ELF: De-template SharedFile. NFCI.

[pcc]

Summary

Depends on D60304

[ruiu]

Nice!

lld/ELF/InputFiles.cpp

1020–1021

Even though this function is not logically complicated, I'd split it into smaller pieces just because it's a bit too long.

[pcc]

• Split out code into functions

[pcc]

lld/ELF/InputFiles.cpp

1020–1021

Okay, I split out a couple of functions that don't need a lot of state from the parse() function. It seemed awkward to split out more than that because of the amount of state that would need to be passed in, but maybe you can give it a try.

[ruiu]

LGTM

lld/ELF/Driver.cpp

template <class ELFT> static void handleLibcall(StringRef Name) {
   if (isBitcode(MB))
     Symtab->fetchLazy<ELFT>(Sym);
 }
 
 // If all references to a DSO happen to be weak, the DSO is not added
 // to DT_NEEDED. If that happens, we need to eliminate shared symbols
 // created from the DSO. Otherwise, they become dangling references
 // that point to a non-existent DSO.
-template <class ELFT> static void demoteSharedSymbols() {
+static void demoteSharedSymbols() {
   for (Symbol *Sym : Symtab->getSymbols()) {
     if (auto *S = dyn_cast<SharedSymbol>(Sym)) {
-      if (!S->getFile<ELFT>().IsNeeded) {
+      if (!S->getFile().IsNeeded) {
         bool Used = S->Used;
         replaceSymbol<Undefined>(S, nullptr, S->getName(), STB_WEAK, S->StOther,
                                  S->Type);
         S->Used = Used;
       }
     }
   }
 }
template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
   // before mergeSections because the .comment section is a mergeable section.
   if (!Config->Relocatable)
     InputSections.push_back(createCommentSection());
 
   // Do size optimizations: garbage collection, merging of SHF_MERGE sections
   // and identical code folding.
   splitSections<ELFT>();
   markLive<ELFT>();
-  demoteSharedSymbols<ELFT>();
+  demoteSharedSymbols();
   mergeSections();
   if (Config->ICF != ICFLevel::None) {
     findKeepUniqueSections<ELFT>(Args);
     doIcf<ELFT>();
   }
 
   // Read the callgraph now that we know what was gced or icfed
   if (Config->CallGraphProfileSort) {

lld/ELF/InputFiles.h

BitcodeFile(MemoryBufferRef M, StringRef ArchiveName,
               uint64_t OffsetInArchive);
   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 {
-  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;
-
+class SharedFile : public ELFFileBase {
 public:
-  std::vector<const Elf_Verdef *> Verdefs;
+  // This is actually a vector of Elf_Verdef pointers.
+  std::vector<const void *> Verdefs;
   std::vector<StringRef> DtNeeded;
   std::string SoName;
 
   static bool classof(const InputFile *F) { return F->kind() == SharedKind; }
 
   SharedFile(MemoryBufferRef M, StringRef DefaultSoName);
 
-  void parseDynamic();
-  void parseRest();
-  uint32_t getAlignment(ArrayRef<Elf_Shdr> Sections, const Elf_Sym &Sym);
-  std::vector<const Elf_Verdef *> parseVerdefs();
-  std::vector<uint32_t> parseVersyms();
+  template <typename ELFT> void parse();
 
   struct NeededVer {
     // The string table offset of the version name in the output file.
     size_t StrTab;
 
     // The version identifier for this version name.
     uint16_t Index;
   };
 
   // Mapping from Elf_Verdef data structures to information about Elf_Vernaux
   // data structures in the output file.
-  std::map<const Elf_Verdef *, NeededVer> VerdefMap;
+  std::map<const void *, NeededVer> VerdefMap;
 
   // Used for --no-allow-shlib-undefined.
   bool AllNeededIsKnown;
 
   // Used for --as-needed
   bool IsNeeded;
 };
 

 }
 
 std::string replaceThinLTOSuffix(StringRef Path);
 
 extern std::vector<BinaryFile *> BinaryFiles;
 extern std::vector<BitcodeFile *> BitcodeFiles;
 extern std::vector<LazyObjFile *> LazyObjFiles;
 extern std::vector<InputFile *> ObjectFiles;
-extern std::vector<InputFile *> SharedFiles;
+extern std::vector<SharedFile *> SharedFiles;
 
 } // namespace elf
 } // namespace lld
 
 #endif

lld/ELF/InputFiles.cpp

 using namespace lld::elf;
 
 bool InputFile::IsInGroup;
 uint32_t InputFile::NextGroupId;
 std::vector<BinaryFile *> elf::BinaryFiles;
 std::vector<BitcodeFile *> elf::BitcodeFiles;
 std::vector<LazyObjFile *> elf::LazyObjFiles;
 std::vector<InputFile *> elf::ObjectFiles;
-std::vector<InputFile *> elf::SharedFiles;
+std::vector<SharedFile *> elf::SharedFiles;
 
 std::unique_ptr<TarWriter> elf::Tar;
 
