| //===- yaml2elf - Convert YAML to a ELF 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 ELF component of yaml2obj. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/SetVector.h" |
| #include "llvm/ADT/StringSet.h" |
| #include "llvm/BinaryFormat/ELF.h" |
| #include "llvm/MC/StringTableBuilder.h" |
| #include "llvm/Object/ELFObjectFile.h" |
| #include "llvm/ObjectYAML/DWARFEmitter.h" |
| #include "llvm/ObjectYAML/DWARFYAML.h" |
| #include "llvm/ObjectYAML/ELFYAML.h" |
| #include "llvm/ObjectYAML/yaml2obj.h" |
| #include "llvm/Support/EndianStream.h" |
| #include "llvm/Support/Errc.h" |
| #include "llvm/Support/Error.h" |
| #include "llvm/Support/LEB128.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/WithColor.h" |
| #include "llvm/Support/YAMLTraits.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| using namespace llvm; |
| |
| // This class is used to build up a contiguous binary blob while keeping |
| // track of an offset in the output (which notionally begins at |
| // `InitialOffset`). |
| // The blob might be limited to an arbitrary size. All attempts to write data |
| // are ignored and the error condition is remembered once the limit is reached. |
| // Such an approach allows us to simplify the code by delaying error reporting |
| // and doing it at a convenient time. |
| namespace { |
| class ContiguousBlobAccumulator { |
| const uint64_t InitialOffset; |
| const uint64_t MaxSize; |
| |
| SmallVector<char, 128> Buf; |
| raw_svector_ostream OS; |
| Error ReachedLimitErr = Error::success(); |
| |
| bool checkLimit(uint64_t Size) { |
| if (!ReachedLimitErr && getOffset() + Size <= MaxSize) |
| return true; |
| if (!ReachedLimitErr) |
| ReachedLimitErr = createStringError(errc::invalid_argument, |
| "reached the output size limit"); |
| return false; |
| } |
| |
| public: |
| ContiguousBlobAccumulator(uint64_t BaseOffset, uint64_t SizeLimit) |
| : InitialOffset(BaseOffset), MaxSize(SizeLimit), OS(Buf) {} |
| |
| uint64_t tell() const { return OS.tell(); } |
| uint64_t getOffset() const { return InitialOffset + OS.tell(); } |
| void writeBlobToStream(raw_ostream &Out) const { Out << OS.str(); } |
| |
| Error takeLimitError() { |
| // Request to write 0 bytes to check we did not reach the limit. |
| checkLimit(0); |
| return std::move(ReachedLimitErr); |
| } |
| |
| /// \returns The new offset. |
| uint64_t padToAlignment(unsigned Align) { |
| uint64_t CurrentOffset = getOffset(); |
| if (ReachedLimitErr) |
| return CurrentOffset; |
| |
| uint64_t AlignedOffset = alignTo(CurrentOffset, Align == 0 ? 1 : Align); |
| uint64_t PaddingSize = AlignedOffset - CurrentOffset; |
| if (!checkLimit(PaddingSize)) |
| return CurrentOffset; |
| |
| writeZeros(PaddingSize); |
| return AlignedOffset; |
| } |
| |
| raw_ostream *getRawOS(uint64_t Size) { |
| if (checkLimit(Size)) |
| return &OS; |
| return nullptr; |
| } |
| |
| void writeAsBinary(const yaml::BinaryRef &Bin, uint64_t N = UINT64_MAX) { |
| if (!checkLimit(Bin.binary_size())) |
| return; |
| Bin.writeAsBinary(OS, N); |
| } |
| |
| void writeZeros(uint64_t Num) { |
| if (checkLimit(Num)) |
| OS.write_zeros(Num); |
| } |
| |
| void write(const char *Ptr, size_t Size) { |
| if (checkLimit(Size)) |
| OS.write(Ptr, Size); |
| } |
| |
| void write(unsigned char C) { |
| if (checkLimit(1)) |
| OS.write(C); |
| } |
| |
| unsigned writeULEB128(uint64_t Val) { |
| if (!checkLimit(sizeof(uint64_t))) |
| return 0; |
| return encodeULEB128(Val, OS); |
| } |
| |
| template <typename T> void write(T Val, support::endianness E) { |
| if (checkLimit(sizeof(T))) |
| support::endian::write<T>(OS, Val, E); |
| } |
| |
| void updateDataAt(uint64_t Pos, void *Data, size_t Size) { |
| assert(Pos >= InitialOffset && Pos + Size <= getOffset()); |
| memcpy(&Buf[Pos - InitialOffset], Data, Size); |
| } |
| }; |
| |
| // Used to keep track of section and symbol names, so that in the YAML file |
| // sections and symbols can be referenced by name instead of by index. |
| class NameToIdxMap { |
| StringMap<unsigned> Map; |
| |
| public: |
| /// \Returns false if name is already present in the map. |
| bool addName(StringRef Name, unsigned Ndx) { |
| return Map.insert({Name, Ndx}).second; |
| } |
| /// \Returns false if name is not present in the map. |
| bool lookup(StringRef Name, unsigned &Idx) const { |
| auto I = Map.find(Name); |
| if (I == Map.end()) |
| return false; |
| Idx = I->getValue(); |
| return true; |
| } |
| /// Asserts if name is not present in the map. |
| unsigned get(StringRef Name) const { |
| unsigned Idx; |
| if (lookup(Name, Idx)) |
| return Idx; |
| assert(false && "Expected section not found in index"); |
| return 0; |
| } |
| unsigned size() const { return Map.size(); } |
| }; |
| |
| namespace { |
| struct Fragment { |
| uint64_t Offset; |
| uint64_t Size; |
| uint32_t Type; |
| uint64_t AddrAlign; |
| }; |
| } // namespace |
| |
| /// "Single point of truth" for the ELF file construction. |
| /// TODO: This class still has a ways to go before it is truly a "single |
| /// point of truth". |
| template <class ELFT> class ELFState { |
| LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) |
| |
| enum class SymtabType { Static, Dynamic }; |
| |
| /// The future ".strtab" section. |
| StringTableBuilder DotStrtab{StringTableBuilder::ELF}; |
| |
| /// The future ".shstrtab" section. |
| StringTableBuilder DotShStrtab{StringTableBuilder::ELF}; |
| |
| /// The future ".dynstr" section. |
| StringTableBuilder DotDynstr{StringTableBuilder::ELF}; |
| |
| NameToIdxMap SN2I; |
| NameToIdxMap SymN2I; |
| NameToIdxMap DynSymN2I; |
| ELFYAML::Object &Doc; |
| |
| StringSet<> ExcludedSectionHeaders; |
| |
| uint64_t LocationCounter = 0; |
| bool HasError = false; |
| yaml::ErrorHandler ErrHandler; |
| void reportError(const Twine &Msg); |
| void reportError(Error Err); |
| |
| std::vector<Elf_Sym> toELFSymbols(ArrayRef<ELFYAML::Symbol> Symbols, |
| const StringTableBuilder &Strtab); |
| unsigned toSectionIndex(StringRef S, StringRef LocSec, StringRef LocSym = ""); |
| unsigned toSymbolIndex(StringRef S, StringRef LocSec, bool IsDynamic); |
| |
| void buildSectionIndex(); |
| void buildSymbolIndexes(); |
| void initProgramHeaders(std::vector<Elf_Phdr> &PHeaders); |
| bool initImplicitHeader(ContiguousBlobAccumulator &CBA, Elf_Shdr &Header, |
| StringRef SecName, ELFYAML::Section *YAMLSec); |
| void initSectionHeaders(std::vector<Elf_Shdr> &SHeaders, |
| ContiguousBlobAccumulator &CBA); |
| void initSymtabSectionHeader(Elf_Shdr &SHeader, SymtabType STType, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec); |
| void initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name, |
| StringTableBuilder &STB, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec); |
| void initDWARFSectionHeader(Elf_Shdr &SHeader, StringRef Name, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec); |
| void setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders, |
| std::vector<Elf_Shdr> &SHeaders); |
| |
| std::vector<Fragment> |
| getPhdrFragments(const ELFYAML::ProgramHeader &Phdr, |
| ArrayRef<typename ELFT::Shdr> SHeaders); |
| |
| void finalizeStrings(); |
| void writeELFHeader(raw_ostream &OS); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::NoBitsSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::RawContentSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::RelocationSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::RelrSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::GroupSection &Group, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::SymtabShndxSection &Shndx, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::SymverSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::VerneedSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::VerdefSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::ARMIndexTableSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::MipsABIFlags &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::DynamicSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::StackSizesSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::BBAddrMapSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::HashSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::AddrsigSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::NoteSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::GnuHashSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::LinkerOptionsSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::DependentLibrariesSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::CallGraphProfileSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| |
