xref: /aosp_15_r20/external/swiftshader/third_party/llvm-16.0/llvm/lib/ObjectYAML/COFFEmitter.cpp (revision 03ce13f70fcc45d86ee91b7ee4cab1936a95046e) 
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/Object/COFF.h"
20 #include "llvm/ObjectYAML/ObjectYAML.h"
21 #include "llvm/ObjectYAML/yaml2obj.h"
22 #include "llvm/Support/BinaryStreamWriter.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 <optional>
29 #include <vector>
30 
31 using namespace llvm;
32 
33 namespace {
34 
35 /// This parses a yaml stream that represents a COFF object file.
36 /// See docs/yaml2obj for the yaml scheema.
37 struct COFFParser {
COFFParser__anonc663d2210111::COFFParser38   COFFParser(COFFYAML::Object &Obj, yaml::ErrorHandler EH)
39       : Obj(Obj), SectionTableStart(0), SectionTableSize(0), ErrHandler(EH) {
40     // A COFF string table always starts with a 4 byte size field. Offsets into
41     // it include this size, so allocate it now.
42     StringTable.append(4, char(0));
43   }
44 
useBigObj__anonc663d2210111::COFFParser45   bool useBigObj() const {
46     return static_cast<int32_t>(Obj.Sections.size()) >
47            COFF::MaxNumberOfSections16;
48   }
49 
isPE__anonc663d2210111::COFFParser50   bool isPE() const { return Obj.OptionalHeader.has_value(); }
is64Bit__anonc663d2210111::COFFParser51   bool is64Bit() const {
52     return Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64 ||
53            Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_ARM64 ||
54            Obj.Header.Machine == COFF::IMAGE_FILE_MACHINE_ARM64EC;
55   }
56 
getFileAlignment__anonc663d2210111::COFFParser57   uint32_t getFileAlignment() const {
58     return Obj.OptionalHeader->Header.FileAlignment;
59   }
60 
getHeaderSize__anonc663d2210111::COFFParser61   unsigned getHeaderSize() const {
62     return useBigObj() ? COFF::Header32Size : COFF::Header16Size;
63   }
64 
getSymbolSize__anonc663d2210111::COFFParser65   unsigned getSymbolSize() const {
66     return useBigObj() ? COFF::Symbol32Size : COFF::Symbol16Size;
67   }
68 
parseSections__anonc663d2210111::COFFParser69   bool parseSections() {
70     for (COFFYAML::Section &Sec : Obj.Sections) {
71       // If the name is less than 8 bytes, store it in place, otherwise
72       // store it in the string table.
73       StringRef Name = Sec.Name;
74 
75       if (Name.size() <= COFF::NameSize) {
76         std::copy(Name.begin(), Name.end(), Sec.Header.Name);
77       } else {
78         // Add string to the string table and format the index for output.
79         unsigned Index = getStringIndex(Name);
80         std::string str = utostr(Index);
81         if (str.size() > 7) {
82           ErrHandler("string table got too large");
83           return false;
84         }
85         Sec.Header.Name[0] = '/';
86         std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
87       }
88 
89       if (Sec.Alignment) {
90         if (Sec.Alignment > 8192) {
91           ErrHandler("section alignment is too large");
92           return false;
93         }
94         if (!isPowerOf2_32(Sec.Alignment)) {
95           ErrHandler("section alignment is not a power of 2");
96           return false;
97         }
98         Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20;
99       }
100     }
101     return true;
102   }
103 
parseSymbols__anonc663d2210111::COFFParser104   bool parseSymbols() {
105     for (COFFYAML::Symbol &Sym : Obj.Symbols) {
106       // If the name is less than 8 bytes, store it in place, otherwise
107       // store it in the string table.
108       StringRef Name = Sym.Name;
109       if (Name.size() <= COFF::NameSize) {
110         std::copy(Name.begin(), Name.end(), Sym.Header.Name);
111       } else {
112         // Add string to the string table and format the index for output.
