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