8264565: Templatize num_arguments() functions of DCmd subclasses

Reviewed-by: coleenp, dholmes

src/hotspot/share/classfile/stringTable.cpp

@@ -698,17 +698,6 @@ void StringtableDCmd::execute(DCmdSource source, TRAPS) {
   VMThread::execute(&dumper);
 }
 
-int StringtableDCmd::num_arguments() {
-  ResourceMark rm;
-  StringtableDCmd* dcmd = new StringtableDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 // Sharing
 #if INCLUDE_CDS_JAVA_HEAP
 oop StringTable::lookup_shared(const jchar* name, int len, unsigned int hash) {

src/hotspot/share/classfile/symbolTable.cpp

@@ -881,14 +881,3 @@ void SymboltableDCmd::execute(DCmdSource source, TRAPS) {
                          _verbose.value());
   VMThread::execute(&dumper);
 }
-
-int SymboltableDCmd::num_arguments() {
-  ResourceMark rm;
-  SymboltableDCmd* dcmd = new SymboltableDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}

src/hotspot/share/classfile/systemDictionary.cpp

@@ -2526,14 +2526,3 @@ void SystemDictionaryDCmd::execute(DCmdSource source, TRAPS) {
                          _verbose.value());
   VMThread::execute(&dumper);
 }
-
-int SystemDictionaryDCmd::num_arguments() {
-  ResourceMark rm;
-  SystemDictionaryDCmd* dcmd = new SystemDictionaryDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}

src/hotspot/share/services/diagnosticCommand.cpp

@@ -219,17 +219,6 @@ void HelpDCmd::execute(DCmdSource source, TRAPS) {
   }
 }
 
-int HelpDCmd::num_arguments() {
-  ResourceMark rm;
-  HelpDCmd* dcmd = new HelpDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 void VersionDCmd::execute(DCmdSource source, TRAPS) {
   output()->print_cr("%s version %s", VM_Version::vm_name(),
           VM_Version::vm_release());
@@ -258,17 +247,6 @@ void PrintVMFlagsDCmd::execute(DCmdSource source, TRAPS) {
   }
 }
 
-int PrintVMFlagsDCmd::num_arguments() {
-    ResourceMark rm;
-    PrintVMFlagsDCmd* dcmd = new PrintVMFlagsDCmd(NULL, false);
-    if (dcmd != NULL) {
-      DCmdMark mark(dcmd);
-      return dcmd->_dcmdparser.num_arguments();
-    } else {
-      return 0;
-    }
-}
-
 SetVMFlagDCmd::SetVMFlagDCmd(outputStream* output, bool heap) :
                                    DCmdWithParser(output, heap),
   _flag("flag name", "The name of the flag we want to set",
@@ -292,17 +270,6 @@ void SetVMFlagDCmd::execute(DCmdSource source, TRAPS) {
   }
 }
 
-int SetVMFlagDCmd::num_arguments() {
-  ResourceMark rm;
-  SetVMFlagDCmd* dcmd = new SetVMFlagDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 void JVMTIDataDumpDCmd::execute(DCmdSource source, TRAPS) {
   if (JvmtiExport::should_post_data_dump()) {
     JvmtiExport::post_data_dump();
@@ -360,16 +327,6 @@ void JVMTIAgentLoadDCmd::execute(DCmdSource source, TRAPS) {
   }
 }
 
-int JVMTIAgentLoadDCmd::num_arguments() {
-  ResourceMark rm;
-  JVMTIAgentLoadDCmd* dcmd = new JVMTIAgentLoadDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
 #endif // INCLUDE_JVMTI
 #endif // INCLUDE_SERVICES
 
@@ -432,17 +389,6 @@ void VMUptimeDCmd::execute(DCmdSource source, TRAPS) {
   output()->print_cr(" s");
 }
 
-int VMUptimeDCmd::num_arguments() {
-  ResourceMark rm;
-  VMUptimeDCmd* dcmd = new VMUptimeDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 void VMInfoDCmd::execute(DCmdSource source, TRAPS) {
   VMError::print_vm_info(_output);
 }
@@ -544,17 +490,6 @@ void HeapDumpDCmd::execute(DCmdSource source, TRAPS) {
   dumper.dump(_filename.value(), output(), (int) level);
 }
 
