1 /*
   2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_METHODOOP_HPP
  26 #define SHARE_VM_OOPS_METHODOOP_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "interpreter/invocationCounter.hpp"
  32 #include "oops/annotations.hpp"
  33 #include "oops/constantPool.hpp"
  34 #include "oops/instanceKlass.hpp"
  35 #include "oops/oop.hpp"
  36 #include "oops/typeArrayOop.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/growableArray.hpp"
  39 
  40 // A Method* represents a Java method.
  41 //
  42 // Memory layout (each line represents a word). Note that most applications load thousands of methods,
  43 // so keeping the size of this structure small has a big impact on footprint.
  44 //
  45 // We put all oops and method_size first for better gc cache locality.
  46 //
  47 // The actual bytecodes are inlined after the end of the Method struct.
  48 //
  49 // There are bits in the access_flags telling whether inlined tables are present.
  50 // Note that accessing the line number and local variable tables is not performance critical at all.
  51 // Accessing the checked exceptions table is used by reflection, so we put that last to make access
  52 // to it fast.
  53 //
  54 // The line number table is compressed and inlined following the byte codes. It is found as the first
  55 // byte following the byte codes. The checked exceptions table and the local variable table are inlined
  56 // after the line number table, and indexed from the end of the method. We do not compress the checked
  57 // exceptions table since the average length is less than 2, and do not bother to compress the local
  58 // variable table either since it is mostly absent.
  59 //
  60 // Note that native_function and signature_handler has to be at fixed offsets (required by the interpreter)
  61 //
  62 // |------------------------------------------------------|
  63 // | header                                               |
  64 // | klass                                                |
  65 // |------------------------------------------------------|
  66 // | ConstMethod*                   (oop)                 |
  67 // |------------------------------------------------------|
  68 // | methodData                     (oop)                 |
  69 // | interp_invocation_count                              |
  70 // |------------------------------------------------------|
  71 // | access_flags                                         |
  72 // | vtable_index                                         |
  73 // |------------------------------------------------------|
  74 // | result_index (C++ interpreter only)                  |
  75 // |------------------------------------------------------|
  76 // | method_size             |   intrinsic_id|   flags    |
  77 // |------------------------------------------------------|
  78 // | throwout_count          |   num_breakpoints          |
  79 // |------------------------------------------------------|
  80 // | invocation_counter                                   |
  81 // | backedge_counter                                     |
  82 // |------------------------------------------------------|
  83 // |           prev_time (tiered only, 64 bit wide)       |
  84 // |                                                      |
  85 // |------------------------------------------------------|
  86 // |                  rate (tiered)                       |
  87 // |------------------------------------------------------|
  88 // | code                           (pointer)             |
  89 // | i2i                            (pointer)             |
  90 // | adapter                        (pointer)             |
  91 // | from_compiled_entry            (pointer)             |
  92 // | from_interpreted_entry         (pointer)             |
  93 // |------------------------------------------------------|
  94 // | native_function       (present only if native)       |
  95 // | signature_handler     (present only if native)       |
  96 // |------------------------------------------------------|
  97 
  98 
  99 class CheckedExceptionElement;
 100 class LocalVariableTableElement;
 101 class AdapterHandlerEntry;
 102 class MethodData;
 103 class ConstMethod;
 104 class InlineTableSizes;
 105 class KlassSizeStats;
 106 
 107 class Method : public Metadata {
 108  friend class VMStructs;
 109  private:
 110   ConstMethod*      _constMethod;                // Method read-only data.
 111   MethodData*       _method_data;
 112   int               _interpreter_invocation_count; // Count of times invoked (reused as prev_event_count in tiered)
 113   AccessFlags       _access_flags;               // Access flags
 114   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
 115                                                  // note: can have vtables with >2**16 elements (because of inheritance)
 116 #ifdef CC_INTERP
 117   int               _result_index;               // C++ interpreter needs for converting results to/from stack
 118 #endif
 119   u2                _method_size;                // size of this object
 120   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
 121   u1                _jfr_towrite  : 1,           // Flags
 122                     _force_inline : 1,
 123                     _hidden       : 1,
 124                     _dont_inline  : 1,
 125                                   : 4;
 126   u2                _interpreter_throwout_count; // Count of times method was exited via exception while interpreting
 127   u2                _number_of_breakpoints;      // fullspeed debugging support
 128   InvocationCounter _invocation_counter;         // Incremented before each activation of the method - used to trigger frequency-based optimizations
 129   InvocationCounter _backedge_counter;           // Incremented before each backedge taken - used to trigger frequencey-based optimizations
 130 
 131 #ifdef TIERED
 132   float             _rate;                        // Events (invocation and backedge counter increments) per millisecond
 133   jlong             _prev_time;                   // Previous time the rate was acquired
 134 #endif
 135 
 136 #ifndef PRODUCT
 137   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 138 #endif
 139   // Entry point for calling both from and to the interpreter.
 140   address _i2i_entry;           // All-args-on-stack calling convention
 141   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
 142   AdapterHandlerEntry* _adapter;
 143   // Entry point for calling from compiled code, to compiled code if it exists
 144   // or else the interpreter.
 145   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 146   // The entry point for calling both from and to compiled code is
 147   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 148   // field can come and go.  It can transition from NULL to not-null at any
 149   // time (whenever a compile completes).  It can transition from not-null to
 150   // NULL only at safepoints (because of a de-opt).
 151   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 152   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 153 
 154   // Constructor
 155   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 156  public:
 157 
 158   static Method* allocate(ClassLoaderData* loader_data,
 159                           int byte_code_size,
 160                           AccessFlags access_flags,
 161                           InlineTableSizes* sizes,
 162                           ConstMethod::MethodType method_type,
 163                           TRAPS);
 164 
 165   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 166   Method(){}
 167 
 168   // The Method vtable is restored by this call when the Method is in the
 169   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 170   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 171   // by their vtable.
 172   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 173   bool is_method() const volatile { return true; }
 174 
 175   // accessors for instance variables
 176 
 177   ConstMethod* constMethod() const             { return _constMethod; }
 178   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 179 
 180 
 181   static address make_adapters(methodHandle mh, TRAPS);
 182   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 183   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 184 
 185   // access flag
 186   AccessFlags access_flags() const               { return _access_flags;  }
 187   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 188 
 189   // name
 190   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 191   int name_index() const                         { return constMethod()->name_index();         }
 192   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 193 
 194   // signature
 195   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 196   int signature_index() const                    { return constMethod()->signature_index();         }
 197   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 198 
 199   // generics support
 200   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 201   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 202   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 203 
 204   // annotations support
 205   AnnotationArray* annotations() const           {
 206     return constMethod()->method_annotations();
 207   }
 208   AnnotationArray* parameter_annotations() const {
 209     return constMethod()->parameter_annotations();
 210   }
 211   AnnotationArray* annotation_default() const    {
 212     return constMethod()->default_annotations();
 213   }
 214   AnnotationArray* type_annotations() const      {
 215     return constMethod()->type_annotations();
 216   }
 217 
 218 #ifdef CC_INTERP
 219   void set_result_index(BasicType type);
 220   int  result_index()                            { return _result_index; }
 221 #endif
 222 
 223   // Helper routine: get klass name + "." + method name + signature as
 224   // C string, for the purpose of providing more useful NoSuchMethodErrors
 225   // and fatal error handling. The string is allocated in resource
 226   // area if a buffer is not provided by the caller.
 227   char* name_and_sig_as_C_string() const;
 228   char* name_and_sig_as_C_string(char* buf, int size) const;
 229 
 230   // Static routine in the situations we don't have a Method*
 231   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 232   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 233 
 234   Bytecodes::Code java_code_at(int bci) const {
 235     return Bytecodes::java_code_at(this, bcp_from(bci));
 236   }
 237   Bytecodes::Code code_at(int bci) const {
 238     return Bytecodes::code_at(this, bcp_from(bci));
 239   }
 240 
 241   // JVMTI breakpoints
 242   Bytecodes::Code orig_bytecode_at(int bci) const;
 243   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 244   void set_breakpoint(int bci);
 245   void clear_breakpoint(int bci);
 246   void clear_all_breakpoints();
 247   // Tracking number of breakpoints, for fullspeed debugging.
