1 /*
2 * Copyright (c) 2022, 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/archiveBuilder.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/systemDictionaryShared.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "interpreter/bytecodeStream.hpp"
33 #include "interpreter/interpreterRuntime.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "oops/constantPool.inline.hpp"
36 #include "oops/instanceKlass.hpp"
37 #include "oops/klass.inline.hpp"
38 #include "runtime/handles.inline.hpp"
39
40 // Returns true if we CAN PROVE that cp_index will always resolve to
41 // the same information at both dump time and run time. This is a
42 // necessary (but not sufficient) condition for pre-resolving cp_index
43 // during CDS archive assembly.
44 bool AOTConstantPoolResolver::is_resolution_deterministic(ConstantPool* cp, int cp_index) {
45 assert(!is_in_archivebuilder_buffer(cp), "sanity");
46
47 if (cp->tag_at(cp_index).is_klass()) {
48 // We require cp_index to be already resolved. This is fine for now, are we
49 // currently archive only CP entries that are already resolved.
50 Klass* resolved_klass = cp->resolved_klass_at(cp_index);
51 return resolved_klass != nullptr && is_class_resolution_deterministic(cp->pool_holder(), resolved_klass);
52 } else if (cp->tag_at(cp_index).is_invoke_dynamic()) {
53 return is_indy_resolution_deterministic(cp, cp_index);
54 } else if (cp->tag_at(cp_index).is_field() ||
55 cp->tag_at(cp_index).is_method() ||
56 cp->tag_at(cp_index).is_interface_method()) {
57 int klass_cp_index = cp->uncached_klass_ref_index_at(cp_index);
58 if (!cp->tag_at(klass_cp_index).is_klass()) {
59 // Not yet resolved
60 return false;
61 }
62 Klass* k = cp->resolved_klass_at(klass_cp_index);
63 if (!is_class_resolution_deterministic(cp->pool_holder(), k)) {
64 return false;
65 }
66
67 if (!k->is_instance_klass()) {
68 // TODO: support non instance klasses as well.
69 return false;
70 }
71
72 // Here, We don't check if this entry can actually be resolved to a valid Field/Method.
73 // This method should be called by the ConstantPool to check Fields/Methods that
74 // have already been successfully resolved.
75 return true;
76 } else {
77 return false;
78 }
79 }
80
81 bool AOTConstantPoolResolver::is_class_resolution_deterministic(InstanceKlass* cp_holder, Klass* resolved_class) {
82 assert(!is_in_archivebuilder_buffer(cp_holder), "sanity");
83 assert(!is_in_archivebuilder_buffer(resolved_class), "sanity");
84
85 if (resolved_class->is_instance_klass()) {
86 InstanceKlass* ik = InstanceKlass::cast(resolved_class);
87
88 if (!ik->is_shared() && SystemDictionaryShared::is_excluded_class(ik)) {
89 return false;
90 }
91
92 if (cp_holder->is_subtype_of(ik)) {
93 // All super types of ik will be resolved in ik->class_loader() before
94 // ik is defined in this loader, so it's safe to archive the resolved klass reference.
95 return true;
96 }
97
98 if (CDSConfig::is_dumping_aot_linked_classes()) {
99 // Need to call try_add_candidate instead of is_candidate, as this may be called
100 // before AOTClassLinker::add_candidates().
101 if (AOTClassLinker::try_add_candidate(ik)) {
102 return true;
103 } else {
104 return false;
105 }
106 } else if (AOTClassLinker::is_vm_class(ik)) {
107 if (ik->class_loader() != cp_holder->class_loader()) {
108 // At runtime, cp_holder() may not be able to resolve to the same
109 // ik. For example, a different version of ik may be defined in
110 // cp->pool_holder()'s loader using MethodHandles.Lookup.defineClass().
111 return false;
112 } else {
113 return true;
114 }
115 } else {
116 return false;
117 }
118 } else if (resolved_class->is_objArray_klass()) {
119 Klass* elem = ObjArrayKlass::cast(resolved_class)->bottom_klass();
120 if (elem->is_instance_klass()) {
121 return is_class_resolution_deterministic(cp_holder, InstanceKlass::cast(elem));
122 } else if (elem->is_typeArray_klass()) {
123 return true;
124 } else {
125 return false;
126 }
127 } else if (resolved_class->is_typeArray_klass()) {
128 return true;
129 } else {
130 return false;
131 }
132 }
133
134 void AOTConstantPoolResolver::preresolve_string_cp_entries(InstanceKlass* ik, TRAPS) {
135 if (!ik->is_linked()) {
136 // The cp->resolved_referenced() array is not ready yet, so we can't call resolve_string().
