Replace `typedef A B` with `using B = A`. NFC.

[ruiu]

Summary

I did this using Perl.

lld/COFF/Driver.cpp

static std::string getOutputPath(StringRef Path) {
   return (S.substr(0, S.rfind('.')) + E).str();
 }
 
 // ErrorOr is not default constructible, so it cannot be used as the type
 // parameter of a future.
 // FIXME: We could open the file in createFutureForFile and avoid needing to
 // return an error here, but for the moment that would cost us a file descriptor
 // (a limited resource on Windows) for the duration that the future is pending.
-typedef std::pair<std::unique_ptr<MemoryBuffer>, std::error_code> MBErrPair;
+using MBErrPair = std::pair<std::unique_ptr<MemoryBuffer>, std::error_code>;
 
 // Create a std::future that opens and maps a file using the best strategy for
 // the host platform.
 static std::future<MBErrPair> createFutureForFile(std::string Path) {
 #if _WIN32
   // On Windows, file I/O is relatively slow so it is best to do this
   // asynchronously.
   auto Strategy = std::launch::async;

lld/COFF/MapFile.cpp

 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
 using namespace lld;
 using namespace lld::coff;
 
-typedef DenseMap<const SectionChunk *, SmallVector<DefinedRegular *, 4>>
-    SymbolMapTy;
+using SymbolMapTy =
+    DenseMap<const SectionChunk *, SmallVector<DefinedRegular *, 4>>;
 
 static const std::string Indent8 = "        ";          // 8 spaces
 static const std::string Indent16 = "                "; // 16 spaces
 
 // Print out the first three columns of a line.
 static void writeHeader(raw_ostream &OS, uint64_t Addr, uint64_t Size,
                         uint64_t Align) {
   OS << format("%08llx %08llx %5lld ", Addr, Size, Align);

lld/ELF/CallGraphSort.cpp

 // Maximum ammount the combined cluster density can be worse than the original
 // cluster to consider merging.
 constexpr int MAX_DENSITY_DEGRADATION = 8;
 
 // Maximum cluster size in bytes.
 constexpr uint64_t MAX_CLUSTER_SIZE = 1024 * 1024;
 } // end anonymous namespace
 
-typedef std::pair<const InputSectionBase *, const InputSectionBase *>
-    SectionPair;
+using SectionPair =
+    std::pair<const InputSectionBase *, const InputSectionBase *>;
 
 // Take the edge list in Config->CallGraphProfile, resolve symbol names to
 // Symbols, and generate a graph between InputSections with the provided
 // weights.
 CallGraphSort::CallGraphSort() {
   MapVector<SectionPair, uint64_t> &Profile = Config->CallGraphProfile;
   DenseMap<const InputSectionBase *, int> SecToCluster;
 

lld/ELF/InputFiles.h

protected:
   std::vector<Symbol *> Symbols;
 
 private:
   const Kind FileKind;
 };
 
 template <typename ELFT> class ELFFileBase : public InputFile {
 public:
-  typedef typename ELFT::Shdr Elf_Shdr;
-  typedef typename ELFT::Sym Elf_Sym;
-  typedef typename ELFT::Word Elf_Word;
-  typedef typename ELFT::SymRange Elf_Sym_Range;
+  using Elf_Shdr = typename ELFT::Shdr;
+  using Elf_Sym = typename ELFT::Sym;
+  using Elf_Word = typename ELFT::Word;
+  using Elf_Sym_Range = typename ELFT::SymRange;
 
   ELFFileBase(Kind K, MemoryBufferRef M);
   static bool classof(const InputFile *F) { return F->isElf(); }
 
   llvm::object::ELFFile<ELFT> getObj() const {
     return check(llvm::object::ELFFile<ELFT>::create(MB.getBuffer()));
   }
 
protected:
   uint32_t FirstGlobal = 0;
   ArrayRef<Elf_Word> SymtabSHNDX;
   StringRef StringTable;
   void initSymtab(ArrayRef<Elf_Shdr> Sections, const Elf_Shdr *Symtab);
 };
 
