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 KlassSizeStats;
 105 
 106 class Method : public Metadata {
 107  friend class VMStructs;
 108  private:
 109   ConstMethod*      _constMethod;                // Method read-only data.
 110   MethodData*       _method_data;
 111   int               _interpreter_invocation_count; // Count of times invoked (reused as prev_event_count in tiered)
 112   AccessFlags       _access_flags;               // Access flags
 113   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
 114                                                  // note: can have vtables with >2**16 elements (because of inheritance)
 115 #ifdef CC_INTERP
 116   int               _result_index;               // C++ interpreter needs for converting results to/from stack
 117 #endif
 118   u2                _method_size;                // size of this object
 119   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
 120   u1                _jfr_towrite  : 1,           // Flags
 121                     _force_inline : 1,
 122                     _hidden       : 1,
 123                     _dont_inline  : 1,
 124                                   : 4;
 125   u2                _interpreter_throwout_count; // Count of times method was exited via exception while interpreting
 126   u2                _number_of_breakpoints;      // fullspeed debugging support
 127   InvocationCounter _invocation_counter;         // Incremented before each activation of the method - used to trigger frequency-based optimizations
 128   InvocationCounter _backedge_counter;           // Incremented before each backedge taken - used to trigger frequencey-based optimizations
 129 
 130 #ifdef TIERED
 131   jlong             _prev_time;                   // Previous time the rate was acquired
 132   float             _rate;                        // Events (invocation and backedge counter increments) per millisecond
 133 #endif
 134 
 135 #ifndef PRODUCT
 136   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 137 #endif
 138   // Entry point for calling both from and to the interpreter.
 139   address _i2i_entry;           // All-args-on-stack calling convention
 140   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
 141   AdapterHandlerEntry* _adapter;
 142   // Entry point for calling from compiled code, to compiled code if it exists
 143   // or else the interpreter.
 144   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 145   // The entry point for calling both from and to compiled code is
 146   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 147   // field can come and go.  It can transition from NULL to not-null at any
 148   // time (whenever a compile completes).  It can transition from not-null to
 149   // NULL only at safepoints (because of a de-opt).
 150   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 151   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 152 
 153   // Constructor
 154   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 155  public:
 156 
 157   static Method* allocate(ClassLoaderData* loader_data,
 158                           int byte_code_size,
 159                           AccessFlags access_flags,
 160                           int compressed_line_number_size,
 161                           int localvariable_table_length,
 162                           int exception_table_length,
 163                           int checked_exceptions_length,
 164                           int method_parameters_length,
 165                           u2 generic_signature_index,
 166                           ConstMethod::MethodType method_type,
 167                           TRAPS);
 168 
 169   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 170   Method(){}
 171 
 172   // The Method vtable is restored by this call when the Method is in the
 173   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 174   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 175   // by their vtable.
 176   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 177   bool is_method() const volatile { return true; }
 178 
 179   // accessors for instance variables
 180 
 181   ConstMethod* constMethod() const             { return _constMethod; }
 182   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 183 
 184 
 185   static address make_adapters(methodHandle mh, TRAPS);
 186   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 187   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 188 
 189   // access flag
 190   AccessFlags access_flags() const               { return _access_flags;  }
 191   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 192 
 193   // name
 194   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 195   int name_index() const                         { return constMethod()->name_index();         }
 196   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 197 
 198   // signature
 199   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 200   int signature_index() const                    { return constMethod()->signature_index();         }
 201   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 202 
 203   // generics support
 204   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 205   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 206   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 207 
 208   // annotations support
 209   AnnotationArray* annotations() const           {
 210     InstanceKlass* ik = method_holder();
 211     if (ik->annotations() == NULL) {
 212       return NULL;
 213     }
 214     return ik->annotations()->get_method_annotations_of(method_idnum());
 215   }
 216   AnnotationArray* parameter_annotations() const {
 217     InstanceKlass* ik = method_holder();
 218     if (ik->annotations() == NULL) {
 219       return NULL;
 220     }
 221     return ik->annotations()->get_method_parameter_annotations_of(method_idnum());
 222   }
 223   AnnotationArray* annotation_default() const    {
 224     InstanceKlass* ik = method_holder();
 225     if (ik->annotations() == NULL) {
 226       return NULL;
 227     }
 228     return ik->annotations()->get_method_default_annotations_of(method_idnum());
 229   }
 230   AnnotationArray* type_annotations() const {
 231   InstanceKlass* ik = method_holder();
 232   Annotations* type_annos = ik->type_annotations();
 233   if (type_annos == NULL)
 234     return NULL;
 235   return type_annos->get_method_annotations_of(method_idnum());
 236 }
 237 
 238 #ifdef CC_INTERP
 239   void set_result_index(BasicType type);
 240   int  result_index()                            { return _result_index; }
 241 #endif
 242 
 243   // Helper routine: get klass name + "." + method name + signature as
 244   // C string, for the purpose of providing more useful NoSuchMethodErrors
 245   // and fatal error handling. The string is allocated in resource
 246   // area if a buffer is not provided by the caller.
