1 /*
2 * Copyright (c) 2014, 2020, 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.AnnotatedElement;
39 import java.net.URI;
40 import java.net.URL;
41 import java.security.AccessController;
42 import java.security.PrivilegedAction;
43 import java.util.HashMap;
44 import java.util.HashSet;
45 import java.util.List;
46 import java.util.Map;
47 import java.util.Objects;
48 import java.util.Optional;
49 import java.util.Set;
50 import java.util.concurrent.ConcurrentHashMap;
51 import java.util.function.Function;
52 import java.util.stream.Collectors;
53 import java.util.stream.Stream;
54
55 import jdk.internal.loader.BuiltinClassLoader;
56 import jdk.internal.loader.BootLoader;
57 import jdk.internal.loader.ClassLoaders;
58 import jdk.internal.misc.VM;
59 import jdk.internal.module.IllegalAccessLogger;
60 import jdk.internal.module.ModuleLoaderMap;
61 import jdk.internal.module.ServicesCatalog;
62 import jdk.internal.module.Resources;
63 import jdk.internal.org.objectweb.asm.AnnotationVisitor;
64 import jdk.internal.org.objectweb.asm.Attribute;
65 import jdk.internal.org.objectweb.asm.ClassReader;
66 import jdk.internal.org.objectweb.asm.ClassVisitor;
67 import jdk.internal.org.objectweb.asm.ClassWriter;
68 import jdk.internal.org.objectweb.asm.ModuleVisitor;
69 import jdk.internal.org.objectweb.asm.Opcodes;
70 import jdk.internal.reflect.CallerSensitive;
71 import jdk.internal.reflect.Reflection;
72 import sun.security.util.SecurityConstants;
73
74 /**
75 * Represents a run-time module, either {@link #isNamed() named} or unnamed.
76 *
77 * <p> Named modules have a {@link #getName() name} and are constructed by the
78 * Java Virtual Machine when a graph of modules is defined to the Java virtual
79 * machine to create a {@linkplain ModuleLayer module layer}. </p>
80 *
81 * <p> An unnamed module does not have a name. There is an unnamed module for
82 * each {@link ClassLoader ClassLoader}, obtained by invoking its {@link
83 * ClassLoader#getUnnamedModule() getUnnamedModule} method. All types that are
84 * not in a named module are members of their defining class loader's unnamed
85 * module. </p>
86 *
87 * <p> The package names that are parameters or returned by methods defined in
88 * this class are the fully-qualified names of the packages as defined in
89 * section {@jls 6.5.3} of <cite>The Java Language Specification</cite>, for
90 * example, {@code "java.lang"}. </p>
91 *
92 * <p> Unless otherwise specified, passing a {@code null} argument to a method
93 * in this class causes a {@link NullPointerException NullPointerException} to
94 * be thrown. </p>
95 *
96 * @since 9
97 * @spec JPMS
98 * @see Class#getModule()
99 */
100
101 public final class Module implements AnnotatedElement {
102
103 // the layer that contains this module, can be null
104 private final ModuleLayer layer;
105
106 // module name and loader, these fields are read by VM
107 private final String name;
108 private final ClassLoader loader;
109
110 // the module descriptor
111 private final ModuleDescriptor descriptor;
112
113
114 /**
115 * Creates a new named Module. The resulting Module will be defined to the
116 * VM but will not read any other modules, will not have any exports setup
117 * and will not be registered in the service catalog.
118 */
119 Module(ModuleLayer layer,
120 ClassLoader loader,
121 ModuleDescriptor descriptor,
122 URI uri)
123 {
124 this.layer = layer;
125 this.name = descriptor.name();
126 this.loader = loader;
127 this.descriptor = descriptor;
128
129 // define module to VM
130
131 boolean isOpen = descriptor.isOpen() || descriptor.isAutomatic();
132 Version version = descriptor.version().orElse(null);
133 String vs = Objects.toString(version, null);
134 String loc = Objects.toString(uri, null);
135 Object[] packages = descriptor.packages().toArray();
136 defineModule0(this, isOpen, vs, loc, packages);
137 }
138
139
140 /**
141 * Create the unnamed Module for the given ClassLoader.
142 *
143 * @see ClassLoader#getUnnamedModule
144 */
145 Module(ClassLoader loader) {
146 this.layer = null;
147 this.name = null;
148 this.loader = loader;
149 this.descriptor = null;
150 }
151
152
153 /**
154 * Creates a named module but without defining the module to the VM.
155 *
156 * @apiNote This constructor is for VM white-box testing.
157 */
158 Module(ClassLoader loader, ModuleDescriptor descriptor) {
159 this.layer = null;
160 this.name = descriptor.name();
161 this.loader = loader;
162 this.descriptor = descriptor;
163 }
164
165
166 /**
167 * Returns {@code true} if this module is a named module.
168 *
169 * @return {@code true} if this is a named module
170 *
171 * @see ClassLoader#getUnnamedModule()
172 */
173 public boolean isNamed() {
174 return name != null;
175 }
176
177 /**
178 * Returns the module name or {@code null} if this module is an unnamed
179 * module.
180 *
181 * @return The module name
182 */
183 public String getName() {
184 return name;
185 }
186
187 /**
188 * Returns the {@code ClassLoader} for this module.
189 *
190 * <p> If there is a security manager then its {@code checkPermission}
191 * method if first called with a {@code RuntimePermission("getClassLoader")}
192 * permission to check that the caller is allowed to get access to the
193 * class loader. </p>
194 *
195 * @return The class loader for this module
196 *
197 * @throws SecurityException
198 * If denied by the security manager
199 */
200 public ClassLoader getClassLoader() {
201 SecurityManager sm = System.getSecurityManager();
202 if (sm != null) {
203 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
204 }
205 return loader;
206 }
207
208 /**
209 * Returns the module descriptor for this module or {@code null} if this
210 * module is an unnamed module.
211 *
212 * @return The module descriptor for this module
213 */
214 public ModuleDescriptor getDescriptor() {
215 return descriptor;
216 }
217
218 /**
219 * Returns the module layer that contains this module or {@code null} if
220 * this module is not in a module layer.
221 *
222 * A module layer contains named modules and therefore this method always
223 * returns {@code null} when invoked on an unnamed module.