| void writeFill(ELFYAML::Fill &Fill, ContiguousBlobAccumulator &CBA); |
| |
| ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH); |
| |
| void assignSectionAddress(Elf_Shdr &SHeader, ELFYAML::Section *YAMLSec); |
| |
| DenseMap<StringRef, size_t> buildSectionHeaderReorderMap(); |
| |
| BumpPtrAllocator StringAlloc; |
| uint64_t alignToOffset(ContiguousBlobAccumulator &CBA, uint64_t Align, |
| llvm::Optional<llvm::yaml::Hex64> Offset); |
| |
| uint64_t getSectionNameOffset(StringRef Name); |
| |
| public: |
| static bool writeELF(raw_ostream &OS, ELFYAML::Object &Doc, |
| yaml::ErrorHandler EH, uint64_t MaxSize); |
| }; |
| } // end anonymous namespace |
| |
| template <class T> static size_t arrayDataSize(ArrayRef<T> A) { |
| return A.size() * sizeof(T); |
| } |
| |
| template <class T> static void writeArrayData(raw_ostream &OS, ArrayRef<T> A) { |
| OS.write((const char *)A.data(), arrayDataSize(A)); |
| } |
| |
| template <class T> static void zero(T &Obj) { memset(&Obj, 0, sizeof(Obj)); } |
| |
| template <class ELFT> |
| ELFState<ELFT>::ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH) |
| : Doc(D), ErrHandler(EH) { |
| std::vector<ELFYAML::Section *> Sections = Doc.getSections(); |
| // Insert SHT_NULL section implicitly when it is not defined in YAML. |
| if (Sections.empty() || Sections.front()->Type != ELF::SHT_NULL) |
| Doc.Chunks.insert( |
| Doc.Chunks.begin(), |
| std::make_unique<ELFYAML::Section>( |
| ELFYAML::Chunk::ChunkKind::RawContent, /*IsImplicit=*/true)); |
| |
| StringSet<> DocSections; |
| ELFYAML::SectionHeaderTable *SecHdrTable = nullptr; |
| for (size_t I = 0; I < Doc.Chunks.size(); ++I) { |
| const std::unique_ptr<ELFYAML::Chunk> &C = Doc.Chunks[I]; |
| |
| // We might have an explicit section header table declaration. |
| if (auto S = dyn_cast<ELFYAML::SectionHeaderTable>(C.get())) { |
| if (SecHdrTable) |
| reportError("multiple section header tables are not allowed"); |
| SecHdrTable = S; |
| continue; |
| } |
| |
| // We add a technical suffix for each unnamed section/fill. It does not |
| // affect the output, but allows us to map them by name in the code and |
| // report better error messages. |
| if (C->Name.empty()) { |
| std::string NewName = ELFYAML::appendUniqueSuffix( |
| /*Name=*/"", "index " + Twine(I)); |
| C->Name = StringRef(NewName).copy(StringAlloc); |
| assert(ELFYAML::dropUniqueSuffix(C->Name).empty()); |
| } |
| |
| if (!DocSections.insert(C->Name).second) |
| reportError("repeated section/fill name: '" + C->Name + |
| "' at YAML section/fill number " + Twine(I)); |
| } |
| |
| std::vector<StringRef> ImplicitSections; |
| if (Doc.DynamicSymbols) |
| ImplicitSections.insert(ImplicitSections.end(), {".dynsym", ".dynstr"}); |
| if (Doc.Symbols) |
| ImplicitSections.push_back(".symtab"); |
| if (Doc.DWARF) |
| for (StringRef DebugSecName : Doc.DWARF->getNonEmptySectionNames()) { |
| std::string SecName = ("." + DebugSecName).str(); |
| ImplicitSections.push_back(StringRef(SecName).copy(StringAlloc)); |
| } |
| ImplicitSections.insert(ImplicitSections.end(), {".strtab"}); |
| if (!SecHdrTable || !SecHdrTable->NoHeaders.getValueOr(false)) |
| ImplicitSections.insert(ImplicitSections.end(), {".shstrtab"}); |
| |
| // Insert placeholders for implicit sections that are not |
| // defined explicitly in YAML. |
| for (StringRef SecName : ImplicitSections) { |
| if (DocSections.count(SecName)) |
| continue; |
| |
| std::unique_ptr<ELFYAML::Section> Sec = std::make_unique<ELFYAML::Section>( |
| ELFYAML::Chunk::ChunkKind::RawContent, true /*IsImplicit*/); |
| Sec->Name = SecName; |
| |
| if (SecName == ".dynsym") |
| Sec->Type = ELF::SHT_DYNSYM; |
| else if (SecName == ".symtab") |
| Sec->Type = ELF::SHT_SYMTAB; |
| else |
| Sec->Type = ELF::SHT_STRTAB; |
| |
| // When the section header table is explicitly defined at the end of the |
| // sections list, it is reasonable to assume that the user wants to reorder |
| // section headers, but still wants to place the section header table after |
| // all sections, like it normally happens. In this case we want to insert |
| // other implicit sections right before the section header table. |
| if (Doc.Chunks.back().get() == SecHdrTable) |
| Doc.Chunks.insert(Doc.Chunks.end() - 1, std::move(Sec)); |
| else |
| Doc.Chunks.push_back(std::move(Sec)); |
| } |
| |
| // Insert the section header table implicitly at the end, when it is not |
| // explicitly defined. |
| if (!SecHdrTable) |
| Doc.Chunks.push_back( |
| std::make_unique<ELFYAML::SectionHeaderTable>(/*IsImplicit=*/true)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeELFHeader(raw_ostream &OS) { |
| using namespace llvm::ELF; |
| |
| Elf_Ehdr Header; |
| zero(Header); |
| Header.e_ident[EI_MAG0] = 0x7f; |
| Header.e_ident[EI_MAG1] = 'E'; |
| Header.e_ident[EI_MAG2] = 'L'; |
| Header.e_ident[EI_MAG3] = 'F'; |
| Header.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32; |
| Header.e_ident[EI_DATA] = Doc.Header.Data; |
| Header.e_ident[EI_VERSION] = EV_CURRENT; |
| Header.e_ident[EI_OSABI] = Doc.Header.OSABI; |
| Header.e_ident[EI_ABIVERSION] = Doc.Header.ABIVersion; |
| Header.e_type = Doc.Header.Type; |
| |
| if (Doc.Header.Machine) |
| Header.e_machine = *Doc.Header.Machine; |
| else |
| Header.e_machine = EM_NONE; |
| |
| Header.e_version = EV_CURRENT; |
| Header.e_entry = Doc.Header.Entry; |
| Header.e_flags = Doc.Header.Flags; |
| Header.e_ehsize = sizeof(Elf_Ehdr); |
| |
| if (Doc.Header.EPhOff) |
| Header.e_phoff = *Doc.Header.EPhOff; |
| else if (!Doc.ProgramHeaders.empty()) |
| Header.e_phoff = sizeof(Header); |
| else |
| Header.e_phoff = 0; |
| |
| if (Doc.Header.EPhEntSize) |
| Header.e_phentsize = *Doc.Header.EPhEntSize; |
| else if (!Doc.ProgramHeaders.empty()) |
| Header.e_phentsize = sizeof(Elf_Phdr); |
| else |
| Header.e_phentsize = 0; |
| |
| if (Doc.Header.EPhNum) |
| Header.e_phnum = *Doc.Header.EPhNum; |
| else if (!Doc.ProgramHeaders.empty()) |
| Header.e_phnum = Doc.ProgramHeaders.size(); |
| else |
| Header.e_phnum = 0; |
| |
| Header.e_shentsize = Doc.Header.EShEntSize ? (uint16_t)*Doc.Header.EShEntSize |
| : sizeof(Elf_Shdr); |
| |
| const ELFYAML::SectionHeaderTable &SectionHeaders = |
| Doc.getSectionHeaderTable(); |
| |
| if (Doc.Header.EShOff) |
| Header.e_shoff = *Doc.Header.EShOff; |
| else if (SectionHeaders.Offset) |
| Header.e_shoff = *SectionHeaders.Offset; |
| else |
| Header.e_shoff = 0; |
| |
| if (Doc.Header.EShNum) |
| Header.e_shnum = *Doc.Header.EShNum; |
| else |
| Header.e_shnum = SectionHeaders.getNumHeaders(Doc.getSections().size()); |
| |
| if (Doc.Header.EShStrNdx) |
| Header.e_shstrndx = *Doc.Header.EShStrNdx; |
| else if (SectionHeaders.Offset && !ExcludedSectionHeaders.count(".shstrtab")) |
| Header.e_shstrndx = SN2I.get(".shstrtab"); |
| else |
| Header.e_shstrndx = 0; |
| |
| OS.write((const char *)&Header, sizeof(Header)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initProgramHeaders(std::vector<Elf_Phdr> &PHeaders) { |
| DenseMap<StringRef, ELFYAML::Fill *> NameToFill; |
| DenseMap<StringRef, size_t> NameToIndex; |
| for (size_t I = 0, E = Doc.Chunks.size(); I != E; ++I) { |
| if (auto S = dyn_cast<ELFYAML::Fill>(Doc.Chunks[I].get())) |
