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 singleton;
259
260 private final Module ALL_UNNAMED_MODULE;
261 private final Set<Module> ALL_UNNAMED_MODULE_SET;
262 private final Module EVERYONE_MODULE;
263 private final Set<Module> EVERYONE_SET;
264
265 public ArchivedData(Module ALL_UNNAMED_MODULE,
266 Set<Module> ALL_UNNAMED_MODULE_SET,
267 Module EVERYONE_MODULE,
268 Set<Module> EVERYONE_SET) {
269 this.ALL_UNNAMED_MODULE = ALL_UNNAMED_MODULE;
270 this.ALL_UNNAMED_MODULE_SET = ALL_UNNAMED_MODULE_SET;
271 this.EVERYONE_MODULE = EVERYONE_MODULE;
272 this.EVERYONE_SET = EVERYONE_SET;
273 }
274
275 static void archive(ArchivedData archivedData) {
276 singleton = archivedData;
277 }
278
279 static ArchivedData get() {
280 return singleton;
281 }
282
283 static {
284 VM.initializeFromArchive(ArchivedData.class);
285 }
286 }
287
288 static {
289 ArchivedData archivedData = ArchivedData.get();
290 if (archivedData != null) {
291 ALL_UNNAMED_MODULE = archivedData.ALL_UNNAMED_MODULE;
292 ALL_UNNAMED_MODULE_SET = archivedData.ALL_UNNAMED_MODULE_SET;
293 EVERYONE_MODULE = archivedData.EVERYONE_MODULE;
294 EVERYONE_SET = archivedData.EVERYONE_SET;
295 } else {
296 ALL_UNNAMED_MODULE = new Module(null);
297 ALL_UNNAMED_MODULE_SET = Set.of(ALL_UNNAMED_MODULE);
298 EVERYONE_MODULE = new Module(null);
299 EVERYONE_SET = Set.of(EVERYONE_MODULE);
300
301 ArchivedData.archive(new ArchivedData(ALL_UNNAMED_MODULE,
302 ALL_UNNAMED_MODULE_SET,
303 EVERYONE_MODULE,
304 EVERYONE_SET));
305 }
306 }
307
308 /**
309 * The holder of data structures to support readability, exports, and
310 * service use added at runtime with the reflective APIs.
311 */
312 private static class ReflectionData {
313 /**
314 * A module (1st key) reads another module (2nd key)
315 */
316 static final WeakPairMap<Module, Module, Boolean> reads =
317 new WeakPairMap<>();
318
319 /**
320 * A module (1st key) exports or opens a package to another module
321 * (2nd key). The map value is a map of package name to a boolean
322 * that indicates if the package is opened.
323 */
324 static final WeakPairMap<Module, Module, Map<String, Boolean>> exports =
325 new WeakPairMap<>();
326
327 /**
328 * A module (1st key) uses a service (2nd key)
329 */
330 static final WeakPairMap<Module, Class<?>, Boolean> uses =
331 new WeakPairMap<>();
332 }
333
334
335 // -- readability --
336
337 // the modules that this module reads
338 private volatile Set<Module> reads;
339
340 /**
341 * Indicates if this module reads the given module. This method returns
342 * {@code true} if invoked to test if this module reads itself. It also
343 * returns {@code true} if invoked on an unnamed module (as unnamed
344 * modules read all modules).
345 *
346 * @param other
347 * The other module
348 *
349 * @return {@code true} if this module reads {@code other}
350 *
351 * @see #addReads(Module)
352 */
353 public boolean canRead(Module other) {
354 Objects.requireNonNull(other);
355
356 // an unnamed module reads all modules
357 if (!this.isNamed())
358 return true;
359
360 // all modules read themselves
361 if (other == this)
362 return true;
363
364 // check if this module reads other
365 if (other.isNamed()) {
366 Set<Module> reads = this.reads; // volatile read
367 if (reads != null && reads.contains(other))
368 return true;
369 }
370
371 // check if this module reads the other module reflectively
372 if (ReflectionData.reads.containsKeyPair(this, other))
373 return true;
374
375 // if other is an unnamed module then check if this module reads
376 // all unnamed modules
377 if (!other.isNamed()
378 && ReflectionData.reads.containsKeyPair(this, ALL_UNNAMED_MODULE))
379 return true;
380
381 return false;
382 }
383
384 /**
385 * If the caller's module is this module then update this module to read
386 * the given module.
387 *
388 * This method is a no-op if {@code other} is this module (all modules read
389 * themselves), this module is an unnamed module (as unnamed modules read
390 * all modules), or this module already reads {@code other}.
391 *
392 * @implNote <em>Read edges</em> added by this method are <em>weak</em> and
393 * do not prevent {@code other} from being GC'ed when this module is
394 * strongly reachable.
395 *
396 * @param other
397 * The other module
398 *
399 * @return this module
400 *
401 * @throws IllegalCallerException
402 * If this is a named module and the caller's module is not this
403 * module
404 *
405 * @see #canRead
406 */
407 @CallerSensitive
408 public Module addReads(Module other) {
409 Objects.requireNonNull(other);
410 if (this.isNamed()) {
411 Module caller = getCallerModule(Reflection.getCallerClass());
412 if (caller != this) {
413 throw new IllegalCallerException(caller + " != " + this);
414 }
415 implAddReads(other, true);
416 }
417 return this;
418 }
419
420 /**
421 * Updates this module to read another module.
422 *
423 * @apiNote Used by the --add-reads command line option.
424 */
425 void implAddReads(Module other) {
426 implAddReads(other, true);
427 }
428
429 /**
430 * Updates this module to read all unnamed modules.
431 *
432 * @apiNote Used by the --add-reads command line option.
433 */
434 void implAddReadsAllUnnamed() {
435 implAddReads(Module.ALL_UNNAMED_MODULE, true);
436 }
437
438 /**
439 * Updates this module to read another module without notifying the VM.
440 *
441 * @apiNote This method is for VM white-box testing.
442 */
443 void implAddReadsNoSync(Module other) {
444 implAddReads(other, false);
445 }
446
447 /**
448 * Makes the given {@code Module} readable to this module.
449 *
450 * If {@code syncVM} is {@code true} then the VM is notified.
