1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_METHODOOP_HPP
  26 #define SHARE_VM_OOPS_METHODOOP_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "interpreter/invocationCounter.hpp"
  32 #include "oops/annotations.hpp"
  33 #include "oops/constantPool.hpp"
  34 #include "oops/methodCounters.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.hpp"
  37 #include "oops/typeArrayOop.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/growableArray.hpp"
  40 
  41 // A Method represents a Java method.
  42 //
  43 // Note that most applications load thousands of methods, so keeping the size of this
  44 // class small has a big impact on footprint.
  45 //
  46 // Note that native_function and signature_handler have to be at fixed offsets
  47 // (required by the interpreter)
  48 //
  49 //  Method embedded field layout (after declared fields):
  50 //   [EMBEDDED native_function       (present only if native) ]
  51 //   [EMBEDDED signature_handler     (present only if native) ]
  52 
  53 class CheckedExceptionElement;
  54 class LocalVariableTableElement;
  55 class AdapterHandlerEntry;
  56 class MethodData;
  57 class MethodCounters;
  58 class ConstMethod;
  59 class InlineTableSizes;
  60 class KlassSizeStats;
  61 
  62 class Method : public Metadata {
  63  friend class VMStructs;
  64  private:
  65   ConstMethod*      _constMethod;                // Method read-only data.
  66   MethodData*       _method_data;
  67   MethodCounters*   _method_counters;
  68   AccessFlags       _access_flags;               // Access flags
  69   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
  70                                                  // note: can have vtables with >2**16 elements (because of inheritance)
  71 #ifdef CC_INTERP
  72   int               _result_index;               // C++ interpreter needs for converting results to/from stack
  73 #endif
  74   u2                _method_size;                // size of this object
  75   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
  76 
  77   // Flags
  78   enum Flags {
  79     _jfr_towrite      = 1 << 0,
  80     _caller_sensitive = 1 << 1,
  81     _force_inline     = 1 << 2,
  82     _dont_inline      = 1 << 3,
  83     _hidden           = 1 << 4,
  84     _running_emcp     = 1 << 5
  85   };
  86   u1 _flags;
  87 
  88 #ifndef PRODUCT
  89   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
  90 #endif
  91   // Entry point for calling both from and to the interpreter.
  92   address _i2i_entry;           // All-args-on-stack calling convention
  93   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
  94   AdapterHandlerEntry* _adapter;
  95   // Entry point for calling from compiled code, to compiled code if it exists
  96   // or else the interpreter.
  97   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
  98   // The entry point for calling both from and to compiled code is
  99   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 100   // field can come and go.  It can transition from NULL to not-null at any
 101   // time (whenever a compile completes).  It can transition from not-null to
 102   // NULL only at safepoints (because of a de-opt).
 103   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 104   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 105 
 106   // Constructor
 107   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 108  public:
 109 
 110   static Method* allocate(ClassLoaderData* loader_data,
 111                           int byte_code_size,
 112                           AccessFlags access_flags,
 113                           InlineTableSizes* sizes,
 114                           ConstMethod::MethodType method_type,
 115                           TRAPS);
 116 
 117   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 118   Method(){}
 119 
 120   // The Method vtable is restored by this call when the Method is in the
 121   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 122   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 123   // by their vtable.
 124   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 125   bool is_method() const volatile { return true; }
 126 
 127   void restore_unshareable_info(TRAPS);
 128 
 129   // accessors for instance variables
 130 
 131   ConstMethod* constMethod() const             { return _constMethod; }
 132   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 133 
 134 
 135   static address make_adapters(methodHandle mh, TRAPS);
 136   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 137   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 138 
 139   // access flag
 140   AccessFlags access_flags() const               { return _access_flags;  }
 141   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 142 
 143   // name
 144   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 145   int name_index() const                         { return constMethod()->name_index();         }
 146   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 147 
 148   // signature
 149   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 150   int signature_index() const                    { return constMethod()->signature_index();         }
 151   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 152 
 153   // generics support
 154   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 155   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 156   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 157 
 158   // annotations support
 159   AnnotationArray* annotations() const           {
 160     return constMethod()->method_annotations();
 161   }
 162   AnnotationArray* parameter_annotations() const {
 163     return constMethod()->parameter_annotations();
 164   }
 165   AnnotationArray* annotation_default() const    {
 166     return constMethod()->default_annotations();
 167   }
 168   AnnotationArray* type_annotations() const      {
 169     return constMethod()->type_annotations();
 170   }
 171 
 172 #ifdef CC_INTERP
 173   void set_result_index(BasicType type);
 174   int  result_index()                            { return _result_index; }
 175 #endif
 176 
 177   // Helper routine: get klass name + "." + method name + signature as
 178   // C string, for the purpose of providing more useful NoSuchMethodErrors
 179   // and fatal error handling. The string is allocated in resource
 180   // area if a buffer is not provided by the caller.
