1 /*
   2  * Copyright (c) 1997, 2015, 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 #include "precompiled.hpp"
  26 #include "classfile/metadataOnStackMark.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/debugInfoRec.hpp"
  30 #include "gc/shared/collectedHeap.inline.hpp"
  31 #include "gc/shared/gcLocker.hpp"
  32 #include "gc/shared/generation.hpp"
  33 #include "interpreter/bytecodeStream.hpp"
  34 #include "interpreter/bytecodeTracer.hpp"
  35 #include "interpreter/bytecodes.hpp"
  36 #include "interpreter/interpreter.hpp"
  37 #include "interpreter/oopMapCache.hpp"
  38 #include "memory/heapInspection.hpp"
  39 #include "memory/metadataFactory.hpp"
  40 #include "memory/oopFactory.hpp"
  41 #include "oops/constMethod.hpp"
  42 #include "oops/method.hpp"
  43 #include "oops/methodData.hpp"
  44 #include "oops/oop.inline.hpp"
  45 #include "oops/symbol.hpp"
  46 #include "prims/jvmtiExport.hpp"
  47 #include "prims/methodHandles.hpp"
  48 #include "prims/nativeLookup.hpp"
  49 #include "runtime/arguments.hpp"
  50 #include "runtime/compilationPolicy.hpp"
  51 #include "runtime/frame.inline.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/orderAccess.inline.hpp"
  54 #include "runtime/relocator.hpp"
  55 #include "runtime/sharedRuntime.hpp"
  56 #include "runtime/signature.hpp"
  57 #include "utilities/quickSort.hpp"
  58 #include "utilities/xmlstream.hpp"
  59 
  60 // Implementation of Method
  61 
  62 Method* Method::allocate(ClassLoaderData* loader_data,
  63                          int byte_code_size,
  64                          AccessFlags access_flags,
  65                          InlineTableSizes* sizes,
  66                          ConstMethod::MethodType method_type,
  67                          TRAPS) {
  68   assert(!access_flags.is_native() || byte_code_size == 0,
  69          "native methods should not contain byte codes");
  70   ConstMethod* cm = ConstMethod::allocate(loader_data,
  71                                           byte_code_size,
  72                                           sizes,
  73                                           method_type,
  74                                           CHECK_NULL);
  75   int size = Method::size(access_flags.is_native());
  76   return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  77 }
  78 
  79 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  80   No_Safepoint_Verifier no_safepoint;
  81   set_constMethod(xconst);
  82   set_access_flags(access_flags);
  83 #ifdef CC_INTERP
  84   set_result_index(T_VOID);
  85 #endif
  86   set_intrinsic_id(vmIntrinsics::_none);
  87   set_jfr_towrite(false);
  88   set_force_inline(false);
  89   set_hidden(false);
  90   set_dont_inline(false);
  91   set_has_injected_profile(false);
  92   set_method_data(NULL);
  93   clear_method_counters();
  94   set_vtable_index(Method::garbage_vtable_index);
  95 
  96   // Fix and bury in Method*
  97   set_interpreter_entry(NULL); // sets i2i entry and from_int
  98   set_adapter_entry(NULL);
  99   clear_code(); // from_c/from_i get set to c2i/i2i
 100 
 101   if (access_flags.is_native()) {
 102     clear_native_function();
 103     set_signature_handler(NULL);
 104   }
 105 
 106   set_accessor_field_name(0);
 107   NOT_PRODUCT(set_compiled_invocation_count(0);)
 108 }
 109 
 110 // Release Method*.  The nmethod will be gone when we get here because
 111 // we've walked the code cache.
 112 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 113   MetadataFactory::free_metadata(loader_data, constMethod());
 114   set_constMethod(NULL);
 115   MetadataFactory::free_metadata(loader_data, method_data());
 116   set_method_data(NULL);
 117   MetadataFactory::free_metadata(loader_data, method_counters());
 118   clear_method_counters();
 119   // The nmethod will be gone when we get here.
 120   if (code() != NULL) _code = NULL;
 121 }
 122 
 123 address Method::get_i2c_entry() {
 124   assert(_adapter != NULL, "must have");
 125   return _adapter->get_i2c_entry();
 126 }
 127 
 128 address Method::get_c2i_entry() {
 129   assert(_adapter != NULL, "must have");
 130   return _adapter->get_c2i_entry();
 131 }
 132 
 133 address Method::get_c2i_unverified_entry() {
 134   assert(_adapter != NULL, "must have");
 135   return _adapter->get_c2i_unverified_entry();
 136 }
 137 
 138 char* Method::name_and_sig_as_C_string() const {
 139   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 140 }
 141 
 142 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 143   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 144 }
 145 
 146 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 147   const char* klass_name = klass->external_name();
 148   int klass_name_len  = (int)strlen(klass_name);
 149   int method_name_len = method_name->utf8_length();
 150   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 151   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 152   strcpy(dest, klass_name);
 153   dest[klass_name_len] = '.';
 154   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 155   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 156   dest[len] = 0;
 157   return dest;
 158 }
 159 
 160 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 161   Symbol* klass_name = klass->name();
 162   klass_name->as_klass_external_name(buf, size);
 163   int len = (int)strlen(buf);
 164 
 165   if (len < size - 1) {
 166     buf[len++] = '.';
 167 
 168     method_name->as_C_string(&(buf[len]), size - len);
 169     len = (int)strlen(buf);
 170 
 171     signature->as_C_string(&(buf[len]), size - len);
 172   }
 173 
 174   return buf;
 175 }
 176 
 177 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {
 178   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 179   // access exception table
 180   ExceptionTable table(mh());
 181   int length = table.length();
 182   // iterate through all entries sequentially
 183   constantPoolHandle pool(THREAD, mh->constants());
 184   for (int i = 0; i < length; i ++) {
 185     //reacquire the table in case a GC happened
 186     ExceptionTable table(mh());
 187     int beg_bci = table.start_pc(i);
 188     int end_bci = table.end_pc(i);
 189     assert(beg_bci <= end_bci, "inconsistent exception table");
 190     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 191       // exception handler bci range covers throw_bci => investigate further
 192       int handler_bci = table.handler_pc(i);
 193       int klass_index = table.catch_type_index(i);
 194       if (klass_index == 0) {
 195         return handler_bci;
 196       } else if (ex_klass.is_null()) {
 197         return handler_bci;
 198       } else {
 199         // we know the exception class => get the constraint class
 200         // this may require loading of the constraint class; if verification
 201         // fails or some other exception occurs, return handler_bci
 202         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 203         KlassHandle klass = KlassHandle(THREAD, k);
 204         assert(klass.not_null(), "klass not loaded");
 205         if (ex_klass->is_subtype_of(klass())) {
 206           return handler_bci;
 207         }
 208       }
 209     }
 210   }
 211 
 212   return -1;
 213 }
 214 
 215 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 216 
 217   Thread* myThread    = Thread::current();
 218   methodHandle h_this(myThread, this);
 219 #if defined(ASSERT) && !INCLUDE_JVMCI
 220   bool has_capability = myThread->is_VM_thread() ||
 221                         myThread->is_ConcurrentGC_thread() ||
 222                         myThread->is_GC_task_thread();
 223 
 224   if (!has_capability) {
 225     if (!VerifyStack && !VerifyLastFrame) {
 226       // verify stack calls this outside VM thread
 227       warning("oopmap should only be accessed by the "
 228               "VM, GC task or CMS threads (or during debugging)");
 229       InterpreterOopMap local_mask;
 230       method_holder()->mask_for(h_this, bci, &local_mask);
 231       local_mask.print();
 232     }
 233   }
 234 #endif
 235   method_holder()->mask_for(h_this, bci, mask);
 236   return;
 237 }
 238 
 239 
 240 int Method::bci_from(address bcp) const {
 241   if (is_native() && bcp == 0) {
 242     return 0;
 243   }
 244 #ifdef ASSERT
 245   {
 246     ResourceMark rm;
 247     assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),
 248            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 249            p2i(bcp), name_and_sig_as_C_string());
 250   }
 251 #endif
 252   return bcp - code_base();
 253 }
 254 
 255 
 256 int Method::validate_bci(int bci) const {
 257   return (bci == 0 || bci < code_size()) ? bci : -1;
 258 }
 259 
 260 // Return bci if it appears to be a valid bcp
 261 // Return -1 otherwise.
 262 // Used by profiling code, when invalid data is a possibility.
 263 // The caller is responsible for validating the Method* itself.
 264 int Method::validate_bci_from_bcp(address bcp) const {
 265   // keep bci as -1 if not a valid bci
 266   int bci = -1;
 267   if (bcp == 0 || bcp == code_base()) {
 268     // code_size() may return 0 and we allow 0 here
 269     // the method may be native
 270     bci = 0;
 271   } else if (contains(bcp)) {
 272     bci = bcp - code_base();
 273   }
 274   // Assert that if we have dodged any asserts, bci is negative.
 275   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 276   return bci;
 277 }
 278 
 279 address Method::bcp_from(int bci) const {
 280   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()), "illegal bci: %d", bci);
 281   address bcp = code_base() + bci;
 282   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 283   return bcp;
 284 }
 285 
 286 address Method::bcp_from(address bcp) const {
 287   if (is_native() && bcp == NULL) {
 288     return code_base();
 289   } else {
 290     return bcp;
 291   }
 292 }
 293 
 294 int Method::size(bool is_native) {
 295   // If native, then include pointers for native_function and signature_handler
 296   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 297   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
 298   return align_object_size(header_size() + extra_words);
 299 }
 300 
 301 
 302 Symbol* Method::klass_name() const {
 303   return method_holder()->name();
 304 }
 305 
 306 
 307 // Attempt to return method oop to original state.  Clear any pointers
 308 // (to objects outside the shared spaces).  We won't be able to predict
 309 // where they should point in a new JVM.  Further initialize some
 310 // entries now in order allow them to be write protected later.
