llvm/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/StringExtras.h"
  15 #include "llvm/ADT/StringMap.h"
  16 #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h"
  17 #include "llvm/ObjectYAML/ObjectYAML.h"
  18 #include "llvm/ObjectYAML/yaml2obj.h"
  19 #include "llvm/Support/BinaryStreamWriter.h"
  20 #include "llvm/Support/Endian.h"
  21 #include "llvm/Support/SourceMgr.h"
  22 #include "llvm/Support/WithColor.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include <optional>
  25 #include <vector>
  26
  27 using namespace llvm;
  28
  29 namespace {
  30
  31 /// This parses a yaml stream that represents a COFF object file.
  32 /// See docs/yaml2obj for the yaml scheema.
  33 struct COFFParser {
  34   COFFParser(COFFYAML::Object &Obj, yaml::ErrorHandler EH)
  35       : Obj(Obj), SectionTableStart(0), SectionTableSize(0), ErrHandler(EH) {
  36     // A COFF string table always starts with a 4 byte size field. Offsets into
  37     // it include this size, so allocate it now.
  38     StringTable.append(4, char(0));
  39   }
  40
  41   bool useBigObj() const {
  42     return static_cast<int32_t>(Obj.Sections.size()) >
  43            COFF::MaxNumberOfSections16;
  44   }
  45
  46   bool isPE() const { return Obj.OptionalHeader.has_value(); }
  47   bool is64Bit() const { return COFF::is64Bit(Obj.Header.Machine); }
  48
  49   uint32_t getFileAlignment() const {
  50     return Obj.OptionalHeader->Header.FileAlignment;
  51   }
  52
  53   unsigned getHeaderSize() const {
  54     return useBigObj() ? COFF::Header32Size : COFF::Header16Size;
  55   }
  56
  57   unsigned getSymbolSize() const {
  58     return useBigObj() ? COFF::Symbol32Size : COFF::Symbol16Size;
  59   }
  60
  61   bool parseSections() {
  62     for (COFFYAML::Section &Sec : Obj.Sections) {
  63       // If the name is less than 8 bytes, store it in place, otherwise
  64       // store it in the string table.
  65       StringRef Name = Sec.Name;
  66
  67       if (Name.size() <= COFF::NameSize) {
  68         std::copy(Name.begin(), Name.end(), Sec.Header.Name);
  69       } else {
  70         // Add string to the string table and format the index for output.
  71         unsigned Index = getStringIndex(Name);
  72         std::string str = utostr(Index);
  73         if (str.size() > 7) {
  74           ErrHandler("string table got too large");
  75           return false;
  76         }
  77         Sec.Header.Name[0] = '/';
  78         std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
  79       }
  80
  81       if (Sec.Alignment) {
  82         if (Sec.Alignment > 8192) {
  83           ErrHandler("section alignment is too large");
  84           return false;
  85         }
  86         if (!isPowerOf2_32(Sec.Alignment)) {
  87           ErrHandler("section alignment is not a power of 2");
  88           return false;
  89         }
  90         Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20;
  91       }
  92     }
  93     return true;
  94   }
  95
  96   bool parseSymbols() {
  97     for (COFFYAML::Symbol &Sym : Obj.Symbols) {
  98       // If the name is less than 8 bytes, store it in place, otherwise
  99       // store it in the string table.
 100       StringRef Name = Sym.Name;
 101       if (Name.size() <= COFF::NameSize) {
 102         std::copy(Name.begin(), Name.end(), Sym.Header.Name);
 103       } else {
 104         // Add string to the string table and format the index for output.
