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     _shared           = 1 << 6
  86   };
  87   u1 _flags;
  88 
  89 #ifndef PRODUCT
  90   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
  91 #endif
  92   // Entry point for calling both from and to the interpreter.
  93   address _i2i_entry;           // All-args-on-stack calling convention
  94   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
  95   AdapterHandlerEntry* _adapter;
  96   // Entry point for calling from compiled code, to compiled code if it exists
  97   // or else the interpreter.
  98   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
  99   // The entry point for calling both from and to compiled code is
 100   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 101   // field can come and go.  It can transition from NULL to not-null at any
 102   // time (whenever a compile completes).  It can transition from not-null to
 103   // NULL only at safepoints (because of a de-opt).
 104   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 105   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 106 
 107   // Constructor
 108   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 109  public:
 110 
 111   static Method* allocate(ClassLoaderData* loader_data,
 112                           int byte_code_size,
 113                           AccessFlags access_flags,
 114                           InlineTableSizes* sizes,
 115                           ConstMethod::MethodType method_type,
 116                           TRAPS);
 117 
 118   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 119   Method(){}
 120 
 121   // The Method vtable is restored by this call when the Method is in the
 122   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 123   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 124   // by their vtable.
 125   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 126   bool is_method() const volatile { return true; }
 127 
 128   void restore_unshareable_info(TRAPS);
 129 
 130   // accessors for instance variables
 131 
 132   ConstMethod* constMethod() const             { return _constMethod; }
 133   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 134 
 135 
 136   static address make_adapters(methodHandle mh, TRAPS);
 137   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 138   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 139 
 140   // access flag
 141   AccessFlags access_flags() const               { return _access_flags;  }
 142   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 143 
 144   // name
 145   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 146   int name_index() const                         { return constMethod()->name_index();         }
 147   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 148 
 149   // signature
 150   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 151   int signature_index() const                    { return constMethod()->signature_index();         }
 152   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 153 
 154   // generics support
 155   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 156   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 157   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 158 
 159   // annotations support
 160   AnnotationArray* annotations() const           {
 161     return constMethod()->method_annotations();
 162   }
 163   AnnotationArray* parameter_annotations() const {
 164     return constMethod()->parameter_annotations();
 165   }
 166   AnnotationArray* annotation_default() const    {
 167     return constMethod()->default_annotations();
 168   }
 169   AnnotationArray* type_annotations() const      {
 170     return constMethod()->type_annotations();
 171   }
 172 
 173 #ifdef CC_INTERP
 174   void set_result_index(BasicType type);
 175   int  result_index()                            { return _result_index; }
 176 #endif
 177 
 178   // Helper routine: get klass name + "." + method name + signature as
 179   // C string, for the purpose of providing more useful NoSuchMethodErrors
 180   // and fatal error handling. The string is allocated in resource
 181   // area if a buffer is not provided by the caller.
 182   char* name_and_sig_as_C_string() const;
 183   char* name_and_sig_as_C_string(char* buf, int size) const;
 184 
 185   // Static routine in the situations we don't have a Method*
 186   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 187   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 188 
 189   Bytecodes::Code java_code_at(int bci) const {
 190     return Bytecodes::java_code_at(this, bcp_from(bci));
 191   }
 192   Bytecodes::Code code_at(int bci) const {
 193     return Bytecodes::code_at(this, bcp_from(bci));
 194   }
 195 
 196   // JVMTI breakpoints
 197   Bytecodes::Code orig_bytecode_at(int bci) const;
 198   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 199   void set_breakpoint(int bci);
 200   void clear_breakpoint(int bci);
 201   void clear_all_breakpoints();
 202   // Tracking number of breakpoints, for fullspeed debugging.
 203   // Only mutated by VM thread.