224 *
225 * <p> <a href="reflect/Proxy.html#dynamicmodule">Dynamic modules</a> are
226 * named modules that are generated at runtime. A dynamic module may or may
227 * not be in a module layer. </p>
228 *
229 * @return The module layer that contains this module
230 *
231 * @see java.lang.reflect.Proxy
232 */
233 public ModuleLayer getLayer() {
234 if (isNamed()) {
235 ModuleLayer layer = this.layer;
236 if (layer != null)
237 return layer;
238
239 // special-case java.base as it is created before the boot layer
240 if (loader == null && name.equals("java.base")) {
241 return ModuleLayer.boot();
242 }
243 }
244 return null;
245 }
246
247 // --
248
249 // special Module to mean "all unnamed modules"
250 private static final Module ALL_UNNAMED_MODULE;
251 private static final Set<Module> ALL_UNNAMED_MODULE_SET;
252
253 // special Module to mean "everyone"
254 private static final Module EVERYONE_MODULE;
255 private static final Set<Module> EVERYONE_SET;
256
257 private static class ArchivedData {
258 private static ArchivedData archivedData;
259 private final Module allUnnamedModule;
260 private final Set<Module> allUnnamedModules;
261 private final Module everyoneModule;
262 private final Set<Module> everyoneSet;
263
264 private ArchivedData() {
265 this.allUnnamedModule = ALL_UNNAMED_MODULE;
266 this.allUnnamedModules = ALL_UNNAMED_MODULE_SET;
267 this.everyoneModule = EVERYONE_MODULE;
268 this.everyoneSet = EVERYONE_SET;
269 }
270
271 static void archive() {
272 archivedData = new ArchivedData();
273 }
274
275 static ArchivedData get() {
276 return archivedData;
277 }
278
279 static {
280 VM.initializeFromArchive(ArchivedData.class);
281 }
282 }
283
284 static {
285 ArchivedData archivedData = ArchivedData.get();
286 if (archivedData != null) {
287 ALL_UNNAMED_MODULE = archivedData.allUnnamedModule;
288 ALL_UNNAMED_MODULE_SET = archivedData.allUnnamedModules;
289 EVERYONE_MODULE = archivedData.everyoneModule;
290 EVERYONE_SET = archivedData.everyoneSet;
291 } else {
292 ALL_UNNAMED_MODULE = new Module(null);
293 ALL_UNNAMED_MODULE_SET = Set.of(ALL_UNNAMED_MODULE);
294 EVERYONE_MODULE = new Module(null);
295 EVERYONE_SET = Set.of(EVERYONE_MODULE);
296 ArchivedData.archive();
297 }
298 }
299
300 /**
301 * The holder of data structures to support readability, exports, and
302 * service use added at runtime with the reflective APIs.
303 */
304 private static class ReflectionData {
305 /**
306 * A module (1st key) reads another module (2nd key)
307 */
308 static final WeakPairMap<Module, Module, Boolean> reads =
309 new WeakPairMap<>();
310
311 /**
312 * A module (1st key) exports or opens a package to another module
313 * (2nd key). The map value is a map of package name to a boolean
314 * that indicates if the package is opened.
315 */
316 static final WeakPairMap<Module, Module, Map<String, Boolean>> exports =
317 new WeakPairMap<>();
318
319 /**
320 * A module (1st key) uses a service (2nd key)
321 */
322 static final WeakPairMap<Module, Class<?>, Boolean> uses =
323 new WeakPairMap<>();
324 }
325
326
327 // -- readability --
328
329 // the modules that this module reads
330 private volatile Set<Module> reads;
331
332 /**
333 * Indicates if this module reads the given module. This method returns
334 * {@code true} if invoked to test if this module reads itself. It also
335 * returns {@code true} if invoked on an unnamed module (as unnamed
336 * modules read all modules).
337 *
338 * @param other
339 * The other module
340 *
341 * @return {@code true} if this module reads {@code other}
342 *
343 * @see #addReads(Module)
344 */
345 public boolean canRead(Module other) {
346 Objects.requireNonNull(other);
347
348 // an unnamed module reads all modules
349 if (!this.isNamed())
350 return true;
351
352 // all modules read themselves
353 if (other == this)
354 return true;
355
356 // check if this module reads other
357 if (other.isNamed()) {
358 Set<Module> reads = this.reads; // volatile read
359 if (reads != null && reads.contains(other))
360 return true;
361 }
362
363 // check if this module reads the other module reflectively
364 if (ReflectionData.reads.containsKeyPair(this, other))
365 return true;
366
367 // if other is an unnamed module then check if this module reads
368 // all unnamed modules
369 if (!other.isNamed()
370 && ReflectionData.reads.containsKeyPair(this, ALL_UNNAMED_MODULE))
371 return true;
372
373 return false;
374 }
375
376 /**
377 * If the caller's module is this module then update this module to read
378 * the given module.
379 *
380 * This method is a no-op if {@code other} is this module (all modules read
381 * themselves), this module is an unnamed module (as unnamed modules read
382 * all modules), or this module already reads {@code other}.
383 *
384 * @implNote <em>Read edges</em> added by this method are <em>weak</em> and
385 * do not prevent {@code other} from being GC'ed when this module is
386 * strongly reachable.
387 *
388 * @param other
389 * The other module
390 *
391 * @return this module
392 *
393 * @throws IllegalCallerException
394 * If this is a named module and the caller's module is not this
395 * module
396 *
397 * @see #canRead
398 */
399 @CallerSensitive
400 public Module addReads(Module other) {
401 Objects.requireNonNull(other);
402 if (this.isNamed()) {
403 Module caller = getCallerModule(Reflection.getCallerClass());
404 if (caller != this) {
405 throw new IllegalCallerException(caller + " != " + this);
406 }
407 implAddReads(other, true);
408 }
409 return this;
410 }
411
412 /**
413 * Updates this module to read another module.
414 *
415 * @apiNote Used by the --add-reads command line option.
416 */
417 void implAddReads(Module other) {
418 implAddReads(other, true);
419 }
420
421 /**
422 * Updates this module to read all unnamed modules.
423 *
424 * @apiNote Used by the --add-reads command line option.
425 */
426 void implAddReadsAllUnnamed() {
427 implAddReads(Module.ALL_UNNAMED_MODULE, true);
428 }
429
430 /**
431 * Updates this module to read another module without notifying the VM.
432 *
433 * @apiNote This method is for VM white-box testing.
434 */
435 void implAddReadsNoSync(Module other) {
436 implAddReads(other, false);
437 }
438
439 /**
440 * Makes the given {@code Module} readable to this module.
441 *
442 * If {@code syncVM} is {@code true} then the VM is notified.
443 */
444 private void implAddReads(Module other, boolean syncVM) {
445 Objects.requireNonNull(other);
446 if (!canRead(other)) {
447 // update VM first, just in case it fails
448 if (syncVM) {
449 if (other == ALL_UNNAMED_MODULE) {
450 addReads0(this, null);
451 } else {
452 addReads0(this, other);
453 }
454 }
455
456 // add reflective read
457 ReflectionData.reads.putIfAbsent(this, other, Boolean.TRUE);
458 }
459 }
460
461
462 // -- exported and open packages --
463
464 // the packages are open to other modules, can be null
465 // if the value contains EVERYONE_MODULE then the package is open to all
466 private volatile Map<String, Set<Module>> openPackages;
467
468 // the packages that are exported, can be null
469 // if the value contains EVERYONE_MODULE then the package is exported to all
470 private volatile Map<String, Set<Module>> exportedPackages;
471
472 /**
473 * Returns {@code true} if this module exports the given package to at
474 * least the given module.
