1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_METHODOOP_HPP
  26 #define SHARE_VM_OOPS_METHODOOP_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "interpreter/invocationCounter.hpp"
  32 #include "oops/annotations.hpp"
  33 #include "oops/constantPool.hpp"
  34 #include "oops/methodCounters.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.hpp"
  37 #include "oops/typeArrayOop.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/growableArray.hpp"
  40 
  41 // A Method represents a Java method.
  42 //
  43 // Note that most applications load thousands of methods, so keeping the size of this
  44 // class small has a big impact on footprint.
  45 //
  46 // Note that native_function and signature_handler have to be at fixed offsets
  47 // (required by the interpreter)
  48 //
  49 //  Method embedded field layout (after declared fields):
  50 //   [EMBEDDED native_function       (present only if native) ]
  51 //   [EMBEDDED signature_handler     (present only if native) ]
  52 
  53 class CheckedExceptionElement;
  54 class LocalVariableTableElement;
  55 class AdapterHandlerEntry;
  56 class MethodData;
  57 class MethodCounters;
  58 class ConstMethod;
  59 class InlineTableSizes;
  60 class KlassSizeStats;
  61 
  62 class Method : public Metadata {
  63  friend class VMStructs;
  64  private:
  65   ConstMethod*      _constMethod;                // Method read-only data.
  66   MethodData*       _method_data;
  67   MethodCounters*   _method_counters;
  68   AccessFlags       _access_flags;               // Access flags
  69   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  70                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  71 #ifdef CC_INTERP
  72   int               _result_index;               // C++ interpreter needs for converting results to/from stack
  73 #endif
  74   u2                _method_size;                // size of this object
  75   u2                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  76 
  77   // Flags
  78   enum Flags {
  79     _jfr_towrite          = 1 << 0,
  80     _caller_sensitive     = 1 << 1,
  81     _force_inline         = 1 << 2,
  82     _dont_inline          = 1 << 3,
  83     _hidden               = 1 << 4,
  84     _has_injected_profile = 1 << 5,
  85     _running_emcp         = 1 << 6,
  86     _intrinsic_candidate  = 1 << 7
  87   };
  88   u1 _flags;
  89 
  90 #ifndef PRODUCT
  91   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
  92 #endif
  93   // Entry point for calling both from and to the interpreter.
  94   address _i2i_entry;           // All-args-on-stack calling convention
  95   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
  96   AdapterHandlerEntry* _adapter;
  97   // Entry point for calling from compiled code, to compiled code if it exists
  98   // or else the interpreter.
  99   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 100   // The entry point for calling both from and to compiled code is
 101   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 102   // field can come and go.  It can transition from NULL to not-null at any
 103   // time (whenever a compile completes).  It can transition from not-null to
 104   // NULL only at safepoints (because of a de-opt).
 105   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 106   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 107 
 108   // Constructor
 109   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 110  public:
 111 
 112   static Method* allocate(ClassLoaderData* loader_data,
 113                           int byte_code_size,
 114                           AccessFlags access_flags,
 115                           InlineTableSizes* sizes,
 116                           ConstMethod::MethodType method_type,
 117                           TRAPS);
 118 
 119   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 120   Method(){}
 121 
 122   // The Method vtable is restored by this call when the Method is in the
 123   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 124   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 125   // by their vtable.
 126   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 127   bool is_method() const volatile { return true; }
 128 
 129   void restore_unshareable_info(TRAPS);
 130 
 131   // accessors for instance variables
 132 
 133   ConstMethod* constMethod() const             { return _constMethod; }
 134   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 135 
 136 
 137   static address make_adapters(methodHandle mh, TRAPS);
 138   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 139   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 140 
 141   // access flag
 142   AccessFlags access_flags() const               { return _access_flags;  }
 143   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 144 
 145   // name
 146   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 147   int name_index() const                         { return constMethod()->name_index();         }
 148   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 149 
 150   // signature
 151   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 152   int signature_index() const                    { return constMethod()->signature_index();         }
 153   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 154 
 155   // generics support
 156   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 157   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 158   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 159 
 160   // annotations support
 161   AnnotationArray* annotations() const           {
 162     return constMethod()->method_annotations();
 163   }
 164   AnnotationArray* parameter_annotations() const {
 165     return constMethod()->parameter_annotations();
 166   }
 167   AnnotationArray* annotation_default() const    {
 168     return constMethod()->default_annotations();
 169   }
 170   AnnotationArray* type_annotations() const      {
 171     return constMethod()->type_annotations();
 172   }
 173 
 174 #ifdef CC_INTERP
 175   void set_result_index(BasicType type);
 176   int  result_index()                            { return _result_index; }
 177 #endif
 178 
 179   // Helper routine: get klass name + "." + method name + signature as
 180   // C string, for the purpose of providing more useful NoSuchMethodErrors
 181   // and fatal error handling. The string is allocated in resource
 182   // area if a buffer is not provided by the caller.
