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

Fri, 04 Oct 2013 10:00:28 -0700

author
darcy
date
Fri, 04 Oct 2013 10:00:28 -0700
changeset 2083
379c04c090cf
parent 1944
aa6c6f8b5622
child 2525
2eb010b6cb22
permissions
-rw-r--r--

8025913: Rename jdk.Supported to jdk.Exported
Reviewed-by: psandoz, forax, lancea, alanb, mchung, jjg

duke@1 1 /*
jjg@1521 2 * Copyright (c) 2005, 2013, 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>
jjg@1326 55 * class CountIdentifiers extends TreeScanner&lt;Integer,Void&gt; {
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 */
darcy@2083 71 @jdk.Exported
duke@1 72 public class TreeScanner<R,P> implements TreeVisitor<R,P> {
duke@1 73
duke@1 74 /** Scan a single node.
duke@1 75 */
duke@1 76 public R scan(Tree node, P p) {
duke@1 77 return (node == null) ? null : node.accept(this, p);
duke@1 78 }
duke@1 79
duke@1 80 private R scanAndReduce(Tree node, P p, R r) {
duke@1 81 return reduce(scan(node, p), r);
duke@1 82 }
duke@1 83
duke@1 84 /** Scan a list of nodes.
duke@1 85 */
duke@1 86 public R scan(Iterable<? extends Tree> nodes, P p) {
duke@1 87 R r = null;
duke@1 88 if (nodes != null) {
duke@1 89 boolean first = true;
duke@1 90 for (Tree node : nodes) {
duke@1 91 r = (first ? scan(node, p) : scanAndReduce(node, p, r));
duke@1 92 first = false;
duke@1 93 }
duke@1 94 }
duke@1 95 return r;
duke@1 96 }
duke@1 97
duke@1 98 private R scanAndReduce(Iterable<? extends Tree> nodes, P p, R r) {
duke@1 99 return reduce(scan(nodes, p), r);
duke@1 100 }
duke@1 101
duke@1 102 /**
duke@1 103 * Reduces two results into a combined result.
duke@1 104 * The default implementation is to return the first parameter.
duke@1 105 * The general contract of the method is that it may take any action whatsoever.
duke@1 106 */
duke@1 107 public R reduce(R r1, R r2) {
duke@1 108 return r1;
duke@1 109 }
duke@1 110
duke@1 111
duke@1 112 /* ***************************************************************************
duke@1 113 * Visitor methods
duke@1 114 ****************************************************************************/
duke@1 115
duke@1 116 public R visitCompilationUnit(CompilationUnitTree node, P p) {
duke@1 117 R r = scan(node.getPackageAnnotations(), p);
duke@1 118 r = scanAndReduce(node.getPackageName(), p, r);
duke@1 119 r = scanAndReduce(node.getImports(), p, r);
duke@1 120 r = scanAndReduce(node.getTypeDecls(), p, r);
duke@1 121 return r;
duke@1 122 }
duke@1 123
duke@1 124 public R visitImport(ImportTree node, P p) {
duke@1 125 return scan(node.getQualifiedIdentifier(), p);
duke@1 126 }
duke@1 127
duke@1 128 public R visitClass(ClassTree node, P p) {
duke@1 129 R r = scan(node.getModifiers(), p);
duke@1 130 r = scanAndReduce(node.getTypeParameters(), p, r);
duke@1 131 r = scanAndReduce(node.getExtendsClause(), p, r);
duke@1 132 r = scanAndReduce(node.getImplementsClause(), p, r);
duke@1 133 r = scanAndReduce(node.getMembers(), p, r);
duke@1 134 return r;
duke@1 135 }
duke@1 136
duke@1 137 public R visitMethod(MethodTree node, P p) {
duke@1 138 R r = scan(node.getModifiers(), p);
duke@1 139 r = scanAndReduce(node.getReturnType(), p, r);
duke@1 140 r = scanAndReduce(node.getTypeParameters(), p, r);
duke@1 141 r = scanAndReduce(node.getParameters(), p, r);
jjg@1521 142 r = scanAndReduce(node.getReceiverParameter(), p, r);
duke@1 143 r = scanAndReduce(node.getThrows(), p, r);
