#include "yaml2obj.h"
#include "llvm/ADT/ArrayRef.h"
+#include "llvm/MC/StringTableBuilder.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/ELFYAML.h"
#include "llvm/Support/ELF.h"
using namespace llvm;
-// There is similar code in yaml2coff, but with some slight COFF-specific
-// variations like different initial state. Might be able to deduplicate
-// some day, but also want to make sure that the Mach-O use case is served.
-//
-// This class has a deliberately small interface, since a lot of
-// implementation variation is possible.
-//
-// TODO: Use an ordered container with a suffix-based comparison in order
-// to deduplicate suffixes. std::map<> with a custom comparator is likely
-// to be the simplest implementation, but a suffix trie could be more
-// suitable for the job.
-namespace {
-class StringTableBuilder {
- /// \brief Indices of strings currently present in `Buf`.
- StringMap<unsigned> StringIndices;
- /// \brief The contents of the string table as we build it.
- std::string Buf;
-public:
- StringTableBuilder() {
- Buf.push_back('\0');
- }
- /// \returns Index of string in string table.
- unsigned addString(StringRef S) {
- StringMapEntry<unsigned> &Entry = StringIndices.GetOrCreateValue(S);
- unsigned &I = Entry.getValue();
- if (I != 0)
- return I;
- I = Buf.size();
- Buf.append(S.begin(), S.end());
- Buf.push_back('\0');
- return I;
- }
- size_t size() const {
- return Buf.size();
- }
- void writeToStream(raw_ostream &OS) {
- OS.write(Buf.data(), Buf.size());
- }
-};
-} // end anonymous namespace
-
// 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`).
/// \returns The new offset.
uint64_t padToAlignment(unsigned Align) {
+ if (Align == 0)
+ Align = 1;
uint64_t CurrentOffset = InitialOffset + OS.tell();
uint64_t AlignedOffset = RoundUpToAlignment(CurrentOffset, Align);
for (; CurrentOffset != AlignedOffset; ++CurrentOffset)
ContiguousBlobAccumulator(uint64_t InitialOffset_)
: InitialOffset(InitialOffset_), Buf(), OS(Buf) {}
template <class Integer>
- raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align = 16) {
+ raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align) {
Offset = padToAlignment(Align);
return OS;
}
};
} // end anonymous namespace
-// Used to keep track of section names, so that in the YAML file sections
-// can be referenced by name instead of by index.
+// 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.
namespace {
-class SectionNameToIdxMap {
+class NameToIdxMap {
StringMap<int> Map;
public:
/// \returns true if name is already present in the map.
- bool addName(StringRef SecName, unsigned i) {
- StringMapEntry<int> &Entry = Map.GetOrCreateValue(SecName, -1);
- if (Entry.getValue() != -1)
- return true;
- Entry.setValue((int)i);
- return false;
+ bool addName(StringRef Name, unsigned i) {
+ return !Map.insert(std::make_pair(Name, (int)i)).second;
}
/// \returns true if name is not present in the map
- bool lookupSection(StringRef SecName, unsigned &Idx) const {
- StringMap<int>::const_iterator I = Map.find(SecName);
+ bool lookup(StringRef Name, unsigned &Idx) const {
+ StringMap<int>::const_iterator I = Map.find(Name);
if (I == Map.end())
return true;
Idx = I->getValue();
memset(&Obj, 0, sizeof(Obj));
}
-/// \brief Create a string table in `SHeader`, which we assume is already
-/// zero'd.
-template <class Elf_Shdr>
-static void createStringTableSectionHeader(Elf_Shdr &SHeader,
- StringTableBuilder &STB,
- ContiguousBlobAccumulator &CBA) {
- SHeader.sh_type = ELF::SHT_STRTAB;
- STB.writeToStream(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
- SHeader.sh_size = STB.size();
- SHeader.sh_addralign = 1;
-}
-
namespace {
/// \brief "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 object::ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
+ typedef typename object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
+ typedef typename object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
+ typedef typename object::ELFFile<ELFT>::Elf_Rel Elf_Rel;
+ typedef typename object::ELFFile<ELFT>::Elf_Rela Elf_Rela;
+
/// \brief The future ".strtab" section.