 // .o file.
 template <class ELFT> class ObjFile : public ELFFileBase<ELFT> {
-  typedef ELFFileBase<ELFT> Base;
-  typedef typename ELFT::Rel Elf_Rel;
-  typedef typename ELFT::Rela Elf_Rela;
-  typedef typename ELFT::Sym Elf_Sym;
-  typedef typename ELFT::Shdr Elf_Shdr;
-  typedef typename ELFT::Word Elf_Word;
-  typedef typename ELFT::CGProfile Elf_CGProfile;
+  using Base = ELFFileBase<ELFT>;
+  using Elf_Rel = typename ELFT::Rel;
+  using Elf_Rela = typename ELFT::Rela;
+  using Elf_Sym = typename ELFT::Sym;
+  using Elf_Shdr = typename ELFT::Shdr;
+  using Elf_Word = typename ELFT::Word;
+  using Elf_CGProfile = typename ELFT::CGProfile;
 
   StringRef getShtGroupSignature(ArrayRef<Elf_Shdr> Sections,
                                  const Elf_Shdr &Sec);
 
 public:
   static bool classof(const InputFile *F) { return F->kind() == Base::ObjKind; }
 
   ArrayRef<Symbol *> getLocalSymbols();
public:
   static bool classof(const InputFile *F) { return F->kind() == BitcodeKind; }
   template <class ELFT>
   void parse(llvm::DenseSet<llvm::CachedHashStringRef> &ComdatGroups);
   std::unique_ptr<llvm::lto::InputFile> Obj;
 };
 
 // .so file.
 template <class ELFT> class SharedFile : public ELFFileBase<ELFT> {
-  typedef ELFFileBase<ELFT> Base;
-  typedef typename ELFT::Dyn Elf_Dyn;
-  typedef typename ELFT::Shdr Elf_Shdr;
-  typedef typename ELFT::Sym Elf_Sym;
-  typedef typename ELFT::SymRange Elf_Sym_Range;
-  typedef typename ELFT::Verdef Elf_Verdef;
-  typedef typename ELFT::Versym Elf_Versym;
+  using Base = ELFFileBase<ELFT>;
+  using Elf_Dyn = typename ELFT::Dyn;
+  using Elf_Shdr = typename ELFT::Shdr;
+  using Elf_Sym = typename ELFT::Sym;
+  using Elf_Sym_Range = typename ELFT::SymRange;
+  using Elf_Verdef = typename ELFT::Verdef;
+  using Elf_Versym = typename ELFT::Versym;
 
   const Elf_Shdr *VersymSec = nullptr;
   const Elf_Shdr *VerdefSec = nullptr;
 
 public:
   std::vector<const Elf_Verdef *> Verdefs;
   std::vector<StringRef> DtNeeded;
   std::string SoName;

lld/ELF/InputSection.cpp

else
     return cast<OutputSection>(this);
   return Sec ? Sec->getParent() : nullptr;
 }
 
 // When a section is compressed, `RawData` consists with a header followed
 // by zlib-compressed data. This function parses a header to initialize
 // `UncompressedSize` member and remove the header from `RawData`.
 void InputSectionBase::parseCompressedHeader() {
-  typedef typename ELF64LE::Chdr Chdr64;
-  typedef typename ELF32LE::Chdr Chdr32;
+  using Chdr64 = typename ELF64LE::Chdr;
+  using Chdr32 = typename ELF32LE::Chdr;
 
   // Old-style header
   if (Name.startswith(".zdebug")) {
     if (!toStringRef(RawData).startswith("ZLIB")) {
       error(toString(this) + ": corrupted compressed section header");
       return;
     }
     RawData = RawData.slice(4);

 
 OutputSection *InputSection::getParent() const {
   return cast_or_null<OutputSection>(Parent);
 }
 
 // Copy SHT_GROUP section contents. Used only for the -r option.
 template <class ELFT> void InputSection::copyShtGroup(uint8_t *Buf) {
   // ELFT::Word is the 32-bit integral type in the target endianness.
-  typedef typename ELFT::Word u32;
+  using u32 = typename ELFT::Word;
   ArrayRef<u32> From = getDataAs<u32>();
   auto *To = reinterpret_cast<u32 *>(Buf);
 
