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/STLExtras.h"
  15 #include "llvm/ADT/StringExtras.h"
  16 #include "llvm/ADT/StringMap.h"
  17 #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
  18 #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h"
  19 #include "llvm/ObjectYAML/ObjectYAML.h"
  20 #include "llvm/ObjectYAML/yaml2obj.h"
  21 #include "llvm/Support/BinaryStreamWriter.h"
  22 #include "llvm/Support/Endian.h"
  23 #include "llvm/Support/MemoryBuffer.h"
  24 #include "llvm/Support/SourceMgr.h"
  25 #include "llvm/Support/WithColor.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include <optional>
  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, yaml::ErrorHandler EH)
  38       : Obj(Obj), SectionTableStart(0), SectionTableSize(0), ErrHandler(EH) {
  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.has_value(); }
  50   bool is64Bit() const { return COFF::is64Bit(Obj.Header.Machine); }
  51
  52   uint32_t getFileAlignment() const {
  53     return Obj.OptionalHeader->Header.FileAlignment;
  54   }
  55
  56   unsigned getHeaderSize() const {
  57     return useBigObj() ? COFF::Header32Size : COFF::Header16Size;
  58   }
  59
  60   unsigned getSymbolSize() const {
  61     return useBigObj() ? COFF::Symbol32Size : COFF::Symbol16Size;
  62   }
  63
  64   bool parseSections() {
  65     for (COFFYAML::Section &Sec : Obj.Sections) {
  66       // If the name is less than 8 bytes, store it in place, otherwise
  67       // store it in the string table.
  68       StringRef Name = Sec.Name;
  69
  70       if (Name.size() <= COFF::NameSize) {
  71         std::copy(Name.begin(), Name.end(), Sec.Header.Name);
  72       } else {
  73         // Add string to the string table and format the index for output.
  74         unsigned Index = getStringIndex(Name);
  75         std::string str = utostr(Index);
  76         if (str.size() > 7) {
  77           ErrHandler("string table got too large");
  78           return false;
  79         }
  80         Sec.Header.Name[0] = '/';
  81         std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
  82       }
  83
  84       if (Sec.Alignment) {
  85         if (Sec.Alignment > 8192) {
  86           ErrHandler("section alignment is too large");
  87           return false;
  88         }
  89         if (!isPowerOf2_32(Sec.Alignment)) {
  90           ErrHandler("section alignment is not a power of 2");
  91           return false;
  92         }
  93         Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20;
  94       }
  95     }
  96     return true;
  97   }
  98
  99   bool parseSymbols() {
 100     for (COFFYAML::Symbol &Sym : Obj.Symbols) {
 101       // If the name is less than 8 bytes, store it in place, otherwise
 102       // store it in the string table.
 103       StringRef Name = Sym.Name;
 104       if (Name.size() <= COFF::NameSize) {
 105         std::copy(Name.begin(), Name.end(), Sym.Header.Name);
 106       } else {
 107         // Add string to the string table and format the index for output.
 108         unsigned Index = getStringIndex(Name);
 109         *reinterpret_cast<support::aligned_ulittle32_t *>(Sym.Header.Name + 4) =
 110             Index;
 111       }
 112
 113       Sym.Header.Type = Sym.SimpleType;
 114       Sym.Header.Type |= Sym.ComplexType << COFF::SCT_COMPLEX_TYPE_SHIFT;
 115     }
 116     return true;
 117   }
 118
 119   bool parse() {
 120     if (!parseSections())
 121       return false;
 122     if (!parseSymbols())
 123       return false;
 124     return true;
 125   }
 126
 127   unsigned getStringIndex(StringRef Str) {
 128     StringMap<unsigned>::iterator i = StringTableMap.find(Str);
 129     if (i == StringTableMap.end()) {
 130       unsigned Index = StringTable.size();
 131       StringTable.append(Str.begin(), Str.end());
 132       StringTable.push_back(0);
 133       StringTableMap[Str] = Index;
 134       return Index;
 135     }
 136     return i->second;
 137   }
 138
 139   COFFYAML::Object &Obj;
 140
 141   codeview::StringsAndChecksums StringsAndChecksums;
 142   BumpPtrAllocator Allocator;
 143   StringMap<unsigned> StringTableMap;
 144   std::string StringTable;
 145   uint32_t SectionTableStart;
 146   uint32_t SectionTableSize;
 147
 148   yaml::ErrorHandler ErrHandler;
 149 };
 150
 151 enum { DOSStubSize = 128 };
 152
 153 } // end anonymous namespace
 154
 155 // Take a CP and assign addresses and sizes to everything. Returns false if the
 156 // layout is not valid to do.
