1 /*
   2  * Copyright (c) 1997, 2024, 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 "cds/cdsConfig.hpp"
  27 #include "cds/cppVtables.hpp"
  28 #include "cds/metaspaceShared.hpp"
  29 #include "classfile/classLoader.hpp"
  30 #include "classfile/classLoaderDataGraph.hpp"
  31 #include "classfile/metadataOnStackMark.hpp"
  32 #include "classfile/symbolTable.hpp"
  33 #include "classfile/systemDictionary.hpp"
  34 #include "classfile/vmClasses.hpp"
  35 #include "code/codeCache.hpp"
  36 #include "code/debugInfoRec.hpp"
  37 #include "compiler/compilationPolicy.hpp"
  38 #include "gc/shared/collectedHeap.inline.hpp"
  39 #include "interpreter/bytecodeStream.hpp"
  40 #include "interpreter/bytecodeTracer.hpp"
  41 #include "interpreter/bytecodes.hpp"
  42 #include "interpreter/interpreter.hpp"
  43 #include "interpreter/oopMapCache.hpp"
  44 #include "logging/log.hpp"
  45 #include "logging/logStream.hpp"
  46 #include "logging/logTag.hpp"
  47 #include "memory/allocation.inline.hpp"
  48 #include "memory/metadataFactory.hpp"
  49 #include "memory/metaspaceClosure.hpp"
  50 #include "memory/oopFactory.hpp"
  51 #include "memory/resourceArea.hpp"
  52 #include "memory/universe.hpp"
  53 #include "nmt/memTracker.hpp"
  54 #include "oops/constMethod.hpp"
  55 #include "oops/constantPool.hpp"
  56 #include "oops/klass.inline.hpp"
  57 #include "oops/method.inline.hpp"
  58 #include "oops/methodData.hpp"
  59 #include "oops/objArrayKlass.hpp"
  60 #include "oops/objArrayOop.inline.hpp"
  61 #include "oops/oop.inline.hpp"
  62 #include "oops/symbol.hpp"
  63 #include "prims/jvmtiExport.hpp"
  64 #include "prims/methodHandles.hpp"
  65 #include "runtime/atomic.hpp"
  66 #include "runtime/arguments.hpp"
  67 #include "runtime/continuationEntry.hpp"
  68 #include "runtime/frame.inline.hpp"
  69 #include "runtime/handles.inline.hpp"
  70 #include "runtime/init.hpp"
  71 #include "runtime/java.hpp"
  72 #include "runtime/orderAccess.hpp"
  73 #include "runtime/perfData.hpp"
  74 #include "runtime/relocator.hpp"
  75 #include "runtime/safepointVerifiers.hpp"
  76 #include "runtime/sharedRuntime.hpp"
  77 #include "runtime/signature.hpp"
  78 #include "runtime/threads.hpp"
  79 #include "runtime/vm_version.hpp"
  80 #include "utilities/align.hpp"
  81 #include "utilities/quickSort.hpp"
  82 #include "utilities/vmError.hpp"
  83 #include "utilities/xmlstream.hpp"
  84 
  85 // Implementation of Method
  86 
  87 Method* Method::allocate(ClassLoaderData* loader_data,
  88                          int byte_code_size,
  89                          AccessFlags access_flags,
  90                          InlineTableSizes* sizes,
  91                          ConstMethod::MethodType method_type,
  92                          Symbol* name,
  93                          TRAPS) {
  94   assert(!access_flags.is_native() || byte_code_size == 0,
  95          "native methods should not contain byte codes");
  96   ConstMethod* cm = ConstMethod::allocate(loader_data,
  97                                           byte_code_size,
  98                                           sizes,
  99                                           method_type,
 100                                           CHECK_NULL);
 101   int size = Method::size(access_flags.is_native());
 102   return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, name);
 103 }
 104 
 105 Method::Method(ConstMethod* xconst, AccessFlags access_flags, Symbol* name) {
 106   NoSafepointVerifier no_safepoint;
 107   set_constMethod(xconst);
 108   set_access_flags(access_flags);
 109   set_intrinsic_id(vmIntrinsics::_none);
 110   clear_method_data();
 111   clear_method_counters();
 112   set_vtable_index(Method::garbage_vtable_index);
 113 
 114   // Fix and bury in Method*
 115   set_interpreter_entry(nullptr); // sets i2i entry and from_int
 116   set_adapter_entry(nullptr);
 117   Method::clear_code(); // from_c/from_i get set to c2i/i2i
 118 
 119   if (access_flags.is_native()) {
 120     clear_native_function();
 121     set_signature_handler(nullptr);
 122   }
 123 
 124   NOT_PRODUCT(set_compiled_invocation_count(0);)
 125   // Name is very useful for debugging.
 126   NOT_PRODUCT(_name = name;)
 127 }
 128 
 129 // Release Method*.  The nmethod will be gone when we get here because
 130 // we've walked the code cache.
 131 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 132   MetadataFactory::free_metadata(loader_data, constMethod());
 133   set_constMethod(nullptr);
 134   MetadataFactory::free_metadata(loader_data, method_data());
 135   clear_method_data();
 136   MetadataFactory::free_metadata(loader_data, method_counters());
 137   clear_method_counters();
 138   // The nmethod will be gone when we get here.
 139   if (code() != nullptr) _code = nullptr;
 140 }
 141 
 142 void Method::release_C_heap_structures() {
 143   if (method_data()) {
 144     method_data()->release_C_heap_structures();
 145 
 146     // Destroy MethodData embedded lock
 147     method_data()->~MethodData();
 148   }
 149 }
 150 
 151 address Method::get_i2c_entry() {
 152   assert(adapter() != nullptr, "must have");
 153   return adapter()->get_i2c_entry();
 154 }
 155 
 156 address Method::get_c2i_entry() {
 157   assert(adapter() != nullptr, "must have");
 158   return adapter()->get_c2i_entry();
 159 }
 160 
 161 address Method::get_c2i_unverified_entry() {
 162   assert(adapter() != nullptr, "must have");
 163   return adapter()->get_c2i_unverified_entry();
 164 }
 165 
 166 address Method::get_c2i_no_clinit_check_entry() {
 167   assert(VM_Version::supports_fast_class_init_checks(), "");
 168   assert(adapter() != nullptr, "must have");
 169   return adapter()->get_c2i_no_clinit_check_entry();
 170 }
 171 
 172 char* Method::name_and_sig_as_C_string() const {
 173   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 174 }
 175 
 176 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 177   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 178 }
 179 
 180 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 181   const char* klass_name = klass->external_name();
 182   int klass_name_len  = (int)strlen(klass_name);
 183   int method_name_len = method_name->utf8_length();
 184   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 185   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 186   strcpy(dest, klass_name);
 187   dest[klass_name_len] = '.';
 188   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 189   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 190   dest[len] = 0;
 191   return dest;
 192 }
 193 
 194 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 195   Symbol* klass_name = klass->name();
 196   klass_name->as_klass_external_name(buf, size);
 197   int len = (int)strlen(buf);
 198 
 199   if (len < size - 1) {
 200     buf[len++] = '.';
 201 
 202     method_name->as_C_string(&(buf[len]), size - len);
 203     len = (int)strlen(buf);
 204 
 205     signature->as_C_string(&(buf[len]), size - len);
 206   }
 207 
 208   return buf;
 209 }
 210 
 211 const char* Method::external_name() const {
 212   return external_name(constants()->pool_holder(), name(), signature());
 213 }
 214 
 215 void Method::print_external_name(outputStream *os) const {
 216   print_external_name(os, constants()->pool_holder(), name(), signature());
 217 }
 218 
 219 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
 220   stringStream ss;
 221   print_external_name(&ss, klass, method_name, signature);
 222   return ss.as_string();
 223 }
 224 
 225 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
 226   signature->print_as_signature_external_return_type(os);
 227   os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
 228   signature->print_as_signature_external_parameters(os);
 229   os->print(")");
 230 }
 231 
 232 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
 233   if (log_is_enabled(Debug, exceptions)) {
 234     ResourceMark rm(THREAD);
 235     log_debug(exceptions)("Looking for catch handler for exception of type \"%s\" in method \"%s\"",
 236                           ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string());
 237   }
 238   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 239   // access exception table
 240   ExceptionTable table(mh());
 241   int length = table.length();
 242   // iterate through all entries sequentially
 243   constantPoolHandle pool(THREAD, mh->constants());
 244   for (int i = 0; i < length; i ++) {
 245     //reacquire the table in case a GC happened
 246     ExceptionTable table(mh());
 247     int beg_bci = table.start_pc(i);
 248     int end_bci = table.end_pc(i);
 249     assert(beg_bci <= end_bci, "inconsistent exception table");
 250     log_debug(exceptions)("  - checking exception table entry for BCI %d to %d",
 251                          beg_bci, end_bci);
 252 
 253     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 254       // exception handler bci range covers throw_bci => investigate further
 255       log_debug(exceptions)("    - entry covers throw point BCI %d", throw_bci);
 256 
 257       int handler_bci = table.handler_pc(i);
 258       int klass_index = table.catch_type_index(i);
 259       if (klass_index == 0) {
 260         if (log_is_enabled(Info, exceptions)) {
 261           ResourceMark rm(THREAD);
 262           log_info(exceptions)("Found catch-all handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
 263                                ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
 264         }
 265         return handler_bci;
 266       } else if (ex_klass == nullptr) {
 267         // Is this even possible?
 268         if (log_is_enabled(Info, exceptions)) {
 269           ResourceMark rm(THREAD);
 270           log_info(exceptions)("null exception class is implicitly caught by handler in method \"%s\" at BCI: %d",
 271                                mh()->name()->as_C_string(), handler_bci);
 272         }
 273         return handler_bci;
 274       } else {
 275         if (log_is_enabled(Debug, exceptions)) {
 276           ResourceMark rm(THREAD);
 277           log_debug(exceptions)("    - resolving catch type \"%s\"",
 278                                pool->klass_name_at(klass_index)->as_C_string());
 279         }
 280         // we know the exception class => get the constraint class
 281         // this may require loading of the constraint class; if verification
 282         // fails or some other exception occurs, return handler_bci
 283         Klass* k = pool->klass_at(klass_index, THREAD);
 284         if (HAS_PENDING_EXCEPTION) {
 285           if (log_is_enabled(Debug, exceptions)) {
 286             ResourceMark rm(THREAD);
 287             log_debug(exceptions)("    - exception \"%s\" occurred resolving catch type",
 288                                  PENDING_EXCEPTION->klass()->external_name());
 289           }
 290           return handler_bci;
 291         }
 292         assert(k != nullptr, "klass not loaded");
 293         if (ex_klass->is_subtype_of(k)) {
 294           if (log_is_enabled(Info, exceptions)) {
 295             ResourceMark rm(THREAD);
 296             log_info(exceptions)("Found matching handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
 297                                  ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
 298           }
 299           return handler_bci;
 300         }
 301       }
 302     }
 303   }
 304 
 305   if (log_is_enabled(Debug, exceptions)) {
 306     ResourceMark rm(THREAD);
 307     log_debug(exceptions)("No catch handler found for exception of type \"%s\" in method \"%s\"",
 308                           ex_klass->external_name(), mh->name()->as_C_string());
 309   }
 310 
 311   return -1;
 312 }
 313 
 314 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 315   methodHandle h_this(Thread::current(), this);
 316   mask_for(h_this, bci, mask);
 317 }
 318 
 319 void Method::mask_for(const methodHandle& this_mh, int bci, InterpreterOopMap* mask) {
 320   assert(this_mh() == this, "Sanity");
 321   method_holder()->mask_for(this_mh, bci, mask);
 322 }
 323 
 324 int Method::bci_from(address bcp) const {
 325   if (is_native() && bcp == nullptr) {
 326     return 0;
 327   }
 328   // Do not have a ResourceMark here because AsyncGetCallTrace stack walking code
 329   // may call this after interrupting a nested ResourceMark.
