1 /*
   2  * Copyright (c) 1997, 2016, 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/debugInfoRec.hpp"
  29 #include "gc_interface/collectedHeap.inline.hpp"
  30 #include "interpreter/bytecodeStream.hpp"
  31 #include "interpreter/bytecodeTracer.hpp"
  32 #include "interpreter/bytecodes.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "interpreter/oopMapCache.hpp"
  35 #include "memory/gcLocker.hpp"
  36 #include "memory/generation.hpp"
  37 #include "memory/heapInspection.hpp"
  38 #include "memory/metadataFactory.hpp"
  39 #include "memory/metaspaceShared.hpp"
  40 #include "memory/oopFactory.hpp"
  41 #include "oops/constMethod.hpp"
  42 #include "oops/methodData.hpp"
  43 #include "oops/method.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 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  61 
  62 // Implementation of Method
  63 
  64 Method* Method::allocate(ClassLoaderData* loader_data,
  65                          int byte_code_size,
  66                          AccessFlags access_flags,
  67                          InlineTableSizes* sizes,
  68                          ConstMethod::MethodType method_type,
  69                          TRAPS) {
  70   assert(!access_flags.is_native() || byte_code_size == 0,
  71          "native methods should not contain byte codes");
  72   ConstMethod* cm = ConstMethod::allocate(loader_data,
  73                                           byte_code_size,
  74                                           sizes,
  75                                           method_type,
  76                                           CHECK_NULL);
  77 
  78   int size = Method::size(access_flags.is_native());
  79 
  80   return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, size);
  81 }
  82 
  83 Method::Method(ConstMethod* xconst, AccessFlags access_flags, int size) {
  84   No_Safepoint_Verifier no_safepoint;
  85   set_constMethod(xconst);
  86   set_access_flags(access_flags);
  87   set_method_size(size);
  88   set_intrinsic_id(vmIntrinsics::_none);
  89   set_jfr_towrite(false);
  90   set_force_inline(false);
  91   set_hidden(false);
  92   set_dont_inline(false);
  93   set_has_injected_profile(false);
  94   set_method_data(NULL);
  95   clear_method_counters();
  96   set_vtable_index(Method::garbage_vtable_index);
  97 
  98   // Fix and bury in Method*
  99   set_interpreter_entry(NULL); // sets i2i entry and from_int
 100   set_adapter_entry(NULL);
 101   clear_code(); // from_c/from_i get set to c2i/i2i
 102 
 103   if (access_flags.is_native()) {
 104     clear_native_function();
 105     set_signature_handler(NULL);
 106   }
 107 
 108   NOT_PRODUCT(set_compiled_invocation_count(0);)
 109 }
 110 
 111 // Release Method*.  The nmethod will be gone when we get here because
 112 // we've walked the code cache.
 113 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 114   clear_jmethod_id(loader_data);
 115   MetadataFactory::free_metadata(loader_data, constMethod());
 116   set_constMethod(NULL);
 117   MetadataFactory::free_metadata(loader_data, method_data());
 118   set_method_data(NULL);
 119   MetadataFactory::free_metadata(loader_data, method_counters());
 120   clear_method_counters();
 121   // The nmethod will be gone when we get here.
 122   if (code() != NULL) _code = NULL;
 123 }
 124 
 125 address Method::get_i2c_entry() {
 126   assert(_adapter != NULL, "must have");
 127   return _adapter->get_i2c_entry();
 128 }
 129 
 130 address Method::get_c2i_entry() {
 131   assert(_adapter != NULL, "must have");
 132   return _adapter->get_c2i_entry();
 133 }
 134 
 135 address Method::get_c2i_unverified_entry() {
 136   assert(_adapter != NULL, "must have");
 137   return _adapter->get_c2i_unverified_entry();
 138 }
 139 
 140 char* Method::name_and_sig_as_C_string() const {
 141   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 142 }
 143 
 144 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 145   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 146 }
 147 
 148 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 149   const char* klass_name = klass->external_name();
 150   int klass_name_len  = (int)strlen(klass_name);
 151   int method_name_len = method_name->utf8_length();
 152   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 153   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 154   strcpy(dest, klass_name);
 155   dest[klass_name_len] = '.';
 156   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 157   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 158   dest[len] = 0;
 159   return dest;
 160 }
 161 
 162 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 163   Symbol* klass_name = klass->name();
 164   klass_name->as_klass_external_name(buf, size);
 165   int len = (int)strlen(buf);
 166 
 167   if (len < size - 1) {
 168     buf[len++] = '.';
 169 
 170     method_name->as_C_string(&(buf[len]), size - len);
 171     len = (int)strlen(buf);
 172 
 173     signature->as_C_string(&(buf[len]), size - len);
 174   }
 175 
 176   return buf;
 177 }
 178 
 179 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {
 180   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 181   // access exception table
 182   ExceptionTable table(mh());
 183   int length = table.length();
 184   // iterate through all entries sequentially
 185   constantPoolHandle pool(THREAD, mh->constants());
 186   for (int i = 0; i < length; i ++) {
 187     //reacquire the table in case a GC happened
 188     ExceptionTable table(mh());
 189     int beg_bci = table.start_pc(i);
 190     int end_bci = table.end_pc(i);
 191     assert(beg_bci <= end_bci, "inconsistent exception table");
 192     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 193       // exception handler bci range covers throw_bci => investigate further
 194       int handler_bci = table.handler_pc(i);
 195       int klass_index = table.catch_type_index(i);
 196       if (klass_index == 0) {
 197         return handler_bci;
 198       } else if (ex_klass.is_null()) {
 199         return handler_bci;
 200       } else {
 201         // we know the exception class => get the constraint class
 202         // this may require loading of the constraint class; if verification
 203         // fails or some other exception occurs, return handler_bci
 204         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 205         KlassHandle klass = KlassHandle(THREAD, k);
 206         assert(klass.not_null(), "klass not loaded");
 207         if (ex_klass->is_subtype_of(klass())) {
 208           return handler_bci;
 209         }
 210       }
 211     }
 212   }
 213 
 214   return -1;
 215 }
 216 
 217 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 218 
 219   Thread* myThread    = Thread::current();
 220   methodHandle h_this(myThread, this);
 221 #ifdef ASSERT
 222   bool has_capability = myThread->is_VM_thread() ||
 223                         myThread->is_ConcurrentGC_thread() ||
 224                         myThread->is_GC_task_thread();
 225 
 226   if (!has_capability) {
 227     if (!VerifyStack && !VerifyLastFrame) {
 228       // verify stack calls this outside VM thread
 229       warning("oopmap should only be accessed by the "
 230               "VM, GC task or CMS threads (or during debugging)");
 231       InterpreterOopMap local_mask;
 232       method_holder()->mask_for(h_this, bci, &local_mask);
 233       local_mask.print();
 234     }
 235   }
 236 #endif
 237   method_holder()->mask_for(h_this, bci, mask);
 238   return;
 239 }
 240 
 241 
 242 int Method::bci_from(address bcp) const {
 243 #ifdef ASSERT
 244   { ResourceMark rm;
 245   assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),
 246          err_msg("bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s", bcp, name_and_sig_as_C_string()));
 247   }
 248 #endif
 249   return bcp - code_base();
 250 }
 251 
 252 
 253 // Return (int)bcx if it appears to be a valid BCI.
 254 // Return bci_from((address)bcx) if it appears to be a valid BCP.
 255 // Return -1 otherwise.
 256 // Used by profiling code, when invalid data is a possibility.
 257 // The caller is responsible for validating the Method* itself.
 258 int Method::validate_bci_from_bcx(intptr_t bcx) const {
 259   // keep bci as -1 if not a valid bci
 260   int bci = -1;
 261   if (bcx == 0 || (address)bcx == code_base()) {
 262     // code_size() may return 0 and we allow 0 here
 263     // the method may be native
 264     bci = 0;
 265   } else if (frame::is_bci(bcx)) {
 266     if (bcx < code_size()) {
 267       bci = (int)bcx;
 268     }
 269   } else if (contains((address)bcx)) {
 270     bci = (address)bcx - code_base();
 271   }
 272   // Assert that if we have dodged any asserts, bci is negative.
