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 22
276 */
277 public boolean isNativeAccessEnabled() {
278 Module target = moduleForNativeAccess();
279 return EnableNativeAccess.isNativeAccessEnabled(target);
280 }
281
282 /**
283 * This class is used to be able to bootstrap without using Unsafe
284 * in the outer Module class as that would create a circular initializer dependency.
285 */
286 private static final class EnableNativeAccess {
287
288 private EnableNativeAccess() {}
289
290 private static final Unsafe UNSAFE = Unsafe.getUnsafe();
291 private static final long FIELD_OFFSET = UNSAFE.objectFieldOffset(Module.class, "enableNativeAccess");
292
293 private static boolean isNativeAccessEnabled(Module target) {
294 return UNSAFE.getBooleanVolatile(target, FIELD_OFFSET);
295 }
296
297 // Atomically sets enableNativeAccess if not already set
298 // returning if the value was updated
299 private static boolean trySetEnableNativeAccess(Module target) {
300 return UNSAFE.compareAndSetBoolean(target, FIELD_OFFSET, false, true);
301 }
302 }
303
304 // Returns the Module object that holds the enableNativeAccess
305 // flag for this module.
306 private Module moduleForNativeAccess() {
307 return isNamed() ? this : ALL_UNNAMED_MODULE;
308 }
309
310 // This is invoked from Reflection.ensureNativeAccess
311 void ensureNativeAccess(Class<?> owner, String methodName, Class<?> currentClass) {
312 // The target module whose enableNativeAccess flag is ensured
313 Module target = moduleForNativeAccess();
314 if (!EnableNativeAccess.isNativeAccessEnabled(target)) {
315 if (ModuleBootstrap.hasEnableNativeAccessFlag()) {
316 throw new IllegalCallerException("Illegal native access from: " + this);
317 }
318 if (EnableNativeAccess.trySetEnableNativeAccess(target)) {
319 // warn and set flag, so that only one warning is reported per module
320 String cls = owner.getName();
321 String mtd = cls + "::" + methodName;
322 String mod = isNamed() ? "module " + getName() : "an unnamed module";
323 String modflag = isNamed() ? getName() : "ALL-UNNAMED";
324 String caller = currentClass != null ?
325 " by " + currentClass.getName() : "";
326 System.err.printf("""
327 WARNING: A restricted method in %s has been called
328 WARNING: %s has been called%s in %s
329 WARNING: Use --enable-native-access=%s to avoid a warning for callers in this module
330 WARNING: Restricted methods will be blocked in a future release unless native access is enabled
331 %n""", cls, mtd, caller, mod, modflag);
332 }
333 }
334 }
335
336 /**
337 * Update all unnamed modules to allow access to restricted methods.
338 */
339 static void implAddEnableNativeAccessToAllUnnamed() {
340 EnableNativeAccess.trySetEnableNativeAccess(ALL_UNNAMED_MODULE);
341 }
342
343 // --
344
345 // special Module to mean "all unnamed modules"
346 private static final Module ALL_UNNAMED_MODULE;
347 private static final Set<Module> ALL_UNNAMED_MODULE_SET;
348
349 // special Module to mean "everyone"
350 private static final Module EVERYONE_MODULE;
351 private static final Set<Module> EVERYONE_SET;
352
353 private static class ArchivedData {
354 private static ArchivedData archivedData;
355 private final Module allUnnamedModule;
356 private final Set<Module> allUnnamedModules;
357 private final Module everyoneModule;
358 private final Set<Module> everyoneSet;
359
360 private ArchivedData() {
361 this.allUnnamedModule = ALL_UNNAMED_MODULE;
362 this.allUnnamedModules = ALL_UNNAMED_MODULE_SET;
363 this.everyoneModule = EVERYONE_MODULE;
364 this.everyoneSet = EVERYONE_SET;
365 }
366
367 static void archive() {
368 archivedData = new ArchivedData();
369 }
370
371 static ArchivedData get() {
372 return archivedData;
373 }
374
375 static {
376 CDS.initializeFromArchive(ArchivedData.class);
377 }
378 }
379
380 static {
381 ArchivedData archivedData = ArchivedData.get();
382 if (archivedData != null) {
383 ALL_UNNAMED_MODULE = archivedData.allUnnamedModule;
384 ALL_UNNAMED_MODULE_SET = archivedData.allUnnamedModules;
385 EVERYONE_MODULE = archivedData.everyoneModule;
386 EVERYONE_SET = archivedData.everyoneSet;
387 } else {
388 ALL_UNNAMED_MODULE = new Module(null);
389 ALL_UNNAMED_MODULE_SET = Set.of(ALL_UNNAMED_MODULE);
390 EVERYONE_MODULE = new Module(null);
391 EVERYONE_SET = Set.of(EVERYONE_MODULE);
392 ArchivedData.archive();
393 }
394 }
395
396 /**
397 * The holder of data structures to support readability, exports, and
398 * service use added at runtime with the reflective APIs.
399 */
400 private static class ReflectionData {
401 /**
402 * A module (1st key) reads another module (2nd key)
403 */
404 static final WeakPairMap<Module, Module, Boolean> reads =
405 new WeakPairMap<>();
406
407 /**
408 * A module (1st key) exports or opens a package to another module
409 * (2nd key). The map value is a map of package name to a boolean
410 * that indicates if the package is opened.
411 */
412 static final WeakPairMap<Module, Module, Map<String, Boolean>> exports =
413 new WeakPairMap<>();
414
415 /**
416 * A module (1st key) uses a service (2nd key)
417 */
418 static final WeakPairMap<Module, Class<?>, Boolean> uses =
419 new WeakPairMap<>();
420 }
421
422
423 // -- readability --
424
425 // the modules that this module reads
426 private volatile Set<Module> reads;
427
428 /**
429 * Indicates if this module reads the given module. This method returns
430 * {@code true} if invoked to test if this module reads itself. It also
431 * returns {@code true} if invoked on an unnamed module (as unnamed
432 * modules read all modules).