 330   assert((is_native() && bcp == code_base()) || contains(bcp) || VMError::is_error_reported(),
 331          "bcp doesn't belong to this method. bcp: " PTR_FORMAT, p2i(bcp));
 332 
 333   return int(bcp - code_base());
 334 }
 335 
 336 
 337 int Method::validate_bci(int bci) const {
 338   return (bci == 0 || bci < code_size()) ? bci : -1;
 339 }
 340 
 341 // Return bci if it appears to be a valid bcp
 342 // Return -1 otherwise.
 343 // Used by profiling code, when invalid data is a possibility.
 344 // The caller is responsible for validating the Method* itself.
 345 int Method::validate_bci_from_bcp(address bcp) const {
 346   // keep bci as -1 if not a valid bci
 347   int bci = -1;
 348   if (bcp == nullptr || bcp == code_base()) {
 349     // code_size() may return 0 and we allow 0 here
 350     // the method may be native
 351     bci = 0;
 352   } else if (contains(bcp)) {
 353     bci = int(bcp - code_base());
 354   }
 355   // Assert that if we have dodged any asserts, bci is negative.
 356   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 357   return bci;
 358 }
 359 
 360 address Method::bcp_from(int bci) const {
 361   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
 362          "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
 363   address bcp = code_base() + bci;
 364   assert((is_native() && bcp == code_base()) || contains(bcp), "bcp doesn't belong to this method");
 365   return bcp;
 366 }
 367 
 368 address Method::bcp_from(address bcp) const {
 369   if (is_native() && bcp == nullptr) {
 370     return code_base();
 371   } else {
 372     return bcp;
 373   }
 374 }
 375 
 376 int Method::size(bool is_native) {
 377   // If native, then include pointers for native_function and signature_handler
 378   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 379   int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
 380   return align_metadata_size(header_size() + extra_words);
 381 }
 382 
 383 Symbol* Method::klass_name() const {
 384   return method_holder()->name();
 385 }
 386 
 387 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 388   log_trace(cds)("Iter(Method): %p", this);
 389 
 390   if (!method_holder()->is_rewritten()) {
 391     it->push(&_constMethod, MetaspaceClosure::_writable);
 392   } else {
 393     it->push(&_constMethod);
 394   }
 395   it->push(&_method_data);
 396   it->push(&_method_counters);
 397   NOT_PRODUCT(it->push(&_name);)
 398 }
 399 
 400 #if INCLUDE_CDS
 401 // Attempt to return method to original state.  Clear any pointers
 402 // (to objects outside the shared spaces).  We won't be able to predict
 403 // where they should point in a new JVM.  Further initialize some
 404 // entries now in order allow them to be write protected later.
 405 
 406 void Method::remove_unshareable_info() {
 407   unlink_method();
 408   JFR_ONLY(REMOVE_METHOD_ID(this);)
 409 }
 410 
 411 void Method::restore_unshareable_info(TRAPS) {
 412   assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
 413   assert(!queued_for_compilation(), "method's queued_for_compilation flag should not be set");
 414 }
 415 #endif
 416 
 417 void Method::set_vtable_index(int index) {
 418   if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
 419     // At runtime initialize_vtable is rerun as part of link_class_impl()
 420     // for a shared class loaded by the non-boot loader to obtain the loader
 421     // constraints based on the runtime classloaders' context.
 422     return; // don't write into the shared class
 423   } else {
 424     _vtable_index = index;
 425   }
 426 }
 427 
 428 void Method::set_itable_index(int index) {
 429   if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
 430     // At runtime initialize_itable is rerun as part of link_class_impl()
 431     // for a shared class loaded by the non-boot loader to obtain the loader
 432     // constraints based on the runtime classloaders' context. The dumptime
 433     // itable index should be the same as the runtime index.
 434     assert(_vtable_index == itable_index_max - index,
 435            "archived itable index is different from runtime index");
 436     return; // don’t write into the shared class
 437   } else {
 438     _vtable_index = itable_index_max - index;
 439   }
 440   assert(valid_itable_index(), "");
 441 }
 442 
 443 // The RegisterNatives call being attempted tried to register with a method that
 444 // is not native.  Ask JVM TI what prefixes have been specified.  Then check
 445 // to see if the native method is now wrapped with the prefixes.  See the
 446 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
 447 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
 448 #if INCLUDE_JVMTI
 449   ResourceMark rm(THREAD);
 450   Method* method;
 451   int name_len = name->utf8_length();
 452   char* name_str = name->as_utf8();
 453   int prefix_count;
 454   char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
 455   for (int i = 0; i < prefix_count; i++) {
 456     char* prefix = prefixes[i];
 457     int prefix_len = (int)strlen(prefix);
 458 
 459     // try adding this prefix to the method name and see if it matches another method name
 460     int trial_len = name_len + prefix_len;
 461     char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
 462     strcpy(trial_name_str, prefix);
 463     strcat(trial_name_str, name_str);
 464     TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
 465     if (trial_name == nullptr) {
 466       continue; // no such symbol, so this prefix wasn't used, try the next prefix
 467     }
 468     method = k->lookup_method(trial_name, signature);
 469     if (method == nullptr) {
 470       continue; // signature doesn't match, try the next prefix
 471     }
 472     if (method->is_native()) {
 473       method->set_is_prefixed_native();
 474       return method; // wahoo, we found a prefixed version of the method, return it
 475     }
 476     // found as non-native, so prefix is good, add it, probably just need more prefixes
 477     name_len = trial_len;
 478     name_str = trial_name_str;
 479   }
 480 #endif // INCLUDE_JVMTI
 481   return nullptr; // not found
 482 }
 483 
 484 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
 485   Method* method = k->lookup_method(name, signature);
 486   if (method == nullptr) {
 487     ResourceMark rm(THREAD);
 488     stringStream st;
 489     st.print("Method '");
 490     print_external_name(&st, k, name, signature);
 491     st.print("' name or signature does not match");
 492     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
 493   }
 494   if (!method->is_native()) {
 495     // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
 496     method = find_prefixed_native(k, name, signature, THREAD);
 497     if (method == nullptr) {
 498       ResourceMark rm(THREAD);
 499       stringStream st;
 500       st.print("Method '");
 501       print_external_name(&st, k, name, signature);
 502       st.print("' is not declared as native");
 503       THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
 504     }
 505   }
 506 
 507   if (entry != nullptr) {
 508     method->set_native_function(entry, native_bind_event_is_interesting);
 509   } else {
 510     method->clear_native_function();
 511   }
 512   if (log_is_enabled(Debug, jni, resolve)) {
 513     ResourceMark rm(THREAD);
 514     log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
 515                             method->method_holder()->external_name(),
 516                             method->name()->as_C_string());
 517   }
 518   return true;
 519 }
 520 
 521 bool Method::was_executed_more_than(int n) {
 522   // Invocation counter is reset when the Method* is compiled.
 523   // If the method has compiled code we therefore assume it has
 524   // be executed more than n times.
 525   if (is_accessor() || is_empty_method() || (code() != nullptr)) {
 526     // interpreter doesn't bump invocation counter of trivial methods
 527     // compiler does not bump invocation counter of compiled methods
 528     return true;
 529   }
 530   else if ((method_counters() != nullptr &&
 531             method_counters()->invocation_counter()->carry()) ||
 532            (method_data() != nullptr &&
 533             method_data()->invocation_counter()->carry())) {
 534     // The carry bit is set when the counter overflows and causes
 535     // a compilation to occur.  We don't know how many times
 536     // the counter has been reset, so we simply assume it has
 537     // been executed more than n times.
 538     return true;
 539   } else {
 540     return invocation_count() > n;
 541   }
 542 }
 543 
 544 void Method::print_invocation_count(outputStream* st) {
 545   //---<  compose+print method return type, klass, name, and signature  >---
 546   if (is_static())       { st->print("static "); }
 547   if (is_final())        { st->print("final "); }
 548   if (is_synchronized()) { st->print("synchronized "); }
 549   if (is_native())       { st->print("native "); }
 550   st->print("%s::", method_holder()->external_name());
 551   name()->print_symbol_on(st);
 552   signature()->print_symbol_on(st);
 553 
 554   if (WizardMode) {
 555     // dump the size of the byte codes
 556     st->print(" {%d}", code_size());
 557   }
 558   st->cr();
 559 
 560   // Counting based on signed int counters tends to overflow with
 561   // longer-running workloads on fast machines. The counters under
 562   // consideration here, however, are limited in range by counting
 563   // logic. See InvocationCounter:count_limit for example.
 564   // No "overflow precautions" need to be implemented here.
 565   st->print_cr ("  interpreter_invocation_count: " INT32_FORMAT_W(11), interpreter_invocation_count());
 566   st->print_cr ("  invocation_counter:           " INT32_FORMAT_W(11), invocation_count());
 567   st->print_cr ("  backedge_counter:             " INT32_FORMAT_W(11), backedge_count());
 568 
 569   if (method_data() != nullptr) {
 570     st->print_cr ("  decompile_count:              " UINT32_FORMAT_W(11), method_data()->decompile_count());
 571   }
 572 
 573 #ifndef PRODUCT
 574   if (CountCompiledCalls) {
 575     st->print_cr ("  compiled_invocation_count:    " INT64_FORMAT_W(11), compiled_invocation_count());
 576   }
 577 #endif
 578 }
 579 
 580 // Build a MethodData* object to hold profiling information collected on this
 581 // method when requested.
 582 void Method::build_profiling_method_data(const methodHandle& method, TRAPS) {
 583   // Do not profile the method if metaspace has hit an OOM previously
 584   // allocating profiling data. Callers clear pending exception so don't
 585   // add one here.