451 */
452 private void implAddReads(Module other, boolean syncVM) {
453 Objects.requireNonNull(other);
454 if (!canRead(other)) {
455 // update VM first, just in case it fails
456 if (syncVM) {
457 if (other == ALL_UNNAMED_MODULE) {
458 addReads0(this, null);
459 } else {
460 addReads0(this, other);
461 }
462 }
463
464 // add reflective read
465 ReflectionData.reads.putIfAbsent(this, other, Boolean.TRUE);
466 }
467 }
468
469
470 // -- exported and open packages --
471
472 // the packages are open to other modules, can be null
473 // if the value contains EVERYONE_MODULE then the package is open to all
474 private volatile Map<String, Set<Module>> openPackages;
475
476 // the packages that are exported, can be null
477 // if the value contains EVERYONE_MODULE then the package is exported to all
478 private volatile Map<String, Set<Module>> exportedPackages;
479
480 /**
481 * Returns {@code true} if this module exports the given package to at
482 * least the given module.
483 *
484 * <p> This method returns {@code true} if invoked to test if a package in
485 * this module is exported to itself. It always returns {@code true} when
486 * invoked on an unnamed module. A package that is {@link #isOpen open} to
487 * the given module is considered exported to that module at run-time and
488 * so this method returns {@code true} if the package is open to the given
489 * module. </p>
490 *
491 * <p> This method does not check if the given module reads this module. </p>
492 *
493 * @param pn
494 * The package name
495 * @param other
496 * The other module
497 *
498 * @return {@code true} if this module exports the package to at least the
499 * given module
500 *
501 * @see ModuleDescriptor#exports()
502 * @see #addExports(String,Module)
503 */
504 public boolean isExported(String pn, Module other) {
505 Objects.requireNonNull(pn);
506 Objects.requireNonNull(other);
507 return implIsExportedOrOpen(pn, other, /*open*/false);
508 }
509
510 /**
511 * Returns {@code true} if this module has <em>opened</em> a package to at
512 * least the given module.
513 *
514 * <p> This method returns {@code true} if invoked to test if a package in
515 * this module is open to itself. It returns {@code true} when invoked on an
516 * {@link ModuleDescriptor#isOpen open} module with a package in the module.
517 * It always returns {@code true} when invoked on an unnamed module. </p>
518 *
519 * <p> This method does not check if the given module reads this module. </p>
520 *
521 * @param pn
522 * The package name
523 * @param other
524 * The other module
525 *
526 * @return {@code true} if this module has <em>opened</em> the package
527 * to at least the given module
528 *
529 * @see ModuleDescriptor#opens()
530 * @see #addOpens(String,Module)
531 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
532 * @see java.lang.invoke.MethodHandles#privateLookupIn
533 */
534 public boolean isOpen(String pn, Module other) {
535 Objects.requireNonNull(pn);
536 Objects.requireNonNull(other);
537 return implIsExportedOrOpen(pn, other, /*open*/true);
538 }
539
540 /**
541 * Returns {@code true} if this module exports the given package
542 * unconditionally.
543 *
544 * <p> This method always returns {@code true} when invoked on an unnamed
545 * module. A package that is {@link #isOpen(String) opened} unconditionally
546 * is considered exported unconditionally at run-time and so this method
547 * returns {@code true} if the package is opened unconditionally. </p>
548 *
549 * <p> This method does not check if the given module reads this module. </p>
550 *
551 * @param pn
552 * The package name
553 *
554 * @return {@code true} if this module exports the package unconditionally
555 *
556 * @see ModuleDescriptor#exports()
557 */
558 public boolean isExported(String pn) {
559 Objects.requireNonNull(pn);
560 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/false);
561 }
562
563 /**
564 * Returns {@code true} if this module has <em>opened</em> a package
565 * unconditionally.
566 *
567 * <p> This method always returns {@code true} when invoked on an unnamed
568 * module. Additionally, it always returns {@code true} when invoked on an
569 * {@link ModuleDescriptor#isOpen open} module with a package in the
570 * module. </p>
571 *
572 * <p> This method does not check if the given module reads this module. </p>
573 *
574 * @param pn
575 * The package name
576 *
577 * @return {@code true} if this module has <em>opened</em> the package
578 * unconditionally
579 *
580 * @see ModuleDescriptor#opens()
581 */
582 public boolean isOpen(String pn) {
583 Objects.requireNonNull(pn);
584 return implIsExportedOrOpen(pn, EVERYONE_MODULE, /*open*/true);
585 }
586
587
588 /**
589 * Returns {@code true} if this module exports or opens the given package
590 * to the given module. If the other module is {@code EVERYONE_MODULE} then
591 * this method tests if the package is exported or opened unconditionally.
592 */
593 private boolean implIsExportedOrOpen(String pn, Module other, boolean open) {
594 // all packages in unnamed modules are open
595 if (!isNamed())
596 return true;
597
598 // all packages are exported/open to self
599 if (other == this && descriptor.packages().contains(pn))
600 return true;
601
602 // all packages in open and automatic modules are open
603 if (descriptor.isOpen() || descriptor.isAutomatic())
604 return descriptor.packages().contains(pn);
605
606 // exported/opened via module declaration/descriptor
607 if (isStaticallyExportedOrOpen(pn, other, open))
608 return true;
609
610 // exported via addExports/addOpens
611 if (isReflectivelyExportedOrOpen(pn, other, open))
612 return true;
613
614 // not exported or open to other
615 return false;
616 }
617
618 /**
619 * Returns {@code true} if this module exports or opens a package to
620 * the given module via its module declaration or CLI options.
621 */
622 private boolean isStaticallyExportedOrOpen(String pn, Module other, boolean open) {
623 // test if package is open to everyone or <other>
624 Map<String, Set<Module>> openPackages = this.openPackages;
625 if (openPackages != null && allows(openPackages.get(pn), other)) {
626 return true;
627 }
628
629 if (!open) {
630 // test package is exported to everyone or <other>
631 Map<String, Set<Module>> exportedPackages = this.exportedPackages;
632 if (exportedPackages != null && allows(exportedPackages.get(pn), other)) {
633 return true;
634 }
635 }
636
637 return false;
638 }
639
640 /**
641 * Returns {@code true} if targets is non-null and contains EVERYONE_MODULE
642 * or the given module. Also returns true if the given module is an unnamed
643 * module and targets contains ALL_UNNAMED_MODULE.
