summaryrefslogtreecommitdiffstats
path: root/tools/yaml2obj/yaml2coff.cpp
blob: 6939bc4a3455c52226c23601ec83caec3a97baf0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
//===- yaml2coff - Convert YAML to a COFF object file ---------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief The COFF component of yaml2obj.
///
//===----------------------------------------------------------------------===//

#include "yaml2obj.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Object/COFF.h"
#include "llvm/Object/COFFYAML.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include <vector>

using namespace llvm;

/// This parses a yaml stream that represents a COFF object file.
/// See docs/yaml2obj for the yaml scheema.
struct COFFParser {
  COFFParser(COFFYAML::Object &Obj)
      : Obj(Obj), SectionTableStart(0), SectionTableSize(0) {
    // A COFF string table always starts with a 4 byte size field. Offsets into
    // it include this size, so allocate it now.
    StringTable.append(4, char(0));
  }

  bool useBigObj() const {
    return static_cast<int32_t>(Obj.Sections.size()) >
           COFF::MaxNumberOfSections16;
  }

  bool isPE() const { return Obj.OptionalHeader.hasValue(); }
  bool is64Bit() const {
    return Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64;
  }

  uint32_t getFileAlignment() const {
    return Obj.OptionalHeader->Header.FileAlignment;
  }

  unsigned getHeaderSize() const {
    return useBigObj() ? COFF::Header32Size : COFF::Header16Size;
  }

  unsigned getSymbolSize() const {
    return useBigObj() ? COFF::Symbol32Size : COFF::Symbol16Size;
  }

  bool parseSections() {
    for (std::vector<COFFYAML::Section>::iterator i = Obj.Sections.begin(),
           e = Obj.Sections.end(); i != e; ++i) {
      COFFYAML::Section &Sec = *i;

      // If the name is less than 8 bytes, store it in place, otherwise
      // store it in the string table.
      StringRef Name = Sec.Name;

      if (Name.size() <= COFF::NameSize) {
        std::copy(Name.begin(), Name.end(), Sec.Header.Name);
      } else {
        // Add string to the string table and format the index for output.
        unsigned Index = getStringIndex(Name);
        std::string str = utostr(Index);
        if (str.size() > 7) {
          errs() << "String table got too large";
          return false;
        }
        Sec.Header.Name[0] = '/';
        std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
      }

      Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20;
    }
    return true;
  }

  bool parseSymbols() {
    for (std::vector<COFFYAML::Symbol>::iterator i = Obj.Symbols.begin(),
           e = Obj.Symbols.end(); i != e; ++i) {
      COFFYAML::Symbol &Sym = *i;

      // If the name is less than 8 bytes, store it in place, otherwise
      // store it in the string table.
      StringRef Name = Sym.Name;
      if (Name.size() <= COFF::NameSize) {
        std::copy(Name.begin(), Name.end(), Sym.Header.Name);
      } else {
        // Add string to the string table and format the index for output.
        unsigned Index = getStringIndex(Name);
        *reinterpret_cast<support::aligned_ulittle32_t*>(
            Sym.Header.Name + 4) = Index;
      }

      Sym.Header.Type = Sym.SimpleType;
      Sym.Header.Type |= Sym.ComplexType << COFF::SCT_COMPLEX_TYPE_SHIFT;
    }
    return true;
  }

  bool parse() {
    if (!parseSections())
      return false;
    if (!parseSymbols())
      return false;
    return true;
  }

  unsigned getStringIndex(StringRef Str) {
    StringMap<unsigned>::iterator i = StringTableMap.find(Str);
    if (i == StringTableMap.end()) {
      unsigned Index = StringTable.size();
      StringTable.append(Str.begin(), Str.end());
      StringTable.push_back(0);
      StringTableMap[Str] = Index;
      return Index;
    }
    return i->second;
  }

  COFFYAML::Object &Obj;

  StringMap<unsigned> StringTableMap;
  std::string StringTable;
  uint32_t SectionTableStart;
  uint32_t SectionTableSize;
};

