1 /*
2 * Copyright (c) 2014, 2023, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.io.IOException;
29 import java.io.InputStream;
30 import java.lang.annotation.Annotation;
31 import java.lang.module.Configuration;
32 import java.lang.module.ModuleReference;
33 import java.lang.module.ModuleDescriptor;
34 import java.lang.module.ModuleDescriptor.Exports;
35 import java.lang.module.ModuleDescriptor.Opens;
36 import java.lang.module.ModuleDescriptor.Version;
37 import java.lang.module.ResolvedModule;
38 import java.lang.reflect.AccessFlag;
39 import java.lang.reflect.AnnotatedElement;
40 import java.net.URI;
41 import java.net.URL;
42 import java.security.AccessController;
43 import java.security.PrivilegedAction;
44 import java.util.HashMap;
45 import java.util.HashSet;
46 import java.util.List;
47 import java.util.Map;
48 import java.util.Objects;
49 import java.util.Optional;
50 import java.util.Set;
51 import java.util.concurrent.ConcurrentHashMap;
52 import java.util.function.Function;
53 import java.util.stream.Collectors;
54 import java.util.stream.Stream;
55 import jdk.internal.classfile.AccessFlags;
56 import jdk.internal.classfile.Attribute;
57 import jdk.internal.classfile.ClassModel;
58 import jdk.internal.classfile.ClassTransform;
59 import jdk.internal.classfile.Classfile;
60 import jdk.internal.classfile.attribute.ModuleAttribute;
61 import jdk.internal.classfile.attribute.RuntimeVisibleAnnotationsAttribute;
62
63 import jdk.internal.javac.PreviewFeature;
64 import jdk.internal.loader.BuiltinClassLoader;
65 import jdk.internal.loader.BootLoader;
66 import jdk.internal.loader.ClassLoaders;
67 import jdk.internal.misc.CDS;
68 import jdk.internal.misc.Unsafe;
69 import jdk.internal.module.ModuleBootstrap;
70 import jdk.internal.module.ModuleLoaderMap;
71 import jdk.internal.module.ServicesCatalog;
72 import jdk.internal.module.Resources;
73 import jdk.internal.reflect.CallerSensitive;
74 import jdk.internal.reflect.Reflection;
75 import jdk.internal.vm.annotation.Stable;
76 import sun.security.util.SecurityConstants;
77
78 /**
79 * Represents a run-time module, either {@link #isNamed() named} or unnamed.
80 *
81 * <p> Named modules have a {@link #getName() name} and are constructed by the
82 * Java Virtual Machine when a graph of modules is defined to the Java virtual
83 * machine to create a {@linkplain ModuleLayer module layer}. </p>
84 *
85 * <p> An unnamed module does not have a name. There is an unnamed module for
86 * each {@link ClassLoader ClassLoader}, obtained by invoking its {@link
87 * ClassLoader#getUnnamedModule() getUnnamedModule} method. All types that are
88 * not in a named module are members of their defining class loader's unnamed
89 * module. </p>
90 *
91 * <p> The package names that are parameters or returned by methods defined in
92 * this class are the fully-qualified names of the packages as defined in
93 * section {@jls 6.5.3} of <cite>The Java Language Specification</cite>, for
94 * example, {@code "java.lang"}. </p>
95 *
96 * <p> Unless otherwise specified, passing a {@code null} argument to a method
97 * in this class causes a {@link NullPointerException NullPointerException} to
98 * be thrown. </p>
99 *
100 * @since 9
101 * @see Class#getModule()
102 * @jls 7.7 Module Declarations
103 */
104
105 public final class Module implements AnnotatedElement {
106
107 // the layer that contains this module, can be null
108 private final ModuleLayer layer;
109
110 // module name and loader, these fields are read by VM
111 private final String name;
112 private final ClassLoader loader;
113
114 // the module descriptor
115 private final ModuleDescriptor descriptor;
116
117 // true, if this module allows restricted native access
118 // Accessing this variable is made through Unsafe in order to use the
119 // memory semantics that preserves ordering and visibility across threads.
120 @Stable
121 private boolean enableNativeAccess;
122
123 /**
124 * Creates a new named Module. The resulting Module will be defined to the
125 * VM but will not read any other modules, will not have any exports setup
126 * and will not be registered in the service catalog.
127 */
128 Module(ModuleLayer layer,
129 ClassLoader loader,
130 ModuleDescriptor descriptor,
131 URI uri)
132 {
133 this.layer = layer;
134 this.name = descriptor.name();
135 this.loader = loader;
136 this.descriptor = descriptor;
137
138 // define module to VM
139
140 boolean isOpen = descriptor.isOpen() || descriptor.isAutomatic();
141 Version version = descriptor.version().orElse(null);
142 String vs = Objects.toString(version, null);
143 String loc = Objects.toString(uri, null);
144 Object[] packages = descriptor.packages().toArray();
145 defineModule0(this, isOpen, vs, loc, packages);
146 if (loader == null || loader == ClassLoaders.platformClassLoader()) {
147 // boot/builtin modules are always native
148 implAddEnableNativeAccess();
149 }
150 }
151
152
153 /**
154 * Create the unnamed Module for the given ClassLoader.
155 *
156 * @see ClassLoader#getUnnamedModule
157 */
158 Module(ClassLoader loader) {
159 this.layer = null;
160 this.name = null;
161 this.loader = loader;
162 this.descriptor = null;
163 }
164
165
166 /**
167 * Creates a named module but without defining the module to the VM.
168 *
169 * @apiNote This constructor is for VM white-box testing.
170 */
171 Module(ClassLoader loader, ModuleDescriptor descriptor) {
172 this.layer = null;
173 this.name = descriptor.name();
174 this.loader = loader;
175 this.descriptor = descriptor;
176 }
177
178
179 /**
180 * Returns {@code true} if this module is a named module.
181 *
182 * @return {@code true} if this is a named module
183 *
184 * @see ClassLoader#getUnnamedModule()
185 * @jls 7.7.5 Unnamed Modules
186 */
187 public boolean isNamed() {
188 return name != null;
189 }
190
191 /**
192 * Returns the module name or {@code null} if this module is an unnamed
193 * module.
194 *
195 * @return The module name
196 */
197 public String getName() {
198 return name;
199 }
200
201 /**
202 * Returns the {@code ClassLoader} for this module.
203 *
204 * <p> If there is a security manager then its {@code checkPermission}
205 * method if first called with a {@code RuntimePermission("getClassLoader")}
206 * permission to check that the caller is allowed to get access to the
207 * class loader. </p>
208 *
209 * @return The class loader for this module
210 *
211 * @throws SecurityException
212 * If denied by the security manager
213 */
214 public ClassLoader getClassLoader() {
215 @SuppressWarnings("removal")
216 SecurityManager sm = System.getSecurityManager();
217 if (sm != null) {
218 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
219 }
220 return loader;
221 }
222
223 /**
224 * Returns the module descriptor for this module or {@code null} if this
225 * module is an unnamed module.
226 *
227 * @return The module descriptor for this module
228 */
229 public ModuleDescriptor getDescriptor() {
230 return descriptor;
231 }
232
233 /**
234 * Returns the module layer that contains this module or {@code null} if
235 * this module is not in a module layer.
236 *
237 * A module layer contains named modules and therefore this method always
238 * returns {@code null} when invoked on an unnamed module.
