1 /*
   2  * Copyright (c) 1997, 2013, 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 // Memory layout (each line represents a word). Note that most applications load thousands of methods,
  44 // so keeping the size of this structure small has a big impact on footprint.
  45 //
  46 // The actual bytecodes are inlined after the end of the Method struct.
  47 //
  48 // There are bits in the access_flags telling whether inlined tables are present.
  49 // Note that accessing the line number and local variable tables is not performance critical at all.
  50 // Accessing the checked exceptions table is used by reflection, so we put that last to make access
  51 // to it fast.
  52 //
  53 // The line number table is compressed and inlined following the byte codes. It is found as the first
  54 // byte following the byte codes. The checked exceptions table and the local variable table are inlined
  55 // after the line number table, and indexed from the end of the method. We do not compress the checked
  56 // exceptions table since the average length is less than 2, and do not bother to compress the local
  57 // variable table either since it is mostly absent.
  58 //
  59 // Note that native_function and signature_handler has to be at fixed offsets (required by the interpreter)
  60 //
  61 // |------------------------------------------------------|
  62 // | header                                               |
  63 // | klass                                                |
  64 // |------------------------------------------------------|
  65 // | ConstMethod*                   (metadata)            |
  66 // |------------------------------------------------------|
  67 // | MethodData*                    (metadata)            |
  68 // | MethodCounters                                       |
  69 // |------------------------------------------------------|
  70 // | access_flags                                         |
  71 // | vtable_index                                         |
  72 // |------------------------------------------------------|
  73 // | result_index (C++ interpreter only)                  |
  74 // |------------------------------------------------------|
  75 // | method_size             | intrinsic_id  |   flags    |
  76 // |------------------------------------------------------|
  77 // | code                           (pointer)             |
  78 // | i2i                            (pointer)             |
  79 // | adapter                        (pointer)             |
  80 // | from_compiled_entry            (pointer)             |
  81 // | from_interpreted_entry         (pointer)             |
  82 // |------------------------------------------------------|
  83 // | native_function       (present only if native)       |
  84 // | signature_handler     (present only if native)       |
  85 // |------------------------------------------------------|
  86 
  87 
  88 class CheckedExceptionElement;
  89 class LocalVariableTableElement;
  90 class AdapterHandlerEntry;
  91 class MethodData;
  92 class MethodCounters;
  93 class ConstMethod;
  94 class InlineTableSizes;
  95 class KlassSizeStats;
  96 
  97 class Method : public Metadata {
  98  friend class VMStructs;
  99  private:
 100   ConstMethod*      _constMethod;                // Method read-only data.
 101   MethodData*       _method_data;
 102   MethodCounters*   _method_counters;
 103   AccessFlags       _access_flags;               // Access flags
 104   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
 105                                                  // note: can have vtables with >2**16 elements (because of inheritance)
 106 #ifdef CC_INTERP
 107   int               _result_index;               // C++ interpreter needs for converting results to/from stack
 108 #endif
 109   u2                _method_size;                // size of this object
 110   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
 111 
 112   // Flags
 113   enum Flags {
 114     _jfr_towrite      = 1 << 0,
 115     _caller_sensitive = 1 << 1,
 116     _force_inline     = 1 << 2,
 117     _dont_inline      = 1 << 3,
 118     _hidden           = 1 << 4
 119   };
 120   u1 _flags;
 121 
 122 #ifndef PRODUCT
 123   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 124 #endif
 125   // Entry point for calling both from and to the interpreter.
 126   address _i2i_entry;           // All-args-on-stack calling convention
 127   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
 128   AdapterHandlerEntry* _adapter;
 129   // Entry point for calling from compiled code, to compiled code if it exists
 130   // or else the interpreter.
 131   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 132   // The entry point for calling both from and to compiled code is
 133   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 134   // field can come and go.  It can transition from NULL to not-null at any
 135   // time (whenever a compile completes).  It can transition from not-null to
 136   // NULL only at safepoints (because of a de-opt).
 137   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 138   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 139 
 140   // Constructor
 141   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 142  public:
 143 
 144   static Method* allocate(ClassLoaderData* loader_data,
 145                           int byte_code_size,
 146                           AccessFlags access_flags,
 147                           InlineTableSizes* sizes,
 148                           ConstMethod::MethodType method_type,
 149                           TRAPS);
 150 
 151   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 152   Method(){}
 153 
 154   // The Method vtable is restored by this call when the Method is in the
 155   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 156   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 157   // by their vtable.