 586   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 587     return;
 588   }
 589 
 590   ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 591   MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 592   if (HAS_PENDING_EXCEPTION) {
 593     CompileBroker::log_metaspace_failure();
 594     ClassLoaderDataGraph::set_metaspace_oom(true);
 595     return;   // return the exception (which is cleared)
 596   }
 597 
 598   if (!Atomic::replace_if_null(&method->_method_data, method_data)) {
 599     MetadataFactory::free_metadata(loader_data, method_data);
 600     return;
 601   }
 602 
 603   if (PrintMethodData && (Verbose || WizardMode)) {
 604     ResourceMark rm(THREAD);
 605     tty->print("build_profiling_method_data for ");
 606     method->print_name(tty);
 607     tty->cr();
 608     // At the end of the run, the MDO, full of data, will be dumped.
 609   }
 610 }
 611 
 612 MethodCounters* Method::build_method_counters(Thread* current, Method* m) {
 613   // Do not profile the method if metaspace has hit an OOM previously
 614   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 615     return nullptr;
 616   }
 617 
 618   methodHandle mh(current, m);
 619   MethodCounters* counters;
 620   if (current->is_Java_thread()) {
 621     JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
 622     // Use the TRAPS version for a JavaThread so it will adjust the GC threshold
 623     // if needed.
 624     counters = MethodCounters::allocate_with_exception(mh, THREAD);
 625     if (HAS_PENDING_EXCEPTION) {
 626       CLEAR_PENDING_EXCEPTION;
 627     }
 628   } else {
 629     // Call metaspace allocation that doesn't throw exception if the
 630     // current thread isn't a JavaThread, ie. the VMThread.
 631     counters = MethodCounters::allocate_no_exception(mh);
 632   }
 633 
 634   if (counters == nullptr) {
 635     CompileBroker::log_metaspace_failure();
 636     ClassLoaderDataGraph::set_metaspace_oom(true);
 637     return nullptr;
 638   }
 639 
 640   if (!mh->init_method_counters(counters)) {
 641     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 642   }
 643 
 644   return mh->method_counters();
 645 }
 646 
 647 bool Method::init_method_counters(MethodCounters* counters) {
 648   // Try to install a pointer to MethodCounters, return true on success.
 649   return Atomic::replace_if_null(&_method_counters, counters);
 650 }
 651 
 652 void Method::set_exception_handler_entered(int handler_bci) {
 653   if (ProfileExceptionHandlers) {
 654     MethodData* mdo = method_data();
 655     if (mdo != nullptr) {
 656       BitData handler_data = mdo->exception_handler_bci_to_data(handler_bci);
 657       handler_data.set_exception_handler_entered();
 658     }
 659   }
 660 }
 661 
 662 int Method::extra_stack_words() {
 663   // not an inline function, to avoid a header dependency on Interpreter
 664   return extra_stack_entries() * Interpreter::stackElementSize;
 665 }
 666 
 667 bool Method::compute_has_loops_flag() {
 668   BytecodeStream bcs(methodHandle(Thread::current(), this));
 669   Bytecodes::Code bc;
 670 
 671   while ((bc = bcs.next()) >= 0) {
 672     switch (bc) {
 673       case Bytecodes::_ifeq:
 674       case Bytecodes::_ifnull:
 675       case Bytecodes::_iflt:
 676       case Bytecodes::_ifle:
 677       case Bytecodes::_ifne:
 678       case Bytecodes::_ifnonnull:
 679       case Bytecodes::_ifgt:
 680       case Bytecodes::_ifge:
 681       case Bytecodes::_if_icmpeq:
 682       case Bytecodes::_if_icmpne:
 683       case Bytecodes::_if_icmplt:
 684       case Bytecodes::_if_icmpgt:
 685       case Bytecodes::_if_icmple:
 686       case Bytecodes::_if_icmpge:
 687       case Bytecodes::_if_acmpeq:
 688       case Bytecodes::_if_acmpne:
 689       case Bytecodes::_goto:
 690       case Bytecodes::_jsr:
 691         if (bcs.dest() < bcs.next_bci()) {
 692           return set_has_loops();
 693         }
 694         break;
 695 
 696       case Bytecodes::_goto_w:
 697       case Bytecodes::_jsr_w:
 698         if (bcs.dest_w() < bcs.next_bci()) {
 699           return set_has_loops();
 700         }
 701         break;
 702 
 703       case Bytecodes::_lookupswitch: {
 704         Bytecode_lookupswitch lookupswitch(this, bcs.bcp());
 705         if (lookupswitch.default_offset() < 0) {
 706           return set_has_loops();
 707         } else {
 708           for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) {
 709             LookupswitchPair pair = lookupswitch.pair_at(i);
 710             if (pair.offset() < 0) {
 711               return set_has_loops();
 712             }
 713           }
 714         }
 715         break;
 716       }
 717       case Bytecodes::_tableswitch: {
 718         Bytecode_tableswitch tableswitch(this, bcs.bcp());
 719         if (tableswitch.default_offset() < 0) {
 720           return set_has_loops();
 721         } else {
 722           for (int i = 0; i < tableswitch.length(); ++i) {
 723             if (tableswitch.dest_offset_at(i) < 0) {
 724               return set_has_loops();
 725             }
 726           }
 727         }
 728         break;
 729       }
 730       default:
 731         break;
 732     }
 733   }
 734 
 735   _flags.set_has_loops_flag_init(true);
 736   return false;
 737 }
 738 
 739 bool Method::is_final_method(AccessFlags class_access_flags) const {
 740   // or "does_not_require_vtable_entry"
 741   // default method or overpass can occur, is not final (reuses vtable entry)
 742   // private methods in classes get vtable entries for backward class compatibility.
 743   if (is_overpass() || is_default_method())  return false;
 744   return is_final() || class_access_flags.is_final();
 745 }
 746 
 747 bool Method::is_final_method() const {
 748   return is_final_method(method_holder()->access_flags());
 749 }
 750 
 751 bool Method::is_default_method() const {
 752   if (method_holder() != nullptr &&
 753       method_holder()->is_interface() &&
 754       !is_abstract() && !is_private()) {
 755     return true;
 756   } else {
 757     return false;
 758   }
 759 }
 760 
 761 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 762   if (is_final_method(class_access_flags))  return true;
 763 #ifdef ASSERT
 764   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 765   if (class_access_flags.is_interface()) {
 766       ResourceMark rm;
 767       assert(is_nonv == is_static() || is_nonv == is_private(),
 768              "nonvirtual unexpected for non-static, non-private: %s",
 769              name_and_sig_as_C_string());
 770   }
 771 #endif
 772   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 773   return vtable_index() == nonvirtual_vtable_index;
 774 }
 775 
 776 bool Method::can_be_statically_bound() const {
 777   return can_be_statically_bound(method_holder()->access_flags());
 778 }
 779 
 780 bool Method::can_be_statically_bound(InstanceKlass* context) const {
 781   return (method_holder() == context) && can_be_statically_bound();
 782 }
 783 
 784 /**
 785  *  Returns false if this is one of specially treated methods for
 786  *  which we have to provide stack trace in throw in compiled code.
 787  *  Returns true otherwise.
 788  */
 789 bool Method::can_omit_stack_trace() {
 790   if (klass_name() == vmSymbols::sun_invoke_util_ValueConversions()) {
 791     return false; // All methods in sun.invoke.util.ValueConversions
 792   }
 793   return true;
 794 }
 795 
 796 bool Method::is_accessor() const {
 797   return is_getter() || is_setter();
 798 }
 799 
 800 bool Method::is_getter() const {
 801   if (code_size() != 5) return false;
 802   if (size_of_parameters() != 1) return false;
 803   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 804   if (java_code_at(1) != Bytecodes::_getfield) return false;
 805   switch (java_code_at(4)) {
 806     case Bytecodes::_ireturn:
 807     case Bytecodes::_lreturn:
 808     case Bytecodes::_freturn:
 809     case Bytecodes::_dreturn:
 810     case Bytecodes::_areturn:
 811       break;
 812     default:
 813       return false;
 814   }
 815   return true;
 816 }
 817 
 818 bool Method::is_setter() const {
 819   if (code_size() != 6) return false;
 820   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 821   switch (java_code_at(1)) {
 822     case Bytecodes::_iload_1:
 823     case Bytecodes::_aload_1:
 824     case Bytecodes::_fload_1:
 825       if (size_of_parameters() != 2) return false;
 826       break;
 827     case Bytecodes::_dload_1:
 828     case Bytecodes::_lload_1:
 829       if (size_of_parameters() != 3) return false;
 830       break;
 831     default:
 832       return false;
 833   }
 834   if (java_code_at(2) != Bytecodes::_putfield) return false;
 835   if (java_code_at(5) != Bytecodes::_return)   return false;
 836   return true;
 837 }
 838 
 839 bool Method::is_constant_getter() const {
 840   int last_index = code_size() - 1;
 841   // Check if the first 1-3 bytecodes are a constant push
 842   // and the last bytecode is a return.
 843   return (2 <= code_size() && code_size() <= 4 &&
 844           Bytecodes::is_const(java_code_at(0)) &&
 845           Bytecodes::length_for(java_code_at(0)) == last_index &&
 846           Bytecodes::is_return(java_code_at(last_index)));
 847 }
 848 
 849 bool Method::has_valid_initializer_flags() const {
 850   return (is_static() ||
 851           method_holder()->major_version() < 51);
 852 }
 853 
 854 bool Method::is_static_initializer() const {
 855   // For classfiles version 51 or greater, ensure that the clinit method is
 856   // static.  Non-static methods with the name "<clinit>" are not static
 857   // initializers. (older classfiles exempted for backward compatibility)
 858   return name() == vmSymbols::class_initializer_name() &&
 859          has_valid_initializer_flags();
 860 }
 861 
 862 bool Method::is_object_initializer() const {
 863    return name() == vmSymbols::object_initializer_name();
 864 }
 865 
 866 bool Method::needs_clinit_barrier() const {
 867   return is_static() && !method_holder()->is_initialized();
 868 }
 869 
 870 bool Method::is_object_wait0() const {
 871   return klass_name() == vmSymbols::java_lang_Object()
 872          && name() == vmSymbols::wait_name();
 873 }
 874 
 875 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 876   int length = method->checked_exceptions_length();
 877   if (length == 0) {  // common case
 878     return objArrayHandle(THREAD, Universe::the_empty_class_array());
 879   } else {
 880     methodHandle h_this(THREAD, method);
 881     objArrayOop m_oop = oopFactory::new_objArray(vmClasses::Class_klass(), length, CHECK_(objArrayHandle()));
 882     objArrayHandle mirrors (THREAD, m_oop);
 883     for (int i = 0; i < length; i++) {
 884       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 885       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 886       if (log_is_enabled(Warning, exceptions) &&
 887           !k->is_subclass_of(vmClasses::Throwable_klass())) {
 888         ResourceMark rm(THREAD);
 889         log_warning(exceptions)(
 890           "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
 891           k->external_name(), method->external_name());
 892       }
 893       mirrors->obj_at_put(i, k->java_mirror());
 894     }
 895     return mirrors;
 896   }
 897 };
 898 
 899 
 900 int Method::line_number_from_bci(int bci) const {
 901   int best_bci  =  0;
 902   int best_line = -1;
 903   if (bci == SynchronizationEntryBCI) bci = 0;
 904   if (0 <= bci && bci < code_size() && has_linenumber_table()) {
 905     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 906     // Not necessarily sorted and not necessarily one-to-one.
