1 /*
  2  * Copyright (c) 2021, 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 "cds/cds_globals.hpp"
 26 #include "cds/classListParser.hpp"
 27 #include "cds/classListWriter.hpp"
 28 #include "cds/lambdaFormInvokers.inline.hpp"
 29 #include "classfile/classFileStream.hpp"
 30 #include "classfile/classLoader.hpp"
 31 #include "classfile/classLoaderData.hpp"
 32 #include "classfile/classLoaderDataGraph.hpp"
 33 #include "classfile/moduleEntry.hpp"
 34 #include "classfile/symbolTable.hpp"
 35 #include "classfile/systemDictionaryShared.hpp"
 36 #include "memory/resourceArea.hpp"
 37 #include "oops/constantPool.inline.hpp"
 38 #include "oops/instanceKlass.hpp"
 39 #include "runtime/javaCalls.hpp"
 40 #include "runtime/mutexLocker.hpp"
 41 
 42 fileStream* ClassListWriter::_classlist_file = nullptr;
 43 
 44 void ClassListWriter::init() {
 45   // For -XX:DumpLoadedClassList=<file> option
 46   if (DumpLoadedClassList != nullptr) {
 47     const char* list_name = make_log_name(DumpLoadedClassList, nullptr);
 48     _classlist_file = new(mtInternal)
 49                          fileStream(list_name);
 50     _classlist_file->print_cr("# NOTE: Do not modify this file.");
 51     _classlist_file->print_cr("#");
 52     _classlist_file->print_cr("# This file is generated via the -XX:DumpLoadedClassList=<class_list_file> option");
 53     _classlist_file->print_cr("# and is used at CDS archive dump time (see -Xshare:dump).");
 54     _classlist_file->print_cr("#");
 55     FREE_C_HEAP_ARRAY(char, list_name);
 56   }
 57 }
 58 
 59 void ClassListWriter::write(const InstanceKlass* k, const ClassFileStream* cfs) {
 60   assert(is_enabled(), "must be");
 61 
 62   if (!ClassLoader::has_jrt_entry()) {
 63     log_warning(aot)("DumpLoadedClassList and CDS are not supported in exploded build");
 64     DumpLoadedClassList = nullptr;
 65     return;
 66   }
 67 
 68   ClassListWriter w;
 69   write_to_stream(k, w.stream(), cfs);
 70 }
 71 
 72 class ClassListWriter::IDTable : public HashTable<
 73   const InstanceKlass*, int,
 74   15889, // prime number
 75   AnyObj::C_HEAP> {};
 76 
 77 ClassListWriter::IDTable* ClassListWriter::_id_table = nullptr;
 78 int ClassListWriter::_total_ids = 0;
 79 
 80 int ClassListWriter::get_id(const InstanceKlass* k) {
 81   assert_locked();
 82   if (_id_table == nullptr) {
 83     _id_table = new (mtClass)IDTable();
 84   }
 85   bool created;
 86   int* v = _id_table->put_if_absent(k, &created);
 87   if (created) {
 88     *v = _total_ids++;
 89   }
 90   return *v;
 91 }
 92 
 93 bool ClassListWriter::has_id(const InstanceKlass* k) {
 94   assert_locked();
 95   if (_id_table != nullptr) {
 96     return _id_table->get(k) != nullptr;
 97   } else {
 98     return false;
 99   }
100 }
101 
102 void ClassListWriter::handle_class_unloading(const InstanceKlass* klass) {
103   assert_locked();
104   if (_id_table != nullptr) {
105     _id_table->remove(klass);
106   }
107 }
108 
109 void ClassListWriter::write_to_stream(const InstanceKlass* k, outputStream* stream, const ClassFileStream* cfs) {
110   assert_locked();
111 
112   ClassLoaderData* loader_data = k->class_loader_data();
113   bool is_builtin_loader = SystemDictionaryShared::is_builtin_loader(loader_data);
114   if (!is_builtin_loader) {
115     // class may be loaded from shared archive
116     if (!k->in_aot_cache()) {
117       if (cfs == nullptr || cfs->source() == nullptr) {
118         // CDS static dump only handles unregistered class with known source.
119         return;
120       }
121       if (strncmp(cfs->source(), "file:", 5) != 0) {
122         return;
123       }
124     } else {
125       // Shared unregistered classes are skipped since their real source are not recorded in shared space.
