1 /*
  2  * Copyright (c) 2021, 2024, 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 "precompiled.hpp"
 26 #include "cds/cds_globals.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/systemDictionaryShared.hpp"
 35 #include "memory/resourceArea.hpp"
 36 #include "oops/constantPool.inline.hpp"
 37 #include "oops/instanceKlass.hpp"
 38 #include "runtime/mutexLocker.hpp"
 39 
 40 fileStream* ClassListWriter::_classlist_file = nullptr;
 41 
 42 void ClassListWriter::init() {
 43   // For -XX:DumpLoadedClassList=<file> option
 44   if (DumpLoadedClassList != nullptr) {
 45     const char* list_name = make_log_name(DumpLoadedClassList, nullptr);
 46     _classlist_file = new(mtInternal)
 47                          fileStream(list_name);
 48     _classlist_file->print_cr("# NOTE: Do not modify this file.");
 49     _classlist_file->print_cr("#");
 50     _classlist_file->print_cr("# This file is generated via the -XX:DumpLoadedClassList=<class_list_file> option");
 51     _classlist_file->print_cr("# and is used at CDS archive dump time (see -Xshare:dump).");
 52     _classlist_file->print_cr("#");
 53     FREE_C_HEAP_ARRAY(char, list_name);
 54   }
 55 }
 56 
 57 void ClassListWriter::write(const InstanceKlass* k, const ClassFileStream* cfs) {
 58   assert(is_enabled(), "must be");
 59 
 60   if (!ClassLoader::has_jrt_entry()) {
 61     log_warning(cds)("DumpLoadedClassList and CDS are not supported in exploded build");
 62     DumpLoadedClassList = nullptr;
 63     return;
 64   }
 65 
 66   ClassListWriter w;
 67   write_to_stream(k, w.stream(), cfs);
 68 }
 69 
 70 class ClassListWriter::IDTable : public ResourceHashtable<
 71   const InstanceKlass*, int,
 72   15889, // prime number
 73   AnyObj::C_HEAP> {};
 74 
 75 ClassListWriter::IDTable* ClassListWriter::_id_table = nullptr;
 76 int ClassListWriter::_total_ids = 0;
 77 
 78 int ClassListWriter::get_id(const InstanceKlass* k) {
 79   assert_locked();
 80   if (_id_table == nullptr) {
 81     _id_table = new (mtClass)IDTable();
 82   }
 83   bool created;
 84   int* v = _id_table->put_if_absent(k, &created);
 85   if (created) {
 86     *v = _total_ids++;
 87   }
 88   return *v;
 89 }
 90 
 91 bool ClassListWriter::has_id(const InstanceKlass* k) {
 92   assert_locked();
 93   if (_id_table != nullptr) {
 94     return _id_table->get(k) != nullptr;
 95   } else {
 96     return false;
 97   }
 98 }
 99 
100 void ClassListWriter::handle_class_unloading(const InstanceKlass* klass) {
101   assert_locked();
102   if (_id_table != nullptr) {
103     _id_table->remove(klass);
104   }
105 }
106 
107 void ClassListWriter::write_to_stream(const InstanceKlass* k, outputStream* stream, const ClassFileStream* cfs) {
108   assert_locked();
109 
110   ClassLoaderData* loader_data = k->class_loader_data();
111   bool is_builtin_loader = SystemDictionaryShared::is_builtin_loader(loader_data);
112   if (!is_builtin_loader) {
113     // class may be loaded from shared archive
114     if (!k->is_shared()) {
115       if (cfs == nullptr || cfs->source() == nullptr) {
116         // CDS static dump only handles unregistered class with known source.
117         return;
118       }
119       if (strncmp(cfs->source(), "file:", 5) != 0) {
120         return;
121       }
122     } else {
123       // Shared unregistered classes are skipped since their real source are not recorded in shared space.
124       return;
125     }
126     if (!SystemDictionaryShared::add_unregistered_class(Thread::current(), (InstanceKlass*)k)) {
127       return;
128     }
129   }
130 
131   // filter out java/lang/invoke/BoundMethodHandle$Species...
132   if (cfs != nullptr && cfs->source() != nullptr && strcmp(cfs->source(), "_ClassSpecializer_generateConcreteSpeciesCode") == 0) {
133     return;
134   }
135 
136   {
137     InstanceKlass* super = k->java_super();
138     if (super != nullptr && !has_id(super)) {
139       return;
140     }
141 
142     Array<InstanceKlass*>* interfaces = k->local_interfaces();
143     int len = interfaces->length();
144     for (int i = 0; i < len; i++) {
145       InstanceKlass* intf = interfaces->at(i);
146       if (!has_id(intf)) {
147         return;
148       }
149     }
150   }
151 
152   if (k->is_hidden()) {
153     return;
154   }
155 
156   if (k->module()->is_patched()) {
157     return;
158   }
159 
160   ResourceMark rm;
161   stream->print("%s id: %d", k->name()->as_C_string(), get_id(k));
162   if (!is_builtin_loader) {
163     InstanceKlass* super = k->java_super();
164     assert(super != nullptr, "must be");
165     stream->print(" super: %d", get_id(super));
166 
167     Array<InstanceKlass*>* interfaces = k->local_interfaces();
168     int len = interfaces->length();
169     if (len > 0) {
170       stream->print(" interfaces:");
171       for (int i = 0; i < len; i++) {
172         InstanceKlass* intf = interfaces->at(i);
173         stream->print(" %d", get_id(intf));
174       }
175     }
176 
177     // NB: the string following "source: " is not really a proper file name, but rather
178     // a truncated URI referring to a file. It must be decoded after reading.