 158   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 159   bool is_method() const volatile { return true; }
 160 
 161   // accessors for instance variables
 162 
 163   ConstMethod* constMethod() const             { return _constMethod; }
 164   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 165 
 166 
 167   static address make_adapters(methodHandle mh, TRAPS);
 168   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 169   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 170 
 171   // access flag
 172   AccessFlags access_flags() const               { return _access_flags;  }
 173   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 174 
 175   // name
 176   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 177   int name_index() const                         { return constMethod()->name_index();         }
 178   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 179 
 180   // signature
 181   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 182   int signature_index() const                    { return constMethod()->signature_index();         }
 183   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 184 
 185   // generics support
 186   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 187   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 188   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 189 
 190   // annotations support
 191   AnnotationArray* annotations() const           {
 192     return constMethod()->method_annotations();
 193   }
 194   AnnotationArray* parameter_annotations() const {
 195     return constMethod()->parameter_annotations();
 196   }
 197   AnnotationArray* annotation_default() const    {
 198     return constMethod()->default_annotations();
 199   }
 200   AnnotationArray* type_annotations() const      {
 201     return constMethod()->type_annotations();
 202   }
 203 
 204 #ifdef CC_INTERP
 205   void set_result_index(BasicType type);
 206   int  result_index()                            { return _result_index; }
 207 #endif
 208 
 209   // Helper routine: get klass name + "." + method name + signature as
 210   // C string, for the purpose of providing more useful NoSuchMethodErrors
 211   // and fatal error handling. The string is allocated in resource
 212   // area if a buffer is not provided by the caller.
 213   char* name_and_sig_as_C_string() const;
 214   char* name_and_sig_as_C_string(char* buf, int size) const;
 215 
 216   // Static routine in the situations we don't have a Method*
 217   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 218   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 219 
 220   Bytecodes::Code java_code_at(int bci) const {
 221     return Bytecodes::java_code_at(this, bcp_from(bci));
 222   }
 223   Bytecodes::Code code_at(int bci) const {
 224     return Bytecodes::code_at(this, bcp_from(bci));
 225   }
 226 
 227   // JVMTI breakpoints
 228   Bytecodes::Code orig_bytecode_at(int bci) const;
 229   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 230   void set_breakpoint(int bci);
 231   void clear_breakpoint(int bci);
 232   void clear_all_breakpoints();
 233   // Tracking number of breakpoints, for fullspeed debugging.
 234   // Only mutated by VM thread.
 235   u2   number_of_breakpoints()             const {
 236     if (method_counters() == NULL) {
 237       return 0;
 238     } else {
 239       return method_counters()->number_of_breakpoints();
 240     }
 241   }
 242   void incr_number_of_breakpoints(TRAPS)         {
 243     MethodCounters* mcs = get_method_counters(CHECK);
 244     if (mcs != NULL) {
 245       mcs->incr_number_of_breakpoints();
 246     }
 247   }
 248   void decr_number_of_breakpoints(TRAPS)         {
 249     MethodCounters* mcs = get_method_counters(CHECK);
 250     if (mcs != NULL) {
 251       mcs->decr_number_of_breakpoints();
 252     }
 253   }
 254   // Initialization only
 255   void clear_number_of_breakpoints()             {
 256     if (method_counters() != NULL) {
 257       method_counters()->clear_number_of_breakpoints();
 258     }
 259   }
 260 
 261   // index into InstanceKlass methods() array
 262   // note: also used by jfr
 263   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 264   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 265 
 266   // code size
 267   int code_size() const                  { return constMethod()->code_size(); }
 268 
 269   // method size
 270   int method_size() const                        { return _method_size; }
 271   void set_method_size(int size) {
 272     assert(0 <= size && size < (1 << 16), "invalid method size");
 273     _method_size = size;
 274   }
 275 
 276   // constant pool for Klass* holding this method
 277   ConstantPool* constants() const              { return constMethod()->constants(); }
 278   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 279 
 280   // max stack
 281   // return original max stack size for method verification
 282   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 283   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 284   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 285 
 286   // max locals
 287   int  max_locals() const                        { return constMethod()->max_locals(); }
 288   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 289 
 290   int highest_comp_level() const;
 291   void set_highest_comp_level(int level);
 292   int highest_osr_comp_level() const;
 293   void set_highest_osr_comp_level(int level);
 294 
 295   // Count of times method was exited via exception while interpreting
 296   void interpreter_throwout_increment(TRAPS) {