 105         unsigned Index = getStringIndex(Name);
 106         *reinterpret_cast<support::aligned_ulittle32_t *>(Sym.Header.Name + 4) =
 107             Index;
 108       }
 109
 110       Sym.Header.Type = Sym.SimpleType;
 111       Sym.Header.Type |= Sym.ComplexType << COFF::SCT_COMPLEX_TYPE_SHIFT;
 112     }
 113     return true;
 114   }
 115
 116   bool parse() {
 117     if (!parseSections())
 118       return false;
 119     if (!parseSymbols())
 120       return false;
 121     return true;
 122   }
 123
 124   unsigned getStringIndex(StringRef Str) {
 125     auto [It, Inserted] = StringTableMap.try_emplace(Str, StringTable.size());
 126     if (Inserted) {
 127       StringTable.append(Str.begin(), Str.end());
 128       StringTable.push_back(0);
 129     }
 130     return It->second;
 131   }
 132
 133   COFFYAML::Object &Obj;
 134
 135   codeview::StringsAndChecksums StringsAndChecksums;
 136   BumpPtrAllocator Allocator;
 137   StringMap<unsigned> StringTableMap;
 138   std::string StringTable;
 139   uint32_t SectionTableStart;
 140   uint32_t SectionTableSize;
 141
 142   yaml::ErrorHandler ErrHandler;
 143 };
 144
 145 enum { DOSStubSize = 128 };
 146
 147 } // end anonymous namespace
 148
 149 // Take a CP and assign addresses and sizes to everything. Returns false if the
 150 // layout is not valid to do.
 151 static bool layoutOptionalHeader(COFFParser &CP) {
 152   if (!CP.isPE())
 153     return true;
 154   unsigned PEHeaderSize = CP.is64Bit() ? sizeof(object::pe32plus_header)
 155                                        : sizeof(object::pe32_header);
 156   CP.Obj.Header.SizeOfOptionalHeader =
 157       PEHeaderSize + sizeof(object::data_directory) *
 158                          CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
 159   return true;
 160 }
 161
 162 static yaml::BinaryRef
 163 toDebugS(ArrayRef<CodeViewYAML::YAMLDebugSubsection> Subsections,
 164          const codeview::StringsAndChecksums &SC, BumpPtrAllocator &Allocator) {
 165   using namespace codeview;
 166   ExitOnError Err("Error occurred writing .debug$S section");
 167   auto CVSS =
 168       Err(CodeViewYAML::toCodeViewSubsectionList(Allocator, Subsections, SC));
 169
 170   std::vector<DebugSubsectionRecordBuilder> Builders;
 171   uint32_t Size = sizeof(uint32_t);
 172   for (auto &SS : CVSS) {
 173     DebugSubsectionRecordBuilder B(SS);
 174     Size += B.calculateSerializedLength();
 175     Builders.push_back(std::move(B));
 176   }
 177   uint8_t *Buffer = Allocator.Allocate<uint8_t>(Size);
 178   MutableArrayRef<uint8_t> Output(Buffer, Size);
 179   BinaryStreamWriter Writer(Output, llvm::endianness::little);
 180
 181   Err(Writer.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC));
 182   for (const auto &B : Builders) {
 183     Err(B.commit(Writer, CodeViewContainer::ObjectFile));
 184   }
 185   return {Output};
 186 }
 187
 188 // Take a CP and assign addresses and sizes to everything. Returns false if the
 189 // layout is not valid to do.
 190 static bool layoutCOFF(COFFParser &CP) {
 191   // The section table starts immediately after the header, including the
 192   // optional header.
 193   CP.SectionTableStart =
 194       CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader;
 195   if (CP.isPE())
 196     CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic);
 197   CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size();
 198
 199   uint32_t CurrentSectionDataOffset =
 200       CP.SectionTableStart + CP.SectionTableSize;
 201
 202   for (COFFYAML::Section &S : CP.Obj.Sections) {
 203     // We support specifying exactly one of SectionData or Subsections.  So if
 204     // there is already some SectionData, then we don't need to do any of this.
 205     if (S.Name == ".debug$S" && S.SectionData.binary_size() == 0) {
 206       CodeViewYAML::initializeStringsAndChecksums(S.DebugS,
 207                                                   CP.StringsAndChecksums);
 208       if (CP.StringsAndChecksums.hasChecksums() &&
 209           CP.StringsAndChecksums.hasStrings())
 210         break;
 211     }
 212   }
 213
 214   // Assign each section data address consecutively.