137 return;
138 }
139 constantPoolHandle cp(THREAD, ik->constants());
140 for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused
141 switch (cp->tag_at(cp_index).value()) {
142 case JVM_CONSTANT_String:
143 resolve_string(cp, cp_index, CHECK); // may throw OOM when interning strings.
144 break;
145 }
146 }
147 }
148
149 // This works only for the boot/platform/app loaders
150 Klass* AOTConstantPoolResolver::find_loaded_class(Thread* current, oop class_loader, Symbol* name) {
151 HandleMark hm(current);
152 Handle h_loader(current, class_loader);
153 Klass* k = SystemDictionary::find_instance_or_array_klass(current, name, h_loader);
154 if (k != nullptr) {
155 return k;
156 }
157 if (h_loader() == SystemDictionary::java_system_loader()) {
158 return find_loaded_class(current, SystemDictionary::java_platform_loader(), name);
159 } else if (h_loader() == SystemDictionary::java_platform_loader()) {
160 return find_loaded_class(current, nullptr, name);
161 } else {
162 assert(h_loader() == nullptr, "This function only works for boot/platform/app loaders %p %p %p",
163 cast_from_oop<address>(h_loader()),
164 cast_from_oop<address>(SystemDictionary::java_system_loader()),
165 cast_from_oop<address>(SystemDictionary::java_platform_loader()));
166 }
167
168 return nullptr;
169 }
170
171 Klass* AOTConstantPoolResolver::find_loaded_class(Thread* current, ConstantPool* cp, int class_cp_index) {
172 Symbol* name = cp->klass_name_at(class_cp_index);
173 return find_loaded_class(current, cp->pool_holder()->class_loader(), name);
174 }
175
176 #if INCLUDE_CDS_JAVA_HEAP
177 void AOTConstantPoolResolver::resolve_string(constantPoolHandle cp, int cp_index, TRAPS) {
178 if (CDSConfig::is_dumping_heap()) {
179 int cache_index = cp->cp_to_object_index(cp_index);
180 ConstantPool::string_at_impl(cp, cp_index, cache_index, CHECK);
181 }
182 }
183 #endif
184
185 void AOTConstantPoolResolver::preresolve_class_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray<bool>* preresolve_list) {
186 if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
187 return;
188 }
189
190 JavaThread* THREAD = current;
191 constantPoolHandle cp(THREAD, ik->constants());
192 for (int cp_index = 1; cp_index < cp->length(); cp_index++) {
193 if (cp->tag_at(cp_index).value() == JVM_CONSTANT_UnresolvedClass) {
194 if (preresolve_list != nullptr && preresolve_list->at(cp_index) == false) {
195 // This class was not resolved during trial run. Don't attempt to resolve it. Otherwise
196 // the compiler may generate less efficient code.
197 continue;
198 }
199 if (find_loaded_class(current, cp(), cp_index) == nullptr) {
200 // Do not resolve any class that has not been loaded yet
201 continue;
202 }
203 Klass* resolved_klass = cp->klass_at(cp_index, THREAD);
204 if (HAS_PENDING_EXCEPTION) {
205 CLEAR_PENDING_EXCEPTION; // just ignore
206 } else {
207 log_trace(cds, resolve)("Resolved class [%3d] %s -> %s", cp_index, ik->external_name(),
208 resolved_klass->external_name());
209 }
210 }
211 }
212 }
213
214 void AOTConstantPoolResolver::preresolve_field_and_method_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray<bool>* preresolve_list) {
215 JavaThread* THREAD = current;
216 constantPoolHandle cp(THREAD, ik->constants());
217 if (cp->cache() == nullptr) {
218 return;
219 }
220 for (int i = 0; i < ik->methods()->length(); i++) {
221 Method* m = ik->methods()->at(i);
222 BytecodeStream bcs(methodHandle(THREAD, m));
223 while (!bcs.is_last_bytecode()) {
224 bcs.next();
225 Bytecodes::Code raw_bc = bcs.raw_code();
226 switch (raw_bc) {
227 case Bytecodes::_getfield:
228 case Bytecodes::_putfield:
229 maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD);
230 if (HAS_PENDING_EXCEPTION) {
231 CLEAR_PENDING_EXCEPTION; // just ignore
232 }
233 break;
234 case Bytecodes::_invokehandle:
235 case Bytecodes::_invokespecial:
236 case Bytecodes::_invokevirtual:
237 case Bytecodes::_invokeinterface:
238 maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD);
239 if (HAS_PENDING_EXCEPTION) {
240 CLEAR_PENDING_EXCEPTION; // just ignore
241 }
242 break;
243 default:
244 break;
245 }
246 }
247 }
248 }
249
250 void AOTConstantPoolResolver::maybe_resolve_fmi_ref(InstanceKlass* ik, Method* m, Bytecodes::Code bc, int raw_index,
251 GrowableArray<bool>* preresolve_list, TRAPS) {
252 methodHandle mh(THREAD, m);
253 constantPoolHandle cp(THREAD, ik->constants());
254 HandleMark hm(THREAD);
255 int cp_index = cp->to_cp_index(raw_index, bc);
256
257 if (cp->is_resolved(raw_index, bc)) {
258 return;
259 }
260
261 if (preresolve_list != nullptr && preresolve_list->at(cp_index) == false) {
262 // This field wasn't resolved during the trial run. Don't attempt to resolve it. Otherwise
263 // the compiler may generate less efficient code.
