| //===- 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/StringSet.h" |
| #include "llvm/BinaryFormat/ELF.h" |
| #include "llvm/MC/StringTableBuilder.h" |
| #include "llvm/Object/ELFObjectFile.h" |
| #include "llvm/ObjectYAML/ELFYAML.h" |
| #include "llvm/ObjectYAML/yaml2obj.h" |
| #include "llvm/Support/EndianStream.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`). |
| namespace { |
| class ContiguousBlobAccumulator { |
| const uint64_t InitialOffset; |
| SmallVector<char, 128> Buf; |
| raw_svector_ostream OS; |
| |
| /// \returns The new offset. |
| uint64_t padToAlignment(unsigned Align) { |
| if (Align == 0) |
| Align = 1; |
| uint64_t CurrentOffset = InitialOffset + OS.tell(); |
| uint64_t AlignedOffset = alignTo(CurrentOffset, Align); |
| OS.write_zeros(AlignedOffset - CurrentOffset); |
| return AlignedOffset; // == CurrentOffset; |
| } |
| |
| public: |
| ContiguousBlobAccumulator(uint64_t InitialOffset_) |
| : InitialOffset(InitialOffset_), Buf(), OS(Buf) {} |
| template <class Integer> |
| raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align) { |
| Offset = padToAlignment(Align); |
| return OS; |
| } |
| void writeBlobToStream(raw_ostream &Out) { Out << OS.str(); } |
| }; |
| |
| // 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(); } |
| }; |
| |
| /// "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 { |
| typedef typename ELFT::Ehdr Elf_Ehdr; |
| typedef typename ELFT::Phdr Elf_Phdr; |
| typedef typename ELFT::Shdr Elf_Shdr; |
| typedef typename ELFT::Sym Elf_Sym; |
| typedef typename ELFT::Rel Elf_Rel; |
| typedef typename ELFT::Rela Elf_Rela; |
| typedef typename ELFT::Relr Elf_Relr; |
| typedef typename ELFT::Dyn Elf_Dyn; |
| |
| 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; |
| |
| bool HasError = false; |
| yaml::ErrorHandler ErrHandler; |
| void reportError(const Twine &Msg); |
| |
| 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 setProgramHeaderLayout(std::vector<Elf_Phdr> &PHeaders, |
| std::vector<Elf_Shdr> &SHeaders); |
| void finalizeStrings(); |
| void writeELFHeader(ContiguousBlobAccumulator &CBA, raw_ostream &OS); |
| 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::Group &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::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::HashSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| void writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::AddrsigSection &Section, |
| ContiguousBlobAccumulator &CBA); |
| |
| ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH); |
| |
| public: |
| static bool writeELF(raw_ostream &OS, ELFYAML::Object &Doc, |
| yaml::ErrorHandler EH); |
| }; |
| } // 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) { |
| StringSet<> DocSections; |
| for (std::unique_ptr<ELFYAML::Section> &D : Doc.Sections) { |
| if (!D->Name.empty()) |
| DocSections.insert(D->Name); |
| |
| // Some sections wants to link to .symtab by default. |
| // That means we want to create the symbol table for them. |
| if (D->Type == llvm::ELF::SHT_REL || D->Type == llvm::ELF::SHT_RELA) |
| if (!Doc.Symbols && D->Link.empty()) |
| Doc.Symbols.emplace(); |
| } |
| |
| // Insert SHT_NULL section implicitly when it is not defined in YAML. |
| if (Doc.Sections.empty() || Doc.Sections.front()->Type != ELF::SHT_NULL) |
| Doc.Sections.insert( |
| Doc.Sections.begin(), |
| std::make_unique<ELFYAML::Section>( |
| ELFYAML::Section::SectionKind::RawContent, /*IsImplicit=*/true)); |
| |
| std::vector<StringRef> ImplicitSections; |
| if (Doc.Symbols) |
| ImplicitSections.push_back(".symtab"); |
| ImplicitSections.insert(ImplicitSections.end(), {".strtab", ".shstrtab"}); |
| |
| if (!Doc.DynamicSymbols.empty()) |
| ImplicitSections.insert(ImplicitSections.end(), {".dynsym", ".dynstr"}); |
| |
| // 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::Section::SectionKind::RawContent, true /*IsImplicit*/); |
| Sec->Name = SecName; |
