1 /*
   2  * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OOPS_METHOD_HPP
  26 #define SHARE_OOPS_METHOD_HPP
  27 
  28 #include "code/compressedStream.hpp"
  29 #include "compiler/compilerDefinitions.hpp"
  30 #include "interpreter/invocationCounter.hpp"
  31 #include "oops/annotations.hpp"
  32 #include "oops/constantPool.hpp"
  33 #include "oops/methodCounters.hpp"
  34 #include "oops/methodFlags.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.hpp"
  37 #include "oops/typeArrayOop.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/align.hpp"
  40 #include "utilities/growableArray.hpp"
  41 #include "utilities/macros.hpp"
  42 #include "utilities/vmEnums.hpp"
  43 #if INCLUDE_JFR
  44 #include "jfr/support/jfrTraceIdExtension.hpp"
  45 #endif
  46 
  47 
  48 // A Method represents a Java method.
  49 //
  50 // Note that most applications load thousands of methods, so keeping the size of this
  51 // class small has a big impact on footprint.
  52 //
  53 // Note that native_function and signature_handler have to be at fixed offsets
  54 // (required by the interpreter)
  55 //
  56 //  Method embedded field layout (after declared fields):
  57 //   [EMBEDDED native_function       (present only if native) ]
  58 //   [EMBEDDED signature_handler     (present only if native) ]
  59 
  60 class CheckedExceptionElement;
  61 class LocalVariableTableElement;
  62 class AdapterHandlerEntry;
  63 class MethodData;
  64 class MethodCounters;
  65 class ConstMethod;
  66 class InlineTableSizes;
  67 class CompiledMethod;
  68 class InterpreterOopMap;
  69 
  70 class Method : public Metadata {
  71  friend class VMStructs;
  72  friend class JVMCIVMStructs;
  73  friend class MethodTest;
  74  private:
  75   // If you add a new field that points to any metaspace object, you
  76   // must add this field to Method::metaspace_pointers_do().
  77   ConstMethod*      _constMethod;                // Method read-only data.
  78   MethodData*       _method_data;
  79   MethodCounters*   _method_counters;
  80   AdapterHandlerEntry* _adapter;
  81   AccessFlags       _access_flags;               // Access flags
  82   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  83   MethodFlags       _flags;
  84 
  85   u2                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  86 
  87   JFR_ONLY(DEFINE_TRACE_FLAG;)
  88 
  89 #ifndef PRODUCT
  90   int64_t _compiled_invocation_count;
  91 
  92   Symbol* _name;
  93 #endif
  94   // Entry point for calling both from and to the interpreter.
  95   address _i2i_entry;           // All-args-on-stack calling convention
  96   // Entry point for calling from compiled code, to compiled code if it exists
  97   // or else the interpreter.
  98   volatile address _from_compiled_entry;           // Cache of: _code ? _code->verified_entry_point()           : _adapter->c2i_entry()
  99   volatile address _from_compiled_inline_ro_entry; // Cache of: _code ? _code->verified_inline_ro_entry_point() : _adapter->c2i_inline_ro_entry()
 100   volatile address _from_compiled_inline_entry;    // Cache of: _code ? _code->verified_inline_entry_point()    : _adapter->c2i_inline_entry()
 101   // The entry point for calling both from and to compiled code is
 102   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 103   // field can come and go.  It can transition from null to not-null at any
 104   // time (whenever a compile completes).  It can transition from not-null to
 105   // null only at safepoints (because of a de-opt).
 106   CompiledMethod* volatile _code;                       // Points to the corresponding piece of native code
 107   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 108 
 109   // Constructor
 110   Method(ConstMethod* xconst, AccessFlags access_flags, Symbol* name);
 111  public:
 112 
 113   static Method* allocate(ClassLoaderData* loader_data,
 114                           int byte_code_size,
 115                           AccessFlags access_flags,
 116                           InlineTableSizes* sizes,
 117                           ConstMethod::MethodType method_type,
 118                           Symbol* name,
 119                           TRAPS);
 120 
 121   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 122   Method(){}
 123 
 124   virtual bool is_method() const { return true; }
 125 
 126 #if INCLUDE_CDS
 127   void remove_unshareable_info();
 128   void restore_unshareable_info(TRAPS);
 129 #endif
 130 
 131   // accessors for instance variables
 132 
 133   ConstMethod* constMethod() const             { return _constMethod; }
 134   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 135 
 136 
 137   static address make_adapters(const methodHandle& mh, TRAPS);
 138   address from_compiled_entry() const;
 139   address from_compiled_inline_ro_entry() const;
 140   address from_compiled_inline_entry() const;
 141   address from_interpreted_entry() const;
 142 
 143   // access flag
 144   AccessFlags access_flags() const               { return _access_flags;  }
 145   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 146 
 147   // name
 148   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 149   u2 name_index() const                          { return constMethod()->name_index();         }
 150   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 151 
 152   // signature
 153   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 154   u2 signature_index() const                     { return constMethod()->signature_index();         }
 155   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 156 
 157   // generics support
 158   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : nullptr); }
 159   u2 generic_signature_index() const             { return constMethod()->generic_signature_index(); }
 160 
 161   // annotations support
 162   AnnotationArray* annotations() const           {
 163     return constMethod()->method_annotations();
 164   }
 165   AnnotationArray* parameter_annotations() const {
 166     return constMethod()->parameter_annotations();
 167   }
 168   AnnotationArray* annotation_default() const    {
 169     return constMethod()->default_annotations();
 170   }
 171   AnnotationArray* type_annotations() const      {
 172     return constMethod()->type_annotations();
 173   }
 174 
 175   // Helper routine: get klass name + "." + method name + signature as
 176   // C string, for the purpose of providing more useful
 177   // fatal error handling. The string is allocated in resource
 178   // area if a buffer is not provided by the caller.
