1 /*
   2  * Copyright (c) 1997, 2026, 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 "cds/aotMetaspace.hpp"
  26 #include "cds/cdsConfig.hpp"
  27 #include "cds/cppVtables.hpp"
  28 #include "classfile/classLoader.hpp"
  29 #include "classfile/classLoaderDataGraph.hpp"
  30 #include "classfile/metadataOnStackMark.hpp"
  31 #include "classfile/symbolTable.hpp"
  32 #include "classfile/systemDictionary.hpp"
  33 #include "classfile/vmClasses.hpp"
  34 #include "code/aotCodeCache.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/bytecodes.hpp"
  40 #include "interpreter/bytecodeStream.hpp"
  41 #include "interpreter/bytecodeTracer.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/constantPool.hpp"
  55 #include "oops/constMethod.hpp"
  56 #include "oops/jmethodIDTable.hpp"
  57 #include "oops/klass.inline.hpp"
  58 #include "oops/method.inline.hpp"
  59 #include "oops/methodData.hpp"
  60 #include "oops/objArrayKlass.hpp"
  61 #include "oops/objArrayOop.inline.hpp"
  62 #include "oops/oop.inline.hpp"
  63 #include "oops/symbol.hpp"
  64 #include "oops/trainingData.hpp"
  65 #include "prims/jvmtiExport.hpp"
  66 #include "prims/methodHandles.hpp"
  67 #include "runtime/arguments.hpp"
  68 #include "runtime/atomicAccess.hpp"
  69 #include "runtime/continuationEntry.hpp"
  70 #include "runtime/frame.inline.hpp"
  71 #include "runtime/handles.inline.hpp"
  72 #include "runtime/init.hpp"
  73 #include "runtime/java.hpp"
  74 #include "runtime/orderAccess.hpp"
  75 #include "runtime/perfData.hpp"
  76 #include "runtime/relocator.hpp"
  77 #include "runtime/safepointVerifiers.hpp"
  78 #include "runtime/sharedRuntime.hpp"
  79 #include "runtime/signature.hpp"
  80 #include "runtime/threads.hpp"
  81 #include "runtime/vm_version.hpp"
  82 #include "utilities/align.hpp"
  83 #include "utilities/quickSort.hpp"
  84 #include "utilities/vmError.hpp"
  85 #include "utilities/xmlstream.hpp"
  86 
  87 // Implementation of Method
  88 
  89 Method* Method::allocate(ClassLoaderData* loader_data,
  90                          int byte_code_size,
  91                          AccessFlags access_flags,
  92                          InlineTableSizes* sizes,
  93                          ConstMethod::MethodType method_type,
  94                          Symbol* name,
  95                          TRAPS) {
  96   assert(!access_flags.is_native() || byte_code_size == 0,
  97          "native methods should not contain byte codes");
  98   ConstMethod* cm = ConstMethod::allocate(loader_data,
  99                                           byte_code_size,
 100                                           sizes,
 101                                           method_type,
 102                                           CHECK_NULL);
 103   int size = Method::size(access_flags.is_native());
 104   return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, name);
 105 }
 106 
 107 Method::Method(ConstMethod* xconst, AccessFlags access_flags, Symbol* name) {
 108   NoSafepointVerifier no_safepoint;
 109   set_constMethod(xconst);
 110   set_access_flags(access_flags);
 111   set_intrinsic_id(vmIntrinsics::_none);
 112   clear_method_data();
 113   clear_method_counters();
 114   set_vtable_index(Method::garbage_vtable_index);
 115 
 116   // Fix and bury in Method*
 117   set_interpreter_entry(nullptr); // sets i2i entry and from_int
 118   set_adapter_entry(nullptr);
 119   Method::clear_code(); // from_c/from_i get set to c2i/i2i
 120 
 121   if (access_flags.is_native()) {
 122     clear_native_function();
 123     set_signature_handler(nullptr);
 124   }
 125 
 126   NOT_PRODUCT(set_compiled_invocation_count(0);)
 127   // Name is very useful for debugging.
 128   NOT_PRODUCT(_name = name;)
 129 }
 130 
 131 // Release Method*.  The nmethod will be gone when we get here because
 132 // we've walked the code cache.
 133 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 134   MetadataFactory::free_metadata(loader_data, constMethod());
 135   set_constMethod(nullptr);
 136   MetadataFactory::free_metadata(loader_data, method_data());
 137   clear_method_data();
 138   MetadataFactory::free_metadata(loader_data, method_counters());
 139   clear_method_counters();
 140   set_adapter_entry(nullptr);
 141   // The nmethod will be gone when we get here.
 142   if (code() != nullptr) _code = nullptr;
 143 }
 144 
 145 void Method::release_C_heap_structures() {
 146   if (method_data()) {
 147     method_data()->release_C_heap_structures();
 148 
 149     // Destroy MethodData embedded lock
 150     method_data()->~MethodData();
 151   }
 152 }
 153 
 154 address Method::get_i2c_entry() {
 155   if (is_abstract()) {
 156     return SharedRuntime::throw_AbstractMethodError_entry();
 157   }
 158   assert(adapter() != nullptr, "must have");
 159   return adapter()->get_i2c_entry();
 160 }
 161 
 162 address Method::get_c2i_entry() {
 163   if (is_abstract()) {
 164     return SharedRuntime::get_handle_wrong_method_abstract_stub();
 165   }
 166   assert(adapter() != nullptr, "must have");
 167   return adapter()->get_c2i_entry();
 168 }
 169 
 170 address Method::get_c2i_unverified_entry() {
 171   if (is_abstract()) {
 172     return SharedRuntime::get_handle_wrong_method_abstract_stub();
 173   }
 174   assert(adapter() != nullptr, "must have");
 175   return adapter()->get_c2i_unverified_entry();
 176 }
 177 
 178 address Method::get_c2i_no_clinit_check_entry() {
 179   if (is_abstract()) {
 180     return nullptr;
 181   }
 182   assert(VM_Version::supports_fast_class_init_checks(), "");
 183   assert(adapter() != nullptr, "must have");
 184   return adapter()->get_c2i_no_clinit_check_entry();
 185 }
 186 
 187 char* Method::name_and_sig_as_C_string(bool use_double_colon) const {
 188   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), use_double_colon);
 189 }
 190 
 191 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 192   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 193 }
 194 
 195 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, bool use_double_colon) {
 196   const char* klass_name = klass->external_name();
 197   int klass_name_len  = (int)strlen(klass_name);
 198   int method_name_len = method_name->utf8_length();
 199   int separator_len   = use_double_colon ? 2 : 1;
 200   int len             = klass_name_len + separator_len + method_name_len + signature->utf8_length();
 201   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 202   strcpy(dest, klass_name);
 203   if (use_double_colon) {
 204     dest[klass_name_len + 0] = ':';
 205     dest[klass_name_len + 1] = ':';
 206   } else {
 207     dest[klass_name_len] = '.';
 208   }
 209   strcpy(&dest[klass_name_len + separator_len], method_name->as_C_string());
 210   strcpy(&dest[klass_name_len + separator_len + method_name_len], signature->as_C_string());
 211   dest[len] = 0;
 212   return dest;
 213 }
 214 
 215 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 216   Symbol* klass_name = klass->name();
 217   klass_name->as_klass_external_name(buf, size);
 218   int len = (int)strlen(buf);
 219 
 220   if (len < size - 1) {
 221     buf[len++] = '.';
 222 
 223     method_name->as_C_string(&(buf[len]), size - len);
 224     len = (int)strlen(buf);
 225 
 226     signature->as_C_string(&(buf[len]), size - len);
 227   }
 228 
 229   return buf;
 230 }
 231 
 232 const char* Method::external_name() const {
 233   return external_name(constants()->pool_holder(), name(), signature());
 234 }
 235 
 236 void Method::print_external_name(outputStream *os) const {
 237   print_external_name(os, constants()->pool_holder(), name(), signature());
 238 }
 239 
 240 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
 241   stringStream ss;
 242   print_external_name(&ss, klass, method_name, signature);
 243   return ss.as_string();
 244 }
 245 
 246 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
 247   signature->print_as_signature_external_return_type(os);
 248   os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
 249   signature->print_as_signature_external_parameters(os);
 250   os->print(")");
 251 }
 252 
 253 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
 254   if (log_is_enabled(Debug, exceptions)) {
 255     ResourceMark rm(THREAD);
 256     log_debug(exceptions)("Looking for catch handler for exception of type \"%s\" in method \"%s\"",
 257                           ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string());
 258   }
 259   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 260   // access exception table
 261   ExceptionTable table(mh());
 262   int length = table.length();
 263   // iterate through all entries sequentially
 264   constantPoolHandle pool(THREAD, mh->constants());
 265   for (int i = 0; i < length; i ++) {
 266     //reacquire the table in case a GC happened
 267     ExceptionTable table(mh());
 268     int beg_bci = table.start_pc(i);
 269     int end_bci = table.end_pc(i);
 270     assert(beg_bci <= end_bci, "inconsistent exception table");
 271     log_debug(exceptions)("  - checking exception table entry for BCI %d to %d",
 272                          beg_bci, end_bci);
 273 
 274     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 275       // exception handler bci range covers throw_bci => investigate further
 276       log_debug(exceptions)("    - entry covers throw point BCI %d", throw_bci);
 277 
 278       int handler_bci = table.handler_pc(i);
 279       int klass_index = table.catch_type_index(i);
 280       if (klass_index == 0) {
 281         if (log_is_enabled(Info, exceptions)) {
 282           ResourceMark rm(THREAD);
 283           log_info(exceptions)("Found catch-all handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
 284                                ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
 285         }
 286         return handler_bci;
 287       } else if (ex_klass == nullptr) {
 288         // Is this even possible?