644 */
645 private boolean allows(Set<Module> targets, Module module) {
646 if (targets != null) {
647 if (targets.contains(EVERYONE_MODULE))
648 return true;
649 if (module != EVERYONE_MODULE) {
650 if (targets.contains(module))
651 return true;
652 if (!module.isNamed() && targets.contains(ALL_UNNAMED_MODULE))
653 return true;
654 }
655 }
656 return false;
657 }
658
659 /**
660 * Returns {@code true} if this module reflectively exports or opens the
661 * given package to the given module.
662 */
663 private boolean isReflectivelyExportedOrOpen(String pn, Module other, boolean open) {
664 // exported or open to all modules
665 Map<String, Boolean> exports = ReflectionData.exports.get(this, EVERYONE_MODULE);
666 if (exports != null) {
667 Boolean b = exports.get(pn);
668 if (b != null) {
669 boolean isOpen = b.booleanValue();
670 if (!open || isOpen) return true;
671 }
672 }
673
674 if (other != EVERYONE_MODULE) {
675
676 // exported or open to other
677 exports = ReflectionData.exports.get(this, other);
678 if (exports != null) {
679 Boolean b = exports.get(pn);
680 if (b != null) {
681 boolean isOpen = b.booleanValue();
682 if (!open || isOpen) return true;
683 }
684 }
685
686 // other is an unnamed module && exported or open to all unnamed
687 if (!other.isNamed()) {
688 exports = ReflectionData.exports.get(this, ALL_UNNAMED_MODULE);
689 if (exports != null) {
690 Boolean b = exports.get(pn);
691 if (b != null) {
692 boolean isOpen = b.booleanValue();
693 if (!open || isOpen) return true;
694 }
695 }
696 }
697
698 }
699
700 return false;
701 }
702
703 /**
704 * Returns {@code true} if this module reflectively exports the
705 * given package to the given module.
706 */
707 boolean isReflectivelyExported(String pn, Module other) {
708 return isReflectivelyExportedOrOpen(pn, other, false);
709 }
710
711 /**
712 * Returns {@code true} if this module reflectively opens the
713 * given package to the given module.
714 */
715 boolean isReflectivelyOpened(String pn, Module other) {
716 return isReflectivelyExportedOrOpen(pn, other, true);
717 }
718
719
720 /**
721 * If the caller's module is this module then update this module to export
722 * the given package to the given module.
723 *
724 * <p> This method has no effect if the package is already exported (or
725 * <em>open</em>) to the given module. </p>
726 *
727 * @apiNote As specified in section {@jvms 5.4.3} of the <cite>The Java
728 * Virtual Machine Specification </cite>, if an attempt to resolve a
729 * symbolic reference fails because of a linkage error, then subsequent
730 * attempts to resolve the reference always fail with the same error that
731 * was thrown as a result of the initial resolution attempt.
732 *
733 * @param pn
734 * The package name
735 * @param other
736 * The module
737 *
738 * @return this module
739 *
740 * @throws IllegalArgumentException
741 * If {@code pn} is {@code null}, or this is a named module and the
742 * package {@code pn} is not a package in this module
743 * @throws IllegalCallerException
744 * If this is a named module and the caller's module is not this
745 * module
746 *
747 * @jvms 5.4.3 Resolution
748 * @see #isExported(String,Module)
749 */
750 @CallerSensitive
751 public Module addExports(String pn, Module other) {
752 if (pn == null)
753 throw new IllegalArgumentException("package is null");
754 Objects.requireNonNull(other);
755
756 if (isNamed()) {
757 Module caller = getCallerModule(Reflection.getCallerClass());
758 if (caller != this) {
759 throw new IllegalCallerException(caller + " != " + this);
760 }
761 implAddExportsOrOpens(pn, other, /*open*/false, /*syncVM*/true);
762 }
763
764 return this;
765 }
766
767 /**
768 * If this module has <em>opened</em> a package to at least the caller
769 * module then update this module to open the package to the given module.
770 * Opening a package with this method allows all types in the package,
771 * and all their members, not just public types and their public members,
772 * to be reflected on by the given module when using APIs that support
773 * private access or a way to bypass or suppress default Java language
774 * access control checks.
775 *
776 * <p> This method has no effect if the package is already <em>open</em>
777 * to the given module. </p>
778 *
779 * @apiNote This method can be used for cases where a <em>consumer
780 * module</em> uses a qualified opens to open a package to an <em>API
781 * module</em> but where the reflective access to the members of classes in
782 * the consumer module is delegated to code in another module. Code in the
783 * API module can use this method to open the package in the consumer module
784 * to the other module.
785 *
786 * @param pn
787 * The package name
788 * @param other
789 * The module
790 *
791 * @return this module
792 *
793 * @throws IllegalArgumentException
794 * If {@code pn} is {@code null}, or this is a named module and the
795 * package {@code pn} is not a package in this module
796 * @throws IllegalCallerException
797 * If this is a named module and this module has not opened the
798 * package to at least the caller's module
799 *
800 * @see #isOpen(String,Module)
801 * @see java.lang.reflect.AccessibleObject#setAccessible(boolean)
802 * @see java.lang.invoke.MethodHandles#privateLookupIn
803 */
804 @CallerSensitive
805 public Module addOpens(String pn, Module other) {
806 if (pn == null)
807 throw new IllegalArgumentException("package is null");
808 Objects.requireNonNull(other);
809
810 if (isNamed()) {
811 Module caller = getCallerModule(Reflection.getCallerClass());
812 if (caller != this && (caller == null || !isOpen(pn, caller)))
813 throw new IllegalCallerException(pn + " is not open to " + caller);
814 implAddExportsOrOpens(pn, other, /*open*/true, /*syncVM*/true);
815 }
816
817 return this;
818 }
819
820
821 /**
822 * Updates this module to export a package unconditionally.
823 *
824 * @apiNote This method is for JDK tests only.
825 */
826 void implAddExports(String pn) {
827 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, false, true);
828 }
829
830 /**
831 * Updates this module to export a package to another module.
