1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OOPS_METHOD_HPP
  26 #define SHARE_OOPS_METHOD_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/compilerDefinitions.hpp"
  31 #include "compiler/oopMap.hpp"
  32 #include "interpreter/invocationCounter.hpp"
  33 #include "oops/annotations.hpp"
  34 #include "oops/constantPool.hpp"
  35 #include "oops/methodCounters.hpp"
  36 #include "oops/instanceKlass.hpp"
  37 #include "oops/oop.hpp"
  38 #include "oops/typeArrayOop.hpp"
  39 #include "utilities/accessFlags.hpp"
  40 #include "utilities/align.hpp"
  41 #include "utilities/growableArray.hpp"
  42 #include "utilities/macros.hpp"
  43 #if INCLUDE_JFR
  44 #include "jfr/support/jfrTraceIdExtension.hpp"
  45 #endif
  46 
  47 
  48 // A Method represents a Java method.
  49 //
  50 // Note that most applications load thousands of methods, so keeping the size of this
  51 // class small has a big impact on footprint.
  52 //
  53 // Note that native_function and signature_handler have to be at fixed offsets
  54 // (required by the interpreter)
  55 //
  56 //  Method embedded field layout (after declared fields):
  57 //   [EMBEDDED native_function       (present only if native) ]
  58 //   [EMBEDDED signature_handler     (present only if native) ]
  59 
  60 class CheckedExceptionElement;
  61 class LocalVariableTableElement;
  62 class AdapterHandlerEntry;
  63 class MethodData;
  64 class MethodCounters;
  65 class ConstMethod;
  66 class InlineTableSizes;
  67 class KlassSizeStats;
  68 class CompiledMethod;
  69 class InterpreterOopMap;
  70 
  71 class Method : public Metadata {
  72  friend class VMStructs;
  73  friend class JVMCIVMStructs;
  74  private:
  75   // If you add a new field that points to any metaspace object, you
  76   // must add this field to Method::metaspace_pointers_do().
  77   ConstMethod*      _constMethod;                // Method read-only data.
  78   MethodData*       _method_data;
  79   MethodCounters*   _method_counters;
  80   AccessFlags       _access_flags;               // Access flags
  81   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  82                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  83   u2                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  84 
  85   // Flags
  86   enum Flags {
  87     _caller_sensitive      = 1 << 0,
  88     _force_inline          = 1 << 1,
  89     _dont_inline           = 1 << 2,
  90     _hidden                = 1 << 3,
  91     _has_injected_profile  = 1 << 4,
  92     _running_emcp          = 1 << 5,
  93     _intrinsic_candidate   = 1 << 6,
  94     _reserved_stack_access = 1 << 7,
  95     _scalarized_args       = 1 << 8,
  96     _c1_needs_stack_repair = 1 << 9,
  97     _c2_needs_stack_repair = 1 << 10
  98   };
  99   mutable u2 _flags;
 100 
 101   JFR_ONLY(DEFINE_TRACE_FLAG;)
 102 
 103 #ifndef PRODUCT
 104   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 105 #endif
 106   // Entry point for calling both from and to the interpreter.
 107   address _i2i_entry;           // All-args-on-stack calling convention
 108   // Entry point for calling from compiled code, to compiled code if it exists
 109   // or else the interpreter.
 110   volatile address _from_compiled_entry;          // Cache of: _code ? _code->verified_entry_point()          : _adapter->c2i_entry()
 111   volatile address _from_compiled_value_ro_entry; // Cache of: _code ? _code->verified_value_ro_entry_point() : _adapter->c2i_value_ro_entry()
 112   volatile address _from_compiled_value_entry;    // Cache of: _code ? _code->verified_value_entry_point()    : _adapter->c2i_value_entry()
 113   // The entry point for calling both from and to compiled code is
 114   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 115   // field can come and go.  It can transition from NULL to not-null at any
 116   // time (whenever a compile completes).  It can transition from not-null to
 117   // NULL only at safepoints (because of a de-opt).
 118   CompiledMethod* volatile _code;                       // Points to the corresponding piece of native code
 119   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 120   int _max_vt_buffer; // max number of VT buffer chunk to use before recycling
 121 
 122 #if INCLUDE_AOT && defined(TIERED)
 123   CompiledMethod* _aot_code;
 124 #endif
 125 
 126   // Constructor
 127   Method(ConstMethod* xconst, AccessFlags access_flags);
 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                           TRAPS);
 136 
 137   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 138   Method(){}
 139 
 140   bool is_method() const volatile { return true; }
 141 
 142   void restore_unshareable_info(TRAPS);
 143 
 144   // accessors for instance variables
 145 
 146   ConstMethod* constMethod() const             { return _constMethod; }
 147   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 148 
 149 
 150   static address make_adapters(const methodHandle& mh, TRAPS);
 151   address from_compiled_entry() const;
 152   address from_compiled_entry_no_trampoline(bool caller_is_c1) const;
 153   address from_interpreted_entry() const;
 154 
 155   // access flag
 156   AccessFlags access_flags() const               { return _access_flags;  }
 157   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 158 
 159   // name
 160   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 161   int name_index() const                         { return constMethod()->name_index();         }
 162   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 163 
 164   // signature
 165   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 166   int signature_index() const                    { return constMethod()->signature_index();         }
 167   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 168 
 169   // generics support
 170   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 171   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 172   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 173 
 174   // annotations support
 175   AnnotationArray* annotations() const           {
 176     return constMethod()->method_annotations();
 177   }
 178   AnnotationArray* parameter_annotations() const {
 179     return constMethod()->parameter_annotations();
 180   }
 181   AnnotationArray* annotation_default() const    {
 182     return constMethod()->default_annotations();
 183   }
 184   AnnotationArray* type_annotations() const      {
 185     return constMethod()->type_annotations();
 186   }
 187 
 188   // Helper routine: get klass name + "." + method name + signature as
 189   // C string, for the purpose of providing more useful
 190   // fatal error handling. The string is allocated in resource
 191   // area if a buffer is not provided by the caller.