 297     MethodCounters* mcs = get_method_counters(CHECK);
 298     if (mcs != NULL) {
 299       mcs->interpreter_throwout_increment();
 300     }
 301   }
 302 
 303   int  interpreter_throwout_count() const        {
 304     if (method_counters() == NULL) {
 305       return 0;
 306     } else {
 307       return method_counters()->interpreter_throwout_count();
 308     }
 309   }
 310 
 311   // size of parameters
 312   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 313   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 314 
 315   bool has_stackmap_table() const {
 316     return constMethod()->has_stackmap_table();
 317   }
 318 
 319   Array<u1>* stackmap_data() const {
 320     return constMethod()->stackmap_data();
 321   }
 322 
 323   void set_stackmap_data(Array<u1>* sd) {
 324     constMethod()->set_stackmap_data(sd);
 325   }
 326 
 327   // exception handler table
 328   bool has_exception_handler() const
 329                              { return constMethod()->has_exception_handler(); }
 330   int exception_table_length() const
 331                              { return constMethod()->exception_table_length(); }
 332   ExceptionTableElement* exception_table_start() const
 333                              { return constMethod()->exception_table_start(); }
 334 
 335   // Finds the first entry point bci of an exception handler for an
 336   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 337   // for ex_klass indicates that the exception klass is not known; in
 338   // this case it matches any constraint class. Returns -1 if the
 339   // exception cannot be handled in this method. The handler
 340   // constraint classes are loaded if necessary. Note that this may
 341   // throw an exception if loading of the constraint classes causes
 342   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 343   // If an exception is thrown, returns the bci of the
 344   // exception handler which caused the exception to be thrown, which
 345   // is needed for proper retries. See, for example,
 346   // InterpreterRuntime::exception_handler_for_exception.
 347   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 348 
 349   // method data access
 350   MethodData* method_data() const              {
 351     return _method_data;
 352   }
 353 
 354   void set_method_data(MethodData* data)       {
 355     // The store into method must be released. On platforms without
 356     // total store order (TSO) the reference may become visible before
 357     // the initialization of data otherwise.
 358     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);
 359   }
 360 
 361   MethodCounters* method_counters() const {
 362     return _method_counters;
 363   }
 364 
 365   void set_method_counters(MethodCounters* counters) {
 366     // The store into method must be released. On platforms without
 367     // total store order (TSO) the reference may become visible before
 368     // the initialization of data otherwise.
 369     OrderAccess::release_store_ptr((volatile void *)&_method_counters, counters);
 370   }
 371 
 372 #ifdef TIERED
 373   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 374   // We can do that since interpreter_invocation_count is not used in tiered.
 375   int prev_event_count() const                   {
 376     if (method_counters() == NULL) {
 377       return 0;
 378     } else {
 379       return method_counters()->interpreter_invocation_count();
 380     }
 381   }
 382   void set_prev_event_count(int count, TRAPS)    {
 383     MethodCounters* mcs = get_method_counters(CHECK);
 384     if (mcs != NULL) {
 385       mcs->set_interpreter_invocation_count(count);
 386     }
 387   }
 388   jlong prev_time() const                        {
 389     return method_counters() == NULL ? 0 : method_counters()->prev_time();
 390   }
 391   void set_prev_time(jlong time, TRAPS)          {
 392     MethodCounters* mcs = get_method_counters(CHECK);
 393     if (mcs != NULL) {
 394       mcs->set_prev_time(time);
 395     }
 396   }
 397   float rate() const                             {
 398     return method_counters() == NULL ? 0 : method_counters()->rate();
 399   }
 400   void set_rate(float rate, TRAPS) {
 401     MethodCounters* mcs = get_method_counters(CHECK);
 402     if (mcs != NULL) {
 403       mcs->set_rate(rate);
 404     }
 405   }
 406 #endif
 407 
 408   int invocation_count();
 409   int backedge_count();
 410 
 411   bool was_executed_more_than(int n);
 412   bool was_never_executed()                      { return !was_executed_more_than(0); }
 413 
 414   static void build_interpreter_method_data(methodHandle method, TRAPS);
 415 
 416   static MethodCounters* build_method_counters(Method* m, TRAPS);
 417 
 418   int interpreter_invocation_count() {
 419     if (TieredCompilation) return invocation_count();
 420     else return (method_counters() == NULL) ? 0 :
 421                  method_counters()->interpreter_invocation_count();
 422   }
 423   int increment_interpreter_invocation_count(TRAPS) {
 424     if (TieredCompilation) ShouldNotReachHere();
 425     MethodCounters* mcs = get_method_counters(CHECK_0);
 426     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 427   }
 428 
 429 #ifndef PRODUCT
 430   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 431   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 432 #else
 433   // for PrintMethodData in a product build
 434   int  compiled_invocation_count() const         { return 0;  }
 435 #endif // not PRODUCT
 436 
 437   // Clear (non-shared space) pointers which could not be relevant
 438   // if this (shared) method were mapped into another JVM.
