1 /*
  2  * Copyright (c) 1999, 2025, 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/ciInstance.hpp"
 27 #include "ci/ciInstanceKlass.hpp"
 28 #include "ci/ciMemberName.hpp"
 29 #include "ci/ciMethod.hpp"
 30 #include "ci/ciMethodData.hpp"
 31 #include "ci/ciMethodHandle.hpp"
 32 #include "ci/ciMethodType.hpp"
 33 #include "ci/ciNullObject.hpp"
 34 #include "ci/ciObjArray.hpp"
 35 #include "ci/ciObjArrayKlass.hpp"
 36 #include "ci/ciObject.hpp"
 37 #include "ci/ciObjectFactory.hpp"
 38 #include "ci/ciReplay.hpp"
 39 #include "ci/ciSymbol.hpp"
 40 #include "ci/ciSymbols.hpp"
 41 #include "ci/ciTypeArray.hpp"
 42 #include "ci/ciTypeArrayKlass.hpp"
 43 #include "ci/ciUtilities.inline.hpp"
 44 #include "classfile/javaClasses.inline.hpp"
 45 #include "classfile/vmClasses.hpp"
 46 #include "compiler/compiler_globals.hpp"
 47 #include "gc/shared/collectedHeap.inline.hpp"
 48 #include "memory/allocation.inline.hpp"
 49 #include "memory/universe.hpp"
 50 #include "oops/oop.inline.hpp"
 51 #include "runtime/handles.inline.hpp"
 52 #include "runtime/signature.hpp"
 53 #include "utilities/macros.hpp"
 54 
 55 // ciObjectFactory
 56 //
 57 // This class handles requests for the creation of new instances
 58 // of ciObject and its subclasses.  It contains a caching mechanism
 59 // which ensures that for each oop, at most one ciObject is created.
 60 // This invariant allows more efficient implementation of ciObject.
 61 //
 62 // Implementation note: the oop->ciObject mapping is represented as
 63 // a table stored in an array.  Even though objects are moved
 64 // by the garbage collector, the compactor preserves their relative
 65 // order; address comparison of oops (in perm space) is safe so long
 66 // as we prohibit GC during our comparisons.  We currently use binary
 67 // search to find the oop in the table, and inserting a new oop
 68 // into the table may be costly.  If this cost ends up being
 69 // problematic the underlying data structure can be switched to some
 70 // sort of balanced binary tree.
 71 
 72 GrowableArray<ciMetadata*>* ciObjectFactory::_shared_ci_metadata = nullptr;
 73 ciSymbol*                 ciObjectFactory::_shared_ci_symbols[vmSymbols::number_of_symbols()];
 74 int                       ciObjectFactory::_shared_ident_limit = 0;
 75 volatile bool             ciObjectFactory::_initialized = false;
 76 
 77 
 78 // ------------------------------------------------------------------
 79 // ciObjectFactory::ciObjectFactory
 80 ciObjectFactory::ciObjectFactory(Arena* arena,
 81                                  int expected_size)
 82                                  : _arena(arena),
 83                                    _ci_metadata(arena, expected_size, 0, nullptr),
 84                                    _unloaded_methods(arena, 4, 0, nullptr),
 85                                    _unloaded_klasses(arena, 8, 0, nullptr),
 86                                    _unloaded_instances(arena, 4, 0, nullptr),
 87                                    _return_addresses(arena, 8, 0, nullptr),
 88                                    _symbols(arena, 100, 0, nullptr),
 89                                    _next_ident(_shared_ident_limit),
 90                                    _non_perm_count(0) {
 91   for (int i = 0; i < NON_PERM_BUCKETS; i++) {
 92     _non_perm_bucket[i] = nullptr;
 93   }
 94 
 95   // If the shared ci objects exist append them to this factory's objects
 96   if (_shared_ci_metadata != nullptr) {
 97     _ci_metadata.appendAll(_shared_ci_metadata);
 98   }
 99 }
100 
101 // ------------------------------------------------------------------
102 // ciObjectFactory::ciObjectFactory
103 void ciObjectFactory::initialize() {
104   ASSERT_IN_VM;
105   JavaThread* thread = JavaThread::current();
106   HandleMark  handle_mark(thread);
107 
108   // This Arena is long lived and exists in the resource mark of the
109   // compiler thread that initializes the initial ciObjectFactory which
110   // creates the shared ciObjects that all later ciObjectFactories use.