 273   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 274   return bci;
 275 }
 276 
 277 address Method::bcp_from(int bci) const {
 278   assert((is_native() && bci == 0)  || (!is_native() && 0 <= bci && bci < code_size()), err_msg("illegal bci: %d", bci));
 279   address bcp = code_base() + bci;
 280   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 281   return bcp;
 282 }
 283 
 284 
 285 int Method::size(bool is_native) {
 286   // If native, then include pointers for native_function and signature_handler
 287   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 288   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
 289   return align_object_size(header_size() + extra_words);
 290 }
 291 
 292 
 293 Symbol* Method::klass_name() const {
 294   Klass* k = method_holder();
 295   assert(k->is_klass(), "must be klass");
 296   InstanceKlass* ik = (InstanceKlass*) k;
 297   return ik->name();
 298 }
 299 
 300 
 301 // Attempt to return method oop to original state.  Clear any pointers
 302 // (to objects outside the shared spaces).  We won't be able to predict
 303 // where they should point in a new JVM.  Further initialize some
 304 // entries now in order allow them to be write protected later.
 305 
 306 void Method::remove_unshareable_info() {
 307   unlink_method();
 308 }
 309 
 310 void Method::set_vtable_index(int index) {
 311   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 312     // At runtime initialize_vtable is rerun as part of link_class_impl()
 313     // for a shared class loaded by the non-boot loader to obtain the loader
 314     // constraints based on the runtime classloaders' context.
 315     return; // don't write into the shared class
 316   } else {
 317     _vtable_index = index;
 318   }
 319 }
 320 
 321 void Method::set_itable_index(int index) {
 322   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 323     // At runtime initialize_itable is rerun as part of link_class_impl()
 324     // for a shared class loaded by the non-boot loader to obtain the loader
 325     // constraints based on the runtime classloaders' context. The dumptime
 326     // itable index should be the same as the runtime index.
 327     assert(_vtable_index == itable_index_max - index,
 328            "archived itable index is different from runtime index");
 329     return; // don’t write into the shared class
 330   } else {
 331     _vtable_index = itable_index_max - index;
 332   }
 333   assert(valid_itable_index(), "");
 334 }
 335 
 336 
 337 
 338 bool Method::was_executed_more_than(int n) {
 339   // Invocation counter is reset when the Method* is compiled.
 340   // If the method has compiled code we therefore assume it has
 341   // be excuted more than n times.
 342   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 343     // interpreter doesn't bump invocation counter of trivial methods
 344     // compiler does not bump invocation counter of compiled methods
 345     return true;
 346   }
 347   else if ((method_counters() != NULL &&
 348             method_counters()->invocation_counter()->carry()) ||
 349            (method_data() != NULL &&
 350             method_data()->invocation_counter()->carry())) {
 351     // The carry bit is set when the counter overflows and causes
 352     // a compilation to occur.  We don't know how many times
 353     // the counter has been reset, so we simply assume it has
 354     // been executed more than n times.
 355     return true;
 356   } else {
 357     return invocation_count() > n;
 358   }
 359 }
 360 
 361 #ifndef PRODUCT
 362 void Method::print_invocation_count() {
 363   if (is_static()) tty->print("static ");
 364   if (is_final()) tty->print("final ");
 365   if (is_synchronized()) tty->print("synchronized ");
 366   if (is_native()) tty->print("native ");
 367   method_holder()->name()->print_symbol_on(tty);
 368   tty->print(".");
 369   name()->print_symbol_on(tty);
 370   signature()->print_symbol_on(tty);
 371 
 372   if (WizardMode) {
 373     // dump the size of the byte codes
 374     tty->print(" {%d}", code_size());
 375   }
 376   tty->cr();
 377 
 378   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 379   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 380   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 381   if (CountCompiledCalls) {
 382     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 383   }
 384 
 385 }
 386 #endif
 387 
 388 // Build a MethodData* object to hold information about this method
 389 // collected in the interpreter.
 390 void Method::build_interpreter_method_data(methodHandle method, TRAPS) {
 391   // Do not profile method if current thread holds the pending list lock,
 392   // which avoids deadlock for acquiring the MethodData_lock.
 393   if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
 394     return;
 395   }
 396 
 397   // Grab a lock here to prevent multiple
 398   // MethodData*s from being created.
 399   MutexLocker ml(MethodData_lock, THREAD);
 400   if (method->method_data() == NULL) {
 401     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 402     MethodData* method_data = MethodData::allocate(loader_data, method, CHECK);
 403     method->set_method_data(method_data);
 404     if (PrintMethodData && (Verbose || WizardMode)) {
 405       ResourceMark rm(THREAD);
 406       tty->print("build_interpreter_method_data for ");
 407       method->print_name(tty);
 408       tty->cr();
 409       // At the end of the run, the MDO, full of data, will be dumped.
 410     }
 411   }
 412 }
 413 
 414 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 415   methodHandle mh(m);
 416   ClassLoaderData* loader_data = mh->method_holder()->class_loader_data();
 417   MethodCounters* counters = MethodCounters::allocate(loader_data, CHECK_NULL);
 418   if (!mh->init_method_counters(counters)) {
 419     MetadataFactory::free_metadata(loader_data, counters);
 420   }
 421   return mh->method_counters();
 422 }
 423 
 424 void Method::cleanup_inline_caches() {
 425   // The current system doesn't use inline caches in the interpreter
 426   // => nothing to do (keep this method around for future use)
 427 }
 428 
 429 
 430 int Method::extra_stack_words() {
 431   // not an inline function, to avoid a header dependency on Interpreter
 432   return extra_stack_entries() * Interpreter::stackElementSize;
 433 }
 434 
 435 
 436 void Method::compute_size_of_parameters(Thread *thread) {
 437   ArgumentSizeComputer asc(signature());
 438   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 439 }
 440 
 441 BasicType Method::result_type() const {
 442   ResultTypeFinder rtf(signature());
 443   return rtf.type();
 444 }
 445 
 446 
 447 bool Method::is_empty_method() const {
 448   return  code_size() == 1
 449       && *code_base() == Bytecodes::_return;
 450 }
 451 
 452 
 453 bool Method::is_vanilla_constructor() const {
 454   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 455   // which only calls the superclass vanilla constructor and possibly does stores of
 456   // zero constants to local fields:
 457   //
 458   //   aload_0
 459   //   invokespecial
 460   //   indexbyte1
 461   //   indexbyte2
 462   //
 463   // followed by an (optional) sequence of:
 464   //
 465   //   aload_0
 466   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 467   //   putfield
 468   //   indexbyte1
 469   //   indexbyte2
 470   //
 471   // followed by:
 472   //
 473   //   return
 474 
 475   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 476   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 477   int size = code_size();
 478   // Check if size match
 479   if (size == 0 || size % 5 != 0) return false;
 480   address cb = code_base();
 481   int last = size - 1;
 482   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 483     // Does not call superclass default constructor
 484     return false;
 485   }
 486   // Check optional sequence
 487   for (int i = 4; i < last; i += 5) {
 488     if (cb[i] != Bytecodes::_aload_0) return false;
 489     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 490     if (cb[i+2] != Bytecodes::_putfield) return false;
 491   }
 492   return true;
 493 }
 494 
 495 
 496 bool Method::compute_has_loops_flag() {
 497   BytecodeStream bcs(this);
 498   Bytecodes::Code bc;
 499 
 500   while ((bc = bcs.next()) >= 0) {
 501     switch( bc ) {
 502       case Bytecodes::_ifeq:
 503       case Bytecodes::_ifnull:
 504       case Bytecodes::_iflt:
 505       case Bytecodes::_ifle:
 506       case Bytecodes::_ifne:
 507       case Bytecodes::_ifnonnull:
 508       case Bytecodes::_ifgt:
 509       case Bytecodes::_ifge:
 510       case Bytecodes::_if_icmpeq:
 511       case Bytecodes::_if_icmpne:
 512       case Bytecodes::_if_icmplt:
 513       case Bytecodes::_if_icmpgt:
 514       case Bytecodes::_if_icmple:
 515       case Bytecodes::_if_icmpge:
 516       case Bytecodes::_if_acmpeq:
 517       case Bytecodes::_if_acmpne:
 518       case Bytecodes::_goto:
 519       case Bytecodes::_jsr:
 520         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 521         break;
 522 
 523       case Bytecodes::_goto_w:
 524       case Bytecodes::_jsr_w:
 525         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 526         break;
 527     }
 528   }
 529   _access_flags.set_loops_flag_init();
 530   return _access_flags.has_loops();
 531 }
 532 
 533 bool Method::is_final_method(AccessFlags class_access_flags) const {
 534   // or "does_not_require_vtable_entry"
 535   // default method or overpass can occur, is not final (reuses vtable entry)
 536   // private methods get vtable entries for backward class compatibility.