 907     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 908     while (stream.read_pair()) {
 909       if (stream.bci() == bci) {
 910         // perfect match
 911         return stream.line();
 912       } else {
 913         // update best_bci/line
 914         if (stream.bci() < bci && stream.bci() >= best_bci) {
 915           best_bci  = stream.bci();
 916           best_line = stream.line();
 917         }
 918       }
 919     }
 920   }
 921   return best_line;
 922 }
 923 
 924 
 925 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 926   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 927     Thread *thread = Thread::current();
 928     Symbol* klass_name = constants()->klass_name_at(klass_index);
 929     Handle loader(thread, method_holder()->class_loader());
 930     Handle prot  (thread, method_holder()->protection_domain());
 931     return SystemDictionary::find_instance_klass(thread, klass_name, loader, prot) != nullptr;
 932   } else {
 933     return true;
 934   }
 935 }
 936 
 937 
 938 bool Method::is_klass_loaded(int refinfo_index, Bytecodes::Code bc, bool must_be_resolved) const {
 939   int klass_index = constants()->klass_ref_index_at(refinfo_index, bc);
 940   if (must_be_resolved) {
 941     // Make sure klass is resolved in constantpool.
 942     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 943   }
 944   return is_klass_loaded_by_klass_index(klass_index);
 945 }
 946 
 947 
 948 void Method::set_native_function(address function, bool post_event_flag) {
 949   assert(function != nullptr, "use clear_native_function to unregister natives");
 950   assert(!is_special_native_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 951   address* native_function = native_function_addr();
 952 
 953   // We can see racers trying to place the same native function into place. Once
 954   // is plenty.
 955   address current = *native_function;
 956   if (current == function) return;
 957   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 958       function != nullptr) {
 959     // native_method_throw_unsatisfied_link_error_entry() should only
 960     // be passed when post_event_flag is false.
 961     assert(function !=
 962       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 963       "post_event_flag mismatch");
 964 
 965     // post the bind event, and possible change the bind function
 966     JvmtiExport::post_native_method_bind(this, &function);
 967   }
 968   *native_function = function;
 969   // This function can be called more than once. We must make sure that we always
 970   // use the latest registered method -> check if a stub already has been generated.
 971   // If so, we have to make it not_entrant.
 972   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
 973   if (nm != nullptr) {
 974     nm->make_not_entrant();
 975   }
 976 }
 977 
 978 
 979 bool Method::has_native_function() const {
 980   if (is_special_native_intrinsic())
 981     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 982   address func = native_function();
 983   return (func != nullptr && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 984 }
 985 
 986 
 987 void Method::clear_native_function() {
 988   // Note: is_method_handle_intrinsic() is allowed here.
 989   set_native_function(
 990     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 991     !native_bind_event_is_interesting);
 992   this->unlink_code();
 993 }
 994 
 995 
 996 void Method::set_signature_handler(address handler) {
 997   address* signature_handler =  signature_handler_addr();
 998   *signature_handler = handler;
 999 }
1000 
1001 
1002 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
1003   assert(reason != nullptr, "must provide a reason");
1004   if (PrintCompilation && report) {
1005     ttyLocker ttyl;
1006     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
1007     if (comp_level == CompLevel_all) {
1008       tty->print("all levels ");
1009     } else {
1010       tty->print("level %d ", comp_level);
1011     }
1012     this->print_short_name(tty);
1013     int size = this->code_size();
1014     if (size > 0) {
1015       tty->print(" (%d bytes)", size);
1016     }
1017     if (reason != nullptr) {
1018       tty->print("   %s", reason);
1019     }
1020     tty->cr();
1021   }
1022   if ((TraceDeoptimization || LogCompilation) && (xtty != nullptr)) {
1023     ttyLocker ttyl;
1024     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
1025                      os::current_thread_id(), is_osr, comp_level);
1026     if (reason != nullptr) {
1027       xtty->print(" reason=\'%s\'", reason);
1028     }
1029     xtty->method(this);
1030     xtty->stamp();
1031     xtty->end_elem();
1032   }
1033 }
1034 
1035 bool Method::is_always_compilable() const {
1036   // Generated adapters must be compiled
1037   if (is_special_native_intrinsic() && is_synthetic()) {
1038     assert(!is_not_c1_compilable(), "sanity check");
1039     assert(!is_not_c2_compilable(), "sanity check");
1040     return true;
1041   }
1042 
1043   return false;
1044 }
1045 
1046 bool Method::is_not_compilable(int comp_level) const {
1047   if (number_of_breakpoints() > 0)
1048     return true;
1049   if (is_always_compilable())
1050     return false;
1051   if (comp_level == CompLevel_any)
1052     return is_not_c1_compilable() && is_not_c2_compilable();
1053   if (is_c1_compile(comp_level))
1054     return is_not_c1_compilable();
1055   if (is_c2_compile(comp_level))
1056     return is_not_c2_compilable();
1057   return false;
1058 }
1059 
1060 // call this when compiler finds that this method is not compilable
1061 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
1062   if (is_always_compilable()) {
1063     // Don't mark a method which should be always compilable
1064     return;
1065   }
1066   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
1067   if (comp_level == CompLevel_all) {
1068     set_is_not_c1_compilable();
1069     set_is_not_c2_compilable();
1070   } else {
1071     if (is_c1_compile(comp_level))
1072       set_is_not_c1_compilable();
1073     if (is_c2_compile(comp_level))
1074       set_is_not_c2_compilable();
1075   }
1076   assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1077 }
1078 
1079 bool Method::is_not_osr_compilable(int comp_level) const {
1080   if (is_not_compilable(comp_level))
1081     return true;
1082   if (comp_level == CompLevel_any)
1083     return is_not_c1_osr_compilable() && is_not_c2_osr_compilable();
1084   if (is_c1_compile(comp_level))
1085     return is_not_c1_osr_compilable();
1086   if (is_c2_compile(comp_level))
1087     return is_not_c2_osr_compilable();
1088   return false;
1089 }
1090 
1091 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1092   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1093   if (comp_level == CompLevel_all) {
1094     set_is_not_c1_osr_compilable();
1095     set_is_not_c2_osr_compilable();
1096   } else {
1097     if (is_c1_compile(comp_level))
1098       set_is_not_c1_osr_compilable();
1099     if (is_c2_compile(comp_level))
1100       set_is_not_c2_osr_compilable();
1101   }
1102   assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1103 }
1104 
1105 // Revert to using the interpreter and clear out the nmethod
1106 void Method::clear_code() {
1107   // this may be null if c2i adapters have not been made yet
1108   // Only should happen at allocate time.
1109   if (adapter() == nullptr) {
1110     _from_compiled_entry    = nullptr;
1111   } else {
1112     _from_compiled_entry    = adapter()->get_c2i_entry();
1113   }
1114   OrderAccess::storestore();
1115   _from_interpreted_entry = _i2i_entry;
1116   OrderAccess::storestore();
1117   _code = nullptr;
1118 }
1119 
1120 void Method::unlink_code(nmethod *compare) {
1121   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
1122   // We need to check if either the _code or _from_compiled_code_entry_point
1123   // refer to this nmethod because there is a race in setting these two fields
1124   // in Method* as seen in bugid 4947125.
1125   if (code() == compare ||
1126       from_compiled_entry() == compare->verified_entry_point()) {
1127     clear_code();
1128   }
1129 }
1130 
1131 void Method::unlink_code() {
1132   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
1133   clear_code();
1134 }
1135 
1136 #if INCLUDE_CDS
1137 // Called by class data sharing to remove any entry points (which are not shared)
1138 void Method::unlink_method() {
1139   assert(CDSConfig::is_dumping_archive(), "sanity");
1140   _code = nullptr;
1141   _adapter = nullptr;
1142   _i2i_entry = nullptr;
1143   _from_compiled_entry = nullptr;
1144   _from_interpreted_entry = nullptr;
1145 
1146   if (is_native()) {
1147     *native_function_addr() = nullptr;
1148     set_signature_handler(nullptr);
1149   }
1150   NOT_PRODUCT(set_compiled_invocation_count(0);)
1151 
1152   clear_method_data();
1153   clear_method_counters();
1154   remove_unshareable_flags();
1155 }
1156 
1157 void Method::remove_unshareable_flags() {
1158   // clear all the flags that shouldn't be in the archived version
1159   assert(!is_old(), "must be");
1160   assert(!is_obsolete(), "must be");
1161   assert(!is_deleted(), "must be");
1162 
1163   set_is_prefixed_native(false);
1164   set_queued_for_compilation(false);
1165   set_is_not_c2_compilable(false);
1166   set_is_not_c1_compilable(false);
1167   set_is_not_c2_osr_compilable(false);
1168   set_on_stack_flag(false);
1169 }
1170 #endif
1171 
1172 // Called when the method_holder is getting linked. Setup entrypoints so the method
1173 // is ready to be called from interpreter, compiler, and vtables.
1174 void Method::link_method(const methodHandle& h_method, TRAPS) {
1175   if (log_is_enabled(Info, perf, class, link)) {
1176     ClassLoader::perf_ik_link_methods_count()->inc();
1177   }
1178 
1179   // If the code cache is full, we may reenter this function for the
1180   // leftover methods that weren't linked.
1181   if (adapter() != nullptr) {
1182     return;
1183   }
1184   assert( _code == nullptr, "nothing compiled yet" );
1185 
1186   // Setup interpreter entrypoint
1187   assert(this == h_method(), "wrong h_method()" );
1188 
1189   assert(adapter() == nullptr, "init'd to null");
1190   address entry = Interpreter::entry_for_method(h_method);
1191   assert(entry != nullptr, "interpreter entry must be non-null");
1192   // Sets both _i2i_entry and _from_interpreted_entry
1193   set_interpreter_entry(entry);
1194 
1195   // Don't overwrite already registered native entries.
1196   if (is_native() && !has_native_function()) {
1197     set_native_function(
1198       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1199       !native_bind_event_is_interesting);
1200   }
1201 
1202   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1203   // special handling of vtables.  An alternative is to make adapters more
1204   // lazily by calling make_adapter() from from_compiled_entry() for the
1205   // normal calls.  For vtable calls life gets more complicated.  When a
1206   // call-site goes mega-morphic we need adapters in all methods which can be
1207   // called from the vtable.  We need adapters on such methods that get loaded
1208   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1209   // problem we'll make these lazily later.