832 *
833 * @apiNote Used by Instrumentation::redefineModule and --add-exports
834 */
835 void implAddExports(String pn, Module other) {
836 implAddExportsOrOpens(pn, other, false, true);
837 }
838
839 /**
840 * Updates this module to export a package to all unnamed modules.
841 *
842 * @apiNote Used by the --add-exports command line option.
843 */
844 void implAddExportsToAllUnnamed(String pn) {
845 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, false, true);
846 }
847
848 /**
849 * Updates this export to export a package unconditionally without
850 * notifying the VM.
851 *
852 * @apiNote This method is for VM white-box testing.
853 */
854 void implAddExportsNoSync(String pn) {
855 implAddExportsOrOpens(pn.replace('/', '.'), Module.EVERYONE_MODULE, false, false);
856 }
857
858 /**
859 * Updates a module to export a package to another module without
860 * notifying the VM.
861 *
862 * @apiNote This method is for VM white-box testing.
863 */
864 void implAddExportsNoSync(String pn, Module other) {
865 implAddExportsOrOpens(pn.replace('/', '.'), other, false, false);
866 }
867
868 /**
869 * Updates this module to open a package unconditionally.
870 *
871 * @apiNote This method is for JDK tests only.
872 */
873 void implAddOpens(String pn) {
874 implAddExportsOrOpens(pn, Module.EVERYONE_MODULE, true, true);
875 }
876
877 /**
878 * Updates this module to open a package to another module.
879 *
880 * @apiNote Used by Instrumentation::redefineModule and --add-opens
881 */
882 void implAddOpens(String pn, Module other) {
883 implAddExportsOrOpens(pn, other, true, true);
884 }
885
886 /**
887 * Updates this module to open a package to all unnamed modules.
888 *
889 * @apiNote Used by the --add-opens command line option.
890 */
891 void implAddOpensToAllUnnamed(String pn) {
892 implAddExportsOrOpens(pn, Module.ALL_UNNAMED_MODULE, true, true);
893 }
894
895 /**
896 * Updates a module to export or open a module to another module.
897 *
898 * If {@code syncVM} is {@code true} then the VM is notified.
899 */
900 private void implAddExportsOrOpens(String pn,
901 Module other,
902 boolean open,
903 boolean syncVM) {
904 Objects.requireNonNull(other);
905 Objects.requireNonNull(pn);
906
907 // all packages are open in unnamed, open, and automatic modules
908 if (!isNamed() || descriptor.isOpen() || descriptor.isAutomatic())
909 return;
910
911 // check if the package is already exported/open to other
912 if (implIsExportedOrOpen(pn, other, open)) {
913
914 // if the package is exported/open for illegal access then we need
915 // to record that it has also been exported/opened reflectively so
916 // that the IllegalAccessLogger doesn't emit a warning.
917 boolean needToAdd = false;
918 if (!other.isNamed()) {
919 IllegalAccessLogger l = IllegalAccessLogger.illegalAccessLogger();
920 if (l != null) {
921 if (open) {
922 needToAdd = l.isOpenForIllegalAccess(this, pn);
923 } else {
924 needToAdd = l.isExportedForIllegalAccess(this, pn);
925 }
926 }
927 }
928 if (!needToAdd) {
929 // nothing to do
930 return;
931 }
932 }
933
934 // can only export a package in the module
935 if (!descriptor.packages().contains(pn)) {
936 throw new IllegalArgumentException("package " + pn
937 + " not in contents");
938 }
939
940 // update VM first, just in case it fails
941 if (syncVM) {
942 if (other == EVERYONE_MODULE) {
943 addExportsToAll0(this, pn);
944 } else if (other == ALL_UNNAMED_MODULE) {
945 addExportsToAllUnnamed0(this, pn);
946 } else {
947 addExports0(this, pn, other);
948 }
949 }
950
951 // add package name to exports if absent
952 Map<String, Boolean> map = ReflectionData.exports
953 .computeIfAbsent(this, other,
954 (m1, m2) -> new ConcurrentHashMap<>());
955 if (open) {
956 map.put(pn, Boolean.TRUE); // may need to promote from FALSE to TRUE
957 } else {
958 map.putIfAbsent(pn, Boolean.FALSE);
959 }
960 }
961
962 /**
963 * Updates a module to open all packages in the given sets to all unnamed
964 * modules.
965 *
966 * @apiNote Used during startup to open packages for illegal access.
967 */
968 void implAddOpensToAllUnnamed(Set<String> concealedPkgs, Set<String> exportedPkgs) {
969 if (jdk.internal.misc.VM.isModuleSystemInited()) {
970 throw new IllegalStateException("Module system already initialized");
971 }
972
973 // replace this module's openPackages map with a new map that opens
974 // the packages to all unnamed modules.
975 Map<String, Set<Module>> openPackages = this.openPackages;
976 if (openPackages == null) {
977 openPackages = new HashMap<>((4 * (concealedPkgs.size() + exportedPkgs.size()) / 3) + 1);
978 } else {
979 openPackages = new HashMap<>(openPackages);
980 }
981 implAddOpensToAllUnnamed(concealedPkgs, openPackages);
982 implAddOpensToAllUnnamed(exportedPkgs, openPackages);
983 this.openPackages = openPackages;
984 }
985
986 private void implAddOpensToAllUnnamed(Set<String> pkgs, Map<String, Set<Module>> openPackages) {
987 for (String pn : pkgs) {
988 Set<Module> prev = openPackages.putIfAbsent(pn, ALL_UNNAMED_MODULE_SET);
989 if (prev != null) {
990 prev.add(ALL_UNNAMED_MODULE);
991 }
992
993 // update VM to export the package
994 addExportsToAllUnnamed0(this, pn);
995 }
996 }
997
998 // -- services --
999
1000 /**
1001 * If the caller's module is this module then update this module to add a
1002 * service dependence on the given service type. This method is intended
1003 * for use by frameworks that invoke {@link java.util.ServiceLoader
1004 * ServiceLoader} on behalf of other modules or where the framework is
1005 * passed a reference to the service type by other code. This method is
1006 * a no-op when invoked on an unnamed module or an automatic module.
