1 /*
  2  * Copyright (c) 1999, 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 "ci/ciCallSite.hpp"
 26 #include "ci/ciFlatArray.hpp"
 27 #include "ci/ciFlatArrayKlass.hpp"
 28 #include "ci/ciInlineKlass.hpp"
 29 #include "ci/ciInstance.hpp"
 30 #include "ci/ciInstanceKlass.hpp"
 31 #include "ci/ciMemberName.hpp"
 32 #include "ci/ciMethod.hpp"
 33 #include "ci/ciMethodData.hpp"
 34 #include "ci/ciMethodHandle.hpp"
 35 #include "ci/ciMethodType.hpp"
 36 #include "ci/ciNullObject.hpp"
 37 #include "ci/ciObjArray.hpp"
 38 #include "ci/ciObjArrayKlass.hpp"
 39 #include "ci/ciObject.hpp"
 40 #include "ci/ciObjectFactory.hpp"
 41 #include "ci/ciRefArrayKlass.hpp"
 42 #include "ci/ciReplay.hpp"
 43 #include "ci/ciSymbol.hpp"
 44 #include "ci/ciSymbols.hpp"
 45 #include "ci/ciTypeArray.hpp"
 46 #include "ci/ciTypeArrayKlass.hpp"
 47 #include "ci/ciUtilities.inline.hpp"
 48 #include "classfile/javaClasses.inline.hpp"
 49 #include "classfile/vmClasses.hpp"
 50 #include "compiler/compiler_globals.hpp"
 51 #include "compiler/compileTask.hpp"
 52 #include "gc/shared/collectedHeap.inline.hpp"
 53 #include "memory/allocation.inline.hpp"
 54 #include "memory/universe.hpp"
 55 #include "oops/instanceKlass.hpp"
 56 #include "oops/oop.inline.hpp"
 57 #include "oops/trainingData.hpp"
 58 #include "runtime/handles.inline.hpp"
 59 #include "runtime/signature.hpp"
 60 #include "utilities/macros.hpp"
 61 
 62 // ciObjectFactory
 63 //
 64 // This class handles requests for the creation of new instances
 65 // of ciObject and its subclasses.  It contains a caching mechanism
 66 // which ensures that for each oop, at most one ciObject is created.
 67 // This invariant allows more efficient implementation of ciObject.
 68 //
 69 // Implementation note: the oop->ciObject mapping is represented as
 70 // a table stored in an array.  Even though objects are moved
 71 // by the garbage collector, the compactor preserves their relative
 72 // order; address comparison of oops (in perm space) is safe so long
 73 // as we prohibit GC during our comparisons.  We currently use binary
 74 // search to find the oop in the table, and inserting a new oop
 75 // into the table may be costly.  If this cost ends up being
 76 // problematic the underlying data structure can be switched to some
 77 // sort of balanced binary tree.
 78 
 79 GrowableArray<ciMetadata*>* ciObjectFactory::_shared_ci_metadata = nullptr;
 80 ciSymbol*                 ciObjectFactory::_shared_ci_symbols[vmSymbols::number_of_symbols()];
 81 int                       ciObjectFactory::_shared_ident_limit = 0;
 82 volatile bool             ciObjectFactory::_initialized = false;
 83 
 84 
 85 // ------------------------------------------------------------------
 86 // ciObjectFactory::ciObjectFactory
 87 ciObjectFactory::ciObjectFactory(Arena* arena,
 88                                  int expected_size)
 89                                  : _arena(arena),
 90                                    _ci_metadata(arena, expected_size, 0, nullptr),
 91                                    _cached_init_state(arena, _shared_ident_limit, 0, (u1)0),
 92                                    _unloaded_methods(arena, 4, 0, nullptr),
 93                                    _unloaded_klasses(arena, 8, 0, nullptr),
 94                                    _unloaded_instances(arena, 4, 0, nullptr),
 95                                    _return_addresses(arena, 8, 0, nullptr),
 96                                    _symbols(arena, 100, 0, nullptr),
 97                                    _next_ident(_shared_ident_limit),
 98                                    _non_perm_count(0) {
 99   for (int i = 0; i < NON_PERM_BUCKETS; i++) {
100     _non_perm_bucket[i] = nullptr;
101   }
102 
103   // If the shared ci objects exist append them to this factory's objects
104   if (_shared_ci_metadata != nullptr) {
105     _ci_metadata.appendAll(_shared_ci_metadata);
106     // ciInstanceKlass for well-known class is shared by all
107     // compiler threads and can be updated concurrently by
108     // other compiler threads during compilation.
