1 /*
   2  * Copyright (c) 1997, 2019, 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_OOPS_METHOD_HPP
  26 #define SHARE_OOPS_METHOD_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/align.hpp"
  41 #include "utilities/growableArray.hpp"
  42 #include "utilities/macros.hpp"
  43 #if INCLUDE_JFR
  44 #include "jfr/support/jfrTraceIdExtension.hpp"
  45 #endif
  46 
  47 
  48 // A Method represents a Java method.
  49 //
  50 // Note that most applications load thousands of methods, so keeping the size of this
  51 // class small has a big impact on footprint.
  52 //
  53 // Note that native_function and signature_handler have to be at fixed offsets
  54 // (required by the interpreter)
  55 //
  56 //  Method embedded field layout (after declared fields):
  57 //   [EMBEDDED native_function       (present only if native) ]
  58 //   [EMBEDDED signature_handler     (present only if native) ]
  59 
  60 class CheckedExceptionElement;
  61 class LocalVariableTableElement;
  62 class AdapterHandlerEntry;
  63 class MethodData;
  64 class MethodCounters;
  65 class ConstMethod;
  66 class InlineTableSizes;
  67 class KlassSizeStats;
  68 class CompiledMethod;
  69 class InterpreterOopMap;
  70 
  71 class Method : public Metadata {
  72  friend class VMStructs;
  73  friend class JVMCIVMStructs;
  74  private:
  75   // If you add a new field that points to any metaspace object, you
  76   // must add this field to Method::metaspace_pointers_do().
  77   ConstMethod*      _constMethod;                // Method read-only data.
  78   MethodData*       _method_data;
  79   MethodCounters*   _method_counters;
  80   AccessFlags       _access_flags;               // Access flags
  81   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  82                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  83   u2                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  84 
  85   // Flags
  86   enum Flags {
  87     _caller_sensitive      = 1 << 0,
  88     _force_inline          = 1 << 1,
  89     _dont_inline           = 1 << 2,
  90     _hidden                = 1 << 3,
  91     _has_injected_profile  = 1 << 4,
  92     _running_emcp          = 1 << 5,
  93     _intrinsic_candidate   = 1 << 6,
  94     _reserved_stack_access = 1 << 7
  95   };
  96   mutable u2 _flags;
  97 
  98   JFR_ONLY(DEFINE_TRACE_FLAG;)
  99 
 100 #ifndef PRODUCT
 101   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 102 #endif
 103   // Entry point for calling both from and to the interpreter.
 104   address _i2i_entry;           // All-args-on-stack calling convention
 105   // Entry point for calling from compiled code, to compiled code if it exists
 106   // or else the interpreter.
 107   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 108   // The entry point for calling both from and to compiled code is
 109   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 110   // field can come and go.  It can transition from NULL to not-null at any
 111   // time (whenever a compile completes).  It can transition from not-null to
 112   // NULL only at safepoints (because of a de-opt).
 113   CompiledMethod* volatile _code;                       // Points to the corresponding piece of native code
 114   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 115 
 116   int _num_stack_arg_slots;
 117   
 118 #if INCLUDE_AOT && defined(TIERED)
 119   CompiledMethod* _aot_code;
 120 #endif
 121 
 122   // Constructor
 123   Method(ConstMethod* xconst, AccessFlags access_flags);
 124  public:
 125 
 126   static Method* allocate(ClassLoaderData* loader_data,
 127                           int byte_code_size,
 128                           AccessFlags access_flags,
 129                           InlineTableSizes* sizes,
 130                           ConstMethod::MethodType method_type,
 131                           TRAPS);
 132 
 133   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 134   Method(){}
 135 
 136   bool is_method() const volatile { return true; }
 137 
 138   void restore_unshareable_info(TRAPS);
 139 
 140   // accessors for instance variables
 141 
 142   ConstMethod* constMethod() const             { return _constMethod; }
 143   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 144 
 145 
 146   static address make_adapters(const methodHandle& mh, TRAPS);
 147   address from_compiled_entry() const;
 148   address from_compiled_entry_no_trampoline() const;
 149   address from_interpreted_entry() const;
 150 
 151   // access flag
 152   AccessFlags access_flags() const               { return _access_flags;  }
 153   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 154 
 155   // name
 156   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 157   int name_index() const                         { return constMethod()->name_index();         }
 158   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 159 
 160   // signature
 161   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 162   int signature_index() const                    { return constMethod()->signature_index();         }
 163   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 164 
 165   // generics support
 166   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 167   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 168   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 169 
 170   // annotations support
 171   AnnotationArray* annotations() const           {
 172     return constMethod()->method_annotations();
 173   }
 174   AnnotationArray* parameter_annotations() const {
 175     return constMethod()->parameter_annotations();
 176   }
 177   AnnotationArray* annotation_default() const    {
 178     return constMethod()->default_annotations();
 179   }
 180   AnnotationArray* type_annotations() const      {
 181     return constMethod()->type_annotations();
 182   }
 183 
 184   // Helper routine: get klass name + "." + method name + signature as
 185   // C string, for the purpose of providing more useful
 186   // fatal error handling. The string is allocated in resource
 187   // area if a buffer is not provided by the caller.