 439   void remove_unshareable_info();
 440 
 441   // nmethod/verified compiler entry
 442   address verified_code_entry();
 443   bool check_code() const;      // Not inline to avoid circular ref
 444   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 445   void clear_code();            // Clear out any compiled code
 446   static void set_code(methodHandle mh, nmethod* code);
 447   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 448   address get_i2c_entry();
 449   address get_c2i_entry();
 450   address get_c2i_unverified_entry();
 451   AdapterHandlerEntry* adapter() {  return _adapter; }
 452   // setup entry points
 453   void link_method(methodHandle method, TRAPS);
 454   // clear entry points. Used by sharing code
 455   void unlink_method();
 456 
 457   // vtable index
 458   enum VtableIndexFlag {
 459     // Valid vtable indexes are non-negative (>= 0).
 460     // These few negative values are used as sentinels.
 461     itable_index_max        = -10, // first itable index, growing downward
 462     pending_itable_index    = -9,  // itable index will be assigned
 463     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 464     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 465     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 466     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 467   };
 468   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 469   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 470   int  vtable_index() const                      { return _vtable_index; }
 471   void set_vtable_index(int index)               { _vtable_index = index; }
 472   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 473   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 474   int  itable_index() const                      { assert(valid_itable_index(), "");
 475                                                    return itable_index_max - _vtable_index; }
 476   void set_itable_index(int index)               { _vtable_index = itable_index_max - index; assert(valid_itable_index(), ""); }
 477 
 478   // interpreter entry
 479   address interpreter_entry() const              { return _i2i_entry; }
 480   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 481   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 482 
 483   // native function (used for native methods only)
 484   enum {
 485     native_bind_event_is_interesting = true
 486   };
 487   address native_function() const                { return *(native_function_addr()); }
 488   address critical_native_function();
 489 
 490   // Must specify a real function (not NULL).
 491   // Use clear_native_function() to unregister.