 157 static bool layoutOptionalHeader(COFFParser &CP) {
 158   if (!CP.isPE())
 159     return true;
 160   unsigned PEHeaderSize = CP.is64Bit() ? sizeof(object::pe32plus_header)
 161                                        : sizeof(object::pe32_header);
 162   CP.Obj.Header.SizeOfOptionalHeader =
 163       PEHeaderSize + sizeof(object::data_directory) *
 164                          CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
 165   return true;
 166 }
 167
 168 static yaml::BinaryRef
 169 toDebugS(ArrayRef<CodeViewYAML::YAMLDebugSubsection> Subsections,
 170          const codeview::StringsAndChecksums &SC, BumpPtrAllocator &Allocator) {
 171   using namespace codeview;
 172   ExitOnError Err("Error occurred writing .debug$S section");
 173   auto CVSS =
 174       Err(CodeViewYAML::toCodeViewSubsectionList(Allocator, Subsections, SC));
 175
 176   std::vector<DebugSubsectionRecordBuilder> Builders;
 177   uint32_t Size = sizeof(uint32_t);
 178   for (auto &SS : CVSS) {
 179     DebugSubsectionRecordBuilder B(SS);
 180     Size += B.calculateSerializedLength();
 181     Builders.push_back(std::move(B));
 182   }
 183   uint8_t *Buffer = Allocator.Allocate<uint8_t>(Size);
 184   MutableArrayRef<uint8_t> Output(Buffer, Size);
 185   BinaryStreamWriter Writer(Output, llvm::endianness::little);
 186
 187   Err(Writer.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC));
 188   for (const auto &B : Builders) {
 189     Err(B.commit(Writer, CodeViewContainer::ObjectFile));
 190   }
 191   return {Output};
 192 }
 193
 194 // Take a CP and assign addresses and sizes to everything. Returns false if the
 195 // layout is not valid to do.
 196 static bool layoutCOFF(COFFParser &CP) {
 197   // The section table starts immediately after the header, including the
 198   // optional header.
 199   CP.SectionTableStart =
 200       CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader;
 201   if (CP.isPE())
 202     CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic);
 203   CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size();
 204
 205   uint32_t CurrentSectionDataOffset =
 206       CP.SectionTableStart + CP.SectionTableSize;
 207
 208   for (COFFYAML::Section &S : CP.Obj.Sections) {
 209     // We support specifying exactly one of SectionData or Subsections.  So if
 210     // there is already some SectionData, then we don't need to do any of this.
 211     if (S.Name == ".debug$S" && S.SectionData.binary_size() == 0) {
 212       CodeViewYAML::initializeStringsAndChecksums(S.DebugS,
 213                                                   CP.StringsAndChecksums);
 214       if (CP.StringsAndChecksums.hasChecksums() &&
 215           CP.StringsAndChecksums.hasStrings())
 216         break;
 217     }
 218   }
 219
 220   // Assign each section data address consecutively.