 192   char* name_and_sig_as_C_string() const;
 193   char* name_and_sig_as_C_string(char* buf, int size) const;
 194 
 195   // Static routine in the situations we don't have a Method*
 196   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 197   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 198 
 199   // Get return type + klass name + "." + method name + ( parameters types )
 200   // as a C string or print it to an outputStream.
 201   // This is to be used to assemble strings passed to Java, so that
 202   // the text more resembles Java code. Used in exception messages.
 203   // Memory is allocated in the resource area; the caller needs
 204   // a ResourceMark.
 205   const char* external_name() const;
 206   void  print_external_name(outputStream *os) const;
 207 
 208   static const char* external_name(                  Klass* klass, Symbol* method_name, Symbol* signature);
 209   static void  print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature);
 210 
 211   Bytecodes::Code java_code_at(int bci) const {
 212     return Bytecodes::java_code_at(this, bcp_from(bci));
 213   }
 214   Bytecodes::Code code_at(int bci) const {
 215     return Bytecodes::code_at(this, bcp_from(bci));
 216   }
 217 
 218   // JVMTI breakpoints
 219 #if !INCLUDE_JVMTI
 220   Bytecodes::Code orig_bytecode_at(int bci) const {
 221     ShouldNotReachHere();
 222     return Bytecodes::_shouldnotreachhere;
 223   }
 224   void set_orig_bytecode_at(int bci, Bytecodes::Code code) {
 225     ShouldNotReachHere();
 226   };
 227   u2   number_of_breakpoints() const {return 0;}
 228 #else // !INCLUDE_JVMTI
 229   Bytecodes::Code orig_bytecode_at(int bci) const;
 230   void set_orig_bytecode_at(int bci, Bytecodes::Code code);
 231   void set_breakpoint(int bci);
 232   void clear_breakpoint(int bci);
 233   void clear_all_breakpoints();
 234   // Tracking number of breakpoints, for fullspeed debugging.
 235   // Only mutated by VM thread.
 236   u2   number_of_breakpoints()             const {
 237     MethodCounters* mcs = method_counters();
 238     if (mcs == NULL) {
 239       return 0;
 240     } else {
 241       return mcs->number_of_breakpoints();
 242     }
 243   }
 244   void incr_number_of_breakpoints(TRAPS)         {
 245     MethodCounters* mcs = get_method_counters(CHECK);
 246     if (mcs != NULL) {
 247       mcs->incr_number_of_breakpoints();
 248     }
 249   }
 250   void decr_number_of_breakpoints(TRAPS)         {
 251     MethodCounters* mcs = get_method_counters(CHECK);
 252     if (mcs != NULL) {
 253       mcs->decr_number_of_breakpoints();
 254     }
 255   }
 256   // Initialization only
 257   void clear_number_of_breakpoints()             {
 258     MethodCounters* mcs = method_counters();
 259     if (mcs != NULL) {
 260       mcs->clear_number_of_breakpoints();
 261     }
 262   }
 263 #endif // !INCLUDE_JVMTI
 264 
 265   // index into InstanceKlass methods() array
 266   // note: also used by jfr
 267   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 268   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 269 
 270   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 271   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 272 
 273   // code size
 274   int code_size() const                  { return constMethod()->code_size(); }
 275 
 276   // method size in words
 277   int method_size() const                { return sizeof(Method)/wordSize + ( is_native() ? 2 : 0 ); }
 278 
 279   // constant pool for Klass* holding this method
 280   ConstantPool* constants() const              { return constMethod()->constants(); }
 281   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 282 
 283   // max stack
 284   // return original max stack size for method verification
 285   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 286   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 287   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 288 
 289   // max locals
 290   int  max_locals() const                        { return constMethod()->max_locals(); }
 291   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 292 
 293   int highest_comp_level() const;
 294   void set_highest_comp_level(int level);
 295   int highest_osr_comp_level() const;
 296   void set_highest_osr_comp_level(int level);
 297 
 298 #if COMPILER2_OR_JVMCI
 299   // Count of times method was exited via exception while interpreting
 300   void interpreter_throwout_increment(TRAPS) {
 301     MethodCounters* mcs = get_method_counters(CHECK);
 302     if (mcs != NULL) {
 303       mcs->interpreter_throwout_increment();
 304     }
 305   }
 306 #endif
 307 
 308   int  interpreter_throwout_count() const        {
 309     MethodCounters* mcs = method_counters();
 310     if (mcs == NULL) {
 311       return 0;
 312     } else {
 313       return mcs->interpreter_throwout_count();
 314     }
 315   }
 316 
 317   // size of parameters
 318   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 319   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 320 
 321   bool has_stackmap_table() const {
 322     return constMethod()->has_stackmap_table();
