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/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 // Memory layout (each line represents a word). Note that most applications load thousands of methods,
  44 // so keeping the size of this structure small has a big impact on footprint.
  45 //
  46 // We put all oops and method_size first for better gc cache locality.
  47 //
  48 // The actual bytecodes are inlined after the end of the Method struct.
  49 //
  50 // There are bits in the access_flags telling whether inlined tables are present.
  51 // Note that accessing the line number and local variable tables is not performance critical at all.
  52 // Accessing the checked exceptions table is used by reflection, so we put that last to make access
  53 // to it fast.
  54 //
  55 // The line number table is compressed and inlined following the byte codes. It is found as the first
  56 // byte following the byte codes. The checked exceptions table and the local variable table are inlined
  57 // after the line number table, and indexed from the end of the method. We do not compress the checked
  58 // exceptions table since the average length is less than 2, and do not bother to compress the local
  59 // variable table either since it is mostly absent.
  60 //
  61 // Note that native_function and signature_handler has to be at fixed offsets (required by the interpreter)
  62 //
  63 // |------------------------------------------------------|
  64 // | header                                               |
  65 // | klass                                                |
  66 // |------------------------------------------------------|
  67 // | ConstMethod*                   (oop)                 |
  68 // |------------------------------------------------------|
  69 // | methodData                     (oop)                 |
  70 // | methodCounters                                       |
  71 // |------------------------------------------------------|
  72 // | access_flags                                         |
  73 // | vtable_index                                         |
  74 // |------------------------------------------------------|
  75 // | result_index (C++ interpreter only)                  |
  76 // |------------------------------------------------------|
  77 // | method_size             |   intrinsic_id|   flags    |
  78 // |------------------------------------------------------|
  79 // | code                           (pointer)             |
  80 // | i2i                            (pointer)             |
  81 // | adapter                        (pointer)             |
  82 // | from_compiled_entry            (pointer)             |
  83 // | from_interpreted_entry         (pointer)             |
  84 // |------------------------------------------------------|
  85 // | native_function       (present only if native)       |
  86 // | signature_handler     (present only if native)       |
  87 // |------------------------------------------------------|
  88 
  89 
  90 class CheckedExceptionElement;
  91 class LocalVariableTableElement;
  92 class AdapterHandlerEntry;
  93 class MethodData;
  94 class MethodCounters;
  95 class ConstMethod;
  96 class InlineTableSizes;
  97 class KlassSizeStats;
  98 
  99 class Method : public Metadata {
 100  friend class VMStructs;
 101  private:
 102   ConstMethod*      _constMethod;                // Method read-only data.
 103   MethodData*       _method_data;
 104   MethodCounters*   _method_counters;
 105   AccessFlags       _access_flags;               // Access flags
 106   int               _vtable_index;               // vtable index of this method (see VtableIndexFlag)
 107                                                  // note: can have vtables with >2**16 elements (because of inheritance)
 108 #ifdef CC_INTERP
 109   int               _result_index;               // C++ interpreter needs for converting results to/from stack
 110 #endif
 111   u2                _method_size;                // size of this object
 112   u1                _intrinsic_id;               // vmSymbols::intrinsic_id (0 == _none)
 113   u1                _jfr_towrite      : 1,       // Flags
 114                     _caller_sensitive : 1,
 115                     _force_inline     : 1,
 116                     _hidden           : 1,
 117                     _dont_inline      : 1,
 118                                       : 3;
 119 
 120 #ifndef PRODUCT
 121   int               _compiled_invocation_count;  // Number of nmethod invocations so far (for perf. debugging)
 122 #endif
 123   // Entry point for calling both from and to the interpreter.
 124   address _i2i_entry;           // All-args-on-stack calling convention
 125   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
 126   AdapterHandlerEntry* _adapter;
 127   // Entry point for calling from compiled code, to compiled code if it exists
 128   // or else the interpreter.
 129   volatile address _from_compiled_entry;        // Cache of: _code ? _code->entry_point() : _adapter->c2i_entry()
 130   // The entry point for calling both from and to compiled code is
 131   // "_code->entry_point()".  Because of tiered compilation and de-opt, this
 132   // field can come and go.  It can transition from NULL to not-null at any
 133   // time (whenever a compile completes).  It can transition from not-null to
 134   // NULL only at safepoints (because of a de-opt).
 135   nmethod* volatile _code;                       // Points to the corresponding piece of native code
 136   volatile address           _from_interpreted_entry; // Cache of _code ? _adapter->i2c_entry() : _i2i_entry
 137 
 138   // Constructor
 139   Method(ConstMethod* xconst, AccessFlags access_flags, int size);
 140  public:
 141 
 142   static Method* allocate(ClassLoaderData* loader_data,
 143                           int byte_code_size,
 144                           AccessFlags access_flags,
 145                           InlineTableSizes* sizes,
 146                           ConstMethod::MethodType method_type,
 147                           TRAPS);
 148 
 149   // CDS and vtbl checking can create an empty Method to get vtbl pointer.
 150   Method(){}
 151 
 152   // The Method vtable is restored by this call when the Method is in the
 153   // shared archive.  See patch_klass_vtables() in metaspaceShared.cpp for
 154   // all the gory details.  SA, dtrace and pstack helpers distinguish metadata
 155   // by their vtable.