1007 *
1008 * <p> This method does not cause {@link Configuration#resolveAndBind
1009 * resolveAndBind} to be re-run. </p>
1010 *
1011 * @param service
1012 * The service type
1013 *
1014 * @return this module
1015 *
1016 * @throws IllegalCallerException
1017 * If this is a named module and the caller's module is not this
1018 * module
1019 *
1020 * @see #canUse(Class)
1021 * @see ModuleDescriptor#uses()
1022 */
1023 @CallerSensitive
1024 public Module addUses(Class<?> service) {
1025 Objects.requireNonNull(service);
1026
1027 if (isNamed() && !descriptor.isAutomatic()) {
1028 Module caller = getCallerModule(Reflection.getCallerClass());
1029 if (caller != this) {
1030 throw new IllegalCallerException(caller + " != " + this);
1031 }
1032 implAddUses(service);
1033 }
1034
1035 return this;
1036 }
1037
1038 /**
1039 * Update this module to add a service dependence on the given service
1040 * type.
1041 */
1042 void implAddUses(Class<?> service) {
1043 if (!canUse(service)) {
1044 ReflectionData.uses.putIfAbsent(this, service, Boolean.TRUE);
1045 }
1046 }
1047
1048
1049 /**
1050 * Indicates if this module has a service dependence on the given service
1051 * type. This method always returns {@code true} when invoked on an unnamed
1052 * module or an automatic module.
1053 *
1054 * @param service
1055 * The service type
1056 *
1057 * @return {@code true} if this module uses service type {@code st}
1058 *
1059 * @see #addUses(Class)
1060 */
1061 public boolean canUse(Class<?> service) {
1062 Objects.requireNonNull(service);
1063
1064 if (!isNamed())
1065 return true;
1066
1067 if (descriptor.isAutomatic())
1068 return true;
1069
1070 // uses was declared
1071 if (descriptor.uses().contains(service.getName()))
1072 return true;
1073
1074 // uses added via addUses
1075 return ReflectionData.uses.containsKeyPair(this, service);
1076 }
1077
1078
1079
1080 // -- packages --
1081
1082 /**
1083 * Returns the set of package names for the packages in this module.
1084 *
1085 * <p> For named modules, the returned set contains an element for each
1086 * package in the module. </p>
1087 *
1088 * <p> For unnamed modules, this method is the equivalent to invoking the
1089 * {@link ClassLoader#getDefinedPackages() getDefinedPackages} method of
1090 * this module's class loader and returning the set of package names. </p>
1091 *
1092 * @return the set of the package names of the packages in this module
1093 */
1094 public Set<String> getPackages() {
1095 if (isNamed()) {
1096 return descriptor.packages();
1097 } else {
1098 // unnamed module
1099 Stream<Package> packages;
1100 if (loader == null) {
1101 packages = BootLoader.packages();
1102 } else {
1103 packages = loader.packages();
1104 }
1105 return packages.map(Package::getName).collect(Collectors.toSet());
1106 }
1107 }
1108
1109
1110 // -- creating Module objects --
1111
1112 /**
1113 * Defines all module in a configuration to the runtime.
1114 *
1115 * @return a map of module name to runtime {@code Module}
1116 *
1117 * @throws IllegalArgumentException
1118 * If the function maps a module to the null or platform class loader
1119 * @throws IllegalStateException
1120 * If the module cannot be defined to the VM or its packages overlap
1121 * with another module mapped to the same class loader
1122 */
1123 static Map<String, Module> defineModules(Configuration cf,
1124 Function<String, ClassLoader> clf,
1125 ModuleLayer layer)
1126 {
1127 boolean isBootLayer = (ModuleLayer.boot() == null);
1128
1129 int numModules = cf.modules().size();
1130 int cap = (int)(numModules / 0.75f + 1.0f);
1131 Map<String, Module> nameToModule = new HashMap<>(cap);
1132
1133 // to avoid repeated lookups and reduce iteration overhead, we create
1134 // arrays holding correlated information about each module.
1135 ResolvedModule[] resolvedModules = new ResolvedModule[numModules];
1136 Module[] modules = new Module[numModules];
1137 ClassLoader[] classLoaders = new ClassLoader[numModules];
1138
1139 resolvedModules = cf.modules().toArray(resolvedModules);
1140
1141 // record that we want to bind the layer to non-boot and non-platform
1142 // module loaders as a final step
1143 HashSet<ClassLoader> toBindLoaders = new HashSet<>(4);
1144 boolean hasPlatformModules = false;
1145
1146 // map each module to a class loader
1147 ClassLoader pcl = ClassLoaders.platformClassLoader();
1148 boolean isModuleLoaderMapper = ModuleLoaderMap.isBuiltinMapper(clf);
1149
1150 for (int index = 0; index < numModules; index++) {
1151 String name = resolvedModules[index].name();
1152 ClassLoader loader = clf.apply(name);
1153
1154 if (loader == null || loader == pcl) {
1155 if (!isModuleLoaderMapper) {
1156 throw new IllegalArgumentException("loader can't be 'null'"
1157 + " or the platform class loader");
1158 }
1159 hasPlatformModules = true;
1160 } else {
1161 toBindLoaders.add(loader);
1162 }
1163
1164 classLoaders[index] = loader;
1165 }
1166
1167 // define each module in the configuration to the VM
1168 for (int index = 0; index < numModules; index++) {
1169 ModuleReference mref = resolvedModules[index].reference();
1170 ModuleDescriptor descriptor = mref.descriptor();
1171 String name = descriptor.name();
1172 ClassLoader loader = classLoaders[index];
1173 Module m;
1174 if (loader == null && name.equals("java.base")) {
1175 // java.base is already defined to the VM
1176 m = Object.class.getModule();
1177 } else {
1178 URI uri = mref.location().orElse(null);
1179 m = new Module(layer, loader, descriptor, uri);
1180 }
1181 nameToModule.put(name, m);
1182 modules[index] = m;
1183 }
1184
1185 // setup readability and exports/opens
1186 for (int index = 0; index < numModules; index++) {
1187 ResolvedModule resolvedModule = resolvedModules[index];
1188 ModuleReference mref = resolvedModule.reference();
1189 ModuleDescriptor descriptor = mref.descriptor();
1190 Module m = modules[index];
1191
1192 // reads
1193 Set<Module> reads = new HashSet<>();
1194
1195 // name -> source Module when in parent layer
1196 Map<String, Module> nameToSource = Map.of();
1197
1198 for (ResolvedModule other : resolvedModule.reads()) {
1199 Module m2 = null;
1200 if (other.configuration() == cf) {
1201 // this configuration
1202 m2 = nameToModule.get(other.name());
1203 assert m2 != null;
1204 } else {
1205 // parent layer