111   Arena* arena = new (mtCompiler) Arena(mtCompiler);
112   ciEnv initial(arena);
113   ciEnv* env = ciEnv::current();
114   env->_factory->init_shared_objects();
115 
116   _initialized = true;
117 
118 }
119 
120 void ciObjectFactory::init_shared_objects() {
121 
122   _next_ident = 1;  // start numbering CI objects at 1
123 
124   {
125     // Create the shared symbols, but not in _shared_ci_metadata.
126     for (auto index : EnumRange<vmSymbolID>{}) {
127       Symbol* vmsym = vmSymbols::symbol_at(index);
128       assert(vmSymbols::find_sid(vmsym) == index, "1-1 mapping");
129       ciSymbol* sym = new (_arena) ciSymbol(vmsym, index);
130       init_ident_of(sym);
131       _shared_ci_symbols[vmSymbols::as_int(index)] = sym;
132     }
133 #ifdef ASSERT
134     for (auto index : EnumRange<vmSymbolID>{}) {
135       Symbol* vmsym = vmSymbols::symbol_at(index);
136       ciSymbol* sym = vm_symbol_at(index);
137       assert(sym->get_symbol() == vmsym, "oop must match");
138     }
139     assert(ciSymbols::void_class_signature()->get_symbol() == vmSymbols::void_class_signature(), "spot check");
140 #endif
141   }
142 
143   for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) {
144     BasicType t = (BasicType)i;
145     if (type2name(t) != nullptr && !is_reference_type(t) &&
146         t != T_NARROWOOP && t != T_NARROWKLASS) {
147       ciType::_basic_types[t] = new (_arena) ciType(t);
148       init_ident_of(ciType::_basic_types[t]);
149     }
150   }
151 
152   ciEnv::_null_object_instance = new (_arena) ciNullObject();
153   init_ident_of(ciEnv::_null_object_instance);
154 
155 #define VM_CLASS_DEFN(name, ignore_s)                              \
156   if (vmClasses::name##_is_loaded()) \
157     ciEnv::_##name = get_metadata(vmClasses::name())->as_instance_klass();
158 
159   VM_CLASSES_DO(VM_CLASS_DEFN)
160 #undef VM_CLASS_DEFN
161 
162   for (int len = -1; len != _ci_metadata.length(); ) {
163     len = _ci_metadata.length();
164     for (int i2 = 0; i2 < len; i2++) {
165       ciMetadata* obj = _ci_metadata.at(i2);
166       assert (obj->is_metadata(), "what else would it be?");
167       if (obj->is_loaded() && obj->is_instance_klass()) {
168         obj->as_instance_klass()->compute_nonstatic_fields();
169         obj->as_instance_klass()->transitive_interfaces();
170       }
171     }
172   }
173 
174   ciEnv::_unloaded_cisymbol = ciObjectFactory::get_symbol(vmSymbols::dummy_symbol());
175   // Create dummy InstanceKlass and ObjArrayKlass object and assign them idents
176   ciEnv::_unloaded_ciinstance_klass = new (_arena) ciInstanceKlass(ciEnv::_unloaded_cisymbol, nullptr);
177   init_ident_of(ciEnv::_unloaded_ciinstance_klass);
178   ciEnv::_unloaded_ciobjarrayklass = new (_arena) ciObjArrayKlass(ciEnv::_unloaded_cisymbol, ciEnv::_unloaded_ciinstance_klass, 1);
179   init_ident_of(ciEnv::_unloaded_ciobjarrayklass);
180   assert(ciEnv::_unloaded_ciobjarrayklass->is_obj_array_klass(), "just checking");
181 
182   get_metadata(Universe::boolArrayKlass());
183   get_metadata(Universe::charArrayKlass());
184   get_metadata(Universe::floatArrayKlass());
185   get_metadata(Universe::doubleArrayKlass());
186   get_metadata(Universe::byteArrayKlass());
187   get_metadata(Universe::shortArrayKlass());
188   get_metadata(Universe::intArrayKlass());
189   get_metadata(Universe::longArrayKlass());
190 
191   assert(_non_perm_count == 0, "no shared non-perm objects");
192 
193   // The shared_ident_limit is the first ident number that will
194   // be used for non-shared objects.  That is, numbers less than
195   // this limit are permanently assigned to shared CI objects,
196   // while the higher numbers are recycled afresh by each new ciEnv.