 289         if (log_is_enabled(Info, exceptions)) {
 290           ResourceMark rm(THREAD);
 291           log_info(exceptions)("null exception class is implicitly caught by handler in method \"%s\" at BCI: %d",
 292                                mh()->name()->as_C_string(), handler_bci);
 293         }
 294         return handler_bci;
 295       } else {
 296         if (log_is_enabled(Debug, exceptions)) {
 297           ResourceMark rm(THREAD);
 298           log_debug(exceptions)("    - resolving catch type \"%s\"",
 299                                pool->klass_name_at(klass_index)->as_C_string());
 300         }
 301         // we know the exception class => get the constraint class
 302         // this may require loading of the constraint class; if verification
 303         // fails or some other exception occurs, return handler_bci
 304         Klass* k = pool->klass_at(klass_index, THREAD);
 305         if (HAS_PENDING_EXCEPTION) {
 306           if (log_is_enabled(Debug, exceptions)) {
 307             ResourceMark rm(THREAD);
 308             log_debug(exceptions)("    - exception \"%s\" occurred resolving catch type",
 309                                  PENDING_EXCEPTION->klass()->external_name());
 310           }
 311           return handler_bci;
 312         }
 313         assert(k != nullptr, "klass not loaded");
 314         if (ex_klass->is_subtype_of(k)) {
 315           if (log_is_enabled(Info, exceptions)) {
 316             ResourceMark rm(THREAD);
 317             log_info(exceptions)("Found matching handler for exception of type \"%s\" in method \"%s\" at BCI: %d",
 318                                  ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci);
 319           }
 320           return handler_bci;
 321         }
 322       }
 323     }
 324   }
 325 
 326   if (log_is_enabled(Debug, exceptions)) {
 327     ResourceMark rm(THREAD);
 328     log_debug(exceptions)("No catch handler found for exception of type \"%s\" in method \"%s\"",
 329                           ex_klass->external_name(), mh->name()->as_C_string());
 330   }
 331 
 332   return -1;
 333 }
 334 
 335 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 336   methodHandle h_this(Thread::current(), this);
 337   mask_for(h_this, bci, mask);
 338 }
 339 
 340 void Method::mask_for(const methodHandle& this_mh, int bci, InterpreterOopMap* mask) {
 341   assert(this_mh() == this, "Sanity");
 342   method_holder()->mask_for(this_mh, bci, mask);
 343 }
 344 
 345 int Method::bci_from(address bcp) const {
 346   if (is_native() && bcp == nullptr) {
 347     return 0;
 348   }
 349   // Do not have a ResourceMark here because AsyncGetCallTrace stack walking code
 350   // may call this after interrupting a nested ResourceMark.
 351   assert((is_native() && bcp == code_base()) || contains(bcp) || VMError::is_error_reported(),
 352          "bcp doesn't belong to this method. bcp: " PTR_FORMAT, p2i(bcp));
 353 
 354   return int(bcp - code_base());
 355 }
 356 
 357 
 358 int Method::validate_bci(int bci) const {
 359   // Called from the verifier, and should return -1 if not valid.
 360   return ((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size())) ? bci : -1;
 361 }
 362 
 363 // Return bci if it appears to be a valid bcp
 364 // Return -1 otherwise.
 365 // Used by profiling code, when invalid data is a possibility.
 366 // The caller is responsible for validating the Method* itself.
 367 int Method::validate_bci_from_bcp(address bcp) const {
 368   // keep bci as -1 if not a valid bci
 369   int bci = -1;
 370   if (bcp == nullptr || bcp == code_base()) {
 371     // code_size() may return 0 and we allow 0 here
 372     // the method may be native
 373     bci = 0;
 374   } else if (contains(bcp)) {
 375     bci = int(bcp - code_base());
 376   }
 377   // Assert that if we have dodged any asserts, bci is negative.
 378   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 379   return bci;
 380 }
 381 
 382 address Method::bcp_from(int bci) const {
 383   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
 384          "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
 385   address bcp = code_base() + bci;
 386   assert((is_native() && bcp == code_base()) || contains(bcp), "bcp doesn't belong to this method");
 387   return bcp;
 388 }
 389 
 390 address Method::bcp_from(address bcp) const {
 391   if (is_native() && bcp == nullptr) {
 392     return code_base();
 393   } else {
 394     return bcp;
 395   }
 396 }
 397 
 398 int Method::size(bool is_native) {
 399   // If native, then include pointers for native_function and signature_handler
 400   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 401   int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
 402   return align_metadata_size(header_size() + extra_words);
 403 }
 404 
 405 Symbol* Method::klass_name() const {
 406   return method_holder()->name();
 407 }
 408 
 409 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 410   log_trace(aot)("Iter(Method): %p", this);
 411 
 412   if (!method_holder()->is_rewritten()) {
 413     it->push(&_constMethod, MetaspaceClosure::_writable);
 414   } else {
 415     it->push(&_constMethod);
 416   }
 417   it->push(&_adapter);
 418   it->push(&_method_data);
 419   it->push(&_method_counters);
 420   NOT_PRODUCT(it->push(&_name);)
 421 }
 422 
 423 #if INCLUDE_CDS
 424 // Attempt to return method to original state.  Clear any pointers
 425 // (to objects outside the shared spaces).  We won't be able to predict
 426 // where they should point in a new JVM.  Further initialize some
 427 // entries now in order allow them to be write protected later.
 428 
 429 void Method::remove_unshareable_info() {
 430   unlink_method();
 431   if (method_data() != nullptr) {
 432     method_data()->remove_unshareable_info();
 433   }
 434   if (method_counters() != nullptr) {
 435     method_counters()->remove_unshareable_info();
 436   }
 437   if (CDSConfig::is_dumping_adapters() && _adapter != nullptr) {
 438     _adapter->remove_unshareable_info();
 439     _adapter = nullptr;
 440   }
 441   JFR_ONLY(REMOVE_METHOD_ID(this);)
 442 }
 443 
 444 void Method::restore_unshareable_info(TRAPS) {
 445   assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
 446   if (method_data() != nullptr) {
 447     method_data()->restore_unshareable_info(CHECK);
 448   }
 449   if (method_counters() != nullptr) {
 450     method_counters()->restore_unshareable_info(CHECK);
 451   }
 452   if (_adapter != nullptr) {
 453     assert(_adapter->is_linked(), "must be");
 454     _from_compiled_entry = _adapter->get_c2i_entry();
 455   }
 456   assert(!queued_for_compilation(), "method's queued_for_compilation flag should not be set");
 457 }
 458 #endif
 459 
 460 void Method::set_vtable_index(int index) {
 461   if (in_aot_cache() && !AOTMetaspace::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
 462     // At runtime initialize_vtable is rerun as part of link_class_impl()
 463     // for a shared class loaded by the non-boot loader to obtain the loader
 464     // constraints based on the runtime classloaders' context.
 465     return; // don't write into the shared class
 466   } else {
 467     _vtable_index = index;
 468   }
 469 }
 470 
 471 void Method::set_itable_index(int index) {
 472   if (in_aot_cache() && !AOTMetaspace::remapped_readwrite() && method_holder()->verified_at_dump_time()) {
 473     // At runtime initialize_itable is rerun as part of link_class_impl()
 474     // for a shared class loaded by the non-boot loader to obtain the loader
 475     // constraints based on the runtime classloaders' context. The dumptime
 476     // itable index should be the same as the runtime index.
 477     assert(_vtable_index == itable_index_max - index,
 478            "archived itable index is different from runtime index");
 479     return; // don't write into the shared class
 480   } else {
 481     _vtable_index = itable_index_max - index;
 482   }
 483   assert(valid_itable_index(), "");
 484 }
 485 
 486 // The RegisterNatives call being attempted tried to register with a method that
 487 // is not native.  Ask JVM TI what prefixes have been specified.  Then check
 488 // to see if the native method is now wrapped with the prefixes.  See the
 489 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details.
 490 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) {
 491 #if INCLUDE_JVMTI
 492   ResourceMark rm(THREAD);
 493   Method* method;
 494   int name_len = name->utf8_length();
 495   char* name_str = name->as_utf8();
 496   int prefix_count;
 497   char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
 498   for (int i = 0; i < prefix_count; i++) {
 499     char* prefix = prefixes[i];
 500     int prefix_len = (int)strlen(prefix);
 501 
 502     // try adding this prefix to the method name and see if it matches another method name
 503     int trial_len = name_len + prefix_len;
 504     char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
 505     strcpy(trial_name_str, prefix);
 506     strcat(trial_name_str, name_str);
 507     TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len);
 508     if (trial_name == nullptr) {
 509       continue; // no such symbol, so this prefix wasn't used, try the next prefix
 510     }
 511     method = k->lookup_method(trial_name, signature);
 512     if (method == nullptr) {
 513       continue; // signature doesn't match, try the next prefix
 514     }
 515     if (method->is_native()) {
 516       method->set_is_prefixed_native();
 517       return method; // wahoo, we found a prefixed version of the method, return it
 518     }
 519     // found as non-native, so prefix is good, add it, probably just need more prefixes
 520     name_len = trial_len;
 521     name_str = trial_name_str;
 522   }
 523 #endif // INCLUDE_JVMTI
 524   return nullptr; // not found
 525 }
 526 
 527 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) {
 528   Method* method = k->lookup_method(name, signature);
 529   if (method == nullptr) {
 530     ResourceMark rm(THREAD);
 531     stringStream st;
 532     st.print("Method '");
 533     print_external_name(&st, k, name, signature);
 534     st.print("' name or signature does not match");
 535     THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
 536   }
 537   if (!method->is_native()) {
 538     // trying to register to a non-native method, see if a JVM TI agent has added prefix(es)
 539     method = find_prefixed_native(k, name, signature, THREAD);
 540     if (method == nullptr) {
 541       ResourceMark rm(THREAD);
 542       stringStream st;
 543       st.print("Method '");
 544       print_external_name(&st, k, name, signature);
 545       st.print("' is not declared as native");
 546       THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false);
 547     }
 548   }
 549 
 550   if (entry != nullptr) {
 551     method->set_native_function(entry, native_bind_event_is_interesting);
 552   } else {
 553     method->clear_native_function();
 554   }
 555   if (log_is_enabled(Debug, jni, resolve)) {
 556     ResourceMark rm(THREAD);
 557     log_debug(jni, resolve)("[Registering JNI native method %s.%s]",
 558                             method->method_holder()->external_name(),
 559                             method->name()->as_C_string());
 560   }
 561   return true;
 562 }
 563 
 564 bool Method::was_executed_more_than(int n) {
 565   // Invocation counter is reset when the Method* is compiled.
 566   // If the method has compiled code we therefore assume it has
 567   // be executed more than n times.
 568   if (is_accessor() || is_empty_method() || (code() != nullptr)) {
 569     // interpreter doesn't bump invocation counter of trivial methods
 570     // compiler does not bump invocation counter of compiled methods
 571     return true;
 572   }
 573   else if ((method_counters() != nullptr &&
 574             method_counters()->invocation_counter()->carry()) ||
 575            (method_data() != nullptr &&
 576             method_data()->invocation_counter()->carry())) {
 577     // The carry bit is set when the counter overflows and causes
 578     // a compilation to occur.  We don't know how many times
 579     // the counter has been reset, so we simply assume it has
 580     // been executed more than n times.