 179   char* name_and_sig_as_C_string() const;
 180   char* name_and_sig_as_C_string(char* buf, int size) const;
 181 
 182   // Static routine in the situations we don't have a Method*
 183   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 184   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 185 
 186   // Get return type + klass name + "." + method name + ( parameters types )
 187   // as a C string or print it to an outputStream.
 188   // This is to be used to assemble strings passed to Java, so that
 189   // the text more resembles Java code. Used in exception messages.
 190   // Memory is allocated in the resource area; the caller needs
 191   // a ResourceMark.
 192   const char* external_name() const;
 193   void  print_external_name(outputStream *os) const;
 194 
 195   static const char* external_name(                  Klass* klass, Symbol* method_name, Symbol* signature);
 196   static void  print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature);
 197 
 198   Bytecodes::Code java_code_at(int bci) const {
 199     return Bytecodes::java_code_at(this, bcp_from(bci));
 200   }
 201   Bytecodes::Code code_at(int bci) const {
 202     return Bytecodes::code_at(this, bcp_from(bci));
 203   }
 204 
 205   // JVMTI breakpoints
 206 #if !INCLUDE_JVMTI
 207   Bytecodes::Code orig_bytecode_at(int bci) const {
 208     ShouldNotReachHere();
 209     return Bytecodes::_shouldnotreachhere;
 210   }
 211   void set_orig_bytecode_at(int bci, Bytecodes::Code code) {
 212     ShouldNotReachHere();
 213   };
 214   u2   number_of_breakpoints() const {return 0;}
 215 #else // !INCLUDE_JVMTI
 216   Bytecodes::Code orig_bytecode_at(int bci) const;
 217   void set_orig_bytecode_at(int bci, Bytecodes::Code code);
 218   void set_breakpoint(int bci);
 219   void clear_breakpoint(int bci);
 220   void clear_all_breakpoints();
 221   // Tracking number of breakpoints, for fullspeed debugging.
 222   // Only mutated by VM thread.
 223   u2   number_of_breakpoints() const {
 224     MethodCounters* mcs = method_counters();
 225     if (mcs == nullptr) {
 226       return 0;
 227     } else {
 228       return mcs->number_of_breakpoints();
 229     }
 230   }
 231   void incr_number_of_breakpoints(Thread* current) {
 232     MethodCounters* mcs = get_method_counters(current);
 233     if (mcs != nullptr) {
 234       mcs->incr_number_of_breakpoints();
 235     }
 236   }
 237   void decr_number_of_breakpoints(Thread* current) {
 238     MethodCounters* mcs = get_method_counters(current);
 239     if (mcs != nullptr) {
 240       mcs->decr_number_of_breakpoints();
 241     }
 242   }
 243   // Initialization only
 244   void clear_number_of_breakpoints() {
 245     MethodCounters* mcs = method_counters();
 246     if (mcs != nullptr) {
 247       mcs->clear_number_of_breakpoints();
 248     }
 249   }
 250 #endif // !INCLUDE_JVMTI
 251 
 252   // index into InstanceKlass methods() array
 253   // note: also used by jfr
 254   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 255   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 256 
 257   u2 orig_method_idnum() const           { return constMethod()->orig_method_idnum(); }
 258   void set_orig_method_idnum(u2 idnum)   { constMethod()->set_orig_method_idnum(idnum); }
 259 
 260   // code size
 261   u2 code_size() const                   { return constMethod()->code_size(); }
 262 
 263   // method size in words
 264   int method_size() const                { return sizeof(Method)/wordSize + ( is_native() ? 2 : 0 ); }
 265 
 266   // constant pool for Klass* holding this method
 267   ConstantPool* constants() const              { return constMethod()->constants(); }
 268   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 269 
 270   // max stack
 271   // return original max stack size for method verification
 272   u2  verifier_max_stack() const               { return constMethod()->max_stack(); }
 273   int          max_stack() const               { return constMethod()->max_stack() + extra_stack_entries(); }
 274   void      set_max_stack(int size)            {        constMethod()->set_max_stack(size); }
 275 
 276   // max locals
 277   u2  max_locals() const                       { return constMethod()->max_locals(); }
 278   void set_max_locals(int size)                { constMethod()->set_max_locals(size); }
 279 
 280   int highest_comp_level() const;
 281   void set_highest_comp_level(int level);
 282   int highest_osr_comp_level() const;
 283   void set_highest_osr_comp_level(int level);
 284 
 285 #if COMPILER2_OR_JVMCI
 286   // Count of times method was exited via exception while interpreting
 287   void interpreter_throwout_increment(Thread* current) {
 288     MethodCounters* mcs = get_method_counters(current);
 289     if (mcs != nullptr) {
 290       mcs->interpreter_throwout_increment();
 291     }
 292   }
 293 #endif
 294 
 295   int  interpreter_throwout_count() const        {
 296     MethodCounters* mcs = method_counters();
