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 AOTConstantPoolResolver::initialize();
69 }
70
71 void AOTClassLinker::dispose() {
72 assert(is_initialized(), "sanity");
73
74 delete _vm_classes;
75 delete _candidates;
76 delete _sorted_candidates;
77 _vm_classes = nullptr;
78 _candidates = nullptr;
79 _sorted_candidates = nullptr;
80
81 assert(!is_initialized(), "sanity");
82
83 AOTConstantPoolResolver::dispose();
84 }
85
86 bool AOTClassLinker::is_vm_class(InstanceKlass* ik) {
87 assert(is_initialized(), "sanity");
88 return (_vm_classes->get(ik) != nullptr);
89 }
90
91 void AOTClassLinker::add_vm_class(InstanceKlass* ik) {
92 assert(is_initialized(), "sanity");
93 bool created;
94 _vm_classes->put_if_absent(ik, &created);
95 if (created) {
96 if (CDSConfig::is_dumping_aot_linked_classes()) {
97 bool v = try_add_candidate(ik);
98 assert(v, "must succeed for VM class");
99 }
100 InstanceKlass* super = ik->java_super();
101 if (super != nullptr) {
102 add_vm_class(super);
103 }
104 Array<InstanceKlass*>* ifs = ik->local_interfaces();
105 for (int i = 0; i < ifs->length(); i++) {
106 add_vm_class(ifs->at(i));
107 }
108 }
109 }
110
111 bool AOTClassLinker::is_candidate(InstanceKlass* ik) {
112 return (_candidates->get(ik) != nullptr);
113 }
114
115 void AOTClassLinker::add_new_candidate(InstanceKlass* ik) {
116 assert(!is_candidate(ik), "caller need to check");
117 _candidates->put_when_absent(ik, true);
118 _sorted_candidates->append(ik);
119
120 if (log_is_enabled(Info, cds, aot, link)) {
121 ResourceMark rm;
122 log_info(cds, aot, link)("%s %s %p", class_category_name(ik), ik->external_name(), ik);
123 }
124 }
125
126 // ik is a candidate for aot-linking; see if it can really work
127 // that way, and return success or failure. Not only must ik itself
128 // look like a class that can be aot-linked but its supers must also be
129 // aot-linkable.
130 bool AOTClassLinker::try_add_candidate(InstanceKlass* ik) {
131 assert(is_initialized(), "sanity");
132 assert(CDSConfig::is_dumping_aot_linked_classes(), "sanity");
133
134 if (!SystemDictionaryShared::is_builtin(ik)) {
135 // not loaded by a class loader which we know about
136 return false;
137 }
138
139 if (is_candidate(ik)) { // already checked.
140 return true;
141 }
142
143 if (!ik->is_linked() && SystemDictionaryShared::has_class_failed_verification(ik)) {
144 return false;
145 }
146
147 if (ik->is_hidden()) {
148 assert(ik->shared_class_loader_type() != ClassLoader::OTHER, "must have been set");
149 if (!CDSConfig::is_dumping_invokedynamic()) {
150 return false;
151 }
152 if (HeapShared::is_lambda_proxy_klass(ik)) {
153 InstanceKlass* nest_host = ik->nest_host_not_null();
154 if (!try_add_candidate(nest_host)) {
155 ResourceMark rm;
156 log_warning(cds, aot, link)("%s cannot be aot-linked because it nest host is not aot-linked", ik->external_name());
157 return false;
158 }
159 }
160 }
161
162 InstanceKlass* s = ik->java_super();
163 if (s != nullptr && !try_add_candidate(s)) {
164 return false;
165 }
166
167 Array<InstanceKlass*>* interfaces = ik->local_interfaces();
168 int num_interfaces = interfaces->length();
169 for (int index = 0; index < num_interfaces; index++) {
170 InstanceKlass* intf = interfaces->at(index);
171 if (!try_add_candidate(intf)) {
172 return false;
173 }
174 }
175
176 // There are no loops in the class hierarchy, and this function is always called single-threaded, so
177 // we know ik has not been added yet.