239 *
240 * <p> <a href="reflect/Proxy.html#dynamicmodule">Dynamic modules</a> are
241 * named modules that are generated at runtime. A dynamic module may or may
242 * not be in a module layer. </p>
243 *
244 * @return The module layer that contains this module
245 *
246 * @see java.lang.reflect.Proxy
247 */
248 public ModuleLayer getLayer() {
249 if (isNamed()) {
250 ModuleLayer layer = this.layer;
251 if (layer != null)
252 return layer;
253
254 // special-case java.base as it is created before the boot layer
255 if (loader == null && name.equals("java.base")) {
256 return ModuleLayer.boot();
257 }
258 }
259 return null;
260 }
261
262 /**
263 * Update this module to allow access to restricted methods.
264 */
265 Module implAddEnableNativeAccess() {
266 EnableNativeAccess.trySetEnableNativeAccess(this);
267 return this;
268 }
269
270 /**
271 * Returns {@code true} if this module can access
272 * <a href="foreign/package-summary.html#restricted"><em>restricted</em></a> methods.
273 *
274 * @return {@code true} if this module can access <em>restricted</em> methods.
275 * @since 20
276 */
277 @PreviewFeature(feature = PreviewFeature.Feature.FOREIGN)
278 public boolean isNativeAccessEnabled() {
279 Module target = moduleForNativeAccess();
280 return EnableNativeAccess.isNativeAccessEnabled(target);
281 }
282
283 /**
284 * This class is used to be able to bootstrap without using Unsafe
285 * in the outer Module class as that would create a circular initializer dependency.
286 */
287 private static final class EnableNativeAccess {
288
289 private EnableNativeAccess() {}
290
291 private static final Unsafe UNSAFE = Unsafe.getUnsafe();
292 private static final long FIELD_OFFSET = UNSAFE.objectFieldOffset(Module.class, "enableNativeAccess");
293
294 private static boolean isNativeAccessEnabled(Module target) {
295 return UNSAFE.getBooleanVolatile(target, FIELD_OFFSET);
296 }
297
298 // Atomically sets enableNativeAccess if not already set
299 // returning if the value was updated
300 private static boolean trySetEnableNativeAccess(Module target) {
301 return UNSAFE.compareAndSetBoolean(target, FIELD_OFFSET, false, true);
302 }
303 }
304
305 // Returns the Module object that holds the enableNativeAccess
306 // flag for this module.
307 private Module moduleForNativeAccess() {
308 return isNamed() ? this : ALL_UNNAMED_MODULE;
309 }
310
311 // This is invoked from Reflection.ensureNativeAccess
312 void ensureNativeAccess(Class<?> owner, String methodName) {
313 // The target module whose enableNativeAccess flag is ensured
314 Module target = moduleForNativeAccess();
315 if (!EnableNativeAccess.isNativeAccessEnabled(target)) {
316 if (ModuleBootstrap.hasEnableNativeAccessFlag()) {
317 throw new IllegalCallerException("Illegal native access from: " + this);
318 }
319 if (EnableNativeAccess.trySetEnableNativeAccess(target)) {
320 // warn and set flag, so that only one warning is reported per module
321 String cls = owner.getName();
322 String mtd = cls + "::" + methodName;
323 String mod = isNamed() ? "module " + getName() : "the unnamed module";
324 String modflag = isNamed() ? getName() : "ALL-UNNAMED";
325 System.err.printf("""
326 WARNING: A restricted method in %s has been called
327 WARNING: %s has been called by %s
328 WARNING: Use --enable-native-access=%s to avoid a warning for this module
329 %n""", cls, mtd, mod, modflag);
330 }
331 }
332 }
333
334 /**
335 * Update all unnamed modules to allow access to restricted methods.
336 */
337 static void implAddEnableNativeAccessToAllUnnamed() {
338 EnableNativeAccess.trySetEnableNativeAccess(ALL_UNNAMED_MODULE);
339 }
340
341 // --
342
343 // special Module to mean "all unnamed modules"
344 private static final Module ALL_UNNAMED_MODULE;
345 private static final Set<Module> ALL_UNNAMED_MODULE_SET;
346
347 // special Module to mean "everyone"
348 private static final Module EVERYONE_MODULE;
349 private static final Set<Module> EVERYONE_SET;
350
351 private static class ArchivedData {
352 private static ArchivedData archivedData;
353 private final Module allUnnamedModule;
354 private final Set<Module> allUnnamedModules;
355 private final Module everyoneModule;
356 private final Set<Module> everyoneSet;
357
358 private ArchivedData() {
359 this.allUnnamedModule = ALL_UNNAMED_MODULE;
360 this.allUnnamedModules = ALL_UNNAMED_MODULE_SET;
361 this.everyoneModule = EVERYONE_MODULE;
362 this.everyoneSet = EVERYONE_SET;
363 }
364
365 static void archive() {
366 archivedData = new ArchivedData();
367 }
368
369 static ArchivedData get() {
370 return archivedData;
371 }
372
373 static {
374 CDS.initializeFromArchive(ArchivedData.class);
375 }
376 }
377
378 static {
379 ArchivedData archivedData = ArchivedData.get();
380 if (archivedData != null) {
381 ALL_UNNAMED_MODULE = archivedData.allUnnamedModule;
382 ALL_UNNAMED_MODULE_SET = archivedData.allUnnamedModules;
383 EVERYONE_MODULE = archivedData.everyoneModule;
384 EVERYONE_SET = archivedData.everyoneSet;
385 } else {
386 ALL_UNNAMED_MODULE = new Module(null);
387 ALL_UNNAMED_MODULE_SET = Set.of(ALL_UNNAMED_MODULE);
388 EVERYONE_MODULE = new Module(null);
389 EVERYONE_SET = Set.of(EVERYONE_MODULE);
390 ArchivedData.archive();
391 }
392 }
393
394 /**
395 * The holder of data structures to support readability, exports, and
396 * service use added at runtime with the reflective APIs.
397 */
398 private static class ReflectionData {
399 /**
400 * A module (1st key) reads another module (2nd key)
401 */
402 static final WeakPairMap<Module, Module, Boolean> reads =
403 new WeakPairMap<>();
404
405 /**
406 * A module (1st key) exports or opens a package to another module
407 * (2nd key). The map value is a map of package name to a boolean
408 * that indicates if the package is opened.
409 */
410 static final WeakPairMap<Module, Module, Map<String, Boolean>> exports =
411 new WeakPairMap<>();
412
413 /**
414 * A module (1st key) uses a service (2nd key)
415 */
416 static final WeakPairMap<Module, Class<?>, Boolean> uses =
417 new WeakPairMap<>();
418 }
419
420
421 // -- readability --
422
423 // the modules that this module reads
424 private volatile Set<Module> reads;
425
426 /**
427 * Indicates if this module reads the given module. This method returns
428 * {@code true} if invoked to test if this module reads itself. It also
429 * returns {@code true} if invoked on an unnamed module (as unnamed
430 * modules read all modules).
431 *
432 * @param other
433 * The other module
434 *
435 * @return {@code true} if this module reads {@code other}
436 *
437 * @see #addReads(Module)
438 */
439 public boolean canRead(Module other) {
440 Objects.requireNonNull(other);
441
442 // an unnamed module reads all modules
443 if (!this.isNamed())
444 return true;
445
446 // all modules read themselves
447 if (other == this)
448 return true;
449
450 // check if this module reads other
451 if (other.isNamed()) {
452 Set<Module> reads = this.reads; // volatile read
453 if (reads != null && reads.contains(other))
454 return true;
455 }
456
457 // check if this module reads the other module reflectively
458 if (ReflectionData.reads.containsKeyPair(this, other))
459 return true;
460
461 // if other is an unnamed module then check if this module reads
462 // all unnamed modules
463 if (!other.isNamed()
464 && ReflectionData.reads.containsKeyPair(this, ALL_UNNAMED_MODULE))
465 return true;
466
467 return false;
468 }
469
470 /**
471 * If the caller's module is this module then update this module to read
472 * the given module.