 323   }
 324 
 325   Array<u1>* stackmap_data() const {
 326     return constMethod()->stackmap_data();
 327   }
 328 
 329   void set_stackmap_data(Array<u1>* sd) {
 330     constMethod()->set_stackmap_data(sd);
 331   }
 332 
 333   // exception handler table
 334   bool has_exception_handler() const
 335                              { return constMethod()->has_exception_handler(); }
 336   int exception_table_length() const
 337                              { return constMethod()->exception_table_length(); }
 338   ExceptionTableElement* exception_table_start() const
 339                              { return constMethod()->exception_table_start(); }
 340 
 341   // Finds the first entry point bci of an exception handler for an
 342   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 343   // for ex_klass indicates that the exception klass is not known; in
 344   // this case it matches any constraint class. Returns -1 if the
 345   // exception cannot be handled in this method. The handler
 346   // constraint classes are loaded if necessary. Note that this may
 347   // throw an exception if loading of the constraint classes causes
 348   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 349   // If an exception is thrown, returns the bci of the
 350   // exception handler which caused the exception to be thrown, which
 351   // is needed for proper retries. See, for example,
 352   // InterpreterRuntime::exception_handler_for_exception.
 353   static int fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS);
 354 
 355   // method data access
 356   MethodData* method_data() const              {
 357     return _method_data;
 358   }
 359 
 360   void set_method_data(MethodData* data);
 361 
 362   MethodCounters* method_counters() const {
 363     return _method_counters;
 364   }
 365 
 366   void clear_method_counters() {
 367     _method_counters = NULL;
 368   }
 369 
 370   bool init_method_counters(MethodCounters* counters);
 371 
 372 #ifdef TIERED
 373   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 374   // We can do that since interpreter_invocation_count is not used in tiered.
 375   int prev_event_count() const                   {
 376     if (method_counters() == NULL) {
 377       return 0;
 378     } else {
 379       return method_counters()->interpreter_invocation_count();
 380     }
 381   }
 382   void set_prev_event_count(int count) {
 383     MethodCounters* mcs = method_counters();
 384     if (mcs != NULL) {
 385       mcs->set_interpreter_invocation_count(count);
 386     }
 387   }
 388   jlong prev_time() const                        {
 389     MethodCounters* mcs = method_counters();
 390     return mcs == NULL ? 0 : mcs->prev_time();
 391   }
 392   void set_prev_time(jlong time) {
 393     MethodCounters* mcs = method_counters();
 394     if (mcs != NULL) {
 395       mcs->set_prev_time(time);
 396     }
 397   }
 398   float rate() const                             {
 399     MethodCounters* mcs = method_counters();
 400     return mcs == NULL ? 0 : mcs->rate();
 401   }
 402   void set_rate(float rate) {
 403     MethodCounters* mcs = method_counters();
 404     if (mcs != NULL) {
 405       mcs->set_rate(rate);
 406     }
 407   }
 408 
 409 #if INCLUDE_AOT
 410   void set_aot_code(CompiledMethod* aot_code) {
 411     _aot_code = aot_code;
 412   }
 413 
 414   CompiledMethod* aot_code() const {
 415     return _aot_code;
 416   }
 417 #else
 418   CompiledMethod* aot_code() const { return NULL; }
 419 #endif // INCLUDE_AOT
 420 #endif // TIERED
 421 
 422   int nmethod_age() const {
 423     if (method_counters() == NULL) {
 424       return INT_MAX;
 425     } else {
 426       return method_counters()->nmethod_age();
 427     }
 428   }
 429 
 430   int invocation_count();
 431   int backedge_count();
 432 
 433   bool was_executed_more_than(int n);
 434   bool was_never_executed()                      { return !was_executed_more_than(0); }
 435 
 436   static void build_interpreter_method_data(const methodHandle& method, TRAPS);
 437 
 438   static MethodCounters* build_method_counters(Method* m, TRAPS);
 439 
 440   int interpreter_invocation_count() {
 441     if (TieredCompilation) {
 442       return invocation_count();
 443     } else {
 444       MethodCounters* mcs = method_counters();
 445       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 446     }
 447   }
 448 #if COMPILER2_OR_JVMCI
 449   int increment_interpreter_invocation_count(TRAPS) {
 450     if (TieredCompilation) ShouldNotReachHere();
 451     MethodCounters* mcs = get_method_counters(CHECK_0);
 452     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 453   }
 454 #endif
 455 
 456 #ifndef PRODUCT
 457   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 458   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 459 #else
 460   // for PrintMethodData in a product build
 461   int  compiled_invocation_count() const         { return 0;  }
 462 #endif // not PRODUCT
 463 
 464   // Clear (non-shared space) pointers which could not be relevant
 465   // if this (shared) method were mapped into another JVM.