433 *
434 * @param other
435 * The other module
436 *
437 * @return {@code true} if this module reads {@code other}
438 *
439 * @see #addReads(Module)
440 */
441 public boolean canRead(Module other) {
442 Objects.requireNonNull(other);
443
444 // an unnamed module reads all modules
445 if (!this.isNamed())
446 return true;
447
448 // all modules read themselves
449 if (other == this)
450 return true;
451
452 // check if this module reads other
453 if (other.isNamed()) {
454 Set<Module> reads = this.reads; // volatile read
455 if (reads != null && reads.contains(other))
456 return true;
457 }
458
459 // check if this module reads the other module reflectively
460 if (ReflectionData.reads.containsKeyPair(this, other))
461 return true;
462
463 // if other is an unnamed module then check if this module reads
464 // all unnamed modules
465 if (!other.isNamed()
466 && ReflectionData.reads.containsKeyPair(this, ALL_UNNAMED_MODULE))
467 return true;
468
469 return false;
470 }
471
472 /**
473 * If the caller's module is this module then update this module to read
474 * the given module.
475 *
476 * This method is a no-op if {@code other} is this module (all modules read
477 * themselves), this module is an unnamed module (as unnamed modules read
478 * all modules), or this module already reads {@code other}.
479 *
480 * @implNote <em>Read edges</em> added by this method are <em>weak</em> and
481 * do not prevent {@code other} from being GC'ed when this module is
482 * strongly reachable.
483 *
484 * @param other
485 * The other module
486 *
487 * @return this module
488 *
489 * @throws IllegalCallerException
490 * If this is a named module and the caller's module is not this
491 * module
492 *
493 * @see #canRead
494 */
495 @CallerSensitive
496 public Module addReads(Module other) {
497 Objects.requireNonNull(other);
498 if (this.isNamed()) {
499 Module caller = getCallerModule(Reflection.getCallerClass());
500 if (caller != this) {
501 throw new IllegalCallerException(caller + " != " + this);
502 }
503 implAddReads(other, true);
504 }
505 return this;
506 }
507
508 /**
509 * Updates this module to read another module.
510 *
511 * @apiNote Used by the --add-reads command line option.
512 */
513 void implAddReads(Module other) {
514 implAddReads(other, true);
515 }
516
517 /**
518 * Updates this module to read all unnamed modules.
519 *
520 * @apiNote Used by the --add-reads command line option.
521 */
522 void implAddReadsAllUnnamed() {
523 implAddReads(Module.ALL_UNNAMED_MODULE, true);
524 }
525
526 /**
527 * Updates this module to read another module without notifying the VM.
528 *
529 * @apiNote This method is for VM white-box testing.
530 */
531 void implAddReadsNoSync(Module other) {
532 implAddReads(other, false);
533 }
534
535 /**
536 * Makes the given {@code Module} readable to this module.
537 *
538 * If {@code syncVM} is {@code true} then the VM is notified.
539 */
540 private void implAddReads(Module other, boolean syncVM) {
541 Objects.requireNonNull(other);
542 if (!canRead(other)) {
543 // update VM first, just in case it fails
544 if (syncVM) {
545 if (other == ALL_UNNAMED_MODULE) {
546 addReads0(this, null);
547 } else {
548 addReads0(this, other);
549 }
550 }
551
552 // add reflective read
553 ReflectionData.reads.putIfAbsent(this, other, Boolean.TRUE);
554 }
555 }
556
557
558 // -- exported and open packages --
559
560 // the packages are open to other modules, can be null
561 // if the value contains EVERYONE_MODULE then the package is open to all
562 private volatile Map<String, Set<Module>> openPackages;
563
564 // the packages that are exported, can be null
565 // if the value contains EVERYONE_MODULE then the package is exported to all
566 private volatile Map<String, Set<Module>> exportedPackages;
567
568 /**
569 * Returns {@code true} if this module exports the given package to at
570 * least the given module.
571 *
572 * <p> This method returns {@code true} if invoked to test if a package in
573 * this module is exported to itself. It always returns {@code true} when
574 * invoked on an unnamed module. A package that is {@link #isOpen open} to
575 * the given module is considered exported to that module at run-time and
576 * so this method returns {@code true} if the package is open to the given
577 * module. </p>
578 *
579 * <p> This method does not check if the given module reads this module. </p>
580 *
581 * @param pn
582 * The package name
583 * @param other
584 * The other module
585 *
586 * @return {@code true} if this module exports the package to at least the
587 * given module
588 *
589 * @see ModuleDescriptor#exports()
590 * @see #addExports(String,Module)
591 */
592 public boolean isExported(String pn, Module other) {
593 Objects.requireNonNull(pn);
594 Objects.requireNonNull(other);
595 return implIsExportedOrOpen(pn, other, /*open*/false);
596 }
597
598 /**
599 * Returns {@code true} if this module has <em>opened</em> a package to at
600 * least the given module.
601 *
602 * <p> This method returns {@code true} if invoked to test if a package in
603 * this module is open to itself. It returns {@code true} when invoked on an
604 * {@link ModuleDescriptor#isOpen open} module with a package in the module.
605 * It always returns {@code true} when invoked on an unnamed module. </p>
606 *
607 * <p> This method does not check if the given module reads this module. </p>
608 *
609 * @apiNote A package {@code p} opened to module {@code M} allows code in
610 * {@code M} do {@linkplain java.lang.reflect.AccessibleObject#setAccessible(boolean)
611 * deep reflection} on all types in the package.
612 * Further, if {@code M} reads this module, it can obtain a
613 * {@link java.lang.invoke.MethodHandles.Lookup Lookup} object that is allowed to
614 * {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[]) define classes}
615 * in package {@code p}.
616 *
617 * @param pn
618 * The package name
619 * @param other
620 * The other module
621 *
622 * @return {@code true} if this module has <em>opened</em> the package
623 * to at least the given module
624 *
625 * @see ModuleDescriptor#opens()
626 * @see #addOpens(String,Module)
627 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
628 * @see java.lang.invoke.MethodHandles#privateLookupIn
629 */
630 public boolean isOpen(String pn, Module other) {
631 Objects.requireNonNull(pn);
632 Objects.requireNonNull(other);
633 return implIsExportedOrOpen(pn, other, /*open*/true);
634 }
635
636 /**
637 * Returns {@code true} if this module exports the given package
638 * unconditionally.
639 *
640 * <p> This method always returns {@code true} when invoked on an unnamed
641 * module. A package that is {@link #isOpen(String) opened} unconditionally
642 * is considered exported unconditionally at run-time and so this method
643 * returns {@code true} if the package is opened unconditionally. </p>
644 *
645 * <p> This method does not check if the given module reads this module. </p>
646 *
647 * @param pn
648 * The package name
649 *
650 * @return {@code true} if this module exports the package unconditionally
651 *
652 * @see ModuleDescriptor#exports()
653 */
654 public boolean isExported(String pn) {
655 Objects.requireNonNull(pn);
656 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/false);
657 }
658
659 /**
660 * Returns {@code true} if this module has <em>opened</em> a package
661 * unconditionally.
