1 /*
   2  * Copyright (c) 1997, 2022, 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 "code/compressedStream.hpp"
  29 #include "compiler/compilerDefinitions.hpp"
  30 #include "interpreter/invocationCounter.hpp"
  31 #include "oops/annotations.hpp"
  32 #include "oops/constantPool.hpp"
  33 #include "oops/methodCounters.hpp"
  34 #include "oops/instanceKlass.hpp"
  35 #include "oops/oop.hpp"
  36 #include "oops/typeArrayOop.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/align.hpp"
  39 #include "utilities/growableArray.hpp"
  40 #include "utilities/macros.hpp"
  41 #include "utilities/vmEnums.hpp"
  42 #if INCLUDE_JFR
  43 #include "jfr/support/jfrTraceIdExtension.hpp"
  44 #endif
  45 
  46 
  47 // A Method represents a Java method.
  48 //
  49 // Note that most applications load thousands of methods, so keeping the size of this
  50 // class small has a big impact on footprint.
  51 //
  52 // Note that native_function and signature_handler have to be at fixed offsets
  53 // (required by the interpreter)
  54 //
  55 //  Method embedded field layout (after declared fields):
  56 //   [EMBEDDED native_function       (present only if native) ]
  57 //   [EMBEDDED signature_handler     (present only if native) ]
  58 
  59 class CheckedExceptionElement;
  60 class LocalVariableTableElement;
  61 class AdapterHandlerEntry;
  62 class MethodData;
  63 class MethodCounters;
  64 class ConstMethod;
  65 class InlineTableSizes;
  66 class CompiledMethod;
  67 class InterpreterOopMap;
  68 
  69 class Method : public Metadata {
  70  friend class VMStructs;
  71  friend class JVMCIVMStructs;
  72  friend class MethodTest;
  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   AdapterHandlerEntry* _adapter;
  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     _intrinsic_candidate    = 1 << 5,
  93     _reserved_stack_access  = 1 << 6,
  94     _scalarized_args        = 1 << 7,
  95     _scalarized_return      = 1 << 8,
  96     _c1_needs_stack_repair  = 1 << 9,
  97     _c2_needs_stack_repair  = 1 << 10,
  98     _scoped                 = 1 << 11,
  99     _changes_current_thread = 1 << 12,
 100     _jvmti_mount_transition = 1 << 13,
 101   };
 102   mutable u2 _flags;
 103 
 104   JFR_ONLY(DEFINE_TRACE_FLAG;)
 105 
 106 #ifndef PRODUCT
 107   int64_t _compiled_invocation_count;
 108 
 109   Symbol* _name;
 110 #endif
 111   // Entry point for calling both from and to the interpreter.
 112   address _i2i_entry;           // All-args-on-stack calling convention
 113   // Entry point for calling from compiled code, to compiled code if it exists
 114   // or else the interpreter.
 115   volatile address _from_compiled_entry;           // Cache of: _code ? _code->verified_entry_point()           : _adapter->c2i_entry()
 116   volatile address _from_compiled_inline_ro_entry; // Cache of: _code ? _code->verified_inline_ro_entry_point() : _adapter->c2i_inline_ro_entry()
 117   volatile address _from_compiled_inline_entry;    // Cache of: _code ? _code->verified_inline_entry_point()    : _adapter->c2i_inline_entry()
 118   // The entry point for calling both from and to compiled code is
 119   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 120   // field can come and go.  It can transition from NULL to not-null at any
 121   // time (whenever a compile completes).  It can transition from not-null to
 122   // NULL only at safepoints (because of a de-opt).
 123   CompiledMethod* volatile _code;                       // Points to the corresponding piece of native code
 124   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 125 
 126   // Constructor
 127   Method(ConstMethod* xconst, AccessFlags access_flags, Symbol* name);
 128  public:
 129 
 130   static Method* allocate(ClassLoaderData* loader_data,
 131                           int byte_code_size,
 132                           AccessFlags access_flags,
 133                           InlineTableSizes* sizes,
 134                           ConstMethod::MethodType method_type,
 135                           Symbol* name,
 136                           TRAPS);
 137 
 138   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 139   Method(){}
 140 
 141   virtual bool is_method() const { return true; }
 142 
 143 #if INCLUDE_CDS
 144   void remove_unshareable_info();
 145   void restore_unshareable_info(TRAPS);
 146 #endif
 147 
 148   // accessors for instance variables
 149 
 150   ConstMethod* constMethod() const             { return _constMethod; }
 151   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 152 
 153 
 154   static address make_adapters(const methodHandle& mh, TRAPS);
 155   address from_compiled_entry() const;
 156   address from_compiled_inline_ro_entry() const;
 157   address from_compiled_inline_entry() const;
 158   address from_interpreted_entry() const;
 159 
 160   // access flag
 161   AccessFlags access_flags() const               { return _access_flags;  }
 162   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 163 
 164   // name
 165   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 166   int name_index() const                         { return constMethod()->name_index();         }
 167   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 168 
 169   // signature
 170   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 171   int signature_index() const                    { return constMethod()->signature_index();         }
 172   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 173 
 174   // generics support
 175   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 176   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 177   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 178 
 179   // annotations support
 180   AnnotationArray* annotations() const           {
 181     return constMethod()->method_annotations();
 182   }
 183   AnnotationArray* parameter_annotations() const {
 184     return constMethod()->parameter_annotations();
 185   }
 186   AnnotationArray* annotation_default() const    {
 187     return constMethod()->default_annotations();
 188   }
 189   AnnotationArray* type_annotations() const      {
 190     return constMethod()->type_annotations();
 191   }
 192 
 193   // Helper routine: get klass name + "." + method name + signature as
 194   // C string, for the purpose of providing more useful
 195   // fatal error handling. The string is allocated in resource
 196   // area if a buffer is not provided by the caller.