| NameToFill[S->Name] = S; |
| NameToIndex[Doc.Chunks[I]->Name] = I + 1; |
| } |
| |
| std::vector<ELFYAML::Section *> Sections = Doc.getSections(); |
| for (size_t I = 0, E = Doc.ProgramHeaders.size(); I != E; ++I) { |
| ELFYAML::ProgramHeader &YamlPhdr = Doc.ProgramHeaders[I]; |
| Elf_Phdr Phdr; |
| zero(Phdr); |
| Phdr.p_type = YamlPhdr.Type; |
| Phdr.p_flags = YamlPhdr.Flags; |
| Phdr.p_vaddr = YamlPhdr.VAddr; |
| Phdr.p_paddr = YamlPhdr.PAddr; |
| PHeaders.push_back(Phdr); |
| |
| if (!YamlPhdr.FirstSec && !YamlPhdr.LastSec) |
| continue; |
| |
| // Get the index of the section, or 0 in the case when the section doesn't exist. |
| size_t First = NameToIndex[*YamlPhdr.FirstSec]; |
| if (!First) |
| reportError("unknown section or fill referenced: '" + *YamlPhdr.FirstSec + |
| "' by the 'FirstSec' key of the program header with index " + |
| Twine(I)); |
| size_t Last = NameToIndex[*YamlPhdr.LastSec]; |
| if (!Last) |
| reportError("unknown section or fill referenced: '" + *YamlPhdr.LastSec + |
| "' by the 'LastSec' key of the program header with index " + |
| Twine(I)); |
| if (!First || !Last) |
| continue; |
| |
| if (First > Last) |
| reportError("program header with index " + Twine(I) + |
| ": the section index of " + *YamlPhdr.FirstSec + |
| " is greater than the index of " + *YamlPhdr.LastSec); |
| |
| for (size_t I = First; I <= Last; ++I) |
| YamlPhdr.Chunks.push_back(Doc.Chunks[I - 1].get()); |
| } |
| } |
| |
| template <class ELFT> |
| unsigned ELFState<ELFT>::toSectionIndex(StringRef S, StringRef LocSec, |
| StringRef LocSym) { |
| assert(LocSec.empty() || LocSym.empty()); |
| |
| unsigned Index; |
| if (!SN2I.lookup(S, Index) && !to_integer(S, Index)) { |
| if (!LocSym.empty()) |
| reportError("unknown section referenced: '" + S + "' by YAML symbol '" + |
| LocSym + "'"); |
| else |
| reportError("unknown section referenced: '" + S + "' by YAML section '" + |
| LocSec + "'"); |
| return 0; |
| } |
| |
| const ELFYAML::SectionHeaderTable &SectionHeaders = |
| Doc.getSectionHeaderTable(); |
| if (SectionHeaders.IsImplicit || |
| (SectionHeaders.NoHeaders && !SectionHeaders.NoHeaders.getValue())) |
| return Index; |
| |
| assert(!SectionHeaders.NoHeaders.getValueOr(false) || |
| !SectionHeaders.Sections); |
| size_t FirstExcluded = |
| SectionHeaders.Sections ? SectionHeaders.Sections->size() : 0; |
| if (Index >= FirstExcluded) { |
| if (LocSym.empty()) |
| reportError("unable to link '" + LocSec + "' to excluded section '" + S + |
| "'"); |
| else |
| reportError("excluded section referenced: '" + S + "' by symbol '" + |
| LocSym + "'"); |
| } |
| return Index; |
| } |
| |
| template <class ELFT> |
| unsigned ELFState<ELFT>::toSymbolIndex(StringRef S, StringRef LocSec, |
| bool IsDynamic) { |
| const NameToIdxMap &SymMap = IsDynamic ? DynSymN2I : SymN2I; |
| unsigned Index; |
| // Here we try to look up S in the symbol table. If it is not there, |
| // treat its value as a symbol index. |
| if (!SymMap.lookup(S, Index) && !to_integer(S, Index)) { |
| reportError("unknown symbol referenced: '" + S + "' by YAML section '" + |
| LocSec + "'"); |
| return 0; |
| } |
| return Index; |
| } |
| |
| template <class ELFT> |
| static void overrideFields(ELFYAML::Section *From, typename ELFT::Shdr &To) { |
| if (!From) |
| return; |
| if (From->ShAddrAlign) |
| To.sh_addralign = *From->ShAddrAlign; |
| if (From->ShFlags) |
| To.sh_flags = *From->ShFlags; |
| if (From->ShName) |
| To.sh_name = *From->ShName; |
| if (From->ShOffset) |
| To.sh_offset = *From->ShOffset; |
| if (From->ShSize) |
| To.sh_size = *From->ShSize; |
| if (From->ShType) |
| To.sh_type = *From->ShType; |
| } |
| |
| template <class ELFT> |
| bool ELFState<ELFT>::initImplicitHeader(ContiguousBlobAccumulator &CBA, |
| Elf_Shdr &Header, StringRef SecName, |
| ELFYAML::Section *YAMLSec) { |
| // Check if the header was already initialized. |
| if (Header.sh_offset) |
| return false; |
| |
| if (SecName == ".symtab") |
| initSymtabSectionHeader(Header, SymtabType::Static, CBA, YAMLSec); |
| else if (SecName == ".strtab") |
| initStrtabSectionHeader(Header, SecName, DotStrtab, CBA, YAMLSec); |
| else if (SecName == ".shstrtab") |
| initStrtabSectionHeader(Header, SecName, DotShStrtab, CBA, YAMLSec); |
| else if (SecName == ".dynsym") |
| initSymtabSectionHeader(Header, SymtabType::Dynamic, CBA, YAMLSec); |
| else if (SecName == ".dynstr") |
| initStrtabSectionHeader(Header, SecName, DotDynstr, CBA, YAMLSec); |
| else if (SecName.startswith(".debug_")) { |
| // If a ".debug_*" section's type is a preserved one, e.g., SHT_DYNAMIC, we |
| // will not treat it as a debug section. |
| if (YAMLSec && !isa<ELFYAML::RawContentSection>(YAMLSec)) |
| return false; |
| initDWARFSectionHeader(Header, SecName, CBA, YAMLSec); |
| } else |
| return false; |
| |
| LocationCounter += Header.sh_size; |
| |
| // Override section fields if requested. |
| overrideFields<ELFT>(YAMLSec, Header); |
| return true; |
| } |
| |
| constexpr char SuffixStart = '('; |
| constexpr char SuffixEnd = ')'; |
| |
| std::string llvm::ELFYAML::appendUniqueSuffix(StringRef Name, |
| const Twine &Msg) { |
| // Do not add a space when a Name is empty. |
| std::string Ret = Name.empty() ? "" : Name.str() + ' '; |
| return Ret + (Twine(SuffixStart) + Msg + Twine(SuffixEnd)).str(); |
| } |
| |
| StringRef llvm::ELFYAML::dropUniqueSuffix(StringRef S) { |
| if (S.empty() || S.back() != SuffixEnd) |
| return S; |
| |
| // A special case for empty names. See appendUniqueSuffix() above. |
| size_t SuffixPos = S.rfind(SuffixStart); |
| if (SuffixPos == 0) |
| return ""; |
| |
| if (SuffixPos == StringRef::npos || S[SuffixPos - 1] != ' ') |
| return S; |
| return S.substr(0, SuffixPos - 1); |
| } |
| |
| template <class ELFT> |
| uint64_t ELFState<ELFT>::getSectionNameOffset(StringRef Name) { |
| // If a section is excluded from section headers, we do not save its name in |
| // the string table. |
| if (ExcludedSectionHeaders.count(Name)) |
| return 0; |
| return DotShStrtab.getOffset(Name); |
| } |
| |
| static uint64_t writeContent(ContiguousBlobAccumulator &CBA, |
| const Optional<yaml::BinaryRef> &Content, |
| const Optional<llvm::yaml::Hex64> &Size) { |
| size_t ContentSize = 0; |
| if (Content) { |
| CBA.writeAsBinary(*Content); |
| ContentSize = Content->binary_size(); |
| } |
| |
| if (!Size) |
| return ContentSize; |
| |
| CBA.writeZeros(*Size - ContentSize); |
| return *Size; |
| } |
| |
| static StringRef getDefaultLinkSec(unsigned SecType) { |
| switch (SecType) { |
| case ELF::SHT_REL: |
| case ELF::SHT_RELA: |
| case ELF::SHT_GROUP: |
| case ELF::SHT_LLVM_CALL_GRAPH_PROFILE: |
| case ELF::SHT_LLVM_ADDRSIG: |
| return ".symtab"; |
| case ELF::SHT_GNU_versym: |
| case ELF::SHT_HASH: |
| case ELF::SHT_GNU_HASH: |
| return ".dynsym"; |
| case ELF::SHT_DYNSYM: |
| case ELF::SHT_GNU_verdef: |
| case ELF::SHT_GNU_verneed: |
| return ".dynstr"; |
| case ELF::SHT_SYMTAB: |
| return ".strtab"; |
| default: |
| return ""; |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders, |
| ContiguousBlobAccumulator &CBA) { |
| // Ensure SHN_UNDEF entry is present. An all-zero section header is a |
| // valid SHN_UNDEF entry since SHT_NULL == 0. |
| SHeaders.resize(Doc.getSections().size()); |
| |
| for (const std::unique_ptr<ELFYAML::Chunk> &D : Doc.Chunks) { |
| if (ELFYAML::Fill *S = dyn_cast<ELFYAML::Fill>(D.get())) { |
| S->Offset = alignToOffset(CBA, /*Align=*/1, S->Offset); |
| writeFill(*S, CBA); |
| LocationCounter += S->Size; |
| continue; |
| } |
| |
| if (ELFYAML::SectionHeaderTable *S = |
| dyn_cast<ELFYAML::SectionHeaderTable>(D.get())) { |
| if (S->NoHeaders.getValueOr(false)) |
| continue; |
| |
| if (!S->Offset) |
| S->Offset = alignToOffset(CBA, sizeof(typename ELFT::uint), |
| /*Offset=*/None); |
| else |
| S->Offset = alignToOffset(CBA, /*Align=*/1, S->Offset); |
| |
| uint64_t Size = S->getNumHeaders(SHeaders.size()) * sizeof(Elf_Shdr); |
