1 /*
   2  * Copyright (c) 1997, 2020, 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 CompiledMethod;
  68 class InterpreterOopMap;
  69 
  70 class Method : public Metadata {
  71  friend class VMStructs;
  72  friend class JVMCIVMStructs;
  73  private:
  74   // If you add a new field that points to any metaspace object, you
  75   // must add this field to Method::metaspace_pointers_do().
  76   ConstMethod*      _constMethod;                // Method read-only data.
  77   MethodData*       _method_data;
  78   MethodCounters*   _method_counters;
  79   AccessFlags       _access_flags;               // Access flags
  80   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  81                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  82   u2                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  83 
  84   // Flags
  85   enum Flags {
  86     _caller_sensitive      = 1 << 0,
  87     _force_inline          = 1 << 1,
  88     _dont_inline           = 1 << 2,
  89     _hidden                = 1 << 3,
  90     _has_injected_profile  = 1 << 4,
  91     _running_emcp          = 1 << 5,
  92     _intrinsic_candidate   = 1 << 6,
  93     _reserved_stack_access = 1 << 7
  94   };
  95   mutable u2 _flags;
  96 
  97   JFR_ONLY(DEFINE_TRACE_FLAG;)
  98 
  99 #ifndef PRODUCT
 100   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 101 #endif
 102   // Entry point for calling both from and to the interpreter.
 103   address _i2i_entry;           // All-args-on-stack calling convention
 104   // Entry point for calling from compiled code, to compiled code if it exists
 105   // or else the interpreter.
 106   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 107   // The entry point for calling both from and to compiled code is
 108   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 109   // field can come and go.  It can transition from NULL to not-null at any
 110   // time (whenever a compile completes).  It can transition from not-null to
 111   // NULL only at safepoints (because of a de-opt).
 112   CompiledMethod* volatile _code;                       // Points to the corresponding piece of native code
 113   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 114 
 115 #if INCLUDE_AOT && defined(TIERED)
 116   CompiledMethod* _aot_code;
 117 #endif
 118 
 119   // Constructor
 120   Method(ConstMethod* xconst, AccessFlags access_flags);
 121  public:
 122 
 123   static Method* allocate(ClassLoaderData* loader_data,
 124                           int byte_code_size,
 125                           AccessFlags access_flags,
 126                           InlineTableSizes* sizes,
 127                           ConstMethod::MethodType method_type,
 128                           TRAPS);
 129 
 130   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 131   Method(){}
 132 
 133   bool is_method() const volatile { return true; }
 134 
 135   void restore_unshareable_info(TRAPS);
 136 
 137   // accessors for instance variables
 138 
 139   ConstMethod* constMethod() const             { return _constMethod; }
 140   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 141 
 142 
 143   static address make_adapters(const methodHandle& mh, TRAPS);
 144   address from_compiled_entry() const;
 145   address from_compiled_entry_no_trampoline() const;
 146   address from_interpreted_entry() const;
 147 
 148   // access flag
 149   AccessFlags access_flags() const               { return _access_flags;  }
 150   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 151 
 152   // name
 153   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 154   int name_index() const                         { return constMethod()->name_index();         }
 155   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 156 
 157   // signature
 158   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 159   int signature_index() const                    { return constMethod()->signature_index();         }
 160   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 161 
 162   // generics support
 163   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 164   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 165   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 166 
 167   // annotations support
 168   AnnotationArray* annotations() const           {
 169     return constMethod()->method_annotations();
 170   }
 171   AnnotationArray* parameter_annotations() const {
 172     return constMethod()->parameter_annotations();
 173   }
 174   AnnotationArray* annotation_default() const    {
 175     return constMethod()->default_annotations();
 176   }
 177   AnnotationArray* type_annotations() const      {
 178     return constMethod()->type_annotations();
 179   }
 180 
 181   // Helper routine: get klass name + "." + method name + signature as
 182   // C string, for the purpose of providing more useful
 183   // fatal error handling. The string is allocated in resource
 184   // area if a buffer is not provided by the caller.
 185   char* name_and_sig_as_C_string() const;
 186   char* name_and_sig_as_C_string(char* buf, int size) const;
 187 
 188   // Static routine in the situations we don't have a Method*
 189   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 190   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 191 
 192   // Get return type + klass name + "." + method name + ( parameters types )
 193   // as a C string or print it to an outputStream.
 194   // This is to be used to assemble strings passed to Java, so that
 195   // the text more resembles Java code. Used in exception messages.
 196   // Memory is allocated in the resource area; the caller needs
 197   // a ResourceMark.
