6839872: remove implementation inheritance from JSR 292 APIs
authorjrose
Fri, 11 Mar 2011 22:33:47 -0800
changeset 8675 e9fef2a9bef7
parent 8674 303a2149d371
child 8676 9098d4e927e1
6839872: remove implementation inheritance from JSR 292 APIs Summary: consolidate runtime support in java.dyn.MethodHandleNatives; include transitional compatibility logic Reviewed-by: twisti
hotspot/src/share/vm/classfile/classFileParser.cpp
hotspot/src/share/vm/classfile/javaClasses.cpp
hotspot/src/share/vm/classfile/systemDictionary.cpp
hotspot/src/share/vm/classfile/systemDictionary.hpp
hotspot/src/share/vm/classfile/vmSymbols.cpp
hotspot/src/share/vm/classfile/vmSymbols.hpp
hotspot/src/share/vm/interpreter/linkResolver.cpp
hotspot/src/share/vm/oops/instanceKlass.hpp
hotspot/src/share/vm/oops/methodOop.cpp
hotspot/src/share/vm/prims/methodHandleWalk.cpp
hotspot/src/share/vm/prims/methodHandles.cpp
hotspot/src/share/vm/prims/nativeLookup.cpp
hotspot/src/share/vm/runtime/globals.hpp
--- a/hotspot/src/share/vm/classfile/classFileParser.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/classfile/classFileParser.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, 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
@@ -146,12 +146,14 @@
         break;
       case JVM_CONSTANT_MethodHandle :
       case JVM_CONSTANT_MethodType :
-        if (!EnableMethodHandles ||
-            _major_version < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
+        if (_major_version < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
           classfile_parse_error(
-            (!EnableMethodHandles ?
-             "This JVM does not support constant tag %u in class file %s" :
-             "Class file version does not support constant tag %u in class file %s"),
+            "Class file version does not support constant tag %u in class file %s",
+            tag, CHECK);
+        }
+        if (!EnableMethodHandles) {
+          classfile_parse_error(
+            "This JVM does not support constant tag %u in class file %s",
             tag, CHECK);
         }
         if (tag == JVM_CONSTANT_MethodHandle) {
@@ -170,12 +172,14 @@
       case JVM_CONSTANT_InvokeDynamicTrans :  // this tag appears only in old classfiles
       case JVM_CONSTANT_InvokeDynamic :
         {
-          if (!EnableInvokeDynamic ||
-              _major_version < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
+          if (_major_version < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {
             classfile_parse_error(
-              (!EnableInvokeDynamic ?
-               "This JVM does not support constant tag %u in class file %s" :
-               "Class file version does not support constant tag %u in class file %s"),
+              "Class file version does not support constant tag %u in class file %s",
+              tag, CHECK);
+          }
+          if (!EnableInvokeDynamic) {
+            classfile_parse_error(
+              "This JVM does not support constant tag %u in class file %s",
               tag, CHECK);
           }
           cfs->guarantee_more(5, CHECK);  // bsm_index, nt, tag/access_flags
@@ -2823,6 +2827,7 @@
     }
   }
 
+  if (AllowTransitionalJSR292 && word_sig_index == 0)  return;
   if (word_sig_index == 0)
     THROW_MSG(vmSymbols::java_lang_VirtualMachineError(),
               "missing I or J signature (for vmentry) in java.dyn.MethodHandle");
@@ -2862,6 +2867,7 @@
     }
   }
 
+  if (AllowTransitionalJSR292 && !found_vmentry)  return;
   if (!found_vmentry)
     THROW_MSG(vmSymbols::java_lang_VirtualMachineError(),
               "missing vmentry byte field in java.dyn.MethodHandle");
@@ -3230,7 +3236,12 @@
     }
 
     // adjust the vmentry field declaration in java.dyn.MethodHandle
-    if (EnableMethodHandles && class_name == vmSymbols::sun_dyn_MethodHandleImpl() && class_loader.is_null()) {
+    if (EnableMethodHandles && class_name == vmSymbols::java_dyn_MethodHandle() && class_loader.is_null()) {
+      java_dyn_MethodHandle_fix_pre(cp, fields, &fac, CHECK_(nullHandle));
+    }
+    if (AllowTransitionalJSR292 &&
+        EnableMethodHandles && class_name == vmSymbols::sun_dyn_MethodHandleImpl() && class_loader.is_null()) {
+      // allow vmentry field in MethodHandleImpl also
       java_dyn_MethodHandle_fix_pre(cp, fields, &fac, CHECK_(nullHandle));
     }
 
--- a/hotspot/src/share/vm/classfile/javaClasses.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/classfile/javaClasses.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, 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
@@ -66,6 +66,28 @@
     return ik->find_local_field(name_symbol, signature_symbol, fd);
 }
 