 188   char* name_and_sig_as_C_string() const;
 189   char* name_and_sig_as_C_string(char* buf, int size) const;
 190 
 191   // Static routine in the situations we don't have a Method*
 192   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 193   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 194 
 195   // Get return type + klass name + "." + method name + ( parameters types )
 196   // as a C string or print it to an outputStream.
 197   // This is to be used to assemble strings passed to Java, so that
 198   // the text more resembles Java code. Used in exception messages.
 199   // Memory is allocated in the resource area; the caller needs
 200   // a ResourceMark.
 201   const char* external_name() const;
 202   void  print_external_name(outputStream *os) const;
 203 
 204   static const char* external_name(                  Klass* klass, Symbol* method_name, Symbol* signature);
 205   static void  print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature);
 206 
 207   Bytecodes::Code java_code_at(int bci) const {
 208     return Bytecodes::java_code_at(this, bcp_from(bci));
 209   }
 210   Bytecodes::Code code_at(int bci) const {
 211     return Bytecodes::code_at(this, bcp_from(bci));
 212   }
 213 
 214   // JVMTI breakpoints
 215 #if !INCLUDE_JVMTI
 216   Bytecodes::Code orig_bytecode_at(int bci) const {
 217     ShouldNotReachHere();
 218     return Bytecodes::_shouldnotreachhere;
 219   }
 220   void set_orig_bytecode_at(int bci, Bytecodes::Code code) {
 221     ShouldNotReachHere();
 222   };
 223   u2   number_of_breakpoints() const {return 0;}
 224 #else // !INCLUDE_JVMTI
 225   Bytecodes::Code orig_bytecode_at(int bci) const;
 226   void set_orig_bytecode_at(int bci, Bytecodes::Code code);
 227   void set_breakpoint(int bci);
 228   void clear_breakpoint(int bci);
 229   void clear_all_breakpoints();
 230   // Tracking number of breakpoints, for fullspeed debugging.
 231   // Only mutated by VM thread.
 232   u2   number_of_breakpoints()             const {
 233     MethodCounters* mcs = method_counters();
 234     if (mcs == NULL) {
 235       return 0;
 236     } else {
 237       return mcs->number_of_breakpoints();
 238     }
 239   }
 240   void incr_number_of_breakpoints(TRAPS)         {
 241     MethodCounters* mcs = get_method_counters(CHECK);
 242     if (mcs != NULL) {
 243       mcs->incr_number_of_breakpoints();
 244     }
 245   }
 246   void decr_number_of_breakpoints(TRAPS)         {
 247     MethodCounters* mcs = get_method_counters(CHECK);
 248     if (mcs != NULL) {
 249       mcs->decr_number_of_breakpoints();
 250     }
 251   }
 252   // Initialization only
 253   void clear_number_of_breakpoints()             {
 254     MethodCounters* mcs = method_counters();
 255     if (mcs != NULL) {
 256       mcs->clear_number_of_breakpoints();
 257     }
 258   }
 259 #endif // !INCLUDE_JVMTI
 260 
 261   // index into InstanceKlass methods() array
 262   // note: also used by jfr
 263   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 264   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 265 
 266   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 267   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 268 
 269   // code size
 270   int code_size() const                  { return constMethod()->code_size(); }
 271 
 272   // method size in words
 273   int method_size() const                { return sizeof(Method)/wordSize + ( is_native() ? 2 : 0 ); }
 274 
 275   // constant pool for Klass* holding this method
 276   ConstantPool* constants() const              { return constMethod()->constants(); }
 277   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 278 
 279   // max stack
 280   // return original max stack size for method verification
 281   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 282   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 283   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 284 
 285   // max locals
 286   int  max_locals() const                        { return constMethod()->max_locals(); }
 287   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 288 
 289   int highest_comp_level() const;
 290   void set_highest_comp_level(int level);
 291   int highest_osr_comp_level() const;
 292   void set_highest_osr_comp_level(int level);
 293 
 294 #if COMPILER2_OR_JVMCI
 295   // Count of times method was exited via exception while interpreting
 296   void interpreter_throwout_increment(TRAPS) {
 297     MethodCounters* mcs = get_method_counters(CHECK);
 298     if (mcs != NULL) {
 299       mcs->interpreter_throwout_increment();
 300     }
 301   }
 302 #endif
 303 
 304   int  interpreter_throwout_count() const        {
 305     MethodCounters* mcs = method_counters();
 306     if (mcs == NULL) {
 307       return 0;
 308     } else {
 309       return mcs->interpreter_throwout_count();
 310     }
 311   }
 312 
 313   // size of parameters
 314   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 315   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 316 
 317   bool has_stackmap_table() const {
 318     return constMethod()->has_stackmap_table();
 319   }
 320 
 321   Array<u1>* stackmap_data() const {
 322     return constMethod()->stackmap_data();
 323   }
 324 
 325   void set_stackmap_data(Array<u1>* sd) {
 326     constMethod()->set_stackmap_data(sd);
 327   }
 328 
 329   // exception handler table
 330   bool has_exception_handler() const
 331                              { return constMethod()->has_exception_handler(); }
 332   int exception_table_length() const
 333                              { return constMethod()->exception_table_length(); }
 334   ExceptionTableElement* exception_table_start() const
 335                              { return constMethod()->exception_table_start(); }
 336 
 337   // Finds the first entry point bci of an exception handler for an
 338   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 339   // for ex_klass indicates that the exception klass is not known; in
 340   // this case it matches any constraint class. Returns -1 if the
 341   // exception cannot be handled in this method. The handler
 342   // constraint classes are loaded if necessary. Note that this may
 343   // throw an exception if loading of the constraint classes causes
 344   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 345   // If an exception is thrown, returns the bci of the
 346   // exception handler which caused the exception to be thrown, which
 347   // is needed for proper retries. See, for example,
 348   // InterpreterRuntime::exception_handler_for_exception.