1210   (void) make_adapters(h_method, CHECK);
1211 
1212   // ONLY USE the h_method now as make_adapter may have blocked
1213 
1214   if (h_method->is_continuation_native_intrinsic()) {
1215     _from_interpreted_entry = nullptr;
1216     _from_compiled_entry = nullptr;
1217     _i2i_entry = nullptr;
1218     if (Continuations::enabled()) {
1219       assert(!Threads::is_vm_complete(), "should only be called during vm init");
1220       AdapterHandlerLibrary::create_native_wrapper(h_method);
1221       if (!h_method->has_compiled_code()) {
1222         THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Initial size of CodeCache is too small");
1223       }
1224       assert(_from_interpreted_entry == get_i2c_entry(), "invariant");
1225     }
1226   }
1227 }
1228 
1229 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1230   PerfTraceTime timer(ClassLoader::perf_method_adapters_time());
1231 
1232   // Adapters for compiled code are made eagerly here.  They are fairly
1233   // small (generally < 100 bytes) and quick to make (and cached and shared)
1234   // so making them eagerly shouldn't be too expensive.
1235   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1236   if (adapter == nullptr ) {
1237     if (!is_init_completed()) {
1238       // Don't throw exceptions during VM initialization because java.lang.* classes
1239       // might not have been initialized, causing problems when constructing the
1240       // Java exception object.
1241       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1242     } else {
1243       THROW_MSG_NULL(vmSymbols::java_lang_OutOfMemoryError(), "Out of space in CodeCache for adapters");
1244     }
1245   }
1246 
1247   mh->set_adapter_entry(adapter);
1248   mh->_from_compiled_entry = adapter->get_c2i_entry();
1249   return adapter->get_c2i_entry();
1250 }
1251 
1252 // The verified_code_entry() must be called when a invoke is resolved
1253 // on this method.
1254 
1255 // It returns the compiled code entry point, after asserting not null.
1256 // This function is called after potential safepoints so that nmethod
1257 // or adapter that it points to is still live and valid.
1258 // This function must not hit a safepoint!
1259 address Method::verified_code_entry() {
1260   debug_only(NoSafepointVerifier nsv;)
1261   assert(_from_compiled_entry != nullptr, "must be set");
1262   return _from_compiled_entry;
1263 }
1264 
1265 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1266 // (could be racing a deopt).
1267 // Not inline to avoid circular ref.
1268 bool Method::check_code() const {
1269   // cached in a register or local.  There's a race on the value of the field.
1270   nmethod *code = Atomic::load_acquire(&_code);
1271   return code == nullptr || (code->method() == nullptr) || (code->method() == (Method*)this && !code->is_osr_method());
1272 }
1273 
1274 // Install compiled code.  Instantly it can execute.
1275 void Method::set_code(const methodHandle& mh, nmethod *code) {
1276   assert_lock_strong(NMethodState_lock);
1277   assert( code, "use clear_code to remove code" );
1278   assert( mh->check_code(), "" );
1279 
1280   guarantee(mh->adapter() != nullptr, "Adapter blob must already exist!");
1281 
1282   // These writes must happen in this order, because the interpreter will
1283   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1284   // which jumps to _from_compiled_entry.
1285   mh->_code = code;             // Assign before allowing compiled code to exec
1286 
1287   int comp_level = code->comp_level();
1288   // In theory there could be a race here. In practice it is unlikely
1289   // and not worth worrying about.
1290   if (comp_level > mh->highest_comp_level()) {
1291     mh->set_highest_comp_level(comp_level);
1292   }
1293 
1294   OrderAccess::storestore();
1295   mh->_from_compiled_entry = code->verified_entry_point();
1296   OrderAccess::storestore();
1297 
1298   if (mh->is_continuation_native_intrinsic()) {
1299     assert(mh->_from_interpreted_entry == nullptr, "initialized incorrectly"); // see link_method
1300 
1301     if (mh->is_continuation_enter_intrinsic()) {
1302       // This is the entry used when we're in interpreter-only mode; see InterpreterMacroAssembler::jump_from_interpreted
1303       mh->_i2i_entry = ContinuationEntry::interpreted_entry();
1304     } else if (mh->is_continuation_yield_intrinsic()) {
1305       mh->_i2i_entry = mh->get_i2c_entry();
1306     } else {
1307       guarantee(false, "Unknown Continuation native intrinsic");
1308     }
1309     // This must come last, as it is what's tested in LinkResolver::resolve_static_call
1310     Atomic::release_store(&mh->_from_interpreted_entry , mh->get_i2c_entry());
1311   } else if (!mh->is_method_handle_intrinsic()) {
1312     // Instantly compiled code can execute.
1313     mh->_from_interpreted_entry = mh->get_i2c_entry();
1314   }
1315 }
1316 
1317 
1318 bool Method::is_overridden_in(Klass* k) const {
1319   InstanceKlass* ik = InstanceKlass::cast(k);
1320 
1321   if (ik->is_interface()) return false;
1322 
1323   // If method is an interface, we skip it - except if it
1324   // is a miranda method
1325   if (method_holder()->is_interface()) {
1326     // Check that method is not a miranda method
1327     if (ik->lookup_method(name(), signature()) == nullptr) {
1328       // No implementation exist - so miranda method
1329       return false;
1330     }
1331     return true;
1332   }
1333 
1334   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1335   if (!has_vtable_index()) {
1336     return false;
1337   } else {
1338     Method* vt_m = ik->method_at_vtable(vtable_index());
1339     return vt_m != this;
1340   }
1341 }
1342 
1343 
1344 // give advice about whether this Method* should be cached or not
1345 bool Method::should_not_be_cached() const {
1346   if (is_old()) {
1347     // This method has been redefined. It is either EMCP or obsolete
1348     // and we don't want to cache it because that would pin the method
1349     // down and prevent it from being collectible if and when it
1350     // finishes executing.
1351     return true;
1352   }
1353 
1354   // caching this method should be just fine
1355   return false;
1356 }
1357 
1358 
1359 /**
1360  *  Returns true if this is one of the specially treated methods for
1361  *  security related stack walks (like Reflection.getCallerClass).
1362  */
1363 bool Method::is_ignored_by_security_stack_walk() const {
1364   if (intrinsic_id() == vmIntrinsics::_invoke) {
1365     // This is Method.invoke() -- ignore it
1366     return true;
1367   }
1368   if (method_holder()->is_subclass_of(vmClasses::reflect_MethodAccessorImpl_klass())) {
1369     // This is an auxiliary frame -- ignore it
1370     return true;
1371   }
1372   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1373     // This is an internal adapter frame for method handles -- ignore it
1374     return true;
1375   }
1376   return false;
1377 }
1378 
1379 
1380 // Constant pool structure for invoke methods:
1381 enum {
1382   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1383   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1384   _imcp_limit
1385 };
1386 
1387 // Test if this method is an MH adapter frame generated by Java code.
1388 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1389 bool Method::is_compiled_lambda_form() const {
1390   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1391 }
1392 
1393 // Test if this method is an internal MH primitive method.
1394 bool Method::is_method_handle_intrinsic() const {
1395   vmIntrinsics::ID iid = intrinsic_id();
1396   return (MethodHandles::is_signature_polymorphic(iid) &&
1397           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1398 }
1399 
1400 bool Method::has_member_arg() const {
1401   vmIntrinsics::ID iid = intrinsic_id();
1402   return (MethodHandles::is_signature_polymorphic(iid) &&
1403           MethodHandles::has_member_arg(iid));
1404 }
1405 
1406 // Make an instance of a signature-polymorphic internal MH primitive.
1407 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1408                                                          Symbol* signature,
1409                                                          TRAPS) {
1410   ResourceMark rm(THREAD);
1411   methodHandle empty;
1412 
1413   InstanceKlass* holder = vmClasses::MethodHandle_klass();
1414   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1415   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1416 
1417   log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1418 
1419   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1420   name->increment_refcount();
1421   signature->increment_refcount();
1422 
1423   int cp_length = _imcp_limit;
1424   ClassLoaderData* loader_data = holder->class_loader_data();
1425   constantPoolHandle cp;
1426   {
1427     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1428     cp = constantPoolHandle(THREAD, cp_oop);
1429   }
1430   cp->copy_fields(holder->constants());
1431   cp->set_pool_holder(holder);
1432   cp->symbol_at_put(_imcp_invoke_name,       name);
1433   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1434   cp->set_has_preresolution();
1435   cp->set_is_for_method_handle_intrinsic();
1436 
1437   // decide on access bits:  public or not?
1438   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1439   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1440   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1441   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1442 
1443   methodHandle m;
1444   {
1445     InlineTableSizes sizes;
1446     Method* m_oop = Method::allocate(loader_data, 0,
1447                                      accessFlags_from(flags_bits), &sizes,
1448                                      ConstMethod::NORMAL,
1449                                      name,
1450                                      CHECK_(empty));
1451     m = methodHandle(THREAD, m_oop);
1452   }
1453   m->set_constants(cp());
1454   m->set_name_index(_imcp_invoke_name);
1455   m->set_signature_index(_imcp_invoke_signature);
1456   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1457   assert(m->signature() == signature, "");
1458   m->constMethod()->compute_from_signature(signature, must_be_static);
1459   m->init_intrinsic_id(klass_id_for_intrinsics(m->method_holder()));
1460   assert(m->is_method_handle_intrinsic(), "");
1461 #ifdef ASSERT
1462   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1463   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1464   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1465 #endif //ASSERT
1466 
1467   // Finally, set up its entry points.
1468   assert(m->can_be_statically_bound(), "");
1469   m->set_vtable_index(Method::nonvirtual_vtable_index);
1470   m->link_method(m, CHECK_(empty));
1471 
1472   if (iid == vmIntrinsics::_linkToNative) {
1473     m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1474   }
1475   if (log_is_enabled(Debug, methodhandles)) {
1476     LogTarget(Debug, methodhandles) lt;
1477     LogStream ls(lt);
1478     m->print_on(&ls);
1479   }
1480 
1481   return m;
1482 }
1483 
1484 #if INCLUDE_CDS
1485 void Method::restore_archived_method_handle_intrinsic(methodHandle m, TRAPS) {
1486   m->link_method(m, CHECK);
1487 
1488   if (m->intrinsic_id() == vmIntrinsics::_linkToNative) {
1489     m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1490   }
1491 }
1492 #endif
1493 
1494 Klass* Method::check_non_bcp_klass(Klass* klass) {
1495   if (klass != nullptr && klass->class_loader() != nullptr) {
1496     if (klass->is_objArray_klass())
1497       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1498     return klass;
1499   }
1500   return nullptr;
1501 }
1502 
1503 
1504 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1505                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1506   // Code below does not work for native methods - they should never get rewritten anyway
1507   assert(!m->is_native(), "cannot rewrite native methods");
1508   // Allocate new Method*
1509   AccessFlags flags = m->access_flags();
1510 
1511   ConstMethod* cm = m->constMethod();
1512   int checked_exceptions_len = cm->checked_exceptions_length();
1513   int localvariable_len = cm->localvariable_table_length();
1514   int exception_table_len = cm->exception_table_length();
1515   int method_parameters_len = cm->method_parameters_length();
1516   int method_annotations_len = cm->method_annotations_length();
1517   int parameter_annotations_len = cm->parameter_annotations_length();
1518   int type_annotations_len = cm->type_annotations_length();
1519   int default_annotations_len = cm->default_annotations_length();
1520 
1521   InlineTableSizes sizes(
1522       localvariable_len,
1523       new_compressed_linenumber_size,
1524       exception_table_len,
1525       checked_exceptions_len,
1526       method_parameters_len,
1527       cm->generic_signature_index(),
1528       method_annotations_len,
1529       parameter_annotations_len,
1530       type_annotations_len,
1531       default_annotations_len,
1532       0);
1533 
1534   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1535   Method* newm_oop = Method::allocate(loader_data,
1536                                       new_code_length,
1537                                       flags,
1538                                       &sizes,
1539                                       m->method_type(),
1540                                       m->name(),
1541                                       CHECK_(methodHandle()));
1542   methodHandle newm (THREAD, newm_oop);
1543 
1544   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1545   ConstMethod* newcm = newm->constMethod();
1546   int new_const_method_size = newm->constMethod()->size();
1547 
1548   // This works because the source and target are both Methods. Some compilers
1549   // (e.g., clang) complain that the target vtable pointer will be stomped,
1550   // so cast away newm()'s and m()'s Methodness.