 221   for (COFFYAML::Section &S : CP.Obj.Sections) {
 222     if (S.Name == ".debug$S") {
 223       if (S.SectionData.binary_size() == 0) {
 224         assert(CP.StringsAndChecksums.hasStrings() &&
 225                "Object file does not have debug string table!");
 226
 227         S.SectionData =
 228             toDebugS(S.DebugS, CP.StringsAndChecksums, CP.Allocator);
 229       }
 230     } else if (S.Name == ".debug$T") {
 231       if (S.SectionData.binary_size() == 0)
 232         S.SectionData = CodeViewYAML::toDebugT(S.DebugT, CP.Allocator, S.Name);
 233     } else if (S.Name == ".debug$P") {
 234       if (S.SectionData.binary_size() == 0)
 235         S.SectionData = CodeViewYAML::toDebugT(S.DebugP, CP.Allocator, S.Name);
 236     } else if (S.Name == ".debug$H") {
 237       if (S.DebugH && S.SectionData.binary_size() == 0)
 238         S.SectionData = CodeViewYAML::toDebugH(*S.DebugH, CP.Allocator);
 239     }
 240
 241     size_t DataSize = S.SectionData.binary_size();
 242     for (auto E : S.StructuredData)
 243       DataSize += E.size();
 244     if (DataSize > 0) {
 245       CurrentSectionDataOffset = alignTo(CurrentSectionDataOffset,
 246                                          CP.isPE() ? CP.getFileAlignment() : 4);
 247       S.Header.SizeOfRawData = DataSize;
 248       if (CP.isPE())
 249         S.Header.SizeOfRawData =
 250             alignTo(S.Header.SizeOfRawData, CP.getFileAlignment());
 251       S.Header.PointerToRawData = CurrentSectionDataOffset;
 252       CurrentSectionDataOffset += S.Header.SizeOfRawData;
 253       if (!S.Relocations.empty()) {
 254         S.Header.PointerToRelocations = CurrentSectionDataOffset;
 255         if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL) {
 256           S.Header.NumberOfRelocations = 0xffff;
 257           CurrentSectionDataOffset += COFF::RelocationSize;
 258         } else
 259           S.Header.NumberOfRelocations = S.Relocations.size();
 260         CurrentSectionDataOffset += S.Relocations.size() * COFF::RelocationSize;
 261       }
 262     } else {
 263       // Leave SizeOfRawData unaltered. For .bss sections in object files, it
 264       // carries the section size.
 265       S.Header.PointerToRawData = 0;
 266     }
 267   }
 268
 269   uint32_t SymbolTableStart = CurrentSectionDataOffset;
 270
 271   // Calculate number of symbols.
 272   uint32_t NumberOfSymbols = 0;
 273   for (std::vector<COFFYAML::Symbol>::iterator i = CP.Obj.Symbols.begin(),
 274                                                e = CP.Obj.Symbols.end();
 275        i != e; ++i) {
 276     uint32_t NumberOfAuxSymbols = 0;
 277     if (i->FunctionDefinition)
 278       NumberOfAuxSymbols += 1;
 279     if (i->bfAndefSymbol)
 280       NumberOfAuxSymbols += 1;
 281     if (i->WeakExternal)
 282       NumberOfAuxSymbols += 1;
 283     if (!i->File.empty())
 284       NumberOfAuxSymbols +=
 285           (i->File.size() + CP.getSymbolSize() - 1) / CP.getSymbolSize();
 286     if (i->SectionDefinition)
 287       NumberOfAuxSymbols += 1;
 288     if (i->CLRToken)
 289       NumberOfAuxSymbols += 1;
 290     i->Header.NumberOfAuxSymbols = NumberOfAuxSymbols;
 291     NumberOfSymbols += 1 + NumberOfAuxSymbols;
 292   }
 293
 294   // Store all the allocated start addresses in the header.
