};
 328
 329 template <size_t NumBytes>
 330 raw_ostream &operator<<(raw_ostream &OS, const zeros_impl<NumBytes> &) {
 331   char Buffer[NumBytes];
 332   memset(Buffer, 0, sizeof(Buffer));
 333   OS.write(Buffer, sizeof(Buffer));
 334   return OS;
 335 }
 336
 337 template <typename T>
 338 zeros_impl<sizeof(T)> zeros(const T &) {
 339   return zeros_impl<sizeof(T)>();
 340 }
 341
 342 struct num_zeros_impl {
 343   size_t N;
 344   num_zeros_impl(size_t N) : N(N) {}
 345 };
 346
 347 raw_ostream &operator<<(raw_ostream &OS, const num_zeros_impl &NZI) {
 348   for (size_t I = 0; I != NZI.N; ++I)
 349     OS.write(0);
 350   return OS;
 351 }
 352
 353 static num_zeros_impl num_zeros(size_t N) {
 354   num_zeros_impl NZI(N);
 355   return NZI;
 356 }
 357
 358 template <typename T>
 359 static uint32_t initializeOptionalHeader(COFFParser &CP, uint16_t Magic, T Header) {
 360   memset(Header, 0, sizeof(*Header));
 361   Header->Magic = Magic;
 362   Header->SectionAlignment = CP.Obj.OptionalHeader->Header.SectionAlignment;
 363   Header->FileAlignment = CP.Obj.OptionalHeader->Header.FileAlignment;
 364   uint32_t SizeOfCode = 0, SizeOfInitializedData = 0,
 365            SizeOfUninitializedData = 0;
 366   uint32_t SizeOfHeaders = alignTo(CP.SectionTableStart + CP.SectionTableSize,
 367                                    Header->FileAlignment);
 368   uint32_t SizeOfImage = alignTo(SizeOfHeaders, Header->SectionAlignment);
 369   uint32_t BaseOfData = 0;
 370   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 371     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_CODE)
 372       SizeOfCode += S.Header.SizeOfRawData;
 373     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
 374       SizeOfInitializedData += S.Header.SizeOfRawData;
 375     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
 376       SizeOfUninitializedData += S.Header.SizeOfRawData;
 377     if (S.Name.equals(".text"))
 378       Header->BaseOfCode = S.Header.VirtualAddress; // RVA
 379     else if (S.Name.equals(".data"))
 380       BaseOfData = S.Header.VirtualAddress; // RVA
 381     if (S.Header.VirtualAddress)
 382       SizeOfImage += alignTo(S.Header.VirtualSize, Header->SectionAlignment);
 383   }
 384   Header->SizeOfCode = SizeOfCode;
 385   Header->SizeOfInitializedData = SizeOfInitializedData;
 386   Header->SizeOfUninitializedData = SizeOfUninitializedData;
 387   Header->AddressOfEntryPoint =
 388       CP.Obj.OptionalHeader->Header.AddressOfEntryPoint; // RVA
 389   Header->ImageBase = CP.Obj.OptionalHeader->Header.ImageBase;
 390   Header->MajorOperatingSystemVersion =
 391       CP.Obj.OptionalHeader->Header.MajorOperatingSystemVersion;
 392   Header->MinorOperatingSystemVersion =
 393       CP.Obj.OptionalHeader->Header.MinorOperatingSystemVersion;
 394   Header->MajorImageVersion =
 395       CP.Obj.OptionalHeader->Header.MajorImageVersion;
 396   Header->MinorImageVersion =
 397       CP.Obj.OptionalHeader->Header.MinorImageVersion;
 398   Header->MajorSubsystemVersion =
 399       CP.Obj.OptionalHeader->Header.MajorSubsystemVersion;
 400   Header->MinorSubsystemVersion =
 401       CP.Obj.OptionalHeader->Header.MinorSubsystemVersion;
 402   Header->SizeOfImage = SizeOfImage;
 403   Header->SizeOfHeaders = SizeOfHeaders;
 404   Header->Subsystem = CP.Obj.OptionalHeader->Header.Subsystem;
 405   Header->DLLCharacteristics = CP.Obj.OptionalHeader->Header.DLLCharacteristics;
 406   Header->SizeOfStackReserve = CP.Obj.OptionalHeader->Header.SizeOfStackReserve;
 407   Header->SizeOfStackCommit = CP.Obj.OptionalHeader->Header.SizeOfStackCommit;
 408   Header->SizeOfHeapReserve = CP.Obj.OptionalHeader->Header.SizeOfHeapReserve;
 409   Header->SizeOfHeapCommit = CP.Obj.OptionalHeader->Header.SizeOfHeapCommit;
 410   Header->NumberOfRvaAndSize = COFF::NUM_DATA_DIRECTORIES + 1;
 411   return BaseOfData;
 412 }
 413
 414 static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
 415   if (CP.isPE()) {
 416     // PE files start with a DOS stub.
