src/share/classes/com/sun/source/util/TreeScanner.java

Tue, 19 Oct 2010 15:02:48 -0700

author
jjg
date
Tue, 19 Oct 2010 15:02:48 -0700
changeset 722
4851ff2ffc10
parent 679
fc73f83cd563
child 724
7755f47542a0
permissions
-rw-r--r--

6987760: remove 308 support from JDK7
Reviewed-by: darcy, mcimadamore

duke@1 1 /*
ohair@554 2 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. 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
ohair@554 7 * published by the Free Software Foundation. Oracle designates this
duke@1 8 * particular file as subject to the "Classpath" exception as provided
ohair@554 9 * by Oracle 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 *
ohair@554 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554 22 * or visit www.oracle.com if you need additional information or have any
ohair@554 23 * questions.
duke@1 24 */
duke@1 25
duke@1 26 package com.sun.source.util;
duke@1 27
duke@1 28 import com.sun.source.tree.*;
duke@1 29
duke@1 30 /**
duke@1 31 * A TreeVisitor that visits all the child tree nodes.
duke@1 32 * To visit nodes of a particular type, just override the
duke@1 33 * corresponding visitXYZ method.
duke@1 34 * Inside your method, call super.visitXYZ to visit descendant
duke@1 35 * nodes.
duke@1 36 *
duke@1 37 * <p>The default implementation of the visitXYZ methods will determine
duke@1 38 * a result as follows:
duke@1 39 * <ul>
duke@1 40 * <li>If the node being visited has no children, the result will be null.
duke@1 41 * <li>If the node being visited has one child, the result will be the
duke@1 42 * result of calling {@code scan} on that child. The child may be a simple node
duke@1 43 * or itself a list of nodes.
duke@1 44 * <li> If the node being visited has more than one child, the result will
duke@1 45 * be determined by calling {@code scan} each child in turn, and then combining the
duke@1 46 * result of each scan after the first with the cumulative result
duke@1 47 * so far, as determined by the {@link #reduce} method. Each child may be either
duke@1 48 * a simple node of a list of nodes. The default behavior of the {@code reduce}
duke@1 49 * method is such that the result of the visitXYZ method will be the result of
duke@1 50 * the last child scanned.
duke@1 51 * </ul>
duke@1 52 *
duke@1 53 * <p>Here is an example to count the number of identifier nodes in a tree:
duke@1 54 * <pre>
duke@1 55 * class CountIdentifiers extends TreeScanner<Integer,Void> {
duke@1 56 * {@literal @}Override
duke@1 57 * public Integer visitIdentifier(IdentifierTree node, Void p) {
duke@1 58 * return 1;
duke@1 59 * }
duke@1 60 * {@literal @}Override
duke@1 61 * public Integer reduce(Integer r1, Integer r2) {
duke@1 62 * return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
duke@1 63 * }
duke@1 64 * }
duke@1 65 * </pre>
duke@1 66 *
duke@1 67 * @author Peter von der Ah&eacute;
duke@1 68 * @author Jonathan Gibbons
duke@1 69 * @since 1.6
duke@1 70 */
duke@1 71 public class TreeScanner<R,P> implements TreeVisitor<R,P> {
duke@1 72
duke@1 73 /** Scan a single node.
duke@1 74 */
duke@1 75 public R scan(Tree node, P p) {
duke@1 76 return (node == null) ? null : node.accept(this, p);
duke@1 77 }
duke@1 78
duke@1 79 private R scanAndReduce(Tree node, P p, R r) {
duke@1 80 return reduce(scan(node, p), r);
duke@1 81 }
duke@1 82
duke@1 83 /** Scan a list of nodes.
duke@1 84 */
duke@1 85 public R scan(Iterable<? extends Tree> nodes, P p) {
duke@1 86 R r = null;
duke@1 87 if (nodes != null) {
duke@1 88 boolean first = true;
duke@1 89 for (Tree node : nodes) {
duke@1 90 r = (first ? scan(node, p) : scanAndReduce(node, p, r));
duke@1 91 first = false;
duke@1 92 }
duke@1 93 }
duke@1 94 return r;
duke@1 95 }
duke@1 96
duke@1 97 private R scanAndReduce(Iterable<? extends Tree> nodes, P p, R r) {
duke@1 98 return reduce(scan(nodes, p), r);
duke@1 99 }
duke@1 100
duke@1 101 /**
duke@1 102 * Reduces two results into a combined result.
duke@1 103 * The default implementation is to return the first parameter.
duke@1 104 * The general contract of the method is that it may take any action whatsoever.