 297     if (mcs == nullptr) {
 298       return 0;
 299     } else {
 300       return mcs->interpreter_throwout_count();
 301     }
 302   }
 303 
 304   u2 size_of_parameters() const { return constMethod()->size_of_parameters(); }
 305 
 306   bool has_stackmap_table() const {
 307     return constMethod()->has_stackmap_table();
 308   }
 309 
 310   Array<u1>* stackmap_data() const {
 311     return constMethod()->stackmap_data();
 312   }
 313 
 314   void set_stackmap_data(Array<u1>* sd) {
 315     constMethod()->set_stackmap_data(sd);
 316   }
 317 
 318   // exception handler table
 319   bool has_exception_handler() const
 320                              { return constMethod()->has_exception_table(); }
 321   u2 exception_table_length() const
 322                              { return constMethod()->exception_table_length(); }
 323   ExceptionTableElement* exception_table_start() const
 324                              { return constMethod()->exception_table_start(); }
 325 
 326   // Finds the first entry point bci of an exception handler for an
 327   // exception of klass ex_klass thrown at throw_bci. A value of null
 328   // for ex_klass indicates that the exception klass is not known; in
 329   // this case it matches any constraint class. Returns -1 if the
 330   // exception cannot be handled in this method. The handler
 331   // constraint classes are loaded if necessary. Note that this may
 332   // throw an exception if loading of the constraint classes causes
 333   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 334   // If an exception is thrown, returns the bci of the
 335   // exception handler which caused the exception to be thrown, which
 336   // is needed for proper retries. See, for example,
 337   // InterpreterRuntime::exception_handler_for_exception.
 338   static int fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS);
 339 
 340   static bool register_native(Klass* k,
 341                               Symbol* name,
 342                               Symbol* signature,
 343                               address entry,
 344                               TRAPS);
 345 
 346   // method data access
 347   MethodData* method_data() const              {
 348     return _method_data;
 349   }
 350 
 351   void set_method_data(MethodData* data);
 352 
 353   MethodCounters* method_counters() const {
 354     return _method_counters;
 355   }
 356 
 357   void clear_method_counters() {
 358     _method_counters = nullptr;
 359   }
 360 
 361   bool init_method_counters(MethodCounters* counters);
 362 
 363   int prev_event_count() const {
 364     MethodCounters* mcs = method_counters();
 365     return mcs == nullptr ? 0 : mcs->prev_event_count();
 366   }
 367   void set_prev_event_count(int count) {
 368     MethodCounters* mcs = method_counters();
 369     if (mcs != nullptr) {
 370       mcs->set_prev_event_count(count);
 371     }
 372   }
 373   jlong prev_time() const {
 374     MethodCounters* mcs = method_counters();
 375     return mcs == nullptr ? 0 : mcs->prev_time();
 376   }
 377   void set_prev_time(jlong time) {
 378     MethodCounters* mcs = method_counters();
 379     if (mcs != nullptr) {
 380       mcs->set_prev_time(time);
 381     }
 382   }
 383   float rate() const {
 384     MethodCounters* mcs = method_counters();
 385     return mcs == nullptr ? 0 : mcs->rate();
 386   }
 387   void set_rate(float rate) {
 388     MethodCounters* mcs = method_counters();
 389     if (mcs != nullptr) {
 390       mcs->set_rate(rate);
 391     }
 392   }
 393 
 394   int invocation_count() const;
 395   int backedge_count() const;
 396 
 397   bool was_executed_more_than(int n);
 398   bool was_never_executed()                     { return !was_executed_more_than(0);  }
 399 
 400   static void build_profiling_method_data(const methodHandle& method, TRAPS);
 401 
 402   static MethodCounters* build_method_counters(Thread* current, Method* m);
 403 
 404   int interpreter_invocation_count()            { return invocation_count();          }
 405 
 406 #ifndef PRODUCT
 407   int64_t  compiled_invocation_count() const    { return _compiled_invocation_count;}
 408   void set_compiled_invocation_count(int count) { _compiled_invocation_count = (int64_t)count; }
 409 #else
 410   // for PrintMethodData in a product build
 411   int64_t  compiled_invocation_count() const    { return 0; }
 412 #endif // not PRODUCT
 413 
 414   // nmethod/verified compiler entry
 415   address verified_code_entry();
 416   address verified_inline_code_entry();
 417   address verified_inline_ro_code_entry();
 418   bool check_code() const;      // Not inline to avoid circular ref
 419   CompiledMethod* code() const;
 420 
 421   // Locks CompiledMethod_lock if not held.
 422   void unlink_code(CompiledMethod *compare);
 423   // Locks CompiledMethod_lock if not held.
 424   void unlink_code();
 425 
 426 private:
 427   // Either called with CompiledMethod_lock held or from constructor.