| // The full section header information might be not available here, so |
| // fill the space with zeroes as a placeholder. |
| CBA.writeZeros(Size); |
| LocationCounter += Size; |
| continue; |
| } |
| |
| ELFYAML::Section *Sec = cast<ELFYAML::Section>(D.get()); |
| bool IsFirstUndefSection = Sec == Doc.getSections().front(); |
| if (IsFirstUndefSection && Sec->IsImplicit) |
| continue; |
| |
| Elf_Shdr &SHeader = SHeaders[SN2I.get(Sec->Name)]; |
| if (Sec->Link) { |
| SHeader.sh_link = toSectionIndex(*Sec->Link, Sec->Name); |
| } else { |
| StringRef LinkSec = getDefaultLinkSec(Sec->Type); |
| unsigned Link = 0; |
| if (!LinkSec.empty() && !ExcludedSectionHeaders.count(LinkSec) && |
| SN2I.lookup(LinkSec, Link)) |
| SHeader.sh_link = Link; |
| } |
| |
| if (Sec->EntSize) |
| SHeader.sh_entsize = *Sec->EntSize; |
| else |
| SHeader.sh_entsize = ELFYAML::getDefaultShEntSize<ELFT>( |
| Doc.Header.Machine.getValueOr(ELF::EM_NONE), Sec->Type, Sec->Name); |
| |
| // We have a few sections like string or symbol tables that are usually |
| // added implicitly to the end. However, if they are explicitly specified |
| // in the YAML, we need to write them here. This ensures the file offset |
| // remains correct. |
| if (initImplicitHeader(CBA, SHeader, Sec->Name, |
| Sec->IsImplicit ? nullptr : Sec)) |
| continue; |
| |
| assert(Sec && "It can't be null unless it is an implicit section. But all " |
| "implicit sections should already have been handled above."); |
| |
| SHeader.sh_name = |
| getSectionNameOffset(ELFYAML::dropUniqueSuffix(Sec->Name)); |
| SHeader.sh_type = Sec->Type; |
| if (Sec->Flags) |
| SHeader.sh_flags = *Sec->Flags; |
| SHeader.sh_addralign = Sec->AddressAlign; |
| |
| // Set the offset for all sections, except the SHN_UNDEF section with index |
| // 0 when not explicitly requested. |
| if (!IsFirstUndefSection || Sec->Offset) |
| SHeader.sh_offset = alignToOffset(CBA, SHeader.sh_addralign, Sec->Offset); |
| |
| assignSectionAddress(SHeader, Sec); |
| |
| if (IsFirstUndefSection) { |
| if (auto RawSec = dyn_cast<ELFYAML::RawContentSection>(Sec)) { |
| // We do not write any content for special SHN_UNDEF section. |
| if (RawSec->Size) |
| SHeader.sh_size = *RawSec->Size; |
| if (RawSec->Info) |
| SHeader.sh_info = *RawSec->Info; |
| } |
| |
| LocationCounter += SHeader.sh_size; |
| overrideFields<ELFT>(Sec, SHeader); |
| continue; |
| } |
| |
| if (!isa<ELFYAML::NoBitsSection>(Sec) && (Sec->Content || Sec->Size)) |
| SHeader.sh_size = writeContent(CBA, Sec->Content, Sec->Size); |
| |
| if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::SymtabShndxSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::RelocationSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::RelrSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::GroupSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::ARMIndexTableSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::MipsABIFlags>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::NoBitsSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::DynamicSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::SymverSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::VerneedSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::VerdefSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::StackSizesSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::HashSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::AddrsigSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::LinkerOptionsSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::NoteSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::GnuHashSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::DependentLibrariesSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::CallGraphProfileSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else if (auto S = dyn_cast<ELFYAML::BBAddrMapSection>(Sec)) { |
| writeSectionContent(SHeader, *S, CBA); |
| } else { |
| llvm_unreachable("Unknown section type"); |
| } |
| |
| LocationCounter += SHeader.sh_size; |
| |
| // Override section fields if requested. |
| overrideFields<ELFT>(Sec, SHeader); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::assignSectionAddress(Elf_Shdr &SHeader, |
| ELFYAML::Section *YAMLSec) { |
| if (YAMLSec && YAMLSec->Address) { |
| SHeader.sh_addr = *YAMLSec->Address; |
| LocationCounter = *YAMLSec->Address; |
| return; |
| } |
| |
| // sh_addr represents the address in the memory image of a process. Sections |
| // in a relocatable object file or non-allocatable sections do not need |
| // sh_addr assignment. |
| if (Doc.Header.Type.value == ELF::ET_REL || |
| !(SHeader.sh_flags & ELF::SHF_ALLOC)) |
| return; |
| |
| LocationCounter = |
| alignTo(LocationCounter, SHeader.sh_addralign ? SHeader.sh_addralign : 1); |
| SHeader.sh_addr = LocationCounter; |
| } |
| |
| static size_t findFirstNonGlobal(ArrayRef<ELFYAML::Symbol> Symbols) { |
| for (size_t I = 0; I < Symbols.size(); ++I) |
| if (Symbols[I].Binding.value != ELF::STB_LOCAL) |
| return I; |
| return Symbols.size(); |
| } |
| |
| template <class ELFT> |
| std::vector<typename ELFT::Sym> |
| ELFState<ELFT>::toELFSymbols(ArrayRef<ELFYAML::Symbol> Symbols, |
| const StringTableBuilder &Strtab) { |
| std::vector<Elf_Sym> Ret; |
| Ret.resize(Symbols.size() + 1); |
| |
| size_t I = 0; |
| for (const ELFYAML::Symbol &Sym : Symbols) { |
| Elf_Sym &Symbol = Ret[++I]; |
| |
| // If NameIndex, which contains the name offset, is explicitly specified, we |
| // use it. This is useful for preparing broken objects. Otherwise, we add |
| // the specified Name to the string table builder to get its offset. |
| if (Sym.StName) |
| Symbol.st_name = *Sym.StName; |
| else if (!Sym.Name.empty()) |
| Symbol.st_name = Strtab.getOffset(ELFYAML::dropUniqueSuffix(Sym.Name)); |
| |
| Symbol.setBindingAndType(Sym.Binding, Sym.Type); |
| if (Sym.Section) |
| Symbol.st_shndx = toSectionIndex(*Sym.Section, "", Sym.Name); |
| else if (Sym.Index) |
| Symbol.st_shndx = *Sym.Index; |
| |
| Symbol.st_value = Sym.Value.getValueOr(yaml::Hex64(0)); |
| Symbol.st_other = Sym.Other ? *Sym.Other : 0; |
| Symbol.st_size = Sym.Size.getValueOr(yaml::Hex64(0)); |
| } |
| |
| return Ret; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader, |
| SymtabType STType, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec) { |
| |
| bool IsStatic = STType == SymtabType::Static; |
| ArrayRef<ELFYAML::Symbol> Symbols; |
| if (IsStatic && Doc.Symbols) |
| Symbols = *Doc.Symbols; |
| else if (!IsStatic && Doc.DynamicSymbols) |
| Symbols = *Doc.DynamicSymbols; |
| |
| ELFYAML::RawContentSection *RawSec = |
| dyn_cast_or_null<ELFYAML::RawContentSection>(YAMLSec); |
| if (RawSec && (RawSec->Content || RawSec->Size)) { |
| bool HasSymbolsDescription = |
| (IsStatic && Doc.Symbols) || (!IsStatic && Doc.DynamicSymbols); |
| if (HasSymbolsDescription) { |
| StringRef Property = (IsStatic ? "`Symbols`" : "`DynamicSymbols`"); |
| if (RawSec->Content) |
| reportError("cannot specify both `Content` and " + Property + |
| " for symbol table section '" + RawSec->Name + "'"); |
| if (RawSec->Size) |
| reportError("cannot specify both `Size` and " + Property + |
| " for symbol table section '" + RawSec->Name + "'"); |
| return; |
| } |
| } |
| |
| SHeader.sh_name = getSectionNameOffset(IsStatic ? ".symtab" : ".dynsym"); |
| |
| if (YAMLSec) |
| SHeader.sh_type = YAMLSec->Type; |
| else |
| SHeader.sh_type = IsStatic ? ELF::SHT_SYMTAB : ELF::SHT_DYNSYM; |
| |
| if (YAMLSec && YAMLSec->Flags) |
| SHeader.sh_flags = *YAMLSec->Flags; |
| else if (!IsStatic) |
| SHeader.sh_flags = ELF::SHF_ALLOC; |
| |
| // If the symbol table section is explicitly described in the YAML |
| // then we should set the fields requested. |
| SHeader.sh_info = (RawSec && RawSec->Info) ? (unsigned)(*RawSec->Info) |
| : findFirstNonGlobal(Symbols) + 1; |
| SHeader.sh_addralign = YAMLSec ? (uint64_t)YAMLSec->AddressAlign : 8; |
