1 /*
   2  * Copyright (c) 1997, 2017, 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/compilerDefinitions.hpp"
  31 #include "compiler/oopMap.hpp"
  32 #include "interpreter/invocationCounter.hpp"
  33 #include "oops/annotations.hpp"
  34 #include "oops/constantPool.hpp"
  35 #include "oops/methodCounters.hpp"
  36 #include "oops/instanceKlass.hpp"
  37 #include "oops/oop.hpp"
  38 #include "oops/typeArrayOop.hpp"
  39 #include "utilities/accessFlags.hpp"
  40 #include "utilities/growableArray.hpp"
  41 
  42 // A Method represents a Java method.
  43 //
  44 // Note that most applications load thousands of methods, so keeping the size of this
  45 // class small has a big impact on footprint.
  46 //
  47 // Note that native_function and signature_handler have to be at fixed offsets
  48 // (required by the interpreter)
  49 //
  50 //  Method embedded field layout (after declared fields):
  51 //   [EMBEDDED native_function       (present only if native) ]
  52 //   [EMBEDDED signature_handler     (present only if native) ]
  53 
  54 class CheckedExceptionElement;
  55 class LocalVariableTableElement;
  56 class AdapterHandlerEntry;
  57 class MethodData;
  58 class MethodCounters;
  59 class ConstMethod;
  60 class InlineTableSizes;
  61 class KlassSizeStats;
  62 class CompiledMethod;
  63 
  64 class Method : public Metadata {
  65  friend class VMStructs;
  66  friend class JVMCIVMStructs;
  67  private:
  68   ConstMethod*      _constMethod;                // Method read-only data.
  69   MethodData*       _method_data;
  70   MethodCounters*   _method_counters;
  71   AccessFlags       _access_flags;               // Access flags
  72   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  73                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  74   u2                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  75 
  76   // Flags
  77   enum Flags {
  78     _caller_sensitive      = 1 << 0,
  79     _force_inline          = 1 << 1,
  80     _dont_inline           = 1 << 2,
  81     _hidden                = 1 << 3,
  82     _has_injected_profile  = 1 << 4,
  83     _running_emcp          = 1 << 5,
  84     _intrinsic_candidate   = 1 << 6,
  85     _reserved_stack_access = 1 << 7
  86   };
  87   mutable u2 _flags;
  88 
  89   TRACE_DEFINE_FLAG;
  90 
  91 #ifndef PRODUCT
  92   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
  93 #endif
  94   // Entry point for calling both from and to the interpreter.
  95   address _i2i_entry;           // All-args-on-stack calling convention
  96   // Entry point for calling from compiled code, to compiled code if it exists
  97   // or else the interpreter.
  98   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
  99   // The entry point for calling both from and to compiled code is
 100   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 101   // field can come and go.  It can transition from NULL to not-null at any
 102   // time (whenever a compile completes).  It can transition from not-null to
 103   // NULL only at safepoints (because of a de-opt).
 104   CompiledMethod* volatile _code;                       // Points to the corresponding piece of native code
 105   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 106 
 107 #if INCLUDE_AOT && defined(TIERED)
 108   CompiledMethod* _aot_code;
 109 #endif
 110 
 111   // Constructor
 112   Method(ConstMethod* xconst, AccessFlags access_flags);
 113  public:
 114 
 115   static Method* allocate(ClassLoaderData* loader_data,
 116                           int byte_code_size,
 117                           AccessFlags access_flags,
 118                           InlineTableSizes* sizes,
 119                           ConstMethod::MethodType method_type,
 120                           TRAPS);
 121 
 122   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 123   Method(){}
 124 
 125   bool is_method() const volatile { return true; }
 126 
 127   void restore_unshareable_info(TRAPS);
 128 
 129   // accessors for instance variables
 130 
 131   ConstMethod* constMethod() const             { return _constMethod; }
 132   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 133 
 134 
 135   static address make_adapters(methodHandle mh, TRAPS);
 136   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 137   volatile address from_compiled_entry_no_trampoline() const;
 138   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 139 
 140   // access flag
 141   AccessFlags access_flags() const               { return _access_flags;  }
 142   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 143 
 144   // name
 145   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 146   int name_index() const                         { return constMethod()->name_index();         }
 147   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 148 
 149   // signature
 150   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 151   int signature_index() const                    { return constMethod()->signature_index();         }
 152   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 153 
 154   // generics support
 155   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 156   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 157   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 158 
 159   // annotations support
 160   AnnotationArray* annotations() const           {
 161     return constMethod()->method_annotations();
 162   }
 163   AnnotationArray* parameter_annotations() const {
 164     return constMethod()->parameter_annotations();
 165   }
 166   AnnotationArray* annotation_default() const    {
 167     return constMethod()->default_annotations();
 168   }
 169   AnnotationArray* type_annotations() const      {
 170     return constMethod()->type_annotations();
 171   }
 172 
 173   // Helper routine: get klass name + "." + method name + signature as
 174   // C string, for the purpose of providing more useful NoSuchMethodErrors
 175   // and fatal error handling. The string is allocated in resource
 176   // area if a buffer is not provided by the caller.