 349   static int fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS);
 350 
 351   // method data access
 352   MethodData* method_data() const              {
 353     return _method_data;
 354   }
 355 
 356   void set_method_data(MethodData* data);
 357 
 358   MethodCounters* method_counters() const {
 359     return _method_counters;
 360   }
 361 
 362   void clear_method_counters() {
 363     _method_counters = NULL;
 364   }
 365 
 366   bool init_method_counters(MethodCounters* counters);
 367 
 368 #ifdef TIERED
 369   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 370   // We can do that since interpreter_invocation_count is not used in tiered.
 371   int prev_event_count() const                   {
 372     if (method_counters() == NULL) {
 373       return 0;
 374     } else {
 375       return method_counters()->interpreter_invocation_count();
 376     }
 377   }
 378   void set_prev_event_count(int count) {
 379     MethodCounters* mcs = method_counters();
 380     if (mcs != NULL) {
 381       mcs->set_interpreter_invocation_count(count);
 382     }
 383   }
 384   jlong prev_time() const                        {
 385     MethodCounters* mcs = method_counters();
 386     return mcs == NULL ? 0 : mcs->prev_time();
 387   }
 388   void set_prev_time(jlong time) {
 389     MethodCounters* mcs = method_counters();
 390     if (mcs != NULL) {
 391       mcs->set_prev_time(time);
 392     }
 393   }
 394   float rate() const                             {
 395     MethodCounters* mcs = method_counters();
 396     return mcs == NULL ? 0 : mcs->rate();
 397   }
 398   void set_rate(float rate) {
 399     MethodCounters* mcs = method_counters();
 400     if (mcs != NULL) {
 401       mcs->set_rate(rate);
 402     }
 403   }
 404 
 405 #if INCLUDE_AOT
 406   void set_aot_code(CompiledMethod* aot_code) {
 407     _aot_code = aot_code;
 408   }
 409 
 410   CompiledMethod* aot_code() const {
 411     return _aot_code;
 412   }
 413 #else
 414   CompiledMethod* aot_code() const { return NULL; }
 415 #endif // INCLUDE_AOT
 416 #endif // TIERED
 417 
 418   int nmethod_age() const {
 419     if (method_counters() == NULL) {
 420       return INT_MAX;
 421     } else {
 422       return method_counters()->nmethod_age();
 423     }
 424   }
 425 
 426   int invocation_count();
 427   int backedge_count();
 428 
 429   bool was_executed_more_than(int n);
 430   bool was_never_executed()                      { return !was_executed_more_than(0); }
 431 
 432   static void build_interpreter_method_data(const methodHandle& method, TRAPS);
 433 
 434   static MethodCounters* build_method_counters(Method* m, TRAPS);
 435 
 436   int interpreter_invocation_count() {
 437     if (TieredCompilation) {
 438       return invocation_count();
 439     } else {
 440       MethodCounters* mcs = method_counters();
 441       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 442     }
 443   }
 444 #if COMPILER2_OR_JVMCI
 445   int increment_interpreter_invocation_count(TRAPS) {
 446     if (TieredCompilation) ShouldNotReachHere();
 447     MethodCounters* mcs = get_method_counters(CHECK_0);
 448     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 449   }
 450 #endif
 451 
 452 #ifndef PRODUCT
 453   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 454   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 455 #else
 456   // for PrintMethodData in a product build
 457   int  compiled_invocation_count() const         { return 0;  }
 458 #endif // not PRODUCT
 459 
 460   // Clear (non-shared space) pointers which could not be relevant
 461   // if this (shared) method were mapped into another JVM.