 248   // Only mutated by VM thread.
 249   u2   number_of_breakpoints() const             { return _number_of_breakpoints; }
 250   void incr_number_of_breakpoints()              { ++_number_of_breakpoints; }
 251   void decr_number_of_breakpoints()              { --_number_of_breakpoints; }
 252   // Initialization only
 253   void clear_number_of_breakpoints()             { _number_of_breakpoints = 0; }
 254 
 255   // index into InstanceKlass methods() array
 256   // note: also used by jfr
 257   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 258   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 259 
 260   // code size
 261   int code_size() const                  { return constMethod()->code_size(); }
 262 
 263   // method size
 264   int method_size() const                        { return _method_size; }
 265   void set_method_size(int size) {
 266     assert(0 <= size && size < (1 << 16), "invalid method size");
 267     _method_size = size;
 268   }
 269 
 270   // constant pool for Klass* holding this method
 271   ConstantPool* constants() const              { return constMethod()->constants(); }
 272   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 273 
 274   // max stack
 275   // return original max stack size for method verification
 276   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 277   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 278   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 279 
 280   // max locals
 281   int  max_locals() const                        { return constMethod()->max_locals(); }
 282   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 283 
 284   int highest_comp_level() const;
 285   void set_highest_comp_level(int level);
 286   int highest_osr_comp_level() const;
 287   void set_highest_osr_comp_level(int level);
 288 
 289   // Count of times method was exited via exception while interpreting
 290   void interpreter_throwout_increment() {
 291     if (_interpreter_throwout_count < 65534) {
 292       _interpreter_throwout_count++;
 293     }
 294   }
 295 
 296   int  interpreter_throwout_count() const        { return _interpreter_throwout_count; }
 297   void set_interpreter_throwout_count(int count) { _interpreter_throwout_count = count; }
 298 
 299   // size of parameters
 300   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 301   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 302 
 303   bool has_stackmap_table() const {
 304     return constMethod()->has_stackmap_table();
 305   }
 306 
 307   Array<u1>* stackmap_data() const {
 308     return constMethod()->stackmap_data();
 309   }
 310 
 311   void set_stackmap_data(Array<u1>* sd) {
 312     constMethod()->set_stackmap_data(sd);
 313   }
 314 
 315   // exception handler table
 316   bool has_exception_handler() const
 317                              { return constMethod()->has_exception_handler(); }
 318   int exception_table_length() const
 319                              { return constMethod()->exception_table_length(); }
 320   ExceptionTableElement* exception_table_start() const
 321                              { return constMethod()->exception_table_start(); }
 322 
 323   // Finds the first entry point bci of an exception handler for an
 324   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 325   // for ex_klass indicates that the exception klass is not known; in
 326   // this case it matches any constraint class. Returns -1 if the
 327   // exception cannot be handled in this method. The handler
 328   // constraint classes are loaded if necessary. Note that this may
 329   // throw an exception if loading of the constraint classes causes
 330   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 331   // If an exception is thrown, returns the bci of the
 332   // exception handler which caused the exception to be thrown, which
 333   // is needed for proper retries. See, for example,
 334   // InterpreterRuntime::exception_handler_for_exception.
 335   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 336 
 337   // method data access
 338   MethodData* method_data() const              {
 339     return _method_data;
 340   }
 341   void set_method_data(MethodData* data)       {
 342     _method_data = data;
 343   }
 344 
 345   // invocation counter
 346   InvocationCounter* invocation_counter() { return &_invocation_counter; }
 347   InvocationCounter* backedge_counter()   { return &_backedge_counter; }
 348 
 349 #ifdef TIERED
 350   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 351   // We can do that since interpreter_invocation_count is not used in tiered.