 537   if (is_overpass() || is_default_method())  return false;
 538   return is_final() || class_access_flags.is_final();
 539 }
 540 
 541 bool Method::is_final_method() const {
 542   return is_final_method(method_holder()->access_flags());
 543 }
 544 
 545 bool Method::is_default_method() const {
 546   if (method_holder() != NULL &&
 547       method_holder()->is_interface() &&
 548       !is_abstract()) {
 549     return true;
 550   } else {
 551     return false;
 552   }
 553 }
 554 
 555 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 556   if (is_final_method(class_access_flags))  return true;
 557 #ifdef ASSERT
 558   ResourceMark rm;
 559   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 560   if (class_access_flags.is_interface()) {
 561       assert(is_nonv == is_static(), err_msg("is_nonv=%s", name_and_sig_as_C_string()));
 562   }
 563 #endif
 564   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 565   return vtable_index() == nonvirtual_vtable_index;
 566 }
 567 
 568 bool Method::can_be_statically_bound() const {
 569   return can_be_statically_bound(method_holder()->access_flags());
 570 }
 571 
 572 bool Method::is_accessor() const {
 573   if (code_size() != 5) return false;
 574   if (size_of_parameters() != 1) return false;
 575   if (java_code_at(0) != Bytecodes::_aload_0 ) return false;
 576   if (java_code_at(1) != Bytecodes::_getfield) return false;
 577   if (java_code_at(4) != Bytecodes::_areturn &&
 578       java_code_at(4) != Bytecodes::_ireturn ) return false;
 579   return true;
 580 }
 581 
 582 bool Method::is_constant_getter() const {
 583   int last_index = code_size() - 1;
 584   // Check if the first 1-3 bytecodes are a constant push
 585   // and the last bytecode is a return.
 586   return (2 <= code_size() && code_size() <= 4 &&
 587           Bytecodes::is_const(java_code_at(0)) &&
 588           Bytecodes::length_for(java_code_at(0)) == last_index &&
 589           Bytecodes::is_return(java_code_at(last_index)));
 590 }
 591 
 592 bool Method::is_initializer() const {
 593   return name() == vmSymbols::object_initializer_name() || is_static_initializer();
 594 }
 595 
 596 bool Method::has_valid_initializer_flags() const {
 597   return (is_static() ||
 598           method_holder()->major_version() < 51);
 599 }
 600 
 601 bool Method::is_static_initializer() const {
 602   // For classfiles version 51 or greater, ensure that the clinit method is
 603   // static.  Non-static methods with the name "<clinit>" are not static
 604   // initializers. (older classfiles exempted for backward compatibility)
 605   return name() == vmSymbols::class_initializer_name() &&
 606          has_valid_initializer_flags();
 607 }
 608 
 609 
 610 objArrayHandle Method::resolved_checked_exceptions_impl(Method* this_oop, TRAPS) {
 611   int length = this_oop->checked_exceptions_length();
 612   if (length == 0) {  // common case
 613     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 614   } else {
 615     methodHandle h_this(THREAD, this_oop);
 616     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 617     objArrayHandle mirrors (THREAD, m_oop);
 618     for (int i = 0; i < length; i++) {
 619       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 620       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 621       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 622       mirrors->obj_at_put(i, k->java_mirror());
 623     }
 624     return mirrors;
 625   }
 626 };
 627 
 628 
 629 int Method::line_number_from_bci(int bci) const {
 630   if (bci == SynchronizationEntryBCI) bci = 0;
 631   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
 632   int best_bci  =  0;
 633   int best_line = -1;
 634 
 635   if (has_linenumber_table()) {
 636     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 637     // Not necessarily sorted and not necessarily one-to-one.
 638     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 639     while (stream.read_pair()) {
 640       if (stream.bci() == bci) {
 641         // perfect match
 642         return stream.line();
 643       } else {
 644         // update best_bci/line
 645         if (stream.bci() < bci && stream.bci() >= best_bci) {
 646           best_bci  = stream.bci();
 647           best_line = stream.line();
 648         }
 649       }
 650     }
 651   }
 652   return best_line;
 653 }
 654 
 655 
 656 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 657   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 658     Thread *thread = Thread::current();
 659     Symbol* klass_name = constants()->klass_name_at(klass_index);
 660     Handle loader(thread, method_holder()->class_loader());
 661     Handle prot  (thread, method_holder()->protection_domain());
 662     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 663   } else {
 664     return true;
 665   }
 666 }
 667 
 668 
 669 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 670   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 671   if (must_be_resolved) {
 672     // Make sure klass is resolved in constantpool.
 673     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 674   }
 675   return is_klass_loaded_by_klass_index(klass_index);
 676 }
 677 
 678 
 679 void Method::set_native_function(address function, bool post_event_flag) {
 680   assert(function != NULL, "use clear_native_function to unregister natives");
 681   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 682   address* native_function = native_function_addr();
 683 
 684   // We can see racers trying to place the same native function into place. Once
 685   // is plenty.
 686   address current = *native_function;
 687   if (current == function) return;
 688   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 689       function != NULL) {
 690     // native_method_throw_unsatisfied_link_error_entry() should only
 691     // be passed when post_event_flag is false.
 692     assert(function !=
 693       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 694       "post_event_flag mis-match");
 695 
 696     // post the bind event, and possible change the bind function
 697     JvmtiExport::post_native_method_bind(this, &function);
 698   }
 699   *native_function = function;
 700   // This function can be called more than once. We must make sure that we always
 701   // use the latest registered method -> check if a stub already has been generated.
 702   // If so, we have to make it not_entrant.
 703   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
 704   if (nm != NULL) {
 705     nm->make_not_entrant();
 706   }
 707 }
 708 
 709 
 710 bool Method::has_native_function() const {
 711   if (is_method_handle_intrinsic())
 712     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 713   address func = native_function();
 714   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 715 }
 716 
 717 
 718 void Method::clear_native_function() {
 719   // Note: is_method_handle_intrinsic() is allowed here.
 720   set_native_function(
 721     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 722     !native_bind_event_is_interesting);
 723   clear_code();
 724 }
 725 
 726 address Method::critical_native_function() {
 727   methodHandle mh(this);
 728   return NativeLookup::lookup_critical_entry(mh);
 729 }
 730 
 731 
 732 void Method::set_signature_handler(address handler) {
 733   address* signature_handler =  signature_handler_addr();
 734   *signature_handler = handler;
 735 }
 736 
 737 
 738 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 739   if (PrintCompilation && report) {
 740     ttyLocker ttyl;
 741     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 742     if (comp_level == CompLevel_all) {
 743       tty->print("all levels ");
 744     } else {
 745       tty->print("levels ");
 746       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 747         tty->print("%d ", i);
 748       }
 749     }
 750     this->print_short_name(tty);
 751     int size = this->code_size();
 752     if (size > 0) {
 753       tty->print(" (%d bytes)", size);
 754     }
 755     if (reason != NULL) {
 756       tty->print("   %s", reason);
 757     }
 758     tty->cr();
 759   }
 760   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 761     ttyLocker ttyl;
 762     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 763                      os::current_thread_id(), is_osr, comp_level);
 764     if (reason != NULL) {
 765       xtty->print(" reason=\'%s\'", reason);
 766     }
 767     xtty->method(this);
 768     xtty->stamp();
 769     xtty->end_elem();
 770   }
 771 }
 772 
 773 bool Method::is_always_compilable() const {
 774   // Generated adapters must be compiled
 775   if (is_method_handle_intrinsic() && is_synthetic()) {
 776     assert(!is_not_c1_compilable(), "sanity check");
 777     assert(!is_not_c2_compilable(), "sanity check");
 778     return true;
 779   }
 780 
 781   return false;
 782 }
 783 
 784 bool Method::is_not_compilable(int comp_level) const {
 785   if (number_of_breakpoints() > 0)
 786     return true;
 787   if (is_always_compilable())
 788     return false;
 789   if (comp_level == CompLevel_any)
 790     return is_not_c1_compilable() || is_not_c2_compilable();
 791   if (is_c1_compile(comp_level))
 792     return is_not_c1_compilable();
 793   if (is_c2_compile(comp_level))
 794     return is_not_c2_compilable();
 795   return false;
 796 }
 797 
 798 // call this when compiler finds that this method is not compilable
 799 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 800   if (is_always_compilable()) {
 801     // Don't mark a method which should be always compilable
 802     return;
 803   }
 804   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 805   if (comp_level == CompLevel_all) {
 806     set_not_c1_compilable();
 807     set_not_c2_compilable();
 808   } else {
 809     if (is_c1_compile(comp_level))
 810       set_not_c1_compilable();
 811     if (is_c2_compile(comp_level))
 812       set_not_c2_compilable();
 813   }
 814   CompilationPolicy::policy()->disable_compilation(this);
 815   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 816 }
 817 
 818 bool Method::is_not_osr_compilable(int comp_level) const {
 819   if (is_not_compilable(comp_level))
 820     return true;
 821   if (comp_level == CompLevel_any)
 822     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 823   if (is_c1_compile(comp_level))
 824     return is_not_c1_osr_compilable();
 825   if (is_c2_compile(comp_level))
 826     return is_not_c2_osr_compilable();
 827   return false;
 828 }
 829 
 830 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 831   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 832   if (comp_level == CompLevel_all) {
 833     set_not_c1_osr_compilable();
 834     set_not_c2_osr_compilable();
 835   } else {
 836     if (is_c1_compile(comp_level))
 837       set_not_c1_osr_compilable();
 838     if (is_c2_compile(comp_level))
 839       set_not_c2_osr_compilable();
 840   }
 841   CompilationPolicy::policy()->disable_compilation(this);
 842   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 843 }
 844 
 845 // Revert to using the interpreter and clear out the nmethod
 846 void Method::clear_code() {
 847 
 848   // this may be NULL if c2i adapters have not been made yet
 849   // Only should happen at allocate time.