662 *
663 * <p> This method always returns {@code true} when invoked on an unnamed
664 * module. Additionally, it always returns {@code true} when invoked on an
665 * {@link ModuleDescriptor#isOpen open} module with a package in the
666 * module. </p>
667 *
668 * <p> This method does not check if the given module reads this module. </p>
669 *
670 * @apiNote A package {@code p} opened to module {@code M} allows code in
671 * {@code M} do {@linkplain java.lang.reflect.AccessibleObject#setAccessible(boolean)
672 * deep reflection} on all types in the package.
673 * Further, if {@code M} reads this module, it can obtain a
674 * {@link java.lang.invoke.MethodHandles.Lookup Lookup} object that is allowed to
675 * {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[]) define classes}
676 * in package {@code p}.
677 *
678 * @param pn
679 * The package name
680 *
681 * @return {@code true} if this module has <em>opened</em> the package
682 * unconditionally
683 *
684 * @see ModuleDescriptor#opens()
685 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
686 * @see java.lang.invoke.MethodHandles#privateLookupIn
687 */
688 public boolean isOpen(String pn) {
689 Objects.requireNonNull(pn);
690 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/true);
691 }
692
693
694 /**
695 * Returns {@code true} if this module exports or opens the given package
696 * to the given module. If the other module is {@code EVERYONE_MODULE} then
697 * this method tests if the package is exported or opened unconditionally.
698 */
699 private boolean implIsExportedOrOpen(String pn, Module other, boolean open) {
700 // all packages in unnamed modules are open
701 if (!isNamed())
702 return true;
703
704 // all packages are exported/open to self
705 if (other == this && descriptor.packages().contains(pn))
706 return true;
707
708 // all packages in open and automatic modules are open
709 if (descriptor.isOpen() || descriptor.isAutomatic())
710 return descriptor.packages().contains(pn);
711
712 // exported/opened via module declaration/descriptor
713 if (isStaticallyExportedOrOpen(pn, other, open))
714 return true;
715
716 // exported via addExports/addOpens
717 if (isReflectivelyExportedOrOpen(pn, other, open))
718 return true;
719
720 // not exported or open to other
721 return false;
722 }
723
724 /**
725 * Returns {@code true} if this module exports or opens a package to
726 * the given module via its module declaration or CLI options.
727 */
728 private boolean isStaticallyExportedOrOpen(String pn, Module other, boolean open) {
729 // test if package is open to everyone or <other>
730 Map<String, Set<Module>> openPackages = this.openPackages;
731 if (openPackages != null && allows(openPackages.get(pn), other)) {
732 return true;
733 }
734
735 if (!open) {
736 // test package is exported to everyone or <other>
737 Map<String, Set<Module>> exportedPackages = this.exportedPackages;
738 if (exportedPackages != null && allows(exportedPackages.get(pn), other)) {
739 return true;
740 }
741 }
742
743 return false;
744 }
745
746 /**
747 * Returns {@code true} if targets is non-null and contains EVERYONE_MODULE
748 * or the given module. Also returns true if the given module is an unnamed
749 * module and targets contains ALL_UNNAMED_MODULE.
750 */
751 private boolean allows(Set<Module> targets, Module module) {
752 if (targets != null) {
753 if (targets.contains(EVERYONE_MODULE))
754 return true;
755 if (module != EVERYONE_MODULE) {
756 if (targets.contains(module))
757 return true;
758 if (!module.isNamed() && targets.contains(ALL_UNNAMED_MODULE))
759 return true;
760 }
761 }
762 return false;
763 }
764
765 /**
766 * Returns {@code true} if this module reflectively exports or opens the
767 * given package to the given module.
768 */
769 private boolean isReflectivelyExportedOrOpen(String pn, Module other, boolean open) {
770 // exported or open to all modules
771 Map<String, Boolean> exports = ReflectionData.exports.get(this, EVERYONE_MODULE);
772 if (exports != null) {
773 Boolean b = exports.get(pn);
774 if (b != null) {
775 boolean isOpen = b.booleanValue();
776 if (!open || isOpen) return true;
777 }
778 }
779
780 if (other != EVERYONE_MODULE) {
781
782 // exported or open to other
783 exports = ReflectionData.exports.get(this, other);
784 if (exports != null) {
785 Boolean b = exports.get(pn);
786 if (b != null) {
787 boolean isOpen = b.booleanValue();
788 if (!open || isOpen) return true;
789 }
790 }
791
792 // other is an unnamed module && exported or open to all unnamed
793 if (!other.isNamed()) {
794 exports = ReflectionData.exports.get(this, ALL_UNNAMED_MODULE);
795 if (exports != null) {
796 Boolean b = exports.get(pn);
797 if (b != null) {
798 boolean isOpen = b.booleanValue();
799 if (!open || isOpen) return true;
800 }
801 }
802 }
803
804 }
805
806 return false;
807 }
808
809 /**
810 * Returns {@code true} if this module reflectively exports the
811 * given package to the given module.
812 */
813 boolean isReflectivelyExported(String pn, Module other) {
814 return isReflectivelyExportedOrOpen(pn, other, false);
815 }
816
817 /**
818 * Returns {@code true} if this module reflectively opens the
819 * given package to the given module.
820 */
821 boolean isReflectivelyOpened(String pn, Module other) {
822 return isReflectivelyExportedOrOpen(pn, other, true);
823 }
824
825
826 /**
827 * If the caller's module is this module then update this module to export
828 * the given package to the given module.
829 *
830 * <p> This method has no effect if the package is already exported (or
831 * <em>open</em>) to the given module. </p>
832 *
833 * @apiNote As specified in section {@jvms 5.4.3} of the <cite>The Java
834 * Virtual Machine Specification </cite>, if an attempt to resolve a
835 * symbolic reference fails because of a linkage error, then subsequent
836 * attempts to resolve the reference always fail with the same error that
837 * was thrown as a result of the initial resolution attempt.