StringTableBuilder DotStrtab;
- /// \brief The section number of the ".strtab" section.
- unsigned DotStrtabSecNo;
- /// \brief The accumulated contents of all sections so far.
- ContiguousBlobAccumulator &SectionContentAccum;
- typedef typename object::ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
- /// \brief The ELF file header.
- Elf_Ehdr &Header;
- SectionNameToIdxMap &SN2I;
+ /// \brief The future ".shstrtab" section.
+ StringTableBuilder DotShStrtab;
+
+ NameToIdxMap SN2I;
+ NameToIdxMap SymN2I;
+ const ELFYAML::Object &Doc;
+
+ bool buildSectionIndex();
+ bool buildSymbolIndex(std::size_t &StartIndex,
+ const std::vector<ELFYAML::Symbol> &Symbols);
+ void initELFHeader(Elf_Ehdr &Header);
+ bool initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
+ ContiguousBlobAccumulator &CBA);
+ void initSymtabSectionHeader(Elf_Shdr &SHeader,
+ ContiguousBlobAccumulator &CBA);
+ void initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
+ StringTableBuilder &STB,
+ ContiguousBlobAccumulator &CBA);
+ void addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
+ std::vector<Elf_Sym> &Syms, unsigned SymbolBinding);
+ void writeSectionContent(Elf_Shdr &SHeader,
+ const ELFYAML::RawContentSection &Section,
+ ContiguousBlobAccumulator &CBA);
+ bool writeSectionContent(Elf_Shdr &SHeader,
+ const ELFYAML::RelocationSection &Section,
+ ContiguousBlobAccumulator &CBA);
+ bool writeSectionContent(Elf_Shdr &SHeader, const ELFYAML::Group &Group,
+ ContiguousBlobAccumulator &CBA);
+ bool writeSectionContent(Elf_Shdr &SHeader,
+ const ELFYAML::MipsABIFlags &Section,
+ ContiguousBlobAccumulator &CBA);
-public:
+ // - SHT_NULL entry (placed first, i.e. 0'th entry)
+ // - symbol table (.symtab) (placed third to last)
+ // - string table (.strtab) (placed second to last)
+ // - section header string table (.shstrtab) (placed last)
+ unsigned getDotSymTabSecNo() const { return Doc.Sections.size() + 1; }
+ unsigned getDotStrTabSecNo() const { return Doc.Sections.size() + 2; }
+ unsigned getDotShStrTabSecNo() const { return Doc.Sections.size() + 3; }
+ unsigned getSectionCount() const { return Doc.Sections.size() + 4; }
- ELFState(Elf_Ehdr &Header_, ContiguousBlobAccumulator &Accum,
- unsigned DotStrtabSecNo_, SectionNameToIdxMap &SN2I_)
- : DotStrtab(), DotStrtabSecNo(DotStrtabSecNo_),
- SectionContentAccum(Accum), Header(Header_), SN2I(SN2I_) {}
+ ELFState(const ELFYAML::Object &D) : Doc(D) {}
- unsigned getDotStrTabSecNo() const { return DotStrtabSecNo; }
- StringTableBuilder &getStringTable() { return DotStrtab; }
- ContiguousBlobAccumulator &getSectionContentAccum() {
- return SectionContentAccum;
- }
- SectionNameToIdxMap &getSN2I() { return SN2I; }
+public:
+ static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc);
};
} // end anonymous namespace
-// FIXME: At this point it is fairly clear that we need to refactor these
-// static functions into methods of a class sharing some typedefs. These
-// ELF type names are insane.