 204   u2   number_of_breakpoints()             const {
 205     MethodCounters* mcs = method_counters();
 206     if (mcs == NULL) {
 207       return 0;
 208     } else {
 209       return mcs->number_of_breakpoints();
 210     }
 211   }
 212   void incr_number_of_breakpoints(TRAPS)         {
 213     MethodCounters* mcs = get_method_counters(CHECK);
 214     if (mcs != NULL) {
 215       mcs->incr_number_of_breakpoints();
 216     }
 217   }
 218   void decr_number_of_breakpoints(TRAPS)         {
 219     MethodCounters* mcs = get_method_counters(CHECK);
 220     if (mcs != NULL) {
 221       mcs->decr_number_of_breakpoints();
 222     }
 223   }
 224   // Initialization only
 225   void clear_number_of_breakpoints()             {
 226     MethodCounters* mcs = method_counters();
 227     if (mcs != NULL) {
 228       mcs->clear_number_of_breakpoints();
 229     }
 230   }
 231 
 232   // index into InstanceKlass methods() array
 233   // note: also used by jfr
 234   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 235   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 236 
 237   // code size
 238   int code_size() const                  { return constMethod()->code_size(); }
 239 
 240   // method size
 241   int method_size() const                        { return _method_size; }
 242   void set_method_size(int size) {
 243     assert(0 <= size && size < (1 << 16), "invalid method size");
 244     _method_size = size;
 245   }
 246 
 247   // constant pool for Klass* holding this method
 248   ConstantPool* constants() const              { return constMethod()->constants(); }
 249   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 250 
 251   // max stack
 252   // return original max stack size for method verification
 253   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 254   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 255   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 256 
 257   // max locals
 258   int  max_locals() const                        { return constMethod()->max_locals(); }
 259   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 260 
 261   int highest_comp_level() const;
 262   void set_highest_comp_level(int level);
 263   int highest_osr_comp_level() const;
 264   void set_highest_osr_comp_level(int level);
 265 
 266   // Count of times method was exited via exception while interpreting
 267   void interpreter_throwout_increment(TRAPS) {
 268     MethodCounters* mcs = get_method_counters(CHECK);
 269     if (mcs != NULL) {
 270       mcs->interpreter_throwout_increment();
 271     }
 272   }
 273 
 274   int  interpreter_throwout_count() const        {
 275     MethodCounters* mcs = method_counters();
 276     if (mcs == NULL) {
 277       return 0;
 278     } else {
 279       return mcs->interpreter_throwout_count();
 280     }
 281   }
 282 
 283   // size of parameters
 284   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 285   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 286 
 287   bool has_stackmap_table() const {
 288     return constMethod()->has_stackmap_table();
 289   }
 290 
 291   Array<u1>* stackmap_data() const {
 292     return constMethod()->stackmap_data();
 293   }
 294 
 295   void set_stackmap_data(Array<u1>* sd) {
 296     constMethod()->set_stackmap_data(sd);
 297   }
 298 
 299   // exception handler table
 300   bool has_exception_handler() const
 301                              { return constMethod()->has_exception_handler(); }
 302   int exception_table_length() const
 303                              { return constMethod()->exception_table_length(); }
 304   ExceptionTableElement* exception_table_start() const
 305                              { return constMethod()->exception_table_start(); }
 306 
 307   // Finds the first entry point bci of an exception handler for an
 308   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 309   // for ex_klass indicates that the exception klass is not known; in
 310   // this case it matches any constraint class. Returns -1 if the
 311   // exception cannot be handled in this method. The handler
 312   // constraint classes are loaded if necessary. Note that this may
 313   // throw an exception if loading of the constraint classes causes
 314   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 315   // If an exception is thrown, returns the bci of the
 316   // exception handler which caused the exception to be thrown, which
 317   // is needed for proper retries. See, for example,
 318   // InterpreterRuntime::exception_handler_for_exception.
 319   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 320 
 321   // method data access
 322   MethodData* method_data() const              {
 323     return _method_data;
 324   }
 325 
 326   void set_method_data(MethodData* data)       {
 327     // The store into method must be released. On platforms without
 328     // total store order (TSO) the reference may become visible before
 329     // the initialization of data otherwise.
 330     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);
 331   }
 332 
 333   MethodCounters* method_counters() const {
 334     return _method_counters;
 335   }
 336 
 337   void clear_method_counters() {
 338     _method_counters = NULL;
 339   }
 340 
 341   bool init_method_counters(MethodCounters* counters) {
 342     // Try to install a pointer to MethodCounters, return true on success.