| Doc.Sections.push_back(std::move(Sec)); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeELFHeader(ContiguousBlobAccumulator &CBA, 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; |
| Header.e_machine = Doc.Header.Machine; |
| Header.e_version = EV_CURRENT; |
| Header.e_entry = Doc.Header.Entry; |
| Header.e_phoff = Doc.ProgramHeaders.size() ? sizeof(Header) : 0; |
| Header.e_flags = Doc.Header.Flags; |
| Header.e_ehsize = sizeof(Elf_Ehdr); |
| Header.e_phentsize = Doc.ProgramHeaders.size() ? sizeof(Elf_Phdr) : 0; |
| Header.e_phnum = Doc.ProgramHeaders.size(); |
| |
| Header.e_shentsize = |
| Doc.Header.SHEntSize ? (uint16_t)*Doc.Header.SHEntSize : sizeof(Elf_Shdr); |
| // Immediately following the ELF header and program headers. |
| // Align the start of the section header and write the ELF header. |
| uint64_t SHOff; |
| CBA.getOSAndAlignedOffset(SHOff, sizeof(typename ELFT::uint)); |
| Header.e_shoff = |
| Doc.Header.SHOff ? typename ELFT::uint(*Doc.Header.SHOff) : SHOff; |
| Header.e_shnum = |
| Doc.Header.SHNum ? (uint16_t)*Doc.Header.SHNum : Doc.Sections.size(); |
| Header.e_shstrndx = Doc.Header.SHStrNdx ? (uint16_t)*Doc.Header.SHStrNdx |
| : SN2I.get(".shstrtab"); |
| |
| OS.write((const char *)&Header, sizeof(Header)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initProgramHeaders(std::vector<Elf_Phdr> &PHeaders) { |
| for (const auto &YamlPhdr : Doc.ProgramHeaders) { |
| Elf_Phdr 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); |
| } |
| } |
| |
| template <class ELFT> |
| unsigned ELFState<ELFT>::toSectionIndex(StringRef S, StringRef LocSec, |
| StringRef LocSym) { |
| unsigned Index; |
| if (SN2I.lookup(S, Index) || to_integer(S, Index)) |
| return Index; |
| |
| assert(LocSec.empty() || LocSym.empty()); |
| if (!LocSym.empty()) |
| reportError("unknown section referenced: '" + S + "' by YAML symbol '" + |
| LocSym + "'"); |
| else |
| reportError("unknown section referenced: '" + S + "' by YAML section '" + |
| LocSec + "'"); |
| return 0; |
| } |
| |
| 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> |
| 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 |
| return false; |
| |
| // Override the fields if requested. |
| if (YAMLSec) { |
| if (YAMLSec->ShName) |
| Header.sh_name = *YAMLSec->ShName; |
| if (YAMLSec->ShOffset) |
| Header.sh_offset = *YAMLSec->ShOffset; |
| if (YAMLSec->ShSize) |
| Header.sh_size = *YAMLSec->ShSize; |
| } |
| |
| return true; |
| } |
| |
| StringRef llvm::ELFYAML::dropUniqueSuffix(StringRef S) { |
| size_t SuffixPos = S.rfind(" ["); |
| if (SuffixPos == StringRef::npos) |
| return S; |
| return S.substr(0, SuffixPos); |
| } |
| |
| 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.Sections.size()); |
| |
| for (size_t I = 0; I < Doc.Sections.size(); ++I) { |
| ELFYAML::Section *Sec = Doc.Sections[I].get(); |
| if (I == 0 && Sec->IsImplicit) |
| continue; |
| |
| // 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. |
| Elf_Shdr &SHeader = SHeaders[I]; |
| 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 = |
| DotShStrtab.getOffset(ELFYAML::dropUniqueSuffix(Sec->Name)); |
| SHeader.sh_type = Sec->Type; |
| if (Sec->Flags) |
| SHeader.sh_flags = *Sec->Flags; |
| SHeader.sh_addr = Sec->Address; |
| SHeader.sh_addralign = Sec->AddressAlign; |
| |
| if (!Sec->Link.empty()) |
| SHeader.sh_link = toSectionIndex(Sec->Link, Sec->Name); |
| |
| if (I == 0) { |
| 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; |
| } |
| if (Sec->EntSize) |
| SHeader.sh_entsize = *Sec->EntSize; |
| } else 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::Group>(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)) { |
| SHeader.sh_entsize = 0; |
| SHeader.sh_size = S->Size; |
| // SHT_NOBITS section does not have content |
| // so just to setup the section offset. |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| } 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 { |
| llvm_unreachable("Unknown section type"); |
| } |
| |
| // Override the fields if requested. |