 295   CP.Obj.Header.NumberOfSections = CP.Obj.Sections.size();
 296   CP.Obj.Header.NumberOfSymbols = NumberOfSymbols;
 297   if (NumberOfSymbols > 0 || CP.StringTable.size() > 4)
 298     CP.Obj.Header.PointerToSymbolTable = SymbolTableStart;
 299   else
 300     CP.Obj.Header.PointerToSymbolTable = 0;
 301
 302   *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0]) =
 303       CP.StringTable.size();
 304
 305   return true;
 306 }
 307
 308 template <typename value_type> struct binary_le_impl {
 309   value_type Value;
 310   binary_le_impl(value_type V) : Value(V) {}
 311 };
 312
 313 template <typename value_type>
 314 raw_ostream &operator<<(raw_ostream &OS,
 315                         const binary_le_impl<value_type> &BLE) {
 316   char Buffer[sizeof(BLE.Value)];
 317   support::endian::write<value_type, llvm::endianness::little>(Buffer,
 318                                                                BLE.Value);
 319   OS.write(Buffer, sizeof(BLE.Value));
 320   return OS;
 321 }
 322
 323 template <typename value_type>
 324 binary_le_impl<value_type> binary_le(value_type V) {
 325   return binary_le_impl<value_type>(V);
 326 }
 327
 328 template <size_t NumBytes> struct zeros_impl {};
 329
 330 template <size_t NumBytes>
 331 raw_ostream &operator<<(raw_ostream &OS, const zeros_impl<NumBytes> &) {
 332   char Buffer[NumBytes];
 333   memset(Buffer, 0, sizeof(Buffer));
 334   OS.write(Buffer, sizeof(Buffer));
 335   return OS;
 336 }
 337
 338 template <typename T> zeros_impl<sizeof(T)> zeros(const T &) {
 339   return zeros_impl<sizeof(T)>();
 340 }
 341
 342 template <typename T>
 343 static uint32_t initializeOptionalHeader(COFFParser &CP, uint16_t Magic,
 344                                          T Header) {
 345   memset(Header, 0, sizeof(*Header));
 346   Header->Magic = Magic;
 347   Header->SectionAlignment = CP.Obj.OptionalHeader->Header.SectionAlignment;
 348   Header->FileAlignment = CP.Obj.OptionalHeader->Header.FileAlignment;
 349   uint32_t SizeOfCode = 0, SizeOfInitializedData = 0,
 350            SizeOfUninitializedData = 0;
 351   uint32_t SizeOfHeaders = alignTo(CP.SectionTableStart + CP.SectionTableSize,
 352                                    Header->FileAlignment);
 353   uint32_t SizeOfImage = alignTo(SizeOfHeaders, Header->SectionAlignment);
 354   uint32_t BaseOfData = 0;
 355   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 356     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_CODE)
 357       SizeOfCode += S.Header.SizeOfRawData;
 358     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
 359       SizeOfInitializedData += S.Header.SizeOfRawData;
 360     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
 361       SizeOfUninitializedData += S.Header.SizeOfRawData;
 362     if (S.Name.equals(".text"))
 363       Header->BaseOfCode = S.Header.VirtualAddress; // RVA
 364     else if (S.Name.equals(".data"))
 365       BaseOfData = S.Header.VirtualAddress; // RVA
 366     if (S.Header.VirtualAddress)
 367       SizeOfImage += alignTo(S.Header.VirtualSize, Header->SectionAlignment);
 368   }
 369   Header->SizeOfCode = SizeOfCode;
 370   Header->SizeOfInitializedData = SizeOfInitializedData;
 371   Header->SizeOfUninitializedData = SizeOfUninitializedData;
 372   Header->AddressOfEntryPoint =
 373       CP.Obj.OptionalHeader->Header.AddressOfEntryPoint; // RVA
 374   Header->ImageBase = CP.Obj.OptionalHeader->Header.ImageBase;
 375   Header->MajorOperatingSystemVersion =
 376       CP.Obj.OptionalHeader->Header.MajorOperatingSystemVersion;
 377   Header->MinorOperatingSystemVersion =
 378       CP.Obj.OptionalHeader->Header.MinorOperatingSystemVersion;
 379   Header->MajorImageVersion = CP.Obj.OptionalHeader->Header.MajorImageVersion;
 380   Header->MinorImageVersion = CP.Obj.OptionalHeader->Header.MinorImageVersion;
 381   Header->MajorSubsystemVersion =
 382       CP.Obj.OptionalHeader->Header.MajorSubsystemVersion;
 383   Header->MinorSubsystemVersion =
 384       CP.Obj.OptionalHeader->Header.MinorSubsystemVersion;
 385   Header->SizeOfImage = SizeOfImage;
 386   Header->SizeOfHeaders = SizeOfHeaders;
 387   Header->Subsystem = CP.Obj.OptionalHeader->Header.Subsystem;
 388   Header->DLLCharacteristics = CP.Obj.OptionalHeader->Header.DLLCharacteristics;
 389   Header->SizeOfStackReserve = CP.Obj.OptionalHeader->Header.SizeOfStackReserve;
 390   Header->SizeOfStackCommit = CP.Obj.OptionalHeader->Header.SizeOfStackCommit;
 391   Header->SizeOfHeapReserve = CP.Obj.OptionalHeader->Header.SizeOfHeapReserve;
 392   Header->SizeOfHeapCommit = CP.Obj.OptionalHeader->Header.SizeOfHeapCommit;
 393   Header->NumberOfRvaAndSize = CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
 394   return BaseOfData;
 395 }
 396
 397 static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
 398   if (CP.isPE()) {
 399     // PE files start with a DOS stub.