126       return;
127     }
128     if (!SystemDictionaryShared::add_unregistered_class(Thread::current(), (InstanceKlass*)k)) {
129       return;
130     }
131   }
132 
133   if (cfs != nullptr && cfs->source() != nullptr) {
134     if (strcmp(cfs->source(), "_ClassSpecializer_generateConcreteSpeciesCode") == 0) {
135       return;
136     }
137 
138     if (strncmp(cfs->source(), "__", 2) == 0) {
139       // generated class: __dynamic_proxy__, __JVM_LookupDefineClass__, etc
140       return;
141     }
142   }
143 
144   {
145     InstanceKlass* super = k->super();
146     if (super != nullptr && !has_id(super)) {
147       return;
148     }
149 
150     Array<InstanceKlass*>* interfaces = k->local_interfaces();
151     int len = interfaces->length();
152     for (int i = 0; i < len; i++) {
153       InstanceKlass* intf = interfaces->at(i);
154       if (!has_id(intf)) {
155         return;
156       }
157     }
158   }
159 
160   if (k->is_hidden()) {
161     return;
162   }
163 
164   if (k->module()->is_patched()) {
165     return;
166   }
167 
168   ResourceMark rm;
169   stream->print("%s id: %d", k->name()->as_C_string(), get_id(k));
170   if (!is_builtin_loader) {
171     InstanceKlass* super = k->super();
172     assert(super != nullptr, "must be");
173     stream->print(" super: %d", get_id(super));
174 
175     Array<InstanceKlass*>* interfaces = k->local_interfaces();
176     int len = interfaces->length();
177     if (len > 0) {
178       stream->print(" interfaces:");
179       for (int i = 0; i < len; i++) {
180         InstanceKlass* intf = interfaces->at(i);
181         stream->print(" %d", get_id(intf));
182       }
183     }
184 
185     // NB: the string following "source: " is not really a proper file name, but rather
186     // a truncated URI referring to a file. It must be decoded after reading.
187 #ifdef _WINDOWS
188     // "file:/C:/dir/foo.jar" -> "C:/dir/foo.jar"
189     stream->print(" source: %s", cfs->source() + 6);
190 #else
191     // "file:/dir/foo.jar" -> "/dir/foo.jar"
192     stream->print(" source: %s", cfs->source() + 5);
193 #endif
194   }
195 
196   stream->cr();
197   stream->flush();
198 }
199 
200 void ClassListWriter::delete_classlist() {
201   if (_classlist_file != nullptr) {
202     delete _classlist_file;
203   }
204 }
205 
206 class ClassListWriter::WriteResolveConstantsCLDClosure : public CLDClosure {
207 public:
208   void do_cld(ClassLoaderData* cld) {
209     for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
210       if (klass->is_instance_klass()) {
211         InstanceKlass* ik = InstanceKlass::cast(klass);
212         write_resolved_constants_for(ik);
213       }
214     }
215   }
216 };
217 
218 void ClassListWriter::write_resolved_constants() {
219   if (!is_enabled()) {
220     return;
221   }
222   MutexLocker lock(ClassLoaderDataGraph_lock);
223   MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
224 
225   WriteResolveConstantsCLDClosure closure;
226   ClassLoaderDataGraph::loaded_cld_do(&closure);
227 }
228 
229 void ClassListWriter::write_resolved_constants_for(InstanceKlass* ik) {
230   if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data()) ||
231       ik->is_hidden()) {
232     return;
233   }
234   if (LambdaFormInvokers::may_be_regenerated_class(ik->name())) {
235     return;
236   }
237   if (ik->name()->equals("jdk/internal/module/SystemModules$all")) {
238     // This class is regenerated during JDK build process, so the classlist
239     // may not match the version that's in the real jdk image.
240     return;
241   }
242 
243   if (!has_id(ik)) { // do not resolve CP for classes loaded by custom loaders.
