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