 462   void remove_unshareable_info();
 463 
 464   // nmethod/verified compiler entry
 465   address verified_code_entry();
 466   bool check_code() const;      // Not inline to avoid circular ref
 467   CompiledMethod* volatile code() const;
 468   void clear_code(bool acquire_lock = true);    // Clear out any compiled code
 469   static void set_code(const methodHandle& mh, CompiledMethod* code);
 470   void set_adapter_entry(AdapterHandlerEntry* adapter) {
 471     constMethod()->set_adapter_entry(adapter);
 472   }
 473   void set_adapter_trampoline(AdapterHandlerEntry** trampoline) {
 474     constMethod()->set_adapter_trampoline(trampoline);
 475   }
 476   void update_adapter_trampoline(AdapterHandlerEntry* adapter) {
 477     constMethod()->update_adapter_trampoline(adapter);
 478   }
 479   void set_from_compiled_entry(address entry) {
 480     _from_compiled_entry =  entry;
 481   }
 482 
 483   address get_i2c_entry();
 484   address get_c2i_entry();
 485   address get_c2i_unverified_entry();
 486   address get_c2i_no_clinit_check_entry();
 487   AdapterHandlerEntry* adapter() const {
 488     return constMethod()->adapter();
 489   }
 490   // setup entry points
 491   void link_method(const methodHandle& method, TRAPS);
 492   // clear entry points. Used by sharing code during dump time
 493   void unlink_method() NOT_CDS_RETURN;
 494 
 495   // the number of argument reg slots that the compiled method uses on the stack.
 496   int num_stack_arg_slots() const { return _num_stack_arg_slots;  };
 497 
 498   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 499   virtual MetaspaceObj::Type type() const { return MethodType; }
 500 
 501   // vtable index
 502   enum VtableIndexFlag {
 503     // Valid vtable indexes are non-negative (>= 0).
 504     // These few negative values are used as sentinels.
 505     itable_index_max        = -10, // first itable index, growing downward
 506     pending_itable_index    = -9,  // itable index will be assigned
 507     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 508     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 509     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 510     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 511   };
 512   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 513   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 514   int  vtable_index() const                      { return _vtable_index; }
 515   void set_vtable_index(int index);
 516   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 517   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 518   int  itable_index() const                      { assert(valid_itable_index(), "");
 519                                                    return itable_index_max - _vtable_index; }
 520   void set_itable_index(int index);
 521 
 522   // interpreter entry
 523   address interpreter_entry() const              { return _i2i_entry; }
 524   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 525   void set_interpreter_entry(address entry) {
 526     assert(!is_shared(),
 527            "shared method's interpreter entry should not be changed at run time");
 528     if (_i2i_entry != entry) {
 529       _i2i_entry = entry;
 530     }
 531     if (_from_interpreted_entry != entry) {
 532       _from_interpreted_entry = entry;
 533     }
 534   }
 535 
 536   // native function (used for native methods only)
 537   enum {
 538     native_bind_event_is_interesting = true
 539   };
 540   address native_function() const                { return *(native_function_addr()); }
 541 
 542   // Must specify a real function (not NULL).
 543   // Use clear_native_function() to unregister.
 544   void set_native_function(address function, bool post_event_flag);
 545   bool has_native_function() const;
 546   void clear_native_function();
 547 
 548   // signature handler (used for native methods only)
 549   address signature_handler() const              { return *(signature_handler_addr()); }
 550   void set_signature_handler(address handler);
 551 
 552   // Interpreter oopmap support
 553   void mask_for(int bci, InterpreterOopMap* mask);
 554 
 555   // operations on invocation counter
 556   void print_invocation_count();
 557 
 558   // byte codes
 559   void    set_code(address code)      { return constMethod()->set_code(code); }
 560   address code_base() const           { return constMethod()->code_base(); }
 561   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 562 
 563   // prints byte codes
 564   void print_codes() const            { print_codes_on(tty); }
 565   void print_codes_on(outputStream* st) const;
 566   void print_codes_on(int from, int to, outputStream* st) const;
 567 
 568   // method parameters
 569   bool has_method_parameters() const
 570                          { return constMethod()->has_method_parameters(); }
 571   int method_parameters_length() const
 572                          { return constMethod()->method_parameters_length(); }
 573   MethodParametersElement* method_parameters_start() const
 574                           { return constMethod()->method_parameters_start(); }
 575 
 576   // checked exceptions
 577   int checked_exceptions_length() const
 578                          { return constMethod()->checked_exceptions_length(); }
 579   CheckedExceptionElement* checked_exceptions_start() const
 580                           { return constMethod()->checked_exceptions_start(); }
 581 
 582   // localvariable table
 583   bool has_localvariable_table() const
 584                           { return constMethod()->has_localvariable_table(); }
 585   int localvariable_table_length() const
 586                         { return constMethod()->localvariable_table_length(); }
 587   LocalVariableTableElement* localvariable_table_start() const
 588                          { return constMethod()->localvariable_table_start(); }
 589 
 590   bool has_linenumber_table() const
 591                               { return constMethod()->has_linenumber_table(); }
 592   u_char* compressed_linenumber_table() const
 593                        { return constMethod()->compressed_linenumber_table(); }
 594 
 595   // method holder (the Klass* holding this method)
 596   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 597 
 598   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 599   Symbol* klass_name() const;                    // returns the name of the method holder