838 *
839 * @param pn
840 * The package name
841 * @param other
842 * The module
843 *
844 * @return this module
845 *
846 * @throws IllegalArgumentException
847 * If {@code pn} is {@code null}, or this is a named module and the
848 * package {@code pn} is not a package in this module
849 * @throws IllegalCallerException
850 * If this is a named module and the caller's module is not this
851 * module
852 *
853 * @jvms 5.4.3 Resolution
854 * @see #isExported(String,Module)
855 */
856 @CallerSensitive
857 public Module addExports(String pn, Module other) {
858 if (pn == null)
859 throw new IllegalArgumentException("package is null");
860 Objects.requireNonNull(other);
861
862 if (isNamed()) {
863 Module caller = getCallerModule(Reflection.getCallerClass());
864 if (caller != this) {
865 throw new IllegalCallerException(caller + " != " + this);
866 }
867 implAddExportsOrOpens(pn, other, /*open*/false, /*syncVM*/true);
868 }
869
870 return this;
871 }
872
873 /**
874 * If this module has <em>opened</em> a package to at least the caller
875 * module then update this module to open the package to the given module.
876 * Opening a package with this method allows all types in the package,
877 * and all their members, not just public types and their public members,
878 * to be reflected on by the given module when using APIs that support
879 * private access or a way to bypass or suppress default Java language
880 * access control checks.
881 *
882 * <p> This method has no effect if the package is already <em>open</em>
883 * to the given module. </p>
884 *
885 * @apiNote This method can be used for cases where a <em>consumer
886 * module</em> uses a qualified opens to open a package to an <em>API
887 * module</em> but where the reflective access to the members of classes in
888 * the consumer module is delegated to code in another module. Code in the
889 * API module can use this method to open the package in the consumer module
890 * to the other module.
891 *
892 * @param pn
893 * The package name
894 * @param other
895 * The module
896 *
897 * @return this module
898 *
899 * @throws IllegalArgumentException
900 * If {@code pn} is {@code null}, or this is a named module and the
901 * package {@code pn} is not a package in this module
902 * @throws IllegalCallerException
903 * If this is a named module and this module has not opened the
904 * package to at least the caller's module
905 *
906 * @see #isOpen(String,Module)
907 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
908 * @see java.lang.invoke.MethodHandles#privateLookupIn
909 */
910 @CallerSensitive
911 public Module addOpens(String pn, Module other) {
912 if (pn == null)
913 throw new IllegalArgumentException("package is null");
914 Objects.requireNonNull(other);
915
916 if (isNamed()) {
917 Module caller = getCallerModule(Reflection.getCallerClass());
918 if (caller != this && (caller == null || !isOpen(pn, caller)))
919 throw new IllegalCallerException(pn + " is not open to " + caller);
920 implAddExportsOrOpens(pn, other, /*open*/true, /*syncVM*/true);
921 }
922
923 return this;
924 }
925
926
927 /**
928 * Updates this module to export a package unconditionally.
929 *
930 * @apiNote This method is for JDK tests only.
931 */
932 void implAddExports(String pn) {
933 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, false, true);
934 }
935
936 /**
937 * Updates this module to export a package to another module.
938 *
939 * @apiNote Used by Instrumentation::redefineModule and --add-exports
940 */
941 void implAddExports(String pn, Module other) {
942 implAddExportsOrOpens(pn, other, false, true);
943 }
944
945 /**
946 * Updates this module to export a package to all unnamed modules.
947 *
948 * @apiNote Used by the --add-exports command line option.
949 */
950 void implAddExportsToAllUnnamed(String pn) {
951 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, false, true);
952 }
953
954 /**
955 * Updates this export to export a package unconditionally without
956 * notifying the VM.
957 *
958 * @apiNote This method is for VM white-box testing.
959 */
960 void implAddExportsNoSync(String pn) {
961 implAddExportsOrOpens(pn.replace('/', '.'), Module.EVERYONE_MODULE, false, false);
962 }
963
964 /**
965 * Updates a module to export a package to another module without
966 * notifying the VM.
967 *
968 * @apiNote This method is for VM white-box testing.
969 */
970 void implAddExportsNoSync(String pn, Module other) {
971 implAddExportsOrOpens(pn.replace('/', '.'), other, false, false);
972 }
973
974 /**
975 * Updates this module to open a package unconditionally.
976 *
977 * @apiNote This method is for JDK tests only.
978 */
979 void implAddOpens(String pn) {
980 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, true, true);
981 }
982
983 /**
984 * Updates this module to open a package to another module.
985 *
986 * @apiNote Used by Instrumentation::redefineModule and --add-opens
987 */
988 void implAddOpens(String pn, Module other) {
989 implAddExportsOrOpens(pn, other, true, true);
990 }
991
992 /**
993 * Updates this module to open a package to all unnamed modules.
994 *
995 * @apiNote Used by the --add-opens command line option.
996 */
997 void implAddOpensToAllUnnamed(String pn) {
998 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, true, true);
999 }
1000
1001 /**
1002 * Updates a module to export or open a module to another module.
1003 *
1004 * If {@code syncVM} is {@code true} then the VM is notified.
1005 */
1006 private void implAddExportsOrOpens(String pn,
1007 Module other,
1008 boolean open,
1009 boolean syncVM) {
1010 Objects.requireNonNull(other);
1011 Objects.requireNonNull(pn);
1012
1013 // all packages are open in unnamed, open, and automatic modules
1014 if (!isNamed() || descriptor.isOpen() || descriptor.isAutomatic())
1015 return;
1016
1017 // check if the package is already exported/open to other
1018 if (implIsExportedOrOpen(pn, other, open))
1019 return;
1020
1021 // can only export a package in the module
1022 if (!descriptor.packages().contains(pn)) {
1023 throw new IllegalArgumentException("package " + pn
1024 + " not in contents");
1025 }
1026
1027 // update VM first, just in case it fails
1028 if (syncVM) {
1029 if (other == EVERYONE_MODULE) {
1030 addExportsToAll0(this, pn);
1031 } else if (other == ALL_UNNAMED_MODULE) {
1032 addExportsToAllUnnamed0(this, pn);
1033 } else {
1034 addExports0(this, pn, other);
1035 }
1036 }
1037
1038 // add package name to exports if absent
1039 Map<String, Boolean> map = ReflectionData.exports
1040 .computeIfAbsent(this, other,
1041 (m1, m2) -> new ConcurrentHashMap<>());
1042 if (open) {
1043 map.put(pn, Boolean.TRUE); // may need to promote from FALSE to TRUE
1044 } else {
1045 map.putIfAbsent(pn, Boolean.FALSE);
1046 }
1047 }
1048
1049 /**
1050 * Updates a module to open all packages in the given sets to all unnamed
1051 * modules.
1052 *
1053 * @apiNote Used during startup to open packages for illegal access.
