Fix equality of implicit closures in the Dart VM.

runtime/lib/function.cc

Index: runtime/lib/function.cc
===================================================================
--- runtime/lib/function.cc	(revision 26064)
+++ runtime/lib/function.cc	(working copy)
@@ -27,4 +27,50 @@
   return result.raw();
 }
 
+
+DEFINE_NATIVE_ENTRY(FunctionImpl_equals, 2) {
+  const Instance& receiver = Instance::CheckedHandle(
+      isolate, arguments->NativeArgAt(0));
+  ASSERT(receiver.IsClosure());
+  GET_NATIVE_ARGUMENT(Instance, other, arguments->NativeArgAt(1));
+  if (receiver.raw() == other.raw()) return Bool::True().raw();
+  if (other.IsClosure()) {
+    const Function& func_a = Function::Handle(Closure::function(receiver));
+    const Function& func_b = Function::Handle(Closure::function(other));
+    if (func_a.raw() == func_b.raw()) {
+      ASSERT(!func_a.IsImplicitStaticClosureFunction());
+      if (func_a.IsImplicitInstanceClosureFunction()) {
+        const Context& context_a = Context::Handle(Closure::context(receiver));
+        const Context& context_b = Context::Handle(Closure::context(other));
+        const Instance& receiver_a = Instance::Handle(context_a.At(0));
+        const Instance& receiver_b = Instance::Handle(context_b.At(0));
+        if (receiver_a.raw() == receiver_b.raw()) return Bool::True().raw();
+      }
+    }
+  }
+  return Bool::False().raw();
+}
+
+
+DEFINE_NATIVE_ENTRY(FunctionImpl_hashCode, 1) {
+  const Instance& receiver = Instance::CheckedHandle(
+      isolate, arguments->NativeArgAt(0));
+  if (receiver.IsClosure()) {
+    const Function& func = Function::Handle(Closure::function(receiver));
+    // Hash together name, class name and signature.
+    const Class& cls = Class::Handle(func.Owner());
+    intptr_t result = String::Handle(func.name()).Hash();
+    result += String::Handle(func.Signature()).Hash();
+    result += String::Handle(cls.Name()).Hash();
+    // Finalize hash value like for strings so that it fits into a smi.
+    result += result << 3;
+    result ^= result >> 11;
+    result += result << 15;
+    result &=((static_cast<intptr_t>(1) << String::kHashBits) - 1);
+    return Smi::New(result);
+  }
+  UNREACHABLE();
+  return Object::null();
+}
+
 }  // namespace dart