 156   void restore_vtable() { guarantee(is_method(), "vtable restored by this call"); }
 157   bool is_method() const volatile { return true; }
 158 
 159   // accessors for instance variables
 160 
 161   ConstMethod* constMethod() const             { return _constMethod; }
 162   void set_constMethod(ConstMethod* xconst)    { _constMethod = xconst; }
 163 
 164 
 165   static address make_adapters(methodHandle mh, TRAPS);
 166   volatile address from_compiled_entry() const   { return (address)OrderAccess::load_ptr_acquire(&_from_compiled_entry); }
 167   volatile address from_interpreted_entry() const{ return (address)OrderAccess::load_ptr_acquire(&_from_interpreted_entry); }
 168 
 169   // access flag
 170   AccessFlags access_flags() const               { return _access_flags;  }
 171   void set_access_flags(AccessFlags flags)       { _access_flags = flags; }
 172 
 173   // name
 174   Symbol* name() const                           { return constants()->symbol_at(name_index()); }
 175   int name_index() const                         { return constMethod()->name_index();         }
 176   void set_name_index(int index)                 { constMethod()->set_name_index(index);       }
 177 
 178   // signature
 179   Symbol* signature() const                      { return constants()->symbol_at(signature_index()); }
 180   int signature_index() const                    { return constMethod()->signature_index();         }
 181   void set_signature_index(int index)            { constMethod()->set_signature_index(index);       }
 182 
 183   // generics support
 184   Symbol* generic_signature() const              { int idx = generic_signature_index(); return ((idx != 0) ? constants()->symbol_at(idx) : (Symbol*)NULL); }
 185   int generic_signature_index() const            { return constMethod()->generic_signature_index(); }
 186   void set_generic_signature_index(int index)    { constMethod()->set_generic_signature_index(index); }
 187 
 188   // annotations support
 189   AnnotationArray* annotations() const           {
 190     return constMethod()->method_annotations();
 191   }
 192   AnnotationArray* parameter_annotations() const {
 193     return constMethod()->parameter_annotations();
 194   }
 195   AnnotationArray* annotation_default() const    {
 196     return constMethod()->default_annotations();
 197   }
 198   AnnotationArray* type_annotations() const      {
 199     return constMethod()->type_annotations();
 200   }
 201 
 202 #ifdef CC_INTERP
 203   void set_result_index(BasicType type);
 204   int  result_index()                            { return _result_index; }
 205 #endif
 206 
 207   // Helper routine: get klass name + "." + method name + signature as
 208   // C string, for the purpose of providing more useful NoSuchMethodErrors
 209   // and fatal error handling. The string is allocated in resource
 210   // area if a buffer is not provided by the caller.
 211   char* name_and_sig_as_C_string() const;
 212   char* name_and_sig_as_C_string(char* buf, int size) const;
 213 
 214   // Static routine in the situations we don't have a Method*
 215   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature);
 216   static char* name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size);
 217 
 218   Bytecodes::Code java_code_at(int bci) const {
 219     return Bytecodes::java_code_at(this, bcp_from(bci));
 220   }
 221   Bytecodes::Code code_at(int bci) const {
 222     return Bytecodes::code_at(this, bcp_from(bci));
 223   }
 224 
 225   // JVMTI breakpoints
 226   Bytecodes::Code orig_bytecode_at(int bci) const;
 227   void        set_orig_bytecode_at(int bci, Bytecodes::Code code);
 228   void set_breakpoint(int bci);
 229   void clear_breakpoint(int bci);
 230   void clear_all_breakpoints();
 231   // Tracking number of breakpoints, for fullspeed debugging.
 232   // Only mutated by VM thread.
 233   u2   number_of_breakpoints()             const {
 234     if (method_counters() == NULL) {
 235       return 0;
 236     } else {
 237       return method_counters()->number_of_breakpoints();
 238     }
 239   }
 240   void incr_number_of_breakpoints(TRAPS)         {
 241     MethodCounters* mcs = get_method_counters(CHECK);
 242     if (mcs != NULL) {
 243       mcs->incr_number_of_breakpoints();
 244     }
 245   }
 246   void decr_number_of_breakpoints(TRAPS)         {
 247     MethodCounters* mcs = get_method_counters(CHECK);
 248     if (mcs != NULL) {
 249       mcs->decr_number_of_breakpoints();
 250     }
 251   }
 252   // Initialization only
 253   void clear_number_of_breakpoints()             {
 254     if (method_counters() != NULL) {
 255       method_counters()->clear_number_of_breakpoints();
 256     }
 257   }
 258 
 259   // index into InstanceKlass methods() array
 260   // note: also used by jfr
 261   u2 method_idnum() const           { return constMethod()->method_idnum(); }
 262   void set_method_idnum(u2 idnum)   { constMethod()->set_method_idnum(idnum); }
 263 
 264   // code size
 265   int code_size() const                  { return constMethod()->code_size(); }
 266 
 267   // method size
 268   int method_size() const                        { return _method_size; }
 269   void set_method_size(int size) {
 270     assert(0 <= size && size < (1 << 16), "invalid method size");
 271     _method_size = size;
 272   }
 273 
 274   // constant pool for Klass* holding this method
 275   ConstantPool* constants() const              { return constMethod()->constants(); }
 276   void set_constants(ConstantPool* c)          { constMethod()->set_constants(c); }
 277 
 278   // max stack
 279   // return original max stack size for method verification
 280   int  verifier_max_stack() const                { return constMethod()->max_stack(); }
 281   int           max_stack() const                { return constMethod()->max_stack() + extra_stack_entries(); }
 282   void      set_max_stack(int size)              {        constMethod()->set_max_stack(size); }
 283 
 284   // max locals
 285   int  max_locals() const                        { return constMethod()->max_locals(); }
 286   void set_max_locals(int size)                  { constMethod()->set_max_locals(size); }
 287 
 288   int highest_comp_level() const;
 289   void set_highest_comp_level(int level);
 290   int highest_osr_comp_level() const;
 291   void set_highest_osr_comp_level(int level);
 292 