 466   void remove_unshareable_info();
 467 
 468   // nmethod/verified compiler entry
 469   address verified_code_entry();
 470   address verified_value_code_entry();
 471   address verified_value_ro_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_value_entry();
 502   address get_c2i_unverified_entry();
 503   address get_c2i_unverified_value_entry();
 504   AdapterHandlerEntry* adapter() const {
 505     return constMethod()->adapter();
 506   }
 507   // setup entry points
 508   void link_method(const methodHandle& method, TRAPS);
 509   // clear entry points. Used by sharing code during dump time
 510   void unlink_method() NOT_CDS_RETURN;
 511 
 512   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 513   virtual MetaspaceObj::Type type() const { return MethodType; }
 514 
 515   // vtable index
 516   enum VtableIndexFlag {
 517     // Valid vtable indexes are non-negative (>= 0).
 518     // These few negative values are used as sentinels.
 519     itable_index_max        = -10, // first itable index, growing downward
 520     pending_itable_index    = -9,  // itable index will be assigned
 521     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 522     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 523     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 524     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 525   };
 526   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 527   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 528   int  vtable_index() const                      { return _vtable_index; }
 529   void set_vtable_index(int index);
 530   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 531   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 532   int  itable_index() const                      { assert(valid_itable_index(), "");
 533                                                    return itable_index_max - _vtable_index; }
 534   void set_itable_index(int index);
 535 
 536   // interpreter entry
 537   address interpreter_entry() const              { return _i2i_entry; }
 538   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 539   void set_interpreter_entry(address entry) {
 540     assert(!is_shared(),
 541            "shared method's interpreter entry should not be changed at run time");
 542     if (_i2i_entry != entry) {
 543       _i2i_entry = entry;
 544     }
 545     if (_from_interpreted_entry != entry) {
 546       _from_interpreted_entry = entry;
 547     }
 548   }
 549 
 550   // native function (used for native methods only)
 551   enum {
 552     native_bind_event_is_interesting = true
 553   };
 554   address native_function() const                { return *(native_function_addr()); }
 555   address critical_native_function();
 556 
 557   // Must specify a real function (not NULL).
 558   // Use clear_native_function() to unregister.
 559   void set_native_function(address function, bool post_event_flag);
 560   bool has_native_function() const;
 561   void clear_native_function();
 562 
 563   // signature handler (used for native methods only)
 564   address signature_handler() const              { return *(signature_handler_addr()); }
 565   void set_signature_handler(address handler);
 566 
 567   // Interpreter oopmap support
 568   void mask_for(int bci, InterpreterOopMap* mask);
 569 
 570   // operations on invocation counter
 571   void print_invocation_count();
 572 
 573   // byte codes
 574   void    set_code(address code)      { return constMethod()->set_code(code); }
 575   address code_base() const           { return constMethod()->code_base(); }
 576   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 577 
 578   // prints byte codes
 579   void print_codes() const            { print_codes_on(tty); }
 580   void print_codes_on(outputStream* st) const;
 581   void print_codes_on(int from, int to, outputStream* st) const;
 582 
 583   // method parameters
 584   bool has_method_parameters() const
 585                          { return constMethod()->has_method_parameters(); }
 586   int method_parameters_length() const
 587                          { return constMethod()->method_parameters_length(); }
 588   MethodParametersElement* method_parameters_start() const
 589                           { return constMethod()->method_parameters_start(); }
 590 
 591   // checked exceptions
 592   int checked_exceptions_length() const
 593                          { return constMethod()->checked_exceptions_length(); }
 594   CheckedExceptionElement* checked_exceptions_start() const
 595                           { return constMethod()->checked_exceptions_start(); }
 596 
 597   // localvariable table
 598   bool has_localvariable_table() const
 599                           { return constMethod()->has_localvariable_table(); }
 600   int localvariable_table_length() const
 601                         { return constMethod()->localvariable_table_length(); }
 602   LocalVariableTableElement* localvariable_table_start() const
 603                          { return constMethod()->localvariable_table_start(); }
 604 
 605   bool has_linenumber_table() const
 606                               { return constMethod()->has_linenumber_table(); }
 607   u_char* compressed_linenumber_table() const
 608                        { return constMethod()->compressed_linenumber_table(); }
 609 
 610   // method holder (the Klass* holding this method)
 611   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 612 
 613   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 614   Symbol* klass_name() const;                    // returns the name of the method holder
 615   BasicType result_type() const;                 // type of the method result
 616   bool may_return_oop() const                    { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY ||  r == T_VALUETYPE); }
 617   ValueKlass* returned_value_type(Thread* thread) const;
 618 
 619   // Checked exceptions thrown by this method (resolved to mirrors)
 620   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 621 
 622   // Access flags
 623   bool is_public() const                         { return access_flags().is_public();      }
 624   bool is_private() const                        { return access_flags().is_private();     }
 625   bool is_protected() const                      { return access_flags().is_protected();   }
 626   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 627   bool is_static() const                         { return access_flags().is_static();      }
 628   bool is_final() const                          { return access_flags().is_final();       }
 629   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 630   bool is_native() const                         { return access_flags().is_native();      }
 631   bool is_abstract() const                       { return access_flags().is_abstract();    }
 632   bool is_strict() const                         { return access_flags().is_strict();      }
 633   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 634 
 635   // returns true if contains only return operation
 636   bool is_empty_method() const;
 637 
 638   // returns true if this is a vanilla constructor
 639   bool is_vanilla_constructor() const;
 640 
 641   // checks method and its method holder
 642   bool is_final_method() const;
 643   bool is_final_method(AccessFlags class_access_flags) const;
 644   // interface method declared with 'default' - excludes private interface methods
 645   bool is_default_method() const;
 646 
 647   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 648   bool can_be_statically_bound() const;
 649   bool can_be_statically_bound(InstanceKlass* context) const;
 650   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 651 
 652   // returns true if the method has any backward branches.