264 return;
265 }
266
267 int klass_cp_index = cp->uncached_klass_ref_index_at(cp_index);
268 if (find_loaded_class(THREAD, cp(), klass_cp_index) == nullptr) {
269 // Do not resolve any field/methods from a class that has not been loaded yet.
270 return;
271 }
272
273 Klass* resolved_klass = cp->klass_ref_at(raw_index, bc, CHECK);
274
275 switch (bc) {
276 case Bytecodes::_getfield:
277 case Bytecodes::_putfield:
278 InterpreterRuntime::resolve_get_put(bc, raw_index, mh, cp, StaticMode::dont_initialize_klass, CHECK);
279 break;
280
281 case Bytecodes::_invokevirtual:
282 case Bytecodes::_invokespecial:
283 case Bytecodes::_invokeinterface:
284 InterpreterRuntime::cds_resolve_invoke(bc, raw_index, cp, CHECK);
285 break;
286
287 case Bytecodes::_invokehandle:
288 InterpreterRuntime::cds_resolve_invokehandle(raw_index, cp, CHECK);
289 break;
290
291 default:
292 ShouldNotReachHere();
293 }
294
295 if (log_is_enabled(Trace, cds, resolve)) {
296 ResourceMark rm(THREAD);
297 bool resolved = cp->is_resolved(raw_index, bc);
298 Symbol* name = cp->name_ref_at(raw_index, bc);
299 Symbol* signature = cp->signature_ref_at(raw_index, bc);
300 log_trace(cds, resolve)("%s %s [%3d] %s -> %s.%s:%s",
301 (resolved ? "Resolved" : "Failed to resolve"),
302 Bytecodes::name(bc), cp_index, ik->external_name(),
303 resolved_klass->external_name(),
304 name->as_C_string(), signature->as_C_string());
305 }
306 }
307
308 void AOTConstantPoolResolver::preresolve_indy_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray<bool>* preresolve_list) {
309 JavaThread* THREAD = current;
310 constantPoolHandle cp(THREAD, ik->constants());
311 if (!CDSConfig::is_dumping_invokedynamic() || cp->cache() == nullptr) {
312 return;
313 }
314
315 assert(preresolve_list != nullptr, "preresolve_indy_cp_entries() should not be called for "
316 "regenerated LambdaForm Invoker classes, which should not have indys anyway.");
317
318 Array<ResolvedIndyEntry>* indy_entries = cp->cache()->resolved_indy_entries();
319 for (int i = 0; i < indy_entries->length(); i++) {
320 ResolvedIndyEntry* rie = indy_entries->adr_at(i);
321 int cp_index = rie->constant_pool_index();
322 if (preresolve_list->at(cp_index) == true) {
323 if (!rie->is_resolved() && is_indy_resolution_deterministic(cp(), cp_index)) {
324 InterpreterRuntime::cds_resolve_invokedynamic(i, cp, THREAD);
325 if (HAS_PENDING_EXCEPTION) {
326 CLEAR_PENDING_EXCEPTION; // just ignore
327 }
328 }
329 if (log_is_enabled(Trace, cds, resolve)) {
330 ResourceMark rm(THREAD);
331 log_trace(cds, resolve)("%s indy [%3d] %s",
332 rie->is_resolved() ? "Resolved" : "Failed to resolve",
333 cp_index, ik->external_name());
334 }
335 }
336 }
337 }
338
339 // Check the MethodType signatures used by parameters to the indy BSMs. Make sure we don't
340 // use types that have been excluded, or else we might end up creating MethodTypes that cannot be stored
341 // in the AOT cache.