-int HeapDumpDCmd::num_arguments() {
-  ResourceMark rm;
-  HeapDumpDCmd* dcmd = new HeapDumpDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 ClassHistogramDCmd::ClassHistogramDCmd(outputStream* output, bool heap) :
                                        DCmdWithParser(output, heap),
   _all("-all", "Inspect all objects, including unreachable objects",
@@ -568,17 +503,6 @@ void ClassHistogramDCmd::execute(DCmdSource source, TRAPS) {
   VMThread::execute(&heapop);
 }
 
-int ClassHistogramDCmd::num_arguments() {
-  ResourceMark rm;
-  ClassHistogramDCmd* dcmd = new ClassHistogramDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 #endif // INCLUDE_SERVICES
 
 ThreadDumpDCmd::ThreadDumpDCmd(outputStream* output, bool heap) :
@@ -603,17 +527,6 @@ void ThreadDumpDCmd::execute(DCmdSource source, TRAPS) {
   VMThread::execute(&op3);
 }
 
-int ThreadDumpDCmd::num_arguments() {
-  ResourceMark rm;
-  ThreadDumpDCmd* dcmd = new ThreadDumpDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 // Enhanced JMX Agent support
 
 JMXStartRemoteDCmd::JMXStartRemoteDCmd(outputStream *output, bool heap_allocated) :
@@ -729,19 +642,6 @@ JMXStartRemoteDCmd::JMXStartRemoteDCmd(outputStream *output, bool heap_allocated
     _dcmdparser.add_dcmd_option(&_jdp_name);
 }
 
-
-int JMXStartRemoteDCmd::num_arguments() {
-  ResourceMark rm;
-  JMXStartRemoteDCmd* dcmd = new JMXStartRemoteDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
-
 void JMXStartRemoteDCmd::execute(DCmdSource source, TRAPS) {
     ResourceMark rm(THREAD);
     HandleMark hm(THREAD);
@@ -929,17 +829,6 @@ void CodeHeapAnalyticsDCmd::execute(DCmdSource source, TRAPS) {
 
   CompileBroker::print_heapinfo(output(), _function.value(), granularity);
 }
-
-int CodeHeapAnalyticsDCmd::num_arguments() {
-  ResourceMark rm;
-  CodeHeapAnalyticsDCmd* dcmd = new CodeHeapAnalyticsDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
 //---<  END  >--- CodeHeap State Analytics.
 
 EventLogDCmd::EventLogDCmd(outputStream* output, bool heap) :
@@ -970,17 +859,6 @@ void EventLogDCmd::execute(DCmdSource source, TRAPS) {
   }
 }
 
-int EventLogDCmd::num_arguments() {
-  ResourceMark rm;
-  EventLogDCmd* dcmd = new EventLogDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 void CompilerDirectivesPrintDCmd::execute(DCmdSource source, TRAPS) {
   DirectivesStack::print(output());
 }
@@ -995,17 +873,6 @@ void CompilerDirectivesAddDCmd::execute(DCmdSource source, TRAPS) {
   DirectivesParser::parse_from_file(_filename.value(), output());
 }
 
-int CompilerDirectivesAddDCmd::num_arguments() {
-  ResourceMark rm;
-  CompilerDirectivesAddDCmd* dcmd = new CompilerDirectivesAddDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 void CompilerDirectivesRemoveDCmd::execute(DCmdSource source, TRAPS) {
   DirectivesStack::pop(1);
 }
@@ -1032,18 +899,6 @@ void ClassHierarchyDCmd::execute(DCmdSource source, TRAPS) {
                                                _print_subclasses.value(), _classname.value());
   VMThread::execute(&printClassHierarchyOp);
 }
-
-int ClassHierarchyDCmd::num_arguments() {
-  ResourceMark rm;
-  ClassHierarchyDCmd* dcmd = new ClassHierarchyDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 #endif
 
 class VM_DumpTouchedMethods : public VM_Operation {
@@ -1061,10 +916,6 @@ public:
   }
 };
 