duke@1 144 r = scanAndReduce(node.getBody(), p, r);
jjg@679 145 r = scanAndReduce(node.getDefaultValue(), p, r);
duke@1 146 return r;
duke@1 147 }
duke@1 148
duke@1 149 public R visitVariable(VariableTree node, P p) {
duke@1 150 R r = scan(node.getModifiers(), p);
duke@1 151 r = scanAndReduce(node.getType(), p, r);
jjg@1757 152 r = scanAndReduce(node.getNameExpression(), p, r);
duke@1 153 r = scanAndReduce(node.getInitializer(), p, r);
duke@1 154 return r;
duke@1 155 }
duke@1 156
duke@1 157 public R visitEmptyStatement(EmptyStatementTree node, P p) {
duke@1 158 return null;
duke@1 159 }
duke@1 160
duke@1 161 public R visitBlock(BlockTree node, P p) {
duke@1 162 return scan(node.getStatements(), p);
duke@1 163 }
duke@1 164
duke@1 165 public R visitDoWhileLoop(DoWhileLoopTree node, P p) {
duke@1 166 R r = scan(node.getStatement(), p);
duke@1 167 r = scanAndReduce(node.getCondition(), p, r);
duke@1 168 return r;
duke@1 169 }
duke@1 170
duke@1 171 public R visitWhileLoop(WhileLoopTree node, P p) {
duke@1 172 R r = scan(node.getCondition(), p);
duke@1 173 r = scanAndReduce(node.getStatement(), p, r);
duke@1 174 return r;
duke@1 175 }
duke@1 176
duke@1 177 public R visitForLoop(ForLoopTree node, P p) {
duke@1 178 R r = scan(node.getInitializer(), p);
duke@1 179 r = scanAndReduce(node.getCondition(), p, r);
duke@1 180 r = scanAndReduce(node.getUpdate(), p, r);
duke@1 181 r = scanAndReduce(node.getStatement(), p, r);
duke@1 182 return r;
duke@1 183 }
duke@1 184
duke@1 185 public R visitEnhancedForLoop(EnhancedForLoopTree node, P p) {
duke@1 186 R r = scan(node.getVariable(), p);
duke@1 187 r = scanAndReduce(node.getExpression(), p, r);
duke@1 188 r = scanAndReduce(node.getStatement(), p, r);
duke@1 189 return r;
duke@1 190 }
duke@1 191
duke@1 192 public R visitLabeledStatement(LabeledStatementTree node, P p) {
duke@1 193 return scan(node.getStatement(), p);
duke@1 194 }
duke@1 195
duke@1 196 public R visitSwitch(SwitchTree node, P p) {
duke@1 197 R r = scan(node.getExpression(), p);
duke@1 198 r = scanAndReduce(node.getCases(), p, r);
duke@1 199 return r;
duke@1 200 }
duke@1 201
duke@1 202 public R visitCase(CaseTree node, P p) {
duke@1 203 R r = scan(node.getExpression(), p);
duke@1 204 r = scanAndReduce(node.getStatements(), p, r);
duke@1 205 return r;
duke@1 206 }
duke@1 207
duke@1 208 public R visitSynchronized(SynchronizedTree node, P p) {
duke@1 209 R r = scan(node.getExpression(), p);
duke@1 210 r = scanAndReduce(node.getBlock(), p, r);
duke@1 211 return r;
duke@1 212 }
duke@1 213
duke@1 214 public R visitTry(TryTree node, P p) {
darcy@609 215 R r = scan(node.getResources(), p);
darcy@609 216 r = scanAndReduce(node.getBlock(), p, r);
duke@1 217 r = scanAndReduce(node.getCatches(), p, r);
duke@1 218 r = scanAndReduce(node.getFinallyBlock(), p, r);
duke@1 219 return r;
duke@1 220 }
duke@1 221
duke@1 222 public R visitCatch(CatchTree node, P p) {
duke@1 223 R r = scan(node.getParameter(), p);
duke@1 224 r = scanAndReduce(node.getBlock(), p, r);
duke@1 225 return r;
duke@1 226 }
duke@1 227
duke@1 228 public R visitConditionalExpression(ConditionalExpressionTree node, P p) {
duke@1 229 R r = scan(node.getCondition(), p);
duke@1 230 r = scanAndReduce(node.getTrueExpression(), p, r);
duke@1 231 r = scanAndReduce(node.getFalseExpression(), p, r);
duke@1 232 return r;
duke@1 233 }
duke@1 234
duke@1 235 public R visitIf(IfTree node, P p) {