 428   void clear_code();
 429 
 430 public:
 431   static void set_code(const methodHandle& mh, CompiledMethod* code);
 432   void set_adapter_entry(AdapterHandlerEntry* adapter) {
 433     _adapter = adapter;
 434   }
 435   void set_from_compiled_entry(address entry) {
 436     _from_compiled_entry = entry;
 437   }
 438   void set_from_compiled_inline_ro_entry(address entry) {
 439     _from_compiled_inline_ro_entry = entry;
 440   }
 441   void set_from_compiled_inline_entry(address entry) {
 442     _from_compiled_inline_entry = entry;
 443   }
 444 
 445   address get_i2c_entry();
 446   address get_c2i_entry();
 447   address get_c2i_inline_entry();
 448   address get_c2i_unverified_entry();
 449   address get_c2i_unverified_inline_entry();
 450   address get_c2i_no_clinit_check_entry();
 451   AdapterHandlerEntry* adapter() const {
 452     return _adapter;
 453   }
 454   // setup entry points
 455   void link_method(const methodHandle& method, TRAPS);
 456   // clear entry points. Used by sharing code during dump time
 457   void unlink_method() NOT_CDS_RETURN;
 458   void remove_unshareable_flags() NOT_CDS_RETURN;
 459 
 460   // the number of argument reg slots that the compiled method uses on the stack.
 461   int num_stack_arg_slots() const { return constMethod()->num_stack_arg_slots(); }
 462 
 463   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
 464   virtual MetaspaceObj::Type type() const { return MethodType; }
 465 
 466   // vtable index
 467   enum VtableIndexFlag {
 468     // Valid vtable indexes are non-negative (>= 0).
 469     // These few negative values are used as sentinels.
 470     itable_index_max        = -10, // first itable index, growing downward
 471     pending_itable_index    = -9,  // itable index will be assigned
 472     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 473     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 474     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 475     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 476   };
 477   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 478   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 479   int  vtable_index() const                      { return _vtable_index; }
 480   void set_vtable_index(int index);
 481   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 482   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 483   int  itable_index() const                      { assert(valid_itable_index(), "");
 484                                                    return itable_index_max - _vtable_index; }
 485   void set_itable_index(int index);
 486 
 487   // interpreter entry
 488   address interpreter_entry() const              { return _i2i_entry; }
 489   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 490   void set_interpreter_entry(address entry) {
 491     if (_i2i_entry != entry) {
 492       _i2i_entry = entry;
 493     }
 494     if (_from_interpreted_entry != entry) {
 495       _from_interpreted_entry = entry;
 496     }
 497   }
 498 
 499   // native function (used for native methods only)
 500   enum {
 501     native_bind_event_is_interesting = true
 502   };
 503   address native_function() const                { return *(native_function_addr()); }
 504 
 505   // Must specify a real function (not null).
 506   // Use clear_native_function() to unregister.
 507   void set_native_function(address function, bool post_event_flag);
 508   bool has_native_function() const;
 509   void clear_native_function();
 510 
 511   // signature handler (used for native methods only)
 512   address signature_handler() const              { return *(signature_handler_addr()); }
 513   void set_signature_handler(address handler);
 514 
 515   // Interpreter oopmap support
 516   void mask_for(int bci, InterpreterOopMap* mask);
 517 
 518   // operations on invocation counter
 519   void print_invocation_count();
 520 
 521   // byte codes
 522   void    set_code(address code)      { return constMethod()->set_code(code); }
 523   address code_base() const           { return constMethod()->code_base(); }
 524   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 525 
 526   // prints byte codes
 527   void print_codes(int flags = 0) const { print_codes_on(tty, flags); }
 528   void print_codes_on(outputStream* st, int flags = 0) const;
 529   void print_codes_on(int from, int to, outputStream* st, int flags = 0) const;
 530 
 531   // method parameters
 532   bool has_method_parameters() const
 533                          { return constMethod()->has_method_parameters(); }
 534   int method_parameters_length() const
 535                          { return constMethod()->method_parameters_length(); }
 536   MethodParametersElement* method_parameters_start() const
 537                          { return constMethod()->method_parameters_start(); }
 538 
 539   // checked exceptions
 540   u2 checked_exceptions_length() const
 541                          { return constMethod()->checked_exceptions_length(); }
 542   CheckedExceptionElement* checked_exceptions_start() const
 543                          { return constMethod()->checked_exceptions_start(); }
 544 
 545   // localvariable table
 546   bool has_localvariable_table() const
 547                           { return constMethod()->has_localvariable_table(); }
 548   u2 localvariable_table_length() const
 549                         { return constMethod()->localvariable_table_length(); }
 550   LocalVariableTableElement* localvariable_table_start() const
 551                          { return constMethod()->localvariable_table_start(); }
 552 
 553   bool has_linenumber_table() const
 554                               { return constMethod()->has_linenumber_table(); }
 555   u_char* compressed_linenumber_table() const
 556                        { return constMethod()->compressed_linenumber_table(); }
 557 
 558   // method holder (the Klass* holding this method)
 559   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 560 
 561   Symbol* klass_name() const;                    // returns the name of the method holder
 562   BasicType result_type() const                  { return constMethod()->result_type(); }
 563   bool is_returning_oop() const                  { BasicType r = result_type(); return is_reference_type(r); }
 564   InlineKlass* returns_inline_type(Thread* thread) const;
 565 
 566   // Checked exceptions thrown by this method (resolved to mirrors)
 567   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 568 
 569   // Access flags
 570   bool is_public() const                         { return access_flags().is_public();      }
 571   bool is_private() const                        { return access_flags().is_private();     }
 572   bool is_protected() const                      { return access_flags().is_protected();   }
 573   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 574   bool is_static() const                         { return access_flags().is_static();      }
 575   bool is_final() const                          { return access_flags().is_final();       }
 576   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 577   bool is_native() const                         { return access_flags().is_native();      }
 578   bool is_abstract() const                       { return access_flags().is_abstract();    }
 579   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 580 
 581   // returns true if contains only return operation
 582   bool is_empty_method() const;
 583 
 584   // returns true if this is a vanilla constructor
 585   bool is_vanilla_constructor() const;
 586 
 587   // checks method and its method holder
 588   bool is_final_method() const;
 589   bool is_final_method(AccessFlags class_access_flags) const;
 590   // interface method declared with 'default' - excludes private interface methods
 591   bool is_default_method() const;
 592 
 593   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 594   bool can_be_statically_bound() const;
 595   bool can_be_statically_bound(InstanceKlass* context) const;
 596   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 597 
 598   // true if method can omit stack trace in throw in compiled code.