 198   const char* external_name() const;
 199   void  print_external_name(outputStream *os) const;
 200 
 201   static const char* external_name(                  Klass* klass, Symbol* method_name, Symbol* signature);
 202   static void  print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature);
 203 
 204   Bytecodes::Code java_code_at(int bci) const {
 205     return Bytecodes::java_code_at(this, bcp_from(bci));
 206   }
 207   Bytecodes::Code code_at(int bci) const {
 208     return Bytecodes::code_at(this, bcp_from(bci));
 209   }
 210 
 211   // JVMTI breakpoints
 212 #if !INCLUDE_JVMTI
 213   Bytecodes::Code orig_bytecode_at(int bci) const {
 214     ShouldNotReachHere();
 215     return Bytecodes::_shouldnotreachhere;
 216   }
 217   void set_orig_bytecode_at(int bci, Bytecodes::Code code) {
 218     ShouldNotReachHere();
 219   };
 220   u2   number_of_breakpoints() const {return 0;}
 221 #else // !INCLUDE_JVMTI
 222   Bytecodes::Code orig_bytecode_at(int bci) const;
 223   void set_orig_bytecode_at(int bci, Bytecodes::Code code);
 224   void set_breakpoint(int bci);
 225   void clear_breakpoint(int bci);
 226   void clear_all_breakpoints();
 227   // Tracking number of breakpoints, for fullspeed debugging.
 228   // Only mutated by VM thread.
 229   u2   number_of_breakpoints()             const {
 230     MethodCounters* mcs = method_counters();
 231     if (mcs == NULL) {
 232       return 0;
 233     } else {
 234       return mcs->number_of_breakpoints();
 235     }
 236   }
 237   void incr_number_of_breakpoints(TRAPS)         {
 238     MethodCounters* mcs = get_method_counters(CHECK);
 239     if (mcs != NULL) {
 240       mcs->incr_number_of_breakpoints();
 241     }
 242   }
 243   void decr_number_of_breakpoints(TRAPS)         {
 244     MethodCounters* mcs = get_method_counters(CHECK);
 245     if (mcs != NULL) {
 246       mcs->decr_number_of_breakpoints();
 247     }
 248   }
 249   // Initialization only
 250   void clear_number_of_breakpoints()             {
 251     MethodCounters* mcs = method_counters();
 252     if (mcs != NULL) {
 253       mcs->clear_number_of_breakpoints();
 254     }
 255   }
 256 #endif // !INCLUDE_JVMTI
 257 
 258   // index into InstanceKlass methods() array
 259   // note: also used by jfr
 260   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 261   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 262 
 263   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 264   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 265 
 266   // code size
 267   int code_size() const                  { return constMethod()->code_size(); }
 268 
 269   // method size in words
 270   int method_size() const                { return sizeof(Method)/wordSize + ( is_native() ? 2 : 0 ); }
 271 
 272   // constant pool for Klass* holding this method
 273   ConstantPool* constants() const              { return constMethod()->constants(); }
 274   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 275 
 276   // max stack
 277   // return original max stack size for method verification
 278   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 279   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 280   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 281 
 282   // max locals
 283   int  max_locals() const                        { return constMethod()->max_locals(); }
 284   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 285 
 286   int highest_comp_level() const;
 287   void set_highest_comp_level(int level);
 288   int highest_osr_comp_level() const;
 289   void set_highest_osr_comp_level(int level);
 290 
 291 #if COMPILER2_OR_JVMCI
 292   // Count of times method was exited via exception while interpreting
 293   void interpreter_throwout_increment(TRAPS) {
 294     MethodCounters* mcs = get_method_counters(CHECK);
 295     if (mcs != NULL) {
 296       mcs->interpreter_throwout_increment();
 297     }
 298   }
 299 #endif
 300 
 301   int  interpreter_throwout_count() const        {
 302     MethodCounters* mcs = method_counters();
 303     if (mcs == NULL) {
 304       return 0;
 305     } else {
 306       return mcs->interpreter_throwout_count();
 307     }
 308   }
 309 
 310   // Derive stuff from the signature at load time.
 311   void compute_from_signature(Symbol* sig);
 312 
 313   // size of parameters (receiver if any + arguments)
 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   static bool register_native(Klass* k,
 352                               Symbol* name,
 353                               Symbol* signature,
 354                               address entry,
 355                               TRAPS);
 356 
 357   // method data access
 358   MethodData* method_data() const              {
 359     return _method_data;
 360   }
 361 
 362   void set_method_data(MethodData* data);
 363 
 364   MethodCounters* method_counters() const {
 365     return _method_counters;
 366   }
 367 
 368   void clear_method_counters() {
 369     _method_counters = NULL;
 370   }
 371 
 372   bool init_method_counters(MethodCounters* counters);
 373 
 374 #ifdef TIERED
 375   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 376   // We can do that since interpreter_invocation_count is not used in tiered.