 177   char* name_and_sig_as_C_string() const;
 178   char* name_and_sig_as_C_string(char* buf, int size) const;
 179 
 180   // Static routine in the situations we don't have a Method*
 181   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 182   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 183 
 184   Bytecodes::Code java_code_at(int bci) const {
 185     return Bytecodes::java_code_at(this, bcp_from(bci));
 186   }
 187   Bytecodes::Code code_at(int bci) const {
 188     return Bytecodes::code_at(this, bcp_from(bci));
 189   }
 190 
 191   // JVMTI breakpoints
 192 #if !INCLUDE_JVMTI
 193   Bytecodes::Code orig_bytecode_at(int bci) const {
 194     ShouldNotReachHere();
 195     return Bytecodes::_shouldnotreachhere;
 196   }
 197   void set_orig_bytecode_at(int bci, Bytecodes::Code code) {
 198     ShouldNotReachHere();
 199   };
 200   u2   number_of_breakpoints() const {return 0;}
 201 #else // !INCLUDE_JVMTI
 202   Bytecodes::Code orig_bytecode_at(int bci) const;
 203   void set_orig_bytecode_at(int bci, Bytecodes::Code code);
 204   void set_breakpoint(int bci);
 205   void clear_breakpoint(int bci);
 206   void clear_all_breakpoints();
 207   // Tracking number of breakpoints, for fullspeed debugging.
 208   // Only mutated by VM thread.
 209   u2   number_of_breakpoints()             const {
 210     MethodCounters* mcs = method_counters();
 211     if (mcs == NULL) {
 212       return 0;
 213     } else {
 214       return mcs->number_of_breakpoints();
 215     }
 216   }
 217   void incr_number_of_breakpoints(TRAPS)         {
 218     MethodCounters* mcs = get_method_counters(CHECK);
 219     if (mcs != NULL) {
 220       mcs->incr_number_of_breakpoints();
 221     }
 222   }
 223   void decr_number_of_breakpoints(TRAPS)         {
 224     MethodCounters* mcs = get_method_counters(CHECK);
 225     if (mcs != NULL) {
 226       mcs->decr_number_of_breakpoints();
 227     }
 228   }
 229   // Initialization only
 230   void clear_number_of_breakpoints()             {
 231     MethodCounters* mcs = method_counters();
 232     if (mcs != NULL) {
 233       mcs->clear_number_of_breakpoints();
 234     }
 235   }
 236 #endif // !INCLUDE_JVMTI
 237 
 238   // index into InstanceKlass methods() array
 239   // note: also used by jfr
 240   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 241   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 242 
 243   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 244   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 245 
 246   // code size
 247   int code_size() const                  { return constMethod()->code_size(); }
 248 
 249   // method size in words
 250   int method_size() const                { return sizeof(Method)/wordSize + ( is_native() ? 2 : 0 ); }
 251 
 252   // constant pool for Klass* holding this method
 253   ConstantPool* constants() const              { return constMethod()->constants(); }
 254   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 255 
 256   // max stack
 257   // return original max stack size for method verification
 258   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 259   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 260   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 261 
 262   // max locals
 263   int  max_locals() const                        { return constMethod()->max_locals(); }
 264   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 265 
 266   int highest_comp_level() const;
 267   void set_highest_comp_level(int level);
 268   int highest_osr_comp_level() const;
 269   void set_highest_osr_comp_level(int level);
 270 
 271 #if defined(COMPILER2) || INCLUDE_JVMCI
 272   // Count of times method was exited via exception while interpreting
 273   void interpreter_throwout_increment(TRAPS) {
 274     MethodCounters* mcs = get_method_counters(CHECK);
 275     if (mcs != NULL) {
 276       mcs->interpreter_throwout_increment();
 277     }
 278   }
 279 #endif
 280 
 281   int  interpreter_throwout_count() const        {
 282     MethodCounters* mcs = method_counters();
 283     if (mcs == NULL) {
 284       return 0;
 285     } else {
 286       return mcs->interpreter_throwout_count();
 287     }
 288   }
 289 
 290   // size of parameters
 291   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 292   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 293 
 294   bool has_stackmap_table() const {
 295     return constMethod()->has_stackmap_table();
 296   }
 297 
 298   Array<u1>* stackmap_data() const {
 299     return constMethod()->stackmap_data();
 300   }
 301 
 302   void set_stackmap_data(Array<u1>* sd) {
 303     constMethod()->set_stackmap_data(sd);
 304   }
 305 
 306   // exception handler table
 307   bool has_exception_handler() const
 308                              { return constMethod()->has_exception_handler(); }
 309   int exception_table_length() const
 310                              { return constMethod()->exception_table_length(); }
 311   ExceptionTableElement* exception_table_start() const
 312                              { return constMethod()->exception_table_start(); }
 313 
 314   // Finds the first entry point bci of an exception handler for an
 315   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 316   // for ex_klass indicates that the exception klass is not known; in
 317   // this case it matches any constraint class. Returns -1 if the
 318   // exception cannot be handled in this method. The handler
 319   // constraint classes are loaded if necessary. Note that this may
 320   // throw an exception if loading of the constraint classes causes
 321   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 322   // If an exception is thrown, returns the bci of the
 323   // exception handler which caused the exception to be thrown, which
 324   // is needed for proper retries. See, for example,
 325   // InterpreterRuntime::exception_handler_for_exception.