 293   // Count of times method was exited via exception while interpreting
 294   void interpreter_throwout_increment(TRAPS) {
 295     MethodCounters* mcs = get_method_counters(CHECK);
 296     if (mcs != NULL) {
 297       mcs->interpreter_throwout_increment();
 298     }
 299   }
 300 
 301   int  interpreter_throwout_count() const        {
 302     if (method_counters() == NULL) {
 303       return 0;
 304     } else {
 305       return method_counters()->interpreter_throwout_count();
 306     }
 307   }
 308 
 309   // size of parameters
 310   int  size_of_parameters() const                { return constMethod()->size_of_parameters(); }
 311   void set_size_of_parameters(int size)          { constMethod()->set_size_of_parameters(size); }
 312 
 313   bool has_stackmap_table() const {
 314     return constMethod()->has_stackmap_table();
 315   }
 316 
 317   Array<u1>* stackmap_data() const {
 318     return constMethod()->stackmap_data();
 319   }
 320 
 321   void set_stackmap_data(Array<u1>* sd) {
 322     constMethod()->set_stackmap_data(sd);
 323   }
 324 
 325   // exception handler table
 326   bool has_exception_handler() const
 327                              { return constMethod()->has_exception_handler(); }
 328   int exception_table_length() const
 329                              { return constMethod()->exception_table_length(); }
 330   ExceptionTableElement* exception_table_start() const
 331                              { return constMethod()->exception_table_start(); }
 332 
 333   // Finds the first entry point bci of an exception handler for an
 334   // exception of klass ex_klass thrown at throw_bci. A value of NULL
 335   // for ex_klass indicates that the exception klass is not known; in
 336   // this case it matches any constraint class. Returns -1 if the
 337   // exception cannot be handled in this method. The handler
 338   // constraint classes are loaded if necessary. Note that this may
 339   // throw an exception if loading of the constraint classes causes
 340   // an IllegalAccessError (bugid 4307310) or an OutOfMemoryError.
 341   // If an exception is thrown, returns the bci of the
 342   // exception handler which caused the exception to be thrown, which
 343   // is needed for proper retries. See, for example,
 344   // InterpreterRuntime::exception_handler_for_exception.
 345   static int fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS);
 346 
 347   // method data access
 348   MethodData* method_data() const              {
 349     return _method_data;
 350   }
 351 
 352   void set_method_data(MethodData* data)       {
 353     _method_data = data;
 354   }
 355 
 356   MethodCounters* method_counters() const {
 357     return _method_counters;
 358   }
 359 
 360 
 361   void set_method_counters(MethodCounters* counters) {
 362     _method_counters = counters;
 363   }
 364 
 365 #ifdef TIERED
 366   // We are reusing interpreter_invocation_count as a holder for the previous event count!
 367   // We can do that since interpreter_invocation_count is not used in tiered.
 368   int prev_event_count() const                   {
 369     if (method_counters() == NULL) {
 370       return 0;
 371     } else {
 372       return method_counters()->interpreter_invocation_count();
 373     }
 374   }
 375   void set_prev_event_count(int count, TRAPS)    {
 376     MethodCounters* mcs = get_method_counters(CHECK);
 377     if (mcs != NULL) {
 378       mcs->set_interpreter_invocation_count(count);
 379     }
 380   }
 381   jlong prev_time() const                        {
 382     return method_counters() == NULL ? 0 : method_counters()->prev_time();
 383   }
 384   void set_prev_time(jlong time, TRAPS)          {
 385     MethodCounters* mcs = get_method_counters(CHECK);
 386     if (mcs != NULL) {
 387       mcs->set_prev_time(time);
 388     }
 389   }
 390   float rate() const                             {
 391     return method_counters() == NULL ? 0 : method_counters()->rate();
 392   }
 393   void set_rate(float rate, TRAPS) {
 394     MethodCounters* mcs = get_method_counters(CHECK);
 395     if (mcs != NULL) {
 396       mcs->set_rate(rate);
 397     }
 398   }
 399 #endif
 400 
 401   int invocation_count();
 402   int backedge_count();
 403 
 404   bool was_executed_more_than(int n);
 405   bool was_never_executed()                      { return !was_executed_more_than(0); }
 406 
 407   static void build_interpreter_method_data(methodHandle method, TRAPS);
 408 
 409   static MethodCounters* build_method_counters(Method* m, TRAPS);
 410 
 411   int interpreter_invocation_count() {
 412     if (TieredCompilation) return invocation_count();
 413     else return (method_counters() == NULL) ? 0 :
 414                  method_counters()->interpreter_invocation_count();
 415   }
 416   int increment_interpreter_invocation_count(TRAPS) {
 417     if (TieredCompilation) ShouldNotReachHere();
 418     MethodCounters* mcs = get_method_counters(CHECK_0);
 419     return (mcs == NULL) ? 0 : mcs->increment_interpreter_invocation_count();
 420   }
 421 
 422 #ifndef PRODUCT
 423   int  compiled_invocation_count() const         { return _compiled_invocation_count;  }
 424   void set_compiled_invocation_count(int count)  { _compiled_invocation_count = count; }
 425 #endif // not PRODUCT
 426 
 427   // Clear (non-shared space) pointers which could not be relevant
 428   // if this (shared) method were mapped into another JVM.
 429   void remove_unshareable_info();
 430 
 431   // nmethod/verified compiler entry
 432   address verified_code_entry();
 433   bool check_code() const;      // Not inline to avoid circular ref
 434   nmethod* volatile code() const                 { assert( check_code(), "" ); return (nmethod *)OrderAccess::load_ptr_acquire(&_code); }
 435   void clear_code();            // Clear out any compiled code
 436   static void set_code(methodHandle mh, nmethod* code);
 437   void set_adapter_entry(AdapterHandlerEntry* adapter) {  _adapter = adapter; }
 438   address get_i2c_entry();
 439   address get_c2i_entry();
 440   address get_c2i_unverified_entry();
 441   AdapterHandlerEntry* adapter() {  return _adapter; }
 442   // setup entry points
 443   void link_method(methodHandle method, TRAPS);
 444   // clear entry points. Used by sharing code
 445   void unlink_method();
 446 
 447   // vtable index
 448   enum VtableIndexFlag {
 449     // Valid vtable indexes are non-negative (>= 0).