+static bool find_hacked_field(instanceKlass* ik,
+                              Symbol* name_symbol, Symbol* signature_symbol,
+                              fieldDescriptor* fd,
+                              bool allow_super = false) {
+  bool found = find_field(ik, name_symbol, signature_symbol, fd, allow_super);
+  if (!found && AllowTransitionalJSR292) {
+    Symbol* backup_sig = SystemDictionary::find_backup_signature(signature_symbol);
+    if (backup_sig != NULL) {
+      found = find_field(ik, name_symbol, backup_sig, fd, allow_super);
+      if (TraceMethodHandles) {
+        ResourceMark rm;
+        tty->print_cr("MethodHandles: %s.%s: backup for %s => %s%s",
+                      ik->name()->as_C_string(), name_symbol->as_C_string(),
+                      signature_symbol->as_C_string(), backup_sig->as_C_string(),
+                      (found ? "" : " (NOT FOUND)"));
+      }
+    }
+  }
+  return found;
+}
+#define find_field find_hacked_field  /* remove after AllowTransitionalJSR292 */
+
 // Helpful routine for computing field offsets at run time rather than hardcoding them
 static void
 compute_offset(int &dest_offset,
@@ -2200,13 +2222,15 @@
 void java_dyn_MethodHandle::compute_offsets() {
   klassOop k = SystemDictionary::MethodHandle_klass();
   if (k != NULL && EnableMethodHandles) {
-    compute_offset(_type_offset,      k, vmSymbols::type_name(),      vmSymbols::java_dyn_MethodType_signature(), true);
-    compute_offset(_vmtarget_offset,  k, vmSymbols::vmtarget_name(),  vmSymbols::object_signature(), true);
-    compute_offset(_vmentry_offset,   k, vmSymbols::vmentry_name(),   vmSymbols::machine_word_signature(), true);
+    bool allow_super = false;
+    if (AllowTransitionalJSR292)  allow_super = true;  // temporary, to access sun.dyn.MethodHandleImpl
+    compute_offset(_type_offset,      k, vmSymbols::type_name(),      vmSymbols::java_dyn_MethodType_signature(), allow_super);
+    compute_offset(_vmtarget_offset,  k, vmSymbols::vmtarget_name(),  vmSymbols::object_signature(), allow_super);
+    compute_offset(_vmentry_offset,   k, vmSymbols::vmentry_name(),   vmSymbols::machine_word_signature(), allow_super);
 
     // Note:  MH.vmslots (if it is present) is a hoisted copy of MH.type.form.vmslots.
     // It is optional pending experiments to keep or toss.
-    compute_optional_offset(_vmslots_offset, k, vmSymbols::vmslots_name(), vmSymbols::int_signature(), true);
+    compute_optional_offset(_vmslots_offset, k, vmSymbols::vmslots_name(), vmSymbols::int_signature(), allow_super);
   }
 }
 
@@ -2504,16 +2528,12 @@
 // Support for java_dyn_CallSite
 
 int java_dyn_CallSite::_target_offset;
-int java_dyn_CallSite::_caller_method_offset;
-int java_dyn_CallSite::_caller_bci_offset;
 
 void java_dyn_CallSite::compute_offsets() {
   if (!EnableInvokeDynamic)  return;
   klassOop k = SystemDictionary::CallSite_klass();
   if (k != NULL) {
     compute_offset(_target_offset, k, vmSymbols::target_name(), vmSymbols::java_dyn_MethodHandle_signature());
-    compute_offset(_caller_method_offset, k, vmSymbols::vmmethod_name(), vmSymbols::sun_dyn_MemberName_signature());
-    compute_offset(_caller_bci_offset, k, vmSymbols::vmindex_name(), vmSymbols::int_signature());
   }
 }
 
@@ -2525,22 +2545,6 @@
   site->obj_field_put(_target_offset, target);
 }
 
-oop java_dyn_CallSite::caller_method(oop site) {
-  return site->obj_field(_caller_method_offset);
-}
-
-void java_dyn_CallSite::set_caller_method(oop site, oop ref) {
-  site->obj_field_put(_caller_method_offset, ref);
-}
-
-jint java_dyn_CallSite::caller_bci(oop site) {
-  return site->int_field(_caller_bci_offset);
-}
-
-void java_dyn_CallSite::set_caller_bci(oop site, jint bci) {
-  site->int_field_put(_caller_bci_offset, bci);
-}
-
 
 // Support for java_security_AccessControlContext
 
--- a/hotspot/src/share/vm/classfile/systemDictionary.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/classfile/systemDictionary.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, 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
@@ -1887,27 +1887,99 @@
   0
 };
 