 850   if (_adapter == NULL) {
 851     _from_compiled_entry    = NULL;
 852   } else {
 853     _from_compiled_entry    = _adapter->get_c2i_entry();
 854   }
 855   OrderAccess::storestore();
 856   _from_interpreted_entry = _i2i_entry;
 857   OrderAccess::storestore();
 858   _code = NULL;
 859 }
 860 
 861 // Called by class data sharing to remove any entry points (which are not shared)
 862 void Method::unlink_method() {
 863   _code = NULL;
 864   _i2i_entry = NULL;
 865   _from_interpreted_entry = NULL;
 866   if (is_native()) {
 867     *native_function_addr() = NULL;
 868     set_signature_handler(NULL);
 869   }
 870   NOT_PRODUCT(set_compiled_invocation_count(0);)
 871   _adapter = NULL;
 872   _from_compiled_entry = NULL;
 873 
 874   // In case of DumpSharedSpaces, _method_data should always be NULL.
 875   //
 876   // During runtime (!DumpSharedSpaces), when we are cleaning a
 877   // shared class that failed to load, this->link_method() may
 878   // have already been called (before an exception happened), so
 879   // this->_method_data may not be NULL.
 880   assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");
 881 
 882   set_method_data(NULL);
 883   clear_method_counters();
 884 }
 885 
 886 // Called when the method_holder is getting linked. Setup entrypoints so the method
 887 // is ready to be called from interpreter, compiler, and vtables.
 888 void Method::link_method(methodHandle h_method, TRAPS) {
 889   // If the code cache is full, we may reenter this function for the
 890   // leftover methods that weren't linked.
 891   if (_i2i_entry != NULL) return;
 892 
 893   assert(_adapter == NULL, "init'd to NULL" );
 894   assert( _code == NULL, "nothing compiled yet" );
 895 
 896   // Setup interpreter entrypoint
 897   assert(this == h_method(), "wrong h_method()" );
 898   address entry = Interpreter::entry_for_method(h_method);
 899   assert(entry != NULL, "interpreter entry must be non-null");
 900   // Sets both _i2i_entry and _from_interpreted_entry
 901   set_interpreter_entry(entry);
 902 
 903   // Don't overwrite already registered native entries.
 904   if (is_native() && !has_native_function()) {
 905     set_native_function(
 906       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 907       !native_bind_event_is_interesting);
 908   }
 909 
 910   // Setup compiler entrypoint.  This is made eagerly, so we do not need
 911   // special handling of vtables.  An alternative is to make adapters more
 912   // lazily by calling make_adapter() from from_compiled_entry() for the
 913   // normal calls.  For vtable calls life gets more complicated.  When a
 914   // call-site goes mega-morphic we need adapters in all methods which can be
 915   // called from the vtable.  We need adapters on such methods that get loaded
 916   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
 917   // problem we'll make these lazily later.
 918   (void) make_adapters(h_method, CHECK);
 919 
 920   // ONLY USE the h_method now as make_adapter may have blocked
 921 
 922 }
 923 
 924 address Method::make_adapters(methodHandle mh, TRAPS) {
 925   // Adapters for compiled code are made eagerly here.  They are fairly
 926   // small (generally < 100 bytes) and quick to make (and cached and shared)
 927   // so making them eagerly shouldn't be too expensive.
 928   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
 929   if (adapter == NULL ) {
 930     THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "out of space in CodeCache for adapters");
 931   }
 932 
 933   mh->set_adapter_entry(adapter);
 934   mh->_from_compiled_entry = adapter->get_c2i_entry();
 935   return adapter->get_c2i_entry();
 936 }
 937 
 938 void Method::restore_unshareable_info(TRAPS) {
 939   // Since restore_unshareable_info can be called more than once for a method, don't
 940   // redo any work.   If this field is restored, there is nothing to do.
 941   if (_from_compiled_entry == NULL) {
 942     // restore method's vtable by calling a virtual function
 943     restore_vtable();
 944 
 945     methodHandle mh(THREAD, this);
 946     link_method(mh, CHECK);
 947   }
 948 }
 949 
 950 
 951 // The verified_code_entry() must be called when a invoke is resolved
 952 // on this method.
 953 
 954 // It returns the compiled code entry point, after asserting not null.
 955 // This function is called after potential safepoints so that nmethod
 956 // or adapter that it points to is still live and valid.
 957 // This function must not hit a safepoint!
 958 address Method::verified_code_entry() {
 959   debug_only(No_Safepoint_Verifier nsv;)
 960   assert(_from_compiled_entry != NULL, "must be set");
 961   return _from_compiled_entry;
 962 }
 963 
 964 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
 965 // (could be racing a deopt).
 966 // Not inline to avoid circular ref.
 967 bool Method::check_code() const {
 968   // cached in a register or local.  There's a race on the value of the field.
 969   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
 970   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
 971 }
 972 
 973 // Install compiled code.  Instantly it can execute.
 974 void Method::set_code(methodHandle mh, nmethod *code) {
 975   assert( code, "use clear_code to remove code" );
 976   assert( mh->check_code(), "" );
 977 
 978   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
 979 
 980   // These writes must happen in this order, because the interpreter will
 981   // directly jump to from_interpreted_entry which jumps to an i2c adapter
 982   // which jumps to _from_compiled_entry.
 983   mh->_code = code;             // Assign before allowing compiled code to exec
 984 
 985   int comp_level = code->comp_level();
 986   // In theory there could be a race here. In practice it is unlikely
 987   // and not worth worrying about.
 988   if (comp_level > mh->highest_comp_level()) {
 989     mh->set_highest_comp_level(comp_level);
 990   }
 991 
 992   OrderAccess::storestore();
 993 #ifdef SHARK
 994   mh->_from_interpreted_entry = code->insts_begin();
 995 #else //!SHARK
 996   mh->_from_compiled_entry = code->verified_entry_point();
 997   OrderAccess::storestore();
 998   // Instantly compiled code can execute.
 999   if (!mh->is_method_handle_intrinsic())
1000     mh->_from_interpreted_entry = mh->get_i2c_entry();
1001 #endif //!SHARK
1002 }
1003 
1004 
1005 bool Method::is_overridden_in(Klass* k) const {
1006   InstanceKlass* ik = InstanceKlass::cast(k);
1007 
1008   if (ik->is_interface()) return false;
1009 
1010   // If method is an interface, we skip it - except if it
1011   // is a miranda method
1012   if (method_holder()->is_interface()) {
1013     // Check that method is not a miranda method
1014     if (ik->lookup_method(name(), signature()) == NULL) {
1015       // No implementation exist - so miranda method
1016       return false;
1017     }
1018     return true;
1019   }
1020 
1021   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1022   assert(ik->vtable() != NULL, "vtable should exist");
1023   if (!has_vtable_index()) {
1024     return false;
1025   } else {
1026     Method* vt_m = ik->method_at_vtable(vtable_index());
1027     return vt_m != this;
1028   }
1029 }
1030 
1031 
1032 // give advice about whether this Method* should be cached or not
1033 bool Method::should_not_be_cached() const {
1034   if (is_old()) {
1035     // This method has been redefined. It is either EMCP or obsolete
1036     // and we don't want to cache it because that would pin the method
1037     // down and prevent it from being collectible if and when it
1038     // finishes executing.