1551   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1552 
1553   // Create shallow copy of ConstMethod.
1554   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1555 
1556   // Reset correct method/const method, method size, and parameter info
1557   newm->set_constMethod(newcm);
1558   newm->constMethod()->set_code_size(new_code_length);
1559   newm->constMethod()->set_constMethod_size(new_const_method_size);
1560   assert(newm->code_size() == new_code_length, "check");
1561   assert(newm->method_parameters_length() == method_parameters_len, "check");
1562   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1563   assert(newm->exception_table_length() == exception_table_len, "check");
1564   assert(newm->localvariable_table_length() == localvariable_len, "check");
1565   // Copy new byte codes
1566   memcpy(newm->code_base(), new_code, new_code_length);
1567   // Copy line number table
1568   if (new_compressed_linenumber_size > 0) {
1569     memcpy(newm->compressed_linenumber_table(),
1570            new_compressed_linenumber_table,
1571            new_compressed_linenumber_size);
1572   }
1573   // Copy method_parameters
1574   if (method_parameters_len > 0) {
1575     memcpy(newm->method_parameters_start(),
1576            m->method_parameters_start(),
1577            method_parameters_len * sizeof(MethodParametersElement));
1578   }
1579   // Copy checked_exceptions
1580   if (checked_exceptions_len > 0) {
1581     memcpy(newm->checked_exceptions_start(),
1582            m->checked_exceptions_start(),
1583            checked_exceptions_len * sizeof(CheckedExceptionElement));
1584   }
1585   // Copy exception table
1586   if (exception_table_len > 0) {
1587     memcpy(newm->exception_table_start(),
1588            m->exception_table_start(),
1589            exception_table_len * sizeof(ExceptionTableElement));
1590   }
1591   // Copy local variable number table
1592   if (localvariable_len > 0) {
1593     memcpy(newm->localvariable_table_start(),
1594            m->localvariable_table_start(),
1595            localvariable_len * sizeof(LocalVariableTableElement));
1596   }
1597   // Copy stackmap table
1598   if (m->has_stackmap_table()) {
1599     int code_attribute_length = m->stackmap_data()->length();
1600     Array<u1>* stackmap_data =
1601       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
1602     memcpy((void*)stackmap_data->adr_at(0),
1603            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1604     newm->set_stackmap_data(stackmap_data);
1605   }
1606 
1607   // copy annotations over to new method
1608   newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
1609   return newm;
1610 }
1611 
1612 vmSymbolID Method::klass_id_for_intrinsics(const Klass* holder) {
1613   // if loader is not the default loader (i.e., non-null), we can't know the intrinsics
1614   // because we are not loading from core libraries
1615   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1616   // which does not use the class default class loader so we check for its loader here
1617   const InstanceKlass* ik = InstanceKlass::cast(holder);
1618   if ((ik->class_loader() != nullptr) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1619     return vmSymbolID::NO_SID;   // regardless of name, no intrinsics here
1620   }
1621 
1622   // see if the klass name is well-known:
1623   Symbol* klass_name = ik->name();
1624   vmSymbolID id = vmSymbols::find_sid(klass_name);
1625   if (id != vmSymbolID::NO_SID && vmIntrinsics::class_has_intrinsics(id)) {
1626     return id;
1627   } else {
1628     return vmSymbolID::NO_SID;
1629   }
1630 }
1631 
1632 void Method::init_intrinsic_id(vmSymbolID klass_id) {
1633   assert(_intrinsic_id == static_cast<int>(vmIntrinsics::_none), "do this just once");
1634   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1635   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1636   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1637 
1638   // the klass name is well-known:
1639   assert(klass_id == klass_id_for_intrinsics(method_holder()), "must be");
1640   assert(klass_id != vmSymbolID::NO_SID, "caller responsibility");
1641 
1642   // ditto for method and signature:
1643   vmSymbolID name_id = vmSymbols::find_sid(name());
1644   if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1645       && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1646       && name_id == vmSymbolID::NO_SID) {
1647     return;
1648   }
1649   vmSymbolID sig_id = vmSymbols::find_sid(signature());
1650   if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1651       && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1652       && sig_id == vmSymbolID::NO_SID) {
1653     return;
1654   }
1655   jshort flags = access_flags().as_short();
1656 
1657   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1658   if (id != vmIntrinsics::_none) {
1659     set_intrinsic_id(id);
1660     if (id == vmIntrinsics::_Class_cast) {
1661       // Even if the intrinsic is rejected, we want to inline this simple method.
1662       set_force_inline();
1663     }
1664     return;
1665   }
1666 
1667   // A few slightly irregular cases:
1668   switch (klass_id) {
1669   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1670   case VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1671   case VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1672     if (!is_native())  break;
1673     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1674     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1675       id = vmIntrinsics::_none;
1676     break;
1677 
1678   default:
1679     break;
1680   }
1681 
1682   if (id != vmIntrinsics::_none) {
1683     // Set up its iid.  It is an alias method.
1684     set_intrinsic_id(id);
1685     return;
1686   }
1687 }
1688 
1689 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1690   if (!THREAD->can_call_java()) {
1691     // There is nothing useful this routine can do from within the Compile thread.
1692     // Hopefully, the signature contains only well-known classes.
1693     // We could scan for this and return true/false, but the caller won't care.
1694     return false;
1695   }
1696   bool sig_is_loaded = true;
1697   ResourceMark rm(THREAD);
1698   for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1699     if (ss.is_reference()) {
1700       // load everything, including arrays "[Lfoo;"
1701       Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD);
1702       // We are loading classes eagerly. If a ClassNotFoundException or
1703       // a LinkageError was generated, be sure to ignore it.
1704       if (HAS_PENDING_EXCEPTION) {
1705         if (PENDING_EXCEPTION->is_a(vmClasses::ClassNotFoundException_klass()) ||
1706             PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass())) {
1707           CLEAR_PENDING_EXCEPTION;
1708         } else {
1709           return false;
1710         }
1711       }
1712       if( klass == nullptr) { sig_is_loaded = false; }
1713     }
1714   }
1715   return sig_is_loaded;
1716 }
1717 
1718 // Exposed so field engineers can debug VM
1719 void Method::print_short_name(outputStream* st) const {
1720   ResourceMark rm;
1721 #ifdef PRODUCT
1722   st->print(" %s::", method_holder()->external_name());
1723 #else
1724   st->print(" %s::", method_holder()->internal_name());
1725 #endif
1726   name()->print_symbol_on(st);
1727   if (WizardMode) signature()->print_symbol_on(st);
1728   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1729     MethodHandles::print_as_basic_type_signature_on(st, signature());
1730 }
1731 
1732 // Comparer for sorting an object array containing
1733 // Method*s.
1734 static int method_comparator(Method* a, Method* b) {
1735   return a->name()->fast_compare(b->name());
1736 }
1737 
1738 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1739 // default_methods also uses this without the ordering for fast find_method
1740 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1741   int length = methods->length();
1742   if (length > 1) {
1743     if (func == nullptr) {
1744       func = method_comparator;
1745     }
1746     {
1747       NoSafepointVerifier nsv;
1748       QuickSort::sort(methods->data(), length, func);
1749     }
1750     // Reset method ordering
1751     if (set_idnums) {
1752       for (u2 i = 0; i < length; i++) {
1753         Method* m = methods->at(i);
1754         m->set_method_idnum(i);
1755         m->set_orig_method_idnum(i);
1756       }
1757     }
1758   }
1759 }
1760 
1761 //-----------------------------------------------------------------------------------
1762 // Non-product code unless JVM/TI needs it
1763 
1764 #if !defined(PRODUCT) || INCLUDE_JVMTI
1765 class SignatureTypePrinter : public SignatureTypeNames {
1766  private:
1767   outputStream* _st;
1768   bool _use_separator;
1769 
1770   void type_name(const char* name) {
1771     if (_use_separator) _st->print(", ");
1772     _st->print("%s", name);
1773     _use_separator = true;
1774   }
1775 
1776  public:
1777   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1778     _st = st;
1779     _use_separator = false;
1780   }
1781 
1782   void print_parameters()              { _use_separator = false; do_parameters_on(this); }
1783   void print_returntype()              { _use_separator = false; do_type(return_type()); }
1784 };
1785 
1786 
1787 void Method::print_name(outputStream* st) const {
1788   Thread *thread = Thread::current();
1789   ResourceMark rm(thread);
1790   st->print("%s ", is_static() ? "static" : "virtual");
1791   if (WizardMode) {
1792     st->print("%s.", method_holder()->internal_name());
1793     name()->print_symbol_on(st);
1794     signature()->print_symbol_on(st);
1795   } else {
1796     SignatureTypePrinter sig(signature(), st);
1797     sig.print_returntype();
1798     st->print(" %s.", method_holder()->internal_name());
1799     name()->print_symbol_on(st);
1800     st->print("(");
1801     sig.print_parameters();
1802     st->print(")");
1803   }
1804 }
1805 #endif // !PRODUCT || INCLUDE_JVMTI
1806 
1807 
1808 void Method::print_codes_on(outputStream* st, int flags) const {
1809   print_codes_on(0, code_size(), st, flags);
1810 }
1811 
1812 void Method::print_codes_on(int from, int to, outputStream* st, int flags) const {
1813   Thread *thread = Thread::current();
1814   ResourceMark rm(thread);
1815   methodHandle mh (thread, (Method*)this);
1816   BytecodeTracer::print_method_codes(mh, from, to, st, flags);
1817 }
1818 
1819 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1820   _bci = 0;
1821   _line = 0;
1822 };
1823 
1824 bool CompressedLineNumberReadStream::read_pair() {
1825   jubyte next = read_byte();
1826   // Check for terminator
1827   if (next == 0) return false;
1828   if (next == 0xFF) {
1829     // Escape character, regular compression used
1830     _bci  += read_signed_int();
1831     _line += read_signed_int();
1832   } else {
1833     // Single byte compression used
1834     _bci  += next >> 3;
1835     _line += next & 0x7;
1836   }
1837   return true;
1838 }
1839 
1840 #if INCLUDE_JVMTI
1841 
1842 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1843   BreakpointInfo* bp = method_holder()->breakpoints();
1844   for (; bp != nullptr; bp = bp->next()) {
1845     if (bp->match(this, bci)) {
1846       return bp->orig_bytecode();
1847     }
1848   }
1849   {
1850     ResourceMark rm;
1851     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1852   }
1853   return Bytecodes::_shouldnotreachhere;
1854 }
1855 
1856 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1857   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1858   BreakpointInfo* bp = method_holder()->breakpoints();
1859   for (; bp != nullptr; bp = bp->next()) {
1860     if (bp->match(this, bci)) {
1861       bp->set_orig_bytecode(code);
1862       // and continue, in case there is more than one
1863     }
1864   }
1865 }
1866 
1867 void Method::set_breakpoint(int bci) {
1868   InstanceKlass* ik = method_holder();
1869   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1870   bp->set_next(ik->breakpoints());
1871   ik->set_breakpoints(bp);
1872   // do this last:
1873   bp->set(this);
1874 }
1875 
1876 static void clear_matches(Method* m, int bci) {
1877   InstanceKlass* ik = m->method_holder();
1878   BreakpointInfo* prev_bp = nullptr;
1879   BreakpointInfo* next_bp;
1880   for (BreakpointInfo* bp = ik->breakpoints(); bp != nullptr; bp = next_bp) {
1881     next_bp = bp->next();
1882     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1883     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1884       // do this first:
1885       bp->clear(m);
1886       // unhook it
1887       if (prev_bp != nullptr)
1888         prev_bp->set_next(next_bp);
1889       else
1890         ik->set_breakpoints(next_bp);
1891       delete bp;
1892       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1893       // at same location. So we have multiple matching (method_index and bci)
1894       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1895       // breakpoint for clear_breakpoint request and keep all other method versions
1896       // BreakpointInfo for future clear_breakpoint request.