+Symbol* SystemDictionary::find_backup_symbol(Symbol* symbol,
+                                             const char* from_prefix,
+                                             const char* to_prefix) {
+  assert(AllowTransitionalJSR292, "");  // delete this subroutine
+  Symbol* backup_symbol = NULL;
+  size_t from_len = strlen(from_prefix);
+  if (strncmp((const char*) symbol->base(), from_prefix, from_len) != 0)
+    return NULL;
+  char buf[100];
+  size_t to_len = strlen(to_prefix);
+  size_t tail_len = symbol->utf8_length() - from_len;
+  size_t new_len = to_len + tail_len;
+  guarantee(new_len < sizeof(buf), "buf too small");
+  memcpy(buf, to_prefix, to_len);
+  memcpy(buf + to_len, symbol->base() + from_len, tail_len);
+  buf[new_len] = '\0';
+  vmSymbols::SID backup_sid = vmSymbols::find_sid(buf);
+  if (backup_sid != vmSymbols::NO_SID) {
+    backup_symbol = vmSymbols::symbol_at(backup_sid);
+  }
+  return backup_symbol;
+}
+
+Symbol* SystemDictionary::find_backup_class_name(Symbol* symbol) {
+  assert(AllowTransitionalJSR292, "");  // delete this subroutine
+  if (symbol == NULL)  return NULL;
+  Symbol* backup_symbol = find_backup_symbol(symbol, "java/lang/invoke/", "java/dyn/");  // AllowTransitionalJSR292 ONLY
+  if (backup_symbol == NULL)
+    backup_symbol = find_backup_symbol(symbol, "java/dyn/", "sun/dyn/");  // AllowTransitionalJSR292 ONLY
+  return backup_symbol;
+}
+
+Symbol* SystemDictionary::find_backup_signature(Symbol* symbol) {
+  assert(AllowTransitionalJSR292, "");  // delete this subroutine
+  if (symbol == NULL)  return NULL;
+  return find_backup_symbol(symbol, "Ljava/lang/invoke/", "Ljava/dyn/");
+}
+
 bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
   assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
   int  info = wk_init_info[id - FIRST_WKID];
   int  sid  = (info >> CEIL_LG_OPTION_LIMIT);
   Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
   klassOop*    klassp = &_well_known_klasses[id];
-  bool must_load = (init_opt < SystemDictionary::Opt);
-  bool try_load  = true;
+  bool pre_load = (init_opt < SystemDictionary::Opt);
+  bool try_load = true;
   if (init_opt == SystemDictionary::Opt_Kernel) {
 #ifndef KERNEL
     try_load = false;
 #endif //KERNEL
   }
-  if ((*klassp) == NULL && try_load) {
+  Symbol* backup_symbol = NULL;  // symbol to try if the current symbol fails
+  if (init_opt == SystemDictionary::Pre_JSR292) {
+    if (!EnableMethodHandles)  try_load = false;  // do not bother to load such classes
+    if (AllowTransitionalJSR292) {
+      backup_symbol = find_backup_class_name(symbol);
+      if (try_load && PreferTransitionalJSR292) {
+        while (backup_symbol != NULL) {
+          (*klassp) = resolve_or_null(backup_symbol, CHECK_0); // try backup early
+          if (TraceMethodHandles) {
+            ResourceMark rm;
+            tty->print_cr("MethodHandles: try backup first for %s => %s (%s)",
+                          symbol->as_C_string(), backup_symbol->as_C_string(),
+                          ((*klassp) == NULL) ? "no such class" : "backup load succeeded");
+          }
+          if ((*klassp) != NULL)  return true;
+          backup_symbol = find_backup_class_name(backup_symbol);  // find next backup
+        }
+      }
+    }
+  }
+  if ((*klassp) != NULL)  return true;
+  if (!try_load)          return false;
+  while (symbol != NULL) {
+    bool must_load = (pre_load && (backup_symbol == NULL));
     if (must_load) {
       (*klassp) = resolve_or_fail(symbol, true, CHECK_0); // load required class
     } else {
       (*klassp) = resolve_or_null(symbol,       CHECK_0); // load optional klass
     }
+    if ((*klassp) != NULL)  return true;
+    // Go around again.  Example of long backup sequence:
+    // java.lang.invoke.MemberName, java.dyn.MemberName, sun.dyn.MemberName, ONLY if AllowTransitionalJSR292
+    if (TraceMethodHandles && (backup_symbol != NULL)) {
+      ResourceMark rm;
+      tty->print_cr("MethodHandles: backup for %s => %s",
+                    symbol->as_C_string(), backup_symbol->as_C_string());
+    }
+    symbol = backup_symbol;
+    if (AllowTransitionalJSR292)
+      backup_symbol = find_backup_class_name(symbol);
   }
-  return ((*klassp) != NULL);
+  return false;
 }
 
 void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
@@ -2348,6 +2420,8 @@
     if (THREAD->is_Compiler_thread())
       return NULL;              // do not attempt from within compiler
     bool for_invokeGeneric = (name_id == vmSymbols::VM_SYMBOL_ENUM_NAME(invokeGeneric_name));
+    if (AllowInvokeForInvokeGeneric && name_id == vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name))
+      for_invokeGeneric = true;
     bool found_on_bcp = false;
     Handle mt = find_method_handle_type(signature, accessing_klass,
                                         for_invokeGeneric,
@@ -2531,10 +2605,14 @@
   args.push_oop(caller_mname());
   args.push_int(caller_bci);
   JavaValue result(T_OBJECT);
+  Symbol* makeDynamicCallSite_signature = vmSymbols::makeDynamicCallSite_signature();
+  if (AllowTransitionalJSR292 && SystemDictionaryHandles::MethodHandleNatives_klass()->name() == vmSymbols::sun_dyn_MethodHandleNatives()) {
+    makeDynamicCallSite_signature = vmSymbols::makeDynamicCallSite_TRANS_signature();
+  }
   JavaCalls::call_static(&result,
                          SystemDictionary::MethodHandleNatives_klass(),
                          vmSymbols::makeDynamicCallSite_name(),
-                         vmSymbols::makeDynamicCallSite_signature(),
+                         makeDynamicCallSite_signature,
                          &args, CHECK_(empty));
   oop call_site_oop = (oop) result.get_jobject();
   assert(call_site_oop->is_oop()
--- a/hotspot/src/share/vm/classfile/systemDictionary.hpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/classfile/systemDictionary.hpp	Fri Mar 11 22:33:47 2011 -0800
@@ -144,18 +144,18 @@
   template(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \
                                                                               \
   /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
-  template(MethodHandle_klass,           java_dyn_MethodHandle,          Opt) \
-  template(MemberName_klass,             sun_dyn_MemberName,             Opt) \
-  template(MethodHandleImpl_klass,       sun_dyn_MethodHandleImpl,       Opt) \
-  template(MethodHandleNatives_klass,    sun_dyn_MethodHandleNatives,    Opt) \
-  template(AdapterMethodHandle_klass,    sun_dyn_AdapterMethodHandle,    Opt) \
-  template(BoundMethodHandle_klass,      sun_dyn_BoundMethodHandle,      Opt) \
-  template(DirectMethodHandle_klass,     sun_dyn_DirectMethodHandle,     Opt) \
-  template(MethodType_klass,             java_dyn_MethodType,            Opt) \
-  template(MethodTypeForm_klass,         java_dyn_MethodTypeForm,        Opt) \
-  template(WrongMethodTypeException_klass, java_dyn_WrongMethodTypeException, Opt) \
-  template(Linkage_klass,                java_dyn_Linkage,               Opt) \
-  template(CallSite_klass,               java_dyn_CallSite,              Opt) \
+  template(MethodHandle_klass,           java_dyn_MethodHandle,          Pre_JSR292) \
+  template(MemberName_klass,             java_dyn_MemberName,            Pre_JSR292) \
+  template(MethodHandleImpl_klass,       java_dyn_MethodHandleImpl,      Pre_JSR292) /* AllowTransitionalJSR292 ONLY */ \
+  template(MethodHandleNatives_klass,    java_dyn_MethodHandleNatives,   Pre_JSR292) \
+  template(AdapterMethodHandle_klass,    java_dyn_AdapterMethodHandle,   Pre_JSR292) \
+  template(BoundMethodHandle_klass,      java_dyn_BoundMethodHandle,     Pre_JSR292) \
+  template(DirectMethodHandle_klass,     java_dyn_DirectMethodHandle,    Pre_JSR292) \
+  template(MethodType_klass,             java_dyn_MethodType,            Pre_JSR292) \
+  template(MethodTypeForm_klass,         java_dyn_MethodTypeForm,        Pre_JSR292) \
+  template(WrongMethodTypeException_klass, java_dyn_WrongMethodTypeException, Pre_JSR292) \
+  template(Linkage_klass,                java_dyn_Linkage,               Pre_JSR292) \
+  template(CallSite_klass,               java_dyn_CallSite,              Pre_JSR292) \
   /* Note: MethodHandle must be first, and CallSite last in group */          \
                                                                               \
   template(StringBuffer_klass,           java_lang_StringBuffer,         Pre) \
@@ -207,6 +207,7 @@
 