 247   char* name_and_sig_as_C_string() const;
 248   char* name_and_sig_as_C_string(char* buf, int size) const;
 249 
 250   // Static routine in the situations we don't have a Method*
 251   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 252   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 253 
 254   Bytecodes::Code java_code_at(int bci) const {
 255     return Bytecodes::java_code_at(this, bcp_from(bci));
 256   }
 257   Bytecodes::Code code_at(int bci) const {
 258     return Bytecodes::code_at(this, bcp_from(bci));
 259   }
 260 
 261   // JVMTI breakpoints
 262   Bytecodes::Code orig_bytecode_at(int bci) const;
 263   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 264   void set_breakpoint(int bci);
 265   void clear_breakpoint(int bci);
 266   void clear_all_breakpoints();
 267   // Tracking number of breakpoints, for fullspeed debugging.
 268   // Only mutated by VM thread.
 269   u2   number_of_breakpoints() const             { return _number_of_breakpoints; }
 270   void incr_number_of_breakpoints()              { ++_number_of_breakpoints; }
 271   void decr_number_of_breakpoints()              { --_number_of_breakpoints; }
 272   // Initialization only
 273   void clear_number_of_breakpoints()             { _number_of_breakpoints = 0; }
 274 
 275   // index into InstanceKlass methods() array
 276   // note: also used by jfr
 277   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 278   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 279 
 280   // code size
 281   int code_size() const                  { return constMethod()->code_size(); }
 282 
 283   // method size
 284   int method_size() const                        { return _method_size; }
 285   void set_method_size(int size) {
 286     assert(0 <= size && size < (1 << 16), "invalid method size");
 287     _method_size = size;
 288   }
 289 
 290   // constant pool for Klass* holding this method
 291   ConstantPool* constants() const              { return constMethod()->constants(); }
 292   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 293 
 294   // max stack
 295   // return original max stack size for method verification
 296   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 297   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 298   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 299 
 300   // max locals
 301   int  max_locals() const                        { return constMethod()->max_locals(); }
 302   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 303 
 304   int highest_comp_level() const;
 305   void set_highest_comp_level(int level);
 306   int highest_osr_comp_level() const;
 307   void set_highest_osr_comp_level(int level);
 308 
 309   // Count of times method was exited via exception while interpreting
 310   void interpreter_throwout_increment() {
 311     if (_interpreter_throwout_count < 65534) {
 312       _interpreter_throwout_count++;
 313     }
 314   }
 315 
 316   int  interpreter_throwout_count() const        { return _interpreter_throwout_count; }
 317   void set_interpreter_throwout_count(int count) { _interpreter_throwout_count = count; }
 318 
 319   // size of parameters
 320   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 321   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 322 
 323   bool has_stackmap_table() const {
 324     return constMethod()->has_stackmap_table();
 325   }
 326 
 327   Array<u1>* stackmap_data() const {
 328     return constMethod()->stackmap_data();
 329   }
 330 
 331   void set_stackmap_data(Array<u1>* sd) {
 332     constMethod()->set_stackmap_data(sd);
 333   }
 334 
 335   // exception handler table
 336   bool has_exception_handler() const
 337                              { return constMethod()->has_exception_handler(); }
 338   int exception_table_length() const
 339                              { return constMethod()->exception_table_length(); }
 340   ExceptionTableElement* exception_table_start() const
 341                              { return constMethod()->exception_table_start(); }
 342 
 343   // Finds the first entry point bci of an exception handler for an
 344   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 345   // for ex_klass indicates that the exception klass is not known; in
 346   // this case it matches any constraint class. Returns -1 if the
 347   // exception cannot be handled in this method. The handler
 348   // constraint classes are loaded if necessary. Note that this may
 349   // throw an exception if loading of the constraint classes causes
 350   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 351   // If an exception is thrown, returns the bci of the
 352   // exception handler which caused the exception to be thrown, which
 353   // is needed for proper retries. See, for example,
 354   // InterpreterRuntime::exception_handler_for_exception.