1897       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1898       // which is being called when class is unloaded. We delete all the Breakpoint
1899       // information for all versions of method. We may not correctly restore the original
1900       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1901       // so these methods won't be used anymore.
1902       if (bci >= 0) {
1903         break;
1904       }
1905     } else {
1906       // This one is a keeper.
1907       prev_bp = bp;
1908     }
1909   }
1910 }
1911 
1912 void Method::clear_breakpoint(int bci) {
1913   assert(bci >= 0, "");
1914   clear_matches(this, bci);
1915 }
1916 
1917 void Method::clear_all_breakpoints() {
1918   clear_matches(this, -1);
1919 }
1920 
1921 #endif // INCLUDE_JVMTI
1922 
1923 int Method::invocation_count() const {
1924   MethodCounters* mcs = method_counters();
1925   MethodData* mdo = method_data();
1926   if (((mcs != nullptr) ? mcs->invocation_counter()->carry() : false) ||
1927       ((mdo != nullptr) ? mdo->invocation_counter()->carry() : false)) {
1928     return InvocationCounter::count_limit;
1929   } else {
1930     return ((mcs != nullptr) ? mcs->invocation_counter()->count() : 0) +
1931            ((mdo != nullptr) ? mdo->invocation_counter()->count() : 0);
1932   }
1933 }
1934 
1935 int Method::backedge_count() const {
1936   MethodCounters* mcs = method_counters();
1937   MethodData* mdo = method_data();
1938   if (((mcs != nullptr) ? mcs->backedge_counter()->carry() : false) ||
1939       ((mdo != nullptr) ? mdo->backedge_counter()->carry() : false)) {
1940     return InvocationCounter::count_limit;
1941   } else {
1942     return ((mcs != nullptr) ? mcs->backedge_counter()->count() : 0) +
1943            ((mdo != nullptr) ? mdo->backedge_counter()->count() : 0);
1944   }
1945 }
1946 
1947 int Method::highest_comp_level() const {
1948   const MethodCounters* mcs = method_counters();
1949   if (mcs != nullptr) {
1950     return mcs->highest_comp_level();
1951   } else {
1952     return CompLevel_none;
1953   }
1954 }
1955 
1956 int Method::highest_osr_comp_level() const {
1957   const MethodCounters* mcs = method_counters();
1958   if (mcs != nullptr) {
1959     return mcs->highest_osr_comp_level();
1960   } else {
1961     return CompLevel_none;
1962   }
1963 }
1964 
1965 void Method::set_highest_comp_level(int level) {
1966   MethodCounters* mcs = method_counters();
1967   if (mcs != nullptr) {
1968     mcs->set_highest_comp_level(level);
1969   }
1970 }
1971 
1972 void Method::set_highest_osr_comp_level(int level) {
1973   MethodCounters* mcs = method_counters();
1974   if (mcs != nullptr) {
1975     mcs->set_highest_osr_comp_level(level);
1976   }
1977 }
1978 
1979 #if INCLUDE_JVMTI
1980 
1981 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1982   _bci = bci;
1983   _name_index = m->name_index();
1984   _signature_index = m->signature_index();
1985   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1986   if (_orig_bytecode == Bytecodes::_breakpoint)
1987     _orig_bytecode = m->orig_bytecode_at(_bci);
1988   _next = nullptr;
1989 }
1990 
1991 void BreakpointInfo::set(Method* method) {
1992 #ifdef ASSERT
1993   {
1994     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1995     if (code == Bytecodes::_breakpoint)
1996       code = method->orig_bytecode_at(_bci);
1997     assert(orig_bytecode() == code, "original bytecode must be the same");
1998   }
1999 #endif
2000   Thread *thread = Thread::current();
2001   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2002   method->incr_number_of_breakpoints(thread);
2003   {
2004     // Deoptimize all dependents on this method
2005     HandleMark hm(thread);
2006     methodHandle mh(thread, method);
2007     CodeCache::mark_dependents_on_method_for_breakpoint(mh);
2008   }
2009 }
2010 
2011 void BreakpointInfo::clear(Method* method) {
2012   *method->bcp_from(_bci) = orig_bytecode();
2013   assert(method->number_of_breakpoints() > 0, "must not go negative");
2014   method->decr_number_of_breakpoints(Thread::current());
2015 }
2016 
2017 #endif // INCLUDE_JVMTI
2018 
2019 // jmethodID handling
2020 
2021 // This is a block allocating object, sort of like JNIHandleBlock, only a
2022 // lot simpler.
2023 // It's allocated on the CHeap because once we allocate a jmethodID, we can
2024 // never get rid of it.
2025 
2026 static const int min_block_size = 8;
2027 
2028 class JNIMethodBlockNode : public CHeapObj<mtClass> {
2029   friend class JNIMethodBlock;
2030   Method**        _methods;
2031   int             _number_of_methods;
2032   int             _top;
2033   JNIMethodBlockNode* _next;
2034 
2035  public:
2036 
2037   JNIMethodBlockNode(int num_methods = min_block_size);
2038 
2039   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
2040 
2041   void ensure_methods(int num_addl_methods) {
2042     if (_top < _number_of_methods) {
2043       num_addl_methods -= _number_of_methods - _top;
2044       if (num_addl_methods <= 0) {
2045         return;
2046       }
2047     }
2048     if (_next == nullptr) {
2049       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
2050     } else {
2051       _next->ensure_methods(num_addl_methods);
2052     }
2053   }
2054 };
2055 
2056 class JNIMethodBlock : public CHeapObj<mtClass> {
2057   JNIMethodBlockNode _head;
2058   JNIMethodBlockNode *_last_free;
2059  public:
2060   static Method* const _free_method;
2061 
2062   JNIMethodBlock(int initial_capacity = min_block_size)
2063       : _head(initial_capacity), _last_free(&_head) {}
2064 
2065   void ensure_methods(int num_addl_methods) {
2066     _last_free->ensure_methods(num_addl_methods);
2067   }
2068 
2069   Method** add_method(Method* m) {
2070     for (JNIMethodBlockNode* b = _last_free; b != nullptr; b = b->_next) {
2071       if (b->_top < b->_number_of_methods) {
2072         // top points to the next free entry.
2073         int i = b->_top;
2074         b->_methods[i] = m;
2075         b->_top++;
2076         _last_free = b;
2077         return &(b->_methods[i]);
2078       } else if (b->_top == b->_number_of_methods) {
2079         // if the next free entry ran off the block see if there's a free entry
2080         for (int i = 0; i < b->_number_of_methods; i++) {
2081           if (b->_methods[i] == _free_method) {
2082             b->_methods[i] = m;
2083             _last_free = b;
2084             return &(b->_methods[i]);
2085           }
2086         }
2087         // Only check each block once for frees.  They're very unlikely.
2088         // Increment top past the end of the block.
2089         b->_top++;
2090       }
2091       // need to allocate a next block.
2092       if (b->_next == nullptr) {
2093         b->_next = _last_free = new JNIMethodBlockNode();
2094       }
2095     }
2096     guarantee(false, "Should always allocate a free block");
2097     return nullptr;
2098   }
2099 
2100   bool contains(Method** m) {
2101     if (m == nullptr) return false;
2102     for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) {
2103       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2104         // This is a bit of extra checking, for two reasons.  One is
2105         // that contains() deals with pointers that are passed in by
2106         // JNI code, so making sure that the pointer is aligned
2107         // correctly is valuable.  The other is that <= and > are
2108         // technically not defined on pointers, so the if guard can
2109         // pass spuriously; no modern compiler is likely to make that
2110         // a problem, though (and if one did, the guard could also
2111         // fail spuriously, which would be bad).
2112         ptrdiff_t idx = m - b->_methods;
2113         if (b->_methods + idx == m) {
2114           return true;
2115         }
2116       }
2117     }
2118     return false;  // not found
2119   }
2120 
2121   // During class unloading the methods are cleared, which is different
2122   // than freed.
2123   void clear_all_methods() {
2124     for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) {
2125       for (int i = 0; i< b->_number_of_methods; i++) {
2126         b->_methods[i] = nullptr;
2127       }
2128     }
2129   }
2130 #ifndef PRODUCT
2131   int count_methods() {
2132     // count all allocated methods
2133     int count = 0;
2134     for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) {
2135       for (int i = 0; i< b->_number_of_methods; i++) {
2136         if (b->_methods[i] != _free_method) count++;
2137       }
2138     }
2139     return count;
2140   }
2141 #endif // PRODUCT
2142 };
2143 
2144 // Something that can't be mistaken for an address or a markWord
2145 Method* const JNIMethodBlock::_free_method = (Method*)55;
2146 
2147 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(nullptr) {
2148   _number_of_methods = MAX2(num_methods, min_block_size);
2149   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2150   for (int i = 0; i < _number_of_methods; i++) {
2151     _methods[i] = JNIMethodBlock::_free_method;
2152   }
2153 }
2154 
2155 void Method::ensure_jmethod_ids(ClassLoaderData* cld, int capacity) {
2156   // Have to add jmethod_ids() to class loader data thread-safely.
