Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2015, 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

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "classfile/metadataOnStackMark.hpp"

 #include "classfile/systemDictionary.hpp"

 #include "code/debugInfoRec.hpp"

 #include "gc_interface/collectedHeap.inline.hpp"

 #include "interpreter/bytecodeStream.hpp"

 #include "interpreter/bytecodeTracer.hpp"

 #include "interpreter/bytecodes.hpp"

 #include "interpreter/interpreter.hpp"

 #include "interpreter/oopMapCache.hpp"

 #include "memory/gcLocker.hpp"

 #include "memory/generation.hpp"

 #include "memory/heapInspection.hpp"

 #include "memory/metadataFactory.hpp"

 #include "memory/oopFactory.hpp"

 #include "oops/constMethod.hpp"

 #include "oops/methodData.hpp"

 #include "oops/method.hpp"

 #include "oops/oop.inline.hpp"

 #include "oops/symbol.hpp"

 #include "prims/jvmtiExport.hpp"

 #include "prims/methodHandles.hpp"

 #include "prims/nativeLookup.hpp"

 #include "runtime/arguments.hpp"

 #include "runtime/compilationPolicy.hpp"

 #include "runtime/frame.inline.hpp"

 #include "runtime/handles.inline.hpp"

 #include "runtime/orderAccess.inline.hpp"

 #include "runtime/relocator.hpp"

 #include "runtime/sharedRuntime.hpp"

 #include "runtime/signature.hpp"

 #include "utilities/quickSort.hpp"

 #include "utilities/xmlstream.hpp"

 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

 // Implementation of Method

 Method* Method::allocate(ClassLoaderData* loader_data,

                          int byte_code_size,

                          AccessFlags access_flags,

                          InlineTableSizes* sizes,

                          ConstMethod::MethodType method_type,

                          TRAPS) {

   assert(!access_flags.is_native() || byte_code_size == 0,

          "native methods should not contain byte codes");

   ConstMethod* cm = ConstMethod::allocate(loader_data,

                                           byte_code_size,

                                           sizes,

                                           method_type,

                                           CHECK_NULL);

   int size = Method::size(access_flags.is_native());

   return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, size);

 }

 Method::Method(ConstMethod* xconst, AccessFlags access_flags, int size) {

   No_Safepoint_Verifier no_safepoint;

   set_constMethod(xconst);

   set_access_flags(access_flags);

   set_method_size(size);

 #ifdef CC_INTERP

   set_result_index(T_VOID);

 #endif

   set_intrinsic_id(vmIntrinsics::_none);

   set_jfr_towrite(false);

   set_force_inline(false);

   set_hidden(false);

   set_dont_inline(false);

   set_method_data(NULL);

   clear_method_counters();

   set_vtable_index(Method::garbage_vtable_index);

   // Fix and bury in Method*

   set_interpreter_entry(NULL); // sets i2i entry and from_int

   set_adapter_entry(NULL);

   clear_code(); // from_c/from_i get set to c2i/i2i

   if (access_flags.is_native()) {

     clear_native_function();

     set_signature_handler(NULL);

   }

   NOT_PRODUCT(set_compiled_invocation_count(0);)

 }

 // Release Method*.  The nmethod will be gone when we get here because

 // we've walked the code cache.

 void Method::deallocate_contents(ClassLoaderData* loader_data) {

   MetadataFactory::free_metadata(loader_data, constMethod());

   set_constMethod(NULL);

   MetadataFactory::free_metadata(loader_data, method_data());

   set_method_data(NULL);

   MetadataFactory::free_metadata(loader_data, method_counters());

   clear_method_counters();

   // The nmethod will be gone when we get here.

   if (code() != NULL) _code = NULL;

 }

 address Method::get_i2c_entry() {

   assert(_adapter != NULL, "must have");

   return _adapter->get_i2c_entry();

 }

 address Method::get_c2i_entry() {

   assert(_adapter != NULL, "must have");

   return _adapter->get_c2i_entry();

 }

 address Method::get_c2i_unverified_entry() {

   assert(_adapter != NULL, "must have");

   return _adapter->get_c2i_unverified_entry();

 }

 char* Method::name_and_sig_as_C_string() const {

   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());

 }

 char* Method::name_and_sig_as_C_string(char* buf, int size) const {

   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);

 }

 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {

   const char* klass_name = klass->external_name();

   int klass_name_len  = (int)strlen(klass_name);

   int method_name_len = method_name->utf8_length();

   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();

   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);

   strcpy(dest, klass_name);

   dest[klass_name_len] = '.';

   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());

   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());

   dest[len] = 0;

   return dest;

 }

 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {

   Symbol* klass_name = klass->name();

   klass_name->as_klass_external_name(buf, size);

   int len = (int)strlen(buf);

   if (len < size - 1) {

     buf[len++] = '.';

     method_name->as_C_string(&(buf[len]), size - len);

     len = (int)strlen(buf);

     signature->as_C_string(&(buf[len]), size - len);

   }

   return buf;

 }

 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {

   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)

   // access exception table

   ExceptionTable table(mh());

   int length = table.length();

   // iterate through all entries sequentially

   constantPoolHandle pool(THREAD, mh->constants());

   for (int i = 0; i < length; i ++) {

     //reacquire the table in case a GC happened

     ExceptionTable table(mh());

     int beg_bci = table.start_pc(i);

     int end_bci = table.end_pc(i);

     assert(beg_bci <= end_bci, "inconsistent exception table");

     if (beg_bci <= throw_bci && throw_bci < end_bci) {

       // exception handler bci range covers throw_bci => investigate further

       int handler_bci = table.handler_pc(i);

       int klass_index = table.catch_type_index(i);

       if (klass_index == 0) {

         return handler_bci;

       } else if (ex_klass.is_null()) {

         return handler_bci;

       } else {

         // we know the exception class => get the constraint class

         // this may require loading of the constraint class; if verification

         // fails or some other exception occurs, return handler_bci

         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));

         KlassHandle klass = KlassHandle(THREAD, k);

         assert(klass.not_null(), "klass not loaded");

         if (ex_klass->is_subtype_of(klass())) {

           return handler_bci;

         }

       }

     }

   }

   return -1;

 }

 void Method::mask_for(int bci, InterpreterOopMap* mask) {

   Thread* myThread    = Thread::current();

   methodHandle h_this(myThread, this);

 #ifdef ASSERT

   bool has_capability = myThread->is_VM_thread() ||

                         myThread->is_ConcurrentGC_thread() ||

                         myThread->is_GC_task_thread();

   if (!has_capability) {

     if (!VerifyStack && !VerifyLastFrame) {

       // verify stack calls this outside VM thread

       warning("oopmap should only be accessed by the "

               "VM, GC task or CMS threads (or during debugging)");

       InterpreterOopMap local_mask;

       method_holder()->mask_for(h_this, bci, &local_mask);

       local_mask.print();

     }

   }

 #endif

   method_holder()->mask_for(h_this, bci, mask);

   return;

 }

 int Method::bci_from(address bcp) const {

 #ifdef ASSERT

   { ResourceMark rm;

   assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),

          err_msg("bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s", bcp, name_and_sig_as_C_string()));

   }

 #endif

   return bcp - code_base();

 }

 // Return (int)bcx if it appears to be a valid BCI.

 // Return bci_from((address)bcx) if it appears to be a valid BCP.

 // Return -1 otherwise.

 // Used by profiling code, when invalid data is a possibility.

