Wed, 09 Apr 2008 13:41:45 +0100
5009937: hiding versus generics versus binary compatibility
Summary: missing implementation of JLS 8.4.8.3 (different arguments with same erasure not always triggering a compiler error)
Reviewed-by: jjg
duke@1 | 1 | /* |
duke@1 | 2 | * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved. |
duke@1 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@1 | 4 | * |
duke@1 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@1 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@1 | 7 | * published by the Free Software Foundation. Sun designates this |
duke@1 | 8 | * particular file as subject to the "Classpath" exception as provided |
duke@1 | 9 | * by Sun in the LICENSE file that accompanied this code. |
duke@1 | 10 | * |
duke@1 | 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@1 | 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@1 | 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@1 | 14 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@1 | 15 | * accompanied this code). |
duke@1 | 16 | * |
duke@1 | 17 | * You should have received a copy of the GNU General Public License version |
duke@1 | 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@1 | 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@1 | 20 | * |
duke@1 | 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@1 | 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@1 | 23 | * have any questions. |
duke@1 | 24 | */ |
duke@1 | 25 | |
duke@1 | 26 | package com.sun.tools.javac.code; |
duke@1 | 27 | |
duke@1 | 28 | import com.sun.tools.javac.util.*; |
duke@1 | 29 | import java.util.Iterator; |
duke@1 | 30 | |
duke@1 | 31 | /** A scope represents an area of visibility in a Java program. The |
duke@1 | 32 | * Scope class is a container for symbols which provides |
duke@1 | 33 | * efficient access to symbols given their names. Scopes are implemented |
duke@1 | 34 | * as hash tables. Scopes can be nested; the next field of a scope points |
duke@1 | 35 | * to its next outer scope. Nested scopes can share their hash tables. |
duke@1 | 36 | * |
duke@1 | 37 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
duke@1 | 38 | * you write code that depends on this, you do so at your own risk. |
duke@1 | 39 | * This code and its internal interfaces are subject to change or |
duke@1 | 40 | * deletion without notice.</b> |
duke@1 | 41 | */ |
duke@1 | 42 | public class Scope { |
duke@1 | 43 | |
duke@1 | 44 | /** The number of scopes that share this scope's hash table. |
duke@1 | 45 | */ |
duke@1 | 46 | private int shared; |
duke@1 | 47 | |
duke@1 | 48 | /** Next enclosing scope (with whom this scope may share a hashtable) |
duke@1 | 49 | */ |
duke@1 | 50 | public Scope next; |
duke@1 | 51 | |
duke@1 | 52 | /** The scope's owner. |
duke@1 | 53 | */ |
duke@1 | 54 | public Symbol owner; |
duke@1 | 55 | |
duke@1 | 56 | /** A hash table for the scope's entries. |
duke@1 | 57 | */ |
duke@1 | 58 | public Entry[] table; |
duke@1 | 59 | |
duke@1 | 60 | /** Mask for hash codes, always equal to (table.length - 1). |
duke@1 | 61 | */ |
duke@1 | 62 | int hashMask; |
duke@1 | 63 | |
duke@1 | 64 | /** A linear list that also contains all entries in |
duke@1 | 65 | * reverse order of appearance (i.e later entries are pushed on top). |
duke@1 | 66 | */ |
duke@1 | 67 | public Entry elems; |
duke@1 | 68 | |
duke@1 | 69 | /** The number of elements in this scope. |
duke@1 | 70 | */ |
duke@1 | 71 | public int nelems = 0; |
duke@1 | 72 | |
duke@1 | 73 | /** Every hash bucket is a list of Entry's which ends in sentinel. |
duke@1 | 74 | */ |
