Reapply "Improve hashCode for closure objects" with fixes.

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_OBJECT_H_
 #define RUNTIME_VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2392 matching lines @@
   // If none exists yet, create one and remember it.
   RawFunction* ImplicitClosureFunction() const;
   void DropUncompiledImplicitClosureFunction() const;
 
   // Return the closure implicitly created for this function.
   // If none exists yet, create one and remember it.
   RawInstance* ImplicitStaticClosure() const;
 
   RawInstance* ImplicitInstanceClosure(const Instance& receiver) const;
 
-  RawSmi* GetClosureHashCode() const;
+  intptr_t ComputeClosureHash() const;
 
   // Redirection information for a redirecting factory.
   bool IsRedirectingFactory() const;
   RawType* RedirectionType() const;
   void SetRedirectionType(const Type& type) const;
   RawString* RedirectionIdentifier() const;
   void SetRedirectionIdentifier(const String& identifier) const;
   RawFunction* RedirectionTarget() const;
   void SetRedirectionTarget(const Function& target) const;
 
@@ skipping 650 matching lines @@
   RawFunction* parent_function() const { return raw_ptr()->parent_function_; }
   void set_parent_function(const Function& value) const;
 
   // Signature type of this closure function.
   RawType* signature_type() const { return raw_ptr()->signature_type_; }
   void set_signature_type(const Type& value) const;
 
   RawInstance* implicit_static_closure() const { return raw_ptr()->closure_; }
   void set_implicit_static_closure(const Instance& closure) const;
 
-  RawObject* hash() const { return raw_ptr()->hash_; }
-  void set_hash(intptr_t value) const;
-
   static RawClosureData* New();
 
   FINAL_HEAP_OBJECT_IMPLEMENTATION(ClosureData, Object);
   friend class Class;
   friend class Function;
   friend class HeapProfiler;
 };
 
 class SignatureData : public Object {
  public:
@@ skipping 2437 matching lines @@
   // the formal parameters given in param_names, and is invoked with
   // the argument values given in param_values.
   RawObject* Evaluate(const Class& method_cls,
                       const String& expr,
                       const Array& param_names,
                       const Array& param_values) const;
 
   // Equivalent to invoking hashCode on this instance.
   virtual RawObject* HashCode() const;
 
+  // Equivalent to invoking identityHashCode with this instance.
+  RawObject* IdentityHashCode() const;
+
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawInstance));
   }
 
   static RawInstance* New(const Class& cls, Heap::Space space = Heap::kNew);
 
   // Array/list element address computations.
   static intptr_t DataOffsetFor(intptr_t cid);
   static intptr_t ElementSizeFor(intptr_t cid);
 
@@ skipping 2795 matching lines @@
   static intptr_t function_type_arguments_offset() {
     return OFFSET_OF(RawClosure, function_type_arguments_);
   }
 
   RawFunction* function() const { return raw_ptr()->function_; }
   static intptr_t function_offset() { return OFFSET_OF(RawClosure, function_); }
 
   RawContext* context() const { return raw_ptr()->context_; }
   static intptr_t context_offset() { return OFFSET_OF(RawClosure, context_); }
 
+  RawSmi* hash() const { return raw_ptr()->hash_; }
+  static intptr_t hash_offset() { return OFFSET_OF(RawClosure, hash_); }
+
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawClosure));
   }
 
   // Returns true if all elements are OK for canonicalization.
   virtual bool CheckAndCanonicalizeFields(Thread* thread,
                                           const char** error_str) const {
     // None of the fields of a closure are instances.
     return true;
   }
 
+  int64_t ComputeHash() const;
+
   static RawClosure* New(const TypeArguments& instantiator_type_arguments,
                          const TypeArguments& function_type_arguments,
                          const Function& function,
                          const Context& context,
                          Heap::Space space = Heap::kNew);
 
  private:
   static RawClosure* New();
 
   FINAL_HEAP_OBJECT_IMPLEMENTATION(Closure, Instance);
@@ skipping 549 matching lines @@
 
 inline void TypeArguments::SetHash(intptr_t value) const {
   // This is only safe because we create a new Smi, which does not cause
   // heap allocation.
   StoreSmi(&raw_ptr()->hash_, Smi::New(value));
 }
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_OBJECT_H_