 343     return Atomic::cmpxchg_ptr(counters, (volatile void*)&_method_counters, NULL) == NULL;
 344   }
 345 
 346 #ifdef TIERED
 347   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 348   // We can do that since interpreter_invocation_count is not used in tiered.
 349   int prev_event_count() const                   {
 350     if (method_counters() == NULL) {
 351       return 0;
 352     } else {
 353       return method_counters()->interpreter_invocation_count();
 354     }
 355   }
 356   void set_prev_event_count(int count) {
 357     MethodCounters* mcs = method_counters();
 358     if (mcs != NULL) {
 359       mcs->set_interpreter_invocation_count(count);
 360     }
 361   }
 362   jlong prev_time() const                        {
 363     MethodCounters* mcs = method_counters();
 364     return mcs == NULL ? 0 : mcs->prev_time();
 365   }
 366   void set_prev_time(jlong time) {
 367     MethodCounters* mcs = method_counters();
 368     if (mcs != NULL) {
 369       mcs->set_prev_time(time);
 370     }
 371   }
 372   float rate() const                             {
 373     MethodCounters* mcs = method_counters();
 374     return mcs == NULL ? 0 : mcs->rate();
 375   }
 376   void set_rate(float rate) {
 377     MethodCounters* mcs = method_counters();
 378     if (mcs != NULL) {
 379       mcs->set_rate(rate);
 380     }
 381   }
 382 #endif
 383   int nmethod_age() const {
 384     if (method_counters() == NULL) {
 385       return INT_MAX;
 386     } else {
 387       return method_counters()->nmethod_age();
 388     }
 389   }
 390 
 391   int invocation_count();
 392   int backedge_count();
 393 
 394   bool was_executed_more_than(int n);
 395   bool was_never_executed()                      { return !was_executed_more_than(0); }
 396 
 397   static void build_interpreter_method_data(methodHandle method, TRAPS);
 398 
 399   static MethodCounters* build_method_counters(Method* m, TRAPS);
 400 
 401   int interpreter_invocation_count() {
 402     if (TieredCompilation) {
 403       return invocation_count();
 404     } else {
 405       MethodCounters* mcs = method_counters();
 406       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 407     }
 408   }
 409   int increment_interpreter_invocation_count(TRAPS) {
 410     if (TieredCompilation) ShouldNotReachHere();
 411     MethodCounters* mcs = get_method_counters(CHECK_0);
 412     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 413   }
 414 
 415 #ifndef PRODUCT
 416   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 417   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 418 #else
 419   // for PrintMethodData in a product build
 420   int  compiled_invocation_count() const         { return 0;  }
 421 #endif // not PRODUCT
 422 
 423   // Clear (non-shared space) pointers which could not be relevant
 424   // if this (shared) method were mapped into another JVM.
 425   void remove_unshareable_info();
 426 
 427   // nmethod/verified compiler entry
 428   address verified_code_entry();
 429   bool check_code() const;      // Not inline to avoid circular ref
 430   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 431   void clear_code();            // Clear out any compiled code
 432   static void set_code(methodHandle mh, nmethod* code);
 433   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 434   address get_i2c_entry();
 435   address get_c2i_entry();
 436   address get_c2i_unverified_entry();
 437   AdapterHandlerEntry* adapter() {  return _adapter; }
 438   // setup entry points
 439   void link_method(methodHandle method, TRAPS);
 440   // clear entry points. Used by sharing code
 441   void unlink_method();
 442 
 443   // vtable index
 444   enum VtableIndexFlag {
 445     // Valid vtable indexes are non-negative (>= 0).
 446     // These few negative values are used as sentinels.