 581     return true;
 582   } else {
 583     return invocation_count() > n;
 584   }
 585 }
 586 
 587 void Method::print_invocation_count(outputStream* st) {
 588   //---<  compose+print method return type, klass, name, and signature  >---
 589   if (is_static())       { st->print("static "); }
 590   if (is_final())        { st->print("final "); }
 591   if (is_synchronized()) { st->print("synchronized "); }
 592   if (is_native())       { st->print("native "); }
 593   st->print("%s::", method_holder()->external_name());
 594   name()->print_symbol_on(st);
 595   signature()->print_symbol_on(st);
 596 
 597   if (WizardMode) {
 598     // dump the size of the byte codes
 599     st->print(" {%d}", code_size());
 600   }
 601   st->cr();
 602 
 603   // Counting based on signed int counters tends to overflow with
 604   // longer-running workloads on fast machines. The counters under
 605   // consideration here, however, are limited in range by counting
 606   // logic. See InvocationCounter:count_limit for example.
 607   // No "overflow precautions" need to be implemented here.
 608   st->print_cr ("  interpreter_invocation_count: " INT32_FORMAT_W(11), interpreter_invocation_count());
 609   st->print_cr ("  invocation_counter:           " INT32_FORMAT_W(11), invocation_count());
 610   st->print_cr ("  backedge_counter:             " INT32_FORMAT_W(11), backedge_count());
 611 
 612   if (method_data() != nullptr) {
 613     st->print_cr ("  decompile_count:              " UINT32_FORMAT_W(11), method_data()->decompile_count());
 614   }
 615 
 616 #ifndef PRODUCT
 617   if (CountCompiledCalls) {
 618     st->print_cr ("  compiled_invocation_count:    " INT64_FORMAT_W(11), compiled_invocation_count());
 619   }
 620 #endif
 621 }
 622 
 623 MethodTrainingData* Method::training_data_or_null() const {
 624   MethodCounters* mcs = method_counters();
 625   if (mcs == nullptr) {
 626     return nullptr;
 627   } else {
 628     MethodTrainingData* mtd = mcs->method_training_data();
 629     if (mtd == mcs->method_training_data_sentinel()) {
 630       return nullptr;
 631     }
 632     return mtd;
 633   }
 634 }
 635 
 636 bool Method::init_training_data(MethodTrainingData* td) {
 637   MethodCounters* mcs = method_counters();
 638   if (mcs == nullptr) {
 639     return false;
 640   } else {
 641     return mcs->init_method_training_data(td);
 642   }
 643 }
 644 
 645 bool Method::install_training_method_data(const methodHandle& method) {
 646   MethodTrainingData* mtd = MethodTrainingData::find(method);
 647   if (mtd != nullptr && mtd->final_profile() != nullptr) {
 648     AtomicAccess::replace_if_null(&method->_method_data, mtd->final_profile());
 649     return true;
 650   }
 651   return false;
 652 }
 653 
 654 // Build a MethodData* object to hold profiling information collected on this
 655 // method when requested.
 656 void Method::build_profiling_method_data(const methodHandle& method, TRAPS) {
 657   if (install_training_method_data(method)) {
 658     return;
 659   }
 660   // Do not profile the method if metaspace has hit an OOM previously
 661   // allocating profiling data. Callers clear pending exception so don't
 662   // add one here.
 663   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 664     return;
 665   }
 666 
 667   ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 668   MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 669   if (HAS_PENDING_EXCEPTION) {
 670     CompileBroker::log_metaspace_failure();
 671     ClassLoaderDataGraph::set_metaspace_oom(true);
 672     return;   // return the exception (which is cleared)
 673   }
 674 
 675   if (!AtomicAccess::replace_if_null(&method->_method_data, method_data)) {
 676     MetadataFactory::free_metadata(loader_data, method_data);
 677     return;
 678   }
 679 
 680   if (PrintMethodData && (Verbose || WizardMode)) {
 681     ResourceMark rm(THREAD);
 682     tty->print("build_profiling_method_data for ");
 683     method->print_name(tty);
 684     tty->cr();
 685     // At the end of the run, the MDO, full of data, will be dumped.
 686   }
 687 }
 688 
 689 MethodCounters* Method::build_method_counters(Thread* current, Method* m) {
 690   // Do not profile the method if metaspace has hit an OOM previously
 691   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 692     return nullptr;
 693   }
 694 
 695   methodHandle mh(current, m);
 696   MethodCounters* counters;
 697   if (current->is_Java_thread()) {
 698     JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
 699     // Use the TRAPS version for a JavaThread so it will adjust the GC threshold
 700     // if needed.
 701     counters = MethodCounters::allocate_with_exception(mh, THREAD);
 702     if (HAS_PENDING_EXCEPTION) {
 703       CLEAR_PENDING_EXCEPTION;
 704     }
 705   } else {
 706     // Call metaspace allocation that doesn't throw exception if the
 707     // current thread isn't a JavaThread, ie. the VMThread.
 708     counters = MethodCounters::allocate_no_exception(mh);
 709   }
 710 
 711   if (counters == nullptr) {
 712     CompileBroker::log_metaspace_failure();
 713     ClassLoaderDataGraph::set_metaspace_oom(true);
 714     return nullptr;
 715   }
 716 
 717   if (!mh->init_method_counters(counters)) {
 718     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 719   }
 720 
 721   return mh->method_counters();
 722 }
 723 
 724 bool Method::init_method_counters(MethodCounters* counters) {
 725   // Try to install a pointer to MethodCounters, return true on success.
 726   return AtomicAccess::replace_if_null(&_method_counters, counters);
 727 }
 728 
 729 void Method::set_exception_handler_entered(int handler_bci) {
 730   if (ProfileExceptionHandlers) {
 731     MethodData* mdo = method_data();
 732     if (mdo != nullptr) {
 733       BitData handler_data = mdo->exception_handler_bci_to_data(handler_bci);
 734       handler_data.set_exception_handler_entered();
 735     }
 736   }
 737 }
 738 
 739 int Method::extra_stack_words() {
 740   // not an inline function, to avoid a header dependency on Interpreter
 741   return extra_stack_entries() * Interpreter::stackElementSize;
 742 }
 743 
 744 bool Method::compute_has_loops_flag() {
 745   BytecodeStream bcs(methodHandle(Thread::current(), this));
 746   Bytecodes::Code bc;
 747 
 748   while ((bc = bcs.next()) >= 0) {
 749     switch (bc) {
 750       case Bytecodes::_ifeq:
 751       case Bytecodes::_ifnull:
 752       case Bytecodes::_iflt:
 753       case Bytecodes::_ifle:
 754       case Bytecodes::_ifne:
 755       case Bytecodes::_ifnonnull:
 756       case Bytecodes::_ifgt:
 757       case Bytecodes::_ifge:
 758       case Bytecodes::_if_icmpeq:
 759       case Bytecodes::_if_icmpne:
 760       case Bytecodes::_if_icmplt:
 761       case Bytecodes::_if_icmpgt:
 762       case Bytecodes::_if_icmple:
 763       case Bytecodes::_if_icmpge:
 764       case Bytecodes::_if_acmpeq:
 765       case Bytecodes::_if_acmpne:
 766       case Bytecodes::_goto:
 767       case Bytecodes::_jsr:
 768         if (bcs.dest() < bcs.next_bci()) {
 769           return set_has_loops();
 770         }
 771         break;
 772 
 773       case Bytecodes::_goto_w:
 774       case Bytecodes::_jsr_w:
 775         if (bcs.dest_w() < bcs.next_bci()) {
 776           return set_has_loops();
 777         }
 778         break;
 779 
 780       case Bytecodes::_lookupswitch: {
 781         Bytecode_lookupswitch lookupswitch(this, bcs.bcp());
 782         if (lookupswitch.default_offset() < 0) {
 783           return set_has_loops();
 784         } else {
 785           for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) {
 786             LookupswitchPair pair = lookupswitch.pair_at(i);
 787             if (pair.offset() < 0) {
 788               return set_has_loops();
 789             }
 790           }
 791         }
 792         break;
 793       }
 794       case Bytecodes::_tableswitch: {
 795         Bytecode_tableswitch tableswitch(this, bcs.bcp());
 796         if (tableswitch.default_offset() < 0) {
 797           return set_has_loops();
 798         } else {
 799           for (int i = 0; i < tableswitch.length(); ++i) {
 800             if (tableswitch.dest_offset_at(i) < 0) {
 801               return set_has_loops();
 802             }
 803           }
 804         }
 805         break;
 806       }
 807       default:
 808         break;
 809     }
 810   }
 811 
 812   _flags.set_has_loops_flag_init(true);
 813   return false;
 814 }
 815 
 816 bool Method::is_final_method(AccessFlags class_access_flags) const {
 817   // or "does_not_require_vtable_entry"
 818   // default method or overpass can occur, is not final (reuses vtable entry)
 819   // private methods in classes get vtable entries for backward class compatibility.
 820   if (is_overpass() || is_default_method())  return false;
 821   return is_final() || class_access_flags.is_final();
 822 }
 823 
 824 bool Method::is_final_method() const {
 825   return is_final_method(method_holder()->access_flags());
 826 }
 827 
 828 bool Method::is_default_method() const {
 829   if (method_holder() != nullptr &&
 830       method_holder()->is_interface() &&
 831       !is_abstract() && !is_private()) {
 832     return true;
 833   } else {
 834     return false;
 835   }
 836 }
 837 
 838 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 839   if (is_final_method(class_access_flags))  return true;
 840 #ifdef ASSERT
 841   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 842   if (class_access_flags.is_interface()) {
 843       ResourceMark rm;
 844       assert(is_nonv == is_static() || is_nonv == is_private(),
 845              "nonvirtual unexpected for non-static, non-private: %s",
 846              name_and_sig_as_C_string());
 847   }
 848 #endif
 849   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 850   return vtable_index() == nonvirtual_vtable_index;
 851 }
 852 
 853 bool Method::can_be_statically_bound() const {
 854   return can_be_statically_bound(method_holder()->access_flags());
 855 }
 856 
 857 bool Method::can_be_statically_bound(InstanceKlass* context) const {
 858   return (method_holder() == context) && can_be_statically_bound();
 859 }
 860 
 861 /**
 862  *  Returns false if this is one of specially treated methods for
 863  *  which we have to provide stack trace in throw in compiled code.
 864  *  Returns true otherwise.