 377   int prev_event_count() const                   {
 378     if (method_counters() == NULL) {
 379       return 0;
 380     } else {
 381       return method_counters()->interpreter_invocation_count();
 382     }
 383   }
 384   void set_prev_event_count(int count) {
 385     MethodCounters* mcs = method_counters();
 386     if (mcs != NULL) {
 387       mcs->set_interpreter_invocation_count(count);
 388     }
 389   }
 390   jlong prev_time() const                        {
 391     MethodCounters* mcs = method_counters();
 392     return mcs == NULL ? 0 : mcs->prev_time();
 393   }
 394   void set_prev_time(jlong time) {
 395     MethodCounters* mcs = method_counters();
 396     if (mcs != NULL) {
 397       mcs->set_prev_time(time);
 398     }
 399   }
 400   float rate() const                             {
 401     MethodCounters* mcs = method_counters();
 402     return mcs == NULL ? 0 : mcs->rate();
 403   }
 404   void set_rate(float rate) {
 405     MethodCounters* mcs = method_counters();
 406     if (mcs != NULL) {
 407       mcs->set_rate(rate);
 408     }
 409   }
 410 
 411 #if INCLUDE_AOT
 412   void set_aot_code(CompiledMethod* aot_code) {
 413     _aot_code = aot_code;
 414   }
 415 
 416   CompiledMethod* aot_code() const {
 417     return _aot_code;
 418   }
 419 #else
 420   CompiledMethod* aot_code() const { return NULL; }
 421 #endif // INCLUDE_AOT
 422 #endif // TIERED
 423 
 424   int nmethod_age() const {
 425     if (method_counters() == NULL) {
 426       return INT_MAX;
 427     } else {
 428       return method_counters()->nmethod_age();
 429     }
 430   }
 431 
 432   int invocation_count();
 433   int backedge_count();
 434 
 435   bool was_executed_more_than(int n);
 436   bool was_never_executed()                      { return !was_executed_more_than(0); }
 437 
 438   static void build_interpreter_method_data(const methodHandle& method, TRAPS);
 439 
 440   static MethodCounters* build_method_counters(Method* m, TRAPS);
 441 
 442   int interpreter_invocation_count() {
 443     if (TieredCompilation) {
 444       return invocation_count();
 445     } else {
 446       MethodCounters* mcs = method_counters();
 447       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 448     }
 449   }
 450 #if COMPILER2_OR_JVMCI
 451   int increment_interpreter_invocation_count(TRAPS) {
 452     if (TieredCompilation) ShouldNotReachHere();
 453     MethodCounters* mcs = get_method_counters(CHECK_0);
 454     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 455   }
 456 #endif
 457 
 458 #ifndef PRODUCT
 459   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 460   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 461 #else
 462   // for PrintMethodData in a product build
 463   int  compiled_invocation_count() const         { return 0;  }
 464 #endif // not PRODUCT
 465 
 466   // Clear (non-shared space) pointers which could not be relevant
 467   // if this (shared) method were mapped into another JVM.
 468   void remove_unshareable_info();
 469 
 470   // nmethod/verified compiler entry
 471   address verified_code_entry();
 472   bool check_code() const;      // Not inline to avoid circular ref
 473   CompiledMethod* volatile code() const;
 474 
 475   // Locks CompiledMethod_lock if not held.
 476   void unlink_code(CompiledMethod *compare);
 477   // Locks CompiledMethod_lock if not held.
 478   void unlink_code();
 479 
 480 private:
 481   // Either called with CompiledMethod_lock held or from constructor.
 482   void clear_code();
 483 
 484 public:
 485   static void set_code(const methodHandle& mh, CompiledMethod* code);
 486   void set_adapter_entry(AdapterHandlerEntry* adapter) {
 487     constMethod()->set_adapter_entry(adapter);
 488   }
 489   void set_adapter_trampoline(AdapterHandlerEntry** trampoline) {
 490     constMethod()->set_adapter_trampoline(trampoline);
 491   }
 492   void update_adapter_trampoline(AdapterHandlerEntry* adapter) {
 493     constMethod()->update_adapter_trampoline(adapter);
 494   }
 495   void set_from_compiled_entry(address entry) {
 496     _from_compiled_entry =  entry;
 497   }
 498 
 499   address get_i2c_entry();
 500   address get_c2i_entry();
 501   address get_c2i_unverified_entry();
 502   address get_c2i_no_clinit_check_entry();
 503   AdapterHandlerEntry* adapter() const {
 504     return constMethod()->adapter();
 505   }
 506   // setup entry points
 507   void link_method(const methodHandle& method, TRAPS);
 508   // clear entry points. Used by sharing code during dump time
 509   void unlink_method() NOT_CDS_RETURN;
 510 
 511   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 512   virtual MetaspaceObj::Type type() const { return MethodType; }
 513 
 514   // vtable index
 515   enum VtableIndexFlag {
 516     // Valid vtable indexes are non-negative (>= 0).