 215   for (COFFYAML::Section &S : CP.Obj.Sections) {
 216     if (S.Name == ".debug$S") {
 217       if (S.SectionData.binary_size() == 0) {
 218         assert(CP.StringsAndChecksums.hasStrings() &&
 219                "Object file does not have debug string table!");
 220
 221         S.SectionData =
 222             toDebugS(S.DebugS, CP.StringsAndChecksums, CP.Allocator);
 223       }
 224     } else if (S.Name == ".debug$T") {
 225       if (S.SectionData.binary_size() == 0)
 226         S.SectionData = CodeViewYAML::toDebugT(S.DebugT, CP.Allocator, S.Name);
 227     } else if (S.Name == ".debug$P") {
 228       if (S.SectionData.binary_size() == 0)
 229         S.SectionData = CodeViewYAML::toDebugT(S.DebugP, CP.Allocator, S.Name);
 230     } else if (S.Name == ".debug$H") {
 231       if (S.DebugH && S.SectionData.binary_size() == 0)
 232         S.SectionData = CodeViewYAML::toDebugH(*S.DebugH, CP.Allocator);
 233     }
 234
 235     size_t DataSize = S.SectionData.binary_size();
 236     for (auto E : S.StructuredData)
 237       DataSize += E.size();
 238     if (DataSize > 0) {
 239       CurrentSectionDataOffset = alignTo(CurrentSectionDataOffset,
 240                                          CP.isPE() ? CP.getFileAlignment() : 4);
 241       S.Header.SizeOfRawData = DataSize;
 242       if (CP.isPE())
 243         S.Header.SizeOfRawData =
 244             alignTo(S.Header.SizeOfRawData, CP.getFileAlignment());
 245       S.Header.PointerToRawData = CurrentSectionDataOffset;
 246       CurrentSectionDataOffset += S.Header.SizeOfRawData;
 247       if (!S.Relocations.empty()) {
 248         S.Header.PointerToRelocations = CurrentSectionDataOffset;
 249         if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL) {
 250           S.Header.NumberOfRelocations = 0xffff;
 251           CurrentSectionDataOffset += COFF::RelocationSize;
 252         } else
 253           S.Header.NumberOfRelocations = S.Relocations.size();
 254         CurrentSectionDataOffset += S.Relocations.size() * COFF::RelocationSize;
 255       }
 256     } else {
 257       // Leave SizeOfRawData unaltered. For .bss sections in object files, it
 258       // carries the section size.
 259       S.Header.PointerToRawData = 0;
 260     }
 261   }
 262
 263   uint32_t SymbolTableStart = CurrentSectionDataOffset;
 264
 265   // Calculate number of symbols.
 266   uint32_t NumberOfSymbols = 0;
 267   for (std::vector<COFFYAML::Symbol>::iterator i = CP.Obj.Symbols.begin(),
 268                                                e = CP.Obj.Symbols.end();
 269        i != e; ++i) {
 270     uint32_t NumberOfAuxSymbols = 0;
 271     if (i->FunctionDefinition)
 272       NumberOfAuxSymbols += 1;
 273     if (i->bfAndefSymbol)
 274       NumberOfAuxSymbols += 1;
 275     if (i->WeakExternal)
 276       NumberOfAuxSymbols += 1;
 277     if (!i->File.empty())
 278       NumberOfAuxSymbols +=
 279           (i->File.size() + CP.getSymbolSize() - 1) / CP.getSymbolSize();
 280     if (i->SectionDefinition)
 281       NumberOfAuxSymbols += 1;
 282     if (i->CLRToken)
 283       NumberOfAuxSymbols += 1;
 284     i->Header.NumberOfAuxSymbols = NumberOfAuxSymbols;
 285     NumberOfSymbols += 1 + NumberOfAuxSymbols;
 286   }
 287
 288   // Store all the allocated start addresses in the header.