475 *
476 * <p> This method returns {@code true} if invoked to test if a package in
477 * this module is exported to itself. It always returns {@code true} when
478 * invoked on an unnamed module. A package that is {@link #isOpen open} to
479 * the given module is considered exported to that module at run-time and
480 * so this method returns {@code true} if the package is open to the given
481 * module. </p>
482 *
483 * <p> This method does not check if the given module reads this module. </p>
484 *
485 * @param pn
486 * The package name
487 * @param other
488 * The other module
489 *
490 * @return {@code true} if this module exports the package to at least the
491 * given module
492 *
493 * @see ModuleDescriptor#exports()
494 * @see #addExports(String,Module)
495 */
496 public boolean isExported(String pn, Module other) {
497 Objects.requireNonNull(pn);
498 Objects.requireNonNull(other);
499 return implIsExportedOrOpen(pn, other, /*open*/false);
500 }
501
502 /**
503 * Returns {@code true} if this module has <em>opened</em> a package to at
504 * least the given module.
505 *
506 * <p> This method returns {@code true} if invoked to test if a package in
507 * this module is open to itself. It returns {@code true} when invoked on an
508 * {@link ModuleDescriptor#isOpen open} module with a package in the module.
509 * It always returns {@code true} when invoked on an unnamed module. </p>
510 *
511 * <p> This method does not check if the given module reads this module. </p>
512 *
513 * @param pn
514 * The package name
515 * @param other
516 * The other module
517 *
518 * @return {@code true} if this module has <em>opened</em> the package
519 * to at least the given module
520 *
521 * @see ModuleDescriptor#opens()
522 * @see #addOpens(String,Module)
523 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
524 * @see java.lang.invoke.MethodHandles#privateLookupIn
525 */
526 public boolean isOpen(String pn, Module other) {
527 Objects.requireNonNull(pn);
528 Objects.requireNonNull(other);
529 return implIsExportedOrOpen(pn, other, /*open*/true);
530 }
531
532 /**
533 * Returns {@code true} if this module exports the given package
534 * unconditionally.
535 *
536 * <p> This method always returns {@code true} when invoked on an unnamed
537 * module. A package that is {@link #isOpen(String) opened} unconditionally
538 * is considered exported unconditionally at run-time and so this method
539 * returns {@code true} if the package is opened unconditionally. </p>
540 *
541 * <p> This method does not check if the given module reads this module. </p>
542 *
543 * @param pn
544 * The package name
545 *
546 * @return {@code true} if this module exports the package unconditionally
547 *
548 * @see ModuleDescriptor#exports()
549 */
550 public boolean isExported(String pn) {
551 Objects.requireNonNull(pn);
552 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/false);
553 }
554
555 /**
556 * Returns {@code true} if this module has <em>opened</em> a package
557 * unconditionally.
558 *
559 * <p> This method always returns {@code true} when invoked on an unnamed
560 * module. Additionally, it always returns {@code true} when invoked on an
561 * {@link ModuleDescriptor#isOpen open} module with a package in the
562 * module. </p>
563 *
564 * <p> This method does not check if the given module reads this module. </p>
565 *
566 * @param pn
567 * The package name
568 *
569 * @return {@code true} if this module has <em>opened</em> the package
570 * unconditionally
571 *
572 * @see ModuleDescriptor#opens()
573 */
574 public boolean isOpen(String pn) {
575 Objects.requireNonNull(pn);
576 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/true);
577 }
578
579
580 /**
581 * Returns {@code true} if this module exports or opens the given package
582 * to the given module. If the other module is {@code EVERYONE_MODULE} then
583 * this method tests if the package is exported or opened unconditionally.
584 */
585 private boolean implIsExportedOrOpen(String pn, Module other, boolean open) {
586 // all packages in unnamed modules are open
587 if (!isNamed())
588 return true;
589
590 // all packages are exported/open to self
591 if (other == this && descriptor.packages().contains(pn))
592 return true;
593
594 // all packages in open and automatic modules are open
595 if (descriptor.isOpen() || descriptor.isAutomatic())
596 return descriptor.packages().contains(pn);
597
598 // exported/opened via module declaration/descriptor
599 if (isStaticallyExportedOrOpen(pn, other, open))
600 return true;
601
602 // exported via addExports/addOpens
603 if (isReflectivelyExportedOrOpen(pn, other, open))
604 return true;
605
606 // not exported or open to other
607 return false;
608 }
609
610 /**
611 * Returns {@code true} if this module exports or opens a package to
612 * the given module via its module declaration or CLI options.
613 */
614 private boolean isStaticallyExportedOrOpen(String pn, Module other, boolean open) {
615 // test if package is open to everyone or <other>
616 Map<String, Set<Module>> openPackages = this.openPackages;
617 if (openPackages != null && allows(openPackages.get(pn), other)) {
618 return true;
619 }
620
621 if (!open) {
622 // test package is exported to everyone or <other>
623 Map<String, Set<Module>> exportedPackages = this.exportedPackages;
624 if (exportedPackages != null && allows(exportedPackages.get(pn), other)) {
625 return true;
626 }
627 }
628
629 return false;
630 }
631
632 /**
633 * Returns {@code true} if targets is non-null and contains EVERYONE_MODULE
634 * or the given module. Also returns true if the given module is an unnamed
635 * module and targets contains ALL_UNNAMED_MODULE.
636 */
637 private boolean allows(Set<Module> targets, Module module) {
638 if (targets != null) {
639 if (targets.contains(EVERYONE_MODULE))
640 return true;
641 if (module != EVERYONE_MODULE) {
642 if (targets.contains(module))
643 return true;
644 if (!module.isNamed() && targets.contains(ALL_UNNAMED_MODULE))
645 return true;
646 }
647 }
648 return false;
649 }
650
651 /**
652 * Returns {@code true} if this module reflectively exports or opens the
653 * given package to the given module.
654 */
655 private boolean isReflectivelyExportedOrOpen(String pn, Module other, boolean open) {
656 // exported or open to all modules
657 Map<String, Boolean> exports = ReflectionData.exports.get(this, EVERYONE_MODULE);
658 if (exports != null) {
659 Boolean b = exports.get(pn);
660 if (b != null) {
661 boolean isOpen = b.booleanValue();
662 if (!open || isOpen) return true;
663 }
664 }
665
666 if (other != EVERYONE_MODULE) {
667
668 // exported or open to other
669 exports = ReflectionData.exports.get(this, other);
670 if (exports != null) {
671 Boolean b = exports.get(pn);
672 if (b != null) {
673 boolean isOpen = b.booleanValue();
674 if (!open || isOpen) return true;
675 }
676 }
677
678 // other is an unnamed module && exported or open to all unnamed
679 if (!other.isNamed()) {
680 exports = ReflectionData.exports.get(this, ALL_UNNAMED_MODULE);
681 if (exports != null) {
682 Boolean b = exports.get(pn);
683 if (b != null) {
684 boolean isOpen = b.booleanValue();
685 if (!open || isOpen) return true;
686 }
687 }
688 }
689
690 }
691
692 return false;
693 }
694
695 /**
696 * Returns {@code true} if this module reflectively exports the
697 * given package to the given module.