duke@1 | 75 | private static final Entry sentinel = new Entry(null, null, null, null); |
duke@1 | 76 | |
duke@1 | 77 | /** The hash table's initial size. |
duke@1 | 78 | */ |
duke@1 | 79 | private static final int INITIAL_SIZE = 0x10; |
duke@1 | 80 | |
duke@1 | 81 | /** A value for the empty scope. |
duke@1 | 82 | */ |
duke@1 | 83 | public static final Scope emptyScope = new Scope(null, null, new Entry[]{}); |
duke@1 | 84 | |
duke@1 | 85 | /** Construct a new scope, within scope next, with given owner, using |
duke@1 | 86 | * given table. The table's length must be an exponent of 2. |
duke@1 | 87 | */ |
duke@1 | 88 | Scope(Scope next, Symbol owner, Entry[] table) { |
duke@1 | 89 | this.next = next; |
duke@1 | 90 | assert emptyScope == null || owner != null; |
duke@1 | 91 | this.owner = owner; |
duke@1 | 92 | this.table = table; |
duke@1 | 93 | this.hashMask = table.length - 1; |
duke@1 | 94 | this.elems = null; |
duke@1 | 95 | this.nelems = 0; |
duke@1 | 96 | this.shared = 0; |
duke@1 | 97 | } |
duke@1 | 98 | |
duke@1 | 99 | /** Construct a new scope, within scope next, with given owner, |
duke@1 | 100 | * using a fresh table of length INITIAL_SIZE. |
duke@1 | 101 | */ |
duke@1 | 102 | public Scope(Symbol owner) { |
duke@1 | 103 | this(null, owner, new Entry[INITIAL_SIZE]); |
duke@1 | 104 | for (int i = 0; i < INITIAL_SIZE; i++) table[i] = sentinel; |
duke@1 | 105 | } |
duke@1 | 106 | |
duke@1 | 107 | /** Construct a fresh scope within this scope, with same owner, |
duke@1 | 108 | * which shares its table with the outer scope. Used in connection with |
duke@1 | 109 | * method leave if scope access is stack-like in order to avoid allocation |
duke@1 | 110 | * of fresh tables. |
duke@1 | 111 | */ |
duke@1 | 112 | public Scope dup() { |
duke@1 | 113 | Scope result = new Scope(this, this.owner, this.table); |
duke@1 | 114 | shared++; |
duke@1 | 115 | // System.out.println("====> duping scope " + this.hashCode() + " owned by " + this.owner + " to " + result.hashCode()); |
duke@1 | 116 | // new Error().printStackTrace(System.out); |
duke@1 | 117 | return result; |
duke@1 | 118 | } |
duke@1 | 119 | |
duke@1 | 120 | /** Construct a fresh scope within this scope, with new owner, |
duke@1 | 121 | * which shares its table with the outer scope. Used in connection with |
duke@1 | 122 | * method leave if scope access is stack-like in order to avoid allocation |
duke@1 | 123 | * of fresh tables. |
duke@1 | 124 | */ |
duke@1 | 125 | public Scope dup(Symbol newOwner) { |
duke@1 | 126 | Scope result = new Scope(this, newOwner, this.table); |
duke@1 | 127 | shared++; |
duke@1 | 128 | // System.out.println("====> duping scope " + this.hashCode() + " owned by " + newOwner + " to " + result.hashCode()); |
duke@1 | 129 | // new Error().printStackTrace(System.out); |
duke@1 | 130 | return result; |
duke@1 | 131 | } |
duke@1 | 132 | |
duke@1 | 133 | /** Construct a fresh scope within this scope, with same owner, |
duke@1 | 134 | * with a new hash table, whose contents initially are those of |
duke@1 | 135 | * the table of its outer scope. |
duke@1 | 136 | */ |
duke@1 | 137 | public Scope dupUnshared() { |
duke@1 | 138 | return new Scope(this, this.owner, this.table.clone()); |
duke@1 | 139 | } |
duke@1 | 140 | |
duke@1 | 141 | /** Remove all entries of this scope from its table, if shared |
duke@1 | 142 | * with next. |
duke@1 | 143 | */ |
duke@1 | 144 | public Scope leave() { |
duke@1 | 145 | assert shared == 0; |
duke@1 | 146 | if (table != next.table) return next; |
duke@1 | 147 | while (elems != null) { |
duke@1 | 148 | int hash = elems.sym.name.index & hashMask; |
