1 /*
2 * Copyright (c) 2024, 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/aotClassLinker.hpp"
26 #include "cds/aotConstantPoolResolver.hpp"
27 #include "cds/aotLinkedClassTable.hpp"
28 #include "cds/archiveBuilder.hpp"
29 #include "cds/archiveUtils.inline.hpp"
30 #include "cds/cdsConfig.hpp"
31 #include "cds/heapShared.hpp"
32 #include "cds/lambdaFormInvokers.inline.hpp"
33 #include "classfile/classLoader.hpp"
34 #include "classfile/dictionary.hpp"
35 #include "classfile/systemDictionary.hpp"
36 #include "classfile/systemDictionaryShared.hpp"
37 #include "classfile/vmClasses.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "oops/constantPool.inline.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/klass.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43
44 AOTClassLinker::ClassesTable* AOTClassLinker::_vm_classes = nullptr;
45 AOTClassLinker::ClassesTable* AOTClassLinker::_candidates = nullptr;
46 GrowableArrayCHeap<InstanceKlass*, mtClassShared>* AOTClassLinker::_sorted_candidates = nullptr;
47
48 #ifdef ASSERT
49 bool AOTClassLinker::is_initialized() {
50 assert(CDSConfig::is_dumping_archive(), "AOTClassLinker is for CDS dumping only");
51 return _vm_classes != nullptr;
52 }
53 #endif
54
55 void AOTClassLinker::initialize() {
56 assert(!is_initialized(), "sanity");
57
58 _vm_classes = new (mtClass)ClassesTable();
59 _candidates = new (mtClass)ClassesTable();
60 _sorted_candidates = new GrowableArrayCHeap<InstanceKlass*, mtClassShared>(1000);
61
62 for (auto id : EnumRange<vmClassID>{}) {
63 add_vm_class(vmClasses::klass_at(id));
64 }
65
66 assert(is_initialized(), "sanity");
67 }
68
69 void AOTClassLinker::dispose() {
70 assert(is_initialized(), "sanity");
71
72 delete _vm_classes;
73 delete _candidates;
74 delete _sorted_candidates;
75 _vm_classes = nullptr;
76 _candidates = nullptr;
77 _sorted_candidates = nullptr;
78
79 assert(!is_initialized(), "sanity");
80 }
81
82 bool AOTClassLinker::is_vm_class(InstanceKlass* ik) {
83 assert(is_initialized(), "sanity");
84 return (_vm_classes->get(ik) != nullptr);
85 }
86
87 void AOTClassLinker::add_vm_class(InstanceKlass* ik) {
88 assert(is_initialized(), "sanity");
89 bool created;
90 _vm_classes->put_if_absent(ik, &created);
91 if (created) {
92 if (CDSConfig::is_dumping_aot_linked_classes()) {
93 bool v = try_add_candidate(ik);
94 assert(v, "must succeed for VM class");
95 }
96 InstanceKlass* super = ik->java_super();
97 if (super != nullptr) {
98 add_vm_class(super);
99 }
100 Array<InstanceKlass*>* ifs = ik->local_interfaces();
101 for (int i = 0; i < ifs->length(); i++) {
102 add_vm_class(ifs->at(i));
103 }
104 }
105 }
106
107 bool AOTClassLinker::is_candidate(InstanceKlass* ik) {
108 return (_candidates->get(ik) != nullptr);
109 }
110
111 void AOTClassLinker::add_new_candidate(InstanceKlass* ik) {
112 assert(!is_candidate(ik), "caller need to check");
113 _candidates->put_when_absent(ik, true);
114 _sorted_candidates->append(ik);
115
116 if (log_is_enabled(Info, aot, link)) {
117 ResourceMark rm;
118 log_info(aot, link)("%s %s %p", class_category_name(ik), ik->external_name(), ik);
119 }
120 }
121
122 // ik is a candidate for aot-linking; see if it can really work
123 // that way, and return success or failure. Not only must ik itself
124 // look like a class that can be aot-linked but its supers must also be
125 // aot-linkable.
126 bool AOTClassLinker::try_add_candidate(InstanceKlass* ik) {
127 assert(is_initialized(), "sanity");
128 assert(CDSConfig::is_dumping_aot_linked_classes(), "sanity");
129
130 if (!SystemDictionaryShared::is_builtin(ik)) {
131 // not loaded by a class loader which we know about
132 return false;
133 }
134
135 if (is_candidate(ik)) { // already checked.
136 return true;
137 }
138
139 if (ik->is_hidden()) {
140 assert(!ik->defined_by_other_loaders(), "hidden classes are archived only for builtin loaders");
141 if (!CDSConfig::is_dumping_method_handles()) {
142 return false;
143 }
144 if (HeapShared::is_lambda_proxy_klass(ik)) {
145 InstanceKlass* nest_host = ik->nest_host_not_null();
146 if (!try_add_candidate(nest_host)) {
147 ResourceMark rm;
148 log_warning(aot, link)("%s cannot be aot-linked because it nest host is not aot-linked", ik->external_name());
149 return false;
150 }
151 }
152 }
153
154 InstanceKlass* s = ik->java_super();
155 if (s != nullptr && !try_add_candidate(s)) {
156 return false;
157 }
158
159 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
160 int num_interfaces = interfaces->length();
161 for (int index = 0; index < num_interfaces; index++) {
162 InstanceKlass* intf = interfaces->at(index);
163 if (!try_add_candidate(intf)) {
164 return false;
165 }
166 }
167
168 // There are no loops in the class hierarchy, and this function is always called single-threaded, so
169 // we know ik has not been added yet.