 355   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 356 
 357   // method data access
 358   MethodData* method_data() const              {
 359     return _method_data;
 360   }
 361   void set_method_data(MethodData* data)       {
 362     _method_data = data;
 363   }
 364 
 365   // invocation counter
 366   InvocationCounter* invocation_counter() { return &_invocation_counter; }
 367   InvocationCounter* backedge_counter()   { return &_backedge_counter; }
 368 
 369 #ifdef TIERED
 370   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 371   // We can do that since interpreter_invocation_count is not used in tiered.
 372   int prev_event_count() const                   { return _interpreter_invocation_count;  }
 373   void set_prev_event_count(int count)           { _interpreter_invocation_count = count; }
 374   jlong prev_time() const                        { return _prev_time; }
 375   void set_prev_time(jlong time)                 { _prev_time = time; }
 376   float rate() const                             { return _rate; }
 377   void set_rate(float rate)                      { _rate = rate; }
 378 #endif
 379 
 380   int invocation_count();
 381   int backedge_count();
 382 
 383   bool was_executed_more_than(int n);
 384   bool was_never_executed()                      { return !was_executed_more_than(0); }
 385 
 386   static void build_interpreter_method_data(methodHandle method, TRAPS);
 387 
 388   int interpreter_invocation_count() {
 389     if (TieredCompilation) return invocation_count();
 390     else return _interpreter_invocation_count;
 391   }
 392   void set_interpreter_invocation_count(int count) { _interpreter_invocation_count = count; }
 393   int increment_interpreter_invocation_count() {
 394     if (TieredCompilation) ShouldNotReachHere();
 395     return ++_interpreter_invocation_count;
 396   }
 397 
 398 #ifndef PRODUCT
 399   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 400   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 401 #endif // not PRODUCT
 402 
 403   // Clear (non-shared space) pointers which could not be relevant
 404   // if this (shared) method were mapped into another JVM.
 405   void remove_unshareable_info();
 406 
 407   // nmethod/verified compiler entry
 408   address verified_code_entry();
 409   bool check_code() const;      // Not inline to avoid circular ref
 410   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 411   void clear_code();            // Clear out any compiled code
 412   static void set_code(methodHandle mh, nmethod* code);
 413   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 414   address get_i2c_entry();
 415   address get_c2i_entry();
 416   address get_c2i_unverified_entry();
 417   AdapterHandlerEntry* adapter() {  return _adapter; }
 418   // setup entry points
 419   void link_method(methodHandle method, TRAPS);
 420   // clear entry points. Used by sharing code
 421   void unlink_method();
 422 
 423   // vtable index
 424   enum VtableIndexFlag {
 425     // Valid vtable indexes are non-negative (>= 0).
 426     // These few negative values are used as sentinels.