 865  */
 866 bool Method::can_omit_stack_trace() {
 867   if (klass_name() == vmSymbols::sun_invoke_util_ValueConversions()) {
 868     return false; // All methods in sun.invoke.util.ValueConversions
 869   }
 870   return true;
 871 }
 872 
 873 bool Method::is_accessor() const {
 874   return is_getter() || is_setter();
 875 }
 876 
 877 bool Method::is_getter() const {
 878   if (code_size() != 5) return false;
 879   if (size_of_parameters() != 1) return false;
 880   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 881   if (java_code_at(1) != Bytecodes::_getfield) return false;
 882   switch (java_code_at(4)) {
 883     case Bytecodes::_ireturn:
 884     case Bytecodes::_lreturn:
 885     case Bytecodes::_freturn:
 886     case Bytecodes::_dreturn:
 887     case Bytecodes::_areturn:
 888       break;
 889     default:
 890       return false;
 891   }
 892   return true;
 893 }
 894 
 895 bool Method::is_setter() const {
 896   if (code_size() != 6) return false;
 897   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 898   switch (java_code_at(1)) {
 899     case Bytecodes::_iload_1:
 900     case Bytecodes::_aload_1:
 901     case Bytecodes::_fload_1:
 902       if (size_of_parameters() != 2) return false;
 903       break;
 904     case Bytecodes::_dload_1:
 905     case Bytecodes::_lload_1:
 906       if (size_of_parameters() != 3) return false;
 907       break;
 908     default:
 909       return false;
 910   }
 911   if (java_code_at(2) != Bytecodes::_putfield) return false;
 912   if (java_code_at(5) != Bytecodes::_return)   return false;
 913   return true;
 914 }
 915 
 916 bool Method::is_constant_getter() const {
 917   int last_index = code_size() - 1;
 918   // Check if the first 1-3 bytecodes are a constant push
 919   // and the last bytecode is a return.
 920   return (2 <= code_size() && code_size() <= 4 &&
 921           Bytecodes::is_const(java_code_at(0)) &&
 922           Bytecodes::length_for(java_code_at(0)) == last_index &&
 923           Bytecodes::is_return(java_code_at(last_index)));
 924 }
 925 
 926 bool Method::has_valid_initializer_flags() const {
 927   return (is_static() ||
 928           method_holder()->major_version() < 51);
 929 }
 930 
 931 bool Method::is_static_initializer() const {
 932   // For classfiles version 51 or greater, ensure that the clinit method is
 933   // static.  Non-static methods with the name "<clinit>" are not static
 934   // initializers. (older classfiles exempted for backward compatibility)
 935   return name() == vmSymbols::class_initializer_name() &&
 936          has_valid_initializer_flags();
 937 }
 938 
 939 bool Method::is_object_initializer() const {
 940    return name() == vmSymbols::object_initializer_name();
 941 }
 942 
 943 bool Method::needs_clinit_barrier() const {
 944   return is_static() && !method_holder()->is_initialized();
 945 }
 946 
 947 bool Method::is_object_wait0() const {
 948   return klass_name() == vmSymbols::java_lang_Object()
 949          && name() == vmSymbols::wait_name();
 950 }
 951 
 952 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 953   int length = method->checked_exceptions_length();
 954   if (length == 0) {  // common case
 955     return objArrayHandle(THREAD, Universe::the_empty_class_array());
 956   } else {
 957     methodHandle h_this(THREAD, method);
 958     objArrayOop m_oop = oopFactory::new_objArray(vmClasses::Class_klass(), length, CHECK_(objArrayHandle()));
 959     objArrayHandle mirrors (THREAD, m_oop);
 960     for (int i = 0; i < length; i++) {
 961       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 962       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 963       if (log_is_enabled(Warning, exceptions) &&
 964           !k->is_subclass_of(vmClasses::Throwable_klass())) {
 965         ResourceMark rm(THREAD);
 966         log_warning(exceptions)(
 967           "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
 968           k->external_name(), method->external_name());
 969       }
 970       mirrors->obj_at_put(i, k->java_mirror());
 971     }
 972     return mirrors;
 973   }
 974 };
 975 
 976 
 977 int Method::line_number_from_bci(int bci) const {
 978   int best_bci  =  0;
 979   int best_line = -1;
 980   if (bci == SynchronizationEntryBCI) bci = 0;
 981   if (0 <= bci && bci < code_size() && has_linenumber_table()) {
 982     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 983     // Not necessarily sorted and not necessarily one-to-one.
 984     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 985     while (stream.read_pair()) {
 986       if (stream.bci() == bci) {
 987         // perfect match
 988         return stream.line();
 989       } else {
 990         // update best_bci/line
 991         if (stream.bci() < bci && stream.bci() >= best_bci) {
 992           best_bci  = stream.bci();
 993           best_line = stream.line();
 994         }
 995       }
 996     }
 997   }
 998   return best_line;
 999 }
1000 
1001 
1002 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
1003   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
1004     Thread *thread = Thread::current();
1005     Symbol* klass_name = constants()->klass_name_at(klass_index);
1006     Handle loader(thread, method_holder()->class_loader());
1007     return SystemDictionary::find_instance_klass(thread, klass_name, loader) != nullptr;
1008   } else {
1009     return true;
1010   }
1011 }
1012 
1013 
1014 bool Method::is_klass_loaded(int refinfo_index, Bytecodes::Code bc, bool must_be_resolved) const {
1015   int klass_index = constants()->klass_ref_index_at(refinfo_index, bc);
1016   if (must_be_resolved) {
1017     // Make sure klass is resolved in constantpool.
1018     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
1019   }
1020   return is_klass_loaded_by_klass_index(klass_index);
1021 }
1022 
1023 
1024 void Method::set_native_function(address function, bool post_event_flag) {
1025   assert(function != nullptr, "use clear_native_function to unregister natives");
1026   assert(!is_special_native_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
1027   address* native_function = native_function_addr();
1028 
1029   // We can see racers trying to place the same native function into place. Once
1030   // is plenty.
1031   address current = *native_function;
1032   if (current == function) return;
1033   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
1034       function != nullptr) {
1035     // native_method_throw_unsatisfied_link_error_entry() should only
1036     // be passed when post_event_flag is false.
1037     assert(function !=
1038       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1039       "post_event_flag mismatch");
1040 
1041     // post the bind event, and possible change the bind function
1042     JvmtiExport::post_native_method_bind(this, &function);
1043   }
1044   *native_function = function;
1045   // This function can be called more than once. We must make sure that we always
1046   // use the latest registered method -> check if a stub already has been generated.
1047   // If so, we have to make it not_entrant.
1048   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
1049   if (nm != nullptr) {
1050     nm->make_not_entrant(nmethod::InvalidationReason::SET_NATIVE_FUNCTION);
1051   }
1052 }
1053 
1054 
1055 bool Method::has_native_function() const {
1056   if (is_special_native_intrinsic())
1057     return false;  // special-cased in SharedRuntime::generate_native_wrapper
1058   address func = native_function();
1059   return (func != nullptr && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
1060 }
1061 
1062 
1063 void Method::clear_native_function() {
1064   // Note: is_method_handle_intrinsic() is allowed here.
1065   set_native_function(
1066     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1067     !native_bind_event_is_interesting);
1068   this->unlink_code();
1069 }
1070 
1071 
1072 void Method::set_signature_handler(address handler) {
1073   address* signature_handler =  signature_handler_addr();
1074   *signature_handler = handler;
1075 }
1076 
1077 
1078 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
1079   assert(reason != nullptr, "must provide a reason");
1080   if (PrintCompilation && report) {
1081     ttyLocker ttyl;
1082     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
1083     if (comp_level == CompLevel_all) {
1084       tty->print("all levels ");
1085     } else {
1086       tty->print("level %d ", comp_level);
1087     }
1088     this->print_short_name(tty);
1089     int size = this->code_size();
1090     if (size > 0) {
1091       tty->print(" (%d bytes)", size);
1092     }
1093     if (reason != nullptr) {
1094       tty->print("   %s", reason);
1095     }
1096     tty->cr();
1097   }
1098   if ((TraceDeoptimization || LogCompilation) && (xtty != nullptr)) {
1099     ttyLocker ttyl;
1100     xtty->begin_elem("make_not_compilable thread='%zu' osr='%d' level='%d'",
1101                      os::current_thread_id(), is_osr, comp_level);
1102     if (reason != nullptr) {
1103       xtty->print(" reason=\'%s\'", reason);
1104     }
1105     xtty->method(this);
1106     xtty->stamp();
1107     xtty->end_elem();
1108   }
1109 }
1110 
1111 bool Method::is_always_compilable() const {
1112   // Generated adapters must be compiled
1113   if (is_special_native_intrinsic() && is_synthetic()) {
1114     assert(!is_not_c1_compilable(), "sanity check");
1115     assert(!is_not_c2_compilable(), "sanity check");
1116     return true;
1117   }
1118 
1119   return false;
1120 }
1121 
1122 bool Method::is_not_compilable(int comp_level) const {
1123   if (number_of_breakpoints() > 0)
1124     return true;
1125   if (is_always_compilable())
1126     return false;
1127   if (comp_level == CompLevel_any)
1128     return is_not_c1_compilable() && is_not_c2_compilable();
1129   if (is_c1_compile(comp_level))
1130     return is_not_c1_compilable();
1131   if (is_c2_compile(comp_level))
1132     return is_not_c2_compilable();
1133   return false;
1134 }
1135 
1136 // call this when compiler finds that this method is not compilable
1137 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
1138   if (is_always_compilable()) {
1139     // Don't mark a method which should be always compilable
1140     return;
1141   }
1142   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
1143   if (comp_level == CompLevel_all) {
1144     set_is_not_c1_compilable();
1145     set_is_not_c2_compilable();
1146   } else {
1147     if (is_c1_compile(comp_level))
1148       set_is_not_c1_compilable();
1149     if (is_c2_compile(comp_level))
1150       set_is_not_c2_compilable();
1151   }
1152   assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1153 }
1154 
1155 bool Method::is_not_osr_compilable(int comp_level) const {
1156   if (is_not_compilable(comp_level))
1157     return true;
1158   if (comp_level == CompLevel_any)
1159     return is_not_c1_osr_compilable() && is_not_c2_osr_compilable();
1160   if (is_c1_compile(comp_level))
1161     return is_not_c1_osr_compilable();
1162   if (is_c2_compile(comp_level))
1163     return is_not_c2_osr_compilable();
1164   return false;
1165 }
1166 
1167 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
1168   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
1169   if (comp_level == CompLevel_all) {
1170     set_is_not_c1_osr_compilable();
1171     set_is_not_c2_osr_compilable();
1172   } else {
1173     if (is_c1_compile(comp_level))
1174       set_is_not_c1_osr_compilable();
1175     if (is_c2_compile(comp_level))
1176       set_is_not_c2_osr_compilable();
1177   }
1178   assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check");
1179 }
1180 
1181 // Revert to using the interpreter and clear out the nmethod
1182 void Method::clear_code() {
1183   // this may be null if c2i adapters have not been made yet
1184   // Only should happen at allocate time.
