1 /*
2 * Copyright (c) 1999, 2016, 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.KindSelector;
36 import com.sun.tools.javac.code.Scope.*;
37 import com.sun.tools.javac.code.Symbol.*;
38 import com.sun.tools.javac.code.Type.*;
39 import com.sun.tools.javac.main.Option.PkgInfo;
40 import com.sun.tools.javac.resources.CompilerProperties.Errors;
41 import com.sun.tools.javac.tree.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.util.*;
44 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
45 import com.sun.tools.javac.util.List;
46
47 import static com.sun.tools.javac.code.Flags.*;
48 import static com.sun.tools.javac.code.Kinds.Kind.*;
49
50 /** This class enters symbols for all encountered definitions into
51 * the symbol table. The pass consists of high-level two phases,
52 * organized as follows:
53 *
54 * <p>In the first phase, all class symbols are entered into their
55 * enclosing scope, descending recursively down the tree for classes
56 * which are members of other classes. The class symbols are given a
57 * TypeEnter object as completer.
58 *
59 * <p>In the second phase classes are completed using
60 * TypeEnter.complete(). Completion might occur on demand, but
61 * any classes that are not completed that way will be eventually
62 * completed by processing the `uncompleted' queue. Completion
63 * entails determination of a class's parameters, supertype and
64 * interfaces, as well as entering all symbols defined in the
65 * class into its scope, with the exception of class symbols which
66 * have been entered in phase 1.
67 *
68 * <p>Whereas the first phase is organized as a sweep through all
69 * compiled syntax trees, the second phase is on-demand. Members of a
70 * class are entered when the contents of a class are first
71 * accessed. This is accomplished by installing completer objects in
72 * class symbols for compiled classes which invoke the type-enter
73 * phase for the corresponding class tree.
74 *
75 * <p>Classes migrate from one phase to the next via queues:
76 *
77 * <pre>{@literal
78 * class enter -> (Enter.uncompleted) --> type enter
79 * -> (Todo) --> attribute
80 * (only for toplevel classes)
81 * }</pre>
82 *
83 * <p><b>This is NOT part of any supported API.
84 * If you write code that depends on this, you do so at your own risk.
85 * This code and its internal interfaces are subject to change or
86 * deletion without notice.</b>
87 */
88 public class Enter extends JCTree.Visitor {
89 protected static final Context.Key<Enter> enterKey = new Context.Key<>();
90
91 Annotate annotate;
92 Log log;
93 Symtab syms;
94 Check chk;
95 TreeMaker make;
96 TypeEnter typeEnter;
97 Types types;
98 Lint lint;
99 Names names;
100 JavaFileManager fileManager;
101 PkgInfo pkginfoOpt;
102 TypeEnvs typeEnvs;
103 Modules modules;
104 JCDiagnostic.Factory diags;
105
106 private final Todo todo;
107
108 public static Enter instance(Context context) {
109 Enter instance = context.get(enterKey);
110 if (instance == null)
111 instance = new Enter(context);
112 return instance;
113 }
114
115 protected Enter(Context context) {
116 context.put(enterKey, this);
117
118 log = Log.instance(context);
119 make = TreeMaker.instance(context);
120 syms = Symtab.instance(context);
121 chk = Check.instance(context);
122 typeEnter = TypeEnter.instance(context);
123 types = Types.instance(context);
124 annotate = Annotate.instance(context);
125 lint = Lint.instance(context);
126 names = Names.instance(context);
127 modules = Modules.instance(context);
128 diags = JCDiagnostic.Factory.instance(context);
129
130 predefClassDef = make.ClassDef(
131 make.Modifiers(PUBLIC),
132 syms.predefClass.name,
133 List.<JCTypeParameter>nil(),
134 null,
135 List.<JCExpression>nil(),
136 List.<JCTree>nil());
137 predefClassDef.sym = syms.predefClass;
138 todo = Todo.instance(context);
139 fileManager = context.get(JavaFileManager.class);
140
141 Options options = Options.instance(context);
142 pkginfoOpt = PkgInfo.get(options);
143 typeEnvs = TypeEnvs.instance(context);
144 }
145
146 /** Accessor for typeEnvs
147 */
148 public Env<AttrContext> getEnv(TypeSymbol sym) {
149 return typeEnvs.get(sym);
150 }
151
152 public Iterable<Env<AttrContext>> getEnvs() {
153 return typeEnvs.values();
154 }
155
156 public Env<AttrContext> getClassEnv(TypeSymbol sym) {
157 Env<AttrContext> localEnv = getEnv(sym);
158 Env<AttrContext> lintEnv = localEnv;
159 while (lintEnv.info.lint == null)
160 lintEnv = lintEnv.next;
161 localEnv.info.lint = lintEnv.info.lint.augment(sym);
162 return localEnv;
163 }
164
165 /** The queue of all classes that might still need to be completed;
166 * saved and initialized by main().