 181   char* name_and_sig_as_C_string() const;
 182   char* name_and_sig_as_C_string(char* buf, int size) const;
 183 
 184   // Static routine in the situations we don't have a Method*
 185   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 186   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 187 
 188   Bytecodes::Code java_code_at(int bci) const {
 189     return Bytecodes::java_code_at(this, bcp_from(bci));
 190   }
 191   Bytecodes::Code code_at(int bci) const {
 192     return Bytecodes::code_at(this, bcp_from(bci));
 193   }
 194 
 195   // JVMTI breakpoints
 196   Bytecodes::Code orig_bytecode_at(int bci) const;
 197   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 198   void set_breakpoint(int bci);
 199   void clear_breakpoint(int bci);
 200   void clear_all_breakpoints();
 201   // Tracking number of breakpoints, for fullspeed debugging.
 202   // Only mutated by VM thread.
 203   u2   number_of_breakpoints()             const {
 204     MethodCounters* mcs = method_counters();
 205     if (mcs == NULL) {
 206       return 0;
 207     } else {
 208       return mcs->number_of_breakpoints();
 209     }
 210   }
 211   void incr_number_of_breakpoints(TRAPS)         {
 212     MethodCounters* mcs = get_method_counters(CHECK);
 213     if (mcs != NULL) {
 214       mcs->incr_number_of_breakpoints();
 215     }
 216   }
 217   void decr_number_of_breakpoints(TRAPS)         {
 218     MethodCounters* mcs = get_method_counters(CHECK);
 219     if (mcs != NULL) {
 220       mcs->decr_number_of_breakpoints();
 221     }
 222   }
 223   // Initialization only
 224   void clear_number_of_breakpoints()             {
 225     MethodCounters* mcs = method_counters();
 226     if (mcs != NULL) {
 227       mcs->clear_number_of_breakpoints();
 228     }
 229   }
 230 
 231   // index into InstanceKlass methods() array
 232   // note: also used by jfr
 233   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 234   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 235 
 236   // code size
 237   int code_size() const                  { return constMethod()->code_size(); }
 238 
 239   // method size
 240   int method_size() const                        { return _method_size; }
 241   void set_method_size(int size) {
 242     assert(0 <= size && size < (1 << 16), "invalid method size");
 243     _method_size = size;
 244   }
 245 
 246   // constant pool for Klass* holding this method
 247   ConstantPool* constants() const              { return constMethod()->constants(); }
 248   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 249 
 250   // max stack
 251   // return original max stack size for method verification
 252   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 253   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 254   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 255 
 256   // max locals
 257   int  max_locals() const                        { return constMethod()->max_locals(); }
 258   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 259 
 260   int highest_comp_level() const;
 261   void set_highest_comp_level(int level);
 262   int highest_osr_comp_level() const;
 263   void set_highest_osr_comp_level(int level);
 264 
 265   // Count of times method was exited via exception while interpreting
 266   void interpreter_throwout_increment(TRAPS) {
 267     MethodCounters* mcs = get_method_counters(CHECK);
 268     if (mcs != NULL) {
 269       mcs->interpreter_throwout_increment();
 270     }
 271   }
 272 
 273   int  interpreter_throwout_count() const        {
 274     MethodCounters* mcs = method_counters();
 275     if (mcs == NULL) {
 276       return 0;
 277     } else {
 278       return mcs->interpreter_throwout_count();
 279     }
 280   }
 281 
 282   // size of parameters
 283   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 284   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 285 
 286   bool has_stackmap_table() const {
 287     return constMethod()->has_stackmap_table();
 288   }
 289 
 290   Array<u1>* stackmap_data() const {
 291     return constMethod()->stackmap_data();
 292   }
 293 
 294   void set_stackmap_data(Array<u1>* sd) {
 295     constMethod()->set_stackmap_data(sd);
 296   }
 297 
 298   // exception handler table
 299   bool has_exception_handler() const
 300                              { return constMethod()->has_exception_handler(); }
 301   int exception_table_length() const
 302                              { return constMethod()->exception_table_length(); }
 303   ExceptionTableElement* exception_table_start() const
 304                              { return constMethod()->exception_table_start(); }
 305 
 306   // Finds the first entry point bci of an exception handler for an
 307   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 308   // for ex_klass indicates that the exception klass is not known; in
 309   // this case it matches any constraint class. Returns -1 if the
 310   // exception cannot be handled in this method. The handler
 311   // constraint classes are loaded if necessary. Note that this may
 312   // throw an exception if loading of the constraint classes causes
 313   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 314   // If an exception is thrown, returns the bci of the
 315   // exception handler which caused the exception to be thrown, which
 316   // is needed for proper retries. See, for example,
 317   // InterpreterRuntime::exception_handler_for_exception.