 326   static int fast_exception_handler_bci_for(methodHandle mh, Klass* ex_klass, int throw_bci, TRAPS);
 327 
 328   // method data access
 329   MethodData* method_data() const              {
 330     return _method_data;
 331   }
 332 
 333   void set_method_data(MethodData* data)       {
 334     // The store into method must be released. On platforms without
 335     // total store order (TSO) the reference may become visible before
 336     // the initialization of data otherwise.
 337     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);
 338   }
 339 
 340   MethodCounters* method_counters() const {
 341     return _method_counters;
 342   }
 343 
 344   void clear_method_counters() {
 345     _method_counters = NULL;
 346   }
 347 
 348   bool init_method_counters(MethodCounters* counters) {
 349     // Try to install a pointer to MethodCounters, return true on success.
 350     return Atomic::cmpxchg_ptr(counters, (volatile void*)&_method_counters, NULL) == NULL;
 351   }
 352 
 353 #ifdef TIERED
 354   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 355   // We can do that since interpreter_invocation_count is not used in tiered.
 356   int prev_event_count() const                   {
 357     if (method_counters() == NULL) {
 358       return 0;
 359     } else {
 360       return method_counters()->interpreter_invocation_count();
 361     }
 362   }
 363   void set_prev_event_count(int count) {
 364     MethodCounters* mcs = method_counters();
 365     if (mcs != NULL) {
 366       mcs->set_interpreter_invocation_count(count);
 367     }
 368   }
 369   jlong prev_time() const                        {
 370     MethodCounters* mcs = method_counters();
 371     return mcs == NULL ? 0 : mcs->prev_time();
 372   }
 373   void set_prev_time(jlong time) {
 374     MethodCounters* mcs = method_counters();
 375     if (mcs != NULL) {
 376       mcs->set_prev_time(time);
 377     }
 378   }
 379   float rate() const                             {
 380     MethodCounters* mcs = method_counters();
 381     return mcs == NULL ? 0 : mcs->rate();
 382   }
 383   void set_rate(float rate) {
 384     MethodCounters* mcs = method_counters();
 385     if (mcs != NULL) {
 386       mcs->set_rate(rate);
 387     }
 388   }
 389 
 390 #if INCLUDE_AOT
 391   void set_aot_code(CompiledMethod* aot_code) {
 392     _aot_code = aot_code;
 393   }
 394 
 395   CompiledMethod* aot_code() const {
 396     return _aot_code;
 397   }
 398 #else
 399   CompiledMethod* aot_code() const { return NULL; }
 400 #endif // INCLUDE_AOT
 401 #endif // TIERED
 402 
 403   int nmethod_age() const {
 404     if (method_counters() == NULL) {
 405       return INT_MAX;
 406     } else {
 407       return method_counters()->nmethod_age();
 408     }
 409   }
 410 
 411   int invocation_count();
 412   int backedge_count();
 413 
 414   bool was_executed_more_than(int n);
 415   bool was_never_executed()                      { return !was_executed_more_than(0); }
 416 
 417   static void build_interpreter_method_data(const methodHandle& method, TRAPS);
 418 
 419   static MethodCounters* build_method_counters(Method* m, TRAPS);
 420 
 421   int interpreter_invocation_count() {
 422     if (TieredCompilation) {
 423       return invocation_count();
 424     } else {
 425       MethodCounters* mcs = method_counters();
 426       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 427     }
 428   }
 429 #if defined(COMPILER2) || INCLUDE_JVMCI
 430   int increment_interpreter_invocation_count(TRAPS) {
 431     if (TieredCompilation) ShouldNotReachHere();
 432     MethodCounters* mcs = get_method_counters(CHECK_0);
 433     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 434   }
 435 #endif
 436 
 437 #ifndef PRODUCT
 438   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 439   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 440 #else
 441   // for PrintMethodData in a product build
 442   int  compiled_invocation_count() const         { return 0;  }
 443 #endif // not PRODUCT
 444 
 445   // Clear (non-shared space) pointers which could not be relevant
 446   // if this (shared) method were mapped into another JVM.
