| 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 | } |