1 /*
  2  * Copyright (c) 2022, 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/aotClassLinker.hpp"
 26 #include "cds/aotClassLocation.hpp"
 27 #include "cds/aotConstantPoolResolver.hpp"
 28 #include "cds/aotLogging.hpp"
 29 #include "cds/archiveBuilder.hpp"
 30 #include "cds/archiveUtils.inline.hpp"
 31 #include "cds/cdsConfig.hpp"
 32 #include "cds/finalImageRecipes.hpp"
 33 #include "cds/heapShared.hpp"
 34 #include "cds/lambdaFormInvokers.inline.hpp"
 35 #include "classfile/classLoader.hpp"
 36 #include "classfile/dictionary.hpp"
 37 #include "classfile/symbolTable.hpp"
 38 #include "classfile/systemDictionary.hpp"
 39 #include "classfile/systemDictionaryShared.hpp"
 40 #include "classfile/vmClasses.hpp"
 41 #include "interpreter/bytecodeStream.hpp"
 42 #include "interpreter/interpreterRuntime.hpp"
 43 #include "memory/resourceArea.hpp"
 44 #include "oops/constantPool.inline.hpp"
 45 #include "oops/fieldStreams.inline.hpp"
 46 #include "oops/instanceKlass.hpp"
 47 #include "oops/klass.inline.hpp"
 48 #include "runtime/handles.inline.hpp"
 49 #include "runtime/javaCalls.hpp"
 50 #include "runtime/signature.hpp"
 51 
 52 // Returns true if we CAN PROVE that cp_index will always resolve to
 53 // the same information at both dump time and run time. This is a
 54 // necessary (but not sufficient) condition for pre-resolving cp_index
 55 // during CDS archive assembly.
 56 bool AOTConstantPoolResolver::is_resolution_deterministic(ConstantPool* cp, int cp_index) {
 57   assert(!is_in_archivebuilder_buffer(cp), "sanity");
 58 
 59   if (cp->tag_at(cp_index).is_klass()) {
 60     // We require cp_index to be already resolved. This is fine for now, are we
 61     // currently archive only CP entries that are already resolved.
 62     Klass* resolved_klass = cp->resolved_klass_at(cp_index);
 63     return resolved_klass != nullptr && is_class_resolution_deterministic(cp->pool_holder(), resolved_klass);
 64   } else if (cp->tag_at(cp_index).is_invoke_dynamic()) {
 65     return is_indy_resolution_deterministic(cp, cp_index);
 66   } else if (cp->tag_at(cp_index).is_field() ||
 67              cp->tag_at(cp_index).is_method() ||
 68              cp->tag_at(cp_index).is_interface_method()) {
 69     int klass_cp_index = cp->uncached_klass_ref_index_at(cp_index);
 70     if (!cp->tag_at(klass_cp_index).is_klass()) {
 71       // Not yet resolved
 72       return false;
 73     }
 74     Klass* k = cp->resolved_klass_at(klass_cp_index);
 75     if (!is_class_resolution_deterministic(cp->pool_holder(), k)) {
 76       return false;
 77     }
 78 
 79     if (!k->is_instance_klass()) {
 80       // TODO: support non instance klasses as well.
 81       return false;
 82     }
 83 
 84     // Here, We don't check if this entry can actually be resolved to a valid Field/Method.
 85     // This method should be called by the ConstantPool to check Fields/Methods that
 86     // have already been successfully resolved.
 87     return true;
 88   } else {
 89     return false;
 90   }
 91 }
 92 
 93 bool AOTConstantPoolResolver::is_class_resolution_deterministic(InstanceKlass* cp_holder, Klass* resolved_class) {
 94   assert(!is_in_archivebuilder_buffer(cp_holder), "sanity");
 95   assert(!is_in_archivebuilder_buffer(resolved_class), "sanity");
 96   assert_at_safepoint(); // try_add_candidate() is called below and requires to be at safepoint.
 97 
 98   if (resolved_class->is_instance_klass()) {
 99     InstanceKlass* ik = InstanceKlass::cast(resolved_class);
100 
101     if (!ik->in_aot_cache() && SystemDictionaryShared::is_excluded_class(ik)) {
102       return false;
103     }
104 
105     if (cp_holder->is_subtype_of(ik)) {
106       // All super types of ik will be resolved in ik->class_loader() before
107       // ik is defined in this loader, so it's safe to archive the resolved klass reference.
108       return true;
109     }
110 
111     if (CDSConfig::is_dumping_aot_linked_classes()) {
112       // Need to call try_add_candidate instead of is_candidate, as this may be called
113       // before AOTClassLinker::add_candidates().
114       if (AOTClassLinker::try_add_candidate(ik)) {
115         return true;
116       } else {
117         return false;
118       }
119     } else if (AOTClassLinker::is_vm_class(ik)) {
120       if (ik->class_loader() != cp_holder->class_loader()) {
121         // At runtime, cp_holder() may not be able to resolve to the same
122         // ik. For example, a different version of ik may be defined in
123         // cp->pool_holder()'s loader using MethodHandles.Lookup.defineClass().