 183   char* name_and_sig_as_C_string() const;
 184   char* name_and_sig_as_C_string(char* buf, int size) const;
 185 
 186   // Static routine in the situations we don't have a Method*
 187   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 188   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 189 
 190   Bytecodes::Code java_code_at(int bci) const {
 191     return Bytecodes::java_code_at(this, bcp_from(bci));
 192   }
 193   Bytecodes::Code code_at(int bci) const {
 194     return Bytecodes::code_at(this, bcp_from(bci));
 195   }
 196 
 197   // JVMTI breakpoints
 198   Bytecodes::Code orig_bytecode_at(int bci) const;
 199   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 200   void set_breakpoint(int bci);
 201   void clear_breakpoint(int bci);
 202   void clear_all_breakpoints();
 203   // Tracking number of breakpoints, for fullspeed debugging.
 204   // Only mutated by VM thread.
 205   u2   number_of_breakpoints()             const {
 206     MethodCounters* mcs = method_counters();
 207     if (mcs == NULL) {
 208       return 0;
 209     } else {
 210       return mcs->number_of_breakpoints();
 211     }
 212   }
 213   void incr_number_of_breakpoints(TRAPS)         {
 214     MethodCounters* mcs = get_method_counters(CHECK);
 215     if (mcs != NULL) {
 216       mcs->incr_number_of_breakpoints();
 217     }
 218   }
 219   void decr_number_of_breakpoints(TRAPS)         {
 220     MethodCounters* mcs = get_method_counters(CHECK);
 221     if (mcs != NULL) {
 222       mcs->decr_number_of_breakpoints();
 223     }
 224   }
 225   // Initialization only
 226   void clear_number_of_breakpoints()             {
 227     MethodCounters* mcs = method_counters();
 228     if (mcs != NULL) {
 229       mcs->clear_number_of_breakpoints();
 230     }
 231   }
 232 
 233   // index into InstanceKlass methods() array
 234   // note: also used by jfr
 235   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 236   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 237 
 238   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 239   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 240 
 241   // code size
 242   int code_size() const                  { return constMethod()->code_size(); }
 243 
 244   // method size
 245   int method_size() const                        { return _method_size; }
 246   void set_method_size(int size) {
 247     assert(0 <= size && size < (1 << 16), "invalid method size");
 248     _method_size = size;
 249   }
 250 
 251   // constant pool for Klass* holding this method
 252   ConstantPool* constants() const              { return constMethod()->constants(); }
 253   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 254 
 255   // max stack
 256   // return original max stack size for method verification
 257   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 258   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 259   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 260 
 261   // max locals
 262   int  max_locals() const                        { return constMethod()->max_locals(); }
 263   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 264 
 265   int highest_comp_level() const;
 266   void set_highest_comp_level(int level);
 267   int highest_osr_comp_level() const;
 268   void set_highest_osr_comp_level(int level);
 269 
 270   // Count of times method was exited via exception while interpreting
 271   void interpreter_throwout_increment(TRAPS) {
 272     MethodCounters* mcs = get_method_counters(CHECK);
 273     if (mcs != NULL) {
 274       mcs->interpreter_throwout_increment();
 275     }
 276   }
 277 
 278   int  interpreter_throwout_count() const        {
 279     MethodCounters* mcs = method_counters();
 280     if (mcs == NULL) {
 281       return 0;
 282     } else {
 283       return mcs->interpreter_throwout_count();
 284     }
 285   }
 286 
 287   // size of parameters
 288   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 289   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 290 
 291   bool has_stackmap_table() const {
 292     return constMethod()->has_stackmap_table();
 293   }
 294 
 295   Array<u1>* stackmap_data() const {
 296     return constMethod()->stackmap_data();
 297   }
 298 
 299   void set_stackmap_data(Array<u1>* sd) {
 300     constMethod()->set_stackmap_data(sd);
 301   }
 302 
 303   // exception handler table
 304   bool has_exception_handler() const
 305                              { return constMethod()->has_exception_handler(); }
 306   int exception_table_length() const
 307                              { return constMethod()->exception_table_length(); }
 308   ExceptionTableElement* exception_table_start() const
 309                              { return constMethod()->exception_table_start(); }
 310 
 311   // Finds the first entry point bci of an exception handler for an
 312   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 313   // for ex_klass indicates that the exception klass is not known; in
 314   // this case it matches any constraint class. Returns -1 if the
 315   // exception cannot be handled in this method. The handler
 316   // constraint classes are loaded if necessary. Note that this may
 317   // throw an exception if loading of the constraint classes causes
 318   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 319   // If an exception is thrown, returns the bci of the
 320   // exception handler which caused the exception to be thrown, which
 321   // is needed for proper retries. See, for example,
 322   // InterpreterRuntime::exception_handler_for_exception.