 599   bool can_omit_stack_trace();
 600 
 601   // Flags getting and setting.
 602 #define M_STATUS_GET_SET(name, ignore)          \
 603   bool name() const { return _flags.name(); }   \
 604   void set_##name(bool x) { _flags.set_##name(x); } \
 605   void set_##name() { _flags.set_##name(true); }
 606   M_STATUS_DO(M_STATUS_GET_SET)
 607 #undef M_STATUS_GET_SET
 608 
 609   // returns true if the method has any backward branches.
 610   bool has_loops() {
 611     return has_loops_flag_init() ? has_loops_flag() : compute_has_loops_flag();
 612   };
 613 
 614   bool compute_has_loops_flag();
 615   bool set_has_loops() {
 616     // set both the flags and that it's been initialized.
 617     set_has_loops_flag();
 618     set_has_loops_flag_init();
 619     return true;
 620   }
 621 
 622   // returns true if the method has any monitors.
 623   bool has_monitors() const                      { return is_synchronized() || has_monitor_bytecodes(); }
 624 
 625   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 626   // properly nest in the method. It might return false, even though they actually nest properly, since the info.
 627   // has not been computed yet.
 628   bool guaranteed_monitor_matching() const       { return monitor_matching(); }
 629   void set_guaranteed_monitor_matching()         { set_monitor_matching(); }
 630 
 631   // returns true if the method is an accessor function (setter/getter).
 632   bool is_accessor() const;
 633 
 634   // returns true if the method is a getter
 635   bool is_getter() const;
 636 
 637   // returns true if the method is a setter
 638   bool is_setter() const;
 639 
 640   // returns true if the method does nothing but return a constant of primitive type
 641   bool is_constant_getter() const;
 642 
 643   // returns true if the method name is <clinit> and the method has
 644   // valid static initializer flags.
 645   bool is_class_initializer() const;
 646 
 647   // returns true if the method name is <init> and the method is not a static factory
 648   bool is_object_constructor() const;
 649 
 650   // returns true if the method is an object constructor or class initializer
 651   // (non-static <init> or <clinit>), but false for factories (static <vnew>).
 652   bool is_object_constructor_or_class_initializer() const;
 653 
 654   // returns true if the method name is <vnew> and the method is static
 655   bool is_static_vnew_factory() const;
 656 
 657   // compiled code support
 658   // NOTE: code() is inherently racy as deopt can be clearing code
 659   // simultaneously. Use with caution.
 660   bool has_compiled_code() const;
 661 
 662   bool needs_clinit_barrier() const;
 663 
 664   // sizing
 665   static int header_size()                       {
 666     return align_up((int)sizeof(Method), wordSize) / wordSize;
 667   }
 668   static int size(bool is_native);
 669   int size() const                               { return method_size(); }
 670   void log_touched(Thread* current);
 671   static void print_touched_methods(outputStream* out);
 672 
 673   // interpreter support
 674   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 675   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 676   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 677   static ByteSize from_compiled_inline_offset()  { return byte_offset_of(Method, _from_compiled_inline_entry); }
 678   static ByteSize from_compiled_inline_ro_offset(){ return byte_offset_of(Method, _from_compiled_inline_ro_entry); }
 679   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 680   static ByteSize flags_offset()                 { return byte_offset_of(Method, _flags); }
 681 
 682   static ByteSize method_counters_offset()       {
 683     return byte_offset_of(Method, _method_counters);
 684   }
 685 #ifndef PRODUCT
 686   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 687 #endif // not PRODUCT
 688   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 689   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 690   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 691   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 692   static ByteSize itable_index_offset()          { return byte_offset_of(Method, _vtable_index ); }
 693 
 694   // for code generation
 695   static ByteSize method_data_offset()  { return byte_offset_of(Method, _method_data); }
 696   static ByteSize intrinsic_id_offset() { return byte_offset_of(Method, _intrinsic_id); }
 697   static int intrinsic_id_size_in_bytes()        { return sizeof(u2); }
 698 
 699   // Static methods that are used to implement member methods where an exposed this pointer
 700   // is needed due to possible GCs
 701   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 702 
 703   // Returns the byte code index from the byte code pointer
 704   int     bci_from(address bcp) const;
 705   address bcp_from(int bci) const;
 706   address bcp_from(address bcp) const;
 707   int validate_bci_from_bcp(address bcp) const;
 708   int validate_bci(int bci) const;
 709 
 710   // Returns the line number for a bci if debugging information for the method is prowided,
 711   // -1 is returned otherwise.