 311 
 312 void Method::remove_unshareable_info() {
 313   unlink_method();
 314 }
 315 
 316 
 317 bool Method::was_executed_more_than(int n) {
 318   // Invocation counter is reset when the Method* is compiled.
 319   // If the method has compiled code we therefore assume it has
 320   // be excuted more than n times.
 321   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 322     // interpreter doesn't bump invocation counter of trivial methods
 323     // compiler does not bump invocation counter of compiled methods
 324     return true;
 325   }
 326   else if ((method_counters() != NULL &&
 327             method_counters()->invocation_counter()->carry()) ||
 328            (method_data() != NULL &&
 329             method_data()->invocation_counter()->carry())) {
 330     // The carry bit is set when the counter overflows and causes
 331     // a compilation to occur.  We don't know how many times
 332     // the counter has been reset, so we simply assume it has
 333     // been executed more than n times.
 334     return true;
 335   } else {
 336     return invocation_count() > n;
 337   }
 338 }
 339 
 340 void Method::print_invocation_count() {
 341   if (is_static()) tty->print("static ");
 342   if (is_final()) tty->print("final ");
 343   if (is_synchronized()) tty->print("synchronized ");
 344   if (is_native()) tty->print("native ");
 345   tty->print("%s::", method_holder()->external_name());
 346   name()->print_symbol_on(tty);
 347   signature()->print_symbol_on(tty);
 348 
 349   if (WizardMode) {
 350     // dump the size of the byte codes
 351     tty->print(" {%d}", code_size());
 352   }
 353   tty->cr();
 354 
 355   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 356   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 357   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 358 #ifndef PRODUCT
 359   if (CountCompiledCalls) {
 360     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 361   }
 362 #endif
 363 }
 364 
 365 // Build a MethodData* object to hold information about this method
 366 // collected in the interpreter.
 367 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
 368   // Do not profile the method if metaspace has hit an OOM previously
 369   // allocating profiling data. Callers clear pending exception so don't
 370   // add one here.
 371   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 372     return;
 373   }
 374 
 375   // Do not profile method if current thread holds the pending list lock,
 376   // which avoids deadlock for acquiring the MethodData_lock.
 377   if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
 378     return;
 379   }
 380 
 381   // Grab a lock here to prevent multiple
 382   // MethodData*s from being created.
 383   MutexLocker ml(MethodData_lock, THREAD);
 384   if (method->method_data() == NULL) {
 385     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 386     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 387     if (HAS_PENDING_EXCEPTION) {
 388       CompileBroker::log_metaspace_failure();
 389       ClassLoaderDataGraph::set_metaspace_oom(true);
 390       return;   // return the exception (which is cleared)
 391     }
 392 
 393     method->set_method_data(method_data);
 394     if (PrintMethodData && (Verbose || WizardMode)) {
 395       ResourceMark rm(THREAD);
 396       tty->print("build_interpreter_method_data for ");
 397       method->print_name(tty);
 398       tty->cr();
 399       // At the end of the run, the MDO, full of data, will be dumped.
 400     }
 401   }
 402 }
 403 
 404 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 405   // Do not profile the method if metaspace has hit an OOM previously
 406   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 407     return NULL;
 408   }
 409 
 410   methodHandle mh(m);
 411   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 412   if (HAS_PENDING_EXCEPTION) {
 413     CompileBroker::log_metaspace_failure();
 414     ClassLoaderDataGraph::set_metaspace_oom(true);
 415     return NULL;   // return the exception (which is cleared)
 416   }
 417   if (!mh->init_method_counters(counters)) {
 418     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 419   }
 420 
 421   if (LogTouchedMethods) {
 422     mh->log_touched(CHECK_NULL);
 423   }
 424 
 425   return mh->method_counters();
 426 }
 427 
 428 void Method::cleanup_inline_caches() {
 429   // The current system doesn't use inline caches in the interpreter
 430   // => nothing to do (keep this method around for future use)
 431 }
 432 
 433 
 434 int Method::extra_stack_words() {
 435   // not an inline function, to avoid a header dependency on Interpreter
 436   return extra_stack_entries() * Interpreter::stackElementSize;
 437 }
 438 
 439 
 440 void Method::compute_size_of_parameters(Thread *thread) {
 441   ArgumentSizeComputer asc(signature());
 442   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 443 }
 444 
 445 #ifdef CC_INTERP
 446 void Method::set_result_index(BasicType type)          {
 447   _result_index = Interpreter::BasicType_as_index(type);
 448 }
 449 #endif
 450 
 451 BasicType Method::result_type() const {
 452   ResultTypeFinder rtf(signature());
 453   return rtf.type();
 454 }
 455 
 456 
 457 bool Method::is_empty_method() const {
 458   return  code_size() == 1
 459       && *code_base() == Bytecodes::_return;
 460 }
 461 
 462 
 463 bool Method::is_vanilla_constructor() const {
 464   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 465   // which only calls the superclass vanilla constructor and possibly does stores of
 466   // zero constants to local fields:
 467   //
 468   //   aload_0
 469   //   invokespecial
 470   //   indexbyte1
 471   //   indexbyte2
 472   //
 473   // followed by an (optional) sequence of:
 474   //
 475   //   aload_0
 476   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 477   //   putfield
 478   //   indexbyte1
 479   //   indexbyte2
 480   //
 481   // followed by:
 482   //
 483   //   return
 484 
 485   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 486   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 487   int size = code_size();
 488   // Check if size match
 489   if (size == 0 || size % 5 != 0) return false;
 490   address cb = code_base();
 491   int last = size - 1;
 492   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 493     // Does not call superclass default constructor
 494     return false;
 495   }
 496   // Check optional sequence
 497   for (int i = 4; i < last; i += 5) {
 498     if (cb[i] != Bytecodes::_aload_0) return false;
 499     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 500     if (cb[i+2] != Bytecodes::_putfield) return false;
 501   }
 502   return true;
 503 }
 504 
 505 
 506 bool Method::compute_has_loops_flag() {
 507   BytecodeStream bcs(this);
 508   Bytecodes::Code bc;
 509 
 510   while ((bc = bcs.next()) >= 0) {
 511     switch( bc ) {
 512       case Bytecodes::_ifeq:
 513       case Bytecodes::_ifnull:
 514       case Bytecodes::_iflt:
 515       case Bytecodes::_ifle:
 516       case Bytecodes::_ifne:
 517       case Bytecodes::_ifnonnull:
 518       case Bytecodes::_ifgt:
 519       case Bytecodes::_ifge:
 520       case Bytecodes::_if_icmpeq:
 521       case Bytecodes::_if_icmpne:
 522       case Bytecodes::_if_icmplt:
 523       case Bytecodes::_if_icmpgt:
 524       case Bytecodes::_if_icmple:
 525       case Bytecodes::_if_icmpge:
 526       case Bytecodes::_if_acmpeq:
 527       case Bytecodes::_if_acmpne:
 528       case Bytecodes::_goto:
 529       case Bytecodes::_jsr:
 530         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 531         break;
 532 
 533       case Bytecodes::_goto_w:
 534       case Bytecodes::_jsr_w:
 535         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 536         break;
 537     }
 538   }
 539   _access_flags.set_loops_flag_init();
 540   return _access_flags.has_loops();
 541 }
 542 
 543 bool Method::is_final_method(AccessFlags class_access_flags) const {
 544   // or "does_not_require_vtable_entry"
 545   // default method or overpass can occur, is not final (reuses vtable entry)
 546   // private methods get vtable entries for backward class compatibility.
 547   if (is_overpass() || is_default_method())  return false;
 548   return is_final() || class_access_flags.is_final();
 549 }
 550 
 551 bool Method::is_final_method() const {
 552   return is_final_method(method_holder()->access_flags());
 553 }
 554 
 555 bool Method::is_default_method() const {
 556   if (method_holder() != NULL &&
 557       method_holder()->is_interface() &&
 558       !is_abstract()) {
 559     return true;
 560   } else {
 561     return false;
 562   }
 563 }
 564 
 565 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 566   if (is_final_method(class_access_flags))  return true;
 567 #ifdef ASSERT
 568   ResourceMark rm;
 569   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 570   if (class_access_flags.is_interface()) {
 571     assert(is_nonv == is_static(), "is_nonv=%s", name_and_sig_as_C_string());
 572   }
 573 #endif
 574   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 575   return vtable_index() == nonvirtual_vtable_index;
 576 }
 577 
 578 bool Method::can_be_statically_bound() const {
 579   return can_be_statically_bound(method_holder()->access_flags());
 580 }
 581 
 582 bool Method::is_accessor() const {
 583   if (code_size() != 5) return false;
 584   if (size_of_parameters() != 1) return false;
 585   if (java_code_at(0) != Bytecodes::_aload_0 ) return false;
 586   if (java_code_at(1) != Bytecodes::_getfield) return false;
 587   if (java_code_at(4) != Bytecodes::_areturn &&
 588       java_code_at(4) != Bytecodes::_ireturn ) return false;
 589   return true;
 590 }
 591 
 592 bool Method::is_constant_getter() const {
 593   int last_index = code_size() - 1;
 594   // Check if the first 1-3 bytecodes are a constant push
 595   // and the last bytecode is a return.