 400     object::dos_header DH;
 401     memset(&DH, 0, sizeof(DH));
 402
 403     // DOS EXEs start with "MZ" magic.
 404     DH.Magic[0] = 'M';
 405     DH.Magic[1] = 'Z';
 406     // Initializing the AddressOfRelocationTable is strictly optional but
 407     // mollifies certain tools which expect it to have a value greater than
 408     // 0x40.
 409     DH.AddressOfRelocationTable = sizeof(DH);
 410     // This is the address of the PE signature.
 411     DH.AddressOfNewExeHeader = DOSStubSize;
 412
 413     // Write out our DOS stub.
 414     OS.write(reinterpret_cast<char *>(&DH), sizeof(DH));
 415     // Write padding until we reach the position of where our PE signature
 416     // should live.
 417     OS.write_zeros(DOSStubSize - sizeof(DH));
 418     // Write out the PE signature.
 419     OS.write(COFF::PEMagic, sizeof(COFF::PEMagic));
 420   }
 421   if (CP.useBigObj()) {
 422     OS << binary_le(static_cast<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN))
 423        << binary_le(static_cast<uint16_t>(0xffff))
 424        << binary_le(
 425               static_cast<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion))
 426        << binary_le(CP.Obj.Header.Machine)
 427        << binary_le(CP.Obj.Header.TimeDateStamp);
 428     OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
 429     OS << zeros(uint32_t(0)) << zeros(uint32_t(0)) << zeros(uint32_t(0))
 430        << zeros(uint32_t(0)) << binary_le(CP.Obj.Header.NumberOfSections)
 431        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 432        << binary_le(CP.Obj.Header.NumberOfSymbols);
 433   } else {
 434     OS << binary_le(CP.Obj.Header.Machine)
 435        << binary_le(static_cast<int16_t>(CP.Obj.Header.NumberOfSections))
 436        << binary_le(CP.Obj.Header.TimeDateStamp)
 437        << binary_le(CP.Obj.Header.PointerToSymbolTable)
 438        << binary_le(CP.Obj.Header.NumberOfSymbols)
 439        << binary_le(CP.Obj.Header.SizeOfOptionalHeader)
 440        << binary_le(CP.Obj.Header.Characteristics);
 441   }
 442   if (CP.isPE()) {
 443     if (CP.is64Bit()) {
 444       object::pe32plus_header PEH;
 445       initializeOptionalHeader(CP, COFF::PE32Header::PE32_PLUS, &PEH);
 446       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 447     } else {
 448       object::pe32_header PEH;
 449       uint32_t BaseOfData =
 450           initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH);
 451       PEH.BaseOfData = BaseOfData;
 452       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
 453     }
 454     for (uint32_t I = 0; I < CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
 455          ++I) {
 456       const std::optional<COFF::DataDirectory> *DataDirectories =
 457           CP.Obj.OptionalHeader->DataDirectories;
 458       uint32_t NumDataDir = std::size(CP.Obj.OptionalHeader->DataDirectories);
 459       if (I >= NumDataDir || !DataDirectories[I]) {
 460         OS << zeros(uint32_t(0));
 461         OS << zeros(uint32_t(0));
 462       } else {
 463         OS << binary_le(DataDirectories[I]->RelativeVirtualAddress);
 464         OS << binary_le(DataDirectories[I]->Size);
 465       }
 466     }
 467   }
 468
 469   assert(OS.tell() == CP.SectionTableStart);
 470   // Output section table.
