1 /*
2 * Copyright (c) 1999, 2018, 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 com.sun.tools.javac.comp;
27
28 import java.util.Map;
29 import java.util.Optional;
30
31 import javax.tools.JavaFileObject;
32 import javax.tools.JavaFileManager;
33
34 import com.sun.tools.javac.code.*;
35 import com.sun.tools.javac.code.Kinds.KindName;
36 import com.sun.tools.javac.code.Kinds.KindSelector;
37 import com.sun.tools.javac.code.Scope.*;
38 import com.sun.tools.javac.code.Symbol.*;
39 import com.sun.tools.javac.code.Type.*;
40 import com.sun.tools.javac.main.Option.PkgInfo;
41 import com.sun.tools.javac.resources.CompilerProperties.Errors;
42 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
43 import com.sun.tools.javac.tree.*;
44 import com.sun.tools.javac.tree.JCTree.*;
45 import com.sun.tools.javac.util.*;
46 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
47 import com.sun.tools.javac.util.List;
48
49 import static com.sun.tools.javac.code.Flags.*;
50 import static com.sun.tools.javac.code.Kinds.Kind.*;
51
52 /** This class enters symbols for all encountered definitions into
53 * the symbol table. The pass consists of high-level two phases,
54 * organized as follows:
55 *
56 * <p>In the first phase, all class symbols are entered into their
57 * enclosing scope, descending recursively down the tree for classes
58 * which are members of other classes. The class symbols are given a
59 * TypeEnter object as completer.
60 *
61 * <p>In the second phase classes are completed using
62 * TypeEnter.complete(). Completion might occur on demand, but
63 * any classes that are not completed that way will be eventually
64 * completed by processing the `uncompleted' queue. Completion
65 * entails determination of a class's parameters, supertype and
66 * interfaces, as well as entering all symbols defined in the
67 * class into its scope, with the exception of class symbols which
68 * have been entered in phase 1.
69 *
70 * <p>Whereas the first phase is organized as a sweep through all
71 * compiled syntax trees, the second phase is on-demand. Members of a
72 * class are entered when the contents of a class are first
73 * accessed. This is accomplished by installing completer objects in
74 * class symbols for compiled classes which invoke the type-enter
75 * phase for the corresponding class tree.
76 *
77 * <p>Classes migrate from one phase to the next via queues:
78 *
79 * <pre>{@literal
80 * class enter -> (Enter.uncompleted) --> type enter
81 * -> (Todo) --> attribute
82 * (only for toplevel classes)
83 * }</pre>
84 *
85 * <p><b>This is NOT part of any supported API.
86 * If you write code that depends on this, you do so at your own risk.
87 * This code and its internal interfaces are subject to change or
88 * deletion without notice.</b>
89 */
90 public class Enter extends JCTree.Visitor {
91 protected static final Context.Key<Enter> enterKey = new Context.Key<>();
92
93 Annotate annotate;
94 Log log;
95 Symtab syms;
96 Check chk;
97 TreeMaker make;
98 TypeEnter typeEnter;
99 Types types;
100 Lint lint;
101 Names names;
102 JavaFileManager fileManager;
103 PkgInfo pkginfoOpt;
104 TypeEnvs typeEnvs;
105 Modules modules;
106 JCDiagnostic.Factory diags;
107
108 private final Todo todo;
109
110 public static Enter instance(Context context) {
111 Enter instance = context.get(enterKey);
112 if (instance == null)
113 instance = new Enter(context);
114 return instance;
115 }
116
117 protected Enter(Context context) {
118 context.put(enterKey, this);
119
120 log = Log.instance(context);
121 make = TreeMaker.instance(context);
122 syms = Symtab.instance(context);
123 chk = Check.instance(context);
124 typeEnter = TypeEnter.instance(context);
125 types = Types.instance(context);
126 annotate = Annotate.instance(context);
127 lint = Lint.instance(context);
128 names = Names.instance(context);
129 modules = Modules.instance(context);
130 diags = JCDiagnostic.Factory.instance(context);
131
132 predefClassDef = make.ClassDef(
133 make.Modifiers(PUBLIC),
134 syms.predefClass.name,
135 List.nil(),
136 null,
137 List.nil(),
138 List.nil());
139 predefClassDef.sym = syms.predefClass;
140 todo = Todo.instance(context);
141 fileManager = context.get(JavaFileManager.class);
142
143 Options options = Options.instance(context);
144 pkginfoOpt = PkgInfo.get(options);
145 typeEnvs = TypeEnvs.instance(context);
146 }
147
148 /** Accessor for typeEnvs
149 */
150 public Env<AttrContext> getEnv(TypeSymbol sym) {
151 return typeEnvs.get(sym);
152 }
153
154 public Iterable<Env<AttrContext>> getEnvs() {
155 return typeEnvs.values();
156 }
157
158 public Env<AttrContext> getClassEnv(TypeSymbol sym) {
159 Env<AttrContext> localEnv = getEnv(sym);
160 if (localEnv == null) return null;
161 Env<AttrContext> lintEnv = localEnv;
162 while (lintEnv.info.lint == null)
163 lintEnv = lintEnv.next;
164 localEnv.info.lint = lintEnv.info.lint.augment(sym);
165 return localEnv;
166 }
167
168 /** The queue of all classes that might still need to be completed;
169 * saved and initialized by main().