 596   return (2 <= code_size() && code_size() <= 4 &&
 597           Bytecodes::is_const(java_code_at(0)) &&
 598           Bytecodes::length_for(java_code_at(0)) == last_index &&
 599           Bytecodes::is_return(java_code_at(last_index)));
 600 }
 601 
 602 bool Method::is_initializer() const {
 603   return name() == vmSymbols::object_initializer_name() || is_static_initializer();
 604 }
 605 
 606 bool Method::has_valid_initializer_flags() const {
 607   return (is_static() ||
 608           method_holder()->major_version() < 51);
 609 }
 610 
 611 bool Method::is_static_initializer() const {
 612   // For classfiles version 51 or greater, ensure that the clinit method is
 613   // static.  Non-static methods with the name "<clinit>" are not static
 614   // initializers. (older classfiles exempted for backward compatibility)
 615   return name() == vmSymbols::class_initializer_name() &&
 616          has_valid_initializer_flags();
 617 }
 618 
 619 
 620 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 621   int length = method->checked_exceptions_length();
 622   if (length == 0) {  // common case
 623     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 624   } else {
 625     methodHandle h_this(THREAD, method);
 626     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 627     objArrayHandle mirrors (THREAD, m_oop);
 628     for (int i = 0; i < length; i++) {
 629       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 630       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 631       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 632       mirrors->obj_at_put(i, k->java_mirror());
 633     }
 634     return mirrors;
 635   }
 636 };
 637 
 638 
 639 int Method::line_number_from_bci(int bci) const {
 640   if (bci == SynchronizationEntryBCI) bci = 0;
 641   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
 642   int best_bci  =  0;
 643   int best_line = -1;
 644 
 645   if (has_linenumber_table()) {
 646     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 647     // Not necessarily sorted and not necessarily one-to-one.
 648     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 649     while (stream.read_pair()) {
 650       if (stream.bci() == bci) {
 651         // perfect match
 652         return stream.line();
 653       } else {
 654         // update best_bci/line
 655         if (stream.bci() < bci && stream.bci() >= best_bci) {
 656           best_bci  = stream.bci();
 657           best_line = stream.line();
 658         }
 659       }
 660     }
 661   }
 662   return best_line;
 663 }
 664 
 665 
 666 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 667   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 668     Thread *thread = Thread::current();
 669     Symbol* klass_name = constants()->klass_name_at(klass_index);
 670     Handle loader(thread, method_holder()->class_loader());
 671     Handle prot  (thread, method_holder()->protection_domain());
 672     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 673   } else {
 674     return true;
 675   }
 676 }
 677 
 678 
 679 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 680   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 681   if (must_be_resolved) {
 682     // Make sure klass is resolved in constantpool.
 683     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 684   }
 685   return is_klass_loaded_by_klass_index(klass_index);
 686 }
 687 
 688 
 689 void Method::set_native_function(address function, bool post_event_flag) {
 690   assert(function != NULL, "use clear_native_function to unregister natives");
 691   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 692   address* native_function = native_function_addr();
 693 
 694   // We can see racers trying to place the same native function into place. Once
 695   // is plenty.
 696   address current = *native_function;
 697   if (current == function) return;
 698   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 699       function != NULL) {
 700     // native_method_throw_unsatisfied_link_error_entry() should only
 701     // be passed when post_event_flag is false.
 702     assert(function !=
 703       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 704       "post_event_flag mis-match");
 705 
 706     // post the bind event, and possible change the bind function
 707     JvmtiExport::post_native_method_bind(this, &function);
 708   }
 709   *native_function = function;
 710   // This function can be called more than once. We must make sure that we always
 711   // use the latest registered method -> check if a stub already has been generated.
 712   // If so, we have to make it not_entrant.
 713   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
 714   if (nm != NULL) {
 715     nm->make_not_entrant();
 716   }
 717 }
 718 
 719 
 720 bool Method::has_native_function() const {
 721   if (is_method_handle_intrinsic())
 722     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 723   address func = native_function();
 724   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 725 }
 726 
 727 
 728 void Method::clear_native_function() {
 729   // Note: is_method_handle_intrinsic() is allowed here.
 730   set_native_function(
 731     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 732     !native_bind_event_is_interesting);
 733   clear_code();
 734 }
 735 
 736 address Method::critical_native_function() {
 737   methodHandle mh(this);
 738   return NativeLookup::lookup_critical_entry(mh);
 739 }
 740 
 741 
 742 void Method::set_signature_handler(address handler) {
 743   address* signature_handler =  signature_handler_addr();
 744   *signature_handler = handler;
 745 }
 746 
 747 
 748 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 749   if (PrintCompilation && report) {
 750     ttyLocker ttyl;
 751     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 752     if (comp_level == CompLevel_all) {
 753       tty->print("all levels ");
 754     } else {
 755       tty->print("levels ");
 756       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 757         tty->print("%d ", i);
 758       }
 759     }
 760     this->print_short_name(tty);
 761     int size = this->code_size();
 762     if (size > 0) {
 763       tty->print(" (%d bytes)", size);
 764     }
 765     if (reason != NULL) {
 766       tty->print("   %s", reason);
 767     }
 768     tty->cr();
 769   }
 770   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 771     ttyLocker ttyl;
 772     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 773                      os::current_thread_id(), is_osr, comp_level);
 774     if (reason != NULL) {
 775       xtty->print(" reason=\'%s\'", reason);
 776     }
 777     xtty->method(this);
 778     xtty->stamp();
 779     xtty->end_elem();
 780   }
 781 }
 782 
 783 bool Method::is_always_compilable() const {
 784   // Generated adapters must be compiled
 785   if (is_method_handle_intrinsic() && is_synthetic()) {
 786     assert(!is_not_c1_compilable(), "sanity check");
 787     assert(!is_not_c2_compilable(), "sanity check");
 788     return true;
 789   }
 790 
 791   return false;
 792 }
 793 
 794 bool Method::is_not_compilable(int comp_level) const {
 795   if (number_of_breakpoints() > 0)
 796     return true;
 797   if (is_always_compilable())
 798     return false;
 799   if (comp_level == CompLevel_any)
 800     return is_not_c1_compilable() || is_not_c2_compilable();
 801   if (is_c1_compile(comp_level))
 802     return is_not_c1_compilable();
 803   if (is_c2_compile(comp_level))
 804     return is_not_c2_compilable();
 805   return false;
 806 }
 807 
 808 // call this when compiler finds that this method is not compilable
 809 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 810   if (is_always_compilable()) {
 811     // Don't mark a method which should be always compilable
 812     return;
 813   }
 814   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 815   if (comp_level == CompLevel_all) {
 816     set_not_c1_compilable();
 817     set_not_c2_compilable();
 818   } else {
 819     if (is_c1_compile(comp_level))
 820       set_not_c1_compilable();
 821     if (is_c2_compile(comp_level))
 822       set_not_c2_compilable();
 823   }
 824   CompilationPolicy::policy()->disable_compilation(this);
 825   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 826 }
 827 
 828 bool Method::is_not_osr_compilable(int comp_level) const {
 829   if (is_not_compilable(comp_level))
 830     return true;
 831   if (comp_level == CompLevel_any)
 832     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 833   if (is_c1_compile(comp_level))
 834     return is_not_c1_osr_compilable();
 835   if (is_c2_compile(comp_level))
 836     return is_not_c2_osr_compilable();
 837   return false;
 838 }
 839 
 840 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 841   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 842   if (comp_level == CompLevel_all) {
 843     set_not_c1_osr_compilable();
 844     set_not_c2_osr_compilable();
 845   } else {
 846     if (is_c1_compile(comp_level))
 847       set_not_c1_osr_compilable();
 848     if (is_c2_compile(comp_level))
 849       set_not_c2_osr_compilable();
 850   }
 851   CompilationPolicy::policy()->disable_compilation(this);
 852   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 853 }
 854 
 855 // Revert to using the interpreter and clear out the nmethod
 856 void Method::clear_code() {
 857 
 858   // this may be NULL if c2i adapters have not been made yet
 859   // Only should happen at allocate time.
 860   if (_adapter == NULL) {
 861     _from_compiled_entry    = NULL;
 862   } else {
 863     _from_compiled_entry    = _adapter->get_c2i_entry();
 864   }
 865   OrderAccess::storestore();
 866   _from_interpreted_entry = _i2i_entry;
 867   OrderAccess::storestore();
 868   _code = NULL;
 869 }
 870 
 871 // Called by class data sharing to remove any entry points (which are not shared)
 872 void Method::unlink_method() {
 873   _code = NULL;
 874   _i2i_entry = NULL;
 875   _from_interpreted_entry = NULL;
 876   if (is_native()) {
 877     *native_function_addr() = NULL;
 878     set_signature_handler(NULL);
 879   }
 880   NOT_PRODUCT(set_compiled_invocation_count(0);)
 881   _adapter = NULL;
 882   _from_compiled_entry = NULL;
 883 
 884   // In case of DumpSharedSpaces, _method_data should always be NULL.
 885   //
 886   // During runtime (!DumpSharedSpaces), when we are cleaning a
 887   // shared class that failed to load, this->link_method() may
 888   // have already been called (before an exception happened), so
 889   // this->_method_data may not be NULL.
 890   assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");
 891 
 892   set_method_data(NULL);
 893   clear_method_counters();
 894 }
 895 
 896 // Called when the method_holder is getting linked. Setup entrypoints so the method
 897 // is ready to be called from interpreter, compiler, and vtables.
 898 void Method::link_method(const methodHandle& h_method, TRAPS) {
 899   // If the code cache is full, we may reenter this function for the
 900   // leftover methods that weren't linked.
 901   if (_i2i_entry != NULL) return;
 902 
 903   assert(_adapter == NULL, "init'd to NULL" );
 904   assert( _code == NULL, "nothing compiled yet" );
 905 
 906   // Setup interpreter entrypoint
 907   assert(this == h_method(), "wrong h_method()" );
 908   address entry = Interpreter::entry_for_method(h_method);
 909   assert(entry != NULL, "interpreter entry must be non-null");
 910   // Sets both _i2i_entry and _from_interpreted_entry
 911   set_interpreter_entry(entry);
 912 
 913   // Don't overwrite already registered native entries.