 352   int prev_event_count() const                   { return _interpreter_invocation_count;  }
 353   void set_prev_event_count(int count)           { _interpreter_invocation_count = count; }
 354   jlong prev_time() const                        { return _prev_time; }
 355   void set_prev_time(jlong time)                 { _prev_time = time; }
 356   float rate() const                             { return _rate; }
 357   void set_rate(float rate)                      { _rate = rate; }
 358 #endif
 359 
 360   int invocation_count();
 361   int backedge_count();
 362 
 363   bool was_executed_more_than(int n);
 364   bool was_never_executed()                      { return !was_executed_more_than(0); }
 365 
 366   static void build_interpreter_method_data(methodHandle method, TRAPS);
 367 
 368   int interpreter_invocation_count() {
 369     if (TieredCompilation) return invocation_count();
 370     else return _interpreter_invocation_count;
 371   }
 372   void set_interpreter_invocation_count(int count) { _interpreter_invocation_count = count; }
 373   int increment_interpreter_invocation_count() {
 374     if (TieredCompilation) ShouldNotReachHere();
 375     return ++_interpreter_invocation_count;
 376   }
 377 
 378 #ifndef PRODUCT
 379   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 380   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 381 #endif // not PRODUCT
 382 
 383   // Clear (non-shared space) pointers which could not be relevant
 384   // if this (shared) method were mapped into another JVM.
 385   void remove_unshareable_info();
 386 
 387   // nmethod/verified compiler entry
 388   address verified_code_entry();
 389   bool check_code() const;      // Not inline to avoid circular ref
 390   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 391   void clear_code();            // Clear out any compiled code
 392   static void set_code(methodHandle mh, nmethod* code);
 393   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 394   address get_i2c_entry();
 395   address get_c2i_entry();
 396   address get_c2i_unverified_entry();
 397   AdapterHandlerEntry* adapter() {  return _adapter; }
 398   // setup entry points
 399   void link_method(methodHandle method, TRAPS);
 400   // clear entry points. Used by sharing code
 401   void unlink_method();
 402 
 403   // vtable index
 404   enum VtableIndexFlag {
 405     // Valid vtable indexes are non-negative (>= 0).
 406     // These few negative values are used as sentinels.
 407     highest_unused_vtable_index_value = -5,
 408     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 409     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 410     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 411     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 412   };
 413   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 414   int  vtable_index() const                      { assert(valid_vtable_index(), "");
 415                                                    return _vtable_index; }
 416   void set_vtable_index(int index)               { _vtable_index = index; }
 417 
 418   // interpreter entry
 419   address interpreter_entry() const              { return _i2i_entry; }
 420   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 421   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 422 
 423   // native function (used for native methods only)
 424   enum {
 425     native_bind_event_is_interesting = true
 426   };
 427   address native_function() const                { return *(native_function_addr()); }
 428   address critical_native_function();
 429 
 430   // Must specify a real function (not NULL).
 431   // Use clear_native_function() to unregister.
 432   void set_native_function(address function, bool post_event_flag);
 433   bool has_native_function() const;
 434   void clear_native_function();
 435 
 436   // signature handler (used for native methods only)
 437   address signature_handler() const              { return *(signature_handler_addr()); }
 438   void set_signature_handler(address handler);
 439 
 440   // Interpreter oopmap support
 441   void mask_for(int bci, InterpreterOopMap* mask);
 442 
 443 #ifndef PRODUCT
 444   // operations on invocation counter
 445   void print_invocation_count();
 446 #endif
 447 
 448   // byte codes
 449   void    set_code(address code)      { return constMethod()->set_code(code); }
 450   address code_base() const           { return constMethod()->code_base(); }
 451   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 452 
 453   // prints byte codes
 454   void print_codes() const            { print_codes_on(tty); }
 455   void print_codes_on(outputStream* st) const                      PRODUCT_RETURN;
 456   void print_codes_on(int from, int to, outputStream* st) const    PRODUCT_RETURN;
 457 
 458   // method parameters
 459   bool has_method_parameters() const
 460                          { return constMethod()->has_method_parameters(); }
 461   int method_parameters_length() const
 462                          { return constMethod()->method_parameters_length(); }
 463   MethodParametersElement* method_parameters_start() const
 464                           { return constMethod()->method_parameters_start(); }
 465 
 466   // checked exceptions
 467   int checked_exceptions_length() const
 468                          { return constMethod()->checked_exceptions_length(); }
 469   CheckedExceptionElement* checked_exceptions_start() const
 470                           { return constMethod()->checked_exceptions_start(); }
 471 
 472   // localvariable table
 473   bool has_localvariable_table() const
 474                           { return constMethod()->has_localvariable_table(); }
 475   int localvariable_table_length() const
 476                         { return constMethod()->localvariable_table_length(); }
 477   LocalVariableTableElement* localvariable_table_start() const
 478                          { return constMethod()->localvariable_table_start(); }
 479 
 480   bool has_linenumber_table() const
 481                               { return constMethod()->has_linenumber_table(); }
 482   u_char* compressed_linenumber_table() const
 483                        { return constMethod()->compressed_linenumber_table(); }
