Delete SplitInputSection.

[• rafael]

Summary

This opens the way for having a different Piece type for EhInputSection.

[ruiu]

LGTM. Nice simplification.

[Eugene.Zelenko]

Committed in r276275.

ELF/InputSection.h

private:
   // We want to save bits to make it cache friendly.
   const uint8_t *Data;
   uint32_t Size : 31;
 
 public:
   uint32_t Live : 1;
 };
 
-// Usually sections are copied to the output as atomic chunks of data,
-// but some special types of sections are split into small pieces of data
-// and each piece is copied to a different place in the output.
-// This class represents such special sections.
-template <class ELFT> class SplitInputSection : public InputSectionBase<ELFT> {
-  typedef typename ELFT::Shdr Elf_Shdr;
-  typedef typename ELFT::uint uintX_t;
-
-public:
-  SplitInputSection(ObjectFile<ELFT> *File, const Elf_Shdr *Header,
-                    typename InputSectionBase<ELFT>::Kind SectionKind);
-
-  // Splittable sections are handled as a sequence of data
-  // rather than a single large blob of data.
-  std::vector<SectionPiece> Pieces;
-
-  // Returns the SectionPiece at a given input section offset.
-  SectionPiece *getSectionPiece(uintX_t Offset);
-  const SectionPiece *getSectionPiece(uintX_t Offset) const;
-};
-
 // This corresponds to a SHF_MERGE section of an input file.
-template <class ELFT> class MergeInputSection : public SplitInputSection<ELFT> {
+template <class ELFT> class MergeInputSection : public InputSectionBase<ELFT> {
   typedef typename ELFT::uint uintX_t;
   typedef typename ELFT::Sym Elf_Sym;
   typedef typename ELFT::Shdr Elf_Shdr;
 
 public:
   MergeInputSection(ObjectFile<ELFT> *F, const Elf_Shdr *Header);
   static bool classof(const InputSectionBase<ELFT> *S);
   void splitIntoPieces();
 
   // Mark the piece at a given offset live. Used by GC.
   void markLiveAt(uintX_t Offset) { LiveOffsets.insert(Offset); }
 
   // Translate an offset in the input section to an offset
   // in the output section.
   uintX_t getOffset(uintX_t Offset) const;
 
   void finalizePieces();
 
+  // Splittable sections are handled as a sequence of data
+  // rather than a single large blob of data.
+  std::vector<SectionPiece> Pieces;
+
+  // Returns the SectionPiece at a given input section offset.
+  SectionPiece *getSectionPiece(uintX_t Offset);
+  const SectionPiece *getSectionPiece(uintX_t Offset) const;
+
 private:
   llvm::DenseMap<uintX_t, uintX_t> OffsetMap;
   llvm::DenseSet<uintX_t> LiveOffsets;
 };
 
 // This corresponds to a .eh_frame section of an input file.
-template <class ELFT> class EhInputSection : public SplitInputSection<ELFT> {
+template <class ELFT> class EhInputSection : public InputSectionBase<ELFT> {
 public:
   typedef typename ELFT::Shdr Elf_Shdr;
   typedef typename ELFT::uint uintX_t;
   EhInputSection(ObjectFile<ELFT> *F, const Elf_Shdr *Header);
   static bool classof(const InputSectionBase<ELFT> *S);
   void split();
 
+  // Splittable sections are handled as a sequence of data
+  // rather than a single large blob of data.
+  std::vector<SectionPiece> Pieces;
+
   // Relocation section that refer to this one.
   const Elf_Shdr *RelocSection = nullptr;
 };
 
 // This corresponds to a non SHF_MERGE section of an input file.
 template <class ELFT> class InputSection : public InputSectionBase<ELFT> {
   friend ICF<ELFT>;
   typedef InputSectionBase<ELFT> Base;