 914   if (is_native() && !has_native_function()) {
 915     set_native_function(
 916       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 917       !native_bind_event_is_interesting);
 918   }
 919 
 920   // Setup compiler entrypoint.  This is made eagerly, so we do not need
 921   // special handling of vtables.  An alternative is to make adapters more
 922   // lazily by calling make_adapter() from from_compiled_entry() for the
 923   // normal calls.  For vtable calls life gets more complicated.  When a
 924   // call-site goes mega-morphic we need adapters in all methods which can be
 925   // called from the vtable.  We need adapters on such methods that get loaded
 926   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
 927   // problem we'll make these lazily later.
 928   (void) make_adapters(h_method, CHECK);
 929 
 930   // ONLY USE the h_method now as make_adapter may have blocked
 931 
 932 }
 933 
 934 address Method::make_adapters(methodHandle mh, TRAPS) {
 935   // Adapters for compiled code are made eagerly here.  They are fairly
 936   // small (generally < 100 bytes) and quick to make (and cached and shared)
 937   // so making them eagerly shouldn't be too expensive.
 938   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
 939   if (adapter == NULL ) {
 940     THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
 941   }
 942 
 943   mh->set_adapter_entry(adapter);
 944   mh->_from_compiled_entry = adapter->get_c2i_entry();
 945   return adapter->get_c2i_entry();
 946 }
 947 
 948 void Method::restore_unshareable_info(TRAPS) {
 949   // Since restore_unshareable_info can be called more than once for a method, don't
 950   // redo any work.   If this field is restored, there is nothing to do.
 951   if (_from_compiled_entry == NULL) {
 952     // restore method's vtable by calling a virtual function
 953     restore_vtable();
 954 
 955     methodHandle mh(THREAD, this);
 956     link_method(mh, CHECK);
 957   }
 958 }
 959 
 960 
 961 // The verified_code_entry() must be called when a invoke is resolved
 962 // on this method.
 963 
 964 // It returns the compiled code entry point, after asserting not null.
 965 // This function is called after potential safepoints so that nmethod
 966 // or adapter that it points to is still live and valid.
 967 // This function must not hit a safepoint!
 968 address Method::verified_code_entry() {
 969   debug_only(No_Safepoint_Verifier nsv;)
 970   assert(_from_compiled_entry != NULL, "must be set");
 971   return _from_compiled_entry;
 972 }
 973 
 974 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
 975 // (could be racing a deopt).
 976 // Not inline to avoid circular ref.
 977 bool Method::check_code() const {
 978   // cached in a register or local.  There's a race on the value of the field.
 979   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
 980   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
 981 }
 982 
 983 // Install compiled code.  Instantly it can execute.
 984 void Method::set_code(methodHandle mh, nmethod *code) {
 985   assert( code, "use clear_code to remove code" );
 986   assert( mh->check_code(), "" );
 987 
 988   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
 989 
 990   // These writes must happen in this order, because the interpreter will
 991   // directly jump to from_interpreted_entry which jumps to an i2c adapter
 992   // which jumps to _from_compiled_entry.
 993   mh->_code = code;             // Assign before allowing compiled code to exec
 994 
 995   int comp_level = code->comp_level();
 996   // In theory there could be a race here. In practice it is unlikely
 997   // and not worth worrying about.
 998   if (comp_level > mh->highest_comp_level()) {
 999     mh->set_highest_comp_level(comp_level);
1000   }
1001 
1002   OrderAccess::storestore();
1003 #ifdef SHARK
1004   mh->_from_interpreted_entry = code->insts_begin();
1005 #else //!SHARK
1006   mh->_from_compiled_entry = code->verified_entry_point();
1007   OrderAccess::storestore();
1008   // Instantly compiled code can execute.
1009   if (!mh->is_method_handle_intrinsic())
1010     mh->_from_interpreted_entry = mh->get_i2c_entry();
1011 #endif //!SHARK
1012 }
1013 
1014 
1015 bool Method::is_overridden_in(Klass* k) const {
1016   InstanceKlass* ik = InstanceKlass::cast(k);
1017 
1018   if (ik->is_interface()) return false;
1019 
1020   // If method is an interface, we skip it - except if it
1021   // is a miranda method
1022   if (method_holder()->is_interface()) {
1023     // Check that method is not a miranda method
1024     if (ik->lookup_method(name(), signature()) == NULL) {
1025       // No implementation exist - so miranda method
1026       return false;
1027     }
1028     return true;
1029   }
1030 
1031   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1032   assert(ik->vtable() != NULL, "vtable should exist");
1033   if (!has_vtable_index()) {
1034     return false;
1035   } else {
1036     Method* vt_m = ik->method_at_vtable(vtable_index());
1037     return vt_m != this;
1038   }
1039 }
1040 
1041 
1042 // give advice about whether this Method* should be cached or not
1043 bool Method::should_not_be_cached() const {
1044   if (is_old()) {
1045     // This method has been redefined. It is either EMCP or obsolete
1046     // and we don't want to cache it because that would pin the method
1047     // down and prevent it from being collectible if and when it
1048     // finishes executing.
1049     return true;
1050   }
1051 
1052   // caching this method should be just fine
1053   return false;
1054 }
1055 
1056 
1057 /**
1058  *  Returns true if this is one of the specially treated methods for
1059  *  security related stack walks (like Reflection.getCallerClass).
1060  */
1061 bool Method::is_ignored_by_security_stack_walk() const {
1062   if (intrinsic_id() == vmIntrinsics::_invoke) {
1063     // This is Method.invoke() -- ignore it
1064     return true;
1065   }
1066   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1067     // This is an auxilary frame -- ignore it
1068     return true;
1069   }
1070   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1071     // This is an internal adapter frame for method handles -- ignore it
1072     return true;
1073   }
1074   return false;
1075 }
1076 
1077 
1078 // Constant pool structure for invoke methods:
1079 enum {
1080   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1081   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1082   _imcp_limit
1083 };
1084 
1085 // Test if this method is an MH adapter frame generated by Java code.
1086 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1087 bool Method::is_compiled_lambda_form() const {
1088   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1089 }
1090 
1091 // Test if this method is an internal MH primitive method.
1092 bool Method::is_method_handle_intrinsic() const {
1093   vmIntrinsics::ID iid = intrinsic_id();
1094   return (MethodHandles::is_signature_polymorphic(iid) &&
1095           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1096 }
1097 
1098 bool Method::has_member_arg() const {
1099   vmIntrinsics::ID iid = intrinsic_id();
1100   return (MethodHandles::is_signature_polymorphic(iid) &&
1101           MethodHandles::has_member_arg(iid));
1102 }
1103 
1104 // Make an instance of a signature-polymorphic internal MH primitive.
1105 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1106                                                          Symbol* signature,
1107                                                          TRAPS) {
1108   ResourceMark rm;
1109   methodHandle empty;
1110 
1111   KlassHandle holder = SystemDictionary::MethodHandle_klass();
1112   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1113   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1114   if (TraceMethodHandles) {
1115     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1116   }
1117 
1118   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1119   name->increment_refcount();
1120   signature->increment_refcount();
1121 
1122   int cp_length = _imcp_limit;
1123   ClassLoaderData* loader_data = holder->class_loader_data();
1124   constantPoolHandle cp;
1125   {
1126     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1127     cp = constantPoolHandle(THREAD, cp_oop);
1128   }
1129   cp->set_pool_holder(InstanceKlass::cast(holder()));
1130   cp->symbol_at_put(_imcp_invoke_name,       name);
1131   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1132   cp->set_has_preresolution();
1133 
1134   // decide on access bits:  public or not?
1135   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1136   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1137   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1138   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1139 
1140   methodHandle m;
1141   {
1142     InlineTableSizes sizes;
1143     Method* m_oop = Method::allocate(loader_data, 0,
1144                                      accessFlags_from(flags_bits), &sizes,
1145                                      ConstMethod::NORMAL, CHECK_(empty));
1146     m = methodHandle(THREAD, m_oop);
1147   }
1148   m->set_constants(cp());
1149   m->set_name_index(_imcp_invoke_name);
1150   m->set_signature_index(_imcp_invoke_signature);
1151   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1152   assert(m->signature() == signature, "");
1153 #ifdef CC_INTERP
1154   ResultTypeFinder rtf(signature);
1155   m->set_result_index(rtf.type());
1156 #endif
1157   m->compute_size_of_parameters(THREAD);
1158   m->init_intrinsic_id();
1159   assert(m->is_method_handle_intrinsic(), "");
1160 #ifdef ASSERT
1161   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1162   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1163   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1164 #endif //ASSERT
1165 
1166   // Finally, set up its entry points.