1185   if (adapter() == nullptr) {
1186     _from_compiled_entry = nullptr;
1187   } else {
1188     _from_compiled_entry = adapter()->get_c2i_entry();
1189   }
1190   OrderAccess::storestore();
1191   _from_interpreted_entry = _i2i_entry;
1192   OrderAccess::storestore();
1193   _code = nullptr;
1194 }
1195 
1196 void Method::unlink_code(nmethod *compare) {
1197   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
1198   // We need to check if either the _code or _from_compiled_code_entry_point
1199   // refer to this nmethod because there is a race in setting these two fields
1200   // in Method* as seen in bugid 4947125.
1201   if (code() == compare ||
1202       from_compiled_entry() == compare->verified_entry_point()) {
1203     clear_code();
1204   }
1205 }
1206 
1207 void Method::unlink_code() {
1208   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
1209   clear_code();
1210 }
1211 
1212 #if INCLUDE_CDS
1213 // Called by class data sharing to remove any entry points (which are not shared)
1214 void Method::unlink_method() {
1215   assert(CDSConfig::is_dumping_archive(), "sanity");
1216   _code = nullptr;
1217   if (!CDSConfig::is_dumping_adapters()) {
1218     _adapter = nullptr;
1219   }
1220   _i2i_entry = nullptr;
1221   _from_compiled_entry = nullptr;
1222   _from_interpreted_entry = nullptr;
1223 
1224   if (is_native()) {
1225     *native_function_addr() = nullptr;
1226     set_signature_handler(nullptr);
1227   }
1228   NOT_PRODUCT(set_compiled_invocation_count(0);)
1229 
1230   clear_method_data();
1231   clear_method_counters();
1232   clear_is_not_c1_compilable();
1233   clear_is_not_c1_osr_compilable();
1234   clear_is_not_c2_compilable();
1235   clear_is_not_c2_osr_compilable();
1236   clear_queued_for_compilation();
1237 
1238   remove_unshareable_flags();
1239 }
1240 
1241 void Method::remove_unshareable_flags() {
1242   // clear all the flags that shouldn't be in the archived version
1243   assert(!is_old(), "must be");
1244   assert(!is_obsolete(), "must be");
1245   assert(!is_deleted(), "must be");
1246 
1247   set_is_prefixed_native(false);
1248   set_queued_for_compilation(false);
1249   set_is_not_c2_compilable(false);
1250   set_is_not_c1_compilable(false);
1251   set_is_not_c2_osr_compilable(false);
1252   set_on_stack_flag(false);
1253 }
1254 #endif
1255 
1256 // Called when the method_holder is getting linked. Setup entrypoints so the method
1257 // is ready to be called from interpreter, compiler, and vtables.
1258 void Method::link_method(const methodHandle& h_method, TRAPS) {
1259   if (log_is_enabled(Info, perf, class, link)) {
1260     ClassLoader::perf_ik_link_methods_count()->inc();
1261   }
1262 
1263   // If the code cache is full, we may reenter this function for the
1264   // leftover methods that weren't linked.
1265   if (adapter() != nullptr) {
1266     if (adapter()->in_aot_cache()) {
1267       assert(adapter()->is_linked(), "Adapter is shared but not linked");
1268     } else {
1269       return;
1270     }
1271   }
1272   assert( _code == nullptr, "nothing compiled yet" );
1273 
1274   // Setup interpreter entrypoint
1275   assert(this == h_method(), "wrong h_method()" );
1276 
1277   assert(adapter() == nullptr || adapter()->is_linked(), "init'd to null or restored from cache");
1278   address entry = Interpreter::entry_for_method(h_method);
1279   assert(entry != nullptr, "interpreter entry must be non-null");
1280   // Sets both _i2i_entry and _from_interpreted_entry
1281   set_interpreter_entry(entry);
1282 
1283   // Don't overwrite already registered native entries.
1284   if (is_native() && !has_native_function()) {
1285     set_native_function(
1286       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1287       !native_bind_event_is_interesting);
1288   }
1289 
1290   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1291   // special handling of vtables.  An alternative is to make adapters more
1292   // lazily by calling make_adapter() from from_compiled_entry() for the
1293   // normal calls.  For vtable calls life gets more complicated.  When a
1294   // call-site goes mega-morphic we need adapters in all methods which can be
1295   // called from the vtable.  We need adapters on such methods that get loaded
1296   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1297   // problem we'll make these lazily later.
1298   if (is_abstract()) {
1299     h_method->_from_compiled_entry = SharedRuntime::get_handle_wrong_method_abstract_stub();
1300   } else if (_adapter == nullptr) {
1301     (void) make_adapters(h_method, CHECK);
1302 #ifndef ZERO
1303     assert(adapter()->is_linked(), "Adapter must have been linked");
1304 #endif
1305     h_method->_from_compiled_entry = adapter()->get_c2i_entry();
1306   }
1307 
1308   // ONLY USE the h_method now as make_adapter may have blocked
1309 
1310   if (h_method->is_continuation_native_intrinsic()) {
1311     _from_interpreted_entry = nullptr;
1312     _from_compiled_entry = nullptr;
1313     _i2i_entry = nullptr;
1314     if (Continuations::enabled()) {
1315       assert(!Threads::is_vm_complete(), "should only be called during vm init");
1316       AdapterHandlerLibrary::create_native_wrapper(h_method);
1317       if (!h_method->has_compiled_code()) {
1318         THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Initial size of CodeCache is too small");
1319       }
1320       assert(_from_interpreted_entry == get_i2c_entry(), "invariant");
1321     }
1322   }
1323 }
1324 
1325 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1326   assert(!mh->is_abstract(), "abstract methods do not have adapters");
1327   PerfTraceTime timer(ClassLoader::perf_method_adapters_time());
1328 
1329   // Adapters for compiled code are made eagerly here.  They are fairly
1330   // small (generally < 100 bytes) and quick to make (and cached and shared)
1331   // so making them eagerly shouldn't be too expensive.
1332   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1333   if (adapter == nullptr ) {
1334     if (!is_init_completed()) {
1335       // Don't throw exceptions during VM initialization because java.lang.* classes
1336       // might not have been initialized, causing problems when constructing the
1337       // Java exception object.
1338       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1339     } else {
1340       THROW_MSG_NULL(vmSymbols::java_lang_OutOfMemoryError(), "Out of space in CodeCache for adapters");
1341     }
1342   }
1343 
1344   mh->set_adapter_entry(adapter);
1345   return adapter->get_c2i_entry();
1346 }
1347 
1348 // The verified_code_entry() must be called when a invoke is resolved
1349 // on this method.
1350 
1351 // It returns the compiled code entry point, after asserting not null.
1352 // This function is called after potential safepoints so that nmethod
1353 // or adapter that it points to is still live and valid.
1354 // This function must not hit a safepoint!
1355 address Method::verified_code_entry() {
1356   DEBUG_ONLY(NoSafepointVerifier nsv;)
1357   assert(_from_compiled_entry != nullptr, "must be set");
1358   return _from_compiled_entry;
1359 }
1360 
1361 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1362 // (could be racing a deopt).
1363 // Not inline to avoid circular ref.
1364 bool Method::check_code() const {
1365   // cached in a register or local.  There's a race on the value of the field.
1366   nmethod *code = AtomicAccess::load_acquire(&_code);
1367   return code == nullptr || (code->method() == nullptr) || (code->method() == (Method*)this && !code->is_osr_method());
1368 }
1369 
1370 // Install compiled code.  Instantly it can execute.
1371 void Method::set_code(const methodHandle& mh, nmethod *code) {
1372   assert_lock_strong(NMethodState_lock);
1373   assert( code, "use clear_code to remove code" );
1374   assert( mh->check_code(), "" );
1375 
1376   guarantee(mh->adapter() != nullptr, "Adapter blob must already exist!");
1377 
1378   // These writes must happen in this order, because the interpreter will
1379   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1380   // which jumps to _from_compiled_entry.
1381   mh->_code = code;             // Assign before allowing compiled code to exec
1382 
1383   int comp_level = code->comp_level();
1384   // In theory there could be a race here. In practice it is unlikely
1385   // and not worth worrying about.
1386   if (comp_level > mh->highest_comp_level()) {
1387     mh->set_highest_comp_level(comp_level);
1388   }
1389 
1390   OrderAccess::storestore();
1391   mh->_from_compiled_entry = code->verified_entry_point();
1392   OrderAccess::storestore();
1393 
1394   if (mh->is_continuation_native_intrinsic()) {
1395     assert(mh->_from_interpreted_entry == nullptr, "initialized incorrectly"); // see link_method
1396 
1397     if (mh->is_continuation_enter_intrinsic()) {
1398       // This is the entry used when we're in interpreter-only mode; see InterpreterMacroAssembler::jump_from_interpreted
1399       mh->_i2i_entry = ContinuationEntry::interpreted_entry();
1400     } else if (mh->is_continuation_yield_intrinsic()) {
1401       mh->_i2i_entry = mh->get_i2c_entry();
1402     } else {
1403       guarantee(false, "Unknown Continuation native intrinsic");
1404     }
1405     // This must come last, as it is what's tested in LinkResolver::resolve_static_call
1406     AtomicAccess::release_store(&mh->_from_interpreted_entry , mh->get_i2c_entry());
1407   } else if (!mh->is_method_handle_intrinsic()) {
1408     // Instantly compiled code can execute.
1409     mh->_from_interpreted_entry = mh->get_i2c_entry();
1410   }
1411 }
1412 
1413 
1414 bool Method::is_overridden_in(Klass* k) const {
1415   InstanceKlass* ik = InstanceKlass::cast(k);
1416 
1417   if (ik->is_interface()) return false;
1418 
1419   // If method is an interface, we skip it - except if it
1420   // is a miranda method
1421   if (method_holder()->is_interface()) {
1422     // Check that method is not a miranda method
1423     if (ik->lookup_method(name(), signature()) == nullptr) {
1424       // No implementation exist - so miranda method
1425       return false;
1426     }
1427     return true;
1428   }
1429 
1430   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1431   if (!has_vtable_index()) {
1432     return false;
1433   } else {
1434     Method* vt_m = ik->method_at_vtable(vtable_index());
1435     return vt_m != this;
1436   }
1437 }
1438 
1439 
1440 // give advice about whether this Method* should be cached or not
1441 bool Method::should_not_be_cached() const {
1442   if (is_old()) {
1443     // This method has been redefined. It is either EMCP or obsolete
1444     // and we don't want to cache it because that would pin the method
1445     // down and prevent it from being collectible if and when it
1446     // finishes executing.