 318   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 319 
 320   // method data access
 321   MethodData* method_data() const              {
 322     return _method_data;
 323   }
 324 
 325   void set_method_data(MethodData* data)       {
 326     // The store into method must be released. On platforms without
 327     // total store order (TSO) the reference may become visible before
 328     // the initialization of data otherwise.
 329     OrderAccess::release_store_ptr((volatile void *)&_method_data, data);
 330   }
 331 
 332   MethodCounters* method_counters() const {
 333     return _method_counters;
 334   }
 335 
 336   void set_method_counters(MethodCounters* counters) {
 337     // The store into method must be released. On platforms without
 338     // total store order (TSO) the reference may become visible before
 339     // the initialization of data otherwise.
 340     OrderAccess::release_store_ptr((volatile void *)&_method_counters, counters);
 341   }
 342 
 343   bool init_method_counters(MethodCounters* counters) {
 344     // Try to install a pointer to MethodCounters, return true on success.
 345     return Atomic::cmpxchg_ptr(counters, (volatile void*)&_method_counters, NULL) == NULL;
 346   }
 347 
 348 #ifdef TIERED
 349   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 350   // We can do that since interpreter_invocation_count is not used in tiered.
 351   int prev_event_count() const                   {
 352     if (method_counters() == NULL) {
 353       return 0;
 354     } else {
 355       return method_counters()->interpreter_invocation_count();
 356     }
 357   }
 358   void set_prev_event_count(int count) {
 359     MethodCounters* mcs = method_counters();
 360     if (mcs != NULL) {
 361       mcs->set_interpreter_invocation_count(count);
 362     }
 363   }
 364   jlong prev_time() const                        {
 365     MethodCounters* mcs = method_counters();
 366     return mcs == NULL ? 0 : mcs->prev_time();
 367   }
 368   void set_prev_time(jlong time) {
 369     MethodCounters* mcs = method_counters();
 370     if (mcs != NULL) {
 371       mcs->set_prev_time(time);
 372     }
 373   }
 374   float rate() const                             {
 375     MethodCounters* mcs = method_counters();
 376     return mcs == NULL ? 0 : mcs->rate();
 377   }
 378   void set_rate(float rate) {
 379     MethodCounters* mcs = method_counters();
 380     if (mcs != NULL) {
 381       mcs->set_rate(rate);
 382     }
 383   }
 384 #endif
 385   int nmethod_age() const {
 386     if (method_counters() == NULL) {
 387       return INT_MAX;
 388     } else {
 389       return method_counters()->nmethod_age();
 390     }
 391   }
 392 
 393   int invocation_count();
 394   int backedge_count();
 395 
 396   bool was_executed_more_than(int n);
 397   bool was_never_executed()                      { return !was_executed_more_than(0); }
 398 
 399   static void build_interpreter_method_data(methodHandle method, TRAPS);
 400 
 401   static MethodCounters* build_method_counters(Method* m, TRAPS);
 402 
 403   int interpreter_invocation_count() {
 404     if (TieredCompilation) {
 405       return invocation_count();
 406     } else {
 407       MethodCounters* mcs = method_counters();
 408       return (mcs == NULL) ? 0 : mcs->interpreter_invocation_count();
 409     }
 410   }
 411   int increment_interpreter_invocation_count(TRAPS) {
 412     if (TieredCompilation) ShouldNotReachHere();
 413     MethodCounters* mcs = get_method_counters(CHECK_0);
 414     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 415   }
 416 
 417 #ifndef PRODUCT
 418   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 419   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 420 #else
 421   // for PrintMethodData in a product build
 422   int  compiled_invocation_count() const         { return 0;  }
 423 #endif // not PRODUCT
 424 
 425   // Clear (non-shared space) pointers which could not be relevant
 426   // if this (shared) method were mapped into another JVM.