 323   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 324 
 325   // method data access
 326   MethodData* method_data() const              {
 327     return _method_data;
 328   }
 329 
 330   void set_method_data(MethodData* data)       {
 331     // The store into method must be released. On platforms without
 332     // total store order (TSO) the reference may become visible before
 333     // the initialization of data otherwise.
 334     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);
 335   }
 336 
 337   MethodCounters* method_counters() const {
 338     return _method_counters;
 339   }
 340 
 341   void clear_method_counters() {
 342     _method_counters = NULL;
 343   }
 344 
 345   bool init_method_counters(MethodCounters* counters) {
 346     // Try to install a pointer to MethodCounters, return true on success.
 347     return Atomic::cmpxchg_ptr(counters, (volatile void*)&_method_counters, NULL) == NULL;
 348   }
 349 
 350 #ifdef TIERED
 351   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 352   // We can do that since interpreter_invocation_count is not used in tiered.
 353   int prev_event_count() const                   {
 354     if (method_counters() == NULL) {
 355       return 0;
 356     } else {
 357       return method_counters()->interpreter_invocation_count();
 358     }
 359   }
 360   void set_prev_event_count(int count) {
 361     MethodCounters* mcs = method_counters();
 362     if (mcs != NULL) {
 363       mcs->set_interpreter_invocation_count(count);
 364     }
 365   }
 366   jlong prev_time() const                        {
 367     MethodCounters* mcs = method_counters();
 368     return mcs == NULL ? 0 : mcs->prev_time();
 369   }
 370   void set_prev_time(jlong time) {
 371     MethodCounters* mcs = method_counters();
 372     if (mcs != NULL) {
 373       mcs->set_prev_time(time);
 374     }
 375   }
 376   float rate() const                             {
 377     MethodCounters* mcs = method_counters();
 378     return mcs == NULL ? 0 : mcs->rate();
 379   }
 380   void set_rate(float rate) {
 381     MethodCounters* mcs = method_counters();
 382     if (mcs != NULL) {
 383       mcs->set_rate(rate);
 384     }
 385   }
 386 #endif
 387   int nmethod_age() const {
 388     if (method_counters() == NULL) {
 389       return INT_MAX;
 390     } else {
 391       return method_counters()->nmethod_age();
 392     }
 393   }
 394 
 395   int invocation_count();
 396   int backedge_count();
 397 
 398   bool was_executed_more_than(int n);
 399   bool was_never_executed()                      { return !was_executed_more_than(0); }
 400 
 401   static void build_interpreter_method_data(methodHandle method, TRAPS);
 402 
 403   static MethodCounters* build_method_counters(Method* m, TRAPS);
 404 
 405   int interpreter_invocation_count() {
 406     if (TieredCompilation) {
 407       return invocation_count();
 408     } else {
 409       MethodCounters* mcs = method_counters();
 410       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 411     }
 412   }
 413   int increment_interpreter_invocation_count(TRAPS) {
 414     if (TieredCompilation) ShouldNotReachHere();
 415     MethodCounters* mcs = get_method_counters(CHECK_0);
 416     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 417   }
 418 
 419 #ifndef PRODUCT
 420   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 421   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 422 #else
 423   // for PrintMethodData in a product build
 424   int  compiled_invocation_count() const         { return 0;  }
 425 #endif // not PRODUCT
 426 
 427   // Clear (non-shared space) pointers which could not be relevant
 428   // if this (shared) method were mapped into another JVM.