1447     return true;
1448   }
1449 
1450   // caching this method should be just fine
1451   return false;
1452 }
1453 
1454 
1455 /**
1456  *  Returns true if this is one of the specially treated methods for
1457  *  security related stack walks (like Reflection.getCallerClass).
1458  */
1459 bool Method::is_ignored_by_security_stack_walk() const {
1460   if (intrinsic_id() == vmIntrinsics::_invoke) {
1461     // This is Method.invoke() -- ignore it
1462     return true;
1463   }
1464   if (method_holder()->is_subclass_of(vmClasses::reflect_MethodAccessorImpl_klass())) {
1465     // This is an auxiliary frame -- ignore it
1466     return true;
1467   }
1468   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1469     // This is an internal adapter frame for method handles -- ignore it
1470     return true;
1471   }
1472   return false;
1473 }
1474 
1475 
1476 // Constant pool structure for invoke methods:
1477 enum {
1478   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1479   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1480   _imcp_limit
1481 };
1482 
1483 // Test if this method is an MH adapter frame generated by Java code.
1484 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1485 bool Method::is_compiled_lambda_form() const {
1486   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1487 }
1488 
1489 // Test if this method is an internal MH primitive method.
1490 bool Method::is_method_handle_intrinsic() const {
1491   vmIntrinsics::ID iid = intrinsic_id();
1492   return (MethodHandles::is_signature_polymorphic(iid) &&
1493           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1494 }
1495 
1496 bool Method::has_member_arg() const {
1497   vmIntrinsics::ID iid = intrinsic_id();
1498   return (MethodHandles::is_signature_polymorphic(iid) &&
1499           MethodHandles::has_member_arg(iid));
1500 }
1501 
1502 // Make an instance of a signature-polymorphic internal MH primitive.
1503 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1504                                                          Symbol* signature,
1505                                                          TRAPS) {
1506   ResourceMark rm(THREAD);
1507   methodHandle empty;
1508 
1509   InstanceKlass* holder = vmClasses::MethodHandle_klass();
1510   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1511   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1512 
1513   log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1514 
1515   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1516   name->increment_refcount();
1517   signature->increment_refcount();
1518 
1519   int cp_length = _imcp_limit;
1520   ClassLoaderData* loader_data = holder->class_loader_data();
1521   constantPoolHandle cp;
1522   {
1523     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1524     cp = constantPoolHandle(THREAD, cp_oop);
1525   }
1526   cp->copy_fields(holder->constants());
1527   cp->set_pool_holder(holder);
1528   cp->symbol_at_put(_imcp_invoke_name,       name);
1529   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1530   cp->set_has_preresolution();
1531   cp->set_is_for_method_handle_intrinsic();
1532 
1533   // decide on access bits:  public or not?
1534   u2 flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1535   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1536   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1537   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1538 
1539   methodHandle m;
1540   {
1541     InlineTableSizes sizes;
1542     Method* m_oop = Method::allocate(loader_data, 0,
1543                                      accessFlags_from(flags_bits), &sizes,
1544                                      ConstMethod::NORMAL,
1545                                      name,
1546                                      CHECK_(empty));
1547     m = methodHandle(THREAD, m_oop);
1548   }
1549   m->set_constants(cp());
1550   m->set_name_index(_imcp_invoke_name);
1551   m->set_signature_index(_imcp_invoke_signature);
1552   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1553   assert(m->signature() == signature, "");
1554   m->constMethod()->compute_from_signature(signature, must_be_static);
1555   m->init_intrinsic_id(klass_id_for_intrinsics(m->method_holder()));
1556   assert(m->is_method_handle_intrinsic(), "");
1557 #ifdef ASSERT
1558   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1559   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1560   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1561 #endif //ASSERT
1562 
1563   // Finally, set up its entry points.
1564   assert(m->can_be_statically_bound(), "");
1565   m->set_vtable_index(Method::nonvirtual_vtable_index);
1566   m->link_method(m, CHECK_(empty));
1567 
1568   if (iid == vmIntrinsics::_linkToNative) {
1569     m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1570   }
1571   if (log_is_enabled(Debug, methodhandles)) {
1572     LogTarget(Debug, methodhandles) lt;
1573     LogStream ls(lt);
1574     m->print_on(&ls);
1575   }
1576 
1577   return m;
1578 }
1579 
1580 #if INCLUDE_CDS
1581 void Method::restore_archived_method_handle_intrinsic(methodHandle m, TRAPS) {
1582   if (m->adapter() != nullptr) {
1583     m->set_from_compiled_entry(m->adapter()->get_c2i_entry());
1584   }
1585   m->link_method(m, CHECK);
1586 
1587   if (m->intrinsic_id() == vmIntrinsics::_linkToNative) {
1588     m->set_interpreter_entry(m->adapter()->get_i2c_entry());
1589   }
1590 }
1591 #endif
1592 
1593 Klass* Method::check_non_bcp_klass(Klass* klass) {
1594   if (klass != nullptr && klass->class_loader() != nullptr) {
1595     if (klass->is_objArray_klass())
1596       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1597     return klass;
1598   }
1599   return nullptr;
1600 }
1601 
1602 
1603 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1604                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1605   // Code below does not work for native methods - they should never get rewritten anyway
1606   assert(!m->is_native(), "cannot rewrite native methods");
1607   // Allocate new Method*
1608   AccessFlags flags = m->access_flags();
1609 
1610   ConstMethod* cm = m->constMethod();
1611   int checked_exceptions_len = cm->checked_exceptions_length();
1612   int localvariable_len = cm->localvariable_table_length();
1613   int exception_table_len = cm->exception_table_length();
1614   int method_parameters_len = cm->method_parameters_length();
1615   int method_annotations_len = cm->method_annotations_length();
1616   int parameter_annotations_len = cm->parameter_annotations_length();
1617   int type_annotations_len = cm->type_annotations_length();
1618   int default_annotations_len = cm->default_annotations_length();
1619 
1620   InlineTableSizes sizes(
1621       localvariable_len,
1622       new_compressed_linenumber_size,
1623       exception_table_len,
1624       checked_exceptions_len,
1625       method_parameters_len,
1626       cm->generic_signature_index(),
1627       method_annotations_len,
1628       parameter_annotations_len,
1629       type_annotations_len,
1630       default_annotations_len,
1631       0);
1632 
1633   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1634   Method* newm_oop = Method::allocate(loader_data,
1635                                       new_code_length,
1636                                       flags,
1637                                       &sizes,
1638                                       m->method_type(),
1639                                       m->name(),
1640                                       CHECK_(methodHandle()));
1641   methodHandle newm (THREAD, newm_oop);
1642 
1643   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1644   ConstMethod* newcm = newm->constMethod();
1645   int new_const_method_size = newm->constMethod()->size();
1646 
1647   // This works because the source and target are both Methods. Some compilers
1648   // (e.g., clang) complain that the target vtable pointer will be stomped,
1649   // so cast away newm()'s and m()'s Methodness.
1650   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1651 
1652   // Create shallow copy of ConstMethod.
1653   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1654 
1655   // Reset correct method/const method, method size, and parameter info
1656   newm->set_constMethod(newcm);
1657   newm->constMethod()->set_code_size(new_code_length);
1658   newm->constMethod()->set_constMethod_size(new_const_method_size);
1659   assert(newm->code_size() == new_code_length, "check");
1660   assert(newm->method_parameters_length() == method_parameters_len, "check");
1661   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1662   assert(newm->exception_table_length() == exception_table_len, "check");
1663   assert(newm->localvariable_table_length() == localvariable_len, "check");
1664   // Copy new byte codes
1665   memcpy(newm->code_base(), new_code, new_code_length);
1666   // Copy line number table
1667   if (new_compressed_linenumber_size > 0) {
1668     memcpy(newm->compressed_linenumber_table(),
1669            new_compressed_linenumber_table,
1670            new_compressed_linenumber_size);
1671   }
1672   // Copy method_parameters
1673   if (method_parameters_len > 0) {
1674     memcpy(newm->method_parameters_start(),
1675            m->method_parameters_start(),
1676            method_parameters_len * sizeof(MethodParametersElement));
1677   }
1678   // Copy checked_exceptions
1679   if (checked_exceptions_len > 0) {
1680     memcpy(newm->checked_exceptions_start(),
1681            m->checked_exceptions_start(),
1682            checked_exceptions_len * sizeof(CheckedExceptionElement));
1683   }
1684   // Copy exception table
1685   if (exception_table_len > 0) {
1686     memcpy(newm->exception_table_start(),
1687            m->exception_table_start(),
1688            exception_table_len * sizeof(ExceptionTableElement));
1689   }
1690   // Copy local variable number table
1691   if (localvariable_len > 0) {
1692     memcpy(newm->localvariable_table_start(),
1693            m->localvariable_table_start(),
1694            localvariable_len * sizeof(LocalVariableTableElement));
1695   }
1696   // Copy stackmap table
1697   if (m->has_stackmap_table()) {
1698     int code_attribute_length = m->stackmap_data()->length();
1699     Array<u1>* stackmap_data =
1700       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle()));
1701     memcpy((void*)stackmap_data->adr_at(0),
1702            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1703     newm->set_stackmap_data(stackmap_data);
1704   }
1705 
1706   // copy annotations over to new method
1707   newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle()));
1708   return newm;
1709 }
1710 
1711 vmSymbolID Method::klass_id_for_intrinsics(const Klass* holder) {
1712   // if loader is not the default loader (i.e., non-null), we can't know the intrinsics
1713   // because we are not loading from core libraries
1714   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1715   // which does not use the class default class loader so we check for its loader here
1716   const InstanceKlass* ik = InstanceKlass::cast(holder);
1717   if ((ik->class_loader() != nullptr) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1718     return vmSymbolID::NO_SID;   // regardless of name, no intrinsics here
1719   }
1720 
1721   // see if the klass name is well-known:
1722   Symbol* klass_name = ik->name();
1723   vmSymbolID id = vmSymbols::find_sid(klass_name);
1724   if (id != vmSymbolID::NO_SID && vmIntrinsics::class_has_intrinsics(id)) {
1725     return id;
1726   } else {
1727     return vmSymbolID::NO_SID;
1728   }
1729 }
1730 
1731 void Method::init_intrinsic_id(vmSymbolID klass_id) {
1732   assert(_intrinsic_id == static_cast<int>(vmIntrinsics::_none), "do this just once");
1733   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1734   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1735   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1736 
1737   // the klass name is well-known:
1738   assert(klass_id == klass_id_for_intrinsics(method_holder()), "must be");
1739   assert(klass_id != vmSymbolID::NO_SID, "caller responsibility");
1740 
1741   // ditto for method and signature:
1742   vmSymbolID name_id = vmSymbols::find_sid(name());
1743   if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1744       && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1745       && name_id == vmSymbolID::NO_SID) {
1746     return;
1747   }
1748   vmSymbolID sig_id = vmSymbols::find_sid(signature());
1749   if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1750       && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1751       && sig_id == vmSymbolID::NO_SID) {
1752     return;
1753   }
1754 
1755   u2 flags = access_flags().as_method_flags();
1756   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1757   if (id != vmIntrinsics::_none) {
1758     set_intrinsic_id(id);
1759     if (id == vmIntrinsics::_Class_cast) {
1760       // Even if the intrinsic is rejected, we want to inline this simple method.