113         unsigned Index = getStringIndex(Name);
114         *reinterpret_cast<support::aligned_ulittle32_t *>(Sym.Header.Name + 4) =
115             Index;
116       }
117 
118       Sym.Header.Type = Sym.SimpleType;
119       Sym.Header.Type |= Sym.ComplexType << COFF::SCT_COMPLEX_TYPE_SHIFT;
120     }
121     return true;
122   }
123 
parse__anonc663d2210111::COFFParser124   bool parse() {
125     if (!parseSections())
126       return false;
127     if (!parseSymbols())
128       return false;
129     return true;
130   }
131 
getStringIndex__anonc663d2210111::COFFParser132   unsigned getStringIndex(StringRef Str) {
133     StringMap<unsigned>::iterator i = StringTableMap.find(Str);
134     if (i == StringTableMap.end()) {
135       unsigned Index = StringTable.size();
136       StringTable.append(Str.begin(), Str.end());
137       StringTable.push_back(0);
138       StringTableMap[Str] = Index;
139       return Index;
140     }
141     return i->second;
142   }
143 
144   COFFYAML::Object &Obj;
145 
146   codeview::StringsAndChecksums StringsAndChecksums;
147   BumpPtrAllocator Allocator;
148   StringMap<unsigned> StringTableMap;
149   std::string StringTable;
150   uint32_t SectionTableStart;
151   uint32_t SectionTableSize;
152 
153   yaml::ErrorHandler ErrHandler;
154 };
155 
156 enum { DOSStubSize = 128 };
157 
158 } // end anonymous namespace
159 
160 // Take a CP and assign addresses and sizes to everything. Returns false if the
161 // layout is not valid to do.
layoutOptionalHeader(COFFParser & CP)162 static bool layoutOptionalHeader(COFFParser &CP) {
163   if (!CP.isPE())
164     return true;
165   unsigned PEHeaderSize = CP.is64Bit() ? sizeof(object::pe32plus_header)
166                                        : sizeof(object::pe32_header);
167   CP.Obj.Header.SizeOfOptionalHeader =
168       PEHeaderSize + sizeof(object::data_directory) *
169                          CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
170   return true;
171 }
172 
173 static yaml::BinaryRef
toDebugS(ArrayRef<CodeViewYAML::YAMLDebugSubsection> Subsections,const codeview::StringsAndChecksums & SC,BumpPtrAllocator & Allocator)174 toDebugS(ArrayRef<CodeViewYAML::YAMLDebugSubsection> Subsections,
175          const codeview::StringsAndChecksums &SC, BumpPtrAllocator &Allocator) {
176   using namespace codeview;
177   ExitOnError Err("Error occurred writing .debug$S section");
178   auto CVSS =
179       Err(CodeViewYAML::toCodeViewSubsectionList(Allocator, Subsections, SC));
180 
181   std::vector<DebugSubsectionRecordBuilder> Builders;
182   uint32_t Size = sizeof(uint32_t);
183   for (auto &SS : CVSS) {
184     DebugSubsectionRecordBuilder B(SS);
185     Size += B.calculateSerializedLength();
186     Builders.push_back(std::move(B));
187   }
188   uint8_t *Buffer = Allocator.Allocate<uint8_t>(Size);
189   MutableArrayRef<uint8_t> Output(Buffer, Size);
190   BinaryStreamWriter Writer(Output, support::little);
191 
192   Err(Writer.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC));
193   for (const auto &B : Builders) {
194     Err(B.commit(Writer, CodeViewContainer::ObjectFile));
195   }
196   return {Output};
197 }
198 
199 // Take a CP and assign addresses and sizes to everything. Returns false if the
200 // layout is not valid to do.
layoutCOFF(COFFParser & CP)201 static bool layoutCOFF(COFFParser &CP) {
202   // The section table starts immediately after the header, including the
203   // optional header.
204   CP.SectionTableStart =
205       CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader;
206   if (CP.isPE())
207     CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic);
208   CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size();
209 
210   uint32_t CurrentSectionDataOffset =
211       CP.SectionTableStart + CP.SectionTableSize;
212 
213   for (COFFYAML::Section &S : CP.Obj.Sections) {
214     // We support specifying exactly one of SectionData or Subsections.  So if
215     // there is already some SectionData, then we don't need to do any of this.
216     if (S.Name == ".debug$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 && 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         if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL) {
258           S.Header.NumberOfRelocations = 0xffff;
259           CurrentSectionDataOffset += COFF::RelocationSize;
260         } else
261           S.Header.NumberOfRelocations = S.Relocations.size();
262         CurrentSectionDataOffset += S.Relocations.size() * COFF::RelocationSize;
263       }
264     } else {
265       // Leave SizeOfRawData unaltered. For .bss sections in object files, it
266       // carries the section size.
