--- old/src/hotspot/share/memory/metaspace/printMetaspaceInfoKlassClosure.cpp	2018-05-19 07:14:07.440398821 +0200
+++ new/src/hotspot/share/memory/metaspace/printMetaspaceInfoKlassClosure.cpp	2018-05-19 07:14:07.296397647 +0200
@@ -37,6 +37,82 @@
 
 namespace metaspace {
 
+bool PrintMetaspaceInfoKlassClosure::print_reflection_invocation_target(outputStream* out, InstanceKlass* magic_accessor_impl_class) {
+  assert(magic_accessor_impl_class->is_subclass_of(SystemDictionary::reflect_ConstructorAccessorImpl_klass()) ||
+         magic_accessor_impl_class->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass()), "Must be.");
+
+  // We extract target class name, method name and sig from the constant pool of the Accessor class.
+  // This is an excerpt of the Constant pool (see jdk/internal/reflect/MethodAccessorGenerator.java:)
+
+  // (^  = Only present if generating SerializationConstructorAccessor)
+  // 1    [UTF-8] [This class's name]
+  // 2    [CONSTANT_Class_info] for above
+  // 3    [UTF-8] "jdk/internal/reflect/{MethodAccessorImpl,ConstructorAccessorImpl,SerializationConstructorAccessorImpl}"
+  // 4    [CONSTANT_Class_info] for above
+  // 5    [UTF-8] [Target class's name]
+  // 6    [CONSTANT_Class_info] for above
+  // 7^   [UTF-8] [Serialization: Class's name in which to invoke constructor]
+  // 8^   [CONSTANT_Class_info] for above
+  // 9    [UTF-8] target method or constructor name
+  // 10   [UTF-8] target method or constructor signature
+
+  // Note that these strings are found at slightly different slots depending on the class type:
+  // - MethodAccessorImpl, ConstructoreAccessorImpl: slots 5, 7 and 8.
+  // - SerializationConstructorAccessorImpl: slots 5, 9 and 10.
+  // Unfortunately SerializationConstructorAccessorImpl is a child of ConstructoreAccessorImpl and there
+  //  is no easy way to tell them apart. So we examine parent class name.
+  const int parent_class_name_cpi = 3;
+  const char* parent_class_name = NULL;
+
+  const int target_class_name_cpi = 5;
+  const char* target_class_name = NULL;
+
+  int target_method_name_cpi = -1;
+  const char* target_method_name = NULL;
+
+  int target_method_signature_cpi = -1;
+  const char* target_method_signature = NULL;
+
+  ConstantPool* const cp = magic_accessor_impl_class->constants();
+  if (!cp->tag_at(parent_class_name_cpi).is_utf8()) {
+    return false;
+  }
+
+  parent_class_name = cp->symbol_at(parent_class_name_cpi)->as_C_string();
+
+  if (strcmp("jdk/internal/reflect/SerializationConstructorAccessorImpl", parent_class_name) == 0) {
+    target_method_name_cpi = 9;
+    target_method_signature_cpi = 10;
+  } else if (strcmp("jdk/internal/reflect/ConstructorAccessorImpl", parent_class_name) == 0 ||
+             strcmp("jdk/internal/reflect/MethodAccessorImpl", parent_class_name) == 0) {
+    target_method_name_cpi = 7;
+    target_method_signature_cpi = 8;
+  } else {
+    return false;
+  }
+
+  assert(target_method_name_cpi != -1 && target_method_signature_cpi != -1, "Must be");
+  if (target_method_name_cpi == -1 || target_method_signature_cpi == -1) {
+    return false; // behave well in release.
+  }
+
+  if (!cp->tag_at(target_class_name_cpi).is_utf8() || !cp->tag_at(target_method_name_cpi).is_utf8() ||
+      !cp->tag_at(target_method_signature_cpi).is_utf8()) {
+    return false;
+  }
+
+  target_class_name = cp->symbol_at(target_class_name_cpi)->as_C_string();
+  target_method_name = cp->symbol_at(target_method_name_cpi)->as_C_string();
+  target_method_signature = cp->symbol_at(target_method_signature_cpi)->as_C_string();
+
+  if (target_class_name == NULL || target_method_name == NULL || target_method_signature == NULL) {
+    return false;
+  }
+  out->print("%s::%s %s", target_class_name, target_method_name, target_method_signature);
+
+  return true;
+}
+
 PrintMetaspaceInfoKlassClosure::PrintMetaspaceInfoKlassClosure(outputStream* out, bool do_print)
 : _out(out), _do_print(do_print)
 , _num_classes(0), _num_instance_classes(0), _num_array_classes(0) {
@@ -54,6 +130,21 @@
     _out->print(UINTX_FORMAT_W(4) ": ", _num_classes);
     ResourceMark rm;
     _out->print("%s", k->external_name());
+
+    if (k->is_instance_klass()) {
+      // For descendants of {Method|ConstructorAccessor}Impl, print target class and method/ctor
+      InstanceKlass* ik = InstanceKlass::cast(k);
+      if (ik->is_initialized()) {
+        if (ik->is_subclass_of(SystemDictionary::reflect_ConstructorAccessorImpl_klass()) ||
+            ik->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
+          _out->print(" (invokes: ");
+          if (!print_reflection_invocation_target(_out, ik)) {
+            _out->print("?");
+          }
+          _out->print(")");
+        }
+      }
+    }
   }
 }