473 *
474 * This method is a no-op if {@code other} is this module (all modules read
475 * themselves), this module is an unnamed module (as unnamed modules read
476 * all modules), or this module already reads {@code other}.
477 *
478 * @implNote <em>Read edges</em> added by this method are <em>weak</em> and
479 * do not prevent {@code other} from being GC'ed when this module is
480 * strongly reachable.
481 *
482 * @param other
483 * The other module
484 *
485 * @return this module
486 *
487 * @throws IllegalCallerException
488 * If this is a named module and the caller's module is not this
489 * module
490 *
491 * @see #canRead
492 */
493 @CallerSensitive
494 public Module addReads(Module other) {
495 Objects.requireNonNull(other);
496 if (this.isNamed()) {
497 Module caller = getCallerModule(Reflection.getCallerClass());
498 if (caller != this) {
499 throw new IllegalCallerException(caller + " != " + this);
500 }
501 implAddReads(other, true);
502 }
503 return this;
504 }
505
506 /**
507 * Updates this module to read another module.
508 *
509 * @apiNote Used by the --add-reads command line option.
510 */
511 void implAddReads(Module other) {
512 implAddReads(other, true);
513 }
514
515 /**
516 * Updates this module to read all unnamed modules.
517 *
518 * @apiNote Used by the --add-reads command line option.
519 */
520 void implAddReadsAllUnnamed() {
521 implAddReads(Module.ALL_UNNAMED_MODULE, true);
522 }
523
524 /**
525 * Updates this module to read another module without notifying the VM.
526 *
527 * @apiNote This method is for VM white-box testing.
528 */
529 void implAddReadsNoSync(Module other) {
530 implAddReads(other, false);
531 }
532
533 /**
534 * Makes the given {@code Module} readable to this module.
535 *
536 * If {@code syncVM} is {@code true} then the VM is notified.
537 */
538 private void implAddReads(Module other, boolean syncVM) {
539 Objects.requireNonNull(other);
540 if (!canRead(other)) {
541 // update VM first, just in case it fails
542 if (syncVM) {
543 if (other == ALL_UNNAMED_MODULE) {
544 addReads0(this, null);
545 } else {
546 addReads0(this, other);
547 }
548 }
549
550 // add reflective read
551 ReflectionData.reads.putIfAbsent(this, other, Boolean.TRUE);
552 }
553 }
554
555
556 // -- exported and open packages --
557
558 // the packages are open to other modules, can be null
559 // if the value contains EVERYONE_MODULE then the package is open to all
560 private volatile Map<String, Set<Module>> openPackages;
561
562 // the packages that are exported, can be null
563 // if the value contains EVERYONE_MODULE then the package is exported to all
564 private volatile Map<String, Set<Module>> exportedPackages;
565
566 /**
567 * Returns {@code true} if this module exports the given package to at
568 * least the given module.
569 *
570 * <p> This method returns {@code true} if invoked to test if a package in
571 * this module is exported to itself. It always returns {@code true} when
572 * invoked on an unnamed module. A package that is {@link #isOpen open} to
573 * the given module is considered exported to that module at run-time and
574 * so this method returns {@code true} if the package is open to the given
575 * module. </p>
576 *
577 * <p> This method does not check if the given module reads this module. </p>
578 *
579 * @param pn
580 * The package name
581 * @param other
582 * The other module
583 *
584 * @return {@code true} if this module exports the package to at least the
585 * given module
586 *
587 * @see ModuleDescriptor#exports()
588 * @see #addExports(String,Module)
589 */
590 public boolean isExported(String pn, Module other) {
591 Objects.requireNonNull(pn);
592 Objects.requireNonNull(other);
593 return implIsExportedOrOpen(pn, other, /*open*/false);
594 }
595
596 /**
597 * Returns {@code true} if this module has <em>opened</em> a package to at
598 * least the given module.
599 *
600 * <p> This method returns {@code true} if invoked to test if a package in
601 * this module is open to itself. It returns {@code true} when invoked on an
602 * {@link ModuleDescriptor#isOpen open} module with a package in the module.
603 * It always returns {@code true} when invoked on an unnamed module. </p>
604 *
605 * <p> This method does not check if the given module reads this module. </p>
606 *
607 * @apiNote A package {@code p} opened to module {@code M} allows code in
608 * {@code M} do {@linkplain java.lang.reflect.AccessibleObject#setAccessible(boolean)
609 * deep reflection} on all types in the package.
610 * Further, if {@code M} reads this module, it can obtain a
611 * {@link java.lang.invoke.MethodHandles.Lookup Lookup} object that is allowed to
612 * {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[]) define classes}
613 * in package {@code p}.
614 *
615 * @param pn
616 * The package name
617 * @param other
618 * The other module
619 *
620 * @return {@code true} if this module has <em>opened</em> the package
621 * to at least the given module
622 *
623 * @see ModuleDescriptor#opens()
624 * @see #addOpens(String,Module)
625 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
626 * @see java.lang.invoke.MethodHandles#privateLookupIn
627 */
628 public boolean isOpen(String pn, Module other) {
629 Objects.requireNonNull(pn);
630 Objects.requireNonNull(other);
631 return implIsExportedOrOpen(pn, other, /*open*/true);
632 }
633
634 /**
635 * Returns {@code true} if this module exports the given package
636 * unconditionally.
637 *
638 * <p> This method always returns {@code true} when invoked on an unnamed
639 * module. A package that is {@link #isOpen(String) opened} unconditionally
640 * is considered exported unconditionally at run-time and so this method
641 * returns {@code true} if the package is opened unconditionally. </p>
642 *
643 * <p> This method does not check if the given module reads this module. </p>
644 *
645 * @param pn
646 * The package name
647 *
648 * @return {@code true} if this module exports the package unconditionally
649 *
650 * @see ModuleDescriptor#exports()
651 */
652 public boolean isExported(String pn) {
653 Objects.requireNonNull(pn);
654 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/false);
655 }
656
657 /**
658 * Returns {@code true} if this module has <em>opened</em> a package
659 * unconditionally.
660 *
661 * <p> This method always returns {@code true} when invoked on an unnamed
662 * module. Additionally, it always returns {@code true} when invoked on an
663 * {@link ModuleDescriptor#isOpen open} module with a package in the
664 * module. </p>
665 *
666 * <p> This method does not check if the given module reads this module. </p>
667 *
668 * @apiNote A package {@code p} opened to module {@code M} allows code in
669 * {@code M} do {@linkplain java.lang.reflect.AccessibleObject#setAccessible(boolean)
670 * deep reflection} on all types in the package.
671 * Further, if {@code M} reads this module, it can obtain a
672 * {@link java.lang.invoke.MethodHandles.Lookup Lookup} object that is allowed to
673 * {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[]) define classes}
674 * in package {@code p}.