 197   char* name_and_sig_as_C_string() const;
 198   char* name_and_sig_as_C_string(char* buf, int size) const;
 199 
 200   // Static routine in the situations we don't have a Method*
 201   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 202   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 203 
 204   // Get return type + klass name + "." + method name + ( parameters types )
 205   // as a C string or print it to an outputStream.
 206   // This is to be used to assemble strings passed to Java, so that
 207   // the text more resembles Java code. Used in exception messages.
 208   // Memory is allocated in the resource area; the caller needs
 209   // a ResourceMark.
 210   const char* external_name() const;
 211   void  print_external_name(outputStream *os) const;
 212 
 213   static const char* external_name(                  Klass* klass, Symbol* method_name, Symbol* signature);
 214   static void  print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature);
 215 
 216   Bytecodes::Code java_code_at(int bci) const {
 217     return Bytecodes::java_code_at(this, bcp_from(bci));
 218   }
 219   Bytecodes::Code code_at(int bci) const {
 220     return Bytecodes::code_at(this, bcp_from(bci));
 221   }
 222 
 223   // JVMTI breakpoints
 224 #if !INCLUDE_JVMTI
 225   Bytecodes::Code orig_bytecode_at(int bci) const {
 226     ShouldNotReachHere();
 227     return Bytecodes::_shouldnotreachhere;
 228   }
 229   void set_orig_bytecode_at(int bci, Bytecodes::Code code) {
 230     ShouldNotReachHere();
 231   };
 232   u2   number_of_breakpoints() const {return 0;}
 233 #else // !INCLUDE_JVMTI
 234   Bytecodes::Code orig_bytecode_at(int bci) const;
 235   void set_orig_bytecode_at(int bci, Bytecodes::Code code);
 236   void set_breakpoint(int bci);
 237   void clear_breakpoint(int bci);
 238   void clear_all_breakpoints();
 239   // Tracking number of breakpoints, for fullspeed debugging.
 240   // Only mutated by VM thread.
 241   u2   number_of_breakpoints() const {
 242     MethodCounters* mcs = method_counters();
 243     if (mcs == NULL) {
 244       return 0;
 245     } else {
 246       return mcs->number_of_breakpoints();
 247     }
 248   }
 249   void incr_number_of_breakpoints(Thread* current) {
 250     MethodCounters* mcs = get_method_counters(current);
 251     if (mcs != NULL) {
 252       mcs->incr_number_of_breakpoints();
 253     }
 254   }
 255   void decr_number_of_breakpoints(Thread* current) {
 256     MethodCounters* mcs = get_method_counters(current);
 257     if (mcs != NULL) {
 258       mcs->decr_number_of_breakpoints();
 259     }
 260   }
 261   // Initialization only
 262   void clear_number_of_breakpoints() {
 263     MethodCounters* mcs = method_counters();
 264     if (mcs != NULL) {
 265       mcs->clear_number_of_breakpoints();
 266     }
 267   }
 268 #endif // !INCLUDE_JVMTI
 269 
 270   // index into InstanceKlass methods() array
 271   // note: also used by jfr
 272   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 273   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 274 
 275   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 276   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 277 
 278   // code size
 279   int code_size() const                  { return constMethod()->code_size(); }
 280 
 281   // method size in words
 282   int method_size() const                { return sizeof(Method)/wordSize + ( is_native() ? 2 : 0 ); }
 283 
 284   // constant pool for Klass* holding this method
 285   ConstantPool* constants() const              { return constMethod()->constants(); }
 286   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 287 
 288   // max stack
 289   // return original max stack size for method verification
 290   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 291   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 292   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 293 
 294   // max locals
 295   int  max_locals() const                        { return constMethod()->max_locals(); }
 296   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 297 
 298   int highest_comp_level() const;
 299   void set_highest_comp_level(int level);
 300   int highest_osr_comp_level() const;
 301   void set_highest_osr_comp_level(int level);
 302 
 303 #if COMPILER2_OR_JVMCI
 304   // Count of times method was exited via exception while interpreting
 305   void interpreter_throwout_increment(Thread* current) {
 306     MethodCounters* mcs = get_method_counters(current);
 307     if (mcs != NULL) {
 308       mcs->interpreter_throwout_increment();
 309     }
 310   }
 311 #endif
 312 
 313   int  interpreter_throwout_count() const        {
 314     MethodCounters* mcs = method_counters();
 315     if (mcs == NULL) {
 316       return 0;
 317     } else {
 318       return mcs->interpreter_throwout_count();
 319     }
 320   }
 321 
 322   // Derive stuff from the signature at load time.