1039     return true;
1040   }
1041 
1042   // caching this method should be just fine
1043   return false;
1044 }
1045 
1046 
1047 /**
1048  *  Returns true if this is one of the specially treated methods for
1049  *  security related stack walks (like Reflection.getCallerClass).
1050  */
1051 bool Method::is_ignored_by_security_stack_walk() const {
1052   const bool use_new_reflection = JDK_Version::is_gte_jdk14x_version() && UseNewReflection;
1053 
1054   if (intrinsic_id() == vmIntrinsics::_invoke) {
1055     // This is Method.invoke() -- ignore it
1056     return true;
1057   }
1058   if (use_new_reflection &&
1059       method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1060     // This is an auxilary frame -- ignore it
1061     return true;
1062   }
1063   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1064     // This is an internal adapter frame for method handles -- ignore it
1065     return true;
1066   }
1067   return false;
1068 }
1069 
1070 
1071 // Constant pool structure for invoke methods:
1072 enum {
1073   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1074   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1075   _imcp_limit
1076 };
1077 
1078 // Test if this method is an MH adapter frame generated by Java code.
1079 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1080 bool Method::is_compiled_lambda_form() const {
1081   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1082 }
1083 
1084 // Test if this method is an internal MH primitive method.
1085 bool Method::is_method_handle_intrinsic() const {
1086   vmIntrinsics::ID iid = intrinsic_id();
1087   return (MethodHandles::is_signature_polymorphic(iid) &&
1088           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1089 }
1090 
1091 bool Method::has_member_arg() const {
1092   vmIntrinsics::ID iid = intrinsic_id();
1093   return (MethodHandles::is_signature_polymorphic(iid) &&
1094           MethodHandles::has_member_arg(iid));
1095 }
1096 
1097 // Make an instance of a signature-polymorphic internal MH primitive.
1098 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1099                                                          Symbol* signature,
1100                                                          TRAPS) {
1101   ResourceMark rm;
1102   methodHandle empty;
1103 
1104   KlassHandle holder = SystemDictionary::MethodHandle_klass();
1105   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1106   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1107   if (TraceMethodHandles) {
1108     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1109   }
1110 
1111   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1112   name->increment_refcount();
1113   signature->increment_refcount();
1114 
1115   int cp_length = _imcp_limit;
1116   ClassLoaderData* loader_data = holder->class_loader_data();
1117   constantPoolHandle cp;
1118   {
1119     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1120     cp = constantPoolHandle(THREAD, cp_oop);
1121   }
1122   cp->set_pool_holder(InstanceKlass::cast(holder()));
1123   cp->symbol_at_put(_imcp_invoke_name,       name);
1124   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1125   cp->set_has_preresolution();
1126 
1127   // decide on access bits:  public or not?
1128   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1129   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1130   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1131   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1132 
1133   methodHandle m;
1134   {
1135     InlineTableSizes sizes;
1136     Method* m_oop = Method::allocate(loader_data, 0,
1137                                      accessFlags_from(flags_bits), &sizes,
1138                                      ConstMethod::NORMAL, CHECK_(empty));
1139     m = methodHandle(THREAD, m_oop);
1140   }
1141   m->set_constants(cp());
1142   m->set_name_index(_imcp_invoke_name);
1143   m->set_signature_index(_imcp_invoke_signature);
1144   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1145   assert(m->signature() == signature, "");
1146   ResultTypeFinder rtf(signature);
1147   m->constMethod()->set_result_type(rtf.type());
1148   m->compute_size_of_parameters(THREAD);
1149   m->init_intrinsic_id();
1150   assert(m->is_method_handle_intrinsic(), "");
1151 #ifdef ASSERT
1152   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1153   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1154   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1155 #endif //ASSERT
1156 
1157   // Finally, set up its entry points.
1158   assert(m->can_be_statically_bound(), "");
1159   m->set_vtable_index(Method::nonvirtual_vtable_index);
1160   m->link_method(m, CHECK_(empty));
1161 
1162   if (TraceMethodHandles && (Verbose || WizardMode))
1163     m->print_on(tty);
1164 
1165   return m;
1166 }
1167 
1168 Klass* Method::check_non_bcp_klass(Klass* klass) {
1169   if (klass != NULL && klass->class_loader() != NULL) {
1170     if (klass->oop_is_objArray())
1171       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1172     return klass;
1173   }
1174   return NULL;
1175 }
1176 
1177 
1178 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
1179                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1180   // Code below does not work for native methods - they should never get rewritten anyway
1181   assert(!m->is_native(), "cannot rewrite native methods");
1182   // Allocate new Method*
1183   AccessFlags flags = m->access_flags();
1184 
1185   ConstMethod* cm = m->constMethod();
1186   int checked_exceptions_len = cm->checked_exceptions_length();
1187   int localvariable_len = cm->localvariable_table_length();
1188   int exception_table_len = cm->exception_table_length();
1189   int method_parameters_len = cm->method_parameters_length();
1190   int method_annotations_len = cm->method_annotations_length();
1191   int parameter_annotations_len = cm->parameter_annotations_length();
1192   int type_annotations_len = cm->type_annotations_length();
1193   int default_annotations_len = cm->default_annotations_length();
1194 
1195   InlineTableSizes sizes(
1196       localvariable_len,
1197       new_compressed_linenumber_size,
1198       exception_table_len,
1199       checked_exceptions_len,
1200       method_parameters_len,
1201       cm->generic_signature_index(),
1202       method_annotations_len,
1203       parameter_annotations_len,
1204       type_annotations_len,
1205       default_annotations_len,
1206       0);
1207 
1208   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1209   Method* newm_oop = Method::allocate(loader_data,
1210                                       new_code_length,
1211                                       flags,
1212                                       &sizes,
1213                                       m->method_type(),
1214                                       CHECK_(methodHandle()));
1215   methodHandle newm (THREAD, newm_oop);
1216   int new_method_size = newm->method_size();
1217 
1218   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1219   ConstMethod* newcm = newm->constMethod();
1220   int new_const_method_size = newm->constMethod()->size();
1221 
1222   memcpy(newm(), m(), sizeof(Method));
1223 
1224   // Create shallow copy of ConstMethod.
1225   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1226 
1227   // Reset correct method/const method, method size, and parameter info
1228   newm->set_constMethod(newcm);
1229   newm->constMethod()->set_code_size(new_code_length);
1230   newm->constMethod()->set_constMethod_size(new_const_method_size);
1231   newm->set_method_size(new_method_size);
1232   assert(newm->code_size() == new_code_length, "check");
1233   assert(newm->method_parameters_length() == method_parameters_len, "check");
1234   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1235   assert(newm->exception_table_length() == exception_table_len, "check");
1236   assert(newm->localvariable_table_length() == localvariable_len, "check");
1237   // Copy new byte codes
1238   memcpy(newm->code_base(), new_code, new_code_length);
1239   // Copy line number table
1240   if (new_compressed_linenumber_size > 0) {
1241     memcpy(newm->compressed_linenumber_table(),
1242            new_compressed_linenumber_table,
1243            new_compressed_linenumber_size);
1244   }
1245   // Copy method_parameters
1246   if (method_parameters_len > 0) {
1247     memcpy(newm->method_parameters_start(),
1248            m->method_parameters_start(),
1249            method_parameters_len * sizeof(MethodParametersElement));
1250   }
1251   // Copy checked_exceptions
1252   if (checked_exceptions_len > 0) {
1253     memcpy(newm->checked_exceptions_start(),
1254            m->checked_exceptions_start(),
1255            checked_exceptions_len * sizeof(CheckedExceptionElement));
1256   }
1257   // Copy exception table
1258   if (exception_table_len > 0) {
1259     memcpy(newm->exception_table_start(),
1260            m->exception_table_start(),
1261            exception_table_len * sizeof(ExceptionTableElement));
1262   }
1263   // Copy local variable number table
1264   if (localvariable_len > 0) {
1265     memcpy(newm->localvariable_table_start(),
1266            m->localvariable_table_start(),
1267            localvariable_len * sizeof(LocalVariableTableElement));
1268   }
1269   // Copy stackmap table
1270   if (m->has_stackmap_table()) {
1271     int code_attribute_length = m->stackmap_data()->length();
1272     Array<u1>* stackmap_data =
1273       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1274     memcpy((void*)stackmap_data->adr_at(0),
1275            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1276     newm->set_stackmap_data(stackmap_data);
1277   }
1278 
1279   // copy annotations over to new method
1280   newcm->copy_annotations_from(cm);
1281   return newm;
1282 }
1283 
1284 vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {
1285   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1286   // because we are not loading from core libraries
1287   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1288   // which does not use the class default class loader so we check for its loader here
1289   InstanceKlass* ik = InstanceKlass::cast(holder);
1290   if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {
1291     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1292   }
1293 
1294   // see if the klass name is well-known:
1295   Symbol* klass_name = ik->name();
1296   return vmSymbols::find_sid(klass_name);
1297 }
1298 
1299 void Method::init_intrinsic_id() {
1300   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1301   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1302   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1303   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1304 
1305   // the klass name is well-known:
1306   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1307   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1308 
1309   // ditto for method and signature:
1310   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1311   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1312       && name_id == vmSymbols::NO_SID)
1313     return;
1314   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1315   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1316       && sig_id == vmSymbols::NO_SID)  return;
1317   jshort flags = access_flags().as_short();
1318 
1319   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1320   if (id != vmIntrinsics::_none) {
1321     set_intrinsic_id(id);
1322     return;
1323   }
1324 
1325   // A few slightly irregular cases:
1326   switch (klass_id) {
1327   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1328     // Second chance: check in regular Math.