 427   void remove_unshareable_info();
 428 
 429   // nmethod/verified compiler entry
 430   address verified_code_entry();
 431   bool check_code() const;      // Not inline to avoid circular ref
 432   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 433   void clear_code();            // Clear out any compiled code
 434   static void set_code(methodHandle mh, nmethod* code);
 435   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 436   address get_i2c_entry();
 437   address get_c2i_entry();
 438   address get_c2i_unverified_entry();
 439   AdapterHandlerEntry* adapter() {  return _adapter; }
 440   // setup entry points
 441   void link_method(methodHandle method, TRAPS);
 442   // clear entry points. Used by sharing code
 443   void unlink_method();
 444 
 445   // vtable index
 446   enum VtableIndexFlag {
 447     // Valid vtable indexes are non-negative (>= 0).
 448     // These few negative values are used as sentinels.
 449     itable_index_max        = -10, // first itable index, growing downward
 450     pending_itable_index    = -9,  // itable index will be assigned
 451     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 452     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 453     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 454     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 455   };
 456   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 457   bool has_vtable_index() const                  { return _vtable_index >= 0; }
 458   int  vtable_index() const                      { return _vtable_index; }
 459   void set_vtable_index(int index)               { _vtable_index = index; }
 460   DEBUG_ONLY(bool valid_itable_index() const     { return _vtable_index <= pending_itable_index; })
 461   bool has_itable_index() const                  { return _vtable_index <= itable_index_max; }
 462   int  itable_index() const                      { assert(valid_itable_index(), "");
 463                                                    return itable_index_max - _vtable_index; }
 464   void set_itable_index(int index)               { _vtable_index = itable_index_max - index; assert(valid_itable_index(), ""); }
 465 
 466   // interpreter entry
 467   address interpreter_entry() const              { return _i2i_entry; }
 468   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 469   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 470 
 471   // native function (used for native methods only)
 472   enum {
 473     native_bind_event_is_interesting = true
 474   };
 475   address native_function() const                { return *(native_function_addr()); }
 476   address critical_native_function();
 477 
 478   // Must specify a real function (not NULL).
 479   // Use clear_native_function() to unregister.
 480   void set_native_function(address function, bool post_event_flag);
 481   bool has_native_function() const;
 482   void clear_native_function();
 483 
 484   // signature handler (used for native methods only)
 485   address signature_handler() const              { return *(signature_handler_addr()); }
 486   void set_signature_handler(address handler);
 487 
 488   // Interpreter oopmap support
 489   void mask_for(int bci, InterpreterOopMap* mask);
 490 
 491   // operations on invocation counter
 492   void print_invocation_count();
 493 
 494   // byte codes
 495   void    set_code(address code)      { return constMethod()->set_code(code); }
 496   address code_base() const           { return constMethod()->code_base(); }
 497   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 498 
 499   // prints byte codes
 500   void print_codes() const            { print_codes_on(tty); }
 501   void print_codes_on(outputStream* st) const;
 502   void print_codes_on(int from, int to, outputStream* st) const;
 503 
 504   // method parameters
 505   bool has_method_parameters() const
 506                          { return constMethod()->has_method_parameters(); }
 507   int method_parameters_length() const
 508                          { return constMethod()->method_parameters_length(); }
 509   MethodParametersElement* method_parameters_start() const
 510                           { return constMethod()->method_parameters_start(); }
 511 
 512   // checked exceptions
 513   int checked_exceptions_length() const
 514                          { return constMethod()->checked_exceptions_length(); }
 515   CheckedExceptionElement* checked_exceptions_start() const
 516                           { return constMethod()->checked_exceptions_start(); }
 517 
 518   // localvariable table
 519   bool has_localvariable_table() const
 520                           { return constMethod()->has_localvariable_table(); }
 521   int localvariable_table_length() const
 522                         { return constMethod()->localvariable_table_length(); }
 523   LocalVariableTableElement* localvariable_table_start() const
 524                          { return constMethod()->localvariable_table_start(); }
 525 
 526   bool has_linenumber_table() const
 527                               { return constMethod()->has_linenumber_table(); }
 528   u_char* compressed_linenumber_table() const
 529                        { return constMethod()->compressed_linenumber_table(); }
 530 
 531   // method holder (the Klass* holding this method)
 532   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 533 
 534   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 535   Symbol* klass_name() const;                    // returns the name of the method holder
 536   BasicType result_type() const;                 // type of the method result