duke@1 | 149 | Entry e = table[hash]; |
duke@1 | 150 | assert e == elems : elems.sym; |
duke@1 | 151 | table[hash] = elems.shadowed; |
duke@1 | 152 | elems = elems.sibling; |
duke@1 | 153 | } |
duke@1 | 154 | assert next.shared > 0; |
duke@1 | 155 | next.shared--; |
duke@1 | 156 | // System.out.println("====> leaving scope " + this.hashCode() + " owned by " + this.owner + " to " + next.hashCode()); |
duke@1 | 157 | // new Error().printStackTrace(System.out); |
duke@1 | 158 | return next; |
duke@1 | 159 | } |
duke@1 | 160 | |
duke@1 | 161 | /** Double size of hash table. |
duke@1 | 162 | */ |
duke@1 | 163 | private void dble() { |
duke@1 | 164 | assert shared == 0; |
duke@1 | 165 | Entry[] oldtable = table; |
duke@1 | 166 | Entry[] newtable = new Entry[oldtable.length * 2]; |
duke@1 | 167 | for (Scope s = this; s != null; s = s.next) { |
duke@1 | 168 | if (s.table == oldtable) { |
duke@1 | 169 | assert s == this || s.shared != 0; |
duke@1 | 170 | s.table = newtable; |
duke@1 | 171 | s.hashMask = newtable.length - 1; |
duke@1 | 172 | } |
duke@1 | 173 | } |
duke@1 | 174 | for (int i = 0; i < newtable.length; i++) newtable[i] = sentinel; |
duke@1 | 175 | for (int i = 0; i < oldtable.length; i++) copy(oldtable[i]); |
duke@1 | 176 | } |
duke@1 | 177 | |
duke@1 | 178 | /** Copy the given entry and all entries shadowed by it to table |
duke@1 | 179 | */ |
duke@1 | 180 | private void copy(Entry e) { |
duke@1 | 181 | if (e.sym != null) { |
duke@1 | 182 | copy(e.shadowed); |
duke@1 | 183 | int hash = e.sym.name.index & hashMask; |
duke@1 | 184 | e.shadowed = table[hash]; |
duke@1 | 185 | table[hash] = e; |
duke@1 | 186 | } |
duke@1 | 187 | } |
duke@1 | 188 | |
duke@1 | 189 | /** Enter symbol sym in this scope. |
duke@1 | 190 | */ |
duke@1 | 191 | public void enter(Symbol sym) { |
duke@1 | 192 | assert shared == 0; |
duke@1 | 193 | enter(sym, this); |
duke@1 | 194 | } |
duke@1 | 195 | |
duke@1 | 196 | public void enter(Symbol sym, Scope s) { |
duke@1 | 197 | enter(sym, s, s); |
duke@1 | 198 | } |
duke@1 | 199 | |
duke@1 | 200 | /** |
duke@1 | 201 | * Enter symbol sym in this scope, but mark that it comes from |
duke@1 | 202 | * given scope `s' accessed through `origin'. The last two |
duke@1 | 203 | * arguments are only used in import scopes. |
duke@1 | 204 | */ |
duke@1 | 205 | public void enter(Symbol sym, Scope s, Scope origin) { |
duke@1 | 206 | assert shared == 0; |
duke@1 | 207 | // Temporarily disabled (bug 6460352): |
duke@1 | 208 | // if (nelems * 3 >= hashMask * 2) dble(); |
duke@1 | 209 | int hash = sym.name.index & hashMask; |
duke@1 | 210 | Entry e = makeEntry(sym, table[hash], elems, s, origin); |
duke@1 | 211 | table[hash] = e; |
duke@1 | 212 | elems = e; |
duke@1 | 213 | nelems++; |
duke@1 | 214 | } |
duke@1 | 215 | |
duke@1 | 216 | Entry makeEntry(Symbol sym, Entry shadowed, Entry sibling, Scope scope, Scope origin) { |
duke@1 | 217 | return new Entry(sym, shadowed, sibling, scope); |
duke@1 | 218 | } |
duke@1 | 219 | |
duke@1 | 220 | /** Remove symbol from this scope. Used when an inner class |
duke@1 | 221 | * attribute tells us that the class isn't a package member. |
duke@1 | 222 | */ |
duke@1 | 223 | public void remove(Symbol sym) { |
duke@1 | 224 | assert shared == 0; |
duke@1 | 225 | Entry e = lookup(sym.name); |
duke@1 | 226 | while (e.scope == this && e.sym != sym) e = e.next(); |
duke@1 | 227 | if (e.scope == null) return; |
duke@1 | 228 | |
duke@1 | 229 | // remove e from table and shadowed list; |
duke@1 | 230 | Entry te = table[sym.name.index & hashMask]; |
duke@1 | 231 | if (te == e) |
duke@1 | 232 | table[sym.name.index & hashMask] = e.shadowed; |