 471   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 472     OS.write(S.Header.Name, COFF::NameSize);
 473     OS << binary_le(S.Header.VirtualSize)
 474        << binary_le(S.Header.VirtualAddress)
 475        << binary_le(S.Header.SizeOfRawData)
 476        << binary_le(S.Header.PointerToRawData)
 477        << binary_le(S.Header.PointerToRelocations)
 478        << binary_le(S.Header.PointerToLineNumbers)
 479        << binary_le(S.Header.NumberOfRelocations)
 480        << binary_le(S.Header.NumberOfLineNumbers)
 481        << binary_le(S.Header.Characteristics);
 482   }
 483   assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize);
 484
 485   unsigned CurSymbol = 0;
 486   StringMap<unsigned> SymbolTableIndexMap;
 487   for (const COFFYAML::Symbol &Sym : CP.Obj.Symbols) {
 488     SymbolTableIndexMap[Sym.Name] = CurSymbol;
 489     CurSymbol += 1 + Sym.Header.NumberOfAuxSymbols;
 490   }
 491
 492   // Output section data.
 493   for (const COFFYAML::Section &S : CP.Obj.Sections) {
 494     if (S.Header.SizeOfRawData == 0 || S.Header.PointerToRawData == 0)
 495       continue;
 496     assert(S.Header.PointerToRawData >= OS.tell());
 497     OS.write_zeros(S.Header.PointerToRawData - OS.tell());
 498     for (auto E : S.StructuredData)
 499       E.writeAsBinary(OS);
 500     S.SectionData.writeAsBinary(OS);
 501     assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
 502     OS.write_zeros(S.Header.PointerToRawData + S.Header.SizeOfRawData -
 503                    OS.tell());
 504     if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL)
 505       OS << binary_le<uint32_t>(/*VirtualAddress=*/ S.Relocations.size() + 1)
 506          << binary_le<uint32_t>(/*SymbolTableIndex=*/ 0)
 507          << binary_le<uint16_t>(/*Type=*/ 0);
 508     for (const COFFYAML::Relocation &R : S.Relocations) {
 509       uint32_t SymbolTableIndex;
 510       if (R.SymbolTableIndex) {
 511         if (!R.SymbolName.empty())
 512           WithColor::error()
 513               << "Both SymbolName and SymbolTableIndex specified\n";
 514         SymbolTableIndex = *R.SymbolTableIndex;
 515       } else {
 516         SymbolTableIndex = SymbolTableIndexMap[R.SymbolName];
 517       }
 518       OS << binary_le(R.VirtualAddress) << binary_le(SymbolTableIndex)
 519          << binary_le(R.Type);
 520     }
 521   }
 522
 523   // Output symbol table.
 524
 525   for (std::vector<COFFYAML::Symbol>::const_iterator i = CP.Obj.Symbols.begin(),
 526                                                      e = CP.Obj.Symbols.end();
 527        i != e; ++i) {
 528     OS.write(i->Header.Name, COFF::NameSize);
 529     OS << binary_le(i->Header.Value);
 530     if (CP.useBigObj())
 531       OS << binary_le(i->Header.SectionNumber);
 532     else
 533       OS << binary_le(static_cast<int16_t>(i->Header.SectionNumber));
 534     OS << binary_le(i->Header.Type) << binary_le(i->Header.StorageClass)
 535        << binary_le(i->Header.NumberOfAuxSymbols);
 536
 537     if (i->FunctionDefinition) {
 538       OS << binary_le(i->FunctionDefinition->TagIndex)
 539          << binary_le(i->FunctionDefinition->TotalSize)
 540          << binary_le(i->FunctionDefinition->PointerToLinenumber)
 541          << binary_le(i->FunctionDefinition->PointerToNextFunction)
 542          << zeros(i->FunctionDefinition->unused);
 543       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 544     }
 545     if (i->bfAndefSymbol) {
 546       OS << zeros(i->bfAndefSymbol->unused1)
 547          << binary_le(i->bfAndefSymbol->Linenumber)
 548          << zeros(i->bfAndefSymbol->unused2)