 712   int line_number_from_bci(int bci) const;
 713 
 714   // Reflection support
 715   bool is_overridden_in(Klass* k) const;
 716 
 717   // Stack walking support
 718   bool is_ignored_by_security_stack_walk() const;
 719 
 720   // JSR 292 support
 721   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 722   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 723   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 724   static methodHandle make_method_handle_intrinsic(vmIntrinsicID iid, // _invokeBasic, _linkToVirtual
 725                                                    Symbol* signature, //anything at all
 726                                                    TRAPS);
 727   // Some special methods don't need to be findable by nmethod iterators and are permanent.
 728   bool can_be_allocated_in_NonNMethod_space() const { return is_method_handle_intrinsic(); }
 729 
 730   // Continuation
 731   inline bool is_continuation_enter_intrinsic() const;
 732   inline bool is_continuation_yield_intrinsic() const;
 733   inline bool is_continuation_native_intrinsic() const;
 734   inline bool is_special_native_intrinsic() const;
 735 
 736   static Klass* check_non_bcp_klass(Klass* klass);
 737 
 738   enum {
 739     // How many extra stack entries for invokedynamic
 740     extra_stack_entries_for_jsr292 = 1
 741   };
 742 
 743   // this operates only on invoke methods:
 744   // presize interpreter frames for extra interpreter stack entries, if needed
 745   // Account for the extra appendix argument for invokehandle/invokedynamic
 746   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 747   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 748 
 749   // RedefineClasses() support:
 750   bool on_stack() const                             { return on_stack_flag(); }
 751   void set_on_stack(const bool value);
 752 
 753   void record_gc_epoch();
 754 
 755   // see the definition in Method*.cpp for the gory details
 756   bool should_not_be_cached() const;
 757 
 758   // Rewriting support
 759   static methodHandle clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
 760                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 761 
 762   // jmethodID handling
 763   // Because the useful life-span of a jmethodID cannot be determined,
 764   // once created they are never reclaimed.  The methods to which they refer,
 765   // however, can be GC'ed away if the class is unloaded or if the method is
 766   // made obsolete or deleted -- in these cases, the jmethodID
 767   // refers to null (as is the case for any weak reference).
 768   static jmethodID make_jmethod_id(ClassLoaderData* cld, Method* mh);
 769   static void destroy_jmethod_id(ClassLoaderData* cld, jmethodID mid);
 770 
 771   // Ensure there is enough capacity in the internal tracking data
 772   // structures to hold the number of jmethodIDs you plan to generate.
 773   // This saves substantial time doing allocations.
 774   static void ensure_jmethod_ids(ClassLoaderData* cld, int capacity);
 775 
 776   // Use resolve_jmethod_id() in situations where the caller is expected
 777   // to provide a valid jmethodID; the only sanity checks are in asserts;
 778   // result guaranteed not to be null.
 779   inline static Method* resolve_jmethod_id(jmethodID mid) {
 780     assert(mid != nullptr, "JNI method id should not be null");
 781     return *((Method**)mid);
 782   }
 783 
 784   // Use checked_resolve_jmethod_id() in situations where the caller
 785   // should provide a valid jmethodID, but might not. Null is returned
 786   // when the jmethodID does not refer to a valid method.
 787   static Method* checked_resolve_jmethod_id(jmethodID mid);
 788 
 789   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 790   static bool is_method_id(jmethodID mid);
 791 
 792   // Clear methods
 793   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 794   static void print_jmethod_ids_count(const ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 795 
 796   // Get this method's jmethodID -- allocate if it doesn't exist
 797   jmethodID jmethod_id();
 798 
 799   // Lookup the jmethodID for this method.  Return null if not found.
 800   // NOTE that this function can be called from a signal handler
 801   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 802   // needs to be async-safe. No allocation should be done and
 803   // so handles are not used to avoid deadlock.
