1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_METHODOOP_HPP
  26 #define SHARE_VM_OOPS_METHODOOP_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "interpreter/invocationCounter.hpp"
  32 #include "oops/annotations.hpp"
  33 #include "oops/constantPool.hpp"
  34 #include "oops/methodCounters.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.hpp"
  37 #include "oops/typeArrayOop.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/growableArray.hpp"
  40 
  41 // A Method represents a Java method.
  42 //
  43 // Note that most applications load thousands of methods, so keeping the size of this
  44 // class small has a big impact on footprint.
  45 //
  46 // Note that native_function and signature_handler have to be at fixed offsets
  47 // (required by the interpreter)
  48 //
  49 //  Method embedded field layout (after declared fields):
  50 //   [EMBEDDED native_function       (present only if native) ]
  51 //   [EMBEDDED signature_handler     (present only if native) ]
  52 
  53 class CheckedExceptionElement;
  54 class LocalVariableTableElement;
  55 class AdapterHandlerEntry;
  56 class MethodData;
  57 class MethodCounters;
  58 class ConstMethod;
  59 class InlineTableSizes;
  60 class KlassSizeStats;
  61 
  62 class Method : public Metadata {
  63  friend class VMStructs;
  64  private:
  65   ConstMethod*      _constMethod;                // Method read-only data.
  66   MethodData*       _method_data;
  67   MethodCounters*   _method_counters;
  68   AccessFlags       _access_flags;               // Access flags
  69   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  70                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  71 #ifdef CC_INTERP
  72   int               _result_index;               // C++ interpreter needs for converting results to/from stack
  73 #endif
  74   u2                _method_size;                // size of this object
  75   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  76 
  77   // Flags
  78   enum Flags {
  79     _jfr_towrite      = 1 << 0,
  80     _caller_sensitive = 1 << 1,
  81     _force_inline     = 1 << 2,
  82     _dont_inline      = 1 << 3,
  83     _hidden           = 1 << 4,
  84     _running_emcp     = 1 << 5
  85   };
  86   u1 _flags;
  87 
  88 #ifndef PRODUCT
  89   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
  90 #endif
  91   // Entry point for calling both from and to the interpreter.
  92   address _i2i_entry;           // All-args-on-stack calling convention
  93   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
  94   AdapterHandlerEntry* _adapter;
  95   // Entry point for calling from compiled code, to compiled code if it exists
  96   // or else the interpreter.
  97   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
  98   // The entry point for calling both from and to compiled code is
  99   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 100   // field can come and go.  It can transition from NULL to not-null at any
 101   // time (whenever a compile completes).  It can transition from not-null to
 102   // NULL only at safepoints (because of a de-opt).
 103   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 104   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 105 
 106   // Constructor
 107   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 108  public:
 109 
 110   static Method* allocate(ClassLoaderData* loader_data,
 111                           int byte_code_size,
 112                           AccessFlags access_flags,
 113                           InlineTableSizes* sizes,
 114                           ConstMethod::MethodType method_type,
 115                           TRAPS);
 116 
 117   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 118   Method(){}
 119 
 120   // The Method vtable is restored by this call when the Method is in the
 121   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 122   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 123   // by their vtable.
 124   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 125   bool is_method() const volatile { return true; }
 126 
 127   void restore_unshareable_info(TRAPS);
 128 
 129   // accessors for instance variables
 130 
 131   ConstMethod* constMethod() const             { return _constMethod; }
 132   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 133 
 134 
 135   static address make_adapters(methodHandle mh, TRAPS);
 136   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 137   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 138 
 139   // access flag
 140   AccessFlags access_flags() const               { return _access_flags;  }
 141   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 142 
 143   // name
 144   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 145   int name_index() const                         { return constMethod()->name_index();         }
 146   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 147 
 148   // signature
 149   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 150   int signature_index() const                    { return constMethod()->signature_index();         }
 151   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 152 
 153   // generics support
 154   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 155   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 156   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 157 
 158   // annotations support
 159   AnnotationArray* annotations() const           {
 160     return constMethod()->method_annotations();
 161   }
 162   AnnotationArray* parameter_annotations() const {
 163     return constMethod()->parameter_annotations();
 164   }
 165   AnnotationArray* annotation_default() const    {
 166     return constMethod()->default_annotations();
 167   }
 168   AnnotationArray* type_annotations() const      {
 169     return constMethod()->type_annotations();
 170   }
 171 
 172 #ifdef CC_INTERP
 173   void set_result_index(BasicType type);
 174   int  result_index()                            { return _result_index; }
 175 #endif
 176 
 177   // Helper routine: get klass name + "." + method name + signature as
 178   // C string, for the purpose of providing more useful NoSuchMethodErrors
 179   // and fatal error handling. The string is allocated in resource
 180   // area if a buffer is not provided by the caller.