109     // Make local copy of class state to avoid state change
110     // during compilation.
111     int len = _ci_metadata.length();
112     for (int i = 0; i < len; i++) {
113       ciMetadata* obj = _ci_metadata.at(i);
114       if (obj->is_loaded() && obj->is_instance_klass()) {
115         ciInstanceKlass* cik = obj->as_instance_klass();
116         precond(cik->is_shared());
117         InstanceKlass::ClassState current_state = cik->_init_state;
118         InstanceKlass::ClassState state = InstanceKlass::fully_initialized;
119         if (current_state != state) {
120           GUARDED_VM_ENTRY( state = cik->get_instanceKlass()->init_state(); )
121           // Update state of shared ciInstanceKlass
122           cik->_init_state = state;
123         }
124         // Cache state for current compilation
125         _cached_init_state.at_put_grow(cik->ident(), (u1)state, 0);
126       }
127     }
128   }
129 }
130 
131 // ------------------------------------------------------------------
132 // ciObjectFactory::ciObjectFactory
133 void ciObjectFactory::initialize() {
134   ASSERT_IN_VM;
135   JavaThread* thread = JavaThread::current();
136   HandleMark  handle_mark(thread);
137 
138   // This Arena is long lived and exists in the resource mark of the
139   // compiler thread that initializes the initial ciObjectFactory which
140   // creates the shared ciObjects that all later ciObjectFactories use.
141   Arena* arena = new (mtCompiler) Arena(mtCompiler);
142   ciEnv initial(arena);
143   ciEnv* env = ciEnv::current();
144   env->_factory->init_shared_objects();
145 
146   _initialized = true;
147 
148 }
149 
150 void ciObjectFactory::init_shared_objects() {
151 
152   _next_ident = 1;  // start numbering CI objects at 1
153 
154   {
155     // Create the shared symbols, but not in _shared_ci_metadata.
156     for (auto index : EnumRange<vmSymbolID>{}) {
157       Symbol* vmsym = vmSymbols::symbol_at(index);
158       assert(vmSymbols::find_sid(vmsym) == index, "1-1 mapping");
159       ciSymbol* sym = new (_arena) ciSymbol(vmsym, index);
160       init_ident_of(sym);
161       _shared_ci_symbols[vmSymbols::as_int(index)] = sym;
162     }
163 #ifdef ASSERT
164     for (auto index : EnumRange<vmSymbolID>{}) {
165       Symbol* vmsym = vmSymbols::symbol_at(index);
166       ciSymbol* sym = vm_symbol_at(index);
167       assert(sym->get_symbol() == vmsym, "oop must match");
168     }
169     assert(ciSymbols::void_class_signature()->get_symbol() == vmSymbols::void_class_signature(), "spot check");
170 #endif
171   }
172 
173   for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) {
174     BasicType t = (BasicType)i;
175     if (type2name(t) != nullptr && t != T_FLAT_ELEMENT && !is_reference_type(t) &&
176         t != T_NARROWOOP && t != T_NARROWKLASS) {
177       ciType::_basic_types[t] = new (_arena) ciType(t);
178       init_ident_of(ciType::_basic_types[t]);
179     }
180   }
181 
182   ciEnv::_null_object_instance = new (_arena) ciNullObject();
183   init_ident_of(ciEnv::_null_object_instance);
184 
185 #define VM_CLASS_DEFN(name, ignore_s)                              \
186   if (vmClasses::name##_is_loaded()) \
187     ciEnv::_##name = get_metadata(vmClasses::name())->as_instance_klass();
188 
189   VM_CLASSES_DO(VM_CLASS_DEFN)
190 #undef VM_CLASS_DEFN
191 
192   for (int len = -1; len != _ci_metadata.length(); ) {
193     len = _ci_metadata.length();
194     for (int i2 = 0; i2 < len; i2++) {
195       ciMetadata* obj = _ci_metadata.at(i2);