1329     switch (name_id) {
1330     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1331     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1332     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1333       // pretend it is the corresponding method in the non-strict class:
1334       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1335       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1336       break;
1337     }
1338     break;
1339 
1340   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.
1341   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1342     if (!is_native())  break;
1343     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1344     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1345       id = vmIntrinsics::_none;
1346     break;
1347   }
1348 
1349   if (id != vmIntrinsics::_none) {
1350     // Set up its iid.  It is an alias method.
1351     set_intrinsic_id(id);
1352     return;
1353   }
1354 }
1355 
1356 // These two methods are static since a GC may move the Method
1357 bool Method::load_signature_classes(methodHandle m, TRAPS) {
1358   if (THREAD->is_Compiler_thread()) {
1359     // There is nothing useful this routine can do from within the Compile thread.
1360     // Hopefully, the signature contains only well-known classes.
1361     // We could scan for this and return true/false, but the caller won't care.
1362     return false;
1363   }
1364   bool sig_is_loaded = true;
1365   Handle class_loader(THREAD, m->method_holder()->class_loader());
1366   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1367   ResourceMark rm(THREAD);
1368   Symbol*  signature = m->signature();
1369   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1370     if (ss.is_object()) {
1371       Symbol* sym = ss.as_symbol(CHECK_(false));
1372       Symbol*  name  = sym;
1373       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1374                                              protection_domain, THREAD);
1375       // We are loading classes eagerly. If a ClassNotFoundException or
1376       // a LinkageError was generated, be sure to ignore it.
1377       if (HAS_PENDING_EXCEPTION) {
1378         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1379             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1380           CLEAR_PENDING_EXCEPTION;
1381         } else {
1382           return false;
1383         }
1384       }
1385       if( klass == NULL) { sig_is_loaded = false; }
1386     }
1387   }
1388   return sig_is_loaded;
1389 }
1390 
1391 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
1392   Handle class_loader(THREAD, m->method_holder()->class_loader());
1393   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1394   ResourceMark rm(THREAD);
1395   Symbol*  signature = m->signature();
1396   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1397     if (ss.type() == T_OBJECT) {
1398       Symbol* name = ss.as_symbol_or_null();
1399       if (name == NULL) return true;
1400       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1401       if (klass == NULL) return true;
1402     }
1403   }
1404   return false;
1405 }
1406 
1407 // Exposed so field engineers can debug VM
1408 void Method::print_short_name(outputStream* st) {
1409   ResourceMark rm;
1410 #ifdef PRODUCT
1411   st->print(" %s::", method_holder()->external_name());
1412 #else
1413   st->print(" %s::", method_holder()->internal_name());
1414 #endif
1415   name()->print_symbol_on(st);
1416   if (WizardMode) signature()->print_symbol_on(st);
1417   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1418     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1419 }
1420 
1421 // Comparer for sorting an object array containing
1422 // Method*s.
1423 static int method_comparator(Method* a, Method* b) {
1424   return a->name()->fast_compare(b->name());
1425 }
1426 
1427 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1428 // default_methods also uses this without the ordering for fast find_method
1429 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1430   int length = methods->length();
1431   if (length > 1) {
1432     {
1433       No_Safepoint_Verifier nsv;
1434       QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);
1435     }
1436     // Reset method ordering
1437     if (set_idnums) {
1438       for (int i = 0; i < length; i++) {
1439         Method* m = methods->at(i);
1440         m->set_method_idnum(i);
1441         m->set_orig_method_idnum(i);
1442       }
1443     }
1444   }
1445 }
1446 
1447 //-----------------------------------------------------------------------------------
1448 // Non-product code unless JVM/TI needs it
1449 
1450 #if !defined(PRODUCT) || INCLUDE_JVMTI
1451 class SignatureTypePrinter : public SignatureTypeNames {
1452  private:
1453   outputStream* _st;
1454   bool _use_separator;
1455 
1456   void type_name(const char* name) {
1457     if (_use_separator) _st->print(", ");
1458     _st->print("%s", name);
1459     _use_separator = true;
1460   }
1461 
1462  public:
1463   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1464     _st = st;
1465     _use_separator = false;
1466   }
1467 
1468   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1469   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1470 };
1471 
1472 
1473 void Method::print_name(outputStream* st) {
1474   Thread *thread = Thread::current();
1475   ResourceMark rm(thread);
1476   SignatureTypePrinter sig(signature(), st);
1477   st->print("%s ", is_static() ? "static" : "virtual");
1478   sig.print_returntype();
1479   st->print(" %s.", method_holder()->internal_name());
1480   name()->print_symbol_on(st);
1481   st->print("(");
1482   sig.print_parameters();
1483   st->print(")");
1484 }
1485 #endif // !PRODUCT || INCLUDE_JVMTI
1486 
1487 
1488 //-----------------------------------------------------------------------------------
1489 // Non-product code
1490 
1491 #ifndef PRODUCT
1492 void Method::print_codes_on(outputStream* st) const {
1493   print_codes_on(0, code_size(), st);
1494 }
1495 
1496 void Method::print_codes_on(int from, int to, outputStream* st) const {
1497   Thread *thread = Thread::current();
1498   ResourceMark rm(thread);
1499   methodHandle mh (thread, (Method*)this);
1500   BytecodeStream s(mh);
1501   s.set_interval(from, to);
1502   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1503   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1504 }
1505 #endif // not PRODUCT
1506 
1507 
1508 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1509 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1510 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1511 // as end-of-stream terminator.
1512 
1513 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1514   // bci and line number does not compress into single byte.
1515   // Write out escape character and use regular compression for bci and line number.
1516   write_byte((jubyte)0xFF);
1517   write_signed_int(bci_delta);
1518   write_signed_int(line_delta);
1519 }
1520 
1521 // See comment in method.hpp which explains why this exists.
1522 #if defined(_M_AMD64) && _MSC_VER >= 1400
1523 #pragma optimize("", off)
1524 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1525   write_pair_inline(bci, line);
1526 }
1527 #pragma optimize("", on)
1528 #endif
1529 
1530 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1531   _bci = 0;
1532   _line = 0;
1533 };
1534 
1535 
1536 bool CompressedLineNumberReadStream::read_pair() {
1537   jubyte next = read_byte();
1538   // Check for terminator
1539   if (next == 0) return false;
1540   if (next == 0xFF) {
1541     // Escape character, regular compression used
1542     _bci  += read_signed_int();
1543     _line += read_signed_int();
1544   } else {
1545     // Single byte compression used
1546     _bci  += next >> 3;
1547     _line += next & 0x7;
1548   }
1549   return true;
1550 }
1551 
1552 
1553 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1554   BreakpointInfo* bp = method_holder()->breakpoints();
1555   for (; bp != NULL; bp = bp->next()) {
1556     if (bp->match(this, bci)) {
1557       return bp->orig_bytecode();
1558     }
1559   }
1560   {
1561     ResourceMark rm;
1562     fatal(err_msg("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci));
1563   }
1564   return Bytecodes::_shouldnotreachhere;
1565 }
1566 
1567 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1568   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1569   BreakpointInfo* bp = method_holder()->breakpoints();
1570   for (; bp != NULL; bp = bp->next()) {
1571     if (bp->match(this, bci)) {
1572       bp->set_orig_bytecode(code);
1573       // and continue, in case there is more than one
1574     }
1575   }
1576 }
1577 
1578 void Method::set_breakpoint(int bci) {
1579   InstanceKlass* ik = method_holder();
1580   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1581   bp->set_next(ik->breakpoints());
1582   ik->set_breakpoints(bp);
1583   // do this last:
1584   bp->set(this);
1585 }
1586 
1587 static void clear_matches(Method* m, int bci) {
1588   InstanceKlass* ik = m->method_holder();
1589   BreakpointInfo* prev_bp = NULL;
1590   BreakpointInfo* next_bp;
1591   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1592     next_bp = bp->next();
1593     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1594     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1595       // do this first:
1596       bp->clear(m);
1597       // unhook it
1598       if (prev_bp != NULL)
1599         prev_bp->set_next(next_bp);
1600       else
1601         ik->set_breakpoints(next_bp);
1602       delete bp;
1603       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1604       // at same location. So we have multiple matching (method_index and bci)
1605       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1606       // breakpoint for clear_breakpoint request and keep all other method versions
1607       // BreakpointInfo for future clear_breakpoint request.