| if (Sec) { |
| if (Sec->ShName) |
| SHeader.sh_name = *Sec->ShName; |
| if (Sec->ShOffset) |
| SHeader.sh_offset = *Sec->ShOffset; |
| if (Sec->ShSize) |
| SHeader.sh_size = *Sec->ShSize; |
| } |
| } |
| } |
| |
| 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(); |
| } |
| |
| static uint64_t writeContent(raw_ostream &OS, |
| const Optional<yaml::BinaryRef> &Content, |
| const Optional<llvm::yaml::Hex64> &Size) { |
| size_t ContentSize = 0; |
| if (Content) { |
| Content->writeAsBinary(OS); |
| ContentSize = Content->binary_size(); |
| } |
| |
| if (!Size) |
| return ContentSize; |
| |
| OS.write_zeros(*Size - ContentSize); |
| return *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 auto &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.NameIndex) |
| Symbol.st_name = *Sym.NameIndex; |
| else if (!Sym.Name.empty()) |
| Symbol.st_name = Strtab.getOffset(ELFYAML::dropUniqueSuffix(Sym.Name)); |
| |
| Symbol.setBindingAndType(Sym.Binding, Sym.Type); |
| if (!Sym.Section.empty()) |
| Symbol.st_shndx = toSectionIndex(Sym.Section, "", Sym.Name); |
| else if (Sym.Index) |
| Symbol.st_shndx = *Sym.Index; |
| |
| Symbol.st_value = Sym.Value; |
| Symbol.st_other = Sym.Other ? *Sym.Other : 0; |
| Symbol.st_size = Sym.Size; |
| } |
| |
| 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) |
| Symbols = Doc.DynamicSymbols; |
| |
| ELFYAML::RawContentSection *RawSec = |
| dyn_cast_or_null<ELFYAML::RawContentSection>(YAMLSec); |
| if (RawSec && !Symbols.empty() && (RawSec->Content || RawSec->Size)) { |
| if (RawSec->Content) |
| reportError("cannot specify both `Content` and " + |
| (IsStatic ? Twine("`Symbols`") : Twine("`DynamicSymbols`")) + |
| " for symbol table section '" + RawSec->Name + "'"); |
| if (RawSec->Size) |
| reportError("cannot specify both `Size` and " + |
| (IsStatic ? Twine("`Symbols`") : Twine("`DynamicSymbols`")) + |
| " for symbol table section '" + RawSec->Name + "'"); |
| return; |
| } |
| |
| zero(SHeader); |
| SHeader.sh_name = DotShStrtab.getOffset(IsStatic ? ".symtab" : ".dynsym"); |
| |
| if (YAMLSec) |
| SHeader.sh_type = YAMLSec->Type; |
| else |
| SHeader.sh_type = IsStatic ? ELF::SHT_SYMTAB : ELF::SHT_DYNSYM; |
| |
| if (RawSec && !RawSec->Link.empty()) { |
| // If the Link field is explicitly defined in the document, |
| // we should use it. |
| SHeader.sh_link = toSectionIndex(RawSec->Link, RawSec->Name); |
| } else { |
| // When we describe the .dynsym section in the document explicitly, it is |
| // allowed to omit the "DynamicSymbols" tag. In this case .dynstr is not |
| // added implicitly and we should be able to leave the Link zeroed if |
| // .dynstr is not defined. |
| unsigned Link = 0; |
| if (IsStatic) |
| Link = SN2I.get(".strtab"); |
| else |
| SN2I.lookup(".dynstr", Link); |
| SHeader.sh_link = Link; |
| } |
| |
| 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_entsize = (YAMLSec && YAMLSec->EntSize) |
| ? (uint64_t)(*YAMLSec->EntSize) |
| : sizeof(Elf_Sym); |
| SHeader.sh_addralign = YAMLSec ? (uint64_t)YAMLSec->AddressAlign : 8; |
| SHeader.sh_addr = YAMLSec ? (uint64_t)YAMLSec->Address : 0; |
| |
| auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| if (RawSec && (RawSec->Content || RawSec->Size)) { |
| assert(Symbols.empty()); |
| SHeader.sh_size = writeContent(OS, RawSec->Content, RawSec->Size); |
| return; |
| } |
| |
| std::vector<Elf_Sym> Syms = |
| toELFSymbols(Symbols, IsStatic ? DotStrtab : DotDynstr); |
| writeArrayData(OS, makeArrayRef(Syms)); |
| SHeader.sh_size = arrayDataSize(makeArrayRef(Syms)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name, |
| StringTableBuilder &STB, |
| ContiguousBlobAccumulator &CBA, |
| ELFYAML::Section *YAMLSec) { |
| zero(SHeader); |
| SHeader.sh_name = DotShStrtab.getOffset(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); |
| |
| auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| if (RawSec && (RawSec->Content || RawSec->Size)) { |