 600   BasicType result_type() const;                 // type of the method result
 601   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 602   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 603 
 604   // Checked exceptions thrown by this method (resolved to mirrors)
 605   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 606 
 607   // Access flags
 608   bool is_public() const                         { return access_flags().is_public();      }
 609   bool is_private() const                        { return access_flags().is_private();     }
 610   bool is_protected() const                      { return access_flags().is_protected();   }
 611   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 612   bool is_static() const                         { return access_flags().is_static();      }
 613   bool is_final() const                          { return access_flags().is_final();       }
 614   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 615   bool is_native() const                         { return access_flags().is_native();      }
 616   bool is_abstract() const                       { return access_flags().is_abstract();    }
 617   bool is_strict() const                         { return access_flags().is_strict();      }
 618   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 619 
 620   // returns true if contains only return operation
 621   bool is_empty_method() const;
 622 
 623   // returns true if this is a vanilla constructor
 624   bool is_vanilla_constructor() const;
 625 
 626   // checks method and its method holder
 627   bool is_final_method() const;
 628   bool is_final_method(AccessFlags class_access_flags) const;
 629   // interface method declared with 'default' - excludes private interface methods
 630   bool is_default_method() const;
 631 
 632   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 633   bool can_be_statically_bound() const;
 634   bool can_be_statically_bound(InstanceKlass* context) const;
 635   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 636 
 637   // returns true if the method has any backward branches.
 638   bool has_loops() {
 639     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 640   };
 641 
 642   bool compute_has_loops_flag();
 643 
 644   bool has_jsrs() {
 645     return access_flags().has_jsrs();
 646   };
 647   void set_has_jsrs() {
 648     _access_flags.set_has_jsrs();
 649   }
 650 
 651   // returns true if the method has any monitors.
 652   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 653   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 654 
 655   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 656 
 657   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 658   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 659   // has not been computed yet.
 660   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 661   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 662 
 663   // returns true if the method is an accessor function (setter/getter).
 664   bool is_accessor() const;
 665 
 666   // returns true if the method is a getter
 667   bool is_getter() const;
 668 
 669   // returns true if the method is a setter
 670   bool is_setter() const;
 671 
 672   // returns true if the method does nothing but return a constant of primitive type
 673   bool is_constant_getter() const;
 674 
 675   // returns true if the method is an initializer (<init> or <clinit>).
 676   bool is_initializer() const;
 677 
 678   // returns true if the method is static OR if the classfile version < 51
 679   bool has_valid_initializer_flags() const;
 680 
 681   // returns true if the method name is <clinit> and the method has
 682   // valid static initializer flags.
 683   bool is_static_initializer() const;
 684 
 685   // returns true if the method name is <init>
 686   bool is_object_initializer() const;
 687 
 688   // compiled code support
 689   // NOTE: code() is inherently racy as deopt can be clearing code
 690   // simultaneously. Use with caution.
 691   bool has_compiled_code() const;
 692 
 693 #ifdef TIERED
 694   bool has_aot_code() const                      { return aot_code() != NULL; }
 695 #endif
 696 
 697   bool needs_clinit_barrier() const;
 698 
 699   // sizing
 700   static int header_size()                       {
 701     return align_up((int)sizeof(Method), wordSize) / wordSize;
 702   }
 703   static int size(bool is_native);
 704   int size() const                               { return method_size(); }
 705 #if INCLUDE_SERVICES
 706   void collect_statistics(KlassSizeStats *sz) const;
 707 #endif
 708   void log_touched(TRAPS);
 709   static void print_touched_methods(outputStream* out);
 710 
 711   // interpreter support
 712   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 713   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 714   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 715   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 716   static ByteSize method_data_offset()           {
 717     return byte_offset_of(Method, _method_data);
 718   }
 719   static ByteSize method_counters_offset()       {
 720     return byte_offset_of(Method, _method_counters);
 721   }
 722 #ifndef PRODUCT
 723   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 724 #endif // not PRODUCT
 725   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 726   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 727   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 728   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 729   static ByteSize itable_index_offset()          { return byte_offset_of(Method, _vtable_index ); }
 730 
 731   // for code generation
 732   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 733   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 734   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 735 
 736   // Static methods that are used to implement member methods where an exposed this pointer
 737   // is needed due to possible GCs
 738   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 739 
 740   // Returns the byte code index from the byte code pointer
 741   int     bci_from(address bcp) const;
 742   address bcp_from(int bci) const;
 743   address bcp_from(address bcp) const;
 744   int validate_bci_from_bcp(address bcp) const;
 745   int validate_bci(int bci) const;
 746 
 747   // Returns the line number for a bci if debugging information for the method is prowided,
 748   // -1 is returned otherwise.