ELF/InputSection.cpp

 template <class ELFT>
 void InputSection<ELFT>::replace(InputSection<ELFT> *Other) {
   this->Alignment = std::max(this->Alignment, Other->Alignment);
   Other->Repl = this->Repl;
   Other->Live = false;
 }
 
 template <class ELFT>
-SplitInputSection<ELFT>::SplitInputSection(
-    elf::ObjectFile<ELFT> *File, const Elf_Shdr *Header,
-    typename InputSectionBase<ELFT>::Kind SectionKind)
-    : InputSectionBase<ELFT>(File, Header, SectionKind) {}
-
-template <class ELFT>
 EhInputSection<ELFT>::EhInputSection(elf::ObjectFile<ELFT> *F,
                                      const Elf_Shdr *Header)
-    : SplitInputSection<ELFT>(F, Header, InputSectionBase<ELFT>::EHFrame) {
+    : InputSectionBase<ELFT>(F, Header, InputSectionBase<ELFT>::EHFrame) {
   // Mark .eh_frame sections as live by default because there are
   // usually no relocations that point to .eh_frames. Otherwise,
   // the garbage collector would drop all .eh_frame sections.
   this->Live = true;
 }
 
 template <class ELFT>
 bool EhInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
static std::vector<SectionPiece> splitNonStrings(ArrayRef<uint8_t> Data,
   for (unsigned I = 0, N = Size; I != N; I += EntSize)
     V.emplace_back(I, Data.slice(I, EntSize));
   return V;
 }
 
 template <class ELFT>
 MergeInputSection<ELFT>::MergeInputSection(elf::ObjectFile<ELFT> *F,
                                            const Elf_Shdr *Header)
-    : SplitInputSection<ELFT>(F, Header, InputSectionBase<ELFT>::Merge) {}
+    : InputSectionBase<ELFT>(F, Header, InputSectionBase<ELFT>::Merge) {}
 
 template <class ELFT> void MergeInputSection<ELFT>::splitIntoPieces() {
   ArrayRef<uint8_t> Data = this->getSectionData();
   uintX_t EntSize = this->Header->sh_entsize;
   if (this->Header->sh_flags & SHF_STRINGS)
     this->Pieces = splitStrings(Data, EntSize);
   else
     this->Pieces = splitNonStrings(Data, EntSize);
 
   if (Config->GcSections)
     for (uintX_t Off : LiveOffsets)
       this->getSectionPiece(Off)->Live = true;
 }
 
 template <class ELFT>
 bool MergeInputSection<ELFT>::classof(const InputSectionBase<ELFT> *S) {
   return S->SectionKind == InputSectionBase<ELFT>::Merge;
 }
 
 // Do binary search to get a section piece at a given input offset.
 template <class ELFT>
-SectionPiece *SplitInputSection<ELFT>::getSectionPiece(uintX_t Offset) {
-  auto *This = static_cast<const SplitInputSection<ELFT> *>(this);
+SectionPiece *MergeInputSection<ELFT>::getSectionPiece(uintX_t Offset) {
+  auto *This = static_cast<const MergeInputSection<ELFT> *>(this);
   return const_cast<SectionPiece *>(This->getSectionPiece(Offset));
 }
 
 template <class ELFT>
 const SectionPiece *
-SplitInputSection<ELFT>::getSectionPiece(uintX_t Offset) const {
+MergeInputSection<ELFT>::getSectionPiece(uintX_t Offset) const {
   ArrayRef<uint8_t> D = this->getSectionData();
   StringRef Data((const char *)D.data(), D.size());
   uintX_t Size = Data.size();
   if (Offset >= Size)
     fatal("entry is past the end of the section");
 
   // Find the element this offset points to.
   auto I = std::upper_bound(

 template class elf::InputSectionBase<ELF64LE>;
 template class elf::InputSectionBase<ELF64BE>;
 
 template class elf::InputSection<ELF32LE>;
 template class elf::InputSection<ELF32BE>;
 template class elf::InputSection<ELF64LE>;
 template class elf::InputSection<ELF64BE>;
 
-template class elf::SplitInputSection<ELF32LE>;
-template class elf::SplitInputSection<ELF32BE>;
-template class elf::SplitInputSection<ELF64LE>;
-template class elf::SplitInputSection<ELF64BE>;
-
 template class elf::EhInputSection<ELF32LE>;
 template class elf::EhInputSection<ELF32BE>;
 template class elf::EhInputSection<ELF64LE>;
 template class elf::EhInputSection<ELF64BE>;
 
 template class elf::MergeInputSection<ELF32LE>;
 template class elf::MergeInputSection<ELF32BE>;
 template class elf::MergeInputSection<ELF64LE>;