duke@1 236 R r = scan(node.getCondition(), p);
duke@1 237 r = scanAndReduce(node.getThenStatement(), p, r);
duke@1 238 r = scanAndReduce(node.getElseStatement(), p, r);
duke@1 239 return r;
duke@1 240 }
duke@1 241
duke@1 242 public R visitExpressionStatement(ExpressionStatementTree node, P p) {
duke@1 243 return scan(node.getExpression(), p);
duke@1 244 }
duke@1 245
duke@1 246 public R visitBreak(BreakTree node, P p) {
duke@1 247 return null;
duke@1 248 }
duke@1 249
duke@1 250 public R visitContinue(ContinueTree node, P p) {
duke@1 251 return null;
duke@1 252 }
duke@1 253
duke@1 254 public R visitReturn(ReturnTree node, P p) {
duke@1 255 return scan(node.getExpression(), p);
duke@1 256 }
duke@1 257
duke@1 258 public R visitThrow(ThrowTree node, P p) {
duke@1 259 return scan(node.getExpression(), p);
duke@1 260 }
duke@1 261
duke@1 262 public R visitAssert(AssertTree node, P p) {
duke@1 263 R r = scan(node.getCondition(), p);
duke@1 264 r = scanAndReduce(node.getDetail(), p, r);
duke@1 265 return r;
duke@1 266 }
duke@1 267
duke@1 268 public R visitMethodInvocation(MethodInvocationTree node, P p) {
duke@1 269 R r = scan(node.getTypeArguments(), p);
duke@1 270 r = scanAndReduce(node.getMethodSelect(), p, r);
duke@1 271 r = scanAndReduce(node.getArguments(), p, r);
duke@1 272 return r;
duke@1 273 }
duke@1 274
duke@1 275 public R visitNewClass(NewClassTree node, P p) {
duke@1 276 R r = scan(node.getEnclosingExpression(), p);
duke@1 277 r = scanAndReduce(node.getIdentifier(), p, r);
duke@1 278 r = scanAndReduce(node.getTypeArguments(), p, r);
duke@1 279 r = scanAndReduce(node.getArguments(), p, r);
duke@1 280 r = scanAndReduce(node.getClassBody(), p, r);
duke@1 281 return r;
duke@1 282 }
duke@1 283
duke@1 284 public R visitNewArray(NewArrayTree node, P p) {
duke@1 285 R r = scan(node.getType(), p);
duke@1 286 r = scanAndReduce(node.getDimensions(), p, r);
duke@1 287 r = scanAndReduce(node.getInitializers(), p, r);
vromero@1944 288 r = scanAndReduce(node.getAnnotations(), p, r);
vromero@1944 289 for (Iterable< ? extends Tree> dimAnno : node.getDimAnnotations()) {
vromero@1944 290 r = scanAndReduce(dimAnno, p, r);
vromero@1944 291 }
duke@1 292 return r;
duke@1 293 }
duke@1 294
mcimadamore@1142 295 public R visitLambdaExpression(LambdaExpressionTree node, P p) {
mcimadamore@1142 296 R r = scan(node.getParameters(), p);
mcimadamore@1142 297 r = scanAndReduce(node.getBody(), p, r);
mcimadamore@1142 298 return r;
mcimadamore@1142 299 }
mcimadamore@1142 300
duke@1 301 public R visitParenthesized(ParenthesizedTree node, P p) {
duke@1 302 return scan(node.getExpression(), p);
duke@1 303 }
duke@1 304
duke@1 305 public R visitAssignment(AssignmentTree node, P p) {
duke@1 306 R r = scan(node.getVariable(), p);
duke@1 307 r = scanAndReduce(node.getExpression(), p, r);
duke@1 308 return r;
duke@1 309 }
duke@1 310
duke@1 311 public R visitCompoundAssignment(CompoundAssignmentTree node, P p) {
duke@1 312 R r = scan(node.getVariable(), p);
duke@1 313 r = scanAndReduce(node.getExpression(), p, r);
duke@1 314 return r;
duke@1 315 }
duke@1 316
duke@1 317 public R visitUnary(UnaryTree node, P p) {
duke@1 318 return scan(node.getExpression(), p);
duke@1 319 }
duke@1 320
duke@1 321 public R visitBinary(BinaryTree node, P p) {
duke@1 322 R r = scan(node.getLeftOperand(), p);
duke@1 323 r = scanAndReduce(node.getRightOperand(), p, r);