 427     highest_unused_vtable_index_value = -5,
 428     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 429     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 430     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 431     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 432   };
 433   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 434   int  vtable_index() const                      { assert(valid_vtable_index(), "");
 435                                                    return _vtable_index; }
 436   void set_vtable_index(int index)               { _vtable_index = index; }
 437 
 438   // interpreter entry
 439   address interpreter_entry() const              { return _i2i_entry; }
 440   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 441   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 442   int  interpreter_kind(void) {
 443      return constMethod()->interpreter_kind();
 444   }
 445   void set_interpreter_kind();
 446   void set_interpreter_kind(int kind) {
 447     constMethod()->set_interpreter_kind(kind);
 448   }
 449 
 450   // native function (used for native methods only)
 451   enum {
 452     native_bind_event_is_interesting = true
 453   };
 454   address native_function() const                { return *(native_function_addr()); }
 455   address critical_native_function();
 456 
 457   // Must specify a real function (not NULL).
 458   // Use clear_native_function() to unregister.
 459   void set_native_function(address function, bool post_event_flag);
 460   bool has_native_function() const;
 461   void clear_native_function();
 462 
 463   // signature handler (used for native methods only)
 464   address signature_handler() const              { return *(signature_handler_addr()); }
 465   void set_signature_handler(address handler);
 466 
 467   // Interpreter oopmap support
 468   void mask_for(int bci, InterpreterOopMap* mask);
 469 
 470 #ifndef PRODUCT
 471   // operations on invocation counter
 472   void print_invocation_count();
 473 #endif
 474 
 475   // byte codes
 476   void    set_code(address code)      { return constMethod()->set_code(code); }
 477   address code_base() const           { return constMethod()->code_base(); }
 478   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 479 
 480   // prints byte codes
 481   void print_codes() const            { print_codes_on(tty); }
 482   void print_codes_on(outputStream* st) const                      PRODUCT_RETURN;
 483   void print_codes_on(int from, int to, outputStream* st) const    PRODUCT_RETURN;
 484 
 485   // method parameters
 486   int method_parameters_length() const
 487                          { return constMethod()->method_parameters_length(); }
 488   MethodParametersElement* method_parameters_start() const
 489                           { return constMethod()->method_parameters_start(); }
 490 
 491   // checked exceptions
 492   int checked_exceptions_length() const
 493                          { return constMethod()->checked_exceptions_length(); }
 494   CheckedExceptionElement* checked_exceptions_start() const
 495                           { return constMethod()->checked_exceptions_start(); }
 496 
 497   // localvariable table
 498   bool has_localvariable_table() const
 499                           { return constMethod()->has_localvariable_table(); }
 500   int localvariable_table_length() const
 501                         { return constMethod()->localvariable_table_length(); }
 502   LocalVariableTableElement* localvariable_table_start() const
 503                          { return constMethod()->localvariable_table_start(); }
 504 
 505   bool has_linenumber_table() const
 506                               { return constMethod()->has_linenumber_table(); }
 507   u_char* compressed_linenumber_table() const
 508                        { return constMethod()->compressed_linenumber_table(); }
 509 
 510   // method holder (the Klass* holding this method)
 511   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 512 
 513   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 514   Symbol* klass_name() const;                    // returns the name of the method holder
 515   BasicType result_type() const;                 // type of the method result
 516   int result_type_index() const;                 // type index of the method result
 517   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 518   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 519 
 520   // Checked exceptions thrown by this method (resolved to mirrors)
 521   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 522 
 523   // Access flags
 524   bool is_public() const                         { return access_flags().is_public();      }
 525   bool is_private() const                        { return access_flags().is_private();     }
 526   bool is_protected() const                      { return access_flags().is_protected();   }
 527   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 528   bool is_static() const                         { return access_flags().is_static();      }
 529   bool is_final() const                          { return access_flags().is_final();       }
 530   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 531   bool is_native() const                         { return access_flags().is_native();      }
 532   bool is_abstract() const                       { return access_flags().is_abstract();    }
 533   bool is_strict() const                         { return access_flags().is_strict();      }
 534   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 535 
 536   // returns true if contains only return operation
 537   bool is_empty_method() const;
 538 
 539   // returns true if this is a vanilla constructor
 540   bool is_vanilla_constructor() const;
 541 
 542   // checks method and its method holder
 543   bool is_final_method() const;
 544   bool is_strict_method() const;
 545 
 546   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 547   bool can_be_statically_bound() const;
 548 
 549   // returns true if the method has any backward branches.