   // The first entry is not a section number but a flag.
   *To++ = From[0];
 
   // Adjust section numbers because section numbers in an input object
   // files are different in the output.

lld/ELF/LinkerScript.h

struct ExprValue {
 
   // Original source location. Used for error messages.
   std::string Loc;
 };
 
 // This represents an expression in the linker script.
 // ScriptParser::readExpr reads an expression and returns an Expr.
 // Later, we evaluate the expression by calling the function.
-typedef std::function<ExprValue()> Expr;
+using Expr = std::function<ExprValue()>;
 
 // This enum is used to implement linker script SECTIONS command.
 // https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS
 enum SectionsCommandKind {
   AssignmentKind, // . = expr or <sym> = expr
   OutputSectionKind,
   InputSectionKind,
   ByteKind    // BYTE(expr), SHORT(expr), LONG(expr) or QUAD(expr)

lld/ELF/MapFile.cpp

 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
 using namespace lld;
 using namespace lld::elf;
 
-typedef DenseMap<const SectionBase *, SmallVector<Defined *, 4>> SymbolMapTy;
+using SymbolMapTy = DenseMap<const SectionBase *, SmallVector<Defined *, 4>>;
 
 static const std::string Indent8 = "        ";          // 8 spaces
 static const std::string Indent16 = "                "; // 16 spaces
 
 // Print out the first three columns of a line.
 static void writeHeader(raw_ostream &OS, uint64_t VMA, uint64_t LMA,
                         uint64_t Size, uint64_t Align) {
   if (Config->Is64)

lld/ELF/OutputSections.cpp

if (SectionCommands.empty() ||
       SectionCommands.push_back(make<InputSectionDescription>(""));
     auto *ISD = cast<InputSectionDescription>(SectionCommands.back());
     ISD->Sections.push_back(IS);
   }
 }
 
 static void sortByOrder(MutableArrayRef<InputSection *> In,
                         llvm::function_ref<int(InputSectionBase *S)> Order) {
-  typedef std::pair<int, InputSection *> Pair;
+  using Pair = std::pair<int, InputSection *>;
   auto Comp = [](const Pair &A, const Pair &B) { return A.first < B.first; };
 
   std::vector<Pair> V;
   for (InputSection *S : In)
     V.push_back({Order(S), S});
   std::stable_sort(V.begin(), V.end(), Comp);
 
   for (size_t I = 0; I < V.size(); ++I)
static void fill(uint8_t *Buf, size_t Size,
   size_t I = 0;
   for (; I + 4 < Size; I += 4)
     memcpy(Buf + I, Filler.data(), 4);
   memcpy(Buf + I, Filler.data(), Size - I);
 }
 
 // Compress section contents if this section contains debug info.
 template <class ELFT> void OutputSection::maybeCompress() {
-  typedef typename ELFT::Chdr Elf_Chdr;
+  using Elf_Chdr = typename ELFT::Chdr;
 
   // Compress only DWARF debug sections.
   if (!Config->CompressDebugSections || (Flags & SHF_ALLOC) ||
       !Name.startswith(".debug_"))
     return;
 
   // Create a section header.
   ZDebugHeader.resize(sizeof(Elf_Chdr));

lld/ELF/Relocations.h

 namespace elf {
 class Symbol;
 class InputSection;
 class InputSectionBase;
 class OutputSection;
 class SectionBase;
 
 // Represents a relocation type, such as R_X86_64_PC32 or R_ARM_THM_CALL.
-typedef uint32_t RelType;
+using RelType = uint32_t;
 
 // List of target-independent relocation types. Relocations read
 // from files are converted to these types so that the main code
 // doesn't have to know about architecture-specific details.
 enum RelExpr {
   R_ABS,
   R_ADDEND,
   R_GOT,

lld/ELF/Relocations.cpp

case R_PLT:
     return R_ABS;
   default:
     return Expr;
   }
 }
 
 // Returns true if a given shared symbol is in a read-only segment in a DSO.
 template <class ELFT> static bool isReadOnly(SharedSymbol &SS) {
-  typedef typename ELFT::Phdr Elf_Phdr;
+  using Elf_Phdr = typename ELFT::Phdr;
 