 447     itable_index_max        = -10, // first itable index, growing downward
 448     pending_itable_index    = -9,  // itable index will be assigned
 449     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 450     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 451     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 452     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 453   };
 454   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 455   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 456   int  vtable_index() const                      { return _vtable_index; }
 457   void set_vtable_index(int index)               { _vtable_index = index; }
 458   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 459   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 460   int  itable_index() const                      { assert(valid_itable_index(), "");
 461                                                    return itable_index_max - _vtable_index; }
 462   void set_itable_index(int index)               { _vtable_index = itable_index_max - index; assert(valid_itable_index(), ""); }
 463 
 464   // interpreter entry
 465   address interpreter_entry() const              { return _i2i_entry; }
 466   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 467   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 468 
 469   // native function (used for native methods only)
 470   enum {
 471     native_bind_event_is_interesting = true
 472   };
 473   address native_function() const                { return *(native_function_addr()); }
 474   address critical_native_function();
 475 
 476   // Must specify a real function (not NULL).
 477   // Use clear_native_function() to unregister.
 478   void set_native_function(address function, bool post_event_flag);
 479   bool has_native_function() const;
 480   void clear_native_function();
 481 
 482   // signature handler (used for native methods only)
 483   address signature_handler() const              { return *(signature_handler_addr()); }
 484   void set_signature_handler(address handler);
 485 
 486   // Interpreter oopmap support
 487   void mask_for(int bci, InterpreterOopMap* mask);
 488 
 489   // operations on invocation counter
 490   void print_invocation_count();
 491 
 492   // byte codes
 493   void    set_code(address code)      { return constMethod()->set_code(code); }
 494   address code_base() const           { return constMethod()->code_base(); }
 495   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 496 
 497   // prints byte codes
 498   void print_codes() const            { print_codes_on(tty); }
 499   void print_codes_on(outputStream* st) const;
 500   void print_codes_on(int from, int to, outputStream* st) const;
 501 
 502   // method parameters
 503   bool has_method_parameters() const
 504                          { return constMethod()->has_method_parameters(); }
 505   int method_parameters_length() const
 506                          { return constMethod()->method_parameters_length(); }
 507   MethodParametersElement* method_parameters_start() const
 508                           { return constMethod()->method_parameters_start(); }
 509 
 510   // checked exceptions
 511   int checked_exceptions_length() const
 512                          { return constMethod()->checked_exceptions_length(); }
 513   CheckedExceptionElement* checked_exceptions_start() const
 514                           { return constMethod()->checked_exceptions_start(); }
 515 
 516   // localvariable table
 517   bool has_localvariable_table() const
 518                           { return constMethod()->has_localvariable_table(); }
 519   int localvariable_table_length() const
 520                         { return constMethod()->localvariable_table_length(); }
 521   LocalVariableTableElement* localvariable_table_start() const
 522                          { return constMethod()->localvariable_table_start(); }
 523 
 524   bool has_linenumber_table() const
 525                               { return constMethod()->has_linenumber_table(); }
 526   u_char* compressed_linenumber_table() const
 527                        { return constMethod()->compressed_linenumber_table(); }
 528 
 529   // method holder (the Klass* holding this method)
 530   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 531 
 532   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 533   Symbol* klass_name() const;                    // returns the name of the method holder
 534   BasicType result_type() const;                 // type of the method result
 535   int result_type_index() const;                 // type index of the method result
 536   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 537   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 538 
 539   // Checked exceptions thrown by this method (resolved to mirrors)
 540   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 541 
 542   // Access flags
 543   bool is_public() const                         { return access_flags().is_public();      }
 544   bool is_private() const                        { return access_flags().is_private();     }
 545   bool is_protected() const                      { return access_flags().is_protected();   }
 546   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 547   bool is_static() const                         { return access_flags().is_static();      }
 548   bool is_final() const                          { return access_flags().is_final();       }
 549   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 550   bool is_native() const                         { return access_flags().is_native();      }
 551   bool is_abstract() const                       { return access_flags().is_abstract();    }
 552   bool is_strict() const                         { return access_flags().is_strict();      }
 553   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 554 
 555   // returns true if contains only return operation
 556   bool is_empty_method() const;
 557 
 558   // returns true if this is a vanilla constructor
 559   bool is_vanilla_constructor() const;
 560 
 561   // checks method and its method holder
 562   bool is_final_method() const;
 563   bool is_final_method(AccessFlags class_access_flags) const;
 564   bool is_default_method() const;
 565 
 566   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 567   bool can_be_statically_bound() const;
 568   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 569 
 570   // returns true if the method has any backward branches.