 181   char* name_and_sig_as_C_string() const;
 182   char* name_and_sig_as_C_string(char* buf, int size) const;
 183 
 184   // Static routine in the situations we don't have a Method*
 185   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 186   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 187 
 188   Bytecodes::Code java_code_at(int bci) const {
 189     return Bytecodes::java_code_at(this, bcp_from(bci));
 190   }
 191   Bytecodes::Code code_at(int bci) const {
 192     return Bytecodes::code_at(this, bcp_from(bci));
 193   }
 194 
 195   // JVMTI breakpoints
 196   Bytecodes::Code orig_bytecode_at(int bci) const;
 197   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 198   void set_breakpoint(int bci);
 199   void clear_breakpoint(int bci);
 200   void clear_all_breakpoints();
 201   // Tracking number of breakpoints, for fullspeed debugging.
 202   // Only mutated by VM thread.
 203   u2   number_of_breakpoints()             const {
 204     MethodCounters* mcs = method_counters();
 205     if (mcs == NULL) {
 206       return 0;
 207     } else {
 208       return mcs->number_of_breakpoints();
 209     }
 210   }
 211   void incr_number_of_breakpoints(TRAPS)         {
 212     MethodCounters* mcs = get_method_counters(CHECK);
 213     if (mcs != NULL) {
 214       mcs->incr_number_of_breakpoints();
 215     }
 216   }
 217   void decr_number_of_breakpoints(TRAPS)         {
 218     MethodCounters* mcs = get_method_counters(CHECK);
 219     if (mcs != NULL) {
 220       mcs->decr_number_of_breakpoints();
 221     }
 222   }
 223   // Initialization only
 224   void clear_number_of_breakpoints()             {
 225     MethodCounters* mcs = method_counters();
 226     if (mcs != NULL) {
 227       mcs->clear_number_of_breakpoints();
 228     }
 229   }
 230 
 231   // index into InstanceKlass methods() array
 232   // note: also used by jfr
 233   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 234   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 235 
 236   // code size
 237   int code_size() const                  { return constMethod()->code_size(); }
 238 
 239   // method size
 240   int method_size() const                        { return _method_size; }
 241   void set_method_size(int size) {
 242     assert(0 <= size && size < (1 << 16), "invalid method size");
 243     _method_size = size;
 244   }
 245 
 246   // constant pool for Klass* holding this method
 247   ConstantPool* constants() const              { return constMethod()->constants(); }
 248   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 249 
 250   // max stack
 251   // return original max stack size for method verification
 252   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 253   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 254   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 255 
 256   // max locals
 257   int  max_locals() const                        { return constMethod()->max_locals(); }
 258   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 259 
 260   int highest_comp_level() const;
 261   void set_highest_comp_level(int level);
 262   int highest_osr_comp_level() const;
 263   void set_highest_osr_comp_level(int level);
 264 
 265   // Count of times method was exited via exception while interpreting
 266   void interpreter_throwout_increment(TRAPS) {
 267     MethodCounters* mcs = get_method_counters(CHECK);
 268     if (mcs != NULL) {
 269       mcs->interpreter_throwout_increment();
 270     }
 271   }
 272 
 273   int  interpreter_throwout_count() const        {
 274     MethodCounters* mcs = method_counters();
 275     if (mcs == NULL) {
 276       return 0;
 277     } else {
 278       return mcs->interpreter_throwout_count();
 279     }
 280   }
 281 
 282   // size of parameters
 283   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 284   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 285 
 286   bool has_stackmap_table() const {
 287     return constMethod()->has_stackmap_table();
 288   }
 289 
 290   Array<u1>* stackmap_data() const {
 291     return constMethod()->stackmap_data();
 292   }
 293 
 294   void set_stackmap_data(Array<u1>* sd) {
 295     constMethod()->set_stackmap_data(sd);
 296   }
 297 
 298   // exception handler table
 299   bool has_exception_handler() const
 300                              { return constMethod()->has_exception_handler(); }
 301   int exception_table_length() const
 302                              { return constMethod()->exception_table_length(); }
 303   ExceptionTableElement* exception_table_start() const
 304                              { return constMethod()->exception_table_start(); }
 305 
 306   // Finds the first entry point bci of an exception handler for an
 307   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 308   // for ex_klass indicates that the exception klass is not known; in
 309   // this case it matches any constraint class. Returns -1 if the
 310   // exception cannot be handled in this method. The handler
 311   // constraint classes are loaded if necessary. Note that this may
 312   // throw an exception if loading of the constraint classes causes
 313   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 314   // If an exception is thrown, returns the bci of the
 315   // exception handler which caused the exception to be thrown, which
 316   // is needed for proper retries. See, for example,
 317   // InterpreterRuntime::exception_handler_for_exception.