196       assert (obj->is_metadata(), "what else would it be?");
197       if (obj->is_loaded() && obj->is_instance_klass()) {
198         obj->as_instance_klass()->compute_nonstatic_fields();
199         obj->as_instance_klass()->transitive_interfaces();
200       }
201     }
202   }
203 
204   ciEnv::_unloaded_cisymbol = ciObjectFactory::get_symbol(vmSymbols::dummy_symbol());
205   // Create dummy InstanceKlass and ObjArrayKlass object and assign them idents
206   ciEnv::_unloaded_ciinstance_klass = new (_arena) ciInstanceKlass(ciEnv::_unloaded_cisymbol, nullptr);
207   init_ident_of(ciEnv::_unloaded_ciinstance_klass);
208   ciEnv::_unloaded_ciobjarrayklass = new (_arena) ciObjArrayKlass(ciEnv::_unloaded_cisymbol, ciEnv::_unloaded_ciinstance_klass, 1);
209   init_ident_of(ciEnv::_unloaded_ciobjarrayklass);
210   assert(ciEnv::_unloaded_ciobjarrayklass->is_obj_array_klass(), "just checking");
211 
212   get_metadata(Universe::boolArrayKlass());
213   get_metadata(Universe::charArrayKlass());
214   get_metadata(Universe::floatArrayKlass());
215   get_metadata(Universe::doubleArrayKlass());
216   get_metadata(Universe::byteArrayKlass());
217   get_metadata(Universe::shortArrayKlass());
218   get_metadata(Universe::intArrayKlass());
219   get_metadata(Universe::longArrayKlass());
220 
221   assert(_non_perm_count == 0, "no shared non-perm objects");
222 
223   // The shared_ident_limit is the first ident number that will
224   // be used for non-shared objects.  That is, numbers less than
225   // this limit are permanently assigned to shared CI objects,
226   // while the higher numbers are recycled afresh by each new ciEnv.
227 
228   _shared_ident_limit = _next_ident;
229   _shared_ci_metadata = &_ci_metadata;
230 }
231 
232 
233 ciSymbol* ciObjectFactory::get_symbol(Symbol* key) {
234   vmSymbolID sid = vmSymbols::find_sid(key);
235   if (sid != vmSymbolID::NO_SID) {
236     // do not pollute the main cache with it
237     return vm_symbol_at(sid);
238   }
239 
240   assert(vmSymbols::find_sid(key) == vmSymbolID::NO_SID, "");
241   ciSymbol* s = new (arena()) ciSymbol(key, vmSymbolID::NO_SID);
242   _symbols.push(s);
243   return s;
244 }
245 
246 // Decrement the refcount when done on symbols referenced by this compilation.
247 void ciObjectFactory::remove_symbols() {
248   for (int i = 0; i < _symbols.length(); i++) {
249     ciSymbol* s = _symbols.at(i);
250     s->get_symbol()->decrement_refcount();
251   }
252   // Since _symbols is resource allocated we're not allowed to delete it
253   // but it'll go away just the same.
254 }
255 
256 // ------------------------------------------------------------------
257 // ciObjectFactory::get
258 //
259 // Get the ciObject corresponding to some oop.  If the ciObject has
260 // already been created, it is returned.  Otherwise, a new ciObject
261 // is created.
262 ciObject* ciObjectFactory::get(oop key) {
263   ASSERT_IN_VM;
264 
265   Handle keyHandle(Thread::current(), key);
266   assert(Universe::heap()->is_in(keyHandle()), "must be");
267 
268   NonPermObject* &bucket = find_non_perm(keyHandle);
269   if (bucket != nullptr) {
270     return bucket->object();
271   }
272 
273   // The ciObject does not yet exist.  Create it and insert it
274   // into the cache.
275   ciObject* new_object = create_new_object(keyHandle());
276   assert(keyHandle() == new_object->get_oop(), "must be properly recorded");
277   init_ident_of(new_object);
278   assert(Universe::heap()->is_in(new_object->get_oop()), "must be");
279 
280   // Not a perm-space object.