2157   // Also have to add the method to the list safely, which the lock
2158   // protects as well.
2159   MutexLocker ml(JmethodIdCreation_lock,  Mutex::_no_safepoint_check_flag);
2160   if (cld->jmethod_ids() == nullptr) {
2161     cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2162   } else {
2163     cld->jmethod_ids()->ensure_methods(capacity);
2164   }
2165 }
2166 
2167 // Add a method id to the jmethod_ids
2168 jmethodID Method::make_jmethod_id(ClassLoaderData* cld, Method* m) {
2169   // Have to add jmethod_ids() to class loader data thread-safely.
2170   // Also have to add the method to the list safely, which the lock
2171   // protects as well.
2172   assert(JmethodIdCreation_lock->owned_by_self(), "sanity check");
2173 
2174   ResourceMark rm;
2175   log_debug(jmethod)("Creating jmethodID for Method %s", m->external_name());
2176   if (cld->jmethod_ids() == nullptr) {
2177     cld->set_jmethod_ids(new JNIMethodBlock());
2178   }
2179   // jmethodID is a pointer to Method*
2180   return (jmethodID)cld->jmethod_ids()->add_method(m);
2181 }
2182 
2183 jmethodID Method::jmethod_id() {
2184   methodHandle mh(Thread::current(), this);
2185   return method_holder()->get_jmethod_id(mh);
2186 }
2187 
2188 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2189   // Can't assert the method_holder is the same because the new method has the
2190   // scratch method holder.
2191   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2192            == new_method->method_holder()->class_loader() ||
2193            new_method->method_holder()->class_loader() == nullptr, // allow Unsafe substitution
2194          "changing to a different class loader");
2195   // Just change the method in place, jmethodID pointer doesn't change.
2196   *((Method**)jmid) = new_method;
2197 }
2198 
2199 bool Method::is_method_id(jmethodID mid) {
2200   Method* m = resolve_jmethod_id(mid);
2201   assert(m != nullptr, "should be called with non-null method");
2202   InstanceKlass* ik = m->method_holder();
2203   ClassLoaderData* cld = ik->class_loader_data();
2204   if (cld->jmethod_ids() == nullptr) return false;
2205   return (cld->jmethod_ids()->contains((Method**)mid));
2206 }
2207 
2208 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2209   if (mid == nullptr) return nullptr;
2210   Method* o = resolve_jmethod_id(mid);
2211   if (o == nullptr || o == JNIMethodBlock::_free_method) {
2212     return nullptr;
2213   }
2214   // Method should otherwise be valid. Assert for testing.
2215   assert(is_valid_method(o), "should be valid jmethodid");
2216   // If the method's class holder object is unreferenced, but not yet marked as
2217   // unloaded, we need to return null here too because after a safepoint, its memory
2218   // will be reclaimed.
2219   return o->method_holder()->is_loader_alive() ? o : nullptr;
2220 };
2221 
2222 void Method::set_on_stack(const bool value) {
2223   // Set both the method itself and its constant pool.  The constant pool
2224   // on stack means some method referring to it is also on the stack.
2225   constants()->set_on_stack(value);
2226 
2227   bool already_set = on_stack_flag();
2228   set_on_stack_flag(value);
2229   if (value && !already_set) {
2230     MetadataOnStackMark::record(this);
2231   }
2232 }
2233 
2234 void Method::record_gc_epoch() {
2235   // If any method is on the stack in continuations, none of them can be reclaimed,
2236   // so save the marking cycle to check for the whole class in the cpCache.
2237   // The cpCache is writeable.
2238   constants()->cache()->record_gc_epoch();
2239 }
2240 
2241 // Called when the class loader is unloaded to make all methods weak.
2242 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2243   loader_data->jmethod_ids()->clear_all_methods();
2244 }
2245 
2246 void Method::clear_jmethod_id() {
2247   // Being at a safepoint prevents racing against other class redefinitions
2248   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
2249   // The jmethodID is not stored in the Method instance, we need to look it up first
2250   jmethodID methodid = find_jmethod_id_or_null();
2251   // We need to make sure that jmethodID actually resolves to this method
2252   // - multiple redefined versions may share jmethodID slots and if a method
2253   //   has already been rewired to a newer version we could be removing reference
2254   //   to a still existing method instance
2255   if (methodid != nullptr && *((Method**)methodid) == this) {
2256     *((Method**)methodid) = nullptr;
2257   }
2258 }
2259 
2260 bool Method::has_method_vptr(const void* ptr) {
2261   Method m;
2262   // This assumes that the vtbl pointer is the first word of a C++ object.
2263   return dereference_vptr(&m) == dereference_vptr(ptr);
2264 }
2265 
2266 // Check that this pointer is valid by checking that the vtbl pointer matches
2267 bool Method::is_valid_method(const Method* m) {
2268   if (m == nullptr) {
2269     return false;
2270   } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2271     // Quick sanity check on pointer.
2272     return false;
2273   } else if (!os::is_readable_range(m, m + 1)) {
2274     return false;
2275   } else if (m->is_shared()) {
2276     return CppVtables::is_valid_shared_method(m);
2277   } else if (Metaspace::contains_non_shared(m)) {
2278     return has_method_vptr((const void*)m);
2279   } else {
2280     return false;
2281   }
2282 }
2283 
2284 #ifndef PRODUCT
2285 void Method::print_jmethod_ids_count(const ClassLoaderData* loader_data, outputStream* out) {
2286   out->print("%d", loader_data->jmethod_ids()->count_methods());
2287 }
2288 #endif // PRODUCT
2289 
2290 
2291 // Printing
2292 
2293 #ifndef PRODUCT
2294 
2295 void Method::print_on(outputStream* st) const {
2296   ResourceMark rm;
2297   assert(is_method(), "must be method");
2298   st->print_cr("%s", internal_name());
2299   st->print_cr(" - this oop:          " PTR_FORMAT, p2i(this));
2300   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2301   st->print   (" - constants:         " PTR_FORMAT " ", p2i(constants()));
2302   constants()->print_value_on(st); st->cr();
2303   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2304   st->print   (" - flags:             0x%x  ", _flags.as_int()); _flags.print_on(st); st->cr();
2305   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2306   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2307   st->print_cr(" - max stack:         %d",   max_stack());
2308   st->print_cr(" - max locals:        %d",   max_locals());
2309   st->print_cr(" - size of params:    %d",   size_of_parameters());
2310   st->print_cr(" - method size:       %d",   method_size());
2311   if (intrinsic_id() != vmIntrinsics::_none)
2312     st->print_cr(" - intrinsic id:      %d %s", vmIntrinsics::as_int(intrinsic_id()), vmIntrinsics::name_at(intrinsic_id()));
2313   if (highest_comp_level() != CompLevel_none)
2314     st->print_cr(" - highest level:     %d", highest_comp_level());
2315   st->print_cr(" - vtable index:      %d",   _vtable_index);
2316   st->print_cr(" - i2i entry:         " PTR_FORMAT, p2i(interpreter_entry()));
2317   st->print(   " - adapters:          ");
2318   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2319   if (a == nullptr)
2320     st->print_cr(PTR_FORMAT, p2i(a));
2321   else
2322     a->print_adapter_on(st);
2323   st->print_cr(" - compiled entry     " PTR_FORMAT, p2i(from_compiled_entry()));
2324   st->print_cr(" - code size:         %d",   code_size());
2325   if (code_size() != 0) {
2326     st->print_cr(" - code start:        " PTR_FORMAT, p2i(code_base()));
2327     st->print_cr(" - code end (excl):   " PTR_FORMAT, p2i(code_base() + code_size()));
2328   }
2329   if (method_data() != nullptr) {
2330     st->print_cr(" - method data:       " PTR_FORMAT, p2i(method_data()));
2331   }
2332   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2333   if (checked_exceptions_length() > 0) {
2334     CheckedExceptionElement* table = checked_exceptions_start();
2335     st->print_cr(" - checked ex start:  " PTR_FORMAT, p2i(table));
2336     if (Verbose) {
2337       for (int i = 0; i < checked_exceptions_length(); i++) {
2338         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2339       }
2340     }
2341   }
2342   if (has_linenumber_table()) {
2343     u_char* table = compressed_linenumber_table();
2344     st->print_cr(" - linenumber start:  " PTR_FORMAT, p2i(table));
2345     if (Verbose) {
2346       CompressedLineNumberReadStream stream(table);
2347       while (stream.read_pair()) {
2348         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2349       }
2350     }
2351   }
2352   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2353   if (localvariable_table_length() > 0) {
2354     LocalVariableTableElement* table = localvariable_table_start();
2355     st->print_cr(" - localvar start:    " PTR_FORMAT, p2i(table));
2356     if (Verbose) {
2357       for (int i = 0; i < localvariable_table_length(); i++) {
2358         int bci = table[i].start_bci;
2359         int len = table[i].length;
2360         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2361         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2362         int slot = table[i].slot;
2363         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2364       }
2365     }
2366   }
2367   if (code() != nullptr) {
2368     st->print   (" - compiled code: ");
2369     code()->print_value_on(st);
2370   }
2371   if (is_native()) {
2372     st->print_cr(" - native function:   " PTR_FORMAT, p2i(native_function()));
2373     st->print_cr(" - signature handler: " PTR_FORMAT, p2i(signature_handler()));
2374   }
2375 }
2376 
2377 void Method::print_linkage_flags(outputStream* st) {
2378   access_flags().print_on(st);
2379   if (is_default_method()) {
2380     st->print("default ");
2381   }
2382   if (is_overpass()) {
2383     st->print("overpass ");
2384   }
2385 }
2386 #endif //PRODUCT
2387 
2388 void Method::print_value_on(outputStream* st) const {
2389   assert(is_method(), "must be method");
2390   st->print("%s", internal_name());
2391   print_address_on(st);
2392   st->print(" ");
2393   name()->print_value_on(st);
2394   st->print(" ");
2395   signature()->print_value_on(st);
2396   st->print(" in ");
2397   method_holder()->print_value_on(st);
2398   if (WizardMode) st->print("#%d", _vtable_index);
2399   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2400   if (WizardMode && code() != nullptr) st->print(" ((nmethod*)%p)", code());
2401 }
2402 
2403 // Verification
2404 
2405 void Method::verify_on(outputStream* st) {
2406   guarantee(is_method(), "object must be method");
2407   guarantee(constants()->is_constantPool(), "should be constant pool");
2408   MethodData* md = method_data();
2409   guarantee(md == nullptr ||
2410       md->is_methodData(), "should be method data");
2411 }