675 *
676 * @param pn
677 * The package name
678 *
679 * @return {@code true} if this module has <em>opened</em> the package
680 * unconditionally
681 *
682 * @see ModuleDescriptor#opens()
683 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
684 * @see java.lang.invoke.MethodHandles#privateLookupIn
685 */
686 public boolean isOpen(String pn) {
687 Objects.requireNonNull(pn);
688 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/true);
689 }
690
691
692 /**
693 * Returns {@code true} if this module exports or opens the given package
694 * to the given module. If the other module is {@code EVERYONE_MODULE} then
695 * this method tests if the package is exported or opened unconditionally.
696 */
697 private boolean implIsExportedOrOpen(String pn, Module other, boolean open) {
698 // all packages in unnamed modules are open
699 if (!isNamed())
700 return true;
701
702 // all packages are exported/open to self
703 if (other == this && descriptor.packages().contains(pn))
704 return true;
705
706 // all packages in open and automatic modules are open
707 if (descriptor.isOpen() || descriptor.isAutomatic())
708 return descriptor.packages().contains(pn);
709
710 // exported/opened via module declaration/descriptor
711 if (isStaticallyExportedOrOpen(pn, other, open))
712 return true;
713
714 // exported via addExports/addOpens
715 if (isReflectivelyExportedOrOpen(pn, other, open))
716 return true;
717
718 // not exported or open to other
719 return false;
720 }
721
722 /**
723 * Returns {@code true} if this module exports or opens a package to
724 * the given module via its module declaration or CLI options.
725 */
726 private boolean isStaticallyExportedOrOpen(String pn, Module other, boolean open) {
727 // test if package is open to everyone or <other>
728 Map<String, Set<Module>> openPackages = this.openPackages;
729 if (openPackages != null && allows(openPackages.get(pn), other)) {
730 return true;
731 }
732
733 if (!open) {
734 // test package is exported to everyone or <other>
735 Map<String, Set<Module>> exportedPackages = this.exportedPackages;
736 if (exportedPackages != null && allows(exportedPackages.get(pn), other)) {
737 return true;
738 }
739 }
740
741 return false;
742 }
743
744 /**
745 * Returns {@code true} if targets is non-null and contains EVERYONE_MODULE
746 * or the given module. Also returns true if the given module is an unnamed
747 * module and targets contains ALL_UNNAMED_MODULE.
748 */
749 private boolean allows(Set<Module> targets, Module module) {
750 if (targets != null) {
751 if (targets.contains(EVERYONE_MODULE))
752 return true;
753 if (module != EVERYONE_MODULE) {
754 if (targets.contains(module))
755 return true;
756 if (!module.isNamed() && targets.contains(ALL_UNNAMED_MODULE))
757 return true;
758 }
759 }
760 return false;
761 }
762
763 /**
764 * Returns {@code true} if this module reflectively exports or opens the
765 * given package to the given module.
766 */
767 private boolean isReflectivelyExportedOrOpen(String pn, Module other, boolean open) {
768 // exported or open to all modules
769 Map<String, Boolean> exports = ReflectionData.exports.get(this, EVERYONE_MODULE);
770 if (exports != null) {
771 Boolean b = exports.get(pn);
772 if (b != null) {
773 boolean isOpen = b.booleanValue();
774 if (!open || isOpen) return true;
775 }
776 }
777
778 if (other != EVERYONE_MODULE) {
779
780 // exported or open to other
781 exports = ReflectionData.exports.get(this, other);
782 if (exports != null) {
783 Boolean b = exports.get(pn);
784 if (b != null) {
785 boolean isOpen = b.booleanValue();
786 if (!open || isOpen) return true;
787 }
788 }
789
790 // other is an unnamed module && exported or open to all unnamed
791 if (!other.isNamed()) {
792 exports = ReflectionData.exports.get(this, ALL_UNNAMED_MODULE);
793 if (exports != null) {
794 Boolean b = exports.get(pn);
795 if (b != null) {
796 boolean isOpen = b.booleanValue();
797 if (!open || isOpen) return true;
798 }
799 }
800 }
801
802 }
803
804 return false;
805 }
806
807 /**
808 * Returns {@code true} if this module reflectively exports the
809 * given package to the given module.
810 */
811 boolean isReflectivelyExported(String pn, Module other) {
812 return isReflectivelyExportedOrOpen(pn, other, false);
813 }
814
815 /**
816 * Returns {@code true} if this module reflectively opens the
817 * given package to the given module.
818 */
819 boolean isReflectivelyOpened(String pn, Module other) {
820 return isReflectivelyExportedOrOpen(pn, other, true);
821 }
822
823
824 /**
825 * If the caller's module is this module then update this module to export
826 * the given package to the given module.
827 *
828 * <p> This method has no effect if the package is already exported (or
829 * <em>open</em>) to the given module. </p>
830 *
831 * @apiNote As specified in section {@jvms 5.4.3} of the <cite>The Java
832 * Virtual Machine Specification </cite>, if an attempt to resolve a
833 * symbolic reference fails because of a linkage error, then subsequent
834 * attempts to resolve the reference always fail with the same error that
835 * was thrown as a result of the initial resolution attempt.
836 *
837 * @param pn
838 * The package name
839 * @param other
840 * The module
841 *
842 * @return this module
843 *
844 * @throws IllegalArgumentException
845 * If {@code pn} is {@code null}, or this is a named module and the
846 * package {@code pn} is not a package in this module
847 * @throws IllegalCallerException
848 * If this is a named module and the caller's module is not this
849 * module
850 *
851 * @jvms 5.4.3 Resolution
852 * @see #isExported(String,Module)
853 */
854 @CallerSensitive
855 public Module addExports(String pn, Module other) {
856 if (pn == null)
857 throw new IllegalArgumentException("package is null");
858 Objects.requireNonNull(other);
859
860 if (isNamed()) {
861 Module caller = getCallerModule(Reflection.getCallerClass());
862 if (caller != this) {
863 throw new IllegalCallerException(caller + " != " + this);
864 }
865 implAddExportsOrOpens(pn, other, /*open*/false, /*syncVM*/true);
866 }
867
868 return this;
869 }
870
871 /**
872 * If this module has <em>opened</em> a package to at least the caller
873 * module then update this module to open the package to the given module.
874 * Opening a package with this method allows all types in the package,
875 * and all their members, not just public types and their public members,
876 * to be reflected on by the given module when using APIs that support
877 * private access or a way to bypass or suppress default Java language
878 * access control checks.
879 *
880 * <p> This method has no effect if the package is already <em>open</em>
881 * to the given module. </p>
882 *
883 * @apiNote This method can be used for cases where a <em>consumer
884 * module</em> uses a qualified opens to open a package to an <em>API
885 * module</em> but where the reflective access to the members of classes in
886 * the consumer module is delegated to code in another module. Code in the
887 * API module can use this method to open the package in the consumer module
888 * to the other module.
889 *
890 * @param pn
891 * The package name
892 * @param other
893 * The module
894 *
895 * @return this module
896 *
897 * @throws IllegalArgumentException
898 * If {@code pn} is {@code null}, or this is a named module and the
899 * package {@code pn} is not a package in this module
900 * @throws IllegalCallerException
901 * If this is a named module and this module has not opened the
902 * package to at least the caller's module
903 *
904 * @see #isOpen(String,Module)
905 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
906 * @see java.lang.invoke.MethodHandles#privateLookupIn
907 */
908 @CallerSensitive
909 public Module addOpens(String pn, Module other) {
910 if (pn == null)
911 throw new IllegalArgumentException("package is null");
912 Objects.requireNonNull(other);
913
914 if (isNamed()) {
915 Module caller = getCallerModule(Reflection.getCallerClass());
916 if (caller != this && (caller == null || !isOpen(pn, caller)))
917 throw new IllegalCallerException(pn + " is not open to " + caller);
918 implAddExportsOrOpens(pn, other, /*open*/true, /*syncVM*/true);
919 }
920
921 return this;
922 }
923
924
925 /**
926 * Updates this module to export a package unconditionally.