 804   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 805 
 806   // Support for inlining of intrinsic methods
 807   vmIntrinsicID intrinsic_id() const          { return (vmIntrinsicID) _intrinsic_id;           }
 808   void     set_intrinsic_id(vmIntrinsicID id) {                           _intrinsic_id = (u2) id; }
 809 
 810   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 811   void init_intrinsic_id(vmSymbolID klass_id);     // updates from _none if a match
 812   static vmSymbolID klass_id_for_intrinsics(const Klass* holder);
 813 
 814   bool caller_sensitive() const     { return constMethod()->caller_sensitive(); }
 815   void set_caller_sensitive() { constMethod()->set_caller_sensitive(); }
 816 
 817   bool changes_current_thread() const { return constMethod()->changes_current_thread(); }
 818   void set_changes_current_thread() { constMethod()->set_changes_current_thread(); }
 819 
 820   bool jvmti_mount_transition() const { return constMethod()->jvmti_mount_transition(); }
 821   void set_jvmti_mount_transition() { constMethod()->set_jvmti_mount_transition(); }
 822 
 823   bool is_hidden() const { return constMethod()->is_hidden(); }
 824   void set_is_hidden() { constMethod()->set_is_hidden(); }
 825 
 826   bool is_scoped() const { return constMethod()->is_scoped(); }
 827   void set_scoped() { constMethod()->set_is_scoped(); }
 828 
 829   bool intrinsic_candidate() const { return constMethod()->intrinsic_candidate(); }
 830   void set_intrinsic_candidate() { constMethod()->set_intrinsic_candidate(); }
 831 
 832   bool has_injected_profile() const { return constMethod()->has_injected_profile(); }
 833   void set_has_injected_profile() { constMethod()->set_has_injected_profile(); }
 834 
 835   bool has_reserved_stack_access() const { return constMethod()->reserved_stack_access(); }
 836   void set_has_reserved_stack_access() { constMethod()->set_reserved_stack_access(); }
 837 
 838   bool has_scalarized_args() const { return constMethod()->has_scalarized_args(); }
 839   void set_has_scalarized_args() { constMethod()->set_has_scalarized_args(); }
 840 
 841   bool has_scalarized_return() const { return constMethod()->has_scalarized_return(); }
 842   void set_has_scalarized_return() { constMethod()->set_has_scalarized_return(); }
 843 
 844   bool is_scalarized_arg(int idx) const;
 845 
 846   bool c1_needs_stack_repair() const { return constMethod()->c1_needs_stack_repair(); }
 847   void set_c1_needs_stack_repair() { constMethod()->set_c1_needs_stack_repair(); }
 848 
 849   bool c2_needs_stack_repair() const { return constMethod()->c2_needs_stack_repair(); }
 850   void set_c2_needs_stack_repair() { constMethod()->set_c2_needs_stack_repair(); }
 851 
 852   bool mismatch() const { return constMethod()->mismatch(); }
 853   void set_mismatch() { constMethod()->set_mismatch(); }
 854 
 855   JFR_ONLY(DEFINE_TRACE_FLAG_ACCESSOR;)
 856 
 857   ConstMethod::MethodType method_type() const {
 858       return _constMethod->method_type();
 859   }
 860   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 861 
 862   // On-stack replacement support
 863   bool has_osr_nmethod(int level, bool match_level) {
 864    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != nullptr;
 865   }
 866 
 867   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 868     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 869   }
 870 
 871   // Find if klass for method is loaded
 872   bool is_klass_loaded_by_klass_index(int klass_index) const;
 873   bool is_klass_loaded(int refinfo_index, Bytecodes::Code bc, bool must_be_resolved = false) const;
 874 
 875   // Indicates whether compilation failed earlier for this method, or
 876   // whether it is not compilable for another reason like having a
 877   // breakpoint set in it.
 878   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 879   void set_not_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 880   void set_not_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 881     set_not_compilable(reason, comp_level, false);
 882   }
 883   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 884   void set_not_osr_compilable(const char* reason, int comp_level = CompLevel_all, bool report = true);
 885   void set_not_osr_compilable_quietly(const char* reason, int comp_level = CompLevel_all) {
 886     set_not_osr_compilable(reason, comp_level, false);
 887   }
 888   bool is_always_compilable() const;
 889 
 890  private:
 891   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 892 
 893  public:
 894   MethodCounters* get_method_counters(Thread* current) {
 895     if (_method_counters == nullptr) {
 896       build_method_counters(current, this);
 897     }
 898     return _method_counters;
 899   }
 900 
 901   void clear_is_not_c1_compilable()           { set_is_not_c1_compilable(false); }
 902   void clear_is_not_c2_compilable()           { set_is_not_c2_compilable(false); }
 903   void clear_is_not_c2_osr_compilable()       { set_is_not_c2_osr_compilable(false); }
 904 
 905   // not_c1_osr_compilable == not_c1_compilable
 906   bool is_not_c1_osr_compilable() const       { return is_not_c1_compilable(); }
 907   void set_is_not_c1_osr_compilable()         { set_is_not_c1_compilable(); }
 908   void clear_is_not_c1_osr_compilable()       { clear_is_not_c1_compilable(); }
 909 
 910   // Background compilation support
 911   void clear_queued_for_compilation()  { set_queued_for_compilation(false);   }
 912 
 913   // Resolve all classes in signature, return 'true' if successful
 914   static bool load_signature_classes(const methodHandle& m, TRAPS);
 915 
 916   // Printing
 917   void print_short_name(outputStream* st = tty) const; // prints as klassname::methodname; Exposed so field engineers can debug VM
 918 #if INCLUDE_JVMTI
 919   void print_name(outputStream* st = tty) const; // prints as "virtual void foo(int)"; exposed for -Xlog:redefine+class
 920 #else
 921   void print_name(outputStream* st = tty) const  PRODUCT_RETURN; // prints as "virtual void foo(int)"
 922 #endif
 923 
 924   typedef int (*method_comparator_func)(Method* a, Method* b);
 925 
 926   // Helper routine used for method sorting
 927   static void sort_methods(Array<Method*>* methods, bool set_idnums = true, method_comparator_func func = nullptr);
 928 
 929   // Deallocation function for redefine classes or if an error occurs
 930   void deallocate_contents(ClassLoaderData* loader_data);
 931 
 932   void release_C_heap_structures();
 933 
 934   Method* get_new_method() const {
 935     InstanceKlass* holder = method_holder();
 936     Method* new_method = holder->method_with_idnum(orig_method_idnum());
 937 
 938     assert(new_method != nullptr, "method_with_idnum() should not be null");
 939     assert(this != new_method, "sanity check");
 940     return new_method;
 941   }
 942 
 943   // Printing
 944 #ifndef PRODUCT
 945   void print_on(outputStream* st) const;
 946 #endif
 947   void print_value_on(outputStream* st) const;
 948   void print_linkage_flags(outputStream* st) PRODUCT_RETURN;
 949 
 950   const char* internal_name() const { return "{method}"; }
 951 
 952   // Check for valid method pointer
 953   static bool has_method_vptr(const void* ptr);
 954   static bool is_valid_method(const Method* m);
 955 
 956   // Verify
 957   void verify() { verify_on(tty); }
 958   void verify_on(outputStream* st);
 959 
 960  private:
 961 
 962   // Inlined elements
 963   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 964   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 965 };
 966 
 967 
 968 // Utility class for compressing line number tables
 969 
 970 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 971  private:
 972   int _bci;
 973   int _line;
 974  public:
 975   // Constructor
 976   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 977   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 978 
 979   // Write (bci, line number) pair to stream
 980   void write_pair_regular(int bci_delta, int line_delta);
 981 
 982   // If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
 983   // we save it as one byte, otherwise we write a 0xFF escape character
 984   // and use regular compression. 0x0 is used as end-of-stream terminator.