 429   void remove_unshareable_info();
 430 
 431   // nmethod/verified compiler entry
 432   address verified_code_entry();
 433   bool check_code() const;      // Not inline to avoid circular ref
 434   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 435   void clear_code();            // Clear out any compiled code
 436   static void set_code(methodHandle mh, nmethod* code);
 437   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 438   address get_i2c_entry();
 439   address get_c2i_entry();
 440   address get_c2i_unverified_entry();
 441   AdapterHandlerEntry* adapter() {  return _adapter; }
 442   // setup entry points
 443   void link_method(methodHandle method, TRAPS);
 444   // clear entry points. Used by sharing code
 445   void unlink_method();
 446 
 447   // vtable index
 448   enum VtableIndexFlag {
 449     // Valid vtable indexes are non-negative (>= 0).
 450     // These few negative values are used as sentinels.
 451     itable_index_max        = -10, // first itable index, growing downward
 452     pending_itable_index    = -9,  // itable index will be assigned
 453     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 454     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 455     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 456     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 457   };
 458   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 459   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 460   int  vtable_index() const                      { return _vtable_index; }
 461   void set_vtable_index(int index)               { _vtable_index = index; }
 462   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 463   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 464   int  itable_index() const                      { assert(valid_itable_index(), "");
 465                                                    return itable_index_max - _vtable_index; }
 466   void set_itable_index(int index)               { _vtable_index = itable_index_max - index; assert(valid_itable_index(), ""); }
 467 
 468   // interpreter entry
 469   address interpreter_entry() const              { return _i2i_entry; }
 470   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 471   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 472 
 473   // native function (used for native methods only)
 474   enum {
 475     native_bind_event_is_interesting = true
 476   };
 477   address native_function() const                { return *(native_function_addr()); }
 478   address critical_native_function();
 479 
 480   // Must specify a real function (not NULL).
 481   // Use clear_native_function() to unregister.
 482   void set_native_function(address function, bool post_event_flag);
 483   bool has_native_function() const;
 484   void clear_native_function();
 485 
 486   // signature handler (used for native methods only)
 487   address signature_handler() const              { return *(signature_handler_addr()); }
 488   void set_signature_handler(address handler);
 489 
 490   // Interpreter oopmap support
 491   void mask_for(int bci, InterpreterOopMap* mask);
 492 
 493   // operations on invocation counter
 494   void print_invocation_count();
 495 
 496   // byte codes
 497   void    set_code(address code)      { return constMethod()->set_code(code); }
 498   address code_base() const           { return constMethod()->code_base(); }
 499   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 500 
 501   // prints byte codes
 502   void print_codes() const            { print_codes_on(tty); }
 503   void print_codes_on(outputStream* st) const;
 504   void print_codes_on(int from, int to, outputStream* st) const;
 505 
 506   // method parameters
 507   bool has_method_parameters() const
 508                          { return constMethod()->has_method_parameters(); }
 509   int method_parameters_length() const
 510                          { return constMethod()->method_parameters_length(); }
 511   MethodParametersElement* method_parameters_start() const
 512                           { return constMethod()->method_parameters_start(); }
 513 
 514   // checked exceptions
 515   int checked_exceptions_length() const
 516                          { return constMethod()->checked_exceptions_length(); }
 517   CheckedExceptionElement* checked_exceptions_start() const
 518                           { return constMethod()->checked_exceptions_start(); }
 519 
 520   // localvariable table
 521   bool has_localvariable_table() const
 522                           { return constMethod()->has_localvariable_table(); }
 523   int localvariable_table_length() const
 524                         { return constMethod()->localvariable_table_length(); }
 525   LocalVariableTableElement* localvariable_table_start() const
 526                          { return constMethod()->localvariable_table_start(); }
 527 
 528   bool has_linenumber_table() const
 529                               { return constMethod()->has_linenumber_table(); }
 530   u_char* compressed_linenumber_table() const
 531                        { return constMethod()->compressed_linenumber_table(); }
 532 
 533   // method holder (the Klass* holding this method)
 534   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 535 
 536   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 537   Symbol* klass_name() const;                    // returns the name of the method holder
 538   BasicType result_type() const;                 // type of the method result
 539   int result_type_index() const;                 // type index of the method result
 540   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 541   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 542 
 543   // Checked exceptions thrown by this method (resolved to mirrors)
 544   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 545 
 546   // Access flags
 547   bool is_public() const                         { return access_flags().is_public();      }
 548   bool is_private() const                        { return access_flags().is_private();     }
 549   bool is_protected() const                      { return access_flags().is_protected();   }
 550   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 551   bool is_static() const                         { return access_flags().is_static();      }
 552   bool is_final() const                          { return access_flags().is_final();       }
 553   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 554   bool is_native() const                         { return access_flags().is_native();      }
 555   bool is_abstract() const                       { return access_flags().is_abstract();    }
 556   bool is_strict() const                         { return access_flags().is_strict();      }
 557   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 558 
 559   // returns true if contains only return operation
 560   bool is_empty_method() const;
 561 
 562   // returns true if this is a vanilla constructor
 563   bool is_vanilla_constructor() const;
 564 
 565   // checks method and its method holder
 566   bool is_final_method() const;
 567   bool is_final_method(AccessFlags class_access_flags) const;
 568   bool is_default_method() const;
 569 
 570   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 571   bool can_be_statically_bound() const;
 572   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 573 
 574   // returns true if the method has any backward branches.