281   insert_non_perm(bucket, keyHandle, new_object);
282   notice_new_object(new_object);
283   return new_object;
284 }
285 
286 void ciObjectFactory::notice_new_object(ciBaseObject* new_object) {
287   if (TrainingData::need_data()) {
288     ciEnv* env = ciEnv::current();
289     if (env->task() != nullptr) {
290       // Note: task will be null during init_compiler_runtime.
291       CompileTrainingData* td = env->task()->training_data();
292       if (td != nullptr) {
293         td->notice_jit_observation(env, new_object);
294       }
295     }
296   }
297 }
298 
299 int ciObjectFactory::metadata_compare(Metadata* const& key, ciMetadata* const& elt) {
300   Metadata* value = elt->constant_encoding();
301   if (key < value)      return -1;
302   else if (key > value) return 1;
303   else                  return 0;
304 }
305 
306 // ------------------------------------------------------------------
307 // ciObjectFactory::cached_metadata
308 //
309 // Get the ciMetadata corresponding to some Metadata. If the ciMetadata has
310 // already been created, it is returned. Otherwise, null is returned.
311 ciMetadata* ciObjectFactory::cached_metadata(Metadata* key) {
312   ASSERT_IN_VM;
313 
314   bool found = false;
315   int index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
316 
317   if (!found) {
318     return nullptr;
319   }
320   return _ci_metadata.at(index)->as_metadata();
321 }
322 
323 
324 // ------------------------------------------------------------------
325 // ciObjectFactory::get_metadata
326 //
327 // Get the ciMetadata corresponding to some Metadata. If the ciMetadata has
328 // already been created, it is returned. Otherwise, a new ciMetadata
329 // is created.
330 ciMetadata* ciObjectFactory::get_metadata(Metadata* key) {
331   ASSERT_IN_VM;
332 
333   if (ReplayCompiles && key->is_klass()) {
334     Klass* k = (Klass*)key;
335     if (k->is_instance_klass() && ciReplay::is_klass_unresolved((InstanceKlass*)k)) {
336       // Klass was unresolved at replay dump time. Simulate this case.
337       return ciEnv::_unloaded_ciinstance_klass;
338     }
339   }
340 
341 #ifdef ASSERT
342   if (CIObjectFactoryVerify) {
343     Metadata* last = nullptr;
344     for (int j = 0; j < _ci_metadata.length(); j++) {
345       Metadata* o = _ci_metadata.at(j)->constant_encoding();
346       assert(last < o, "out of order");
347       last = o;
348     }
349   }
350 #endif // ASSERT
351   int len = _ci_metadata.length();
352   bool found = false;
353   int index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
354 #ifdef ASSERT
355   if (CIObjectFactoryVerify) {
356     for (int i = 0; i < _ci_metadata.length(); i++) {
357       if (_ci_metadata.at(i)->constant_encoding() == key) {
358         assert(index == i, " bad lookup");
359       }
360     }
361   }
362 #endif
363 
364   if (!found) {
365     // The ciMetadata does not yet exist. Create it and insert it
366     // into the cache.
367     ciMetadata* new_object = create_new_metadata(key);
368     init_ident_of(new_object);
369     assert(new_object->is_metadata(), "must be");
370 
371     if (len != _ci_metadata.length()) {
372       // creating the new object has recursively entered new objects
373       // into the table.  We need to recompute our index.
374       index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
375     }
376     assert(!found, "no double insert");
377     _ci_metadata.insert_before(index, new_object);
378     notice_new_object(new_object);
379     return new_object;
380   }
381   return _ci_metadata.at(index)->as_metadata();
382 }
383 
384 // ------------------------------------------------------------------
385 // ciObjectFactory::create_new_object
386 //
387 // Create a new ciObject from an oop.
388 //
389 // Implementation note: this functionality could be virtual behavior
390 // of the oop itself.  For now, we explicitly marshal the object.