197 
198   _shared_ident_limit = _next_ident;
199   _shared_ci_metadata = &_ci_metadata;
200 }
201 
202 
203 ciSymbol* ciObjectFactory::get_symbol(Symbol* key) {
204   vmSymbolID sid = vmSymbols::find_sid(key);
205   if (sid != vmSymbolID::NO_SID) {
206     // do not pollute the main cache with it
207     return vm_symbol_at(sid);
208   }
209 
210   assert(vmSymbols::find_sid(key) == vmSymbolID::NO_SID, "");
211   ciSymbol* s = new (arena()) ciSymbol(key, vmSymbolID::NO_SID);
212   _symbols.push(s);
213   return s;
214 }
215 
216 // Decrement the refcount when done on symbols referenced by this compilation.
217 void ciObjectFactory::remove_symbols() {
218   for (int i = 0; i < _symbols.length(); i++) {
219     ciSymbol* s = _symbols.at(i);
220     s->get_symbol()->decrement_refcount();
221   }
222   // Since _symbols is resource allocated we're not allowed to delete it
223   // but it'll go away just the same.
224 }
225 
226 // ------------------------------------------------------------------
227 // ciObjectFactory::get
228 //
229 // Get the ciObject corresponding to some oop.  If the ciObject has
230 // already been created, it is returned.  Otherwise, a new ciObject
231 // is created.
232 ciObject* ciObjectFactory::get(oop key) {
233   ASSERT_IN_VM;
234 
235   assert(Universe::heap()->is_in(key), "must be");
236 
237   NonPermObject* &bucket = find_non_perm(key);
238   if (bucket != nullptr) {
239     return bucket->object();
240   }
241 
242   // The ciObject does not yet exist.  Create it and insert it
243   // into the cache.
244   Handle keyHandle(Thread::current(), key);
245   ciObject* new_object = create_new_object(keyHandle());
246   assert(keyHandle() == new_object->get_oop(), "must be properly recorded");
247   init_ident_of(new_object);
248   assert(Universe::heap()->is_in(new_object->get_oop()), "must be");
249 
250   // Not a perm-space object.
251   insert_non_perm(bucket, keyHandle(), new_object);
252   return new_object;
253 }
254 
255 int ciObjectFactory::metadata_compare(Metadata* const& key, ciMetadata* const& elt) {
256   Metadata* value = elt->constant_encoding();
257   if (key < value)      return -1;
258   else if (key > value) return 1;
259   else                  return 0;
260 }
261 
262 // ------------------------------------------------------------------
263 // ciObjectFactory::cached_metadata
264 //
265 // Get the ciMetadata corresponding to some Metadata. If the ciMetadata has
266 // already been created, it is returned. Otherwise, null is returned.
267 ciMetadata* ciObjectFactory::cached_metadata(Metadata* key) {
268   ASSERT_IN_VM;
269 
270   bool found = false;
271   int index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
272 
273   if (!found) {
274     return nullptr;
275   }
276   return _ci_metadata.at(index)->as_metadata();
277 }
278 
279 
280 // ------------------------------------------------------------------
281 // ciObjectFactory::get_metadata
282 //
283 // Get the ciMetadata corresponding to some Metadata. If the ciMetadata has
284 // already been created, it is returned. Otherwise, a new ciMetadata
285 // is created.
286 ciMetadata* ciObjectFactory::get_metadata(Metadata* key) {
287   ASSERT_IN_VM;
288 
289   if (ReplayCompiles && key->is_klass()) {
290     Klass* k = (Klass*)key;
291     if (k->is_instance_klass() && ciReplay::is_klass_unresolved((InstanceKlass*)k)) {
292       // Klass was unresolved at replay dump time. Simulate this case.