 484 
 485   // method holder (the Klass* holding this method)
 486   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 487 
 488   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 489   Symbol* klass_name() const;                    // returns the name of the method holder
 490   BasicType result_type() const;                 // type of the method result
 491   int result_type_index() const;                 // type index of the method result
 492   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 493   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 494 
 495   // Checked exceptions thrown by this method (resolved to mirrors)
 496   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 497 
 498   // Access flags
 499   bool is_public() const                         { return access_flags().is_public();      }
 500   bool is_private() const                        { return access_flags().is_private();     }
 501   bool is_protected() const                      { return access_flags().is_protected();   }
 502   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 503   bool is_static() const                         { return access_flags().is_static();      }
 504   bool is_final() const                          { return access_flags().is_final();       }
 505   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 506   bool is_native() const                         { return access_flags().is_native();      }
 507   bool is_abstract() const                       { return access_flags().is_abstract();    }
 508   bool is_strict() const                         { return access_flags().is_strict();      }
 509   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 510 
 511   // returns true if contains only return operation
 512   bool is_empty_method() const;
 513 
 514   // returns true if this is a vanilla constructor
 515   bool is_vanilla_constructor() const;
 516 
 517   // checks method and its method holder
 518   bool is_final_method() const;
 519   bool is_strict_method() const;
 520 
 521   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 522   bool can_be_statically_bound() const;
 523 
 524   // returns true if the method has any backward branches.
 525   bool has_loops() {
 526     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 527   };
 528 
 529   bool compute_has_loops_flag();
 530 
 531   bool has_jsrs() {
 532     return access_flags().has_jsrs();
 533   };
 534   void set_has_jsrs() {
 535     _access_flags.set_has_jsrs();
 536   }
 537 
 538   // returns true if the method has any monitors.
 539   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 540   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 541 
 542   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 543 
 544   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 545   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 546   // has not been computed yet.
 547   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 548   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 549 
 550   // returns true if the method is an accessor function (setter/getter).
 551   bool is_accessor() const;
 552 
 553   // returns true if the method is an initializer (<init> or <clinit>).
 554   bool is_initializer() const;
 555 
 556   // returns true if the method is static OR if the classfile version < 51
 557   bool has_valid_initializer_flags() const;
 558 
 559   // returns true if the method name is <clinit> and the method has
 560   // valid static initializer flags.
 561   bool is_static_initializer() const;
 562 
 563   // compiled code support
 564   // NOTE: code() is inherently racy as deopt can be clearing code
 565   // simultaneously. Use with caution.
 566   bool has_compiled_code() const                 { return code() != NULL; }
 567 
 568   // sizing
 569   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 570   static int size(bool is_native);
 571   int size() const                               { return method_size(); }
 572 #if INCLUDE_SERVICES
 573   void collect_statistics(KlassSizeStats *sz) const;
 574 #endif
 575 
 576   // interpreter support
 577   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 578   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 579 #ifdef CC_INTERP
 580   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 581 #endif /* CC_INTERP */
 582   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 583   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 584   static ByteSize invocation_counter_offset()    { return byte_offset_of(Method, _invocation_counter); }
 585   static ByteSize backedge_counter_offset()      { return byte_offset_of(Method, _backedge_counter); }
 586   static ByteSize method_data_offset()           {
 587     return byte_offset_of(Method, _method_data);
 588   }
 589   static ByteSize interpreter_invocation_counter_offset() { return byte_offset_of(Method, _interpreter_invocation_count); }
 590 #ifndef PRODUCT
 591   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 592 #endif // not PRODUCT
 593   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 594   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 595   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 596   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 597 
 598   // for code generation
 599   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 600   static int interpreter_invocation_counter_offset_in_bytes()
 601                                                  { return offset_of(Method, _interpreter_invocation_count); }
 602   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 603   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 604 
 605   // Static methods that are used to implement member methods where an exposed this pointer
 606   // is needed due to possible GCs
 607   static objArrayHandle resolved_checked_exceptions_impl(Method* this_oop, TRAPS);
 608 
 609   // Returns the byte code index from the byte code pointer
 610   int     bci_from(address bcp) const;
 611   address bcp_from(int     bci) const;
 612   int validate_bci_from_bcx(intptr_t bcx) const;
 613 
 614   // Returns the line number for a bci if debugging information for the method is prowided,
 615   // -1 is returned otherwise.
