Enter.java revision 2571:10fc81ac75b4
1/* 2 * Copyright (c) 1999, 2014, 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 26package com.sun.tools.javac.comp; 27 28import java.util.*; 29import javax.tools.JavaFileObject; 30import javax.tools.JavaFileManager; 31 32import com.sun.tools.javac.code.*; 33import com.sun.tools.javac.code.Scope.*; 34import com.sun.tools.javac.code.Symbol.*; 35import com.sun.tools.javac.code.Type.*; 36import com.sun.tools.javac.jvm.*; 37import com.sun.tools.javac.main.Option.PkgInfo; 38import com.sun.tools.javac.tree.*; 39import com.sun.tools.javac.tree.JCTree.*; 40import com.sun.tools.javac.util.*; 41import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 42import com.sun.tools.javac.util.List; 43 44 45import static com.sun.tools.javac.code.Flags.*; 46import static com.sun.tools.javac.code.Kinds.*; 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 entered 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>{@literal 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 supported API. 88 * If 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 */ 92public class Enter extends JCTree.Visitor { 93 protected static final Context.Key<Enter> enterKey = new Context.Key<>(); 94 95 Log log; 96 Symtab syms; 97 Check chk; 98 TreeMaker make; 99 Annotate annotate; 100 MemberEnter memberEnter; 101 Types types; 102 Lint lint; 103 Names names; 104 JavaFileManager fileManager; 105 PkgInfo pkginfoOpt; 106 TypeEnvs typeEnvs; 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 memberEnter = MemberEnter.instance(context); 125 types = Types.instance(context); 126 annotate = Annotate.instance(context); 127 lint = Lint.instance(context); 128 names = Names.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 return localEnv; 201 } 202 203 /** Create a fresh environment for toplevels. 204 * @param tree The toplevel tree. 205 */ 206 Env<AttrContext> topLevelEnv(JCCompilationUnit tree) { 207 Env<AttrContext> localEnv = new Env<>(tree, new AttrContext()); 208 localEnv.toplevel = tree; 209 localEnv.enclClass = predefClassDef; 210 tree.toplevelScope = WriteableScope.create(tree.packge); 211 tree.namedImportScope = new NamedImportScope(tree.packge, tree.toplevelScope); 212 tree.starImportScope = new StarImportScope(tree.packge); 213 localEnv.info.scope = tree.toplevelScope; 214 localEnv.info.lint = lint; 215 return localEnv; 216 } 217 218 public Env<AttrContext> getTopLevelEnv(JCCompilationUnit tree) { 219 Env<AttrContext> localEnv = new Env<>(tree, new AttrContext()); 220 localEnv.toplevel = tree; 221 localEnv.enclClass = predefClassDef; 222 localEnv.info.scope = tree.toplevelScope; 223 localEnv.info.lint = lint; 224 return localEnv; 225 } 226 227 /** The scope in which a member definition in environment env is to be entered 228 * This is usually the environment's scope, except for class environments, 229 * where the local scope is for type variables, and the this and super symbol 230 * only, and members go into the class member scope. 231 */ 232 WriteableScope enterScope(Env<AttrContext> env) { 233 return (env.tree.hasTag(JCTree.Tag.CLASSDEF)) 234 ? ((JCClassDecl) env.tree).sym.members_field 235 : env.info.scope; 236 } 237 238/* ************************************************************************ 239 * Visitor methods for phase 1: class enter 240 *************************************************************************/ 241 242 /** Visitor argument: the current environment. 243 */ 244 protected Env<AttrContext> env; 245 246 /** Visitor result: the computed type. 247 */ 248 Type result; 249 250 /** Visitor method: enter all classes in given tree, catching any 251 * completion failure exceptions. Return the tree's type. 252 * 253 * @param tree The tree to be visited. 254 * @param env The environment visitor argument. 255 */ 256 Type classEnter(JCTree tree, Env<AttrContext> env) { 257 Env<AttrContext> prevEnv = this.env; 258 try { 259 this.env = env; 260 tree.accept(this); 261 return result; 262 } catch (CompletionFailure ex) { 263 return chk.completionError(tree.pos(), ex); 264 } finally { 265 this.env = prevEnv; 266 } 267 } 268 269 /** Visitor method: enter classes of a list of trees, returning a list of types. 