 InputFile::InputFile(Kind K, MemoryBufferRef M)
     : MB(M), GroupId(NextGroupId), FileKind(K) {
   // All files within the same --{start,end}-group get the same group ID.
   // Otherwise, a new file will get a new group ID.
   if (!IsInGroup)
if (Tar && C.getParent()->isThin())
     Tar->append(relativeToRoot(CHECK(C.getFullName(), this)), MB.getBuffer());
 
   InputFile *File = createObjectFile(
       MB, getName(), C.getParent()->isThin() ? 0 : C.getChildOffset());
   File->GroupId = GroupId;
   return File;
 }
 
-template <class ELFT>
-SharedFile<ELFT>::SharedFile(MemoryBufferRef M, StringRef DefaultSoName)
+SharedFile::SharedFile(MemoryBufferRef M, StringRef DefaultSoName)
     : ELFFileBase(SharedKind, M), SoName(DefaultSoName),
-      IsNeeded(!Config->AsNeeded) {
-  parseHeader<ELFT>();
+      IsNeeded(!Config->AsNeeded) {}
+
+// Parse the version definitions in the object file if present, and return a
+// vector whose nth element contains a pointer to the Elf_Verdef for version
+// identifier n. Version identifiers that are not definitions map to nullptr.
+template <typename ELFT>
+static std::vector<const void *> parseVerdefs(const uint8_t *Base,
+                                              const typename ELFT::Shdr *Sec) {
+  if (!Sec)
+    return {};
+
+  // We cannot determine the largest verdef identifier without inspecting
+  // every Elf_Verdef, but both bfd and gold assign verdef identifiers
+  // sequentially starting from 1, so we predict that the largest identifier
+  // will be VerdefCount.
+  unsigned VerdefCount = Sec->sh_info;
+  std::vector<const void *> Verdefs(VerdefCount + 1);
+
+  // Build the Verdefs array by following the chain of Elf_Verdef objects
+  // from the start of the .gnu.version_d section.
+  const uint8_t *Verdef = Base + Sec->sh_offset;
+  for (unsigned I = 0; I != VerdefCount; ++I) {
+    auto *CurVerdef = reinterpret_cast<const typename ELFT::Verdef *>(Verdef);
+    Verdef += CurVerdef->vd_next;
+    unsigned VerdefIndex = CurVerdef->vd_ndx;
+    Verdefs.resize(VerdefIndex + 1);
+    Verdefs[VerdefIndex] = CurVerdef;
+  }
+  return Verdefs;
 }
 
-// Partially parse the shared object file so that we can call
-// getSoName on this object.
-template <class ELFT> void SharedFile<ELFT>::parseDynamic() {
+// We do not usually care about alignments of data in shared object
+// files because the loader takes care of it. However, if we promote a
+// DSO symbol to point to .bss due to copy relocation, we need to keep
+// the original alignment requirements. We infer it in this function.
+template <typename ELFT>
+static uint64_t getAlignment(ArrayRef<typename ELFT::Shdr> Sections,
+                             const typename ELFT::Sym &Sym) {
+  uint64_t Ret = UINT64_MAX;
+  if (Sym.st_value)
+    Ret = 1ULL << countTrailingZeros((uint64_t)Sym.st_value);
+  if (0 < Sym.st_shndx && Sym.st_shndx < Sections.size())
+    Ret = std::min<uint64_t>(Ret, Sections[Sym.st_shndx].sh_addralign);
+  return (Ret > UINT32_MAX) ? 0 : Ret;
+}
+
+// Fully parse the shared object file.
+//
+// This function parses symbol versions. If a DSO has version information,
+// the file has a ".gnu.version_d" section which contains symbol version
+// definitions. Each symbol is associated to one version through a table in
+// ".gnu.version" section. That table is a parallel array for the symbol
+// table, and each table entry contains an index in ".gnu.version_d".
+//
+// The special index 0 is reserved for VERF_NDX_LOCAL and 1 is for
+// VER_NDX_GLOBAL. There's no table entry for these special versions in
+// ".gnu.version_d".
+//
+// The file format for symbol versioning is perhaps a bit more complicated
+// than necessary, but you can easily understand the code if you wrap your
+// head around the data structure described above.
+template <class ELFT> void SharedFile::parse() {
+  using Elf_Dyn = typename ELFT::Dyn;
+  using Elf_Shdr = typename ELFT::Shdr;
+  using Elf_Sym = typename ELFT::Sym;
+  using Elf_Verdef = typename ELFT::Verdef;
+  using Elf_Versym = typename ELFT::Versym;
+
   ArrayRef<Elf_Dyn> DynamicTags;
   const ELFFile<ELFT> Obj = this->getObj<ELFT>();
   ArrayRef<Elf_Shdr> Sections = CHECK(Obj.sections(), this);
 
+  const Elf_Shdr *VersymSec = nullptr;
+  const Elf_Shdr *VerdefSec = nullptr;
+
   // Search for .dynsym, .dynamic, .symtab, .gnu.version and .gnu.version_d.
   for (const Elf_Shdr &Sec : Sections) {
     switch (Sec.sh_type) {
     default:
       continue;
     case SHT_DYNSYM:
       this->initSymtab<ELFT>(Sections, &Sec);
       break;
     case SHT_DYNAMIC:
       DynamicTags =
           CHECK(Obj.template getSectionContentsAsArray<Elf_Dyn>(&Sec), this);
       break;
     case SHT_GNU_versym:
-      this->VersymSec = &Sec;
+      VersymSec = &Sec;
       break;
     case SHT_GNU_verdef:
-      this->VerdefSec = &Sec;
+      VerdefSec = &Sec;
       break;
     }
   }
 