 492   void set_native_function(address function, bool post_event_flag);
 493   bool has_native_function() const;
 494   void clear_native_function();
 495 
 496   // signature handler (used for native methods only)
 497   address signature_handler() const              { return *(signature_handler_addr()); }
 498   void set_signature_handler(address handler);
 499 
 500   // Interpreter oopmap support
 501   void mask_for(int bci, InterpreterOopMap* mask);
 502 
 503   // operations on invocation counter
 504   void print_invocation_count();
 505 
 506   // byte codes
 507   void    set_code(address code)      { return constMethod()->set_code(code); }
 508   address code_base() const           { return constMethod()->code_base(); }
 509   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 510 
 511   // prints byte codes
 512   void print_codes() const            { print_codes_on(tty); }
 513   void print_codes_on(outputStream* st) const;
 514   void print_codes_on(int from, int to, outputStream* st) const;
 515 
 516   // method parameters
 517   bool has_method_parameters() const
 518                          { return constMethod()->has_method_parameters(); }
 519   int method_parameters_length() const
 520                          { return constMethod()->method_parameters_length(); }
 521   MethodParametersElement* method_parameters_start() const
 522                           { return constMethod()->method_parameters_start(); }
 523 
 524   // checked exceptions
 525   int checked_exceptions_length() const
 526                          { return constMethod()->checked_exceptions_length(); }
 527   CheckedExceptionElement* checked_exceptions_start() const
 528                           { return constMethod()->checked_exceptions_start(); }
 529 
 530   // localvariable table
 531   bool has_localvariable_table() const
 532                           { return constMethod()->has_localvariable_table(); }
 533   int localvariable_table_length() const
 534                         { return constMethod()->localvariable_table_length(); }
 535   LocalVariableTableElement* localvariable_table_start() const
 536                          { return constMethod()->localvariable_table_start(); }
 537 
 538   bool has_linenumber_table() const
 539                               { return constMethod()->has_linenumber_table(); }
 540   u_char* compressed_linenumber_table() const
 541                        { return constMethod()->compressed_linenumber_table(); }
 542 
 543   // method holder (the Klass* holding this method)
 544   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 545 
 546   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 547   Symbol* klass_name() const;                    // returns the name of the method holder
 548   BasicType result_type() const;                 // type of the method result
 549   int result_type_index() const;                 // type index of the method result
 550   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 551   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 552 
 553   // Checked exceptions thrown by this method (resolved to mirrors)
 554   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 555 
 556   // Access flags
 557   bool is_public() const                         { return access_flags().is_public();      }
 558   bool is_private() const                        { return access_flags().is_private();     }
 559   bool is_protected() const                      { return access_flags().is_protected();   }
 560   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 561   bool is_static() const                         { return access_flags().is_static();      }
 562   bool is_final() const                          { return access_flags().is_final();       }
 563   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 564   bool is_native() const                         { return access_flags().is_native();      }
 565   bool is_abstract() const                       { return access_flags().is_abstract();    }
 566   bool is_strict() const                         { return access_flags().is_strict();      }
 567   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 568 
 569   // returns true if contains only return operation
 570   bool is_empty_method() const;
 571 
 572   // returns true if this is a vanilla constructor
 573   bool is_vanilla_constructor() const;
 574 
 575   // checks method and its method holder
 576   bool is_final_method() const;
 577   bool is_final_method(AccessFlags class_access_flags) const;
 578   bool is_default_method() const;
 579 
 580   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 581   bool can_be_statically_bound() const;
 582   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 583 
 584   // returns true if the method has any backward branches.
 585   bool has_loops() {
 586     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 587   };
 588 
 589   bool compute_has_loops_flag();
 590 
 591   bool has_jsrs() {
 592     return access_flags().has_jsrs();
 593   };
 594   void set_has_jsrs() {
 595     _access_flags.set_has_jsrs();
 596   }
 597 
 598   // returns true if the method has any monitors.
 599   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 600   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 601 
 602   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 603 
 604   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 605   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 606   // has not been computed yet.
 607   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 608   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 609 
 610   // returns true if the method is an accessor function (setter/getter).
 611   bool is_accessor() const;
 612 
 613   // returns true if the method is an initializer (<init> or <clinit>).
 614   bool is_initializer() const;
 615 
 616   // returns true if the method is static OR if the classfile version < 51
 617   bool has_valid_initializer_flags() const;
 618 
 619   // returns true if the method name is <clinit> and the method has
 620   // valid static initializer flags.
 621   bool is_static_initializer() const;
 622 
 623   // compiled code support
 624   // NOTE: code() is inherently racy as deopt can be clearing code
 625   // simultaneously. Use with caution.
 626   bool has_compiled_code() const                 { return code() != NULL; }
 627 
 628   // sizing
 629   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 630   static int size(bool is_native);
 631   int size() const                               { return method_size(); }
 632 #if INCLUDE_SERVICES
 633   void collect_statistics(KlassSizeStats *sz) const;
 634 #endif
 635 
 636   // interpreter support
 637   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 638   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 639 #ifdef CC_INTERP
 640   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 641 #endif /* CC_INTERP */
 642   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 643   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 644   static ByteSize method_data_offset()           {
 645     return byte_offset_of(Method, _method_data);
 646   }
 647   static ByteSize method_counters_offset()       {
 648     return byte_offset_of(Method, _method_counters);
 649   }
 650 #ifndef PRODUCT
 651   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 652 #endif // not PRODUCT
 653   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 654   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 655   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 656   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 657 
 658   // for code generation
 659   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 660   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 661   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 662 
 663   // Static methods that are used to implement member methods where an exposed this pointer
 664   // is needed due to possible GCs
 665   static objArrayHandle resolved_checked_exceptions_impl(Method* this_oop, TRAPS);
 666 
 667   // Returns the byte code index from the byte code pointer
 668   int     bci_from(address bcp) const;
 669   address bcp_from(int     bci) const;
 670   int validate_bci_from_bcx(intptr_t bcx) const;
 671 
 672   // Returns the line number for a bci if debugging information for the method is prowided,
 673   // -1 is returned otherwise.