1167   assert(m->can_be_statically_bound(), "");
1168   m->set_vtable_index(Method::nonvirtual_vtable_index);
1169   m->link_method(m, CHECK_(empty));
1170 
1171   if (TraceMethodHandles && (Verbose || WizardMode))
1172     m->print_on(tty);
1173 
1174   return m;
1175 }
1176 
1177 Klass* Method::check_non_bcp_klass(Klass* klass) {
1178   if (klass != NULL && klass->class_loader() != NULL) {
1179     if (klass->is_objArray_klass())
1180       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1181     return klass;
1182   }
1183   return NULL;
1184 }
1185 
1186 
1187 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
1188                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1189   // Code below does not work for native methods - they should never get rewritten anyway
1190   assert(!m->is_native(), "cannot rewrite native methods");
1191   // Allocate new Method*
1192   AccessFlags flags = m->access_flags();
1193 
1194   ConstMethod* cm = m->constMethod();
1195   int checked_exceptions_len = cm->checked_exceptions_length();
1196   int localvariable_len = cm->localvariable_table_length();
1197   int exception_table_len = cm->exception_table_length();
1198   int method_parameters_len = cm->method_parameters_length();
1199   int method_annotations_len = cm->method_annotations_length();
1200   int parameter_annotations_len = cm->parameter_annotations_length();
1201   int type_annotations_len = cm->type_annotations_length();
1202   int default_annotations_len = cm->default_annotations_length();
1203 
1204   InlineTableSizes sizes(
1205       localvariable_len,
1206       new_compressed_linenumber_size,
1207       exception_table_len,
1208       checked_exceptions_len,
1209       method_parameters_len,
1210       cm->generic_signature_index(),
1211       method_annotations_len,
1212       parameter_annotations_len,
1213       type_annotations_len,
1214       default_annotations_len,
1215       0);
1216 
1217   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1218   Method* newm_oop = Method::allocate(loader_data,
1219                                       new_code_length,
1220                                       flags,
1221                                       &sizes,
1222                                       m->method_type(),
1223                                       CHECK_(methodHandle()));
1224   methodHandle newm (THREAD, newm_oop);
1225 
1226   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1227   ConstMethod* newcm = newm->constMethod();
1228   int new_const_method_size = newm->constMethod()->size();
1229 
1230   memcpy(newm(), m(), sizeof(Method));
1231 
1232   // Create shallow copy of ConstMethod.
1233   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1234 
1235   // Reset correct method/const method, method size, and parameter info
1236   newm->set_constMethod(newcm);
1237   newm->constMethod()->set_code_size(new_code_length);
1238   newm->constMethod()->set_constMethod_size(new_const_method_size);
1239   assert(newm->code_size() == new_code_length, "check");
1240   assert(newm->method_parameters_length() == method_parameters_len, "check");
1241   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1242   assert(newm->exception_table_length() == exception_table_len, "check");
1243   assert(newm->localvariable_table_length() == localvariable_len, "check");
1244   // Copy new byte codes
1245   memcpy(newm->code_base(), new_code, new_code_length);
1246   // Copy line number table
1247   if (new_compressed_linenumber_size > 0) {
1248     memcpy(newm->compressed_linenumber_table(),
1249            new_compressed_linenumber_table,
1250            new_compressed_linenumber_size);
1251   }
1252   // Copy method_parameters
1253   if (method_parameters_len > 0) {
1254     memcpy(newm->method_parameters_start(),
1255            m->method_parameters_start(),
1256            method_parameters_len * sizeof(MethodParametersElement));
1257   }
1258   // Copy checked_exceptions
1259   if (checked_exceptions_len > 0) {
1260     memcpy(newm->checked_exceptions_start(),
1261            m->checked_exceptions_start(),
1262            checked_exceptions_len * sizeof(CheckedExceptionElement));
1263   }
1264   // Copy exception table
1265   if (exception_table_len > 0) {
1266     memcpy(newm->exception_table_start(),
1267            m->exception_table_start(),
1268            exception_table_len * sizeof(ExceptionTableElement));
1269   }
1270   // Copy local variable number table
1271   if (localvariable_len > 0) {
1272     memcpy(newm->localvariable_table_start(),
1273            m->localvariable_table_start(),
1274            localvariable_len * sizeof(LocalVariableTableElement));
1275   }
1276   // Copy stackmap table
1277   if (m->has_stackmap_table()) {
1278     int code_attribute_length = m->stackmap_data()->length();
1279     Array<u1>* stackmap_data =
1280       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1281     memcpy((void*)stackmap_data->adr_at(0),
1282            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1283     newm->set_stackmap_data(stackmap_data);
1284   }
1285 
1286   // copy annotations over to new method
1287   newcm->copy_annotations_from(cm);
1288   return newm;
1289 }
1290 
1291 vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {
1292   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1293   // because we are not loading from core libraries
1294   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1295   // which does not use the class default class loader so we check for its loader here
1296   InstanceKlass* ik = InstanceKlass::cast(holder);
1297   if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {
1298     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1299   }
1300 
1301   // see if the klass name is well-known:
1302   Symbol* klass_name = ik->name();
1303   return vmSymbols::find_sid(klass_name);
1304 }
1305 
1306 static bool is_unsafe_alias(vmSymbols::SID name_id) {
1307   // All 70 intrinsic candidate methods from sun.misc.Unsafe in 1.8.
1308   // Some have the same method name but different signature, e.g.
1309   // getByte(long), getByte(Object,long)
1310   switch (name_id) {
1311     case vmSymbols::VM_SYMBOL_ENUM_NAME(allocateInstance_name):
1312     case vmSymbols::VM_SYMBOL_ENUM_NAME(copyMemory_name):
1313     case vmSymbols::VM_SYMBOL_ENUM_NAME(loadFence_name):
1314     case vmSymbols::VM_SYMBOL_ENUM_NAME(storeFence_name):
1315     case vmSymbols::VM_SYMBOL_ENUM_NAME(fullFence_name):
1316     case vmSymbols::VM_SYMBOL_ENUM_NAME(getObject_name):
1317     case vmSymbols::VM_SYMBOL_ENUM_NAME(getBoolean_name):
1318     case vmSymbols::VM_SYMBOL_ENUM_NAME(getByte_name):
1319     case vmSymbols::VM_SYMBOL_ENUM_NAME(getShort_name):
1320     case vmSymbols::VM_SYMBOL_ENUM_NAME(getChar_name):
1321     case vmSymbols::VM_SYMBOL_ENUM_NAME(getInt_name):
1322     case vmSymbols::VM_SYMBOL_ENUM_NAME(getLong_name):
1323     case vmSymbols::VM_SYMBOL_ENUM_NAME(getFloat_name):
1324     case vmSymbols::VM_SYMBOL_ENUM_NAME(getDouble_name):
1325     case vmSymbols::VM_SYMBOL_ENUM_NAME(putObject_name):
1326     case vmSymbols::VM_SYMBOL_ENUM_NAME(putBoolean_name):
1327     case vmSymbols::VM_SYMBOL_ENUM_NAME(putByte_name):
1328     case vmSymbols::VM_SYMBOL_ENUM_NAME(putShort_name):
1329     case vmSymbols::VM_SYMBOL_ENUM_NAME(putChar_name):
1330     case vmSymbols::VM_SYMBOL_ENUM_NAME(putInt_name):
1331     case vmSymbols::VM_SYMBOL_ENUM_NAME(putLong_name):
1332     case vmSymbols::VM_SYMBOL_ENUM_NAME(putFloat_name):
1333     case vmSymbols::VM_SYMBOL_ENUM_NAME(putDouble_name):
1334     case vmSymbols::VM_SYMBOL_ENUM_NAME(getObjectVolatile_name):
1335     case vmSymbols::VM_SYMBOL_ENUM_NAME(getBooleanVolatile_name):
1336     case vmSymbols::VM_SYMBOL_ENUM_NAME(getByteVolatile_name):
1337     case vmSymbols::VM_SYMBOL_ENUM_NAME(getShortVolatile_name):
1338     case vmSymbols::VM_SYMBOL_ENUM_NAME(getCharVolatile_name):
1339     case vmSymbols::VM_SYMBOL_ENUM_NAME(getIntVolatile_name):
1340     case vmSymbols::VM_SYMBOL_ENUM_NAME(getLongVolatile_name):
1341     case vmSymbols::VM_SYMBOL_ENUM_NAME(getFloatVolatile_name):
1342     case vmSymbols::VM_SYMBOL_ENUM_NAME(getDoubleVolatile_name):
1343     case vmSymbols::VM_SYMBOL_ENUM_NAME(putObjectVolatile_name):
1344     case vmSymbols::VM_SYMBOL_ENUM_NAME(putBooleanVolatile_name):
1345     case vmSymbols::VM_SYMBOL_ENUM_NAME(putByteVolatile_name):
1346     case vmSymbols::VM_SYMBOL_ENUM_NAME(putShortVolatile_name):
1347     case vmSymbols::VM_SYMBOL_ENUM_NAME(putCharVolatile_name):
1348     case vmSymbols::VM_SYMBOL_ENUM_NAME(putIntVolatile_name):
1349     case vmSymbols::VM_SYMBOL_ENUM_NAME(putLongVolatile_name):
1350     case vmSymbols::VM_SYMBOL_ENUM_NAME(putFloatVolatile_name):
1351     case vmSymbols::VM_SYMBOL_ENUM_NAME(putDoubleVolatile_name):
1352     case vmSymbols::VM_SYMBOL_ENUM_NAME(getAddress_name):
1353     case vmSymbols::VM_SYMBOL_ENUM_NAME(putAddress_name):
1354     case vmSymbols::VM_SYMBOL_ENUM_NAME(compareAndSwapObject_name):
1355     case vmSymbols::VM_SYMBOL_ENUM_NAME(compareAndSwapLong_name):
1356     case vmSymbols::VM_SYMBOL_ENUM_NAME(compareAndSwapInt_name):
1357     case vmSymbols::VM_SYMBOL_ENUM_NAME(putOrderedObject_name):
1358     case vmSymbols::VM_SYMBOL_ENUM_NAME(putOrderedLong_name):
1359     case vmSymbols::VM_SYMBOL_ENUM_NAME(putOrderedInt_name):
1360     case vmSymbols::VM_SYMBOL_ENUM_NAME(getAndAddInt_name):
1361     case vmSymbols::VM_SYMBOL_ENUM_NAME(getAndAddLong_name):
1362     case vmSymbols::VM_SYMBOL_ENUM_NAME(getAndSetInt_name):
1363     case vmSymbols::VM_SYMBOL_ENUM_NAME(getAndSetLong_name):
1364     case vmSymbols::VM_SYMBOL_ENUM_NAME(getAndSetObject_name):
1365     case vmSymbols::VM_SYMBOL_ENUM_NAME(park_name):
1366     case vmSymbols::VM_SYMBOL_ENUM_NAME(unpark_name):
1367       return true;
1368   }
1369 
1370   return false;
1371 }
1372 
1373 void Method::init_intrinsic_id() {
1374   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1375   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1376   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1377   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1378 
1379   // the klass name is well-known:
1380   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1381   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1382 
1383   // ditto for method and signature:
1384   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1385   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1386       && name_id == vmSymbols::NO_SID)
1387     return;
1388   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1389   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1390       && sig_id == vmSymbols::NO_SID)  return;
1391   jshort flags = access_flags().as_short();
1392 
1393   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1394   if (id != vmIntrinsics::_none) {
1395     set_intrinsic_id(id);
1396     if (id == vmIntrinsics::_Class_cast) {
1397       // Even if the intrinsic is rejected, we want to inline this simple method.