 571   bool has_loops() {
 572     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 573   };
 574 
 575   bool compute_has_loops_flag();
 576 
 577   bool has_jsrs() {
 578     return access_flags().has_jsrs();
 579   };
 580   void set_has_jsrs() {
 581     _access_flags.set_has_jsrs();
 582   }
 583 
 584   // returns true if the method has any monitors.
 585   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 586   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 587 
 588   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 589 
 590   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 591   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 592   // has not been computed yet.
 593   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 594   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 595 
 596   // returns true if the method is an accessor function (setter/getter).
 597   bool is_accessor() const;
 598 
 599   // returns true if the method does nothing but return a constant of primitive type
 600   bool is_constant_getter() const;
 601 
 602   // returns true if the method is an initializer (<init> or <clinit>).
 603   bool is_initializer() const;
 604 
 605   // returns true if the method is static OR if the classfile version < 51
 606   bool has_valid_initializer_flags() const;
 607 
 608   // returns true if the method name is <clinit> and the method has
 609   // valid static initializer flags.
 610   bool is_static_initializer() const;
 611 
 612   // compiled code support
 613   // NOTE: code() is inherently racy as deopt can be clearing code
 614   // simultaneously. Use with caution.
 615   bool has_compiled_code() const                 { return code() != NULL; }
 616 
 617   // sizing
 618   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 619   static int size(bool is_native);
 620   int size() const                               { return method_size(); }
 621 #if INCLUDE_SERVICES
 622   void collect_statistics(KlassSizeStats *sz) const;
 623 #endif
 624 
 625   // interpreter support
 626   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 627   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 628 #ifdef CC_INTERP
 629   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 630 #endif /* CC_INTERP */
 631   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 632   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 633   static ByteSize method_data_offset()           {
 634     return byte_offset_of(Method, _method_data);
 635   }
 636   static ByteSize method_counters_offset()       {
 637     return byte_offset_of(Method, _method_counters);
 638   }
 639 #ifndef PRODUCT
 640   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 641 #endif // not PRODUCT
 642   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 643   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 644   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 645   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 646 
 647   // for code generation
 648   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 649   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 650   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 651 
 652   // Static methods that are used to implement member methods where an exposed this pointer
 653   // is needed due to possible GCs
 654   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 655 
 656   // Returns the byte code index from the byte code pointer
 657   int     bci_from(address bcp) const;
 658   address bcp_from(int bci) const;
 659   address bcp_from(address bcp) const;
 660   int validate_bci_from_bcp(address bcp) const;
 661   int validate_bci(int bci) const;
 662 
 663   // Returns the line number for a bci if debugging information for the method is prowided,
 664   // -1 is returned otherwise.
 665   int line_number_from_bci(int bci) const;
 666 
 667   // Reflection support
 668   bool is_overridden_in(Klass* k) const;
 669 
 670   // Stack walking support
 671   bool is_ignored_by_security_stack_walk() const;
 672 
 673   // JSR 292 support
 674   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 675   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 676   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 677   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 678                                                    Symbol* signature, //anything at all
 679                                                    TRAPS);
 680   static Klass* check_non_bcp_klass(Klass* klass);
 681 
 682   // How many extra stack entries for invokedynamic when it's enabled
 683   static const int extra_stack_entries_for_jsr292 = 1;
 684 
 685   // this operates only on invoke methods:
 686   // presize interpreter frames for extra interpreter stack entries, if needed
 687   // Account for the extra appendix argument for invokehandle/invokedynamic
 688   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 689   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 690 
 691   // RedefineClasses() support:
 692   bool is_old() const                               { return access_flags().is_old(); }
 693   void set_is_old()                                 { _access_flags.set_is_old(); }
 694   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 695   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 696   bool is_deleted() const                           { return access_flags().is_deleted(); }
 697   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 698 
 699   bool is_running_emcp() const {
 700     // EMCP methods are old but not obsolete or deleted. Equivalent
 701     // Modulo Constant Pool means the method is equivalent except
 702     // the constant pool and instructions that access the constant
 703     // pool might be different.
