1 | /* |
2 | * Copyright 1999-2006 Sun Microsystems, Inc. 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. Sun designates this |
8 | * particular file as subject to the "Classpath" exception as provided |
9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
23 | * have any questions. |
24 | */ |
25 | |
26 | package com.sun.tools.javac.comp; |
27 | |
28 | import java.util.*; |
29 | import java.util.Set; |
30 | import javax.tools.JavaFileObject; |
31 | import javax.tools.JavaFileManager; |
32 | |
33 | import com.sun.tools.javac.code.*; |
34 | import com.sun.tools.javac.jvm.*; |
35 | import com.sun.tools.javac.tree.*; |
36 | import com.sun.tools.javac.util.*; |
37 | import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; |
38 | import com.sun.tools.javac.util.List; |
39 | |
40 | import com.sun.tools.javac.code.Type.*; |
41 | import com.sun.tools.javac.code.Symbol.*; |
42 | import com.sun.tools.javac.tree.JCTree.*; |
43 | |
44 | import static com.sun.tools.javac.code.Flags.*; |
45 | import static com.sun.tools.javac.code.Kinds.*; |
46 | import static com.sun.tools.javac.code.TypeTags.*; |
47 | |
48 | /** This class enters symbols for all encountered definitions into |
49 | * the symbol table. The pass consists of two phases, organized as |
50 | * follows: |
51 | * |
52 | * <p>In the first phase, all class symbols are intered into their |
53 | * enclosing scope, descending recursively down the tree for classes |
54 | * which are members of other classes. The class symbols are given a |
55 | * MemberEnter object as completer. |
56 | * |
57 | * <p>In the second phase classes are completed using |
58 | * MemberEnter.complete(). Completion might occur on demand, but |
59 | * any classes that are not completed that way will be eventually |
60 | * completed by processing the `uncompleted' queue. Completion |
61 | * entails (1) determination of a class's parameters, supertype and |
62 | * interfaces, as well as (2) entering all symbols defined in the |
63 | * class into its scope, with the exception of class symbols which |
64 | * have been entered in phase 1. (2) depends on (1) having been |
65 | * completed for a class and all its superclasses and enclosing |
66 | * classes. That's why, after doing (1), we put classes in a |
67 | * `halfcompleted' queue. Only when we have performed (1) for a class |
68 | * and all it's superclasses and enclosing classes, we proceed to |
69 | * (2). |
70 | * |
71 | * <p>Whereas the first phase is organized as a sweep through all |
72 | * compiled syntax trees, the second phase is demand. Members of a |
73 | * class are entered when the contents of a class are first |
74 | * accessed. This is accomplished by installing completer objects in |
75 | * class symbols for compiled classes which invoke the member-enter |
76 | * phase for the corresponding class tree. |
77 | * |
78 | * <p>Classes migrate from one phase to the next via queues: |
79 | * |
80 | * <pre> |
81 | * class enter -> (Enter.uncompleted) --> member enter (1) |
82 | * -> (MemberEnter.halfcompleted) --> member enter (2) |
83 | * -> (Todo) --> attribute |
84 | * (only for toplevel classes) |
85 | * </pre> |
86 | * |
87 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
88 | * you write code that depends on this, you do so at your own risk. |
89 | * This code and its internal interfaces are subject to change or |
90 | * deletion without notice.</b> |
91 | */ |
92 | public class Enter extends JCTree.Visitor { |
93 | protected static final Context.Key<Enter> enterKey = |
94 | new Context.Key<Enter>(); |
95 | |
96 | Log log; |