 323   void compute_from_signature(Symbol* sig);
 324 
 325   // size of parameters (receiver if any + arguments)
 326   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 327   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 328 
 329   bool has_stackmap_table() const {
 330     return constMethod()->has_stackmap_table();
 331   }
 332 
 333   Array<u1>* stackmap_data() const {
 334     return constMethod()->stackmap_data();
 335   }
 336 
 337   void set_stackmap_data(Array<u1>* sd) {
 338     constMethod()->set_stackmap_data(sd);
 339   }
 340 
 341   // exception handler table
 342   bool has_exception_handler() const
 343                              { return constMethod()->has_exception_handler(); }
 344   int exception_table_length() const
 345                              { return constMethod()->exception_table_length(); }
 346   ExceptionTableElement* exception_table_start() const
 347                              { return constMethod()->exception_table_start(); }
 348 
 349   // Finds the first entry point bci of an exception handler for an
 350   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 351   // for ex_klass indicates that the exception klass is not known; in
 352   // this case it matches any constraint class. Returns -1 if the
 353   // exception cannot be handled in this method. The handler
 354   // constraint classes are loaded if necessary. Note that this may
 355   // throw an exception if loading of the constraint classes causes
 356   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 357   // If an exception is thrown, returns the bci of the
 358   // exception handler which caused the exception to be thrown, which
 359   // is needed for proper retries. See, for example,
 360   // InterpreterRuntime::exception_handler_for_exception.
 361   static int fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS);
 362 
 363   static bool register_native(Klass* k,
 364                               Symbol* name,
 365                               Symbol* signature,
 366                               address entry,
 367                               TRAPS);
 368 
 369   // method data access
 370   MethodData* method_data() const              {
 371     return _method_data;
 372   }
 373 
 374   void set_method_data(MethodData* data);
 375 
 376   MethodCounters* method_counters() const {
 377     return _method_counters;
 378   }
 379 
 380   void clear_method_counters() {
 381     _method_counters = NULL;
 382   }
 383 
 384   bool init_method_counters(MethodCounters* counters);
 385 
 386   int prev_event_count() const {
 387     MethodCounters* mcs = method_counters();
 388     return mcs == NULL ? 0 : mcs->prev_event_count();
 389   }
 390   void set_prev_event_count(int count) {
 391     MethodCounters* mcs = method_counters();
 392     if (mcs != NULL) {
 393       mcs->set_prev_event_count(count);
 394     }
 395   }
 396   jlong prev_time() const {
 397     MethodCounters* mcs = method_counters();
 398     return mcs == NULL ? 0 : mcs->prev_time();
 399   }
 400   void set_prev_time(jlong time) {
 401     MethodCounters* mcs = method_counters();
 402     if (mcs != NULL) {
 403       mcs->set_prev_time(time);
 404     }
 405   }
 406   float rate() const {
 407     MethodCounters* mcs = method_counters();
 408     return mcs == NULL ? 0 : mcs->rate();
 409   }
 410   void set_rate(float rate) {
 411     MethodCounters* mcs = method_counters();
 412     if (mcs != NULL) {
 413       mcs->set_rate(rate);
 414     }
 415   }
 416 
 417   int invocation_count() const;
 418   int backedge_count() const;
 419 
 420   bool was_executed_more_than(int n);
 421   bool was_never_executed()                     { return !was_executed_more_than(0);  }
 422 
 423   static void build_profiling_method_data(const methodHandle& method, TRAPS);
 424 
 425   static MethodCounters* build_method_counters(Thread* current, Method* m);
 426 
 427   int interpreter_invocation_count()            { return invocation_count();          }
 428 
 429 #ifndef PRODUCT
 430   int64_t  compiled_invocation_count() const    { return _compiled_invocation_count;}
 431   void set_compiled_invocation_count(int count) { _compiled_invocation_count = (int64_t)count; }
 432 #else
 433   // for PrintMethodData in a product build
 434   int64_t  compiled_invocation_count() const    { return 0; }
 435 #endif // not PRODUCT
 436 
 437   // nmethod/verified compiler entry
 438   address verified_code_entry();
 439   address verified_inline_code_entry();
 440   address verified_inline_ro_code_entry();
 441   bool check_code() const;      // Not inline to avoid circular ref
 442   CompiledMethod* volatile code() const;
 443 
 444   // Locks CompiledMethod_lock if not held.
 445   void unlink_code(CompiledMethod *compare);
 446   // Locks CompiledMethod_lock if not held.
 447   void unlink_code();
 448 
 449 private:
 450   // Either called with CompiledMethod_lock held or from constructor.
 451   void clear_code();
 452 
 453 public:
 454   static void set_code(const methodHandle& mh, CompiledMethod* code);
 455   void set_adapter_entry(AdapterHandlerEntry* adapter) {
 456     _adapter = adapter;
 457   }
 458   void set_from_compiled_entry(address entry) {
 459     _from_compiled_entry = entry;
 460   }
 461   void set_from_compiled_inline_ro_entry(address entry) {
 462     _from_compiled_inline_ro_entry = entry;
 463   }
 464   void set_from_compiled_inline_entry(address entry) {
 465     _from_compiled_inline_entry = entry;
 466   }
 467 
 468   address get_i2c_entry();
 469   address get_c2i_entry();
 470   address get_c2i_inline_entry();
 471   address get_c2i_unverified_entry();
 472   address get_c2i_unverified_inline_entry();
 473   address get_c2i_no_clinit_check_entry();
 474   AdapterHandlerEntry* adapter() const {
 475     return _adapter;
 476   }
 477   // setup entry points
 478   void link_method(const methodHandle& method, TRAPS);
 479   // clear entry points. Used by sharing code during dump time
 480   void unlink_method() NOT_CDS_RETURN;
 481 
 482   // the number of argument reg slots that the compiled method uses on the stack.