124         return false;
125       } else {
126         return true;
127       }
128     } else {
129       return false;
130     }
131   } else if (resolved_class->is_objArray_klass()) {
132     if (CDSConfig::is_dumping_dynamic_archive()) {
133       // This is difficult to handle. See JDK-8374639
134       return false;
135     }
136     Klass* elem = ObjArrayKlass::cast(resolved_class)->bottom_klass();
137     if (elem->is_instance_klass()) {
138       return is_class_resolution_deterministic(cp_holder, InstanceKlass::cast(elem));
139     } else if (elem->is_typeArray_klass()) {
140       return true;
141     } else {
142       return false;
143     }
144   } else if (resolved_class->is_typeArray_klass()) {
145     return true;
146   } else {
147     return false;
148   }
149 }
150 
151 void AOTConstantPoolResolver::preresolve_string_cp_entries(InstanceKlass* ik, TRAPS) {
152   if (!ik->is_linked()) {
153     // The cp->resolved_referenced() array is not ready yet, so we can't call resolve_string().
154     return;
155   }
156   constantPoolHandle cp(THREAD, ik->constants());
157   for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused
158     switch (cp->tag_at(cp_index).value()) {
159     case JVM_CONSTANT_String:
160       resolve_string(cp, cp_index, CHECK); // may throw OOM when interning strings.
161       break;
162     }
163   }
164 
165   // Normally, we don't want to archive any CP entries that were not resolved
166   // in the training run. Otherwise the AOT/JIT may inline too much code that has not
167   // been executed.
168   //
169   // However, we want to aggressively resolve all klass/field/method constants for
170   // LambdaForm Invoker Holder classes, Lambda Proxy classes, and LambdaForm classes,
171   // so that the compiler can inline through them.
172   if (SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
173     bool eager_resolve = false;
174 
175     if (LambdaFormInvokers::may_be_regenerated_class(ik->name())) {
176       eager_resolve = true;
177     }
178     if (ik->is_hidden() && HeapShared::is_archivable_hidden_klass(ik)) {
179       eager_resolve = true;
180     }
181 
182     if (eager_resolve) {
183       preresolve_class_cp_entries(THREAD, ik, nullptr);
184       preresolve_field_and_method_cp_entries(THREAD, ik, nullptr);
185     }
186   }
187 }
188 
189 // This works only for the boot/platform/app loaders
190 Klass* AOTConstantPoolResolver::find_loaded_class(Thread* current, oop class_loader, Symbol* name) {
191   HandleMark hm(current);
192   Handle h_loader(current, class_loader);
193   Klass* k = SystemDictionary::find_instance_or_array_klass(current, name, h_loader);
194   if (k != nullptr) {
195     return k;
196   }
197   if (h_loader() == SystemDictionary::java_system_loader()) {
198     return find_loaded_class(current, SystemDictionary::java_platform_loader(), name);
199   } else if (h_loader() == SystemDictionary::java_platform_loader()) {
200     return find_loaded_class(current, nullptr, name);
201   } else {
202     assert(h_loader() == nullptr, "This function only works for boot/platform/app loaders %p %p %p",
203            cast_from_oop<address>(h_loader()),
204            cast_from_oop<address>(SystemDictionary::java_system_loader()),
205            cast_from_oop<address>(SystemDictionary::java_platform_loader()));
206   }
207 
208   return nullptr;
209 }
210 
211 Klass* AOTConstantPoolResolver::find_loaded_class(Thread* current, ConstantPool* cp, int class_cp_index) {
212   Symbol* name = cp->klass_name_at(class_cp_index);
213   return find_loaded_class(current, cp->pool_holder()->class_loader(), name);
214 }
215 
216 #if INCLUDE_CDS_JAVA_HEAP
217 void AOTConstantPoolResolver::resolve_string(constantPoolHandle cp, int cp_index, TRAPS) {
218   if (CDSConfig::is_dumping_heap()) {
219     int cache_index = cp->cp_to_object_index(cp_index);
220     ConstantPool::string_at_impl(cp, cp_index, cache_index, CHECK);
221   }
222 }
223 #endif
224 
225 void AOTConstantPoolResolver::preresolve_class_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray<bool>* preresolve_list) {
226   if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
227     return;
228   }
229 
230   JavaThread* THREAD = current;
231   constantPoolHandle cp(THREAD, ik->constants());
232   for (int cp_index = 1; cp_index < cp->length(); cp_index++) {
233     if (cp->tag_at(cp_index).value() == JVM_CONSTANT_UnresolvedClass) {
234       if (preresolve_list != nullptr && preresolve_list->at(cp_index) == false) {
235         // This class was not resolved during trial run. Don't attempt to resolve it. Otherwise
236         // the compiler may generate less efficient code.