 575   bool has_loops() {
 576     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 577   };
 578 
 579   bool compute_has_loops_flag();
 580 
 581   bool has_jsrs() {
 582     return access_flags().has_jsrs();
 583   };
 584   void set_has_jsrs() {
 585     _access_flags.set_has_jsrs();
 586   }
 587 
 588   // returns true if the method has any monitors.
 589   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 590   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 591 
 592   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 593 
 594   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 595   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 596   // has not been computed yet.
 597   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 598   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 599 
 600   // returns true if the method is an accessor function (setter/getter).
 601   bool is_accessor() const;
 602 
 603   // returns true if the method does nothing but return a constant of primitive type
 604   bool is_constant_getter() const;
 605 
 606   // returns true if the method is an initializer (<init> or <clinit>).
 607   bool is_initializer() const;
 608 
 609   // returns true if the method is static OR if the classfile version < 51
 610   bool has_valid_initializer_flags() const;
 611 
 612   // returns true if the method name is <clinit> and the method has
 613   // valid static initializer flags.
 614   bool is_static_initializer() const;
 615 
 616   // compiled code support
 617   // NOTE: code() is inherently racy as deopt can be clearing code
 618   // simultaneously. Use with caution.
 619   bool has_compiled_code() const                 { return code() != NULL; }
 620 
 621   // sizing
 622   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 623   static int size(bool is_native);
 624   int size() const                               { return method_size(); }
 625 #if INCLUDE_SERVICES
 626   void collect_statistics(KlassSizeStats *sz) const;
 627 #endif
 628   void log_touched(TRAPS);
 629   static void print_touched_methods(outputStream* out);
 630 
 631   // interpreter support
 632   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 633   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 634 #ifdef CC_INTERP
 635   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 636 #endif /* CC_INTERP */
 637   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 638   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 639   static ByteSize method_data_offset()           {
 640     return byte_offset_of(Method, _method_data);
 641   }
 642   static ByteSize method_counters_offset()       {
 643     return byte_offset_of(Method, _method_counters);
 644   }
 645 #ifndef PRODUCT
 646   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 647 #endif // not PRODUCT
 648   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 649   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 650   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 651   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 652 
 653   // for code generation
 654   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 655   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 656   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 657 
 658   // Static methods that are used to implement member methods where an exposed this pointer
 659   // is needed due to possible GCs
 660   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 661 
 662   // Returns the byte code index from the byte code pointer
 663   int     bci_from(address bcp) const;
 664   address bcp_from(int bci) const;
 665   address bcp_from(address bcp) const;
 666   int validate_bci_from_bcp(address bcp) const;
 667   int validate_bci(int bci) const;
 668 
 669   // Returns the line number for a bci if debugging information for the method is prowided,
 670   // -1 is returned otherwise.