 // The caller is responsible for validating the Method* itself.

 int Method::validate_bci_from_bcx(intptr_t bcx) const {

   // keep bci as -1 if not a valid bci

   int bci = -1;

   if (bcx == 0 || (address)bcx == code_base()) {

     // code_size() may return 0 and we allow 0 here

     // the method may be native

     bci = 0;

   } else if (frame::is_bci(bcx)) {

     if (bcx < code_size()) {

       bci = (int)bcx;

     }

   } else if (contains((address)bcx)) {

     bci = (address)bcx - code_base();

   }

   // Assert that if we have dodged any asserts, bci is negative.

   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");

   return bci;

 }

 address Method::bcp_from(int bci) const {

   assert((is_native() && bci == 0)  || (!is_native() && 0 <= bci && bci < code_size()), err_msg("illegal bci: %d", bci));

   address bcp = code_base() + bci;

   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");

   return bcp;

 }

 int Method::size(bool is_native) {

   // If native, then include pointers for native_function and signature_handler

   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;

   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;

   return align_object_size(header_size() + extra_words);

 }

 Symbol* Method::klass_name() const {

   Klass* k = method_holder();

   assert(k->is_klass(), "must be klass");

   InstanceKlass* ik = (InstanceKlass*) k;

   return ik->name();

 }

 // Attempt to return method oop to original state.  Clear any pointers

 // (to objects outside the shared spaces).  We won't be able to predict

 // where they should point in a new JVM.  Further initialize some

 // entries now in order allow them to be write protected later.

 void Method::remove_unshareable_info() {

   unlink_method();

 }

 bool Method::was_executed_more_than(int n) {

   // Invocation counter is reset when the Method* is compiled.

   // If the method has compiled code we therefore assume it has

   // be excuted more than n times.

   if (is_accessor() || is_empty_method() || (code() != NULL)) {

     // interpreter doesn't bump invocation counter of trivial methods

     // compiler does not bump invocation counter of compiled methods

     return true;

   }

   else if ((method_counters() != NULL &&

             method_counters()->invocation_counter()->carry()) ||

            (method_data() != NULL &&

             method_data()->invocation_counter()->carry())) {

     // The carry bit is set when the counter overflows and causes

     // a compilation to occur.  We don't know how many times

     // the counter has been reset, so we simply assume it has

     // been executed more than n times.

     return true;

   } else {

     return invocation_count() > n;

   }

 }

 #ifndef PRODUCT

 void Method::print_invocation_count() {

   if (is_static()) tty->print("static ");

   if (is_final()) tty->print("final ");

   if (is_synchronized()) tty->print("synchronized ");

   if (is_native()) tty->print("native ");

   method_holder()->name()->print_symbol_on(tty);

   tty->print(".");

   name()->print_symbol_on(tty);

   signature()->print_symbol_on(tty);

   if (WizardMode) {

     // dump the size of the byte codes

     tty->print(" {%d}", code_size());

   }

   tty->cr();

   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());

   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());

   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());

   if (CountCompiledCalls) {

     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());

   }

 }

 #endif

 // Build a MethodData* object to hold information about this method

 // collected in the interpreter.

 void Method::build_interpreter_method_data(methodHandle method, TRAPS) {

   // Do not profile method if current thread holds the pending list lock,

   // which avoids deadlock for acquiring the MethodData_lock.

   if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {

     return;

   }

   // Grab a lock here to prevent multiple

   // MethodData*s from being created.

   MutexLocker ml(MethodData_lock, THREAD);

   if (method->method_data() == NULL) {

     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();

     MethodData* method_data = MethodData::allocate(loader_data, method, CHECK);

     method->set_method_data(method_data);

     if (PrintMethodData && (Verbose || WizardMode)) {

       ResourceMark rm(THREAD);

       tty->print("build_interpreter_method_data for ");

       method->print_name(tty);

       tty->cr();

       // At the end of the run, the MDO, full of data, will be dumped.

     }

   }

 }

 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {

   methodHandle mh(m);

   ClassLoaderData* loader_data = mh->method_holder()->class_loader_data();

   MethodCounters* counters = MethodCounters::allocate(loader_data, CHECK_NULL);

   if (!mh->init_method_counters(counters)) {

     MetadataFactory::free_metadata(loader_data, counters);

   }

   return mh->method_counters();

 }

 void Method::cleanup_inline_caches() {

   // The current system doesn't use inline caches in the interpreter

   // => nothing to do (keep this method around for future use)

 }

 int Method::extra_stack_words() {

   // not an inline function, to avoid a header dependency on Interpreter

   return extra_stack_entries() * Interpreter::stackElementSize;

 }

 void Method::compute_size_of_parameters(Thread *thread) {

   ArgumentSizeComputer asc(signature());

   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));

 }

 #ifdef CC_INTERP

 void Method::set_result_index(BasicType type)          {

   _result_index = Interpreter::BasicType_as_index(type);

 }

 #endif

 BasicType Method::result_type() const {

   ResultTypeFinder rtf(signature());

   return rtf.type();

 }

 bool Method::is_empty_method() const {

   return  code_size() == 1

       && *code_base() == Bytecodes::_return;

 }

 bool Method::is_vanilla_constructor() const {

   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method

   // which only calls the superclass vanilla constructor and possibly does stores of

   // zero constants to local fields:

   //

   //   aload_0

   //   invokespecial

   //   indexbyte1

   //   indexbyte2

   //

   // followed by an (optional) sequence of:

   //

   //   aload_0

   //   aconst_null / iconst_0 / fconst_0 / dconst_0

   //   putfield

   //   indexbyte1

   //   indexbyte2

   //

   // followed by:

   //

   //   return

   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");

   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");

   int size = code_size();

   // Check if size match

   if (size == 0 || size % 5 != 0) return false;

   address cb = code_base();

   int last = size - 1;

   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {

     // Does not call superclass default constructor

     return false;

   }

   // Check optional sequence

   for (int i = 4; i < last; i += 5) {

     if (cb[i] != Bytecodes::_aload_0) return false;

     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;

     if (cb[i+2] != Bytecodes::_putfield) return false;

   }

   return true;

 }

 bool Method::compute_has_loops_flag() {

   BytecodeStream bcs(this);

   Bytecodes::Code bc;

   while ((bc = bcs.next()) >= 0) {

     switch( bc ) {

       case Bytecodes::_ifeq:

       case Bytecodes::_ifnull:

       case Bytecodes::_iflt:

       case Bytecodes::_ifle:

       case Bytecodes::_ifne:

       case Bytecodes::_ifnonnull:

       case Bytecodes::_ifgt:

       case Bytecodes::_ifge:

       case Bytecodes::_if_icmpeq:

       case Bytecodes::_if_icmpne:

       case Bytecodes::_if_icmplt:

       case Bytecodes::_if_icmpgt:

       case Bytecodes::_if_icmple:

       case Bytecodes::_if_icmpge:

       case Bytecodes::_if_acmpeq:

       case Bytecodes::_if_acmpne:

       case Bytecodes::_goto:

       case Bytecodes::_jsr:

         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();

         break;

       case Bytecodes::_goto_w:

       case Bytecodes::_jsr_w:

         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();

         break;

     }

   }

   _access_flags.set_loops_flag_init();

   return _access_flags.has_loops();

 }

 bool Method::is_final_method(AccessFlags class_access_flags) const {

   // or "does_not_require_vtable_entry"

   // default method or overpass can occur, is not final (reuses vtable entry)

   // private methods get vtable entries for backward class compatibility.

   if (is_overpass() || is_default_method())  return false;

   return is_final() || class_access_flags.is_final();

 }

 bool Method::is_final_method() const {

   return is_final_method(method_holder()->access_flags());

 }

 bool Method::is_default_method() const {

   if (method_holder() != NULL &&

       method_holder()->is_interface() &&

       !is_abstract()) {

     return true;

   } else {

     return false;

   }

 }

 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {

   if (is_final_method(class_access_flags))  return true;

 #ifdef ASSERT

   ResourceMark rm;

   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);

   if (class_access_flags.is_interface()) {

       assert(is_nonv == is_static(), err_msg("is_nonv=%s", name_and_sig_as_C_string()));

   }

 #endif

   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");

   return vtable_index() == nonvirtual_vtable_index;

 }

 bool Method::can_be_statically_bound() const {

   return can_be_statically_bound(method_holder()->access_flags());

 }

 bool Method::is_accessor() const {

   if (code_size() != 5) return false;

   if (size_of_parameters() != 1) return false;

   if (java_code_at(0) != Bytecodes::_aload_0 ) return false;

   if (java_code_at(1) != Bytecodes::_getfield) return false;

   if (java_code_at(4) != Bytecodes::_areturn &&

       java_code_at(4) != Bytecodes::_ireturn ) return false;

   return true;

 }

 bool Method::is_constant_getter() const {

   int last_index = code_size() - 1;

   // Check if the first 1-3 bytecodes are a constant push

   // and the last bytecode is a return.

   return (2 <= code_size() && code_size() <= 4 &&

           Bytecodes::is_const(java_code_at(0)) &&

           Bytecodes::length_for(java_code_at(0)) == last_index &&

           Bytecodes::is_return(java_code_at(last_index)));

 }

 bool Method::is_initializer() const {

   return name() == vmSymbols::object_initializer_name() || is_static_initializer();

 }

 bool Method::has_valid_initializer_flags() const {

   return (is_static() ||

           method_holder()->major_version() < 51);

 }

 bool Method::is_static_initializer() const {

   // For classfiles version 51 or greater, ensure that the clinit method is

   // static.  Non-static methods with the name "<clinit>" are not static

   // initializers. (older classfiles exempted for backward compatibility)

   return name() == vmSymbols::class_initializer_name() &&

          has_valid_initializer_flags();

 }

 objArrayHandle Method::resolved_checked_exceptions_impl(Method* this_oop, TRAPS) {

   int length = this_oop->checked_exceptions_length();

   if (length == 0) {  // common case

     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());

   } else {

     methodHandle h_this(THREAD, this_oop);

     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));

     objArrayHandle mirrors (THREAD, m_oop);

     for (int i = 0; i < length; i++) {

       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe

       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));

       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");

       mirrors->obj_at_put(i, k->java_mirror());

     }

     return mirrors;

   }

 };

 int Method::line_number_from_bci(int bci) const {

   if (bci == SynchronizationEntryBCI) bci = 0;

   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");

   int best_bci  =  0;

   int best_line = -1;

   if (has_linenumber_table()) {

     // The line numbers are a short array of 2-tuples [start_pc, line_number].

     // Not necessarily sorted and not necessarily one-to-one.

     CompressedLineNumberReadStream stream(compressed_linenumber_table());

     while (stream.read_pair()) {

       if (stream.bci() == bci) {

         // perfect match

         return stream.line();

       } else {

         // update best_bci/line

         if (stream.bci() < bci && stream.bci() >= best_bci) {

           best_bci  = stream.bci();

           best_line = stream.line();

         }

       }

     }

   }

   return best_line;

 }

 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {

   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {

     Thread *thread = Thread::current();

     Symbol* klass_name = constants()->klass_name_at(klass_index);

     Handle loader(thread, method_holder()->class_loader());

     Handle prot  (thread, method_holder()->protection_domain());

     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;

   } else {

     return true;

   }

 }

 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {

   int klass_index = constants()->klass_ref_index_at(refinfo_index);

   if (must_be_resolved) {

     // Make sure klass is resolved in constantpool.

     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;

   }

   return is_klass_loaded_by_klass_index(klass_index);

 }

 void Method::set_native_function(address function, bool post_event_flag) {

   assert(function != NULL, "use clear_native_function to unregister natives");

   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");

   address* native_function = native_function_addr();

   // We can see racers trying to place the same native function into place. Once

   // is plenty.

   address current = *native_function;

   if (current == function) return;

   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&

       function != NULL) {

     // native_method_throw_unsatisfied_link_error_entry() should only

     // be passed when post_event_flag is false.

     assert(function !=

       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),

       "post_event_flag mis-match");

     // post the bind event, and possible change the bind function

     JvmtiExport::post_native_method_bind(this, &function);

   }

   *native_function = function;

   // This function can be called more than once. We must make sure that we always

   // use the latest registered method -> check if a stub already has been generated.

   // If so, we have to make it not_entrant.

   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates

   if (nm != NULL) {

     nm->make_not_entrant();

   }

 }

 bool Method::has_native_function() const {

   if (is_method_handle_intrinsic())

     return false;  // special-cased in SharedRuntime::generate_native_wrapper

   address func = native_function();

   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());

 }

 void Method::clear_native_function() {

   // Note: is_method_handle_intrinsic() is allowed here.

   set_native_function(

     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),

     !native_bind_event_is_interesting);

   clear_code();

 }

 address Method::critical_native_function() {

   methodHandle mh(this);

   return NativeLookup::lookup_critical_entry(mh);

 }

 void Method::set_signature_handler(address handler) {

   address* signature_handler =  signature_handler_addr();

   *signature_handler = handler;

 }

 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {

   if (PrintCompilation && report) {

     ttyLocker ttyl;

     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");

     if (comp_level == CompLevel_all) {

       tty->print("all levels ");

     } else {

       tty->print("levels ");

       for (int i = (int)CompLevel_none; i <= comp_level; i++) {

         tty->print("%d ", i);

       }

     }

     this->print_short_name(tty);

     int size = this->code_size();

     if (size > 0) {

       tty->print(" (%d bytes)", size);

     }

     if (reason != NULL) {

       tty->print("   %s", reason);

     }

     tty->cr();

   }

   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {

     ttyLocker ttyl;

     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",

                      os::current_thread_id(), is_osr, comp_level);

     if (reason != NULL) {

       xtty->print(" reason=\'%s\'", reason);

     }

     xtty->method(this);

     xtty->stamp();

     xtty->end_elem();

   }

 }

 bool Method::is_always_compilable() const {

   // Generated adapters must be compiled

   if (is_method_handle_intrinsic() && is_synthetic()) {

     assert(!is_not_c1_compilable(), "sanity check");

     assert(!is_not_c2_compilable(), "sanity check");

     return true;

   }

   return false;

 }

 bool Method::is_not_compilable(int comp_level) const {

   if (number_of_breakpoints() > 0)

     return true;

   if (is_always_compilable())

     return false;

   if (comp_level == CompLevel_any)

     return is_not_c1_compilable() || is_not_c2_compilable();

   if (is_c1_compile(comp_level))

     return is_not_c1_compilable();

   if (is_c2_compile(comp_level))

     return is_not_c2_compilable();

   return false;

 }

 // call this when compiler finds that this method is not compilable

 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {

   if (is_always_compilable()) {

     // Don't mark a method which should be always compilable

     return;

   }

   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);

   if (comp_level == CompLevel_all) {

     set_not_c1_compilable();

     set_not_c2_compilable();

   } else {

     if (is_c1_compile(comp_level))

       set_not_c1_compilable();

     if (is_c2_compile(comp_level))

       set_not_c2_compilable();

   }

   CompilationPolicy::policy()->disable_compilation(this);

   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");

 }

 bool Method::is_not_osr_compilable(int comp_level) const {

   if (is_not_compilable(comp_level))

     return true;

   if (comp_level == CompLevel_any)

     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();

   if (is_c1_compile(comp_level))

     return is_not_c1_osr_compilable();

   if (is_c2_compile(comp_level))

     return is_not_c2_osr_compilable();

   return false;

 }

 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {

   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);

   if (comp_level == CompLevel_all) {

     set_not_c1_osr_compilable();

     set_not_c2_osr_compilable();

   } else {

     if (is_c1_compile(comp_level))

       set_not_c1_osr_compilable();

     if (is_c2_compile(comp_level))

       set_not_c2_osr_compilable();

   }

   CompilationPolicy::policy()->disable_compilation(this);

   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");

 }

 // Revert to using the interpreter and clear out the nmethod

 void Method::clear_code() {

   // this may be NULL if c2i adapters have not been made yet

   // Only should happen at allocate time.

   if (_adapter == NULL) {

     _from_compiled_entry    = NULL;

   } else {

     _from_compiled_entry    = _adapter->get_c2i_entry();

   }

   OrderAccess::storestore();

   _from_interpreted_entry = _i2i_entry;

   OrderAccess::storestore();

   _code = NULL;

 }

 // Called by class data sharing to remove any entry points (which are not shared)

 void Method::unlink_method() {

   _code = NULL;

   _i2i_entry = NULL;

   _from_interpreted_entry = NULL;

   if (is_native()) {

     *native_function_addr() = NULL;

     set_signature_handler(NULL);

   }

   NOT_PRODUCT(set_compiled_invocation_count(0);)

   _adapter = NULL;

   _from_compiled_entry = NULL;

   // In case of DumpSharedSpaces, _method_data should always be NULL.

   //

   // During runtime (!DumpSharedSpaces), when we are cleaning a

   // shared class that failed to load, this->link_method() may

   // have already been called (before an exception happened), so

   // this->_method_data may not be NULL.

   assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");

   set_method_data(NULL);

   clear_method_counters();

 }

 // Called when the method_holder is getting linked. Setup entrypoints so the method

 // is ready to be called from interpreter, compiler, and vtables.

 void Method::link_method(methodHandle h_method, TRAPS) {

   // If the code cache is full, we may reenter this function for the

   // leftover methods that weren't linked.

   if (_i2i_entry != NULL) return;

   assert(_adapter == NULL, "init'd to NULL" );

   assert( _code == NULL, "nothing compiled yet" );

   // Setup interpreter entrypoint

   assert(this == h_method(), "wrong h_method()" );

   address entry = Interpreter::entry_for_method(h_method);

   assert(entry != NULL, "interpreter entry must be non-null");

   // Sets both _i2i_entry and _from_interpreted_entry

   set_interpreter_entry(entry);

   // Don't overwrite already registered native entries.

   if (is_native() && !has_native_function()) {

     set_native_function(

       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),

       !native_bind_event_is_interesting);

   }

   // Setup compiler entrypoint.  This is made eagerly, so we do not need

   // special handling of vtables.  An alternative is to make adapters more

   // lazily by calling make_adapter() from from_compiled_entry() for the

   // normal calls.  For vtable calls life gets more complicated.  When a

   // call-site goes mega-morphic we need adapters in all methods which can be

   // called from the vtable.  We need adapters on such methods that get loaded

   // later.  Ditto for mega-morphic itable calls.  If this proves to be a

   // problem we'll make these lazily later.

   (void) make_adapters(h_method, CHECK);

   // ONLY USE the h_method now as make_adapter may have blocked

 }

 address Method::make_adapters(methodHandle mh, TRAPS) {

   // Adapters for compiled code are made eagerly here.  They are fairly

   // small (generally < 100 bytes) and quick to make (and cached and shared)

   // so making them eagerly shouldn't be too expensive.

   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);

   if (adapter == NULL ) {

     THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "out of space in CodeCache for adapters");

   }

   mh->set_adapter_entry(adapter);

   mh->_from_compiled_entry = adapter->get_c2i_entry();

   return adapter->get_c2i_entry();

 }

 void Method::restore_unshareable_info(TRAPS) {

   // Since restore_unshareable_info can be called more than once for a method, don't

   // redo any work.   If this field is restored, there is nothing to do.

   if (_from_compiled_entry == NULL) {

     // restore method's vtable by calling a virtual function

     restore_vtable();

     methodHandle mh(THREAD, this);

     link_method(mh, CHECK);

   }

 }

 // The verified_code_entry() must be called when a invoke is resolved

 // on this method.

 // It returns the compiled code entry point, after asserting not null.

 // This function is called after potential safepoints so that nmethod

 // or adapter that it points to is still live and valid.

 // This function must not hit a safepoint!

 address Method::verified_code_entry() {

   debug_only(No_Safepoint_Verifier nsv;)

   assert(_from_compiled_entry != NULL, "must be set");

   return _from_compiled_entry;

 }

 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all

 // (could be racing a deopt).

 // Not inline to avoid circular ref.

 bool Method::check_code() const {

   // cached in a register or local.  There's a race on the value of the field.

   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);

   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());

 }

 // Install compiled code.  Instantly it can execute.

 void Method::set_code(methodHandle mh, nmethod *code) {

   assert( code, "use clear_code to remove code" );

   assert( mh->check_code(), "" );

   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");

   // These writes must happen in this order, because the interpreter will

   // directly jump to from_interpreted_entry which jumps to an i2c adapter

   // which jumps to _from_compiled_entry.

   mh->_code = code;             // Assign before allowing compiled code to exec

   int comp_level = code->comp_level();

   // In theory there could be a race here. In practice it is unlikely

   // and not worth worrying about.

   if (comp_level > mh->highest_comp_level()) {

     mh->set_highest_comp_level(comp_level);

   }

   OrderAccess::storestore();

 #ifdef SHARK

   mh->_from_interpreted_entry = code->insts_begin();

 #else //!SHARK

   mh->_from_compiled_entry = code->verified_entry_point();

   OrderAccess::storestore();

   // Instantly compiled code can execute.

   if (!mh->is_method_handle_intrinsic())

     mh->_from_interpreted_entry = mh->get_i2c_entry();

 #endif //!SHARK

 }

 bool Method::is_overridden_in(Klass* k) const {

   InstanceKlass* ik = InstanceKlass::cast(k);

   if (ik->is_interface()) return false;

   // If method is an interface, we skip it - except if it

   // is a miranda method

   if (method_holder()->is_interface()) {

     // Check that method is not a miranda method

     if (ik->lookup_method(name(), signature()) == NULL) {

       // No implementation exist - so miranda method

       return false;

     }

     return true;

   }

   assert(ik->is_subclass_of(method_holder()), "should be subklass");

   assert(ik->vtable() != NULL, "vtable should exist");

   if (!has_vtable_index()) {

     return false;

   } else {

     Method* vt_m = ik->method_at_vtable(vtable_index());

     return vt_m != this;

   }

 }

 // give advice about whether this Method* should be cached or not

 bool Method::should_not_be_cached() const {

   if (is_old()) {

     // This method has been redefined. It is either EMCP or obsolete

     // and we don't want to cache it because that would pin the method

     // down and prevent it from being collectible if and when it

     // finishes executing.

     return true;

   }

   // caching this method should be just fine

   return false;

 }

 /**

  *  Returns true if this is one of the specially treated methods for

  *  security related stack walks (like Reflection.getCallerClass).

  */

 bool Method::is_ignored_by_security_stack_walk() const {

   const bool use_new_reflection = JDK_Version::is_gte_jdk14x_version() && UseNewReflection;

   if (intrinsic_id() == vmIntrinsics::_invoke) {

     // This is Method.invoke() -- ignore it

     return true;

   }

   if (use_new_reflection &&

       method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {

     // This is an auxilary frame -- ignore it

     return true;

   }

   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {

     // This is an internal adapter frame for method handles -- ignore it

     return true;

   }

   return false;

 }

 // Constant pool structure for invoke methods:

 enum {

   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.

   _imcp_invoke_signature,       // utf8: (variable Symbol*)

   _imcp_limit

 };

 // Test if this method is an MH adapter frame generated by Java code.

 // Cf. java/lang/invoke/InvokerBytecodeGenerator

 bool Method::is_compiled_lambda_form() const {

   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;

 }

 // Test if this method is an internal MH primitive method.

 bool Method::is_method_handle_intrinsic() const {

   vmIntrinsics::ID iid = intrinsic_id();

   return (MethodHandles::is_signature_polymorphic(iid) &&

           MethodHandles::is_signature_polymorphic_intrinsic(iid));

 }

 bool Method::has_member_arg() const {

   vmIntrinsics::ID iid = intrinsic_id();

   return (MethodHandles::is_signature_polymorphic(iid) &&

           MethodHandles::has_member_arg(iid));

 }

 // Make an instance of a signature-polymorphic internal MH primitive.

 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,

                                                          Symbol* signature,

                                                          TRAPS) {

   ResourceMark rm;

   methodHandle empty;

   KlassHandle holder = SystemDictionary::MethodHandle_klass();

   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);

   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");

   if (TraceMethodHandles) {

     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());

   }

   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)

   name->increment_refcount();

   signature->increment_refcount();

   int cp_length = _imcp_limit;

   ClassLoaderData* loader_data = holder->class_loader_data();

   constantPoolHandle cp;

   {

     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));

     cp = constantPoolHandle(THREAD, cp_oop);

   }

   cp->set_pool_holder(InstanceKlass::cast(holder()));

   cp->symbol_at_put(_imcp_invoke_name,       name);

   cp->symbol_at_put(_imcp_invoke_signature,  signature);

   cp->set_has_preresolution();

   // decide on access bits:  public or not?

   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);

   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);

   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;

   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");

   methodHandle m;

   {

     InlineTableSizes sizes;

     Method* m_oop = Method::allocate(loader_data, 0,

                                      accessFlags_from(flags_bits), &sizes,

                                      ConstMethod::NORMAL, CHECK_(empty));

     m = methodHandle(THREAD, m_oop);

   }

   m->set_constants(cp());

   m->set_name_index(_imcp_invoke_name);

   m->set_signature_index(_imcp_invoke_signature);

   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");

   assert(m->signature() == signature, "");

 #ifdef CC_INTERP

   ResultTypeFinder rtf(signature);

   m->set_result_index(rtf.type());

 #endif

   m->compute_size_of_parameters(THREAD);

   m->init_intrinsic_id();

   assert(m->is_method_handle_intrinsic(), "");

 #ifdef ASSERT

   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();

   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");

   assert(m->intrinsic_id() == iid, "correctly predicted iid");

 #endif //ASSERT

   // Finally, set up its entry points.

   assert(m->can_be_statically_bound(), "");

   m->set_vtable_index(Method::nonvirtual_vtable_index);

   m->link_method(m, CHECK_(empty));

   if (TraceMethodHandles && (Verbose || WizardMode))

     m->print_on(tty);

   return m;

 }

 Klass* Method::check_non_bcp_klass(Klass* klass) {

   if (klass != NULL && klass->class_loader() != NULL) {

     if (klass->oop_is_objArray())

       klass = ObjArrayKlass::cast(klass)->bottom_klass();

     return klass;

   }

   return NULL;

 }

 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,

                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {

   // Code below does not work for native methods - they should never get rewritten anyway

   assert(!m->is_native(), "cannot rewrite native methods");

   // Allocate new Method*

   AccessFlags flags = m->access_flags();

   ConstMethod* cm = m->constMethod();

   int checked_exceptions_len = cm->checked_exceptions_length();

   int localvariable_len = cm->localvariable_table_length();

   int exception_table_len = cm->exception_table_length();

   int method_parameters_len = cm->method_parameters_length();

   int method_annotations_len = cm->method_annotations_length();

   int parameter_annotations_len = cm->parameter_annotations_length();

   int type_annotations_len = cm->type_annotations_length();

   int default_annotations_len = cm->default_annotations_length();

   InlineTableSizes sizes(

       localvariable_len,

       new_compressed_linenumber_size,

       exception_table_len,

       checked_exceptions_len,

       method_parameters_len,

       cm->generic_signature_index(),

       method_annotations_len,

       parameter_annotations_len,

       type_annotations_len,

       default_annotations_len,

       0);

   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();

   Method* newm_oop = Method::allocate(loader_data,

                                       new_code_length,

                                       flags,

                                       &sizes,

                                       m->method_type(),

                                       CHECK_(methodHandle()));

   methodHandle newm (THREAD, newm_oop);

   int new_method_size = newm->method_size();

   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*

   ConstMethod* newcm = newm->constMethod();

   int new_const_method_size = newm->constMethod()->size();

   memcpy(newm(), m(), sizeof(Method));

   // Create shallow copy of ConstMethod.

   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));

   // Reset correct method/const method, method size, and parameter info

   newm->set_constMethod(newcm);

   newm->constMethod()->set_code_size(new_code_length);

   newm->constMethod()->set_constMethod_size(new_const_method_size);

   newm->set_method_size(new_method_size);

   assert(newm->code_size() == new_code_length, "check");

   assert(newm->method_parameters_length() == method_parameters_len, "check");

   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");

   assert(newm->exception_table_length() == exception_table_len, "check");

   assert(newm->localvariable_table_length() == localvariable_len, "check");

   // Copy new byte codes

   memcpy(newm->code_base(), new_code, new_code_length);

   // Copy line number table

   if (new_compressed_linenumber_size > 0) {

     memcpy(newm->compressed_linenumber_table(),

            new_compressed_linenumber_table,

            new_compressed_linenumber_size);

   }

   // Copy method_parameters

   if (method_parameters_len > 0) {

     memcpy(newm->method_parameters_start(),

            m->method_parameters_start(),

            method_parameters_len * sizeof(MethodParametersElement));

   }

   // Copy checked_exceptions

   if (checked_exceptions_len > 0) {

     memcpy(newm->checked_exceptions_start(),

            m->checked_exceptions_start(),

            checked_exceptions_len * sizeof(CheckedExceptionElement));

   }

   // Copy exception table

   if (exception_table_len > 0) {

     memcpy(newm->exception_table_start(),

            m->exception_table_start(),

            exception_table_len * sizeof(ExceptionTableElement));

   }

   // Copy local variable number table

   if (localvariable_len > 0) {

     memcpy(newm->localvariable_table_start(),

            m->localvariable_table_start(),

            localvariable_len * sizeof(LocalVariableTableElement));

   }

   // Copy stackmap table

   if (m->has_stackmap_table()) {

     int code_attribute_length = m->stackmap_data()->length();

     Array<u1>* stackmap_data =

       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);

     memcpy((void*)stackmap_data->adr_at(0),

            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);

     newm->set_stackmap_data(stackmap_data);

   }

   // copy annotations over to new method

   newcm->copy_annotations_from(cm);

   return newm;

 }

 vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {

   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics

   // because we are not loading from core libraries

   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar

   // which does not use the class default class loader so we check for its loader here

   InstanceKlass* ik = InstanceKlass::cast(holder);

   if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {

     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here

   }

   // see if the klass name is well-known:

   Symbol* klass_name = ik->name();

   return vmSymbols::find_sid(klass_name);

 }

 void Method::init_intrinsic_id() {

   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");

   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));

   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");

   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");

   // the klass name is well-known:

   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());

   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");

   // ditto for method and signature:

   vmSymbols::SID  name_id = vmSymbols::find_sid(name());

   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)

       && name_id == vmSymbols::NO_SID)

     return;

   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());

   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)

       && sig_id == vmSymbols::NO_SID)  return;

   jshort flags = access_flags().as_short();

   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);

   if (id != vmIntrinsics::_none) {

     set_intrinsic_id(id);

     return;

   }

   // A few slightly irregular cases:

   switch (klass_id) {

   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):

     // Second chance: check in regular Math.

     switch (name_id) {

     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):

     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):

     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):

       // pretend it is the corresponding method in the non-strict class:

       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);

       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);

       break;

     }

     break;

   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.

   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):

     if (!is_native())  break;

     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());

     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))

       id = vmIntrinsics::_none;

     break;

   }

   if (id != vmIntrinsics::_none) {

     // Set up its iid.  It is an alias method.

     set_intrinsic_id(id);

     return;

   }

 }

 // These two methods are static since a GC may move the Method

 bool Method::load_signature_classes(methodHandle m, TRAPS) {

   if (THREAD->is_Compiler_thread()) {

     // There is nothing useful this routine can do from within the Compile thread.

     // Hopefully, the signature contains only well-known classes.

     // We could scan for this and return true/false, but the caller won't care.

     return false;

   }

   bool sig_is_loaded = true;

   Handle class_loader(THREAD, m->method_holder()->class_loader());

   Handle protection_domain(THREAD, m->method_holder()->protection_domain());

   ResourceMark rm(THREAD);

   Symbol*  signature = m->signature();

   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {

     if (ss.is_object()) {

       Symbol* sym = ss.as_symbol(CHECK_(false));

       Symbol*  name  = sym;

       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,

                                              protection_domain, THREAD);

       // We are loading classes eagerly. If a ClassNotFoundException or

       // a LinkageError was generated, be sure to ignore it.

       if (HAS_PENDING_EXCEPTION) {

         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||

             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {

           CLEAR_PENDING_EXCEPTION;

         } else {

           return false;

         }

       }

       if( klass == NULL) { sig_is_loaded = false; }

     }

   }

   return sig_is_loaded;

 }

 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {

   Handle class_loader(THREAD, m->method_holder()->class_loader());

   Handle protection_domain(THREAD, m->method_holder()->protection_domain());

   ResourceMark rm(THREAD);

   Symbol*  signature = m->signature();

   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {

     if (ss.type() == T_OBJECT) {

       Symbol* name = ss.as_symbol_or_null();

       if (name == NULL) return true;

       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);

       if (klass == NULL) return true;

     }

   }

   return false;

 }

 // Exposed so field engineers can debug VM

 void Method::print_short_name(outputStream* st) {

   ResourceMark rm;

 #ifdef PRODUCT

   st->print(" %s::", method_holder()->external_name());

 #else

   st->print(" %s::", method_holder()->internal_name());

 #endif

   name()->print_symbol_on(st);

   if (WizardMode) signature()->print_symbol_on(st);

   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))

     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);

 }

 // Comparer for sorting an object array containing

 // Method*s.

 static int method_comparator(Method* a, Method* b) {

   return a->name()->fast_compare(b->name());

 }

 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array

 // default_methods also uses this without the ordering for fast find_method

 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {

   int length = methods->length();

   if (length > 1) {

     {

       No_Safepoint_Verifier nsv;

       QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);

     }

     // Reset method ordering

     if (set_idnums) {

       for (int i = 0; i < length; i++) {

         Method* m = methods->at(i);

         m->set_method_idnum(i);

         m->set_orig_method_idnum(i);

       }

     }

   }

 }

 //-----------------------------------------------------------------------------------

 // Non-product code unless JVM/TI needs it

 #if !defined(PRODUCT) || INCLUDE_JVMTI

 class SignatureTypePrinter : public SignatureTypeNames {

  private:

   outputStream* _st;

   bool _use_separator;

   void type_name(const char* name) {

     if (_use_separator) _st->print(", ");

     _st->print("%s", name);

     _use_separator = true;

   }

  public:

   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {

     _st = st;

     _use_separator = false;

   }

   void print_parameters()              { _use_separator = false; iterate_parameters(); }

   void print_returntype()              { _use_separator = false; iterate_returntype(); }

 };

 void Method::print_name(outputStream* st) {

   Thread *thread = Thread::current();

   ResourceMark rm(thread);

   SignatureTypePrinter sig(signature(), st);

   st->print("%s ", is_static() ? "static" : "virtual");

   sig.print_returntype();

   st->print(" %s.", method_holder()->internal_name());

   name()->print_symbol_on(st);

   st->print("(");

   sig.print_parameters();

   st->print(")");

 }

 #endif // !PRODUCT || INCLUDE_JVMTI

 //-----------------------------------------------------------------------------------

 // Non-product code

 #ifndef PRODUCT

 void Method::print_codes_on(outputStream* st) const {

   print_codes_on(0, code_size(), st);

 }

 void Method::print_codes_on(int from, int to, outputStream* st) const {

   Thread *thread = Thread::current();

   ResourceMark rm(thread);

   methodHandle mh (thread, (Method*)this);

   BytecodeStream s(mh);

   s.set_interval(from, to);

   BytecodeTracer::set_closure(BytecodeTracer::std_closure());

   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);

 }

 #endif // not PRODUCT

 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas

 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)

 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used

 // as end-of-stream terminator.

 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {

   // bci and line number does not compress into single byte.

   // Write out escape character and use regular compression for bci and line number.

   write_byte((jubyte)0xFF);

   write_signed_int(bci_delta);

   write_signed_int(line_delta);

 }

 // See comment in method.hpp which explains why this exists.

 #if defined(_M_AMD64) && _MSC_VER >= 1400

 #pragma optimize("", off)

 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {

   write_pair_inline(bci, line);

 }

 #pragma optimize("", on)

 #endif

 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {

   _bci = 0;

   _line = 0;

 };

 bool CompressedLineNumberReadStream::read_pair() {

   jubyte next = read_byte();

   // Check for terminator

   if (next == 0) return false;

   if (next == 0xFF) {

     // Escape character, regular compression used

     _bci  += read_signed_int();

     _line += read_signed_int();

   } else {

     // Single byte compression used

     _bci  += next >> 3;

     _line += next & 0x7;

   }

   return true;

 }

 Bytecodes::Code Method::orig_bytecode_at(int bci) const {

   BreakpointInfo* bp = method_holder()->breakpoints();

   for (; bp != NULL; bp = bp->next()) {

     if (bp->match(this, bci)) {

       return bp->orig_bytecode();

     }

   }

   {

     ResourceMark rm;

     fatal(err_msg("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci));

   }

   return Bytecodes::_shouldnotreachhere;

 }

 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {

   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");

   BreakpointInfo* bp = method_holder()->breakpoints();

   for (; bp != NULL; bp = bp->next()) {

     if (bp->match(this, bci)) {

       bp->set_orig_bytecode(code);

       // and continue, in case there is more than one

     }

   }

 }

 void Method::set_breakpoint(int bci) {

   InstanceKlass* ik = method_holder();

   BreakpointInfo *bp = new BreakpointInfo(this, bci);

   bp->set_next(ik->breakpoints());

   ik->set_breakpoints(bp);

   // do this last:

   bp->set(this);

 }

 static void clear_matches(Method* m, int bci) {

   InstanceKlass* ik = m->method_holder();

   BreakpointInfo* prev_bp = NULL;

   BreakpointInfo* next_bp;

   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {

     next_bp = bp->next();

     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).

     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {

       // do this first:

       bp->clear(m);

       // unhook it

       if (prev_bp != NULL)

         prev_bp->set_next(next_bp);

       else

         ik->set_breakpoints(next_bp);

       delete bp;

       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods

       // at same location. So we have multiple matching (method_index and bci)

       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one

       // breakpoint for clear_breakpoint request and keep all other method versions

       // BreakpointInfo for future clear_breakpoint request.

       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)

       // which is being called when class is unloaded. We delete all the Breakpoint

       // information for all versions of method. We may not correctly restore the original

       // bytecode in all method versions, but that is ok. Because the class is being unloaded

       // so these methods won't be used anymore.

       if (bci >= 0) {

         break;

       }

     } else {

       // This one is a keeper.

       prev_bp = bp;

     }

   }

 }

 void Method::clear_breakpoint(int bci) {

   assert(bci >= 0, "");

   clear_matches(this, bci);

 }

 void Method::clear_all_breakpoints() {

   clear_matches(this, -1);

 }

 int Method::invocation_count() {

   MethodCounters *mcs = method_counters();

   if (TieredCompilation) {

     MethodData* const mdo = method_data();

     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||

         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {

       return InvocationCounter::count_limit;

     } else {

       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +

              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);

     }

   } else {

     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();

   }

 }

 int Method::backedge_count() {

   MethodCounters *mcs = method_counters();

   if (TieredCompilation) {

     MethodData* const mdo = method_data();

     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||

         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {

       return InvocationCounter::count_limit;

     } else {

       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +

              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);

     }

   } else {

     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();

   }

 }

 int Method::highest_comp_level() const {

   const MethodCounters* mcs = method_counters();

   if (mcs != NULL) {

     return mcs->highest_comp_level();

   } else {

     return CompLevel_none;

   }

 }

 int Method::highest_osr_comp_level() const {

   const MethodCounters* mcs = method_counters();

   if (mcs != NULL) {

     return mcs->highest_osr_comp_level();

   } else {

     return CompLevel_none;

   }

 }

 void Method::set_highest_comp_level(int level) {

   MethodCounters* mcs = method_counters();

   if (mcs != NULL) {

     mcs->set_highest_comp_level(level);

   }

 }

 void Method::set_highest_osr_comp_level(int level) {

   MethodCounters* mcs = method_counters();

   if (mcs != NULL) {

     mcs->set_highest_osr_comp_level(level);

   }

 }

 BreakpointInfo::BreakpointInfo(Method* m, int bci) {

   _bci = bci;

   _name_index = m->name_index();

   _signature_index = m->signature_index();

   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);

   if (_orig_bytecode == Bytecodes::_breakpoint)

     _orig_bytecode = m->orig_bytecode_at(_bci);

   _next = NULL;

 }

 void BreakpointInfo::set(Method* method) {

 #ifdef ASSERT

   {

     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);

     if (code == Bytecodes::_breakpoint)

       code = method->orig_bytecode_at(_bci);

     assert(orig_bytecode() == code, "original bytecode must be the same");

   }

 #endif

   Thread *thread = Thread::current();

   *method->bcp_from(_bci) = Bytecodes::_breakpoint;

   method->incr_number_of_breakpoints(thread);

   SystemDictionary::notice_modification();

   {

     // Deoptimize all dependents on this method

     HandleMark hm(thread);

     methodHandle mh(thread, method);

     Universe::flush_dependents_on_method(mh);

   }

 }

 void BreakpointInfo::clear(Method* method) {

   *method->bcp_from(_bci) = orig_bytecode();

   assert(method->number_of_breakpoints() > 0, "must not go negative");

   method->decr_number_of_breakpoints(Thread::current());

 }

 // jmethodID handling

 // This is a block allocating object, sort of like JNIHandleBlock, only a

 // lot simpler.  There aren't many of these, they aren't long, they are rarely

 // deleted and so we can do some suboptimal things.

 // It's allocated on the CHeap because once we allocate a jmethodID, we can

 // never get rid of it.

 // It would be nice to be able to parameterize the number of methods for

 // the null_class_loader but then we'd have to turn this and ClassLoaderData

 // into templates.

 // I feel like this brain dead class should exist somewhere in the STL

 class JNIMethodBlock : public CHeapObj<mtClass> {

   enum { number_of_methods = 8 };

   Method*         _methods[number_of_methods];

   int             _top;

   JNIMethodBlock* _next;

  public:

   static Method* const _free_method;

   JNIMethodBlock() : _next(NULL), _top(0) {

     for (int i = 0; i< number_of_methods; i++) _methods[i] = _free_method;

   }

   Method** add_method(Method* m) {

     if (_top < number_of_methods) {

       // top points to the next free entry.

       int i = _top;

       _methods[i] = m;

       _top++;

       return &_methods[i];

     } else if (_top == number_of_methods) {

       // if the next free entry ran off the block see if there's a free entry

       for (int i = 0; i< number_of_methods; i++) {

         if (_methods[i] == _free_method) {

           _methods[i] = m;

           return &_methods[i];

         }

       }

       // Only check each block once for frees.  They're very unlikely.

       // Increment top past the end of the block.

       _top++;

     }

     // need to allocate a next block.

     if (_next == NULL) {

       _next = new JNIMethodBlock();

     }

     return _next->add_method(m);

   }

   bool contains(Method** m) {

     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {

       for (int i = 0; i< number_of_methods; i++) {

         if (&(b->_methods[i]) == m) {

           return true;

         }

       }

     }

     return false;  // not found

   }

   // Doesn't really destroy it, just marks it as free so it can be reused.

   void destroy_method(Method** m) {

 #ifdef ASSERT

     assert(contains(m), "should be a methodID");

 #endif // ASSERT

     *m = _free_method;

   }

   // During class unloading the methods are cleared, which is different

   // than freed.

   void clear_all_methods() {

     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {

       for (int i = 0; i< number_of_methods; i++) {

         _methods[i] = NULL;

       }

     }

   }

 #ifndef PRODUCT

   int count_methods() {

     // count all allocated methods

     int count = 0;

     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {

       for (int i = 0; i< number_of_methods; i++) {

         if (_methods[i] != _free_method) count++;

       }

     }

     return count;

   }

 #endif // PRODUCT

 };

 // Something that can't be mistaken for an address or a markOop

 Method* const JNIMethodBlock::_free_method = (Method*)55;

 // Add a method id to the jmethod_ids

 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {

   ClassLoaderData* cld = loader_data;

   if (!SafepointSynchronize::is_at_safepoint()) {

     // Have to add jmethod_ids() to class loader data thread-safely.