270 */ 271 <T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) { 272 ListBuffer<Type> ts = new ListBuffer<>(); 273 for (List<T> l = trees; l.nonEmpty(); l = l.tail) { 274 Type t = classEnter(l.head, env); 275 if (t != null) 276 ts.append(t); 277 } 278 return ts.toList(); 279 } 280 281 @Override 282 public void visitTopLevel(JCCompilationUnit tree) { 283 JavaFileObject prev = log.useSource(tree.sourcefile); 284 boolean addEnv = false; 285 boolean isPkgInfo = tree.sourcefile.isNameCompatible("package-info", 286 JavaFileObject.Kind.SOURCE); 287 JCPackageDecl pd = tree.getPackage(); 288 if (pd != null) { 289 tree.packge = pd.packge = syms.enterPackage(TreeInfo.fullName(pd.pid)); 290 if ( pd.annotations.nonEmpty() 291 || pkginfoOpt == PkgInfo.ALWAYS 292 || tree.docComments != null) { 293 if (isPkgInfo) { 294 addEnv = true; 295 } else if (pd.annotations.nonEmpty()) { 296 log.error(pd.annotations.head.pos(), 297 "pkg.annotations.sb.in.package-info.java"); 298 } 299 } 300 } else { 301 tree.packge = syms.unnamedPackage; 302 } 303 tree.packge.complete(); // Find all classes in package. 304 Env<AttrContext> topEnv = topLevelEnv(tree); 305 Env<AttrContext> packageEnv = isPkgInfo ? topEnv.dup(pd) : null; 306 307 // Save environment of package-info.java file. 308 if (isPkgInfo) { 309 Env<AttrContext> env0 = typeEnvs.get(tree.packge); 310 if (env0 != null) { 311 JCCompilationUnit tree0 = env0.toplevel; 312 if (!fileManager.isSameFile(tree.sourcefile, tree0.sourcefile)) { 313 log.warning(pd != null ? pd.pid.pos() : null, 314 "pkg-info.already.seen", 315 tree.packge); 316 } 317 } 318 typeEnvs.put(tree.packge, packageEnv); 319 320 for (Symbol q = tree.packge; q != null && q.kind == PCK; q = q.owner) 321 q.flags_field |= EXISTS; 322 323 Name name = names.package_info; 324 ClassSymbol c = syms.enterClass(name, tree.packge); 325 c.flatname = names.fromString(tree.packge + "." + name); 326 c.sourcefile = tree.sourcefile; 327 c.completer = null; 328 c.members_field = WriteableScope.create(c); 329 tree.packge.package_info = c; 330 } 331 classEnter(tree.defs, topEnv); 332 if (addEnv) { 333 todo.append(packageEnv); 334 } 335 log.useSource(prev); 336 result = null; 337 } 338 339 @Override 340 public void visitClassDef(JCClassDecl tree) { 341 Symbol owner = env.info.scope.owner; 342 WriteableScope enclScope = enterScope(env); 343 ClassSymbol c; 344 if (owner.kind == PCK) { 345 // We are seeing a toplevel class. 346 PackageSymbol packge = (PackageSymbol)owner; 347 for (Symbol q = packge; q != null && q.kind == PCK; q = q.owner) 348 q.flags_field |= EXISTS; 349 c = syms.enterClass(tree.name, packge); 350 packge.members().enterIfAbsent(c); 351 if ((tree.mods.flags & PUBLIC) != 0 && !classNameMatchesFileName(c, env)) { 352 log.error(tree.pos(), 353 "class.public.should.be.in.file", tree.name); 354 } 355 } else { 356 if (!tree.name.isEmpty() && 357 !chk.checkUniqueClassName(tree.pos(), tree.name, enclScope)) { 358 result = null; 359 return; 360 } 361 if (owner.kind == TYP) { 362 // We are seeing a member class. 363 c = syms.enterClass(tree.name, (TypeSymbol)owner); 364 if ((owner.flags_field & INTERFACE) != 0) { 365 tree.mods.flags |= PUBLIC | STATIC; 366 } 367 } else { 368 // We are seeing a local class. 369 c = syms.defineClass(tree.name, owner); 370 c.flatname = chk.localClassName(c); 371 if (!c.name.isEmpty()) 372 chk.checkTransparentClass(tree.pos(), c, env.info.scope); 373 } 374 } 375 tree.sym = c; 376 377 // Enter class into `compiled' table and enclosing scope. 378 if (chk.compiled.get(c.flatname) != null) { 379 duplicateClass(tree.pos(), c); 380 result = types.createErrorType(tree.name, (TypeSymbol)owner, Type.noType); 381 tree.sym = (ClassSymbol)result.tsym; 382 return; 383 } 384 chk.compiled.put(c.flatname, c); 385 enclScope.enter(c); 386 387 // Set up an environment for class block and store in `typeEnvs' 388 // table, to be retrieved later in memberEnter and attribution. 