-  if (this->VersymSec && this->getELFSyms<ELFT>().empty())
+  if (VersymSec && this->getELFSyms<ELFT>().empty()) {
     error("SHT_GNU_versym should be associated with symbol table");
+    return;
+  }
 
   // Search for a DT_SONAME tag to initialize this->SoName.
   for (const Elf_Dyn &Dyn : DynamicTags) {
     if (Dyn.d_tag == DT_NEEDED) {
       uint64_t Val = Dyn.getVal();
       if (Val >= this->StringTable.size())
         fatal(toString(this) + ": invalid DT_NEEDED entry");
       DtNeeded.push_back(this->StringTable.data() + Val);
     } else if (Dyn.d_tag == DT_SONAME) {
       uint64_t Val = Dyn.getVal();
       if (Val >= this->StringTable.size())
         fatal(toString(this) + ": invalid DT_SONAME entry");
       SoName = this->StringTable.data() + Val;
     }
   }
-}
-
-// Parses ".gnu.version" section which is a parallel array for the symbol table.
-// If a given file doesn't have ".gnu.version" section, returns VER_NDX_GLOBAL.
-template <class ELFT> std::vector<uint32_t> SharedFile<ELFT>::parseVersyms() {
-  size_t Size = this->getELFSyms<ELFT>().size() - this->FirstGlobal;
-  if (!VersymSec)
-    return std::vector<uint32_t>(Size, VER_NDX_GLOBAL);
-
-  const char *Base = this->MB.getBuffer().data();
-  const Elf_Versym *Versym =
-      reinterpret_cast<const Elf_Versym *>(Base + VersymSec->sh_offset) +
-      this->FirstGlobal;
-
-  std::vector<uint32_t> Ret(Size);
-  for (size_t I = 0; I < Size; ++I)
-    Ret[I] = Versym[I].vs_index;
-  return Ret;
-}
 
-// Parse the version definitions in the object file if present. Returns a vector
-// whose nth element contains a pointer to the Elf_Verdef for version identifier
-// n. Version identifiers that are not definitions map to nullptr.
-template <class ELFT>
-std::vector<const typename ELFT::Verdef *> SharedFile<ELFT>::parseVerdefs() {
-  if (!VerdefSec)
-    return {};
+  // DSOs are uniquified not by filename but by soname.
+  DenseMap<StringRef, SharedFile *>::iterator It;
+  bool WasInserted;
+  std::tie(It, WasInserted) = Symtab->SoNames.try_emplace(SoName, this);
+
+  // If a DSO appears more than once on the command line with and without
+  // --as-needed, --no-as-needed takes precedence over --as-needed because a
+  // user can add an extra DSO with --no-as-needed to force it to be added to
+  // the dependency list.
+  It->second->IsNeeded |= IsNeeded;
+  if (!WasInserted)
+    return;
 
-  // We cannot determine the largest verdef identifier without inspecting
-  // every Elf_Verdef, but both bfd and gold assign verdef identifiers
-  // sequentially starting from 1, so we predict that the largest identifier
-  // will be VerdefCount.
-  unsigned VerdefCount = VerdefSec->sh_info;
-  std::vector<const Elf_Verdef *> Verdefs(VerdefCount + 1);
+  SharedFiles.push_back(this);
 
-  // Build the Verdefs array by following the chain of Elf_Verdef objects
-  // from the start of the .gnu.version_d section.
-  const char *Base = this->MB.getBuffer().data();
-  const char *Verdef = Base + VerdefSec->sh_offset;
-  for (unsigned I = 0; I != VerdefCount; ++I) {
-    auto *CurVerdef = reinterpret_cast<const Elf_Verdef *>(Verdef);
-    Verdef += CurVerdef->vd_next;
-    unsigned VerdefIndex = CurVerdef->vd_ndx;
-    Verdefs.resize(VerdefIndex + 1);
-    Verdefs[VerdefIndex] = CurVerdef;
-  }
-
-  return Verdefs;
-}
+  Verdefs = parseVerdefs<ELFT>(Obj.base(), VerdefSec);
 