-TouchedMethodsDCmd::TouchedMethodsDCmd(outputStream* output, bool heap) :
-                                       DCmdWithParser(output, heap)
-{}
-
 void TouchedMethodsDCmd::execute(DCmdSource source, TRAPS) {
   if (!LogTouchedMethods) {
     output()->print_cr("VM.print_touched_methods command requires -XX:+LogTouchedMethods");
@@ -1073,19 +924,11 @@ void TouchedMethodsDCmd::execute(DCmdSource source, TRAPS) {
   VM_DumpTouchedMethods dumper(output());
   VMThread::execute(&dumper);
 }
-
-int TouchedMethodsDCmd::num_arguments() {
-  return 0;
-}
-
 #if INCLUDE_JVMTI
 extern "C" typedef char const* (JNICALL *debugInit_startDebuggingViaCommandPtr)(JNIEnv* env, jthread thread, char const** transport_name,
                                                                                 char const** address, jboolean* first_start);
 static debugInit_startDebuggingViaCommandPtr dvc_start_ptr = NULL;
 
-DebugOnCmdStartDCmd::DebugOnCmdStartDCmd(outputStream* output, bool heap) : DCmdWithParser(output, heap) {
-}
-
 void DebugOnCmdStartDCmd::execute(DCmdSource source, TRAPS) {
   char const* transport = NULL;
   char const* addr = NULL;

src/hotspot/share/services/diagnosticCommand.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -52,7 +52,6 @@ public:
            "'help all' will show help for all commands.";
   }
   static const char* impact() { return "Low"; }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -69,7 +68,6 @@ public:
                         "java.vm.version", "read"};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -86,7 +84,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS) {
     Arguments::print_on(_output);
   }
@@ -108,7 +105,6 @@ public:
                           "*", "read"};
       return p;
     }
-    static int num_arguments() { return 0; }
     virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -130,7 +126,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -153,7 +148,6 @@ public:
                         "control", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -172,7 +166,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -194,7 +187,6 @@ public:
                         "control", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 #endif // INCLUDE_JVMTI
@@ -217,9 +209,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() {
-    return 0;
-  };
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -235,7 +224,6 @@ public:
   static const char* impact() {
     return "Low";
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -252,7 +240,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -266,7 +253,6 @@ public:
     static const char* impact() {
       return "Medium: Depends on Java heap size and content.";
     }
-    static int num_arguments() { return 0; }
     virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -280,7 +266,6 @@ public:
     static const char* impact() {
       return "Medium: Depends on Java content.";
     }
-    static int num_arguments() { return 0; }
     virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -294,7 +279,6 @@ public:
   static const char* impact() {
     return "Medium";
   }
-  static int num_arguments() { return 0; }
   static const JavaPermission permission() {
     JavaPermission p = {"java.lang.management.ManagementPermission",
       "monitor", NULL};
@@ -314,7 +298,6 @@ public:
   static const char* impact() {
     return "Medium";
   }
-  static int num_arguments() { return 0; }
   static const JavaPermission permission() {
     JavaPermission p = {"java.lang.management.ManagementPermission",
       "monitor", NULL};
@@ -348,7 +331,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 #endif // INCLUDE_SERVICES
@@ -373,7 +355,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -400,13 +381,12 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
-class TouchedMethodsDCmd : public DCmdWithParser {
+class TouchedMethodsDCmd : public DCmd {
 public:
-  TouchedMethodsDCmd(outputStream* output, bool heap);
+  TouchedMethodsDCmd(outputStream* output, bool heap) : DCmd(output, heap) {}
   static const char* name() {
     return "VM.print_touched_methods";
   }
@@ -416,7 +396,6 @@ public:
   static const char* impact() {
     return "Medium: Depends on Java content.";
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -439,7 +418,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -488,10 +466,7 @@ public:
     return "Start remote management agent.";
   }
 
-  static int num_arguments();
-
   virtual void execute(DCmdSource source, TRAPS);
-
 };
 
 class JMXStartLocalDCmd : public DCmd {
@@ -573,7 +548,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -595,7 +569,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 #endif // LINUX
@@ -617,7 +590,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -638,7 +610,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -664,7 +635,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 //---<  END  >--- CodeHeap State Analytics.
@@ -686,7 +656,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -707,7 +676,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -730,7 +698,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -751,7 +718,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -817,7 +783,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -840,7 +805,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
@@ -863,14 +827,13 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 
 #if INCLUDE_JVMTI
-class DebugOnCmdStartDCmd : public DCmdWithParser {
+class DebugOnCmdStartDCmd : public DCmd {
 public:
-  DebugOnCmdStartDCmd(outputStream* output, bool heap);
+  DebugOnCmdStartDCmd(outputStream* output, bool heap) : DCmd(output, heap) {}
   static const char* name() {
     return "VM.start_java_debugging";
   }
@@ -884,7 +847,6 @@ public:
     JavaPermission p = { "java.lang.management.ManagementPermission", "control", NULL };
     return p;
   }
-  static int num_arguments() { return 0; }
   virtual void execute(DCmdSource source, TRAPS);
 };
 #endif // INCLUDE_JVMTI
@@ -909,7 +871,6 @@ public:
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 };
 