267       S.Header.PointerToRawData = 0;
268     }
269   }
270 
271   uint32_t SymbolTableStart = CurrentSectionDataOffset;
272 
273   // Calculate number of symbols.
274   uint32_t NumberOfSymbols = 0;
275   for (std::vector<COFFYAML::Symbol>::iterator i = CP.Obj.Symbols.begin(),
276                                                e = CP.Obj.Symbols.end();
277        i != e; ++i) {
278     uint32_t NumberOfAuxSymbols = 0;
279     if (i->FunctionDefinition)
280       NumberOfAuxSymbols += 1;
281     if (i->bfAndefSymbol)
282       NumberOfAuxSymbols += 1;
283     if (i->WeakExternal)
284       NumberOfAuxSymbols += 1;
285     if (!i->File.empty())
286       NumberOfAuxSymbols +=
287           (i->File.size() + CP.getSymbolSize() - 1) / CP.getSymbolSize();
288     if (i->SectionDefinition)
289       NumberOfAuxSymbols += 1;
290     if (i->CLRToken)
291       NumberOfAuxSymbols += 1;
292     i->Header.NumberOfAuxSymbols = NumberOfAuxSymbols;
293     NumberOfSymbols += 1 + NumberOfAuxSymbols;
294   }
295 
296   // Store all the allocated start addresses in the header.
297   CP.Obj.Header.NumberOfSections = CP.Obj.Sections.size();
298   CP.Obj.Header.NumberOfSymbols = NumberOfSymbols;
299   if (NumberOfSymbols > 0 || CP.StringTable.size() > 4)
300     CP.Obj.Header.PointerToSymbolTable = SymbolTableStart;
301   else
302     CP.Obj.Header.PointerToSymbolTable = 0;
303 
304   *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0]) =
305       CP.StringTable.size();
306 
307   return true;
308 }
309 
310 template <typename value_type> struct binary_le_impl {
311   value_type Value;
binary_le_implbinary_le_impl312   binary_le_impl(value_type V) : Value(V) {}
313 };
314 
315 template <typename value_type>
operator <<(raw_ostream & OS,const binary_le_impl<value_type> & BLE)316 raw_ostream &operator<<(raw_ostream &OS,
317                         const binary_le_impl<value_type> &BLE) {
318   char Buffer[sizeof(BLE.Value)];
319   support::endian::write<value_type, support::little, support::unaligned>(
320       Buffer, BLE.Value);
321   OS.write(Buffer, sizeof(BLE.Value));
322   return OS;
323 }
324 
325 template <typename value_type>
binary_le(value_type V)326 binary_le_impl<value_type> binary_le(value_type V) {
327   return binary_le_impl<value_type>(V);
328 }
329 
330 template <size_t NumBytes> struct zeros_impl {};
331 
332 template <size_t NumBytes>
operator <<(raw_ostream & OS,const zeros_impl<NumBytes> &)333 raw_ostream &operator<<(raw_ostream &OS, const zeros_impl<NumBytes> &) {
334   char Buffer[NumBytes];
335   memset(Buffer, 0, sizeof(Buffer));
336   OS.write(Buffer, sizeof(Buffer));
337   return OS;
338 }
339 
zeros(const T &)340 template <typename T> zeros_impl<sizeof(T)> zeros(const T &) {
341   return zeros_impl<sizeof(T)>();
342 }
343 
344 template <typename T>
initializeOptionalHeader(COFFParser & CP,uint16_t Magic,T Header)345 static uint32_t initializeOptionalHeader(COFFParser &CP, uint16_t Magic,
346                                          T Header) {
347   memset(Header, 0, sizeof(*Header));
348   Header->Magic = Magic;
349   Header->SectionAlignment = CP.Obj.OptionalHeader->Header.SectionAlignment;
350   Header->FileAlignment = CP.Obj.OptionalHeader->Header.FileAlignment;
351   uint32_t SizeOfCode = 0, SizeOfInitializedData = 0,
352            SizeOfUninitializedData = 0;
353   uint32_t SizeOfHeaders = alignTo(CP.SectionTableStart + CP.SectionTableSize,
354                                    Header->FileAlignment);