| |
| assignSectionAddress(SHeader, YAMLSec); |
| |
| SHeader.sh_offset = |
| alignToOffset(CBA, SHeader.sh_addralign, RawSec ? RawSec->Offset : None); |
| |
| if (RawSec && (RawSec->Content || RawSec->Size)) { |
| assert(Symbols.empty()); |
| SHeader.sh_size = writeContent(CBA, RawSec->Content, RawSec->Size); |
| return; |
| } |
| |
| std::vector<Elf_Sym> Syms = |
| toELFSymbols(Symbols, IsStatic ? DotStrtab : DotDynstr); |
| SHeader.sh_size = Syms.size() * sizeof(Elf_Sym); |
| CBA.write((const char *)Syms.data(), SHeader.sh_size); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name, |
| StringTableBuilder &STB, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec) { |
| SHeader.sh_name = getSectionNameOffset(Name); |
| SHeader.sh_type = YAMLSec ? YAMLSec->Type : ELF::SHT_STRTAB; |
| SHeader.sh_addralign = YAMLSec ? (uint64_t)YAMLSec->AddressAlign : 1; |
| |
| ELFYAML::RawContentSection *RawSec = |
| dyn_cast_or_null<ELFYAML::RawContentSection>(YAMLSec); |
| |
| SHeader.sh_offset = alignToOffset(CBA, SHeader.sh_addralign, |
| YAMLSec ? YAMLSec->Offset : None); |
| |
| if (RawSec && (RawSec->Content || RawSec->Size)) { |
| SHeader.sh_size = writeContent(CBA, RawSec->Content, RawSec->Size); |
| } else { |
| if (raw_ostream *OS = CBA.getRawOS(STB.getSize())) |
| STB.write(*OS); |
| SHeader.sh_size = STB.getSize(); |
| } |
| |
| if (RawSec && RawSec->Info) |
| SHeader.sh_info = *RawSec->Info; |
| |
| if (YAMLSec && YAMLSec->Flags) |
| SHeader.sh_flags = *YAMLSec->Flags; |
| else if (Name == ".dynstr") |
| SHeader.sh_flags = ELF::SHF_ALLOC; |
| |
| assignSectionAddress(SHeader, YAMLSec); |
| } |
| |
| static bool shouldEmitDWARF(DWARFYAML::Data &DWARF, StringRef Name) { |
| SetVector<StringRef> DebugSecNames = DWARF.getNonEmptySectionNames(); |
| return Name.consume_front(".") && DebugSecNames.count(Name); |
| } |
| |
| template <class ELFT> |
| Expected<uint64_t> emitDWARF(typename ELFT::Shdr &SHeader, StringRef Name, |
| const DWARFYAML::Data &DWARF, |
| ContiguousBlobAccumulator &CBA) { |
| // We are unable to predict the size of debug data, so we request to write 0 |
| // bytes. This should always return us an output stream unless CBA is already |
| // in an error state. |
| raw_ostream *OS = CBA.getRawOS(0); |
| if (!OS) |
| return 0; |
| |
| uint64_t BeginOffset = CBA.tell(); |
| |
| auto EmitFunc = DWARFYAML::getDWARFEmitterByName(Name.substr(1)); |
| if (Error Err = EmitFunc(*OS, DWARF)) |
| return std::move(Err); |
| |
| return CBA.tell() - BeginOffset; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initDWARFSectionHeader(Elf_Shdr &SHeader, StringRef Name, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec) { |
| SHeader.sh_name = getSectionNameOffset(ELFYAML::dropUniqueSuffix(Name)); |
| SHeader.sh_type = YAMLSec ? YAMLSec->Type : ELF::SHT_PROGBITS; |
| SHeader.sh_addralign = YAMLSec ? (uint64_t)YAMLSec->AddressAlign : 1; |
| SHeader.sh_offset = alignToOffset(CBA, SHeader.sh_addralign, |
| YAMLSec ? YAMLSec->Offset : None); |
| |
| ELFYAML::RawContentSection *RawSec = |
| dyn_cast_or_null<ELFYAML::RawContentSection>(YAMLSec); |
| if (Doc.DWARF && shouldEmitDWARF(*Doc.DWARF, Name)) { |
| if (RawSec && (RawSec->Content || RawSec->Size)) |
| reportError("cannot specify section '" + Name + |
| "' contents in the 'DWARF' entry and the 'Content' " |
| "or 'Size' in the 'Sections' entry at the same time"); |
| else { |
| if (Expected<uint64_t> ShSizeOrErr = |
| emitDWARF<ELFT>(SHeader, Name, *Doc.DWARF, CBA)) |
| SHeader.sh_size = *ShSizeOrErr; |
| else |
| reportError(ShSizeOrErr.takeError()); |
| } |
| } else if (RawSec) |
| SHeader.sh_size = writeContent(CBA, RawSec->Content, RawSec->Size); |
| else |
| llvm_unreachable("debug sections can only be initialized via the 'DWARF' " |
| "entry or a RawContentSection"); |
| |
| if (RawSec && RawSec->Info) |
| SHeader.sh_info = *RawSec->Info; |
| |
| if (YAMLSec && YAMLSec->Flags) |
| SHeader.sh_flags = *YAMLSec->Flags; |
| else if (Name == ".debug_str") |
| SHeader.sh_flags = ELF::SHF_MERGE | ELF::SHF_STRINGS; |
| |
| assignSectionAddress(SHeader, YAMLSec); |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::reportError(const Twine &Msg) { |
| ErrHandler(Msg); |
| HasError = true; |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::reportError(Error Err) { |
| handleAllErrors(std::move(Err), [&](const ErrorInfoBase &Err) { |
| reportError(Err.message()); |
| }); |
| } |
| |
| template <class ELFT> |
| std::vector<Fragment> |
| ELFState<ELFT>::getPhdrFragments(const ELFYAML::ProgramHeader &Phdr, |
| ArrayRef<Elf_Shdr> SHeaders) { |
| std::vector<Fragment> Ret; |
| for (const ELFYAML::Chunk *C : Phdr.Chunks) { |
| if (const ELFYAML::Fill *F = dyn_cast<ELFYAML::Fill>(C)) { |
| Ret.push_back({*F->Offset, F->Size, llvm::ELF::SHT_PROGBITS, |
| /*ShAddrAlign=*/1}); |
| continue; |
| } |
| |
| const ELFYAML::Section *S = cast<ELFYAML::Section>(C); |
| const Elf_Shdr &H = SHeaders[SN2I.get(S->Name)]; |
| Ret.push_back({H.sh_offset, H.sh_size, H.sh_type, H.sh_addralign}); |
| } |
| return Ret; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders, |
| std::vector<Elf_Shdr> &SHeaders) { |
| uint32_t PhdrIdx = 0; |
| for (auto &YamlPhdr : Doc.ProgramHeaders) { |
| Elf_Phdr &PHeader = PHeaders[PhdrIdx++]; |
| std::vector<Fragment> Fragments = getPhdrFragments(YamlPhdr, SHeaders); |
| if (!llvm::is_sorted(Fragments, [](const Fragment &A, const Fragment &B) { |
| return A.Offset < B.Offset; |
| })) |
| reportError("sections in the program header with index " + |
| Twine(PhdrIdx) + " are not sorted by their file offset"); |
| |
| if (YamlPhdr.Offset) { |
| if (!Fragments.empty() && *YamlPhdr.Offset > Fragments.front().Offset) |
| reportError("'Offset' for segment with index " + Twine(PhdrIdx) + |
| " must be less than or equal to the minimum file offset of " |
| "all included sections (0x" + |
| Twine::utohexstr(Fragments.front().Offset) + ")"); |
| PHeader.p_offset = *YamlPhdr.Offset; |
| } else if (!Fragments.empty()) { |
| PHeader.p_offset = Fragments.front().Offset; |
| } |
| |
| // Set the file size if not set explicitly. |
| if (YamlPhdr.FileSize) { |
| PHeader.p_filesz = *YamlPhdr.FileSize; |
| } else if (!Fragments.empty()) { |
| uint64_t FileSize = Fragments.back().Offset - PHeader.p_offset; |
| // SHT_NOBITS sections occupy no physical space in a file, we should not |
| // take their sizes into account when calculating the file size of a |
| // segment. |
| if (Fragments.back().Type != llvm::ELF::SHT_NOBITS) |
| FileSize += Fragments.back().Size; |
| PHeader.p_filesz = FileSize; |
| } |
| |
| // Find the maximum offset of the end of a section in order to set p_memsz. |
| uint64_t MemOffset = PHeader.p_offset; |
| for (const Fragment &F : Fragments) |
| MemOffset = std::max(MemOffset, F.Offset + F.Size); |
| // Set the memory size if not set explicitly. |
| PHeader.p_memsz = YamlPhdr.MemSize ? uint64_t(*YamlPhdr.MemSize) |
| : MemOffset - PHeader.p_offset; |
| |
| if (YamlPhdr.Align) { |
| PHeader.p_align = *YamlPhdr.Align; |
| } else { |
| // Set the alignment of the segment to be the maximum alignment of the |
| // sections so that by default the segment has a valid and sensible |
| // alignment. |
| PHeader.p_align = 1; |
| for (const Fragment &F : Fragments) |
| PHeader.p_align = std::max((uint64_t)PHeader.p_align, F.AddrAlign); |
| } |
| } |
| } |
| |
| bool llvm::ELFYAML::shouldAllocateFileSpace( |
| ArrayRef<ELFYAML::ProgramHeader> Phdrs, const ELFYAML::NoBitsSection &S) { |
| for (const ELFYAML::ProgramHeader &PH : Phdrs) { |
| auto It = llvm::find_if( |
| PH.Chunks, [&](ELFYAML::Chunk *C) { return C->Name == S.Name; }); |
| if (std::any_of(It, PH.Chunks.end(), [](ELFYAML::Chunk *C) { |
| return (isa<ELFYAML::Fill>(C) || |
| cast<ELFYAML::Section>(C)->Type != ELF::SHT_NOBITS); |
| })) |
| return true; |
| } |
| return false; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::NoBitsSection &S, |