   // Determine if the symbol is read-only by scanning the DSO's program headers.
   const SharedFile<ELFT> &File = SS.getFile<ELFT>();
   for (const Elf_Phdr &Phdr : check(File.getObj().program_headers()))
     if ((Phdr.p_type == ELF::PT_LOAD || Phdr.p_type == ELF::PT_GNU_RELRO) &&
         !(Phdr.p_flags & ELF::PF_W) && SS.Value >= Phdr.p_vaddr &&
         SS.Value < Phdr.p_vaddr + Phdr.p_memsz)
       return true;
   return false;
 }
 
 // Returns symbols at the same offset as a given symbol, including SS itself.
 //
 // If two or more symbols are at the same offset, and at least one of
 // them are copied by a copy relocation, all of them need to be copied.
 // Otherwise, they would refer to different places at runtime.
 template <class ELFT>
 static SmallSet<SharedSymbol *, 4> getSymbolsAt(SharedSymbol &SS) {
-  typedef typename ELFT::Sym Elf_Sym;
+  using Elf_Sym = typename ELFT::Sym;
 
   SharedFile<ELFT> &File = SS.getFile<ELFT>();
 
   SmallSet<SharedSymbol *, 4> Ret;
   for (const Elf_Sym &S : File.getGlobalELFSyms()) {
     if (S.st_shndx == SHN_UNDEF || S.st_shndx == SHN_ABS ||
         S.getType() == STT_TLS || S.st_value != SS.Value)
       continue;

lld/ELF/SyntheticSections.h

private:
   // https://dmz-portal.mips.com/wiki/MIPS_Multi_GOT
 
   // Number of "Header" entries.
   static const unsigned HeaderEntriesNum = 2;
 
   uint64_t Size = 0;
 
   // Symbol and addend.
-  typedef std::pair<Symbol *, int64_t> GotEntry;
+  using GotEntry = std::pair<Symbol *, int64_t>;
 
   struct FileGot {
     InputFile *File = nullptr;
     size_t StartIndex = 0;
 
     struct PageBlock {
       size_t FirstIndex;
       size_t Count;
private:
   // load address. This means we need to write the symbol virtual address
   // plus the original addend as the final relocation addend.
   bool UseSymVA;
   int64_t Addend;
   const OutputSection *OutputSec;
 };
 
 template <class ELFT> class DynamicSection final : public SyntheticSection {
-  typedef typename ELFT::Dyn Elf_Dyn;
-  typedef typename ELFT::Rel Elf_Rel;
-  typedef typename ELFT::Rela Elf_Rela;
-  typedef typename ELFT::Relr Elf_Relr;
-  typedef typename ELFT::Shdr Elf_Shdr;
-  typedef typename ELFT::Sym Elf_Sym;
+  using Elf_Dyn = typename ELFT::Dyn;
+  using Elf_Rel = typename ELFT::Rel;
+  using Elf_Rela = typename ELFT::Rela;
+  using Elf_Relr = typename ELFT::Relr;
+  using Elf_Shdr = typename ELFT::Shdr;
+  using Elf_Sym = typename ELFT::Sym;
 
   // finalizeContents() fills this vector with the section contents.
   std::vector<std::pair<int32_t, std::function<uint64_t()>>> Entries;
 
 public:
   DynamicSection();
   void finalizeContents() override;
   void writeTo(uint8_t *Buf) override;

 
 protected:
   std::vector<DynamicReloc> Relocs;
   size_t NumRelativeRelocs = 0;
 };
 
 template <class ELFT>
 class RelocationSection final : public RelocationBaseSection {
-  typedef typename ELFT::Rel Elf_Rel;
-  typedef typename ELFT::Rela Elf_Rela;
+  using Elf_Rel = typename ELFT::Rel;
+  using Elf_Rela = typename ELFT::Rela;
 
 public:
   RelocationSection(StringRef Name, bool Sort);
   void writeTo(uint8_t *Buf) override;
 
 private:
   bool Sort;
 };
 