1398       set_force_inline(true);
1399     }
1400     return;
1401   }
1402 
1403   // A few slightly irregular cases:
1404   switch (klass_id) {
1405   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1406     // Second chance: check in regular Math.
1407     switch (name_id) {
1408     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1409     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1410     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1411       // pretend it is the corresponding method in the non-strict class:
1412       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1413       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1414       break;
1415     }
1416     break;
1417 
1418   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.
1419   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1420     if (!is_native())  break;
1421     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1422     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1423       id = vmIntrinsics::_none;
1424     break;
1425 
1426   case vmSymbols::VM_SYMBOL_ENUM_NAME(sun_misc_Unsafe):
1427     // Map sun.misc.Unsafe to jdk.internal.misc.Unsafe
1428     if (!is_unsafe_alias(name_id))  break;
1429     // pretend it is the corresponding method in the internal Unsafe class:
1430     klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(jdk_internal_misc_Unsafe);
1431     id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1432     break;
1433   }
1434 
1435   if (id != vmIntrinsics::_none) {
1436     // Set up its iid.  It is an alias method.
1437     set_intrinsic_id(id);
1438     return;
1439   }
1440 }
1441 
1442 // These two methods are static since a GC may move the Method
1443 bool Method::load_signature_classes(methodHandle m, TRAPS) {
1444   if (!THREAD->can_call_java()) {
1445     // There is nothing useful this routine can do from within the Compile thread.
1446     // Hopefully, the signature contains only well-known classes.
1447     // We could scan for this and return true/false, but the caller won't care.
1448     return false;
1449   }
1450   bool sig_is_loaded = true;
1451   Handle class_loader(THREAD, m->method_holder()->class_loader());
1452   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1453   ResourceMark rm(THREAD);
1454   Symbol*  signature = m->signature();
1455   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1456     if (ss.is_object()) {
1457       Symbol* sym = ss.as_symbol(CHECK_(false));
1458       Symbol*  name  = sym;
1459       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1460                                              protection_domain, THREAD);
1461       // We are loading classes eagerly. If a ClassNotFoundException or
1462       // a LinkageError was generated, be sure to ignore it.
1463       if (HAS_PENDING_EXCEPTION) {
1464         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1465             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1466           CLEAR_PENDING_EXCEPTION;
1467         } else {
1468           return false;
1469         }
1470       }
1471       if( klass == NULL) { sig_is_loaded = false; }
1472     }
1473   }
1474   return sig_is_loaded;
1475 }
1476 
1477 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
1478   Handle class_loader(THREAD, m->method_holder()->class_loader());
1479   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1480   ResourceMark rm(THREAD);
1481   Symbol*  signature = m->signature();
1482   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1483     if (ss.type() == T_OBJECT) {
1484       Symbol* name = ss.as_symbol_or_null();
1485       if (name == NULL) return true;
1486       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1487       if (klass == NULL) return true;
1488     }
1489   }
1490   return false;
1491 }
1492 
1493 // Exposed so field engineers can debug VM
1494 void Method::print_short_name(outputStream* st) {
1495   ResourceMark rm;
1496 #ifdef PRODUCT
1497   st->print(" %s::", method_holder()->external_name());
1498 #else
1499   st->print(" %s::", method_holder()->internal_name());
1500 #endif
1501   name()->print_symbol_on(st);
1502   if (WizardMode) signature()->print_symbol_on(st);
1503   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1504     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1505 }
1506 
1507 // Comparer for sorting an object array containing
1508 // Method*s.
1509 static int method_comparator(Method* a, Method* b) {
1510   return a->name()->fast_compare(b->name());
1511 }
1512 
1513 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1514 // default_methods also uses this without the ordering for fast find_method
1515 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1516   int length = methods->length();
1517   if (length > 1) {
1518     {
1519       No_Safepoint_Verifier nsv;
1520       QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);
1521     }
1522     // Reset method ordering
1523     if (set_idnums) {
1524       for (int i = 0; i < length; i++) {
1525         Method* m = methods->at(i);
1526         m->set_method_idnum(i);
1527         m->set_orig_method_idnum(i);
1528       }
1529     }
1530   }
1531 }
1532 
1533 //-----------------------------------------------------------------------------------
1534 // Non-product code unless JVM/TI needs it
1535 
1536 #if !defined(PRODUCT) || INCLUDE_JVMTI
1537 class SignatureTypePrinter : public SignatureTypeNames {
1538  private:
1539   outputStream* _st;
1540   bool _use_separator;
1541 
1542   void type_name(const char* name) {
1543     if (_use_separator) _st->print(", ");
1544     _st->print("%s", name);
1545     _use_separator = true;
1546   }
1547 
1548  public:
1549   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1550     _st = st;
1551     _use_separator = false;
1552   }
1553 
1554   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1555   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1556 };
1557 
1558 
1559 void Method::print_name(outputStream* st) {
1560   Thread *thread = Thread::current();
1561   ResourceMark rm(thread);
1562   st->print("%s ", is_static() ? "static" : "virtual");
1563   if (WizardMode) {
1564     st->print("%s.", method_holder()->internal_name());
1565     name()->print_symbol_on(st);
1566     signature()->print_symbol_on(st);
1567   } else {
1568     SignatureTypePrinter sig(signature(), st);
1569     sig.print_returntype();
1570     st->print(" %s.", method_holder()->internal_name());
1571     name()->print_symbol_on(st);
1572     st->print("(");
1573     sig.print_parameters();
1574     st->print(")");
1575   }
1576 }
1577 #endif // !PRODUCT || INCLUDE_JVMTI
1578 
1579 
1580 void Method::print_codes_on(outputStream* st) const {
1581   print_codes_on(0, code_size(), st);
1582 }
1583 
1584 void Method::print_codes_on(int from, int to, outputStream* st) const {
1585   Thread *thread = Thread::current();
1586   ResourceMark rm(thread);
1587   methodHandle mh (thread, (Method*)this);
1588   BytecodeStream s(mh);
1589   s.set_interval(from, to);
1590   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1591   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1592 }
1593 
1594 
1595 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1596 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1597 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1598 // as end-of-stream terminator.
1599 
1600 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1601   // bci and line number does not compress into single byte.
1602   // Write out escape character and use regular compression for bci and line number.
1603   write_byte((jubyte)0xFF);
1604   write_signed_int(bci_delta);
1605   write_signed_int(line_delta);
1606 }
1607 
1608 // See comment in method.hpp which explains why this exists.
1609 #if defined(_M_AMD64) && _MSC_VER >= 1400
1610 #pragma optimize("", off)
1611 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1612   write_pair_inline(bci, line);
1613 }
1614 #pragma optimize("", on)
1615 #endif
1616 
1617 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1618   _bci = 0;
1619   _line = 0;
1620 };
1621 
1622 
1623 bool CompressedLineNumberReadStream::read_pair() {
1624   jubyte next = read_byte();
1625   // Check for terminator
1626   if (next == 0) return false;
1627   if (next == 0xFF) {
1628     // Escape character, regular compression used
1629     _bci  += read_signed_int();
1630     _line += read_signed_int();
1631   } else {
1632     // Single byte compression used
1633     _bci  += next >> 3;
1634     _line += next & 0x7;
1635   }
1636   return true;
1637 }
1638 
1639 
1640 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1641   BreakpointInfo* bp = method_holder()->breakpoints();
1642   for (; bp != NULL; bp = bp->next()) {
1643     if (bp->match(this, bci)) {
1644       return bp->orig_bytecode();
1645     }
1646   }
1647   {
1648     ResourceMark rm;
1649     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1650   }
1651   return Bytecodes::_shouldnotreachhere;
1652 }
1653 
1654 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1655   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1656   BreakpointInfo* bp = method_holder()->breakpoints();
1657   for (; bp != NULL; bp = bp->next()) {
1658     if (bp->match(this, bci)) {
1659       bp->set_orig_bytecode(code);
1660       // and continue, in case there is more than one
1661     }
1662   }
1663 }
1664 
1665 void Method::set_breakpoint(int bci) {
1666   InstanceKlass* ik = method_holder();
1667   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1668   bp->set_next(ik->breakpoints());
1669   ik->set_breakpoints(bp);
1670   // do this last:
1671   bp->set(this);
1672 }
1673 
1674 static void clear_matches(Method* m, int bci) {
1675   InstanceKlass* ik = m->method_holder();
1676   BreakpointInfo* prev_bp = NULL;
1677   BreakpointInfo* next_bp;
1678   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1679     next_bp = bp->next();
1680     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1681     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1682       // do this first:
1683       bp->clear(m);
1684       // unhook it
1685       if (prev_bp != NULL)
1686         prev_bp->set_next(next_bp);
1687       else
1688         ik->set_breakpoints(next_bp);
1689       delete bp;
1690       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1691       // at same location. So we have multiple matching (method_index and bci)
1692       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1693       // breakpoint for clear_breakpoint request and keep all other method versions
1694       // BreakpointInfo for future clear_breakpoint request.