698 */
699 boolean isReflectivelyExported(String pn, Module other) {
700 return isReflectivelyExportedOrOpen(pn, other, false);
701 }
702
703 /**
704 * Returns {@code true} if this module reflectively opens the
705 * given package to the given module.
706 */
707 boolean isReflectivelyOpened(String pn, Module other) {
708 return isReflectivelyExportedOrOpen(pn, other, true);
709 }
710
711
712 /**
713 * If the caller's module is this module then update this module to export
714 * the given package to the given module.
715 *
716 * <p> This method has no effect if the package is already exported (or
717 * <em>open</em>) to the given module. </p>
718 *
719 * @apiNote As specified in section {@jvms 5.4.3} of the <cite>The Java
720 * Virtual Machine Specification </cite>, if an attempt to resolve a
721 * symbolic reference fails because of a linkage error, then subsequent
722 * attempts to resolve the reference always fail with the same error that
723 * was thrown as a result of the initial resolution attempt.
724 *
725 * @param pn
726 * The package name
727 * @param other
728 * The module
729 *
730 * @return this module
731 *
732 * @throws IllegalArgumentException
733 * If {@code pn} is {@code null}, or this is a named module and the
734 * package {@code pn} is not a package in this module
735 * @throws IllegalCallerException
736 * If this is a named module and the caller's module is not this
737 * module
738 *
739 * @jvms 5.4.3 Resolution
740 * @see #isExported(String,Module)
741 */
742 @CallerSensitive
743 public Module addExports(String pn, Module other) {
744 if (pn == null)
745 throw new IllegalArgumentException("package is null");
746 Objects.requireNonNull(other);
747
748 if (isNamed()) {
749 Module caller = getCallerModule(Reflection.getCallerClass());
750 if (caller != this) {
751 throw new IllegalCallerException(caller + " != " + this);
752 }
753 implAddExportsOrOpens(pn, other, /*open*/false, /*syncVM*/true);
754 }
755
756 return this;
757 }
758
759 /**
760 * If this module has <em>opened</em> a package to at least the caller
761 * module then update this module to open the package to the given module.
762 * Opening a package with this method allows all types in the package,
763 * and all their members, not just public types and their public members,
764 * to be reflected on by the given module when using APIs that support
765 * private access or a way to bypass or suppress default Java language
766 * access control checks.
767 *
768 * <p> This method has no effect if the package is already <em>open</em>
769 * to the given module. </p>
770 *
771 * @apiNote This method can be used for cases where a <em>consumer
772 * module</em> uses a qualified opens to open a package to an <em>API
773 * module</em> but where the reflective access to the members of classes in
774 * the consumer module is delegated to code in another module. Code in the
775 * API module can use this method to open the package in the consumer module
776 * to the other module.
777 *
778 * @param pn
779 * The package name
780 * @param other
781 * The module
782 *
783 * @return this module
784 *
785 * @throws IllegalArgumentException
786 * If {@code pn} is {@code null}, or this is a named module and the
787 * package {@code pn} is not a package in this module
788 * @throws IllegalCallerException
789 * If this is a named module and this module has not opened the
790 * package to at least the caller's module
791 *
792 * @see #isOpen(String,Module)
793 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
794 * @see java.lang.invoke.MethodHandles#privateLookupIn
795 */
796 @CallerSensitive
797 public Module addOpens(String pn, Module other) {
798 if (pn == null)
799 throw new IllegalArgumentException("package is null");
800 Objects.requireNonNull(other);
801
802 if (isNamed()) {
803 Module caller = getCallerModule(Reflection.getCallerClass());
804 if (caller != this && (caller == null || !isOpen(pn, caller)))
805 throw new IllegalCallerException(pn + " is not open to " + caller);
806 implAddExportsOrOpens(pn, other, /*open*/true, /*syncVM*/true);
807 }
808
809 return this;
810 }
811
812
813 /**
814 * Updates this module to export a package unconditionally.
815 *
816 * @apiNote This method is for JDK tests only.
817 */
818 void implAddExports(String pn) {
819 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, false, true);
820 }
821
822 /**
823 * Updates this module to export a package to another module.
824 *
825 * @apiNote Used by Instrumentation::redefineModule and --add-exports
826 */
827 void implAddExports(String pn, Module other) {
828 implAddExportsOrOpens(pn, other, false, true);
829 }
830
831 /**
832 * Updates this module to export a package to all unnamed modules.
833 *
834 * @apiNote Used by the --add-exports command line option.
835 */
836 void implAddExportsToAllUnnamed(String pn) {
837 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, false, true);
838 }
839
840 /**
841 * Updates this export to export a package unconditionally without
842 * notifying the VM.
843 *
844 * @apiNote This method is for VM white-box testing.
845 */
846 void implAddExportsNoSync(String pn) {
847 implAddExportsOrOpens(pn.replace('/', '.'), Module.EVERYONE_MODULE, false, false);
848 }
849
850 /**
851 * Updates a module to export a package to another module without
852 * notifying the VM.
853 *
854 * @apiNote This method is for VM white-box testing.
855 */
856 void implAddExportsNoSync(String pn, Module other) {
857 implAddExportsOrOpens(pn.replace('/', '.'), other, false, false);
858 }
859
860 /**
861 * Updates this module to open a package unconditionally.
862 *
863 * @apiNote This method is for JDK tests only.
864 */
865 void implAddOpens(String pn) {
866 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, true, true);
867 }
868
869 /**
870 * Updates this module to open a package to another module.
871 *
872 * @apiNote Used by Instrumentation::redefineModule and --add-opens
873 */
874 void implAddOpens(String pn, Module other) {
875 implAddExportsOrOpens(pn, other, true, true);
876 }
877
878 /**
879 * Updates this module to open a package to all unnamed modules.
880 *
881 * @apiNote Used by the --add-opens command line option.
882 */
883 void implAddOpensToAllUnnamed(String pn) {
884 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, true, true);
885 }
886
887 /**
888 * Updates a module to export or open a module to another module.
889 *
890 * If {@code syncVM} is {@code true} then the VM is notified.
891 */
892 private void implAddExportsOrOpens(String pn,
893 Module other,
894 boolean open,
895 boolean syncVM) {
896 Objects.requireNonNull(other);
897 Objects.requireNonNull(pn);
898
899 // all packages are open in unnamed, open, and automatic modules
900 if (!isNamed() || descriptor.isOpen() || descriptor.isAutomatic())
901 return;
902
903 // check if the package is already exported/open to other
904 if (implIsExportedOrOpen(pn, other, open)) {
905
906 // if the package is exported/open for illegal access then we need
907 // to record that it has also been exported/opened reflectively so
908 // that the IllegalAccessLogger doesn't emit a warning.