391 ciObject* ciObjectFactory::create_new_object(oop o) {
392   EXCEPTION_CONTEXT;
393 
394   if (o->is_instance()) {
395     instanceHandle h_i(THREAD, (instanceOop)o);
396     if (java_lang_invoke_CallSite::is_instance(o))
397       return new (arena()) ciCallSite(h_i);
398     else if (java_lang_invoke_MemberName::is_instance(o))
399       return new (arena()) ciMemberName(h_i);
400     else if (java_lang_invoke_MethodHandle::is_instance(o))
401       return new (arena()) ciMethodHandle(h_i);
402     else if (java_lang_invoke_MethodType::is_instance(o))
403       return new (arena()) ciMethodType(h_i);
404     else
405       return new (arena()) ciInstance(h_i);
406   } else if (o->is_refArray()) {
407     objArrayHandle h_oa(THREAD, (objArrayOop)o);
408     return new (arena()) ciObjArray(h_oa);
409   } else if (o->is_typeArray()) {
410     typeArrayHandle h_ta(THREAD, (typeArrayOop)o);
411     return new (arena()) ciTypeArray(h_ta);
412   } else if (o->is_flatArray()) {
413     flatArrayHandle h_ta(THREAD, (flatArrayOop)o);
414     return new (arena()) ciFlatArray(h_ta);
415   }
416 
417   // The oop is of some type not supported by the compiler interface.
418   ShouldNotReachHere();
419   return nullptr;
420 }
421 
422 // ------------------------------------------------------------------
423 // ciObjectFactory::create_new_metadata
424 //
425 // Create a new ciMetadata from a Metadata*.
426 //
427 // Implementation note: in order to keep Metadata live, an auxiliary ciObject
428 // is used, which points to it's holder.
429 ciMetadata* ciObjectFactory::create_new_metadata(Metadata* o) {
430   EXCEPTION_CONTEXT;
431 
432   if (o->is_klass()) {
433     Klass* k = (Klass*)o;
434     if (k->is_inline_klass()) {
435       return new (arena()) ciInlineKlass(k);
436     } else if (k->is_instance_klass()) {
437       assert(!ReplayCompiles || ciReplay::no_replay_state() || !ciReplay::is_klass_unresolved((InstanceKlass*)k), "must be whitelisted for replay compilation");
438       return new (arena()) ciInstanceKlass(k);
439     } else if (k->is_objArray_klass()) {
440       if (k->is_flatArray_klass()) {
441         return new (arena()) ciFlatArrayKlass(k);
442       } else if (k->is_refArray_klass()) {
443         return new (arena()) ciRefArrayKlass(k);
444       } else {
445         return new (arena()) ciObjArrayKlass(k);
446       }
447     } else if (k->is_typeArray_klass()) {
448       return new (arena()) ciTypeArrayKlass(k);
449     }
450   } else if (o->is_method()) {
451     methodHandle h_m(THREAD, (Method*)o);
452     ciEnv *env = CURRENT_THREAD_ENV;
453     ciInstanceKlass* holder = env->get_instance_klass(h_m()->method_holder());
454     return new (arena()) ciMethod(h_m, holder);
455   } else if (o->is_methodData()) {
456     // Hold methodHandle alive - might not be necessary ???
457     methodHandle h_m(THREAD, ((MethodData*)o)->method());
458     return new (arena()) ciMethodData((MethodData*)o);
459   }
460 
461   // The Metadata* is of some type not supported by the compiler interface.
462   ShouldNotReachHere();
463   return nullptr;
464 }
465 
466 //------------------------------------------------------------------
467 // ciObjectFactory::get_unloaded_method
468 //
469 // Get the ciMethod representing an unloaded/unfound method.
470 //
471 // Implementation note: unloaded methods are currently stored in
472 // an unordered array, requiring a linear-time lookup for each
473 // unloaded method.  This may need to change.
474 ciMethod* ciObjectFactory::get_unloaded_method(ciInstanceKlass* holder,
475                                                ciSymbol*        name,
476                                                ciSymbol*        signature,
477                                                ciInstanceKlass* accessor) {
478   assert(accessor != nullptr, "need origin of access");
479   ciSignature* that = nullptr;
480   for (int i = 0; i < _unloaded_methods.length(); i++) {
481     ciMethod* entry = _unloaded_methods.at(i);
482     if (entry->holder()->equals(holder) &&
483         entry->name()->equals(name) &&
484         entry->signature()->as_symbol()->equals(signature)) {
485       // Short-circuit slow resolve.