927 *
928 * @apiNote This method is for JDK tests only.
929 */
930 void implAddExports(String pn) {
931 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, false, true);
932 }
933
934 /**
935 * Updates this module to export a package to another module.
936 *
937 * @apiNote Used by Instrumentation::redefineModule and --add-exports
938 */
939 void implAddExports(String pn, Module other) {
940 implAddExportsOrOpens(pn, other, false, true);
941 }
942
943 /**
944 * Updates this module to export a package to all unnamed modules.
945 *
946 * @apiNote Used by the --add-exports command line option.
947 */
948 void implAddExportsToAllUnnamed(String pn) {
949 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, false, true);
950 }
951
952 /**
953 * Updates this export to export a package unconditionally without
954 * notifying the VM.
955 *
956 * @apiNote This method is for VM white-box testing.
957 */
958 void implAddExportsNoSync(String pn) {
959 implAddExportsOrOpens(pn.replace('/', '.'), Module.EVERYONE_MODULE, false, false);
960 }
961
962 /**
963 * Updates a module to export a package to another module without
964 * notifying the VM.
965 *
966 * @apiNote This method is for VM white-box testing.
967 */
968 void implAddExportsNoSync(String pn, Module other) {
969 implAddExportsOrOpens(pn.replace('/', '.'), other, false, false);
970 }
971
972 /**
973 * Updates this module to open a package unconditionally.
974 *
975 * @apiNote This method is for JDK tests only.
976 */
977 void implAddOpens(String pn) {
978 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, true, true);
979 }
980
981 /**
982 * Updates this module to open a package to another module.
983 *
984 * @apiNote Used by Instrumentation::redefineModule and --add-opens
985 */
986 void implAddOpens(String pn, Module other) {
987 implAddExportsOrOpens(pn, other, true, true);
988 }
989
990 /**
991 * Updates this module to open a package to all unnamed modules.
992 *
993 * @apiNote Used by the --add-opens command line option.
994 */
995 void implAddOpensToAllUnnamed(String pn) {
996 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, true, true);
997 }
998
999 /**
1000 * Updates a module to export or open a module to another module.
1001 *
1002 * If {@code syncVM} is {@code true} then the VM is notified.
1003 */
1004 private void implAddExportsOrOpens(String pn,
1005 Module other,
1006 boolean open,
1007 boolean syncVM) {
1008 Objects.requireNonNull(other);
1009 Objects.requireNonNull(pn);
1010
1011 // all packages are open in unnamed, open, and automatic modules
1012 if (!isNamed() || descriptor.isOpen() || descriptor.isAutomatic())
1013 return;
1014
1015 // check if the package is already exported/open to other
1016 if (implIsExportedOrOpen(pn, other, open))
1017 return;
1018
1019 // can only export a package in the module
1020 if (!descriptor.packages().contains(pn)) {
1021 throw new IllegalArgumentException("package " + pn
1022 + " not in contents");
1023 }
1024
1025 // update VM first, just in case it fails
1026 if (syncVM) {
1027 if (other == EVERYONE_MODULE) {
1028 addExportsToAll0(this, pn);
1029 } else if (other == ALL_UNNAMED_MODULE) {
1030 addExportsToAllUnnamed0(this, pn);
1031 } else {
1032 addExports0(this, pn, other);
1033 }
1034 }
1035
1036 // add package name to exports if absent
1037 Map<String, Boolean> map = ReflectionData.exports
1038 .computeIfAbsent(this, other,
1039 (m1, m2) -> new ConcurrentHashMap<>());
1040 if (open) {
1041 map.put(pn, Boolean.TRUE); // may need to promote from FALSE to TRUE
1042 } else {
1043 map.putIfAbsent(pn, Boolean.FALSE);
1044 }
1045 }
1046
1047 /**
1048 * Updates a module to open all packages in the given sets to all unnamed
1049 * modules.
1050 *
1051 * @apiNote Used during startup to open packages for illegal access.
1052 */
1053 void implAddOpensToAllUnnamed(Set<String> concealedPkgs, Set<String> exportedPkgs) {
1054 if (jdk.internal.misc.VM.isModuleSystemInited()) {
1055 throw new IllegalStateException("Module system already initialized");
1056 }
1057
1058 // replace this module's openPackages map with a new map that opens
1059 // the packages to all unnamed modules.
1060 Map<String, Set<Module>> openPackages = this.openPackages;
1061 if (openPackages == null) {
1062 openPackages = HashMap.newHashMap(concealedPkgs.size() + exportedPkgs.size());
1063 } else {
1064 openPackages = new HashMap<>(openPackages);
1065 }
1066 implAddOpensToAllUnnamed(concealedPkgs, openPackages);
1067 implAddOpensToAllUnnamed(exportedPkgs, openPackages);
1068 this.openPackages = openPackages;
1069 }
1070
1071 private void implAddOpensToAllUnnamed(Set<String> pkgs, Map<String, Set<Module>> openPackages) {
1072 for (String pn : pkgs) {
1073 Set<Module> prev = openPackages.putIfAbsent(pn, ALL_UNNAMED_MODULE_SET);
1074 if (prev != null) {
1075 prev.add(ALL_UNNAMED_MODULE);
1076 }
1077
1078 // update VM to export the package
1079 addExportsToAllUnnamed0(this, pn);
1080 }
1081 }
1082
1083 // -- services --
1084
1085 /**
1086 * If the caller's module is this module then update this module to add a
1087 * service dependence on the given service type. This method is intended
1088 * for use by frameworks that invoke {@link java.util.ServiceLoader
1089 * ServiceLoader} on behalf of other modules or where the framework is
1090 * passed a reference to the service type by other code. This method is
1091 * a no-op when invoked on an unnamed module or an automatic module.
1092 *
1093 * <p> This method does not cause {@link Configuration#resolveAndBind
1094 * resolveAndBind} to be re-run. </p>
1095 *
1096 * @param service
1097 * The service type
1098 *
1099 * @return this module
1100 *
1101 * @throws IllegalCallerException
1102 * If this is a named module and the caller's module is not this
1103 * module
1104 *
1105 * @see #canUse(Class)
1106 * @see ModuleDescriptor#uses()
1107 */
1108 @CallerSensitive
1109 public Module addUses(Class<?> service) {
1110 Objects.requireNonNull(service);
1111
1112 if (isNamed() && !descriptor.isAutomatic()) {
1113 Module caller = getCallerModule(Reflection.getCallerClass());
1114 if (caller != this) {
1115 throw new IllegalCallerException(caller + " != " + this);
1116 }
1117 implAddUses(service);
1118 }
1119
1120 return this;
1121 }
1122
1123 /**
1124 * Update this module to add a service dependence on the given service
1125 * type.
1126 */
1127 void implAddUses(Class<?> service) {
1128 if (!canUse(service)) {
1129 ReflectionData.uses.putIfAbsent(this, service, Boolean.TRUE);
1130 }
1131 }
1132
1133
1134 /**
1135 * Indicates if this module has a service dependence on the given service
1136 * type. This method always returns {@code true} when invoked on an unnamed
1137 * module or an automatic module.