 450     // These few negative values are used as sentinels.
 451     highest_unused_vtable_index_value = -5,
 452     invalid_vtable_index    = -4,  // distinct from any valid vtable index
 453     garbage_vtable_index    = -3,  // not yet linked; no vtable layout yet
 454     nonvirtual_vtable_index = -2   // there is no need for vtable dispatch
 455     // 6330203 Note:  Do not use -1, which was overloaded with many meanings.
 456   };
 457   DEBUG_ONLY(bool valid_vtable_index() const     { return _vtable_index >= nonvirtual_vtable_index; })
 458   int  vtable_index() const                      { assert(valid_vtable_index(), "");
 459                                                    return _vtable_index; }
 460   void set_vtable_index(int index)               { _vtable_index = index; }
 461 
 462   // interpreter entry
 463   address interpreter_entry() const              { return _i2i_entry; }
 464   // Only used when first initialize so we can set _i2i_entry and _from_interpreted_entry
 465   void set_interpreter_entry(address entry)      { _i2i_entry = entry;  _from_interpreted_entry = entry; }
 466 
 467   // native function (used for native methods only)
 468   enum {
 469     native_bind_event_is_interesting = true
 470   };
 471   address native_function() const                { return *(native_function_addr()); }
 472   address critical_native_function();
 473 
 474   // Must specify a real function (not NULL).
 475   // Use clear_native_function() to unregister.
 476   void set_native_function(address function, bool post_event_flag);
 477   bool has_native_function() const;
 478   void clear_native_function();
 479 
 480   // signature handler (used for native methods only)
 481   address signature_handler() const              { return *(signature_handler_addr()); }
 482   void set_signature_handler(address handler);
 483 
 484   // Interpreter oopmap support
 485   void mask_for(int bci, InterpreterOopMap* mask);
 486 
 487 #ifndef PRODUCT
 488   // operations on invocation counter
 489   void print_invocation_count();
 490 #endif
 491 
 492   // byte codes
 493   void    set_code(address code)      { return constMethod()->set_code(code); }
 494   address code_base() const           { return constMethod()->code_base(); }
 495   bool    contains(address bcp) const { return constMethod()->contains(bcp); }
 496 
 497   // prints byte codes
 498   void print_codes() const            { print_codes_on(tty); }
 499   void print_codes_on(outputStream* st) const                      PRODUCT_RETURN;
 500   void print_codes_on(int from, int to, outputStream* st) const    PRODUCT_RETURN;
 501 
 502   // method parameters
 503   bool has_method_parameters() const
 504                          { return constMethod()->has_method_parameters(); }
 505   int method_parameters_length() const
 506                          { return constMethod()->method_parameters_length(); }
 507   MethodParametersElement* method_parameters_start() const
 508                           { return constMethod()->method_parameters_start(); }
 509 
 510   // checked exceptions
 511   int checked_exceptions_length() const
 512                          { return constMethod()->checked_exceptions_length(); }
 513   CheckedExceptionElement* checked_exceptions_start() const
 514                           { return constMethod()->checked_exceptions_start(); }
 515 
 516   // localvariable table
 517   bool has_localvariable_table() const
 518                           { return constMethod()->has_localvariable_table(); }
 519   int localvariable_table_length() const
 520                         { return constMethod()->localvariable_table_length(); }
 521   LocalVariableTableElement* localvariable_table_start() const
 522                          { return constMethod()->localvariable_table_start(); }
 523 
 524   bool has_linenumber_table() const
 525                               { return constMethod()->has_linenumber_table(); }
 526   u_char* compressed_linenumber_table() const
 527                        { return constMethod()->compressed_linenumber_table(); }
 528 
 529   // method holder (the Klass* holding this method)
 530   InstanceKlass* method_holder() const         { return constants()->pool_holder(); }
 531 
 532   void compute_size_of_parameters(Thread *thread); // word size of parameters (receiver if any + arguments)
 533   Symbol* klass_name() const;                    // returns the name of the method holder
 534   BasicType result_type() const;                 // type of the method result
 535   int result_type_index() const;                 // type index of the method result
 536   bool is_returning_oop() const                  { BasicType r = result_type(); return (r == T_OBJECT || r == T_ARRAY); }
 537   bool is_returning_fp() const                   { BasicType r = result_type(); return (r == T_FLOAT || r == T_DOUBLE); }
 538 
 539   // Checked exceptions thrown by this method (resolved to mirrors)
 540   objArrayHandle resolved_checked_exceptions(TRAPS) { return resolved_checked_exceptions_impl(this, THREAD); }
 541 
 542   // Access flags
 543   bool is_public() const                         { return access_flags().is_public();      }
 544   bool is_private() const                        { return access_flags().is_private();     }
 545   bool is_protected() const                      { return access_flags().is_protected();   }
 546   bool is_package_private() const                { return !is_public() && !is_private() && !is_protected(); }
 547   bool is_static() const                         { return access_flags().is_static();      }
 548   bool is_final() const                          { return access_flags().is_final();       }
 549   bool is_synchronized() const                   { return access_flags().is_synchronized();}
 550   bool is_native() const                         { return access_flags().is_native();      }
 551   bool is_abstract() const                       { return access_flags().is_abstract();    }
 552   bool is_strict() const                         { return access_flags().is_strict();      }
 553   bool is_synthetic() const                      { return access_flags().is_synthetic();   }
 554 
 555   // returns true if contains only return operation
 556   bool is_empty_method() const;
 557 
 558   // returns true if this is a vanilla constructor
 559   bool is_vanilla_constructor() const;
 560 
 561   // checks method and its method holder
 562   bool is_final_method() const;
 563   bool is_strict_method() const;
 564 
 565   // true if method needs no dynamic dispatch (final and/or no vtable entry)
 566   bool can_be_statically_bound() const;
 567 
 568   // returns true if the method has any backward branches.