486       if (entry->signature()->accessing_klass() == accessor) {
487         // We've found a match.
488         return entry;
489       } else {
490         // Lazily create ciSignature
491         if (that == nullptr)  that = new (arena()) ciSignature(accessor, constantPoolHandle(), signature);
492         if (entry->signature()->equals(that)) {
493           // We've found a match.
494           return entry;
495         }
496       }
497     }
498   }
499 
500   // This is a new unloaded method.  Create it and stick it in
501   // the cache.
502   ciMethod* new_method = new (arena()) ciMethod(holder, name, signature, accessor);
503 
504   init_ident_of(new_method);
505   _unloaded_methods.append(new_method);
506 
507   return new_method;
508 }
509 
510 //------------------------------------------------------------------
511 // ciObjectFactory::get_unloaded_klass
512 //
513 // Get a ciKlass representing an unloaded klass.
514 //
515 // Implementation note: unloaded klasses are currently stored in
516 // an unordered array, requiring a linear-time lookup for each
517 // unloaded klass.  This may need to change.
518 ciKlass* ciObjectFactory::get_unloaded_klass(ciKlass* accessing_klass,
519                                              ciSymbol* name,
520                                              bool create_if_not_found) {
521   EXCEPTION_CONTEXT;
522   oop loader = nullptr;
523   oop domain = nullptr;
524   if (accessing_klass != nullptr) {
525     loader = accessing_klass->loader();
526   }
527   for (int i = 0; i < _unloaded_klasses.length(); i++) {
528     ciKlass* entry = _unloaded_klasses.at(i);
529     if (entry->name()->equals(name) &&
530         entry->loader() == loader) {
531       // We've found a match.
532       return entry;
533     }
534   }
535 
536   if (!create_if_not_found)
537     return nullptr;
538 
539   // This is a new unloaded klass.  Create it and stick it in
540   // the cache.
541   ciKlass* new_klass = nullptr;
542 
543   // Two cases: this is an unloaded ObjArrayKlass or an
544   // unloaded InstanceKlass.  Deal with both.
545   if (name->char_at(0) == JVM_SIGNATURE_ARRAY) {
546     // Decompose the name.'
547     SignatureStream ss(name->get_symbol(), false);
548     int dimension = ss.skip_array_prefix();  // skip all '['s
549     BasicType element_type = ss.type();
550     assert(element_type != T_ARRAY, "unsuccessful decomposition");
551     ciKlass* element_klass = nullptr;
552     if (element_type == T_OBJECT) {
553       ciEnv *env = CURRENT_THREAD_ENV;
554       ciSymbol* ci_name = env->get_symbol(ss.as_symbol());
555       element_klass =
556         env->get_klass_by_name(accessing_klass, ci_name, false)->as_instance_klass();
557     } else {
558       assert(dimension > 1, "one dimensional type arrays are always loaded.");
559 
560       // The type array itself takes care of one of the dimensions.
561       dimension--;
562 
563       // The element klass is a TypeArrayKlass.
564       element_klass = ciTypeArrayKlass::make(element_type);
565     }
566     new_klass = new (arena()) ciObjArrayKlass(name, element_klass, dimension);
567   } else {
568     jobject loader_handle = nullptr;
569     if (accessing_klass != nullptr) {
570       loader_handle = accessing_klass->loader_handle();
571     }
572     new_klass = new (arena()) ciInstanceKlass(name, loader_handle);
573   }
574   init_ident_of(new_klass);
575   _unloaded_klasses.append(new_klass);
576 
577   return new_klass;
578 }
579 
580 
581 //------------------------------------------------------------------
582 // ciObjectFactory::get_unloaded_instance
583 //
584 // Get a ciInstance representing an as-yet undetermined instance of a given class.
585 //
586 ciInstance* ciObjectFactory::get_unloaded_instance(ciInstanceKlass* instance_klass) {
587   for (int i = 0; i < _unloaded_instances.length(); i++) {
588     ciInstance* entry = _unloaded_instances.at(i);
589     if (entry->klass()->equals(instance_klass)) {
590       // We've found a match.
591       return entry;
592     }
593   }
594 
595   // This is a new unloaded instance.  Create it and stick it in
596   // the cache.