 template <class ELFT>
 class AndroidPackedRelocationSection final : public RelocationBaseSection {
-  typedef typename ELFT::Rel Elf_Rel;
-  typedef typename ELFT::Rela Elf_Rela;
+  using Elf_Rel = typename ELFT::Rel;
+  using Elf_Rela = typename ELFT::Rela;
 
 public:
   AndroidPackedRelocationSection(StringRef Name);
 
   bool updateAllocSize() override;
   size_t getSize() const override { return RelocData.size(); }
   void writeTo(uint8_t *Buf) override {
     memcpy(Buf, RelocData.data(), RelocData.size());
public:
   std::vector<RelativeReloc> Relocs;
 };
 
 // RelrSection is used to encode offsets for relative relocations.
 // Proposal for adding SHT_RELR sections to generic-abi is here:
 //   https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg
 // For more details, see the comment in RelrSection::updateAllocSize().
 template <class ELFT> class RelrSection final : public RelrBaseSection {
-  typedef typename ELFT::Relr Elf_Relr;
+  using Elf_Relr = typename ELFT::Relr;
 
 public:
   RelrSection();
 
   bool updateAllocSize() override;
   size_t getSize() const override { return RelrRelocs.size() * this->Entsize; }
   void writeTo(uint8_t *Buf) override {
     memcpy(Buf, RelrRelocs.data(), getSize());
protected:
 
   llvm::once_flag OnceFlag;
   llvm::DenseMap<Symbol *, size_t> SymbolIndexMap;
   llvm::DenseMap<OutputSection *, size_t> SectionIndexMap;
 };
 
 template <class ELFT>
 class SymbolTableSection final : public SymbolTableBaseSection {
-  typedef typename ELFT::Sym Elf_Sym;
+  using Elf_Sym = typename ELFT::Sym;
 
 public:
   SymbolTableSection(StringTableSection &StrTabSec);
   void writeTo(uint8_t *Buf) override;
 };
 
 class SymtabShndxSection final : public SyntheticSection {
 public:

 
 // The .gnu.version_r section defines the version identifiers used by
 // .gnu.version. It contains a linked list of Elf_Verneed data structures. Each
 // Elf_Verneed specifies the version requirements for a single DSO, and contains
 // a reference to a linked list of Elf_Vernaux data structures which define the
 // mapping from version identifiers to version names.
 template <class ELFT>
 class VersionNeedSection final : public VersionNeedBaseSection {
-  typedef typename ELFT::Verneed Elf_Verneed;
-  typedef typename ELFT::Vernaux Elf_Vernaux;
+  using Elf_Verneed = typename ELFT::Verneed;
+  using Elf_Vernaux = typename ELFT::Vernaux;
 
   // A vector of shared files that need Elf_Verneed data structures and the
   // string table offsets of their sonames.
   std::vector<std::pair<SharedFile<ELFT> *, size_t>> Needed;
 
 public:
   void addSymbol(Symbol *Sym) override;
   void finalizeContents() override;
private:
   constexpr static size_t NumShards = 32;
   std::vector<llvm::StringTableBuilder> Shards;
   size_t ShardOffsets[NumShards];
 };
 
 // .MIPS.abiflags section.
 template <class ELFT>
 class MipsAbiFlagsSection final : public SyntheticSection {
-  typedef llvm::object::Elf_Mips_ABIFlags<ELFT> Elf_Mips_ABIFlags;
+  using Elf_Mips_ABIFlags = llvm::object::Elf_Mips_ABIFlags<ELFT>;
 
 public:
   static MipsAbiFlagsSection *create();
 
   MipsAbiFlagsSection(Elf_Mips_ABIFlags Flags);
   size_t getSize() const override { return sizeof(Elf_Mips_ABIFlags); }
   void writeTo(uint8_t *Buf) override;
 
 private:
   Elf_Mips_ABIFlags Flags;
 };
 