| SHeader.sh_size = writeContent(OS, RawSec->Content, RawSec->Size); |
| } else { |
| STB.write(OS); |
| SHeader.sh_size = STB.getSize(); |
| } |
| |
| if (YAMLSec && YAMLSec->EntSize) |
| SHeader.sh_entsize = *YAMLSec->EntSize; |
| |
| 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; |
| |
| // If the section is explicitly described in the YAML |
| // then we want to use its section address. |
| if (YAMLSec) |
| SHeader.sh_addr = YAMLSec->Address; |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::reportError(const Twine &Msg) { |
| ErrHandler(Msg); |
| HasError = true; |
| } |
| |
| 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<Elf_Shdr *> Sections; |
| for (const ELFYAML::SectionName &SecName : YamlPhdr.Sections) { |
| unsigned Index; |
| if (!SN2I.lookup(SecName.Section, Index)) { |
| reportError("unknown section referenced: '" + SecName.Section + |
| "' by program header"); |
| continue; |
| } |
| Sections.push_back(&SHeaders[Index]); |
| } |
| |
| if (YamlPhdr.Offset) { |
| PHeader.p_offset = *YamlPhdr.Offset; |
| } else { |
| if (YamlPhdr.Sections.size()) |
| PHeader.p_offset = UINT32_MAX; |
| else |
| PHeader.p_offset = 0; |
| |
| // Find the minimum offset for the program header. |
| for (Elf_Shdr *SHeader : Sections) |
| PHeader.p_offset = std::min(PHeader.p_offset, SHeader->sh_offset); |
| } |
| |
| // Find the maximum offset of the end of a section in order to set p_filesz |
| // and p_memsz. When setting p_filesz, trailing SHT_NOBITS sections are not |
| // counted. |
| uint64_t FileOffset = PHeader.p_offset, MemOffset = PHeader.p_offset; |
| for (Elf_Shdr *SHeader : Sections) { |
| uint64_t End = SHeader->sh_offset + SHeader->sh_size; |
| MemOffset = std::max(MemOffset, End); |
| |
| if (SHeader->sh_type != llvm::ELF::SHT_NOBITS) |
| FileOffset = std::max(FileOffset, End); |
| } |
| |
| // Set the file size and the memory size if not set explicitly. |
| PHeader.p_filesz = YamlPhdr.FileSize ? uint64_t(*YamlPhdr.FileSize) |
| : FileOffset - PHeader.p_offset; |
| 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 (Elf_Shdr *SHeader : Sections) |
| PHeader.p_align = std::max(PHeader.p_align, SHeader->sh_addralign); |
| } |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::RawContentSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| SHeader.sh_size = writeContent(OS, Section.Content, Section.Size); |
| |
| if (Section.EntSize) |
| SHeader.sh_entsize = *Section.EntSize; |
| else if (Section.Type == llvm::ELF::SHT_RELR) |
| SHeader.sh_entsize = sizeof(Elf_Relr); |
| else |
| SHeader.sh_entsize = 0; |
| |
| if (Section.Info) |
| SHeader.sh_info = *Section.Info; |
| } |
| |
| static bool isMips64EL(const ELFYAML::Object &Doc) { |
| return Doc.Header.Machine == ELFYAML::ELF_EM(llvm::ELF::EM_MIPS) && |
| Doc.Header.Class == ELFYAML::ELF_ELFCLASS(ELF::ELFCLASS64) && |
| Doc.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"); |
| |
| bool IsRela = Section.Type == llvm::ELF::SHT_RELA; |
| SHeader.sh_entsize = IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel); |
| SHeader.sh_size = SHeader.sh_entsize * Section.Relocations.size(); |
| |
| // For relocation section set link to .symtab by default. |
| if (Section.Link.empty()) |
| SHeader.sh_link = SN2I.get(".symtab"); |
| |
| if (!Section.RelocatableSec.empty()) |
| SHeader.sh_info = toSectionIndex(Section.RelocatableSec, Section.Name); |
| |
| auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| for (const auto &Rel : Section.Relocations) { |
| unsigned SymIdx = Rel.Symbol ? toSymbolIndex(*Rel.Symbol, Section.Name, |
| Section.Link == ".dynsym") |
| : 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)); |
| OS.write((const char *)&REntry, sizeof(REntry)); |
| } else { |
| Elf_Rel REntry; |
| zero(REntry); |
| REntry.r_offset = Rel.Offset; |
| REntry.setSymbolAndType(SymIdx, Rel.Type, isMips64EL(Doc)); |
| OS.write((const char *)&REntry, sizeof(REntry)); |
| } |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent( |