 674   int line_number_from_bci(int bci) const;
 675 
 676   // Reflection support
 677   bool is_overridden_in(Klass* k) const;
 678 
 679   // Stack walking support
 680   bool is_ignored_by_security_stack_walk() const;
 681 
 682   // JSR 292 support
 683   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 684   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 685   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 686   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 687                                                    Symbol* signature, //anything at all
 688                                                    TRAPS);
 689   static Klass* check_non_bcp_klass(Klass* klass);
 690 
 691   // How many extra stack entries for invokedynamic when it's enabled
 692   static const int extra_stack_entries_for_jsr292 = 1;
 693 
 694   // this operates only on invoke methods:
 695   // presize interpreter frames for extra interpreter stack entries, if needed
 696   // Account for the extra appendix argument for invokehandle/invokedynamic
 697   static int extra_stack_entries() { return EnableInvokeDynamic ? extra_stack_entries_for_jsr292 : 0; }
 698   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 699 
 700   // RedefineClasses() support:
 701   bool is_old() const                               { return access_flags().is_old(); }
 702   void set_is_old()                                 { _access_flags.set_is_old(); }
 703   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 704   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 705   bool on_stack() const                             { return access_flags().on_stack(); }
 706   void set_on_stack(const bool value);
 707 
 708   // see the definition in Method*.cpp for the gory details
 709   bool should_not_be_cached() const;
 710 
 711   // JVMTI Native method prefixing support:
 712   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 713   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 714 
 715   // Rewriting support
 716   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 717                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 718 
 719   // jmethodID handling
 720   // Because the useful life-span of a jmethodID cannot be determined,
 721   // once created they are never reclaimed.  The methods to which they refer,
 722   // however, can be GC'ed away if the class is unloaded or if the method is
 723   // made obsolete or deleted -- in these cases, the jmethodID
 724   // refers to NULL (as is the case for any weak reference).
 725   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 726   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 727 
 728   // Use resolve_jmethod_id() in situations where the caller is expected
 729   // to provide a valid jmethodID; the only sanity checks are in asserts;
 730   // result guaranteed not to be NULL.
 731   inline static Method* resolve_jmethod_id(jmethodID mid) {
 732     assert(mid != NULL, "JNI method id should not be null");
 733     return *((Method**)mid);
 734   }
 735 
 736   // Use checked_resolve_jmethod_id() in situations where the caller
 737   // should provide a valid jmethodID, but might not. NULL is returned
 738   // when the jmethodID does not refer to a valid method.
 739   static Method* checked_resolve_jmethod_id(jmethodID mid);
 740 
 741   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 742   static bool is_method_id(jmethodID mid);
 743 
 744   // Clear methods
 745   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 746   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 747 
 748   // Get this method's jmethodID -- allocate if it doesn't exist
 749   jmethodID jmethod_id()                            { methodHandle this_h(this);
 750                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 751 
 752   // Lookup the jmethodID for this method.  Return NULL if not found.
 753   // NOTE that this function can be called from a signal handler
 754   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 755   // needs to be async-safe. No allocation should be done and
 756   // so handles are not used to avoid deadlock.