 671   int line_number_from_bci(int bci) const;
 672 
 673   // Reflection support
 674   bool is_overridden_in(Klass* k) const;
 675 
 676   // Stack walking support
 677   bool is_ignored_by_security_stack_walk() const;
 678 
 679   // JSR 292 support
 680   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 681   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 682   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 683   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 684                                                    Symbol* signature, //anything at all
 685                                                    TRAPS);
 686   static Klass* check_non_bcp_klass(Klass* klass);
 687 
 688   // How many extra stack entries for invokedynamic when it's enabled
 689   static const int extra_stack_entries_for_jsr292 = 1;
 690 
 691   // this operates only on invoke methods:
 692   // presize interpreter frames for extra interpreter stack entries, if needed
 693   // Account for the extra appendix argument for invokehandle/invokedynamic
 694   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 695   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 696 
 697   // RedefineClasses() support:
 698   bool is_old() const                               { return access_flags().is_old(); }
 699   void set_is_old()                                 { _access_flags.set_is_old(); }
 700   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 701   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 702   bool is_deleted() const                           { return access_flags().is_deleted(); }
 703   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 704 
 705   bool is_running_emcp() const {
 706     // EMCP methods are old but not obsolete or deleted. Equivalent
 707     // Modulo Constant Pool means the method is equivalent except
 708     // the constant pool and instructions that access the constant
 709     // pool might be different.
 710     // If a breakpoint is set in a redefined method, its EMCP methods that are
 711     // still running must have a breakpoint also.
 712     return (_flags & _running_emcp) != 0;
 713   }
 714 
 715   void set_running_emcp(bool x) {
 716     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 717   }
 718 
 719   bool on_stack() const                             { return access_flags().on_stack(); }
 720   void set_on_stack(const bool value);
 721 
 722   // see the definition in Method*.cpp for the gory details
 723   bool should_not_be_cached() const;
 724 
 725   // JVMTI Native method prefixing support:
 726   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 727   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 728 
 729   // Rewriting support
 730   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 731                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 732 
 733   // jmethodID handling
 734   // Because the useful life-span of a jmethodID cannot be determined,
 735   // once created they are never reclaimed.  The methods to which they refer,
 736   // however, can be GC'ed away if the class is unloaded or if the method is
 737   // made obsolete or deleted -- in these cases, the jmethodID
 738   // refers to NULL (as is the case for any weak reference).
 739   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 740   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 741 
 742   // Ensure there is enough capacity in the internal tracking data
 743   // structures to hold the number of jmethodIDs you plan to generate.
 744   // This saves substantial time doing allocations.
 745   static void ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity);
 746 
 747   // Use resolve_jmethod_id() in situations where the caller is expected
 748   // to provide a valid jmethodID; the only sanity checks are in asserts;
 749   // result guaranteed not to be NULL.
 750   inline static Method* resolve_jmethod_id(jmethodID mid) {
 751     assert(mid != NULL, "JNI method id should not be null");
 752     return *((Method**)mid);
 753   }
 754 
 755   // Use checked_resolve_jmethod_id() in situations where the caller
 756   // should provide a valid jmethodID, but might not. NULL is returned
 757   // when the jmethodID does not refer to a valid method.
 758   static Method* checked_resolve_jmethod_id(jmethodID mid);
 759 
 760   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 761   static bool is_method_id(jmethodID mid);
 762 
 763   // Clear methods
 764   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 765   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 766 
 767   // Get this method's jmethodID -- allocate if it doesn't exist
 768   jmethodID jmethod_id()                            { methodHandle this_h(this);
 769                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 770 
 771   // Lookup the jmethodID for this method.  Return NULL if not found.
 772   // NOTE that this function can be called from a signal handler
 773   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 774   // needs to be async-safe. No allocation should be done and
 775   // so handles are not used to avoid deadlock.