 653   bool has_loops() {
 654     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 655   };
 656 
 657   bool compute_has_loops_flag();
 658 
 659   bool has_jsrs() {
 660     return access_flags().has_jsrs();
 661   };
 662   void set_has_jsrs() {
 663     _access_flags.set_has_jsrs();
 664   }
 665 
 666   // returns true if the method has any monitors.
 667   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 668   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 669 
 670   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 671 
 672   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 673   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 674   // has not been computed yet.
 675   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 676   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 677 
 678   // returns true if the method is an accessor function (setter/getter).
 679   bool is_accessor() const;
 680 
 681   // returns true if the method is a getter
 682   bool is_getter() const;
 683 
 684   // returns true if the method is a setter
 685   bool is_setter() const;
 686 
 687   // returns true if the method does nothing but return a constant of primitive type
 688   bool is_constant_getter() const;
 689 
 690   // returns true if the method name is <clinit> and the method has
 691   // valid static initializer flags.
 692   bool is_class_initializer() const;
 693 
 694   // returns true if the method name is <init> and the method is not a static factory
 695   bool is_object_constructor() const;
 696 
 697   // returns true if the method is an object constructor or class initializer
 698   // (non-static <init> or <clinit>), but false for factories (static <init>).
 699   bool is_object_constructor_or_class_initializer() const;
 700 
 701   // returns true if the method name is <init> and the method is static
 702   bool is_static_init_factory() const;
 703 
 704   // compiled code support
 705   // NOTE: code() is inherently racy as deopt can be clearing code
 706   // simultaneously. Use with caution.
 707   bool has_compiled_code() const;
 708 
 709 #ifdef TIERED
 710   bool has_aot_code() const                      { return aot_code() != NULL; }
 711 #endif
 712 
 713   bool needs_clinit_barrier() const;
 714 
 715   // sizing
 716   static int header_size()                       {
 717     return align_up((int)sizeof(Method), wordSize) / wordSize;
 718   }
 719   static int size(bool is_native);
 720   int size() const                               { return method_size(); }
 721 #if INCLUDE_SERVICES
 722   void collect_statistics(KlassSizeStats *sz) const;
 723 #endif
 724   void log_touched(TRAPS);
 725   static void print_touched_methods(outputStream* out);
 726 
 727   // interpreter support
 728   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 729   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 730   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 731   static ByteSize from_compiled_value_offset()   { return byte_offset_of(Method, _from_compiled_value_entry); }
 732   static ByteSize from_compiled_value_ro_offset(){ return byte_offset_of(Method, _from_compiled_value_ro_entry); }
 733   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 734   static ByteSize flags_offset()                 { return byte_offset_of(Method, _flags); }
 735   static ByteSize method_data_offset()           {
 736     return byte_offset_of(Method, _method_data);
 737   }
 738   static ByteSize method_counters_offset()       {
 739     return byte_offset_of(Method, _method_counters);
 740   }
 741 #ifndef PRODUCT
 742   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 743 #endif // not PRODUCT
 744   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 745   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 746   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 747   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 748   static ByteSize itable_index_offset()          { return byte_offset_of(Method, _vtable_index ); }
 749 
 750   // for code generation
 751   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 752   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 753   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 754 
 755   static ByteSize max_vt_buffer_offset()         { return byte_offset_of(Method, _max_vt_buffer); }
 756 
 757   // Static methods that are used to implement member methods where an exposed this pointer
 758   // is needed due to possible GCs
 759   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 760 
 761   // Returns the byte code index from the byte code pointer
 762   int     bci_from(address bcp) const;
 763   address bcp_from(int bci) const;
 764   address bcp_from(address bcp) const;
 765   int validate_bci_from_bcp(address bcp) const;
 766   int validate_bci(int bci) const;
 767 
 768   // Returns the line number for a bci if debugging information for the method is prowided,
 769   // -1 is returned otherwise.