template <class ELFT>
-static void
-addSymbols(const std::vector<ELFYAML::Symbol> &Symbols, ELFState<ELFT> &State,
- std::vector<typename object::ELFFile<ELFT>::Elf_Sym> &Syms,
- unsigned SymbolBinding) {
- typedef typename object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
- for (unsigned i = 0, e = Symbols.size(); i != e; ++i) {
- const ELFYAML::Symbol &Sym = Symbols[i];
+void ELFState<ELFT>::initELFHeader(Elf_Ehdr &Header) {
+ using namespace llvm::ELF;
+ 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;
+ bool IsLittleEndian = ELFT::TargetEndianness == support::little;
+ Header.e_ident[EI_DATA] = IsLittleEndian ? ELFDATA2LSB : ELFDATA2MSB;
+ Header.e_ident[EI_VERSION] = EV_CURRENT;
+ Header.e_ident[EI_OSABI] = Doc.Header.OSABI;
+ Header.e_ident[EI_ABIVERSION] = 0;
+ 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_flags = Doc.Header.Flags;
+ Header.e_ehsize = sizeof(Elf_Ehdr);
+ Header.e_shentsize = sizeof(Elf_Shdr);
+ // Immediately following the ELF header.
+ Header.e_shoff = sizeof(Header);
+ Header.e_shnum = getSectionCount();
+ Header.e_shstrndx = getDotShStrTabSecNo();
+}
+
+template <class ELFT>
+bool 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.
+ Elf_Shdr SHeader;
+ zero(SHeader);
+ SHeaders.push_back(SHeader);
+
+ for (const auto &Sec : Doc.Sections)
+ DotShStrtab.add(Sec->Name);
+ DotShStrtab.finalize(StringTableBuilder::ELF);
+
+ for (const auto &Sec : Doc.Sections) {
+ zero(SHeader);
+ SHeader.sh_name = DotShStrtab.getOffset(Sec->Name);
+ SHeader.sh_type = Sec->Type;
+ SHeader.sh_flags = Sec->Flags;
+ SHeader.sh_addr = Sec->Address;
+ SHeader.sh_addralign = Sec->AddressAlign;
+
+ if (!Sec->Link.empty()) {
+ unsigned Index;
+ if (SN2I.lookup(Sec->Link, Index)) {
+ errs() << "error: Unknown section referenced: '" << Sec->Link
+ << "' at YAML section '" << Sec->Name << "'.\n";
+ return false;
+ }
+ SHeader.sh_link = Index;
+ }
+
+ if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec.get()))
+ writeSectionContent(SHeader, *S, CBA);
+ else if (auto S = dyn_cast<ELFYAML::RelocationSection>(Sec.get())) {
+ if (S->Link.empty())
+ // For relocation section set link to .symtab by default.
+ SHeader.sh_link = getDotSymTabSecNo();
+
+ unsigned Index;
+ if (SN2I.lookup(S->Info, Index)) {
+ errs() << "error: Unknown section referenced: '" << S->Info
+ << "' at YAML section '" << S->Name << "'.\n";
+ return false;
+ }
+ SHeader.sh_info = Index;
+
+ if (!writeSectionContent(SHeader, *S, CBA))
+ return false;
+ } else if (auto S = dyn_cast<ELFYAML::Group>(Sec.get())) {
+ unsigned SymIdx;
+ if (SymN2I.lookup(S->Info, SymIdx)) {
+ errs() << "error: Unknown symbol referenced: '" << S->Info
+ << "' at YAML section '" << S->Name << "'.\n";
+ return false;
+ }
+ SHeader.sh_info = SymIdx;
+ if (!writeSectionContent(SHeader, *S, CBA))
+ return false;
+ } else if (auto S = dyn_cast<ELFYAML::MipsABIFlags>(Sec.get())) {
+ if (!writeSectionContent(SHeader, *S, CBA))
+ return false;
+ } else if (auto S = dyn_cast<ELFYAML::NoBitsSection>(Sec.get())) {
+ 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
+ llvm_unreachable("Unknown section type");
+
+ SHeaders.push_back(SHeader);
+ }
+ return true;
+}
+
+template <class ELFT>
+void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
+ ContiguousBlobAccumulator &CBA) {
+ zero(SHeader);
+ SHeader.sh_name = DotShStrtab.getOffset(".symtab");
+ SHeader.sh_type = ELF::SHT_SYMTAB;
+ SHeader.sh_link = getDotStrTabSecNo();
+ // One greater than symbol table index of the last local symbol.