   enum InitOption {
     Pre,                        // preloaded; error if not present
+    Pre_JSR292,                 // preloaded if EnableMethodHandles
 
     // Order is significant.  Options before this point require resolve_or_fail.
     // Options after this point will use resolve_or_null instead.
@@ -401,6 +402,7 @@
   }
 
   static klassOop check_klass_Pre(klassOop k) { return check_klass(k); }
+  static klassOop check_klass_Pre_JSR292(klassOop k) { return EnableInvokeDynamic ? check_klass(k) : k; }
   static klassOop check_klass_Opt(klassOop k) { return k; }
   static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt
   static klassOop check_klass_Opt_Only_JDK15(klassOop k) {
@@ -420,6 +422,8 @@
     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
   }
 
+  static Symbol* find_backup_symbol(Symbol* symbol, const char* from_prefix, const char* to_prefix);
+
 public:
   #define WK_KLASS_DECLARE(name, ignore_symbol, option) \
     static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); }
@@ -441,6 +445,9 @@
 
   static void load_abstract_ownable_synchronizer_klass(TRAPS);
 
+  static Symbol* find_backup_class_name(Symbol* class_name_symbol);
+  static Symbol* find_backup_signature(Symbol* signature_symbol);
+
 private:
   // Tells whether ClassLoader.loadClassInternal is present
   static bool has_loadClassInternal()       { return _has_loadClassInternal; }
--- a/hotspot/src/share/vm/classfile/vmSymbols.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/classfile/vmSymbols.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, 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
@@ -277,6 +277,12 @@
   return sid;
 }
 