244     return;
245   }
246 
247   ResourceMark rm;
248   ConstantPool* cp = ik->constants();
249   GrowableArray<bool> list(cp->length(), cp->length(), false);
250   bool print = false;
251 
252   for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused
253     switch (cp->tag_at(cp_index).value()) {
254     case JVM_CONSTANT_Class:
255       {
256         Klass* k = cp->resolved_klass_at(cp_index);
257         if (k->is_instance_klass()) {
258           list.at_put(cp_index, true);
259           print = true;
260         }
261       }
262       break;
263     }
264   }
265 
266   if (cp->cache() != nullptr) {
267     Array<ResolvedIndyEntry>* indy_entries = cp->cache()->resolved_indy_entries();
268     if (indy_entries != nullptr) {
269       for (int i = 0; i < indy_entries->length(); i++) {
270         ResolvedIndyEntry* rie = indy_entries->adr_at(i);
271         int cp_index = rie->constant_pool_index();
272         if (rie->is_resolved()) {
273           list.at_put(cp_index, true);
274           print = true;
275         }
276       }
277     }
278 
279     Array<ResolvedFieldEntry>* field_entries = cp->cache()->resolved_field_entries();
280     if (field_entries != nullptr) {
281       for (int i = 0; i < field_entries->length(); i++) {
282         ResolvedFieldEntry* rfe = field_entries->adr_at(i);
283         if (rfe->is_resolved(Bytecodes::_getstatic) ||
284             rfe->is_resolved(Bytecodes::_putstatic) ||
285             rfe->is_resolved(Bytecodes::_getfield) ||
286             rfe->is_resolved(Bytecodes::_putfield)) {
287           list.at_put(rfe->constant_pool_index(), true);
288           print = true;
289         }
290       }
291     }
292 
293     Array<ResolvedMethodEntry>* method_entries = cp->cache()->resolved_method_entries();
294     if (method_entries != nullptr) {
295       for (int i = 0; i < method_entries->length(); i++) {
296         ResolvedMethodEntry* rme = method_entries->adr_at(i);
297         if (rme->is_resolved(Bytecodes::_invokevirtual) ||
298             rme->is_resolved(Bytecodes::_invokespecial) ||
299             rme->is_resolved(Bytecodes::_invokeinterface) ||
300             rme->is_resolved(Bytecodes::_invokestatic) ||
301             rme->is_resolved(Bytecodes::_invokehandle)) {
302           list.at_put(rme->constant_pool_index(), true);
303           print = true;
304         }
305       }
306     }
307   }
308 
309   if (print) {
310     outputStream* stream = _classlist_file;
311     stream->print("@cp %s", ik->name()->as_C_string());
312     for (int i = 0; i < list.length(); i++) {
313       if (list.at(i)) {
314         constantTag cp_tag = cp->tag_at(i).value();
315         assert(cp_tag.value() == JVM_CONSTANT_Class ||
316                cp_tag.value() == JVM_CONSTANT_Fieldref ||
317                cp_tag.value() == JVM_CONSTANT_Methodref||
318                cp_tag.value() == JVM_CONSTANT_InterfaceMethodref ||
319                cp_tag.value() == JVM_CONSTANT_InvokeDynamic, "sanity");
320         stream->print(" %d", i);
321       }
322     }
323     stream->cr();
324   }
325 }
326 
327 void ClassListWriter::write_loader_negative_lookup_cache_for(oop loader, const char* loader_type) {
328   TempNewSymbol method = SymbolTable::new_symbol("negativeLookupCacheContents");
329   TempNewSymbol signature = SymbolTable::new_symbol("()Ljava/lang/String;");
330 
331   EXCEPTION_MARK;
332   HandleMark hm(THREAD);
333 
334   JavaValue result(T_OBJECT);
335   JavaCalls::call_virtual(&result,
336                           Handle(THREAD, loader),
337                           loader->klass(),
338                           method,
339                           signature,
340                           CHECK);
341 
342   if (HAS_PENDING_EXCEPTION) {
343     log_warning(cds)("Error during BuiltinClassLoader::negativeLookupCacheContents() call for %s loader", loader_type);
344     CLEAR_PENDING_EXCEPTION;
345     return;
346   } else if (result.get_oop() == nullptr) {
347     return;
348   }
349 
350   ResourceMark rm;
351   const char* cache_contents = java_lang_String::as_utf8_string(result.get_oop());
352   log_debug(cds)("%s loader negative cache: %s", loader_type, cache_contents);
353 
354   outputStream* stream = _classlist_file;
355   const size_t buffer_size = strlen(ClassListParser::LOADER_NEGATIVE_CACHE_TAG) + 1 /* for space*/
356                     + strlen(loader_type) + 1 /* for space */ + strlen(cache_contents) + 1 /* for null character */;
357   char* buffer = NEW_C_HEAP_ARRAY(char, buffer_size, mtInternal);
358   _classlist_file->set_scratch_buffer(buffer, buffer_size);
359   MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
360   stream->print("%s %s %s", ClassListParser::LOADER_NEGATIVE_CACHE_TAG, loader_type, cache_contents);
361   stream->cr();
362   _classlist_file->set_scratch_buffer(nullptr, 0);
363 }
364 
365 void ClassListWriter::write_loader_negative_lookup_cache() {
366   if (!is_enabled()) {
367     return;
368   }
369 
370   write_loader_negative_lookup_cache_for(SystemDictionary::java_platform_loader(), "platform");
371   write_loader_negative_lookup_cache_for(SystemDictionary::java_system_loader(), "app");
372 }
--- EOF ---