 537   int result_type_index() const;                 // type index of the method result
 538   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 539   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 540 
 541   // Checked exceptions thrown by this method (resolved to mirrors)
 542   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 543 
 544   // Access flags
 545   bool is_public() const                         { return access_flags().is_public();      }
 546   bool is_private() const                        { return access_flags().is_private();     }
 547   bool is_protected() const                      { return access_flags().is_protected();   }
 548   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 549   bool is_static() const                         { return access_flags().is_static();      }
 550   bool is_final() const                          { return access_flags().is_final();       }
 551   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 552   bool is_native() const                         { return access_flags().is_native();      }
 553   bool is_abstract() const                       { return access_flags().is_abstract();    }
 554   bool is_strict() const                         { return access_flags().is_strict();      }
 555   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 556 
 557   // returns true if contains only return operation
 558   bool is_empty_method() const;
 559 
 560   // returns true if this is a vanilla constructor
 561   bool is_vanilla_constructor() const;
 562 
 563   // checks method and its method holder
 564   bool is_final_method() const;
 565   bool is_final_method(AccessFlags class_access_flags) const;
 566   bool is_default_method() const;
 567 
 568   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 569   bool can_be_statically_bound() const;
 570   bool can_be_statically_bound(AccessFlags class_access_flags) const;
 571 
 572   // returns true if the method has any backward branches.
 573   bool has_loops() {
 574     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 575   };
 576 
 577   bool compute_has_loops_flag();
 578 
 579   bool has_jsrs() {
 580     return access_flags().has_jsrs();
 581   };
 582   void set_has_jsrs() {
 583     _access_flags.set_has_jsrs();
 584   }
 585 
 586   // returns true if the method has any monitors.
 587   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 588   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 589 
 590   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 591 
 592   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 593   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 594   // has not been computed yet.
 595   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 596   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 597 
 598   // returns true if the method is an accessor function (setter/getter).
 599   bool is_accessor() const;
 600 
 601   // returns true if the method is an initializer (<init> or <clinit>).
 602   bool is_initializer() const;
 603 
 604   // returns true if the method is static OR if the classfile version < 51
 605   bool has_valid_initializer_flags() const;
 606 
 607   // returns true if the method name is <clinit> and the method has
 608   // valid static initializer flags.
 609   bool is_static_initializer() const;
 610 
 611   // compiled code support
 612   // NOTE: code() is inherently racy as deopt can be clearing code
 613   // simultaneously. Use with caution.
 614   bool has_compiled_code() const                 { return code() != NULL; }
 615 
 616   // sizing
 617   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 618   static int size(bool is_native);
 619   int size() const                               { return method_size(); }
 620 #if INCLUDE_SERVICES
 621   void collect_statistics(KlassSizeStats *sz) const;
 622 #endif
 623 
 624   // interpreter support
 625   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 626   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 627 #ifdef CC_INTERP
 628   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 629 #endif /* CC_INTERP */
 630   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 631   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 632   static ByteSize method_data_offset()           {
 633     return byte_offset_of(Method, _method_data);
 634   }
 635   static ByteSize method_counters_offset()       {
 636     return byte_offset_of(Method, _method_counters);
 637   }
 638 #ifndef PRODUCT
 639   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 640 #endif // not PRODUCT
 641   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 642   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 643   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 644   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 645 
 646   // for code generation
 647   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 648   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 649   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 650 
 651   // Static methods that are used to implement member methods where an exposed this pointer
 652   // is needed due to possible GCs
 653   static objArrayHandle resolved_checked_exceptions_impl(Method* method, TRAPS);
 654 
 655   // Returns the byte code index from the byte code pointer
 656   int     bci_from(address bcp) const;
 657   address bcp_from(int bci) const;
 658   address bcp_from(address bcp) const;
 659   int validate_bci_from_bcp(address bcp) const;
 660   int validate_bci(int bci) const;
 661 
 662   // Returns the line number for a bci if debugging information for the method is prowided,
 663   // -1 is returned otherwise.