 318   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 319 
 320   // method data access
 321   MethodData* method_data() const              {
 322     return _method_data;
 323   }
 324 
 325   void set_method_data(MethodData* data)       {
 326     // The store into method must be released. On platforms without
 327     // total store order (TSO) the reference may become visible before
 328     // the initialization of data otherwise.
 329     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);
 330   }
 331 
 332   MethodCounters* method_counters() const {
 333     return _method_counters;
 334   }
 335 
 336   void set_method_counters(MethodCounters* counters) {
 337     // The store into method must be released. On platforms without
 338     // total store order (TSO) the reference may become visible before
 339     // the initialization of data otherwise.
 340     OrderAccess::release_store_ptr((volatile void *)&_method_counters, counters);
 341   }
 342 
 343 #ifdef TIERED
 344   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 345   // We can do that since interpreter_invocation_count is not used in tiered.
 346   int prev_event_count() const                   {
 347     if (method_counters() == NULL) {
 348       return 0;
 349     } else {
 350       return method_counters()->interpreter_invocation_count();
 351     }
 352   }
 353   void set_prev_event_count(int count) {
 354     MethodCounters* mcs = method_counters();
 355     if (mcs != NULL) {
 356       mcs->set_interpreter_invocation_count(count);
 357     }
 358   }
 359   jlong prev_time() const                        {
 360     MethodCounters* mcs = method_counters();
 361     return mcs == NULL ? 0 : mcs->prev_time();
 362   }
 363   void set_prev_time(jlong time) {
 364     MethodCounters* mcs = method_counters();
 365     if (mcs != NULL) {
 366       mcs->set_prev_time(time);
 367     }
 368   }
 369   float rate() const                             {
 370     MethodCounters* mcs = method_counters();
 371     return mcs == NULL ? 0 : mcs->rate();
 372   }
 373   void set_rate(float rate) {
 374     MethodCounters* mcs = method_counters();
 375     if (mcs != NULL) {
 376       mcs->set_rate(rate);
 377     }
 378   }
 379 #endif
 380   int nmethod_age() const {
 381     if (method_counters() == NULL) {
 382       return INT_MAX;
 383     } else {
 384       return method_counters()->nmethod_age();
 385     }
 386   }
 387 
 388   int invocation_count();
 389   int backedge_count();
 390 
 391   bool was_executed_more_than(int n);
 392   bool was_never_executed()                      { return !was_executed_more_than(0); }
 393 
 394   static void build_interpreter_method_data(methodHandle method, TRAPS);
 395 
 396   static MethodCounters* build_method_counters(Method* m, TRAPS);
 397 
 398   int interpreter_invocation_count() {
 399     if (TieredCompilation) {
 400       return invocation_count();
 401     } else {
 402       MethodCounters* mcs = method_counters();
 403       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 404     }
 405   }
 406   int increment_interpreter_invocation_count(TRAPS) {
 407     if (TieredCompilation) ShouldNotReachHere();
 408     MethodCounters* mcs = get_method_counters(CHECK_0);
 409     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 410   }
 411 
 412 #ifndef PRODUCT
 413   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 414   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 415 #else
 416   // for PrintMethodData in a product build
 417   int  compiled_invocation_count() const         { return 0;  }
 418 #endif // not PRODUCT
 419 
 420   // Clear (non-shared space) pointers which could not be relevant
 421   // if this (shared) method were mapped into another JVM.