170 */
171 ListBuffer<ClassSymbol> uncompleted;
172
173 /** The queue of modules whose imports still need to be checked. */
174 ListBuffer<JCCompilationUnit> unfinishedModules = new ListBuffer<>();
175
176 /** A dummy class to serve as enclClass for toplevel environments.
177 */
178 private JCClassDecl predefClassDef;
179
180 /* ************************************************************************
181 * environment construction
182 *************************************************************************/
183
184
185 /** Create a fresh environment for class bodies.
186 * This will create a fresh scope for local symbols of a class, referred
187 * to by the environments info.scope field.
188 * This scope will contain
189 * - symbols for this and super
190 * - symbols for any type parameters
191 * In addition, it serves as an anchor for scopes of methods and initializers
192 * which are nested in this scope via Scope.dup().
193 * This scope should not be confused with the members scope of a class.
194 *
195 * @param tree The class definition.
196 * @param env The environment current outside of the class definition.
197 */
198 public Env<AttrContext> classEnv(JCClassDecl tree, Env<AttrContext> env) {
199 Env<AttrContext> localEnv =
200 env.dup(tree, env.info.dup(WriteableScope.create(tree.sym)));
201 localEnv.enclClass = tree;
202 localEnv.outer = env;
203 localEnv.info.isSelfCall = false;
204 localEnv.info.lint = null; // leave this to be filled in by Attr,
205 // when annotations have been processed
206 localEnv.info.isAnonymousDiamond = TreeInfo.isDiamond(env.tree);
207 return localEnv;
208 }
209
210 /** Create a fresh environment for toplevels.
211 * @param tree The toplevel tree.
212 */
213 Env<AttrContext> topLevelEnv(JCCompilationUnit tree) {
214 Env<AttrContext> localEnv = new Env<>(tree, new AttrContext());
215 localEnv.toplevel = tree;
216 localEnv.enclClass = predefClassDef;
217 tree.toplevelScope = WriteableScope.create(tree.packge);
218 tree.namedImportScope = new NamedImportScope(tree.packge);
219 tree.starImportScope = new StarImportScope(tree.packge);
220 localEnv.info.scope = tree.toplevelScope;
221 localEnv.info.lint = lint;
222 return localEnv;
223 }
224
225 public Env<AttrContext> getTopLevelEnv(JCCompilationUnit tree) {
226 Env<AttrContext> localEnv = new Env<>(tree, new AttrContext());
227 localEnv.toplevel = tree;
228 localEnv.enclClass = predefClassDef;
229 localEnv.info.scope = tree.toplevelScope;
230 localEnv.info.lint = lint;
231 return localEnv;
232 }
233
234 /** The scope in which a member definition in environment env is to be entered
235 * This is usually the environment's scope, except for class environments,
236 * where the local scope is for type variables, and the this and super symbol
237 * only, and members go into the class member scope.
238 */
239 WriteableScope enterScope(Env<AttrContext> env) {
240 return (env.tree.hasTag(JCTree.Tag.CLASSDEF))
241 ? ((JCClassDecl) env.tree).sym.members_field
242 : env.info.scope;
243 }
244
245 /** Create a fresh environment for modules.
246 *
247 * @param tree The module definition.
248 * @param env The environment current outside of the module definition.
249 */
250 public Env<AttrContext> moduleEnv(JCModuleDecl tree, Env<AttrContext> env) {
251 Assert.checkNonNull(tree.sym);
252 Env<AttrContext> localEnv =
253 env.dup(tree, env.info.dup(WriteableScope.create(tree.sym)));
254 localEnv.enclClass = predefClassDef;
255 localEnv.outer = env;
256 localEnv.info.isSelfCall = false;
257 localEnv.info.lint = null; // leave this to be filled in by Attr,
258 // when annotations have been processed
259 return localEnv;
260 }
261
262
263 /* ************************************************************************
264 * Visitor methods for phase 1: class enter
265 *************************************************************************/
266
267 /** Visitor argument: the current environment.