1054 */
1055 void implAddOpensToAllUnnamed(Set<String> concealedPkgs, Set<String> exportedPkgs) {
1056 if (jdk.internal.misc.VM.isModuleSystemInited()) {
1057 throw new IllegalStateException("Module system already initialized");
1058 }
1059
1060 // replace this module's openPackages map with a new map that opens
1061 // the packages to all unnamed modules.
1062 Map<String, Set<Module>> openPackages = this.openPackages;
1063 if (openPackages == null) {
1064 openPackages = HashMap.newHashMap(concealedPkgs.size() + exportedPkgs.size());
1065 } else {
1066 openPackages = new HashMap<>(openPackages);
1067 }
1068 implAddOpensToAllUnnamed(concealedPkgs, openPackages);
1069 implAddOpensToAllUnnamed(exportedPkgs, openPackages);
1070 this.openPackages = openPackages;
1071 }
1072
1073 private void implAddOpensToAllUnnamed(Set<String> pkgs, Map<String, Set<Module>> openPackages) {
1074 for (String pn : pkgs) {
1075 Set<Module> prev = openPackages.putIfAbsent(pn, ALL_UNNAMED_MODULE_SET);
1076 if (prev != null) {
1077 prev.add(ALL_UNNAMED_MODULE);
1078 }
1079
1080 // update VM to export the package
1081 addExportsToAllUnnamed0(this, pn);
1082 }
1083 }
1084
1085 // -- services --
1086
1087 /**
1088 * If the caller's module is this module then update this module to add a
1089 * service dependence on the given service type. This method is intended
1090 * for use by frameworks that invoke {@link java.util.ServiceLoader
1091 * ServiceLoader} on behalf of other modules or where the framework is
1092 * passed a reference to the service type by other code. This method is
1093 * a no-op when invoked on an unnamed module or an automatic module.
1094 *
1095 * <p> This method does not cause {@link Configuration#resolveAndBind
1096 * resolveAndBind} to be re-run. </p>
1097 *
1098 * @param service
1099 * The service type
1100 *
1101 * @return this module
1102 *
1103 * @throws IllegalCallerException
1104 * If this is a named module and the caller's module is not this
1105 * module
1106 *
1107 * @see #canUse(Class)
1108 * @see ModuleDescriptor#uses()
1109 */
1110 @CallerSensitive
1111 public Module addUses(Class<?> service) {
1112 Objects.requireNonNull(service);
1113
1114 if (isNamed() && !descriptor.isAutomatic()) {
1115 Module caller = getCallerModule(Reflection.getCallerClass());
1116 if (caller != this) {
1117 throw new IllegalCallerException(caller + " != " + this);
1118 }
1119 implAddUses(service);
1120 }
1121
1122 return this;
1123 }
1124
1125 /**
1126 * Update this module to add a service dependence on the given service
1127 * type.
1128 */
1129 void implAddUses(Class<?> service) {
1130 if (!canUse(service)) {
1131 ReflectionData.uses.putIfAbsent(this, service, Boolean.TRUE);
1132 }
1133 }
1134
1135
1136 /**
1137 * Indicates if this module has a service dependence on the given service
1138 * type. This method always returns {@code true} when invoked on an unnamed
1139 * module or an automatic module.
1140 *
1141 * @param service
1142 * The service type
1143 *
1144 * @return {@code true} if this module uses service type {@code st}
1145 *
1146 * @see #addUses(Class)
1147 */
1148 public boolean canUse(Class<?> service) {
1149 Objects.requireNonNull(service);
1150
1151 if (!isNamed())
1152 return true;
1153
1154 if (descriptor.isAutomatic())
1155 return true;
1156
1157 // uses was declared
1158 if (descriptor.uses().contains(service.getName()))
1159 return true;
1160
1161 // uses added via addUses
1162 return ReflectionData.uses.containsKeyPair(this, service);
1163 }
1164
1165
1166
1167 // -- packages --
1168
1169 /**
1170 * Returns the set of package names for the packages in this module.
1171 *
1172 * <p> For named modules, the returned set contains an element for each
1173 * package in the module. </p>
1174 *
1175 * <p> For unnamed modules, the returned set contains an element for
1176 * each package that {@link ClassLoader#getDefinedPackages() has been defined}
1177 * in the unnamed module.</p>
1178 *
1179 * @return the set of the package names of the packages in this module
1180 */
1181 public Set<String> getPackages() {
1182 if (isNamed()) {
1183 return descriptor.packages();
1184 } else {
1185 // unnamed module
1186 Stream<Package> packages;
1187 if (loader == null) {
1188 packages = BootLoader.packages();
1189 } else {
1190 packages = loader.packages();
1191 }
1192 return packages.filter(p -> p.module() == this)
1193 .map(Package::getName).collect(Collectors.toSet());
1194 }
1195 }
1196
1197 // -- creating Module objects --
1198
1199 /**
1200 * Defines all module in a configuration to the runtime.
1201 *
1202 * @return a map of module name to runtime {@code Module}
1203 *
1204 * @throws IllegalArgumentException
1205 * If the function maps a module to the null or platform class loader
1206 * @throws IllegalStateException
1207 * If the module cannot be defined to the VM or its packages overlap
1208 * with another module mapped to the same class loader
1209 */
1210 static Map<String, Module> defineModules(Configuration cf,
1211 Function<String, ClassLoader> clf,
1212 ModuleLayer layer)
1213 {
1214 boolean isBootLayer = (ModuleLayer.boot() == null);
1215
1216 int numModules = cf.modules().size();
1217 Map<String, Module> nameToModule = HashMap.newHashMap(numModules);
1218
1219 // to avoid repeated lookups and reduce iteration overhead, we create
1220 // arrays holding correlated information about each module.