1206 for (ModuleLayer parent: layer.parents()) {
1207 m2 = findModule(parent, other);
1208 if (m2 != null)
1209 break;
1210 }
1211 assert m2 != null;
1212 if (nameToSource.isEmpty())
1213 nameToSource = new HashMap<>();
1214 nameToSource.put(other.name(), m2);
1215 }
1216 reads.add(m2);
1217
1218 // update VM view
1219 addReads0(m, m2);
1220 }
1221 m.reads = reads;
1222
1223 // automatic modules read all unnamed modules
1224 if (descriptor.isAutomatic()) {
1225 m.implAddReads(ALL_UNNAMED_MODULE, true);
1226 }
1227
1228 // exports and opens, skipped for open and automatic
1229 if (!descriptor.isOpen() && !descriptor.isAutomatic()) {
1230 if (isBootLayer && descriptor.opens().isEmpty()) {
1231 // no open packages, no qualified exports to modules in parent layers
1232 initExports(m, nameToModule);
1233 } else {
1234 initExportsAndOpens(m, nameToSource, nameToModule, layer.parents());
1235 }
1236 }
1237 }
1238
1239 // if there are modules defined to the boot or platform class loaders
1240 // then register the modules in the class loader's services catalog
1241 if (hasPlatformModules) {
1242 ServicesCatalog bootCatalog = BootLoader.getServicesCatalog();
1243 ServicesCatalog pclCatalog = ServicesCatalog.getServicesCatalog(pcl);
1244 for (int index = 0; index < numModules; index++) {
1245 ResolvedModule resolvedModule = resolvedModules[index];
1246 ModuleReference mref = resolvedModule.reference();
1247 ModuleDescriptor descriptor = mref.descriptor();
1248 if (!descriptor.provides().isEmpty()) {
1249 Module m = modules[index];
1250 ClassLoader loader = classLoaders[index];
1251 if (loader == null) {
1252 bootCatalog.register(m);
1253 } else if (loader == pcl) {
1254 pclCatalog.register(m);
1255 }
1256 }
1257 }
1258 }
1259
1260 // record that there is a layer with modules defined to the class loader
1261 for (ClassLoader loader : toBindLoaders) {
1262 layer.bindToLoader(loader);
1263 }
1264
1265 return nameToModule;
1266 }
1267
1268 /**
1269 * Find the runtime Module corresponding to the given ResolvedModule
1270 * in the given parent layer (or its parents).
1271 */
1272 private static Module findModule(ModuleLayer parent,
1273 ResolvedModule resolvedModule) {
1274 Configuration cf = resolvedModule.configuration();
1275 String dn = resolvedModule.name();
1276 return parent.layers()
1277 .filter(l -> l.configuration() == cf)
1278 .findAny()
1279 .map(layer -> {
1280 Optional<Module> om = layer.findModule(dn);
1281 assert om.isPresent() : dn + " not found in layer";
1282 Module m = om.get();
1283 assert m.getLayer() == layer : m + " not in expected layer";
1284 return m;
1285 })
1286 .orElse(null);
1287 }
1288
1289 /**
1290 * Initialize/setup a module's exports.
1291 *
1292 * @param m the module
1293 * @param nameToModule map of module name to Module (for qualified exports)
1294 */
1295 private static void initExports(Module m, Map<String, Module> nameToModule) {
1296 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1297
1298 for (Exports exports : m.getDescriptor().exports()) {
1299 String source = exports.source();
1300 if (exports.isQualified()) {
1301 // qualified exports
1302 Set<Module> targets = new HashSet<>();
1303 for (String target : exports.targets()) {
1304 Module m2 = nameToModule.get(target);
1305 if (m2 != null) {
1306 addExports0(m, source, m2);
1307 targets.add(m2);
1308 }
1309 }
1310 if (!targets.isEmpty()) {
1311 exportedPackages.put(source, targets);
1312 }
1313 } else {
1314 // unqualified exports
1315 addExportsToAll0(m, source);
1316 exportedPackages.put(source, EVERYONE_SET);
1317 }
1318 }
1319
1320 if (!exportedPackages.isEmpty())
1321 m.exportedPackages = exportedPackages;
1322 }
1323
1324 /**
1325 * Initialize/setup a module's exports.
1326 *
1327 * @param m the module
1328 * @param nameToSource map of module name to Module for modules that m reads
1329 * @param nameToModule map of module name to Module for modules in the layer
1330 * under construction
1331 * @param parents the parent layers
1332 */
1333 private static void initExportsAndOpens(Module m,
1334 Map<String, Module> nameToSource,
1335 Map<String, Module> nameToModule,
1336 List<ModuleLayer> parents) {
1337 ModuleDescriptor descriptor = m.getDescriptor();
1338 Map<String, Set<Module>> openPackages = new HashMap<>();
1339 Map<String, Set<Module>> exportedPackages = new HashMap<>();
1340
1341 // process the open packages first
1342 for (Opens opens : descriptor.opens()) {
1343 String source = opens.source();
1344
1345 if (opens.isQualified()) {
1346 // qualified opens
1347 Set<Module> targets = new HashSet<>();
1348 for (String target : opens.targets()) {
1349 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1350 if (m2 != null) {
1351 addExports0(m, source, m2);
1352 targets.add(m2);
1353 }
1354 }
1355 if (!targets.isEmpty()) {
1356 openPackages.put(source, targets);
1357 }
1358 } else {
1359 // unqualified opens
1360 addExportsToAll0(m, source);
1361 openPackages.put(source, EVERYONE_SET);
1362 }
1363 }
1364
1365 // next the exports, skipping exports when the package is open
1366 for (Exports exports : descriptor.exports()) {
1367 String source = exports.source();
1368
1369 // skip export if package is already open to everyone
1370 Set<Module> openToTargets = openPackages.get(source);
1371 if (openToTargets != null && openToTargets.contains(EVERYONE_MODULE))
1372 continue;
1373
1374 if (exports.isQualified()) {
1375 // qualified exports
1376 Set<Module> targets = new HashSet<>();
1377 for (String target : exports.targets()) {
1378 Module m2 = findModule(target, nameToSource, nameToModule, parents);
1379 if (m2 != null) {
1380 // skip qualified export if already open to m2
1381 if (openToTargets == null || !openToTargets.contains(m2)) {
1382 addExports0(m, source, m2);
1383 targets.add(m2);
1384 }
1385 }
1386 }
1387 if (!targets.isEmpty()) {
1388 exportedPackages.put(source, targets);
1389 }
1390 } else {
1391 // unqualified exports
1392 addExportsToAll0(m, source);
1393 exportedPackages.put(source, EVERYONE_SET);
1394 }
1395 }
1396
1397 if (!openPackages.isEmpty())
1398 m.openPackages = openPackages;
1399 if (!exportedPackages.isEmpty())
1400 m.exportedPackages = exportedPackages;
1401 }
1402
1403 /**
1404 * Find the runtime Module with the given name. The module name is the
1405 * name of a target module in a qualified exports or opens directive.