 550   bool has_loops() {
 551     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 552   };
 553 
 554   bool compute_has_loops_flag();
 555 
 556   bool has_jsrs() {
 557     return access_flags().has_jsrs();
 558   };
 559   void set_has_jsrs() {
 560     _access_flags.set_has_jsrs();
 561   }
 562 
 563   // returns true if the method has any monitors.
 564   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 565   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 566 
 567   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 568 
 569   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 570   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 571   // has not been computed yet.
 572   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 573   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 574 
 575   // returns true if the method is an accessor function (setter/getter).
 576   bool is_accessor() const;
 577 
 578   // returns true if the method is an initializer (<init> or <clinit>).
 579   bool is_initializer() const;
 580 
 581   // returns true if the method is static OR if the classfile version < 51
 582   bool has_valid_initializer_flags() const;
 583 
 584   // returns true if the method name is <clinit> and the method has
 585   // valid static initializer flags.
 586   bool is_static_initializer() const;
 587 
 588   // compiled code support
 589   // NOTE: code() is inherently racy as deopt can be clearing code
 590   // simultaneously. Use with caution.
 591   bool has_compiled_code() const                 { return code() != NULL; }
 592 
 593   // sizing
 594   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 595   static int size(bool is_native);
 596   int size() const                               { return method_size(); }
 597 #if INCLUDE_SERVICES
 598   void collect_statistics(KlassSizeStats *sz) const;
 599 #endif
 600 
 601   // interpreter support
 602   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 603   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 604 #ifdef CC_INTERP
 605   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 606 #endif /* CC_INTERP */
 607   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 608   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 609   static ByteSize invocation_counter_offset()    { return byte_offset_of(Method, _invocation_counter); }
 610   static ByteSize backedge_counter_offset()      { return byte_offset_of(Method, _backedge_counter); }
 611   static ByteSize method_data_offset()           {
 612     return byte_offset_of(Method, _method_data);
 613   }
 614   static ByteSize interpreter_invocation_counter_offset() { return byte_offset_of(Method, _interpreter_invocation_count); }
 615 #ifndef PRODUCT
 616   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 617 #endif // not PRODUCT
 618   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 619   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 620   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 621   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 622 
 623   // for code generation
 624   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 625   static int interpreter_invocation_counter_offset_in_bytes()
 626                                                  { return offset_of(Method, _interpreter_invocation_count); }
 627   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 628   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 629 
 630   // Static methods that are used to implement member methods where an exposed this pointer
 631   // is needed due to possible GCs
 632   static objArrayHandle resolved_checked_exceptions_impl(Method* this_oop, TRAPS);
 633 
 634   // Returns the byte code index from the byte code pointer
 635   int     bci_from(address bcp) const;
 636   address bcp_from(int     bci) const;
 637   int validate_bci_from_bcx(intptr_t bcx) const;
 638 
 639   // Returns the line number for a bci if debugging information for the method is prowided,
 640   // -1 is returned otherwise.