909 boolean needToAdd = false;
910 if (!other.isNamed()) {
911 IllegalAccessLogger l = IllegalAccessLogger.illegalAccessLogger();
912 if (l != null) {
913 if (open) {
914 needToAdd = l.isOpenForIllegalAccess(this, pn);
915 } else {
916 needToAdd = l.isExportedForIllegalAccess(this, pn);
917 }
918 }
919 }
920 if (!needToAdd) {
921 // nothing to do
922 return;
923 }
924 }
925
926 // can only export a package in the module
927 if (!descriptor.packages().contains(pn)) {
928 throw new IllegalArgumentException("package " + pn
929 + " not in contents");
930 }
931
932 // update VM first, just in case it fails
933 if (syncVM) {
934 if (other == EVERYONE_MODULE) {
935 addExportsToAll0(this, pn);
936 } else if (other == ALL_UNNAMED_MODULE) {
937 addExportsToAllUnnamed0(this, pn);
938 } else {
939 addExports0(this, pn, other);
940 }
941 }
942
943 // add package name to exports if absent
944 Map<String, Boolean> map = ReflectionData.exports
945 .computeIfAbsent(this, other,
946 (m1, m2) -> new ConcurrentHashMap<>());
947 if (open) {
948 map.put(pn, Boolean.TRUE); // may need to promote from FALSE to TRUE
949 } else {
950 map.putIfAbsent(pn, Boolean.FALSE);
951 }
952 }
953
954 /**
955 * Updates a module to open all packages in the given sets to all unnamed
956 * modules.
957 *
958 * @apiNote Used during startup to open packages for illegal access.
959 */
960 void implAddOpensToAllUnnamed(Set<String> concealedPkgs, Set<String> exportedPkgs) {
961 if (jdk.internal.misc.VM.isModuleSystemInited()) {
962 throw new IllegalStateException("Module system already initialized");
963 }
964
965 // replace this module's openPackages map with a new map that opens
966 // the packages to all unnamed modules.
967 Map<String, Set<Module>> openPackages = this.openPackages;
968 if (openPackages == null) {
969 openPackages = new HashMap<>((4 * (concealedPkgs.size() + exportedPkgs.size()) / 3) + 1);
970 } else {
971 openPackages = new HashMap<>(openPackages);
972 }
973 implAddOpensToAllUnnamed(concealedPkgs, openPackages);
974 implAddOpensToAllUnnamed(exportedPkgs, openPackages);
975 this.openPackages = openPackages;
976 }
977
978 private void implAddOpensToAllUnnamed(Set<String> pkgs, Map<String, Set<Module>> openPackages) {
979 for (String pn : pkgs) {
980 Set<Module> prev = openPackages.putIfAbsent(pn, ALL_UNNAMED_MODULE_SET);
981 if (prev != null) {
982 prev.add(ALL_UNNAMED_MODULE);
983 }
984
985 // update VM to export the package
986 addExportsToAllUnnamed0(this, pn);
987 }
988 }
989
990 // -- services --
991
992 /**
993 * If the caller's module is this module then update this module to add a
994 * service dependence on the given service type. This method is intended
995 * for use by frameworks that invoke {@link java.util.ServiceLoader
996 * ServiceLoader} on behalf of other modules or where the framework is
997 * passed a reference to the service type by other code. This method is
998 * a no-op when invoked on an unnamed module or an automatic module.
999 *
1000 * <p> This method does not cause {@link Configuration#resolveAndBind
1001 * resolveAndBind} to be re-run. </p>
1002 *
1003 * @param service
1004 * The service type
1005 *
1006 * @return this module
1007 *
1008 * @throws IllegalCallerException
1009 * If this is a named module and the caller's module is not this
1010 * module
1011 *
1012 * @see #canUse(Class)
1013 * @see ModuleDescriptor#uses()
1014 */
1015 @CallerSensitive
1016 public Module addUses(Class<?> service) {
1017 Objects.requireNonNull(service);
1018
1019 if (isNamed() && !descriptor.isAutomatic()) {
1020 Module caller = getCallerModule(Reflection.getCallerClass());
1021 if (caller != this) {
1022 throw new IllegalCallerException(caller + " != " + this);
1023 }
1024 implAddUses(service);
1025 }
1026
1027 return this;
1028 }
1029
1030 /**
1031 * Update this module to add a service dependence on the given service
1032 * type.
1033 */
1034 void implAddUses(Class<?> service) {
1035 if (!canUse(service)) {
1036 ReflectionData.uses.putIfAbsent(this, service, Boolean.TRUE);
1037 }
1038 }
1039
1040
1041 /**
1042 * Indicates if this module has a service dependence on the given service
1043 * type. This method always returns {@code true} when invoked on an unnamed
1044 * module or an automatic module.
1045 *
1046 * @param service
1047 * The service type
1048 *
1049 * @return {@code true} if this module uses service type {@code st}
1050 *
1051 * @see #addUses(Class)
1052 */
1053 public boolean canUse(Class<?> service) {
1054 Objects.requireNonNull(service);
1055
1056 if (!isNamed())
1057 return true;
1058
1059 if (descriptor.isAutomatic())
1060 return true;
1061
1062 // uses was declared
1063 if (descriptor.uses().contains(service.getName()))
1064 return true;
1065
1066 // uses added via addUses
1067 return ReflectionData.uses.containsKeyPair(this, service);
1068 }
1069
1070
1071
1072 // -- packages --
1073
1074 /**
1075 * Returns the set of package names for the packages in this module.
1076 *
1077 * <p> For named modules, the returned set contains an element for each
1078 * package in the module. </p>
1079 *
1080 * <p> For unnamed modules, this method is the equivalent to invoking the
1081 * {@link ClassLoader#getDefinedPackages() getDefinedPackages} method of
1082 * this module's class loader and returning the set of package names. </p>
1083 *
1084 * @return the set of the package names of the packages in this module
1085 */
1086 public Set<String> getPackages() {
1087 if (isNamed()) {
1088 return descriptor.packages();
1089 } else {
1090 // unnamed module
1091 Stream<Package> packages;
1092 if (loader == null) {
1093 packages = BootLoader.packages();
1094 } else {
1095 packages = loader.packages();
1096 }
1097 return packages.map(Package::getName).collect(Collectors.toSet());
1098 }
1099 }
1100
1101
1102 // -- creating Module objects --
1103
1104 /**
1105 * Defines all module in a configuration to the runtime.
1106 *
1107 * @return a map of module name to runtime {@code Module}
1108 *
1109 * @throws IllegalArgumentException
1110 * If the function maps a module to the null or platform class loader
1111 * @throws IllegalStateException
1112 * If the module cannot be defined to the VM or its packages overlap
1113 * with another module mapped to the same class loader
1114 */
1115 static Map<String, Module> defineModules(Configuration cf,
1116 Function<String, ClassLoader> clf,
1117 ModuleLayer layer)
1118 {
1119 boolean isBootLayer = (ModuleLayer.boot() == null);
1120
1121 int numModules = cf.modules().size();
1122 int cap = (int)(numModules / 0.75f + 1.0f);
1123 Map<String, Module> nameToModule = new HashMap<>(cap);
1124
1125 // to avoid repeated lookups and reduce iteration overhead, we create
1126 // arrays holding correlated information about each module.