1761       set_force_inline();
1762     }
1763     return;
1764   }
1765 
1766   // A few slightly irregular cases:
1767   switch (klass_id) {
1768   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1769   case VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1770   case VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1771     if (!is_native())  break;
1772     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1773     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1774       id = vmIntrinsics::_none;
1775     break;
1776 
1777   default:
1778     break;
1779   }
1780 
1781   if (id != vmIntrinsics::_none) {
1782     // Set up its iid.  It is an alias method.
1783     set_intrinsic_id(id);
1784     return;
1785   }
1786 }
1787 
1788 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1789   if (!THREAD->can_call_java()) {
1790     // There is nothing useful this routine can do from within the Compile thread.
1791     // Hopefully, the signature contains only well-known classes.
1792     // We could scan for this and return true/false, but the caller won't care.
1793     return false;
1794   }
1795   bool sig_is_loaded = true;
1796   ResourceMark rm(THREAD);
1797   for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) {
1798     if (ss.is_reference()) {
1799       // load everything, including arrays "[Lfoo;"
1800       Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD);
1801       // We are loading classes eagerly. If a ClassNotFoundException or
1802       // a LinkageError was generated, be sure to ignore it.
1803       if (HAS_PENDING_EXCEPTION) {
1804         if (PENDING_EXCEPTION->is_a(vmClasses::ClassNotFoundException_klass()) ||
1805             PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass())) {
1806           CLEAR_PENDING_EXCEPTION;
1807         } else {
1808           return false;
1809         }
1810       }
1811       if( klass == nullptr) { sig_is_loaded = false; }
1812     }
1813   }
1814   return sig_is_loaded;
1815 }
1816 
1817 // Exposed so field engineers can debug VM
1818 void Method::print_short_name(outputStream* st) const {
1819   ResourceMark rm;
1820 #ifdef PRODUCT
1821   st->print(" %s::", method_holder()->external_name());
1822 #else
1823   st->print(" %s::", method_holder()->internal_name());
1824 #endif
1825   name()->print_symbol_on(st);
1826   if (WizardMode) signature()->print_symbol_on(st);
1827   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1828     MethodHandles::print_as_basic_type_signature_on(st, signature());
1829 }
1830 
1831 // Comparer for sorting an object array containing
1832 // Method*s.
1833 static int method_comparator(Method* a, Method* b) {
1834   return a->name()->fast_compare(b->name());
1835 }
1836 
1837 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1838 // default_methods also uses this without the ordering for fast find_method
1839 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1840   int length = methods->length();
1841   if (length > 1) {
1842     if (func == nullptr) {
1843       func = method_comparator;
1844     }
1845     {
1846       NoSafepointVerifier nsv;
1847       QuickSort::sort(methods->data(), length, func);
1848     }
1849     // Reset method ordering
1850     if (set_idnums) {
1851       for (u2 i = 0; i < length; i++) {
1852         Method* m = methods->at(i);
1853         m->set_method_idnum(i);
1854         m->set_orig_method_idnum(i);
1855       }
1856     }
1857   }
1858 }
1859 
1860 //-----------------------------------------------------------------------------------
1861 // Non-product code unless JVM/TI needs it
1862 
1863 #if !defined(PRODUCT) || INCLUDE_JVMTI
1864 class SignatureTypePrinter : public SignatureTypeNames {
1865  private:
1866   outputStream* _st;
1867   bool _use_separator;
1868 
1869   void type_name(const char* name) {
1870     if (_use_separator) _st->print(", ");
1871     _st->print("%s", name);
1872     _use_separator = true;
1873   }
1874 
1875  public:
1876   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1877     _st = st;
1878     _use_separator = false;
1879   }
1880 
1881   void print_parameters()              { _use_separator = false; do_parameters_on(this); }
1882   void print_returntype()              { _use_separator = false; do_type(return_type()); }
1883 };
1884 
1885 
1886 void Method::print_name(outputStream* st) const {
1887   Thread *thread = Thread::current();
1888   ResourceMark rm(thread);
1889   st->print("%s ", is_static() ? "static" : "virtual");
1890   if (WizardMode) {
1891     st->print("%s.", method_holder()->internal_name());
1892     name()->print_symbol_on(st);
1893     signature()->print_symbol_on(st);
1894   } else {
1895     SignatureTypePrinter sig(signature(), st);
1896     sig.print_returntype();
1897     st->print(" %s.", method_holder()->internal_name());
1898     name()->print_symbol_on(st);
1899     st->print("(");
1900     sig.print_parameters();
1901     st->print(")");
1902   }
1903 }
1904 #endif // !PRODUCT || INCLUDE_JVMTI
1905 
1906 
1907 void Method::print_codes_on(outputStream* st, int flags, bool buffered) const {
1908   print_codes_on(0, code_size(), st, flags, buffered);
1909 }
1910 
1911 void Method::print_codes_on(int from, int to, outputStream* st, int flags, bool buffered) const {
1912   Thread *thread = Thread::current();
1913   ResourceMark rm(thread);
1914   methodHandle mh (thread, (Method*)this);
1915   BytecodeTracer::print_method_codes(mh, from, to, st, flags, buffered);
1916 }
1917 
1918 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1919   _bci = 0;
1920   _line = 0;
1921 };
1922 
1923 bool CompressedLineNumberReadStream::read_pair() {
1924   jubyte next = read_byte();
1925   // Check for terminator
1926   if (next == 0) return false;
1927   if (next == 0xFF) {
1928     // Escape character, regular compression used
1929     _bci  += read_signed_int();
1930     _line += read_signed_int();
1931   } else {
1932     // Single byte compression used
1933     _bci  += next >> 3;
1934     _line += next & 0x7;
1935   }
1936   return true;
1937 }
1938 
1939 #if INCLUDE_JVMTI
1940 
1941 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1942   BreakpointInfo* bp = method_holder()->breakpoints();
1943   for (; bp != nullptr; bp = bp->next()) {
1944     if (bp->match(this, bci)) {
1945       return bp->orig_bytecode();
1946     }
1947   }
1948   {
1949     ResourceMark rm;
1950     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1951   }
1952   return Bytecodes::_shouldnotreachhere;
1953 }
1954 
1955 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1956   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1957   BreakpointInfo* bp = method_holder()->breakpoints();
1958   for (; bp != nullptr; bp = bp->next()) {
1959     if (bp->match(this, bci)) {
1960       bp->set_orig_bytecode(code);
1961       // and continue, in case there is more than one
1962     }
1963   }
1964 }
1965 
1966 void Method::set_breakpoint(int bci) {
1967   InstanceKlass* ik = method_holder();
1968   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1969   bp->set_next(ik->breakpoints());
1970   ik->set_breakpoints(bp);
1971   // do this last:
1972   bp->set(this);
1973 }
1974 
1975 static void clear_matches(Method* m, int bci) {
1976   InstanceKlass* ik = m->method_holder();
1977   BreakpointInfo* prev_bp = nullptr;
1978   BreakpointInfo* next_bp;
1979   for (BreakpointInfo* bp = ik->breakpoints(); bp != nullptr; bp = next_bp) {
1980     next_bp = bp->next();
1981     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1982     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1983       // do this first:
1984       bp->clear(m);
1985       // unhook it
1986       if (prev_bp != nullptr)
1987         prev_bp->set_next(next_bp);
1988       else
1989         ik->set_breakpoints(next_bp);
1990       delete bp;
1991       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1992       // at same location. So we have multiple matching (method_index and bci)
1993       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1994       // breakpoint for clear_breakpoint request and keep all other method versions
1995       // BreakpointInfo for future clear_breakpoint request.
1996       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1997       // which is being called when class is unloaded. We delete all the Breakpoint
1998       // information for all versions of method. We may not correctly restore the original
1999       // bytecode in all method versions, but that is ok. Because the class is being unloaded
2000       // so these methods won't be used anymore.
2001       if (bci >= 0) {
2002         break;
2003       }
2004     } else {
2005       // This one is a keeper.
2006       prev_bp = bp;
2007     }
2008   }
2009 }
2010 
2011 void Method::clear_breakpoint(int bci) {
2012   assert(bci >= 0, "");
2013   clear_matches(this, bci);
2014 }
2015 
2016 void Method::clear_all_breakpoints() {
2017   clear_matches(this, -1);
2018 }
2019 
2020 #endif // INCLUDE_JVMTI
2021 
2022 int Method::highest_osr_comp_level() const {
2023   const MethodCounters* mcs = method_counters();
2024   if (mcs != nullptr) {
2025     return mcs->highest_osr_comp_level();
2026   } else {
2027     return CompLevel_none;
2028   }
2029 }
2030 
2031 void Method::set_highest_comp_level(int level) {
2032   MethodCounters* mcs = method_counters();
2033   if (mcs != nullptr) {
2034     mcs->set_highest_comp_level(level);
2035   }
2036 }
2037 
2038 void Method::set_highest_osr_comp_level(int level) {
2039   MethodCounters* mcs = method_counters();
2040   if (mcs != nullptr) {
2041     mcs->set_highest_osr_comp_level(level);
2042   }
2043 }
2044 
2045 #if INCLUDE_JVMTI
2046 
2047 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
2048   _bci = bci;
2049   _name_index = m->name_index();
2050   _signature_index = m->signature_index();
2051   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
2052   if (_orig_bytecode == Bytecodes::_breakpoint)
2053     _orig_bytecode = m->orig_bytecode_at(_bci);
2054   _next = nullptr;
2055 }
2056 
2057 void BreakpointInfo::set(Method* method) {
2058 #ifdef ASSERT
2059   {
2060     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
2061     if (code == Bytecodes::_breakpoint)
2062       code = method->orig_bytecode_at(_bci);
2063     assert(orig_bytecode() == code, "original bytecode must be the same");
2064   }
2065 #endif
2066   Thread *thread = Thread::current();
2067   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
2068   method->incr_number_of_breakpoints(thread);
2069   {
2070     // Deoptimize all dependents on this method
2071     HandleMark hm(thread);
2072     methodHandle mh(thread, method);
2073     CodeCache::mark_dependents_on_method_for_breakpoint(mh);
2074   }
2075 }
2076 
2077 void BreakpointInfo::clear(Method* method) {
2078   *method->bcp_from(_bci) = orig_bytecode();
2079   assert(method->number_of_breakpoints() > 0, "must not go negative");
2080   method->decr_number_of_breakpoints(Thread::current());
2081 }
2082 
2083 #endif // INCLUDE_JVMTI
2084 
2085 // jmethodID handling
2086 // jmethodIDs are 64-bit integers that will never run out and are mapped in a table
2087 // to their Method and vice versa.  If JNI code has access to stale jmethodID, this
2088 // wastes no memory but the Method* returned is null.