 664   int line_number_from_bci(int bci) const;
 665 
 666   // Reflection support
 667   bool is_overridden_in(Klass* k) const;
 668 
 669   // Stack walking support
 670   bool is_ignored_by_security_stack_walk() const;
 671 
 672   // JSR 292 support
 673   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 674   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 675   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 676   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 677                                                    Symbol* signature, //anything at all
 678                                                    TRAPS);
 679   static Klass* check_non_bcp_klass(Klass* klass);
 680 
 681   // How many extra stack entries for invokedynamic when it's enabled
 682   static const int extra_stack_entries_for_jsr292 = 1;
 683 
 684   // this operates only on invoke methods:
 685   // presize interpreter frames for extra interpreter stack entries, if needed
 686   // Account for the extra appendix argument for invokehandle/invokedynamic
 687   static int extra_stack_entries() { return extra_stack_entries_for_jsr292; }
 688   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 689 
 690   // RedefineClasses() support:
 691   bool is_old() const                               { return access_flags().is_old(); }
 692   void set_is_old()                                 { _access_flags.set_is_old(); }
 693   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 694   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 695   bool is_deleted() const                           { return access_flags().is_deleted(); }
 696   void set_is_deleted()                             { _access_flags.set_is_deleted(); }
 697 
 698   bool is_running_emcp() const {
 699     // EMCP methods are old but not obsolete or deleted. Equivalent
 700     // Modulo Constant Pool means the method is equivalent except
 701     // the constant pool and instructions that access the constant
 702     // pool might be different.
 703     // If a breakpoint is set in a redefined method, its EMCP methods that are
 704     // still running must have a breakpoint also.
 705     return (_flags & _running_emcp) != 0;
 706   }
 707 
 708   void set_running_emcp(bool x) {
 709     _flags = x ? (_flags | _running_emcp) : (_flags & ~_running_emcp);
 710   }
 711 
 712   bool on_stack() const                             { return access_flags().on_stack(); }
 713   void set_on_stack(const bool value);
 714 
 715   // see the definition in Method*.cpp for the gory details
 716   bool should_not_be_cached() const;
 717 
 718   // JVMTI Native method prefixing support:
 719   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 720   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 721 
 722   // Rewriting support
 723   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 724                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 725 
 726   // jmethodID handling
 727   // Because the useful life-span of a jmethodID cannot be determined,
 728   // once created they are never reclaimed.  The methods to which they refer,
 729   // however, can be GC'ed away if the class is unloaded or if the method is
 730   // made obsolete or deleted -- in these cases, the jmethodID
 731   // refers to NULL (as is the case for any weak reference).
 732   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 733   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 734 
 735   // Use resolve_jmethod_id() in situations where the caller is expected
 736   // to provide a valid jmethodID; the only sanity checks are in asserts;
 737   // result guaranteed not to be NULL.
 738   inline static Method* resolve_jmethod_id(jmethodID mid) {
 739     assert(mid != NULL, "JNI method id should not be null");
 740     return *((Method**)mid);
 741   }
 742 
 743   // Use checked_resolve_jmethod_id() in situations where the caller
 744   // should provide a valid jmethodID, but might not. NULL is returned
 745   // when the jmethodID does not refer to a valid method.
 746   static Method* checked_resolve_jmethod_id(jmethodID mid);
 747 
 748   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 749   static bool is_method_id(jmethodID mid);
 750 
 751   // Clear methods
 752   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 753   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 754 
 755   // Get this method's jmethodID -- allocate if it doesn't exist
 756   jmethodID jmethod_id()                            { methodHandle this_h(this);
 757                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 758 
 759   // Lookup the jmethodID for this method.  Return NULL if not found.
 760   // NOTE that this function can be called from a signal handler
 761   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 762   // needs to be async-safe. No allocation should be done and
 763   // so handles are not used to avoid deadlock.