| ContiguousBlobAccumulator &CBA) { |
| if (!S.Size) |
| return; |
| |
| SHeader.sh_size = *S.Size; |
| |
| // When a nobits section is followed by a non-nobits section or fill |
| // in the same segment, we allocate the file space for it. This behavior |
| // matches linkers. |
| if (shouldAllocateFileSpace(Doc.ProgramHeaders, S)) |
| CBA.writeZeros(*S.Size); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::RawContentSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (Section.Info) |
| SHeader.sh_info = *Section.Info; |
| } |
| |
| static bool isMips64EL(const ELFYAML::Object &Obj) { |
| return Obj.getMachine() == llvm::ELF::EM_MIPS && |
| Obj.Header.Class == ELFYAML::ELF_ELFCLASS(ELF::ELFCLASS64) && |
| Obj.Header.Data == ELFYAML::ELF_ELFDATA(ELF::ELFDATA2LSB); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::RelocationSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| assert((Section.Type == llvm::ELF::SHT_REL || |
| Section.Type == llvm::ELF::SHT_RELA) && |
| "Section type is not SHT_REL nor SHT_RELA"); |
| |
| if (!Section.RelocatableSec.empty()) |
| SHeader.sh_info = toSectionIndex(Section.RelocatableSec, Section.Name); |
| |
| if (!Section.Relocations) |
| return; |
| |
| const bool IsRela = Section.Type == llvm::ELF::SHT_RELA; |
| for (const ELFYAML::Relocation &Rel : *Section.Relocations) { |
| const bool IsDynamic = Section.Link && (*Section.Link == ".dynsym"); |
| unsigned SymIdx = |
| Rel.Symbol ? toSymbolIndex(*Rel.Symbol, Section.Name, IsDynamic) : 0; |
| if (IsRela) { |
| Elf_Rela REntry; |
| zero(REntry); |
| REntry.r_offset = Rel.Offset; |
| REntry.r_addend = Rel.Addend; |
| REntry.setSymbolAndType(SymIdx, Rel.Type, isMips64EL(Doc)); |
| CBA.write((const char *)&REntry, sizeof(REntry)); |
| } else { |
| Elf_Rel REntry; |
| zero(REntry); |
| REntry.r_offset = Rel.Offset; |
| REntry.setSymbolAndType(SymIdx, Rel.Type, isMips64EL(Doc)); |
| CBA.write((const char *)&REntry, sizeof(REntry)); |
| } |
| } |
| |
| SHeader.sh_size = (IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel)) * |
| Section.Relocations->size(); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::RelrSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Entries) |
| return; |
| |
| for (llvm::yaml::Hex64 E : *Section.Entries) { |
| if (!ELFT::Is64Bits && E > UINT32_MAX) |
| reportError(Section.Name + ": the value is too large for 32-bits: 0x" + |
| Twine::utohexstr(E)); |
| CBA.write<uintX_t>(E, ELFT::TargetEndianness); |
| } |
| |
| SHeader.sh_size = sizeof(uintX_t) * Section.Entries->size(); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::SymtabShndxSection &Shndx, |
| ContiguousBlobAccumulator &CBA) { |
| if (Shndx.Content || Shndx.Size) { |
| SHeader.sh_size = writeContent(CBA, Shndx.Content, Shndx.Size); |
| return; |
| } |
| |
| if (!Shndx.Entries) |
| return; |
| |
| for (uint32_t E : *Shndx.Entries) |
| CBA.write<uint32_t>(E, ELFT::TargetEndianness); |
| SHeader.sh_size = Shndx.Entries->size() * SHeader.sh_entsize; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::GroupSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| assert(Section.Type == llvm::ELF::SHT_GROUP && |
| "Section type is not SHT_GROUP"); |
| |
| if (Section.Signature) |
| SHeader.sh_info = |
| toSymbolIndex(*Section.Signature, Section.Name, /*IsDynamic=*/false); |
| |
| if (!Section.Members) |
| return; |
| |
| for (const ELFYAML::SectionOrType &Member : *Section.Members) { |
| unsigned int SectionIndex = 0; |
| if (Member.sectionNameOrType == "GRP_COMDAT") |
| SectionIndex = llvm::ELF::GRP_COMDAT; |
| else |
| SectionIndex = toSectionIndex(Member.sectionNameOrType, Section.Name); |
| CBA.write<uint32_t>(SectionIndex, ELFT::TargetEndianness); |
| } |
| SHeader.sh_size = SHeader.sh_entsize * Section.Members->size(); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::SymverSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Entries) |
| return; |
| |
| for (uint16_t Version : *Section.Entries) |
| CBA.write<uint16_t>(Version, ELFT::TargetEndianness); |
| SHeader.sh_size = Section.Entries->size() * SHeader.sh_entsize; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::StackSizesSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Entries) |
| return; |
| |
| if (!Section.Entries) |
| return; |
| |
| for (const ELFYAML::StackSizeEntry &E : *Section.Entries) { |
| CBA.write<uintX_t>(E.Address, ELFT::TargetEndianness); |
| SHeader.sh_size += sizeof(uintX_t) + CBA.writeULEB128(E.Size); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::BBAddrMapSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Entries) |
| return; |
| |
| for (const ELFYAML::BBAddrMapEntry &E : *Section.Entries) { |
| // Write the address of the function. |
| CBA.write<uintX_t>(E.Address, ELFT::TargetEndianness); |
| // Write number of BBEntries (number of basic blocks in the function). |
| size_t NumBlocks = E.BBEntries ? E.BBEntries->size() : 0; |
| SHeader.sh_size += sizeof(uintX_t) + CBA.writeULEB128(NumBlocks); |
| if (!NumBlocks) |
| continue; |
| // Write all BBEntries. |
| for (const ELFYAML::BBAddrMapEntry::BBEntry &BBE : *E.BBEntries) |
| SHeader.sh_size += CBA.writeULEB128(BBE.AddressOffset) + |
| CBA.writeULEB128(BBE.Size) + |
| CBA.writeULEB128(BBE.Metadata); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::LinkerOptionsSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Options) |
| return; |
| |
| for (const ELFYAML::LinkerOption &LO : *Section.Options) { |
| CBA.write(LO.Key.data(), LO.Key.size()); |
| CBA.write('\0'); |
| CBA.write(LO.Value.data(), LO.Value.size()); |
| CBA.write('\0'); |
| SHeader.sh_size += (LO.Key.size() + LO.Value.size() + 2); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::DependentLibrariesSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Libs) |
| return; |
| |
| for (StringRef Lib : *Section.Libs) { |
| CBA.write(Lib.data(), Lib.size()); |
| CBA.write('\0'); |
| SHeader.sh_size += Lib.size() + 1; |
| } |
| } |
| |
| template <class ELFT> |
| uint64_t |
| ELFState<ELFT>::alignToOffset(ContiguousBlobAccumulator &CBA, uint64_t Align, |
| llvm::Optional<llvm::yaml::Hex64> Offset) { |
| uint64_t CurrentOffset = CBA.getOffset(); |
| uint64_t AlignedOffset; |
| |
| if (Offset) { |
| if ((uint64_t)*Offset < CurrentOffset) { |
| reportError("the 'Offset' value (0x" + |
| Twine::utohexstr((uint64_t)*Offset) + ") goes backward"); |
| return CurrentOffset; |
| } |
| |
| // We ignore an alignment when an explicit offset has been requested. |
| AlignedOffset = *Offset; |
| } else { |
| AlignedOffset = alignTo(CurrentOffset, std::max(Align, (uint64_t)1)); |
| } |
| |
| CBA.writeZeros(AlignedOffset - CurrentOffset); |
| return AlignedOffset; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::CallGraphProfileSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Entries) |
| return; |
| |
| for (const ELFYAML::CallGraphEntry &E : *Section.Entries) { |
| unsigned From = toSymbolIndex(E.From, Section.Name, /*IsDynamic=*/false); |
| unsigned To = toSymbolIndex(E.To, Section.Name, /*IsDynamic=*/false); |
| |
| CBA.write<uint32_t>(From, ELFT::TargetEndianness); |
| CBA.write<uint32_t>(To, ELFT::TargetEndianness); |
| CBA.write<uint64_t>(E.Weight, ELFT::TargetEndianness); |
| SHeader.sh_size += 16; |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::HashSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Bucket) |
| return; |
| |
| if (!Section.Bucket) |
| return; |
| |
| CBA.write<uint32_t>( |
| Section.NBucket.getValueOr(llvm::yaml::Hex64(Section.Bucket->size())), |
| ELFT::TargetEndianness); |
| CBA.write<uint32_t>( |
| Section.NChain.getValueOr(llvm::yaml::Hex64(Section.Chain->size())), |
| ELFT::TargetEndianness); |
| |
| for (uint32_t Val : *Section.Bucket) |
| CBA.write<uint32_t>(Val, ELFT::TargetEndianness); |
| for (uint32_t Val : *Section.Chain) |
| CBA.write<uint32_t>(Val, ELFT::TargetEndianness); |
| |