 749   int line_number_from_bci(int bci) const;
 750 
 751   // Reflection support
 752   bool is_overridden_in(Klass* k) const;
 753 
 754   // Stack walking support
 755   bool is_ignored_by_security_stack_walk() const;
 756 
 757   // JSR 292 support
 758   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 759   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 760   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 761   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 762                                                    Symbol* signature, //anything at all
 763                                                    TRAPS);
 764   static Klass* check_non_bcp_klass(Klass* klass);
 765 
 766   enum {
 767     // How many extra stack entries for invokedynamic
 768     extra_stack_entries_for_jsr292 = 1
 769   };
 770 
 771   // this operates only on invoke methods:
 772   // presize interpreter frames for extra interpreter stack entries, if needed
 773   // Account for the extra appendix argument for invokehandle/invokedynamic
 774   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 775   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 776 
 777   // RedefineClasses() support:
 778   bool is_old() const                               { return access_flags().is_old(); }
 779   void set_is_old()                                 { _access_flags.set_is_old(); }
 780   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 781   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 782   bool is_deleted() const                           { return access_flags().is_deleted(); }
 783   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 784 
 785   bool is_running_emcp() const {
 786     // EMCP methods are old but not obsolete or deleted. Equivalent
 787     // Modulo Constant Pool means the method is equivalent except
 788     // the constant pool and instructions that access the constant
 789     // pool might be different.
 790     // If a breakpoint is set in a redefined method, its EMCP methods that are
 791     // still running must have a breakpoint also.
 792     return (_flags & _running_emcp) != 0;
 793   }
 794 
 795   void set_running_emcp(bool x) {
 796     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 797   }
 798 
 799   bool on_stack() const                             { return access_flags().on_stack(); }
 800   void set_on_stack(const bool value);
 801 
 802   // see the definition in Method*.cpp for the gory details
 803   bool should_not_be_cached() const;
 804 
 805   // JVMTI Native method prefixing support:
 806   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 807   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 808 
 809   // Rewriting support
 810   static methodHandle clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
 811                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 812 
 813   // jmethodID handling
 814   // Because the useful life-span of a jmethodID cannot be determined,
 815   // once created they are never reclaimed.  The methods to which they refer,
 816   // however, can be GC'ed away if the class is unloaded or if the method is
 817   // made obsolete or deleted -- in these cases, the jmethodID
 818   // refers to NULL (as is the case for any weak reference).
 819   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 820   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 821 
 822   // Ensure there is enough capacity in the internal tracking data
 823   // structures to hold the number of jmethodIDs you plan to generate.
 824   // This saves substantial time doing allocations.
 825   static void ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity);
 826 
 827   // Use resolve_jmethod_id() in situations where the caller is expected
 828   // to provide a valid jmethodID; the only sanity checks are in asserts;
 829   // result guaranteed not to be NULL.
 830   inline static Method* resolve_jmethod_id(jmethodID mid) {
 831     assert(mid != NULL, "JNI method id should not be null");
 832     return *((Method**)mid);
 833   }
 834 
 835   // Use checked_resolve_jmethod_id() in situations where the caller
 836   // should provide a valid jmethodID, but might not. NULL is returned
 837   // when the jmethodID does not refer to a valid method.
 838   static Method* checked_resolve_jmethod_id(jmethodID mid);
 839 
 840   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 841   static bool is_method_id(jmethodID mid);
 842 
 843   // Clear methods
 844   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 845   static void print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 846 
 847   // Get this method's jmethodID -- allocate if it doesn't exist
 848   jmethodID jmethod_id()                            { return method_holder()->get_jmethod_id(this); }
 849 
 850   // Lookup the jmethodID for this method.  Return NULL if not found.
 851   // NOTE that this function can be called from a signal handler
 852   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 853   // needs to be async-safe. No allocation should be done and
 854   // so handles are not used to avoid deadlock.