167 */
168 ListBuffer<ClassSymbol> uncompleted;
169
170 /** A dummy class to serve as enclClass for toplevel environments.
171 */
172 private JCClassDecl predefClassDef;
173
174 /* ************************************************************************
175 * environment construction
176 *************************************************************************/
177
178
179 /** Create a fresh environment for class bodies.
180 * This will create a fresh scope for local symbols of a class, referred
181 * to by the environments info.scope field.
182 * This scope will contain
183 * - symbols for this and super
184 * - symbols for any type parameters
185 * In addition, it serves as an anchor for scopes of methods and initializers
186 * which are nested in this scope via Scope.dup().
187 * This scope should not be confused with the members scope of a class.
188 *
189 * @param tree The class definition.
190 * @param env The environment current outside of the class definition.
191 */
192 public Env<AttrContext> classEnv(JCClassDecl tree, Env<AttrContext> env) {
193 Env<AttrContext> localEnv =
194 env.dup(tree, env.info.dup(WriteableScope.create(tree.sym)));
195 localEnv.enclClass = tree;
196 localEnv.outer = env;
197 localEnv.info.isSelfCall = false;
198 localEnv.info.lint = null; // leave this to be filled in by Attr,
199 // when annotations have been processed
200 localEnv.info.isAnonymousDiamond = TreeInfo.isDiamond(env.tree);
201 return localEnv;
202 }
203
204 /** Create a fresh environment for toplevels.
205 * @param tree The toplevel tree.
206 */
207 Env<AttrContext> topLevelEnv(JCCompilationUnit tree) {
208 Env<AttrContext> localEnv = new Env<>(tree, new AttrContext());
209 localEnv.toplevel = tree;
210 localEnv.enclClass = predefClassDef;
211 tree.toplevelScope = WriteableScope.create(tree.packge);
212 tree.namedImportScope = new NamedImportScope(tree.packge, tree.toplevelScope);
213 tree.starImportScope = new StarImportScope(tree.packge);
214 localEnv.info.scope = tree.toplevelScope;
215 localEnv.info.lint = lint;
216 return localEnv;
217 }
218
219 public Env<AttrContext> getTopLevelEnv(JCCompilationUnit tree) {
220 Env<AttrContext> localEnv = new Env<>(tree, new AttrContext());
221 localEnv.toplevel = tree;
222 localEnv.enclClass = predefClassDef;
223 localEnv.info.scope = tree.toplevelScope;
224 localEnv.info.lint = lint;
225 return localEnv;
226 }
227
228 /** The scope in which a member definition in environment env is to be entered
229 * This is usually the environment's scope, except for class environments,
230 * where the local scope is for type variables, and the this and super symbol
231 * only, and members go into the class member scope.
232 */
233 WriteableScope enterScope(Env<AttrContext> env) {
234 return (env.tree.hasTag(JCTree.Tag.CLASSDEF))
235 ? ((JCClassDecl) env.tree).sym.members_field
236 : env.info.scope;
237 }
238
239 /** Create a fresh environment for modules.
240 *
241 * @param tree The module definition.
242 * @param env The environment current outside of the module definition.