178 assert(CDSConfig::current_thread_is_vm_or_dumper(), "that's why we don't need locks");
179 add_new_candidate(ik);
180
181 return true;
182 }
183
184 void AOTClassLinker::add_candidates() {
185 assert_at_safepoint();
186 if (CDSConfig::is_dumping_aot_linked_classes()) {
187 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
188 for (GrowableArrayIterator<Klass*> it = klasses->begin(); it != klasses->end(); ++it) {
189 Klass* k = *it;
190 if (k->is_instance_klass()) {
191 try_add_candidate(InstanceKlass::cast(k));
192 }
193 }
194 }
195 }
196
197 void AOTClassLinker::write_to_archive() {
198 assert(is_initialized(), "sanity");
199 assert_at_safepoint();
200
201 if (CDSConfig::is_dumping_aot_linked_classes()) {
202 AOTLinkedClassTable* table = AOTLinkedClassTable::get(CDSConfig::is_dumping_static_archive());
203 table->set_boot(write_classes(nullptr, true));
204 table->set_boot2(write_classes(nullptr, false));
205 table->set_platform(write_classes(SystemDictionary::java_platform_loader(), false));
206 table->set_app(write_classes(SystemDictionary::java_system_loader(), false));
207 }
208 }
209
210 Array<InstanceKlass*>* AOTClassLinker::write_classes(oop class_loader, bool is_javabase) {
211 ResourceMark rm;
212 GrowableArray<InstanceKlass*> list;
213
214 for (int i = 0; i < _sorted_candidates->length(); i++) {
215 InstanceKlass* ik = _sorted_candidates->at(i);
216 if (ik->class_loader() != class_loader) {
217 continue;
218 }
219 if ((ik->module() == ModuleEntryTable::javabase_moduleEntry()) != is_javabase) {
220 continue;
221 }
222
223 if (ik->is_shared() && CDSConfig::is_dumping_dynamic_archive()) {
224 if (CDSConfig::is_using_aot_linked_classes()) {
225 // This class was recorded as AOT-linked for the base archive,
226 // so there's no need to do so again for the dynamic archive.
227 } else {
228 list.append(ik);
229 }
230 } else {
231 list.append(ArchiveBuilder::current()->get_buffered_addr(ik));
232 }
233 }
234
235 if (list.length() == 0) {
236 return nullptr;
237 } else {
238 const char* category = class_category_name(list.at(0));
239 log_info(cds, aot, link)("wrote %d class(es) for category %s", list.length(), category);
240 return ArchiveUtils::archive_array(&list);
241 }
242 }
243
244 int AOTClassLinker::num_platform_initiated_classes() {
245 if (CDSConfig::is_dumping_aot_linked_classes()) {
246 // AOTLinkedClassBulkLoader will initiate loading of all public boot classes in the platform loader.
247 return count_public_classes(nullptr);
248 } else {
249 return 0;
250 }
251 }
252
253 int AOTClassLinker::num_app_initiated_classes() {
254 if (CDSConfig::is_dumping_aot_linked_classes()) {
255 // AOTLinkedClassBulkLoader will initiate loading of all public boot/platform classes in the app loader.
256 return count_public_classes(nullptr) + count_public_classes(SystemDictionary::java_platform_loader());
257 } else {
258 return 0;
259 }
260 }
261
262 int AOTClassLinker::count_public_classes(oop loader) {
263 int n = 0;
264 for (int i = 0; i < _sorted_candidates->length(); i++) {
265 InstanceKlass* ik = _sorted_candidates->at(i);
266 if (ik->is_public() && !ik->is_hidden() && ik->class_loader() == loader) {
267 n++;
268 }
269 }
270
271 return n;
272 }
273
274 // Used in logging: "boot1", "boot2", "plat", "app" and "unreg", or "array"
275 const char* AOTClassLinker::class_category_name(Klass* k) {
276 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
277 k = ArchiveBuilder::current()->get_source_addr(k);
278 }
279
280 if (k->is_array_klass()) {
281 return "array";
282 } else {
283 oop loader = k->class_loader();
284 if (loader == nullptr) {
285 if (k->module() != nullptr &&
286 k->module()->name() != nullptr &&
287 k->module()->name()->equals("java.base")) {
288 return "boot1"; // boot classes in java.base are loaded in the 1st phase
289 } else {
290 return "boot2"; // boot classes outside of java.base are loaded in the 2nd phase phase
291 }
292 } else {
293 if (loader == SystemDictionary::java_platform_loader()) {
294 return "plat";
295 } else if (loader == SystemDictionary::java_system_loader()) {
296 return "app";
297 } else {
298 return "unreg";
299 }
300 }
301 }
302 }
303
304 const char* AOTClassLinker::class_category_name(AOTLinkedClassCategory category) {
305 switch (category) {
306 case AOTLinkedClassCategory::BOOT1:
307 return "boot1";
308 case AOTLinkedClassCategory::BOOT2:
309 return "boot2";
310 case AOTLinkedClassCategory::PLATFORM:
311 return "plat";
312 case AOTLinkedClassCategory::APP:
313 return "app";
314 case AOTLinkedClassCategory::UNREGISTERED:
315 default:
316 return "unreg";
317 }
318 }