 447   void remove_unshareable_info();
 448 
 449   // nmethod/verified compiler entry
 450   address verified_code_entry();
 451   bool check_code() const;      // Not inline to avoid circular ref
 452   CompiledMethod* volatile code() const                 { assert( check_code(), "" ); return (CompiledMethod *)OrderAccess::load_ptr_acquire(&_code); }
 453   void clear_code(bool acquire_lock = true);    // Clear out any compiled code
 454   static void set_code(methodHandle mh, CompiledMethod* code);
 455   void set_adapter_entry(AdapterHandlerEntry* adapter) {
 456     constMethod()->set_adapter_entry(adapter);
 457   }
 458   void update_adapter_trampoline(AdapterHandlerEntry* adapter) {
 459     constMethod()->update_adapter_trampoline(adapter);
 460   }
 461 
 462   address get_i2c_entry();
 463   address get_c2i_entry();
 464   address get_c2i_unverified_entry();
 465   AdapterHandlerEntry* adapter() const {
 466     return constMethod()->adapter();
 467   }
 468   // setup entry points
 469   void link_method(const methodHandle& method, TRAPS);
 470   // clear entry points. Used by sharing code during dump time
 471   void unlink_method() NOT_CDS_RETURN;
 472 
 473   // vtable index
 474   enum VtableIndexFlag {
 475     // Valid vtable indexes are non-negative (>= 0).
 476     // These few negative values are used as sentinels.
 477     itable_index_max        = -10, // first itable index, growing downward
 478     pending_itable_index    = -9,  // itable index will be assigned
 479     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 480     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 481     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 482     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 483   };
 484   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 485   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 486   int  vtable_index() const                      { return _vtable_index; }
 487   void set_vtable_index(int index);
 488   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 489   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 490   int  itable_index() const                      { assert(valid_itable_index(), "");
 491                                                    return itable_index_max - _vtable_index; }
 492   void set_itable_index(int index);
 493 
 494   // interpreter entry
 495   address interpreter_entry() const              { return _i2i_entry; }
 496   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 497   void set_interpreter_entry(address entry) {
 498     assert(!is_shared(), "shared method's interpreter entry should not be changed at run time");
 499     if (_i2i_entry != entry) {
 500       _i2i_entry = entry;
 501     }
 502     if (_from_interpreted_entry != entry) {
 503       _from_interpreted_entry = entry;
 504     }
 505   }
 506 
 507   // native function (used for native methods only)
 508   enum {
 509     native_bind_event_is_interesting = true
 510   };
 511   address native_function() const                { return *(native_function_addr()); }
 512   address critical_native_function();
 513 
 514   // Must specify a real function (not NULL).
 515   // Use clear_native_function() to unregister.
 516   void set_native_function(address function, bool post_event_flag);
 517   bool has_native_function() const;
 518   void clear_native_function();
 519 
 520   // signature handler (used for native methods only)
 521   address signature_handler() const              { return *(signature_handler_addr()); }
 522   void set_signature_handler(address handler);
 523 
 524   // Interpreter oopmap support
 525   void mask_for(int bci, InterpreterOopMap* mask);
 526 
 527   // operations on invocation counter
 528   void print_invocation_count();
 529 
 530   // byte codes
 531   void    set_code(address code)      { return constMethod()->set_code(code); }
 532   address code_base() const           { return constMethod()->code_base(); }
 533   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 534 
 535   // prints byte codes
 536   void print_codes() const            { print_codes_on(tty); }
 537   void print_codes_on(outputStream* st) const;
 538   void print_codes_on(int from, int to, outputStream* st) const;
 539 
 540   // method parameters
 541   bool has_method_parameters() const
 542                          { return constMethod()->has_method_parameters(); }
 543   int method_parameters_length() const
 544                          { return constMethod()->method_parameters_length(); }
 545   MethodParametersElement* method_parameters_start() const
 546                           { return constMethod()->method_parameters_start(); }
 547 
 548   // checked exceptions
 549   int checked_exceptions_length() const
 550                          { return constMethod()->checked_exceptions_length(); }
 551   CheckedExceptionElement* checked_exceptions_start() const
 552                           { return constMethod()->checked_exceptions_start(); }
 553 
 554   // localvariable table
 555   bool has_localvariable_table() const
 556                           { return constMethod()->has_localvariable_table(); }
 557   int localvariable_table_length() const
 558                         { return constMethod()->localvariable_table_length(); }
 559   LocalVariableTableElement* localvariable_table_start() const
 560                          { return constMethod()->localvariable_table_start(); }
 561 
 562   bool has_linenumber_table() const
 563                               { return constMethod()->has_linenumber_table(); }
 564   u_char* compressed_linenumber_table() const
 565                        { return constMethod()->compressed_linenumber_table(); }
 566 
 567   // method holder (the Klass* holding this method)
 568   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 569 
 570   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 571   Symbol* klass_name() const;                    // returns the name of the method holder
 572   BasicType result_type() const;                 // type of the method result
 573   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 574   bool is_returning_vt() const                   { BasicType r = result_type(); return r == T_VALUETYPE; }