 517     // These few negative values are used as sentinels.
 518     itable_index_max        = -10, // first itable index, growing downward
 519     pending_itable_index    = -9,  // itable index will be assigned
 520     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 521     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 522     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 523     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 524   };
 525   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 526   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 527   int  vtable_index() const                      { return _vtable_index; }
 528   void set_vtable_index(int index);
 529   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 530   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 531   int  itable_index() const                      { assert(valid_itable_index(), "");
 532                                                    return itable_index_max - _vtable_index; }
 533   void set_itable_index(int index);
 534 
 535   // interpreter entry
 536   address interpreter_entry() const              { return _i2i_entry; }
 537   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 538   void set_interpreter_entry(address entry) {
 539     assert(!is_shared(),
 540            "shared method's interpreter entry should not be changed at run time");
 541     if (_i2i_entry != entry) {
 542       _i2i_entry = entry;
 543     }
 544     if (_from_interpreted_entry != entry) {
 545       _from_interpreted_entry = entry;
 546     }
 547   }
 548 
 549   // native function (used for native methods only)
 550   enum {
 551     native_bind_event_is_interesting = true
 552   };
 553   address native_function() const                { return *(native_function_addr()); }
 554 
 555   // Must specify a real function (not NULL).
 556   // Use clear_native_function() to unregister.
 557   void set_native_function(address function, bool post_event_flag);
 558   bool has_native_function() const;
 559   void clear_native_function();
 560 
 561   // signature handler (used for native methods only)
 562   address signature_handler() const              { return *(signature_handler_addr()); }
 563   void set_signature_handler(address handler);
 564 
 565   // Interpreter oopmap support
 566   void mask_for(int bci, InterpreterOopMap* mask);
 567 
 568   // operations on invocation counter
 569   void print_invocation_count();
 570 
 571   // byte codes
 572   void    set_code(address code)      { return constMethod()->set_code(code); }
 573   address code_base() const           { return constMethod()->code_base(); }
 574   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 575 
 576   // prints byte codes
 577   void print_codes() const            { print_codes_on(tty); }
 578   void print_codes_on(outputStream* st) const;
 579   void print_codes_on(int from, int to, outputStream* st) const;
 580 
 581   // method parameters
 582   bool has_method_parameters() const
 583                          { return constMethod()->has_method_parameters(); }
 584   int method_parameters_length() const
 585                          { return constMethod()->method_parameters_length(); }
 586   MethodParametersElement* method_parameters_start() const
 587                           { return constMethod()->method_parameters_start(); }
 588 
 589   // checked exceptions
 590   int checked_exceptions_length() const
 591                          { return constMethod()->checked_exceptions_length(); }
 592   CheckedExceptionElement* checked_exceptions_start() const
 593                           { return constMethod()->checked_exceptions_start(); }
 594 
 595   // localvariable table
 596   bool has_localvariable_table() const
 597                           { return constMethod()->has_localvariable_table(); }
 598   int localvariable_table_length() const
 599                         { return constMethod()->localvariable_table_length(); }
 600   LocalVariableTableElement* localvariable_table_start() const
 601                          { return constMethod()->localvariable_table_start(); }
 602 
 603   bool has_linenumber_table() const
 604                               { return constMethod()->has_linenumber_table(); }
 605   u_char* compressed_linenumber_table() const
 606                        { return constMethod()->compressed_linenumber_table(); }
 607 
 608   // method holder (the Klass* holding this method)
 609   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 610 
 611   Symbol* klass_name() const;                    // returns the name of the method holder
 612   BasicType result_type() const                  { return constMethod()->result_type(); }
 613   bool is_returning_oop() const                  { BasicType r = result_type(); return is_reference_type(r); }
 614   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 615 
 616   // Checked exceptions thrown by this method (resolved to mirrors)
 617   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 618 
 619   // Access flags
 620   bool is_public() const                         { return access_flags().is_public();      }
 621   bool is_private() const                        { return access_flags().is_private();     }
 622   bool is_protected() const                      { return access_flags().is_protected();   }
 623   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 624   bool is_static() const                         { return access_flags().is_static();      }
 625   bool is_final() const                          { return access_flags().is_final();       }
 626   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 627   bool is_native() const                         { return access_flags().is_native();      }
 628   bool is_abstract() const                       { return access_flags().is_abstract();    }
 629   bool is_strict() const                         { return access_flags().is_strict();      }
 630   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 631 
 632   // returns true if contains only return operation
 633   bool is_empty_method() const;
 634 
 635   // returns true if this is a vanilla constructor
 636   bool is_vanilla_constructor() const;
 637 
 638   // checks method and its method holder
 639   bool is_final_method() const;
 640   bool is_final_method(AccessFlags class_access_flags) const;
 641   // interface method declared with 'default' - excludes private interface methods
 642   bool is_default_method() const;
 643 
 644   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 645   bool can_be_statically_bound() const;
 646   bool can_be_statically_bound(InstanceKlass* context) const;
 647   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 648 
 649   // returns true if the method has any backward branches.