 569   bool has_loops() {
 570     return access_flags().loops_flag_init() ? access_flags().has_loops() : compute_has_loops_flag();
 571   };
 572 
 573   bool compute_has_loops_flag();
 574 
 575   bool has_jsrs() {
 576     return access_flags().has_jsrs();
 577   };
 578   void set_has_jsrs() {
 579     _access_flags.set_has_jsrs();
 580   }
 581 
 582   // returns true if the method has any monitors.
 583   bool has_monitors() const                      { return is_synchronized() || access_flags().has_monitor_bytecodes(); }
 584   bool has_monitor_bytecodes() const             { return access_flags().has_monitor_bytecodes(); }
 585 
 586   void set_has_monitor_bytecodes()               { _access_flags.set_has_monitor_bytecodes(); }
 587 
 588   // monitor matching. This returns a conservative estimate of whether the monitorenter/monitorexit bytecodes
 589   // propererly nest in the method. It might return false, even though they actually nest properly, since the info.
 590   // has not been computed yet.
 591   bool guaranteed_monitor_matching() const       { return access_flags().is_monitor_matching(); }
 592   void set_guaranteed_monitor_matching()         { _access_flags.set_monitor_matching(); }
 593 
 594   // returns true if the method is an accessor function (setter/getter).
 595   bool is_accessor() const;
 596 
 597   // returns true if the method is an initializer (<init> or <clinit>).
 598   bool is_initializer() const;
 599 
 600   // returns true if the method is static OR if the classfile version < 51
 601   bool has_valid_initializer_flags() const;
 602 
 603   // returns true if the method name is <clinit> and the method has
 604   // valid static initializer flags.
 605   bool is_static_initializer() const;
 606 
 607   // compiled code support
 608   // NOTE: code() is inherently racy as deopt can be clearing code
 609   // simultaneously. Use with caution.
 610   bool has_compiled_code() const                 { return code() != NULL; }
 611 
 612   // sizing
 613   static int header_size()                       { return sizeof(Method)/HeapWordSize; }
 614   static int size(bool is_native);
 615   int size() const                               { return method_size(); }
 616 #if INCLUDE_SERVICES
 617   void collect_statistics(KlassSizeStats *sz) const;
 618 #endif
 619 
 620   // interpreter support
 621   static ByteSize const_offset()                 { return byte_offset_of(Method, _constMethod       ); }
 622   static ByteSize access_flags_offset()          { return byte_offset_of(Method, _access_flags      ); }
 623 #ifdef CC_INTERP
 624   static ByteSize result_index_offset()          { return byte_offset_of(Method, _result_index ); }
 625 #endif /* CC_INTERP */
 626   static ByteSize from_compiled_offset()         { return byte_offset_of(Method, _from_compiled_entry); }
 627   static ByteSize code_offset()                  { return byte_offset_of(Method, _code); }
 628   static ByteSize method_data_offset()           {
 629     return byte_offset_of(Method, _method_data);
 630   }
 631   static ByteSize method_counters_offset()       {
 632     return byte_offset_of(Method, _method_counters);
 633   }
 634 #ifndef PRODUCT
 635   static ByteSize compiled_invocation_counter_offset() { return byte_offset_of(Method, _compiled_invocation_count); }
 636 #endif // not PRODUCT
 637   static ByteSize native_function_offset()       { return in_ByteSize(sizeof(Method));                 }
 638   static ByteSize from_interpreted_offset()      { return byte_offset_of(Method, _from_interpreted_entry ); }
 639   static ByteSize interpreter_entry_offset()     { return byte_offset_of(Method, _i2i_entry ); }
 640   static ByteSize signature_handler_offset()     { return in_ByteSize(sizeof(Method) + wordSize);      }
 641 
 642   // for code generation
 643   static int method_data_offset_in_bytes()       { return offset_of(Method, _method_data); }
 644   static int intrinsic_id_offset_in_bytes()      { return offset_of(Method, _intrinsic_id); }
 645   static int intrinsic_id_size_in_bytes()        { return sizeof(u1); }
 646 
 647   // Static methods that are used to implement member methods where an exposed this pointer
 648   // is needed due to possible GCs
 649   static objArrayHandle resolved_checked_exceptions_impl(Method* this_oop, TRAPS);
 650 
 651   // Returns the byte code index from the byte code pointer
 652   int     bci_from(address bcp) const;
 653   address bcp_from(int     bci) const;
 654   int validate_bci_from_bcx(intptr_t bcx) const;
 655 
 656   // Returns the line number for a bci if debugging information for the method is prowided,
 657   // -1 is returned otherwise.
 658   int line_number_from_bci(int bci) const;
 659 
 660   // Reflection support
 661   bool is_overridden_in(Klass* k) const;
 662 
 663   // Stack walking support
 664   bool is_ignored_by_security_stack_walk() const;
 665 
 666   // JSR 292 support
 667   bool is_method_handle_intrinsic() const;          // MethodHandles::is_signature_polymorphic_intrinsic(intrinsic_id)
 668   bool is_compiled_lambda_form() const;             // intrinsic_id() == vmIntrinsics::_compiledLambdaForm
 669   bool has_member_arg() const;                      // intrinsic_id() == vmIntrinsics::_linkToSpecial, etc.