 289   CP.Obj.Header.NumberOfSections = CP.Obj.Sections.size();
 290   CP.Obj.Header.NumberOfSymbols = NumberOfSymbols;
 291   if (NumberOfSymbols > 0 || CP.StringTable.size() > 4)
 292     CP.Obj.Header.PointerToSymbolTable = SymbolTableStart;
 293   else
 294     CP.Obj.Header.PointerToSymbolTable = 0;
 295
 296   *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0]) =
 297       CP.StringTable.size();
 298
 299   return true;
 300 }
 301
 302 template <typename value_type> struct binary_le_impl {
 303   value_type Value;
 304   binary_le_impl(value_type V) : Value(V) {}
 305 };
 306
 307 template <typename value_type>
 308 raw_ostream &operator<<(raw_ostream &OS,
 309                         const binary_le_impl<value_type> &BLE) {
 310   char Buffer[sizeof(BLE.Value)];
 311   support::endian::write<value_type, llvm::endianness::little>(Buffer,
 312                                                                BLE.Value);
 313   OS.write(Buffer, sizeof(BLE.Value));
 314   return OS;
 315 }
 316
 317 template <typename value_type>
 318 binary_le_impl<value_type> binary_le(value_type V) {
 319   return binary_le_impl<value_type>(V);
 320 }
 321
 322 template <size_t NumBytes> struct zeros_impl {};
 323
 324 template <size_t NumBytes>
 325 raw_ostream &operator<<(raw_ostream &OS, const zeros_impl<NumBytes> &) {
 326   char Buffer[NumBytes];
 327   memset(Buffer, 0, sizeof(Buffer));
 328   OS.write(Buffer, sizeof(Buffer));
 329   return OS;
 330 }
 331
 332 template <typename T> zeros_impl<sizeof(T)> zeros(const T &) {
 333   return zeros_impl<sizeof(T)>();
 334 }
 335
 336 template <typename T>
 337 static uint32_t initializeOptionalHeader(COFFParser &CP, uint16_t Magic,
 338                                          T Header) {
 339   memset(Header, 0, sizeof(*Header));
 340   Header->Magic = Magic;
 341   Header->SectionAlignment = CP.Obj.OptionalHeader->Header.SectionAlignment;
 342   Header->FileAlignment = CP.Obj.OptionalHeader->Header.FileAlignment;
 343   uint32_t SizeOfCode = 0, SizeOfInitializedData = 0,
 344            SizeOfUninitializedData = 0;
 345   uint32_t SizeOfHeaders = alignTo(CP.SectionTableStart + CP.SectionTableSize,
 346                                    Header->FileAlignment);
 347   uint32_t SizeOfImage = alignTo(SizeOfHeaders, Header->SectionAlignment);
 348   uint32_t BaseOfData = 0;
 349   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 350     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_CODE)
 351       SizeOfCode += S.Header.SizeOfRawData;
 352     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
 353       SizeOfInitializedData += S.Header.SizeOfRawData;
 354     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
 355       SizeOfUninitializedData += S.Header.SizeOfRawData;
 356     if (S.Name == ".text")
 357       Header->BaseOfCode = S.Header.VirtualAddress; // RVA
 358     else if (S.Name == ".data")
 359       BaseOfData = S.Header.VirtualAddress; // RVA
 360     if (S.Header.VirtualAddress)
 361       SizeOfImage += alignTo(S.Header.VirtualSize, Header->SectionAlignment);
 362   }
 363   Header->SizeOfCode = SizeOfCode;
 364   Header->SizeOfInitializedData = SizeOfInitializedData;
 365   Header->SizeOfUninitializedData = SizeOfUninitializedData;
 366   Header->AddressOfEntryPoint =
 367       CP.Obj.OptionalHeader->Header.AddressOfEntryPoint; // RVA
 368   Header->ImageBase = CP.Obj.OptionalHeader->Header.ImageBase;
 369   Header->MajorOperatingSystemVersion =
 370       CP.Obj.OptionalHeader->Header.MajorOperatingSystemVersion;
 371   Header->MinorOperatingSystemVersion =
 372       CP.Obj.OptionalHeader->Header.MinorOperatingSystemVersion;
 373   Header->MajorImageVersion = CP.Obj.OptionalHeader->Header.MajorImageVersion;
 374   Header->MinorImageVersion = CP.Obj.OptionalHeader->Header.MinorImageVersion;
 375   Header->MajorSubsystemVersion =
 376       CP.Obj.OptionalHeader->Header.MajorSubsystemVersion;
 377   Header->MinorSubsystemVersion =
 378       CP.Obj.OptionalHeader->Header.MinorSubsystemVersion;
 379   Header->SizeOfImage = SizeOfImage;
 380   Header->SizeOfHeaders = SizeOfHeaders;
 381   Header->Subsystem = CP.Obj.OptionalHeader->Header.Subsystem;
 382   Header->DLLCharacteristics = CP.Obj.OptionalHeader->Header.DLLCharacteristics;
 383   Header->SizeOfStackReserve = CP.Obj.OptionalHeader->Header.SizeOfStackReserve;
 384   Header->SizeOfStackCommit = CP.Obj.OptionalHeader->Header.SizeOfStackCommit;
 385   Header->SizeOfHeapReserve = CP.Obj.OptionalHeader->Header.SizeOfHeapReserve;
 386   Header->SizeOfHeapCommit = CP.Obj.OptionalHeader->Header.SizeOfHeapCommit;
 387   Header->NumberOfRvaAndSize = CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
 388   return BaseOfData;
 389 }
 390
 391 static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
 392   if (CP.isPE()) {
 393     // PE files start with a DOS stub.