// Take a CP and assign addresses and sizes to everything. Returns false if the
// layout is not valid to do.
static bool layoutOptionalHeader(COFFParser &CP) {
  if (!CP.isPE())
    return true;
  unsigned PEHeaderSize = CP.is64Bit() ? sizeof(object::pe32plus_header)
                                       : sizeof(object::pe32_header);
  CP.Obj.Header.SizeOfOptionalHeader =
      PEHeaderSize +
      sizeof(object::data_directory) * (COFF::NUM_DATA_DIRECTORIES + 1);
  return true;
}

namespace {
enum { DOSStubSize = 128 };
}

// Take a CP and assign addresses and sizes to everything. Returns false if the
// layout is not valid to do.
static bool layoutCOFF(COFFParser &CP) {
  // The section table starts immediately after the header, including the
  // optional header.
  CP.SectionTableStart =
      CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader;
  if (CP.isPE())
    CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic);
  CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size();

  uint32_t CurrentSectionDataOffset =
      CP.SectionTableStart + CP.SectionTableSize;

  // Assign each section data address consecutively.
  for (COFFYAML::Section &S : CP.Obj.Sections) {
    if (S.SectionData.binary_size() > 0) {
      CurrentSectionDataOffset = RoundUpToAlignment(
          CurrentSectionDataOffset, CP.isPE() ? CP.getFileAlignment() : 4);
      S.Header.SizeOfRawData = S.SectionData.binary_size();
      if (CP.isPE())
        S.Header.SizeOfRawData =
            RoundUpToAlignment(S.Header.SizeOfRawData, CP.getFileAlignment());
      S.Header.PointerToRawData = CurrentSectionDataOffset;
      CurrentSectionDataOffset += S.Header.SizeOfRawData;
      if (!S.Relocations.empty()) {
        S.Header.PointerToRelocations = CurrentSectionDataOffset;
        S.Header.NumberOfRelocations = S.Relocations.size();
        CurrentSectionDataOffset +=
            S.Header.NumberOfRelocations * COFF::RelocationSize;
      }
    } else {
      S.Header.SizeOfRawData = 0;
      S.Header.PointerToRawData = 0;
    }
  }

  uint32_t SymbolTableStart = CurrentSectionDataOffset;

  // Calculate number of symbols.
  uint32_t NumberOfSymbols = 0;
  for (std::vector<COFFYAML::Symbol>::iterator i = CP.Obj.Symbols.begin(),
                                               e = CP.Obj.Symbols.end();
                                               i != e; ++i) {
    uint32_t NumberOfAuxSymbols = 0;
    if (i->FunctionDefinition)
      NumberOfAuxSymbols += 1;
    if (i->bfAndefSymbol)
      NumberOfAuxSymbols += 1;
    if (i->WeakExternal)
      NumberOfAuxSymbols += 1;
    if (!i->File.empty())
      NumberOfAuxSymbols +=
          (i->File.size() + CP.getSymbolSize() - 1) / CP.getSymbolSize();
    if (i->SectionDefinition)
      NumberOfAuxSymbols += 1;
    if (i->CLRToken)
      NumberOfAuxSymbols += 1;
    i->Header.NumberOfAuxSymbols = NumberOfAuxSymbols;
    NumberOfSymbols += 1 + NumberOfAuxSymbols;
  }

  // Store all the allocated start addresses in the header.
  CP.Obj.Header.NumberOfSections = CP.Obj.Sections.size();
  CP.Obj.Header.NumberOfSymbols = NumberOfSymbols;
  if (NumberOfSymbols > 0 || CP.StringTable.size() > 4)
    CP.Obj.Header.PointerToSymbolTable = SymbolTableStart;
  else
    CP.Obj.Header.PointerToSymbolTable = 0;

  *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0])
    = CP.StringTable.size();

  return true;
}

template <typename value_type>
struct binary_le_impl {
  value_type Value;
  binary_le_impl(value_type V) : Value(V) {}
};

template <typename value_type>
raw_ostream &operator <<( raw_ostream &OS
                        , const binary_le_impl<value_type> &BLE) {
  char Buffer[sizeof(BLE.Value)];
  support::endian::write<value_type, support::little, support::unaligned>(
    Buffer, BLE.Value);
  OS.write(Buffer, sizeof(BLE.Value));
  return OS;
}

template <typename value_type>
binary_le_impl<value_type> binary_le(value_type V) {
  return binary_le_impl<value_type>(V);
}

template <size_t NumBytes>
struct zeros_impl {
  zeros_impl() {}
};

template <size_t NumBytes>
raw_ostream &operator<<(raw_ostream &OS, const zeros_impl<NumBytes> &) {
  char Buffer[NumBytes];
  memset(Buffer, 0, sizeof(Buffer));
  OS.write(Buffer, sizeof(Buffer));
  return OS;
}