97 | Symtab syms; |
98 | Check chk; |
99 | TreeMaker make; |
100 | ClassReader reader; |
101 | Annotate annotate; |
102 | MemberEnter memberEnter; |
103 | Lint lint; |
104 | JavaFileManager fileManager; |
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 | reader = ClassReader.instance(context); |
120 | make = TreeMaker.instance(context); |
121 | syms = Symtab.instance(context); |
122 | chk = Check.instance(context); |
123 | memberEnter = MemberEnter.instance(context); |
124 | annotate = Annotate.instance(context); |
125 | lint = Lint.instance(context); |
126 | |
127 | predefClassDef = make.ClassDef( |
128 | make.Modifiers(PUBLIC), |
129 | syms.predefClass.name, null, null, null, null); |
130 | predefClassDef.sym = syms.predefClass; |
131 | todo = Todo.instance(context); |
132 | fileManager = context.get(JavaFileManager.class); |
133 | } |
134 | |
135 | /** A hashtable mapping classes and packages to the environments current |
136 | * at the points of their definitions. |
137 | */ |
138 | Map<TypeSymbol,Env<AttrContext>> typeEnvs = |
139 | new HashMap<TypeSymbol,Env<AttrContext>>(); |
140 | |
141 | /** Accessor for typeEnvs |
142 | */ |
143 | public Env<AttrContext> getEnv(TypeSymbol sym) { |
144 | return typeEnvs.get(sym); |
145 | } |
146 | |
147 | public Env<AttrContext> getClassEnv(TypeSymbol sym) { |
148 | Env<AttrContext> localEnv = getEnv(sym); |
149 | Env<AttrContext> lintEnv = localEnv; |
150 | while (lintEnv.info.lint == null) |
151 | lintEnv = lintEnv.next; |
152 | localEnv.info.lint = lintEnv.info.lint.augment(sym.attributes_field, sym.flags()); |
153 | return localEnv; |
154 | } |
155 | |
156 | /** The queue of all classes that might still need to be completed; |
157 | * saved and initialized by main(). |
158 | */ |
159 | ListBuffer<ClassSymbol> uncompleted; |
160 | |
161 | /** A dummy class to serve as enclClass for toplevel environments. |
162 | */ |
163 | private JCClassDecl predefClassDef; |
164 | |
165 | /* ************************************************************************ |
166 | * environment construction |
167 | *************************************************************************/ |
168 | |
169 | |
170 | /** Create a fresh environment for class bodies. |
171 | * This will create a fresh scope for local symbols of a class, referred |
172 | * to by the environments info.scope field. |
173 | * This scope will contain |
174 | * - symbols for this and super |
175 | * - symbols for any type parameters |
176 | * In addition, it serves as an anchor for scopes of methods and initializers |
177 | * which are nested in this scope via Scope.dup(). |
178 | * This scope should not be confused with the members scope of a class. |
179 | * |
180 | * @param tree The class definition. |
181 | * @param env The environment current outside of the class definition. |
182 | */ |
183 | public Env<AttrContext> classEnv(JCClassDecl tree, Env<AttrContext> env) { |
184 | Env<AttrContext> localEnv = |
185 | env.dup(tree, env.info.dup(new Scope(tree.sym))); |
186 | localEnv.enclClass = tree; |
187 | localEnv.outer = env; |
188 | localEnv.info.isSelfCall = false; |
189 | localEnv.info.lint = null; // leave this to be filled in by Attr, |
190 | // when annotations have been processed |
191 | return localEnv; |
192 | } |
193 | |
194 | /** Create a fresh environment for toplevels. |
195 | * @param tree The toplevel tree. |
196 | */ |
197 | Env<AttrContext> topLevelEnv(JCCompilationUnit tree) { |
198 | Env<AttrContext> localEnv = new Env<AttrContext>(tree, new AttrContext()); |
199 | localEnv.toplevel = tree; |
