[ELF] - Detemplate of HashTableSection<ELFT>

[grimar]

Summary

Detemplation of one more synthetic section.

[ruiu]

ELF/SyntheticSections.cpp

1643 ↗

(On Diff #116560)

A more natural way of writing the same expression is Buckets + Hash

[grimar]

• Addressed review comment.

[ruiu]

LGTM

lld/trunk/ELF/SyntheticSections.h

private:
   };
 
   std::vector<Entry> Symbols;
   size_t MaskWords;
   size_t NBuckets = 0;
   size_t Size = 0;
 };
 
-template <class ELFT> class HashTableSection final : public SyntheticSection {
+class HashTableSection final : public SyntheticSection {
 public:
   HashTableSection();
   void finalizeContents() override;
   void writeTo(uint8_t *Buf) override;
   size_t getSize() const override { return Size; }
 
 private:
   size_t Size = 0;
struct InX {
   static InputSection *ARMAttributes;
   static BssSection *Bss;
   static BssSection *BssRelRo;
   static BuildIdSection *BuildId;
   static SyntheticSection *Dynamic;
   static StringTableSection *DynStrTab;
   static SymbolTableBaseSection *DynSymTab;
   static GnuHashTableSection *GnuHashTab;
+  static HashTableSection *HashTab;
   static InputSection *Interp;
   static GdbIndexSection *GdbIndex;
   static GotSection *Got;
   static GotPltSection *GotPlt;
   static IgotPltSection *IgotPlt;
   static MipsGotSection *MipsGot;
   static MipsRldMapSection *MipsRldMap;
   static PltSection *Plt;
   static PltSection *Iplt;
   static StringTableSection *ShStrTab;
   static StringTableSection *StrTab;
   static SymbolTableBaseSection *SymTab;
 };
 
 template <class ELFT> struct In : public InX {
   static EhFrameHeader<ELFT> *EhFrameHdr;
   static EhFrameSection<ELFT> *EhFrame;
-  static HashTableSection<ELFT> *HashTab;
   static RelocationSection<ELFT> *RelaDyn;
   static RelocationSection<ELFT> *RelaPlt;
   static RelocationSection<ELFT> *RelaIplt;
   static VersionDefinitionSection<ELFT> *VerDef;
   static VersionTableSection<ELFT> *VerSym;
   static VersionNeedSection<ELFT> *VerNeed;
 };
 
 template <class ELFT> EhFrameHeader<ELFT> *In<ELFT>::EhFrameHdr;
 template <class ELFT> EhFrameSection<ELFT> *In<ELFT>::EhFrame;
-template <class ELFT> HashTableSection<ELFT> *In<ELFT>::HashTab;
 template <class ELFT> RelocationSection<ELFT> *In<ELFT>::RelaDyn;
 template <class ELFT> RelocationSection<ELFT> *In<ELFT>::RelaPlt;
 template <class ELFT> RelocationSection<ELFT> *In<ELFT>::RelaIplt;
 template <class ELFT> VersionDefinitionSection<ELFT> *In<ELFT>::VerDef;
 template <class ELFT> VersionTableSection<ELFT> *In<ELFT>::VerSym;
 template <class ELFT> VersionNeedSection<ELFT> *In<ELFT>::VerNeed;
 } // namespace elf
 } // namespace lld
 
 #endif

lld/trunk/ELF/SyntheticSections.cpp

template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
   add({DT_SYMTAB, InX::DynSymTab});
   add({DT_SYMENT, sizeof(Elf_Sym)});
   add({DT_STRTAB, InX::DynStrTab});
   add({DT_STRSZ, InX::DynStrTab->getSize()});
   if (!Config->ZText)
     add({DT_TEXTREL, (uint64_t)0});
   if (InX::GnuHashTab)
     add({DT_GNU_HASH, InX::GnuHashTab});
-  if (In<ELFT>::HashTab)
-    add({DT_HASH, In<ELFT>::HashTab});
+  if (InX::HashTab)
+    add({DT_HASH, InX::HashTab});
 
   if (Out::PreinitArray) {
     add({DT_PREINIT_ARRAY, Out::PreinitArray});
     add({DT_PREINIT_ARRAYSZ, Out::PreinitArray, Entry::SecSize});
   }
   if (Out::InitArray) {
     add({DT_INIT_ARRAY, Out::InitArray});
     add({DT_INIT_ARRAYSZ, Out::InitArray, Entry::SecSize});
std::stable_sort(Symbols.begin(), Symbols.end(),
                      return L.Hash % NBuckets < R.Hash % NBuckets;
                    });
 
   V.erase(Mid, V.end());
   for (const Entry &Ent : Symbols)
     V.push_back({Ent.Body, Ent.StrTabOffset});
 }
 
-template <class ELFT>
-HashTableSection<ELFT>::HashTableSection()
+HashTableSection::HashTableSection()
     : SyntheticSection(SHF_ALLOC, SHT_HASH, 4, ".hash") {
   this->Entsize = 4;
 }
 
-template <class ELFT> void HashTableSection<ELFT>::finalizeContents() {
+void HashTableSection::finalizeContents() {
   getParent()->Link = InX::DynSymTab->getParent()->SectionIndex;
 
   unsigned NumEntries = 2;                       // nbucket and nchain.
   NumEntries += InX::DynSymTab->getNumSymbols(); // The chain entries.
 