2089 
2090 // Add a method id to the jmethod_ids
2091 jmethodID Method::make_jmethod_id(ClassLoaderData* cld, Method* m) {
2092   // Have to add jmethod_ids() to class loader data thread-safely.
2093   // Also have to add the method to the InstanceKlass list safely, which the lock
2094   // protects as well.
2095   assert(JmethodIdCreation_lock->owned_by_self(), "sanity check");
2096   jmethodID jmid = JmethodIDTable::make_jmethod_id(m);
2097   assert(jmid != nullptr, "must be created");
2098 
2099   // Add to growable array in CLD.
2100   cld->add_jmethod_id(jmid);
2101   return jmid;
2102 }
2103 
2104 // This looks in the InstanceKlass cache, then calls back to make_jmethod_id if not found.
2105 jmethodID Method::jmethod_id() {
2106   return method_holder()->get_jmethod_id(this);
2107 }
2108 
2109 // Get the Method out of the table given the method id.
2110 Method* Method::resolve_jmethod_id(jmethodID mid) {
2111   assert(mid != nullptr, "JNI method id should not be null");
2112   return JmethodIDTable::resolve_jmethod_id(mid);
2113 }
2114 
2115 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2116   // Can't assert the method_holder is the same because the new method has the
2117   // scratch method holder.
2118   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2119            == new_method->method_holder()->class_loader() ||
2120          new_method->method_holder()->class_loader() == nullptr, // allow substitution to Unsafe method
2121          "changing to a different class loader");
2122   JmethodIDTable::change_method_associated_with_jmethod_id(jmid, new_method);
2123 }
2124 
2125 // If there's a jmethodID for this method, clear the Method
2126 // but leave jmethodID for this method in the table.
2127 // It's deallocated with class unloading.
2128 void Method::clear_jmethod_id() {
2129   jmethodID mid = method_holder()->jmethod_id_or_null(this);
2130   if (mid != nullptr) {
2131     JmethodIDTable::clear_jmethod_id(mid, this);
2132   }
2133 }
2134 
2135 bool Method::validate_jmethod_id(jmethodID mid) {
2136   Method* m = resolve_jmethod_id(mid);
2137   assert(m != nullptr, "should be called with non-null method");
2138   InstanceKlass* ik = m->method_holder();
2139   ClassLoaderData* cld = ik->class_loader_data();
2140   if (cld->jmethod_ids() == nullptr) return false;
2141   return (cld->jmethod_ids()->contains(mid));
2142 }
2143 
2144 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2145   if (mid == nullptr) return nullptr;
2146   Method* o = resolve_jmethod_id(mid);
2147   if (o == nullptr) {
2148     return nullptr;
2149   }
2150   // Method should otherwise be valid. Assert for testing.
2151   assert(is_valid_method(o), "should be valid jmethodid");
2152   // If the method's class holder object is unreferenced, but not yet marked as
2153   // unloaded, we need to return null here too because after a safepoint, its memory
2154   // will be reclaimed.
2155   return o->method_holder()->is_loader_alive() ? o : nullptr;
2156 }
2157 
2158 void Method::set_on_stack(const bool value) {
2159   // Set both the method itself and its constant pool.  The constant pool
2160   // on stack means some method referring to it is also on the stack.
2161   constants()->set_on_stack(value);
2162 
2163   bool already_set = on_stack_flag();
2164   set_on_stack_flag(value);
2165   if (value && !already_set) {
2166     MetadataOnStackMark::record(this);
2167   }
2168 }
2169 
2170 void Method::record_gc_epoch() {
2171   // If any method is on the stack in continuations, none of them can be reclaimed,
2172   // so save the marking cycle to check for the whole class in the cpCache.
2173   // The cpCache is writeable.
2174   constants()->cache()->record_gc_epoch();
2175 }
2176 
2177 bool Method::has_method_vptr(const void* ptr) {
2178   Method m;
2179   // This assumes that the vtbl pointer is the first word of a C++ object.
2180   return dereference_vptr(&m) == dereference_vptr(ptr);
2181 }
2182 
2183 // Check that this pointer is valid by checking that the vtbl pointer matches
2184 bool Method::is_valid_method(const Method* m) {
2185   if (m == nullptr) {
2186     return false;
2187   } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2188     // Quick sanity check on pointer.
2189     return false;
2190   } else if (!os::is_readable_range(m, m + 1)) {
2191     return false;
2192   } else if (m->in_aot_cache()) {
2193     return CppVtables::is_valid_shared_method(m);
2194   } else if (Metaspace::contains_non_shared(m)) {
2195     return has_method_vptr((const void*)m);
2196   } else {
2197     return false;
2198   }
2199 }
2200 
2201 // Printing
2202 
2203 #ifndef PRODUCT
2204 
2205 void Method::print_on(outputStream* st) const {
2206   ResourceMark rm;
2207   assert(is_method(), "must be method");
2208   st->print_cr("%s", internal_name());
2209   st->print_cr(" - this oop:          " PTR_FORMAT, p2i(this));
2210   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2211   st->print   (" - constants:         " PTR_FORMAT " ", p2i(constants()));
2212   constants()->print_value_on(st); st->cr();
2213   st->print   (" - access:            0x%x  ", access_flags().as_method_flags()); access_flags().print_on(st); st->cr();
2214   st->print   (" - flags:             0x%x  ", _flags.as_int()); _flags.print_on(st); st->cr();
2215   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2216   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2217   st->print_cr(" - max stack:         %d",   max_stack());
2218   st->print_cr(" - max locals:        %d",   max_locals());
2219   st->print_cr(" - size of params:    %d",   size_of_parameters());
2220   st->print_cr(" - method size:       %d",   method_size());
2221   if (intrinsic_id() != vmIntrinsics::_none)
2222     st->print_cr(" - intrinsic id:      %d %s", vmIntrinsics::as_int(intrinsic_id()), vmIntrinsics::name_at(intrinsic_id()));
2223   if (highest_comp_level() != CompLevel_none)
2224     st->print_cr(" - highest level:     %d", highest_comp_level());
2225   st->print_cr(" - vtable index:      %d",   _vtable_index);
2226   st->print_cr(" - i2i entry:         " PTR_FORMAT, p2i(interpreter_entry()));
2227   st->print(   " - adapters:          ");
2228   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2229   if (a == nullptr)
2230     st->print_cr(PTR_FORMAT, p2i(a));
2231   else
2232     a->print_adapter_on(st);
2233   st->print_cr(" - compiled entry     " PTR_FORMAT, p2i(from_compiled_entry()));
2234   st->print_cr(" - code size:         %d",   code_size());
2235   if (code_size() != 0) {
2236     st->print_cr(" - code start:        " PTR_FORMAT, p2i(code_base()));
2237     st->print_cr(" - code end (excl):   " PTR_FORMAT, p2i(code_base() + code_size()));
2238   }
2239   if (method_data() != nullptr) {
2240     st->print_cr(" - method data:       " PTR_FORMAT, p2i(method_data()));
2241   }
2242   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2243   if (checked_exceptions_length() > 0) {
2244     CheckedExceptionElement* table = checked_exceptions_start();
2245     st->print_cr(" - checked ex start:  " PTR_FORMAT, p2i(table));
2246     if (Verbose) {
2247       for (int i = 0; i < checked_exceptions_length(); i++) {
2248         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2249       }
2250     }
2251   }
2252   if (has_linenumber_table()) {
2253     u_char* table = compressed_linenumber_table();
2254     st->print_cr(" - linenumber start:  " PTR_FORMAT, p2i(table));
2255     if (Verbose) {
2256       CompressedLineNumberReadStream stream(table);
2257       while (stream.read_pair()) {
2258         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2259       }
2260     }
2261   }
2262   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2263   if (localvariable_table_length() > 0) {
2264     LocalVariableTableElement* table = localvariable_table_start();
2265     st->print_cr(" - localvar start:    " PTR_FORMAT, p2i(table));
2266     if (Verbose) {
2267       for (int i = 0; i < localvariable_table_length(); i++) {
2268         int bci = table[i].start_bci;
2269         int len = table[i].length;
2270         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2271         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2272         int slot = table[i].slot;
2273         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2274       }
2275     }
2276   }
2277   if (code() != nullptr) {
2278     st->print   (" - compiled code: ");
2279     code()->print_value_on(st);
2280   }
2281   if (is_native()) {
2282     st->print_cr(" - native function:   " PTR_FORMAT, p2i(native_function()));
2283     st->print_cr(" - signature handler: " PTR_FORMAT, p2i(signature_handler()));
2284   }
2285 }
2286 
2287 void Method::print_linkage_flags(outputStream* st) {
2288   access_flags().print_on(st);
2289   if (is_default_method()) {
2290     st->print("default ");
2291   }
2292   if (is_overpass()) {
2293     st->print("overpass ");
2294   }
2295 }
2296 #endif //PRODUCT
2297 
2298 void Method::print_value_on(outputStream* st) const {
2299   assert(is_method(), "must be method");
2300   st->print("%s", internal_name());
2301   print_address_on(st);
2302   st->print(" ");
2303   name()->print_value_on(st);
2304   st->print(" ");
2305   signature()->print_value_on(st);
2306   st->print(" in ");
2307   method_holder()->print_value_on(st);
2308   if (WizardMode) st->print("#%d", _vtable_index);
2309   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2310   if (WizardMode && code() != nullptr) st->print(" ((nmethod*)%p)", code());
2311 }
2312 
2313 // Verification
2314 
2315 void Method::verify_on(outputStream* st) {
2316   guarantee(is_method(), "object must be method");
2317   guarantee(constants()->is_constantPool(), "should be constant pool");
2318   MethodData* md = method_data();
2319   guarantee(md == nullptr ||
2320       md->is_methodData(), "should be method data");
2321 }