293       return ciEnv::_unloaded_ciinstance_klass;
294     }
295   }
296 
297 #ifdef ASSERT
298   if (CIObjectFactoryVerify) {
299     Metadata* last = nullptr;
300     for (int j = 0; j < _ci_metadata.length(); j++) {
301       Metadata* o = _ci_metadata.at(j)->constant_encoding();
302       assert(last < o, "out of order");
303       last = o;
304     }
305   }
306 #endif // ASSERT
307   int len = _ci_metadata.length();
308   bool found = false;
309   int index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
310 #ifdef ASSERT
311   if (CIObjectFactoryVerify) {
312     for (int i = 0; i < _ci_metadata.length(); i++) {
313       if (_ci_metadata.at(i)->constant_encoding() == key) {
314         assert(index == i, " bad lookup");
315       }
316     }
317   }
318 #endif
319 
320   if (!found) {
321     // The ciMetadata does not yet exist. Create it and insert it
322     // into the cache.
323     ciMetadata* new_object = create_new_metadata(key);
324     init_ident_of(new_object);
325     assert(new_object->is_metadata(), "must be");
326 
327     if (len != _ci_metadata.length()) {
328       // creating the new object has recursively entered new objects
329       // into the table.  We need to recompute our index.
330       index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
331     }
332     assert(!found, "no double insert");
333     _ci_metadata.insert_before(index, new_object);
334     return new_object;
335   }
336   return _ci_metadata.at(index)->as_metadata();
337 }
338 
339 // ------------------------------------------------------------------
340 // ciObjectFactory::create_new_object
341 //
342 // Create a new ciObject from an oop.
343 //
344 // Implementation note: this functionality could be virtual behavior
345 // of the oop itself.  For now, we explicitly marshal the object.
346 ciObject* ciObjectFactory::create_new_object(oop o) {
347   EXCEPTION_CONTEXT;
348 
349   if (o->is_instance()) {
350     instanceHandle h_i(THREAD, (instanceOop)o);
351     if (java_lang_invoke_CallSite::is_instance(o))
352       return new (arena()) ciCallSite(h_i);
353     else if (java_lang_invoke_MemberName::is_instance(o))
354       return new (arena()) ciMemberName(h_i);
355     else if (java_lang_invoke_MethodHandle::is_instance(o))
356       return new (arena()) ciMethodHandle(h_i);
357     else if (java_lang_invoke_MethodType::is_instance(o))
358       return new (arena()) ciMethodType(h_i);
359     else
360       return new (arena()) ciInstance(h_i);
361   } else if (o->is_objArray()) {
362     objArrayHandle h_oa(THREAD, (objArrayOop)o);
363     return new (arena()) ciObjArray(h_oa);
364   } else if (o->is_typeArray()) {
365     typeArrayHandle h_ta(THREAD, (typeArrayOop)o);
366     return new (arena()) ciTypeArray(h_ta);
367   }
368 
369   // The oop is of some type not supported by the compiler interface.
370   ShouldNotReachHere();
371   return nullptr;
372 }
373 
374 // ------------------------------------------------------------------
375 // ciObjectFactory::create_new_metadata
376 //
377 // Create a new ciMetadata from a Metadata*.
378 //
379 // Implementation note: in order to keep Metadata live, an auxiliary ciObject
380 // is used, which points to it's holder.
381 ciMetadata* ciObjectFactory::create_new_metadata(Metadata* o) {
382   EXCEPTION_CONTEXT;
383 
384   if (o->is_klass()) {
385     Klass* k = (Klass*)o;
386     if (k->is_instance_klass()) {
387       assert(!ReplayCompiles || ciReplay::no_replay_state() || !ciReplay::is_klass_unresolved((InstanceKlass*)k), "must be whitelisted for replay compilation");
388       return new (arena()) ciInstanceKlass(k);
389     } else if (k->is_objArray_klass()) {
390       return new (arena()) ciObjArrayKlass(k);
391     } else if (k->is_typeArray_klass()) {
392       return new (arena()) ciTypeArrayKlass(k);
393     }
394   } else if (o->is_method()) {
395     methodHandle h_m(THREAD, (Method*)o);
396     ciEnv *env = CURRENT_THREAD_ENV;
397     ciInstanceKlass* holder = env->get_instance_klass(h_m()->method_holder());
398     return new (arena()) ciMethod(h_m, holder);
399   } else if (o->is_methodData()) {
400     // Hold methodHandle alive - might not be necessary ???
401     methodHandle h_m(THREAD, ((MethodData*)o)->method());
402     return new (arena()) ciMethodData((MethodData*)o);
403   }
404 
405   // The Metadata* is of some type not supported by the compiler interface.