 394     object::dos_header DH;
 395     memset(&DH, 0, sizeof(DH));
 396
 397     // DOS EXEs start with "MZ" magic.
 398     DH.Magic[0] = 'M';
 399     DH.Magic[1] = 'Z';
 400     // Initializing the AddressOfRelocationTable is strictly optional but
 401     // mollifies certain tools which expect it to have a value greater than
 402     // 0x40.
 403     DH.AddressOfRelocationTable = sizeof(DH);
 404     // This is the address of the PE signature.
 405     DH.AddressOfNewExeHeader = DOSStubSize;
 406
 407     // Write out our DOS stub.
 408     OS.write(reinterpret_cast<char *>(&DH), sizeof(DH));
 409     // Write padding until we reach the position of where our PE signature
 410     // should live.
 411     OS.write_zeros(DOSStubSize - sizeof(DH));
 412     // Write out the PE signature.
 413     OS.write(COFF::PEMagic, sizeof(COFF::PEMagic));
 414   }
 415   if (CP.useBigObj()) {
 416     OS << binary_le(static_cast<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN))
 417        << binary_le(static_cast<uint16_t>(0xffff))
 418        << binary_le(
 419               static_cast<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion))
 420        << binary_le(CP.Obj.Header.Machine)
 421        << binary_le(CP.Obj.Header.TimeDateStamp);
 422     OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
 423     OS << zeros(uint32_t(0)) << zeros(uint32_t(0)) << zeros(uint32_t(0))
 424        << zeros(uint32_t(0)) << binary_le(CP.Obj.Header.NumberOfSections)
 425        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 426        << binary_le(CP.Obj.Header.NumberOfSymbols);
 427   } else {
 428     OS << binary_le(CP.Obj.Header.Machine)
 429        << binary_le(static_cast<int16_t>(CP.Obj.Header.NumberOfSections))
 430        << binary_le(CP.Obj.Header.TimeDateStamp)
 431        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 432        << binary_le(CP.Obj.Header.NumberOfSymbols)
 433        << binary_le(CP.Obj.Header.SizeOfOptionalHeader)
 434        << binary_le(CP.Obj.Header.Characteristics);
 435   }
 436   if (CP.isPE()) {
 437     if (CP.is64Bit()) {
 438       object::pe32plus_header PEH;
 439       initializeOptionalHeader(CP, COFF::PE32Header::PE32_PLUS, &PEH);
 440       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 441     } else {
 442       object::pe32_header PEH;
 443       uint32_t BaseOfData =
 444           initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH);
 445       PEH.BaseOfData = BaseOfData;
 446       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 447     }
 448     for (uint32_t I = 0; I < CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
 449          ++I) {
 450       const std::optional<COFF::DataDirectory> *DataDirectories =
 451           CP.Obj.OptionalHeader->DataDirectories;
 452       uint32_t NumDataDir = std::size(CP.Obj.OptionalHeader->DataDirectories);
 453       if (I >= NumDataDir || !DataDirectories[I]) {
 454         OS << zeros(uint32_t(0));
 455         OS << zeros(uint32_t(0));
 456       } else {
 457         OS << binary_le(DataDirectories[I]->RelativeVirtualAddress);
 458         OS << binary_le(DataDirectories[I]->Size);
 459       }
 460     }
 461   }
 462
 463   assert(OS.tell() == CP.SectionTableStart);
 464   // Output section table.