243 */
244 public Env<AttrContext> moduleEnv(JCModuleDecl tree, Env<AttrContext> env) {
245 Assert.checkNonNull(tree.sym);
246 Env<AttrContext> localEnv =
247 env.dup(tree, env.info.dup(WriteableScope.create(tree.sym)));
248 localEnv.enclClass = predefClassDef;
249 localEnv.outer = env;
250 localEnv.info.isSelfCall = false;
251 localEnv.info.lint = null; // leave this to be filled in by Attr,
252 // when annotations have been processed
253 return localEnv;
254 }
255
256
257 /* ************************************************************************
258 * Visitor methods for phase 1: class enter
259 *************************************************************************/
260
261 /** Visitor argument: the current environment.
262 */
263 protected Env<AttrContext> env;
264
265 /** Visitor result: the computed type.
266 */
267 Type result;
268
269 /** Visitor method: enter all classes in given tree, catching any
270 * completion failure exceptions. Return the tree's type.
271 *
272 * @param tree The tree to be visited.
273 * @param env The environment visitor argument.
274 */
275 Type classEnter(JCTree tree, Env<AttrContext> env) {
276 Env<AttrContext> prevEnv = this.env;
277 try {
278 this.env = env;
279 annotate.blockAnnotations();
280 tree.accept(this);
281 return result;
282 } catch (CompletionFailure ex) {
283 return chk.completionError(tree.pos(), ex);
284 } finally {
285 annotate.unblockAnnotations();
286 this.env = prevEnv;
287 }
288 }
289
290 /** Visitor method: enter classes of a list of trees, returning a list of types.
291 */
292 <T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) {
293 ListBuffer<Type> ts = new ListBuffer<>();
294 for (List<T> l = trees; l.nonEmpty(); l = l.tail) {
295 Type t = classEnter(l.head, env);
296 if (t != null)
297 ts.append(t);
298 }
299 return ts.toList();
300 }
301
302 @Override
303 public void visitTopLevel(JCCompilationUnit tree) {
304 // Assert.checkNonNull(tree.modle, tree.sourcefile.toString());
305
306 JavaFileObject prev = log.useSource(tree.sourcefile);
307 boolean addEnv = false;
308 boolean isPkgInfo = tree.sourcefile.isNameCompatible("package-info",
309 JavaFileObject.Kind.SOURCE);
310 if (TreeInfo.isModuleInfo(tree)) {
311 tree.packge = syms.rootPackage;
312 Env<AttrContext> topEnv = topLevelEnv(tree);
313 classEnter(tree.defs, topEnv);
314 tree.modle.usesProvidesCompleter = modules.getUsesProvidesCompleter();
315 } else {
316 JCPackageDecl pd = tree.getPackage();
317 if (pd != null) {
318 tree.packge = pd.packge = syms.enterPackage(tree.modle, TreeInfo.fullName(pd.pid));
319 if ( pd.annotations.nonEmpty()
320 || pkginfoOpt == PkgInfo.ALWAYS
321 || tree.docComments != null) {
322 if (isPkgInfo) {
323 addEnv = true;
324 } else if (pd.annotations.nonEmpty()) {
325 log.error(pd.annotations.head.pos(),
326 "pkg.annotations.sb.in.package-info.java");
327 }
328 }
329 } else {
330 tree.packge = tree.modle.unnamedPackage;
331 }
332
333 Map<Name, PackageSymbol> visiblePackages = tree.modle.visiblePackages;
334 Optional<ModuleSymbol> dependencyWithPackage =
335 syms.listPackageModules(tree.packge.fullname)
336 .stream()
337 .filter(m -> m != tree.modle)
338 .filter(cand -> visiblePackages.get(tree.packge.fullname) == syms.getPackage(cand, tree.packge.fullname))
339 .findAny();
340
341 if (dependencyWithPackage.isPresent()) {
342 @SuppressWarnings("deprecation")
343 ModuleSymbol moduleSymbol = dependencyWithPackage.get();
344 log.error(pd, Errors.PackageInOtherModule(moduleSymbol));
345 }
346
347 tree.packge.complete(); // Find all classes in package.
348
349 Env<AttrContext> topEnv = topLevelEnv(tree);
350 Env<AttrContext> packageEnv = isPkgInfo ? topEnv.dup(pd) : null;
351
352 // Save environment of package-info.java file.