 764   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 765 
 766   // Support for inlining of intrinsic methods
 767   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 768   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 769 
 770   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 771   void init_intrinsic_id();     // updates from _none if a match
 772   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 773 
 774   bool jfr_towrite() {
 775     return (_flags & _jfr_towrite) != 0;
 776   }
 777   void set_jfr_towrite(bool x) {
 778     _flags = x ? (_flags | _jfr_towrite) : (_flags & ~_jfr_towrite);
 779   }
 780 
 781   bool caller_sensitive() {
 782     return (_flags & _caller_sensitive) != 0;
 783   }
 784   void set_caller_sensitive(bool x) {
 785     _flags = x ? (_flags | _caller_sensitive) : (_flags & ~_caller_sensitive);
 786   }
 787 
 788   bool force_inline() {
 789     return (_flags & _force_inline) != 0;
 790   }
 791   void set_force_inline(bool x) {
 792     _flags = x ? (_flags | _force_inline) : (_flags & ~_force_inline);
 793   }
 794 
 795   bool dont_inline() {
 796     return (_flags & _dont_inline) != 0;
 797   }
 798   void set_dont_inline(bool x) {
 799     _flags = x ? (_flags | _dont_inline) : (_flags & ~_dont_inline);
 800   }
 801 
 802   bool is_hidden() {
 803     return (_flags & _hidden) != 0;
 804   }
 805   void set_hidden(bool x) {
 806     _flags = x ? (_flags | _hidden) : (_flags & ~_hidden);
 807   }
 808 
 809   ConstMethod::MethodType method_type() const {
 810       return _constMethod->method_type();
 811   }
 812   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 813 
 814   // On-stack replacement support
 815   bool has_osr_nmethod(int level, bool match_level) {
 816    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 817   }
 818 
 819   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 820     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 821   }
 822 
 823   // Inline cache support
 824   void cleanup_inline_caches();
 825 
 826   // Find if klass for method is loaded
 827   bool is_klass_loaded_by_klass_index(int klass_index) const;
 828   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 829 
 830   // Indicates whether compilation failed earlier for this method, or
 831   // whether it is not compilable for another reason like having a
 832   // breakpoint set in it.
 833   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 834   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 835   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 836     set_not_compilable(comp_level, false);
 837   }
 838   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 839   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 840   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 841     set_not_osr_compilable(comp_level, false);
 842   }
 843   bool is_always_compilable() const;
 844 
 845  private:
 846   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 847 
 848  public:
 849   MethodCounters* get_method_counters(TRAPS) {
 850     if (_method_counters == NULL) {
 851       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 852     }
 853     return _method_counters;
 854   }
 855 
 856   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 857   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 858   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 859   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 860   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 861   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 862 
 863   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 864   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 865   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 866   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 867   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 868   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 869 
 870   // Background compilation support
 871   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 872   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 873   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 874 
 875   // Resolve all classes in signature, return 'true' if successful
 876   static bool load_signature_classes(methodHandle m, TRAPS);
 877 
 878   // Return if true if not all classes references in signature, including return type, has been loaded
 879   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 880 
 881   // Printing
 882   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 883 #if INCLUDE_JVMTI
 884   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 885 #else
 886   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 887 #endif
 888 
 889   // Helper routine used for method sorting
 890   static void sort_methods(Array<Method*>* methods, bool idempotent = false, bool set_idnums = true);
 891 
 892   // Deallocation function for redefine classes or if an error occurs
 893   void deallocate_contents(ClassLoaderData* loader_data);
 894 
 895   // Printing
 896 #ifndef PRODUCT
 897   void print_on(outputStream* st) const;
 898 #endif
 899   void print_value_on(outputStream* st) const;
 900 
 901   const char* internal_name() const { return "{method}"; }
 902 
 903   // Check for valid method pointer
 904   static bool has_method_vptr(const void* ptr);
 905   bool is_valid_method() const;
 906 
 907   // Verify
 908   void verify() { verify_on(tty); }
 909   void verify_on(outputStream* st);
 910 
 911  private:
 912 
 913   // Inlined elements
 914   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 915   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 916 };
 917 
 918 
 919 // Utility class for compressing line number tables
 920 
 921 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 922  private:
 923   int _bci;
 924   int _line;
 925  public:
 926   // Constructor
 927   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 928   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 929 
 930   // Write (bci, line number) pair to stream
 931   void write_pair_regular(int bci_delta, int line_delta);
 932 
 933   inline void write_pair_inline(int bci, int line) {
 934     int bci_delta = bci - _bci;
 935     int line_delta = line - _line;
 936     _bci = bci;
 937     _line = line;
 938     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 939     if (bci_delta == 0 && line_delta == 0) return;
 940     // Check if bci is 5-bit and line number 3-bit unsigned.
 941     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 942       // Compress into single byte.
 943       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 944       // Check that value doesn't match escape character.
 945       if (value != 0xFF) {
 946         write_byte(value);
 947         return;
 948       }
 949     }
 950     write_pair_regular(bci_delta, line_delta);
 951   }
 952 
 953 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 954 // Disabling optimization doesn't work for methods in header files
 955 // so we force it to call through the non-optimized version in the .cpp.