 757   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 758 
 759   // Support for inlining of intrinsic methods
 760   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 761   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 762 
 763   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 764   void init_intrinsic_id();     // updates from _none if a match
 765   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 766 
 767   bool jfr_towrite() {
 768     return (_flags & _jfr_towrite) != 0;
 769   }
 770   void set_jfr_towrite(bool x) {
 771     _flags = x ? (_flags | _jfr_towrite) : (_flags & ~_jfr_towrite);
 772   }
 773 
 774   bool caller_sensitive() {
 775     return (_flags & _caller_sensitive) != 0;
 776   }
 777   void set_caller_sensitive(bool x) {
 778     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 779   }
 780 
 781   bool force_inline() {
 782     return (_flags & _force_inline) != 0;
 783   }
 784   void set_force_inline(bool x) {
 785     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 786   }
 787 
 788   bool dont_inline() {
 789     return (_flags & _dont_inline) != 0;
 790   }
 791   void set_dont_inline(bool x) {
 792     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 793   }
 794 
 795   bool is_hidden() {
 796     return (_flags & _hidden) != 0;
 797   }
 798   void set_hidden(bool x) {
 799     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 800   }
 801 
 802   ConstMethod::MethodType method_type() const {
 803       return _constMethod->method_type();
 804   }
 805   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 806 
 807   // On-stack replacement support
 808   bool has_osr_nmethod(int level, bool match_level) {
 809    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 810   }
 811 
 812   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 813     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 814   }
 815 
 816   // Inline cache support
 817   void cleanup_inline_caches();
 818 
 819   // Find if klass for method is loaded
 820   bool is_klass_loaded_by_klass_index(int klass_index) const;
 821   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 822 
 823   // Indicates whether compilation failed earlier for this method, or
 824   // whether it is not compilable for another reason like having a
 825   // breakpoint set in it.
 826   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 827   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 828   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 829     set_not_compilable(comp_level, false);
 830   }
 831   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 832   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 833   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 834     set_not_osr_compilable(comp_level, false);
 835   }
 836   bool is_always_compilable() const;
 837 
 838  private:
 839   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 840 
 841  public:
 842   MethodCounters* get_method_counters(TRAPS) {
 843     if (_method_counters == NULL) {
 844       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 845     }
 846     return _method_counters;
 847   }
 848 
 849   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 850   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 851   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 852   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 853   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 854   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 855 
 856   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 857   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 858   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 859   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 860   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 861   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 862 
 863   // Background compilation support
 864   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 865   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 866   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 867 
 868   // Resolve all classes in signature, return 'true' if successful
 869   static bool load_signature_classes(methodHandle m, TRAPS);
 870 
 871   // Return if true if not all classes references in signature, including return type, has been loaded
 872   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 873 
 874   // Printing
 875   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 876 #if INCLUDE_JVMTI
 877   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 878 #else
 879   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 880 #endif
 881 
 882   // Helper routine used for method sorting
 883   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);
 884 
 885   // Deallocation function for redefine classes or if an error occurs
 886   void deallocate_contents(ClassLoaderData* loader_data);
 887 
 888   // Printing
 889 #ifndef PRODUCT
 890   void print_on(outputStream* st) const;
 891 #endif
 892   void print_value_on(outputStream* st) const;
 893 
 894   const char* internal_name() const { return "{method}"; }
 895 
 896   // Check for valid method pointer
 897   bool is_valid_method() const;
 898 
 899   // Verify
 900   void verify() { verify_on(tty); }
 901   void verify_on(outputStream* st);
 902 
 903  private:
 904 
 905   // Inlined elements
 906   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 907   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 908 };
 909 
 910 
 911 // Utility class for compressing line number tables
 912 
 913 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 914  private:
 915   int _bci;
 916   int _line;
 917  public:
 918   // Constructor
 919   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 920   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 921 
 922   // Write (bci, line number) pair to stream
 923   void write_pair_regular(int bci_delta, int line_delta);
 924 
 925   inline void write_pair_inline(int bci, int line) {
 926     int bci_delta = bci - _bci;
 927     int line_delta = line - _line;
 928     _bci = bci;
 929     _line = line;
 930     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 931     if (bci_delta == 0 && line_delta == 0) return;
 932     // Check if bci is 5-bit and line number 3-bit unsigned.
 933     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 934       // Compress into single byte.
 935       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 936       // Check that value doesn't match escape character.
 937       if (value != 0xFF) {
 938         write_byte(value);
 939         return;
 940       }
 941     }
 942     write_pair_regular(bci_delta, line_delta);
 943   }
 944 
 945 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 946 // Disabling optimization doesn't work for methods in header files
 947 // so we force it to call through the non-optimized version in the .cpp.