353 if (isPkgInfo) {
354 Env<AttrContext> env0 = typeEnvs.get(tree.packge);
355 if (env0 != null) {
356 JCCompilationUnit tree0 = env0.toplevel;
357 if (!fileManager.isSameFile(tree.sourcefile, tree0.sourcefile)) {
358 log.warning(pd != null ? pd.pid.pos() : null,
359 "pkg-info.already.seen",
360 tree.packge);
361 }
362 }
363 typeEnvs.put(tree.packge, packageEnv);
364
365 for (Symbol q = tree.packge; q != null && q.kind == PCK; q = q.owner)
366 q.flags_field |= EXISTS;
367
368 Name name = names.package_info;
369 ClassSymbol c = syms.enterClass(tree.modle, name, tree.packge);
370 c.flatname = names.fromString(tree.packge + "." + name);
371 c.sourcefile = tree.sourcefile;
372 c.completer = Completer.NULL_COMPLETER;
373 c.members_field = WriteableScope.create(c);
374 tree.packge.package_info = c;
375 }
376 classEnter(tree.defs, topEnv);
377 if (addEnv) {
378 todo.append(packageEnv);
379 }
380 }
381 log.useSource(prev);
382 result = null;
383 }
384
385 @Override
386 public void visitClassDef(JCClassDecl tree) {
387 Symbol owner = env.info.scope.owner;
388 WriteableScope enclScope = enterScope(env);
389 ClassSymbol c;
390 if (owner.kind == PCK) {
391 // We are seeing a toplevel class.
392 PackageSymbol packge = (PackageSymbol)owner;
393 for (Symbol q = packge; q != null && q.kind == PCK; q = q.owner)
394 q.flags_field |= EXISTS;
395 c = syms.enterClass(env.toplevel.modle, tree.name, packge);
396 packge.members().enterIfAbsent(c);
397 if ((tree.mods.flags & PUBLIC) != 0 && !classNameMatchesFileName(c, env)) {
398 log.error(tree.pos(),
399 "class.public.should.be.in.file", tree.name);
400 }
401 } else {
402 if (!tree.name.isEmpty() &&
403 !chk.checkUniqueClassName(tree.pos(), tree.name, enclScope)) {
404 result = null;
405 return;
406 }
407 if (owner.kind == TYP) {
408 // We are seeing a member class.
409 c = syms.enterClass(env.toplevel.modle, tree.name, (TypeSymbol)owner);
410 if ((owner.flags_field & INTERFACE) != 0) {
411 tree.mods.flags |= PUBLIC | STATIC;
412 }
413 } else {
414 // We are seeing a local class.
415 c = syms.defineClass(tree.name, owner);
416 c.flatname = chk.localClassName(c);
417 if (!c.name.isEmpty())
418 chk.checkTransparentClass(tree.pos(), c, env.info.scope);
419 }
420 }
421 tree.sym = c;
422
423 // Enter class into `compiled' table and enclosing scope.
424 if (chk.getCompiled(c) != null) {
425 duplicateClass(tree.pos(), c);
426 result = types.createErrorType(tree.name, (TypeSymbol)owner, Type.noType);
427 tree.sym = (ClassSymbol)result.tsym;
428 return;
429 }
430 chk.putCompiled(c);
431 enclScope.enter(c);
432
433 // Set up an environment for class block and store in `typeEnvs'
434 // table, to be retrieved later in memberEnter and attribution.
435 Env<AttrContext> localEnv = classEnv(tree, env);
436 typeEnvs.put(c, localEnv);
437
438 // Fill out class fields.
439 c.completer = Completer.NULL_COMPLETER; // do not allow the initial completer linger on.
440 c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree);
441 c.sourcefile = env.toplevel.sourcefile;
442 c.members_field = WriteableScope.create(c);
443
444 ClassType ct = (ClassType)c.type;
445 if (owner.kind != PCK && (c.flags_field & STATIC) == 0) {
446 // We are seeing a local or inner class.
447 // Set outer_field of this class to closest enclosing class
448 // which contains this class in a non-static context
449 // (its "enclosing instance class"), provided such a class exists.