duke@1 324 return r;
duke@1 325 }
duke@1 326
duke@1 327 public R visitTypeCast(TypeCastTree node, P p) {
duke@1 328 R r = scan(node.getType(), p);
duke@1 329 r = scanAndReduce(node.getExpression(), p, r);
duke@1 330 return r;
duke@1 331 }
duke@1 332
duke@1 333 public R visitInstanceOf(InstanceOfTree node, P p) {
duke@1 334 R r = scan(node.getExpression(), p);
duke@1 335 r = scanAndReduce(node.getType(), p, r);
duke@1 336 return r;
duke@1 337 }
duke@1 338
duke@1 339 public R visitArrayAccess(ArrayAccessTree node, P p) {
duke@1 340 R r = scan(node.getExpression(), p);
duke@1 341 r = scanAndReduce(node.getIndex(), p, r);
duke@1 342 return r;
duke@1 343 }
duke@1 344
duke@1 345 public R visitMemberSelect(MemberSelectTree node, P p) {
duke@1 346 return scan(node.getExpression(), p);
duke@1 347 }
duke@1 348
mcimadamore@1143 349 public R visitMemberReference(MemberReferenceTree node, P p) {
mcimadamore@1143 350 R r = scan(node.getQualifierExpression(), p);
mcimadamore@1143 351 r = scanAndReduce(node.getTypeArguments(), p, r);
mcimadamore@1143 352 return r;
mcimadamore@1143 353 }
mcimadamore@1143 354
duke@1 355 public R visitIdentifier(IdentifierTree node, P p) {
duke@1 356 return null;
duke@1 357 }
duke@1 358
duke@1 359 public R visitLiteral(LiteralTree node, P p) {
duke@1 360 return null;
duke@1 361 }
duke@1 362
duke@1 363 public R visitPrimitiveType(PrimitiveTypeTree node, P p) {
duke@1 364 return null;
duke@1 365 }
duke@1 366
duke@1 367 public R visitArrayType(ArrayTypeTree node, P p) {
duke@1 368 return scan(node.getType(), p);
duke@1 369 }
duke@1 370
duke@1 371 public R visitParameterizedType(ParameterizedTypeTree node, P p) {
duke@1 372 R r = scan(node.getType(), p);
duke@1 373 r = scanAndReduce(node.getTypeArguments(), p, r);
duke@1 374 return r;
duke@1 375 }
duke@1 376
darcy@969 377 public R visitUnionType(UnionTypeTree node, P p) {
jjg@724 378 return scan(node.getTypeAlternatives(), p);
mcimadamore@550 379 }
mcimadamore@550 380
mcimadamore@1436 381 public R visitIntersectionType(IntersectionTypeTree node, P p) {
mcimadamore@1436 382 return scan(node.getBounds(), p);
mcimadamore@1436 383 }
mcimadamore@1436 384
duke@1 385 public R visitTypeParameter(TypeParameterTree node, P p) {
jjg@1521 386 R r = scan(node.getAnnotations(), p);
jjg@1521 387 r = scanAndReduce(node.getBounds(), p, r);
jjg@308 388 return r;
duke@1 389 }
duke@1 390
duke@1 391 public R visitWildcard(WildcardTree node, P p) {
duke@1 392 return scan(node.getBound(), p);
duke@1 393 }
duke@1 394
duke@1 395 public R visitModifiers(ModifiersTree node, P p) {
duke@1 396 return scan(node.getAnnotations(), p);
duke@1 397 }
duke@1 398
duke@1 399 public R visitAnnotation(AnnotationTree node, P p) {
duke@1 400 R r = scan(node.getAnnotationType(), p);
duke@1 401 r = scanAndReduce(node.getArguments(), p, r);
duke@1 402 return r;
duke@1 403 }
duke@1 404
jjg@1521 405 public R visitAnnotatedType(AnnotatedTypeTree node, P p) {
jjg@1521 406 R r = scan(node.getAnnotations(), p);
jjg@1521 407 r = scanAndReduce(node.getUnderlyingType(), p, r);
jjg@1521 408 return r;
jjg@1521 409 }
jjg@1521 410
duke@1 411 public R visitOther(Tree node, P p) {
duke@1 412 return null;
duke@1 413 }
duke@1 414
duke@1 415 public R visitErroneous(ErroneousTree node, P p) {
duke@1 416 return null;
duke@1 417 }
duke@1 418 }

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