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 #ifndef SHARE_CI_CIINSTANCEKLASS_HPP
 26 #define SHARE_CI_CIINSTANCEKLASS_HPP
 27 
 28 #include "ci/ciConstantPoolCache.hpp"
 29 #include "ci/ciFlags.hpp"
 30 #include "ci/ciKlass.hpp"
 31 #include "ci/ciSymbol.hpp"
 32 #include "oops/instanceKlass.hpp"
 33 
 34 // ciInstanceKlass
 35 //
 36 // This class represents a Klass* in the HotSpot virtual machine
 37 // whose Klass part is an InstanceKlass.  It may or may not
 38 // be loaded.
 39 class ciInstanceKlass : public ciKlass {
 40   CI_PACKAGE_ACCESS
 41   friend class ciBytecodeStream;
 42   friend class ciEnv;
 43   friend class ciExceptionHandler;
 44   friend class ciMethod;
 45   friend class ciField;
 46   friend class ciReplay;
 47   friend class CompileTrainingData;
 48 
 49 private:
 50   enum SubklassValue { subklass_unknown, subklass_false, subklass_true };
 51 
 52   jobject                _loader;
 53 
 54   InstanceKlass::ClassState _init_state;           // state of class
 55   bool                   _is_shared;
 56   bool                   _has_finalizer;
 57   SubklassValue          _has_subklass;
 58   bool                   _has_nonstatic_fields;
 59   bool                   _has_nonstatic_concrete_methods;
 60   bool                   _is_hidden;
 61   bool                   _is_record;
 62   bool                   _has_trusted_loader;
 63 
 64   ciFlags                _flags;
 65 
 66   // Lazy fields get filled in only upon request.
 67   ciInstanceKlass*       _super;
 68   ciInstance*            _java_mirror;
 69 
 70   ciConstantPoolCache*   _field_cache;  // cached map index->field
 71 
 72   // Fields declared in the bytecode (without nested fields in flat fields),
 73   // ordered in JavaFieldStream order, with superclasses first (i.e. from lang.java.Object
 74   // to most derived class).
 75   const GrowableArray<ciField*>* _declared_nonstatic_fields;
 76 
 77   // Fields laid out in memory (flat fields are expanded into their components). The ciField object
 78   // for each primitive component has the holder being this ciInstanceKlass or one of its
 79   // superclasses.
 80   // Fields are in the same order as in _declared_nonstatic_fields, but flat fields are replaced by
 81   // the list of their own fields, ordered the same way (hierarchy traversed top-down, in
 82   // JavaFieldStream order).
 83   const GrowableArray<ciField*>* _nonstatic_fields;
 84 
 85   int                    _has_injected_fields; // any non static injected fields? lazily initialized.
 86 
 87   // The possible values of the _implementor fall into following three cases:
 88   //   null: no implementor.
 89   //   A ciInstanceKlass that's not itself: one implementor.
 90   //   Itself: more than one implementor.
 91   ciInstanceKlass*       _implementor;
 92   GrowableArray<ciInstanceKlass*>* _transitive_interfaces;
 93 
 94   void compute_injected_fields();
 95   bool compute_injected_fields_helper();
 96   void compute_transitive_interfaces();
 97 
 98 protected:
 99   ciInstanceKlass(Klass* k);
100   ciInstanceKlass(ciSymbol* name, jobject loader, BasicType bt = T_OBJECT); // for unloaded klasses
101 
102   InstanceKlass* get_instanceKlass() const {
103     return InstanceKlass::cast(get_Klass());
104   }
105 
106   oop loader();
107   jobject loader_handle();
108 
109   const char* type_string() { return "ciInstanceKlass"; }
110 
111   bool is_in_package_impl(const char* packagename, int len);
112 
113   void print_impl(outputStream* st);
114 
115   ciConstantPoolCache* field_cache();
116 
117   bool is_shared() { return _is_shared; }
118 
119   void compute_shared_init_state();
120   bool compute_shared_has_subklass();
121   void compute_nonstatic_fields();
122   void compute_nonstatic_fields_impl(const GrowableArray<ciField*>* super_declared_fields, const GrowableArray<ciField*>* super_fields);
123   bool compute_has_trusted_loader();
124 
125   // Update the init_state for shared klasses
126   void update_if_shared(InstanceKlass::ClassState expected) {
127     if (_is_shared && _init_state != expected) {
128       if (is_loaded()) compute_shared_init_state();
129     }
130   }
131 
132 public:
133   // Has this klass been initialized?