237         continue;
238       }
239       if (find_loaded_class(current, cp(), cp_index) == nullptr) {
240         // Do not resolve any class that has not been loaded yet
241         continue;
242       }
243       Klass* resolved_klass = cp->klass_at(cp_index, THREAD);
244       if (HAS_PENDING_EXCEPTION) {
245         CLEAR_PENDING_EXCEPTION; // just ignore
246       } else {
247         log_trace(aot, resolve)("Resolved class  [%3d] %s -> %s", cp_index, ik->external_name(),
248                                 resolved_klass->external_name());
249       }
250     }
251   }
252 }
253 
254 void AOTConstantPoolResolver::preresolve_field_and_method_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray<bool>* preresolve_list) {
255   JavaThread* THREAD = current;
256   constantPoolHandle cp(THREAD, ik->constants());
257   if (cp->cache() == nullptr) {
258     return;
259   }
260   for (int i = 0; i < ik->methods()->length(); i++) {
261     Method* m = ik->methods()->at(i);
262     BytecodeStream bcs(methodHandle(THREAD, m));
263     while (!bcs.is_last_bytecode()) {
264       bcs.next();
265       Bytecodes::Code raw_bc = bcs.raw_code();
266       switch (raw_bc) {
267       case Bytecodes::_getstatic:
268       case Bytecodes::_putstatic:
269         maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD);
270         if (HAS_PENDING_EXCEPTION) {
271           CLEAR_PENDING_EXCEPTION; // just ignore
272         }
273         break;
274       case Bytecodes::_getfield:
275       // no-fast bytecode
276       case Bytecodes::_nofast_getfield:
277       // fast bytecodes
278       case Bytecodes::_fast_agetfield:
279       case Bytecodes::_fast_bgetfield:
280       case Bytecodes::_fast_cgetfield:
281       case Bytecodes::_fast_dgetfield:
282       case Bytecodes::_fast_fgetfield:
283       case Bytecodes::_fast_igetfield:
284       case Bytecodes::_fast_lgetfield:
285       case Bytecodes::_fast_sgetfield:
286         raw_bc = Bytecodes::_getfield;
287         maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD);
288         if (HAS_PENDING_EXCEPTION) {
289           CLEAR_PENDING_EXCEPTION; // just ignore
290         }
291         break;
292 
293       case Bytecodes::_putfield:
294       // no-fast bytecode
295       case Bytecodes::_nofast_putfield:
296       // fast bytecodes
297       case Bytecodes::_fast_aputfield:
298       case Bytecodes::_fast_bputfield:
299       case Bytecodes::_fast_zputfield:
300       case Bytecodes::_fast_cputfield:
301       case Bytecodes::_fast_dputfield:
302       case Bytecodes::_fast_fputfield:
303       case Bytecodes::_fast_iputfield:
304       case Bytecodes::_fast_lputfield:
305       case Bytecodes::_fast_sputfield:
306         raw_bc = Bytecodes::_putfield;
307         maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD);
308         if (HAS_PENDING_EXCEPTION) {
309           CLEAR_PENDING_EXCEPTION; // just ignore
310         }
311         break;
312       case Bytecodes::_invokehandle:
313       case Bytecodes::_invokespecial:
314       case Bytecodes::_invokevirtual:
315       case Bytecodes::_invokeinterface:
316       case Bytecodes::_invokestatic:
317         maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD);
318         if (HAS_PENDING_EXCEPTION) {
319           CLEAR_PENDING_EXCEPTION; // just ignore
320         }
321         break;
322       default:
323         break;
324       }
325     }
326   }
327 }
328 
329 void AOTConstantPoolResolver::maybe_resolve_fmi_ref(InstanceKlass* ik, Method* m, Bytecodes::Code bc, int raw_index,
330                                            GrowableArray<bool>* preresolve_list, TRAPS) {
331   methodHandle mh(THREAD, m);
332   constantPoolHandle cp(THREAD, ik->constants());
333   HandleMark hm(THREAD);
334   int cp_index = cp->to_cp_index(raw_index, bc);
335 
336   if (cp->is_resolved(raw_index, bc)) {
337     return;
338   }
339 
340   if (preresolve_list != nullptr && preresolve_list->at(cp_index) == false) {
341     // This field wasn't resolved during the trial run. Don't attempt to resolve it. Otherwise
342     // the compiler may generate less efficient code.
343     return;
344   }
345 
346   int klass_cp_index = cp->uncached_klass_ref_index_at(cp_index);
347   if (find_loaded_class(THREAD, cp(), klass_cp_index) == nullptr) {
348     // Do not resolve any field/methods from a class that has not been loaded yet.