 776   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 777 
 778   // Support for inlining of intrinsic methods
 779   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 780   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u2) id; }
 781 
 782   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 783   void init_intrinsic_id();     // updates from _none if a match
 784   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 785 
 786   bool jfr_towrite() {
 787     return (_flags & _jfr_towrite) != 0;
 788   }
 789   void set_jfr_towrite(bool x) {
 790     _flags = x ? (_flags | _jfr_towrite) : (_flags & ~_jfr_towrite);
 791   }
 792 
 793   bool caller_sensitive() {
 794     return (_flags & _caller_sensitive) != 0;
 795   }
 796   void set_caller_sensitive(bool x) {
 797     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 798   }
 799 
 800   bool force_inline() {
 801     return (_flags & _force_inline) != 0;
 802   }
 803   void set_force_inline(bool x) {
 804     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 805   }
 806 
 807   bool dont_inline() {
 808     return (_flags & _dont_inline) != 0;
 809   }
 810   void set_dont_inline(bool x) {
 811     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 812   }
 813 
 814   bool is_hidden() {
 815     return (_flags & _hidden) != 0;
 816   }
 817   void set_hidden(bool x) {
 818     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 819   }
 820 
 821   bool intrinsic_candidate() {
 822     return (_flags & _intrinsic_candidate) != 0;
 823   }
 824   void set_intrinsic_candidate(bool x) {
 825     _flags = x ? (_flags | _intrinsic_candidate) : (_flags & ~_intrinsic_candidate);
 826   }
 827 
 828   bool has_injected_profile() {
 829     return (_flags & _has_injected_profile) != 0;
 830   }
 831   void set_has_injected_profile(bool x) {
 832     _flags = x ? (_flags | _has_injected_profile) : (_flags & ~_has_injected_profile);
 833   }
 834 
 835   ConstMethod::MethodType method_type() const {
 836       return _constMethod->method_type();
 837   }
 838   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 839 
 840   // On-stack replacement support
 841   bool has_osr_nmethod(int level, bool match_level) {
 842    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 843   }
 844 
 845   int mark_osr_nmethods() {
 846     return method_holder()->mark_osr_nmethods(this);
 847   }
 848 
 849   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 850     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 851   }
 852 
 853   // Inline cache support
 854   void cleanup_inline_caches();
 855 
 856   // Find if klass for method is loaded
 857   bool is_klass_loaded_by_klass_index(int klass_index) const;
 858   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 859 
 860   // Indicates whether compilation failed earlier for this method, or
 861   // whether it is not compilable for another reason like having a
 862   // breakpoint set in it.
 863   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 864   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 865   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 866     set_not_compilable(comp_level, false);
 867   }
 868   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 869   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 870   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 871     set_not_osr_compilable(comp_level, false);
 872   }
 873   bool is_always_compilable() const;
 874 
 875  private:
 876   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 877 
 878  public:
 879   MethodCounters* get_method_counters(TRAPS) {
 880     if (_method_counters == NULL) {
 881       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 882     }
 883     return _method_counters;
 884   }
 885 
 886   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 887   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 888   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 889   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 890   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 891   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 892 
 893   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 894   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 895   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 896   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 897   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 898   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 899 
 900   // Background compilation support
 901   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 902   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 903   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 904 
 905   // Resolve all classes in signature, return 'true' if successful
 906   static bool load_signature_classes(methodHandle m, TRAPS);
 907 
 908   // Return if true if not all classes references in signature, including return type, has been loaded
 909   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 910 
 911   // Printing
 912   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 913 #if INCLUDE_JVMTI
 914   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 915 #else
 916   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 917 #endif
 918 
 919   // Helper routine used for method sorting
 920   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);
 921 
 922   // Deallocation function for redefine classes or if an error occurs
 923   void deallocate_contents(ClassLoaderData* loader_data);
 924 
 925   // Printing
 926 #ifndef PRODUCT
 927   void print_on(outputStream* st) const;
 928 #endif
 929   void print_value_on(outputStream* st) const;
 930 
 931   const char* internal_name() const { return "{method}"; }
 932 
 933   // Check for valid method pointer
 934   static bool has_method_vptr(const void* ptr);
 935   bool is_valid_method() const;
 936 
 937   // Verify
 938   void verify() { verify_on(tty); }
 939   void verify_on(outputStream* st);
 940 
 941  private:
 942 
 943   // Inlined elements
 944   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 945   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 946 };
 947 
 948 
 949 // Utility class for compressing line number tables
 950 
 951 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 952  private:
 953   int _bci;
 954   int _line;
 955  public:
 956   // Constructor
 957   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 958   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 959 
 960   // Write (bci, line number) pair to stream
 961   void write_pair_regular(int bci_delta, int line_delta);
 962 
 963   inline void write_pair_inline(int bci, int line) {
 964     int bci_delta = bci - _bci;
 965     int line_delta = line - _line;
 966     _bci = bci;
 967     _line = line;
 968     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 969     if (bci_delta == 0 && line_delta == 0) return;
 970     // Check if bci is 5-bit and line number 3-bit unsigned.
 971     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 972       // Compress into single byte.
 973       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 974       // Check that value doesn't match escape character.
 975       if (value != 0xFF) {
 976         write_byte(value);
 977         return;
 978       }
 979     }
 980     write_pair_regular(bci_delta, line_delta);
 981   }
 982 
 983 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 984 // Disabling optimization doesn't work for methods in header files
 985 // so we force it to call through the non-optimized version in the .cpp.