duke@1 | 233 | else while (true) { |
duke@1 | 234 | if (te.shadowed == e) { |
duke@1 | 235 | te.shadowed = e.shadowed; |
duke@1 | 236 | break; |
duke@1 | 237 | } |
duke@1 | 238 | te = te.shadowed; |
duke@1 | 239 | } |
duke@1 | 240 | |
duke@1 | 241 | // remove e from elems and sibling list |
duke@1 | 242 | te = elems; |
duke@1 | 243 | if (te == e) |
duke@1 | 244 | elems = e.sibling; |
duke@1 | 245 | else while (true) { |
duke@1 | 246 | if (te.sibling == e) { |
duke@1 | 247 | te.sibling = e.sibling; |
duke@1 | 248 | break; |
duke@1 | 249 | } |
duke@1 | 250 | te = te.sibling; |
duke@1 | 251 | } |
duke@1 | 252 | } |
duke@1 | 253 | |
duke@1 | 254 | /** Enter symbol sym in this scope if not already there. |
duke@1 | 255 | */ |
duke@1 | 256 | public void enterIfAbsent(Symbol sym) { |
duke@1 | 257 | assert shared == 0; |
duke@1 | 258 | Entry e = lookup(sym.name); |
duke@1 | 259 | while (e.scope == this && e.sym.kind != sym.kind) e = e.next(); |
duke@1 | 260 | if (e.scope != this) enter(sym); |
duke@1 | 261 | } |
duke@1 | 262 | |
duke@1 | 263 | /** Given a class, is there already a class with same fully |
duke@1 | 264 | * qualified name in this (import) scope? |
duke@1 | 265 | */ |
duke@1 | 266 | public boolean includes(Symbol c) { |
duke@1 | 267 | for (Scope.Entry e = lookup(c.name); |
duke@1 | 268 | e.scope == this; |
duke@1 | 269 | e = e.next()) { |
duke@1 | 270 | if (e.sym == c) return true; |
duke@1 | 271 | } |
duke@1 | 272 | return false; |
duke@1 | 273 | } |
duke@1 | 274 | |
duke@1 | 275 | /** Return the entry associated with given name, starting in |
duke@1 | 276 | * this scope and proceeding outwards. If no entry was found, |
duke@1 | 277 | * return the sentinel, which is characterized by having a null in |
duke@1 | 278 | * both its scope and sym fields, whereas both fields are non-null |
duke@1 | 279 | * for regular entries. |
duke@1 | 280 | */ |
duke@1 | 281 | public Entry lookup(Name name) { |
duke@1 | 282 | Entry e = table[name.index & hashMask]; |
duke@1 | 283 | while (e.scope != null && e.sym.name != name) |
duke@1 | 284 | e = e.shadowed; |
duke@1 | 285 | return e; |
duke@1 | 286 | } |
duke@1 | 287 | |
duke@1 | 288 | public Iterable<Symbol> getElements() { |
duke@1 | 289 | return new Iterable<Symbol>() { |
duke@1 | 290 | public Iterator<Symbol> iterator() { |
duke@1 | 291 | return new Iterator<Symbol>() { |
duke@1 | 292 | private Scope currScope = Scope.this; |
duke@1 | 293 | private Scope.Entry currEntry = elems; |
duke@1 | 294 | { |
duke@1 | 295 | update(); |
duke@1 | 296 | } |
duke@1 | 297 | |
duke@1 | 298 | public boolean hasNext() { |
duke@1 | 299 | return currEntry != null; |
duke@1 | 300 | } |
duke@1 | 301 | |
duke@1 | 302 | public Symbol next() { |
duke@1 | 303 | Symbol sym = (currEntry == null ? null : currEntry.sym); |
duke@1 | 304 | currEntry = currEntry.sibling; |
duke@1 | 305 | update(); |
duke@1 | 306 | return sym; |
duke@1 | 307 | } |
duke@1 | 308 | |
duke@1 | 309 | public void remove() { |
duke@1 | 310 | throw new UnsupportedOperationException(); |
duke@1 | 311 | } |
duke@1 | 312 | |
duke@1 | 313 | private void update() { |
duke@1 | 314 | while (currEntry == null && currScope.next != null) { |
duke@1 | 315 | currScope = currScope.next; |
duke@1 | 316 | currEntry = currScope.elems; |
duke@1 | 317 | } |
duke@1 | 318 | } |
duke@1 | 319 | }; |
duke@1 | 320 | } |
duke@1 | 321 | }; |
duke@1 | 322 | |
duke@1 | 323 | } |
duke@1 | 324 | |
duke@1 | 325 | public String toString() { |
duke@1 | 326 | StringBuilder result = new StringBuilder(); |
duke@1 | 327 | result.append("Scope["); |