 483   int num_stack_arg_slots() const { return constMethod()->num_stack_arg_slots(); }
 484 
 485   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 486   virtual MetaspaceObj::Type type() const { return MethodType; }
 487 
 488   // vtable index
 489   enum VtableIndexFlag {
 490     // Valid vtable indexes are non-negative (>= 0).
 491     // These few negative values are used as sentinels.
 492     itable_index_max        = -10, // first itable index, growing downward
 493     pending_itable_index    = -9,  // itable index will be assigned
 494     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 495     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 496     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 497     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 498   };
 499   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 500   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 501   int  vtable_index() const                      { return _vtable_index; }
 502   void set_vtable_index(int index);
 503   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 504   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 505   int  itable_index() const                      { assert(valid_itable_index(), "");
 506                                                    return itable_index_max - _vtable_index; }
 507   void set_itable_index(int index);
 508 
 509   // interpreter entry
 510   address interpreter_entry() const              { return _i2i_entry; }
 511   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 512   void set_interpreter_entry(address entry) {
 513     if (_i2i_entry != entry) {
 514       _i2i_entry = entry;
 515     }
 516     if (_from_interpreted_entry != entry) {
 517       _from_interpreted_entry = entry;
 518     }
 519   }
 520 
 521   // native function (used for native methods only)
 522   enum {
 523     native_bind_event_is_interesting = true
 524   };
 525   address native_function() const                { return *(native_function_addr()); }
 526 
 527   // Must specify a real function (not NULL).
 528   // Use clear_native_function() to unregister.
 529   void set_native_function(address function, bool post_event_flag);
 530   bool has_native_function() const;
 531   void clear_native_function();
 532 
 533   // signature handler (used for native methods only)
 534   address signature_handler() const              { return *(signature_handler_addr()); }
 535   void set_signature_handler(address handler);
 536 
 537   // Interpreter oopmap support
 538   void mask_for(int bci, InterpreterOopMap* mask);
 539 
 540   // operations on invocation counter
 541   void print_invocation_count();
 542 
 543   // byte codes
 544   void    set_code(address code)      { return constMethod()->set_code(code); }
 545   address code_base() const           { return constMethod()->code_base(); }
 546   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 547 
 548   // prints byte codes
 549   void print_codes(int flags = 0) const { print_codes_on(tty, flags); }
 550   void print_codes_on(outputStream* st, int flags = 0) const;
 551   void print_codes_on(int from, int to, outputStream* st, int flags = 0) const;
 552 
 553   // method parameters
 554   bool has_method_parameters() const
 555                          { return constMethod()->has_method_parameters(); }
 556   int method_parameters_length() const
 557                          { return constMethod()->method_parameters_length(); }
 558   MethodParametersElement* method_parameters_start() const
 559                           { return constMethod()->method_parameters_start(); }
 560 
 561   // checked exceptions
 562   int checked_exceptions_length() const
 563                          { return constMethod()->checked_exceptions_length(); }
 564   CheckedExceptionElement* checked_exceptions_start() const
 565                           { return constMethod()->checked_exceptions_start(); }
 566 
 567   // localvariable table
 568   bool has_localvariable_table() const
 569                           { return constMethod()->has_localvariable_table(); }
 570   int localvariable_table_length() const
 571                         { return constMethod()->localvariable_table_length(); }
 572   LocalVariableTableElement* localvariable_table_start() const
 573                          { return constMethod()->localvariable_table_start(); }
 574 
 575   bool has_linenumber_table() const
 576                               { return constMethod()->has_linenumber_table(); }
 577   u_char* compressed_linenumber_table() const
 578                        { return constMethod()->compressed_linenumber_table(); }
 579 
 580   // method holder (the Klass* holding this method)
 581   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 582 
 583   Symbol* klass_name() const;                    // returns the name of the method holder
 584   BasicType result_type() const                  { return constMethod()->result_type(); }
 585   bool is_returning_oop() const                  { BasicType r = result_type(); return is_reference_type(r); }
 586   InlineKlass* returns_inline_type(Thread* thread) const;
 587 
 588   // Checked exceptions thrown by this method (resolved to mirrors)
 589   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 590 
 591   // Access flags
 592   bool is_public() const                         { return access_flags().is_public();      }
 593   bool is_private() const                        { return access_flags().is_private();     }
 594   bool is_protected() const                      { return access_flags().is_protected();   }
 595   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 596   bool is_static() const                         { return access_flags().is_static();      }
 597   bool is_final() const                          { return access_flags().is_final();       }
 598   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 599   bool is_native() const                         { return access_flags().is_native();      }
 600   bool is_abstract() const                       { return access_flags().is_abstract();    }
 601   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 602 
 603   // returns true if contains only return operation
 604   bool is_empty_method() const;
 605 
 606   // returns true if this is a vanilla constructor
 607   bool is_vanilla_constructor() const;
 608 
 609   // checks method and its method holder
 610   bool is_final_method() const;
 611   bool is_final_method(AccessFlags class_access_flags) const;
 612   // interface method declared with 'default' - excludes private interface methods
 613   bool is_default_method() const;
 614 
 615   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 616   bool can_be_statically_bound() const;
 617   bool can_be_statically_bound(InstanceKlass* context) const;
 618   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 619 
 620   // true if method can omit stack trace in throw in compiled code.