 616   int line_number_from_bci(int bci) const;
 617 
 618   // Reflection support
 619   bool is_overridden_in(Klass* k) const;
 620 
 621   // JSR 292 support
 622   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 623   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 624   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 625   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 626                                                    Symbol* signature, //anything at all
 627                                                    TRAPS);
 628   static Klass* check_non_bcp_klass(Klass* klass);
 629   // these operate only on invoke methods:
 630   // presize interpreter frames for extra interpreter stack entries, if needed
 631   // method handles want to be able to push a few extra values (e.g., a bound receiver), and
 632   // invokedynamic sometimes needs to push a bootstrap method, call site, and arglist,
 633   // all without checking for a stack overflow
 634   static int extra_stack_entries() { return EnableInvokeDynamic ? 2 : 0; }
 635   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize()
 636 
 637   // RedefineClasses() support:
 638   bool is_old() const                               { return access_flags().is_old(); }
 639   void set_is_old()                                 { _access_flags.set_is_old(); }
 640   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 641   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 642   bool on_stack() const                             { return access_flags().on_stack(); }
 643   void set_on_stack(const bool value);
 644 
 645   // see the definition in Method*.cpp for the gory details
 646   bool should_not_be_cached() const;
 647 
 648   // JVMTI Native method prefixing support:
 649   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 650   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 651 
 652   // Rewriting support
 653   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 654                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 655 
 656   // jmethodID handling
 657   // Because the useful life-span of a jmethodID cannot be determined,
 658   // once created they are never reclaimed.  The methods to which they refer,
 659   // however, can be GC'ed away if the class is unloaded or if the method is
 660   // made obsolete or deleted -- in these cases, the jmethodID
 661   // refers to NULL (as is the case for any weak reference).
 662   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 663   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 664 
 665   // Use resolve_jmethod_id() in situations where the caller is expected
 666   // to provide a valid jmethodID; the only sanity checks are in asserts;
 667   // result guaranteed not to be NULL.
 668   inline static Method* resolve_jmethod_id(jmethodID mid) {
 669     assert(mid != NULL, "JNI method id should not be null");
 670     return *((Method**)mid);
 671   }
 672 
 673   // Use checked_resolve_jmethod_id() in situations where the caller
 674   // should provide a valid jmethodID, but might not. NULL is returned
 675   // when the jmethodID does not refer to a valid method.
 676   static Method* checked_resolve_jmethod_id(jmethodID mid);
 677 
 678   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 679   static bool is_method_id(jmethodID mid);
 680 
 681   // Clear methods
 682   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 683   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 684 
 685   // Get this method's jmethodID -- allocate if it doesn't exist
 686   jmethodID jmethod_id()                            { methodHandle this_h(this);
 687                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 688 
 689   // Lookup the jmethodID for this method.  Return NULL if not found.
 690   // NOTE that this function can be called from a signal handler
 691   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 692   // needs to be async-safe. No allocation should be done and
 693   // so handles are not used to avoid deadlock.