1138 *
1139 * @param service
1140 * The service type
1141 *
1142 * @return {@code true} if this module uses service type {@code st}
1143 *
1144 * @see #addUses(Class)
1145 */
1146 public boolean canUse(Class<?> service) {
1147 Objects.requireNonNull(service);
1148
1149 if (!isNamed())
1150 return true;
1151
1152 if (descriptor.isAutomatic())
1153 return true;
1154
1155 // uses was declared
1156 if (descriptor.uses().contains(service.getName()))
1157 return true;
1158
1159 // uses added via addUses
1160 return ReflectionData.uses.containsKeyPair(this, service);
1161 }
1162
1163
1164
1165 // -- packages --
1166
1167 /**
1168 * Returns the set of package names for the packages in this module.
1169 *
1170 * <p> For named modules, the returned set contains an element for each
1171 * package in the module. </p>
1172 *
1173 * <p> For unnamed modules, the returned set contains an element for
1174 * each package that {@link ClassLoader#getDefinedPackages() has been defined}
1175 * in the unnamed module.</p>
1176 *
1177 * @return the set of the package names of the packages in this module
1178 */
1179 public Set<String> getPackages() {
1180 if (isNamed()) {
1181 return descriptor.packages();
1182 } else {
1183 // unnamed module
1184 Stream<Package> packages;
1185 if (loader == null) {
1186 packages = BootLoader.packages();
1187 } else {
1188 packages = loader.packages();
1189 }
1190 return packages.filter(p -> p.module() == this)
1191 .map(Package::getName).collect(Collectors.toSet());
1192 }
1193 }
1194
1195 // -- creating Module objects --
1196
1197 /**
1198 * Defines all module in a configuration to the runtime.
1199 *
1200 * @return a map of module name to runtime {@code Module}
1201 *
1202 * @throws IllegalArgumentException
1203 * If the function maps a module to the null or platform class loader
1204 * @throws IllegalStateException
1205 * If the module cannot be defined to the VM or its packages overlap
1206 * with another module mapped to the same class loader
1207 */
1208 static Map<String, Module> defineModules(Configuration cf,
1209 Function<String, ClassLoader> clf,
1210 ModuleLayer layer)
1211 {
1212 boolean isBootLayer = (ModuleLayer.boot() == null);
1213
1214 int numModules = cf.modules().size();
1215 Map<String, Module> nameToModule = HashMap.newHashMap(numModules);
1216
1217 // to avoid repeated lookups and reduce iteration overhead, we create
1218 // arrays holding correlated information about each module.
1219 ResolvedModule[] resolvedModules = new ResolvedModule[numModules];
1220 Module[] modules = new Module[numModules];
1221 ClassLoader[] classLoaders = new ClassLoader[numModules];
1222
1223 resolvedModules = cf.modules().toArray(resolvedModules);
1224
1225 // record that we want to bind the layer to non-boot and non-platform
1226 // module loaders as a final step
1227 HashSet<ClassLoader> toBindLoaders = new HashSet<>(4);
1228 boolean hasPlatformModules = false;
1229
1230 // map each module to a class loader
1231 ClassLoader pcl = ClassLoaders.platformClassLoader();
1232 boolean isModuleLoaderMapper = ModuleLoaderMap.isBuiltinMapper(clf);
1233
1234 for (int index = 0; index < numModules; index++) {
1235 String name = resolvedModules[index].name();
1236 ClassLoader loader = clf.apply(name);
1237
1238 if (loader == null || loader == pcl) {
1239 if (!isModuleLoaderMapper) {
1240 throw new IllegalArgumentException("loader can't be 'null'"
1241 + " or the platform class loader");
1242 }
1243 hasPlatformModules = true;
1244 } else {
1245 toBindLoaders.add(loader);
1246 }
1247
1248 classLoaders[index] = loader;
1249 }
1250
1251 // define each module in the configuration to the VM
1252 for (int index = 0; index < numModules; index++) {
1253 ModuleReference mref = resolvedModules[index].reference();
1254 ModuleDescriptor descriptor = mref.descriptor();
1255 String name = descriptor.name();
1256 ClassLoader loader = classLoaders[index];
1257 Module m;
1258 if (loader == null && name.equals("java.base")) {
1259 // java.base is already defined to the VM
1260 m = Object.class.getModule();
1261 } else {
1262 URI uri = mref.location().orElse(null);
1263 m = new Module(layer, loader, descriptor, uri);
1264 }
1265 nameToModule.put(name, m);
1266 modules[index] = m;
1267 }
1268
1269 // setup readability and exports/opens
1270 for (int index = 0; index < numModules; index++) {
1271 ResolvedModule resolvedModule = resolvedModules[index];
1272 ModuleReference mref = resolvedModule.reference();
1273 ModuleDescriptor descriptor = mref.descriptor();
1274 Module m = modules[index];
1275
1276 // reads
1277 Set<Module> reads = new HashSet<>();
1278
1279 // name -> source Module when in parent layer
1280 Map<String, Module> nameToSource = Map.of();
1281
1282 for (ResolvedModule other : resolvedModule.reads()) {
1283 Module m2 = null;
1284 if (other.configuration() == cf) {
1285 // this configuration
1286 m2 = nameToModule.get(other.name());
1287 assert m2 != null;
1288 } else {
1289 // parent layer
1290 for (ModuleLayer parent: layer.parents()) {
1291 m2 = findModule(parent, other);
1292 if (m2 != null)
1293 break;
1294 }
1295 assert m2 != null;
1296 if (nameToSource.isEmpty())
1297 nameToSource = new HashMap<>();
1298 nameToSource.put(other.name(), m2);
1299 }
1300 reads.add(m2);
1301
1302 // update VM view
1303 addReads0(m, m2);
1304 }
1305 m.reads = reads;
1306
1307 // automatic modules read all unnamed modules
1308 if (descriptor.isAutomatic()) {
1309 m.implAddReads(ALL_UNNAMED_MODULE, true);
1310 }
1311
1312 // exports and opens, skipped for open and automatic
1313 if (!descriptor.isOpen() && !descriptor.isAutomatic()) {
1314 if (isBootLayer && descriptor.opens().isEmpty()) {
1315 // no open packages, no qualified exports to modules in parent layers
1316 initExports(m, nameToModule);
1317 } else {
1318 initExportsAndOpens(m, nameToSource, nameToModule, layer.parents());
1319 }
1320 }
1321 }
1322
1323 // if there are modules defined to the boot or platform class loaders
1324 // then register the modules in the class loader's services catalog
1325 if (hasPlatformModules) {
1326 ServicesCatalog bootCatalog = BootLoader.getServicesCatalog();
1327 ServicesCatalog pclCatalog = ServicesCatalog.getServicesCatalog(pcl);
1328 for (int index = 0; index < numModules; index++) {
1329 ResolvedModule resolvedModule = resolvedModules[index];
1330 ModuleReference mref = resolvedModule.reference();
1331 ModuleDescriptor descriptor = mref.descriptor();
1332 if (!descriptor.provides().isEmpty()) {
1333 Module m = modules[index];
1334 ClassLoader loader = classLoaders[index];
1335 if (loader == null) {
1336 bootCatalog.register(m);
1337 } else if (loader == pcl) {
1338 pclCatalog.register(m);
1339 }
1340 }
1341 }
1342 }
1343
1344 // record that there is a layer with modules defined to the class loader
1345 for (ClassLoader loader : toBindLoaders) {
1346 layer.bindToLoader(loader);
1347 }
1348
1349 return nameToModule;
1350 }
1351
1352 /**
1353 * Find the runtime Module corresponding to the given ResolvedModule
1354 * in the given parent layer (or its parents).