 670   static methodHandle make_method_handle_intrinsic(vmIntrinsics::ID iid, // _invokeBasic, _linkToVirtual
 671                                                    Symbol* signature, //anything at all
 672                                                    TRAPS);
 673   static Klass* check_non_bcp_klass(Klass* klass);
 674 
 675   // How many extra stack entries for invokedynamic when it's enabled
 676   static const int extra_stack_entries_for_jsr292 = 1;
 677 
 678   // this operates only on invoke methods:
 679   // presize interpreter frames for extra interpreter stack entries, if needed
 680   // Account for the extra appendix argument for invokehandle/invokedynamic
 681   static int extra_stack_entries() { return EnableInvokeDynamic ? extra_stack_entries_for_jsr292 : 0; }
 682   static int extra_stack_words();  // = extra_stack_entries() * Interpreter::stackElementSize
 683 
 684   // RedefineClasses() support:
 685   bool is_old() const                               { return access_flags().is_old(); }
 686   void set_is_old()                                 { _access_flags.set_is_old(); }
 687   bool is_obsolete() const                          { return access_flags().is_obsolete(); }
 688   void set_is_obsolete()                            { _access_flags.set_is_obsolete(); }
 689   bool on_stack() const                             { return access_flags().on_stack(); }
 690   void set_on_stack(const bool value);
 691 
 692   // see the definition in Method*.cpp for the gory details
 693   bool should_not_be_cached() const;
 694 
 695   // JVMTI Native method prefixing support:
 696   bool is_prefixed_native() const                   { return access_flags().is_prefixed_native(); }
 697   void set_is_prefixed_native()                     { _access_flags.set_is_prefixed_native(); }
 698 
 699   // Rewriting support
 700   static methodHandle clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
 701                                           u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS);
 702 
 703   // jmethodID handling
 704   // Because the useful life-span of a jmethodID cannot be determined,
 705   // once created they are never reclaimed.  The methods to which they refer,
 706   // however, can be GC'ed away if the class is unloaded or if the method is
 707   // made obsolete or deleted -- in these cases, the jmethodID
 708   // refers to NULL (as is the case for any weak reference).
 709   static jmethodID make_jmethod_id(ClassLoaderData* loader_data, Method* mh);
 710   static void destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID mid);
 711 
 712   // Use resolve_jmethod_id() in situations where the caller is expected
 713   // to provide a valid jmethodID; the only sanity checks are in asserts;
 714   // result guaranteed not to be NULL.
 715   inline static Method* resolve_jmethod_id(jmethodID mid) {
 716     assert(mid != NULL, "JNI method id should not be null");
 717     return *((Method**)mid);
 718   }
 719 
 720   // Use checked_resolve_jmethod_id() in situations where the caller
 721   // should provide a valid jmethodID, but might not. NULL is returned
 722   // when the jmethodID does not refer to a valid method.
 723   static Method* checked_resolve_jmethod_id(jmethodID mid);
 724 
 725   static void change_method_associated_with_jmethod_id(jmethodID old_jmid_ptr, Method* new_method);
 726   static bool is_method_id(jmethodID mid);
 727 
 728   // Clear methods
 729   static void clear_jmethod_ids(ClassLoaderData* loader_data);
 730   static void print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) PRODUCT_RETURN;
 731 
 732   // Get this method's jmethodID -- allocate if it doesn't exist
 733   jmethodID jmethod_id()                            { methodHandle this_h(this);
 734                                                       return InstanceKlass::get_jmethod_id(method_holder(), this_h); }
 735 
 736   // Lookup the jmethodID for this method.  Return NULL if not found.
 737   // NOTE that this function can be called from a signal handler
 738   // (see AsyncGetCallTrace support for Forte Analyzer) and this
 739   // needs to be async-safe. No allocation should be done and
 740   // so handles are not used to avoid deadlock.
 741   jmethodID find_jmethod_id_or_null()               { return method_holder()->jmethod_id_or_null(this); }
 742 
 743   // JNI static invoke cached itable index accessors
 744   int cached_itable_index()                         { return method_holder()->cached_itable_index(method_idnum()); }
 745   void set_cached_itable_index(int index)           { method_holder()->set_cached_itable_index(method_idnum(), index); }
 746 
 747   // Support for inlining of intrinsic methods
 748   vmIntrinsics::ID intrinsic_id() const          { return (vmIntrinsics::ID) _intrinsic_id;           }
 749   void     set_intrinsic_id(vmIntrinsics::ID id) {                           _intrinsic_id = (u1) id; }
 750 
 751   // Helper routines for intrinsic_id() and vmIntrinsics::method().
 752   void init_intrinsic_id();     // updates from _none if a match
 753   static vmSymbols::SID klass_id_for_intrinsics(Klass* holder);
 754 
 755   bool     jfr_towrite()            { return _jfr_towrite;          }
 756   void set_jfr_towrite(bool x)      {        _jfr_towrite = x;      }
 757   bool     caller_sensitive()       { return _caller_sensitive;     }
 758   void set_caller_sensitive(bool x) {        _caller_sensitive = x; }
 759   bool     force_inline()           { return _force_inline;         }
 760   void set_force_inline(bool x)     {        _force_inline = x;     }
 761   bool     dont_inline()            { return _dont_inline;          }
 762   void set_dont_inline(bool x)      {        _dont_inline = x;      }
 763   bool  is_hidden()                 { return _hidden;               }
 764   void set_hidden(bool x)           {        _hidden = x;           }
 765   ConstMethod::MethodType method_type() const {
 766       return _constMethod->method_type();
 767   }
 768   bool is_overpass() const { return method_type() == ConstMethod::OVERPASS; }
 769 
 770   // On-stack replacement support
 771   bool has_osr_nmethod(int level, bool match_level) {
 772    return method_holder()->lookup_osr_nmethod(this, InvocationEntryBci, level, match_level) != NULL;
 773   }
 774 
 775   nmethod* lookup_osr_nmethod_for(int bci, int level, bool match_level) {
 776     return method_holder()->lookup_osr_nmethod(this, bci, level, match_level);
 777   }
 778 
 779   // Inline cache support
 780   void cleanup_inline_caches();
 781 
 782   // Find if klass for method is loaded
 783   bool is_klass_loaded_by_klass_index(int klass_index) const;
 784   bool is_klass_loaded(int refinfo_index, bool must_be_resolved = false) const;
 785 
 786   // Indicates whether compilation failed earlier for this method, or
 787   // whether it is not compilable for another reason like having a
 788   // breakpoint set in it.