406   ShouldNotReachHere();
407   return nullptr;
408 }
409 
410 //------------------------------------------------------------------
411 // ciObjectFactory::get_unloaded_method
412 //
413 // Get the ciMethod representing an unloaded/unfound method.
414 //
415 // Implementation note: unloaded methods are currently stored in
416 // an unordered array, requiring a linear-time lookup for each
417 // unloaded method.  This may need to change.
418 ciMethod* ciObjectFactory::get_unloaded_method(ciInstanceKlass* holder,
419                                                ciSymbol*        name,
420                                                ciSymbol*        signature,
421                                                ciInstanceKlass* accessor) {
422   assert(accessor != nullptr, "need origin of access");
423   ciSignature* that = nullptr;
424   for (int i = 0; i < _unloaded_methods.length(); i++) {
425     ciMethod* entry = _unloaded_methods.at(i);
426     if (entry->holder()->equals(holder) &&
427         entry->name()->equals(name) &&
428         entry->signature()->as_symbol()->equals(signature)) {
429       // Short-circuit slow resolve.
430       if (entry->signature()->accessing_klass() == accessor) {
431         // We've found a match.
432         return entry;
433       } else {
434         // Lazily create ciSignature
435         if (that == nullptr)  that = new (arena()) ciSignature(accessor, constantPoolHandle(), signature);
436         if (entry->signature()->equals(that)) {
437           // We've found a match.
438           return entry;
439         }
440       }
441     }
442   }
443 
444   // This is a new unloaded method.  Create it and stick it in
445   // the cache.
446   ciMethod* new_method = new (arena()) ciMethod(holder, name, signature, accessor);
447 
448   init_ident_of(new_method);
449   _unloaded_methods.append(new_method);
450 
451   return new_method;
452 }
453 
454 //------------------------------------------------------------------
455 // ciObjectFactory::get_unloaded_klass
456 //
457 // Get a ciKlass representing an unloaded klass.
458 //
459 // Implementation note: unloaded klasses are currently stored in
460 // an unordered array, requiring a linear-time lookup for each
461 // unloaded klass.  This may need to change.
462 ciKlass* ciObjectFactory::get_unloaded_klass(ciKlass* accessing_klass,
463                                              ciSymbol* name,
464                                              bool create_if_not_found) {
465   EXCEPTION_CONTEXT;
466   oop loader = nullptr;
467   oop domain = nullptr;
468   if (accessing_klass != nullptr) {
469     loader = accessing_klass->loader();
470   }
471   for (int i = 0; i < _unloaded_klasses.length(); i++) {
472     ciKlass* entry = _unloaded_klasses.at(i);
473     if (entry->name()->equals(name) &&
474         entry->loader() == loader) {
475       // We've found a match.
476       return entry;
477     }
478   }
479 
480   if (!create_if_not_found)
481     return nullptr;
482 
483   // This is a new unloaded klass.  Create it and stick it in
484   // the cache.
485   ciKlass* new_klass = nullptr;
486 
487   // Two cases: this is an unloaded ObjArrayKlass or an
488   // unloaded InstanceKlass.  Deal with both.
489   if (name->char_at(0) == JVM_SIGNATURE_ARRAY) {
490     // Decompose the name.'
491     SignatureStream ss(name->get_symbol(), false);
492     int dimension = ss.skip_array_prefix();  // skip all '['s
493     BasicType element_type = ss.type();
494     assert(element_type != T_ARRAY, "unsuccessful decomposition");
495     ciKlass* element_klass = nullptr;
496     if (element_type == T_OBJECT) {
497       ciEnv *env = CURRENT_THREAD_ENV;
498       ciSymbol* ci_name = env->get_symbol(ss.as_symbol());
499       element_klass =
500         env->get_klass_by_name(accessing_klass, ci_name, false)->as_instance_klass();
501     } else {
502       assert(dimension > 1, "one dimensional type arrays are always loaded.");
503 
504       // The type array itself takes care of one of the dimensions.
505       dimension--;
506 
507       // The element klass is a TypeArrayKlass.