268 */
269 protected Env<AttrContext> env;
270
271 /** Visitor result: the computed type.
272 */
273 Type result;
274
275 /** Visitor method: enter all classes in given tree, catching any
276 * completion failure exceptions. Return the tree's type.
277 *
278 * @param tree The tree to be visited.
279 * @param env The environment visitor argument.
280 */
281 Type classEnter(JCTree tree, Env<AttrContext> env) {
282 Env<AttrContext> prevEnv = this.env;
283 try {
284 this.env = env;
285 annotate.blockAnnotations();
286 tree.accept(this);
287 return result;
288 } catch (CompletionFailure ex) {
289 return chk.completionError(tree.pos(), ex);
290 } finally {
291 annotate.unblockAnnotations();
292 this.env = prevEnv;
293 }
294 }
295
296 /** Visitor method: enter classes of a list of trees, returning a list of types.
297 */
298 <T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) {
299 ListBuffer<Type> ts = new ListBuffer<>();
300 for (List<T> l = trees; l.nonEmpty(); l = l.tail) {
301 Type t = classEnter(l.head, env);
302 if (t != null)
303 ts.append(t);
304 }
305 return ts.toList();
306 }
307
308 @Override
309 public void visitTopLevel(JCCompilationUnit tree) {
310 // Assert.checkNonNull(tree.modle, tree.sourcefile.toString());
311
312 JavaFileObject prev = log.useSource(tree.sourcefile);
313 boolean addEnv = false;
314 boolean isPkgInfo = tree.sourcefile.isNameCompatible("package-info",
315 JavaFileObject.Kind.SOURCE);
316 if (TreeInfo.isModuleInfo(tree)) {
317 JCPackageDecl pd = tree.getPackage();
318 if (pd != null) {
319 log.error(pd.pos(), Errors.NoPkgInModuleInfoJava);
320 }
321 tree.packge = syms.rootPackage;
322 Env<AttrContext> topEnv = topLevelEnv(tree);
323 classEnter(tree.defs, topEnv);
324 tree.modle.usesProvidesCompleter = modules.getUsesProvidesCompleter();
325 } else {
326 JCPackageDecl pd = tree.getPackage();
327 if (pd != null) {
328 tree.packge = pd.packge = syms.enterPackage(tree.modle, TreeInfo.fullName(pd.pid));
329 if ( pd.annotations.nonEmpty()
330 || pkginfoOpt == PkgInfo.ALWAYS
331 || tree.docComments != null) {
332 if (isPkgInfo) {
333 addEnv = true;
334 } else if (pd.annotations.nonEmpty()) {
335 log.error(pd.annotations.head.pos(),
336 Errors.PkgAnnotationsSbInPackageInfoJava);
337 }
338 }
339 } else {
340 tree.packge = tree.modle.unnamedPackage;
341 }
342
343 Map<Name, PackageSymbol> visiblePackages = tree.modle.visiblePackages;
344 Optional<ModuleSymbol> dependencyWithPackage =
345 syms.listPackageModules(tree.packge.fullname)
346 .stream()
347 .filter(m -> m != tree.modle)
348 .filter(cand -> visiblePackages.get(tree.packge.fullname) == syms.getPackage(cand, tree.packge.fullname))
349 .findAny();
350
351 if (dependencyWithPackage.isPresent()) {
352 log.error(pd, Errors.PackageInOtherModule(dependencyWithPackage.get()));
353 }
354
355 tree.packge.complete(); // Find all classes in package.
356
357 Env<AttrContext> topEnv = topLevelEnv(tree);
358 Env<AttrContext> packageEnv = isPkgInfo ? topEnv.dup(pd) : null;
359
360 // Save environment of package-info.java file.