| Elf_Shdr &SHeader, const ELFYAML::SymtabShndxSection &Shndx, |
| ContiguousBlobAccumulator &CBA) { |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| for (uint32_t E : Shndx.Entries) |
| support::endian::write<uint32_t>(OS, E, ELFT::TargetEndianness); |
| |
| SHeader.sh_entsize = Shndx.EntSize ? (uint64_t)*Shndx.EntSize : 4; |
| SHeader.sh_size = Shndx.Entries.size() * SHeader.sh_entsize; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::Group &Section, |
| ContiguousBlobAccumulator &CBA) { |
| assert(Section.Type == llvm::ELF::SHT_GROUP && |
| "Section type is not SHT_GROUP"); |
| |
| SHeader.sh_entsize = 4; |
| SHeader.sh_size = SHeader.sh_entsize * Section.Members.size(); |
| SHeader.sh_info = |
| toSymbolIndex(Section.Signature, Section.Name, /*IsDynamic=*/false); |
| |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| 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); |
| support::endian::write<uint32_t>(OS, SectionIndex, ELFT::TargetEndianness); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::SymverSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| for (uint16_t Version : Section.Entries) |
| support::endian::write<uint16_t>(OS, Version, ELFT::TargetEndianness); |
| |
| SHeader.sh_entsize = Section.EntSize ? (uint64_t)*Section.EntSize : 2; |
| 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) { |
| using uintX_t = typename ELFT::uint; |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| if (Section.Content || Section.Size) { |
| SHeader.sh_size = writeContent(OS, Section.Content, Section.Size); |
| return; |
| } |
| |
| for (const ELFYAML::StackSizeEntry &E : *Section.Entries) { |
| support::endian::write<uintX_t>(OS, E.Address, ELFT::TargetEndianness); |
| SHeader.sh_size += sizeof(uintX_t) + encodeULEB128(E.Size, OS); |
| } |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::HashSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| unsigned Link = 0; |
| if (Section.Link.empty() && SN2I.lookup(".dynsym", Link)) |
| SHeader.sh_link = Link; |
| |
| if (Section.Content || Section.Size) { |
| SHeader.sh_size = writeContent(OS, Section.Content, Section.Size); |
| return; |
| } |
| |
| support::endian::write<uint32_t>(OS, Section.Bucket->size(), |
| ELFT::TargetEndianness); |
| support::endian::write<uint32_t>(OS, Section.Chain->size(), |
| ELFT::TargetEndianness); |
| for (uint32_t Val : *Section.Bucket) |
| support::endian::write<uint32_t>(OS, Val, ELFT::TargetEndianness); |
| for (uint32_t Val : *Section.Chain) |
| support::endian::write<uint32_t>(OS, 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) { |
| typedef typename ELFT::Verdef Elf_Verdef; |
| typedef typename ELFT::Verdaux Elf_Verdaux; |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| 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; |
| VerDef.vd_flags = E.Flags; |
| VerDef.vd_ndx = E.VersionNdx; |
| VerDef.vd_hash = E.Hash; |
| 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); |
| OS.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); |
| OS.write((const char *)&VernAux, sizeof(Elf_Verdaux)); |
| } |
| } |
| |
| SHeader.sh_size = Section.Entries.size() * sizeof(Elf_Verdef) + |
| AuxCnt * sizeof(Elf_Verdaux); |
| SHeader.sh_info = Section.Info; |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::VerneedSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| typedef typename ELFT::Verneed Elf_Verneed; |
| typedef typename ELFT::Vernaux Elf_Vernaux; |
| |
| auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| 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); |
| OS.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); |
| OS.write((const char *)&VernAux, sizeof(Elf_Vernaux)); |
| } |
| } |
| |
| SHeader.sh_size = Section.VerneedV.size() * sizeof(Elf_Verneed) + |
| AuxCnt * sizeof(Elf_Vernaux); |
| SHeader.sh_info = Section.Info; |
| } |
| |
| 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_entsize = sizeof(Flags); |
| SHeader.sh_size = SHeader.sh_entsize; |