1355 */
1356 private static Module findModule(ModuleLayer parent,
1357 ResolvedModule resolvedModule) {
1358 Configuration cf = resolvedModule.configuration();
1359 String dn = resolvedModule.name();
1360 return parent.layers()
1361 .filter(l -> l.configuration() == cf)
1362 .findAny()
1363 .map(layer -> {
1364 Optional<Module> om = layer.findModule(dn);
1365 assert om.isPresent() : dn + " not found in layer";
1366 Module m = om.get();
1367 assert m.getLayer() == layer : m + " not in expected layer";
1368 return m;
1369 })
1370 .orElse(null);
1371 }
1372
1373 /**
1374 * Initialize/setup a module's exports.
1375 *
1376 * @param m the module
1377 * @param nameToModule map of module name to Module (for qualified exports)
1378 */
1379 private static void initExports(Module m, Map<String, Module> nameToModule) {
1380 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1381
1382 for (Exports exports : m.getDescriptor().exports()) {
1383 String source = exports.source();
1384 if (exports.isQualified()) {
1385 // qualified exports
1386 Set<Module> targets = new HashSet<>();
1387 for (String target : exports.targets()) {
1388 Module m2 = nameToModule.get(target);
1389 if (m2 != null) {
1390 addExports0(m, source, m2);
1391 targets.add(m2);
1392 }
1393 }
1394 if (!targets.isEmpty()) {
1395 exportedPackages.put(source, targets);
1396 }
1397 } else {
1398 // unqualified exports
1399 addExportsToAll0(m, source);
1400 exportedPackages.put(source, EVERYONE_SET);
1401 }
1402 }
1403
1404 if (!exportedPackages.isEmpty())
1405 m.exportedPackages = exportedPackages;
1406 }
1407
1408 /**
1409 * Initialize/setup a module's exports.
1410 *
1411 * @param m the module
1412 * @param nameToSource map of module name to Module for modules that m reads
1413 * @param nameToModule map of module name to Module for modules in the layer
1414 * under construction
1415 * @param parents the parent layers
1416 */
1417 private static void initExportsAndOpens(Module m,
1418 Map<String, Module> nameToSource,
1419 Map<String, Module> nameToModule,
1420 List<ModuleLayer> parents) {
1421 ModuleDescriptor descriptor = m.getDescriptor();
1422 Map<String, Set<Module>> openPackages = new HashMap<>();
1423 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1424
1425 // process the open packages first
1426 for (Opens opens : descriptor.opens()) {
1427 String source = opens.source();
1428
1429 if (opens.isQualified()) {
1430 // qualified opens
1431 Set<Module> targets = new HashSet<>();
1432 for (String target : opens.targets()) {
1433 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1434 if (m2 != null) {
1435 addExports0(m, source, m2);
1436 targets.add(m2);
1437 }
1438 }
1439 if (!targets.isEmpty()) {
1440 openPackages.put(source, targets);
1441 }
1442 } else {
1443 // unqualified opens
1444 addExportsToAll0(m, source);
1445 openPackages.put(source, EVERYONE_SET);
1446 }
1447 }
1448
1449 // next the exports, skipping exports when the package is open
1450 for (Exports exports : descriptor.exports()) {
1451 String source = exports.source();
1452
1453 // skip export if package is already open to everyone
1454 Set<Module> openToTargets = openPackages.get(source);
1455 if (openToTargets != null && openToTargets.contains(EVERYONE_MODULE))
1456 continue;
1457
1458 if (exports.isQualified()) {
1459 // qualified exports
1460 Set<Module> targets = new HashSet<>();
1461 for (String target : exports.targets()) {
1462 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1463 if (m2 != null) {
1464 // skip qualified export if already open to m2
1465 if (openToTargets == null || !openToTargets.contains(m2)) {
1466 addExports0(m, source, m2);
1467 targets.add(m2);
1468 }
1469 }
1470 }
1471 if (!targets.isEmpty()) {
1472 exportedPackages.put(source, targets);
1473 }
1474 } else {
1475 // unqualified exports
1476 addExportsToAll0(m, source);
1477 exportedPackages.put(source, EVERYONE_SET);
1478 }
1479 }
1480
1481 if (!openPackages.isEmpty())
1482 m.openPackages = openPackages;
1483 if (!exportedPackages.isEmpty())
1484 m.exportedPackages = exportedPackages;
1485 }
1486
1487 /**
1488 * Find the runtime Module with the given name. The module name is the
1489 * name of a target module in a qualified exports or opens directive.
1490 *
1491 * @param target The target module to find
1492 * @param nameToSource The modules in parent layers that are read
1493 * @param nameToModule The modules in the layer under construction
1494 * @param parents The parent layers
1495 */
1496 private static Module findModule(String target,
1497 Map<String, Module> nameToSource,
1498 Map<String, Module> nameToModule,
1499 List<ModuleLayer> parents) {
1500 Module m = nameToSource.get(target);
1501 if (m == null) {
1502 m = nameToModule.get(target);
1503 if (m == null) {
1504 for (ModuleLayer parent : parents) {
1505 m = parent.findModule(target).orElse(null);
1506 if (m != null) break;
1507 }
1508 }
1509 }
1510 return m;
1511 }
1512
1513
1514 // -- annotations --
1515
1516 /**
1517 * {@inheritDoc}
1518 * This method returns {@code null} when invoked on an unnamed module.
1519 *
1520 * <p> Note that any annotation returned by this method is a
1521 * declaration annotation.
1522 */
1523 @Override
1524 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
1525 return moduleInfoClass().getDeclaredAnnotation(annotationClass);
1526 }
1527
1528 /**
1529 * {@inheritDoc}
1530 * This method returns an empty array when invoked on an unnamed module.
1531 *
1532 * <p> Note that any annotations returned by this method are
1533 * declaration annotations.
1534 */
1535 @Override
1536 public Annotation[] getAnnotations() {
1537 return moduleInfoClass().getAnnotations();
1538 }
1539
1540 /**
1541 * {@inheritDoc}
1542 * This method returns an empty array when invoked on an unnamed module.
1543 *
1544 * <p> Note that any annotations returned by this method are
1545 * declaration annotations.
1546 */
1547 @Override
1548 public Annotation[] getDeclaredAnnotations() {
1549 return moduleInfoClass().getDeclaredAnnotations();
1550 }
1551
1552 // cached class file with annotations
1553 private volatile Class<?> moduleInfoClass;
1554
1555 @SuppressWarnings("removal")
1556 private Class<?> moduleInfoClass() {
1557 Class<?> clazz = this.moduleInfoClass;
1558 if (clazz != null)
1559 return clazz;
1560
1561 synchronized (this) {
1562 clazz = this.moduleInfoClass;
1563 if (clazz == null) {
1564 if (isNamed()) {
1565 PrivilegedAction<Class<?>> pa = this::loadModuleInfoClass;
1566 clazz = AccessController.doPrivileged(pa);
1567 }
1568 if (clazz == null) {
1569 class DummyModuleInfo { }
1570 clazz = DummyModuleInfo.class;
1571 }
1572 this.moduleInfoClass = clazz;
1573 }
1574 return clazz;
1575 }
1576 }
1577
1578 private Class<?> loadModuleInfoClass() {
1579 Class<?> clazz = null;
1580 try (InputStream in = getResourceAsStream("module-info.class")) {
1581 if (in != null)
1582 clazz = loadModuleInfoClass(in);
1583 } catch (Exception ignore) { }
1584 return clazz;
1585 }
1586
1587 /**
1588 * Loads module-info.class as a package-private interface in a class loader
1589 * that is a child of this module's class loader.