1406 *
1407 * @param target The target module to find
1408 * @param nameToSource The modules in parent layers that are read
1409 * @param nameToModule The modules in the layer under construction
1410 * @param parents The parent layers
1411 */
1412 private static Module findModule(String target,
1413 Map<String, Module> nameToSource,
1414 Map<String, Module> nameToModule,
1415 List<ModuleLayer> parents) {
1416 Module m = nameToSource.get(target);
1417 if (m == null) {
1418 m = nameToModule.get(target);
1419 if (m == null) {
1420 for (ModuleLayer parent : parents) {
1421 m = parent.findModule(target).orElse(null);
1422 if (m != null) break;
1423 }
1424 }
1425 }
1426 return m;
1427 }
1428
1429
1430 // -- annotations --
1431
1432 /**
1433 * {@inheritDoc}
1434 * This method returns {@code null} when invoked on an unnamed module.
1435 *
1436 * <p> Note that any annotation returned by this method is a
1437 * declaration annotation.
1438 */
1439 @Override
1440 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
1441 return moduleInfoClass().getDeclaredAnnotation(annotationClass);
1442 }
1443
1444 /**
1445 * {@inheritDoc}
1446 * This method returns an empty array when invoked on an unnamed module.
1447 *
1448 * <p> Note that any annotations returned by this method are
1449 * declaration annotations.
1450 */
1451 @Override
1452 public Annotation[] getAnnotations() {
1453 return moduleInfoClass().getAnnotations();
1454 }
1455
1456 /**
1457 * {@inheritDoc}
1458 * This method returns an empty array when invoked on an unnamed module.
1459 *
1460 * <p> Note that any annotations returned by this method are
1461 * declaration annotations.
1462 */
1463 @Override
1464 public Annotation[] getDeclaredAnnotations() {
1465 return moduleInfoClass().getDeclaredAnnotations();
1466 }
1467
1468 // cached class file with annotations
1469 private volatile Class<?> moduleInfoClass;
1470
1471 private Class<?> moduleInfoClass() {
1472 Class<?> clazz = this.moduleInfoClass;
1473 if (clazz != null)
1474 return clazz;
1475
1476 synchronized (this) {
1477 clazz = this.moduleInfoClass;
1478 if (clazz == null) {
1479 if (isNamed()) {
1480 PrivilegedAction<Class<?>> pa = this::loadModuleInfoClass;
1481 clazz = AccessController.doPrivileged(pa);
1482 }
1483 if (clazz == null) {
1484 class DummyModuleInfo { }
1485 clazz = DummyModuleInfo.class;
1486 }
1487 this.moduleInfoClass = clazz;
1488 }
1489 return clazz;
1490 }
1491 }
1492
1493 private Class<?> loadModuleInfoClass() {
1494 Class<?> clazz = null;
1495 try (InputStream in = getResourceAsStream("module-info.class")) {
1496 if (in != null)
1497 clazz = loadModuleInfoClass(in);
1498 } catch (Exception ignore) { }
1499 return clazz;
1500 }
1501
1502 /**
1503 * Loads module-info.class as a package-private interface in a class loader
1504 * that is a child of this module's class loader.
1505 */
1506 private Class<?> loadModuleInfoClass(InputStream in) throws IOException {
1507 final String MODULE_INFO = "module-info";
1508
1509 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS
1510 + ClassWriter.COMPUTE_FRAMES);
1511
1512 ClassVisitor cv = new ClassVisitor(Opcodes.ASM7, cw) {
1513 @Override
1514 public void visit(int version,
1515 int access,
1516 String name,
1517 String signature,
1518 String superName,
1519 String[] interfaces) {
1520 cw.visit(version,
1521 Opcodes.ACC_INTERFACE
1522 + Opcodes.ACC_ABSTRACT
1523 + Opcodes.ACC_SYNTHETIC,
1524 MODULE_INFO,
1525 null,
1526 "java/lang/Object",
1527 null);
1528 }
1529 @Override
1530 public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
1531 // keep annotations
1532 return super.visitAnnotation(desc, visible);
1533 }
1534 @Override
1535 public void visitAttribute(Attribute attr) {
1536 // drop non-annotation attributes
1537 }
1538 @Override
1539 public ModuleVisitor visitModule(String name, int flags, String version) {
1540 // drop Module attribute
1541 return null;
1542 }
1543 };
1544
1545 ClassReader cr = new ClassReader(in);
1546 cr.accept(cv, 0);
1547 byte[] bytes = cw.toByteArray();
1548
1549 ClassLoader cl = new ClassLoader(loader) {
1550 @Override
1551 protected Class<?> findClass(String cn)throws ClassNotFoundException {
1552 if (cn.equals(MODULE_INFO)) {
1553 return super.defineClass(cn, bytes, 0, bytes.length);
1554 } else {
1555 throw new ClassNotFoundException(cn);
1556 }
1557 }
1558 @Override
1559 protected Class<?> loadClass(String cn, boolean resolve)
1560 throws ClassNotFoundException
1561 {
1562 synchronized (getClassLoadingLock(cn)) {
1563 Class<?> c = findLoadedClass(cn);
1564 if (c == null) {
1565 if (cn.equals(MODULE_INFO)) {
1566 c = findClass(cn);
1567 } else {
1568 c = super.loadClass(cn, resolve);
1569 }
1570 }
1571 if (resolve)
1572 resolveClass(c);
1573 return c;
1574 }
1575 }
1576 };
1577
1578 try {
1579 return cl.loadClass(MODULE_INFO);
1580 } catch (ClassNotFoundException e) {
1581 throw new InternalError(e);
1582 }
1583 }
1584
1585
1586 // -- misc --
1587
1588
1589 /**
1590 * Returns an input stream for reading a resource in this module.