 855   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 856 
 857   // Support for inlining of intrinsic methods
 858   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 859   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u2) id; }
 860 
 861   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 862   void init_intrinsic_id();     // updates from _none if a match
 863   static vmSymbols::SID klass_id_for_intrinsics(const Klass* holder);
 864 
 865   bool caller_sensitive() {
 866     return (_flags & _caller_sensitive) != 0;
 867   }
 868   void set_caller_sensitive(bool x) {
 869     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 870   }
 871 
 872   bool force_inline() {
 873     return (_flags & _force_inline) != 0;
 874   }
 875   void set_force_inline(bool x) {
 876     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 877   }
 878 
 879   bool dont_inline() {
 880     return (_flags & _dont_inline) != 0;
 881   }
 882   void set_dont_inline(bool x) {
 883     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 884   }
 885 
 886   bool is_hidden() {
 887     return (_flags & _hidden) != 0;
 888   }
 889   void set_hidden(bool x) {
 890     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 891   }
 892 
 893   bool intrinsic_candidate() {
 894     return (_flags & _intrinsic_candidate) != 0;
 895   }
 896   void set_intrinsic_candidate(bool x) {
 897     _flags = x ? (_flags | _intrinsic_candidate) : (_flags & ~_intrinsic_candidate);
 898   }
 899 
 900   bool has_injected_profile() {
 901     return (_flags & _has_injected_profile) != 0;
 902   }
 903   void set_has_injected_profile(bool x) {
 904     _flags = x ? (_flags | _has_injected_profile) : (_flags & ~_has_injected_profile);
 905   }
 906 
 907   bool has_reserved_stack_access() {
 908     return (_flags & _reserved_stack_access) != 0;
 909   }
 910 
 911   void set_has_reserved_stack_access(bool x) {
 912     _flags = x ? (_flags | _reserved_stack_access) : (_flags & ~_reserved_stack_access);
 913   }
 914 
 915   JFR_ONLY(DEFINE_TRACE_FLAG_ACCESSOR;)
 916 
 917   ConstMethod::MethodType method_type() const {
 918       return _constMethod->method_type();
 919   }
 920   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 921 
 922   // On-stack replacement support
 923   bool has_osr_nmethod(int level, bool match_level) {
 924    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 925   }
 926 
 927   int mark_osr_nmethods() {
 928     return method_holder()->mark_osr_nmethods(this);
 929   }
 930 
 931   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 932     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 933   }
 934 
 935   // Find if klass for method is loaded
 936   bool is_klass_loaded_by_klass_index(int klass_index) const;
 937   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 938 
 939   // Indicates whether compilation failed earlier for this method, or
 940   // whether it is not compilable for another reason like having a
 941   // breakpoint set in it.
 942   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 943   void set_not_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 944   void set_not_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 945     set_not_compilable(reason, comp_level, false);
 946   }
 947   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 948   void set_not_osr_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 949   void set_not_osr_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 950     set_not_osr_compilable(reason, comp_level, false);
 951   }
 952   bool is_always_compilable() const;
 953 
 954  private:
 955   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 956 
 957  public:
 958   MethodCounters* get_method_counters(TRAPS) {
 959     if (_method_counters == NULL) {
 960       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 961     }
 962     return _method_counters;
 963   }
 964 
 965   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 966   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 967   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 968   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 969   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 970   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 971 
 972   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 973   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 974   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 975   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 976   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 977   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 978 
 979   // Background compilation support
 980   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 981   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 982   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 983 
 984   // Resolve all classes in signature, return 'true' if successful
 985   static bool load_signature_classes(const methodHandle& m, TRAPS);
 986 
 987   // Return if true if not all classes references in signature, including return type, has been loaded
 988   static bool has_unloaded_classes_in_signature(const methodHandle& m, TRAPS);
 989 
 990   // Printing
 991   void print_short_name(outputStream* st = tty) const; // prints as klassname::methodname; Exposed so field engineers can debug VM
 992 #if INCLUDE_JVMTI
 993   void print_name(outputStream* st = tty) const; // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 994 #else
 995   void print_name(outputStream* st = tty) const  PRODUCT_RETURN; // prints as "virtual void foo(int)"
 996 #endif
 997 
 998   // Helper routine used for method sorting
 999   static void sort_methods(Array<Method*>* methods, bool set_idnums = true);
1000 
1001   // Deallocation function for redefine classes or if an error occurs
1002   void deallocate_contents(ClassLoaderData* loader_data);
1003 
1004   Method* get_new_method() const {
1005     InstanceKlass* holder = method_holder();
1006     Method* new_method = holder->method_with_idnum(orig_method_idnum());
1007 
1008     assert(new_method != NULL, "method_with_idnum() should not be NULL");
1009     assert(this != new_method, "sanity check");
1010     return new_method;
1011   }
1012 
1013   // Printing
1014 #ifndef PRODUCT
1015   void print_on(outputStream* st) const;
1016 #endif
1017   void print_value_on(outputStream* st) const;
1018   void print_linkage_flags(outputStream* st) PRODUCT_RETURN;
1019 
1020   const char* internal_name() const { return "{method}"; }
1021 
1022   // Check for valid method pointer
1023   static bool has_method_vptr(const void* ptr);
1024   static bool is_valid_method(const Method* m);
1025 
1026   // Verify
1027   void verify() { verify_on(tty); }
1028   void verify_on(outputStream* st);
1029 
1030  private:
1031 
1032   // Inlined elements
1033   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
1034   address* signature_handler_addr() const        { return native_function_addr() + 1; }
1035 
1036   void set_num_stack_arg_slots();
1037 };
1038 
1039 
1040 // Utility class for compressing line number tables
1041 
1042 class CompressedLineNumberWriteStream: public CompressedWriteStream {
1043  private:
1044   int _bci;
1045   int _line;
1046  public:
1047   // Constructor
1048   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
1049   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
1050 
1051   // Write (bci, line number) pair to stream
1052   void write_pair_regular(int bci_delta, int line_delta);
1053 
1054   // If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1055   // we save it as one byte, otherwise we write a 0xFF escape character
1056   // and use regular compression. 0x0 is used as end-of-stream terminator.