 704     // If a breakpoint is set in a redefined method, its EMCP methods that are
 705     // still running must have a breakpoint also.
 706     return (_flags & _running_emcp) != 0;
 707   }
 708 
 709   void set_running_emcp(bool x) {
 710     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 711   }
 712 
 713   bool on_stack() const                             { return access_flags().on_stack(); }
 714   void set_on_stack(const bool value);
 715 
 716   // see the definition in Method*.cpp for the gory details
 717   bool should_not_be_cached() const;
 718 
 719   // JVMTI Native method prefixing support:
 720   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 721   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 722 
 723   // Rewriting support
 724   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 725                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 726 
 727   // jmethodID handling
 728   // Because the useful life-span of a jmethodID cannot be determined,
 729   // once created they are never reclaimed.  The methods to which they refer,
 730   // however, can be GC'ed away if the class is unloaded or if the method is
 731   // made obsolete or deleted -- in these cases, the jmethodID
 732   // refers to NULL (as is the case for any weak reference).
 733   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 734   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 735 
 736   // Ensure there is enough capacity in the internal tracking data
 737   // structures to hold the number of jmethodIDs you plan to generate.
 738   // This saves substantial time doing allocations.
 739   static void ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity);
 740 
 741   // Use resolve_jmethod_id() in situations where the caller is expected
 742   // to provide a valid jmethodID; the only sanity checks are in asserts;
 743   // result guaranteed not to be NULL.
 744   inline static Method* resolve_jmethod_id(jmethodID mid) {
 745     assert(mid != NULL, "JNI method id should not be null");
 746     return *((Method**)mid);
 747   }
 748 
 749   // Use checked_resolve_jmethod_id() in situations where the caller
 750   // should provide a valid jmethodID, but might not. NULL is returned
 751   // when the jmethodID does not refer to a valid method.
 752   static Method* checked_resolve_jmethod_id(jmethodID mid);
 753 
 754   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 755   static bool is_method_id(jmethodID mid);
 756 
 757   // Clear methods
 758   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 759   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 760 
 761   // Get this method's jmethodID -- allocate if it doesn't exist
 762   jmethodID jmethod_id()                            { methodHandle this_h(this);
 763                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 764 
 765   // Lookup the jmethodID for this method.  Return NULL if not found.
 766   // NOTE that this function can be called from a signal handler
 767   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 768   // needs to be async-safe. No allocation should be done and
 769   // so handles are not used to avoid deadlock.
 770   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 771 
 772   // Support for inlining of intrinsic methods
 773   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 774   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 775 
 776   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 777   void init_intrinsic_id();     // updates from _none if a match
 778   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 779 
 780   bool jfr_towrite() {
 781     return (_flags & _jfr_towrite) != 0;
 782   }
 783   void set_jfr_towrite(bool x) {
 784     _flags = x ? (_flags | _jfr_towrite) : (_flags & ~_jfr_towrite);
 785   }
 786 
 787   bool caller_sensitive() {
 788     return (_flags & _caller_sensitive) != 0;
 789   }
 790   void set_caller_sensitive(bool x) {
 791     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 792   }
 793 
 794   bool force_inline() {
 795     return (_flags & _force_inline) != 0;
 796   }
 797   void set_force_inline(bool x) {
 798     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 799   }
 800 
 801   bool dont_inline() {
 802     return (_flags & _dont_inline) != 0;
 803   }
 804   void set_dont_inline(bool x) {
 805     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 806   }
 807 
 808   bool is_hidden() {
 809     return (_flags & _hidden) != 0;
 810   }
 811   void set_hidden(bool x) {
 812     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 813   }
 814 
 815   bool is_shared() {
 816     return (_flags & _shared) != 0;
 817   }
 818   void set_shared(bool x) {
 819     _flags = x ? (_flags | _shared) : (_flags & ~_shared);
 820   }
 821 
 822   ConstMethod::MethodType method_type() const {
 823       return _constMethod->method_type();
 824   }
 825   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 826 
 827   // On-stack replacement support
 828   bool has_osr_nmethod(int level, bool match_level) {
 829    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 830   }
 831 
 832   int mark_osr_nmethods() {
 833     return method_holder()->mark_osr_nmethods(this);
 834   }
 835 
 836   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 837     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 838   }
 839 
 840   // Inline cache support
 841   void cleanup_inline_caches();
 842 
 843   // Find if klass for method is loaded
 844   bool is_klass_loaded_by_klass_index(int klass_index) const;
 845   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 846 
 847   // Indicates whether compilation failed earlier for this method, or
 848   // whether it is not compilable for another reason like having a
 849   // breakpoint set in it.