+vmSymbols::SID vmSymbols::find_sid(const char* symbol_name) {
+  Symbol* symbol = SymbolTable::probe(symbol_name, (int) strlen(symbol_name));
+  if (symbol == NULL)  return NO_SID;
+  return find_sid(symbol);
+}
+
 static vmIntrinsics::ID wrapper_intrinsic(BasicType type, bool unboxing) {
 #define TYPE2(type, unboxing) ((int)(type)*2 + ((unboxing) ? 1 : 0))
   switch (TYPE2(type, unboxing)) {
--- a/hotspot/src/share/vm/classfile/vmSymbols.hpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/classfile/vmSymbols.hpp	Fri Mar 11 22:33:47 2011 -0800
@@ -240,13 +240,18 @@
   /* internal classes known only to the JVM: */                                                   \
   template(java_dyn_MethodTypeForm,                   "java/dyn/MethodTypeForm")                  \
   template(java_dyn_MethodTypeForm_signature,         "Ljava/dyn/MethodTypeForm;")                \
-  template(sun_dyn_MemberName,                        "sun/dyn/MemberName")                       \
-  template(sun_dyn_MemberName_signature,              "Lsun/dyn/MemberName;")                     \
-  template(sun_dyn_MethodHandleImpl,                  "sun/dyn/MethodHandleImpl")                 \
-  template(sun_dyn_MethodHandleNatives,               "sun/dyn/MethodHandleNatives")              \
-  template(sun_dyn_AdapterMethodHandle,               "sun/dyn/AdapterMethodHandle")              \
-  template(sun_dyn_BoundMethodHandle,                 "sun/dyn/BoundMethodHandle")                \
-  template(sun_dyn_DirectMethodHandle,                "sun/dyn/DirectMethodHandle")               \
+  template(java_dyn_MemberName,                       "java/dyn/MemberName")                      \
+  template(java_dyn_MethodHandleImpl,                 "java/dyn/MethodHandleImpl")                \
+  template(java_dyn_MethodHandleNatives,              "java/dyn/MethodHandleNatives")             \
+  template(java_dyn_AdapterMethodHandle,              "java/dyn/AdapterMethodHandle")             \
+  template(java_dyn_BoundMethodHandle,                "java/dyn/BoundMethodHandle")               \
+  template(java_dyn_DirectMethodHandle,               "java/dyn/DirectMethodHandle")              \
+  template(sun_dyn_MemberName,                        "sun/dyn/MemberName")             /* AllowTransitionalJSR292 ONLY */ \
+  template(sun_dyn_MethodHandleImpl,                  "sun/dyn/MethodHandleImpl")       /* AllowTransitionalJSR292 ONLY */ \
+  template(sun_dyn_MethodHandleNatives,               "sun/dyn/MethodHandleNatives")    /* AllowTransitionalJSR292 ONLY */ \
+  template(sun_dyn_AdapterMethodHandle,               "sun/dyn/AdapterMethodHandle")    /* AllowTransitionalJSR292 ONLY */ \
+  template(sun_dyn_BoundMethodHandle,                 "sun/dyn/BoundMethodHandle")      /* AllowTransitionalJSR292 ONLY */ \
+  template(sun_dyn_DirectMethodHandle,                "sun/dyn/DirectMethodHandle")     /* AllowTransitionalJSR292 ONLY */ \
   /* internal up-calls made only by the JVM, via class sun.dyn.MethodHandleNatives: */            \
   template(findMethodHandleType_name,                 "findMethodHandleType")                     \
   template(findMethodHandleType_signature, "(Ljava/lang/Class;[Ljava/lang/Class;)Ljava/dyn/MethodType;") \
@@ -255,7 +260,8 @@
   template(linkMethodHandleConstant_name,             "linkMethodHandleConstant")                 \
   template(linkMethodHandleConstant_signature, "(Ljava/lang/Class;ILjava/lang/Class;Ljava/lang/String;Ljava/lang/Object;)Ljava/dyn/MethodHandle;") \
   template(makeDynamicCallSite_name,                  "makeDynamicCallSite")                      \
-  template(makeDynamicCallSite_signature, "(Ljava/dyn/MethodHandle;Ljava/lang/String;Ljava/dyn/MethodType;Ljava/lang/Object;Lsun/dyn/MemberName;I)Ljava/dyn/CallSite;") \
+  template(makeDynamicCallSite_signature, "(Ljava/dyn/MethodHandle;Ljava/lang/String;Ljava/dyn/MethodType;Ljava/lang/Object;Ljava/dyn/MemberName;I)Ljava/dyn/CallSite;") \
+  template(makeDynamicCallSite_TRANS_signature, "(Ljava/dyn/MethodHandle;Ljava/lang/String;Ljava/dyn/MethodType;Ljava/lang/Object;Lsun/dyn/MemberName;I)Ljava/dyn/CallSite;") /* AllowTransitionalJSR292 ONLY */ \
   NOT_LP64(  do_alias(machine_word_signature,         int_signature)  )                           \
   LP64_ONLY( do_alias(machine_word_signature,         long_signature) )                           \
                                                                                                   \
@@ -882,7 +888,8 @@
                                                                                                                           \
   do_intrinsic(_invoke,                   java_lang_reflect_Method, invoke_name, object_object_array_object_signature, F_R) \
   /*   (symbols invoke_name and invoke_signature defined above) */                                                      \
-  do_intrinsic(_checkSpreadArgument,      sun_dyn_MethodHandleImpl, checkSpreadArgument_name, checkSpreadArgument_signature, F_S) \
+  do_intrinsic(_checkSpreadArgument,      java_dyn_MethodHandleNatives, checkSpreadArgument_name, checkSpreadArgument_signature, F_S) \
+  do_intrinsic(_checkSpreadArgument_TRANS, sun_dyn_MethodHandleImpl,    checkSpreadArgument_name, checkSpreadArgument_signature, F_S) /* AllowTransitionalJSR292 ONLY */ \
    do_name(    checkSpreadArgument_name,       "checkSpreadArgument")                                                   \
    do_name(    checkSpreadArgument_signature,  "(Ljava/lang/Object;I)V")                                                \
   do_intrinsic(_invokeExact,              java_dyn_MethodHandle, invokeExact_name,   object_array_object_signature, F_RN) \
@@ -995,6 +1002,7 @@
 
   // Returns symbol's SID if one is assigned, else NO_SID.
   static SID find_sid(Symbol* symbol);
+  static SID find_sid(const char* symbol_name);
 
 #ifndef PRODUCT
   // No need for this in the product:
--- a/hotspot/src/share/vm/interpreter/linkResolver.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/interpreter/linkResolver.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, 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
@@ -221,7 +221,9 @@
       // Make sure the Java part of the runtime has been booted up.
       klassOop natives = SystemDictionary::MethodHandleNatives_klass();
       if (natives == NULL || instanceKlass::cast(natives)->is_not_initialized()) {
-        SystemDictionary::resolve_or_fail(vmSymbols::sun_dyn_MethodHandleNatives(),
+        Symbol* natives_name = vmSymbols::java_dyn_MethodHandleNatives();
+        if (natives != NULL && AllowTransitionalJSR292)  natives_name = Klass::cast(natives)->name();
+        SystemDictionary::resolve_or_fail(natives_name,
                                           Handle(),
                                           Handle(),
                                           true,
--- a/hotspot/src/share/vm/oops/instanceKlass.hpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/oops/instanceKlass.hpp	Fri Mar 11 22:33:47 2011 -0800
@@ -194,7 +194,7 @@
   // Implementors of this interface (not valid if it overflows)
   klassOop        _implementors[implementors_limit];
   // invokedynamic bootstrap method (a java.dyn.MethodHandle)
-  oop             _bootstrap_method;
+  oop             _bootstrap_method;  // AllowTransitionalJSR292 ONLY
   // Annotations for this class, or null if none.
   typeArrayOop    _class_annotations;
   // Annotation objects (byte arrays) for fields, or null if no annotations.
@@ -529,7 +529,7 @@
                                                         _enclosing_method_method_index = method_index; }
 