| SHeader.sh_size = (2 + Section.Bucket->size() + Section.Chain->size()) * 4; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::VerdefSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| |
| if (Section.Info) |
| SHeader.sh_info = *Section.Info; |
| else if (Section.Entries) |
| SHeader.sh_info = Section.Entries->size(); |
| |
| if (!Section.Entries) |
| return; |
| |
| uint64_t AuxCnt = 0; |
| for (size_t I = 0; I < Section.Entries->size(); ++I) { |
| const ELFYAML::VerdefEntry &E = (*Section.Entries)[I]; |
| |
| Elf_Verdef VerDef; |
| VerDef.vd_version = E.Version.getValueOr(1); |
| VerDef.vd_flags = E.Flags.getValueOr(0); |
| VerDef.vd_ndx = E.VersionNdx.getValueOr(0); |
| VerDef.vd_hash = E.Hash.getValueOr(0); |
| VerDef.vd_aux = sizeof(Elf_Verdef); |
| VerDef.vd_cnt = E.VerNames.size(); |
| if (I == Section.Entries->size() - 1) |
| VerDef.vd_next = 0; |
| else |
| VerDef.vd_next = |
| sizeof(Elf_Verdef) + E.VerNames.size() * sizeof(Elf_Verdaux); |
| CBA.write((const char *)&VerDef, sizeof(Elf_Verdef)); |
| |
| for (size_t J = 0; J < E.VerNames.size(); ++J, ++AuxCnt) { |
| Elf_Verdaux VernAux; |
| VernAux.vda_name = DotDynstr.getOffset(E.VerNames[J]); |
| if (J == E.VerNames.size() - 1) |
| VernAux.vda_next = 0; |
| else |
| VernAux.vda_next = sizeof(Elf_Verdaux); |
| CBA.write((const char *)&VernAux, sizeof(Elf_Verdaux)); |
| } |
| } |
| |
| SHeader.sh_size = Section.Entries->size() * sizeof(Elf_Verdef) + |
| AuxCnt * sizeof(Elf_Verdaux); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::VerneedSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (Section.Info) |
| SHeader.sh_info = *Section.Info; |
| else if (Section.VerneedV) |
| SHeader.sh_info = Section.VerneedV->size(); |
| |
| if (!Section.VerneedV) |
| return; |
| |
| uint64_t AuxCnt = 0; |
| for (size_t I = 0; I < Section.VerneedV->size(); ++I) { |
| const ELFYAML::VerneedEntry &VE = (*Section.VerneedV)[I]; |
| |
| Elf_Verneed VerNeed; |
| VerNeed.vn_version = VE.Version; |
| VerNeed.vn_file = DotDynstr.getOffset(VE.File); |
| if (I == Section.VerneedV->size() - 1) |
| VerNeed.vn_next = 0; |
| else |
| VerNeed.vn_next = |
| sizeof(Elf_Verneed) + VE.AuxV.size() * sizeof(Elf_Vernaux); |
| VerNeed.vn_cnt = VE.AuxV.size(); |
| VerNeed.vn_aux = sizeof(Elf_Verneed); |
| CBA.write((const char *)&VerNeed, sizeof(Elf_Verneed)); |
| |
| for (size_t J = 0; J < VE.AuxV.size(); ++J, ++AuxCnt) { |
| const ELFYAML::VernauxEntry &VAuxE = VE.AuxV[J]; |
| |
| Elf_Vernaux VernAux; |
| VernAux.vna_hash = VAuxE.Hash; |
| VernAux.vna_flags = VAuxE.Flags; |
| VernAux.vna_other = VAuxE.Other; |
| VernAux.vna_name = DotDynstr.getOffset(VAuxE.Name); |
| if (J == VE.AuxV.size() - 1) |
| VernAux.vna_next = 0; |
| else |
| VernAux.vna_next = sizeof(Elf_Vernaux); |
| CBA.write((const char *)&VernAux, sizeof(Elf_Vernaux)); |
| } |
| } |
| |
| SHeader.sh_size = Section.VerneedV->size() * sizeof(Elf_Verneed) + |
| AuxCnt * sizeof(Elf_Vernaux); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::ARMIndexTableSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Entries) |
| return; |
| |
| for (const ELFYAML::ARMIndexTableEntry &E : *Section.Entries) { |
| CBA.write<uint32_t>(E.Offset, ELFT::TargetEndianness); |
| CBA.write<uint32_t>(E.Value, ELFT::TargetEndianness); |
| } |
| SHeader.sh_size = Section.Entries->size() * 8; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::MipsABIFlags &Section, |
| ContiguousBlobAccumulator &CBA) { |
| assert(Section.Type == llvm::ELF::SHT_MIPS_ABIFLAGS && |
| "Section type is not SHT_MIPS_ABIFLAGS"); |
| |
| object::Elf_Mips_ABIFlags<ELFT> Flags; |
| zero(Flags); |
| SHeader.sh_size = SHeader.sh_entsize; |
| |
| Flags.version = Section.Version; |
| Flags.isa_level = Section.ISALevel; |
| Flags.isa_rev = Section.ISARevision; |
| Flags.gpr_size = Section.GPRSize; |
| Flags.cpr1_size = Section.CPR1Size; |
| Flags.cpr2_size = Section.CPR2Size; |
| Flags.fp_abi = Section.FpABI; |
| Flags.isa_ext = Section.ISAExtension; |
| Flags.ases = Section.ASEs; |
| Flags.flags1 = Section.Flags1; |
| Flags.flags2 = Section.Flags2; |
| CBA.write((const char *)&Flags, sizeof(Flags)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::DynamicSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| assert(Section.Type == llvm::ELF::SHT_DYNAMIC && |
| "Section type is not SHT_DYNAMIC"); |
| |
| if (!Section.Entries) |
| return; |
| |
| for (const ELFYAML::DynamicEntry &DE : *Section.Entries) { |
| CBA.write<uintX_t>(DE.Tag, ELFT::TargetEndianness); |
| CBA.write<uintX_t>(DE.Val, ELFT::TargetEndianness); |
| } |
| SHeader.sh_size = 2 * sizeof(uintX_t) * Section.Entries->size(); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::AddrsigSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Symbols) |
| return; |
| |
| if (!Section.Symbols) |
| return; |
| |
| for (StringRef Sym : *Section.Symbols) |
| SHeader.sh_size += |
| CBA.writeULEB128(toSymbolIndex(Sym, Section.Name, /*IsDynamic=*/false)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::NoteSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.Notes) |
| return; |
| |
| uint64_t Offset = CBA.tell(); |
| for (const ELFYAML::NoteEntry &NE : *Section.Notes) { |
| // Write name size. |
| if (NE.Name.empty()) |
| CBA.write<uint32_t>(0, ELFT::TargetEndianness); |
| else |
| CBA.write<uint32_t>(NE.Name.size() + 1, ELFT::TargetEndianness); |
| |
| // Write description size. |
| if (NE.Desc.binary_size() == 0) |
| CBA.write<uint32_t>(0, ELFT::TargetEndianness); |
| else |
| CBA.write<uint32_t>(NE.Desc.binary_size(), ELFT::TargetEndianness); |
| |
| // Write type. |
| CBA.write<uint32_t>(NE.Type, ELFT::TargetEndianness); |
| |
| // Write name, null terminator and padding. |
| if (!NE.Name.empty()) { |
| CBA.write(NE.Name.data(), NE.Name.size()); |
| CBA.write('\0'); |
| CBA.padToAlignment(4); |
| } |
| |
| // Write description and padding. |
| if (NE.Desc.binary_size() != 0) { |
| CBA.writeAsBinary(NE.Desc); |
| CBA.padToAlignment(4); |
| } |
| } |
| |
| SHeader.sh_size = CBA.tell() - Offset; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::GnuHashSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| if (!Section.HashBuckets) |
| return; |
| |
| if (!Section.Header) |
| return; |
| |
| // We write the header first, starting with the hash buckets count. Normally |
| // it is the number of entries in HashBuckets, but the "NBuckets" property can |
| // be used to override this field, which is useful for producing broken |
| // objects. |
| if (Section.Header->NBuckets) |
| CBA.write<uint32_t>(*Section.Header->NBuckets, ELFT::TargetEndianness); |
| else |
| CBA.write<uint32_t>(Section.HashBuckets->size(), ELFT::TargetEndianness); |
| |
| // Write the index of the first symbol in the dynamic symbol table accessible |
| // via the hash table. |
| CBA.write<uint32_t>(Section.Header->SymNdx, ELFT::TargetEndianness); |
| |
| // Write the number of words in the Bloom filter. As above, the "MaskWords" |
| // property can be used to set this field to any value. |
| if (Section.Header->MaskWords) |
| CBA.write<uint32_t>(*Section.Header->MaskWords, ELFT::TargetEndianness); |
| else |
| CBA.write<uint32_t>(Section.BloomFilter->size(), ELFT::TargetEndianness); |
| |
| // Write the shift constant used by the Bloom filter. |
| CBA.write<uint32_t>(Section.Header->Shift2, ELFT::TargetEndianness); |
| |
| // We've finished writing the header. Now write the Bloom filter. |
| for (llvm::yaml::Hex64 Val : *Section.BloomFilter) |
| CBA.write<uintX_t>(Val, ELFT::TargetEndianness); |
| |
| // Write an array of hash buckets. |
| for (llvm::yaml::Hex32 Val : *Section.HashBuckets) |
| CBA.write<uint32_t>(Val, ELFT::TargetEndianness); |
| |
| // Write an array of hash values. |
| for (llvm::yaml::Hex32 Val : *Section.HashValues) |
| CBA.write<uint32_t>(Val, ELFT::TargetEndianness); |
| |
| SHeader.sh_size = 16 /*Header size*/ + |
| Section.BloomFilter->size() * sizeof(typename ELFT::uint) + |
| Section.HashBuckets->size() * 4 + |