349     return;
350   }
351 
352   Klass* resolved_klass = cp->klass_ref_at(raw_index, bc, CHECK);
353   const char* is_static = "";
354 
355   switch (bc) {
356   case Bytecodes::_getstatic:
357   case Bytecodes::_putstatic:
358     if (!VM_Version::supports_fast_class_init_checks()) {
359       return; // Do not resolve since interpreter lacks fast clinit barriers support
360     }
361     InterpreterRuntime::resolve_get_put(bc, raw_index, mh, cp, ClassInitMode::dont_init, CHECK);
362     is_static = " *** static";
363     break;
364 
365   case Bytecodes::_getfield:
366   case Bytecodes::_putfield:
367     InterpreterRuntime::resolve_get_put(bc, raw_index, mh, cp, ClassInitMode::dont_init, CHECK);
368     break;
369 
370   case Bytecodes::_invokestatic:
371     if (!VM_Version::supports_fast_class_init_checks()) {
372       return; // Do not resolve since interpreter lacks fast clinit barriers support
373     }
374     InterpreterRuntime::cds_resolve_invoke(bc, raw_index, cp, CHECK);
375     is_static = " *** static";
376     break;
377 
378   case Bytecodes::_invokevirtual:
379   case Bytecodes::_invokespecial:
380   case Bytecodes::_invokeinterface:
381     InterpreterRuntime::cds_resolve_invoke(bc, raw_index, cp, CHECK);
382     break;
383 
384   case Bytecodes::_invokehandle:
385     if (CDSConfig::is_dumping_method_handles()) {
386       ResolvedMethodEntry* method_entry = cp->resolved_method_entry_at(raw_index);
387       int cp_index = method_entry->constant_pool_index();
388       Symbol* sig = cp->uncached_signature_ref_at(cp_index);
389       Klass* k;
390       if (check_methodtype_signature(cp(), sig, &k, true)) {
391         InterpreterRuntime::cds_resolve_invokehandle(raw_index, cp, CHECK);
392       }
393     }
394     break;
395 
396   default:
397     ShouldNotReachHere();
398   }
399 
400   if (log_is_enabled(Trace, aot, resolve)) {
401     ResourceMark rm(THREAD);
402     bool resolved = cp->is_resolved(raw_index, bc);
403     Symbol* name = cp->name_ref_at(raw_index, bc);
404     Symbol* signature = cp->signature_ref_at(raw_index, bc);
405     log_trace(aot, resolve)("%s %s [%3d] %s -> %s.%s:%s%s",
406                             (resolved ? "Resolved" : "Failed to resolve"),
407                             Bytecodes::name(bc), cp_index, ik->external_name(),
408                             resolved_klass->external_name(),
409                             name->as_C_string(), signature->as_C_string(), is_static);
410   }
411 }
412 
413 void AOTConstantPoolResolver::preresolve_indy_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray<bool>* preresolve_list) {
414   JavaThread* THREAD = current;
415   constantPoolHandle cp(THREAD, ik->constants());
416   if (!CDSConfig::is_dumping_invokedynamic() || cp->cache() == nullptr) {
417     return;
418   }
419 
420   assert(preresolve_list != nullptr, "preresolve_indy_cp_entries() should not be called for "
421          "regenerated LambdaForm Invoker classes, which should not have indys anyway.");
422 
423   Array<ResolvedIndyEntry>* indy_entries = cp->cache()->resolved_indy_entries();
424   for (int i = 0; i < indy_entries->length(); i++) {
425     ResolvedIndyEntry* rie = indy_entries->adr_at(i);
426     int cp_index = rie->constant_pool_index();
427     if (preresolve_list->at(cp_index) == true) {
428       if (!rie->is_resolved() && is_indy_resolution_deterministic(cp(), cp_index)) {
429         InterpreterRuntime::cds_resolve_invokedynamic(i, cp, THREAD);
430         if (HAS_PENDING_EXCEPTION) {
431           CLEAR_PENDING_EXCEPTION; // just ignore
432         }
433       }
434       if (log_is_enabled(Trace, aot, resolve)) {
435         ResourceMark rm(THREAD);
436         log_trace(aot, resolve)("%s indy   [%3d] %s",
437                                 rie->is_resolved() ? "Resolved" : "Failed to resolve",
438                                 cp_index, ik->external_name());
439       }
440     }
441   }
442 }
443 
444 // Check the MethodType signatures used by parameters to the indy BSMs. Make sure we don't
445 // use types that have been excluded, or else we might end up creating MethodTypes that cannot be stored
446 // in the AOT cache.
447 bool AOTConstantPoolResolver::check_methodtype_signature(ConstantPool* cp, Symbol* sig, Klass** return_type_ret, bool is_invokehandle) {
448   ResourceMark rm;
449   for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
450     if (ss.is_reference()) {
451       Symbol* type = ss.as_symbol();
452       Klass* k = find_loaded_class(Thread::current(), cp->pool_holder()->class_loader(), type);
453       if (k == nullptr) {
454         return false;
455       }
456 
457       if (SystemDictionaryShared::should_be_excluded(k)) {
458         if (log_is_enabled(Warning, aot, resolve)) {
459           ResourceMark rm;
460           log_warning(aot, resolve)("Cannot aot-resolve %s because %s is excluded",
461                                     is_invokehandle ? "invokehandle" : "Lambda proxy",
462                                     k->external_name());
463         }
464         return false;
465       }
466 
467       // cp->pool_holder() must be able to resolve k in production run
468       precond(CDSConfig::is_dumping_aot_linked_classes());
469       precond(SystemDictionaryShared::is_builtin_loader(cp->pool_holder()->class_loader_data()));
470       precond(SystemDictionaryShared::is_builtin_loader(k->class_loader_data()));
471 
472       if (ss.at_return_type() && return_type_ret != nullptr) {
473         *return_type_ret = k;
474       }
475     }
476   }
477   return true;
478 }
479 
480 bool AOTConstantPoolResolver::check_lambda_metafactory_signature(ConstantPool* cp, Symbol* sig) {
481   Klass* k;
482   if (!check_methodtype_signature(cp, sig, &k)) {
483     return false;
484   }
485 
486   // <k> is the interface type implemented by the lambda proxy
487   if (!k->is_interface()) {
488     // cp->pool_holder() doesn't look like a valid class generated by javac
489     return false;
490   }
491 
492 
493   // The linked lambda callsite has an instance of the interface implemented by this lambda. If this
494   // interface requires its <clinit> to be executed, then we must delay the execution to the production run
495   // as <clinit> can have side effects ==> exclude such cases.