 575   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 576 #ifdef ASSERT
 577   ValueKlass* returned_value_type(Thread* thread) const;
 578 #endif
 579 
 580   // Checked exceptions thrown by this method (resolved to mirrors)
 581   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 582 
 583   // Access flags
 584   bool is_public() const                         { return access_flags().is_public();      }
 585   bool is_private() const                        { return access_flags().is_private();     }
 586   bool is_protected() const                      { return access_flags().is_protected();   }
 587   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 588   bool is_static() const                         { return access_flags().is_static();      }
 589   bool is_final() const                          { return access_flags().is_final();       }
 590   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 591   bool is_native() const                         { return access_flags().is_native();      }
 592   bool is_abstract() const                       { return access_flags().is_abstract();    }
 593   bool is_strict() const                         { return access_flags().is_strict();      }
 594   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 595 
 596   // returns true if contains only return operation
 597   bool is_empty_method() const;
 598 
 599   // returns true if this is a vanilla constructor
 600   bool is_vanilla_constructor() const;
 601 
 602   // checks method and its method holder
 603   bool is_final_method() const;
 604   bool is_final_method(AccessFlags class_access_flags) const;
 605   // interface method declared with 'default' - excludes private interface methods
 606   bool is_default_method() const;
 607 
 608   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 609   bool can_be_statically_bound() const;
 610   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 611 
 612   // returns true if the method has any backward branches.
 613   bool has_loops() {
 614     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 615   };
 616 
 617   bool compute_has_loops_flag();
 618 
 619   bool has_jsrs() {
 620     return access_flags().has_jsrs();
 621   };
 622   void set_has_jsrs() {
 623     _access_flags.set_has_jsrs();
 624   }
 625 
 626   // returns true if the method has any monitors.
 627   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 628   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 629 
 630   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 631 
 632   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 633   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 634   // has not been computed yet.
 635   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 636   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 637 
 638   // returns true if the method is an accessor function (setter/getter).
 639   bool is_accessor() const;
 640 
 641   // returns true if the method is a getter
 642   bool is_getter() const;
 643 
 644   // returns true if the method is a setter
 645   bool is_setter() const;
 646 
 647   // returns true if the method does nothing but return a constant of primitive type
 648   bool is_constant_getter() const;
 649 
 650   // returns true if the method is an initializer (<init> or <clinit>).
 651   bool is_initializer() const;
 652 
 653   // returns true if the method is static OR if the classfile version < 51
 654   bool has_valid_initializer_flags() const;
 655 
 656   // returns true if the method name is <clinit> and the method has
 657   // valid static initializer flags.
 658   bool is_static_initializer() const;
 659 
 660   // returns true if the method name is <init>
 661   bool is_object_initializer() const;
 662 
 663   // compiled code support
 664   // NOTE: code() is inherently racy as deopt can be clearing code
 665   // simultaneously. Use with caution.
 666   bool has_compiled_code() const                 { return code() != NULL; }
 667 
 668 #ifdef TIERED
 669   bool has_aot_code() const                      { return aot_code() != NULL; }
 670 #endif
 671 
 672   // sizing
 673   static int header_size()                       {
 674     return align_size_up(sizeof(Method), wordSize) / wordSize;
 675   }
 676   static int size(bool is_native);
 677   int size() const                               { return method_size(); }
 678 #if INCLUDE_SERVICES
 679   void collect_statistics(KlassSizeStats *sz) const;
 680 #endif
 681   void log_touched(TRAPS);
 682   static void print_touched_methods(outputStream* out);
 683 
 684   // interpreter support
 685   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 686   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 687   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 688   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 689   static ByteSize method_data_offset()           {
 690     return byte_offset_of(Method, _method_data);
 691   }
 692   static ByteSize method_counters_offset()       {
 693     return byte_offset_of(Method, _method_counters);
 694   }
 695 #ifndef PRODUCT
 696   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 697 #endif // not PRODUCT
 698   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 699   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 700   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 701   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 702 
 703   // for code generation
 704   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 705   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 706   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 707 
 708   // Static methods that are used to implement member methods where an exposed this pointer
 709   // is needed due to possible GCs
 710   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 711 
 712   // Returns the byte code index from the byte code pointer
 713   int     bci_from(address bcp) const;
 714   address bcp_from(int bci) const;
 715   address bcp_from(address bcp) const;
 716   int validate_bci_from_bcp(address bcp) const;
 717   int validate_bci(int bci) const;
 718 
 719   // Returns the line number for a bci if debugging information for the method is prowided,
 720   // -1 is returned otherwise.