 417     object::dos_header DH;
 418     memset(&DH, 0, sizeof(DH));
 419
 420     // DOS EXEs start with "MZ" magic.
 421     DH.Magic[0] = 'M';
 422     DH.Magic[1] = 'Z';
 423     // Initializing the AddressOfRelocationTable is strictly optional but
 424     // mollifies certain tools which expect it to have a value greater than
 425     // 0x40.
 426     DH.AddressOfRelocationTable = sizeof(DH);
 427     // This is the address of the PE signature.
 428     DH.AddressOfNewExeHeader = DOSStubSize;
 429
 430     // Write out our DOS stub.
 431     OS.write(reinterpret_cast<char *>(&DH), sizeof(DH));
 432     // Write padding until we reach the position of where our PE signature
 433     // should live.
 434     OS << num_zeros(DOSStubSize - sizeof(DH));
 435     // Write out the PE signature.
 436     OS.write(COFF::PEMagic, sizeof(COFF::PEMagic));
 437   }
 438   if (CP.useBigObj()) {
 439     OS << binary_le(static_cast<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN))
 440        << binary_le(static_cast<uint16_t>(0xffff))
 441        << binary_le(static_cast<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion))
 442        << binary_le(CP.Obj.Header.Machine)
 443        << binary_le(CP.Obj.Header.TimeDateStamp);
 444     OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
 445     OS << zeros(uint32_t(0))
 446        << zeros(uint32_t(0))
 447        << zeros(uint32_t(0))
 448        << zeros(uint32_t(0))
 449        << binary_le(CP.Obj.Header.NumberOfSections)
 450        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 451        << binary_le(CP.Obj.Header.NumberOfSymbols);
 452   } else {
 453     OS << binary_le(CP.Obj.Header.Machine)
 454        << binary_le(static_cast<int16_t>(CP.Obj.Header.NumberOfSections))
 455        << binary_le(CP.Obj.Header.TimeDateStamp)
 456        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 457        << binary_le(CP.Obj.Header.NumberOfSymbols)
 458        << binary_le(CP.Obj.Header.SizeOfOptionalHeader)
 459        << binary_le(CP.Obj.Header.Characteristics);
 460   }
 461   if (CP.isPE()) {
 462     if (CP.is64Bit()) {
 463       object::pe32plus_header PEH;
 464       initializeOptionalHeader(CP, COFF::PE32Header::PE32_PLUS, &PEH);
 465       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 466     } else {
 467       object::pe32_header PEH;
 468       uint32_t BaseOfData = initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH);
 469       PEH.BaseOfData = BaseOfData;
 470       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 471     }
 472     for (const Optional<COFF::DataDirectory> &DD :
 473          CP.Obj.OptionalHeader->DataDirectories) {
 474       if (!DD.hasValue()) {
 475         OS << zeros(uint32_t(0));
 476         OS << zeros(uint32_t(0));
 477       } else {
 478         OS << binary_le(DD->RelativeVirtualAddress);
 479         OS << binary_le(DD->Size);
 480       }
 481     }
 482     OS << zeros(uint32_t(0));
 483     OS << zeros(uint32_t(0));
 484   }
 485
 486   assert(OS.tell() == CP.SectionTableStart);
 487   // Output section table.
 488   for (std::vector<COFFYAML::Section>::iterator i = CP.Obj.Sections.begin(),
 489                                                 e = CP.Obj.Sections.end();
 490                                                 i != e; ++i) {
 491     OS.write(i->Header.Name, COFF::NameSize);
 492     OS << binary_le(i->Header.VirtualSize)
 493        << binary_le(i->Header.VirtualAddress)
 494        << binary_le(i->Header.SizeOfRawData)
 495        << binary_le(i->Header.PointerToRawData)
 496        << binary_le(i->Header.PointerToRelocations)
 497        << binary_le(i->Header.PointerToLineNumbers)
 498        << binary_le(i->Header.NumberOfRelocations)
 499        << binary_le(i->Header.NumberOfLineNumbers)
 500        << binary_le(i->Header.Characteristics);
 501   }
 502   assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize);
 503
 504   unsigned CurSymbol = 0;
 505   StringMap<unsigned> SymbolTableIndexMap;
 506   for (std::vector<COFFYAML::Symbol>::iterator I = CP.Obj.Symbols.begin(),
 507                                                E = CP.Obj.Symbols.end();
 508        I != E; ++I) {
 509     SymbolTableIndexMap[I->Name] = CurSymbol;
 510     CurSymbol += 1 + I->Header.NumberOfAuxSymbols;
 511   }
 512
 513   // Output section data.