496   InstanceKlass* intf = InstanceKlass::cast(k);
497   bool exclude = intf->interface_needs_clinit_execution_as_super();
498   if (log_is_enabled(Debug, aot, resolve)) {
499     ResourceMark rm;
500     log_debug(aot, resolve)("%s aot-resolve Lambda proxy of interface type %s",
501                             exclude ? "Cannot" : "Can", k->external_name());
502   }
503   return !exclude;
504 }
505 
506 bool AOTConstantPoolResolver::check_lambda_metafactory_methodtype_arg(ConstantPool* cp, int bsms_attribute_index, int arg_i) {
507   int mt_index = cp->bsm_attribute_entry(bsms_attribute_index)->argument(arg_i);
508   if (!cp->tag_at(mt_index).is_method_type()) {
509     // malformed class?
510     return false;
511   }
512 
513   Symbol* sig = cp->method_type_signature_at(mt_index);
514   if (log_is_enabled(Debug, aot, resolve)) {
515     ResourceMark rm;
516     log_debug(aot, resolve)("Checking MethodType for LambdaMetafactory BSM arg %d: %s", arg_i, sig->as_C_string());
517   }
518 
519   return check_methodtype_signature(cp, sig);
520 }
521 
522 bool AOTConstantPoolResolver::check_lambda_metafactory_methodhandle_arg(ConstantPool* cp, int bsms_attribute_index, int arg_i) {
523   int mh_index = cp->bsm_attribute_entry(bsms_attribute_index)->argument(arg_i);
524   if (!cp->tag_at(mh_index).is_method_handle()) {
525     // malformed class?
526     return false;
527   }
528 
529   // klass and sigature of the method (no need to check the method name)
530   Symbol* sig = cp->method_handle_signature_ref_at(mh_index);
531   Symbol* klass_name = cp->klass_name_at(cp->method_handle_klass_index_at(mh_index));
532 
533   if (log_is_enabled(Debug, aot, resolve)) {
534     ResourceMark rm;
535     log_debug(aot, resolve)("Checking MethodType of MethodHandle for LambdaMetafactory BSM arg %d: %s", arg_i, sig->as_C_string());
536   }
537 
538   {
539     Klass* k = find_loaded_class(Thread::current(), cp->pool_holder()->class_loader(), klass_name);
540     if (k == nullptr) {
541       // Dumping AOT cache: all classes should have been loaded by FinalImageRecipes::load_all_classes(). k must have
542       // been a class that was excluded when FinalImageRecipes recorded all classes at the end of the training run.
543       //
544       // Dumping static CDS archive: all classes in the classlist have already been loaded, before we resolve
545       // constants. k must have been a class that was excluded when the classlist was written
546       // at the end of the training run.
547       if (log_is_enabled(Warning, aot, resolve)) {
548         ResourceMark rm;
549         log_warning(aot, resolve)("Cannot aot-resolve Lambda proxy because %s is not loaded", klass_name->as_C_string());
550       }
551       return false;
552     }
553     if (SystemDictionaryShared::should_be_excluded(k)) {
554       if (log_is_enabled(Warning, aot, resolve)) {
555         ResourceMark rm;
556         log_warning(aot, resolve)("Cannot aot-resolve Lambda proxy because %s is excluded", k->external_name());
557       }
558       return false;
559     }
560 
561     // cp->pool_holder() must be able to resolve k in production run
562     precond(CDSConfig::is_dumping_aot_linked_classes());
563     precond(SystemDictionaryShared::is_builtin_loader(cp->pool_holder()->class_loader_data()));
564     precond(SystemDictionaryShared::is_builtin_loader(k->class_loader_data()));
565   }
566 
567   return check_methodtype_signature(cp, sig);
568 }
569 
570 bool AOTConstantPoolResolver::is_indy_resolution_deterministic(ConstantPool* cp, int cp_index) {
571   assert(cp->tag_at(cp_index).is_invoke_dynamic(), "sanity");
572   if (!CDSConfig::is_dumping_invokedynamic()) {
573     return false;
574   }
575 
576   InstanceKlass* pool_holder = cp->pool_holder();
577   if (!SystemDictionaryShared::is_builtin(pool_holder)) {
578     return false;
579   }
580 
581   int bsm = cp->bootstrap_method_ref_index_at(cp_index);
582   int bsm_ref = cp->method_handle_index_at(bsm);
583   Symbol* bsm_name = cp->uncached_name_ref_at(bsm_ref);
584   Symbol* bsm_signature = cp->uncached_signature_ref_at(bsm_ref);
585   Symbol* bsm_klass = cp->klass_name_at(cp->uncached_klass_ref_index_at(bsm_ref));
586 
587   // We currently support only StringConcatFactory::makeConcatWithConstants() and LambdaMetafactory::metafactory()
588   // We should mark the allowed BSMs in the JDK code using a private annotation.