 650   bool has_loops() {
 651     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 652   };
 653 
 654   bool compute_has_loops_flag();
 655 
 656   bool has_jsrs() {
 657     return access_flags().has_jsrs();
 658   };
 659   void set_has_jsrs() {
 660     _access_flags.set_has_jsrs();
 661   }
 662 
 663   // returns true if the method has any monitors.
 664   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 665   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 666 
 667   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 668 
 669   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 670   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 671   // has not been computed yet.
 672   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 673   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 674 
 675   // returns true if the method is an accessor function (setter/getter).
 676   bool is_accessor() const;
 677 
 678   // returns true if the method is a getter
 679   bool is_getter() const;
 680 
 681   // returns true if the method is a setter
 682   bool is_setter() const;
 683 
 684   // returns true if the method does nothing but return a constant of primitive type
 685   bool is_constant_getter() const;
 686 
 687   // returns true if the method is an initializer (<init> or <clinit>).
 688   bool is_initializer() const;
 689 
 690   // returns true if the method is static OR if the classfile version < 51
 691   bool has_valid_initializer_flags() const;
 692 
 693   // returns true if the method name is <clinit> and the method has
 694   // valid static initializer flags.
 695   bool is_static_initializer() const;
 696 
 697   // returns true if the method name is <init>
 698   bool is_object_initializer() const;
 699 
 700   // compiled code support
 701   // NOTE: code() is inherently racy as deopt can be clearing code
 702   // simultaneously. Use with caution.
 703   bool has_compiled_code() const;
 704 
 705 #ifdef TIERED
 706   bool has_aot_code() const                      { return aot_code() != NULL; }
 707 #endif
 708 
 709   bool needs_clinit_barrier() const;
 710 
 711   // sizing
 712   static int header_size()                       {
 713     return align_up((int)sizeof(Method), wordSize) / wordSize;
 714   }
 715   static int size(bool is_native);
 716   int size() const                               { return method_size(); }
 717   void log_touched(TRAPS);
 718   static void print_touched_methods(outputStream* out);
 719 
 720   // interpreter support
 721   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 722   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 723   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 724   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 725   static ByteSize method_data_offset()           {
 726     return byte_offset_of(Method, _method_data);
 727   }
 728   static ByteSize method_counters_offset()       {
 729     return byte_offset_of(Method, _method_counters);
 730   }
 731 #ifndef PRODUCT
 732   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 733 #endif // not PRODUCT
 734   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 735   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 736   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 737   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 738   static ByteSize itable_index_offset()          { return byte_offset_of(Method, _vtable_index ); }
 739 
 740   // for code generation
 741   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 742   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 743   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 744 
 745   // Static methods that are used to implement member methods where an exposed this pointer
 746   // is needed due to possible GCs
 747   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 748 
 749   // Returns the byte code index from the byte code pointer
 750   int     bci_from(address bcp) const;
 751   address bcp_from(int bci) const;
 752   address bcp_from(address bcp) const;
 753   int validate_bci_from_bcp(address bcp) const;
 754   int validate_bci(int bci) const;
 755 
 756   // Returns the line number for a bci if debugging information for the method is prowided,
 757   // -1 is returned otherwise.