200 | localEnv.enclClass = predefClassDef; |
201 | tree.namedImportScope = new Scope.ImportScope(tree.packge); |
202 | tree.starImportScope = new Scope.ImportScope(tree.packge); |
203 | localEnv.info.scope = tree.namedImportScope; |
204 | localEnv.info.lint = lint; |
205 | return localEnv; |
206 | } |
207 | |
208 | public Env<AttrContext> getTopLevelEnv(JCCompilationUnit tree) { |
209 | Env<AttrContext> localEnv = new Env<AttrContext>(tree, new AttrContext()); |
210 | localEnv.toplevel = tree; |
211 | localEnv.enclClass = predefClassDef; |
212 | localEnv.info.scope = tree.namedImportScope; |
213 | localEnv.info.lint = lint; |
214 | return localEnv; |
215 | } |
216 | |
217 | /** The scope in which a member definition in environment env is to be entered |
218 | * This is usually the environment's scope, except for class environments, |
219 | * where the local scope is for type variables, and the this and super symbol |
220 | * only, and members go into the class member scope. |
221 | */ |
222 | Scope enterScope(Env<AttrContext> env) { |
223 | return (env.tree.getTag() == JCTree.CLASSDEF) |
224 | ? ((JCClassDecl) env.tree).sym.members_field |
225 | : env.info.scope; |
226 | } |
227 | |
228 | /* ************************************************************************ |
229 | * Visitor methods for phase 1: class enter |
230 | *************************************************************************/ |
231 | |
232 | /** Visitor argument: the current environment. |
233 | */ |
234 | protected Env<AttrContext> env; |
235 | |
236 | /** Visitor result: the computed type. |
237 | */ |
238 | Type result; |
239 | |
240 | /** Visitor method: enter all classes in given tree, catching any |
241 | * completion failure exceptions. Return the tree's type. |
242 | * |
243 | * @param tree The tree to be visited. |
244 | * @param env The environment visitor argument. |
245 | */ |
246 | Type classEnter(JCTree tree, Env<AttrContext> env) { |
247 | Env<AttrContext> prevEnv = this.env; |
248 | try { |
249 | this.env = env; |
250 | tree.accept(this); |
251 | return result; |
252 | } catch (CompletionFailure ex) { |
253 | return chk.completionError(tree.pos(), ex); |
254 | } finally { |
255 | this.env = prevEnv; |
256 | } |
257 | } |
258 | |
259 | /** Visitor method: enter classes of a list of trees, returning a list of types. |
260 | */ |
261 | <T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) { |
262 | ListBuffer<Type> ts = new ListBuffer<Type>(); |
263 | for (List<T> l = trees; l.nonEmpty(); l = l.tail) |
264 | ts.append(classEnter(l.head, env)); |
265 | return ts.toList(); |
266 | } |
267 | |
268 | public void visitTopLevel(JCCompilationUnit tree) { |
269 | JavaFileObject prev = log.useSource(tree.sourcefile); |
270 | boolean addEnv = false; |
271 | boolean isPkgInfo = tree.sourcefile.isNameCompatible("package-info", |
272 | JavaFileObject.Kind.SOURCE); |
273 | if (tree.pid != null) { |
274 | tree.packge = reader.enterPackage(TreeInfo.fullName(tree.pid)); |
275 | if (tree.packageAnnotations.nonEmpty()) { |
276 | if (isPkgInfo) { |
277 | addEnv = true; |
278 | } else { |
279 | log.error(tree.packageAnnotations.head.pos(), |
280 | "pkg.annotations.sb.in.package-info.java"); |
281 | } |
282 | } |
283 | } else { |
284 | tree.packge = syms.unnamedPackage; |
285 | } |
286 | tree.packge.complete(); // Find all classes in package. |
287 | Env<AttrContext> env = topLevelEnv(tree); |
288 | |
289 | // Save environment of package-info.java file. |
290 | if (isPkgInfo) { |
291 | Env<AttrContext> env0 = typeEnvs.get(tree.packge); |
292 | if (env0 == null) { |