361 if (isPkgInfo) {
362 Env<AttrContext> env0 = typeEnvs.get(tree.packge);
363 if (env0 != null) {
364 JCCompilationUnit tree0 = env0.toplevel;
365 if (!fileManager.isSameFile(tree.sourcefile, tree0.sourcefile)) {
366 log.warning(pd != null ? pd.pid.pos() : null,
367 Warnings.PkgInfoAlreadySeen(tree.packge));
368 }
369 }
370 typeEnvs.put(tree.packge, packageEnv);
371
372 for (Symbol q = tree.packge; q != null && q.kind == PCK; q = q.owner)
373 q.flags_field |= EXISTS;
374
375 Name name = names.package_info;
376 ClassSymbol c = syms.enterClass(tree.modle, name, tree.packge);
377 c.flatname = names.fromString(tree.packge + "." + name);
378 c.sourcefile = tree.sourcefile;
379 c.completer = Completer.NULL_COMPLETER;
380 c.members_field = WriteableScope.create(c);
381 tree.packge.package_info = c;
382 tree.packge.sourcefile = tree.sourcefile;
383 }
384 classEnter(tree.defs, topEnv);
385 if (addEnv) {
386 todo.append(packageEnv);
387 }
388 }
389 log.useSource(prev);
390 result = null;
391 }
392
393 @Override
394 public void visitClassDef(JCClassDecl tree) {
395 Symbol owner = env.info.scope.owner;
396 WriteableScope enclScope = enterScope(env);
397 ClassSymbol c;
398 if (owner.kind == PCK) {
399 // We are seeing a toplevel class.
400 PackageSymbol packge = (PackageSymbol)owner;
401 for (Symbol q = packge; q != null && q.kind == PCK; q = q.owner)
402 q.flags_field |= EXISTS;
403 c = syms.enterClass(env.toplevel.modle, tree.name, packge);
404 packge.members().enterIfAbsent(c);
405 if ((tree.mods.flags & PUBLIC) != 0 && !classNameMatchesFileName(c, env)) {
406 KindName topElement = KindName.CLASS;
407 if ((tree.mods.flags & ENUM) != 0) {
408 topElement = KindName.ENUM;
409 } else if ((tree.mods.flags & INTERFACE) != 0) {
410 topElement = KindName.INTERFACE;
411 }
412 log.error(tree.pos(),
413 Errors.ClassPublicShouldBeInFile(topElement, tree.name));
414 }
415 } else {
416 if (!tree.name.isEmpty() &&
417 !chk.checkUniqueClassName(tree.pos(), tree.name, enclScope)) {
418 result = null;
419 return;
420 }
421 if (owner.kind == TYP) {
422 // We are seeing a member class.
423 c = syms.enterClass(env.toplevel.modle, tree.name, (TypeSymbol)owner);
424 if (c.owner != owner) {
425 if (c.name != tree.name) {
426 log.error(tree.pos(), Errors.SameBinaryName(c.name, tree.name));
427 result = types.createErrorType(tree.name, (TypeSymbol)owner, Type.noType);
428 tree.sym = (ClassSymbol)result.tsym;
429 return;
430 }
431 //anonymous class loaded from a classfile may be recreated from source (see below)
432 //if this class is a member of such an anonymous class, fix the owner:
433 Assert.check(owner.owner.kind != TYP, owner::toString);
434 Assert.check(c.owner.kind == TYP, () -> c.owner.toString());
435 ClassSymbol cowner = (ClassSymbol) c.owner;
436 if (cowner.members_field != null) {
437 cowner.members_field.remove(c);
438 }
439 c.owner = owner;
440 }
441 if ((owner.flags_field & INTERFACE) != 0) {
442 tree.mods.flags |= PUBLIC | STATIC;
443 }
444 } else {
445 // We are seeing a local class.
446 c = syms.defineClass(tree.name, owner);
447 c.flatname = chk.localClassName(c);
448 if (!c.name.isEmpty())
449 chk.checkTransparentClass(tree.pos(), c, env.info.scope);
450 }
451 }
452 tree.sym = c;
453
454 // Enter class into `compiled' table and enclosing scope.
455 if (chk.getCompiled(c) != null) {
456 duplicateClass(tree.pos(), c);
457 result = types.createErrorType(tree.name, (TypeSymbol)owner, Type.noType);
458 tree.sym = (ClassSymbol)result.tsym;
459 return;
460 }
461 chk.putCompiled(c);
462 enclScope.enter(c);
463
464 // Set up an environment for class block and store in `typeEnvs'
465 // table, to be retrieved later in memberEnter and attribution.
466 Env<AttrContext> localEnv = classEnv(tree, env);
467 typeEnvs.put(c, localEnv);
468
469 // Fill out class fields.
470 c.completer = Completer.NULL_COMPLETER; // do not allow the initial completer linger on.
471 c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree);
472 c.sourcefile = env.toplevel.sourcefile;
473 c.members_field = WriteableScope.create(c);
474 c.clearAnnotationMetadata();
475
476 ClassType ct = (ClassType)c.type;
477 if (owner.kind != PCK && (c.flags_field & STATIC) == 0) {
478 // We are seeing a local or inner class.
479 // Set outer_field of this class to closest enclosing class
480 // which contains this class in a non-static context
481 // (its "enclosing instance class"), provided such a class exists.