 948 // It's gross, but it's the only way we can ensure that all callers are
 949 // fixed.  _MSC_VER is defined by the windows compiler
 950 #if defined(_M_AMD64) && _MSC_VER >= 1400
 951   void write_pair(int bci, int line);
 952 #else
 953   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 954 #endif
 955 
 956   // Write end-of-stream marker
 957   void write_terminator()                        { write_byte(0); }
 958 };
 959 
 960 
 961 // Utility class for decompressing line number tables
 962 
 963 class CompressedLineNumberReadStream: public CompressedReadStream {
 964  private:
 965   int _bci;
 966   int _line;
 967  public:
 968   // Constructor
 969   CompressedLineNumberReadStream(u_char* buffer);
 970   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 971   bool read_pair();
 972   // Accessing bci and line number (after calling read_pair)
 973   int bci() const                               { return _bci; }
 974   int line() const                              { return _line; }
 975 };
 976 
 977 
 978 /// Fast Breakpoints.
 979 
 980 // If this structure gets more complicated (because bpts get numerous),
 981 // move it into its own header.
 982 
 983 // There is presently no provision for concurrent access
 984 // to breakpoint lists, which is only OK for JVMTI because
 985 // breakpoints are written only at safepoints, and are read
 986 // concurrently only outside of safepoints.
 987 
 988 class BreakpointInfo : public CHeapObj<mtClass> {
 989   friend class VMStructs;
 990  private:
 991   Bytecodes::Code  _orig_bytecode;
 992   int              _bci;
 993   u2               _name_index;       // of method
 994   u2               _signature_index;  // of method
 995   BreakpointInfo*  _next;             // simple storage allocation
 996 
 997  public:
 998   BreakpointInfo(Method* m, int bci);
 999 
1000   // accessors
1001   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1002   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1003   int         bci()                                   { return _bci; }
1004 
1005   BreakpointInfo*          next() const               { return _next; }
1006   void                 set_next(BreakpointInfo* n)    { _next = n; }
1007 
1008   // helps for searchers
1009   bool match(const Method* m, int bci) {
1010     return bci == _bci && match(m);
1011   }
1012 
1013   bool match(const Method* m) {
1014     return _name_index == m->name_index() &&
1015       _signature_index == m->signature_index();
1016   }
1017 
1018   void set(Method* method);
1019   void clear(Method* method);
1020 };
1021 
1022 // Utility class for access exception handlers
1023 class ExceptionTable : public StackObj {
1024  private:
1025   ExceptionTableElement* _table;
1026   u2  _length;
1027 
1028  public:
1029   ExceptionTable(const Method* m) {
1030     if (m->has_exception_handler()) {
1031       _table = m->exception_table_start();
1032       _length = m->exception_table_length();
1033     } else {
1034       _table = NULL;
1035       _length = 0;
1036     }
1037   }
1038 
1039   int length() const {
1040     return _length;
1041   }
1042 
1043   u2 start_pc(int idx) const {
1044     assert(idx < _length, "out of bounds");
1045     return _table[idx].start_pc;
1046   }
1047 
1048   void set_start_pc(int idx, u2 value) {
1049     assert(idx < _length, "out of bounds");
1050     _table[idx].start_pc = value;
1051   }
1052 
1053   u2 end_pc(int idx) const {
1054     assert(idx < _length, "out of bounds");
1055     return _table[idx].end_pc;
1056   }
1057 
1058   void set_end_pc(int idx, u2 value) {
1059     assert(idx < _length, "out of bounds");
1060     _table[idx].end_pc = value;
1061   }
1062 
1063   u2 handler_pc(int idx) const {
1064     assert(idx < _length, "out of bounds");
1065     return _table[idx].handler_pc;
1066   }
1067 
1068   void set_handler_pc(int idx, u2 value) {
1069     assert(idx < _length, "out of bounds");
1070     _table[idx].handler_pc = value;
1071   }
1072 
1073   u2 catch_type_index(int idx) const {
1074     assert(idx < _length, "out of bounds");
1075     return _table[idx].catch_type_index;
1076   }
1077 
1078   void set_catch_type_index(int idx, u2 value) {
1079     assert(idx < _length, "out of bounds");
1080     _table[idx].catch_type_index = value;
1081   }
1082 };
1083 
1084 #endif // SHARE_VM_OOPS_METHODOOP_HPP