 621   bool can_omit_stack_trace();
 622 
 623   // returns true if the method has any backward branches.
 624   bool has_loops() {
 625     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 626   };
 627 
 628   bool compute_has_loops_flag();
 629 
 630   bool has_jsrs() {
 631     return access_flags().has_jsrs();
 632   };
 633   void set_has_jsrs() {
 634     _access_flags.set_has_jsrs();
 635   }
 636 
 637   // returns true if the method has any monitors.
 638   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 639   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 640 
 641   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 642 
 643   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 644   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 645   // has not been computed yet.
 646   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 647   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 648 
 649   // returns true if the method is an accessor function (setter/getter).
 650   bool is_accessor() const;
 651 
 652   // returns true if the method is a getter
 653   bool is_getter() const;
 654 
 655   // returns true if the method is a setter
 656   bool is_setter() const;
 657 
 658   // returns true if the method does nothing but return a constant of primitive type
 659   bool is_constant_getter() const;
 660 
 661   // returns true if the method name is <clinit> and the method has
 662   // valid static initializer flags.
 663   bool is_class_initializer() const;
 664 
 665   // returns true if the method name is <init> and the method is not a static factory
 666   bool is_object_constructor() const;
 667 
 668   // returns true if the method is an object constructor or class initializer
 669   // (non-static <init> or <clinit>), but false for factories (static <vnew>).
 670   bool is_object_constructor_or_class_initializer() const;
 671 
 672   // returns true if the method name is <vnew> and the method is static
 673   bool is_static_vnew_factory() const;
 674 
 675   // compiled code support
 676   // NOTE: code() is inherently racy as deopt can be clearing code
 677   // simultaneously. Use with caution.
 678   bool has_compiled_code() const;
 679 
 680   bool needs_clinit_barrier() const;
 681 
 682   // sizing
 683   static int header_size()                       {
 684     return align_up((int)sizeof(Method), wordSize) / wordSize;
 685   }
 686   static int size(bool is_native);
 687   int size() const                               { return method_size(); }
 688   void log_touched(Thread* current);
 689   static void print_touched_methods(outputStream* out);
 690 
 691   // interpreter support
 692   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 693   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 694   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 695   static ByteSize from_compiled_inline_offset()  { return byte_offset_of(Method, _from_compiled_inline_entry); }
 696   static ByteSize from_compiled_inline_ro_offset(){ return byte_offset_of(Method, _from_compiled_inline_ro_entry); }
 697   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 698   static ByteSize flags_offset()                 { return byte_offset_of(Method, _flags); }
 699   static ByteSize method_data_offset()           {
 700     return byte_offset_of(Method, _method_data);
 701   }
 702   static ByteSize method_counters_offset()       {
 703     return byte_offset_of(Method, _method_counters);
 704   }
 705 #ifndef PRODUCT
 706   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 707 #endif // not PRODUCT
 708   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 709   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 710   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 711   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 712   static ByteSize itable_index_offset()          { return byte_offset_of(Method, _vtable_index ); }
 713 
 714   // for code generation
 715   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 716   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 717   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 718 
 719   // Static methods that are used to implement member methods where an exposed this pointer
 720   // is needed due to possible GCs
 721   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 722 
 723   // Returns the byte code index from the byte code pointer
 724   int     bci_from(address bcp) const;
 725   address bcp_from(int bci) const;
 726   address bcp_from(address bcp) const;
 727   int validate_bci_from_bcp(address bcp) const;
 728   int validate_bci(int bci) const;
 729 
 730   // Returns the line number for a bci if debugging information for the method is prowided,
 731   // -1 is returned otherwise.
 732   int line_number_from_bci(int bci) const;
 733 
 734   // Reflection support
 735   bool is_overridden_in(Klass* k) const;
 736 
 737   // Stack walking support
 738   bool is_ignored_by_security_stack_walk() const;
 739 
 740   // JSR 292 support
 741   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 742   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 743   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 744   static methodHandle make_method_handle_intrinsic(vmIntrinsicID iid, // _invokeBasic, _linkToVirtual
 745                                                    Symbol* signature, //anything at all
 746                                                    TRAPS);
 747   // Some special methods don't need to be findable by nmethod iterators and are permanent.