342 bool AOTConstantPoolResolver::check_methodtype_signature(ConstantPool* cp, Symbol* sig, Klass** return_type_ret) {
343 ResourceMark rm;
344 for (SignatureStream ss(sig); !ss.is_done(); ss.next()) {
345 if (ss.is_reference()) {
346 Symbol* type = ss.as_symbol();
347 Klass* k = find_loaded_class(Thread::current(), cp->pool_holder()->class_loader(), type);
348 if (k == nullptr) {
349 return false;
350 }
351
352 if (SystemDictionaryShared::should_be_excluded(k)) {
353 if (log_is_enabled(Warning, cds, resolve)) {
354 ResourceMark rm;
355 log_warning(cds, resolve)("Cannot aot-resolve Lambda proxy because %s is excluded", k->external_name());
356 }
357 return false;
358 }
359
360 if (ss.at_return_type() && return_type_ret != nullptr) {
361 *return_type_ret = k;
362 }
363 }
364 }
365 return true;
366 }
367
368 bool AOTConstantPoolResolver::check_lambda_metafactory_signature(ConstantPool* cp, Symbol* sig) {
369 Klass* k;
370 if (!check_methodtype_signature(cp, sig, &k)) {
371 return false;
372 }
373
374 // <k> is the interface type implemented by the lambda proxy
375 if (!k->is_interface()) {
376 // cp->pool_holder() doesn't look like a valid class generated by javac
377 return false;
378 }
379
380
381 // The linked lambda callsite has an instance of the interface implemented by this lambda. If this
382 // interface requires its <clinit> to be executed, then we must delay the execution to the production run
383 // as <clinit> can have side effects ==> exclude such cases.
384 InstanceKlass* intf = InstanceKlass::cast(k);
385 bool exclude = intf->interface_needs_clinit_execution_as_super();
386 if (log_is_enabled(Debug, cds, resolve)) {
387 ResourceMark rm;
388 log_debug(cds, resolve)("%s aot-resolve Lambda proxy of interface type %s",
389 exclude ? "Cannot" : "Can", k->external_name());
390 }
391 return !exclude;
392 }
393
394 bool AOTConstantPoolResolver::check_lambda_metafactory_methodtype_arg(ConstantPool* cp, int bsms_attribute_index, int arg_i) {
395 int mt_index = cp->operand_argument_index_at(bsms_attribute_index, arg_i);
396 if (!cp->tag_at(mt_index).is_method_type()) {
397 // malformed class?
398 return false;
399 }
400
401 Symbol* sig = cp->method_type_signature_at(mt_index);
402 if (log_is_enabled(Debug, cds, resolve)) {
403 ResourceMark rm;
404 log_debug(cds, resolve)("Checking MethodType for LambdaMetafactory BSM arg %d: %s", arg_i, sig->as_C_string());
405 }
406
407 return check_methodtype_signature(cp, sig);
408 }
409
410 bool AOTConstantPoolResolver::check_lambda_metafactory_methodhandle_arg(ConstantPool* cp, int bsms_attribute_index, int arg_i) {
411 int mh_index = cp->operand_argument_index_at(bsms_attribute_index, arg_i);
412 if (!cp->tag_at(mh_index).is_method_handle()) {
413 // malformed class?
414 return false;
415 }
416
417 Symbol* sig = cp->method_handle_signature_ref_at(mh_index);
418 if (log_is_enabled(Debug, cds, resolve)) {
419 ResourceMark rm;
420 log_debug(cds, resolve)("Checking MethodType of MethodHandle for LambdaMetafactory BSM arg %d: %s", arg_i, sig->as_C_string());
421 }
422 return check_methodtype_signature(cp, sig);
423 }
424
425 bool AOTConstantPoolResolver::is_indy_resolution_deterministic(ConstantPool* cp, int cp_index) {
426 assert(cp->tag_at(cp_index).is_invoke_dynamic(), "sanity");
427 if (!CDSConfig::is_dumping_invokedynamic()) {
428 return false;
429 }
430
431 InstanceKlass* pool_holder = cp->pool_holder();
432 if (!SystemDictionaryShared::is_builtin(pool_holder)) {
433 return false;
434 }
435
436 int bsm = cp->bootstrap_method_ref_index_at(cp_index);
437 int bsm_ref = cp->method_handle_index_at(bsm);
438 Symbol* bsm_name = cp->uncached_name_ref_at(bsm_ref);
439 Symbol* bsm_signature = cp->uncached_signature_ref_at(bsm_ref);
440 Symbol* bsm_klass = cp->klass_name_at(cp->uncached_klass_ref_index_at(bsm_ref));
441
442 // We currently support only StringConcatFactory::makeConcatWithConstants() and LambdaMetafactory::metafactory()
443 // We should mark the allowed BSMs in the JDK code using a private annotation.