1221 ResolvedModule[] resolvedModules = new ResolvedModule[numModules];
1222 Module[] modules = new Module[numModules];
1223 ClassLoader[] classLoaders = new ClassLoader[numModules];
1224
1225 resolvedModules = cf.modules().toArray(resolvedModules);
1226
1227 // record that we want to bind the layer to non-boot and non-platform
1228 // module loaders as a final step
1229 HashSet<ClassLoader> toBindLoaders = new HashSet<>(4);
1230 boolean hasPlatformModules = false;
1231
1232 // map each module to a class loader
1233 ClassLoader pcl = ClassLoaders.platformClassLoader();
1234 boolean isModuleLoaderMapper = ModuleLoaderMap.isBuiltinMapper(clf);
1235
1236 for (int index = 0; index < numModules; index++) {
1237 String name = resolvedModules[index].name();
1238 ClassLoader loader = clf.apply(name);
1239
1240 if (loader == null || loader == pcl) {
1241 if (!isModuleLoaderMapper) {
1242 throw new IllegalArgumentException("loader can't be 'null'"
1243 + " or the platform class loader");
1244 }
1245 hasPlatformModules = true;
1246 } else {
1247 toBindLoaders.add(loader);
1248 }
1249
1250 classLoaders[index] = loader;
1251 }
1252
1253 // define each module in the configuration to the VM
1254 for (int index = 0; index < numModules; index++) {
1255 ModuleReference mref = resolvedModules[index].reference();
1256 ModuleDescriptor descriptor = mref.descriptor();
1257 String name = descriptor.name();
1258 ClassLoader loader = classLoaders[index];
1259 Module m;
1260 if (loader == null && name.equals("java.base")) {
1261 // java.base is already defined to the VM
1262 m = Object.class.getModule();
1263 } else {
1264 URI uri = mref.location().orElse(null);
1265 m = new Module(layer, loader, descriptor, uri);
1266 }
1267 nameToModule.put(name, m);
1268 modules[index] = m;
1269 }
1270
1271 // setup readability and exports/opens
1272 for (int index = 0; index < numModules; index++) {
1273 ResolvedModule resolvedModule = resolvedModules[index];
1274 ModuleReference mref = resolvedModule.reference();
1275 ModuleDescriptor descriptor = mref.descriptor();
1276 Module m = modules[index];
1277
1278 // reads
1279 Set<Module> reads = new HashSet<>();
1280
1281 // name -> source Module when in parent layer
1282 Map<String, Module> nameToSource = Map.of();
1283
1284 for (ResolvedModule other : resolvedModule.reads()) {
1285 Module m2 = null;
1286 if (other.configuration() == cf) {
1287 // this configuration
1288 m2 = nameToModule.get(other.name());
1289 assert m2 != null;
1290 } else {
1291 // parent layer
1292 for (ModuleLayer parent: layer.parents()) {
1293 m2 = findModule(parent, other);
1294 if (m2 != null)
1295 break;
1296 }
1297 assert m2 != null;
1298 if (nameToSource.isEmpty())
1299 nameToSource = new HashMap<>();
1300 nameToSource.put(other.name(), m2);
1301 }
1302 reads.add(m2);
1303
1304 // update VM view
1305 addReads0(m, m2);
1306 }
1307 m.reads = reads;
1308
1309 // automatic modules read all unnamed modules
1310 if (descriptor.isAutomatic()) {
1311 m.implAddReads(ALL_UNNAMED_MODULE, true);
1312 }
1313
1314 // exports and opens, skipped for open and automatic
1315 if (!descriptor.isOpen() && !descriptor.isAutomatic()) {
1316 if (isBootLayer && descriptor.opens().isEmpty()) {
1317 // no open packages, no qualified exports to modules in parent layers
1318 initExports(m, nameToModule);
1319 } else {
1320 initExportsAndOpens(m, nameToSource, nameToModule, layer.parents());
1321 }
1322 }
1323 }
1324
1325 // if there are modules defined to the boot or platform class loaders
1326 // then register the modules in the class loader's services catalog
1327 if (hasPlatformModules) {
1328 ServicesCatalog bootCatalog = BootLoader.getServicesCatalog();
1329 ServicesCatalog pclCatalog = ServicesCatalog.getServicesCatalog(pcl);
1330 for (int index = 0; index < numModules; index++) {
1331 ResolvedModule resolvedModule = resolvedModules[index];
1332 ModuleReference mref = resolvedModule.reference();
1333 ModuleDescriptor descriptor = mref.descriptor();
1334 if (!descriptor.provides().isEmpty()) {
1335 Module m = modules[index];
1336 ClassLoader loader = classLoaders[index];
1337 if (loader == null) {
1338 bootCatalog.register(m);
1339 } else if (loader == pcl) {
1340 pclCatalog.register(m);
1341 }
1342 }
1343 }
1344 }
1345
1346 // record that there is a layer with modules defined to the class loader
1347 for (ClassLoader loader : toBindLoaders) {
1348 layer.bindToLoader(loader);
1349 }
1350
1351 return nameToModule;
1352 }
1353
1354 /**
1355 * Find the runtime Module corresponding to the given ResolvedModule
1356 * in the given parent layer (or its parents).
1357 */
1358 private static Module findModule(ModuleLayer parent,
1359 ResolvedModule resolvedModule) {
1360 Configuration cf = resolvedModule.configuration();
1361 String dn = resolvedModule.name();
1362 return parent.layers()
1363 .filter(l -> l.configuration() == cf)
1364 .findAny()
1365 .map(layer -> {
1366 Optional<Module> om = layer.findModule(dn);
1367 assert om.isPresent() : dn + " not found in layer";
1368 Module m = om.get();
1369 assert m.getLayer() == layer : m + " not in expected layer";
1370 return m;
1371 })
1372 .orElse(null);
1373 }
1374
1375 /**
1376 * Initialize/setup a module's exports.
1377 *
1378 * @param m the module
1379 * @param nameToModule map of module name to Module (for qualified exports)
1380 */
1381 private static void initExports(Module m, Map<String, Module> nameToModule) {
1382 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1383
1384 for (Exports exports : m.getDescriptor().exports()) {
1385 String source = exports.source();
1386 if (exports.isQualified()) {
1387 // qualified exports
1388 Set<Module> targets = new HashSet<>();
1389 for (String target : exports.targets()) {
1390 Module m2 = nameToModule.get(target);
1391 if (m2 != null) {
1392 addExports0(m, source, m2);
1393 targets.add(m2);
1394 }
1395 }
1396 if (!targets.isEmpty()) {
1397 exportedPackages.put(source, targets);
1398 }
1399 } else {
1400 // unqualified exports
1401 addExportsToAll0(m, source);
1402 exportedPackages.put(source, EVERYONE_SET);
1403 }
1404 }
1405
1406 if (!exportedPackages.isEmpty())
1407 m.exportedPackages = exportedPackages;
1408 }
1409
1410 /**
1411 * Initialize/setup a module's exports.