 770   int line_number_from_bci(int bci) const;
 771 
 772   // Reflection support
 773   bool is_overridden_in(Klass* k) const;
 774 
 775   // Stack walking support
 776   bool is_ignored_by_security_stack_walk() const;
 777 
 778   // JSR 292 support
 779   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 780   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 781   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 782   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 783                                                    Symbol* signature, //anything at all
 784                                                    TRAPS);
 785   static Klass* check_non_bcp_klass(Klass* klass);
 786 
 787   enum {
 788     // How many extra stack entries for invokedynamic
 789     extra_stack_entries_for_jsr292 = 1
 790   };
 791 
 792   // this operates only on invoke methods:
 793   // presize interpreter frames for extra interpreter stack entries, if needed
 794   // Account for the extra appendix argument for invokehandle/invokedynamic
 795   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 796   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 797 
 798   // RedefineClasses() support:
 799   bool is_old() const                               { return access_flags().is_old(); }
 800   void set_is_old()                                 { _access_flags.set_is_old(); }
 801   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 802   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 803   bool is_deleted() const                           { return access_flags().is_deleted(); }
 804   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 805 
 806   bool is_running_emcp() const {
 807     // EMCP methods are old but not obsolete or deleted. Equivalent
 808     // Modulo Constant Pool means the method is equivalent except
 809     // the constant pool and instructions that access the constant
 810     // pool might be different.
 811     // If a breakpoint is set in a redefined method, its EMCP methods that are
 812     // still running must have a breakpoint also.
 813     return (_flags & _running_emcp) != 0;
 814   }
 815 
 816   void set_running_emcp(bool x) {
 817     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 818   }
 819 
 820   bool on_stack() const                             { return access_flags().on_stack(); }
 821   void set_on_stack(const bool value);
 822 
 823   // see the definition in Method*.cpp for the gory details
 824   bool should_not_be_cached() const;
 825 
 826   // JVMTI Native method prefixing support:
 827   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 828   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 829 
 830   // Rewriting support
 831   static methodHandle clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
 832                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 833 
 834   // jmethodID handling
 835   // Because the useful life-span of a jmethodID cannot be determined,
 836   // once created they are never reclaimed.  The methods to which they refer,
 837   // however, can be GC'ed away if the class is unloaded or if the method is
 838   // made obsolete or deleted -- in these cases, the jmethodID
 839   // refers to NULL (as is the case for any weak reference).
 840   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 841   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 842 
 843   // Ensure there is enough capacity in the internal tracking data
 844   // structures to hold the number of jmethodIDs you plan to generate.
 845   // This saves substantial time doing allocations.
 846   static void ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity);
 847 
 848   // Use resolve_jmethod_id() in situations where the caller is expected
 849   // to provide a valid jmethodID; the only sanity checks are in asserts;
 850   // result guaranteed not to be NULL.
 851   inline static Method* resolve_jmethod_id(jmethodID mid) {
 852     assert(mid != NULL, "JNI method id should not be null");
 853     return *((Method**)mid);
 854   }
 855 
 856   // Use checked_resolve_jmethod_id() in situations where the caller
 857   // should provide a valid jmethodID, but might not. NULL is returned
 858   // when the jmethodID does not refer to a valid method.
 859   static Method* checked_resolve_jmethod_id(jmethodID mid);
 860 
 861   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 862   static bool is_method_id(jmethodID mid);
 863 
 864   // Clear methods
 865   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 866   static void print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 867 
 868   // Get this method's jmethodID -- allocate if it doesn't exist
 869   jmethodID jmethod_id()                            { return method_holder()->get_jmethod_id(this); }
 870 
 871   // Lookup the jmethodID for this method.  Return NULL if not found.
 872   // NOTE that this function can be called from a signal handler
 873   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 874   // needs to be async-safe. No allocation should be done and
 875   // so handles are not used to avoid deadlock.