134   bool                   is_initialized() {
135     update_if_shared(InstanceKlass::fully_initialized);
136     return _init_state == InstanceKlass::fully_initialized;
137   }
138   bool                   is_not_initialized() {
139     update_if_shared(InstanceKlass::fully_initialized);
140     return _init_state < InstanceKlass::being_initialized;
141   }
142   // Is this klass being initialized?
143   bool                   is_being_initialized() {
144     update_if_shared(InstanceKlass::being_initialized);
145     return _init_state == InstanceKlass::being_initialized;
146   }
147   // Has this klass been linked?
148   bool                   is_linked() {
149     update_if_shared(InstanceKlass::linked);
150     return _init_state >= InstanceKlass::linked;
151   }
152   // Is this klass in error state?
153   bool                   is_in_error_state() {
154     update_if_shared(InstanceKlass::initialization_error);
155     return _init_state == InstanceKlass::initialization_error;
156   }
157 
158   // General klass information.
159   ciFlags                flags()          {
160     assert(is_loaded(), "must be loaded");
161     return _flags;
162   }
163   bool                   has_finalizer()  {
164     assert(is_loaded(), "must be loaded");
165     return _has_finalizer; }
166   bool                   has_subklass()   {
167     assert(is_loaded(), "must be loaded");
168     // Ignore cached subklass_false case.
169     // It could be invalidated by concurrent class loading and
170     // can result in type paradoxes during compilation when
171     // a subclass is observed, but has_subklass() returns false.
172     if (_has_subklass == subklass_true) {
173       return true;
174     }
175     if (flags().is_final()) {
176       return false;
177     }
178     return compute_shared_has_subklass();
179   }
180 
181   jint                   layout_helper_size_in_bytes()  {
182     return Klass::layout_helper_size_in_bytes(layout_helper());
183   }
184   jint                   size_helper()  {
185     return (Klass::layout_helper_size_in_bytes(layout_helper())
186             >> LogHeapWordSize);
187   }
188   jint                   has_nonstatic_fields()  {
189     assert(is_loaded(), "must be loaded");
190     return _has_nonstatic_fields; }
191   ciInstanceKlass*       super();
192   jint                   nof_implementors() {
193     ciInstanceKlass* impl;
194     assert(is_loaded(), "must be loaded");
195     impl = implementor();
196     if (impl == nullptr) {
197       return 0;
198     } else if (impl != this) {
199       return 1;
200     } else {
201       return 2;
202     }
203   }
204   bool has_nonstatic_concrete_methods()  {
205     assert(is_loaded(), "must be loaded");
206     return _has_nonstatic_concrete_methods;
207   }
208 
209   bool is_hidden() const {
210     return _is_hidden;
211   }
212 
213   bool is_record() const {
214     return _is_record;
215   }
216 
217   ciInstanceKlass* get_canonical_holder(int offset);
218   ciField* get_field_by_offset(int field_offset, bool is_static);
219   ciField* get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static);
220   // Get field descriptor at field_offset ignoring flattening
221   ciField* get_non_flat_field_by_offset(int field_offset);
222   // Get the index of the declared field that contains this offset
223   int field_index_by_offset(int offset);
224 
225   // Total number of nonstatic fields (including inherited)
226   int nof_declared_nonstatic_fields() {
227     if (_declared_nonstatic_fields == nullptr) {
228       compute_nonstatic_fields();
229     }
230     return _declared_nonstatic_fields->length();
231   }
232 
233   int nof_nonstatic_fields() {