355   uint32_t SizeOfImage = alignTo(SizeOfHeaders, Header->SectionAlignment);
356   uint32_t BaseOfData = 0;
357   for (const COFFYAML::Section &S : CP.Obj.Sections) {
358     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_CODE)
359       SizeOfCode += S.Header.SizeOfRawData;
360     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
361       SizeOfInitializedData += S.Header.SizeOfRawData;
362     if (S.Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
363       SizeOfUninitializedData += S.Header.SizeOfRawData;
364     if (S.Name.equals(".text"))
365       Header->BaseOfCode = S.Header.VirtualAddress; // RVA
366     else if (S.Name.equals(".data"))
367       BaseOfData = S.Header.VirtualAddress; // RVA
368     if (S.Header.VirtualAddress)
369       SizeOfImage += alignTo(S.Header.VirtualSize, Header->SectionAlignment);
370   }
371   Header->SizeOfCode = SizeOfCode;
372   Header->SizeOfInitializedData = SizeOfInitializedData;
373   Header->SizeOfUninitializedData = SizeOfUninitializedData;
374   Header->AddressOfEntryPoint =
375       CP.Obj.OptionalHeader->Header.AddressOfEntryPoint; // RVA
376   Header->ImageBase = CP.Obj.OptionalHeader->Header.ImageBase;
377   Header->MajorOperatingSystemVersion =
378       CP.Obj.OptionalHeader->Header.MajorOperatingSystemVersion;
379   Header->MinorOperatingSystemVersion =
380       CP.Obj.OptionalHeader->Header.MinorOperatingSystemVersion;
381   Header->MajorImageVersion = CP.Obj.OptionalHeader->Header.MajorImageVersion;
382   Header->MinorImageVersion = CP.Obj.OptionalHeader->Header.MinorImageVersion;
383   Header->MajorSubsystemVersion =
384       CP.Obj.OptionalHeader->Header.MajorSubsystemVersion;
385   Header->MinorSubsystemVersion =
386       CP.Obj.OptionalHeader->Header.MinorSubsystemVersion;
387   Header->SizeOfImage = SizeOfImage;
388   Header->SizeOfHeaders = SizeOfHeaders;
389   Header->Subsystem = CP.Obj.OptionalHeader->Header.Subsystem;
390   Header->DLLCharacteristics = CP.Obj.OptionalHeader->Header.DLLCharacteristics;
391   Header->SizeOfStackReserve = CP.Obj.OptionalHeader->Header.SizeOfStackReserve;
392   Header->SizeOfStackCommit = CP.Obj.OptionalHeader->Header.SizeOfStackCommit;
393   Header->SizeOfHeapReserve = CP.Obj.OptionalHeader->Header.SizeOfHeapReserve;
394   Header->SizeOfHeapCommit = CP.Obj.OptionalHeader->Header.SizeOfHeapCommit;
395   Header->NumberOfRvaAndSize = CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
396   return BaseOfData;
397 }
398 
writeCOFF(COFFParser & CP,raw_ostream & OS)399 static bool writeCOFF(COFFParser &CP, raw_ostream &OS) {
400   if (CP.isPE()) {
401     // PE files start with a DOS stub.
402     object::dos_header DH;
403     memset(&DH, 0, sizeof(DH));
404 
405     // DOS EXEs start with "MZ" magic.
406     DH.Magic[0] = 'M';
407     DH.Magic[1] = 'Z';
408     // Initializing the AddressOfRelocationTable is strictly optional but
409     // mollifies certain tools which expect it to have a value greater than
410     // 0x40.
411     DH.AddressOfRelocationTable = sizeof(DH);
412     // This is the address of the PE signature.
413     DH.AddressOfNewExeHeader = DOSStubSize;
414 
415     // Write out our DOS stub.
416     OS.write(reinterpret_cast<char *>(&DH), sizeof(DH));
417     // Write padding until we reach the position of where our PE signature
418     // should live.
419     OS.write_zeros(DOSStubSize - sizeof(DH));
420     // Write out the PE signature.