duke@1 | 328 | for (Scope s = this; s != null ; s = s.next) { |
duke@1 | 329 | if (s != this) result.append(" | "); |
duke@1 | 330 | for (Entry e = s.elems; e != null; e = e.sibling) { |
duke@1 | 331 | if (e != s.elems) result.append(", "); |
duke@1 | 332 | result.append(e.sym); |
duke@1 | 333 | } |
duke@1 | 334 | } |
duke@1 | 335 | result.append("]"); |
duke@1 | 336 | return result.toString(); |
duke@1 | 337 | } |
duke@1 | 338 | |
duke@1 | 339 | /** A class for scope entries. |
duke@1 | 340 | */ |
duke@1 | 341 | public static class Entry { |
duke@1 | 342 | |
duke@1 | 343 | /** The referenced symbol. |
duke@1 | 344 | * sym == null iff this == sentinel |
duke@1 | 345 | */ |
duke@1 | 346 | public Symbol sym; |
duke@1 | 347 | |
duke@1 | 348 | /** An entry with the same hash code, or sentinel. |
duke@1 | 349 | */ |
duke@1 | 350 | private Entry shadowed; |
duke@1 | 351 | |
duke@1 | 352 | /** Next entry in same scope. |
duke@1 | 353 | */ |
duke@1 | 354 | public Entry sibling; |
duke@1 | 355 | |
duke@1 | 356 | /** The entry's scope. |
duke@1 | 357 | * scope == null iff this == sentinel |
duke@1 | 358 | * for an entry in an import scope, this is the scope |
duke@1 | 359 | * where the entry came from (i.e. was imported from). |
duke@1 | 360 | */ |
duke@1 | 361 | public Scope scope; |
duke@1 | 362 | |
duke@1 | 363 | public Entry(Symbol sym, Entry shadowed, Entry sibling, Scope scope) { |
duke@1 | 364 | this.sym = sym; |
duke@1 | 365 | this.shadowed = shadowed; |
duke@1 | 366 | this.sibling = sibling; |
duke@1 | 367 | this.scope = scope; |
duke@1 | 368 | } |
duke@1 | 369 | |
duke@1 | 370 | /** Return next entry with the same name as this entry, proceeding |
duke@1 | 371 | * outwards if not found in this scope. |
duke@1 | 372 | */ |
duke@1 | 373 | public Entry next() { |
duke@1 | 374 | Entry e = shadowed; |
duke@1 | 375 | while (e.scope != null && e.sym.name != sym.name) |
duke@1 | 376 | e = e.shadowed; |
duke@1 | 377 | return e; |
duke@1 | 378 | } |
duke@1 | 379 | |
duke@1 | 380 | public Scope getOrigin() { |
duke@1 | 381 | // The origin is only recorded for import scopes. For all |
duke@1 | 382 | // other scope entries, the "enclosing" type is available |
duke@1 | 383 | // from other sources. See Attr.visitSelect and |
duke@1 | 384 | // Attr.visitIdent. Rather than throwing an assertion |
duke@1 | 385 | // error, we return scope which will be the same as origin |
duke@1 | 386 | // in many cases. |
duke@1 | 387 | return scope; |
duke@1 | 388 | } |
duke@1 | 389 | } |
duke@1 | 390 | |
duke@1 | 391 | public static class ImportScope extends Scope { |
duke@1 | 392 | |
duke@1 | 393 | public ImportScope(Symbol owner) { |
duke@1 | 394 | super(owner); |
duke@1 | 395 | } |
duke@1 | 396 | |
duke@1 | 397 | @Override |
duke@1 | 398 | Entry makeEntry(Symbol sym, Entry shadowed, Entry sibling, Scope scope, Scope origin) { |
duke@1 | 399 | return new ImportEntry(sym, shadowed, sibling, scope, origin); |
duke@1 | 400 | } |
duke@1 | 401 | |
duke@1 | 402 | public Entry lookup(Name name) { |
duke@1 | 403 | Entry e = table[name.index & hashMask]; |
duke@1 | 404 | while (e.scope != null && |
duke@1 | 405 | (e.sym.name != name || |
duke@1 | 406 | /* Since an inner class will show up in package and |
duke@1 | 407 | * import scopes until its inner class attribute has |
duke@1 | 408 | * been processed, we have to weed it out here. This |
duke@1 | 409 | * is done by comparing the owners of the entry's |
duke@1 | 410 | * scope and symbol fields. The scope field's owner |
duke@1 | 411 | * points to where the class originally was imported |
duke@1 | 412 | * from. The symbol field's owner points to where the |