1127 ResolvedModule[] resolvedModules = new ResolvedModule[numModules];
1128 Module[] modules = new Module[numModules];
1129 ClassLoader[] classLoaders = new ClassLoader[numModules];
1130
1131 resolvedModules = cf.modules().toArray(resolvedModules);
1132
1133 // record that we want to bind the layer to non-boot and non-platform
1134 // module loaders as a final step
1135 HashSet<ClassLoader> toBindLoaders = new HashSet<>(4);
1136 boolean hasPlatformModules = false;
1137
1138 // map each module to a class loader
1139 ClassLoader pcl = ClassLoaders.platformClassLoader();
1140 boolean isModuleLoaderMapper = ModuleLoaderMap.isBuiltinMapper(clf);
1141
1142 for (int index = 0; index < numModules; index++) {
1143 String name = resolvedModules[index].name();
1144 ClassLoader loader = clf.apply(name);
1145
1146 if (loader == null || loader == pcl) {
1147 if (!isModuleLoaderMapper) {
1148 throw new IllegalArgumentException("loader can't be 'null'"
1149 + " or the platform class loader");
1150 }
1151 hasPlatformModules = true;
1152 } else {
1153 toBindLoaders.add(loader);
1154 }
1155
1156 classLoaders[index] = loader;
1157 }
1158
1159 // define each module in the configuration to the VM
1160 for (int index = 0; index < numModules; index++) {
1161 ModuleReference mref = resolvedModules[index].reference();
1162 ModuleDescriptor descriptor = mref.descriptor();
1163 String name = descriptor.name();
1164 ClassLoader loader = classLoaders[index];
1165 Module m;
1166 if (loader == null && name.equals("java.base")) {
1167 // java.base is already defined to the VM
1168 m = Object.class.getModule();
1169 } else {
1170 URI uri = mref.location().orElse(null);
1171 m = new Module(layer, loader, descriptor, uri);
1172 }
1173 nameToModule.put(name, m);
1174 modules[index] = m;
1175 }
1176
1177 // setup readability and exports/opens
1178 for (int index = 0; index < numModules; index++) {
1179 ResolvedModule resolvedModule = resolvedModules[index];
1180 ModuleReference mref = resolvedModule.reference();
1181 ModuleDescriptor descriptor = mref.descriptor();
1182 Module m = modules[index];
1183
1184 // reads
1185 Set<Module> reads = new HashSet<>();
1186
1187 // name -> source Module when in parent layer
1188 Map<String, Module> nameToSource = Map.of();
1189
1190 for (ResolvedModule other : resolvedModule.reads()) {
1191 Module m2 = null;
1192 if (other.configuration() == cf) {
1193 // this configuration
1194 m2 = nameToModule.get(other.name());
1195 assert m2 != null;
1196 } else {
1197 // parent layer
1198 for (ModuleLayer parent: layer.parents()) {
1199 m2 = findModule(parent, other);
1200 if (m2 != null)
1201 break;
1202 }
1203 assert m2 != null;
1204 if (nameToSource.isEmpty())
1205 nameToSource = new HashMap<>();
1206 nameToSource.put(other.name(), m2);
1207 }
1208 reads.add(m2);
1209
1210 // update VM view
1211 addReads0(m, m2);
1212 }
1213 m.reads = reads;
1214
1215 // automatic modules read all unnamed modules
1216 if (descriptor.isAutomatic()) {
1217 m.implAddReads(ALL_UNNAMED_MODULE, true);
1218 }
1219
1220 // exports and opens, skipped for open and automatic
1221 if (!descriptor.isOpen() && !descriptor.isAutomatic()) {
1222 if (isBootLayer && descriptor.opens().isEmpty()) {
1223 // no open packages, no qualified exports to modules in parent layers
1224 initExports(m, nameToModule);
1225 } else {
1226 initExportsAndOpens(m, nameToSource, nameToModule, layer.parents());
1227 }
1228 }
1229 }
1230
1231 // if there are modules defined to the boot or platform class loaders
1232 // then register the modules in the class loader's services catalog
1233 if (hasPlatformModules) {
1234 ServicesCatalog bootCatalog = BootLoader.getServicesCatalog();
1235 ServicesCatalog pclCatalog = ServicesCatalog.getServicesCatalog(pcl);
1236 for (int index = 0; index < numModules; index++) {
1237 ResolvedModule resolvedModule = resolvedModules[index];
1238 ModuleReference mref = resolvedModule.reference();
1239 ModuleDescriptor descriptor = mref.descriptor();
1240 if (!descriptor.provides().isEmpty()) {
1241 Module m = modules[index];
1242 ClassLoader loader = classLoaders[index];
1243 if (loader == null) {
1244 bootCatalog.register(m);
1245 } else if (loader == pcl) {
1246 pclCatalog.register(m);
1247 }
1248 }
1249 }
1250 }
1251
1252 // record that there is a layer with modules defined to the class loader
1253 for (ClassLoader loader : toBindLoaders) {
1254 layer.bindToLoader(loader);
1255 }
1256
1257 return nameToModule;
1258 }
1259
1260 /**
1261 * Find the runtime Module corresponding to the given ResolvedModule
1262 * in the given parent layer (or its parents).
1263 */
1264 private static Module findModule(ModuleLayer parent,
1265 ResolvedModule resolvedModule) {
1266 Configuration cf = resolvedModule.configuration();
1267 String dn = resolvedModule.name();
1268 return parent.layers()
1269 .filter(l -> l.configuration() == cf)
1270 .findAny()
1271 .map(layer -> {
1272 Optional<Module> om = layer.findModule(dn);
1273 assert om.isPresent() : dn + " not found in layer";
1274 Module m = om.get();
1275 assert m.getLayer() == layer : m + " not in expected layer";
1276 return m;
1277 })
1278 .orElse(null);
1279 }
1280
1281 /**
1282 * Initialize/setup a module's exports.
1283 *
1284 * @param m the module
1285 * @param nameToModule map of module name to Module (for qualified exports)
1286 */
1287 private static void initExports(Module m, Map<String, Module> nameToModule) {
1288 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1289
1290 for (Exports exports : m.getDescriptor().exports()) {
1291 String source = exports.source();
1292 if (exports.isQualified()) {
1293 // qualified exports
1294 Set<Module> targets = new HashSet<>();
1295 for (String target : exports.targets()) {
1296 Module m2 = nameToModule.get(target);
1297 if (m2 != null) {
1298 addExports0(m, source, m2);
1299 targets.add(m2);
1300 }
1301 }
1302 if (!targets.isEmpty()) {
1303 exportedPackages.put(source, targets);
1304 }
1305 } else {
1306 // unqualified exports
1307 addExportsToAll0(m, source);
1308 exportedPackages.put(source, EVERYONE_SET);
1309 }
1310 }
1311
1312 if (!exportedPackages.isEmpty())
1313 m.exportedPackages = exportedPackages;
1314 }
1315
1316 /**
1317 * Initialize/setup a module's exports.