589   // See notes on RFE JDK-8342481.
590 
591   if (bsm_klass->equals("java/lang/invoke/StringConcatFactory") &&
592       bsm_name->equals("makeConcatWithConstants") &&
593       bsm_signature->equals("(Ljava/lang/invoke/MethodHandles$Lookup;"
594                              "Ljava/lang/String;"
595                              "Ljava/lang/invoke/MethodType;"
596                              "Ljava/lang/String;"
597                              "[Ljava/lang/Object;"
598                             ")Ljava/lang/invoke/CallSite;")) {
599     Symbol* factory_type_sig = cp->uncached_signature_ref_at(cp_index);
600     if (log_is_enabled(Debug, aot, resolve)) {
601       ResourceMark rm;
602       log_debug(aot, resolve)("Checking StringConcatFactory callsite signature [%d]: %s", cp_index, factory_type_sig->as_C_string());
603     }
604 
605     Klass* k;
606     if (!check_methodtype_signature(cp, factory_type_sig, &k)) {
607       return false;
608     }
609     if (k != vmClasses::String_klass()) {
610       // bad class file?
611       return false;
612     }
613 
614     return true;
615   }
616 
617   if (bsm_klass->equals("java/lang/invoke/LambdaMetafactory") &&
618       bsm_name->equals("metafactory") &&
619       bsm_signature->equals("(Ljava/lang/invoke/MethodHandles$Lookup;"
620                              "Ljava/lang/String;"
621                              "Ljava/lang/invoke/MethodType;"
622                              "Ljava/lang/invoke/MethodType;"
623                              "Ljava/lang/invoke/MethodHandle;"
624                              "Ljava/lang/invoke/MethodType;"
625                             ")Ljava/lang/invoke/CallSite;")) {
626     /*
627      * An indy callsite is associated with the following MethodType and MethodHandles:
628      *
629      * https://github.com/openjdk/jdk/blob/580eb62dc097efeb51c76b095c1404106859b673/src/java.base/share/classes/java/lang/invoke/LambdaMetafactory.java#L293-L309
630      *
631      * MethodType factoryType         The expected signature of the {@code CallSite}.  The
632      *                                parameter types represent the types of capture variables;
633      *                                the return type is the interface to implement.   When
634      *                                used with {@code invokedynamic}, this is provided by
635      *                                the {@code NameAndType} of the {@code InvokeDynamic}
636      *
637      * MethodType interfaceMethodType Signature and return type of method to be
638      *                                implemented by the function object.
639      *
640      * MethodHandle implementation    A direct method handle describing the implementation
641      *                                method which should be called (with suitable adaptation
642      *                                of argument types and return types, and with captured
643      *                                arguments prepended to the invocation arguments) at
644      *                                invocation time.
645      *
646      * MethodType dynamicMethodType   The signature and return type that should
647      *                                be enforced dynamically at invocation time.
648      *                                In simple use cases this is the same as
649      *                                {@code interfaceMethodType}.
650      */
651     Symbol* factory_type_sig = cp->uncached_signature_ref_at(cp_index);
652     if (log_is_enabled(Debug, aot, resolve)) {
653       ResourceMark rm;
654       log_debug(aot, resolve)("Checking lambda callsite signature [%d]: %s", cp_index, factory_type_sig->as_C_string());
655     }
656 
657     if (!check_lambda_metafactory_signature(cp, factory_type_sig)) {
658       return false;
659     }
660 
661     int bsms_attribute_index = cp->bootstrap_methods_attribute_index(cp_index);
662     int arg_count = cp->bsm_attribute_entry(bsms_attribute_index)->argument_count();
663     if (arg_count != 3) {
664       // Malformed class?
665       return false;
666     }
667 
668     // interfaceMethodType
669     if (!check_lambda_metafactory_methodtype_arg(cp, bsms_attribute_index, 0)) {
670       return false;
671     }
672 
673     // implementation
674     if (!check_lambda_metafactory_methodhandle_arg(cp, bsms_attribute_index, 1)) {
675       return false;
676     }
677 
678     // dynamicMethodType
679     if (!check_lambda_metafactory_methodtype_arg(cp, bsms_attribute_index, 2)) {
680       return false;
681     }
682 
683     return true;
684   }
685 
686   return false;
687 }
688 #ifdef ASSERT
689 bool AOTConstantPoolResolver::is_in_archivebuilder_buffer(address p) {
690   if (!Thread::current()->is_VM_thread() || ArchiveBuilder::current() == nullptr) {
691     return false;
692   } else {
693     return ArchiveBuilder::current()->is_in_buffer_space(p);
694   }
695 }
696 #endif
697 
698 // Paranoid check -- if any field/method signature in <ik> is referencing a class that is known to be
699 // excluded, do not archive any reflection data in <ik>.