421     OS.write(COFF::PEMagic, sizeof(COFF::PEMagic));
422   }
423   if (CP.useBigObj()) {
424     OS << binary_le(static_cast<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN))
425        << binary_le(static_cast<uint16_t>(0xffff))
426        << binary_le(
427               static_cast<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion))
428        << binary_le(CP.Obj.Header.Machine)
429        << binary_le(CP.Obj.Header.TimeDateStamp);
430     OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
431     OS << zeros(uint32_t(0)) << zeros(uint32_t(0)) << zeros(uint32_t(0))
432        << zeros(uint32_t(0)) << binary_le(CP.Obj.Header.NumberOfSections)
433        << binary_le(CP.Obj.Header.PointerToSymbolTable)
434        << binary_le(CP.Obj.Header.NumberOfSymbols);
435   } else {
436     OS << binary_le(CP.Obj.Header.Machine)
437        << binary_le(static_cast<int16_t>(CP.Obj.Header.NumberOfSections))
438        << binary_le(CP.Obj.Header.TimeDateStamp)
439        << binary_le(CP.Obj.Header.PointerToSymbolTable)
440        << binary_le(CP.Obj.Header.NumberOfSymbols)
441        << binary_le(CP.Obj.Header.SizeOfOptionalHeader)
442        << binary_le(CP.Obj.Header.Characteristics);
443   }
444   if (CP.isPE()) {
445     if (CP.is64Bit()) {
446       object::pe32plus_header PEH;
447       initializeOptionalHeader(CP, COFF::PE32Header::PE32_PLUS, &PEH);
448       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
449     } else {
450       object::pe32_header PEH;
451       uint32_t BaseOfData =
452           initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH);
453       PEH.BaseOfData = BaseOfData;
454       OS.write(reinterpret_cast<char *>(&PEH), sizeof(PEH));
455     }
456     for (uint32_t I = 0; I < CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize;
457          ++I) {
458       const std::optional<COFF::DataDirectory> *DataDirectories =
459           CP.Obj.OptionalHeader->DataDirectories;
460       uint32_t NumDataDir = std::size(CP.Obj.OptionalHeader->DataDirectories);
461       if (I >= NumDataDir || !DataDirectories[I]) {
462         OS << zeros(uint32_t(0));
463         OS << zeros(uint32_t(0));
464       } else {
465         OS << binary_le(DataDirectories[I]->RelativeVirtualAddress);
466         OS << binary_le(DataDirectories[I]->Size);
467       }
468     }
469   }
470 
471   assert(OS.tell() == CP.SectionTableStart);
472   // Output section table.
473   for (const COFFYAML::Section &S : CP.Obj.Sections) {
474     OS.write(S.Header.Name, COFF::NameSize);
475     OS << binary_le(S.Header.VirtualSize)
476        << binary_le(S.Header.VirtualAddress)
477        << binary_le(S.Header.SizeOfRawData)
478        << binary_le(S.Header.PointerToRawData)
479        << binary_le(S.Header.PointerToRelocations)
480        << binary_le(S.Header.PointerToLineNumbers)
481        << binary_le(S.Header.NumberOfRelocations)
482        << binary_le(S.Header.NumberOfLineNumbers)
483        << binary_le(S.Header.Characteristics);
484   }
485   assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize);
486 
487   unsigned CurSymbol = 0;
488   StringMap<unsigned> SymbolTableIndexMap;
489   for (const COFFYAML::Symbol &Sym : CP.Obj.Symbols) {
490     SymbolTableIndexMap[Sym.Name] = CurSymbol;
491     CurSymbol += 1 + Sym.Header.NumberOfAuxSymbols;
492   }
493 
494   // Output section data.
495   for (const COFFYAML::Section &S : CP.Obj.Sections) {
496     if (S.Header.SizeOfRawData == 0 || S.Header.PointerToRawData == 0)
497       continue;
498     assert(S.Header.PointerToRawData >= OS.tell());
499     OS.write_zeros(S.Header.PointerToRawData - OS.tell());
500     S.SectionData.writeAsBinary(OS);
501     assert(S.Header.SizeOfRawData >= S.SectionData.binary_size());
502     OS.write_zeros(S.Header.SizeOfRawData - S.SectionData.binary_size());
503     if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL)
504       OS << binary_le<uint32_t>(/*VirtualAddress=*/ S.Relocations.size() + 1)
505          << binary_le<uint32_t>(/*SymbolTableIndex=*/ 0)
506          << binary_le<uint16_t>(/*Type=*/ 0);
507     for (const COFFYAML::Relocation &R : S.Relocations) {
508       uint32_t SymbolTableIndex;
509       if (R.SymbolTableIndex) {
510         if (!R.SymbolName.empty())
511           WithColor::error()
512               << "Both SymbolName and SymbolTableIndex specified\n";
513         SymbolTableIndex = *R.SymbolTableIndex;
514       } else {
515         SymbolTableIndex = SymbolTableIndexMap[R.SymbolName];
516       }
517       OS << binary_le(R.VirtualAddress) << binary_le(SymbolTableIndex)
518          << binary_le(R.Type);
519     }
520   }
521 
522   // Output symbol table.