389 Env<AttrContext> localEnv = classEnv(tree, env); 390 typeEnvs.put(c, localEnv); 391 392 // Fill out class fields. 393 c.completer = memberEnter; 394 c.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, c, tree); 395 c.sourcefile = env.toplevel.sourcefile; 396 c.members_field = WriteableScope.create(c); 397 398 ClassType ct = (ClassType)c.type; 399 if (owner.kind != PCK && (c.flags_field & STATIC) == 0) { 400 // We are seeing a local or inner class. 401 // Set outer_field of this class to closest enclosing class 402 // which contains this class in a non-static context 403 // (its "enclosing instance class"), provided such a class exists. 404 Symbol owner1 = owner; 405 while ((owner1.kind & (VAR | MTH)) != 0 && 406 (owner1.flags_field & STATIC) == 0) { 407 owner1 = owner1.owner; 408 } 409 if (owner1.kind == TYP) { 410 ct.setEnclosingType(owner1.type); 411 } 412 } 413 414 // Enter type parameters. 415 ct.typarams_field = classEnter(tree.typarams, localEnv); 416 417 // Add non-local class to uncompleted, to make sure it will be 418 // completed later. 419 if (!c.isLocal() && uncompleted != null) uncompleted.append(c); 420// System.err.println("entering " + c.fullname + " in " + c.owner);//DEBUG 421 422 // Recursively enter all member classes. 423 classEnter(tree.defs, localEnv); 424 425 result = c.type; 426 } 427 //where 428 /** Does class have the same name as the file it appears in? 429 */ 430 private static boolean classNameMatchesFileName(ClassSymbol c, 431 Env<AttrContext> env) { 432 return env.toplevel.sourcefile.isNameCompatible(c.name.toString(), 433 JavaFileObject.Kind.SOURCE); 434 } 435 436 /** Complain about a duplicate class. */ 437 protected void duplicateClass(DiagnosticPosition pos, ClassSymbol c) { 438 log.error(pos, "duplicate.class", c.fullname); 439 } 440 441 /** Class enter visitor method for type parameters. 442 * Enter a symbol for type parameter in local scope, after checking that it 443 * is unique. 444 */ 445 @Override 446 public void visitTypeParameter(JCTypeParameter tree) { 447 TypeVar a = (tree.type != null) 448 ? (TypeVar)tree.type 449 : new TypeVar(tree.name, env.info.scope.owner, syms.botType); 450 tree.type = a; 451 if (chk.checkUnique(tree.pos(), a.tsym, env.info.scope)) { 452 env.info.scope.enter(a.tsym); 453 } 454 result = a; 455 } 456 457 /** Default class enter visitor method: do nothing. 458 */ 459 @Override 460 public void visitTree(JCTree tree) { 461 result = null; 462 } 463 464 /** Main method: enter all classes in a list of toplevel trees. 465 * @param trees The list of trees to be processed. 466 */ 467 public void main(List<JCCompilationUnit> trees) { 468 complete(trees, null); 469 } 470 471 /** Main method: enter one class from a list of toplevel trees and 472 * place the rest on uncompleted for later processing. 473 * @param trees The list of trees to be processed. 474 * @param c The class symbol to be processed. 475 */ 476 public void complete(List<JCCompilationUnit> trees, ClassSymbol c) { 477 annotate.enterStart(); 478 ListBuffer<ClassSymbol> prevUncompleted = uncompleted; 479 if (memberEnter.completionEnabled) uncompleted = new ListBuffer<>(); 480 481 try { 482 // enter all classes, and construct uncompleted list 483 classEnter(trees, null); 484 485 // complete all uncompleted classes in memberEnter 486 if (memberEnter.completionEnabled) { 487 while (uncompleted.nonEmpty()) { 488 ClassSymbol clazz = uncompleted.next(); 489 if (c == null || c == clazz || prevUncompleted == null) 490 clazz.complete(); 491 else 492 // defer 493 prevUncompleted.append(clazz); 494 } 495 496 // if there remain any unimported toplevels (these must have 497 // no classes at all), process their import statements as well. 498 for (JCCompilationUnit tree : trees) { 499 if (tree.starImportScope.isEmpty()) { 500 JavaFileObject prev = log.useSource(tree.sourcefile); 501 Env<AttrContext> topEnv = topLevelEnv(tree); 502 memberEnter.memberEnter(tree, topEnv); 503 log.useSource(prev); 504 } 505 } 506 } 507 } finally { 508 uncompleted = prevUncompleted; 509 annotate.enterDone(); 510 } 511 } 512 513 public void newRound() { 514 typeEnvs.clear(); 515 } 516} 517