 721   int line_number_from_bci(int bci) const;
 722 
 723   // Reflection support
 724   bool is_overridden_in(Klass* k) const;
 725 
 726   // Stack walking support
 727   bool is_ignored_by_security_stack_walk() const;
 728 
 729   // JSR 292 support
 730   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 731   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 732   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 733   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 734                                                    Symbol* signature, //anything at all
 735                                                    TRAPS);
 736   static Klass* check_non_bcp_klass(Klass* klass);
 737 
 738   enum {
 739     // How many extra stack entries for invokedynamic
 740     extra_stack_entries_for_jsr292 = 1
 741   };
 742 
 743   // this operates only on invoke methods:
 744   // presize interpreter frames for extra interpreter stack entries, if needed
 745   // Account for the extra appendix argument for invokehandle/invokedynamic
 746   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 747   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 748 
 749   // RedefineClasses() support:
 750   bool is_old() const                               { return access_flags().is_old(); }
 751   void set_is_old()                                 { _access_flags.set_is_old(); }
 752   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 753   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 754   bool is_deleted() const                           { return access_flags().is_deleted(); }
 755   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 756 
 757   bool is_running_emcp() const {
 758     // EMCP methods are old but not obsolete or deleted. Equivalent
 759     // Modulo Constant Pool means the method is equivalent except
 760     // the constant pool and instructions that access the constant
 761     // pool might be different.
 762     // If a breakpoint is set in a redefined method, its EMCP methods that are
 763     // still running must have a breakpoint also.
 764     return (_flags & _running_emcp) != 0;
 765   }
 766 
 767   void set_running_emcp(bool x) {
 768     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 769   }
 770 
 771   bool on_stack() const                             { return access_flags().on_stack(); }
 772   void set_on_stack(const bool value);
 773 
 774   // see the definition in Method*.cpp for the gory details
 775   bool should_not_be_cached() const;
 776 
 777   // JVMTI Native method prefixing support:
 778   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 779   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 780 
 781   // Rewriting support
 782   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 783                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 784 
 785   // jmethodID handling
 786   // Because the useful life-span of a jmethodID cannot be determined,
 787   // once created they are never reclaimed.  The methods to which they refer,
 788   // however, can be GC'ed away if the class is unloaded or if the method is
 789   // made obsolete or deleted -- in these cases, the jmethodID
 790   // refers to NULL (as is the case for any weak reference).
 791   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 792   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 793 
 794   // Ensure there is enough capacity in the internal tracking data
 795   // structures to hold the number of jmethodIDs you plan to generate.
 796   // This saves substantial time doing allocations.
 797   static void ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity);
 798 
 799   // Use resolve_jmethod_id() in situations where the caller is expected
 800   // to provide a valid jmethodID; the only sanity checks are in asserts;
 801   // result guaranteed not to be NULL.
 802   inline static Method* resolve_jmethod_id(jmethodID mid) {
 803     assert(mid != NULL, "JNI method id should not be null");
 804     return *((Method**)mid);
 805   }
 806 
 807   // Use checked_resolve_jmethod_id() in situations where the caller
 808   // should provide a valid jmethodID, but might not. NULL is returned
 809   // when the jmethodID does not refer to a valid method.
 810   static Method* checked_resolve_jmethod_id(jmethodID mid);
 811 
 812   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 813   static bool is_method_id(jmethodID mid);
 814 
 815   // Clear methods
 816   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 817   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 818 
 819   // Get this method's jmethodID -- allocate if it doesn't exist
 820   jmethodID jmethod_id()                            { return method_holder()->get_jmethod_id(this); }
 821 
 822   // Lookup the jmethodID for this method.  Return NULL if not found.
 823   // NOTE that this function can be called from a signal handler
 824   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 825   // needs to be async-safe. No allocation should be done and
 826   // so handles are not used to avoid deadlock.