508       element_klass = ciTypeArrayKlass::make(element_type);
509     }
510     new_klass = new (arena()) ciObjArrayKlass(name, element_klass, dimension);
511   } else {
512     jobject loader_handle = nullptr;
513     if (accessing_klass != nullptr) {
514       loader_handle = accessing_klass->loader_handle();
515     }
516     new_klass = new (arena()) ciInstanceKlass(name, loader_handle);
517   }
518   init_ident_of(new_klass);
519   _unloaded_klasses.append(new_klass);
520 
521   return new_klass;
522 }
523 
524 
525 //------------------------------------------------------------------
526 // ciObjectFactory::get_unloaded_instance
527 //
528 // Get a ciInstance representing an as-yet undetermined instance of a given class.
529 //
530 ciInstance* ciObjectFactory::get_unloaded_instance(ciInstanceKlass* instance_klass) {
531   for (int i = 0; i < _unloaded_instances.length(); i++) {
532     ciInstance* entry = _unloaded_instances.at(i);
533     if (entry->klass()->equals(instance_klass)) {
534       // We've found a match.
535       return entry;
536     }
537   }
538 
539   // This is a new unloaded instance.  Create it and stick it in
540   // the cache.
541   ciInstance* new_instance = new (arena()) ciInstance(instance_klass);
542 
543   init_ident_of(new_instance);
544   _unloaded_instances.append(new_instance);
545 
546   // make sure it looks the way we want:
547   assert(!new_instance->is_loaded(), "");
548   assert(new_instance->klass() == instance_klass, "");
549 
550   return new_instance;
551 }
552 
553 
554 //------------------------------------------------------------------
555 // ciObjectFactory::get_unloaded_klass_mirror
556 //
557 // Get a ciInstance representing an unresolved klass mirror.
558 //
559 // Currently, this ignores the parameters and returns a unique unloaded instance.
560 ciInstance* ciObjectFactory::get_unloaded_klass_mirror(ciKlass* type) {
561   assert(ciEnv::_Class_klass != nullptr, "");
562   return get_unloaded_instance(ciEnv::_Class_klass->as_instance_klass());
563 }
564 
565 //------------------------------------------------------------------
566 // ciObjectFactory::get_unloaded_method_handle_constant
567 //
568 // Get a ciInstance representing an unresolved method handle constant.
569 //
570 // Currently, this ignores the parameters and returns a unique unloaded instance.
571 ciInstance* ciObjectFactory::get_unloaded_method_handle_constant(ciKlass*  holder,
572                                                                  ciSymbol* name,
573                                                                  ciSymbol* signature,
574                                                                  int       ref_kind) {
575   assert(ciEnv::_MethodHandle_klass != nullptr, "");
576   return get_unloaded_instance(ciEnv::_MethodHandle_klass->as_instance_klass());
577 }
578 
579 //------------------------------------------------------------------
580 // ciObjectFactory::get_unloaded_method_type_constant
581 //
582 // Get a ciInstance representing an unresolved method type constant.
583 //
584 // Currently, this ignores the parameters and returns a unique unloaded instance.
585 ciInstance* ciObjectFactory::get_unloaded_method_type_constant(ciSymbol* signature) {
586   assert(ciEnv::_MethodType_klass != nullptr, "");
587   return get_unloaded_instance(ciEnv::_MethodType_klass->as_instance_klass());
588 }
589 
590 ciInstance* ciObjectFactory::get_unloaded_object_constant() {
591   assert(ciEnv::_Object_klass != nullptr, "");
592   return get_unloaded_instance(ciEnv::_Object_klass->as_instance_klass());
593 }
594 
595 //------------------------------------------------------------------
596 // ciObjectFactory::get_empty_methodData
597 //
598 // Get the ciMethodData representing the methodData for a method with
599 // none.
600 ciMethodData* ciObjectFactory::get_empty_methodData() {
601   ciMethodData* new_methodData = new (arena()) ciMethodData();
602   init_ident_of(new_methodData);
603   return new_methodData;
604 }
605 
606 //------------------------------------------------------------------
607 // ciObjectFactory::get_return_address
608 //
609 // Get a ciReturnAddress for a specified bci.
610 ciReturnAddress* ciObjectFactory::get_return_address(int bci) {
611   for (int i = 0; i < _return_addresses.length(); i++) {
612     ciReturnAddress* entry = _return_addresses.at(i);
613     if (entry->bci() == bci) {
614       // We've found a match.