 758   int line_number_from_bci(int bci) const;
 759 
 760   // Reflection support
 761   bool is_overridden_in(Klass* k) const;
 762 
 763   // Stack walking support
 764   bool is_ignored_by_security_stack_walk() const;
 765 
 766   // JSR 292 support
 767   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 768   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 769   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 770   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 771                                                    Symbol* signature, //anything at all
 772                                                    TRAPS);
 773   static Klass* check_non_bcp_klass(Klass* klass);
 774 
 775   enum {
 776     // How many extra stack entries for invokedynamic
 777     extra_stack_entries_for_jsr292 = 1
 778   };
 779 
 780   // this operates only on invoke methods:
 781   // presize interpreter frames for extra interpreter stack entries, if needed
 782   // Account for the extra appendix argument for invokehandle/invokedynamic
 783   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 784   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 785 
 786   // RedefineClasses() support:
 787   bool is_old() const                               { return access_flags().is_old(); }
 788   void set_is_old()                                 { _access_flags.set_is_old(); }
 789   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 790   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 791   bool is_deleted() const                           { return access_flags().is_deleted(); }
 792   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 793 
 794   bool is_running_emcp() const {
 795     // EMCP methods are old but not obsolete or deleted. Equivalent
 796     // Modulo Constant Pool means the method is equivalent except
 797     // the constant pool and instructions that access the constant
 798     // pool might be different.
 799     // If a breakpoint is set in a redefined method, its EMCP methods that are
 800     // still running must have a breakpoint also.
 801     return (_flags & _running_emcp) != 0;
 802   }
 803 
 804   void set_running_emcp(bool x) {
 805     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 806   }
 807 
 808   bool on_stack() const                             { return access_flags().on_stack(); }
 809   void set_on_stack(const bool value);
 810 
 811   // see the definition in Method*.cpp for the gory details
 812   bool should_not_be_cached() const;
 813 
 814   // JVMTI Native method prefixing support:
 815   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 816   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 817 
 818   // Rewriting support
 819   static methodHandle clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
 820                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 821 
 822   // jmethodID handling
 823   // Because the useful life-span of a jmethodID cannot be determined,
 824   // once created they are never reclaimed.  The methods to which they refer,
 825   // however, can be GC'ed away if the class is unloaded or if the method is
 826   // made obsolete or deleted -- in these cases, the jmethodID
 827   // refers to NULL (as is the case for any weak reference).
 828   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 829   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 830 
 831   // Ensure there is enough capacity in the internal tracking data
 832   // structures to hold the number of jmethodIDs you plan to generate.
 833   // This saves substantial time doing allocations.
 834   static void ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity);
 835 
 836   // Use resolve_jmethod_id() in situations where the caller is expected
 837   // to provide a valid jmethodID; the only sanity checks are in asserts;
 838   // result guaranteed not to be NULL.
 839   inline static Method* resolve_jmethod_id(jmethodID mid) {
 840     assert(mid != NULL, "JNI method id should not be null");
 841     return *((Method**)mid);
 842   }
 843 
 844   // Use checked_resolve_jmethod_id() in situations where the caller
 845   // should provide a valid jmethodID, but might not. NULL is returned
 846   // when the jmethodID does not refer to a valid method.
 847   static Method* checked_resolve_jmethod_id(jmethodID mid);
 848 
 849   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 850   static bool is_method_id(jmethodID mid);
 851 
 852   // Clear methods
 853   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 854   static void print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 855 
 856   // Get this method's jmethodID -- allocate if it doesn't exist
 857   jmethodID jmethod_id();
 858 
 859   // Lookup the jmethodID for this method.  Return NULL if not found.
 860   // NOTE that this function can be called from a signal handler
 861   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 862   // needs to be async-safe. No allocation should be done and
 863   // so handles are not used to avoid deadlock.
