8307553: Remove dead code MetaspaceClosure::push_method_entry

Reviewed-by: coleenp, ccheung

src/hotspot/share/cds/archiveBuilder.cpp

@@ -167,7 +167,6 @@ ArchiveBuilder::ArchiveBuilder() :
 {
   _klasses = new (mtClassShared) GrowableArray<Klass*>(4 * K, mtClassShared);
   _symbols = new (mtClassShared) GrowableArray<Symbol*>(256 * K, mtClassShared);
-  _special_refs = new (mtClassShared) GrowableArray<SpecialRefInfo>(24 * K, mtClassShared);
 
   assert(_current == nullptr, "must be");
   _current = this;
@@ -185,7 +184,6 @@ ArchiveBuilder::~ArchiveBuilder() {
 
   delete _klasses;
   delete _symbols;
-  delete _special_refs;
   if (_shared_rs.is_reserved()) {
     _shared_rs.release();
   }
@@ -422,13 +420,6 @@ public:
     return _builder->gather_one_source_obj(enclosing_ref(), ref, read_only);
   }
 
-  virtual void push_special(SpecialRef type, Ref* ref, intptr_t* p) {
-    assert(type == _method_entry_ref, "only special type allowed for now");
-    address src_obj = ref->obj();
-    size_t field_offset = pointer_delta(p, src_obj,  sizeof(u1));
-    _builder->add_special_ref(type, src_obj, field_offset);
-  };
-
   virtual void do_pending_ref(Ref* ref) {
     if (ref->obj() != nullptr) {
       _builder->remember_embedded_pointer_in_copied_obj(enclosing_ref(), ref);
@@ -470,10 +461,6 @@ bool ArchiveBuilder::gather_one_source_obj(MetaspaceClosure::Ref* enclosing_ref,
   }
 }
 
-void ArchiveBuilder::add_special_ref(MetaspaceClosure::SpecialRef type, address src_obj, size_t field_offset) {
-  _special_refs->append(SpecialRefInfo(type, src_obj, field_offset));
-}
-
 void ArchiveBuilder::remember_embedded_pointer_in_copied_obj(MetaspaceClosure::Ref* enclosing_ref,
                                                              MetaspaceClosure::Ref* ref) {
   assert(ref->obj() != nullptr, "should have checked");
@@ -672,21 +659,6 @@ void ArchiveBuilder::relocate_embedded_pointers(ArchiveBuilder::SourceObjList* s
   }
 }
 
-void ArchiveBuilder::update_special_refs() {
-  for (int i = 0; i < _special_refs->length(); i++) {
-    SpecialRefInfo s = _special_refs->at(i);
-    size_t field_offset = s.field_offset();
-    address src_obj = s.src_obj();
-    address dst_obj = get_buffered_addr(src_obj);
-    intptr_t* src_p = (intptr_t*)(src_obj + field_offset);
-    intptr_t* dst_p = (intptr_t*)(dst_obj + field_offset);
-    assert(s.type() == MetaspaceClosure::_method_entry_ref, "only special type allowed for now");
-
-    assert(*src_p == *dst_p, "must be a copy");
-    ArchivePtrMarker::mark_pointer((address*)dst_p);
-  }
-}
-
 class RefRelocator: public MetaspaceClosure {
   ArchiveBuilder* _builder;
 
@@ -715,7 +687,6 @@ void ArchiveBuilder::relocate_metaspaceobj_embedded_pointers() {
   log_info(cds)("Relocating embedded pointers in core regions ... ");
   relocate_embedded_pointers(&_rw_src_objs);
   relocate_embedded_pointers(&_ro_src_objs);
-  update_special_refs();
 }
 
 // We must relocate vmClasses::_klasses[] only after we have copied the

src/hotspot/share/cds/archiveBuilder.hpp

@@ -122,23 +122,6 @@ public:
   };
 
 private:
-  class SpecialRefInfo {
-    // We have a "special pointer" of the given _type at _field_offset of _src_obj.
-    // See MetaspaceClosure::push_special().
-    MetaspaceClosure::SpecialRef _type;
-    address _src_obj;
-    size_t _field_offset;
-
-  public:
-    SpecialRefInfo() {}
-    SpecialRefInfo(MetaspaceClosure::SpecialRef type, address src_obj, size_t field_offset)
-      : _type(type), _src_obj(src_obj), _field_offset(field_offset) {}
-
-    MetaspaceClosure::SpecialRef type() const { return _type;         }
-    address src_obj()                   const { return _src_obj;      }
-    size_t field_offset()               const { return _field_offset; }
-  };
-
   class SourceObjInfo {
     MetaspaceClosure::Ref* _ref; // The object that's copied into the buffer
     uintx _ptrmap_start;     // The bit-offset of the start of this object (inclusive)
@@ -230,7 +213,6 @@ private:
   ResizeableResourceHashtable<address, address, AnyObj::C_HEAP, mtClassShared> _buffered_to_src_table;
   GrowableArray<Klass*>* _klasses;
   GrowableArray<Symbol*>* _symbols;
-  GrowableArray<SpecialRefInfo>* _special_refs;
 
   // statistics
   DumpAllocStats _alloc_stats;
@@ -268,7 +250,6 @@ private:
   void make_shallow_copies(DumpRegion *dump_region, const SourceObjList* src_objs);
   void make_shallow_copy(DumpRegion *dump_region, SourceObjInfo* src_info);
 
-  void update_special_refs();
   void relocate_embedded_pointers(SourceObjList* src_objs);
 
   bool is_excluded(Klass* k);
@@ -357,7 +338,6 @@ public:
   void gather_source_objs();
   bool gather_klass_and_symbol(MetaspaceClosure::Ref* ref, bool read_only);
   bool gather_one_source_obj(MetaspaceClosure::Ref* enclosing_ref, MetaspaceClosure::Ref* ref, bool read_only);
-  void add_special_ref(MetaspaceClosure::SpecialRef type, address src_obj, size_t field_offset);
   void remember_embedded_pointer_in_copied_obj(MetaspaceClosure::Ref* enclosing_ref, MetaspaceClosure::Ref* ref);
 
   DumpRegion* rw_region() { return &_rw_region; }

src/hotspot/share/memory/metaspaceClosure.hpp

@@ -78,10 +78,6 @@ public:
     _default
   };
 
-  enum SpecialRef {
-    _method_entry_ref
-  };
-
   // class MetaspaceClosure::Ref --
   //
   // MetaspaceClosure can be viewed as a very simple type of copying garbage
@@ -356,19 +352,6 @@ public:
   }
 #endif
 
-  template <class T> void push_method_entry(T** mpp, intptr_t* p) {
-    Ref* ref = new MSORef<T>(mpp, _default);
-    push_special(_method_entry_ref, ref, (intptr_t*)p);
-    if (!ref->keep_after_pushing()) {
-      delete ref;
-    }
-  }
-
-  // This is for tagging special pointers that are not a reference to MetaspaceObj. It's currently
-  // used to mark the method entry points in Method/ConstMethod.
-  virtual void push_special(SpecialRef type, Ref* obj, intptr_t* p) {
-    assert(type == _method_entry_ref, "only special type allowed for now");
-  }
 };
 
 // This is a special MetaspaceClosure that visits each unique MetaspaceObj once.