179 #ifdef _WINDOWS
180     // "file:/C:/dir/foo.jar" -> "C:/dir/foo.jar"
181     stream->print(" source: %s", cfs->source() + 6);
182 #else
183     // "file:/dir/foo.jar" -> "/dir/foo.jar"
184     stream->print(" source: %s", cfs->source() + 5);
185 #endif
186   }
187 
188   stream->cr();
189   stream->flush();
190 }
191 
192 void ClassListWriter::delete_classlist() {
193   if (_classlist_file != nullptr) {
194     delete _classlist_file;
195   }
196 }
197 
198 class ClassListWriter::WriteResolveConstantsCLDClosure : public CLDClosure {
199 public:
200   void do_cld(ClassLoaderData* cld) {
201     for (Klass* klass = cld->klasses(); klass != nullptr; klass = klass->next_link()) {
202       if (klass->is_instance_klass()) {
203         InstanceKlass* ik = InstanceKlass::cast(klass);
204         write_resolved_constants_for(ik);
205       }
206     }
207   }
208 };
209 
210 void ClassListWriter::write_resolved_constants() {
211   if (!is_enabled()) {
212     return;
213   }
214   MutexLocker lock(ClassLoaderDataGraph_lock);
215   MutexLocker lock2(ClassListFile_lock, Mutex::_no_safepoint_check_flag);
216 
217   WriteResolveConstantsCLDClosure closure;
218   ClassLoaderDataGraph::loaded_cld_do(&closure);
219 }
220 
221 void ClassListWriter::write_resolved_constants_for(InstanceKlass* ik) {
222   if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data()) ||
223       ik->is_hidden()) {
224     return;
225   }
226   if (LambdaFormInvokers::may_be_regenerated_class(ik->name())) {
227     return;
228   }
229   if (ik->name()->equals("jdk/internal/module/SystemModules$all")) {
230     // This class is regenerated during JDK build process, so the classlist
231     // may not match the version that's in the real jdk image.
232     return;
233   }
234 
235   if (!has_id(ik)) { // do not resolve CP for classes loaded by custom loaders.
236     return;
237   }
238 
239   ResourceMark rm;
240   ConstantPool* cp = ik->constants();
241   GrowableArray<bool> list(cp->length(), cp->length(), false);
242   bool print = false;
243 
244   for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused
245     switch (cp->tag_at(cp_index).value()) {
246     case JVM_CONSTANT_Class:
247       {
248         Klass* k = cp->resolved_klass_at(cp_index);
249         if (k->is_instance_klass()) {
250           list.at_put(cp_index, true);
251           print = true;
252         }
253       }
254       break;
255     }
256   }
257 
258   if (cp->cache() != nullptr) {
259     Array<ResolvedFieldEntry>* field_entries = cp->cache()->resolved_field_entries();
260     if (field_entries != nullptr) {
261       for (int i = 0; i < field_entries->length(); i++) {
262         ResolvedFieldEntry* rfe = field_entries->adr_at(i);
263         if (rfe->is_resolved(Bytecodes::_getfield) ||
264             rfe->is_resolved(Bytecodes::_putfield)) {
265           list.at_put(rfe->constant_pool_index(), true);
266           print = true;
267         }
268       }
269     }
270 
271     Array<ResolvedMethodEntry>* method_entries = cp->cache()->resolved_method_entries();
272     if (method_entries != nullptr) {
273       for (int i = 0; i < method_entries->length(); i++) {
274         ResolvedMethodEntry* rme = method_entries->adr_at(i);
275         if (rme->is_resolved(Bytecodes::_invokevirtual) ||
276             rme->is_resolved(Bytecodes::_invokespecial) ||
277             rme->is_resolved(Bytecodes::_invokeinterface)) {
278           list.at_put(rme->constant_pool_index(), true);
279           print = true;
280         }
281       }
282     }
283   }
284 
285   if (print) {
286     outputStream* stream = _classlist_file;
287     stream->print("@cp %s", ik->name()->as_C_string());
288     for (int i = 0; i < list.length(); i++) {
289       if (list.at(i)) {
290         constantTag cp_tag = cp->tag_at(i).value();
291         assert(cp_tag.value() == JVM_CONSTANT_Class ||
292                cp_tag.value() == JVM_CONSTANT_Fieldref ||
293                cp_tag.value() == JVM_CONSTANT_Methodref||
294                cp_tag.value() == JVM_CONSTANT_InterfaceMethodref, "sanity");
295         stream->print(" %d", i);
296       }
297     }
298     stream->cr();
299   }
300 }