1318 *
1319 * @param m the module
1320 * @param nameToSource map of module name to Module for modules that m reads
1321 * @param nameToModule map of module name to Module for modules in the layer
1322 * under construction
1323 * @param parents the parent layers
1324 */
1325 private static void initExportsAndOpens(Module m,
1326 Map<String, Module> nameToSource,
1327 Map<String, Module> nameToModule,
1328 List<ModuleLayer> parents) {
1329 ModuleDescriptor descriptor = m.getDescriptor();
1330 Map<String, Set<Module>> openPackages = new HashMap<>();
1331 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1332
1333 // process the open packages first
1334 for (Opens opens : descriptor.opens()) {
1335 String source = opens.source();
1336
1337 if (opens.isQualified()) {
1338 // qualified opens
1339 Set<Module> targets = new HashSet<>();
1340 for (String target : opens.targets()) {
1341 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1342 if (m2 != null) {
1343 addExports0(m, source, m2);
1344 targets.add(m2);
1345 }
1346 }
1347 if (!targets.isEmpty()) {
1348 openPackages.put(source, targets);
1349 }
1350 } else {
1351 // unqualified opens
1352 addExportsToAll0(m, source);
1353 openPackages.put(source, EVERYONE_SET);
1354 }
1355 }
1356
1357 // next the exports, skipping exports when the package is open
1358 for (Exports exports : descriptor.exports()) {
1359 String source = exports.source();
1360
1361 // skip export if package is already open to everyone
1362 Set<Module> openToTargets = openPackages.get(source);
1363 if (openToTargets != null && openToTargets.contains(EVERYONE_MODULE))
1364 continue;
1365
1366 if (exports.isQualified()) {
1367 // qualified exports
1368 Set<Module> targets = new HashSet<>();
1369 for (String target : exports.targets()) {
1370 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1371 if (m2 != null) {
1372 // skip qualified export if already open to m2
1373 if (openToTargets == null || !openToTargets.contains(m2)) {
1374 addExports0(m, source, m2);
1375 targets.add(m2);
1376 }
1377 }
1378 }
1379 if (!targets.isEmpty()) {
1380 exportedPackages.put(source, targets);
1381 }
1382 } else {
1383 // unqualified exports
1384 addExportsToAll0(m, source);
1385 exportedPackages.put(source, EVERYONE_SET);
1386 }
1387 }
1388
1389 if (!openPackages.isEmpty())
1390 m.openPackages = openPackages;
1391 if (!exportedPackages.isEmpty())
1392 m.exportedPackages = exportedPackages;
1393 }
1394
1395 /**
1396 * Find the runtime Module with the given name. The module name is the
1397 * name of a target module in a qualified exports or opens directive.
1398 *
1399 * @param target The target module to find
1400 * @param nameToSource The modules in parent layers that are read
1401 * @param nameToModule The modules in the layer under construction
1402 * @param parents The parent layers
1403 */
1404 private static Module findModule(String target,
1405 Map<String, Module> nameToSource,
1406 Map<String, Module> nameToModule,
1407 List<ModuleLayer> parents) {
1408 Module m = nameToSource.get(target);
1409 if (m == null) {
1410 m = nameToModule.get(target);
1411 if (m == null) {
1412 for (ModuleLayer parent : parents) {
1413 m = parent.findModule(target).orElse(null);
1414 if (m != null) break;
1415 }
1416 }
1417 }
1418 return m;
1419 }
1420
1421
1422 // -- annotations --
1423
1424 /**
1425 * {@inheritDoc}
1426 * This method returns {@code null} when invoked on an unnamed module.
1427 *
1428 * <p> Note that any annotation returned by this method is a
1429 * declaration annotation.
1430 */
1431 @Override
1432 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
1433 return moduleInfoClass().getDeclaredAnnotation(annotationClass);
1434 }
1435
1436 /**
1437 * {@inheritDoc}
1438 * This method returns an empty array when invoked on an unnamed module.
1439 *
1440 * <p> Note that any annotations returned by this method are
1441 * declaration annotations.
1442 */
1443 @Override
1444 public Annotation[] getAnnotations() {
1445 return moduleInfoClass().getAnnotations();
1446 }
1447
1448 /**
1449 * {@inheritDoc}
1450 * This method returns an empty array when invoked on an unnamed module.
1451 *
1452 * <p> Note that any annotations returned by this method are
1453 * declaration annotations.
1454 */
1455 @Override
1456 public Annotation[] getDeclaredAnnotations() {
1457 return moduleInfoClass().getDeclaredAnnotations();
1458 }
1459
1460 // cached class file with annotations
1461 private volatile Class<?> moduleInfoClass;
1462
1463 private Class<?> moduleInfoClass() {
1464 Class<?> clazz = this.moduleInfoClass;
1465 if (clazz != null)
1466 return clazz;
1467
1468 synchronized (this) {
1469 clazz = this.moduleInfoClass;
1470 if (clazz == null) {
1471 if (isNamed()) {
1472 PrivilegedAction<Class<?>> pa = this::loadModuleInfoClass;
1473 clazz = AccessController.doPrivileged(pa);
1474 }
1475 if (clazz == null) {
1476 class DummyModuleInfo { }
1477 clazz = DummyModuleInfo.class;
1478 }
1479 this.moduleInfoClass = clazz;
1480 }
1481 return clazz;
1482 }
1483 }
1484
1485 private Class<?> loadModuleInfoClass() {
1486 Class<?> clazz = null;
1487 try (InputStream in = getResourceAsStream("module-info.class")) {
1488 if (in != null)
1489 clazz = loadModuleInfoClass(in);
1490 } catch (Exception ignore) { }
1491 return clazz;
1492 }
1493
1494 /**
1495 * Loads module-info.class as a package-private interface in a class loader
1496 * that is a child of this module's class loader.