1695       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1696       // which is being called when class is unloaded. We delete all the Breakpoint
1697       // information for all versions of method. We may not correctly restore the original
1698       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1699       // so these methods won't be used anymore.
1700       if (bci >= 0) {
1701         break;
1702       }
1703     } else {
1704       // This one is a keeper.
1705       prev_bp = bp;
1706     }
1707   }
1708 }
1709 
1710 void Method::clear_breakpoint(int bci) {
1711   assert(bci >= 0, "");
1712   clear_matches(this, bci);
1713 }
1714 
1715 void Method::clear_all_breakpoints() {
1716   clear_matches(this, -1);
1717 }
1718 
1719 
1720 int Method::invocation_count() {
1721   MethodCounters *mcs = method_counters();
1722   if (TieredCompilation) {
1723     MethodData* const mdo = method_data();
1724     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1725         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1726       return InvocationCounter::count_limit;
1727     } else {
1728       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1729              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1730     }
1731   } else {
1732     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1733   }
1734 }
1735 
1736 int Method::backedge_count() {
1737   MethodCounters *mcs = method_counters();
1738   if (TieredCompilation) {
1739     MethodData* const mdo = method_data();
1740     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1741         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1742       return InvocationCounter::count_limit;
1743     } else {
1744       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1745              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1746     }
1747   } else {
1748     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1749   }
1750 }
1751 
1752 int Method::highest_comp_level() const {
1753   const MethodCounters* mcs = method_counters();
1754   if (mcs != NULL) {
1755     return mcs->highest_comp_level();
1756   } else {
1757     return CompLevel_none;
1758   }
1759 }
1760 
1761 int Method::highest_osr_comp_level() const {
1762   const MethodCounters* mcs = method_counters();
1763   if (mcs != NULL) {
1764     return mcs->highest_osr_comp_level();
1765   } else {
1766     return CompLevel_none;
1767   }
1768 }
1769 
1770 void Method::set_highest_comp_level(int level) {
1771   MethodCounters* mcs = method_counters();
1772   if (mcs != NULL) {
1773     mcs->set_highest_comp_level(level);
1774   }
1775 }
1776 
1777 void Method::set_highest_osr_comp_level(int level) {
1778   MethodCounters* mcs = method_counters();
1779   if (mcs != NULL) {
1780     mcs->set_highest_osr_comp_level(level);
1781   }
1782 }
1783 
1784 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1785   _bci = bci;
1786   _name_index = m->name_index();
1787   _signature_index = m->signature_index();
1788   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1789   if (_orig_bytecode == Bytecodes::_breakpoint)
1790     _orig_bytecode = m->orig_bytecode_at(_bci);
1791   _next = NULL;
1792 }
1793 
1794 void BreakpointInfo::set(Method* method) {
1795 #ifdef ASSERT
1796   {
1797     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1798     if (code == Bytecodes::_breakpoint)
1799       code = method->orig_bytecode_at(_bci);
1800     assert(orig_bytecode() == code, "original bytecode must be the same");
1801   }
1802 #endif
1803   Thread *thread = Thread::current();
1804   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1805   method->incr_number_of_breakpoints(thread);
1806   SystemDictionary::notice_modification();
1807   {
1808     // Deoptimize all dependents on this method
1809     HandleMark hm(thread);
1810     methodHandle mh(thread, method);
1811     CodeCache::flush_dependents_on_method(mh);
1812   }
1813 }
1814 
1815 void BreakpointInfo::clear(Method* method) {
1816   *method->bcp_from(_bci) = orig_bytecode();
1817   assert(method->number_of_breakpoints() > 0, "must not go negative");
1818   method->decr_number_of_breakpoints(Thread::current());
1819 }
1820 
1821 // jmethodID handling
1822 
1823 // This is a block allocating object, sort of like JNIHandleBlock, only a
1824 // lot simpler.
1825 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1826 // never get rid of it.
1827 
1828 static const int min_block_size = 8;
1829 
1830 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1831   friend class JNIMethodBlock;
1832   Method**        _methods;
1833   int             _number_of_methods;
1834   int             _top;
1835   JNIMethodBlockNode* _next;
1836 
1837  public:
1838 
1839   JNIMethodBlockNode(int num_methods = min_block_size);
1840 
1841   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1842 
1843   void ensure_methods(int num_addl_methods) {
1844     if (_top < _number_of_methods) {
1845       num_addl_methods -= _number_of_methods - _top;
1846       if (num_addl_methods <= 0) {
1847         return;
1848       }
1849     }
1850     if (_next == NULL) {
1851       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1852     } else {
1853       _next->ensure_methods(num_addl_methods);
1854     }
1855   }
1856 };
1857 
1858 class JNIMethodBlock : public CHeapObj<mtClass> {
1859   JNIMethodBlockNode _head;
1860   JNIMethodBlockNode *_last_free;
1861  public:
1862   static Method* const _free_method;
1863 
1864   JNIMethodBlock(int initial_capacity = min_block_size)
1865       : _head(initial_capacity), _last_free(&_head) {}
1866 
1867   void ensure_methods(int num_addl_methods) {
1868     _last_free->ensure_methods(num_addl_methods);
1869   }
1870 
1871   Method** add_method(Method* m) {
1872     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
1873       if (b->_top < b->_number_of_methods) {
1874         // top points to the next free entry.
1875         int i = b->_top;
1876         b->_methods[i] = m;
1877         b->_top++;
1878         _last_free = b;
1879         return &(b->_methods[i]);
1880       } else if (b->_top == b->_number_of_methods) {
1881         // if the next free entry ran off the block see if there's a free entry
1882         for (int i = 0; i < b->_number_of_methods; i++) {
1883           if (b->_methods[i] == _free_method) {
1884             b->_methods[i] = m;
1885             _last_free = b;
1886             return &(b->_methods[i]);
1887           }
1888         }
1889         // Only check each block once for frees.  They're very unlikely.
1890         // Increment top past the end of the block.
1891         b->_top++;
1892       }
1893       // need to allocate a next block.
1894       if (b->_next == NULL) {
1895         b->_next = _last_free = new JNIMethodBlockNode();
1896       }
1897     }
1898     guarantee(false, "Should always allocate a free block");
1899     return NULL;
1900   }
1901 
1902   bool contains(Method** m) {
1903     if (m == NULL) return false;
1904     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1905       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
1906         // This is a bit of extra checking, for two reasons.  One is
1907         // that contains() deals with pointers that are passed in by
1908         // JNI code, so making sure that the pointer is aligned
1909         // correctly is valuable.  The other is that <= and > are
1910         // technically not defined on pointers, so the if guard can
1911         // pass spuriously; no modern compiler is likely to make that
1912         // a problem, though (and if one did, the guard could also
1913         // fail spuriously, which would be bad).
1914         ptrdiff_t idx = m - b->_methods;
1915         if (b->_methods + idx == m) {
1916           return true;
1917         }
1918       }
1919     }
1920     return false;  // not found
1921   }
1922 
1923   // Doesn't really destroy it, just marks it as free so it can be reused.
1924   void destroy_method(Method** m) {
1925 #ifdef ASSERT
1926     assert(contains(m), "should be a methodID");
1927 #endif // ASSERT
1928     *m = _free_method;
1929   }
1930 
1931   // During class unloading the methods are cleared, which is different
1932   // than freed.
1933   void clear_all_methods() {
1934     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1935       for (int i = 0; i< b->_number_of_methods; i++) {
1936         b->_methods[i] = NULL;
1937       }
1938     }
1939   }
1940 #ifndef PRODUCT
1941   int count_methods() {
1942     // count all allocated methods
1943     int count = 0;
1944     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1945       for (int i = 0; i< b->_number_of_methods; i++) {
1946         if (b->_methods[i] != _free_method) count++;
1947       }
1948     }
1949     return count;
1950   }
1951 #endif // PRODUCT
1952 };
1953 
1954 // Something that can't be mistaken for an address or a markOop
1955 Method* const JNIMethodBlock::_free_method = (Method*)55;
1956 
1957 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _next(NULL), _top(0) {
1958   _number_of_methods = MAX2(num_methods, min_block_size);
1959   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
1960   for (int i = 0; i < _number_of_methods; i++) {
1961     _methods[i] = JNIMethodBlock::_free_method;
1962   }
1963 }
1964 
1965 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
1966   ClassLoaderData* cld = loader_data;
1967   if (!SafepointSynchronize::is_at_safepoint()) {
1968     // Have to add jmethod_ids() to class loader data thread-safely.
1969     // Also have to add the method to the list safely, which the cld lock
1970     // protects as well.
1971     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1972     if (cld->jmethod_ids() == NULL) {
1973       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
1974     } else {
1975       cld->jmethod_ids()->ensure_methods(capacity);
1976     }
1977   } else {
1978     // At safepoint, we are single threaded and can set this.
1979     if (cld->jmethod_ids() == NULL) {
1980       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
1981     } else {
1982       cld->jmethod_ids()->ensure_methods(capacity);
1983     }
1984   }
1985 }
1986 
1987 // Add a method id to the jmethod_ids
1988 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
1989   ClassLoaderData* cld = loader_data;
1990 
1991   if (!SafepointSynchronize::is_at_safepoint()) {
1992     // Have to add jmethod_ids() to class loader data thread-safely.
1993     // Also have to add the method to the list safely, which the cld lock
1994     // protects as well.
1995     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1996     if (cld->jmethod_ids() == NULL) {
1997       cld->set_jmethod_ids(new JNIMethodBlock());
1998     }
1999     // jmethodID is a pointer to Method*
2000     return (jmethodID)cld->jmethod_ids()->add_method(m);
2001   } else {
2002     // At safepoint, we are single threaded and can set this.