| |
| auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| 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; |
| OS.write((const char *)&Flags, sizeof(Flags)); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::DynamicSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| typedef typename ELFT::uint uintX_t; |
| |
| assert(Section.Type == llvm::ELF::SHT_DYNAMIC && |
| "Section type is not SHT_DYNAMIC"); |
| |
| if (!Section.Entries.empty() && Section.Content) |
| reportError("cannot specify both raw content and explicit entries " |
| "for dynamic section '" + |
| Section.Name + "'"); |
| |
| if (Section.Content) |
| SHeader.sh_size = Section.Content->binary_size(); |
| else |
| SHeader.sh_size = 2 * sizeof(uintX_t) * Section.Entries.size(); |
| if (Section.EntSize) |
| SHeader.sh_entsize = *Section.EntSize; |
| else |
| SHeader.sh_entsize = sizeof(Elf_Dyn); |
| |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| for (const ELFYAML::DynamicEntry &DE : Section.Entries) { |
| support::endian::write<uintX_t>(OS, DE.Tag, ELFT::TargetEndianness); |
| support::endian::write<uintX_t>(OS, DE.Val, ELFT::TargetEndianness); |
| } |
| if (Section.Content) |
| Section.Content->writeAsBinary(OS); |
| } |
| |
| template <class ELFT> |
| void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader, |
| const ELFYAML::AddrsigSection &Section, |
| ContiguousBlobAccumulator &CBA) { |
| raw_ostream &OS = |
| CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign); |
| |
| unsigned Link = 0; |
| if (Section.Link.empty() && SN2I.lookup(".symtab", Link)) |
| SHeader.sh_link = Link; |
| |
| if (Section.Content || Section.Size) { |
| SHeader.sh_size = writeContent(OS, Section.Content, Section.Size); |
| return; |
| } |
| |
| for (const ELFYAML::AddrsigSymbol &Sym : *Section.Symbols) { |
| uint64_t Val = |
| Sym.Name ? toSymbolIndex(*Sym.Name, Section.Name, /*IsDynamic=*/false) |
| : (uint32_t)*Sym.Index; |
| SHeader.sh_size += encodeULEB128(Val, OS); |
| } |
| } |
| |
| template <class ELFT> void ELFState<ELFT>::buildSectionIndex() { |
| for (unsigned I = 0, E = Doc.Sections.size(); I != E; ++I) { |
| StringRef Name = Doc.Sections[I]->Name; |
| if (Name.empty()) |
| continue; |
| |
| DotShStrtab.add(ELFYAML::dropUniqueSuffix(Name)); |
| if (!SN2I.addName(Name, I)) |
| reportError("repeated section name: '" + Name + |
| "' at YAML section number " + Twine(I)); |
| } |
| |
| 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); |
| 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. |
| 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 std::unique_ptr<ELFYAML::Section> &Sec : Doc.Sections) { |
| if (auto VerNeed = dyn_cast<ELFYAML::VerneedSection>(Sec.get())) { |
| 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.get())) { |
| 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) { |
| ELFState<ELFT> State(Doc, EH); |
| |
| // 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(); |
| |
| 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(); |
| ContiguousBlobAccumulator CBA(SectionContentBeginOffset); |
| |
| std::vector<Elf_Shdr> SHeaders; |
| State.initSectionHeaders(SHeaders, CBA); |
| |
| // Now we can decide segment offsets |
| State.setProgramHeaderLayout(PHeaders, SHeaders); |
| |
| if (State.HasError) |
| return false; |
| |
| State.writeELFHeader(CBA, OS); |
| writeArrayData(OS, makeArrayRef(PHeaders)); |
| CBA.writeBlobToStream(OS); |
| writeArrayData(OS, makeArrayRef(SHeaders)); |
| return true; |
| } |
| |
| namespace llvm { |
| namespace yaml { |
| |
| bool yaml2elf(llvm::ELFYAML::Object &Doc, raw_ostream &Out, ErrorHandler EH) { |
| 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); |
| return ELFState<object::ELF64BE>::writeELF(Out, Doc, EH); |
| } |
| if (IsLE) |
| return ELFState<object::ELF32LE>::writeELF(Out, Doc, EH); |
| return ELFState<object::ELF32BE>::writeELF(Out, Doc, EH); |
| } |
| |
| } // namespace yaml |
| } // namespace llvm |