 827   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 828 
 829   // Support for inlining of intrinsic methods
 830   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 831   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u2) id; }
 832 
 833   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 834   void init_intrinsic_id();     // updates from _none if a match
 835   static vmSymbols::SID klass_id_for_intrinsics(const Klass* holder);
 836 
 837   bool caller_sensitive() {
 838     return (_flags & _caller_sensitive) != 0;
 839   }
 840   void set_caller_sensitive(bool x) {
 841     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 842   }
 843 
 844   bool force_inline() {
 845     return (_flags & _force_inline) != 0;
 846   }
 847   void set_force_inline(bool x) {
 848     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 849   }
 850 
 851   bool dont_inline() {
 852     return (_flags & _dont_inline) != 0;
 853   }
 854   void set_dont_inline(bool x) {
 855     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 856   }
 857 
 858   bool is_hidden() {
 859     return (_flags & _hidden) != 0;
 860   }
 861   void set_hidden(bool x) {
 862     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 863   }
 864 
 865   bool intrinsic_candidate() {
 866     return (_flags & _intrinsic_candidate) != 0;
 867   }
 868   void set_intrinsic_candidate(bool x) {
 869     _flags = x ? (_flags | _intrinsic_candidate) : (_flags & ~_intrinsic_candidate);
 870   }
 871 
 872   bool has_injected_profile() {
 873     return (_flags & _has_injected_profile) != 0;
 874   }
 875   void set_has_injected_profile(bool x) {
 876     _flags = x ? (_flags | _has_injected_profile) : (_flags & ~_has_injected_profile);
 877   }
 878 
 879   bool has_reserved_stack_access() {
 880     return (_flags & _reserved_stack_access) != 0;
 881   }
 882 
 883   void set_has_reserved_stack_access(bool x) {
 884     _flags = x ? (_flags | _reserved_stack_access) : (_flags & ~_reserved_stack_access);
 885   }
 886 
 887   TRACE_DEFINE_FLAG_ACCESSOR;
 888 
 889   ConstMethod::MethodType method_type() const {
 890       return _constMethod->method_type();
 891   }
 892   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 893 
 894   // On-stack replacement support
 895   bool has_osr_nmethod(int level, bool match_level) {
 896    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 897   }
 898 
 899   int mark_osr_nmethods() {
 900     return method_holder()->mark_osr_nmethods(this);
 901   }
 902 
 903   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 904     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 905   }
 906 
 907   // Inline cache support
 908   void cleanup_inline_caches();
 909 
 910   // Find if klass for method is loaded
 911   bool is_klass_loaded_by_klass_index(int klass_index) const;
 912   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 913 
 914   // Indicates whether compilation failed earlier for this method, or
 915   // whether it is not compilable for another reason like having a
 916   // breakpoint set in it.
 917   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 918   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 919   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 920     set_not_compilable(comp_level, false);
 921   }
 922   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 923   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 924   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 925     set_not_osr_compilable(comp_level, false);
 926   }
 927   bool is_always_compilable() const;
 928 
 929  private:
 930   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 931 
 932  public:
 933   MethodCounters* get_method_counters(TRAPS) {
 934     if (_method_counters == NULL) {
 935       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 936     }
 937     return _method_counters;
 938   }
 939 
 940   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 941   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 942   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 943   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 944   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 945   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 946 
 947   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 948   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 949   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 950   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 951   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 952   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 953 
 954   // Background compilation support
 955   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 956   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 957   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 958 
 959   // Resolve all classes in signature, return 'true' if successful
 960   static bool load_signature_classes(methodHandle m, TRAPS);
 961 
 962   // Return if true if not all classes references in signature, including return type, has been loaded
 963   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 964 
 965   // Printing
 966   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 967 #if INCLUDE_JVMTI
 968   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 969 #else
 970   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 971 #endif
 972 
 973   // Helper routine used for method sorting
 974   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);
 975 
 976   // Deallocation function for redefine classes or if an error occurs
 977   void deallocate_contents(ClassLoaderData* loader_data);
 978 
 979   // Printing
 980 #ifndef PRODUCT
 981   void print_on(outputStream* st) const;
 982 #endif
 983   void print_value_on(outputStream* st) const;
 984   void print_linkage_flags(outputStream* st) PRODUCT_RETURN;
 985 
 986   const char* internal_name() const { return "{method}"; }
 987 
 988   // Check for valid method pointer
 989   static bool has_method_vptr(const void* ptr);
 990   bool is_valid_method() const;
 991 
 992   // Verify
 993   void verify() { verify_on(tty); }
 994   void verify_on(outputStream* st);
 995 
 996  private:
 997 
 998   // Inlined elements
 999   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
1000   address* signature_handler_addr() const        { return native_function_addr() + 1; }
1001 };
1002 
1003 
1004 // Utility class for compressing line number tables
1005 
1006 class CompressedLineNumberWriteStream: public CompressedWriteStream {
1007  private:
1008   int _bci;
1009   int _line;
1010  public:
1011   // Constructor
1012   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
1013   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
1014 
1015   // Write (bci, line number) pair to stream
1016   void write_pair_regular(int bci_delta, int line_delta);
1017 
1018   inline void write_pair_inline(int bci, int line) {
1019     int bci_delta = bci - _bci;
1020     int line_delta = line - _line;
1021     _bci = bci;
1022     _line = line;
1023     // Skip (0,0) deltas - they do not add information and conflict with terminator.
1024     if (bci_delta == 0 && line_delta == 0) return;
1025     // Check if bci is 5-bit and line number 3-bit unsigned.
1026     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
1027       // Compress into single byte.