 864   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 865 
 866   // Support for inlining of intrinsic methods
 867   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 868   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u2) id; }
 869 
 870   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 871   void init_intrinsic_id();     // updates from _none if a match
 872   static vmSymbols::SID klass_id_for_intrinsics(const Klass* holder);
 873 
 874   bool caller_sensitive() {
 875     return (_flags & _caller_sensitive) != 0;
 876   }
 877   void set_caller_sensitive(bool x) {
 878     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 879   }
 880 
 881   bool force_inline() {
 882     return (_flags & _force_inline) != 0;
 883   }
 884   void set_force_inline(bool x) {
 885     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 886   }
 887 
 888   bool dont_inline() {
 889     return (_flags & _dont_inline) != 0;
 890   }
 891   void set_dont_inline(bool x) {
 892     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 893   }
 894 
 895   bool is_hidden() {
 896     return (_flags & _hidden) != 0;
 897   }
 898   void set_hidden(bool x) {
 899     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 900   }
 901 
 902   bool intrinsic_candidate() {
 903     return (_flags & _intrinsic_candidate) != 0;
 904   }
 905   void set_intrinsic_candidate(bool x) {
 906     _flags = x ? (_flags | _intrinsic_candidate) : (_flags & ~_intrinsic_candidate);
 907   }
 908 
 909   bool has_injected_profile() {
 910     return (_flags & _has_injected_profile) != 0;
 911   }
 912   void set_has_injected_profile(bool x) {
 913     _flags = x ? (_flags | _has_injected_profile) : (_flags & ~_has_injected_profile);
 914   }
 915 
 916   bool has_reserved_stack_access() {
 917     return (_flags & _reserved_stack_access) != 0;
 918   }
 919 
 920   void set_has_reserved_stack_access(bool x) {
 921     _flags = x ? (_flags | _reserved_stack_access) : (_flags & ~_reserved_stack_access);
 922   }
 923 
 924   JFR_ONLY(DEFINE_TRACE_FLAG_ACCESSOR;)
 925 
 926   ConstMethod::MethodType method_type() const {
 927       return _constMethod->method_type();
 928   }
 929   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 930 
 931   // On-stack replacement support
 932   bool has_osr_nmethod(int level, bool match_level) {
 933    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 934   }
 935 
 936   int mark_osr_nmethods() {
 937     return method_holder()->mark_osr_nmethods(this);
 938   }
 939 
 940   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 941     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 942   }
 943 
 944   // Find if klass for method is loaded
 945   bool is_klass_loaded_by_klass_index(int klass_index) const;
 946   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 947 
 948   // Indicates whether compilation failed earlier for this method, or
 949   // whether it is not compilable for another reason like having a
 950   // breakpoint set in it.
 951   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 952   void set_not_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 953   void set_not_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 954     set_not_compilable(reason, comp_level, false);
 955   }
 956   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 957   void set_not_osr_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 958   void set_not_osr_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 959     set_not_osr_compilable(reason, comp_level, false);
 960   }
 961   bool is_always_compilable() const;
 962 
 963  private:
 964   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 965 
 966  public:
 967   MethodCounters* get_method_counters(TRAPS) {
 968     if (_method_counters == NULL) {
 969       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 970     }
 971     return _method_counters;
 972   }
 973 
 974   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 975   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 976   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 977   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 978   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 979   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 980 
 981   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 982   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 983   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 984   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 985   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 986   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 987 
 988   // Background compilation support
 989   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 990   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 991   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 992 
 993   // Resolve all classes in signature, return 'true' if successful
 994   static bool load_signature_classes(const methodHandle& m, TRAPS);
 995 
 996   // Return if true if not all classes references in signature, including return type, has been loaded
 997   static bool has_unloaded_classes_in_signature(const methodHandle& m, TRAPS);
 998 
 999   // Printing
1000   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
1001 #if INCLUDE_JVMTI
1002   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
1003 #else
1004   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
1005 #endif
1006 
1007   typedef int (*method_comparator_func)(Method* a, Method* b);
1008 
1009   // Helper routine used for method sorting
1010   static void sort_methods(Array<Method*>* methods, bool set_idnums = true, method_comparator_func func = NULL);
1011 
1012   // Deallocation function for redefine classes or if an error occurs
1013   void deallocate_contents(ClassLoaderData* loader_data);
1014 
1015   void release_C_heap_structures();
1016 
1017   Method* get_new_method() const {
1018     InstanceKlass* holder = method_holder();
1019     Method* new_method = holder->method_with_idnum(orig_method_idnum());
1020 
1021     assert(new_method != NULL, "method_with_idnum() should not be NULL");
1022     assert(this != new_method, "sanity check");
1023     return new_method;
1024   }
1025 
1026   // Printing
1027 #ifndef PRODUCT
1028   void print_on(outputStream* st) const;
1029 #endif
1030   void print_value_on(outputStream* st) const;
1031   void print_linkage_flags(outputStream* st) PRODUCT_RETURN;
1032 
1033   const char* internal_name() const { return "{method}"; }
1034 
1035   // Check for valid method pointer
1036   static bool has_method_vptr(const void* ptr);
1037   static bool is_valid_method(const Method* m);
1038 
1039   // Verify
1040   void verify() { verify_on(tty); }
1041   void verify_on(outputStream* st);
1042 
1043  private:
1044 
1045   // Inlined elements
1046   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
1047   address* signature_handler_addr() const        { return native_function_addr() + 1; }
1048 };
1049 
1050 
1051 // Utility class for compressing line number tables
1052 
1053 class CompressedLineNumberWriteStream: public CompressedWriteStream {
1054  private:
1055   int _bci;
1056   int _line;
1057  public:
1058   // Constructor
1059   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
1060   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
1061 
1062   // Write (bci, line number) pair to stream
1063   void write_pair_regular(int bci_delta, int line_delta);
1064 
1065   // If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1066   // we save it as one byte, otherwise we write a 0xFF escape character
1067   // and use regular compression. 0x0 is used as end-of-stream terminator.