 465   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 466     OS.write(S.Header.Name, COFF::NameSize);
 467     OS << binary_le(S.Header.VirtualSize)
 468        << binary_le(S.Header.VirtualAddress)
 469        << binary_le(S.Header.SizeOfRawData)
 470        << binary_le(S.Header.PointerToRawData)
 471        << binary_le(S.Header.PointerToRelocations)
 472        << binary_le(S.Header.PointerToLineNumbers)
 473        << binary_le(S.Header.NumberOfRelocations)
 474        << binary_le(S.Header.NumberOfLineNumbers)
 475        << binary_le(S.Header.Characteristics);
 476   }
 477   assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize);
 478
 479   unsigned CurSymbol = 0;
 480   StringMap<unsigned> SymbolTableIndexMap;
 481   for (const COFFYAML::Symbol &Sym : CP.Obj.Symbols) {
 482     SymbolTableIndexMap[Sym.Name] = CurSymbol;
 483     CurSymbol += 1 + Sym.Header.NumberOfAuxSymbols;
 484   }
 485
 486   // Output section data.
 487   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 488     if (S.Header.SizeOfRawData == 0 || S.Header.PointerToRawData == 0)
 489       continue;
 490     assert(S.Header.PointerToRawData >= OS.tell());
 491     OS.write_zeros(S.Header.PointerToRawData - OS.tell());
 492     for (auto E : S.StructuredData)
 493       E.writeAsBinary(OS);
 494     S.SectionData.writeAsBinary(OS);
 495     assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
 496     OS.write_zeros(S.Header.PointerToRawData + S.Header.SizeOfRawData -
 497                    OS.tell());
 498     if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL)
 499       OS << binary_le<uint32_t>(/*VirtualAddress=*/ S.Relocations.size() + 1)
 500          << binary_le<uint32_t>(/*SymbolTableIndex=*/ 0)
 501          << binary_le<uint16_t>(/*Type=*/ 0);
 502     for (const COFFYAML::Relocation &R : S.Relocations) {
 503       uint32_t SymbolTableIndex;
 504       if (R.SymbolTableIndex) {
 505         if (!R.SymbolName.empty())
 506           WithColor::error()
 507               << "Both SymbolName and SymbolTableIndex specified\n";
 508         SymbolTableIndex = *R.SymbolTableIndex;
 509       } else {
 510         SymbolTableIndex = SymbolTableIndexMap[R.SymbolName];
 511       }
 512       OS << binary_le(R.VirtualAddress) << binary_le(SymbolTableIndex)
 513          << binary_le(R.Type);
 514     }
 515   }
 516
 517   // Output symbol table.
 518
 519   for (std::vector<COFFYAML::Symbol>::const_iterator i = CP.Obj.Symbols.begin(),
 520                                                      e = CP.Obj.Symbols.end();
 521        i != e; ++i) {
 522     OS.write(i->Header.Name, COFF::NameSize);
 523     OS << binary_le(i->Header.Value);
 524     if (CP.useBigObj())
 525       OS << binary_le(i->Header.SectionNumber);
 526     else
 527       OS << binary_le(static_cast<int16_t>(i->Header.SectionNumber));
 528     OS << binary_le(i->Header.Type) << binary_le(i->Header.StorageClass)
 529        << binary_le(i->Header.NumberOfAuxSymbols);
 530
 531     if (i->FunctionDefinition) {
 532       OS << binary_le(i->FunctionDefinition->TagIndex)
 533          << binary_le(i->FunctionDefinition->TotalSize)
 534          << binary_le(i->FunctionDefinition->PointerToLinenumber)
 535          << binary_le(i->FunctionDefinition->PointerToNextFunction)
 536          << zeros(i->FunctionDefinition->unused);
 537       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 538     }
 539     if (i->bfAndefSymbol) {
 540       OS << zeros(i->bfAndefSymbol->unused1)
 541          << binary_le(i->bfAndefSymbol->Linenumber)
 542          << zeros(i->bfAndefSymbol->unused2)