1590 */
1591 private Class<?> loadModuleInfoClass(InputStream in) throws IOException {
1592 final String MODULE_INFO = "module-info";
1593 var cc = Classfile.of(Classfile.ConstantPoolSharingOption.NEW_POOL);
1594 byte[] bytes = cc.transform(cc.parse(in.readAllBytes()), (clb, cle) -> {
1595 switch (cle) {
1596 case AccessFlags af -> clb.withFlags(AccessFlag.INTERFACE,
1597 AccessFlag.ABSTRACT, AccessFlag.SYNTHETIC);
1598 // keep annotations
1599 case RuntimeVisibleAnnotationsAttribute a -> clb.with(a);
1600 // drop non-annotation attributes
1601 case Attribute<?> a -> {}
1602 default -> clb.with(cle);
1603 }});
1604 ClassLoader cl = new ClassLoader(loader) {
1605 @Override
1606 protected Class<?> findClass(String cn)throws ClassNotFoundException {
1607 if (cn.equals(MODULE_INFO)) {
1608 return super.defineClass(cn, bytes, 0, bytes.length);
1609 } else {
1610 throw new ClassNotFoundException(cn);
1611 }
1612 }
1613 @Override
1614 protected Class<?> loadClass(String cn, boolean resolve)
1615 throws ClassNotFoundException
1616 {
1617 synchronized (getClassLoadingLock(cn)) {
1618 Class<?> c = findLoadedClass(cn);
1619 if (c == null) {
1620 if (cn.equals(MODULE_INFO)) {
1621 c = findClass(cn);
1622 } else {
1623 c = super.loadClass(cn, resolve);
1624 }
1625 }
1626 if (resolve)
1627 resolveClass(c);
1628 return c;
1629 }
1630 }
1631 };
1632
1633 try {
1634 return cl.loadClass(MODULE_INFO);
1635 } catch (ClassNotFoundException e) {
1636 throw new InternalError(e);
1637 }
1638 }
1639
1640
1641 // -- misc --
1642
1643
1644 /**
1645 * Returns an input stream for reading a resource in this module.
1646 * The {@code name} parameter is a {@code '/'}-separated path name that
1647 * identifies the resource. As with {@link Class#getResourceAsStream
1648 * Class.getResourceAsStream}, this method delegates to the module's class
1649 * loader {@link ClassLoader#findResource(String,String)
1650 * findResource(String,String)} method, invoking it with the module name
1651 * (or {@code null} when the module is unnamed) and the name of the
1652 * resource. If the resource name has a leading slash then it is dropped
1653 * before delegation.
1654 *
1655 * <p> A resource in a named module may be <em>encapsulated</em> so that
1656 * it cannot be located by code in other modules. Whether a resource can be
1657 * located or not is determined as follows: </p>
1658 *
1659 * <ul>
1660 * <li> If the resource name ends with "{@code .class}" then it is not
1661 * encapsulated. </li>
1662 *
1663 * <li> A <em>package name</em> is derived from the resource name. If
1664 * the package name is a {@linkplain #getPackages() package} in the
1665 * module then the resource can only be located by the caller of this
1666 * method when the package is {@linkplain #isOpen(String,Module) open}
1667 * to at least the caller's module. If the resource is not in a
1668 * package in the module then the resource is not encapsulated. </li>
1669 * </ul>
1670 *
1671 * <p> In the above, the <em>package name</em> for a resource is derived
1672 * from the subsequence of characters that precedes the last {@code '/'} in
1673 * the name and then replacing each {@code '/'} character in the subsequence
1674 * with {@code '.'}. A leading slash is ignored when deriving the package
1675 * name. As an example, the package name derived for a resource named
1676 * "{@code a/b/c/foo.properties}" is "{@code a.b.c}". A resource name
1677 * with the name "{@code META-INF/MANIFEST.MF}" is never encapsulated
1678 * because "{@code META-INF}" is not a legal package name. </p>
1679 *
1680 * <p> This method returns {@code null} if the resource is not in this
1681 * module, the resource is encapsulated and cannot be located by the caller,
1682 * or access to the resource is denied by the security manager. </p>
1683 *
1684 * @param name
1685 * The resource name
1686 *
1687 * @return An input stream for reading the resource or {@code null}
1688 *
1689 * @throws IOException
1690 * If an I/O error occurs
1691 *
1692 * @see Class#getResourceAsStream(String)
1693 */
1694 @CallerSensitive
1695 public InputStream getResourceAsStream(String name) throws IOException {
1696 if (name.startsWith("/")) {
1697 name = name.substring(1);
1698 }
1699
1700 if (isNamed() && Resources.canEncapsulate(name)) {
1701 Module caller = getCallerModule(Reflection.getCallerClass());
1702 if (caller != this && caller != Object.class.getModule()) {
1703 String pn = Resources.toPackageName(name);
1704 if (getPackages().contains(pn)) {
1705 if (caller == null) {
1706 if (!isOpen(pn)) {
1707 return null;
1708 }
1709 } else if (!isOpen(pn, caller)) {
1710 // package not open to caller
1711 return null;
1712 }
1713 }
1714 }
1715 }
1716
1717 String mn = this.name;
1718
1719 // special-case built-in class loaders to avoid URL connection
1720 if (loader == null) {
1721 return BootLoader.findResourceAsStream(mn, name);
1722 } else if (loader instanceof BuiltinClassLoader) {
1723 return ((BuiltinClassLoader) loader).findResourceAsStream(mn, name);
1724 }
1725
1726 // locate resource in module
1727 URL url = loader.findResource(mn, name);
1728 if (url != null) {
1729 try {
1730 return url.openStream();
1731 } catch (SecurityException e) { }
1732 }
1733
1734 return null;
1735 }
1736
1737 /**
1738 * Returns the string representation of this module. For a named module,
1739 * the representation is the string {@code "module"}, followed by a space,
1740 * and then the module name. For an unnamed module, the representation is
1741 * the string {@code "unnamed module"}, followed by a space, and then an
1742 * implementation specific string that identifies the unnamed module.
1743 *
1744 * @return The string representation of this module
1745 */
1746 @Override
1747 public String toString() {
1748 if (isNamed()) {
1749 return "module " + name;
1750 } else {
1751 String id = Integer.toHexString(System.identityHashCode(this));
1752 return "unnamed module @" + id;
1753 }
1754 }
1755
1756 /**
1757 * Returns the module that a given caller class is a member of. Returns
1758 * {@code null} if the caller is {@code null}.
1759 */
1760 private Module getCallerModule(Class<?> caller) {
1761 return (caller != null) ? caller.getModule() : null;
1762 }
1763
1764
1765 // -- native methods --
1766
1767 // JVM_DefineModule
1768 private static native void defineModule0(Module module,
1769 boolean isOpen,
1770 String version,
1771 String location,
1772 Object[] pns);
1773
1774 // JVM_AddReadsModule
1775 private static native void addReads0(Module from, Module to);
1776
1777 // JVM_AddModuleExports
1778 private static native void addExports0(Module from, String pn, Module to);
1779
1780 // JVM_AddModuleExportsToAll
1781 private static native void addExportsToAll0(Module from, String pn);
1782
1783 // JVM_AddModuleExportsToAllUnnamed
1784 private static native void addExportsToAllUnnamed0(Module from, String pn);
1785 }