 422   void remove_unshareable_info();
 423 
 424   // nmethod/verified compiler entry
 425   address verified_code_entry();
 426   bool check_code() const;      // Not inline to avoid circular ref
 427   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 428   void clear_code();            // Clear out any compiled code
 429   static void set_code(methodHandle mh, nmethod* code);
 430   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 431   address get_i2c_entry();
 432   address get_c2i_entry();
 433   address get_c2i_unverified_entry();
 434   AdapterHandlerEntry* adapter() {  return _adapter; }
 435   // setup entry points
 436   void link_method(methodHandle method, TRAPS);
 437   // clear entry points. Used by sharing code
 438   void unlink_method();
 439 
 440   // vtable index
 441   enum VtableIndexFlag {
 442     // Valid vtable indexes are non-negative (>= 0).
 443     // These few negative values are used as sentinels.
 444     itable_index_max        = -10, // first itable index, growing downward
 445     pending_itable_index    = -9,  // itable index will be assigned
 446     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 447     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 448     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 449     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 450   };
 451   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 452   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 453   int  vtable_index() const                      { return _vtable_index; }
 454   void set_vtable_index(int index)               { _vtable_index = index; }
 455   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 456   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 457   int  itable_index() const                      { assert(valid_itable_index(), "");
 458                                                    return itable_index_max - _vtable_index; }
 459   void set_itable_index(int index)               { _vtable_index = itable_index_max - index; assert(valid_itable_index(), ""); }
 460 
 461   // interpreter entry
 462   address interpreter_entry() const              { return _i2i_entry; }
 463   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 464   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 465 
 466   // native function (used for native methods only)
 467   enum {
 468     native_bind_event_is_interesting = true
 469   };
 470   address native_function() const                { return *(native_function_addr()); }
 471   address critical_native_function();
 472 
 473   // Must specify a real function (not NULL).
 474   // Use clear_native_function() to unregister.
 475   void set_native_function(address function, bool post_event_flag);
 476   bool has_native_function() const;
 477   void clear_native_function();
 478 
 479   // signature handler (used for native methods only)
 480   address signature_handler() const              { return *(signature_handler_addr()); }
 481   void set_signature_handler(address handler);
 482 
 483   // Interpreter oopmap support
 484   void mask_for(int bci, InterpreterOopMap* mask);
 485 
 486   // operations on invocation counter
 487   void print_invocation_count();
 488 
 489   // byte codes
 490   void    set_code(address code)      { return constMethod()->set_code(code); }
 491   address code_base() const           { return constMethod()->code_base(); }
 492   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 493 
 494   // prints byte codes
 495   void print_codes() const            { print_codes_on(tty); }
 496   void print_codes_on(outputStream* st) const;
 497   void print_codes_on(int from, int to, outputStream* st) const;
 498 
 499   // method parameters
 500   bool has_method_parameters() const
 501                          { return constMethod()->has_method_parameters(); }
 502   int method_parameters_length() const
 503                          { return constMethod()->method_parameters_length(); }
 504   MethodParametersElement* method_parameters_start() const
 505                           { return constMethod()->method_parameters_start(); }
 506 
 507   // checked exceptions
 508   int checked_exceptions_length() const
 509                          { return constMethod()->checked_exceptions_length(); }
 510   CheckedExceptionElement* checked_exceptions_start() const
 511                           { return constMethod()->checked_exceptions_start(); }
 512 
 513   // localvariable table
 514   bool has_localvariable_table() const
 515                           { return constMethod()->has_localvariable_table(); }
 516   int localvariable_table_length() const
 517                         { return constMethod()->localvariable_table_length(); }
 518   LocalVariableTableElement* localvariable_table_start() const
 519                          { return constMethod()->localvariable_table_start(); }
 520 
 521   bool has_linenumber_table() const
 522                               { return constMethod()->has_linenumber_table(); }
 523   u_char* compressed_linenumber_table() const
 524                        { return constMethod()->compressed_linenumber_table(); }
 525 
 526   // method holder (the Klass* holding this method)
 527   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 528 
 529   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 530   Symbol* klass_name() const;                    // returns the name of the method holder
 531   BasicType result_type() const;                 // type of the method result
 532   int result_type_index() const;                 // type index of the method result