450 Symbol owner1 = owner;
451 while (owner1.kind.matches(KindSelector.VAL_MTH) &&
452 (owner1.flags_field & STATIC) == 0) {
453 owner1 = owner1.owner;
454 }
455 if (owner1.kind == TYP) {
456 ct.setEnclosingType(owner1.type);
457 }
458 }
459
460 // Enter type parameters.
461 ct.typarams_field = classEnter(tree.typarams, localEnv);
462
463 // install further completer for this type.
464 c.completer = typeEnter;
465
466 // Add non-local class to uncompleted, to make sure it will be
467 // completed later.
468 if (!c.isLocal() && uncompleted != null) uncompleted.append(c);
469 // System.err.println("entering " + c.fullname + " in " + c.owner);//DEBUG
470
471 // Recursively enter all member classes.
472 classEnter(tree.defs, localEnv);
473
474 // Assert.checkNonNull(c.modle, c.sourcefile.toString());
475
476 result = c.type;
477 }
478 //where
479 /** Does class have the same name as the file it appears in?
480 */
481 private static boolean classNameMatchesFileName(ClassSymbol c,
482 Env<AttrContext> env) {
483 return env.toplevel.sourcefile.isNameCompatible(c.name.toString(),
484 JavaFileObject.Kind.SOURCE);
485 }
486
487 /** Complain about a duplicate class. */
488 protected void duplicateClass(DiagnosticPosition pos, ClassSymbol c) {
489 log.error(pos, "duplicate.class", c.fullname);
490 }
491
492 /** Class enter visitor method for type parameters.
493 * Enter a symbol for type parameter in local scope, after checking that it
494 * is unique.
495 */
496 @Override
497 public void visitTypeParameter(JCTypeParameter tree) {
498 TypeVar a = (tree.type != null)
499 ? (TypeVar)tree.type
500 : new TypeVar(tree.name, env.info.scope.owner, syms.botType);
501 tree.type = a;
502 if (chk.checkUnique(tree.pos(), a.tsym, env.info.scope)) {
503 env.info.scope.enter(a.tsym);
504 }
505 result = a;
506 }
507
508 @Override
509 public void visitModuleDef(JCModuleDecl tree) {
510 Env<AttrContext> moduleEnv = moduleEnv(tree, env);
511 typeEnvs.put(tree.sym, moduleEnv);
512 todo.append(moduleEnv);
513 }
514
515 /** Default class enter visitor method: do nothing.
516 */
517 @Override
518 public void visitTree(JCTree tree) {
519 result = null;
520 }
521
522 /** Main method: enter all classes in a list of toplevel trees.
523 * @param trees The list of trees to be processed.
524 */
525 public void main(List<JCCompilationUnit> trees) {
526 complete(trees, null);
527 }
528
529 /** Main method: enter classes from the list of toplevel trees, possibly
530 * skipping TypeEnter for all but 'c' by placing them on the uncompleted
531 * list.
532 * @param trees The list of trees to be processed.
533 * @param c The class symbol to be processed or null to process all.
534 */
535 public void complete(List<JCCompilationUnit> trees, ClassSymbol c) {
536 annotate.blockAnnotations();
537 ListBuffer<ClassSymbol> prevUncompleted = uncompleted;
538 if (typeEnter.completionEnabled) uncompleted = new ListBuffer<>();
539
540 try {
541 // enter all classes, and construct uncompleted list
542 classEnter(trees, null);
543
544 // complete all uncompleted classes in memberEnter
545 if (typeEnter.completionEnabled) {
546 while (uncompleted.nonEmpty()) {
547 ClassSymbol clazz = uncompleted.next();
548 if (c == null || c == clazz || prevUncompleted == null)
549 clazz.complete();
550 else
551 // defer
552 prevUncompleted.append(clazz);
553 }
554
555 typeEnter.ensureImportsChecked(trees);
556 }
557 } finally {
558 uncompleted = prevUncompleted;
559 annotate.unblockAnnotations();
560 }
561 }
562
563 public void newRound() {
564 typeEnvs.clear();
565 }
566 }