 876   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 877 
 878   // Support for inlining of intrinsic methods
 879   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 880   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u2) id; }
 881 
 882   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 883   void init_intrinsic_id();     // updates from _none if a match
 884   static vmSymbols::SID klass_id_for_intrinsics(const Klass* holder);
 885 
 886   bool caller_sensitive() {
 887     return (_flags & _caller_sensitive) != 0;
 888   }
 889   void set_caller_sensitive(bool x) {
 890     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 891   }
 892 
 893   bool force_inline() {
 894     return (_flags & _force_inline) != 0;
 895   }
 896   void set_force_inline(bool x) {
 897     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 898   }
 899 
 900   bool dont_inline() {
 901     return (_flags & _dont_inline) != 0;
 902   }
 903   void set_dont_inline(bool x) {
 904     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 905   }
 906 
 907   bool is_hidden() {
 908     return (_flags & _hidden) != 0;
 909   }
 910   void set_hidden(bool x) {
 911     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 912   }
 913 
 914   bool intrinsic_candidate() {
 915     return (_flags & _intrinsic_candidate) != 0;
 916   }
 917   void set_intrinsic_candidate(bool x) {
 918     _flags = x ? (_flags | _intrinsic_candidate) : (_flags & ~_intrinsic_candidate);
 919   }
 920 
 921   bool has_injected_profile() {
 922     return (_flags & _has_injected_profile) != 0;
 923   }
 924   void set_has_injected_profile(bool x) {
 925     _flags = x ? (_flags | _has_injected_profile) : (_flags & ~_has_injected_profile);
 926   }
 927 
 928   bool has_reserved_stack_access() {
 929     return (_flags & _reserved_stack_access) != 0;
 930   }
 931 
 932   void set_has_reserved_stack_access(bool x) {
 933     _flags = x ? (_flags | _reserved_stack_access) : (_flags & ~_reserved_stack_access);
 934   }
 935 
 936   bool has_scalarized_args() {
 937     return (_flags & _scalarized_args) != 0;
 938   }
 939 
 940   void set_has_scalarized_args(bool x) {
 941     _flags = x ? (_flags | _scalarized_args) : (_flags & ~_scalarized_args);
 942   }
 943 
 944   bool c1_needs_stack_repair() {
 945     return (_flags & _c1_needs_stack_repair) != 0;
 946   }
 947 
 948   bool c2_needs_stack_repair() {
 949     return (_flags & _c2_needs_stack_repair) != 0;
 950   }
 951 
 952   void set_c1_needs_stack_repair(bool x) {
 953     _flags = x ? (_flags | _c1_needs_stack_repair) : (_flags & ~_c1_needs_stack_repair);
 954   }
 955 
 956   void set_c2_needs_stack_repair(bool x) {
 957     _flags = x ? (_flags | _c2_needs_stack_repair) : (_flags & ~_c2_needs_stack_repair);
 958   }
 959 
 960   JFR_ONLY(DEFINE_TRACE_FLAG_ACCESSOR;)
 961 
 962   ConstMethod::MethodType method_type() const {
 963       return _constMethod->method_type();
 964   }
 965   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 966 
 967   // On-stack replacement support
 968   bool has_osr_nmethod(int level, bool match_level) {
 969    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 970   }
 971 
 972   int mark_osr_nmethods() {
 973     return method_holder()->mark_osr_nmethods(this);
 974   }
 975 
 976   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 977     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 978   }
 979 
 980   // Find if klass for method is loaded
 981   bool is_klass_loaded_by_klass_index(int klass_index) const;
 982   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 983 
 984   // Indicates whether compilation failed earlier for this method, or
 985   // whether it is not compilable for another reason like having a
 986   // breakpoint set in it.
 987   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 988   void set_not_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 989   void set_not_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 990     set_not_compilable(reason, comp_level, false);
 991   }
 992   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 993   void set_not_osr_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 994   void set_not_osr_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 995     set_not_osr_compilable(reason, comp_level, false);
 996   }
 997   bool is_always_compilable() const;
 998 
 999  private:
1000   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
1001 
1002  public:
1003   MethodCounters* get_method_counters(TRAPS) {
1004     if (_method_counters == NULL) {
1005       build_method_counters(this, CHECK_AND_CLEAR_NULL);
1006     }
1007     return _method_counters;
1008   }
1009 
1010   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
1011   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
1012   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
1013   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
1014   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
1015   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
1016 
1017   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
1018   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
1019   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
1020   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
1021   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
1022   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
1023 
1024   // Background compilation support
1025   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
1026   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
1027   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
1028 
1029   // Resolve all classes in signature, return 'true' if successful
1030   static bool load_signature_classes(const methodHandle& m, TRAPS);
1031 
1032   // Return if true if not all classes references in signature, including return type, has been loaded
1033   static bool has_unloaded_classes_in_signature(const methodHandle& m, TRAPS);
1034 
1035   // Printing
1036   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
1037 #if INCLUDE_JVMTI
1038   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
1039 #else
1040   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
1041 #endif
1042 
1043   // Helper routine used for method sorting
1044   static void sort_methods(Array<Method*>* methods, bool set_idnums = true);
1045 
1046   // Deallocation function for redefine classes or if an error occurs
1047   void deallocate_contents(ClassLoaderData* loader_data);
1048 
1049   Method* get_new_method() const {
1050     InstanceKlass* holder = method_holder();
1051     Method* new_method = holder->method_with_idnum(orig_method_idnum());
1052 
1053     assert(new_method != NULL, "method_with_idnum() should not be NULL");
1054     assert(this != new_method, "sanity check");
1055     return new_method;
1056   }
1057 
1058   // Printing
1059 #ifndef PRODUCT
1060   void print_on(outputStream* st) const;
1061 #endif
1062   void print_value_on(outputStream* st) const;
1063   void print_linkage_flags(outputStream* st) PRODUCT_RETURN;
1064 
1065   const char* internal_name() const { return "{method}"; }
1066 
1067   // Check for valid method pointer
1068   static bool has_method_vptr(const void* ptr);
1069   static bool is_valid_method(const Method* m);
1070 
1071   // Verify
1072   void verify() { verify_on(tty); }
1073   void verify_on(outputStream* st);
1074 
1075  private:
1076 
1077   // Inlined elements
1078   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
1079   address* signature_handler_addr() const        { return native_function_addr() + 1; }
1080 };
1081 
1082 
1083 // Utility class for compressing line number tables
1084 
1085 class CompressedLineNumberWriteStream: public CompressedWriteStream {
1086  private:
1087   int _bci;
1088   int _line;
1089  public:
1090   // Constructor
1091   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
1092   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
1093 
1094   // Write (bci, line number) pair to stream
1095   void write_pair_regular(int bci_delta, int line_delta);
1096 
1097   // If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1098   // we save it as one byte, otherwise we write a 0xFF escape character
1099   // and use regular compression. 0x0 is used as end-of-stream terminator.
