//===- yaml2coff - Convert YAML to a COFF object file ---------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// /// /// \file /// The COFF component of yaml2obj. /// //===----------------------------------------------------------------------===// #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/StringExtras.h" #include "llvm/ADT/StringMap.h" #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h" #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h" #include "llvm/ObjectYAML/ObjectYAML.h" #include "llvm/ObjectYAML/yaml2obj.h" #include "llvm/Support/BinaryStreamWriter.h" #include "llvm/Support/Endian.h" #include "llvm/Support/MemoryBuffer.h" #include "llvm/Support/SourceMgr.h" #include "llvm/Support/WithColor.h" #include "llvm/Support/raw_ostream.h" #include #include using namespace llvm; namespace { /// This parses a yaml stream that represents a COFF object file. /// See docs/yaml2obj for the yaml scheema. struct COFFParser { COFFParser(COFFYAML::Object &Obj, yaml::ErrorHandler EH) : Obj(Obj), SectionTableStart(0), SectionTableSize(0), ErrHandler(EH) { // 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(Obj.Sections.size()) > COFF::MaxNumberOfSections16; } bool isPE() const { return Obj.OptionalHeader.has_value(); } bool is64Bit() const { return COFF::is64Bit(Obj.Header.Machine); } 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 (COFFYAML::Section &Sec : Obj.Sections) { // 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) { ErrHandler("string table got too large"); return false; } Sec.Header.Name[0] = '/'; std::copy(str.begin(), str.end(), Sec.Header.Name + 1); } if (Sec.Alignment) { if (Sec.Alignment > 8192) { ErrHandler("section alignment is too large"); return false; } if (!isPowerOf2_32(Sec.Alignment)) { ErrHandler("section alignment is not a power of 2"); return false; } Sec.Header.Characteristics |= (Log2_32(Sec.Alignment) + 1) << 20; } } return true; } bool parseSymbols() { for (COFFYAML::Symbol &Sym : Obj.Symbols) { // 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(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::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; codeview::StringsAndChecksums StringsAndChecksums; BumpPtrAllocator Allocator; StringMap StringTableMap; std::string StringTable; uint32_t SectionTableStart; uint32_t SectionTableSize; yaml::ErrorHandler ErrHandler; }; enum { DOSStubSize = 128 }; } // end anonymous namespace // 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) * CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize; return true; } static yaml::BinaryRef toDebugS(ArrayRef Subsections, const codeview::StringsAndChecksums &SC, BumpPtrAllocator &Allocator) { using namespace codeview; ExitOnError Err("Error occurred writing .debug$S section"); auto CVSS = Err(CodeViewYAML::toCodeViewSubsectionList(Allocator, Subsections, SC)); std::vector Builders; uint32_t Size = sizeof(uint32_t); for (auto &SS : CVSS) { DebugSubsectionRecordBuilder B(SS); Size += B.calculateSerializedLength(); Builders.push_back(std::move(B)); } uint8_t *Buffer = Allocator.Allocate(Size); MutableArrayRef Output(Buffer, Size); BinaryStreamWriter Writer(Output, llvm::endianness::little); Err(Writer.writeInteger(COFF::DEBUG_SECTION_MAGIC)); for (const auto &B : Builders) { Err(B.commit(Writer, CodeViewContainer::ObjectFile)); } return {Output}; } // Take a CP and assign addresses and sizes to everything. Returns false if the // layout is not valid to do. static bool layoutCOFF(COFFParser &CP) { // The section table starts immediately after the header, including the // optional header. CP.SectionTableStart = CP.getHeaderSize() + CP.Obj.Header.SizeOfOptionalHeader; if (CP.isPE()) CP.SectionTableStart += DOSStubSize + sizeof(COFF::PEMagic); CP.SectionTableSize = COFF::SectionSize * CP.Obj.Sections.size(); uint32_t CurrentSectionDataOffset = CP.SectionTableStart + CP.SectionTableSize; for (COFFYAML::Section &S : CP.Obj.Sections) { // We support specifying exactly one of SectionData or Subsections. So if // there is already some SectionData, then we don't need to do any of this. if (S.Name == ".debug$S" && S.SectionData.binary_size() == 0) { CodeViewYAML::initializeStringsAndChecksums(S.DebugS, CP.StringsAndChecksums); if (CP.StringsAndChecksums.hasChecksums() && CP.StringsAndChecksums.hasStrings()) break; } } // Assign each section data address consecutively. for (COFFYAML::Section &S : CP.Obj.Sections) { if (S.Name == ".debug$S") { if (S.SectionData.binary_size() == 0) { assert(CP.StringsAndChecksums.hasStrings() && "Object file does not have debug string table!"); S.SectionData = toDebugS(S.DebugS, CP.StringsAndChecksums, CP.Allocator); } } else if (S.Name == ".debug$T") { if (S.SectionData.binary_size() == 0) S.SectionData = CodeViewYAML::toDebugT(S.DebugT, CP.Allocator, S.Name); } else if (S.Name == ".debug$P") { if (S.SectionData.binary_size() == 0) S.SectionData = CodeViewYAML::toDebugT(S.DebugP, CP.Allocator, S.Name); } else if (S.Name == ".debug$H") { if (S.DebugH && S.SectionData.binary_size() == 0) S.SectionData = CodeViewYAML::toDebugH(*S.DebugH, CP.Allocator); } size_t DataSize = S.SectionData.binary_size(); for (auto E : S.StructuredData) DataSize += E.size(); if (DataSize > 0) { CurrentSectionDataOffset = alignTo(CurrentSectionDataOffset, CP.isPE() ? CP.getFileAlignment() : 4); S.Header.SizeOfRawData = DataSize; if (CP.isPE()) S.Header.SizeOfRawData = alignTo(S.Header.SizeOfRawData, CP.getFileAlignment()); S.Header.PointerToRawData = CurrentSectionDataOffset; CurrentSectionDataOffset += S.Header.SizeOfRawData; if (!S.Relocations.empty()) { S.Header.PointerToRelocations = CurrentSectionDataOffset; if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL) { S.Header.NumberOfRelocations = 0xffff; CurrentSectionDataOffset += COFF::RelocationSize; } else S.Header.NumberOfRelocations = S.Relocations.size(); CurrentSectionDataOffset += S.Relocations.size() * COFF::RelocationSize; } } else { // Leave SizeOfRawData unaltered. For .bss sections in object files, it // carries the section size. S.Header.PointerToRawData = 0; } } uint32_t SymbolTableStart = CurrentSectionDataOffset; // Calculate number of symbols. uint32_t NumberOfSymbols = 0; for (std::vector::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(&CP.StringTable[0]) = CP.StringTable.size(); return true; } template struct binary_le_impl { value_type Value; binary_le_impl(value_type V) : Value(V) {} }; template raw_ostream &operator<<(raw_ostream &OS, const binary_le_impl &BLE) { char Buffer[sizeof(BLE.Value)]; support::endian::write(Buffer, BLE.Value); OS.write(Buffer, sizeof(BLE.Value)); return OS; } template binary_le_impl binary_le(value_type V) { return binary_le_impl(V); } template struct zeros_impl {}; template raw_ostream &operator<<(raw_ostream &OS, const zeros_impl &) { char Buffer[NumBytes]; memset(Buffer, 0, sizeof(Buffer)); OS.write(Buffer, sizeof(Buffer)); return OS; } template zeros_impl zeros(const T &) { return zeros_impl(); } template 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 = alignTo(CP.SectionTableStart + CP.SectionTableSize, Header->FileAlignment); uint32_t SizeOfImage = alignTo(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 == ".text") Header->BaseOfCode = S.Header.VirtualAddress; // RVA else if (S.Name == ".data") BaseOfData = S.Header.VirtualAddress; // RVA if (S.Header.VirtualAddress) SizeOfImage += alignTo(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 = CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize; 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(&DH), sizeof(DH)); // Write padding until we reach the position of where our PE signature // should live. OS.write_zeros(DOSStubSize - sizeof(DH)); // Write out the PE signature. OS.write(COFF::PEMagic, sizeof(COFF::PEMagic)); } if (CP.useBigObj()) { OS << binary_le(static_cast(COFF::IMAGE_FILE_MACHINE_UNKNOWN)) << binary_le(static_cast(0xffff)) << binary_le( static_cast(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(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(&PEH), sizeof(PEH)); } else { object::pe32_header PEH; uint32_t BaseOfData = initializeOptionalHeader(CP, COFF::PE32Header::PE32, &PEH); PEH.BaseOfData = BaseOfData; OS.write(reinterpret_cast(&PEH), sizeof(PEH)); } for (uint32_t I = 0; I < CP.Obj.OptionalHeader->Header.NumberOfRvaAndSize; ++I) { const std::optional *DataDirectories = CP.Obj.OptionalHeader->DataDirectories; uint32_t NumDataDir = std::size(CP.Obj.OptionalHeader->DataDirectories); if (I >= NumDataDir || !DataDirectories[I]) { OS << zeros(uint32_t(0)); OS << zeros(uint32_t(0)); } else { OS << binary_le(DataDirectories[I]->RelativeVirtualAddress); OS << binary_le(DataDirectories[I]->Size); } } } assert(OS.tell() == CP.SectionTableStart); // Output section table. for (const COFFYAML::Section &S : CP.Obj.Sections) { OS.write(S.Header.Name, COFF::NameSize); OS << binary_le(S.Header.VirtualSize) << binary_le(S.Header.VirtualAddress) << binary_le(S.Header.SizeOfRawData) << binary_le(S.Header.PointerToRawData) << binary_le(S.Header.PointerToRelocations) << binary_le(S.Header.PointerToLineNumbers) << binary_le(S.Header.NumberOfRelocations) << binary_le(S.Header.NumberOfLineNumbers) << binary_le(S.Header.Characteristics); } assert(OS.tell() == CP.SectionTableStart + CP.SectionTableSize); unsigned CurSymbol = 0; StringMap SymbolTableIndexMap; for (const COFFYAML::Symbol &Sym : CP.Obj.Symbols) { SymbolTableIndexMap[Sym.Name] = CurSymbol; CurSymbol += 1 + Sym.Header.NumberOfAuxSymbols; } // Output section data. for (const COFFYAML::Section &S : CP.Obj.Sections) { if (S.Header.SizeOfRawData == 0 || S.Header.PointerToRawData == 0) continue; assert(S.Header.PointerToRawData >= OS.tell()); OS.write_zeros(S.Header.PointerToRawData - OS.tell()); for (auto E : S.StructuredData) E.writeAsBinary(OS); S.SectionData.writeAsBinary(OS); assert(S.Header.SizeOfRawData >= S.SectionData.binary_size()); OS.write_zeros(S.Header.PointerToRawData + S.Header.SizeOfRawData - OS.tell()); if (S.Header.Characteristics & COFF::IMAGE_SCN_LNK_NRELOC_OVFL) OS << binary_le(/*VirtualAddress=*/ S.Relocations.size() + 1) << binary_le(/*SymbolTableIndex=*/ 0) << binary_le(/*Type=*/ 0); for (const COFFYAML::Relocation &R : S.Relocations) { uint32_t SymbolTableIndex; if (R.SymbolTableIndex) { if (!R.SymbolName.empty()) WithColor::error() << "Both SymbolName and SymbolTableIndex specified\n"; SymbolTableIndex = *R.SymbolTableIndex; } else { SymbolTableIndex = SymbolTableIndexMap[R.SymbolName]; } OS << binary_le(R.VirtualAddress) << binary_le(SymbolTableIndex) << binary_le(R.Type); } } // Output symbol table. for (std::vector::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(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); OS.write_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); OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size); } if (i->WeakExternal) { OS << binary_le(i->WeakExternal->TagIndex) << binary_le(i->WeakExternal->Characteristics) << zeros(i->WeakExternal->unused); OS.write_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.write_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(i->SectionDefinition->Number)) << binary_le(i->SectionDefinition->Selection) << zeros(i->SectionDefinition->unused) << binary_le(static_cast(i->SectionDefinition->Number >> 16)); OS.write_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); OS.write_zeros(CP.getSymbolSize() - COFF::Symbol16Size); } } // Output string table. if (CP.Obj.Header.PointerToSymbolTable) OS.write(&CP.StringTable[0], CP.StringTable.size()); return true; } size_t COFFYAML::SectionDataEntry::size() const { size_t Size = Binary.binary_size(); if (UInt32) Size += sizeof(*UInt32); if (LoadConfig32) Size += LoadConfig32->Size; if (LoadConfig64) Size += LoadConfig64->Size; return Size; } template static void writeLoadConfig(T &S, raw_ostream &OS) { OS.write(reinterpret_cast(&S), std::min(sizeof(S), static_cast(S.Size))); if (sizeof(S) < S.Size) OS.write_zeros(S.Size - sizeof(S)); } void COFFYAML::SectionDataEntry::writeAsBinary(raw_ostream &OS) const { if (UInt32) OS << binary_le(*UInt32); Binary.writeAsBinary(OS); if (LoadConfig32) writeLoadConfig(*LoadConfig32, OS); if (LoadConfig64) writeLoadConfig(*LoadConfig64, OS); } namespace llvm { namespace yaml { bool yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out, ErrorHandler ErrHandler) { COFFParser CP(Doc, ErrHandler); if (!CP.parse()) { ErrHandler("failed to parse YAML file"); return false; } if (!layoutOptionalHeader(CP)) { ErrHandler("failed to layout optional header for COFF file"); return false; } if (!layoutCOFF(CP)) { ErrHandler("failed to layout COFF file"); return false; } if (!writeCOFF(CP, Out)) { ErrHandler("failed to write COFF file"); return false; } return true; } } // namespace yaml } // namespace llvm