615       return entry;
616     }
617   }
618 
619   ciReturnAddress* new_ret_addr = new (arena()) ciReturnAddress(bci);
620   init_ident_of(new_ret_addr);
621   _return_addresses.append(new_ret_addr);
622   return new_ret_addr;
623 }
624 
625 // ------------------------------------------------------------------
626 // ciObjectFactory::init_ident_of
627 void ciObjectFactory::init_ident_of(ciBaseObject* obj) {
628   obj->set_ident(_next_ident++);
629 }
630 
631 static ciObjectFactory::NonPermObject* emptyBucket = nullptr;
632 
633 // ------------------------------------------------------------------
634 // ciObjectFactory::find_non_perm
635 //
636 // Use a small hash table, hashed on the klass of the key.
637 // If there is no entry in the cache corresponding to this oop, return
638 // the null tail of the bucket into which the oop should be inserted.
639 ciObjectFactory::NonPermObject* &ciObjectFactory::find_non_perm(oop key) {
640   assert(Universe::heap()->is_in(key), "must be");
641   ciMetadata* klass = get_metadata(key->klass());
642   NonPermObject* *bp = &_non_perm_bucket[(unsigned) klass->hash() % NON_PERM_BUCKETS];
643   for (NonPermObject* p; (p = (*bp)) != nullptr; bp = &p->next()) {
644     if (is_equal(p, key))  break;
645   }
646   return (*bp);
647 }
648 
649 
650 
651 // ------------------------------------------------------------------
652 // Code for for NonPermObject
653 //
654 inline ciObjectFactory::NonPermObject::NonPermObject(ciObjectFactory::NonPermObject* &bucket, oop key, ciObject* object) {
655   assert(ciObjectFactory::is_initialized(), "");
656   _object = object;
657   _next = bucket;
658   bucket = this;
659 }
660 
661 
662 
663 // ------------------------------------------------------------------
664 // ciObjectFactory::insert_non_perm
665 //
666 // Insert a ciObject into the non-perm table.
667 void ciObjectFactory::insert_non_perm(ciObjectFactory::NonPermObject* &where, oop key, ciObject* obj) {
668   assert(Universe::heap()->is_in_or_null(key), "must be");
669   assert(&where != &emptyBucket, "must not try to fill empty bucket");
670   NonPermObject* p = new (arena()) NonPermObject(where, key, obj);
671   assert(where == p && is_equal(p, key) && p->object() == obj, "entry must match");
672   assert(find_non_perm(key) == p, "must find the same spot");
673   ++_non_perm_count;
674 }
675 
676 // ------------------------------------------------------------------
677 // ciObjectFactory::vm_symbol_at
678 // Get the ciSymbol corresponding to some index in vmSymbols.
679 ciSymbol* ciObjectFactory::vm_symbol_at(vmSymbolID sid) {
680   int index = vmSymbols::as_int(sid);
681   return _shared_ci_symbols[index];
682 }
683 
684 // ------------------------------------------------------------------
685 // ciObjectFactory::metadata_do
686 void ciObjectFactory::metadata_do(MetadataClosure* f) {
687   for (int j = 0; j < _ci_metadata.length(); j++) {
688     Metadata* o = _ci_metadata.at(j)->constant_encoding();
689     f->do_metadata(o);
690   }
691 }
692 
693 // ------------------------------------------------------------------
694 // ciObjectFactory::print_contents_impl
695 void ciObjectFactory::print_contents_impl() {
696   int len = _ci_metadata.length();
697   tty->print_cr("ciObjectFactory (%d) meta data contents:", len);
698   for (int i = 0; i < len; i++) {
699     _ci_metadata.at(i)->print();
700     tty->cr();
701   }
702 }
703 
704 // ------------------------------------------------------------------
705 // ciObjectFactory::print_contents
706 void ciObjectFactory::print_contents() {
707   print();
708   tty->cr();
709   GUARDED_VM_ENTRY(print_contents_impl();)
710 }
711 
712 // ------------------------------------------------------------------
713 // ciObjectFactory::print
714 //
715 // Print debugging information about the object factory
716 void ciObjectFactory::print() {
717   tty->print("<ciObjectFactory oops=%d metadata=%d unloaded_methods=%d unloaded_instances=%d unloaded_klasses=%d>",
718              _non_perm_count, _ci_metadata.length(), _unloaded_methods.length(),
719              _unloaded_instances.length(),
720              _unloaded_klasses.length());
721 }