   // JSR 292 support
-  oop bootstrap_method() const                        { return _bootstrap_method; }
+  oop bootstrap_method() const                        { return _bootstrap_method; }  // AllowTransitionalJSR292 ONLY
   void set_bootstrap_method(oop mh)                   { oop_store(&_bootstrap_method, mh); }
 
   // jmethodID support
@@ -817,7 +817,7 @@
   oop* adr_signers() const           { return (oop*)&this->_signers;}
   oop* adr_inner_classes() const     { return (oop*)&this->_inner_classes;}
   oop* adr_implementors() const      { return (oop*)&this->_implementors[0];}
-  oop* adr_bootstrap_method() const  { return (oop*)&this->_bootstrap_method;}
+  oop* adr_bootstrap_method() const  { return (oop*)&this->_bootstrap_method;}  // AllowTransitionalJSR292 ONLY
   oop* adr_methods_jmethod_ids() const             { return (oop*)&this->_methods_jmethod_ids;}
   oop* adr_methods_cached_itable_indices() const   { return (oop*)&this->_methods_cached_itable_indices;}
   oop* adr_class_annotations() const   { return (oop*)&this->_class_annotations;}
--- a/hotspot/src/share/vm/oops/methodOop.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/oops/methodOop.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -855,7 +855,7 @@
   case vmSymbols::VM_SYMBOL_ENUM_NAME(invokeGeneric_name):
     return true;
   }
-  if (AllowTransitionalJSR292
+  if ((AllowTransitionalJSR292 || AllowInvokeForInvokeGeneric)
       && name_sid == vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name))
     return true;
   return false;
@@ -1127,7 +1127,8 @@
       id = vmIntrinsics::_invokeExact;
       break;
     case vmSymbols::VM_SYMBOL_ENUM_NAME(invoke_name):
-      if (AllowTransitionalJSR292)  id = vmIntrinsics::_invokeExact;
+      if (AllowInvokeForInvokeGeneric)   id = vmIntrinsics::_invokeGeneric;
+      else if (AllowTransitionalJSR292)  id = vmIntrinsics::_invokeExact;
       break;
     }
     break;
--- a/hotspot/src/share/vm/prims/methodHandleWalk.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/prims/methodHandleWalk.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -100,7 +100,6 @@
 BasicType MethodHandleChain::compute_bound_arg_type(oop target, methodOop m, int arg_slot, TRAPS) {
   // There is no direct indication of whether the argument is primitive or not.
   // It is implied by the _vmentry code, and by the MethodType of the target.
-  // FIXME: Make it explicit MethodHandleImpl refactors out from MethodHandle
   BasicType arg_type = T_VOID;
   if (target != NULL) {
     oop mtype = java_dyn_MethodHandle::type(target);
@@ -960,6 +959,13 @@
   if (m == NULL) {
     // Get the intrinsic methodOop.
     m = vmIntrinsics::method_for(iid);
+    if (m == NULL && iid == vmIntrinsics::_checkSpreadArgument && AllowTransitionalJSR292) {
+      m = vmIntrinsics::method_for(vmIntrinsics::_checkSpreadArgument_TRANS);
+    }
+    if (m == NULL) {
+      ArgToken zero;
+      lose(vmIntrinsics::name_at(iid), CHECK_(zero));
+    }
   }
 
   klassOop  klass   = m->method_holder();
--- a/hotspot/src/share/vm/prims/methodHandles.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/prims/methodHandles.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -2523,17 +2523,16 @@
 JVM_END
 
 JVM_ENTRY(jobject, MHI_getBootstrap(JNIEnv *env, jobject igcls, jclass caller_jh)) {
+  if (!AllowTransitionalJSR292)
+    THROW_MSG_NULL(vmSymbols::java_lang_IllegalArgumentException(), "getBootstrap: transitional only");
   instanceKlassHandle ik = MethodHandles::resolve_instance_klass(caller_jh, THREAD);
   return JNIHandles::make_local(THREAD, ik->bootstrap_method());
 }
 JVM_END
 
 JVM_ENTRY(void, MHI_setCallSiteTarget(JNIEnv *env, jobject igcls, jobject site_jh, jobject target_jh)) {
-  // No special action required, yet.
-  oop site_oop = JNIHandles::resolve(site_jh);
-  if (!java_dyn_CallSite::is_instance(site_oop))
-    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "not a CallSite");
-  java_dyn_CallSite::set_target(site_oop, JNIHandles::resolve(target_jh));
+  if (!AllowTransitionalJSR292)
+    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "setCallSite: transitional only");
 }
 JVM_END
 
@@ -2543,8 +2542,10 @@
 #define ADR "J"
 
 #define LANG "Ljava/lang/"
-#define JDYN "Ljava/dyn/"
-#define IDYN "Lsun/dyn/"
+#define JLINV "Ljava/lang/invoke/" /* standard package */
+#define JDYN "Ljava/dyn/" /* alternative package to JLINV if AllowTransitionalJSR292 */
+#define IDYN "Lsun/dyn/"  /* alternative package to JDYN if AllowTransitionalJSR292 */
+// FIXME: After AllowTransitionalJSR292 is removed, replace JDYN and IDYN by JLINV.
 