700 bool AOTConstantPoolResolver::check_signature_for_reflection_data(InstanceKlass* ik, Symbol* sig, bool is_method) {
701   precond(SafepointSynchronize::is_at_safepoint());
702   ResourceMark rm;
703   for (SignatureStream ss(sig, is_method); !ss.is_done(); ss.next()) {
704     if (ss.is_reference()) {
705       Symbol* klass_name = ss.as_symbol(/*probe_only=*/true);
706       if (klass_name == nullptr) {
707         // This symbol has never been created during the assembly phase, so it can't
708         // possibly be referencing an excluded class.
709         continue;
710       }
711       if (Signature::is_array(klass_name)) {
712         SignatureStream ss2(klass_name, false);
713         ss2.skip_array_prefix();
714         if (ss2.is_reference() && ss2.as_symbol(/*probe_only=*/true) == nullptr) {
715           // klass_name is an array klass that has not been loaded during the assembly phase, so it can't
716           // possibly be referencing an excluded class.
717           continue;
718         }
719       }
720       Klass* k = find_loaded_class(Thread::current(), ik->class_loader(), klass_name);
721       if (k == nullptr) {
722         // No class of this name has been loaded for this loader, so this name can't
723         // possibly be referencing an excluded class.
724         continue;
725       }
726       if (SystemDictionaryShared::should_be_excluded(k)) {
727         if (log_is_enabled(Warning, aot, resolve)) {
728           ResourceMark rm;
729           log_warning(aot, resolve)("Cannot archive reflection data in %s because it refers to excluded class %s",
730                                     ik->external_name(), k->external_name());
731         }
732         return false;
733       }
734     }
735   }
736   return true;
737 }
738 
739 bool AOTConstantPoolResolver::can_archive_reflection_data_declared_fields(InstanceKlass* ik) {
740   for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
741     if (!check_signature_for_reflection_data(ik, fs.signature(), /*is_method=*/false)) {
742       return false;
743     }
744   }
745 
746   return true;
747 }
748 
749 bool AOTConstantPoolResolver::can_archive_reflection_data_declared_methods(InstanceKlass* ik) {
750   Array<Method*>* methods = ik->methods();
751   for (int i = 0; i < methods->length(); i++) {
752     Method* m = methods->at(i);
753     if (!check_signature_for_reflection_data(ik, m->signature(), /*is_method=*/true)) {
754       return false;
755     }
756   }
757 
758   return true;
759 }
760 
761 // This is called by AOT assembly phase to see if java_lang_Class::reflection_data(k) can be
762 // archived.
763 bool AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass* ik) {
764   // At this point, we have resolved the reflection data of *all* classes
765   // recorded by FinalImageRecipes.
766   // When we are in the AOT safepoint, we will archive the reflection
767   // data of <ik> *only if* it doesn't reference any excluded classes.
768   precond(SafepointSynchronize::is_at_safepoint());
769 
770   if (!can_archive_reflection_data_declared_fields(ik)) {
771     return false;
772   }
773   if (!can_archive_reflection_data_declared_methods(ik)) {
774     return false;
775   }
776 
777   if (log_is_enabled(Info, aot, resolve)) {
778     ResourceMark rm;
779     log_info(aot, resolve)("Archived reflection data in %s", ik->external_name());
780   }
781 
782   return true;
783 }
784 
785 int AOTConstantPoolResolver::class_reflection_data_flags(InstanceKlass* ik, TRAPS) {
786   assert(java_lang_Class::has_reflection_data(ik->java_mirror()), "must be");
787 
788   HandleMark hm(THREAD);
789   JavaCallArguments args(Handle(THREAD, ik->java_mirror()));
790   JavaValue result(T_INT);
791   JavaCalls::call_special(&result,
792                           vmClasses::Class_klass(),
793                           vmSymbols::encodeReflectionData_name(),
794                           vmSymbols::void_int_signature(),
795                           &args, CHECK_0);
796   int flags = result.get_jint();
797   aot_log_info(aot)("Encode ReflectionData: %s (flags=0x%x)", ik->external_name(), flags);
798   return flags;
799 }
800 
801 void AOTConstantPoolResolver::generate_reflection_data(JavaThread* current, InstanceKlass* ik, int rd_flags) {
802   aot_log_info(aot)("Generate ReflectionData: %s (flags=" INT32_FORMAT_X ")", ik->external_name(), rd_flags);
803   JavaThread* THREAD = current; // for exception macros
804   JavaCallArguments args(Handle(THREAD, ik->java_mirror()));
805   args.push_int(rd_flags);
806   JavaValue result(T_OBJECT);
807   JavaCalls::call_special(&result,
808                           vmClasses::Class_klass(),
809                           vmSymbols::generateReflectionData_name(),
810                           vmSymbols::int_void_signature(),
811                           &args, THREAD);
812   if (HAS_PENDING_EXCEPTION) {