444 // See notes on RFE JDK-8342481.
445
446 if (bsm_klass->equals("java/lang/invoke/StringConcatFactory") &&
447 bsm_name->equals("makeConcatWithConstants") &&
448 bsm_signature->equals("(Ljava/lang/invoke/MethodHandles$Lookup;"
449 "Ljava/lang/String;"
450 "Ljava/lang/invoke/MethodType;"
451 "Ljava/lang/String;"
452 "[Ljava/lang/Object;"
453 ")Ljava/lang/invoke/CallSite;")) {
454 Symbol* factory_type_sig = cp->uncached_signature_ref_at(cp_index);
455 if (log_is_enabled(Debug, cds, resolve)) {
456 ResourceMark rm;
457 log_debug(cds, resolve)("Checking StringConcatFactory callsite signature [%d]: %s", cp_index, factory_type_sig->as_C_string());
458 }
459
460 Klass* k;
461 if (!check_methodtype_signature(cp, factory_type_sig, &k)) {
462 return false;
463 }
464 if (k != vmClasses::String_klass()) {
465 // bad class file?
466 return false;
467 }
468
469 return true;
470 }
471
472 if (bsm_klass->equals("java/lang/invoke/LambdaMetafactory") &&
473 bsm_name->equals("metafactory") &&
474 bsm_signature->equals("(Ljava/lang/invoke/MethodHandles$Lookup;"
475 "Ljava/lang/String;"
476 "Ljava/lang/invoke/MethodType;"
477 "Ljava/lang/invoke/MethodType;"
478 "Ljava/lang/invoke/MethodHandle;"
479 "Ljava/lang/invoke/MethodType;"
480 ")Ljava/lang/invoke/CallSite;")) {
481 /*
482 * An indy callsite is associated with the following MethodType and MethodHandles:
483 *
484 * https://github.com/openjdk/jdk/blob/580eb62dc097efeb51c76b095c1404106859b673/src/java.base/share/classes/java/lang/invoke/LambdaMetafactory.java#L293-L309
485 *
486 * MethodType factoryType The expected signature of the {@code CallSite}. The
487 * parameter types represent the types of capture variables;
488 * the return type is the interface to implement. When
489 * used with {@code invokedynamic}, this is provided by
490 * the {@code NameAndType} of the {@code InvokeDynamic}
491 *
492 * MethodType interfaceMethodType Signature and return type of method to be
493 * implemented by the function object.
494 *
495 * MethodHandle implementation A direct method handle describing the implementation
496 * method which should be called (with suitable adaptation
497 * of argument types and return types, and with captured
498 * arguments prepended to the invocation arguments) at
499 * invocation time.
500 *
501 * MethodType dynamicMethodType The signature and return type that should
502 * be enforced dynamically at invocation time.
503 * In simple use cases this is the same as
504 * {@code interfaceMethodType}.
505 */
506 Symbol* factory_type_sig = cp->uncached_signature_ref_at(cp_index);
507 if (log_is_enabled(Debug, cds, resolve)) {
508 ResourceMark rm;
509 log_debug(cds, resolve)("Checking lambda callsite signature [%d]: %s", cp_index, factory_type_sig->as_C_string());
510 }
511
512 if (!check_lambda_metafactory_signature(cp, factory_type_sig)) {
513 return false;
514 }
515
516 int bsms_attribute_index = cp->bootstrap_methods_attribute_index(cp_index);
517 int arg_count = cp->operand_argument_count_at(bsms_attribute_index);
518 if (arg_count != 3) {
519 // Malformed class?
520 return false;
521 }
522
523 // interfaceMethodType
524 if (!check_lambda_metafactory_methodtype_arg(cp, bsms_attribute_index, 0)) {
525 return false;
526 }
527
528 // implementation
529 if (!check_lambda_metafactory_methodhandle_arg(cp, bsms_attribute_index, 1)) {
530 return false;
531 }
532
533 // dynamicMethodType
534 if (!check_lambda_metafactory_methodtype_arg(cp, bsms_attribute_index, 2)) {
535 return false;
536 }
537
538 return true;
539 }
540
541 return false;
542 }
543 #ifdef ASSERT
544 bool AOTConstantPoolResolver::is_in_archivebuilder_buffer(address p) {
545 if (!Thread::current()->is_VM_thread() || ArchiveBuilder::current() == nullptr) {
546 return false;
547 } else {
548 return ArchiveBuilder::current()->is_in_buffer_space(p);
549 }
550 }
551 #endif