 #define OBJ   LANG"Object;"
 #define CLS   LANG"Class;"
@@ -2552,7 +2553,6 @@
 #define CST   JDYN"CallSite;"
 #define MT    JDYN"MethodType;"
 #define MH    JDYN"MethodHandle;"
-#define MHI   IDYN"MethodHandleImpl;"
 #define MEM   IDYN"MemberName;"
 #define AMH   IDYN"AdapterMethodHandle;"
 #define BMH   IDYN"BoundMethodHandle;"
@@ -2581,12 +2581,38 @@
 };
 
 // More entry points specifically for EnableInvokeDynamic.
+// FIXME: Remove methods2 after AllowTransitionalJSR292 is removed.
 static JNINativeMethod methods2[] = {
   {CC"registerBootstrap",       CC"("CLS MH")V",                FN_PTR(MHI_registerBootstrap)},
   {CC"getBootstrap",            CC"("CLS")"MH,                  FN_PTR(MHI_getBootstrap)},
   {CC"setCallSiteTarget",       CC"("CST MH")V",                FN_PTR(MHI_setCallSiteTarget)}
 };
 
+static void hack_signatures(JNINativeMethod* methods, jint num_methods, const char* from_sig, const char* to_sig) {
+  for (int i = 0; i < num_methods; i++) {
+    const char* sig = methods[i].signature;
+    if (!strstr(sig, from_sig))  continue;
+    size_t buflen = strlen(sig) + 100;
+    char* buf = NEW_C_HEAP_ARRAY(char, buflen);
+    char* bufp = buf;
+    const char* sigp = sig;
+    size_t from_len = strlen(from_sig), to_len = strlen(to_sig);
+    while (*sigp != '\0') {
+      assert(bufp < buf + buflen - to_len - 1, "oob");
+      if (strncmp(sigp, from_sig, from_len) != 0) {
+        *bufp++ = *sigp++;
+      } else {
+        strcpy(bufp, to_sig);
+        bufp += to_len;
+        sigp += from_len;
+      }
+    }
+    *bufp = '\0';
+    methods[i].signature = buf;  // replace with new signature
+    if (TraceMethodHandles)
+      tty->print_cr("MethodHandleNatives: %s: change signature %s => %s", methods[i].name, sig, buf);
+  }
+}
 
 // This one function is exported, used by NativeLookup.
 
@@ -2600,45 +2626,76 @@
     return;  // bind nothing
   }
 
+  if (SystemDictionary::MethodHandleNatives_klass() != NULL &&
+      SystemDictionary::MethodHandleNatives_klass() != java_lang_Class::as_klassOop(JNIHandles::resolve(MHN_class))) {
+    warning("multiple versions of MethodHandleNatives in boot classpath; consider using -XX:+PreferTransitionalJSR292");
+    THROW_MSG(vmSymbols::java_lang_InternalError(), "multiple versions of MethodHandleNatives in boot classpath; consider using -XX:+PreferTransitionalJSR292");
+  }
+
   bool enable_MH = true;
 
-  {
+  // Loop control.  FIXME: Replace by dead reckoning after AllowTransitionalJSR292 is removed.
+  bool registered_natives = false;
+  bool try_plain = true, try_JDYN = true, try_IDYN = true;
+  for (;;) {
     ThreadToNativeFromVM ttnfv(thread);
 
+    if      (try_plain) { try_plain = false; }
+    else if (try_JDYN)  { try_JDYN  = false; hack_signatures(methods, sizeof(methods)/sizeof(JNINativeMethod), IDYN, JDYN); }
+    else if (try_IDYN)  { try_IDYN  = false; hack_signatures(methods, sizeof(methods)/sizeof(JNINativeMethod), JDYN, JLINV); }
+    else                { break; }
     int status = env->RegisterNatives(MHN_class, methods, sizeof(methods)/sizeof(JNINativeMethod));
     if (env->ExceptionOccurred()) {
-      MethodHandles::set_enabled(false);
-      warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
-      enable_MH = false;
       env->ExceptionClear();
+      // and try again...
+    } else {
+      registered_natives = true;
+      break;
     }
   }
+  if (!registered_natives) {
+    MethodHandles::set_enabled(false);
+    warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
+    enable_MH = false;
+  }
 
   if (enable_MH) {
+    bool found_raise_exception = false;
+    KlassHandle MHN_klass = SystemDictionaryHandles::MethodHandleNatives_klass();
     KlassHandle MHI_klass = SystemDictionaryHandles::MethodHandleImpl_klass();
-    if (MHI_klass.not_null()) {
+    // Loop control.  FIXME: Replace by dead reckoning after AllowTransitionalJSR292 is removed.
+    bool try_MHN = true, try_MHI = AllowTransitionalJSR292;
+    for (;;) {
+      KlassHandle try_klass;
+      if      (try_MHN) { try_MHN = false; try_klass = MHN_klass; }
+      else if (try_MHI) { try_MHI = false; try_klass = MHI_klass; }
+      else              { break; }
+      if (try_klass.is_null())  continue;
       TempNewSymbol raiseException_name = SymbolTable::new_symbol("raiseException", CHECK);
       TempNewSymbol raiseException_sig = SymbolTable::new_symbol("(ILjava/lang/Object;Ljava/lang/Object;)V", CHECK);
-      methodOop raiseException_method  = instanceKlass::cast(MHI_klass->as_klassOop())
+      methodOop raiseException_method  = instanceKlass::cast(try_klass->as_klassOop())
                     ->find_method(raiseException_name, raiseException_sig);
       if (raiseException_method != NULL && raiseException_method->is_static()) {
         MethodHandles::set_raise_exception_method(raiseException_method);
-      } else {
-        warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
-        enable_MH = false;
+        found_raise_exception = true;
+        break;
       }
-    } else {
+    }
+    if (!found_raise_exception) {
+      warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
       enable_MH = false;
     }
   }
 
   if (enable_MH) {
-    // We need to link the MethodHandleImpl klass before we generate
-    // the method handle adapters as the _raise_exception adapter uses
-    // one of its methods (and its c2i-adapter).
-    KlassHandle    k  = SystemDictionaryHandles::MethodHandleImpl_klass();
-    instanceKlass* ik = instanceKlass::cast(k());
-    ik->link_class(CHECK);
+    if (AllowTransitionalJSR292) {
+      // We need to link the MethodHandleImpl klass before we generate
+      // the method handle adapters as the _raise_exception adapter uses
+      // one of its methods (and its c2i-adapter).
+      KlassHandle    k  = SystemDictionaryHandles::MethodHandleImpl_klass();
+      instanceKlass* ik = instanceKlass::cast(k());
+      ik->link_class(CHECK);
+    }
 