1412 *
1413 * @param m the module
1414 * @param nameToSource map of module name to Module for modules that m reads
1415 * @param nameToModule map of module name to Module for modules in the layer
1416 * under construction
1417 * @param parents the parent layers
1418 */
1419 private static void initExportsAndOpens(Module m,
1420 Map<String, Module> nameToSource,
1421 Map<String, Module> nameToModule,
1422 List<ModuleLayer> parents) {
1423 ModuleDescriptor descriptor = m.getDescriptor();
1424 Map<String, Set<Module>> openPackages = new HashMap<>();
1425 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1426
1427 // process the open packages first
1428 for (Opens opens : descriptor.opens()) {
1429 String source = opens.source();
1430
1431 if (opens.isQualified()) {
1432 // qualified opens
1433 Set<Module> targets = new HashSet<>();
1434 for (String target : opens.targets()) {
1435 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1436 if (m2 != null) {
1437 addExports0(m, source, m2);
1438 targets.add(m2);
1439 }
1440 }
1441 if (!targets.isEmpty()) {
1442 openPackages.put(source, targets);
1443 }
1444 } else {
1445 // unqualified opens
1446 addExportsToAll0(m, source);
1447 openPackages.put(source, EVERYONE_SET);
1448 }
1449 }
1450
1451 // next the exports, skipping exports when the package is open
1452 for (Exports exports : descriptor.exports()) {
1453 String source = exports.source();
1454
1455 // skip export if package is already open to everyone
1456 Set<Module> openToTargets = openPackages.get(source);
1457 if (openToTargets != null && openToTargets.contains(EVERYONE_MODULE))
1458 continue;
1459
1460 if (exports.isQualified()) {
1461 // qualified exports
1462 Set<Module> targets = new HashSet<>();
1463 for (String target : exports.targets()) {
1464 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1465 if (m2 != null) {
1466 // skip qualified export if already open to m2
1467 if (openToTargets == null || !openToTargets.contains(m2)) {
1468 addExports0(m, source, m2);
1469 targets.add(m2);
1470 }
1471 }
1472 }
1473 if (!targets.isEmpty()) {
1474 exportedPackages.put(source, targets);
1475 }
1476 } else {
1477 // unqualified exports
1478 addExportsToAll0(m, source);
1479 exportedPackages.put(source, EVERYONE_SET);
1480 }
1481 }
1482
1483 if (!openPackages.isEmpty())
1484 m.openPackages = openPackages;
1485 if (!exportedPackages.isEmpty())
1486 m.exportedPackages = exportedPackages;
1487 }
1488
1489 /**
1490 * Find the runtime Module with the given name. The module name is the
1491 * name of a target module in a qualified exports or opens directive.
1492 *
1493 * @param target The target module to find
1494 * @param nameToSource The modules in parent layers that are read
1495 * @param nameToModule The modules in the layer under construction
1496 * @param parents The parent layers
1497 */
1498 private static Module findModule(String target,
1499 Map<String, Module> nameToSource,
1500 Map<String, Module> nameToModule,
1501 List<ModuleLayer> parents) {
1502 Module m = nameToSource.get(target);
1503 if (m == null) {
1504 m = nameToModule.get(target);
1505 if (m == null) {
1506 for (ModuleLayer parent : parents) {
1507 m = parent.findModule(target).orElse(null);
1508 if (m != null) break;
1509 }
1510 }
1511 }
1512 return m;
1513 }
1514
1515
1516 // -- annotations --
1517
1518 /**
1519 * {@inheritDoc}
1520 * This method returns {@code null} when invoked on an unnamed module.
1521 *
1522 * <p> Note that any annotation returned by this method is a
1523 * declaration annotation.
1524 */
1525 @Override
1526 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
1527 return moduleInfoClass().getDeclaredAnnotation(annotationClass);
1528 }
1529
1530 /**
1531 * {@inheritDoc}
1532 * This method returns an empty array when invoked on an unnamed module.
1533 *
1534 * <p> Note that any annotations returned by this method are
1535 * declaration annotations.
1536 */
1537 @Override
1538 public Annotation[] getAnnotations() {
1539 return moduleInfoClass().getAnnotations();
1540 }
1541
1542 /**
1543 * {@inheritDoc}
1544 * This method returns an empty array when invoked on an unnamed module.
1545 *
1546 * <p> Note that any annotations returned by this method are
1547 * declaration annotations.
1548 */
1549 @Override
1550 public Annotation[] getDeclaredAnnotations() {
1551 return moduleInfoClass().getDeclaredAnnotations();
1552 }
1553
1554 // cached class file with annotations
1555 private volatile Class<?> moduleInfoClass;
1556
1557 @SuppressWarnings("removal")
1558 private Class<?> moduleInfoClass() {
1559 Class<?> clazz = this.moduleInfoClass;
1560 if (clazz != null)
1561 return clazz;
1562
1563 synchronized (this) {
1564 clazz = this.moduleInfoClass;
1565 if (clazz == null) {
1566 if (isNamed()) {
1567 PrivilegedAction<Class<?>> pa = this::loadModuleInfoClass;
1568 clazz = AccessController.doPrivileged(pa);
1569 }
1570 if (clazz == null) {
1571 class DummyModuleInfo { }
1572 clazz = DummyModuleInfo.class;
1573 }
1574 this.moduleInfoClass = clazz;
1575 }
1576 return clazz;
1577 }
1578 }
1579
1580 private Class<?> loadModuleInfoClass() {
1581 Class<?> clazz = null;
1582 try (InputStream in = getResourceAsStream("module-info.class")) {
1583 if (in != null)
1584 clazz = loadModuleInfoClass(in);
1585 } catch (Exception ignore) { }
1586 return clazz;
1587 }
1588
1589 /**
1590 * Loads module-info.class as a package-private interface in a class loader
1591 * that is a child of this module's class loader.