duke@1 105 */
duke@1 106 public R reduce(R r1, R r2) {
duke@1 107 return r1;
duke@1 108 }
duke@1 109
duke@1 110
duke@1 111 /* ***************************************************************************
duke@1 112 * Visitor methods
duke@1 113 ****************************************************************************/
duke@1 114
duke@1 115 public R visitCompilationUnit(CompilationUnitTree node, P p) {
duke@1 116 R r = scan(node.getPackageAnnotations(), p);
duke@1 117 r = scanAndReduce(node.getPackageName(), p, r);
duke@1 118 r = scanAndReduce(node.getImports(), p, r);
duke@1 119 r = scanAndReduce(node.getTypeDecls(), p, r);
duke@1 120 return r;
duke@1 121 }
duke@1 122
duke@1 123 public R visitImport(ImportTree node, P p) {
duke@1 124 return scan(node.getQualifiedIdentifier(), p);
duke@1 125 }
duke@1 126
duke@1 127 public R visitClass(ClassTree node, P p) {
duke@1 128 R r = scan(node.getModifiers(), p);
duke@1 129 r = scanAndReduce(node.getTypeParameters(), p, r);
duke@1 130 r = scanAndReduce(node.getExtendsClause(), p, r);
duke@1 131 r = scanAndReduce(node.getImplementsClause(), p, r);
duke@1 132 r = scanAndReduce(node.getMembers(), p, r);
duke@1 133 return r;
duke@1 134 }
duke@1 135
duke@1 136 public R visitMethod(MethodTree node, P p) {
duke@1 137 R r = scan(node.getModifiers(), p);
duke@1 138 r = scanAndReduce(node.getReturnType(), p, r);
duke@1 139 r = scanAndReduce(node.getTypeParameters(), p, r);
duke@1 140 r = scanAndReduce(node.getParameters(), p, r);
jjg@722 141 //308 r = scanAndReduce(node.getReceiverAnnotations(), p, r);
duke@1 142 r = scanAndReduce(node.getThrows(), p, r);
duke@1 143 r = scanAndReduce(node.getBody(), p, r);
jjg@679 144 r = scanAndReduce(node.getDefaultValue(), p, r);
duke@1 145 return r;
duke@1 146 }
duke@1 147
duke@1 148 public R visitVariable(VariableTree node, P p) {
duke@1 149 R r = scan(node.getModifiers(), p);
duke@1 150 r = scanAndReduce(node.getType(), p, r);
duke@1 151 r = scanAndReduce(node.getInitializer(), p, r);
duke@1 152 return r;
duke@1 153 }
duke@1 154
duke@1 155 public R visitEmptyStatement(EmptyStatementTree node, P p) {
duke@1 156 return null;
duke@1 157 }
duke@1 158
duke@1 159 public R visitBlock(BlockTree node, P p) {
duke@1 160 return scan(node.getStatements(), p);
duke@1 161 }
duke@1 162
duke@1 163 public R visitDoWhileLoop(DoWhileLoopTree node, P p) {
duke@1 164 R r = scan(node.getStatement(), p);
duke@1 165 r = scanAndReduce(node.getCondition(), p, r);
duke@1 166 return r;
duke@1 167 }
duke@1 168
duke@1 169 public R visitWhileLoop(WhileLoopTree node, P p) {
duke@1 170 R r = scan(node.getCondition(), p);
duke@1 171 r = scanAndReduce(node.getStatement(), p, r);
duke@1 172 return r;
duke@1 173 }
duke@1 174
duke@1 175 public R visitForLoop(ForLoopTree node, P p) {
duke@1 176 R r = scan(node.getInitializer(), p);
duke@1 177 r = scanAndReduce(node.getCondition(), p, r);
duke@1 178 r = scanAndReduce(node.getUpdate(), p, r);
duke@1 179 r = scanAndReduce(node.getStatement(), p, r);
duke@1 180 return r;
duke@1 181 }
duke@1 182
duke@1 183 public R visitEnhancedForLoop(EnhancedForLoopTree node, P p) {
duke@1 184 R r = scan(node.getVariable(), p);
duke@1 185 r = scanAndReduce(node.getExpression(), p, r);
duke@1 186 r = scanAndReduce(node.getStatement(), p, r);
duke@1 187 return r;
duke@1 188 }
duke@1 189
duke@1 190 public R visitLabeledStatement(LabeledStatementTree node, P p) {
duke@1 191 return scan(node.getStatement(), p);
duke@1 192 }
duke@1 193
duke@1 194 public R visitSwitch(SwitchTree node, P p) {
duke@1 195 R r = scan(node.getExpression(), p);