1057   void write_pair_inline(int bci, int line);
1058 
1059   void write_pair(int bci, int line);
1060 
1061   // Write end-of-stream marker
1062   void write_terminator()                        { write_byte(0); }
1063 };
1064 
1065 
1066 // Utility class for decompressing line number tables
1067 
1068 class CompressedLineNumberReadStream: public CompressedReadStream {
1069  private:
1070   int _bci;
1071   int _line;
1072  public:
1073   // Constructor
1074   CompressedLineNumberReadStream(u_char* buffer);
1075   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1076   bool read_pair();
1077   // Accessing bci and line number (after calling read_pair)
1078   int bci() const                               { return _bci; }
1079   int line() const                              { return _line; }
1080 };
1081 
1082 
1083 #if INCLUDE_JVMTI
1084 
1085 /// Fast Breakpoints.
1086 
1087 // If this structure gets more complicated (because bpts get numerous),
1088 // move it into its own header.
1089 
1090 // There is presently no provision for concurrent access
1091 // to breakpoint lists, which is only OK for JVMTI because
1092 // breakpoints are written only at safepoints, and are read
1093 // concurrently only outside of safepoints.
1094 
1095 class BreakpointInfo : public CHeapObj<mtClass> {
1096   friend class VMStructs;
1097  private:
1098   Bytecodes::Code  _orig_bytecode;
1099   int              _bci;
1100   u2               _name_index;       // of method
1101   u2               _signature_index;  // of method
1102   BreakpointInfo*  _next;             // simple storage allocation
1103 
1104  public:
1105   BreakpointInfo(Method* m, int bci);
1106 
1107   // accessors
1108   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1109   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1110   int         bci()                                   { return _bci; }
1111 
1112   BreakpointInfo*          next() const               { return _next; }
1113   void                 set_next(BreakpointInfo* n)    { _next = n; }
1114 
1115   // helps for searchers
1116   bool match(const Method* m, int bci) {
1117     return bci == _bci && match(m);
1118   }
1119 
1120   bool match(const Method* m) {
1121     return _name_index == m->name_index() &&
1122       _signature_index == m->signature_index();
1123   }
1124 
1125   void set(Method* method);
1126   void clear(Method* method);
1127 };
1128 
1129 #endif // INCLUDE_JVMTI
1130 
1131 // Utility class for access exception handlers
1132 class ExceptionTable : public StackObj {
1133  private:
1134   ExceptionTableElement* _table;
1135   u2  _length;
1136 
1137  public:
1138   ExceptionTable(const Method* m) {
1139     if (m->has_exception_handler()) {
1140       _table = m->exception_table_start();
1141       _length = m->exception_table_length();
1142     } else {
1143       _table = NULL;
1144       _length = 0;
1145     }
1146   }
1147 
1148   int length() const {
1149     return _length;
1150   }
1151 
1152   u2 start_pc(int idx) const {
1153     assert(idx < _length, "out of bounds");
1154     return _table[idx].start_pc;
1155   }
1156 
1157   void set_start_pc(int idx, u2 value) {
1158     assert(idx < _length, "out of bounds");
1159     _table[idx].start_pc = value;
1160   }
1161 
1162   u2 end_pc(int idx) const {
1163     assert(idx < _length, "out of bounds");
1164     return _table[idx].end_pc;
1165   }
1166 
1167   void set_end_pc(int idx, u2 value) {
1168     assert(idx < _length, "out of bounds");
1169     _table[idx].end_pc = value;
1170   }
1171 
1172   u2 handler_pc(int idx) const {
1173     assert(idx < _length, "out of bounds");
1174     return _table[idx].handler_pc;
1175   }
1176 
1177   void set_handler_pc(int idx, u2 value) {
1178     assert(idx < _length, "out of bounds");
1179     _table[idx].handler_pc = value;
1180   }
1181 
1182   u2 catch_type_index(int idx) const {
1183     assert(idx < _length, "out of bounds");
1184     return _table[idx].catch_type_index;
1185   }
1186 
1187   void set_catch_type_index(int idx, u2 value) {
1188     assert(idx < _length, "out of bounds");
1189     _table[idx].catch_type_index = value;
1190   }
1191 };
1192 
1193 #endif // SHARE_OOPS_METHOD_HPP