 985   void write_pair_inline(int bci, int line);
 986 
 987   void write_pair(int bci, int line);
 988 
 989   // Write end-of-stream marker
 990   void write_terminator()                        { write_byte(0); }
 991 };
 992 
 993 
 994 // Utility class for decompressing line number tables
 995 
 996 class CompressedLineNumberReadStream: public CompressedReadStream {
 997  private:
 998   int _bci;
 999   int _line;
1000  public:
1001   // Constructor
1002   CompressedLineNumberReadStream(u_char* buffer);
1003   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
1004   bool read_pair();
1005   // Accessing bci and line number (after calling read_pair)
1006   int bci() const                               { return _bci; }
1007   int line() const                              { return _line; }
1008 };
1009 
1010 
1011 #if INCLUDE_JVMTI
1012 
1013 /// Fast Breakpoints.
1014 
1015 // If this structure gets more complicated (because bpts get numerous),
1016 // move it into its own header.
1017 
1018 // There is presently no provision for concurrent access
1019 // to breakpoint lists, which is only OK for JVMTI because
1020 // breakpoints are written only at safepoints, and are read
1021 // concurrently only outside of safepoints.
1022 
1023 class BreakpointInfo : public CHeapObj<mtClass> {
1024   friend class VMStructs;
1025  private:
1026   Bytecodes::Code  _orig_bytecode;
1027   int              _bci;
1028   u2               _name_index;       // of method
1029   u2               _signature_index;  // of method
1030   BreakpointInfo*  _next;             // simple storage allocation
1031 
1032  public:
1033   BreakpointInfo(Method* m, int bci);
1034 
1035   // accessors
1036   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1037   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1038   int         bci()                                   { return _bci; }
1039 
1040   BreakpointInfo*          next() const               { return _next; }
1041   void                 set_next(BreakpointInfo* n)    { _next = n; }
1042 
1043   // helps for searchers
1044   bool match(const Method* m, int bci) {
1045     return bci == _bci && match(m);
1046   }
1047 
1048   bool match(const Method* m) {
1049     return _name_index == m->name_index() &&
1050       _signature_index == m->signature_index();
1051   }
1052 
1053   void set(Method* method);
1054   void clear(Method* method);
1055 };
1056 
1057 #endif // INCLUDE_JVMTI
1058 
1059 // Utility class for access exception handlers
1060 class ExceptionTable : public StackObj {
1061  private:
1062   ExceptionTableElement* _table;
1063   u2  _length;
1064 
1065  public:
1066   ExceptionTable(const Method* m) {
1067     if (m->has_exception_handler()) {
1068       _table = m->exception_table_start();
1069       _length = m->exception_table_length();
1070     } else {
1071       _table = nullptr;
1072       _length = 0;
1073     }
1074   }
1075 
1076   u2 length() const {
1077     return _length;
1078   }
1079 
1080   u2 start_pc(int idx) const {
1081     assert(idx < _length, "out of bounds");
1082     return _table[idx].start_pc;
1083   }
1084 
1085   void set_start_pc(int idx, u2 value) {
1086     assert(idx < _length, "out of bounds");
1087     _table[idx].start_pc = value;
1088   }
1089 
1090   u2 end_pc(int idx) const {
1091     assert(idx < _length, "out of bounds");
1092     return _table[idx].end_pc;
1093   }
1094 
1095   void set_end_pc(int idx, u2 value) {
1096     assert(idx < _length, "out of bounds");
1097     _table[idx].end_pc = value;
1098   }
1099 
1100   u2 handler_pc(int idx) const {
1101     assert(idx < _length, "out of bounds");
1102     return _table[idx].handler_pc;
1103   }
1104 
1105   void set_handler_pc(int idx, u2 value) {
1106     assert(idx < _length, "out of bounds");
1107     _table[idx].handler_pc = value;
1108   }
1109 
1110   u2 catch_type_index(int idx) const {
1111     assert(idx < _length, "out of bounds");
1112     return _table[idx].catch_type_index;
1113   }
1114 
1115   void set_catch_type_index(int idx, u2 value) {
1116     assert(idx < _length, "out of bounds");
1117     _table[idx].catch_type_index = value;
1118   }
1119 };
1120 
1121 #endif // SHARE_OOPS_METHOD_HPP