 956 // It's gross, but it's the only way we can ensure that all callers are
 957 // fixed.  _MSC_VER is defined by the windows compiler
 958 #if defined(_M_AMD64) && _MSC_VER >= 1400
 959   void write_pair(int bci, int line);
 960 #else
 961   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 962 #endif
 963 
 964   // Write end-of-stream marker
 965   void write_terminator()                        { write_byte(0); }
 966 };
 967 
 968 
 969 // Utility class for decompressing line number tables
 970 
 971 class CompressedLineNumberReadStream: public CompressedReadStream {
 972  private:
 973   int _bci;
 974   int _line;
 975  public:
 976   // Constructor
 977   CompressedLineNumberReadStream(u_char* buffer);
 978   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 979   bool read_pair();
 980   // Accessing bci and line number (after calling read_pair)
 981   int bci() const                               { return _bci; }
 982   int line() const                              { return _line; }
 983 };
 984 
 985 
 986 /// Fast Breakpoints.
 987 
 988 // If this structure gets more complicated (because bpts get numerous),
 989 // move it into its own header.
 990 
 991 // There is presently no provision for concurrent access
 992 // to breakpoint lists, which is only OK for JVMTI because
 993 // breakpoints are written only at safepoints, and are read
 994 // concurrently only outside of safepoints.
 995 
 996 class BreakpointInfo : public CHeapObj<mtClass> {
 997   friend class VMStructs;
 998  private:
 999   Bytecodes::Code  _orig_bytecode;
1000   int              _bci;
1001   u2               _name_index;       // of method
1002   u2               _signature_index;  // of method
1003   BreakpointInfo*  _next;             // simple storage allocation
1004 
1005  public:
1006   BreakpointInfo(Method* m, int bci);
1007 
1008   // accessors
1009   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
1010   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
1011   int         bci()                                   { return _bci; }
1012 
1013   BreakpointInfo*          next() const               { return _next; }
1014   void                 set_next(BreakpointInfo* n)    { _next = n; }
1015 
1016   // helps for searchers
1017   bool match(const Method* m, int bci) {
1018     return bci == _bci && match(m);
1019   }
1020 
1021   bool match(const Method* m) {
1022     return _name_index == m->name_index() &&
1023       _signature_index == m->signature_index();
1024   }
1025 
1026   void set(Method* method);
1027   void clear(Method* method);
1028 };
1029 
1030 // Utility class for access exception handlers
1031 class ExceptionTable : public StackObj {
1032  private:
1033   ExceptionTableElement* _table;
1034   u2  _length;
1035 
1036  public:
1037   ExceptionTable(const Method* m) {
1038     if (m->has_exception_handler()) {
1039       _table = m->exception_table_start();
1040       _length = m->exception_table_length();
1041     } else {
1042       _table = NULL;
1043       _length = 0;
1044     }
1045   }
1046 
1047   int length() const {
1048     return _length;
1049   }
1050 
1051   u2 start_pc(int idx) const {
1052     assert(idx < _length, "out of bounds");
1053     return _table[idx].start_pc;
1054   }
1055 
1056   void set_start_pc(int idx, u2 value) {
1057     assert(idx < _length, "out of bounds");
1058     _table[idx].start_pc = value;
1059   }
1060 
1061   u2 end_pc(int idx) const {
1062     assert(idx < _length, "out of bounds");
1063     return _table[idx].end_pc;
1064   }
1065 
1066   void set_end_pc(int idx, u2 value) {
1067     assert(idx < _length, "out of bounds");
1068     _table[idx].end_pc = value;
1069   }
1070 
1071   u2 handler_pc(int idx) const {
1072     assert(idx < _length, "out of bounds");
1073     return _table[idx].handler_pc;
1074   }
1075 
1076   void set_handler_pc(int idx, u2 value) {
1077     assert(idx < _length, "out of bounds");
1078     _table[idx].handler_pc = value;
1079   }
1080 
1081   u2 catch_type_index(int idx) const {
1082     assert(idx < _length, "out of bounds");
1083     return _table[idx].catch_type_index;
1084   }
1085 
1086   void set_catch_type_index(int idx, u2 value) {
1087     assert(idx < _length, "out of bounds");
1088     _table[idx].catch_type_index = value;
1089   }
1090 };
1091 
1092 #endif // SHARE_VM_OOPS_METHODOOP_HPP