 // .MIPS.options section.
 template <class ELFT> class MipsOptionsSection final : public SyntheticSection {
-  typedef llvm::object::Elf_Mips_Options<ELFT> Elf_Mips_Options;
-  typedef llvm::object::Elf_Mips_RegInfo<ELFT> Elf_Mips_RegInfo;
+  using Elf_Mips_Options = llvm::object::Elf_Mips_Options<ELFT>;
+  using Elf_Mips_RegInfo = llvm::object::Elf_Mips_RegInfo<ELFT>;
 
 public:
   static MipsOptionsSection *create();
 
   MipsOptionsSection(Elf_Mips_RegInfo Reginfo);
   void writeTo(uint8_t *Buf) override;
 
   size_t getSize() const override {
     return sizeof(Elf_Mips_Options) + sizeof(Elf_Mips_RegInfo);
   }
 
 private:
   Elf_Mips_RegInfo Reginfo;
 };
 
 // MIPS .reginfo section.
 template <class ELFT> class MipsReginfoSection final : public SyntheticSection {
-  typedef llvm::object::Elf_Mips_RegInfo<ELFT> Elf_Mips_RegInfo;
+  using Elf_Mips_RegInfo = llvm::object::Elf_Mips_RegInfo<ELFT>;
 
 public:
   static MipsReginfoSection *create();
 
   MipsReginfoSection(Elf_Mips_RegInfo Reginfo);
   size_t getSize() const override { return sizeof(Elf_Mips_RegInfo); }
   void writeTo(uint8_t *Buf) override;
 

lld/ELF/SyntheticSections.cpp

readPubNamesAndTypes(const LLDDwarfObj<ELFT> &Obj,
   return Ret;
 }
 
 // Create a list of symbols from a given list of symbol names and types
 // by uniquifying them by name.
 static std::vector<GdbIndexSection::GdbSymbol>
 createSymbols(ArrayRef<std::vector<GdbIndexSection::NameAttrEntry>> NameAttrs,
               const std::vector<GdbIndexSection::GdbChunk> &Chunks) {
-  typedef GdbIndexSection::GdbSymbol GdbSymbol;
-  typedef GdbIndexSection::NameAttrEntry NameAttrEntry;
+  using GdbSymbol = GdbIndexSection::GdbSymbol;
+  using NameAttrEntry = GdbIndexSection::NameAttrEntry;
 
   // For each chunk, compute the number of compilation units preceding it.
   uint32_t CuIdx = 0;
   std::vector<uint32_t> CuIdxs(Chunks.size());
   for (uint32_t I = 0, E = Chunks.size(); I != E; ++I) {
     CuIdxs[I] = CuIdx;
     CuIdx += Chunks[I].CompilationUnits.size();
   }

 }
 
 // .eh_frame_hdr contains a binary search table of pointers to FDEs.
 // Each entry of the search table consists of two values,
 // the starting PC from where FDEs covers, and the FDE's address.
 // It is sorted by PC.
 void EhFrameHeader::write() {
   uint8_t *Buf = Out::BufferStart + getParent()->Offset + OutSecOff;
-  typedef EhFrameSection::FdeData FdeData;
+  using FdeData = EhFrameSection::FdeData;
 
   std::vector<FdeData> Fdes = In.EhFrame->getFdeData();
 
   Buf[0] = 1;
   Buf[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4;
   Buf[2] = DW_EH_PE_udata4;
   Buf[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4;
   write32(Buf + 4, In.EhFrame->getParent()->Addr - this->getVA() - 4);

lld/ELF/Writer.cpp

 using namespace lld;
 using namespace lld::elf;
 
 namespace {
 // The writer writes a SymbolTable result to a file.
 template <class ELFT> class Writer {
 public:
   Writer() : Buffer(errorHandler().OutputBuffer) {}
-  typedef typename ELFT::Shdr Elf_Shdr;
-  typedef typename ELFT::Ehdr Elf_Ehdr;
-  typedef typename ELFT::Phdr Elf_Phdr;
+  using Elf_Shdr = typename ELFT::Shdr;
+  using Elf_Ehdr = typename ELFT::Ehdr;
+  using Elf_Phdr = typename ELFT::Phdr;
 
   void run();
 
 private:
   void copyLocalSymbols();
   void addSectionSymbols();
   void forEachRelSec(llvm::function_ref<void(InputSectionBase &)> Fn);
   void sortSections();