293 | typeEnvs.put(tree.packge, env); |
294 | } else { |
295 | JCCompilationUnit tree0 = env0.toplevel; |
296 | if (!fileManager.isSameFile(tree.sourcefile, tree0.sourcefile)) { |
297 | log.warning(tree.pid != null ? tree.pid.pos() |
298 | : null, |
299 | "pkg-info.already.seen", |
300 | tree.packge); |
301 | if (addEnv || (tree0.packageAnnotations.isEmpty() && |
302 | tree.docComments != null && |
303 | tree.docComments.get(tree) != null)) { |
304 | typeEnvs.put(tree.packge, env); |
305 | } |
306 | } |
307 | } |
308 | } |
309 | classEnter(tree.defs, env); |
310 | if (addEnv) { |
311 | todo.append(env); |
312 | } |
313 | log.useSource(prev); |
314 | result = null; |
315 | } |
316 | |
317 | public void visitClassDef(JCClassDecl tree) { |
318 | Symbol owner = env.info.scope.owner; |
319 | Scope enclScope = enterScope(env); |
320 | ClassSymbol c; |
321 | if (owner.kind == PCK) { |
322 | // We are seeing a toplevel class. |
323 | PackageSymbol packge = (PackageSymbol)owner; |
324 | for (Symbol q = packge; q != null && q.kind == PCK; q = q.owner) |
325 | q.flags_field |= EXISTS; |
326 | c = reader.enterClass(tree.name, packge); |
327 | packge.members().enterIfAbsent(c); |
328 | if ((tree.mods.flags & PUBLIC) != 0 && !classNameMatchesFileName(c, env)) { |
329 | log.error(tree.pos(), |
330 | "class.public.should.be.in.file", tree.name); |
331 | } |
332 | } else { |
333 | if (tree.name.len != 0 && |
334 | !chk.checkUniqueClassName(tree.pos(), tree.name, enclScope)) { |
335 | result = null; |
336 | return; |
337 | } |
338 | if (owner.kind == TYP) { |
339 | // We are seeing a member class. |
340 | c = reader.enterClass(tree.name, (TypeSymbol)owner); |
341 | if ((owner.flags_field & INTERFACE) != 0) { |
342 | tree.mods.flags |= PUBLIC | STATIC; |
343 | } |
344 | } else { |
345 | // We are seeing a local class. |
346 | c = reader.defineClass(tree.name, owner); |
347 | c.flatname = chk.localClassName(c); |
348 | if (c.name.len != 0) |
349 | chk.checkTransparentClass(tree.pos(), c, env.info.scope); |
350 | } |
351 | } |
352 | tree.sym = c; |
353 | |
354 | // Enter class into `compiled' table and enclosing scope. |
355 | if (chk.compiled.get(c.flatname) != null) { |
356 | duplicateClass(tree.pos(), c); |
357 | result = new ErrorType(tree.name, (TypeSymbol)owner); |
358 | tree.sym = (ClassSymbol)result.tsym; |
359 | return; |
360 | } |
361 | chk.compiled.put(c.flatname, c); |
362 | enclScope.enter(c); |
363 | |
364 | // Set up an environment for class block and store in `typeEnvs' |
365 | // table, to be retrieved later in memberEnter and attribution. |
366 | Env<AttrContext> localEnv = classEnv(tree, env); |
367 | typeEnvs.put(c, localEnv); |
368 | |
369 | // Fill out class fields. |
370 | c.completer = memberEnter; |
371 | c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree); |
372 | c.sourcefile = env.toplevel.sourcefile; |
373 | c.members_field = new Scope(c); |
374 | |
375 | ClassType ct = (ClassType)c.type; |
376 | if (owner.kind != PCK && (c.flags_field & STATIC) == 0) { |
377 | // We are seeing a local or inner class. |
378 | // Set outer_field of this class to closest enclosing class |
379 | // which contains this class in a non-static context |
380 | // (its "enclosing instance class"), provided such a class exists. |
381 | Symbol owner1 = owner; |
382 | while ((owner1.kind & (VAR | MTH)) != 0 && |
383 | (owner1.flags_field & STATIC) == 0) { |
384 | owner1 = owner1.owner; |
385 | } |
386 | if (owner1.kind == TYP) { |
387 | ct.setEnclosingType(owner1.type); |
388 | } |
389 | } |
390 | |
391 | // Enter type parameters. |