src/hotspot/share/services/diagnosticFramework.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,10 +27,12 @@
 
 #include "classfile/vmSymbols.hpp"
 #include "memory/allocation.hpp"
+#include "memory/resourceArea.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/os.hpp"
 #include "runtime/vmThread.hpp"
 #include "utilities/ostream.hpp"
+#include <type_traits>
 
 
 enum DCmdSource {
@@ -274,6 +276,10 @@ public:
     JavaPermission p = {NULL, NULL, NULL};
     return p;
   }
+  // num_arguments() is used by the DCmdFactoryImpl::get_num_arguments() template functions.
+  // - For subclasses of DCmdWithParser, it's calculated by DCmdParser::num_arguments().
+  // - Other subclasses of DCmd have zero arguments by default. You can change this
+  //   by defining your own version of MyDCmd::num_arguments().
   static int num_arguments()        { return 0; }
   outputStream* output() const      { return _output; }
   bool is_heap_allocated() const    { return _is_heap_allocated; }
@@ -321,6 +327,9 @@ public:
   virtual void print_help(const char* name) const;
   virtual GrowableArray<const char*>* argument_name_array() const;
   virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array() const;
+  DCmdParser* dcmdparser() {
+    return &_dcmdparser;
+  }
 };
 
 class DCmdMark : public StackObj {
@@ -404,7 +413,7 @@ private:
 template <class DCmdClass> class DCmdFactoryImpl : public DCmdFactory {
 public:
   DCmdFactoryImpl(uint32_t flags, bool enabled, bool hidden) :
-    DCmdFactory(DCmdClass::num_arguments(), flags, enabled, hidden) { }
+    DCmdFactory(get_num_arguments<DCmdClass>(), flags, enabled, hidden) { }
   // Returns a resourceArea allocated instance
   DCmd* create_resource_instance(outputStream* output) const {
     return new DCmdClass(output, false);
@@ -424,6 +433,24 @@ public:
   const char* disabled_message() const {
      return DCmdClass::disabled_message();
   }
+
+private:
+  template <typename T, ENABLE_IF(!std::is_base_of<DCmdWithParser, T>::value)>
+  static int get_num_arguments() {
+    return T::num_arguments();
+  }
+
+  template <typename T, ENABLE_IF(std::is_base_of<DCmdWithParser, T>::value)>
+  static int get_num_arguments() {
+    ResourceMark rm;
+    DCmdClass* dcmd = new DCmdClass(NULL, false);
+    if (dcmd != NULL) {
+      DCmdMark mark(dcmd);
+      return dcmd->dcmdparser()->num_arguments();
+    } else {
+      return 0;
+    }
+  }
 };
 
 // This class provides a convenient way to register Dcmds, without a need to change

src/hotspot/share/services/nmtDCmd.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -160,17 +160,6 @@ void NMTDCmd::execute(DCmdSource source, TRAPS) {
   }
 }
 
-int NMTDCmd::num_arguments() {
-  ResourceMark rm;
-  NMTDCmd* dcmd = new NMTDCmd(NULL, false);
-  if (dcmd != NULL) {
-    DCmdMark mark(dcmd);
-    return dcmd->_dcmdparser.num_arguments();
-  } else {
-    return 0;
-  }
-}
-
 void NMTDCmd::report(bool summaryOnly, size_t scale_unit) {
   MemBaseline baseline;
   if (baseline.baseline(summaryOnly)) {

src/hotspot/share/services/nmtDCmd.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,7 +60,6 @@ class NMTDCmd: public DCmdWithParser {
                         "monitor", NULL};
     return p;
   }
-  static int num_arguments();
   virtual void execute(DCmdSource source, TRAPS);
 
  private: