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 /*

  * 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.

  *

  */

 #ifndef SHARE_VM_OOPS_METHODOOP_HPP

 #define SHARE_VM_OOPS_METHODOOP_HPP

 #include "classfile/vmSymbols.hpp"

 #include "code/compressedStream.hpp"

 #include "compiler/oopMap.hpp"

 #include "interpreter/invocationCounter.hpp"

 #include "oops/annotations.hpp"

 #include "oops/constantPool.hpp"

 #include "oops/methodCounters.hpp"

 #include "oops/instanceKlass.hpp"

 #include "oops/oop.hpp"

 #include "oops/typeArrayOop.hpp"

 #include "utilities/accessFlags.hpp"

 #include "utilities/growableArray.hpp"

 // A Method* represents a Java method.

 //

 // Memory layout (each line represents a word). Note that most applications load thousands of methods,

 // so keeping the size of this structure small has a big impact on footprint.

 //

 // We put all oops and method_size first for better gc cache locality.

 //

 // The actual bytecodes are inlined after the end of the Method struct.

 //

 // There are bits in the access_flags telling whether inlined tables are present.

 // Note that accessing the line number and local variable tables is not performance critical at all.

 // Accessing the checked exceptions table is used by reflection, so we put that last to make access

 // to it fast.

 //

 // The line number table is compressed and inlined following the byte codes. It is found as the first

 // byte following the byte codes. The checked exceptions table and the local variable table are inlined

 // after the line number table, and indexed from the end of the method. We do not compress the checked

 // exceptions table since the average length is less than 2, and do not bother to compress the local

 // variable table either since it is mostly absent.

 //

 // Note that native_function and signature_handler has to be at fixed offsets (required by the interpreter)

 //

 // |------------------------------------------------------|

 // | header                                               |

 // | klass                                                |

 // |------------------------------------------------------|

 // | ConstMethod*                   (oop)                 |

 // |------------------------------------------------------|

 // | methodData                     (oop)                 |

 // | methodCounters                                       |

 // |------------------------------------------------------|

 // | access_flags                                         |

 // | vtable_index                                         |

 // |------------------------------------------------------|

 // | result_index (C++ interpreter only)                  |

 // |------------------------------------------------------|

 // | method_size             |   intrinsic_id|   flags    |

 // |------------------------------------------------------|

 // | code                           (pointer)             |

 // | i2i                            (pointer)             |

 // | adapter                        (pointer)             |

 // | from_compiled_entry            (pointer)             |

 // | from_interpreted_entry         (pointer)             |

 // |------------------------------------------------------|

 // | native_function       (present only if native)       |

 // | signature_handler     (present only if native)       |

 // |------------------------------------------------------|

 class CheckedExceptionElement;

 class LocalVariableTableElement;

 class AdapterHandlerEntry;

 class MethodData;

 class MethodCounters;

 class ConstMethod;

 class InlineTableSizes;

 class KlassSizeStats;

 class Method : public Metadata {

  friend class VMStructs;

  private:

   ConstMethod*      _constMethod;                // Method read-only data.

   MethodData*       _method_data;

   MethodCounters*   _method_counters;

   AccessFlags       _access_flags;               // Access flags

   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)

                                                  // note: can have vtables with >2**16 elements (because of inheritance)

 #ifdef CC_INTERP

   int               _result_index;               // C++ interpreter needs for converting results to/from stack

 #endif

   u2                _method_size;                // size of this object

   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)

   u1                _jfr_towrite          : 1,   // Flags

                     _caller_sensitive     : 1,

                     _force_inline         : 1,

                     _hidden               : 1,

                     _dont_inline          : 1,

                     _has_injected_profile : 1,

                                           : 2;

 #ifndef PRODUCT

   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)

 #endif

   // Entry point for calling both from and to the interpreter.

   address _i2i_entry;           // All-args-on-stack calling convention

   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.

   AdapterHandlerEntry* _adapter;

   // Entry point for calling from compiled code, to compiled code if it exists

   // or else the interpreter.

   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()

   // The entry point for calling both from and to compiled code is

   // "_code->entry_point()".  Because of tiered compilation and de-opt, this

   // field can come and go.  It can transition from NULL to not-null at any

   // time (whenever a compile completes).  It can transition from not-null to

   // NULL only at safepoints (because of a de-opt).

   nmethod* volatile _code;                       // Points to the corresponding piece of native code

   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry

   // Constructor

   Method(ConstMethod* xconst, AccessFlags access_flags, int size);

  public:

   static Method* allocate(ClassLoaderData* loader_data,

                           int byte_code_size,

                           AccessFlags access_flags,

                           InlineTableSizes* sizes,

                           ConstMethod::MethodType method_type,

                           TRAPS);

   // CDS and vtbl checking can create an empty Method to get vtbl pointer.

   Method(){}

   // The Method vtable is restored by this call when the Method is in the

   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for

   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata

   // by their vtable.

   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }

   bool is_method() const volatile { return true; }

   void restore_unshareable_info(TRAPS);

   // accessors for instance variables

   ConstMethod* constMethod() const             { return _constMethod; }

   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }

   static address make_adapters(methodHandle mh, TRAPS);

   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }

   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }

   // access flag

   AccessFlags access_flags() const               { return _access_flags;  }

   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }

   // name

   Symbol* name() const                           { return constants()->symbol_at(name_index()); }

   int name_index() const                         { return constMethod()->name_index();         }

   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }

   // signature

   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }

   int signature_index() const                    { return constMethod()->signature_index();         }

   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }

   // generics support

   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }

   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }

   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }

   // annotations support

   AnnotationArray* annotations() const           {

     return constMethod()->method_annotations();

   }

   AnnotationArray* parameter_annotations() const {

     return constMethod()->parameter_annotations();

   }

   AnnotationArray* annotation_default() const    {

     return constMethod()->default_annotations();

   }

   AnnotationArray* type_annotations() const      {

     return constMethod()->type_annotations();

   }

 #ifdef CC_INTERP

   void set_result_index(BasicType type);

   int  result_index()                            { return _result_index; }

 #endif

   // Helper routine: get klass name + "." + method name + signature as

   // C string, for the purpose of providing more useful NoSuchMethodErrors

   // and fatal error handling. The string is allocated in resource

   // area if a buffer is not provided by the caller.

   char* name_and_sig_as_C_string() const;

   char* name_and_sig_as_C_string(char* buf, int size) const;

   // Static routine in the situations we don't have a Method*

   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);

   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);

   Bytecodes::Code java_code_at(int bci) const {

     return Bytecodes::java_code_at(this, bcp_from(bci));

   }

   Bytecodes::Code code_at(int bci) const {

     return Bytecodes::code_at(this, bcp_from(bci));

   }

   // JVMTI breakpoints

   Bytecodes::Code orig_bytecode_at(int bci) const;

   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);

   void set_breakpoint(int bci);

   void clear_breakpoint(int bci);

   void clear_all_breakpoints();

   // Tracking number of breakpoints, for fullspeed debugging.

   // Only mutated by VM thread.

   u2   number_of_breakpoints()             const {

     MethodCounters* mcs = method_counters();

     if (mcs == NULL) {

       return 0;

     } else {

       return mcs->number_of_breakpoints();

     }

   }

   void incr_number_of_breakpoints(TRAPS)         {

     MethodCounters* mcs = get_method_counters(CHECK);

     if (mcs != NULL) {

       mcs->incr_number_of_breakpoints();

     }

   }

   void decr_number_of_breakpoints(TRAPS)         {

     MethodCounters* mcs = get_method_counters(CHECK);

     if (mcs != NULL) {

       mcs->decr_number_of_breakpoints();

     }

   }

   // Initialization only

   void clear_number_of_breakpoints()             {

     MethodCounters* mcs = method_counters();

     if (mcs != NULL) {

       mcs->clear_number_of_breakpoints();

     }

   }

   // index into InstanceKlass methods() array

   // note: also used by jfr

   u2 method_idnum() const           { return constMethod()->method_idnum(); }

   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }

   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }

   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }

   // code size

   int code_size() const                  { return constMethod()->code_size(); }

   // method size

   int method_size() const                        { return _method_size; }

   void set_method_size(int size) {

     assert(0 <= size && size < (1 << 16), "invalid method size");

     _method_size = size;

   }

   // constant pool for Klass* holding this method

   ConstantPool* constants() const              { return constMethod()->constants(); }

   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }

   // max stack

   // return original max stack size for method verification

   int  verifier_max_stack() const                { return constMethod()->max_stack(); }

   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }

   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }

   // max locals

   int  max_locals() const                        { return constMethod()->max_locals(); }

   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }

   int highest_comp_level() const;

   void set_highest_comp_level(int level);

   int highest_osr_comp_level() const;

   void set_highest_osr_comp_level(int level);

   // Count of times method was exited via exception while interpreting

   void interpreter_throwout_increment(TRAPS) {

     MethodCounters* mcs = get_method_counters(CHECK);

     if (mcs != NULL) {

       mcs->interpreter_throwout_increment();

     }

   }

   int  interpreter_throwout_count() const        {

     MethodCounters* mcs = method_counters();

     if (mcs == NULL) {

       return 0;

     } else {

       return mcs->interpreter_throwout_count();

     }

   }

   // size of parameters

   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }

   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }

   bool has_stackmap_table() const {

     return constMethod()->has_stackmap_table();

   }

   Array<u1>* stackmap_data() const {

     return constMethod()->stackmap_data();

   }

   void set_stackmap_data(Array<u1>* sd) {

     constMethod()->set_stackmap_data(sd);

   }

   // exception handler table

   bool has_exception_handler() const

                              { return constMethod()->has_exception_handler(); }

   int exception_table_length() const

                              { return constMethod()->exception_table_length(); }

   ExceptionTableElement* exception_table_start() const

                              { return constMethod()->exception_table_start(); }

   // Finds the first entry point bci of an exception handler for an

   // exception of klass ex_klass thrown at throw_bci. A value of NULL

   // for ex_klass indicates that the exception klass is not known; in

   // this case it matches any constraint class. Returns -1 if the

   // exception cannot be handled in this method. The handler

   // constraint classes are loaded if necessary. Note that this may

   // throw an exception if loading of the constraint classes causes

   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.

   // If an exception is thrown, returns the bci of the

   // exception handler which caused the exception to be thrown, which

   // is needed for proper retries. See, for example,

   // InterpreterRuntime::exception_handler_for_exception.

   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);

   // method data access

   MethodData* method_data() const              {

     return _method_data;

   }

   void set_method_data(MethodData* data)       {

     // The store into method must be released. On platforms without

     // total store order (TSO) the reference may become visible before

     // the initialization of data otherwise.

     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);

   }

   MethodCounters* method_counters() const {

     return _method_counters;

   }

   void clear_method_counters() {

     _method_counters = NULL;

   }

   bool init_method_counters(MethodCounters* counters) {

     // Try to install a pointer to MethodCounters, return true on success.

     return Atomic::cmpxchg_ptr(counters, (volatile void*)&_method_counters, NULL) == NULL;

   }

 #ifdef TIERED

   // We are reusing interpreter_invocation_count as a holder for the previous event count!

   // We can do that since interpreter_invocation_count is not used in tiered.

   int prev_event_count() const                   {

     if (method_counters() == NULL) {

       return 0;

     } else {

       return method_counters()->interpreter_invocation_count();

     }

   }

   void set_prev_event_count(int count) {

     MethodCounters* mcs = method_counters();

     if (mcs != NULL) {

       mcs->set_interpreter_invocation_count(count);

     }

   }

   jlong prev_time() const                        {

     MethodCounters* mcs = method_counters();

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

   }

   void set_prev_time(jlong time) {

     MethodCounters* mcs = method_counters();

     if (mcs != NULL) {

       mcs->set_prev_time(time);

     }

   }

   float rate() const                             {

     MethodCounters* mcs = method_counters();

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

   }

   void set_rate(float rate) {

     MethodCounters* mcs = method_counters();

     if (mcs != NULL) {

       mcs->set_rate(rate);

     }

   }

 #endif

   int invocation_count();

   int backedge_count();

   bool was_executed_more_than(int n);

   bool was_never_executed()                      { return !was_executed_more_than(0); }

   static void build_interpreter_method_data(methodHandle method, TRAPS);

   static MethodCounters* build_method_counters(Method* m, TRAPS);

   int interpreter_invocation_count() {

     if (TieredCompilation) {

       return invocation_count();

     } else {

       MethodCounters* mcs = method_counters();

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

     }

   }

   int increment_interpreter_invocation_count(TRAPS) {

     if (TieredCompilation) ShouldNotReachHere();

     MethodCounters* mcs = get_method_counters(CHECK_0);

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

   }

 #ifndef PRODUCT

   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }

   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }

 #endif // not PRODUCT

   // Clear (non-shared space) pointers which could not be relevant

   // if this (shared) method were mapped into another JVM.

   void remove_unshareable_info();

   // nmethod/verified compiler entry

   address verified_code_entry();

   bool check_code() const;      // Not inline to avoid circular ref

   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }

   void clear_code();            // Clear out any compiled code

   static void set_code(methodHandle mh, nmethod* code);

   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }

   address get_i2c_entry();

   address get_c2i_entry();

   address get_c2i_unverified_entry();

   AdapterHandlerEntry* adapter() {  return _adapter; }

   // setup entry points

   void link_method(methodHandle method, TRAPS);

   // clear entry points. Used by sharing code

   void unlink_method();

   // vtable index

   enum VtableIndexFlag {

     // Valid vtable indexes are non-negative (>= 0).

     // These few negative values are used as sentinels.

     itable_index_max        = -10, // first itable index, growing downward

     pending_itable_index    = -9,  // itable index will be assigned

     invalid_vtable_index    = -4,  // distinct from any valid vtable index

     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet

     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch

     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.

   };

   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })

   bool has_vtable_index() const                  { return _vtable_index >= 0; }

   int  vtable_index() const                      { return _vtable_index; }

   void set_vtable_index(int index)               { _vtable_index = index; }

   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })

   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }

   int  itable_index() const                      { assert(valid_itable_index(), "");

                                                    return itable_index_max - _vtable_index; }

   void set_itable_index(int index)               { _vtable_index = itable_index_max - index; assert(valid_itable_index(), ""); }

   // interpreter entry

   address interpreter_entry() const              { return _i2i_entry; }

   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry

   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }

   // native function (used for native methods only)

   enum {

     native_bind_event_is_interesting = true

   };

   address native_function() const                { return *(native_function_addr()); }

   address critical_native_function();

   // Must specify a real function (not NULL).

   // Use clear_native_function() to unregister.

   void set_native_function(address function, bool post_event_flag);

   bool has_native_function() const;

   void clear_native_function();

   // signature handler (used for native methods only)

   address signature_handler() const              { return *(signature_handler_addr()); }

   void set_signature_handler(address handler);

   // Interpreter oopmap support

   void mask_for(int bci, InterpreterOopMap* mask);

 #ifndef PRODUCT

   // operations on invocation counter

   void print_invocation_count();

 #endif

   // byte codes

   void    set_code(address code)      { return constMethod()->set_code(code); }

   address code_base() const           { return constMethod()->code_base(); }

   bool    contains(address bcp) const { return constMethod()->contains(bcp); }

   // prints byte codes

   void print_codes() const            { print_codes_on(tty); }

   void print_codes_on(outputStream* st) const                      PRODUCT_RETURN;

   void print_codes_on(int from, int to, outputStream* st) const    PRODUCT_RETURN;

   // method parameters

   bool has_method_parameters() const

                          { return constMethod()->has_method_parameters(); }

   int method_parameters_length() const

                          { return constMethod()->method_parameters_length(); }

   MethodParametersElement* method_parameters_start() const

                           { return constMethod()->method_parameters_start(); }

   // checked exceptions

   int checked_exceptions_length() const

                          { return constMethod()->checked_exceptions_length(); }

   CheckedExceptionElement* checked_exceptions_start() const

                           { return constMethod()->checked_exceptions_start(); }

   // localvariable table

   bool has_localvariable_table() const

                           { return constMethod()->has_localvariable_table(); }

   int localvariable_table_length() const

                         { return constMethod()->localvariable_table_length(); }

   LocalVariableTableElement* localvariable_table_start() const

                          { return constMethod()->localvariable_table_start(); }

   bool has_linenumber_table() const

                               { return constMethod()->has_linenumber_table(); }

   u_char* compressed_linenumber_table() const

                        { return constMethod()->compressed_linenumber_table(); }

   // method holder (the Klass* holding this method)

   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }

   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)

   Symbol* klass_name() const;                    // returns the name of the method holder

   BasicType result_type() const;                 // type of the method result

   int result_type_index() const;                 // type index of the method result

   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }

   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }

   // Checked exceptions thrown by this method (resolved to mirrors)

   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }

   // Access flags

   bool is_public() const                         { return access_flags().is_public();      }

   bool is_private() const                        { return access_flags().is_private();     }

   bool is_protected() const                      { return access_flags().is_protected();   }

   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }

   bool is_static() const                         { return access_flags().is_static();      }

   bool is_final() const                          { return access_flags().is_final();       }

   bool is_synchronized() const                   { return access_flags().is_synchronized();}

   bool is_native() const                         { return access_flags().is_native();      }

   bool is_abstract() const                       { return access_flags().is_abstract();    }

   bool is_strict() const                         { return access_flags().is_strict();      }

   bool is_synthetic() const                      { return access_flags().is_synthetic();   }

   // returns true if contains only return operation

   bool is_empty_method() const;

   // returns true if this is a vanilla constructor

   bool is_vanilla_constructor() const;

   // checks method and its method holder

   bool is_final_method() const;

   bool is_final_method(AccessFlags class_access_flags) const;

   bool is_default_method() const;

   // true if method needs no dynamic dispatch (final and/or no vtable entry)

   bool can_be_statically_bound() const;

   bool can_be_statically_bound(AccessFlags class_access_flags) const;

   // returns true if the method has any backward branches.

   bool has_loops() {

     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();

   };

   bool compute_has_loops_flag();

   bool has_jsrs() {

     return access_flags().has_jsrs();

   };

   void set_has_jsrs() {

     _access_flags.set_has_jsrs();

   }

   // returns true if the method has any monitors.

   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }

   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }

   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }

   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes

   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.

   // has not been computed yet.

   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }

   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }

   // returns true if the method is an accessor function (setter/getter).

   bool is_accessor() const;

   // returns true if the method does nothing but return a constant of primitive type

   bool is_constant_getter() const;

   // returns true if the method is an initializer (<init> or <clinit>).

   bool is_initializer() const;

   // returns true if the method is static OR if the classfile version < 51

   bool has_valid_initializer_flags() const;

   // returns true if the method name is <clinit> and the method has

   // valid static initializer flags.

   bool is_static_initializer() const;

   // compiled code support

   // NOTE: code() is inherently racy as deopt can be clearing code

   // simultaneously. Use with caution.

   bool has_compiled_code() const                 { return code() != NULL; }

   // sizing

   static int header_size()                       { return sizeof(Method)/HeapWordSize; }

   static int size(bool is_native);

   int size() const                               { return method_size(); }

 #if INCLUDE_SERVICES

   void collect_statistics(KlassSizeStats *sz) const;

 #endif

   // interpreter support

   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }

   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }

 #ifdef CC_INTERP

   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }

 #endif /* CC_INTERP */

   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }

   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }

   static ByteSize method_data_offset()           {

     return byte_offset_of(Method, _method_data);

   }

   static ByteSize method_counters_offset()       {

     return byte_offset_of(Method, _method_counters);

   }

 #ifndef PRODUCT

   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }

 #endif // not PRODUCT

   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }

   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }

   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }

   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }

   // for code generation

   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }

   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }

   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }

   // Static methods that are used to implement member methods where an exposed this pointer

   // is needed due to possible GCs

   static objArrayHandle resolved_checked_exceptions_impl(Method* this_oop, TRAPS);

   // Returns the byte code index from the byte code pointer

   int     bci_from(address bcp) const;

   address bcp_from(int     bci) const;

   int validate_bci_from_bcx(intptr_t bcx) const;

   // Returns the line number for a bci if debugging information for the method is prowided,

   // -1 is returned otherwise.

   int line_number_from_bci(int bci) const;

   // Reflection support

   bool is_overridden_in(Klass* k) const;

   // Stack walking support

   bool is_ignored_by_security_stack_walk() const;

   // JSR 292 support

   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)

   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm

   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.

   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual

                                                    Symbol* signature, //anything at all

                                                    TRAPS);

   static Klass* check_non_bcp_klass(Klass* klass);

   // How many extra stack entries for invokedynamic when it's enabled

   static const int extra_stack_entries_for_jsr292 = 1;

   // this operates only on invoke methods:

   // presize interpreter frames for extra interpreter stack entries, if needed

   // Account for the extra appendix argument for invokehandle/invokedynamic

   static int extra_stack_entries() { return EnableInvokeDynamic ? extra_stack_entries_for_jsr292 : 0; }

   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize

   // RedefineClasses() support:

   bool is_old() const                               { return access_flags().is_old(); }

   void set_is_old()                                 { _access_flags.set_is_old(); }

   bool is_obsolete() const                          { return access_flags().is_obsolete(); }

   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }

   bool is_deleted() const                           { return access_flags().is_deleted(); }

   void set_is_deleted()                             { _access_flags.set_is_deleted(); }

   bool on_stack() const                             { return access_flags().on_stack(); }

   void set_on_stack(const bool value);

   // see the definition in Method*.cpp for the gory details

   bool should_not_be_cached() const;

   // JVMTI Native method prefixing support:

   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }

   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }

   // Rewriting support

   static methodHandle 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);

   // jmethodID handling

   // Because the useful life-span of a jmethodID cannot be determined,

   // once created they are never reclaimed.  The methods to which they refer,

   // however, can be GC'ed away if the class is unloaded or if the method is

   // made obsolete or deleted -- in these cases, the jmethodID

   // refers to NULL (as is the case for any weak reference).

   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);

   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);

   // Use resolve_jmethod_id() in situations where the caller is expected

   // to provide a valid jmethodID; the only sanity checks are in asserts;

   // result guaranteed not to be NULL.

   inline static Method* resolve_jmethod_id(jmethodID mid) {

     assert(mid != NULL, "JNI method id should not be null");

     return *((Method**)mid);

   }

   // Use checked_resolve_jmethod_id() in situations where the caller

   // should provide a valid jmethodID, but might not. NULL is returned

   // when the jmethodID does not refer to a valid method.

   static Method* checked_resolve_jmethod_id(jmethodID mid);

   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);

   static bool is_method_id(jmethodID mid);

   // Clear methods

   static void clear_jmethod_ids(ClassLoaderData* loader_data);

   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;

   // Get this method's jmethodID -- allocate if it doesn't exist

   jmethodID jmethod_id()                            { methodHandle this_h(this);

                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }

   // Lookup the jmethodID for this method.  Return NULL if not found.

   // NOTE that this function can be called from a signal handler

   // (see AsyncGetCallTrace support for Forte Analyzer) and this

   // needs to be async-safe. No allocation should be done and

   // so handles are not used to avoid deadlock.

   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }

   // Support for inlining of intrinsic methods

   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }

   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }

   // Helper routines for intrinsic_id() and vmIntrinsics::method().

   void init_intrinsic_id();     // updates from _none if a match

   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);

   bool     jfr_towrite()                { return _jfr_towrite;              }

   void set_jfr_towrite(bool x)          {        _jfr_towrite = x;          }

   bool     caller_sensitive()           { return _caller_sensitive;         }

   void set_caller_sensitive(bool x)     {        _caller_sensitive = x;     }

   bool     force_inline()               { return _force_inline;             }

   void set_force_inline(bool x)         {        _force_inline = x;         }

   bool     dont_inline()                { return _dont_inline;              }

   void set_dont_inline(bool x)          {        _dont_inline = x;          }

   bool  is_hidden()                     { return _hidden;                   }

   void set_hidden(bool x)               {        _hidden = x;               }

   bool     has_injected_profile()       { return _has_injected_profile;     }

   void set_has_injected_profile(bool x) {        _has_injected_profile = x; }

   ConstMethod::MethodType method_type() const {

       return _constMethod->method_type();

   }

   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }

   // On-stack replacement support

   bool has_osr_nmethod(int level, bool match_level) {

    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;

   }

   int mark_osr_nmethods() {

     return method_holder()->mark_osr_nmethods(this);

   }

   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {

     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);

   }

   // Inline cache support

   void cleanup_inline_caches();

   // Find if klass for method is loaded

   bool is_klass_loaded_by_klass_index(int klass_index) const;

   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;

   // Indicates whether compilation failed earlier for this method, or

   // whether it is not compilable for another reason like having a

   // breakpoint set in it.

   bool  is_not_compilable(int comp_level = CompLevel_any) const;

   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);

   void set_not_compilable_quietly(int comp_level = CompLevel_all) {

     set_not_compilable(comp_level, false);

   }

   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;

   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);

   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {

     set_not_osr_compilable(comp_level, false);

   }

   bool is_always_compilable() const;

  private:

   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);

  public:

   MethodCounters* get_method_counters(TRAPS) {

     if (_method_counters == NULL) {

       build_method_counters(this, CHECK_AND_CLEAR_NULL);

     }

     return _method_counters;

   }

   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }

   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }

   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }

   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }

   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }

   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }

   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit

   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit

   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit

   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }

   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }

   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }

   // Background compilation support

   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }

   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }

   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }

   // Resolve all classes in signature, return 'true' if successful

   static bool load_signature_classes(methodHandle m, TRAPS);

   // Return if true if not all classes references in signature, including return type, has been loaded

   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);

   // Printing

   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM

 #if INCLUDE_JVMTI

   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses

 #else

   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"

 #endif

   // Helper routine used for method sorting

   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);

   // Deallocation function for redefine classes or if an error occurs

   void deallocate_contents(ClassLoaderData* loader_data);

   // Printing

 #ifndef PRODUCT

   void print_on(outputStream* st) const;

 #endif

   void print_value_on(outputStream* st) const;

   const char* internal_name() const { return "{method}"; }

   // Check for valid method pointer

   static bool has_method_vptr(const void* ptr);

   bool is_valid_method() const;

   // Verify

   void verify() { verify_on(tty); }

   void verify_on(outputStream* st);

  private:

   // Inlined elements

   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }

   address* signature_handler_addr() const        { return native_function_addr() + 1; }

 };

 // Utility class for compressing line number tables

 class CompressedLineNumberWriteStream: public CompressedWriteStream {

  private:

   int _bci;

   int _line;

  public:

   // Constructor

   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}

   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}

   // Write (bci, line number) pair to stream

   void write_pair_regular(int bci_delta, int line_delta);

   inline void write_pair_inline(int bci, int line) {

     int bci_delta = bci - _bci;

     int line_delta = line - _line;

     _bci = bci;

     _line = line;

     // Skip (0,0) deltas - they do not add information and conflict with terminator.

     if (bci_delta == 0 && line_delta == 0) return;

     // Check if bci is 5-bit and line number 3-bit unsigned.

     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {

       // Compress into single byte.

       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;

       // Check that value doesn't match escape character.

       if (value != 0xFF) {

         write_byte(value);

         return;

       }

     }

     write_pair_regular(bci_delta, line_delta);

   }

 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.

 // Disabling optimization doesn't work for methods in header files

 // so we force it to call through the non-optimized version in the .cpp.

 // It's gross, but it's the only way we can ensure that all callers are

 // fixed.  _MSC_VER is defined by the windows compiler

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

   void write_pair(int bci, int line);

 #else

   void write_pair(int bci, int line) { write_pair_inline(bci, line); }

 #endif

   // Write end-of-stream marker

   void write_terminator()                        { write_byte(0); }

 };

 // Utility class for decompressing line number tables

 class CompressedLineNumberReadStream: public CompressedReadStream {

  private:

   int _bci;

   int _line;

  public:

   // Constructor

   CompressedLineNumberReadStream(u_char* buffer);

   // Read (bci, line number) pair from stream. Returns false at end-of-stream.

   bool read_pair();

   // Accessing bci and line number (after calling read_pair)

   int bci() const                               { return _bci; }

   int line() const                              { return _line; }

 };

 /// Fast Breakpoints.

 // If this structure gets more complicated (because bpts get numerous),

 // move it into its own header.

 // There is presently no provision for concurrent access

 // to breakpoint lists, which is only OK for JVMTI because

 // breakpoints are written only at safepoints, and are read

 // concurrently only outside of safepoints.

 class BreakpointInfo : public CHeapObj<mtClass> {

   friend class VMStructs;

  private:

   Bytecodes::Code  _orig_bytecode;

   int              _bci;

   u2               _name_index;       // of method

   u2               _signature_index;  // of method

   BreakpointInfo*  _next;             // simple storage allocation

  public:

   BreakpointInfo(Method* m, int bci);

   // accessors

   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }

   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }

   int         bci()                                   { return _bci; }

   BreakpointInfo*          next() const               { return _next; }

   void                 set_next(BreakpointInfo* n)    { _next = n; }

   // helps for searchers

   bool match(const Method* m, int bci) {

     return bci == _bci && match(m);

   }

   bool match(const Method* m) {

     return _name_index == m->name_index() &&

       _signature_index == m->signature_index();

   }

   void set(Method* method);

   void clear(Method* method);

 };

 // Utility class for access exception handlers

 class ExceptionTable : public StackObj {

  private:

   ExceptionTableElement* _table;

   u2  _length;

  public:

   ExceptionTable(const Method* m) {

     if (m->has_exception_handler()) {

       _table = m->exception_table_start();

       _length = m->exception_table_length();

     } else {

       _table = NULL;

       _length = 0;

     }

   }

   int length() const {

     return _length;

   }

   u2 start_pc(int idx) const {

     assert(idx < _length, "out of bounds");

     return _table[idx].start_pc;

   }

   void set_start_pc(int idx, u2 value) {

     assert(idx < _length, "out of bounds");

     _table[idx].start_pc = value;

   }

   u2 end_pc(int idx) const {

     assert(idx < _length, "out of bounds");

     return _table[idx].end_pc;

   }

   void set_end_pc(int idx, u2 value) {

     assert(idx < _length, "out of bounds");

     _table[idx].end_pc = value;

   }

   u2 handler_pc(int idx) const {

     assert(idx < _length, "out of bounds");

     return _table[idx].handler_pc;

   }

   void set_handler_pc(int idx, u2 value) {

     assert(idx < _length, "out of bounds");

     _table[idx].handler_pc = value;

   }

   u2 catch_type_index(int idx) const {

     assert(idx < _length, "out of bounds");

     return _table[idx].catch_type_index;

   }

   void set_catch_type_index(int idx, u2 value) {

     assert(idx < _length, "out of bounds");

     _table[idx].catch_type_index = value;

   }

 };

 #endif // SHARE_VM_OOPS_METHODOOP_HPP