597   ciInstance* new_instance = new (arena()) ciInstance(instance_klass);
598 
599   init_ident_of(new_instance);
600   _unloaded_instances.append(new_instance);
601 
602   // make sure it looks the way we want:
603   assert(!new_instance->is_loaded(), "");
604   assert(new_instance->klass() == instance_klass, "");
605 
606   return new_instance;
607 }
608 
609 
610 //------------------------------------------------------------------
611 // ciObjectFactory::get_unloaded_klass_mirror
612 //
613 // Get a ciInstance representing an unresolved klass mirror.
614 //
615 // Currently, this ignores the parameters and returns a unique unloaded instance.
616 ciInstance* ciObjectFactory::get_unloaded_klass_mirror(ciKlass* type) {
617   assert(ciEnv::_Class_klass != nullptr, "");
618   return get_unloaded_instance(ciEnv::_Class_klass->as_instance_klass());
619 }
620 
621 //------------------------------------------------------------------
622 // ciObjectFactory::get_unloaded_method_handle_constant
623 //
624 // Get a ciInstance representing an unresolved method handle constant.
625 //
626 // Currently, this ignores the parameters and returns a unique unloaded instance.
627 ciInstance* ciObjectFactory::get_unloaded_method_handle_constant(ciKlass*  holder,
628                                                                  ciSymbol* name,
629                                                                  ciSymbol* signature,
630                                                                  int       ref_kind) {
631   assert(ciEnv::_MethodHandle_klass != nullptr, "");
632   return get_unloaded_instance(ciEnv::_MethodHandle_klass->as_instance_klass());
633 }
634 
635 //------------------------------------------------------------------
636 // ciObjectFactory::get_unloaded_method_type_constant
637 //
638 // Get a ciInstance representing an unresolved method type constant.
639 //
640 // Currently, this ignores the parameters and returns a unique unloaded instance.
641 ciInstance* ciObjectFactory::get_unloaded_method_type_constant(ciSymbol* signature) {
642   assert(ciEnv::_MethodType_klass != nullptr, "");
643   return get_unloaded_instance(ciEnv::_MethodType_klass->as_instance_klass());
644 }
645 
646 ciInstance* ciObjectFactory::get_unloaded_object_constant() {
647   assert(ciEnv::_Object_klass != nullptr, "");
648   return get_unloaded_instance(ciEnv::_Object_klass->as_instance_klass());
649 }
650 
651 //------------------------------------------------------------------
652 // ciObjectFactory::get_empty_methodData
653 //
654 // Get the ciMethodData representing the methodData for a method with
655 // none.
656 ciMethodData* ciObjectFactory::get_empty_methodData() {
657   ciMethodData* new_methodData = new (arena()) ciMethodData();
658   init_ident_of(new_methodData);
659   return new_methodData;
660 }
661 
662 //------------------------------------------------------------------
663 // ciObjectFactory::get_return_address
664 //
665 // Get a ciReturnAddress for a specified bci.
666 ciReturnAddress* ciObjectFactory::get_return_address(int bci) {
667   for (int i = 0; i < _return_addresses.length(); i++) {
668     ciReturnAddress* entry = _return_addresses.at(i);
669     if (entry->bci() == bci) {
670       // We've found a match.
671       return entry;
672     }
673   }
674 
675   ciReturnAddress* new_ret_addr = new (arena()) ciReturnAddress(bci);
676   init_ident_of(new_ret_addr);
677   _return_addresses.append(new_ret_addr);
678   return new_ret_addr;
679 }
680 
681 ciWrapper* ciObjectFactory::make_early_larval_wrapper(ciType* type) {
682   ciWrapper* wrapper = new (arena()) ciWrapper(type, ciWrapper::EarlyLarval);
683   init_ident_of(wrapper);
684   return wrapper;
685 }
686 
687 ciWrapper* ciObjectFactory::make_null_free_wrapper(ciType* type) {
688   ciWrapper* wrapper = new (arena()) ciWrapper(type, ciWrapper::NullFree);
689   init_ident_of(wrapper);
690   return wrapper;
691 }
692 
693 // ------------------------------------------------------------------
694 // ciObjectFactory::init_ident_of
695 void ciObjectFactory::init_ident_of(ciBaseObject* obj) {
696   obj->set_ident(_next_ident++);
697 }
698 
699 static ciObjectFactory::NonPermObject* emptyBucket = nullptr;
700 
701 // ------------------------------------------------------------------
702 // ciObjectFactory::find_non_perm
703 //
704 // Use a small hash table, hashed on the klass of the key.