2003     if (cld->jmethod_ids() == NULL) {
2004       cld->set_jmethod_ids(new JNIMethodBlock());
2005     }
2006     // jmethodID is a pointer to Method*
2007     return (jmethodID)cld->jmethod_ids()->add_method(m);
2008   }
2009 }
2010 
2011 // Mark a jmethodID as free.  This is called when there is a data race in
2012 // InstanceKlass while creating the jmethodID cache.
2013 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2014   ClassLoaderData* cld = loader_data;
2015   Method** ptr = (Method**)m;
2016   assert(cld->jmethod_ids() != NULL, "should have method handles");
2017   cld->jmethod_ids()->destroy_method(ptr);
2018 }
2019 
2020 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2021   // Can't assert the method_holder is the same because the new method has the
2022   // scratch method holder.
2023   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2024            == new_method->method_holder()->class_loader(),
2025          "changing to a different class loader");
2026   // Just change the method in place, jmethodID pointer doesn't change.
2027   *((Method**)jmid) = new_method;
2028 }
2029 
2030 bool Method::is_method_id(jmethodID mid) {
2031   Method* m = resolve_jmethod_id(mid);
2032   assert(m != NULL, "should be called with non-null method");
2033   InstanceKlass* ik = m->method_holder();
2034   ClassLoaderData* cld = ik->class_loader_data();
2035   if (cld->jmethod_ids() == NULL) return false;
2036   return (cld->jmethod_ids()->contains((Method**)mid));
2037 }
2038 
2039 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2040   if (mid == NULL) return NULL;
2041   Method* o = resolve_jmethod_id(mid);
2042   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2043     return NULL;
2044   }
2045   return o;
2046 };
2047 
2048 void Method::set_on_stack(const bool value) {
2049   // Set both the method itself and its constant pool.  The constant pool
2050   // on stack means some method referring to it is also on the stack.
2051   constants()->set_on_stack(value);
2052 
2053   bool already_set = on_stack();
2054   _access_flags.set_on_stack(value);
2055   if (value && !already_set) {
2056     MetadataOnStackMark::record(this);
2057   }
2058 }
2059 
2060 // Called when the class loader is unloaded to make all methods weak.
2061 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2062   loader_data->jmethod_ids()->clear_all_methods();
2063 }
2064 
2065 bool Method::has_method_vptr(const void* ptr) {
2066   Method m;
2067   // This assumes that the vtbl pointer is the first word of a C++ object.
2068   // This assumption is also in universe.cpp patch_klass_vtble
2069   void* vtbl2 = dereference_vptr((const void*)&m);
2070   void* this_vtbl = dereference_vptr(ptr);
2071   return vtbl2 == this_vtbl;
2072 }
2073 
2074 // Check that this pointer is valid by checking that the vtbl pointer matches
2075 bool Method::is_valid_method() const {
2076   if (this == NULL) {
2077     return false;
2078   } else if (!is_metaspace_object()) {
2079     return false;
2080   } else {
2081     return has_method_vptr((const void*)this);
2082   }
2083 }
2084 
2085 #ifndef PRODUCT
2086 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
2087   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2088 }
2089 #endif // PRODUCT
2090 
2091 
2092 // Printing
2093 
2094 #ifndef PRODUCT
2095 
2096 void Method::print_on(outputStream* st) const {
2097   ResourceMark rm;
2098   assert(is_method(), "must be method");
2099   st->print_cr("%s", internal_name());
2100   // get the effect of PrintOopAddress, always, for methods:
2101   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2102   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2103   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2104   constants()->print_value_on(st); st->cr();
2105   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2106   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2107   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2108   st->print_cr(" - max stack:         %d",   max_stack());
2109   st->print_cr(" - max locals:        %d",   max_locals());
2110   st->print_cr(" - size of params:    %d",   size_of_parameters());
2111   st->print_cr(" - method size:       %d",   method_size());
2112   if (intrinsic_id() != vmIntrinsics::_none)
2113     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2114   if (highest_comp_level() != CompLevel_none)
2115     st->print_cr(" - highest level:     %d", highest_comp_level());
2116   st->print_cr(" - vtable index:      %d",   _vtable_index);
2117   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2118   st->print(   " - adapters:          ");
2119   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2120   if (a == NULL)
2121     st->print_cr(INTPTR_FORMAT, p2i(a));
2122   else
2123     a->print_adapter_on(st);
2124   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2125   st->print_cr(" - code size:         %d",   code_size());
2126   if (code_size() != 0) {
2127     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2128     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2129   }
2130   if (method_data() != NULL) {
2131     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2132   }
2133   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2134   if (checked_exceptions_length() > 0) {
2135     CheckedExceptionElement* table = checked_exceptions_start();
2136     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2137     if (Verbose) {
2138       for (int i = 0; i < checked_exceptions_length(); i++) {
2139         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2140       }
2141     }
2142   }
2143   if (has_linenumber_table()) {
2144     u_char* table = compressed_linenumber_table();
2145     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2146     if (Verbose) {
2147       CompressedLineNumberReadStream stream(table);
2148       while (stream.read_pair()) {
2149         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2150       }
2151     }
2152   }
2153   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2154   if (localvariable_table_length() > 0) {
2155     LocalVariableTableElement* table = localvariable_table_start();
2156     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2157     if (Verbose) {
2158       for (int i = 0; i < localvariable_table_length(); i++) {
2159         int bci = table[i].start_bci;
2160         int len = table[i].length;
2161         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2162         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2163         int slot = table[i].slot;
2164         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2165       }
2166     }
2167   }
2168   if (code() != NULL) {
2169     st->print   (" - compiled code: ");
2170     code()->print_value_on(st);
2171   }
2172   if (is_native()) {
2173     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2174     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2175   }
2176 }
2177 
2178 #endif //PRODUCT
2179 
2180 void Method::print_value_on(outputStream* st) const {
2181   assert(is_method(), "must be method");
2182   st->print("%s", internal_name());
2183   print_address_on(st);
2184   st->print(" ");
2185   name()->print_value_on(st);
2186   st->print(" ");
2187   signature()->print_value_on(st);
2188   st->print(" in ");
2189   method_holder()->print_value_on(st);
2190   if (WizardMode) st->print("#%d", _vtable_index);
2191   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2192   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2193 }
2194 
2195 #if INCLUDE_SERVICES
2196 // Size Statistics
2197 void Method::collect_statistics(KlassSizeStats *sz) const {
2198   int mysize = sz->count(this);
2199   sz->_method_bytes += mysize;
2200   sz->_method_all_bytes += mysize;
2201   sz->_rw_bytes += mysize;
2202 
2203   if (constMethod()) {
2204     constMethod()->collect_statistics(sz);
2205   }
2206   if (method_data()) {
2207     method_data()->collect_statistics(sz);
2208   }
2209 }
2210 #endif // INCLUDE_SERVICES
2211 
2212 // LogTouchedMethods and PrintTouchedMethods
2213 
2214 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2215 // the Method may be garbage collected. Let's roll our own hash table.
2216 class TouchedMethodRecord : CHeapObj<mtTracing> {
2217 public:
2218   // It's OK to store Symbols here because they will NOT be GC'ed if
2219   // LogTouchedMethods is enabled.
2220   TouchedMethodRecord* _next;
2221   Symbol* _class_name;
2222   Symbol* _method_name;
2223   Symbol* _method_signature;
2224 };
2225 
2226 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2227 static TouchedMethodRecord** _touched_method_table = NULL;
2228 
2229 void Method::log_touched(TRAPS) {
2230 
2231   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2232   Symbol* my_class = klass_name();
2233   Symbol* my_name  = name();
2234   Symbol* my_sig   = signature();
2235 
2236   unsigned int hash = my_class->identity_hash() +
2237                       my_name->identity_hash() +
2238                       my_sig->identity_hash();
2239   juint index = juint(hash) % table_size;
2240 
2241   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2242   if (_touched_method_table == NULL) {
2243     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2244                                               mtTracing, CURRENT_PC);
2245     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2246   }
2247 
2248   TouchedMethodRecord* ptr = _touched_method_table[index];
2249   while (ptr) {
2250     if (ptr->_class_name       == my_class &&
2251         ptr->_method_name      == my_name &&
2252         ptr->_method_signature == my_sig) {
2253       return;
2254     }
2255     if (ptr->_next == NULL) break;
2256     ptr = ptr->_next;
2257   }
2258   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2259   my_class->set_permanent();  // prevent reclaimed by GC
2260   my_name->set_permanent();
2261   my_sig->set_permanent();
2262   nptr->_class_name         = my_class;
2263   nptr->_method_name        = my_name;
2264   nptr->_method_signature   = my_sig;
2265   nptr->_next               = NULL;
2266 
2267   if (ptr == NULL) {
2268     // first
2269     _touched_method_table[index] = nptr;
2270   } else {
2271     ptr->_next = nptr;
2272   }
2273 }
2274 
2275 void Method::print_touched_methods(outputStream* out) {
2276   MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2277   out->print_cr("# Method::print_touched_methods version 1");
2278   if (_touched_method_table) {
2279     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2280       TouchedMethodRecord* ptr = _touched_method_table[i];
2281       while(ptr) {
2282         ptr->_class_name->print_symbol_on(out);       out->print(".");
2283         ptr->_method_name->print_symbol_on(out);      out->print(":");
2284         ptr->_method_signature->print_symbol_on(out); out->cr();
2285         ptr = ptr->_next;
2286       }
2287     }
2288   }
2289 }
2290 
2291 // Verification
2292 
2293 void Method::verify_on(outputStream* st) {
2294   guarantee(is_method(), "object must be method");
2295   guarantee(constants()->is_constantPool(), "should be constant pool");
2296   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2297   MethodData* md = method_data();
2298   guarantee(md == NULL ||
2299       md->is_methodData(), "should be method data");
2300 }