-// We do not usually care about alignments of data in shared object
-// files because the loader takes care of it. However, if we promote a
-// DSO symbol to point to .bss due to copy relocation, we need to keep
-// the original alignment requirements. We infer it in this function.
-template <class ELFT>
-uint32_t SharedFile<ELFT>::getAlignment(ArrayRef<Elf_Shdr> Sections,
-                                        const Elf_Sym &Sym) {
-  uint64_t Ret = UINT64_MAX;
-  if (Sym.st_value)
-    Ret = 1ULL << countTrailingZeros((uint64_t)Sym.st_value);
-  if (0 < Sym.st_shndx && Sym.st_shndx < Sections.size())
-    Ret = std::min<uint64_t>(Ret, Sections[Sym.st_shndx].sh_addralign);
-  return (Ret > UINT32_MAX) ? 0 : Ret;
+  // Parse ".gnu.version" section which is a parallel array for the symbol
+  // table. If a given file doesn't have a ".gnu.version" section, we use
+  // VER_NDX_GLOBAL.
+  size_t Size = this->getELFSyms<ELFT>().size() - this->FirstGlobal;
+  std::vector<uint32_t> Versyms(Size, VER_NDX_GLOBAL);
+  if (VersymSec) {
+    ArrayRef<Elf_Versym> Versym =
+        CHECK(Obj.template getSectionContentsAsArray<Elf_Versym>(VersymSec),
+              this)
+            .slice(FirstGlobal);
+    for (size_t I = 0; I < Size; ++I)
+      Versyms[I] = Versym[I].vs_index;
   }
 
-// Fully parse the shared object file. This must be called after parseDynamic().
-//
-// This function parses symbol versions. If a DSO has version information,
-// the file has a ".gnu.version_d" section which contains symbol version
-// definitions. Each symbol is associated to one version through a table in
-// ".gnu.version" section. That table is a parallel array for the symbol
-// table, and each table entry contains an index in ".gnu.version_d".
-//
-// The special index 0 is reserved for VERF_NDX_LOCAL and 1 is for
-// VER_NDX_GLOBAL. There's no table entry for these special versions in
-// ".gnu.version_d".
-//
-// The file format for symbol versioning is perhaps a bit more complicated
-// than necessary, but you can easily understand the code if you wrap your
-// head around the data structure described above.
-template <class ELFT> void SharedFile<ELFT>::parseRest() {
-  Verdefs = parseVerdefs();                       // parse .gnu.version_d
-  std::vector<uint32_t> Versyms = parseVersyms(); // parse .gnu.version
-  ArrayRef<Elf_Shdr> Sections = CHECK(this->getObj<ELFT>().sections(), this);
-
   // System libraries can have a lot of symbols with versions. Using a
   // fixed buffer for computing the versions name (foo@ver) can save a
   // lot of allocations.
   SmallString<0> VersionedNameBuffer;
 
   // Add symbols to the symbol table.
   ArrayRef<Elf_Sym> Syms = this->getGlobalELFSyms<ELFT>();
   for (size_t I = 0; I < Syms.size(); ++I) {
     const Elf_Sym &Sym = Syms[I];
for (size_t I = 0; I < Syms.size(); ++I) {
     // MIPS BFD linker puts _gp_disp symbol into DSO files and incorrectly
     // assigns VER_NDX_LOCAL to this section global symbol. Here is a
     // workaround for this bug.
     uint32_t Idx = Versyms[I] & ~VERSYM_HIDDEN;
     if (Config->EMachine == EM_MIPS && Idx == VER_NDX_LOCAL &&
         Name == "_gp_disp")
       continue;
 
-    uint64_t Alignment = getAlignment(Sections, Sym);
+    uint64_t Alignment = getAlignment<ELFT>(Sections, Sym);
     if (!(Versyms[I] & VERSYM_HIDDEN))
-      Symtab->addShared(Name, *this, Sym, Alignment, Idx);
+      Symtab->addShared<ELFT>(Name, *this, Sym, Alignment, Idx);
 
     // Also add the symbol with the versioned name to handle undefined symbols
     // with explicit versions.
     if (Idx == VER_NDX_GLOBAL)
       continue;
 
     if (Idx >= Verdefs.size() || Idx == VER_NDX_LOCAL) {
       error("corrupt input file: version definition index " + Twine(Idx) +
             " for symbol " + Name + " is out of bounds\n>>> defined in " +
             toString(this));
       continue;
     }
 
     StringRef VerName =
-        this->StringTable.data() + Verdefs[Idx]->getAux()->vda_name;
+        this->StringTable.data() +
+        reinterpret_cast<const Elf_Verdef *>(Verdefs[Idx])->getAux()->vda_name;
     VersionedNameBuffer.clear();
     Name = (Name + "@" + VerName).toStringRef(VersionedNameBuffer);
-    Symtab->addShared(Saver.save(Name), *this, Sym, Alignment, Idx);
+    Symtab->addShared<ELFT>(Saver.save(Name), *this, Sym, Alignment, Idx);
   }
 }
 
 static ELFKind getBitcodeELFKind(const Triple &T) {
   if (T.isLittleEndian())
     return T.isArch64Bit() ? ELF64LEKind : ELF32LEKind;
   return T.isArch64Bit() ? ELF64BEKind : ELF32BEKind;
 }
InputFile *elf::createObjectFile(MemoryBufferRef MB, StringRef ArchiveName,
   case ELF64BEKind:
     return make<ObjFile<ELF64BE>>(MB, ArchiveName);
   default:
     llvm_unreachable("getELFKind");
   }
 }
 