 789   bool  is_not_compilable(int comp_level = CompLevel_any) const;
 790   void set_not_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 791   void set_not_compilable_quietly(int comp_level = CompLevel_all) {
 792     set_not_compilable(comp_level, false);
 793   }
 794   bool  is_not_osr_compilable(int comp_level = CompLevel_any) const;
 795   void set_not_osr_compilable(int comp_level = CompLevel_all, bool report = true, const char* reason = NULL);
 796   void set_not_osr_compilable_quietly(int comp_level = CompLevel_all) {
 797     set_not_osr_compilable(comp_level, false);
 798   }
 799 
 800  private:
 801   void print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason);
 802 
 803   MethodCounters* get_method_counters(TRAPS) {
 804     if (_method_counters == NULL) {
 805       build_method_counters(this, CHECK_AND_CLEAR_NULL);
 806     }
 807     return _method_counters;
 808   }
 809 
 810  public:
 811   bool   is_not_c1_compilable() const         { return access_flags().is_not_c1_compilable();  }
 812   void  set_not_c1_compilable()               {       _access_flags.set_not_c1_compilable();   }
 813   void clear_not_c1_compilable()              {       _access_flags.clear_not_c1_compilable(); }
 814   bool   is_not_c2_compilable() const         { return access_flags().is_not_c2_compilable();  }
 815   void  set_not_c2_compilable()               {       _access_flags.set_not_c2_compilable();   }
 816   void clear_not_c2_compilable()              {       _access_flags.clear_not_c2_compilable(); }
 817 
 818   bool    is_not_c1_osr_compilable() const    { return is_not_c1_compilable(); }  // don't waste an accessFlags bit
 819   void   set_not_c1_osr_compilable()          {       set_not_c1_compilable(); }  // don't waste an accessFlags bit
 820   void clear_not_c1_osr_compilable()          {     clear_not_c1_compilable(); }  // don't waste an accessFlags bit
 821   bool   is_not_c2_osr_compilable() const     { return access_flags().is_not_c2_osr_compilable();  }
 822   void  set_not_c2_osr_compilable()           {       _access_flags.set_not_c2_osr_compilable();   }
 823   void clear_not_c2_osr_compilable()          {       _access_flags.clear_not_c2_osr_compilable(); }
 824 
 825   // Background compilation support
 826   bool queued_for_compilation() const  { return access_flags().queued_for_compilation(); }
 827   void set_queued_for_compilation()    { _access_flags.set_queued_for_compilation();     }
 828   void clear_queued_for_compilation()  { _access_flags.clear_queued_for_compilation();   }
 829 
 830   // Resolve all classes in signature, return 'true' if successful
 831   static bool load_signature_classes(methodHandle m, TRAPS);
 832 
 833   // Return if true if not all classes references in signature, including return type, has been loaded
 834   static bool has_unloaded_classes_in_signature(methodHandle m, TRAPS);
 835 
 836   // Printing
 837   void print_short_name(outputStream* st = tty); // prints as klassname::methodname; Exposed so field engineers can debug VM
 838 #if INCLUDE_JVMTI
 839   void print_name(outputStream* st = tty); // prints as "virtual void foo(int)"; exposed for TraceRedefineClasses
 840 #else
 841   void print_name(outputStream* st = tty)        PRODUCT_RETURN; // prints as "virtual void foo(int)"
 842 #endif
 843 
 844   // Helper routine used for method sorting
 845   static void sort_methods(Array<Method*>* methods, bool idempotent = false);
 846 
 847   // Deallocation function for redefine classes or if an error occurs
 848   void deallocate_contents(ClassLoaderData* loader_data);
 849 
 850   // Printing
 851 #ifndef PRODUCT
 852   void print_on(outputStream* st) const;
 853 #endif
 854   void print_value_on(outputStream* st) const;
 855 
 856   const char* internal_name() const { return "{method}"; }
 857 
 858   // Check for valid method pointer
 859   bool is_valid_method() const;
 860 
 861   // Verify
 862   void verify() { verify_on(tty); }
 863   void verify_on(outputStream* st);
 864 
 865  private:
 866 
 867   // Inlined elements
 868   address* native_function_addr() const          { assert(is_native(), "must be native"); return (address*) (this+1); }
 869   address* signature_handler_addr() const        { return native_function_addr() + 1; }
 870 };
 871 
 872 
 873 // Utility class for compressing line number tables
 874 
 875 class CompressedLineNumberWriteStream: public CompressedWriteStream {
 876  private:
 877   int _bci;
 878   int _line;
 879  public:
 880   // Constructor
 881   CompressedLineNumberWriteStream(int initial_size) : CompressedWriteStream(initial_size), _bci(0), _line(0) {}
 882   CompressedLineNumberWriteStream(u_char* buffer, int initial_size) : CompressedWriteStream(buffer, initial_size), _bci(0), _line(0) {}
 883 
 884   // Write (bci, line number) pair to stream
 885   void write_pair_regular(int bci_delta, int line_delta);
 886 
 887   inline void write_pair_inline(int bci, int line) {
 888     int bci_delta = bci - _bci;
 889     int line_delta = line - _line;
 890     _bci = bci;
 891     _line = line;
 892     // Skip (0,0) deltas - they do not add information and conflict with terminator.