template <typename T>
zeros_impl<sizeof(T)> zeros(const T &) {
  return zeros_impl<sizeof(T)>();
}

struct num_zeros_impl {
  size_t N;
  num_zeros_impl(size_t N) : N(N) {}
};

raw_ostream &operator<<(raw_ostream &OS, const num_zeros_impl &NZI) {
  for (size_t I = 0; I != NZI.N; ++I)
    OS.write(0);
  return OS;
}

static num_zeros_impl num_zeros(size_t N) {
  num_zeros_impl NZI(N);
  return NZI;
}

template <typename T>
static uint32_t initializeOptionalHeader(COFFParser &CP, uint16_t Magic, T Header) {
  memset(Header, 0, sizeof(*Header));
  Header->Magic = Magic;
  Header->SectionAlignment = CP.Obj.OptionalHeader->Header.SectionAlignment;
  Header->FileAlignment = CP.Obj.OptionalHeader->Header.FileAlignment;
  uint32_t SizeOfCode = 0, SizeOfInitializedData = 0,
           SizeOfUninitializedData = 0;
  uint32_t SizeOfHeaders = RoundUpToAlignment(
      CP.SectionTableStart + CP.SectionTableSize, Header->FileAlignment);
  uint32_t SizeOfImage =
      RoundUpToAlignment(SizeOfHeaders, Header->SectionAlignment);
  uint32_t BaseOfData = 0;
  for (const COFFYAML::Section &S : CP.Obj.Sections) {
    if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_CODE)
      SizeOfCode += S.Header.SizeOfRawData;
    if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
      SizeOfInitializedData += S.Header.SizeOfRawData;
    if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
      SizeOfUninitializedData += S.Header.SizeOfRawData;
    if (S.Name.equals(".text"))
      Header->BaseOfCode = S.Header.VirtualAddress; // RVA
    else if (S.Name.equals(".data"))
      BaseOfData = S.Header.VirtualAddress; // RVA
    if (S.Header.VirtualAddress)
      SizeOfImage +=
          RoundUpToAlignment(S.Header.VirtualSize, Header->SectionAlignment);
  }
  Header->SizeOfCode = SizeOfCode;
  Header->SizeOfInitializedData = SizeOfInitializedData;
  Header->SizeOfUninitializedData = SizeOfUninitializedData;
  Header->AddressOfEntryPoint =
      CP.Obj.OptionalHeader->Header.AddressOfEntryPoint; // RVA
  Header->ImageBase = CP.Obj.OptionalHeader->Header.ImageBase;
  Header->MajorOperatingSystemVersion =
      CP.Obj.OptionalHeader->Header.MajorOperatingSystemVersion;
  Header->MinorOperatingSystemVersion =
      CP.Obj.OptionalHeader->Header.MinorOperatingSystemVersion;
  Header->MajorImageVersion =
      CP.Obj.OptionalHeader->Header.MajorImageVersion;
  Header->MinorImageVersion =
      CP.Obj.OptionalHeader->Header.MinorImageVersion;
  Header->MajorSubsystemVersion =
      CP.Obj.OptionalHeader->Header.MajorSubsystemVersion;
  Header->MinorSubsystemVersion =
      CP.Obj.OptionalHeader->Header.MinorSubsystemVersion;
  Header->SizeOfImage = SizeOfImage;
  Header->SizeOfHeaders = SizeOfHeaders;
  Header->Subsystem = CP.Obj.OptionalHeader->Header.Subsystem;
  Header->DLLCharacteristics = CP.Obj.OptionalHeader->Header.DLLCharacteristics;
  Header->SizeOfStackReserve = CP.Obj.OptionalHeader->Header.SizeOfStackReserve;
  Header->SizeOfStackCommit = CP.Obj.OptionalHeader->Header.SizeOfStackCommit;
  Header->SizeOfHeapReserve = CP.Obj.OptionalHeader->Header.SizeOfHeapReserve;
  Header->SizeOfHeapCommit = CP.Obj.OptionalHeader->Header.SizeOfHeapCommit;
  Header->NumberOfRvaAndSize = COFF::NUM_DATA_DIRECTORIES + 1;
  return BaseOfData;
}

static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
  if (CP.isPE()) {
    // PE files start with a DOS stub.
    object::dos_header DH;
    memset(&DH, 0, sizeof(DH));