 641   int line_number_from_bci(int bci) const;
 642 
 643   // Reflection support
 644   bool is_overridden_in(Klass* k) const;
 645 
 646   // JSR 292 support
 647   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 648   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 649   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 650   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 651                                                    Symbol* signature, //anything at all
 652                                                    TRAPS);
 653   static Klass* check_non_bcp_klass(Klass* klass);
 654   // these operate only on invoke methods:
 655   // presize interpreter frames for extra interpreter stack entries, if needed
 656   // method handles want to be able to push a few extra values (e.g., a bound receiver), and
 657   // invokedynamic sometimes needs to push a bootstrap method, call site, and arglist,
 658   // all without checking for a stack overflow
 659   static int extra_stack_entries() { return EnableInvokeDynamic ? 2 : 0; }
 660   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize()
 661 
 662   // RedefineClasses() support:
 663   bool is_old() const                               { return access_flags().is_old(); }
 664   void set_is_old()                                 { _access_flags.set_is_old(); }
 665   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 666   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 667   bool on_stack() const                             { return access_flags().on_stack(); }
 668   void set_on_stack(const bool value);
 669 
 670   // see the definition in Method*.cpp for the gory details
 671   bool should_not_be_cached() const;
 672 
 673   // JVMTI Native method prefixing support:
 674   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 675   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 676 
 677   // Rewriting support
 678   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 679                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 680 
 681   // jmethodID handling
 682   // Because the useful life-span of a jmethodID cannot be determined,
 683   // once created they are never reclaimed.  The methods to which they refer,
 684   // however, can be GC'ed away if the class is unloaded or if the method is
 685   // made obsolete or deleted -- in these cases, the jmethodID
 686   // refers to NULL (as is the case for any weak reference).
 687   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 688   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 689 
 690   // Use resolve_jmethod_id() in situations where the caller is expected
 691   // to provide a valid jmethodID; the only sanity checks are in asserts;
 692   // result guaranteed not to be NULL.
 693   inline static Method* resolve_jmethod_id(jmethodID mid) {
 694     assert(mid != NULL, "JNI method id should not be null");
 695     return *((Method**)mid);
 696   }
 697 
 698   // Use checked_resolve_jmethod_id() in situations where the caller
 699   // should provide a valid jmethodID, but might not. NULL is returned
 700   // when the jmethodID does not refer to a valid method.
 701   static Method* checked_resolve_jmethod_id(jmethodID mid);
 702 
 703   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 704   static bool is_method_id(jmethodID mid);
 705 
 706   // Clear methods
 707   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 708   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 709 
 710   // Get this method's jmethodID -- allocate if it doesn't exist
 711   jmethodID jmethod_id()                            { methodHandle this_h(this);
 712                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 713 
 714   // Lookup the jmethodID for this method.  Return NULL if not found.
 715   // NOTE that this function can be called from a signal handler
 716   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 717   // needs to be async-safe. No allocation should be done and
 718   // so handles are not used to avoid deadlock.
 719   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 720 
 721   // JNI static invoke cached itable index accessors
 722   int cached_itable_index()                         { return method_holder()->cached_itable_index(method_idnum()); }
 723   void set_cached_itable_index(int index)           { method_holder()->set_cached_itable_index(method_idnum(), index); }
 724 
 725   // Support for inlining of intrinsic methods
 726   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 727   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 728 
 729   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 730   void init_intrinsic_id();     // updates from _none if a match
 731   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 732 
 733   bool jfr_towrite()                 { return _jfr_towrite; }
 734   void set_jfr_towrite(bool towrite) { _jfr_towrite = towrite; }
 735 
 736   bool     force_inline()       { return _force_inline;     }
 737   void set_force_inline(bool x) {        _force_inline = x; }
 738   bool     dont_inline()        { return _dont_inline;      }
 739   void set_dont_inline(bool x)  {        _dont_inline = x;  }
 740   bool  is_hidden()             { return _hidden;           }
 741   void set_hidden(bool x)       {        _hidden = x;       }
 742   ConstMethod::MethodType method_type() const {
 743       return _constMethod->method_type();
 744   }
 745   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 746 
 747   // On-stack replacement support
 748   bool has_osr_nmethod(int level, bool match_level) {
 749    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 750   }
 751 
 752   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 753     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 754   }
 755 
 756   // Inline cache support
 757   void cleanup_inline_caches();
 758 
 759   // Find if klass for method is loaded
 760   bool is_klass_loaded_by_klass_index(int klass_index) const;
 761   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 762 
 763   // Indicates whether compilation failed earlier for this method, or
 764   // whether it is not compilable for another reason like having a
 765   // breakpoint set in it.