duke@1 196 r = scanAndReduce(node.getCases(), p, r);
duke@1 197 return r;
duke@1 198 }
duke@1 199
duke@1 200 public R visitCase(CaseTree node, P p) {
duke@1 201 R r = scan(node.getExpression(), p);
duke@1 202 r = scanAndReduce(node.getStatements(), p, r);
duke@1 203 return r;
duke@1 204 }
duke@1 205
duke@1 206 public R visitSynchronized(SynchronizedTree node, P p) {
duke@1 207 R r = scan(node.getExpression(), p);
duke@1 208 r = scanAndReduce(node.getBlock(), p, r);
duke@1 209 return r;
duke@1 210 }
duke@1 211
duke@1 212 public R visitTry(TryTree node, P p) {
darcy@609 213 R r = scan(node.getResources(), p);
darcy@609 214 r = scanAndReduce(node.getBlock(), p, r);
duke@1 215 r = scanAndReduce(node.getCatches(), p, r);
duke@1 216 r = scanAndReduce(node.getFinallyBlock(), p, r);
duke@1 217 return r;
duke@1 218 }
duke@1 219
duke@1 220 public R visitCatch(CatchTree node, P p) {
duke@1 221 R r = scan(node.getParameter(), p);
duke@1 222 r = scanAndReduce(node.getBlock(), p, r);
duke@1 223 return r;
duke@1 224 }
duke@1 225
duke@1 226 public R visitConditionalExpression(ConditionalExpressionTree node, P p) {
duke@1 227 R r = scan(node.getCondition(), p);
duke@1 228 r = scanAndReduce(node.getTrueExpression(), p, r);
duke@1 229 r = scanAndReduce(node.getFalseExpression(), p, r);
duke@1 230 return r;
duke@1 231 }
duke@1 232
duke@1 233 public R visitIf(IfTree node, P p) {
duke@1 234 R r = scan(node.getCondition(), p);
duke@1 235 r = scanAndReduce(node.getThenStatement(), p, r);
duke@1 236 r = scanAndReduce(node.getElseStatement(), p, r);
duke@1 237 return r;
duke@1 238 }
duke@1 239
duke@1 240 public R visitExpressionStatement(ExpressionStatementTree node, P p) {
duke@1 241 return scan(node.getExpression(), p);
duke@1 242 }
duke@1 243
duke@1 244 public R visitBreak(BreakTree node, P p) {
duke@1 245 return null;
duke@1 246 }
duke@1 247
duke@1 248 public R visitContinue(ContinueTree node, P p) {
duke@1 249 return null;
duke@1 250 }
duke@1 251
duke@1 252 public R visitReturn(ReturnTree node, P p) {
duke@1 253 return scan(node.getExpression(), p);
duke@1 254 }
duke@1 255
duke@1 256 public R visitThrow(ThrowTree node, P p) {
duke@1 257 return scan(node.getExpression(), p);
duke@1 258 }
duke@1 259
duke@1 260 public R visitAssert(AssertTree node, P p) {
duke@1 261 R r = scan(node.getCondition(), p);
duke@1 262 r = scanAndReduce(node.getDetail(), p, r);
duke@1 263 return r;
duke@1 264 }
duke@1 265
duke@1 266 public R visitMethodInvocation(MethodInvocationTree node, P p) {
duke@1 267 R r = scan(node.getTypeArguments(), p);
duke@1 268 r = scanAndReduce(node.getMethodSelect(), p, r);
duke@1 269 r = scanAndReduce(node.getArguments(), p, r);
duke@1 270 return r;
duke@1 271 }
duke@1 272
duke@1 273 public R visitNewClass(NewClassTree node, P p) {
duke@1 274 R r = scan(node.getEnclosingExpression(), p);
duke@1 275 r = scanAndReduce(node.getIdentifier(), p, r);
duke@1 276 r = scanAndReduce(node.getTypeArguments(), p, r);
duke@1 277 r = scanAndReduce(node.getArguments(), p, r);
duke@1 278 r = scanAndReduce(node.getClassBody(), p, r);
duke@1 279 return r;
duke@1 280 }
duke@1 281
duke@1 282 public R visitNewArray(NewArrayTree node, P p) {
duke@1 283 R r = scan(node.getType(), p);
duke@1 284 r = scanAndReduce(node.getDimensions(), p, r);
duke@1 285 r = scanAndReduce(node.getInitializers(), p, r);
duke@1 286 return r;
duke@1 287 }
duke@1 288
duke@1 289 public R visitParenthesized(ParenthesizedTree node, P p) {
duke@1 290 return scan(node.getExpression(), p);
duke@1 291 }
duke@1 292
duke@1 293 public R visitAssignment(AssignmentTree node, P p) {