 748   bool can_be_allocated_in_NonNMethod_space() const { return is_method_handle_intrinsic(); }
 749 
 750   // Continuation
 751   inline bool is_continuation_enter_intrinsic() const;
 752   inline bool is_continuation_yield_intrinsic() const;
 753   inline bool is_continuation_native_intrinsic() const;
 754   inline bool is_special_native_intrinsic() const;
 755 
 756   static Klass* check_non_bcp_klass(Klass* klass);
 757 
 758   enum {
 759     // How many extra stack entries for invokedynamic
 760     extra_stack_entries_for_jsr292 = 1
 761   };
 762 
 763   // this operates only on invoke methods:
 764   // presize interpreter frames for extra interpreter stack entries, if needed
 765   // Account for the extra appendix argument for invokehandle/invokedynamic
 766   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 767   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 768 
 769   // RedefineClasses() support:
 770   bool is_old() const                               { return access_flags().is_old(); }
 771   void set_is_old()                                 { _access_flags.set_is_old(); }
 772   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 773   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 774   bool is_deleted() const                           { return access_flags().is_deleted(); }
 775   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 776 
 777   bool on_stack() const                             { return access_flags().on_stack(); }
 778   void set_on_stack(const bool value);
 779 
 780   void record_gc_epoch();
 781 
 782   // see the definition in Method*.cpp for the gory details
 783   bool should_not_be_cached() const;
 784 
 785   // JVMTI Native method prefixing support:
 786   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 787   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 788 
 789   // Rewriting support
 790   static methodHandle clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
 791                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 792 
 793   // jmethodID handling
 794   // Because the useful life-span of a jmethodID cannot be determined,
 795   // once created they are never reclaimed.  The methods to which they refer,
 796   // however, can be GC'ed away if the class is unloaded or if the method is
 797   // made obsolete or deleted -- in these cases, the jmethodID
 798   // refers to NULL (as is the case for any weak reference).
 799   static jmethodID make_jmethod_id(ClassLoaderData* cld, Method* mh);
 800   static void destroy_jmethod_id(ClassLoaderData* cld, jmethodID mid);
 801 
 802   // Ensure there is enough capacity in the internal tracking data
 803   // structures to hold the number of jmethodIDs you plan to generate.
 804   // This saves substantial time doing allocations.
 805   static void ensure_jmethod_ids(ClassLoaderData* cld, int capacity);
 806 
 807   // Use resolve_jmethod_id() in situations where the caller is expected
 808   // to provide a valid jmethodID; the only sanity checks are in asserts;
 809   // result guaranteed not to be NULL.
 810   inline static Method* resolve_jmethod_id(jmethodID mid) {
 811     assert(mid != NULL, "JNI method id should not be null");
 812     return *((Method**)mid);
 813   }
 814 
 815   // Use checked_resolve_jmethod_id() in situations where the caller
 816   // should provide a valid jmethodID, but might not. NULL is returned
 817   // when the jmethodID does not refer to a valid method.
 818   static Method* checked_resolve_jmethod_id(jmethodID mid);
 819 
 820   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 821   static bool is_method_id(jmethodID mid);
 822 
 823   // Clear methods
 824   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 825   static void print_jmethod_ids_count(const ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 826 
 827   // Get this method's jmethodID -- allocate if it doesn't exist
 828   jmethodID jmethod_id();
 829 
 830   // Lookup the jmethodID for this method.  Return NULL if not found.
 831   // NOTE that this function can be called from a signal handler
 832   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 833   // needs to be async-safe. No allocation should be done and
 834   // so handles are not used to avoid deadlock.
 835   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 836 
 837   // Support for inlining of intrinsic methods
 838   vmIntrinsicID intrinsic_id() const          { return (vmIntrinsicID) _intrinsic_id;           }
 839   void     set_intrinsic_id(vmIntrinsicID id) {                           _intrinsic_id = (u2) id; }
 840 
 841   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 842   void init_intrinsic_id(vmSymbolID klass_id);     // updates from _none if a match
 843   static vmSymbolID klass_id_for_intrinsics(const Klass* holder);
 844 
 845   bool caller_sensitive() {
 846     return (_flags & _caller_sensitive) != 0;
 847   }
 848   void set_caller_sensitive(bool x) {
 849     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 850   }
 851 
 852   bool force_inline() {
 853     return (_flags & _force_inline) != 0;
 854   }
 855   void set_force_inline(bool x) {
 856     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 857   }
 858 
 859   bool dont_inline() {
 860     return (_flags & _dont_inline) != 0;
 861   }
 862   void set_dont_inline(bool x) {
 863     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 864   }
 865 
 866   bool changes_current_thread() {
 867     return (_flags & _changes_current_thread) != 0;
 868   }
 869   void set_changes_current_thread(bool x) {
 870     _flags = x ? (_flags | _changes_current_thread) : (_flags & ~_changes_current_thread);
 871   }
 872 
 873   bool jvmti_mount_transition() {
 874     return (_flags & _jvmti_mount_transition) != 0;
 875   }
 876   void set_jvmti_mount_transition(bool x) {
 877     _flags = x ? (_flags | _jvmti_mount_transition) : (_flags & ~_jvmti_mount_transition);
 878   }
 879 
 880   bool is_hidden() const {
 881     return (_flags & _hidden) != 0;
 882   }
 883 
 884   void set_hidden(bool x) {
 885     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 886   }
 887 
 888   bool is_scoped() const {
 889     return (_flags & _scoped) != 0;
 890   }
 891 
 892   void set_scoped(bool x) {
 893     _flags = x ? (_flags | _scoped) : (_flags & ~_scoped);
 894   }
 895 
 896   bool intrinsic_candidate() {
 897     return (_flags & _intrinsic_candidate) != 0;
 898   }
 899   void set_intrinsic_candidate(bool x) {
 900     _flags = x ? (_flags | _intrinsic_candidate) : (_flags & ~_intrinsic_candidate);
 901   }
 902 
 903   bool has_injected_profile() {
 904     return (_flags & _has_injected_profile) != 0;
 905   }
 906   void set_has_injected_profile(bool x) {
 907     _flags = x ? (_flags | _has_injected_profile) : (_flags & ~_has_injected_profile);
 908   }
 909 
 910   bool has_reserved_stack_access() {
 911     return (_flags & _reserved_stack_access) != 0;
 912   }
 913 