 514   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 515     if (!S.Header.SizeOfRawData)
 516       continue;
 517     assert(S.Header.PointerToRawData >= OS.tell());
 518     OS << num_zeros(S.Header.PointerToRawData - OS.tell());
 519     S.SectionData.writeAsBinary(OS);
 520     assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
 521     OS << num_zeros(S.Header.SizeOfRawData - S.SectionData.binary_size());
 522     for (const COFFYAML::Relocation &R : S.Relocations) {
 523       uint32_t SymbolTableIndex;
 524       if (R.SymbolTableIndex) {
 525         if (!R.SymbolName.empty())
 526           WithColor::error()
 527               << "Both SymbolName and SymbolTableIndex specified\n";
 528         SymbolTableIndex = *R.SymbolTableIndex;
 529       } else {
 530         SymbolTableIndex = SymbolTableIndexMap[R.SymbolName];
 531       }
 532       OS << binary_le(R.VirtualAddress)
 533          << binary_le(SymbolTableIndex)
 534          << binary_le(R.Type);
 535     }
 536   }
 537
 538   // Output symbol table.
 539
 540   for (std::vector<COFFYAML::Symbol>::const_iterator i = CP.Obj.Symbols.begin(),
 541                                                      e = CP.Obj.Symbols.end();
 542                                                      i != e; ++i) {
 543     OS.write(i->Header.Name, COFF::NameSize);
 544     OS << binary_le(i->Header.Value);
 545     if (CP.useBigObj())
 546        OS << binary_le(i->Header.SectionNumber);
 547     else
 548        OS << binary_le(static_cast<int16_t>(i->Header.SectionNumber));
 549     OS << binary_le(i->Header.Type)
 550        << binary_le(i->Header.StorageClass)
 551        << binary_le(i->Header.NumberOfAuxSymbols);
 552
 553     if (i->FunctionDefinition)
 554       OS << binary_le(i->FunctionDefinition->TagIndex)
 555          << binary_le(i->FunctionDefinition->TotalSize)
 556          << binary_le(i->FunctionDefinition->PointerToLinenumber)
 557          << binary_le(i->FunctionDefinition->PointerToNextFunction)
 558          << zeros(i->FunctionDefinition->unused)
 559          << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 560     if (i->bfAndefSymbol)
 561       OS << zeros(i->bfAndefSymbol->unused1)
 562          << binary_le(i->bfAndefSymbol->Linenumber)
 563          << zeros(i->bfAndefSymbol->unused2)
 564          << binary_le(i->bfAndefSymbol->PointerToNextFunction)
 565          << zeros(i->bfAndefSymbol->unused3)
 566          << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 567     if (i->WeakExternal)
 568       OS << binary_le(i->WeakExternal->TagIndex)
 569          << binary_le(i->WeakExternal->Characteristics)
 570          << zeros(i->WeakExternal->unused)
 571          << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 572     if (!i->File.empty()) {
 573       unsigned SymbolSize = CP.getSymbolSize();
 574       uint32_t NumberOfAuxRecords =
 575           (i->File.size() + SymbolSize - 1) / SymbolSize;
 576       uint32_t NumberOfAuxBytes = NumberOfAuxRecords * SymbolSize;
 577       uint32_t NumZeros = NumberOfAuxBytes - i->File.size();
 578       OS.write(i->File.data(), i->File.size());
 579       OS << num_zeros(NumZeros);
 580     }
 581     if (i->SectionDefinition)
 582       OS << binary_le(i->SectionDefinition->Length)
 583          << binary_le(i->SectionDefinition->NumberOfRelocations)
 584          << binary_le(i->SectionDefinition->NumberOfLinenumbers)
 585          << binary_le(i->SectionDefinition->CheckSum)
 586          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number))
 587          << binary_le(i->SectionDefinition->Selection)
 588          << zeros(i->SectionDefinition->unused)
 589          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number >> 16))
 590          << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 591     if (i->CLRToken)
 592       OS << binary_le(i->CLRToken->AuxType)
 593          << zeros(i->CLRToken->unused1)
 594          << binary_le(i->CLRToken->SymbolTableIndex)
 595          << zeros(i->CLRToken->unused2)
 596          << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 597   }
 598
 599   // Output string table.
 600   if (CP.Obj.Header.PointerToSymbolTable)
 601     OS.write(&CP.StringTable[0], CP.StringTable.size());
 602   return true;
 603 }
 604
 605 int yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out) {
 606   COFFParser CP(Doc);
 607   if (!CP.parse()) {
 608     errs() << "yaml2obj: Failed to parse YAML file!\n";
 609     return 1;
 610   }
 611
 612   if (!layoutOptionalHeader(CP)) {
 613     errs() << "yaml2obj: Failed to layout optional header for COFF file!\n";
 614     return 1;
 615   }
 616
 617   if (!layoutCOFF(CP)) {
 618     errs() << "yaml2obj: Failed to layout COFF file!\n";
 619     return 1;
 620   }
 621   if (!writeCOFF(CP, Out)) {
 622     errs() << "yaml2obj: Failed to write COFF file!\n";
 623     return 1;
 624   }
 625   return 0;
 626 }