 549          << binary_le(i->bfAndefSymbol->PointerToNextFunction)
 550          << zeros(i->bfAndefSymbol->unused3);
 551       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 552     }
 553     if (i->WeakExternal) {
 554       OS << binary_le(i->WeakExternal->TagIndex)
 555          << binary_le(i->WeakExternal->Characteristics)
 556          << zeros(i->WeakExternal->unused);
 557       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 558     }
 559     if (!i->File.empty()) {
 560       unsigned SymbolSize = CP.getSymbolSize();
 561       uint32_t NumberOfAuxRecords =
 562           (i->File.size() + SymbolSize - 1) / SymbolSize;
 563       uint32_t NumberOfAuxBytes = NumberOfAuxRecords * SymbolSize;
 564       uint32_t NumZeros = NumberOfAuxBytes - i->File.size();
 565       OS.write(i->File.data(), i->File.size());
 566       OS.write_zeros(NumZeros);
 567     }
 568     if (i->SectionDefinition) {
 569       OS << binary_le(i->SectionDefinition->Length)
 570          << binary_le(i->SectionDefinition->NumberOfRelocations)
 571          << binary_le(i->SectionDefinition->NumberOfLinenumbers)
 572          << binary_le(i->SectionDefinition->CheckSum)
 573          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number))
 574          << binary_le(i->SectionDefinition->Selection)
 575          << zeros(i->SectionDefinition->unused)
 576          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number >> 16));
 577       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 578     }
 579     if (i->CLRToken) {
 580       OS << binary_le(i->CLRToken->AuxType) << zeros(i->CLRToken->unused1)
 581          << binary_le(i->CLRToken->SymbolTableIndex)
 582          << zeros(i->CLRToken->unused2);
 583       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
 584     }
 585   }
 586
 587   // Output string table.
 588   if (CP.Obj.Header.PointerToSymbolTable)
 589     OS.write(&CP.StringTable[0], CP.StringTable.size());
 590   return true;
 591 }
 592
 593 size_t COFFYAML::SectionDataEntry::size() const {
 594   size_t Size = Binary.binary_size();
 595   if (UInt32)
 596     Size += sizeof(*UInt32);
 597   if (LoadConfig32)
 598     Size += LoadConfig32->Size;
 599   if (LoadConfig64)
 600     Size += LoadConfig64->Size;
 601   return Size;
 602 }
 603
 604 template <typename T> static void writeLoadConfig(T &S, raw_ostream &OS) {
 605   OS.write(reinterpret_cast<const char *>(&S),
 606            std::min(sizeof(S), static_cast<size_t>(S.Size)));
 607   if (sizeof(S) < S.Size)
 608     OS.write_zeros(S.Size - sizeof(S));
 609 }
 610
 611 void COFFYAML::SectionDataEntry::writeAsBinary(raw_ostream &OS) const {
 612   if (UInt32)
 613     OS << binary_le(*UInt32);
 614   Binary.writeAsBinary(OS);
 615   if (LoadConfig32)
 616     writeLoadConfig(*LoadConfig32, OS);
 617   if (LoadConfig64)
 618     writeLoadConfig(*LoadConfig64, OS);
 619 }
 620
 621 namespace llvm {
 622 namespace yaml {
 623
 624 bool yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out,
 625                ErrorHandler ErrHandler) {
 626   COFFParser CP(Doc, ErrHandler);
 627   if (!CP.parse()) {
 628     ErrHandler("failed to parse YAML file");
 629     return false;
 630   }
 631
 632   if (!layoutOptionalHeader(CP)) {
 633     ErrHandler("failed to layout optional header for COFF file");
 634     return false;
 635   }
 636
 637   if (!layoutCOFF(CP)) {
 638     ErrHandler("failed to layout COFF file");
 639     return false;
 640   }
 641   if (!writeCOFF(CP, Out)) {
 642     ErrHandler("failed to write COFF file");
 643     return false;
 644   }
 645   return true;
 646 }
 647
 648 } // namespace yaml
 649 } // namespace llvm