1028       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
1029       // Check that value doesn't match escape character.
1030       if (value != 0xFF) {
1031         write_byte(value);
1032         return;
1033       }
1034     }
1035     write_pair_regular(bci_delta, line_delta);
1036   }
1037 
1038 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
1039 // Disabling optimization doesn't work for methods in header files
1040 // so we force it to call through the non-optimized version in the .cpp.
1041 // It's gross, but it's the only way we can ensure that all callers are
1042 // fixed.  _MSC_VER is defined by the windows compiler
1043 #if defined(_M_AMD64) && _MSC_VER >= 1400
1044   void write_pair(int bci, int line);
1045 #else
1046   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
1047 #endif
1048 
1049   // Write end-of-stream marker
1050   void write_terminator()                        { write_byte(0); }
1051 };
1052 
1053 
1054 // Utility class for decompressing line number tables
1055 
1056 class CompressedLineNumberReadStream: public CompressedReadStream {
1057  private:
1058   int _bci;
1059   int _line;
1060  public:
1061   // Constructor
1062   CompressedLineNumberReadStream(u_char* buffer);
1063   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1064   bool read_pair();
1065   // Accessing bci and line number (after calling read_pair)
1066   int bci() const                               { return _bci; }
1067   int line() const                              { return _line; }
1068 };
1069 
1070 
1071 #if INCLUDE_JVMTI
1072 
1073 /// Fast Breakpoints.
1074 
1075 // If this structure gets more complicated (because bpts get numerous),
1076 // move it into its own header.
1077 
1078 // There is presently no provision for concurrent access
1079 // to breakpoint lists, which is only OK for JVMTI because
1080 // breakpoints are written only at safepoints, and are read
1081 // concurrently only outside of safepoints.
1082 
1083 class BreakpointInfo : public CHeapObj<mtClass> {
1084   friend class VMStructs;
1085  private:
1086   Bytecodes::Code  _orig_bytecode;
1087   int              _bci;
1088   u2               _name_index;       // of method
1089   u2               _signature_index;  // of method
1090   BreakpointInfo*  _next;             // simple storage allocation
1091 
1092  public:
1093   BreakpointInfo(Method* m, int bci);
1094 
1095   // accessors
1096   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1097   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1098   int         bci()                                   { return _bci; }
1099 
1100   BreakpointInfo*          next() const               { return _next; }
1101   void                 set_next(BreakpointInfo* n)    { _next = n; }
1102 
1103   // helps for searchers
1104   bool match(const Method* m, int bci) {
1105     return bci == _bci && match(m);
1106   }
1107 
1108   bool match(const Method* m) {
1109     return _name_index == m->name_index() &&
1110       _signature_index == m->signature_index();
1111   }
1112 
1113   void set(Method* method);
1114   void clear(Method* method);
1115 };
1116 
1117 #endif // INCLUDE_JVMTI
1118 
1119 // Utility class for access exception handlers
1120 class ExceptionTable : public StackObj {
1121  private:
1122   ExceptionTableElement* _table;
1123   u2  _length;
1124 
1125  public:
1126   ExceptionTable(const Method* m) {
1127     if (m->has_exception_handler()) {
1128       _table = m->exception_table_start();
1129       _length = m->exception_table_length();
1130     } else {
1131       _table = NULL;
1132       _length = 0;
1133     }
1134   }
1135 
1136   int length() const {
1137     return _length;
1138   }
1139 
1140   u2 start_pc(int idx) const {
1141     assert(idx < _length, "out of bounds");
1142     return _table[idx].start_pc;
1143   }
1144 
1145   void set_start_pc(int idx, u2 value) {
1146     assert(idx < _length, "out of bounds");
1147     _table[idx].start_pc = value;
1148   }
1149 
1150   u2 end_pc(int idx) const {
1151     assert(idx < _length, "out of bounds");
1152     return _table[idx].end_pc;
1153   }
1154 
1155   void set_end_pc(int idx, u2 value) {
1156     assert(idx < _length, "out of bounds");
1157     _table[idx].end_pc = value;
1158   }
1159 
1160   u2 handler_pc(int idx) const {
1161     assert(idx < _length, "out of bounds");
1162     return _table[idx].handler_pc;
1163   }
1164 
1165   void set_handler_pc(int idx, u2 value) {
1166     assert(idx < _length, "out of bounds");
1167     _table[idx].handler_pc = value;
1168   }
1169 
1170   u2 catch_type_index(int idx) const {
1171     assert(idx < _length, "out of bounds");
1172     return _table[idx].catch_type_index;
1173   }
1174 
1175   void set_catch_type_index(int idx, u2 value) {
1176     assert(idx < _length, "out of bounds");
1177     _table[idx].catch_type_index = value;
1178   }
1179 };
1180 
1181 #endif // SHARE_VM_OOPS_METHODOOP_HPP