     // Also have to add the method to the list safely, which the cld lock

     // protects as well.

     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);

     if (cld->jmethod_ids() == NULL) {

       cld->set_jmethod_ids(new JNIMethodBlock());

     }

     // jmethodID is a pointer to Method*

     return (jmethodID)cld->jmethod_ids()->add_method(m);

   } else {

     // At safepoint, we are single threaded and can set this.

     if (cld->jmethod_ids() == NULL) {

       cld->set_jmethod_ids(new JNIMethodBlock());

     }

     // jmethodID is a pointer to Method*

     return (jmethodID)cld->jmethod_ids()->add_method(m);

   }

 }

 // Mark a jmethodID as free.  This is called when there is a data race in

 // InstanceKlass while creating the jmethodID cache.

 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {

   ClassLoaderData* cld = loader_data;

   Method** ptr = (Method**)m;

   assert(cld->jmethod_ids() != NULL, "should have method handles");

   cld->jmethod_ids()->destroy_method(ptr);

 }

 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {

   // Can't assert the method_holder is the same because the new method has the

   // scratch method holder.

   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()

            == new_method->method_holder()->class_loader(),

          "changing to a different class loader");

   // Just change the method in place, jmethodID pointer doesn't change.

   *((Method**)jmid) = new_method;

 }

 bool Method::is_method_id(jmethodID mid) {

   Method* m = resolve_jmethod_id(mid);

   assert(m != NULL, "should be called with non-null method");

   InstanceKlass* ik = m->method_holder();

   ClassLoaderData* cld = ik->class_loader_data();

   if (cld->jmethod_ids() == NULL) return false;

   return (cld->jmethod_ids()->contains((Method**)mid));

 }

 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {

   if (mid == NULL) return NULL;

   Method* o = resolve_jmethod_id(mid);

   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {

     return NULL;

   }

   return o;

 };

 void Method::set_on_stack(const bool value) {

   // Set both the method itself and its constant pool.  The constant pool

   // on stack means some method referring to it is also on the stack.

   constants()->set_on_stack(value);

   bool succeeded = _access_flags.set_on_stack(value);

   if (value && succeeded) {

     MetadataOnStackMark::record(this, Thread::current());

   }

 }

 // Called when the class loader is unloaded to make all methods weak.

 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {

   loader_data->jmethod_ids()->clear_all_methods();

 }

 bool Method::has_method_vptr(const void* ptr) {

   Method m;

   // This assumes that the vtbl pointer is the first word of a C++ object.

   // This assumption is also in universe.cpp patch_klass_vtble

   void* vtbl2 = dereference_vptr((const void*)&m);

   void* this_vtbl = dereference_vptr(ptr);

   return vtbl2 == this_vtbl;

 }

 // Check that this pointer is valid by checking that the vtbl pointer matches

 bool Method::is_valid_method() const {

   if (this == NULL) {

     return false;

   } else if (!is_metaspace_object()) {

     return false;

   } else {

     return has_method_vptr((const void*)this);

   }

 }

 #ifndef PRODUCT

 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {

   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());

 }

 #endif // PRODUCT

 // Printing

 #ifndef PRODUCT

 void Method::print_on(outputStream* st) const {

   ResourceMark rm;

   assert(is_method(), "must be method");

   st->print_cr("%s", internal_name());

   // get the effect of PrintOopAddress, always, for methods:

   st->print_cr(" - this oop:          "INTPTR_FORMAT, (intptr_t)this);

   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();

   st->print   (" - constants:         "INTPTR_FORMAT" ", (address)constants());

   constants()->print_value_on(st); st->cr();

   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();

   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();

   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();

   st->print_cr(" - max stack:         %d",   max_stack());

   st->print_cr(" - max locals:        %d",   max_locals());

   st->print_cr(" - size of params:    %d",   size_of_parameters());

   st->print_cr(" - method size:       %d",   method_size());

   if (intrinsic_id() != vmIntrinsics::_none)

     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));

   if (highest_comp_level() != CompLevel_none)

     st->print_cr(" - highest level:     %d", highest_comp_level());

   st->print_cr(" - vtable index:      %d",   _vtable_index);

   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, interpreter_entry());

   st->print(   " - adapters:          ");

   AdapterHandlerEntry* a = ((Method*)this)->adapter();

   if (a == NULL)

     st->print_cr(INTPTR_FORMAT, a);

   else

     a->print_adapter_on(st);

   st->print_cr(" - compiled entry     " INTPTR_FORMAT, from_compiled_entry());

   st->print_cr(" - code size:         %d",   code_size());

   if (code_size() != 0) {

     st->print_cr(" - code start:        " INTPTR_FORMAT, code_base());

     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, code_base() + code_size());

   }

   if (method_data() != NULL) {

     st->print_cr(" - method data:       " INTPTR_FORMAT, (address)method_data());

   }

   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());

   if (checked_exceptions_length() > 0) {

     CheckedExceptionElement* table = checked_exceptions_start();

     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, table);

     if (Verbose) {

       for (int i = 0; i < checked_exceptions_length(); i++) {

         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));

       }

     }

   }

   if (has_linenumber_table()) {

     u_char* table = compressed_linenumber_table();

     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, table);

     if (Verbose) {

       CompressedLineNumberReadStream stream(table);

       while (stream.read_pair()) {

         st->print_cr("   - line %d: %d", stream.line(), stream.bci());

       }

     }

   }

   st->print_cr(" - localvar length:   %d",   localvariable_table_length());

   if (localvariable_table_length() > 0) {

     LocalVariableTableElement* table = localvariable_table_start();

     st->print_cr(" - localvar start:    " INTPTR_FORMAT, table);

     if (Verbose) {

       for (int i = 0; i < localvariable_table_length(); i++) {

         int bci = table[i].start_bci;

         int len = table[i].length;

         const char* name = constants()->printable_name_at(table[i].name_cp_index);

         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);

         int slot = table[i].slot;

         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);

       }

     }

   }

   if (code() != NULL) {

     st->print   (" - compiled code: ");

     code()->print_value_on(st);

   }

   if (is_native()) {

     st->print_cr(" - native function:   " INTPTR_FORMAT, native_function());

     st->print_cr(" - signature handler: " INTPTR_FORMAT, signature_handler());

   }

 }

 #endif //PRODUCT

 void Method::print_value_on(outputStream* st) const {

   assert(is_method(), "must be method");

   st->print("%s", internal_name());

   print_address_on(st);

   st->print(" ");

   name()->print_value_on(st);

   st->print(" ");

   signature()->print_value_on(st);

   st->print(" in ");

   method_holder()->print_value_on(st);

   if (WizardMode) st->print("#%d", _vtable_index);

   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());

   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());

 }

 #if INCLUDE_SERVICES

 // Size Statistics

 void Method::collect_statistics(KlassSizeStats *sz) const {

   int mysize = sz->count(this);

   sz->_method_bytes += mysize;

   sz->_method_all_bytes += mysize;

   sz->_rw_bytes += mysize;

   if (constMethod()) {

     constMethod()->collect_statistics(sz);

   }

   if (method_data()) {

     method_data()->collect_statistics(sz);

   }

 }

 #endif // INCLUDE_SERVICES

 // Verification

 void Method::verify_on(outputStream* st) {

   guarantee(is_method(), "object must be method");

   guarantee(constants()->is_constantPool(), "should be constant pool");

   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");

   MethodData* md = method_data();

   guarantee(md == NULL ||

       md->is_methodData(), "should be method data");

 }