1608       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1609       // which is being called when class is unloaded. We delete all the Breakpoint
1610       // information for all versions of method. We may not correctly restore the original
1611       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1612       // so these methods won't be used anymore.
1613       if (bci >= 0) {
1614         break;
1615       }
1616     } else {
1617       // This one is a keeper.
1618       prev_bp = bp;
1619     }
1620   }
1621 }
1622 
1623 void Method::clear_breakpoint(int bci) {
1624   assert(bci >= 0, "");
1625   clear_matches(this, bci);
1626 }
1627 
1628 void Method::clear_all_breakpoints() {
1629   clear_matches(this, -1);
1630 }
1631 
1632 
1633 int Method::invocation_count() {
1634   MethodCounters *mcs = method_counters();
1635   if (TieredCompilation) {
1636     MethodData* const mdo = method_data();
1637     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1638         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1639       return InvocationCounter::count_limit;
1640     } else {
1641       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1642              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1643     }
1644   } else {
1645     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1646   }
1647 }
1648 
1649 int Method::backedge_count() {
1650   MethodCounters *mcs = method_counters();
1651   if (TieredCompilation) {
1652     MethodData* const mdo = method_data();
1653     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1654         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1655       return InvocationCounter::count_limit;
1656     } else {
1657       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1658              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1659     }
1660   } else {
1661     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1662   }
1663 }
1664 
1665 int Method::highest_comp_level() const {
1666   const MethodCounters* mcs = method_counters();
1667   if (mcs != NULL) {
1668     return mcs->highest_comp_level();
1669   } else {
1670     return CompLevel_none;
1671   }
1672 }
1673 
1674 int Method::highest_osr_comp_level() const {
1675   const MethodCounters* mcs = method_counters();
1676   if (mcs != NULL) {
1677     return mcs->highest_osr_comp_level();
1678   } else {
1679     return CompLevel_none;
1680   }
1681 }
1682 
1683 void Method::set_highest_comp_level(int level) {
1684   MethodCounters* mcs = method_counters();
1685   if (mcs != NULL) {
1686     mcs->set_highest_comp_level(level);
1687   }
1688 }
1689 
1690 void Method::set_highest_osr_comp_level(int level) {
1691   MethodCounters* mcs = method_counters();
1692   if (mcs != NULL) {
1693     mcs->set_highest_osr_comp_level(level);
1694   }
1695 }
1696 
1697 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1698   _bci = bci;
1699   _name_index = m->name_index();
1700   _signature_index = m->signature_index();
1701   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1702   if (_orig_bytecode == Bytecodes::_breakpoint)
1703     _orig_bytecode = m->orig_bytecode_at(_bci);
1704   _next = NULL;
1705 }
1706 
1707 void BreakpointInfo::set(Method* method) {
1708 #ifdef ASSERT
1709   {
1710     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1711     if (code == Bytecodes::_breakpoint)
1712       code = method->orig_bytecode_at(_bci);
1713     assert(orig_bytecode() == code, "original bytecode must be the same");
1714   }
1715 #endif
1716   Thread *thread = Thread::current();
1717   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1718   method->incr_number_of_breakpoints(thread);
1719   SystemDictionary::notice_modification();
1720   {
1721     // Deoptimize all dependents on this method
1722     HandleMark hm(thread);
1723     methodHandle mh(thread, method);
1724     Universe::flush_dependents_on_method(mh);
1725   }
1726 }
1727 
1728 void BreakpointInfo::clear(Method* method) {
1729   *method->bcp_from(_bci) = orig_bytecode();
1730   assert(method->number_of_breakpoints() > 0, "must not go negative");
1731   method->decr_number_of_breakpoints(Thread::current());
1732 }
1733 
1734 // jmethodID handling
1735 
1736 // This is a block allocating object, sort of like JNIHandleBlock, only a
1737 // lot simpler.  There aren't many of these, they aren't long, they are rarely
1738 // deleted and so we can do some suboptimal things.
1739 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1740 // never get rid of it.
1741 // It would be nice to be able to parameterize the number of methods for
1742 // the null_class_loader but then we'd have to turn this and ClassLoaderData
1743 // into templates.
1744 
1745 // I feel like this brain dead class should exist somewhere in the STL
1746 
1747 class JNIMethodBlock : public CHeapObj<mtClass> {
1748   enum { number_of_methods = 8 };
1749 
1750   Method*         _methods[number_of_methods];
1751   int             _top;
1752   JNIMethodBlock* _next;
1753  public:
1754   static Method* const _free_method;
1755 
1756   JNIMethodBlock() : _next(NULL), _top(0) {
1757     for (int i = 0; i< number_of_methods; i++) _methods[i] = _free_method;
1758   }
1759 
1760   Method** add_method(Method* m) {
1761     if (_top < number_of_methods) {
1762       // top points to the next free entry.
1763       int i = _top;
1764       _methods[i] = m;
1765       _top++;
1766       return &_methods[i];
1767     } else if (_top == number_of_methods) {
1768       // if the next free entry ran off the block see if there's a free entry
1769       for (int i = 0; i< number_of_methods; i++) {
1770         if (_methods[i] == _free_method) {
1771           _methods[i] = m;
1772           return &_methods[i];
1773         }
1774       }
1775       // Only check each block once for frees.  They're very unlikely.
1776       // Increment top past the end of the block.
1777       _top++;
1778     }
1779     // need to allocate a next block.
1780     if (_next == NULL) {
1781       _next = new JNIMethodBlock();
1782     }
1783     return _next->add_method(m);
1784   }
1785 
1786   bool contains(Method** m) {
1787     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1788       for (int i = 0; i< number_of_methods; i++) {
1789         if (&(b->_methods[i]) == m) {
1790           return true;
1791         }
1792       }
1793     }
1794     return false;  // not found
1795   }
1796 
1797   // Doesn't really destroy it, just marks it as free so it can be reused.
1798   void destroy_method(Method** m) {
1799 #ifdef ASSERT
1800     assert(contains(m), "should be a methodID");
1801 #endif // ASSERT
1802     *m = _free_method;
1803   }
1804   void clear_method(Method* m) {
1805     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1806       for (int i = 0; i < number_of_methods; i++) {
1807         if (b->_methods[i] == m) {
1808           b->_methods[i] = NULL;
1809           return;
1810         }
1811       }
1812     }
1813     // not found
1814   }
1815 
1816   // During class unloading the methods are cleared, which is different
1817   // than freed.
1818   void clear_all_methods() {
1819     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1820       for (int i = 0; i< number_of_methods; i++) {
1821         b->_methods[i] = NULL;
1822       }
1823     }
1824   }
1825 #ifndef PRODUCT
1826   int count_methods() {
1827     // count all allocated methods
1828     int count = 0;
1829     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1830       for (int i = 0; i< number_of_methods; i++) {
1831         if (b->_methods[i] != _free_method) count++;
1832       }
1833     }
1834     return count;
1835   }
1836 #endif // PRODUCT
1837 };
1838 
1839 // Something that can't be mistaken for an address or a markOop
1840 Method* const JNIMethodBlock::_free_method = (Method*)55;
1841 
1842 // Add a method id to the jmethod_ids
1843 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
1844   ClassLoaderData* cld = loader_data;
1845 
1846   if (!SafepointSynchronize::is_at_safepoint()) {
1847     // Have to add jmethod_ids() to class loader data thread-safely.
1848     // Also have to add the method to the list safely, which the cld lock
1849     // protects as well.