 893     if (bci_delta == 0 && line_delta == 0) return;
 894     // Check if bci is 5-bit and line number 3-bit unsigned.
 895     if (((bci_delta & ~0x1F) == 0) && ((line_delta & ~0x7) == 0)) {
 896       // Compress into single byte.
 897       jubyte value = ((jubyte) bci_delta << 3) | (jubyte) line_delta;
 898       // Check that value doesn't match escape character.
 899       if (value != 0xFF) {
 900         write_byte(value);
 901         return;
 902       }
 903     }
 904     write_pair_regular(bci_delta, line_delta);
 905   }
 906 
 907 // Windows AMD64 + Apr 2005 PSDK with /O2 generates bad code for write_pair.
 908 // Disabling optimization doesn't work for methods in header files
 909 // so we force it to call through the non-optimized version in the .cpp.
 910 // It's gross, but it's the only way we can ensure that all callers are
 911 // fixed.  _MSC_VER is defined by the windows compiler
 912 #if defined(_M_AMD64) && _MSC_VER >= 1400
 913   void write_pair(int bci, int line);
 914 #else
 915   void write_pair(int bci, int line) { write_pair_inline(bci, line); }
 916 #endif
 917 
 918   // Write end-of-stream marker
 919   void write_terminator()                        { write_byte(0); }
 920 };
 921 
 922 
 923 // Utility class for decompressing line number tables
 924 
 925 class CompressedLineNumberReadStream: public CompressedReadStream {
 926  private:
 927   int _bci;
 928   int _line;
 929  public:
 930   // Constructor
 931   CompressedLineNumberReadStream(u_char* buffer);
 932   // Read (bci, line number) pair from stream. Returns false at end-of-stream.
 933   bool read_pair();
 934   // Accessing bci and line number (after calling read_pair)
 935   int bci() const                               { return _bci; }
 936   int line() const                              { return _line; }
 937 };
 938 
 939 
 940 /// Fast Breakpoints.
 941 
 942 // If this structure gets more complicated (because bpts get numerous),
 943 // move it into its own header.
 944 
 945 // There is presently no provision for concurrent access
 946 // to breakpoint lists, which is only OK for JVMTI because
 947 // breakpoints are written only at safepoints, and are read
 948 // concurrently only outside of safepoints.
 949 
 950 class BreakpointInfo : public CHeapObj<mtClass> {
 951   friend class VMStructs;
 952  private:
 953   Bytecodes::Code  _orig_bytecode;
 954   int              _bci;
 955   u2               _name_index;       // of method
 956   u2               _signature_index;  // of method
 957   BreakpointInfo*  _next;             // simple storage allocation
 958 
 959  public:
 960   BreakpointInfo(Method* m, int bci);
 961 
 962   // accessors
 963   Bytecodes::Code orig_bytecode()                     { return _orig_bytecode; }
 964   void        set_orig_bytecode(Bytecodes::Code code) { _orig_bytecode = code; }
 965   int         bci()                                   { return _bci; }
 966 
 967   BreakpointInfo*          next() const               { return _next; }
 968   void                 set_next(BreakpointInfo* n)    { _next = n; }
 969 
 970   // helps for searchers
 971   bool match(const Method* m, int bci) {
 972     return bci == _bci && match(m);
 973   }
 974 
 975   bool match(const Method* m) {
 976     return _name_index == m->name_index() &&
 977       _signature_index == m->signature_index();
 978   }
 979 
 980   void set(Method* method);
 981   void clear(Method* method);
 982 };
 983 
 984 // Utility class for access exception handlers
 985 class ExceptionTable : public StackObj {
 986  private:
 987   ExceptionTableElement* _table;
 988   u2  _length;
 989 
 990  public:
 991   ExceptionTable(const Method* m) {
 992     if (m->has_exception_handler()) {
 993       _table = m->exception_table_start();
 994       _length = m->exception_table_length();
 995     } else {
 996       _table = NULL;
 997       _length = 0;
 998     }
 999   }
1000 
1001   int length() const {
1002     return _length;
1003   }
1004 
1005   u2 start_pc(int idx) const {
1006     assert(idx < _length, "out of bounds");
1007     return _table[idx].start_pc;
1008   }
1009 
1010   void set_start_pc(int idx, u2 value) {
1011     assert(idx < _length, "out of bounds");
1012     _table[idx].start_pc = value;
1013   }
1014 
1015   u2 end_pc(int idx) const {
1016     assert(idx < _length, "out of bounds");
1017     return _table[idx].end_pc;
1018   }
1019 
1020   void set_end_pc(int idx, u2 value) {
1021     assert(idx < _length, "out of bounds");
1022     _table[idx].end_pc = value;
1023   }
1024 
1025   u2 handler_pc(int idx) const {
1026     assert(idx < _length, "out of bounds");
1027     return _table[idx].handler_pc;
1028   }
1029 
1030   void set_handler_pc(int idx, u2 value) {
1031     assert(idx < _length, "out of bounds");
1032     _table[idx].handler_pc = value;
1033   }
1034 
1035   u2 catch_type_index(int idx) const {
1036     assert(idx < _length, "out of bounds");
1037     return _table[idx].catch_type_index;
1038   }
1039 
1040   void set_catch_type_index(int idx, u2 value) {
1041     assert(idx < _length, "out of bounds");
1042     _table[idx].catch_type_index = value;
1043   }
1044 };
1045 
1046 #endif // SHARE_VM_OOPS_METHODOOP_HPP