   // Create as many buckets as there are symbols.
   // FIXME: This is simplistic. We can try to optimize it, but implementing
   // support for SHT_GNU_HASH is probably even more profitable.
   NumEntries += InX::DynSymTab->getNumSymbols();
   this->Size = NumEntries * 4;
 }
 
-template <class ELFT> void HashTableSection<ELFT>::writeTo(uint8_t *Buf) {
-  // A 32-bit integer type in the target endianness.
-  typedef typename ELFT::Word Elf_Word;
-
+void HashTableSection::writeTo(uint8_t *Buf) {
   unsigned NumSymbols = InX::DynSymTab->getNumSymbols();
 
-  auto *P = reinterpret_cast<Elf_Word *>(Buf);
-  *P++ = NumSymbols; // nbucket
-  *P++ = NumSymbols; // nchain
+  uint32_t *P = reinterpret_cast<uint32_t *>(Buf);
+  write32(P++, NumSymbols, Config->Endianness); // nbucket
+  write32(P++, NumSymbols, Config->Endianness); // nchain
 
-  Elf_Word *Buckets = P;
-  Elf_Word *Chains = P + NumSymbols;
+  uint32_t *Buckets = P;
+  uint32_t *Chains = P + NumSymbols;
 
   for (const SymbolTableEntry &S : InX::DynSymTab->getSymbols()) {
     SymbolBody *Body = S.Symbol;
     StringRef Name = Body->getName();
     unsigned I = Body->DynsymIndex;
     uint32_t Hash = hashSysV(Name) % NumSymbols;
     Chains[I] = Buckets[Hash];
-    Buckets[Hash] = I;
+    write32(Buckets + Hash, I, Config->Endianness);
   }
 }
 
 PltSection::PltSection(size_t S)
     : SyntheticSection(SHF_ALLOC | SHF_EXECINSTR, SHT_PROGBITS, 16, ".plt"),
       HeaderSize(S) {
   // The PLT needs to be writable on SPARC as the dynamic linker will
   // modify the instructions in the PLT entries.

 SyntheticSection *InX::Dynamic;
 StringTableSection *InX::DynStrTab;
 SymbolTableBaseSection *InX::DynSymTab;
 InputSection *InX::Interp;
 GdbIndexSection *InX::GdbIndex;
 GotSection *InX::Got;
 GotPltSection *InX::GotPlt;
 GnuHashTableSection *InX::GnuHashTab;
+HashTableSection *InX::HashTab;
 IgotPltSection *InX::IgotPlt;
 MipsGotSection *InX::MipsGot;
 MipsRldMapSection *InX::MipsRldMap;
 PltSection *InX::Plt;
 PltSection *InX::Iplt;
 StringTableSection *InX::ShStrTab;
 StringTableSection *InX::StrTab;
 SymbolTableBaseSection *InX::SymTab;

 template class elf::RelocationSection<ELF64LE>;
 template class elf::RelocationSection<ELF64BE>;
 
 template class elf::SymbolTableSection<ELF32LE>;
 template class elf::SymbolTableSection<ELF32BE>;
 template class elf::SymbolTableSection<ELF64LE>;
 template class elf::SymbolTableSection<ELF64BE>;
 
-template class elf::HashTableSection<ELF32LE>;
-template class elf::HashTableSection<ELF32BE>;
-template class elf::HashTableSection<ELF64LE>;
-template class elf::HashTableSection<ELF64BE>;
-
 template class elf::EhFrameHeader<ELF32LE>;
 template class elf::EhFrameHeader<ELF32BE>;
 template class elf::EhFrameHeader<ELF64LE>;
 template class elf::EhFrameHeader<ELF64BE>;
 
 template class elf::VersionTableSection<ELF32LE>;
 template class elf::VersionTableSection<ELF32BE>;
 template class elf::VersionTableSection<ELF64LE>;

lld/trunk/ELF/Writer.cpp

if (Config->HasDynSymTab) {
     Add(In<ELFT>::VerNeed);
 
     if (Config->GnuHash) {
       InX::GnuHashTab = make<GnuHashTableSection>();
       Add(InX::GnuHashTab);
     }
 
     if (Config->SysvHash) {
-      In<ELFT>::HashTab = make<HashTableSection<ELFT>>();
-      Add(In<ELFT>::HashTab);
+      InX::HashTab = make<HashTableSection>();
+      Add(InX::HashTab);
     }
 
     Add(InX::Dynamic);
     Add(InX::DynStrTab);
     Add(In<ELFT>::RelaDyn);
   }
 
   // Add .got. MIPS' .got is so different from the other archs,
template <class ELFT> void Writer<ELFT>::finalizeSections() {
   // Some symbols are defined in term of program headers. Now that we
   // have the headers, we can find out which sections they point to.
   setReservedSymbolSections();
 
   // Dynamic section must be the last one in this list and dynamic
   // symbol table section (DynSymTab) must be the first one.
   applySynthetic({InX::DynSymTab,    InX::Bss,
                   InX::BssRelRo,     InX::GnuHashTab,
-                  In<ELFT>::HashTab, InX::SymTab,
+                  InX::HashTab,      InX::SymTab,
                   InX::ShStrTab,     InX::StrTab,
                   In<ELFT>::VerDef,  InX::DynStrTab,
                   InX::Got,          InX::MipsGot,
                   InX::IgotPlt,      InX::GotPlt,
                   In<ELFT>::RelaDyn, In<ELFT>::RelaIplt,
                   In<ELFT>::RelaPlt, InX::Plt,
                   InX::Iplt,         In<ELFT>::EhFrameHdr,
                   In<ELFT>::VerSym,  In<ELFT>::VerNeed,