+ SHeader.sh_info = Doc.Symbols.Local.size() + 1;
+ SHeader.sh_entsize = sizeof(Elf_Sym);
+
+ std::vector<Elf_Sym> Syms;
+ {
+ // Ensure STN_UNDEF is present
+ Elf_Sym Sym;
+ zero(Sym);
+ Syms.push_back(Sym);
+ }
+
+ // Add symbol names to .strtab.
+ for (const auto &Sym : Doc.Symbols.Local)
+ DotStrtab.add(Sym.Name);
+ for (const auto &Sym : Doc.Symbols.Global)
+ DotStrtab.add(Sym.Name);
+ for (const auto &Sym : Doc.Symbols.Weak)
+ DotStrtab.add(Sym.Name);
+ DotStrtab.finalize(StringTableBuilder::ELF);
+
+ addSymbols(Doc.Symbols.Local, Syms, ELF::STB_LOCAL);
+ addSymbols(Doc.Symbols.Global, Syms, ELF::STB_GLOBAL);
+ addSymbols(Doc.Symbols.Weak, Syms, ELF::STB_WEAK);
+
+ writeArrayData(
+ CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign),
+ makeArrayRef(Syms));
+ SHeader.sh_size = arrayDataSize(makeArrayRef(Syms));
+}
+
+template <class ELFT>
+void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
+ StringTableBuilder &STB,
+ ContiguousBlobAccumulator &CBA) {
+ zero(SHeader);
+ SHeader.sh_name = DotShStrtab.getOffset(Name);
+ SHeader.sh_type = ELF::SHT_STRTAB;
+ CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign)
+ << STB.data();
+ SHeader.sh_size = STB.data().size();
+ SHeader.sh_addralign = 1;
+}
+
+template <class ELFT>
+void ELFState<ELFT>::addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
+ std::vector<Elf_Sym> &Syms,
+ unsigned SymbolBinding) {
+ for (const auto &Sym : Symbols) {
Elf_Sym Symbol;
zero(Symbol);
if (!Sym.Name.empty())
- Symbol.st_name = State.getStringTable().addString(Sym.Name);
+ Symbol.st_name = DotStrtab.getOffset(Sym.Name);
Symbol.setBindingAndType(SymbolBinding, Sym.Type);
if (!Sym.Section.empty()) {
unsigned Index;
- if (State.getSN2I().lookupSection(Sym.Section, Index)) {
+ if (SN2I.lookup(Sym.Section, Index)) {
errs() << "error: Unknown section referenced: '" << Sym.Section
<< "' by YAML symbol " << Sym.Name << ".\n";
exit(1);
Symbol.st_shndx = Index;
} // else Symbol.st_shndex == SHN_UNDEF (== 0), since it was zero'd earlier.
Symbol.st_value = Sym.Value;
+ Symbol.st_other = Sym.Other;
Symbol.st_size = Sym.Size;
Syms.push_back(Symbol);
}
}
template <class ELFT>
-static void
-handleSymtabSectionHeader(const ELFYAML::LocalGlobalWeakSymbols &Symbols,
- ELFState<ELFT> &State,
- typename object::ELFFile<ELFT>::Elf_Shdr &SHeader) {
+void
+ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+ const ELFYAML::RawContentSection &Section,
+ ContiguousBlobAccumulator &CBA) {
+ assert(Section.Size >= Section.Content.binary_size() &&
+ "Section size and section content are inconsistent");
+ raw_ostream &OS =
+ CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+ Section.Content.writeAsBinary(OS);
+ for (auto i = Section.Content.binary_size(); i < Section.Size; ++i)
+ OS.write(0);
+ SHeader.sh_entsize = 0;
+ SHeader.sh_size = Section.Size;
+}
- typedef typename object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
- SHeader.sh_type = ELF::SHT_SYMTAB;
- SHeader.sh_link = State.getDotStrTabSecNo();
- // One greater than symbol table index of the last local symbol.