duke@1 | 413 | * class is situated now. This can change when an |
duke@1 | 414 | * inner class is read (see ClassReader.enterClass). |
duke@1 | 415 | * By comparing the two fields we make sure that we do |
duke@1 | 416 | * not accidentally import an inner class that started |
duke@1 | 417 | * life as a flat class in a package. */ |
duke@1 | 418 | e.sym.owner != e.scope.owner)) |
duke@1 | 419 | e = e.shadowed; |
duke@1 | 420 | return e; |
duke@1 | 421 | } |
duke@1 | 422 | |
duke@1 | 423 | static class ImportEntry extends Entry { |
duke@1 | 424 | private Scope origin; |
duke@1 | 425 | |
duke@1 | 426 | ImportEntry(Symbol sym, Entry shadowed, Entry sibling, Scope scope, Scope origin) { |
duke@1 | 427 | super(sym, shadowed, sibling, scope); |
duke@1 | 428 | this.origin = origin; |
duke@1 | 429 | } |
duke@1 | 430 | public Entry next() { |
duke@1 | 431 | Entry e = super.shadowed; |
duke@1 | 432 | while (e.scope != null && |
duke@1 | 433 | (e.sym.name != sym.name || |
duke@1 | 434 | e.sym.owner != e.scope.owner)) // see lookup() |
duke@1 | 435 | e = e.shadowed; |
duke@1 | 436 | return e; |
duke@1 | 437 | } |
duke@1 | 438 | |
duke@1 | 439 | @Override |
duke@1 | 440 | public Scope getOrigin() { return origin; } |
duke@1 | 441 | } |
duke@1 | 442 | } |
duke@1 | 443 | |
duke@1 | 444 | /** An empty scope, into which you can't place anything. Used for |
duke@1 | 445 | * the scope for a variable initializer. |
duke@1 | 446 | */ |
duke@1 | 447 | public static class DelegatedScope extends Scope { |
duke@1 | 448 | Scope delegatee; |
duke@1 | 449 | public static final Entry[] emptyTable = new Entry[0]; |
duke@1 | 450 | |
duke@1 | 451 | public DelegatedScope(Scope outer) { |
duke@1 | 452 | super(outer, outer.owner, emptyTable); |
duke@1 | 453 | delegatee = outer; |
duke@1 | 454 | } |
duke@1 | 455 | public Scope dup() { |
duke@1 | 456 | return new DelegatedScope(next); |
duke@1 | 457 | } |
duke@1 | 458 | public Scope dupUnshared() { |
duke@1 | 459 | return new DelegatedScope(next); |
duke@1 | 460 | } |
duke@1 | 461 | public Scope leave() { |
duke@1 | 462 | return next; |
duke@1 | 463 | } |
duke@1 | 464 | public void enter(Symbol sym) { |
duke@1 | 465 | // only anonymous classes could be put here |
duke@1 | 466 | } |
duke@1 | 467 | public void enter(Symbol sym, Scope s) { |
duke@1 | 468 | // only anonymous classes could be put here |
duke@1 | 469 | } |
duke@1 | 470 | public void remove(Symbol sym) { |
duke@1 | 471 | throw new AssertionError(sym); |
duke@1 | 472 | } |
duke@1 | 473 | public Entry lookup(Name name) { |
duke@1 | 474 | return delegatee.lookup(name); |
duke@1 | 475 | } |
duke@1 | 476 | } |
duke@1 | 477 | |
duke@1 | 478 | /** An error scope, for which the owner should be an error symbol. */ |
duke@1 | 479 | public static class ErrorScope extends Scope { |
duke@1 | 480 | ErrorScope(Scope next, Symbol errSymbol, Entry[] table) { |
duke@1 | 481 | super(next, /*owner=*/errSymbol, table); |
duke@1 | 482 | } |
duke@1 | 483 | public ErrorScope(Symbol errSymbol) { |
duke@1 | 484 | super(errSymbol); |
duke@1 | 485 | } |
duke@1 | 486 | public Scope dup() { |
duke@1 | 487 | return new ErrorScope(this, owner, table); |
duke@1 | 488 | } |
duke@1 | 489 | public Scope dupUnshared() { |
duke@1 | 490 | return new ErrorScope(this, owner, table.clone()); |
duke@1 | 491 | } |
duke@1 | 492 | public Entry lookup(Name name) { |
duke@1 | 493 | Entry e = super.lookup(name); |
duke@1 | 494 | if (e.scope == null) |
duke@1 | 495 | return new Entry(owner, null, null, null); |
duke@1 | 496 | else |
duke@1 | 497 | return e; |
duke@1 | 498 | } |
duke@1 | 499 | } |
duke@1 | 500 | } |