 766   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 767   void set_not_compilable(int comp_level = CompLevel_all, bool report = true);
 768   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 769     set_not_compilable(comp_level, false);
 770   }
 771   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 772   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true);
 773   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 774     set_not_osr_compilable(comp_level, false);
 775   }
 776 
 777  private:
 778   void print_made_not_compilable(int comp_level, bool is_osr, bool report);
 779 
 780  public:
 781   bool  is_not_c1_compilable() const          { return access_flags().is_not_c1_compilable(); }
 782   void set_not_c1_compilable()                {       _access_flags.set_not_c1_compilable();  }
 783   bool  is_not_c2_compilable() const          { return access_flags().is_not_c2_compilable(); }
 784   void set_not_c2_compilable()                {       _access_flags.set_not_c2_compilable();  }
 785 
 786   bool  is_not_c1_osr_compilable() const      { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 787   void set_not_c1_osr_compilable()            {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 788   bool  is_not_c2_osr_compilable() const      { return access_flags().is_not_c2_osr_compilable(); }
 789   void set_not_c2_osr_compilable()            {       _access_flags.set_not_c2_osr_compilable();  }
 790 
 791   // Background compilation support
 792   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 793   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 794   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 795 
 796   // Resolve all classes in signature, return 'true' if successful
 797   static bool load_signature_classes(methodHandle m, TRAPS);
 798 
 799   // Return if true if not all classes references in signature, including return type, has been loaded
 800   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 801 
 802   // Printing
 803   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 804   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 805 
 806   // Helper routine used for method sorting
 807   static void sort_methods(Array<Method*>* methods,
 808                            Array<AnnotationArray*>* methods_annotations,
 809                            Array<AnnotationArray*>* methods_parameter_annotations,
 810                            Array<AnnotationArray*>* methods_default_annotations,
 811                            Array<AnnotationArray*>* methods_type_annotations,
 812                            bool idempotent = false);
 813 
 814   // Deallocation function for redefine classes or if an error occurs
 815   void deallocate_contents(ClassLoaderData* loader_data);
 816 
 817   // Printing
 818 #ifndef PRODUCT
 819   void print_on(outputStream* st) const;
 820 #endif
 821   void print_value_on(outputStream* st) const;
 822 
 823   const char* internal_name() const { return "{method}"; }
 824 
 825   // Check for valid method pointer
 826   bool is_valid_method() const;
 827 
 828   // Verify
 829   void verify() { verify_on(tty); }
 830   void verify_on(outputStream* st);
 831 
 832  private:
 833 
 834   // Inlined elements
 835   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 836   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 837 };
 838 
 839 
 840 // Utility class for compressing line number tables
 841 
 842 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 843  private:
 844   int _bci;
 845   int _line;
 846  public:
 847   // Constructor
 848   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 849   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 850 
 851   // Write (bci, line number) pair to stream
 852   void write_pair_regular(int bci_delta, int line_delta);
 853 
 854   inline void write_pair_inline(int bci, int line) {
 855     int bci_delta = bci - _bci;
 856     int line_delta = line - _line;
 857     _bci = bci;
 858     _line = line;
 859     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 860     if (bci_delta == 0 && line_delta == 0) return;
 861     // Check if bci is 5-bit and line number 3-bit unsigned.
 862     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 863       // Compress into single byte.
 864       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 865       // Check that value doesn't match escape character.
 866       if (value != 0xFF) {
 867         write_byte(value);
 868         return;
 869       }
 870     }
 871     write_pair_regular(bci_delta, line_delta);
 872   }
 873 
 874 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 875 // Disabling optimization doesn't work for methods in header files
 876 // so we force it to call through the non-optimized version in the .cpp.