 850   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 851   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 852   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 853     set_not_compilable(comp_level, false);
 854   }
 855   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 856   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 857   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 858     set_not_osr_compilable(comp_level, false);
 859   }
 860   bool is_always_compilable() const;
 861 
 862  private:
 863   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 864 
 865  public:
 866   MethodCounters* get_method_counters(TRAPS) {
 867     if (_method_counters == NULL) {
 868       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 869     }
 870     return _method_counters;
 871   }
 872 
 873   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 874   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 875   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 876   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 877   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 878   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 879 
 880   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 881   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 882   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 883   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 884   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 885   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 886 
 887   // Background compilation support
 888   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 889   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 890   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 891 
 892   // Resolve all classes in signature, return 'true' if successful
 893   static bool load_signature_classes(methodHandle m, TRAPS);
 894 
 895   // Return if true if not all classes references in signature, including return type, has been loaded
 896   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 897 
 898   // Printing
 899   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 900 #if INCLUDE_JVMTI
 901   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 902 #else
 903   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 904 #endif
 905 
 906   // Helper routine used for method sorting
 907   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);
 908 
 909   // Deallocation function for redefine classes or if an error occurs
 910   void deallocate_contents(ClassLoaderData* loader_data);
 911 
 912   // Printing
 913 #ifndef PRODUCT
 914   void print_on(outputStream* st) const;
 915 #endif
 916   void print_value_on(outputStream* st) const;
 917 
 918   const char* internal_name() const { return "{method}"; }
 919 
 920   // Check for valid method pointer
 921   static bool has_method_vptr(const void* ptr);
 922   bool is_valid_method() const;
 923 
 924   // Verify
 925   void verify() { verify_on(tty); }
 926   void verify_on(outputStream* st);
 927 
 928  private:
 929 
 930   // Inlined elements
 931   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 932   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 933 };
 934 
 935 
 936 // Utility class for compressing line number tables
 937 
 938 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 939  private:
 940   int _bci;
 941   int _line;
 942  public:
 943   // Constructor
 944   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 945   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 946 
 947   // Write (bci, line number) pair to stream
 948   void write_pair_regular(int bci_delta, int line_delta);
 949 
 950   inline void write_pair_inline(int bci, int line) {
 951     int bci_delta = bci - _bci;
 952     int line_delta = line - _line;
 953     _bci = bci;
 954     _line = line;
 955     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 956     if (bci_delta == 0 && line_delta == 0) return;
 957     // Check if bci is 5-bit and line number 3-bit unsigned.
 958     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 959       // Compress into single byte.
 960       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 961       // Check that value doesn't match escape character.
 962       if (value != 0xFF) {
 963         write_byte(value);
 964         return;
 965       }
 966     }
 967     write_pair_regular(bci_delta, line_delta);
 968   }
 969 
 970 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 971 // Disabling optimization doesn't work for methods in header files
 972 // so we force it to call through the non-optimized version in the .cpp.