1497 */
1498 private Class<?> loadModuleInfoClass(InputStream in) throws IOException {
1499 final String MODULE_INFO = "module-info";
1500
1501 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS
1502 + ClassWriter.COMPUTE_FRAMES);
1503
1504 ClassVisitor cv = new ClassVisitor(Opcodes.ASM7, cw) {
1505 @Override
1506 public void visit(int version,
1507 int access,
1508 String name,
1509 String signature,
1510 String superName,
1511 String[] interfaces) {
1512 cw.visit(version,
1513 Opcodes.ACC_INTERFACE
1514 + Opcodes.ACC_ABSTRACT
1515 + Opcodes.ACC_SYNTHETIC,
1516 MODULE_INFO,
1517 null,
1518 "java/lang/Object",
1519 null);
1520 }
1521 @Override
1522 public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
1523 // keep annotations
1524 return super.visitAnnotation(desc, visible);
1525 }
1526 @Override
1527 public void visitAttribute(Attribute attr) {
1528 // drop non-annotation attributes
1529 }
1530 @Override
1531 public ModuleVisitor visitModule(String name, int flags, String version) {
1532 // drop Module attribute
1533 return null;
1534 }
1535 };
1536
1537 ClassReader cr = new ClassReader(in);
1538 cr.accept(cv, 0);
1539 byte[] bytes = cw.toByteArray();
1540
1541 ClassLoader cl = new ClassLoader(loader) {
1542 @Override
1543 protected Class<?> findClass(String cn)throws ClassNotFoundException {
1544 if (cn.equals(MODULE_INFO)) {
1545 return super.defineClass(cn, bytes, 0, bytes.length);
1546 } else {
1547 throw new ClassNotFoundException(cn);
1548 }
1549 }
1550 @Override
1551 protected Class<?> loadClass(String cn, boolean resolve)
1552 throws ClassNotFoundException
1553 {
1554 synchronized (getClassLoadingLock(cn)) {
1555 Class<?> c = findLoadedClass(cn);
1556 if (c == null) {
1557 if (cn.equals(MODULE_INFO)) {
1558 c = findClass(cn);
1559 } else {
1560 c = super.loadClass(cn, resolve);
1561 }
1562 }
1563 if (resolve)
1564 resolveClass(c);
1565 return c;
1566 }
1567 }
1568 };
1569
1570 try {
1571 return cl.loadClass(MODULE_INFO);
1572 } catch (ClassNotFoundException e) {
1573 throw new InternalError(e);
1574 }
1575 }
1576
1577
1578 // -- misc --
1579
1580
1581 /**
1582 * Returns an input stream for reading a resource in this module.
1583 * The {@code name} parameter is a {@code '/'}-separated path name that
1584 * identifies the resource. As with {@link Class#getResourceAsStream
1585 * Class.getResourceAsStream}, this method delegates to the module's class
1586 * loader {@link ClassLoader#findResource(String,String)
1587 * findResource(String,String)} method, invoking it with the module name
1588 * (or {@code null} when the module is unnamed) and the name of the
1589 * resource. If the resource name has a leading slash then it is dropped
1590 * before delegation.
1591 *
1592 * <p> A resource in a named module may be <em>encapsulated</em> so that
1593 * it cannot be located by code in other modules. Whether a resource can be
1594 * located or not is determined as follows: </p>
1595 *
1596 * <ul>
1597 * <li> If the resource name ends with "{@code .class}" then it is not
1598 * encapsulated. </li>
1599 *
1600 * <li> A <em>package name</em> is derived from the resource name. If
1601 * the package name is a {@linkplain #getPackages() package} in the
1602 * module then the resource can only be located by the caller of this
1603 * method when the package is {@linkplain #isOpen(String,Module) open}
1604 * to at least the caller's module. If the resource is not in a
1605 * package in the module then the resource is not encapsulated. </li>
1606 * </ul>
1607 *
1608 * <p> In the above, the <em>package name</em> for a resource is derived
1609 * from the subsequence of characters that precedes the last {@code '/'} in
1610 * the name and then replacing each {@code '/'} character in the subsequence
1611 * with {@code '.'}. A leading slash is ignored when deriving the package
1612 * name. As an example, the package name derived for a resource named
1613 * "{@code a/b/c/foo.properties}" is "{@code a.b.c}". A resource name
1614 * with the name "{@code META-INF/MANIFEST.MF}" is never encapsulated
1615 * because "{@code META-INF}" is not a legal package name. </p>
1616 *
1617 * <p> This method returns {@code null} if the resource is not in this
1618 * module, the resource is encapsulated and cannot be located by the caller,
1619 * or access to the resource is denied by the security manager. </p>
1620 *
1621 * @param name
1622 * The resource name
1623 *
1624 * @return An input stream for reading the resource or {@code null}
1625 *
1626 * @throws IOException
1627 * If an I/O error occurs
1628 *
1629 * @see Class#getResourceAsStream(String)
1630 */
1631 @CallerSensitive
1632 public InputStream getResourceAsStream(String name) throws IOException {
1633 if (name.startsWith("/")) {
1634 name = name.substring(1);
1635 }
1636
1637 if (isNamed() && Resources.canEncapsulate(name)) {
1638 Module caller = getCallerModule(Reflection.getCallerClass());
1639 if (caller != this && caller != Object.class.getModule()) {
1640 String pn = Resources.toPackageName(name);
1641 if (getPackages().contains(pn)) {
1642 if (caller == null && !isOpen(pn)) {
1643 // no caller, package not open
1644 return null;
1645 }
1646 if (!isOpen(pn, caller)) {
1647 // package not open to caller
1648 return null;
1649 }
1650 }
1651 }
1652 }
1653
1654 String mn = this.name;
1655
1656 // special-case built-in class loaders to avoid URL connection
1657 if (loader == null) {
1658 return BootLoader.findResourceAsStream(mn, name);
1659 } else if (loader instanceof BuiltinClassLoader) {
1660 return ((BuiltinClassLoader) loader).findResourceAsStream(mn, name);
1661 }
1662
1663 // locate resource in module
1664 URL url = loader.findResource(mn, name);
1665 if (url != null) {
1666 try {
1667 return url.openStream();
1668 } catch (SecurityException e) { }
1669 }
1670
1671 return null;
1672 }
1673
1674 /**
1675 * Returns the string representation of this module. For a named module,
1676 * the representation is the string {@code "module"}, followed by a space,
1677 * and then the module name. For an unnamed module, the representation is
1678 * the string {@code "unnamed module"}, followed by a space, and then an
1679 * implementation specific string that identifies the unnamed module.
1680 *
1681 * @return The string representation of this module
1682 */
1683 @Override
1684 public String toString() {
1685 if (isNamed()) {
1686 return "module " + name;
1687 } else {
1688 String id = Integer.toHexString(System.identityHashCode(this));
1689 return "unnamed module @" + id;
1690 }
1691 }
1692
1693 /**
1694 * Returns the module that a given caller class is a member of. Returns
1695 * {@code null} if the caller is {@code null}.
1696 */
1697 private Module getCallerModule(Class<?> caller) {
1698 return (caller != null) ? caller.getModule() : null;
1699 }
1700
1701
1702 // -- native methods --
1703
1704 // JVM_DefineModule
1705 private static native void defineModule0(Module module,
1706 boolean isOpen,
1707 String version,
1708 String location,
1709 Object[] pns);
1710
1711 // JVM_AddReadsModule
1712 private static native void addReads0(Module from, Module to);
1713
1714 // JVM_AddModuleExports
1715 private static native void addExports0(Module from, String pn, Module to);
1716
1717 // JVM_AddModuleExportsToAll
1718 private static native void addExportsToAll0(Module from, String pn);
1719
1720 // JVM_AddModuleExportsToAllUnnamed
1721 private static native void addExportsToAllUnnamed0(Module from, String pn);
1722 }