 877 // It's gross, but it's the only way we can ensure that all callers are
 878 // fixed.  _MSC_VER is defined by the windows compiler
 879 #if defined(_M_AMD64) && _MSC_VER >= 1400
 880   void write_pair(int bci, int line);
 881 #else
 882   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 883 #endif
 884 
 885   // Write end-of-stream marker
 886   void write_terminator()                        { write_byte(0); }
 887 };
 888 
 889 
 890 // Utility class for decompressing line number tables
 891 
 892 class CompressedLineNumberReadStream: public CompressedReadStream {
 893  private:
 894   int _bci;
 895   int _line;
 896  public:
 897   // Constructor
 898   CompressedLineNumberReadStream(u_char* buffer);
 899   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 900   bool read_pair();
 901   // Accessing bci and line number (after calling read_pair)
 902   int bci() const                               { return _bci; }
 903   int line() const                              { return _line; }
 904 };
 905 
 906 
 907 /// Fast Breakpoints.
 908 
 909 // If this structure gets more complicated (because bpts get numerous),
 910 // move it into its own header.
 911 
 912 // There is presently no provision for concurrent access
 913 // to breakpoint lists, which is only OK for JVMTI because
 914 // breakpoints are written only at safepoints, and are read
 915 // concurrently only outside of safepoints.
 916 
 917 class BreakpointInfo : public CHeapObj<mtClass> {
 918   friend class VMStructs;
 919  private:
 920   Bytecodes::Code  _orig_bytecode;
 921   int              _bci;
 922   u2               _name_index;       // of method
 923   u2               _signature_index;  // of method
 924   BreakpointInfo*  _next;             // simple storage allocation
 925 
 926  public:
 927   BreakpointInfo(Method* m, int bci);
 928 
 929   // accessors
 930   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
 931   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
 932   int         bci()                                   { return _bci; }
 933 
 934   BreakpointInfo*          next() const               { return _next; }
 935   void                 set_next(BreakpointInfo* n)    { _next = n; }
 936 
 937   // helps for searchers
 938   bool match(const Method* m, int bci) {
 939     return bci == _bci && match(m);
 940   }
 941 
 942   bool match(const Method* m) {
 943     return _name_index == m->name_index() &&
 944       _signature_index == m->signature_index();
 945   }
 946 
 947   void set(Method* method);
 948   void clear(Method* method);
 949 };
 950 
 951 // Utility class for access exception handlers
 952 class ExceptionTable : public StackObj {
 953  private:
 954   ExceptionTableElement* _table;
 955   u2  _length;
 956 
 957  public:
 958   ExceptionTable(Method* m) {
 959     if (m->has_exception_handler()) {
 960       _table = m->exception_table_start();
 961       _length = m->exception_table_length();
 962     } else {
 963       _table = NULL;
 964       _length = 0;
 965     }
 966   }
 967 
 968   int length() const {
 969     return _length;
 970   }
 971 
 972   u2 start_pc(int idx) const {
 973     assert(idx < _length, "out of bounds");
 974     return _table[idx].start_pc;
 975   }
 976 
 977   void set_start_pc(int idx, u2 value) {
 978     assert(idx < _length, "out of bounds");
 979     _table[idx].start_pc = value;
 980   }
 981 
 982   u2 end_pc(int idx) const {
 983     assert(idx < _length, "out of bounds");
 984     return _table[idx].end_pc;
 985   }
 986 
 987   void set_end_pc(int idx, u2 value) {
 988     assert(idx < _length, "out of bounds");
 989     _table[idx].end_pc = value;
 990   }
 991 
 992   u2 handler_pc(int idx) const {
 993     assert(idx < _length, "out of bounds");
 994     return _table[idx].handler_pc;
 995   }
 996 
 997   void set_handler_pc(int idx, u2 value) {
 998     assert(idx < _length, "out of bounds");
 999     _table[idx].handler_pc = value;
1000   }
1001 
1002   u2 catch_type_index(int idx) const {
1003     assert(idx < _length, "out of bounds");
1004     return _table[idx].catch_type_index;
1005   }
1006 
1007   void set_catch_type_index(int idx, u2 value) {
1008     assert(idx < _length, "out of bounds");
1009     _table[idx].catch_type_index = value;
1010   }
1011 };
1012 
1013 #endif // SHARE_VM_OOPS_METHODOOP_HPP