813     Handle exc_handle(THREAD, PENDING_EXCEPTION);
814     CLEAR_PENDING_EXCEPTION;
815 
816     log_warning(aot)("Exception during Class::generateReflectionData() call for %s", ik->external_name());
817     LogStreamHandle(Debug, aot) log;
818     if (log.is_enabled()) {
819       java_lang_Throwable::print_stack_trace(exc_handle, &log);
820     }
821   }
822 }
823 
824 Klass* AOTConstantPoolResolver::resolve_boot_class_or_fail(const char* class_name, TRAPS) {
825   Handle class_loader;
826   TempNewSymbol class_name_sym = SymbolTable::new_symbol(class_name);
827   return SystemDictionary::resolve_or_fail(class_name_sym, class_loader, true, THREAD);
828 }
829 
830 void AOTConstantPoolResolver::trace_dynamic_proxy_class(oop loader, const char* proxy_name, objArrayOop interfaces, int access_flags) {
831   if (interfaces->length() < 1) {
832     return;
833   }
834   if (CDSConfig::is_dumping_preimage_static_archive()) {
835     FinalImageRecipes::add_dynamic_proxy_class(loader, proxy_name, interfaces, access_flags);
836   }
837 }
838 
839 void AOTConstantPoolResolver::init_dynamic_proxy_cache(TRAPS) {
840   static bool inited = false;
841   if (inited) {
842     return;
843   }
844   inited = true;
845 
846   Klass* klass = resolve_boot_class_or_fail("java/lang/reflect/Proxy", CHECK);
847   TempNewSymbol method = SymbolTable::new_symbol("initCacheForCDS");
848   TempNewSymbol signature = SymbolTable::new_symbol("(Ljava/lang/ClassLoader;Ljava/lang/ClassLoader;)V");
849 
850   JavaCallArguments args;
851   args.push_oop(Handle(THREAD, SystemDictionary::java_platform_loader()));
852   args.push_oop(Handle(THREAD, SystemDictionary::java_system_loader()));
853   JavaValue result(T_VOID);
854   JavaCalls::call_static(&result,
855                          klass,
856                          method,
857                          signature,
858                          &args, CHECK);
859 }
860 
861 
862 void AOTConstantPoolResolver::define_dynamic_proxy_class(Handle loader, Handle proxy_name, Handle interfaces, int access_flags, TRAPS) {
863   if (!CDSConfig::is_dumping_dynamic_proxies()) {
864     return;
865   }
866   init_dynamic_proxy_cache(CHECK);
867 
868   Klass* klass = resolve_boot_class_or_fail("java/lang/reflect/Proxy$ProxyBuilder", CHECK);
869   TempNewSymbol method = SymbolTable::new_symbol("defineProxyClassForCDS");
870   TempNewSymbol signature = SymbolTable::new_symbol("(Ljava/lang/ClassLoader;Ljava/lang/String;[Ljava/lang/Class;I)Ljava/lang/Class;");
871 
872   JavaCallArguments args;
873   args.push_oop(Handle(THREAD, loader()));
874   args.push_oop(Handle(THREAD, proxy_name()));
875   args.push_oop(Handle(THREAD, interfaces()));
876   args.push_int(access_flags);
877   JavaValue result(T_OBJECT);
878   JavaCalls::call_static(&result,
879                          klass,
880                          method,
881                          signature,
882                          &args, CHECK);
883 
884   // Assumptions:
885   // FMG is archived, which means -modulepath and -Xbootclasspath are both not specified.
886   // All named modules are loaded from the system modules files.
887   // TODO: test support for -Xbootclasspath after JDK-8322322. Some of the code below need to be changed.
888   // TODO: we just give dummy shared_classpath_index for the generated class so that it will be archived.
889   //       The index is not used at runtime (see SystemDictionaryShared::load_shared_class_for_builtin_loader, which
890   //       uses a null ProtectionDomain for this class)
891   oop mirror = result.get_oop();
892   assert(mirror != nullptr, "class must have been generated if not OOM");
893   InstanceKlass* ik = InstanceKlass::cast(java_lang_Class::as_Klass(mirror));
894   if (ik->defined_by_boot_loader() || ik->defined_by_platform_loader()) {
895     assert(ik->module()->is_named(), "dynamic proxies defined in unnamed modules for boot/platform loaders not supported");
896     ik->set_shared_classpath_index(0);
897   } else {
898     assert(ik->defined_by_app_loader(), "must be");
899     ik->set_shared_classpath_index(AOTClassLocationConfig::dumptime()->app_cp_start_index());
900   }
901 
902   ArchiveBuilder::alloc_stats()->record_dynamic_proxy_class();
903   if (log_is_enabled(Info, cds, dynamic, proxy)) {
904     ResourceMark rm(THREAD);
905     stringStream ss;
906     const char* prefix = "";
907     ss.print("%s (%-7s, cp index = %d) implements ", ik->external_name(),
908              ArchiveUtils::builtin_loader_name(loader()), ik->shared_classpath_index());
909     objArrayOop intfs = (objArrayOop)interfaces();
910     for (int i = 0; i < intfs->length(); i++) {
911       oop intf_mirror = intfs->obj_at(i);
912       ss.print("%s%s", prefix, java_lang_Class::as_Klass(intf_mirror)->external_name());
913       prefix = ", ";
914     }
915 
916     log_info(cds, dynamic, proxy)("%s", ss.freeze());
917   }
918 }