 InputFile *elf::createSharedFile(MemoryBufferRef MB, StringRef DefaultSoName) {
+  auto *F = make<SharedFile>(MB, DefaultSoName);
   switch (getELFKind(MB, "")) {
   case ELF32LEKind:
-    return make<SharedFile<ELF32LE>>(MB, DefaultSoName);
+    F->parseHeader<ELF32LE>();
+    break;
   case ELF32BEKind:
-    return make<SharedFile<ELF32BE>>(MB, DefaultSoName);
+    F->parseHeader<ELF32BE>();
+    break;
   case ELF64LEKind:
-    return make<SharedFile<ELF64LE>>(MB, DefaultSoName);
+    F->parseHeader<ELF64LE>();
+    break;
   case ELF64BEKind:
-    return make<SharedFile<ELF64BE>>(MB, DefaultSoName);
+    F->parseHeader<ELF64BE>();
+    break;
   default:
     llvm_unreachable("getELFKind");
   }
+  return F;
 }
 
 MemoryBufferRef LazyObjFile::getBuffer() {
   if (AddedToLink)
     return MemoryBufferRef();
   AddedToLink = true;
   return MB;
 }

 template void LazyObjFile::parse<ELF64LE>();
 template void LazyObjFile::parse<ELF64BE>();
 
 template class elf::ObjFile<ELF32LE>;
 template class elf::ObjFile<ELF32BE>;
 template class elf::ObjFile<ELF64LE>;
 template class elf::ObjFile<ELF64BE>;
 
-template class elf::SharedFile<ELF32LE>;
-template class elf::SharedFile<ELF32BE>;
-template class elf::SharedFile<ELF64LE>;
-template class elf::SharedFile<ELF64BE>;
+template void SharedFile::parse<ELF32LE>();
+template void SharedFile::parse<ELF32BE>();
+template void SharedFile::parse<ELF64LE>();
+template void SharedFile::parse<ELF64BE>();

lld/ELF/MarkLive.cpp

if (auto *D = dyn_cast<Defined>(&Sym)) {
 
     if (!IsLSDA || !(RelSec->Flags & SHF_EXECINSTR))
       enqueue(RelSec, Offset);
     return;
   }
 
   if (auto *SS = dyn_cast<SharedSymbol>(&Sym))
     if (!SS->isWeak())
-      SS->getFile<ELFT>().IsNeeded = true;
+      SS->getFile().IsNeeded = true;
 
   for (InputSectionBase *Sec : CNamedSections.lookup(Sym.getName()))
     enqueue(Sec, 0);
 }
 
 // The .eh_frame section is an unfortunate special case.
 // The section is divided in CIEs and FDEs and the relocations it can have are
 // * CIEs can refer to a personality function.
template <class ELFT> void elf::markLive() {
   if (!Config->GcSections) {
     for (InputSectionBase *Sec : InputSections)
       Sec->Live = true;
 
     // If a DSO defines a symbol referenced in a regular object, it is needed.
     for (Symbol *Sym : Symtab->getSymbols())
       if (auto *S = dyn_cast<SharedSymbol>(Sym))
         if (S->IsUsedInRegularObj && !S->isWeak())
-          S->getFile<ELFT>().IsNeeded = true;
+          S->getFile().IsNeeded = true;
     return;
   }
 
   // Otheriwse, do mark-sweep GC.
   //
   // The -gc-sections option works only for SHF_ALLOC sections
   // (sections that are memory-mapped at runtime). So we can
   // unconditionally make non-SHF_ALLOC sections alive except

lld/ELF/Relocations.cpp

static RelExpr fromPlt(RelExpr 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) {
   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>();
+  const SharedFile &File = SS.getFile();
   for (const Elf_Phdr &Phdr :
        check(File.template getObj<ELFT>().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) {
   using Elf_Sym = typename ELFT::Sym;
 
-  SharedFile<ELFT> &File = SS.getFile<ELFT>();
+  SharedFile &File = SS.getFile();
 
   SmallSet<SharedSymbol *, 4> Ret;
   for (const Elf_Sym &S : File.template getGlobalELFSyms<ELFT>()) {
     if (S.st_shndx == SHN_UNDEF || S.st_shndx == SHN_ABS ||
         S.getType() == STT_TLS || S.st_value != SS.Value)
       continue;
     StringRef Name = check(S.getName(File.getStringTable()));
     Symbol *Sym = Symtab->find(Name);

lld/ELF/SymbolTable.h

public:
   Symbol *addUndefined(StringRef Name, uint8_t Binding, uint8_t StOther,
                        uint8_t Type, bool CanOmitFromDynSym, InputFile *File);
 
   Defined *addDefined(StringRef Name, uint8_t StOther, uint8_t Type,
                       uint64_t Value, uint64_t Size, uint8_t Binding,
                       SectionBase *Section, InputFile *File);
 
   template <class ELFT>
-  void addShared(StringRef Name, SharedFile<ELFT> &F,
-                 const typename ELFT::Sym &Sym, uint32_t Alignment,
-                 uint32_t VerdefIndex);
+  void addShared(StringRef Name, SharedFile &F, const typename ELFT::Sym &Sym,
+                 uint32_t Alignment, uint32_t VerdefIndex);
 
   template <class ELFT>
   void addLazyArchive(StringRef Name, ArchiveFile &F,
                       const llvm::object::Archive::Symbol S);
 
   template <class ELFT> void addLazyObject(StringRef Name, LazyObjFile &Obj);
 