1068   void write_pair_inline(int bci, int line);
1069 
1070   void write_pair(int bci, int line);
1071 
1072   // Write end-of-stream marker
1073   void write_terminator()                        { write_byte(0); }
1074 };
1075 
1076 
1077 // Utility class for decompressing line number tables
1078 
1079 class CompressedLineNumberReadStream: public CompressedReadStream {
1080  private:
1081   int _bci;
1082   int _line;
1083  public:
1084   // Constructor
1085   CompressedLineNumberReadStream(u_char* buffer);
1086   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1087   bool read_pair();
1088   // Accessing bci and line number (after calling read_pair)
1089   int bci() const                               { return _bci; }
1090   int line() const                              { return _line; }
1091 };
1092 
1093 
1094 #if INCLUDE_JVMTI
1095 
1096 /// Fast Breakpoints.
1097 
1098 // If this structure gets more complicated (because bpts get numerous),
1099 // move it into its own header.
1100 
1101 // There is presently no provision for concurrent access
1102 // to breakpoint lists, which is only OK for JVMTI because
1103 // breakpoints are written only at safepoints, and are read
1104 // concurrently only outside of safepoints.
1105 
1106 class BreakpointInfo : public CHeapObj<mtClass> {
1107   friend class VMStructs;
1108  private:
1109   Bytecodes::Code  _orig_bytecode;
1110   int              _bci;
1111   u2               _name_index;       // of method
1112   u2               _signature_index;  // of method
1113   BreakpointInfo*  _next;             // simple storage allocation
1114 
1115  public:
1116   BreakpointInfo(Method* m, int bci);
1117 
1118   // accessors
1119   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1120   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1121   int         bci()                                   { return _bci; }
1122 
1123   BreakpointInfo*          next() const               { return _next; }
1124   void                 set_next(BreakpointInfo* n)    { _next = n; }
1125 
1126   // helps for searchers
1127   bool match(const Method* m, int bci) {
1128     return bci == _bci && match(m);
1129   }
1130 
1131   bool match(const Method* m) {
1132     return _name_index == m->name_index() &&
1133       _signature_index == m->signature_index();
1134   }
1135 
1136   void set(Method* method);
1137   void clear(Method* method);
1138 };
1139 
1140 #endif // INCLUDE_JVMTI
1141 
1142 // Utility class for access exception handlers
1143 class ExceptionTable : public StackObj {
1144  private:
1145   ExceptionTableElement* _table;
1146   u2  _length;
1147 
1148  public:
1149   ExceptionTable(const Method* m) {
1150     if (m->has_exception_handler()) {
1151       _table = m->exception_table_start();
1152       _length = m->exception_table_length();
1153     } else {
1154       _table = NULL;
1155       _length = 0;
1156     }
1157   }
1158 
1159   int length() const {
1160     return _length;
1161   }
1162 
1163   u2 start_pc(int idx) const {
1164     assert(idx < _length, "out of bounds");
1165     return _table[idx].start_pc;
1166   }
1167 
1168   void set_start_pc(int idx, u2 value) {
1169     assert(idx < _length, "out of bounds");
1170     _table[idx].start_pc = value;
1171   }
1172 
1173   u2 end_pc(int idx) const {
1174     assert(idx < _length, "out of bounds");
1175     return _table[idx].end_pc;
1176   }
1177 
1178   void set_end_pc(int idx, u2 value) {
1179     assert(idx < _length, "out of bounds");
1180     _table[idx].end_pc = value;
1181   }
1182 
1183   u2 handler_pc(int idx) const {
1184     assert(idx < _length, "out of bounds");
1185     return _table[idx].handler_pc;
1186   }
1187 
1188   void set_handler_pc(int idx, u2 value) {
1189     assert(idx < _length, "out of bounds");
1190     _table[idx].handler_pc = value;
1191   }
1192 
1193   u2 catch_type_index(int idx) const {
1194     assert(idx < _length, "out of bounds");
1195     return _table[idx].catch_type_index;
1196   }
1197 
1198   void set_catch_type_index(int idx, u2 value) {
1199     assert(idx < _length, "out of bounds");
1200     _table[idx].catch_type_index = value;
1201   }
1202 };
1203 
1204 #endif // SHARE_OOPS_METHOD_HPP