 914   void set_has_reserved_stack_access(bool x) {
 915     _flags = x ? (_flags | _reserved_stack_access) : (_flags & ~_reserved_stack_access);
 916   }
 917 
 918   bool has_scalarized_args() const {
 919     return (_flags & _scalarized_args) != 0;
 920   }
 921 
 922   void set_has_scalarized_args(bool x) {
 923     _flags = x ? (_flags | _scalarized_args) : (_flags & ~_scalarized_args);
 924   }
 925 
 926   bool has_scalarized_return() const {
 927     return (_flags & _scalarized_return) != 0;
 928   }
 929 
 930   void set_has_scalarized_return(bool x) {
 931     _flags = x ? (_flags | _scalarized_return) : (_flags & ~_scalarized_return);
 932   }
 933 
 934   bool is_scalarized_arg(int idx) const;
 935 
 936   bool c1_needs_stack_repair() {
 937     return (_flags & _c1_needs_stack_repair) != 0;
 938   }
 939 
 940   bool c2_needs_stack_repair() {
 941     return (_flags & _c2_needs_stack_repair) != 0;
 942   }
 943 
 944   void set_c1_needs_stack_repair(bool x) {
 945     _flags = x ? (_flags | _c1_needs_stack_repair) : (_flags & ~_c1_needs_stack_repair);
 946   }
 947 
 948   void set_c2_needs_stack_repair(bool x) {
 949     _flags = x ? (_flags | _c2_needs_stack_repair) : (_flags & ~_c2_needs_stack_repair);
 950   }
 951 
 952   JFR_ONLY(DEFINE_TRACE_FLAG_ACCESSOR;)
 953 
 954   ConstMethod::MethodType method_type() const {
 955       return _constMethod->method_type();
 956   }
 957   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 958 
 959   // On-stack replacement support
 960   bool has_osr_nmethod(int level, bool match_level) {
 961    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 962   }
 963 
 964   int mark_osr_nmethods() {
 965     return method_holder()->mark_osr_nmethods(this);
 966   }
 967 
 968   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 969     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 970   }
 971 
 972   // Find if klass for method is loaded
 973   bool is_klass_loaded_by_klass_index(int klass_index) const;
 974   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 975 
 976   // Indicates whether compilation failed earlier for this method, or
 977   // whether it is not compilable for another reason like having a
 978   // breakpoint set in it.
 979   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 980   void set_not_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 981   void set_not_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 982     set_not_compilable(reason, comp_level, false);
 983   }
 984   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 985   void set_not_osr_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 986   void set_not_osr_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 987     set_not_osr_compilable(reason, comp_level, false);
 988   }
 989   bool is_always_compilable() const;
 990 
 991  private:
 992   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 993 
 994  public:
 995   MethodCounters* get_method_counters(Thread* current) {
 996     if (_method_counters == NULL) {
 997       build_method_counters(current, this);
 998     }
 999     return _method_counters;
1000   }
1001 
1002   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
1003   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
1004   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
1005   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
1006   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
1007   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
1008 
1009   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
1010   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
1011   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
1012   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
1013   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
1014   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
1015 
1016   // Background compilation support
1017   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
1018   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
1019   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
1020 
1021   // Resolve all classes in signature, return 'true' if successful
1022   static bool load_signature_classes(const methodHandle& m, TRAPS);
1023 
1024   // Printing
1025   void print_short_name(outputStream* st = tty) const; // prints as klassname::methodname; Exposed so field engineers can debug VM
1026 #if INCLUDE_JVMTI
1027   void print_name(outputStream* st = tty) const; // prints as "virtual void foo(int)"; exposed for -Xlog:redefine+class
1028 #else
1029   void print_name(outputStream* st = tty) const  PRODUCT_RETURN; // prints as "virtual void foo(int)"
1030 #endif
1031 
1032   typedef int (*method_comparator_func)(Method* a, Method* b);
1033 
1034   // Helper routine used for method sorting
1035   static void sort_methods(Array<Method*>* methods, bool set_idnums = true, method_comparator_func func = NULL);
1036 
1037   // Deallocation function for redefine classes or if an error occurs
1038   void deallocate_contents(ClassLoaderData* loader_data);
1039 
1040   void release_C_heap_structures();
1041 
1042   Method* get_new_method() const {
1043     InstanceKlass* holder = method_holder();
1044     Method* new_method = holder->method_with_idnum(orig_method_idnum());
1045 
1046     assert(new_method != NULL, "method_with_idnum() should not be NULL");
1047     assert(this != new_method, "sanity check");
1048     return new_method;
1049   }
1050 
1051   // Printing
1052 #ifndef PRODUCT
1053   void print_on(outputStream* st) const;
1054 #endif
1055   void print_value_on(outputStream* st) const;
1056   void print_linkage_flags(outputStream* st) PRODUCT_RETURN;
1057 
1058   const char* internal_name() const { return "{method}"; }
1059 
1060   // Check for valid method pointer
1061   static bool has_method_vptr(const void* ptr);
1062   static bool is_valid_method(const Method* m);
1063 
1064   // Verify
1065   void verify() { verify_on(tty); }
1066   void verify_on(outputStream* st);
1067 
1068  private:
1069 
1070   // Inlined elements
1071   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
1072   address* signature_handler_addr() const        { return native_function_addr() + 1; }
1073 
1074   void set_num_stack_arg_slots(int n) { constMethod()->set_num_stack_arg_slots(n); }
1075 };
1076 
1077 
1078 // Utility class for compressing line number tables
1079 
1080 class CompressedLineNumberWriteStream: public CompressedWriteStream {
1081  private:
1082   int _bci;
1083   int _line;
1084  public:
1085   // Constructor
1086   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
1087   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
1088 
1089   // Write (bci, line number) pair to stream
1090   void write_pair_regular(int bci_delta, int line_delta);
1091 
1092   // If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1093   // we save it as one byte, otherwise we write a 0xFF escape character
1094   // and use regular compression. 0x0 is used as end-of-stream terminator.