1100   void write_pair_inline(int bci, int line);
1101 
1102   void write_pair(int bci, int line);
1103 
1104   // Write end-of-stream marker
1105   void write_terminator()                        { write_byte(0); }
1106 };
1107 
1108 
1109 // Utility class for decompressing line number tables
1110 
1111 class CompressedLineNumberReadStream: public CompressedReadStream {
1112  private:
1113   int _bci;
1114   int _line;
1115  public:
1116   // Constructor
1117   CompressedLineNumberReadStream(u_char* buffer);
1118   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1119   bool read_pair();
1120   // Accessing bci and line number (after calling read_pair)
1121   int bci() const                               { return _bci; }
1122   int line() const                              { return _line; }
1123 };
1124 
1125 
1126 #if INCLUDE_JVMTI
1127 
1128 /// Fast Breakpoints.
1129 
1130 // If this structure gets more complicated (because bpts get numerous),
1131 // move it into its own header.
1132 
1133 // There is presently no provision for concurrent access
1134 // to breakpoint lists, which is only OK for JVMTI because
1135 // breakpoints are written only at safepoints, and are read
1136 // concurrently only outside of safepoints.
1137 
1138 class BreakpointInfo : public CHeapObj<mtClass> {
1139   friend class VMStructs;
1140  private:
1141   Bytecodes::Code  _orig_bytecode;
1142   int              _bci;
1143   u2               _name_index;       // of method
1144   u2               _signature_index;  // of method
1145   BreakpointInfo*  _next;             // simple storage allocation
1146 
1147  public:
1148   BreakpointInfo(Method* m, int bci);
1149 
1150   // accessors
1151   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1152   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1153   int         bci()                                   { return _bci; }
1154 
1155   BreakpointInfo*          next() const               { return _next; }
1156   void                 set_next(BreakpointInfo* n)    { _next = n; }
1157 
1158   // helps for searchers
1159   bool match(const Method* m, int bci) {
1160     return bci == _bci && match(m);
1161   }
1162 
1163   bool match(const Method* m) {
1164     return _name_index == m->name_index() &&
1165       _signature_index == m->signature_index();
1166   }
1167 
1168   void set(Method* method);
1169   void clear(Method* method);
1170 };
1171 
1172 #endif // INCLUDE_JVMTI
1173 
1174 // Utility class for access exception handlers
1175 class ExceptionTable : public StackObj {
1176  private:
1177   ExceptionTableElement* _table;
1178   u2  _length;
1179 
1180  public:
1181   ExceptionTable(const Method* m) {
1182     if (m->has_exception_handler()) {
1183       _table = m->exception_table_start();
1184       _length = m->exception_table_length();
1185     } else {
1186       _table = NULL;
1187       _length = 0;
1188     }
1189   }
1190 
1191   int length() const {
1192     return _length;
1193   }
1194 
1195   u2 start_pc(int idx) const {
1196     assert(idx < _length, "out of bounds");
1197     return _table[idx].start_pc;
1198   }
1199 
1200   void set_start_pc(int idx, u2 value) {
1201     assert(idx < _length, "out of bounds");
1202     _table[idx].start_pc = value;
1203   }
1204 
1205   u2 end_pc(int idx) const {
1206     assert(idx < _length, "out of bounds");
1207     return _table[idx].end_pc;
1208   }
1209 
1210   void set_end_pc(int idx, u2 value) {
1211     assert(idx < _length, "out of bounds");
1212     _table[idx].end_pc = value;
1213   }
1214 
1215   u2 handler_pc(int idx) const {
1216     assert(idx < _length, "out of bounds");
1217     return _table[idx].handler_pc;
1218   }
1219 
1220   void set_handler_pc(int idx, u2 value) {
1221     assert(idx < _length, "out of bounds");
1222     _table[idx].handler_pc = value;
1223   }
1224 
1225   u2 catch_type_index(int idx) const {
1226     assert(idx < _length, "out of bounds");
1227     return _table[idx].catch_type_index;
1228   }
1229 
1230   void set_catch_type_index(int idx, u2 value) {
1231     assert(idx < _length, "out of bounds");
1232     _table[idx].catch_type_index = value;
1233   }
1234 };
1235 
1236 #endif // SHARE_OOPS_METHOD_HPP