 694   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 695 
 696   // JNI static invoke cached itable index accessors
 697   int cached_itable_index()                         { return method_holder()->cached_itable_index(method_idnum()); }
 698   void set_cached_itable_index(int index)           { method_holder()->set_cached_itable_index(method_idnum(), index); }
 699 
 700   // Support for inlining of intrinsic methods
 701   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 702   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 703 
 704   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 705   void init_intrinsic_id();     // updates from _none if a match
 706   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 707 
 708   bool jfr_towrite()                 { return _jfr_towrite; }
 709   void set_jfr_towrite(bool towrite) { _jfr_towrite = towrite; }
 710 
 711   bool     force_inline()       { return _force_inline;     }
 712   void set_force_inline(bool x) {        _force_inline = x; }
 713   bool     dont_inline()        { return _dont_inline;      }
 714   void set_dont_inline(bool x)  {        _dont_inline = x;  }
 715   bool  is_hidden()             { return _hidden;           }
 716   void set_hidden(bool x)       {        _hidden = x;       }
 717   ConstMethod::MethodType method_type() const {
 718       return _constMethod->method_type();
 719   }
 720   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 721 
 722   // On-stack replacement support
 723   bool has_osr_nmethod(int level, bool match_level) {
 724    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 725   }
 726 
 727   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 728     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 729   }
 730 
 731   // Inline cache support
 732   void cleanup_inline_caches();
 733 
 734   // Find if klass for method is loaded
 735   bool is_klass_loaded_by_klass_index(int klass_index) const;
 736   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 737 
 738   // Indicates whether compilation failed earlier for this method, or
 739   // whether it is not compilable for another reason like having a
 740   // breakpoint set in it.
 741   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 742   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 743   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 744     set_not_compilable(comp_level, false);
 745   }
 746   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 747   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 748   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 749     set_not_osr_compilable(comp_level, false);
 750   }
 751 
 752  private:
 753   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 754 
 755  public:
 756   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 757   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 758   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 759   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 760   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 761   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 762 
 763   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 764   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 765   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 766   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 767   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 768   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 769 
 770   // Background compilation support
 771   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 772   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 773   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 774 
 775   // Resolve all classes in signature, return 'true' if successful
 776   static bool load_signature_classes(methodHandle m, TRAPS);
 777 
 778   // Return if true if not all classes references in signature, including return type, has been loaded
 779   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 780 
 781   // Printing
 782   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 783 #if INCLUDE_JVMTI
 784   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 785 #else
 786   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 787 #endif
 788 
 789   // Helper routine used for method sorting
 790   static void sort_methods(Array<Method*>* methods, bool idempotent = false);
 791 
 792   // Deallocation function for redefine classes or if an error occurs
 793   void deallocate_contents(ClassLoaderData* loader_data);
 794 
 795   // Printing
 796 #ifndef PRODUCT
 797   void print_on(outputStream* st) const;
 798 #endif
 799   void print_value_on(outputStream* st) const;
 800 
 801   const char* internal_name() const { return "{method}"; }
 802 
 803   // Check for valid method pointer
 804   bool is_valid_method() const;
 805 
 806   // Verify
 807   void verify() { verify_on(tty); }
 808   void verify_on(outputStream* st);
 809 
 810  private:
 811 
 812   // Inlined elements
 813   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 814   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 815 };
 816 
 817 
 818 // Utility class for compressing line number tables
 819 
 820 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 821  private:
 822   int _bci;
 823   int _line;
 824  public:
 825   // Constructor
 826   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 827   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 828 
 829   // Write (bci, line number) pair to stream
 830   void write_pair_regular(int bci_delta, int line_delta);
 831 
 832   inline void write_pair_inline(int bci, int line) {
 833     int bci_delta = bci - _bci;
 834     int line_delta = line - _line;
 835     _bci = bci;
 836     _line = line;
 837     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 838     if (bci_delta == 0 && line_delta == 0) return;
 839     // Check if bci is 5-bit and line number 3-bit unsigned.
 840     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 841       // Compress into single byte.
 842       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 843       // Check that value doesn't match escape character.
 844       if (value != 0xFF) {
 845         write_byte(value);
 846         return;
 847       }
 848     }
 849     write_pair_regular(bci_delta, line_delta);
 850   }
 851 
 852 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 853 // Disabling optimization doesn't work for methods in header files
 854 // so we force it to call through the non-optimized version in the .cpp.