1095   void write_pair_inline(int bci, int line);
1096 
1097   void write_pair(int bci, int line);
1098 
1099   // Write end-of-stream marker
1100   void write_terminator()                        { write_byte(0); }
1101 };
1102 
1103 
1104 // Utility class for decompressing line number tables
1105 
1106 class CompressedLineNumberReadStream: public CompressedReadStream {
1107  private:
1108   int _bci;
1109   int _line;
1110  public:
1111   // Constructor
1112   CompressedLineNumberReadStream(u_char* buffer);
1113   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1114   bool read_pair();
1115   // Accessing bci and line number (after calling read_pair)
1116   int bci() const                               { return _bci; }
1117   int line() const                              { return _line; }
1118 };
1119 
1120 
1121 #if INCLUDE_JVMTI
1122 
1123 /// Fast Breakpoints.
1124 
1125 // If this structure gets more complicated (because bpts get numerous),
1126 // move it into its own header.
1127 
1128 // There is presently no provision for concurrent access
1129 // to breakpoint lists, which is only OK for JVMTI because
1130 // breakpoints are written only at safepoints, and are read
1131 // concurrently only outside of safepoints.
1132 
1133 class BreakpointInfo : public CHeapObj<mtClass> {
1134   friend class VMStructs;
1135  private:
1136   Bytecodes::Code  _orig_bytecode;
1137   int              _bci;
1138   u2               _name_index;       // of method
1139   u2               _signature_index;  // of method
1140   BreakpointInfo*  _next;             // simple storage allocation
1141 
1142  public:
1143   BreakpointInfo(Method* m, int bci);
1144 
1145   // accessors
1146   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1147   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1148   int         bci()                                   { return _bci; }
1149 
1150   BreakpointInfo*          next() const               { return _next; }
1151   void                 set_next(BreakpointInfo* n)    { _next = n; }
1152 
1153   // helps for searchers
1154   bool match(const Method* m, int bci) {
1155     return bci == _bci && match(m);
1156   }
1157 
1158   bool match(const Method* m) {
1159     return _name_index == m->name_index() &&
1160       _signature_index == m->signature_index();
1161   }
1162 
1163   void set(Method* method);
1164   void clear(Method* method);
1165 };
1166 
1167 #endif // INCLUDE_JVMTI
1168 
1169 // Utility class for access exception handlers
1170 class ExceptionTable : public StackObj {
1171  private:
1172   ExceptionTableElement* _table;
1173   u2  _length;
1174 
1175  public:
1176   ExceptionTable(const Method* m) {
1177     if (m->has_exception_handler()) {
1178       _table = m->exception_table_start();
1179       _length = m->exception_table_length();
1180     } else {
1181       _table = NULL;
1182       _length = 0;
1183     }
1184   }
1185 
1186   int length() const {
1187     return _length;
1188   }
1189 
1190   u2 start_pc(int idx) const {
1191     assert(idx < _length, "out of bounds");
1192     return _table[idx].start_pc;
1193   }
1194 
1195   void set_start_pc(int idx, u2 value) {
1196     assert(idx < _length, "out of bounds");
1197     _table[idx].start_pc = value;
1198   }
1199 
1200   u2 end_pc(int idx) const {
1201     assert(idx < _length, "out of bounds");
1202     return _table[idx].end_pc;
1203   }
1204 
1205   void set_end_pc(int idx, u2 value) {
1206     assert(idx < _length, "out of bounds");
1207     _table[idx].end_pc = value;
1208   }
1209 
1210   u2 handler_pc(int idx) const {
1211     assert(idx < _length, "out of bounds");
1212     return _table[idx].handler_pc;
1213   }
1214 
1215   void set_handler_pc(int idx, u2 value) {
1216     assert(idx < _length, "out of bounds");
1217     _table[idx].handler_pc = value;
1218   }
1219 
1220   u2 catch_type_index(int idx) const {
1221     assert(idx < _length, "out of bounds");
1222     return _table[idx].catch_type_index;
1223   }
1224 
1225   void set_catch_type_index(int idx, u2 value) {
1226     assert(idx < _length, "out of bounds");
1227     _table[idx].catch_type_index = value;
1228   }
1229 };
1230 
1231 #endif // SHARE_OOPS_METHOD_HPP