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