   Symbol *addBitcode(StringRef Name, uint8_t Binding, uint8_t StOther,
public:
 
   Symbol *find(StringRef Name);
 
   void trace(StringRef Name);
 
   void handleDynamicList();
 
   // Set of .so files to not link the same shared object file more than once.
-  llvm::DenseMap<StringRef, InputFile *> SoNames;
+  llvm::DenseMap<StringRef, SharedFile *> SoNames;
 
 private:
   std::pair<Symbol *, bool> insertName(StringRef Name);
 
   std::vector<Symbol *> findByVersion(SymbolVersion Ver);
   std::vector<Symbol *> findAllByVersion(SymbolVersion Ver);
 
   llvm::StringMap<std::vector<Symbol *>> &getDemangledSyms();

lld/ELF/SymbolTable.cpp

if (auto *F = dyn_cast<LazyObjFile>(File)) {
     F->parse<ELFT>();
     return;
   }
 
   if (Config->Trace)
     message(toString(File));
 
   // .so file
-  if (auto *F = dyn_cast<SharedFile<ELFT>>(File)) {
-    // DSOs are uniquified not by filename but by soname.
-    F->parseDynamic();
-    if (errorCount())
-      return;
-
-    // If a DSO appears more than once on the command line with and without
-    // --as-needed, --no-as-needed takes precedence over --as-needed because a
-    // user can add an extra DSO with --no-as-needed to force it to be added to
-    // the dependency list.
-    DenseMap<StringRef, InputFile *>::iterator It;
-    bool WasInserted;
-    std::tie(It, WasInserted) = SoNames.try_emplace(F->SoName, F);
-    cast<SharedFile<ELFT>>(It->second)->IsNeeded |= F->IsNeeded;
-    if (!WasInserted)
-      return;
-
-    SharedFiles.push_back(F);
-    F->parseRest();
+  if (auto *F = dyn_cast<SharedFile>(File)) {
+    F->parse<ELFT>();
     return;
   }
 
   // LLVM bitcode file
   if (auto *F = dyn_cast<BitcodeFile>(File)) {
     BitcodeFiles.push_back(F);
     F->parse<ELFT>(ComdatGroups);
     return;
replaceSymbol<Defined>(S, File, Name, Binding, StOther, Type, Value, Size,
                            Section);
   else if (Cmp == 0)
     reportDuplicate(S, File, dyn_cast_or_null<InputSectionBase>(Section),
                     Value);
   return cast<Defined>(S);
 }
 
 template <typename ELFT>
-void SymbolTable::addShared(StringRef Name, SharedFile<ELFT> &File,
+void SymbolTable::addShared(StringRef Name, SharedFile &File,
                             const typename ELFT::Sym &Sym, uint32_t Alignment,
                             uint32_t VerdefIndex) {
   // DSO symbols do not affect visibility in the output, so we pass STV_DEFAULT
   // as the visibility, which will leave the visibility in the symbol table
   // unchanged.
   Symbol *S;
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name, STV_DEFAULT,

 template void SymbolTable::addLazyObject<ELF64LE>(StringRef, LazyObjFile &);
 template void SymbolTable::addLazyObject<ELF64BE>(StringRef, LazyObjFile &);
 
 template void SymbolTable::fetchLazy<ELF32LE>(Symbol *);
 template void SymbolTable::fetchLazy<ELF32BE>(Symbol *);
 template void SymbolTable::fetchLazy<ELF64LE>(Symbol *);
 template void SymbolTable::fetchLazy<ELF64BE>(Symbol *);
 
-template void SymbolTable::addShared<ELF32LE>(StringRef, SharedFile<ELF32LE> &,
+template void SymbolTable::addShared<ELF32LE>(StringRef, SharedFile &,
                                               const typename ELF32LE::Sym &,
                                               uint32_t Alignment, uint32_t);
-template void SymbolTable::addShared<ELF32BE>(StringRef, SharedFile<ELF32BE> &,
+template void SymbolTable::addShared<ELF32BE>(StringRef, SharedFile &,
                                               const typename ELF32BE::Sym &,
                                               uint32_t Alignment, uint32_t);
-template void SymbolTable::addShared<ELF64LE>(StringRef, SharedFile<ELF64LE> &,
+template void SymbolTable::addShared<ELF64LE>(StringRef, SharedFile &,
                                               const typename ELF64LE::Sym &,
                                               uint32_t Alignment, uint32_t);
-template void SymbolTable::addShared<ELF64BE>(StringRef, SharedFile<ELF64BE> &,
+template void SymbolTable::addShared<ELF64BE>(StringRef, SharedFile &,
                                               const typename ELF64BE::Sym &,
                                               uint32_t Alignment, uint32_t);

lld/ELF/Symbols.h

 //===- Symbols.h ------------------------------------------------*- C++ -*-===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines various types of Symbols.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLD_ELF_SYMBOLS_H
 #define LLD_ELF_SYMBOLS_H
 