482 Symbol owner1 = owner;
483 while (owner1.kind.matches(KindSelector.VAL_MTH) &&
484 (owner1.flags_field & STATIC) == 0) {
485 owner1 = owner1.owner;
486 }
487 if (owner1.kind == TYP) {
488 ct.setEnclosingType(owner1.type);
489 }
490 }
491
492 // Enter type parameters.
493 ct.typarams_field = classEnter(tree.typarams, localEnv);
494 ct.allparams_field = null;
495
496 // install further completer for this type.
497 c.completer = typeEnter;
498
499 // Add non-local class to uncompleted, to make sure it will be
500 // completed later.
501 if (!c.isLocal() && uncompleted != null) uncompleted.append(c);
502 // System.err.println("entering " + c.fullname + " in " + c.owner);//DEBUG
503
504 // Recursively enter all member classes.
505 classEnter(tree.defs, localEnv);
506
507 // Assert.checkNonNull(c.modle, c.sourcefile.toString());
508
509 result = c.type;
510 }
511 //where
512 /** Does class have the same name as the file it appears in?
513 */
514 private static boolean classNameMatchesFileName(ClassSymbol c,
515 Env<AttrContext> env) {
516 return env.toplevel.sourcefile.isNameCompatible(c.name.toString(),
517 JavaFileObject.Kind.SOURCE);
518 }
519
520 /** Complain about a duplicate class. */
521 protected void duplicateClass(DiagnosticPosition pos, ClassSymbol c) {
522 log.error(pos, Errors.DuplicateClass(c.fullname));
523 }
524
525 /** Class enter visitor method for type parameters.
526 * Enter a symbol for type parameter in local scope, after checking that it
527 * is unique.
528 */
529 @Override
530 public void visitTypeParameter(JCTypeParameter tree) {
531 TypeVar a = (tree.type != null)
532 ? (TypeVar)tree.type
533 : new TypeVar(tree.name, env.info.scope.owner, syms.botType);
534 tree.type = a;
535 if (chk.checkUnique(tree.pos(), a.tsym, env.info.scope)) {
536 env.info.scope.enter(a.tsym);
537 }
538 result = a;
539 }
540
541 @Override
542 public void visitModuleDef(JCModuleDecl tree) {
543 Env<AttrContext> moduleEnv = moduleEnv(tree, env);
544 typeEnvs.put(tree.sym, moduleEnv);
545 if (modules.isInModuleGraph(tree.sym)) {
546 todo.append(moduleEnv);
547 }
548 }
549
550 /** Default class enter visitor method: do nothing.
551 */
552 @Override
553 public void visitTree(JCTree tree) {
554 result = null;
555 }
556
557 /** Main method: enter all classes in a list of toplevel trees.
558 * @param trees The list of trees to be processed.
559 */
560 public void main(List<JCCompilationUnit> trees) {
561 complete(trees, null);
562 }
563
564 /** Main method: enter classes from the list of toplevel trees, possibly
565 * skipping TypeEnter for all but 'c' by placing them on the uncompleted
566 * list.
567 * @param trees The list of trees to be processed.
568 * @param c The class symbol to be processed or null to process all.
569 */
570 public void complete(List<JCCompilationUnit> trees, ClassSymbol c) {
571 annotate.blockAnnotations();
572 ListBuffer<ClassSymbol> prevUncompleted = uncompleted;
573 if (typeEnter.completionEnabled) uncompleted = new ListBuffer<>();
574
575 try {
576 // enter all classes, and construct uncompleted list
577 classEnter(trees, null);
578
579 // complete all uncompleted classes in memberEnter
580 if (typeEnter.completionEnabled) {
581 while (uncompleted.nonEmpty()) {
582 ClassSymbol clazz = uncompleted.next();
583 if (c == null || c == clazz || prevUncompleted == null)
584 clazz.complete();
585 else
586 // defer
587 prevUncompleted.append(clazz);
588 }
589
590 if (!modules.modulesInitialized()) {
591 for (JCCompilationUnit cut : trees) {
592 if (cut.getModuleDecl() != null) {
593 unfinishedModules.append(cut);
594 } else {
595 typeEnter.ensureImportsChecked(List.of(cut));
596 }
597 }
598 } else {
599 typeEnter.ensureImportsChecked(unfinishedModules.toList());
600 unfinishedModules.clear();
601 typeEnter.ensureImportsChecked(trees);
602 }
603 }
604 } finally {
605 uncompleted = prevUncompleted;
606 annotate.unblockAnnotations();
607 }
608 }
609
610 public void newRound() {
611 typeEnvs.clear();
612 }
613 }