 533   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 534   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 535 
 536   // Checked exceptions thrown by this method (resolved to mirrors)
 537   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 538 
 539   // Access flags
 540   bool is_public() const                         { return access_flags().is_public();      }
 541   bool is_private() const                        { return access_flags().is_private();     }
 542   bool is_protected() const                      { return access_flags().is_protected();   }
 543   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 544   bool is_static() const                         { return access_flags().is_static();      }
 545   bool is_final() const                          { return access_flags().is_final();       }
 546   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 547   bool is_native() const                         { return access_flags().is_native();      }
 548   bool is_abstract() const                       { return access_flags().is_abstract();    }
 549   bool is_strict() const                         { return access_flags().is_strict();      }
 550   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 551 
 552   // returns true if contains only return operation
 553   bool is_empty_method() const;
 554 
 555   // returns true if this is a vanilla constructor
 556   bool is_vanilla_constructor() const;
 557 
 558   // checks method and its method holder
 559   bool is_final_method() const;
 560   bool is_final_method(AccessFlags class_access_flags) const;
 561   bool is_default_method() const;
 562 
 563   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 564   bool can_be_statically_bound() const;
 565   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 566 
 567   // returns true if the method has any backward branches.
 568   bool has_loops() {
 569     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 570   };
 571 
 572   bool compute_has_loops_flag();
 573 
 574   bool has_jsrs() {
 575     return access_flags().has_jsrs();
 576   };
 577   void set_has_jsrs() {
 578     _access_flags.set_has_jsrs();
 579   }
 580 
 581   // returns true if the method has any monitors.
 582   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 583   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 584 
 585   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 586 
 587   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 588   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 589   // has not been computed yet.
 590   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 591   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 592 
 593   // returns true if the method is an accessor function (setter/getter).
 594   bool is_accessor() const;
 595 
 596   // returns true if the method is an initializer (<init> or <clinit>).
 597   bool is_initializer() const;
 598 
 599   // returns true if the method is static OR if the classfile version < 51
 600   bool has_valid_initializer_flags() const;
 601 
 602   // returns true if the method name is <clinit> and the method has
 603   // valid static initializer flags.
 604   bool is_static_initializer() const;
 605 
 606   // compiled code support
 607   // NOTE: code() is inherently racy as deopt can be clearing code
 608   // simultaneously. Use with caution.
 609   bool has_compiled_code() const                 { return code() != NULL; }
 610 
 611   // sizing
 612   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 613   static int size(bool is_native);
 614   int size() const                               { return method_size(); }
 615 #if INCLUDE_SERVICES
 616   void collect_statistics(KlassSizeStats *sz) const;
 617 #endif
 618 
 619   // interpreter support
 620   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 621   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 622 #ifdef CC_INTERP
 623   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 624 #endif /* CC_INTERP */
 625   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 626   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 627   static ByteSize method_data_offset()           {
 628     return byte_offset_of(Method, _method_data);
 629   }
 630   static ByteSize method_counters_offset()       {
 631     return byte_offset_of(Method, _method_counters);
 632   }
 633 #ifndef PRODUCT
 634   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 635 #endif // not PRODUCT
 636   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 637   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 638   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 639   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 640 
 641   // for code generation
 642   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 643   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 644   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 645 
 646   // Static methods that are used to implement member methods where an exposed this pointer
 647   // is needed due to possible GCs
 648   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 649 
 650   // Returns the byte code index from the byte code pointer
 651   int     bci_from(address bcp) const;
 652   address bcp_from(int bci) const;
 653   address bcp_from(address bcp) const;
 654   int validate_bci_from_bcp(address bcp) const;
 655   int validate_bci(int bci) const;
 656 
 657   // Returns the line number for a bci if debugging information for the method is prowided,
 658   // -1 is returned otherwise.