- SHeader.sh_info = Symbols.Local.size() + 1;
- SHeader.sh_entsize = sizeof(Elf_Sym);
+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);
+}
- std::vector<Elf_Sym> Syms;
- {
- // Ensure STN_UNDEF is present
- Elf_Sym Sym;
- zero(Sym);
- Syms.push_back(Sym);
+template <class ELFT>
+bool
+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();
+
+ auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+
+ for (const auto &Rel : Section.Relocations) {
+ unsigned SymIdx = 0;
+ // Some special relocation, R_ARM_v4BX for instance, does not have
+ // an external reference. So it ignores the return value of lookup()
+ // here.
+ SymN2I.lookup(Rel.Symbol, SymIdx);
+
+ 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));
+ }
}
- addSymbols(Symbols.Local, State, Syms, ELF::STB_LOCAL);
- addSymbols(Symbols.Global, State, Syms, ELF::STB_GLOBAL);
- addSymbols(Symbols.Weak, State, Syms, ELF::STB_WEAK);
+ return true;
+}
- ContiguousBlobAccumulator &CBA = State.getSectionContentAccum();
- writeArrayData(CBA.getOSAndAlignedOffset(SHeader.sh_offset),
- makeArrayRef(Syms));
- SHeader.sh_size = arrayDataSize(makeArrayRef(Syms));
+template <class ELFT>
+bool ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
+ const ELFYAML::Group &Section,
+ ContiguousBlobAccumulator &CBA) {
+ typedef typename object::ELFFile<ELFT>::Elf_Word Elf_Word;
+ assert(Section.Type == llvm::ELF::SHT_GROUP &&
+ "Section type is not SHT_GROUP");
+
+ SHeader.sh_entsize = sizeof(Elf_Word);
+ SHeader.sh_size = SHeader.sh_entsize * Section.Members.size();
+
+ auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+
+ for (auto member : Section.Members) {
+ Elf_Word SIdx;
+ unsigned int sectionIndex = 0;
+ if (member.sectionNameOrType == "GRP_COMDAT")
+ sectionIndex = llvm::ELF::GRP_COMDAT;
+ else if (SN2I.lookup(member.sectionNameOrType, sectionIndex)) {
+ errs() << "error: Unknown section referenced: '"
+ << member.sectionNameOrType << "' at YAML section' "
+ << Section.Name << "\n";
+ return false;
+ }
+ SIdx = sectionIndex;
+ OS.write((const char *)&SIdx, sizeof(SIdx));
+ }
+ return true;
}
template <class ELFT>
-static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
- using namespace llvm::ELF;
- typedef typename object::ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
- typedef typename object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
+bool 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));
+
+ return true;
+}
+
+template <class ELFT> bool ELFState<ELFT>::buildSectionIndex() {
+ SN2I.addName(".symtab", getDotSymTabSecNo());
+ SN2I.addName(".strtab", getDotStrTabSecNo());
+ SN2I.addName(".shstrtab", getDotShStrTabSecNo());
+
+ for (unsigned i = 0, e = Doc.Sections.size(); i != e; ++i) {
+ StringRef Name = Doc.Sections[i]->Name;
+ if (Name.empty())
+ continue;
+ // "+ 1" to take into account the SHT_NULL entry.