+#include "InputFiles.h"
 #include "InputSection.h"
 #include "lld/Common/LLVM.h"
 #include "lld/Common/Strings.h"
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/ELF.h"
 
 namespace lld {
 namespace elf {
 class Symbol;
 class InputFile;
 } // namespace elf
 
 std::string toString(const elf::Symbol &);
 std::string toString(const elf::InputFile *);
 
 namespace elf {
 
-template <class ELFT> class SharedFile;
-
 // This is a StringRef-like container that doesn't run strlen().
 //
 // ELF string tables contain a lot of null-terminated strings. Most of them
 // are not necessary for the linker because they are names of local symbols,
 // and the linker doesn't use local symbol names for name resolution. So, we
 // use this class to represents strings read from string tables.
 struct StringRefZ {
   StringRefZ(const char *S) : Data(S), Size(-1) {}
SharedSymbol(InputFile &File, StringRef Name, uint8_t Binding,
     //
     // For DSO symbols, we always call them through PLT slots anyway.
     // So there's no difference between GNU ifunc and regular function
     // symbols if they are in DSOs. So we can handle GNU_IFUNC as FUNC.
     if (this->Type == llvm::ELF::STT_GNU_IFUNC)
       this->Type = llvm::ELF::STT_FUNC;
   }
 
-  template <class ELFT> SharedFile<ELFT> &getFile() const {
-    return *cast<SharedFile<ELFT>>(File);
-  }
+  SharedFile &getFile() const { return *cast<SharedFile>(File); }
 
   uint32_t Alignment;
 
   uint64_t Value; // st_value
   uint64_t Size;  // st_size
 };
 
 // LazyArchive and LazyObject represent a symbols that is not yet in the link,

lld/ELF/SyntheticSections.h

 // mapping from version identifiers to version names.
 template <class ELFT>
 class VersionNeedSection final : public VersionNeedBaseSection {
   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;
+  std::vector<std::pair<SharedFile *, size_t>> Needed;
 
 public:
   void addSymbol(Symbol *Sym) override;
   void finalizeContents() override;
   void writeTo(uint8_t *Buf) override;
   size_t getSize() const override;
   size_t getNeedNum() const override { return Needed.size(); }
   bool isNeeded() const override;

lld/ELF/SyntheticSections.cpp

for (StringRef S : Config->FilterList)
     addInt(DT_FILTER, In.DynStrTab->addString(S));
   for (StringRef S : Config->AuxiliaryList)
     addInt(DT_AUXILIARY, In.DynStrTab->addString(S));
 
   if (!Config->Rpath.empty())
     addInt(Config->EnableNewDtags ? DT_RUNPATH : DT_RPATH,
            In.DynStrTab->addString(Config->Rpath));
 
-  for (InputFile *File : SharedFiles) {
-    SharedFile<ELFT> *F = cast<SharedFile<ELFT>>(File);
-    if (F->IsNeeded)
-      addInt(DT_NEEDED, In.DynStrTab->addString(F->SoName));
-  }
+  for (SharedFile *File : SharedFiles)
+    if (File->IsNeeded)
+      addInt(DT_NEEDED, In.DynStrTab->addString(File->SoName));
   if (!Config->SoName.empty())
     addInt(DT_SONAME, In.DynStrTab->addString(Config->SoName));
 
   // Set DT_FLAGS and DT_FLAGS_1.
   uint32_t DtFlags = 0;
   uint32_t DtFlags1 = 0;
   if (Config->Bsymbolic)
     DtFlags |= DF_SYMBOLIC;
: SyntheticSection(SHF_ALLOC, SHT_GNU_verneed, sizeof(uint32_t),
                        ".gnu.version_r") {
   // Identifiers in verneed section start at 2 because 0 and 1 are reserved
   // for VER_NDX_LOCAL and VER_NDX_GLOBAL.
   // First identifiers are reserved by verdef section if it exist.
   NextIndex = getVerDefNum() + 1;
 }
 
 template <class ELFT> void VersionNeedSection<ELFT>::addSymbol(Symbol *SS) {
-  auto &File = cast<SharedFile<ELFT>>(*SS->File);
+  auto &File = cast<SharedFile>(*SS->File);
   if (SS->VerdefIndex == VER_NDX_GLOBAL) {
     SS->VersionId = VER_NDX_GLOBAL;
     return;
   }
 
   // If we don't already know that we need an Elf_Verneed for this DSO, prepare
   // to create one by adding it to our needed list and creating a dynstr entry
   // for the soname.
   if (File.VerdefMap.empty())
     Needed.push_back({&File, In.DynStrTab->addString(File.SoName)});
-  const typename ELFT::Verdef *Ver = File.Verdefs[SS->VerdefIndex];
-  typename SharedFile<ELFT>::NeededVer &NV = File.VerdefMap[Ver];
+  auto *Ver = reinterpret_cast<const typename ELFT::Verdef *>(
+      File.Verdefs[SS->VerdefIndex]);
+  typename SharedFile::NeededVer &NV = File.VerdefMap[Ver];
 