 659   int line_number_from_bci(int bci) const;
 660 
 661   // Reflection support
 662   bool is_overridden_in(Klass* k) const;
 663 
 664   // Stack walking support
 665   bool is_ignored_by_security_stack_walk() const;
 666 
 667   // JSR 292 support
 668   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 669   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 670   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 671   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 672                                                    Symbol* signature, //anything at all
 673                                                    TRAPS);
 674   static Klass* check_non_bcp_klass(Klass* klass);
 675 
 676   // How many extra stack entries for invokedynamic when it's enabled
 677   static const int extra_stack_entries_for_jsr292 = 1;
 678 
 679   // this operates only on invoke methods:
 680   // presize interpreter frames for extra interpreter stack entries, if needed
 681   // Account for the extra appendix argument for invokehandle/invokedynamic
 682   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 683   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 684 
 685   // RedefineClasses() support:
 686   bool is_old() const                               { return access_flags().is_old(); }
 687   void set_is_old()                                 { _access_flags.set_is_old(); }
 688   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 689   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 690   bool is_deleted() const                           { return access_flags().is_deleted(); }
 691   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 692 
 693   bool is_running_emcp() const {
 694     // EMCP methods are old but not obsolete or deleted. Equivalent
 695     // Modulo Constant Pool means the method is equivalent except
 696     // the constant pool and instructions that access the constant
 697     // pool might be different.
 698     // If a breakpoint is set in a redefined method, its EMCP methods that are
 699     // still running must have a breakpoint also.
 700     return (_flags & _running_emcp) != 0;
 701   }
 702 
 703   void set_running_emcp(bool x) {
 704     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 705   }
 706 
 707   bool on_stack() const                             { return access_flags().on_stack(); }
 708   void set_on_stack(const bool value);
 709 
 710   // see the definition in Method*.cpp for the gory details
 711   bool should_not_be_cached() const;
 712 
 713   // JVMTI Native method prefixing support:
 714   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 715   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 716 
 717   // Rewriting support
 718   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 719                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 720 
 721   // jmethodID handling
 722   // Because the useful life-span of a jmethodID cannot be determined,
 723   // once created they are never reclaimed.  The methods to which they refer,
 724   // however, can be GC'ed away if the class is unloaded or if the method is
 725   // made obsolete or deleted -- in these cases, the jmethodID
 726   // refers to NULL (as is the case for any weak reference).
 727   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 728   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 729 
 730   // Use resolve_jmethod_id() in situations where the caller is expected
 731   // to provide a valid jmethodID; the only sanity checks are in asserts;
 732   // result guaranteed not to be NULL.
 733   inline static Method* resolve_jmethod_id(jmethodID mid) {
 734     assert(mid != NULL, "JNI method id should not be null");
 735     return *((Method**)mid);
 736   }
 737 
 738   // Use checked_resolve_jmethod_id() in situations where the caller
 739   // should provide a valid jmethodID, but might not. NULL is returned
 740   // when the jmethodID does not refer to a valid method.
 741   static Method* checked_resolve_jmethod_id(jmethodID mid);
 742 
 743   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 744   static bool is_method_id(jmethodID mid);
 745 
 746   // Clear methods
 747   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 748   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 749 
 750   // Get this method's jmethodID -- allocate if it doesn't exist
 751   jmethodID jmethod_id()                            { methodHandle this_h(this);
 752                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 753 
 754   // Lookup the jmethodID for this method.  Return NULL if not found.
 755   // NOTE that this function can be called from a signal handler
 756   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 757   // needs to be async-safe. No allocation should be done and
 758   // so handles are not used to avoid deadlock.