+ if (SN2I.addName(Name, i + 1)) {
+ errs() << "error: Repeated section name: '" << Name
+ << "' at YAML section number " << i << ".\n";
+ return false;
+ }
+ }
+ return true;
+}
+
+template <class ELFT>
+bool
+ELFState<ELFT>::buildSymbolIndex(std::size_t &StartIndex,
+ const std::vector<ELFYAML::Symbol> &Symbols) {
+ for (const auto &Sym : Symbols) {
+ ++StartIndex;
+ if (Sym.Name.empty())
+ continue;
+ if (SymN2I.addName(Sym.Name, StartIndex)) {
+ errs() << "error: Repeated symbol name: '" << Sym.Name << "'.\n";
+ return false;
+ }
+ }
+ return true;
+}
+
+template <class ELFT>
+int ELFState<ELFT>::writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
+ ELFState<ELFT> State(Doc);
+ if (!State.buildSectionIndex())
+ return 1;
- const ELFYAML::FileHeader &Hdr = Doc.Header;
+ std::size_t StartSymIndex = 0;
+ if (!State.buildSymbolIndex(StartSymIndex, Doc.Symbols.Local) ||
+ !State.buildSymbolIndex(StartSymIndex, Doc.Symbols.Global) ||
+ !State.buildSymbolIndex(StartSymIndex, Doc.Symbols.Weak))
+ return 1;
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;
- bool IsLittleEndian = ELFT::TargetEndianness == support::little;
- Header.e_ident[EI_DATA] = IsLittleEndian ? ELFDATA2LSB : ELFDATA2MSB;
- Header.e_ident[EI_VERSION] = EV_CURRENT;
- Header.e_ident[EI_OSABI] = Hdr.OSABI;
- Header.e_ident[EI_ABIVERSION] = 0;
- Header.e_type = Hdr.Type;
- Header.e_machine = Hdr.Machine;
- Header.e_version = EV_CURRENT;
- Header.e_entry = Hdr.Entry;
- Header.e_ehsize = sizeof(Elf_Ehdr);
+ State.initELFHeader(Header);
// TODO: Flesh out section header support.
// TODO: Program headers.
- Header.e_shentsize = sizeof(Elf_Shdr);
- // Immediately following the ELF header.
- Header.e_shoff = sizeof(Header);
- const std::vector<ELFYAML::Section> &Sections = Doc.Sections;
- // "+ 4" for
- // - SHT_NULL entry (placed first, i.e. 0'th entry)
- // - symbol table (.symtab) (placed third to last)
- // - string table (.strtab) (placed second to last)
- // - section header string table. (placed last)
- Header.e_shnum = Sections.size() + 4;
- // Place section header string table last.
- Header.e_shstrndx = Header.e_shnum - 1;
- const unsigned DotStrtabSecNo = Header.e_shnum - 2;
-
// XXX: This offset is tightly coupled with the order that we write
// things to `OS`.
const size_t SectionContentBeginOffset =
Header.e_ehsize + Header.e_shentsize * Header.e_shnum;
ContiguousBlobAccumulator CBA(SectionContentBeginOffset);
- SectionNameToIdxMap SN2I;
- for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
- StringRef Name = Sections[i].Name;
- if (Name.empty())
- continue;
- // "+ 1" to take into account the SHT_NULL entry.
- if (SN2I.addName(Name, i + 1)) {
- errs() << "error: Repeated section name: '" << Name
- << "' at YAML section number " << i << ".\n";
- return 1;
- }
- }
- ELFState<ELFT> State(Header, CBA, DotStrtabSecNo, SN2I);
+ // Doc might not contain .symtab, .strtab and .shstrtab sections,
+ // but we will emit them, so make sure to add them to ShStrTabSHeader.
+ State.DotShStrtab.add(".symtab");
+ State.DotShStrtab.add(".strtab");
+ State.DotShStrtab.add(".shstrtab");
- StringTableBuilder SHStrTab;
std::vector<Elf_Shdr> SHeaders;
- {
- // Ensure SHN_UNDEF entry is present. An all-zero section header is a
- // valid SHN_UNDEF entry since SHT_NULL == 0.