1592 */
1593 private Class<?> loadModuleInfoClass(InputStream in) throws IOException {
1594 final String MODULE_INFO = "module-info";
1595 var cc = Classfile.of(Classfile.ConstantPoolSharingOption.NEW_POOL);
1596 byte[] bytes = cc.transform(cc.parse(in.readAllBytes()), (clb, cle) -> {
1597 switch (cle) {
1598 case AccessFlags af -> clb.withFlags(AccessFlag.INTERFACE,
1599 AccessFlag.ABSTRACT, AccessFlag.SYNTHETIC);
1600 // keep annotations
1601 case RuntimeVisibleAnnotationsAttribute a -> clb.with(a);
1602 // drop non-annotation attributes
1603 case Attribute<?> a -> {}
1604 default -> clb.with(cle);
1605 }});
1606 ClassLoader cl = new ClassLoader(loader) {
1607 @Override
1608 protected Class<?> findClass(String cn)throws ClassNotFoundException {
1609 if (cn.equals(MODULE_INFO)) {
1610 return super.defineClass(cn, bytes, 0, bytes.length);
1611 } else {
1612 throw new ClassNotFoundException(cn);
1613 }
1614 }
1615 @Override
1616 protected Class<?> loadClass(String cn, boolean resolve)
1617 throws ClassNotFoundException
1618 {
1619 synchronized (getClassLoadingLock(cn)) {
1620 Class<?> c = findLoadedClass(cn);
1621 if (c == null) {
1622 if (cn.equals(MODULE_INFO)) {
1623 c = findClass(cn);
1624 } else {
1625 c = super.loadClass(cn, resolve);
1626 }
1627 }
1628 if (resolve)
1629 resolveClass(c);
1630 return c;
1631 }
1632 }
1633 };
1634
1635 try {
1636 return cl.loadClass(MODULE_INFO);
1637 } catch (ClassNotFoundException e) {
1638 throw new InternalError(e);
1639 }
1640 }
1641
1642
1643 // -- misc --
1644
1645
1646 /**
1647 * Returns an input stream for reading a resource in this module.
1648 * The {@code name} parameter is a {@code '/'}-separated path name that
1649 * identifies the resource. As with {@link Class#getResourceAsStream
1650 * Class.getResourceAsStream}, this method delegates to the module's class
1651 * loader {@link ClassLoader#findResource(String,String)
1652 * findResource(String,String)} method, invoking it with the module name
1653 * (or {@code null} when the module is unnamed) and the name of the
1654 * resource. If the resource name has a leading slash then it is dropped
1655 * before delegation.
1656 *
1657 * <p> A resource in a named module may be <em>encapsulated</em> so that
1658 * it cannot be located by code in other modules. Whether a resource can be
1659 * located or not is determined as follows: </p>
1660 *
1661 * <ul>
1662 * <li> If the resource name ends with "{@code .class}" then it is not
1663 * encapsulated. </li>
1664 *
1665 * <li> A <em>package name</em> is derived from the resource name. If
1666 * the package name is a {@linkplain #getPackages() package} in the
1667 * module then the resource can only be located by the caller of this
1668 * method when the package is {@linkplain #isOpen(String,Module) open}
1669 * to at least the caller's module. If the resource is not in a
1670 * package in the module then the resource is not encapsulated. </li>
1671 * </ul>
1672 *
1673 * <p> In the above, the <em>package name</em> for a resource is derived
1674 * from the subsequence of characters that precedes the last {@code '/'} in
1675 * the name and then replacing each {@code '/'} character in the subsequence
1676 * with {@code '.'}. A leading slash is ignored when deriving the package
1677 * name. As an example, the package name derived for a resource named
1678 * "{@code a/b/c/foo.properties}" is "{@code a.b.c}". A resource name
1679 * with the name "{@code META-INF/MANIFEST.MF}" is never encapsulated
1680 * because "{@code META-INF}" is not a legal package name. </p>
1681 *
1682 * <p> This method returns {@code null} if the resource is not in this
1683 * module, the resource is encapsulated and cannot be located by the caller,
1684 * or access to the resource is denied by the security manager. </p>
1685 *
1686 * @param name
1687 * The resource name
1688 *
1689 * @return An input stream for reading the resource or {@code null}
1690 *
1691 * @throws IOException
1692 * If an I/O error occurs
1693 *
1694 * @see Class#getResourceAsStream(String)
1695 */
1696 @CallerSensitive
1697 public InputStream getResourceAsStream(String name) throws IOException {
1698 if (name.startsWith("/")) {
1699 name = name.substring(1);
1700 }
1701
1702 if (isNamed() && Resources.canEncapsulate(name)) {
1703 Module caller = getCallerModule(Reflection.getCallerClass());
1704 if (caller != this && caller != Object.class.getModule()) {
1705 String pn = Resources.toPackageName(name);
1706 if (getPackages().contains(pn)) {
1707 if (caller == null) {
1708 if (!isOpen(pn)) {
1709 return null;
1710 }
1711 } else if (!isOpen(pn, caller)) {
1712 // package not open to caller
1713 return null;
1714 }
1715 }
1716 }
1717 }
1718
1719 String mn = this.name;
1720
1721 // special-case built-in class loaders to avoid URL connection
1722 if (loader == null) {
1723 return BootLoader.findResourceAsStream(mn, name);
1724 } else if (loader instanceof BuiltinClassLoader) {
1725 return ((BuiltinClassLoader) loader).findResourceAsStream(mn, name);
1726 }
1727
1728 // locate resource in module
1729 URL url = loader.findResource(mn, name);
1730 if (url != null) {
1731 try {
1732 return url.openStream();
1733 } catch (SecurityException e) { }
1734 }
1735
1736 return null;
1737 }
1738
1739 /**
1740 * Returns the string representation of this module. For a named module,
1741 * the representation is the string {@code "module"}, followed by a space,
1742 * and then the module name. For an unnamed module, the representation is
1743 * the string {@code "unnamed module"}, followed by a space, and then an
1744 * implementation specific string that identifies the unnamed module.
1745 *
1746 * @return The string representation of this module
1747 */
1748 @Override
1749 public String toString() {
1750 if (isNamed()) {
1751 return "module " + name;
1752 } else {
1753 String id = Integer.toHexString(System.identityHashCode(this));
1754 return "unnamed module @" + id;
1755 }
1756 }
1757
1758 /**
1759 * Returns the module that a given caller class is a member of. Returns
1760 * {@code null} if the caller is {@code null}.
1761 */
1762 private Module getCallerModule(Class<?> caller) {
1763 return (caller != null) ? caller.getModule() : null;
1764 }
1765
1766
1767 // -- native methods --
1768
1769 // JVM_DefineModule
1770 private static native void defineModule0(Module module,
1771 boolean isOpen,
1772 String version,
1773 String location,
1774 Object[] pns);
1775
1776 // JVM_AddReadsModule
1777 private static native void addReads0(Module from, Module to);
1778
1779 // JVM_AddModuleExports
1780 private static native void addExports0(Module from, String pn, Module to);
1781
1782 // JVM_AddModuleExportsToAll
1783 private static native void addExportsToAll0(Module from, String pn);
1784
1785 // JVM_AddModuleExportsToAllUnnamed
1786 private static native void addExportsToAllUnnamed0(Module from, String pn);
1787 }