 759   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 760 
 761   // Support for inlining of intrinsic methods
 762   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 763   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 764 
 765   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 766   void init_intrinsic_id();     // updates from _none if a match
 767   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 768 
 769   bool jfr_towrite() {
 770     return (_flags & _jfr_towrite) != 0;
 771   }
 772   void set_jfr_towrite(bool x) {
 773     _flags = x ? (_flags | _jfr_towrite) : (_flags & ~_jfr_towrite);
 774   }
 775 
 776   bool caller_sensitive() {
 777     return (_flags & _caller_sensitive) != 0;
 778   }
 779   void set_caller_sensitive(bool x) {
 780     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 781   }
 782 
 783   bool force_inline() {
 784     return (_flags & _force_inline) != 0;
 785   }
 786   void set_force_inline(bool x) {
 787     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 788   }
 789 
 790   bool dont_inline() {
 791     return (_flags & _dont_inline) != 0;
 792   }
 793   void set_dont_inline(bool x) {
 794     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 795   }
 796 
 797   bool is_hidden() {
 798     return (_flags & _hidden) != 0;
 799   }
 800   void set_hidden(bool x) {
 801     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 802   }
 803 
 804   ConstMethod::MethodType method_type() const {
 805       return _constMethod->method_type();
 806   }
 807   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 808 
 809   // On-stack replacement support
 810   bool has_osr_nmethod(int level, bool match_level) {
 811    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 812   }
 813 
 814   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 815     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 816   }
 817 
 818   // Inline cache support
 819   void cleanup_inline_caches();
 820 
 821   // Find if klass for method is loaded
 822   bool is_klass_loaded_by_klass_index(int klass_index) const;
 823   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 824 
 825   // Indicates whether compilation failed earlier for this method, or
 826   // whether it is not compilable for another reason like having a
 827   // breakpoint set in it.
 828   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 829   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 830   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 831     set_not_compilable(comp_level, false);
 832   }
 833   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 834   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 835   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 836     set_not_osr_compilable(comp_level, false);
 837   }
 838   bool is_always_compilable() const;
 839 
 840  private:
 841   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 842 
 843  public:
 844   MethodCounters* get_method_counters(TRAPS) {
 845     if (_method_counters == NULL) {
 846       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 847     }
 848     return _method_counters;
 849   }
 850 
 851   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 852   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 853   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 854   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 855   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 856   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 857 
 858   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 859   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 860   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 861   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 862   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 863   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 864 
 865   // Background compilation support
 866   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 867   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 868   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 869 
 870   // Resolve all classes in signature, return 'true' if successful
 871   static bool load_signature_classes(methodHandle m, TRAPS);
 872 
 873   // Return if true if not all classes references in signature, including return type, has been loaded
 874   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 875 
 876   // Printing
 877   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 878 #if INCLUDE_JVMTI
 879   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 880 #else
 881   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 882 #endif
 883 
 884   // Helper routine used for method sorting
 885   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);
 886 
 887   // Deallocation function for redefine classes or if an error occurs
 888   void deallocate_contents(ClassLoaderData* loader_data);
 889 
 890   // Printing
 891 #ifndef PRODUCT
 892   void print_on(outputStream* st) const;
 893 #endif
 894   void print_value_on(outputStream* st) const;
 895 
 896   const char* internal_name() const { return "{method}"; }
 897 
 898   // Check for valid method pointer
 899   static bool has_method_vptr(const void* ptr);
 900   bool is_valid_method() const;
 901 
 902   // Verify
 903   void verify() { verify_on(tty); }
 904   void verify_on(outputStream* st);
 905 
 906  private:
 907 
 908   // Inlined elements
 909   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 910   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 911 };
 912 
 913 
 914 // Utility class for compressing line number tables
 915 
 916 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 917  private:
 918   int _bci;
 919   int _line;
 920  public:
 921   // Constructor
 922   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 923   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 924 
 925   // Write (bci, line number) pair to stream
 926   void write_pair_regular(int bci_delta, int line_delta);
 927 
 928   inline void write_pair_inline(int bci, int line) {
 929     int bci_delta = bci - _bci;
 930     int line_delta = line - _line;
 931     _bci = bci;
 932     _line = line;
 933     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 934     if (bci_delta == 0 && line_delta == 0) return;
 935     // Check if bci is 5-bit and line number 3-bit unsigned.
 936     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 937       // Compress into single byte.
 938       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 939       // Check that value doesn't match escape character.
 940       if (value != 0xFF) {
 941         write_byte(value);
 942         return;
 943       }
 944     }
 945     write_pair_regular(bci_delta, line_delta);
 946   }
 947 
 948 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 949 // Disabling optimization doesn't work for methods in header files
 950 // so we force it to call through the non-optimized version in the .cpp.