234     if (_nonstatic_fields == nullptr) {
235       compute_nonstatic_fields();
236     }
237     return _nonstatic_fields->length();
238   }
239 
240   bool has_injected_fields() {
241     if (_has_injected_fields == -1) {
242       compute_injected_fields();
243     }
244     return _has_injected_fields > 0 ? true : false;
245   }
246 
247   bool has_object_fields() const;
248 
249   ciField* declared_nonstatic_field_at(int i) {
250     assert(_declared_nonstatic_fields != nullptr, "should be initialized");
251     return _declared_nonstatic_fields->at(i);
252   }
253 
254   ciField* nonstatic_field_at(int i) {
255     assert(_nonstatic_fields != nullptr, "");
256     return _nonstatic_fields->at(i);
257   }
258 
259   ciInstanceKlass* unique_concrete_subklass();
260   bool has_finalizable_subclass();
261 
262   bool has_class_initializer();
263 
264   bool contains_field_offset(int offset);
265 
266   // Get the instance of java.lang.Class corresponding to
267   // this klass.  This instance is used for locking of
268   // synchronized static methods of this klass.
269   ciInstance*            java_mirror();
270 
271   // Java access flags
272   bool is_public      () { return flags().is_public(); }
273   bool is_final       () { return flags().is_final(); }
274   bool is_interface   () { return flags().is_interface(); }
275   bool is_abstract    () { return flags().is_abstract(); }
276   bool is_abstract_value_klass() { return is_abstract() && !flags().is_identity(); }
277 
278   ciMethod* find_method(ciSymbol* name, ciSymbol* signature);
279   // Note:  To find a method from name and type strings, use ciSymbol::make,
280   // but consider adding to vmSymbols.hpp instead.
281 
282   bool is_leaf_type();
283   ciInstanceKlass* implementor();
284 
285   ciInstanceKlass* unique_implementor() {
286     assert(is_loaded(), "must be loaded");
287     ciInstanceKlass* impl = implementor();
288     return (impl != this ? impl : nullptr);
289   }
290 
291   virtual bool can_be_inline_klass(bool is_exact = false);
292 
293   // Is the defining class loader of this class the default loader?
294   bool uses_default_loader() const;
295 
296   bool is_java_lang_Object() const;
297 
298   BasicType box_klass_type() const;
299   bool is_box_klass() const;
300   bool is_boxed_value_offset(int offset) const;
301 
302   // Is this klass in the given package?
303   bool is_in_package(const char* packagename) {
304     return is_in_package(packagename, (int) strlen(packagename));
305   }
306   bool is_in_package(const char* packagename, int len);
307 
308   // What kind of ciObject is this?
309   bool is_instance_klass() const { return true; }
310 
311   virtual ciKlass* exact_klass() {
312     if (is_loaded() && is_final() && !is_interface()) {
313       return this;
314     }
315     return nullptr;
316   }
317 
318   bool can_be_instantiated() {
319     assert(is_loaded(), "must be loaded");
320     return !is_interface() && !is_abstract();
321   }
322 
323   bool has_trusted_loader() const {
324     return _has_trusted_loader;
325   }
326   GrowableArray<ciInstanceKlass*>* transitive_interfaces() const;
327 
328   // Replay support
329 
330   // Dump the current state of this klass for compilation replay.
331   virtual void dump_replay_data(outputStream* out);
332 
333   static void dump_replay_instanceKlass(outputStream* out, InstanceKlass* ik);
334 
335 
336   // Return stable class name suitable for replay file.
337   const char *replay_name() const;
338 
339 #ifdef ASSERT
340   bool debug_final_field_at(int offset);
341   bool debug_stable_field_at(int offset);
342 #endif
343 };
344 
345 #endif // SHARE_CI_CIINSTANCEKLASS_HPP