170 assert(CDSConfig::current_thread_is_vm_or_dumper(), "that's why we don't need locks");
171 add_new_candidate(ik);
172
173 return true;
174 }
175
176 void AOTClassLinker::add_candidates() {
177 assert_at_safepoint();
178 if (CDSConfig::is_dumping_aot_linked_classes()) {
179 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
180 for (GrowableArrayIterator<Klass*> it = klasses->begin(); it != klasses->end(); ++it) {
181 Klass* k = *it;
182 if (k->is_instance_klass()) {
183 try_add_candidate(InstanceKlass::cast(k));
184 }
185 }
186 }
187 }
188
189 void AOTClassLinker::write_to_archive() {
190 assert(is_initialized(), "sanity");
191 assert_at_safepoint();
192
193 if (CDSConfig::is_dumping_aot_linked_classes()) {
194 AOTLinkedClassTable* table = AOTLinkedClassTable::get(CDSConfig::is_dumping_static_archive());
195 table->set_boot(write_classes(nullptr, true));
196 table->set_boot2(write_classes(nullptr, false));
197 table->set_platform(write_classes(SystemDictionary::java_platform_loader(), false));
198 table->set_app(write_classes(SystemDictionary::java_system_loader(), false));
199 }
200 }
201
202 Array<InstanceKlass*>* AOTClassLinker::write_classes(oop class_loader, bool is_javabase) {
203 ResourceMark rm;
204 GrowableArray<InstanceKlass*> list;
205
206 for (int i = 0; i < _sorted_candidates->length(); i++) {
207 InstanceKlass* ik = _sorted_candidates->at(i);
208 if (ik->class_loader() != class_loader) {
209 continue;
210 }
211 if ((ik->module() == ModuleEntryTable::javabase_moduleEntry()) != is_javabase) {
212 continue;
213 }
214
215 if (ik->is_shared() && CDSConfig::is_dumping_dynamic_archive()) {
216 if (CDSConfig::is_using_aot_linked_classes()) {
217 // This class was recorded as AOT-linked for the base archive,
218 // so there's no need to do so again for the dynamic archive.
219 } else {
220 list.append(ik);
221 }
222 } else {
223 list.append(ArchiveBuilder::current()->get_buffered_addr(ik));
224 }
225 }
226
227 if (list.length() == 0) {
228 return nullptr;
229 } else {
230 const char* category = class_category_name(list.at(0));
231 log_info(aot, link)("wrote %d class(es) for category %s", list.length(), category);
232 return ArchiveUtils::archive_array(&list);
233 }
234 }
235
236 int AOTClassLinker::num_platform_initiated_classes() {
237 if (CDSConfig::is_dumping_aot_linked_classes()) {
238 // AOTLinkedClassBulkLoader will initiate loading of all public boot classes in the platform loader.
239 return count_public_classes(nullptr);
240 } else {
241 return 0;
242 }
243 }
244
245 int AOTClassLinker::num_app_initiated_classes() {
246 if (CDSConfig::is_dumping_aot_linked_classes()) {
247 // AOTLinkedClassBulkLoader will initiate loading of all public boot/platform classes in the app loader.
248 return count_public_classes(nullptr) + count_public_classes(SystemDictionary::java_platform_loader());
249 } else {
250 return 0;
251 }
252 }
253
254 int AOTClassLinker::count_public_classes(oop loader) {
255 int n = 0;
256 for (int i = 0; i < _sorted_candidates->length(); i++) {
257 InstanceKlass* ik = _sorted_candidates->at(i);
258 if (ik->is_public() && !ik->is_hidden() && ik->class_loader() == loader) {
259 n++;
260 }
261 }
262
263 return n;
264 }
265
266 // Used in logging: "boot1", "boot2", "plat", "app" and "unreg", or "array"
267 const char* AOTClassLinker::class_category_name(Klass* k) {
268 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
269 k = ArchiveBuilder::current()->get_source_addr(k);
270 }
271
272 if (k->is_array_klass()) {
273 return "array";
274 } else {
275 oop loader = k->class_loader();
276 if (loader == nullptr) {
277 if (k->module() != nullptr &&
278 k->module()->name() != nullptr &&
279 k->module()->name()->equals("java.base")) {
280 return "boot1"; // boot classes in java.base are loaded in the 1st phase
281 } else {
282 return "boot2"; // boot classes outside of java.base are loaded in the 2nd phase phase
283 }
284 } else {
285 if (loader == SystemDictionary::java_platform_loader()) {
286 return "plat";
287 } else if (loader == SystemDictionary::java_system_loader()) {
288 return "app";
289 } else {
290 return "unreg";
291 }
292 }
293 }
294 }
295
296 const char* AOTClassLinker::class_category_name(AOTLinkedClassCategory category) {
297 switch (category) {
298 case AOTLinkedClassCategory::BOOT1:
299 return "boot1";
300 case AOTLinkedClassCategory::BOOT2:
301 return "boot2";
302 case AOTLinkedClassCategory::PLATFORM:
303 return "plat";
304 case AOTLinkedClassCategory::APP:
305 return "app";
306 case AOTLinkedClassCategory::UNREGISTERED:
307 default:
308 return "unreg";
309 }
310 }