     MethodHandles::generate_adapters();
     MethodHandles::set_enabled(true);
@@ -2649,7 +2706,7 @@
     return;  // bind nothing
   }
 
-  {
+  if (AllowTransitionalJSR292) {
     ThreadToNativeFromVM ttnfv(thread);
 
     int status = env->RegisterNatives(MHN_class, methods2, sizeof(methods2)/sizeof(JNINativeMethod));
@@ -2657,8 +2714,6 @@
       MethodHandles::set_enabled(false);
       warning("JSR 292 method handle code is mismatched to this JVM.  Disabling support.");
       env->ExceptionClear();
-    } else {
-      MethodHandles::set_enabled(true);
     }
   }
 }
--- a/hotspot/src/share/vm/prims/nativeLookup.cpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/prims/nativeLookup.cpp	Fri Mar 11 22:33:47 2011 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, 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
@@ -107,29 +107,29 @@
   void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass);
 }
 
+#define CC (char*)  /* cast a literal from (const char*) */
+#define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
+
+static JNINativeMethod lookup_special_native_methods[] = {
+  // Next two functions only exist for compatibility with 1.3.1 and earlier.
+  { CC"Java_java_io_ObjectOutputStream_getPrimitiveFieldValues",   NULL, FN_PTR(JVM_GetPrimitiveFieldValues)     },  // intercept ObjectOutputStream getPrimitiveFieldValues for faster serialization
+  { CC"Java_java_io_ObjectInputStream_setPrimitiveFieldValues",    NULL, FN_PTR(JVM_SetPrimitiveFieldValues)     },  // intercept ObjectInputStream setPrimitiveFieldValues for faster serialization
+
+  { CC"Java_sun_misc_Unsafe_registerNatives",                      NULL, FN_PTR(JVM_RegisterUnsafeMethods)       },
+  { CC"Java_sun_dyn_MethodHandleNatives_registerNatives",          NULL, FN_PTR(JVM_RegisterMethodHandleMethods) },  // AllowTransitionalJSR292
+  { CC"Java_java_dyn_MethodHandleNatives_registerNatives",         NULL, FN_PTR(JVM_RegisterMethodHandleMethods) },  // AllowTransitionalJSR292
+  { CC"Java_sun_misc_Perf_registerNatives",                        NULL, FN_PTR(JVM_RegisterPerfMethods)         }
+};
+
 static address lookup_special_native(char* jni_name) {
-  // NB: To ignore the jni prefix and jni postfix strstr is used matching.
-  if (!JDK_Version::is_gte_jdk14x_version()) {
-    // These functions only exist for compatibility with 1.3.1 and earlier
-    // Intercept ObjectOutputStream getPrimitiveFieldValues for faster serialization
-    if (strstr(jni_name, "Java_java_io_ObjectOutputStream_getPrimitiveFieldValues") != NULL) {
-      return CAST_FROM_FN_PTR(address, JVM_GetPrimitiveFieldValues);
-    }
-    // Intercept ObjectInputStream setPrimitiveFieldValues for faster serialization
-    if (strstr(jni_name, "Java_java_io_ObjectInputStream_setPrimitiveFieldValues") != NULL) {
-      return CAST_FROM_FN_PTR(address, JVM_SetPrimitiveFieldValues);
+  int i = !JDK_Version::is_gte_jdk14x_version() ? 0 : 2;  // see comment in lookup_special_native_methods
+  int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
+  for (; i < count; i++) {
+    // NB: To ignore the jni prefix and jni postfix strstr is used matching.
+    if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) {
+      return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr);
     }
   }
-  if (strstr(jni_name, "Java_sun_misc_Unsafe_registerNatives") != NULL) {
-    return CAST_FROM_FN_PTR(address, JVM_RegisterUnsafeMethods);
-  }
-  if (strstr(jni_name, "Java_sun_dyn_MethodHandleNatives_registerNatives") != NULL) {
-    return CAST_FROM_FN_PTR(address, JVM_RegisterMethodHandleMethods);
-  }
-  if (strstr(jni_name, "Java_sun_misc_Perf_registerNatives") != NULL) {
-    return CAST_FROM_FN_PTR(address, JVM_RegisterPerfMethods);
-  }
-
   return NULL;
 }
 
--- a/hotspot/src/share/vm/runtime/globals.hpp	Fri Mar 11 21:19:15 2011 -0800
+++ b/hotspot/src/share/vm/runtime/globals.hpp	Fri Mar 11 22:33:47 2011 -0800
@@ -3719,6 +3719,13 @@
   experimental(bool, AllowTransitionalJSR292, true,                         \
           "recognize pre-PFD formats of invokedynamic")                     \
                                                                             \
+  experimental(bool, PreferTransitionalJSR292, false,                       \
+          "prefer pre-PFD APIs on boot class path, if they exist")          \
+                                                                            \
+  experimental(bool, AllowInvokeForInvokeGeneric, false,                    \
+          "accept MethodHandle.invoke and MethodHandle.invokeGeneric "      \
+          "as equivalent methods")                                          \
+                                                                            \
   develop(bool, TraceInvokeDynamic, false,                                  \
           "trace internal invoke dynamic operations")                       \
                                                                             \