523 
524   for (std::vector<COFFYAML::Symbol>::const_iterator i = CP.Obj.Symbols.begin(),
525                                                      e = CP.Obj.Symbols.end();
526        i != e; ++i) {
527     OS.write(i->Header.Name, COFF::NameSize);
528     OS << binary_le(i->Header.Value);
529     if (CP.useBigObj())
530       OS << binary_le(i->Header.SectionNumber);
531     else
532       OS << binary_le(static_cast<int16_t>(i->Header.SectionNumber));
533     OS << binary_le(i->Header.Type) << binary_le(i->Header.StorageClass)
534        << binary_le(i->Header.NumberOfAuxSymbols);
535 
536     if (i->FunctionDefinition) {
537       OS << binary_le(i->FunctionDefinition->TagIndex)
538          << binary_le(i->FunctionDefinition->TotalSize)
539          << binary_le(i->FunctionDefinition->PointerToLinenumber)
540          << binary_le(i->FunctionDefinition->PointerToNextFunction)
541          << zeros(i->FunctionDefinition->unused);
542       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
543     }
544     if (i->bfAndefSymbol) {
545       OS << zeros(i->bfAndefSymbol->unused1)
546          << binary_le(i->bfAndefSymbol->Linenumber)
547          << zeros(i->bfAndefSymbol->unused2)
548          << binary_le(i->bfAndefSymbol->PointerToNextFunction)
549          << zeros(i->bfAndefSymbol->unused3);
550       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
551     }
552     if (i->WeakExternal) {
553       OS << binary_le(i->WeakExternal->TagIndex)
554          << binary_le(i->WeakExternal->Characteristics)
555          << zeros(i->WeakExternal->unused);
556       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
557     }
558     if (!i->File.empty()) {
559       unsigned SymbolSize = CP.getSymbolSize();
560       uint32_t NumberOfAuxRecords =
561           (i->File.size() + SymbolSize - 1) / SymbolSize;
562       uint32_t NumberOfAuxBytes = NumberOfAuxRecords * SymbolSize;
563       uint32_t NumZeros = NumberOfAuxBytes - i->File.size();
564       OS.write(i->File.data(), i->File.size());
565       OS.write_zeros(NumZeros);
566     }
567     if (i->SectionDefinition) {
568       OS << binary_le(i->SectionDefinition->Length)
569          << binary_le(i->SectionDefinition->NumberOfRelocations)
570          << binary_le(i->SectionDefinition->NumberOfLinenumbers)
571          << binary_le(i->SectionDefinition->CheckSum)
572          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number))
573          << binary_le(i->SectionDefinition->Selection)
574          << zeros(i->SectionDefinition->unused)
575          << binary_le(static_cast<int16_t>(i->SectionDefinition->Number >> 16));
576       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
577     }
578     if (i->CLRToken) {
579       OS << binary_le(i->CLRToken->AuxType) << zeros(i->CLRToken->unused1)
580          << binary_le(i->CLRToken->SymbolTableIndex)
581          << zeros(i->CLRToken->unused2);
582       OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size);
583     }
584   }
585 
586   // Output string table.
587   if (CP.Obj.Header.PointerToSymbolTable)
588     OS.write(&CP.StringTable[0], CP.StringTable.size());
589   return true;
590 }
591 
592 namespace llvm {
593 namespace yaml {
594 
yaml2coff(llvm::COFFYAML::Object & Doc,raw_ostream & Out,ErrorHandler ErrHandler)595 bool yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out,
596                ErrorHandler ErrHandler) {
597   COFFParser CP(Doc, ErrHandler);
598   if (!CP.parse()) {
599     ErrHandler("failed to parse YAML file");
600     return false;
601   }
602 
603   if (!layoutOptionalHeader(CP)) {
604     ErrHandler("failed to layout optional header for COFF file");
605     return false;
606   }
607 
608   if (!layoutCOFF(CP)) {
609     ErrHandler("failed to layout COFF file");
610     return false;
611   }
612   if (!writeCOFF(CP, Out)) {
613     ErrHandler("failed to write COFF file");
614     return false;
615   }
616   return true;
617 }
618 
619 } // namespace yaml
620 } // namespace llvm
621