1591 * The {@code name} parameter is a {@code '/'}-separated path name that
1592 * identifies the resource. As with {@link Class#getResourceAsStream
1593 * Class.getResourceAsStream}, this method delegates to the module's class
1594 * loader {@link ClassLoader#findResource(String,String)
1595 * findResource(String,String)} method, invoking it with the module name
1596 * (or {@code null} when the module is unnamed) and the name of the
1597 * resource. If the resource name has a leading slash then it is dropped
1598 * before delegation.
1599 *
1600 * <p> A resource in a named module may be <em>encapsulated</em> so that
1601 * it cannot be located by code in other modules. Whether a resource can be
1602 * located or not is determined as follows: </p>
1603 *
1604 * <ul>
1605 * <li> If the resource name ends with "{@code .class}" then it is not
1606 * encapsulated. </li>
1607 *
1608 * <li> A <em>package name</em> is derived from the resource name. If
1609 * the package name is a {@linkplain #getPackages() package} in the
1610 * module then the resource can only be located by the caller of this
1611 * method when the package is {@linkplain #isOpen(String,Module) open}
1612 * to at least the caller's module. If the resource is not in a
1613 * package in the module then the resource is not encapsulated. </li>
1614 * </ul>
1615 *
1616 * <p> In the above, the <em>package name</em> for a resource is derived
1617 * from the subsequence of characters that precedes the last {@code '/'} in
1618 * the name and then replacing each {@code '/'} character in the subsequence
1619 * with {@code '.'}. A leading slash is ignored when deriving the package
1620 * name. As an example, the package name derived for a resource named
1621 * "{@code a/b/c/foo.properties}" is "{@code a.b.c}". A resource name
1622 * with the name "{@code META-INF/MANIFEST.MF}" is never encapsulated
1623 * because "{@code META-INF}" is not a legal package name. </p>
1624 *
1625 * <p> This method returns {@code null} if the resource is not in this
1626 * module, the resource is encapsulated and cannot be located by the caller,
1627 * or access to the resource is denied by the security manager. </p>
1628 *
1629 * @param name
1630 * The resource name
1631 *
1632 * @return An input stream for reading the resource or {@code null}
1633 *
1634 * @throws IOException
1635 * If an I/O error occurs
1636 *
1637 * @see Class#getResourceAsStream(String)
1638 */
1639 @CallerSensitive
1640 public InputStream getResourceAsStream(String name) throws IOException {
1641 if (name.startsWith("/")) {
1642 name = name.substring(1);
1643 }
1644
1645 if (isNamed() && Resources.canEncapsulate(name)) {
1646 Module caller = getCallerModule(Reflection.getCallerClass());
1647 if (caller != this && caller != Object.class.getModule()) {
1648 String pn = Resources.toPackageName(name);
1649 if (getPackages().contains(pn)) {
1650 if (caller == null && !isOpen(pn)) {
1651 // no caller, package not open
1652 return null;
1653 }
1654 if (!isOpen(pn, caller)) {
1655 // package not open to caller
1656 return null;
1657 }
1658 }
1659 }
1660 }
1661
1662 String mn = this.name;
1663
1664 // special-case built-in class loaders to avoid URL connection
1665 if (loader == null) {
1666 return BootLoader.findResourceAsStream(mn, name);
1667 } else if (loader instanceof BuiltinClassLoader) {
1668 return ((BuiltinClassLoader) loader).findResourceAsStream(mn, name);
1669 }
1670
1671 // locate resource in module
1672 URL url = loader.findResource(mn, name);
1673 if (url != null) {
1674 try {
1675 return url.openStream();
1676 } catch (SecurityException e) { }
1677 }
1678
1679 return null;
1680 }
1681
1682 /**
1683 * Returns the string representation of this module. For a named module,
1684 * the representation is the string {@code "module"}, followed by a space,
1685 * and then the module name. For an unnamed module, the representation is
1686 * the string {@code "unnamed module"}, followed by a space, and then an
1687 * implementation specific string that identifies the unnamed module.
1688 *
1689 * @return The string representation of this module
1690 */
1691 @Override
1692 public String toString() {
1693 if (isNamed()) {
1694 return "module " + name;
1695 } else {
1696 String id = Integer.toHexString(System.identityHashCode(this));
1697 return "unnamed module @" + id;
1698 }
1699 }
1700
1701 /**
1702 * Returns the module that a given caller class is a member of. Returns
1703 * {@code null} if the caller is {@code null}.
1704 */
1705 private Module getCallerModule(Class<?> caller) {
1706 return (caller != null) ? caller.getModule() : null;
1707 }
1708
1709
1710 // -- native methods --
1711
1712 // JVM_DefineModule
1713 private static native void defineModule0(Module module,
1714 boolean isOpen,
1715 String version,
1716 String location,
1717 Object[] pns);
1718
1719 // JVM_AddReadsModule
1720 private static native void addReads0(Module from, Module to);
1721
1722 // JVM_AddModuleExports
1723 private static native void addExports0(Module from, String pn, Module to);
1724
1725 // JVM_AddModuleExportsToAll
1726 private static native void addExportsToAll0(Module from, String pn);
1727
1728 // JVM_AddModuleExportsToAllUnnamed
1729 private static native void addExportsToAllUnnamed0(Module from, String pn);
1730 }