[llvm-objcopy] Remove unused field from Object

[alexander-shaposhnikov]

Summary

The class Object contained std::shared_ptr<MemoryBuffer> OwnedData
which was not used anywhere. Besides avoiding two stage initialization (1st - ctor, 2nd - the actual work done by the builder) the motivation to remove it comes from the plan to add (currently missing) support for static libraries (archives) (bintuils strip supports them),
llvm::object::Archive::Child exposes MemoryBufferRef and doesn't transfer / share the ownership.

NFC.

Test plan: make check-all

[alexander-shaposhnikov]

Object.h

622 ↗

(On Diff #150219)

Object is never deleted polymorphically, it's not even a part of a hierarchy, probably the class itself should be marked final.

[jhenderson]

Object.h

587 ↗

(On Diff #150219)

Don't you actually want to remove this field though?

[alexander-shaposhnikov]

Object.h

587 ↗

(On Diff #150219)

right, right, wrong diff

[alexander-shaposhnikov]

attach the correct diff

[jhenderson]

Okay, that makes more sense!

LGTM.

[paulsemel]

LGTM

llvm/trunk/tools/llvm-objcopy/Object.h

public:
   ELFReader(StringRef File);
 };
 
 class Object {
 private:
   using SecPtr = std::unique_ptr<SectionBase>;
   using SegPtr = std::unique_ptr<Segment>;
 
-  std::shared_ptr<MemoryBuffer> OwnedData;
   std::vector<SecPtr> Sections;
   std::vector<SegPtr> Segments;
 
 public:
   template <class T>
   using Range = iterator_range<
       pointee_iterator<typename std::vector<std::unique_ptr<T>>::iterator>>;
 
public:
   uint32_t Type;
   uint32_t Machine;
   uint32_t Version;
   uint32_t Flags;
 
   StringTableSection *SectionNames = nullptr;
   SymbolTableSection *SymbolTable = nullptr;
 
-  explicit Object(std::shared_ptr<MemoryBuffer> Data)
-      : OwnedData(std::move(Data)) {}
-  virtual ~Object() = default;
-
   void sortSections();
   SectionTableRef sections() { return SectionTableRef(Sections); }
   ConstRange<SectionBase> sections() const {
     return make_pointee_range(Sections);
   }
   Range<Segment> segments() { return make_pointee_range(Segments); }
   ConstRange<Segment> segments() const { return make_pointee_range(Segments); }
 

llvm/trunk/tools/llvm-objcopy/Object.cpp

ElfType ELFReader::getElfType() const {
   if (isa<ELFObjectFile<ELF32BE>>(Bin.get()))
     return ELFT_ELF32BE;
   if (isa<ELFObjectFile<ELF64BE>>(Bin.get()))
     return ELFT_ELF64BE;
   llvm_unreachable("Invalid ELFType");
 }
 
 std::unique_ptr<Object> ELFReader::create() const {
-  auto Obj = llvm::make_unique<Object>(Data);
+  auto Obj = llvm::make_unique<Object>();
   if (auto *o = dyn_cast<ELFObjectFile<ELF32LE>>(Bin.get())) {
     ELFBuilder<ELF32LE> Builder(*o, *Obj);
     Builder.build();
     return Obj;
   } else if (auto *o = dyn_cast<ELFObjectFile<ELF64LE>>(Bin.get())) {
     ELFBuilder<ELF64LE> Builder(*o, *Obj);
     Builder.build();
     return Obj;