705 // If there is no entry in the cache corresponding to this oop, return
706 // the null tail of the bucket into which the oop should be inserted.
707 ciObjectFactory::NonPermObject* &ciObjectFactory::find_non_perm(Handle keyHandle) {
708   assert(Universe::heap()->is_in(keyHandle()), "must be");
709   ciMetadata* klass = get_metadata(keyHandle->klass()); // This may safepoint!
710   NonPermObject* *bp = &_non_perm_bucket[(unsigned) klass->hash() % NON_PERM_BUCKETS];
711   for (NonPermObject* p; (p = (*bp)) != nullptr; bp = &p->next()) {
712     if (is_equal(p, keyHandle()))  break;
713   }
714   return (*bp);
715 }
716 
717 
718 
719 // ------------------------------------------------------------------
720 // Code for for NonPermObject
721 //
722 inline ciObjectFactory::NonPermObject::NonPermObject(ciObjectFactory::NonPermObject* &bucket, oop key, ciObject* object) {
723   assert(ciObjectFactory::is_initialized(), "");
724   _object = object;
725   _next = bucket;
726   bucket = this;
727 }
728 
729 
730 
731 // ------------------------------------------------------------------
732 // ciObjectFactory::insert_non_perm
733 //
734 // Insert a ciObject into the non-perm table.
735 void ciObjectFactory::insert_non_perm(ciObjectFactory::NonPermObject* &where, Handle keyHandle, ciObject* obj) {
736   assert(Universe::heap()->is_in_or_null(keyHandle()), "must be");
737   assert(&where != &emptyBucket, "must not try to fill empty bucket");
738   NonPermObject* p = new (arena()) NonPermObject(where, keyHandle(), obj);
739   assert(where == p && is_equal(p, keyHandle()) && p->object() == obj, "entry must match");
740   assert(find_non_perm(keyHandle) == p, "must find the same spot");
741   ++_non_perm_count;
742 }
743 
744 // ------------------------------------------------------------------
745 // ciObjectFactory::vm_symbol_at
746 // Get the ciSymbol corresponding to some index in vmSymbols.
747 ciSymbol* ciObjectFactory::vm_symbol_at(vmSymbolID sid) {
748   int index = vmSymbols::as_int(sid);
749   return _shared_ci_symbols[index];
750 }
751 
752 // ------------------------------------------------------------------
753 // ciObjectFactory::metadata_do
754 void ciObjectFactory::metadata_do(MetadataClosure* f) {
755   for (int j = 0; j < _ci_metadata.length(); j++) {
756     Metadata* o = _ci_metadata.at(j)->constant_encoding();
757     f->do_metadata(o);
758   }
759 }
760 
761 // ------------------------------------------------------------------
762 // ciObjectFactory::print_contents_impl
763 void ciObjectFactory::print_contents_impl() {
764   int len = _ci_metadata.length();
765   tty->print_cr("ciObjectFactory (%d) meta data contents:", len);
766   for (int i = 0; i < len; i++) {
767     _ci_metadata.at(i)->print();
768     tty->cr();
769   }
770 }
771 
772 // ------------------------------------------------------------------
773 // ciObjectFactory::print_contents
774 void ciObjectFactory::print_contents() {
775   print();
776   tty->cr();
777   GUARDED_VM_ENTRY(print_contents_impl();)
778 }
779 
780 // ------------------------------------------------------------------
781 // ciObjectFactory::print
782 //
783 // Print debugging information about the object factory
784 void ciObjectFactory::print() {
785   tty->print("<ciObjectFactory oops=%d metadata=%d unloaded_methods=%d unloaded_instances=%d unloaded_klasses=%d>",
786              _non_perm_count, _ci_metadata.length(), _unloaded_methods.length(),
787              _unloaded_instances.length(),
788              _unloaded_klasses.length());
789 }