    // DOS EXEs start with "MZ" magic.
    DH.Magic[0] = 'M';
    DH.Magic[1] = 'Z';
    // Initializing the AddressOfRelocationTable is strictly optional but
    // mollifies certain tools which expect it to have a value greater than
    // 0x40.
    DH.AddressOfRelocationTable = sizeof(DH);
    // This is the address of the PE signature.
    DH.AddressOfNewExeHeader = DOSStubSize;

    // Write out our DOS stub.
    OS.write(reinterpret_cast<char *>(&DH), sizeof(DH));
    // Write padding until we reach the position of where our PE signature
    // should live.
    OS << num_zeros(DOSStubSize - sizeof(DH));
    // Write out the PE signature.
    OS.write(COFF::PEMagic, sizeof(COFF::PEMagic));
  }
  if (CP.useBigObj()) {
    OS << binary_le(static_cast<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN))
       << binary_le(static_cast<uint16_t>(0xffff))
       << binary_le(static_cast<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion))
       << binary_le(CP.Obj.Header.Machine)
       << binary_le(CP.Obj.Header.TimeDateStamp);
    OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
    OS << zeros(uint32_t(0))
       << zeros(uint32_t(0))
       << zeros(uint32_t(0))
       << zeros(uint32_t(0))
       << binary_le(CP.Obj.Header.NumberOfSections)
       << binary_le(CP.Obj.Header.PointerToSymbolTable)
       << binary_le(CP.Obj.Header.NumberOfSymbols);
  } else {
    OS << binary_le(CP.Obj.Header.Machine)
       << binary_le(static_cast<int16_t>(CP.Obj.Header.NumberOfSections))
       << binary_le(CP.Obj.Header.TimeDateStamp)
       << binary_le(CP.Obj.Header.PointerToSymbolTable)
       << binary_le(CP.Obj.Header.NumberOfSymbols)
       << binary_le(CP.Obj.Header.SizeOfOptionalHeader)
       << binary_le(CP.Obj.Header.Characteristics);
  }
  if (CP.isPE()) {
    if (CP.is64Bit()) {
      object::pe32plus_header PEH;
      initializeOptionalHeader(CP, COFF::PE32Header::PE32_PLUS, &PEH);
      OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
    } else {
      object::pe32_header PEH;
      uint32_t BaseOfData = initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH);
      PEH.BaseOfData = BaseOfData;
      OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
    }
    for (const Optional<COFF::DataDirectory> &DD :
         CP.Obj.OptionalHeader->DataDirectories) {
      if (!DD.hasValue()) {
        OS << zeros(uint32_t(0));
        OS << zeros(uint32_t(0));
      } else {
        OS << binary_le(DD->RelativeVirtualAddress);
        OS << binary_le(DD->Size);
      }
    }
    OS << zeros(uint32_t(0));
    OS << zeros(uint32_t(0));
  }

  assert(OS.tell() == CP.SectionTableStart);
  // Output section table.
  for (std::vector<COFFYAML::Section>::iterator i = CP.Obj.Sections.begin(),
                                                e = CP.Obj.Sections.end();
                                                i != e; ++i) {
    OS.write(i->Header.Name, COFF::NameSize);
    OS << binary_le(i->Header.VirtualSize)
       << binary_le(i->Header.VirtualAddress)
       << binary_le(i->Header.SizeOfRawData)
       << binary_le(i->Header.PointerToRawData)
       << binary_le(i->Header.PointerToRelocations)
       << binary_le(i->Header.PointerToLineNumbers)
       << binary_le(i->Header.NumberOfRelocations)
       << binary_le(i->Header.NumberOfLineNumbers)
       << binary_le(i->Header.Characteristics);
  }
  assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize);

  unsigned CurSymbol = 0;
  StringMap<unsigned> SymbolTableIndexMap;
  for (std::vector<COFFYAML::Symbol>::iterator I = CP.Obj.Symbols.begin(),
                                               E = CP.Obj.Symbols.end();
       I != E; ++I) {
    SymbolTableIndexMap[I->Name] = CurSymbol;
    CurSymbol += 1 + I->Header.NumberOfAuxSymbols;
  }