 951 // It's gross, but it's the only way we can ensure that all callers are
 952 // fixed.  _MSC_VER is defined by the windows compiler
 953 #if defined(_M_AMD64) && _MSC_VER >= 1400
 954   void write_pair(int bci, int line);
 955 #else
 956   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 957 #endif
 958 
 959   // Write end-of-stream marker
 960   void write_terminator()                        { write_byte(0); }
 961 };
 962 
 963 
 964 // Utility class for decompressing line number tables
 965 
 966 class CompressedLineNumberReadStream: public CompressedReadStream {
 967  private:
 968   int _bci;
 969   int _line;
 970  public:
 971   // Constructor
 972   CompressedLineNumberReadStream(u_char* buffer);
 973   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 974   bool read_pair();
 975   // Accessing bci and line number (after calling read_pair)
 976   int bci() const                               { return _bci; }
 977   int line() const                              { return _line; }
 978 };
 979 
 980 
 981 /// Fast Breakpoints.
 982 
 983 // If this structure gets more complicated (because bpts get numerous),
 984 // move it into its own header.
 985 
 986 // There is presently no provision for concurrent access
 987 // to breakpoint lists, which is only OK for JVMTI because
 988 // breakpoints are written only at safepoints, and are read
 989 // concurrently only outside of safepoints.
 990 
 991 class BreakpointInfo : public CHeapObj<mtClass> {
 992   friend class VMStructs;
 993  private:
 994   Bytecodes::Code  _orig_bytecode;
 995   int              _bci;
 996   u2               _name_index;       // of method
 997   u2               _signature_index;  // of method
 998   BreakpointInfo*  _next;             // simple storage allocation
 999 
1000  public:
1001   BreakpointInfo(Method* m, int bci);
1002 
1003   // accessors
1004   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1005   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1006   int         bci()                                   { return _bci; }
1007 
1008   BreakpointInfo*          next() const               { return _next; }
1009   void                 set_next(BreakpointInfo* n)    { _next = n; }
1010 
1011   // helps for searchers
1012   bool match(const Method* m, int bci) {
1013     return bci == _bci && match(m);
1014   }
1015 
1016   bool match(const Method* m) {
1017     return _name_index == m->name_index() &&
1018       _signature_index == m->signature_index();
1019   }
1020 
1021   void set(Method* method);
1022   void clear(Method* method);
1023 };
1024 
1025 // Utility class for access exception handlers
1026 class ExceptionTable : public StackObj {
1027  private:
1028   ExceptionTableElement* _table;
1029   u2  _length;
1030 
1031  public:
1032   ExceptionTable(const Method* m) {
1033     if (m->has_exception_handler()) {
1034       _table = m->exception_table_start();
1035       _length = m->exception_table_length();
1036     } else {
1037       _table = NULL;
1038       _length = 0;
1039     }
1040   }
1041 
1042   int length() const {
1043     return _length;
1044   }
1045 
1046   u2 start_pc(int idx) const {
1047     assert(idx < _length, "out of bounds");
1048     return _table[idx].start_pc;
1049   }
1050 
1051   void set_start_pc(int idx, u2 value) {
1052     assert(idx < _length, "out of bounds");
1053     _table[idx].start_pc = value;
1054   }
1055 
1056   u2 end_pc(int idx) const {
1057     assert(idx < _length, "out of bounds");
1058     return _table[idx].end_pc;
1059   }
1060 
1061   void set_end_pc(int idx, u2 value) {
1062     assert(idx < _length, "out of bounds");
1063     _table[idx].end_pc = value;
1064   }
1065 
1066   u2 handler_pc(int idx) const {
1067     assert(idx < _length, "out of bounds");
1068     return _table[idx].handler_pc;
1069   }
1070 
1071   void set_handler_pc(int idx, u2 value) {
1072     assert(idx < _length, "out of bounds");
1073     _table[idx].handler_pc = value;
1074   }
1075 
1076   u2 catch_type_index(int idx) const {
1077     assert(idx < _length, "out of bounds");
1078     return _table[idx].catch_type_index;
1079   }
1080 
1081   void set_catch_type_index(int idx, u2 value) {
1082     assert(idx < _length, "out of bounds");
1083     _table[idx].catch_type_index = value;
1084   }
1085 };
1086 
1087 #endif // SHARE_VM_OOPS_METHODOOP_HPP