 543          << binary_le(i->bfAndefSymbol->PointerToNextFunction)
 544          << zeros(i->bfAndefSymbol->unused3);
 545       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 546     }
 547     if (i->WeakExternal) {
 548       OS << binary_le(i->WeakExternal->TagIndex)
 549          << binary_le(i->WeakExternal->Characteristics)
 550          << zeros(i->WeakExternal->unused);
 551       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 552     }
 553     if (!i->File.empty()) {
 554       unsigned SymbolSize = CP.getSymbolSize();
 555       uint32_t NumberOfAuxRecords =
 556           (i->File.size() + SymbolSize - 1) / SymbolSize;
 557       uint32_t NumberOfAuxBytes = NumberOfAuxRecords * SymbolSize;
 558       uint32_t NumZeros = NumberOfAuxBytes - i->File.size();
 559       OS.write(i->File.data(), i->File.size());
 560       OS.write_zeros(NumZeros);
 561     }
 562     if (i->SectionDefinition) {
 563       OS << binary_le(i->SectionDefinition->Length)
 564          << binary_le(i->SectionDefinition->NumberOfRelocations)
 565          << binary_le(i->SectionDefinition->NumberOfLinenumbers)
 566          << binary_le(i->SectionDefinition->CheckSum)
 567          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number))
 568          << binary_le(i->SectionDefinition->Selection)
 569          << zeros(i->SectionDefinition->unused)
 570          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number >> 16));
 571       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 572     }
 573     if (i->CLRToken) {
 574       OS << binary_le(i->CLRToken->AuxType) << zeros(i->CLRToken->unused1)
 575          << binary_le(i->CLRToken->SymbolTableIndex)
 576          << zeros(i->CLRToken->unused2);
 577       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 578     }
 579   }
 580
 581   // Output string table.
 582   if (CP.Obj.Header.PointerToSymbolTable)
 583     OS.write(&CP.StringTable[0], CP.StringTable.size());
 584   return true;
 585 }
 586
 587 size_t COFFYAML::SectionDataEntry::size() const {
 588   size_t Size = Binary.binary_size();
 589   if (UInt32)
 590     Size += sizeof(*UInt32);
 591   if (LoadConfig32)
 592     Size += LoadConfig32->Size;
 593   if (LoadConfig64)
 594     Size += LoadConfig64->Size;
 595   return Size;
 596 }
 597
 598 template <typename T> static void writeLoadConfig(T &S, raw_ostream &OS) {
 599   OS.write(reinterpret_cast<const char *>(&S),
 600            std::min(sizeof(S), static_cast<size_t>(S.Size)));
 601   if (sizeof(S) < S.Size)
 602     OS.write_zeros(S.Size - sizeof(S));
 603 }
 604
 605 void COFFYAML::SectionDataEntry::writeAsBinary(raw_ostream &OS) const {
 606   if (UInt32)
 607     OS << binary_le(*UInt32);
 608   Binary.writeAsBinary(OS);
 609   if (LoadConfig32)
 610     writeLoadConfig(*LoadConfig32, OS);
 611   if (LoadConfig64)
 612     writeLoadConfig(*LoadConfig64, OS);
 613 }
 614
 615 namespace llvm {
 616 namespace yaml {
 617
 618 bool yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out,
 619                ErrorHandler ErrHandler) {
 620   COFFParser CP(Doc, ErrHandler);
 621   if (!CP.parse()) {
 622     ErrHandler("failed to parse YAML file");
 623     return false;
 624   }
 625
 626   if (!layoutOptionalHeader(CP)) {
 627     ErrHandler("failed to layout optional header for COFF file");
 628     return false;
 629   }
 630
 631   if (!layoutCOFF(CP)) {
 632     ErrHandler("failed to layout COFF file");
 633     return false;
 634   }
 635   if (!writeCOFF(CP, Out)) {
 636     ErrHandler("failed to write COFF file");
 637     return false;
 638   }
 639   return true;
 640 }
 641
 642 } // namespace yaml
 643 } // namespace llvm