 973 // It's gross, but it's the only way we can ensure that all callers are
 974 // fixed.  _MSC_VER is defined by the windows compiler
 975 #if defined(_M_AMD64) && _MSC_VER >= 1400
 976   void write_pair(int bci, int line);
 977 #else
 978   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 979 #endif
 980 
 981   // Write end-of-stream marker
 982   void write_terminator()                        { write_byte(0); }
 983 };
 984 
 985 
 986 // Utility class for decompressing line number tables
 987 
 988 class CompressedLineNumberReadStream: public CompressedReadStream {
 989  private:
 990   int _bci;
 991   int _line;
 992  public:
 993   // Constructor
 994   CompressedLineNumberReadStream(u_char* buffer);
 995   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 996   bool read_pair();
 997   // Accessing bci and line number (after calling read_pair)
 998   int bci() const                               { return _bci; }
 999   int line() const                              { return _line; }
1000 };
1001 
1002 
1003 /// Fast Breakpoints.
1004 
1005 // If this structure gets more complicated (because bpts get numerous),
1006 // move it into its own header.
1007 
1008 // There is presently no provision for concurrent access
1009 // to breakpoint lists, which is only OK for JVMTI because
1010 // breakpoints are written only at safepoints, and are read
1011 // concurrently only outside of safepoints.
1012 
1013 class BreakpointInfo : public CHeapObj<mtClass> {
1014   friend class VMStructs;
1015  private:
1016   Bytecodes::Code  _orig_bytecode;
1017   int              _bci;
1018   u2               _name_index;       // of method
1019   u2               _signature_index;  // of method
1020   BreakpointInfo*  _next;             // simple storage allocation
1021 
1022  public:
1023   BreakpointInfo(Method* m, int bci);
1024 
1025   // accessors
1026   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1027   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1028   int         bci()                                   { return _bci; }
1029 
1030   BreakpointInfo*          next() const               { return _next; }
1031   void                 set_next(BreakpointInfo* n)    { _next = n; }
1032 
1033   // helps for searchers
1034   bool match(const Method* m, int bci) {
1035     return bci == _bci && match(m);
1036   }
1037 
1038   bool match(const Method* m) {
1039     return _name_index == m->name_index() &&
1040       _signature_index == m->signature_index();
1041   }
1042 
1043   void set(Method* method);
1044   void clear(Method* method);
1045 };
1046 
1047 // Utility class for access exception handlers
1048 class ExceptionTable : public StackObj {
1049  private:
1050   ExceptionTableElement* _table;
1051   u2  _length;
1052 
1053  public:
1054   ExceptionTable(const Method* m) {
1055     if (m->has_exception_handler()) {
1056       _table = m->exception_table_start();
1057       _length = m->exception_table_length();
1058     } else {
1059       _table = NULL;
1060       _length = 0;
1061     }
1062   }
1063 
1064   int length() const {
1065     return _length;
1066   }
1067 
1068   u2 start_pc(int idx) const {
1069     assert(idx < _length, "out of bounds");
1070     return _table[idx].start_pc;
1071   }
1072 
1073   void set_start_pc(int idx, u2 value) {
1074     assert(idx < _length, "out of bounds");
1075     _table[idx].start_pc = value;
1076   }
1077 
1078   u2 end_pc(int idx) const {
1079     assert(idx < _length, "out of bounds");
1080     return _table[idx].end_pc;
1081   }
1082 
1083   void set_end_pc(int idx, u2 value) {
1084     assert(idx < _length, "out of bounds");
1085     _table[idx].end_pc = value;
1086   }
1087 
1088   u2 handler_pc(int idx) const {
1089     assert(idx < _length, "out of bounds");
1090     return _table[idx].handler_pc;
1091   }
1092 
1093   void set_handler_pc(int idx, u2 value) {
1094     assert(idx < _length, "out of bounds");
1095     _table[idx].handler_pc = value;
1096   }
1097 
1098   u2 catch_type_index(int idx) const {
1099     assert(idx < _length, "out of bounds");
1100     return _table[idx].catch_type_index;
1101   }
1102 
1103   void set_catch_type_index(int idx, u2 value) {
1104     assert(idx < _length, "out of bounds");
1105     _table[idx].catch_type_index = value;
1106   }
1107 };
1108 
1109 #endif // SHARE_VM_OOPS_METHODOOP_HPP