- Elf_Shdr SHdr;
- zero(SHdr);
- SHeaders.push_back(SHdr);
- }
- for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
- const ELFYAML::Section &Sec = Sections[i];
- Elf_Shdr SHeader;
- zero(SHeader);
- SHeader.sh_name = SHStrTab.addString(Sec.Name);
- SHeader.sh_type = Sec.Type;
- SHeader.sh_flags = Sec.Flags;
- SHeader.sh_addr = Sec.Address;
-
- Sec.Content.writeAsBinary(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
- SHeader.sh_size = Sec.Content.binary_size();
-
- if (!Sec.Link.empty()) {
- unsigned Index;
- if (SN2I.lookupSection(Sec.Link, Index)) {
- errs() << "error: Unknown section referenced: '" << Sec.Link
- << "' at YAML section number " << i << ".\n";
- return 1;
- }
- SHeader.sh_link = Index;
- }
- SHeader.sh_info = 0;
- SHeader.sh_addralign = Sec.AddressAlign;
- SHeader.sh_entsize = 0;
- SHeaders.push_back(SHeader);
- }
+ if(!State.initSectionHeaders(SHeaders, CBA))
+ return 1;
// .symtab section.
Elf_Shdr SymtabSHeader;
- zero(SymtabSHeader);
- SymtabSHeader.sh_name = SHStrTab.addString(StringRef(".symtab"));
- handleSymtabSectionHeader<ELFT>(Doc.Symbols, State, SymtabSHeader);
+ State.initSymtabSectionHeader(SymtabSHeader, CBA);
SHeaders.push_back(SymtabSHeader);
// .strtab string table header.
Elf_Shdr DotStrTabSHeader;
- zero(DotStrTabSHeader);
- DotStrTabSHeader.sh_name = SHStrTab.addString(StringRef(".strtab"));
- createStringTableSectionHeader(DotStrTabSHeader, State.getStringTable(), CBA);
+ State.initStrtabSectionHeader(DotStrTabSHeader, ".strtab", State.DotStrtab,
+ CBA);
SHeaders.push_back(DotStrTabSHeader);
- // Section header string table header.
- Elf_Shdr SHStrTabSHeader;
- zero(SHStrTabSHeader);
- createStringTableSectionHeader(SHStrTabSHeader, SHStrTab, CBA);
- SHeaders.push_back(SHStrTabSHeader);
+ // .shstrtab string table header.
+ Elf_Shdr ShStrTabSHeader;
+ State.initStrtabSectionHeader(ShStrTabSHeader, ".shstrtab", State.DotShStrtab,
+ CBA);
+ SHeaders.push_back(ShStrTabSHeader);
OS.write((const char *)&Header, sizeof(Header));
writeArrayData(OS, makeArrayRef(SHeaders));
return Doc.Header.Data == ELFYAML::ELF_ELFDATA(ELF::ELFDATA2LSB);
}
-int yaml2elf(llvm::raw_ostream &Out, llvm::MemoryBuffer *Buf) {
- yaml::Input YIn(Buf->getBuffer());
+int yaml2elf(yaml::Input &YIn, raw_ostream &Out) {
ELFYAML::Object Doc;
YIn >> Doc;
if (YIn.error()) {
return 1;
}
using object::ELFType;
- typedef ELFType<support::little, 8, true> LE64;
- typedef ELFType<support::big, 8, true> BE64;
- typedef ELFType<support::little, 4, false> LE32;
- typedef ELFType<support::big, 4, false> BE32;
+ typedef ELFType<support::little, true> LE64;
+ typedef ELFType<support::big, true> BE64;
+ typedef ELFType<support::little, false> LE32;
+ typedef ELFType<support::big, false> BE32;
if (is64Bit(Doc)) {
if (isLittleEndian(Doc))
- return writeELF<LE64>(outs(), Doc);
+ return ELFState<LE64>::writeELF(Out, Doc);
else
- return writeELF<BE64>(outs(), Doc);
+ return ELFState<BE64>::writeELF(Out, Doc);
} else {
if (isLittleEndian(Doc))
- return writeELF<LE32>(outs(), Doc);
+ return ELFState<LE32>::writeELF(Out, Doc);
else
- return writeELF<BE32>(outs(), Doc);
+ return ELFState<BE32>::writeELF(Out, Doc);
}
}