1850     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1851     if (cld->jmethod_ids() == NULL) {
1852       cld->set_jmethod_ids(new JNIMethodBlock());
1853     }
1854     // jmethodID is a pointer to Method*
1855     return (jmethodID)cld->jmethod_ids()->add_method(m);
1856   } else {
1857     // At safepoint, we are single threaded and can set this.
1858     if (cld->jmethod_ids() == NULL) {
1859       cld->set_jmethod_ids(new JNIMethodBlock());
1860     }
1861     // jmethodID is a pointer to Method*
1862     return (jmethodID)cld->jmethod_ids()->add_method(m);
1863   }
1864 }
1865 
1866 // Mark a jmethodID as free.  This is called when there is a data race in
1867 // InstanceKlass while creating the jmethodID cache.
1868 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
1869   ClassLoaderData* cld = loader_data;
1870   Method** ptr = (Method**)m;
1871   assert(cld->jmethod_ids() != NULL, "should have method handles");
1872   cld->jmethod_ids()->destroy_method(ptr);
1873 }
1874 
1875 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
1876   // Can't assert the method_holder is the same because the new method has the
1877   // scratch method holder.
1878   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
1879            == new_method->method_holder()->class_loader(),
1880          "changing to a different class loader");
1881   // Just change the method in place, jmethodID pointer doesn't change.
1882   *((Method**)jmid) = new_method;
1883 }
1884 
1885 bool Method::is_method_id(jmethodID mid) {
1886   Method* m = resolve_jmethod_id(mid);
1887   if (m == NULL) {
1888     return false;
1889   }
1890   InstanceKlass* ik = m->method_holder();
1891   if (ik == NULL) {
1892     return false;
1893   }
1894   ClassLoaderData* cld = ik->class_loader_data();
1895   if (cld->jmethod_ids() == NULL) return false;
1896   return (cld->jmethod_ids()->contains((Method**)mid));
1897 }
1898 
1899 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
1900   if (mid == NULL) return NULL;
1901   if (!Method::is_method_id(mid)) {
1902     return NULL;
1903   }
1904   Method* o = resolve_jmethod_id(mid);
1905   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
1906     return NULL;
1907   }
1908   return o;
1909 };
1910 
1911 void Method::set_on_stack(const bool value) {
1912   // Set both the method itself and its constant pool.  The constant pool
1913   // on stack means some method referring to it is also on the stack.
1914   constants()->set_on_stack(value);
1915 
1916   bool succeeded = _access_flags.set_on_stack(value);
1917   if (value && succeeded) {
1918     MetadataOnStackMark::record(this, Thread::current());
1919   }
1920 }
1921 
1922 void Method::clear_jmethod_id(ClassLoaderData* loader_data) {
1923   loader_data->jmethod_ids()->clear_method(this);
1924 }
1925 
1926 // Called when the class loader is unloaded to make all methods weak.
1927 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
1928   loader_data->jmethod_ids()->clear_all_methods();
1929 }
1930 
1931 bool Method::has_method_vptr(const void* ptr) {
1932   Method m;
1933   // This assumes that the vtbl pointer is the first word of a C++ object.
1934   // This assumption is also in universe.cpp patch_klass_vtble
1935   void* vtbl2 = dereference_vptr((const void*)&m);
1936   void* this_vtbl = dereference_vptr(ptr);
1937   return vtbl2 == this_vtbl;
1938 }
1939 
1940 // Check that this pointer is valid by checking that the vtbl pointer matches
1941 bool Method::is_valid_method() const {
1942   if (this == NULL) {
1943     return false;
1944   } else if (!is_metaspace_object()) {
1945     return false;
1946   } else {
1947     return has_method_vptr((const void*)this);
1948   }
1949 }
1950 
1951 #ifndef PRODUCT
1952 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
1953   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
1954 }
1955 #endif // PRODUCT
1956 
1957 
1958 // Printing
1959 
1960 #ifndef PRODUCT
1961 
1962 void Method::print_on(outputStream* st) const {
1963   ResourceMark rm;
1964   assert(is_method(), "must be method");
1965   st->print_cr("%s", internal_name());
1966   // get the effect of PrintOopAddress, always, for methods:
1967   st->print_cr(" - this oop:          "INTPTR_FORMAT, (intptr_t)this);
1968   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
1969   st->print   (" - constants:         "INTPTR_FORMAT" ", (address)constants());
1970   constants()->print_value_on(st); st->cr();
1971   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
1972   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
1973   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
1974   st->print_cr(" - max stack:         %d",   max_stack());
1975   st->print_cr(" - max locals:        %d",   max_locals());
1976   st->print_cr(" - size of params:    %d",   size_of_parameters());
1977   st->print_cr(" - method size:       %d",   method_size());
1978   if (intrinsic_id() != vmIntrinsics::_none)
1979     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
1980   if (highest_comp_level() != CompLevel_none)
1981     st->print_cr(" - highest level:     %d", highest_comp_level());
1982   st->print_cr(" - vtable index:      %d",   _vtable_index);
1983   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, interpreter_entry());
1984   st->print(   " - adapters:          ");
1985   AdapterHandlerEntry* a = ((Method*)this)->adapter();
1986   if (a == NULL)
1987     st->print_cr(INTPTR_FORMAT, a);
1988   else
1989     a->print_adapter_on(st);
1990   st->print_cr(" - compiled entry     " INTPTR_FORMAT, from_compiled_entry());
1991   st->print_cr(" - code size:         %d",   code_size());
1992   if (code_size() != 0) {
1993     st->print_cr(" - code start:        " INTPTR_FORMAT, code_base());
1994     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, code_base() + code_size());
1995   }
1996   if (method_data() != NULL) {
1997     st->print_cr(" - method data:       " INTPTR_FORMAT, (address)method_data());
1998   }
1999   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2000   if (checked_exceptions_length() > 0) {
2001     CheckedExceptionElement* table = checked_exceptions_start();
2002     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, table);
2003     if (Verbose) {
2004       for (int i = 0; i < checked_exceptions_length(); i++) {
2005         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2006       }
2007     }
2008   }
2009   if (has_linenumber_table()) {
2010     u_char* table = compressed_linenumber_table();
2011     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, table);
2012     if (Verbose) {
2013       CompressedLineNumberReadStream stream(table);
2014       while (stream.read_pair()) {
2015         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2016       }
2017     }
2018   }
2019   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2020   if (localvariable_table_length() > 0) {
2021     LocalVariableTableElement* table = localvariable_table_start();
2022     st->print_cr(" - localvar start:    " INTPTR_FORMAT, table);
2023     if (Verbose) {
2024       for (int i = 0; i < localvariable_table_length(); i++) {
2025         int bci = table[i].start_bci;
2026         int len = table[i].length;
2027         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2028         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2029         int slot = table[i].slot;
2030         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2031       }
2032     }
2033   }
2034   if (code() != NULL) {
2035     st->print   (" - compiled code: ");
2036     code()->print_value_on(st);
2037   }
2038   if (is_native()) {
2039     st->print_cr(" - native function:   " INTPTR_FORMAT, native_function());
2040     st->print_cr(" - signature handler: " INTPTR_FORMAT, signature_handler());
2041   }
2042 }
2043 
2044 #endif //PRODUCT
2045 
2046 void Method::print_value_on(outputStream* st) const {
2047   assert(is_method(), "must be method");
2048   st->print("%s", internal_name());
2049   print_address_on(st);
2050   st->print(" ");
2051   name()->print_value_on(st);
2052   st->print(" ");
2053   signature()->print_value_on(st);
2054   st->print(" in ");
2055   method_holder()->print_value_on(st);
2056   if (WizardMode) st->print("#%d", _vtable_index);
2057   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2058   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2059 }
2060 
2061 #if INCLUDE_SERVICES
2062 // Size Statistics
2063 void Method::collect_statistics(KlassSizeStats *sz) const {
2064   int mysize = sz->count(this);
2065   sz->_method_bytes += mysize;
2066   sz->_method_all_bytes += mysize;
2067   sz->_rw_bytes += mysize;
2068 
2069   if (constMethod()) {
2070     constMethod()->collect_statistics(sz);
2071   }
2072   if (method_data()) {
2073     method_data()->collect_statistics(sz);
2074   }
2075 }
2076 #endif // INCLUDE_SERVICES
2077 
2078 // Verification
2079 
2080 void Method::verify_on(outputStream* st) {
2081   guarantee(is_method(), "object must be method");
2082   guarantee(constants()->is_constantPool(), "should be constant pool");
2083   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2084   MethodData* md = method_data();
2085   guarantee(md == NULL ||
2086       md->is_methodData(), "should be method data");
2087 }