duke@1 294 R r = scan(node.getVariable(), p);
duke@1 295 r = scanAndReduce(node.getExpression(), p, r);
duke@1 296 return r;
duke@1 297 }
duke@1 298
duke@1 299 public R visitCompoundAssignment(CompoundAssignmentTree node, P p) {
duke@1 300 R r = scan(node.getVariable(), p);
duke@1 301 r = scanAndReduce(node.getExpression(), p, r);
duke@1 302 return r;
duke@1 303 }
duke@1 304
duke@1 305 public R visitUnary(UnaryTree node, P p) {
duke@1 306 return scan(node.getExpression(), p);
duke@1 307 }
duke@1 308
duke@1 309 public R visitBinary(BinaryTree node, P p) {
duke@1 310 R r = scan(node.getLeftOperand(), p);
duke@1 311 r = scanAndReduce(node.getRightOperand(), p, r);
duke@1 312 return r;
duke@1 313 }
duke@1 314
duke@1 315 public R visitTypeCast(TypeCastTree node, P p) {
duke@1 316 R r = scan(node.getType(), p);
duke@1 317 r = scanAndReduce(node.getExpression(), p, r);
duke@1 318 return r;
duke@1 319 }
duke@1 320
duke@1 321 public R visitInstanceOf(InstanceOfTree node, P p) {
duke@1 322 R r = scan(node.getExpression(), p);
duke@1 323 r = scanAndReduce(node.getType(), p, r);
duke@1 324 return r;
duke@1 325 }
duke@1 326
duke@1 327 public R visitArrayAccess(ArrayAccessTree node, P p) {
duke@1 328 R r = scan(node.getExpression(), p);
duke@1 329 r = scanAndReduce(node.getIndex(), p, r);
duke@1 330 return r;
duke@1 331 }
duke@1 332
duke@1 333 public R visitMemberSelect(MemberSelectTree node, P p) {
duke@1 334 return scan(node.getExpression(), p);
duke@1 335 }
duke@1 336
duke@1 337 public R visitIdentifier(IdentifierTree node, P p) {
duke@1 338 return null;
duke@1 339 }
duke@1 340
duke@1 341 public R visitLiteral(LiteralTree node, P p) {
duke@1 342 return null;
duke@1 343 }
duke@1 344
duke@1 345 public R visitPrimitiveType(PrimitiveTypeTree node, P p) {
duke@1 346 return null;
duke@1 347 }
duke@1 348
duke@1 349 public R visitArrayType(ArrayTypeTree node, P p) {
duke@1 350 return scan(node.getType(), p);
duke@1 351 }
duke@1 352
duke@1 353 public R visitParameterizedType(ParameterizedTypeTree node, P p) {
duke@1 354 R r = scan(node.getType(), p);
duke@1 355 r = scanAndReduce(node.getTypeArguments(), p, r);
duke@1 356 return r;
duke@1 357 }
duke@1 358
mcimadamore@550 359 public R visitDisjointType(DisjointTypeTree node, P p) {
mcimadamore@550 360 return scan(node.getTypeComponents(), p);
mcimadamore@550 361 }
mcimadamore@550 362
duke@1 363 public R visitTypeParameter(TypeParameterTree node, P p) {
jjg@722 364 R r = scan(node.getBounds(), p);
jjg@722 365 //308 R r = scanAndReduce(node.getAnnotations(), p, r);
jjg@308 366 return r;
duke@1 367 }
duke@1 368
duke@1 369 public R visitWildcard(WildcardTree node, P p) {
duke@1 370 return scan(node.getBound(), p);
duke@1 371 }
duke@1 372
duke@1 373 public R visitModifiers(ModifiersTree node, P p) {
duke@1 374 return scan(node.getAnnotations(), p);
duke@1 375 }
duke@1 376
duke@1 377 public R visitAnnotation(AnnotationTree node, P p) {
duke@1 378 R r = scan(node.getAnnotationType(), p);
duke@1 379 r = scanAndReduce(node.getArguments(), p, r);
duke@1 380 return r;
duke@1 381 }
duke@1 382
jjg@722 383 //308 public R visitAnnotatedType(AnnotatedTypeTree node, P p) {
jjg@722 384 //308 R r = scan(node.getAnnotations(), p);
jjg@722 385 //308 r = scanAndReduce(node.getUnderlyingType(), p, r);
jjg@722 386 //308 return r;
jjg@722 387 //308 }
jjg@308 388
duke@1 389 public R visitOther(Tree node, P p) {
duke@1 390 return null;
duke@1 391 }
duke@1 392
duke@1 393 public R visitErroneous(ErroneousTree node, P p) {
duke@1 394 return null;
duke@1 395 }
duke@1 396 }

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