| Section.HashValues->size() * 4; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeFill(ELFYAML::Fill &Fill, |
| ContiguousBlobAccumulator &CBA) { |
| size_t PatternSize = Fill.Pattern ? Fill.Pattern->binary_size() : 0; |
| if (!PatternSize) { |
| CBA.writeZeros(Fill.Size); |
| return; |
| } |
| |
| // Fill the content with the specified pattern. |
| uint64_t Written = 0; |
| for (; Written + PatternSize <= Fill.Size; Written += PatternSize) |
| CBA.writeAsBinary(*Fill.Pattern); |
| CBA.writeAsBinary(*Fill.Pattern, Fill.Size - Written); |
| } |
| |
| template <class ELFT> |
| DenseMap<StringRef, size_t> ELFState<ELFT>::buildSectionHeaderReorderMap() { |
| const ELFYAML::SectionHeaderTable &SectionHeaders = |
| Doc.getSectionHeaderTable(); |
| if (SectionHeaders.IsImplicit || SectionHeaders.NoHeaders) |
| return DenseMap<StringRef, size_t>(); |
| |
| DenseMap<StringRef, size_t> Ret; |
| size_t SecNdx = 0; |
| StringSet<> Seen; |
| |
| auto AddSection = [&](const ELFYAML::SectionHeader &Hdr) { |
| if (!Ret.try_emplace(Hdr.Name, ++SecNdx).second) |
| reportError("repeated section name: '" + Hdr.Name + |
| "' in the section header description"); |
| Seen.insert(Hdr.Name); |
| }; |
| |
| if (SectionHeaders.Sections) |
| for (const ELFYAML::SectionHeader &Hdr : *SectionHeaders.Sections) |
| AddSection(Hdr); |
| |
| if (SectionHeaders.Excluded) |
| for (const ELFYAML::SectionHeader &Hdr : *SectionHeaders.Excluded) |
| AddSection(Hdr); |
| |
| for (const ELFYAML::Section *S : Doc.getSections()) { |
| // Ignore special first SHT_NULL section. |
| if (S == Doc.getSections().front()) |
| continue; |
| if (!Seen.count(S->Name)) |
| reportError("section '" + S->Name + |
| "' should be present in the 'Sections' or 'Excluded' lists"); |
| Seen.erase(S->Name); |
| } |
| |
| for (const auto &It : Seen) |
| reportError("section header contains undefined section '" + It.getKey() + |
| "'"); |
| return Ret; |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::buildSectionIndex() { |
| // A YAML description can have an explicit section header declaration that |
| // allows to change the order of section headers. |
| DenseMap<StringRef, size_t> ReorderMap = buildSectionHeaderReorderMap(); |
| |
| if (HasError) |
| return; |
| |
| // Build excluded section headers map. |
| std::vector<ELFYAML::Section *> Sections = Doc.getSections(); |
| const ELFYAML::SectionHeaderTable &SectionHeaders = |
| Doc.getSectionHeaderTable(); |
| if (SectionHeaders.Excluded) |
| for (const ELFYAML::SectionHeader &Hdr : *SectionHeaders.Excluded) |
| if (!ExcludedSectionHeaders.insert(Hdr.Name).second) |
| llvm_unreachable("buildSectionIndex() failed"); |
| |
| if (SectionHeaders.NoHeaders.getValueOr(false)) |
| for (const ELFYAML::Section *S : Sections) |
| if (!ExcludedSectionHeaders.insert(S->Name).second) |
| llvm_unreachable("buildSectionIndex() failed"); |
| |
| size_t SecNdx = -1; |
| for (const ELFYAML::Section *S : Sections) { |
| ++SecNdx; |
| |
| size_t Index = ReorderMap.empty() ? SecNdx : ReorderMap.lookup(S->Name); |
| if (!SN2I.addName(S->Name, Index)) |
| llvm_unreachable("buildSectionIndex() failed"); |
| |
| if (!ExcludedSectionHeaders.count(S->Name)) |
| DotShStrtab.add(ELFYAML::dropUniqueSuffix(S->Name)); |
| } |
| |
| DotShStrtab.finalize(); |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::buildSymbolIndexes() { |
| auto Build = [this](ArrayRef<ELFYAML::Symbol> V, NameToIdxMap &Map) { |
| for (size_t I = 0, S = V.size(); I < S; ++I) { |
| const ELFYAML::Symbol &Sym = V[I]; |
| if (!Sym.Name.empty() && !Map.addName(Sym.Name, I + 1)) |
| reportError("repeated symbol name: '" + Sym.Name + "'"); |
| } |
| }; |
| |
| if (Doc.Symbols) |
| Build(*Doc.Symbols, SymN2I); |
| if (Doc.DynamicSymbols) |
| Build(*Doc.DynamicSymbols, DynSymN2I); |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::finalizeStrings() { |
| // Add the regular symbol names to .strtab section. |
| if (Doc.Symbols) |
| for (const ELFYAML::Symbol &Sym : *Doc.Symbols) |
| DotStrtab.add(ELFYAML::dropUniqueSuffix(Sym.Name)); |
| DotStrtab.finalize(); |
| |
| // Add the dynamic symbol names to .dynstr section. |
| if (Doc.DynamicSymbols) |
| for (const ELFYAML::Symbol &Sym : *Doc.DynamicSymbols) |
| DotDynstr.add(ELFYAML::dropUniqueSuffix(Sym.Name)); |
| |
| // SHT_GNU_verdef and SHT_GNU_verneed sections might also |
| // add strings to .dynstr section. |
| for (const ELFYAML::Chunk *Sec : Doc.getSections()) { |
| if (auto VerNeed = dyn_cast<ELFYAML::VerneedSection>(Sec)) { |
| if (VerNeed->VerneedV) { |
| for (const ELFYAML::VerneedEntry &VE : *VerNeed->VerneedV) { |
| DotDynstr.add(VE.File); |
| for (const ELFYAML::VernauxEntry &Aux : VE.AuxV) |
| DotDynstr.add(Aux.Name); |
| } |
| } |
| } else if (auto VerDef = dyn_cast<ELFYAML::VerdefSection>(Sec)) { |
| if (VerDef->Entries) |
| for (const ELFYAML::VerdefEntry &E : *VerDef->Entries) |
| for (StringRef Name : E.VerNames) |
| DotDynstr.add(Name); |
| } |
| } |
| |
| DotDynstr.finalize(); |
| } |
| |
| template <class ELFT> |
| bool ELFState<ELFT>::writeELF(raw_ostream &OS, ELFYAML::Object &Doc, |
| yaml::ErrorHandler EH, uint64_t MaxSize) { |
| ELFState<ELFT> State(Doc, EH); |
| if (State.HasError) |
| return false; |
| |
| // Finalize .strtab and .dynstr sections. We do that early because want to |
| // finalize the string table builders before writing the content of the |
| // sections that might want to use them. |
| State.finalizeStrings(); |
| |
| State.buildSectionIndex(); |
| State.buildSymbolIndexes(); |
| |
| if (State.HasError) |
| return false; |
| |
| std::vector<Elf_Phdr> PHeaders; |
| State.initProgramHeaders(PHeaders); |
| |
| // XXX: This offset is tightly coupled with the order that we write |
| // things to `OS`. |
| const size_t SectionContentBeginOffset = |
| sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * Doc.ProgramHeaders.size(); |
| // It is quite easy to accidentally create output with yaml2obj that is larger |
| // than intended, for example, due to an issue in the YAML description. |
| // We limit the maximum allowed output size, but also provide a command line |
| // option to change this limitation. |
| ContiguousBlobAccumulator CBA(SectionContentBeginOffset, MaxSize); |
| |
| std::vector<Elf_Shdr> SHeaders; |
| State.initSectionHeaders(SHeaders, CBA); |
| |
| // Now we can decide segment offsets. |
| State.setProgramHeaderLayout(PHeaders, SHeaders); |
| |
| bool ReachedLimit = CBA.getOffset() > MaxSize; |
| if (Error E = CBA.takeLimitError()) { |
| // We report a custom error message instead below. |
| consumeError(std::move(E)); |
| ReachedLimit = true; |
| } |
| |
| if (ReachedLimit) |
| State.reportError( |
| "the desired output size is greater than permitted. Use the " |
| "--max-size option to change the limit"); |
| |
| if (State.HasError) |
| return false; |
| |
| State.writeELFHeader(OS); |
| writeArrayData(OS, makeArrayRef(PHeaders)); |
| |
| const ELFYAML::SectionHeaderTable &SHT = Doc.getSectionHeaderTable(); |
| if (!SHT.NoHeaders.getValueOr(false)) |
| CBA.updateDataAt(*SHT.Offset, SHeaders.data(), |
| SHT.getNumHeaders(SHeaders.size()) * sizeof(Elf_Shdr)); |
| |
| CBA.writeBlobToStream(OS); |
| return true; |
| } |
| |
| namespace llvm { |
| namespace yaml { |
| |
| bool yaml2elf(llvm::ELFYAML::Object &Doc, raw_ostream &Out, ErrorHandler EH, |
| uint64_t MaxSize) { |
| bool IsLE = Doc.Header.Data == ELFYAML::ELF_ELFDATA(ELF::ELFDATA2LSB); |
| bool Is64Bit = Doc.Header.Class == ELFYAML::ELF_ELFCLASS(ELF::ELFCLASS64); |
| if (Is64Bit) { |
| if (IsLE) |
| return ELFState<object::ELF64LE>::writeELF(Out, Doc, EH, MaxSize); |
| return ELFState<object::ELF64BE>::writeELF(Out, Doc, EH, MaxSize); |
| } |
| if (IsLE) |
| return ELFState<object::ELF32LE>::writeELF(Out, Doc, EH, MaxSize); |
| return ELFState<object::ELF32BE>::writeELF(Out, Doc, EH, MaxSize); |
| } |
| |
| } // namespace yaml |
| } // namespace llvm |