 855 // It's gross, but it's the only way we can ensure that all callers are
 856 // fixed.  _MSC_VER is defined by the windows compiler
 857 #if defined(_M_AMD64) && _MSC_VER >= 1400
 858   void write_pair(int bci, int line);
 859 #else
 860   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 861 #endif
 862 
 863   // Write end-of-stream marker
 864   void write_terminator()                        { write_byte(0); }
 865 };
 866 
 867 
 868 // Utility class for decompressing line number tables
 869 
 870 class CompressedLineNumberReadStream: public CompressedReadStream {
 871  private:
 872   int _bci;
 873   int _line;
 874  public:
 875   // Constructor
 876   CompressedLineNumberReadStream(u_char* buffer);
 877   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 878   bool read_pair();
 879   // Accessing bci and line number (after calling read_pair)
 880   int bci() const                               { return _bci; }
 881   int line() const                              { return _line; }
 882 };
 883 
 884 
 885 /// Fast Breakpoints.
 886 
 887 // If this structure gets more complicated (because bpts get numerous),
 888 // move it into its own header.
 889 
 890 // There is presently no provision for concurrent access
 891 // to breakpoint lists, which is only OK for JVMTI because
 892 // breakpoints are written only at safepoints, and are read
 893 // concurrently only outside of safepoints.
 894 
 895 class BreakpointInfo : public CHeapObj<mtClass> {
 896   friend class VMStructs;
 897  private:
 898   Bytecodes::Code  _orig_bytecode;
 899   int              _bci;
 900   u2               _name_index;       // of method
 901   u2               _signature_index;  // of method
 902   BreakpointInfo*  _next;             // simple storage allocation
 903 
 904  public:
 905   BreakpointInfo(Method* m, int bci);
 906 
 907   // accessors
 908   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
 909   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
 910   int         bci()                                   { return _bci; }
 911 
 912   BreakpointInfo*          next() const               { return _next; }
 913   void                 set_next(BreakpointInfo* n)    { _next = n; }
 914 
 915   // helps for searchers
 916   bool match(const Method* m, int bci) {
 917     return bci == _bci && match(m);
 918   }
 919 
 920   bool match(const Method* m) {
 921     return _name_index == m->name_index() &&
 922       _signature_index == m->signature_index();
 923   }
 924 
 925   void set(Method* method);
 926   void clear(Method* method);
 927 };
 928 
 929 // Utility class for access exception handlers
 930 class ExceptionTable : public StackObj {
 931  private:
 932   ExceptionTableElement* _table;
 933   u2  _length;
 934 
 935  public:
 936   ExceptionTable(Method* m) {
 937     if (m->has_exception_handler()) {
 938       _table = m->exception_table_start();
 939       _length = m->exception_table_length();
 940     } else {
 941       _table = NULL;
 942       _length = 0;
 943     }
 944   }
 945 
 946   int length() const {
 947     return _length;
 948   }
 949 
 950   u2 start_pc(int idx) const {
 951     assert(idx < _length, "out of bounds");
 952     return _table[idx].start_pc;
 953   }
 954 
 955   void set_start_pc(int idx, u2 value) {
 956     assert(idx < _length, "out of bounds");
 957     _table[idx].start_pc = value;
 958   }
 959 
 960   u2 end_pc(int idx) const {
 961     assert(idx < _length, "out of bounds");
 962     return _table[idx].end_pc;
 963   }
 964 
 965   void set_end_pc(int idx, u2 value) {
 966     assert(idx < _length, "out of bounds");
 967     _table[idx].end_pc = value;
 968   }
 969 
 970   u2 handler_pc(int idx) const {
 971     assert(idx < _length, "out of bounds");
 972     return _table[idx].handler_pc;
 973   }
 974 
 975   void set_handler_pc(int idx, u2 value) {
 976     assert(idx < _length, "out of bounds");
 977     _table[idx].handler_pc = value;
 978   }
 979 
 980   u2 catch_type_index(int idx) const {
 981     assert(idx < _length, "out of bounds");
 982     return _table[idx].catch_type_index;
 983   }
 984 
 985   void set_catch_type_index(int idx, u2 value) {
 986     assert(idx < _length, "out of bounds");
 987     _table[idx].catch_type_index = value;
 988   }
 989 };
 990 
 991 #endif // SHARE_VM_OOPS_METHODOOP_HPP