392 | ct.typarams_field = classEnter(tree.typarams, localEnv); |
393 | |
394 | // Add non-local class to uncompleted, to make sure it will be |
395 | // completed later. |
396 | if (!c.isLocal() && uncompleted != null) uncompleted.append(c); |
397 | // System.err.println("entering " + c.fullname + " in " + c.owner);//DEBUG |
398 | |
399 | // Recursively enter all member classes. |
400 | classEnter(tree.defs, localEnv); |
401 | |
402 | result = c.type; |
403 | } |
404 | //where |
405 | /** Does class have the same name as the file it appears in? |
406 | */ |
407 | private static boolean classNameMatchesFileName(ClassSymbol c, |
408 | Env<AttrContext> env) { |
409 | return env.toplevel.sourcefile.isNameCompatible(c.name.toString(), |
410 | JavaFileObject.Kind.SOURCE); |
411 | } |
412 | |
413 | /** Complain about a duplicate class. */ |
414 | protected void duplicateClass(DiagnosticPosition pos, ClassSymbol c) { |
415 | log.error(pos, "duplicate.class", c.fullname); |
416 | } |
417 | |
418 | /** Class enter visitor method for type parameters. |
419 | * Enter a symbol for type parameter in local scope, after checking that it |
420 | * is unique. |
421 | */ |
422 | public void visitTypeParameter(JCTypeParameter tree) { |
423 | TypeVar a = (tree.type != null) |
424 | ? (TypeVar)tree.type |
425 | : new TypeVar(tree.name, env.info.scope.owner, syms.botType); |
426 | tree.type = a; |
427 | if (chk.checkUnique(tree.pos(), a.tsym, env.info.scope)) { |
428 | env.info.scope.enter(a.tsym); |
429 | } |
430 | result = a; |
431 | } |
432 | |
433 | /** Default class enter visitor method: do nothing. |
434 | */ |
435 | public void visitTree(JCTree tree) { |
436 | result = null; |
437 | } |
438 | |
439 | /** Main method: enter all classes in a list of toplevel trees. |
440 | * @param trees The list of trees to be processed. |
441 | */ |
442 | public void main(List<JCCompilationUnit> trees) { |
443 | complete(trees, null); |
444 | } |
445 | |
446 | /** Main method: enter one class from a list of toplevel trees and |
447 | * place the rest on uncompleted for later processing. |
448 | * @param trees The list of trees to be processed. |
449 | * @param c The class symbol to be processed. |
450 | */ |
451 | public void complete(List<JCCompilationUnit> trees, ClassSymbol c) { |
452 | annotate.enterStart(); |
453 | ListBuffer<ClassSymbol> prevUncompleted = uncompleted; |
454 | if (memberEnter.completionEnabled) uncompleted = new ListBuffer<ClassSymbol>(); |
455 | |
456 | try { |
457 | // enter all classes, and construct uncompleted list |
458 | classEnter(trees, null); |
459 | |
460 | // complete all uncompleted classes in memberEnter |
461 | if (memberEnter.completionEnabled) { |
462 | while (uncompleted.nonEmpty()) { |
463 | ClassSymbol clazz = uncompleted.next(); |
464 | if (c == null || c == clazz || prevUncompleted == null) |
465 | clazz.complete(); |
466 | else |
467 | // defer |
468 | prevUncompleted.append(clazz); |
469 | } |
470 | |
471 | // if there remain any unimported toplevels (these must have |
472 | // no classes at all), process their import statements as well. |
473 | for (JCCompilationUnit tree : trees) { |
474 | if (tree.starImportScope.elems == null) { |
475 | JavaFileObject prev = log.useSource(tree.sourcefile); |
476 | Env<AttrContext> env = typeEnvs.get(tree); |
477 | if (env == null) |
478 | env = topLevelEnv(tree); |
479 | memberEnter.memberEnter(tree, env); |
480 | log.useSource(prev); |
481 | } |
482 | } |
483 | } |
484 | } finally { |
485 | uncompleted = prevUncompleted; |
486 | annotate.enterDone(); |
487 | } |
488 | } |
489 | } |