 986 // It's gross, but it's the only way we can ensure that all callers are
 987 // fixed.  _MSC_VER is defined by the windows compiler
 988 #if defined(_M_AMD64) && _MSC_VER >= 1400
 989   void write_pair(int bci, int line);
 990 #else
 991   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 992 #endif
 993 
 994   // Write end-of-stream marker
 995   void write_terminator()                        { write_byte(0); }
 996 };
 997 
 998 
 999 // Utility class for decompressing line number tables
1000 
1001 class CompressedLineNumberReadStream: public CompressedReadStream {
1002  private:
1003   int _bci;
1004   int _line;
1005  public:
1006   // Constructor
1007   CompressedLineNumberReadStream(u_char* buffer);
1008   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1009   bool read_pair();
1010   // Accessing bci and line number (after calling read_pair)
1011   int bci() const                               { return _bci; }
1012   int line() const                              { return _line; }
1013 };
1014 
1015 
1016 /// Fast Breakpoints.
1017 
1018 // If this structure gets more complicated (because bpts get numerous),
1019 // move it into its own header.
1020 
1021 // There is presently no provision for concurrent access
1022 // to breakpoint lists, which is only OK for JVMTI because
1023 // breakpoints are written only at safepoints, and are read
1024 // concurrently only outside of safepoints.
1025 
1026 class BreakpointInfo : public CHeapObj<mtClass> {
1027   friend class VMStructs;
1028  private:
1029   Bytecodes::Code  _orig_bytecode;
1030   int              _bci;
1031   u2               _name_index;       // of method
1032   u2               _signature_index;  // of method
1033   BreakpointInfo*  _next;             // simple storage allocation
1034 
1035  public:
1036   BreakpointInfo(Method* m, int bci);
1037 
1038   // accessors
1039   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1040   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1041   int         bci()                                   { return _bci; }
1042 
1043   BreakpointInfo*          next() const               { return _next; }
1044   void                 set_next(BreakpointInfo* n)    { _next = n; }
1045 
1046   // helps for searchers
1047   bool match(const Method* m, int bci) {
1048     return bci == _bci && match(m);
1049   }
1050 
1051   bool match(const Method* m) {
1052     return _name_index == m->name_index() &&
1053       _signature_index == m->signature_index();
1054   }
1055 
1056   void set(Method* method);
1057   void clear(Method* method);
1058 };
1059 
1060 // Utility class for access exception handlers
1061 class ExceptionTable : public StackObj {
1062  private:
1063   ExceptionTableElement* _table;
1064   u2  _length;
1065 
1066  public:
1067   ExceptionTable(const Method* m) {
1068     if (m->has_exception_handler()) {
1069       _table = m->exception_table_start();
1070       _length = m->exception_table_length();
1071     } else {
1072       _table = NULL;
1073       _length = 0;
1074     }
1075   }
1076 
1077   int length() const {
1078     return _length;
1079   }
1080 
1081   u2 start_pc(int idx) const {
1082     assert(idx < _length, "out of bounds");
1083     return _table[idx].start_pc;
1084   }
1085 
1086   void set_start_pc(int idx, u2 value) {
1087     assert(idx < _length, "out of bounds");
1088     _table[idx].start_pc = value;
1089   }
1090 
1091   u2 end_pc(int idx) const {
1092     assert(idx < _length, "out of bounds");
1093     return _table[idx].end_pc;
1094   }
1095 
1096   void set_end_pc(int idx, u2 value) {
1097     assert(idx < _length, "out of bounds");
1098     _table[idx].end_pc = value;
1099   }
1100 
1101   u2 handler_pc(int idx) const {
1102     assert(idx < _length, "out of bounds");
1103     return _table[idx].handler_pc;
1104   }
1105 
1106   void set_handler_pc(int idx, u2 value) {
1107     assert(idx < _length, "out of bounds");
1108     _table[idx].handler_pc = value;
1109   }
1110 
1111   u2 catch_type_index(int idx) const {
1112     assert(idx < _length, "out of bounds");
1113     return _table[idx].catch_type_index;
1114   }
1115 
1116   void set_catch_type_index(int idx, u2 value) {
1117     assert(idx < _length, "out of bounds");
1118     _table[idx].catch_type_index = value;
1119   }
1120 };
1121 
1122 #endif // SHARE_VM_OOPS_METHODOOP_HPP