   // If we don't already know that we need an Elf_Vernaux for this Elf_Verdef,
   // prepare to create one by allocating a version identifier and creating a
   // dynstr entry for the version name.
   if (NV.Index == 0) {
     NV.StrTab = In.DynStrTab->addString(File.getStringTable().data() +
                                         Ver->getAux()->vda_name);
     NV.Index = NextIndex++;
   }
   SS->VersionId = NV.Index;
 }
 
 template <class ELFT> void VersionNeedSection<ELFT>::writeTo(uint8_t *Buf) {
   // The Elf_Verneeds need to appear first, followed by the Elf_Vernauxs.
   auto *Verneed = reinterpret_cast<Elf_Verneed *>(Buf);
   auto *Vernaux = reinterpret_cast<Elf_Vernaux *>(Verneed + Needed.size());
 
-  for (std::pair<SharedFile<ELFT> *, size_t> &P : Needed) {
+  for (std::pair<SharedFile *, size_t> &P : Needed) {
     // Create an Elf_Verneed for this DSO.
     Verneed->vn_version = 1;
     Verneed->vn_cnt = P.first->VerdefMap.size();
     Verneed->vn_file = P.second;
     Verneed->vn_aux =
         reinterpret_cast<char *>(Vernaux) - reinterpret_cast<char *>(Verneed);
     Verneed->vn_next = sizeof(Elf_Verneed);
     ++Verneed;
 
     // Create the Elf_Vernauxs for this Elf_Verneed. The loop iterates over
     // VerdefMap, which will only contain references to needed version
     // definitions. Each Elf_Vernaux is based on the information contained in
     // the Elf_Verdef in the source DSO. This loop iterates over a std::map of
     // pointers, but is deterministic because the pointers refer to Elf_Verdef
     // data structures within a single input file.
     for (auto &NV : P.first->VerdefMap) {
-      Vernaux->vna_hash = NV.first->vd_hash;
+      Vernaux->vna_hash =
+          reinterpret_cast<const typename ELFT::Verdef *>(NV.first)->vd_hash;
       Vernaux->vna_flags = 0;
       Vernaux->vna_other = NV.second.Index;
       Vernaux->vna_name = NV.second.StrTab;
       Vernaux->vna_next = sizeof(Elf_Vernaux);
       ++Vernaux;
     }
 
     Vernaux[-1].vna_next = 0;
   }
   Verneed[-1].vn_next = 0;
 }
 
 template <class ELFT> void VersionNeedSection<ELFT>::finalizeContents() {
   if (OutputSection *Sec = In.DynStrTab->getParent())
     getParent()->Link = Sec->SectionIndex;
   getParent()->Info = Needed.size();
 }
 
 template <class ELFT> size_t VersionNeedSection<ELFT>::getSize() const {
   unsigned Size = Needed.size() * sizeof(Elf_Verneed);
-  for (const std::pair<SharedFile<ELFT> *, size_t> &P : Needed)
+  for (const std::pair<SharedFile *, size_t> &P : Needed)
     Size += P.first->VerdefMap.size() * sizeof(Elf_Vernaux);
   return Size;
 }
 
 template <class ELFT> bool VersionNeedSection<ELFT>::isNeeded() const {
   return getNeedNum() != 0;
 }
 

lld/ELF/Writer.cpp

template <class ELFT> void Writer<ELFT>::finalizeSections() {
   if (!Config->AllowShlibUndefined) {
     // Error on undefined symbols in a shared object, if all of its DT_NEEDED
     // entires are seen. These cases would otherwise lead to runtime errors
     // reported by the dynamic linker.
     //
     // ld.bfd traces all DT_NEEDED to emulate the logic of the dynamic linker to
     // catch more cases. That is too much for us. Our approach resembles the one
     // used in ld.gold, achieves a good balance to be useful but not too smart.
-    for (InputFile *File : SharedFiles) {
-      SharedFile<ELFT> *F = cast<SharedFile<ELFT>>(File);
-      F->AllNeededIsKnown = llvm::all_of(F->DtNeeded, [&](StringRef Needed) {
+    for (SharedFile *File : SharedFiles)
+      File->AllNeededIsKnown =
+          llvm::all_of(File->DtNeeded, [&](StringRef Needed) {
             return Symtab->SoNames.count(Needed);
           });
-    }
     for (Symbol *Sym : Symtab->getSymbols())
       if (Sym->isUndefined() && !Sym->isWeak())
-        if (auto *F = dyn_cast_or_null<SharedFile<ELFT>>(Sym->File))
+        if (auto *F = dyn_cast_or_null<SharedFile>(Sym->File))
           if (F->AllNeededIsKnown)
             error(toString(F) + ": undefined reference to " + toString(*Sym));
   }
 
   // Now that we have defined all possible global symbols including linker-
   // synthesized ones. Visit all symbols to give the finishing touches.
   for (Symbol *Sym : Symtab->getSymbols()) {
     if (!includeInSymtab(*Sym))
       continue;
     if (In.SymTab)
       In.SymTab->addSymbol(Sym);
 
     if (Sym->includeInDynsym()) {
       In.DynSymTab->addSymbol(Sym);
-      if (auto *File = dyn_cast_or_null<SharedFile<ELFT>>(Sym->File))
+      if (auto *File = dyn_cast_or_null<SharedFile>(Sym->File))
         if (File->IsNeeded && !Sym->isUndefined())
           In.VerNeed->addSymbol(Sym);
     }
   }
 
   // Do not proceed if there was an undefined symbol.
   if (errorCount())
     return;