  // Output section data.
  for (const COFFYAML::Section &S : CP.Obj.Sections) {
    if (!S.Header.SizeOfRawData)
      continue;
    assert(S.Header.PointerToRawData >= OS.tell());
    OS << num_zeros(S.Header.PointerToRawData - OS.tell());
    S.SectionData.writeAsBinary(OS);
    assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
    OS << num_zeros(S.Header.SizeOfRawData - S.SectionData.binary_size());
    for (const COFFYAML::Relocation &R : S.Relocations) {
      uint32_t SymbolTableIndex = SymbolTableIndexMap[R.SymbolName];
      OS << binary_le(R.VirtualAddress)
         << binary_le(SymbolTableIndex)
         << binary_le(R.Type);
    }
  }

  // Output symbol table.

  for (std::vector<COFFYAML::Symbol>::const_iterator i = CP.Obj.Symbols.begin(),
                                                     e = CP.Obj.Symbols.end();
                                                     i != e; ++i) {
    OS.write(i->Header.Name, COFF::NameSize);
    OS << binary_le(i->Header.Value);
    if (CP.useBigObj())
       OS << binary_le(i->Header.SectionNumber);
    else
       OS << binary_le(static_cast<int16_t>(i->Header.SectionNumber));
    OS << binary_le(i->Header.Type)
       << binary_le(i->Header.StorageClass)
       << binary_le(i->Header.NumberOfAuxSymbols);

    if (i->FunctionDefinition)
      OS << binary_le(i->FunctionDefinition->TagIndex)
         << binary_le(i->FunctionDefinition->TotalSize)
         << binary_le(i->FunctionDefinition->PointerToLinenumber)
         << binary_le(i->FunctionDefinition->PointerToNextFunction)
         << zeros(i->FunctionDefinition->unused)
         << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
    if (i->bfAndefSymbol)
      OS << zeros(i->bfAndefSymbol->unused1)
         << binary_le(i->bfAndefSymbol->Linenumber)
         << zeros(i->bfAndefSymbol->unused2)
         << binary_le(i->bfAndefSymbol->PointerToNextFunction)
         << zeros(i->bfAndefSymbol->unused3)
         << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
    if (i->WeakExternal)
      OS << binary_le(i->WeakExternal->TagIndex)
         << binary_le(i->WeakExternal->Characteristics)
         << zeros(i->WeakExternal->unused)
         << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
    if (!i->File.empty()) {
      unsigned SymbolSize = CP.getSymbolSize();
      uint32_t NumberOfAuxRecords =
          (i->File.size() + SymbolSize - 1) / SymbolSize;
      uint32_t NumberOfAuxBytes = NumberOfAuxRecords * SymbolSize;
      uint32_t NumZeros = NumberOfAuxBytes - i->File.size();
      OS.write(i->File.data(), i->File.size());
      OS << num_zeros(NumZeros);
    }
    if (i->SectionDefinition)
      OS << binary_le(i->SectionDefinition->Length)
         << binary_le(i->SectionDefinition->NumberOfRelocations)
         << binary_le(i->SectionDefinition->NumberOfLinenumbers)
         << binary_le(i->SectionDefinition->CheckSum)
         << binary_le(static_cast<int16_t>(i->SectionDefinition->Number))
         << binary_le(i->SectionDefinition->Selection)
         << zeros(i->SectionDefinition->unused)
         << binary_le(static_cast<int16_t>(i->SectionDefinition->Number >> 16))
         << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
    if (i->CLRToken)
      OS << binary_le(i->CLRToken->AuxType)
         << zeros(i->CLRToken->unused1)
         << binary_le(i->CLRToken->SymbolTableIndex)
         << zeros(i->CLRToken->unused2)
         << num_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
  }

  // Output string table.
  if (CP.Obj.Header.PointerToSymbolTable)
    OS.write(&CP.StringTable[0], CP.StringTable.size());
  return true;
}

int yaml2coff(yaml::Input &YIn, raw_ostream &Out) {
  COFFYAML::Object Doc;
  YIn >> Doc;
  if (YIn.error()) {
    errs() << "yaml2obj: Failed to parse YAML file!\n";
    return 1;
  }

  COFFParser CP(Doc);
  if (!CP.parse()) {
    errs() << "yaml2obj: Failed to parse YAML file!\n";
    return 1;
  }

  if (!layoutOptionalHeader(CP)) {
    errs() << "yaml2obj: Failed to layout optional header for COFF file!\n";
    return 1;
  }
  if (!layoutCOFF(CP)) {
    errs() << "yaml2obj: Failed to layout COFF file!\n";
    return 1;
  }
  if (!writeCOFF(CP, Out)) {
    errs() << "yaml2obj: Failed to write COFF file!\n";
    return 1;
  }
  return 0;
}