1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/com/sun/source/util/TreeScanner.java Wed Apr 27 01:34:52 2016 +0800
1.3 @@ -0,0 +1,418 @@
1.4 +/*
1.5 + * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package com.sun.source.util;
1.30 +
1.31 +import com.sun.source.tree.*;
1.32 +
1.33 +/**
1.34 + * A TreeVisitor that visits all the child tree nodes.
1.35 + * To visit nodes of a particular type, just override the
1.36 + * corresponding visitXYZ method.
1.37 + * Inside your method, call super.visitXYZ to visit descendant
1.38 + * nodes.
1.39 + *
1.40 + * <p>The default implementation of the visitXYZ methods will determine
1.41 + * a result as follows:
1.42 + * <ul>
1.43 + * <li>If the node being visited has no children, the result will be null.
1.44 + * <li>If the node being visited has one child, the result will be the
1.45 + * result of calling {@code scan} on that child. The child may be a simple node
1.46 + * or itself a list of nodes.
1.47 + * <li> If the node being visited has more than one child, the result will
1.48 + * be determined by calling {@code scan} each child in turn, and then combining the
1.49 + * result of each scan after the first with the cumulative result
1.50 + * so far, as determined by the {@link #reduce} method. Each child may be either
1.51 + * a simple node of a list of nodes. The default behavior of the {@code reduce}
1.52 + * method is such that the result of the visitXYZ method will be the result of
1.53 + * the last child scanned.
1.54 + * </ul>
1.55 + *
1.56 + * <p>Here is an example to count the number of identifier nodes in a tree:
1.57 + * <pre>
1.58 + * class CountIdentifiers extends TreeScanner<Integer,Void> {
1.59 + * {@literal @}Override
1.60 + * public Integer visitIdentifier(IdentifierTree node, Void p) {
1.61 + * return 1;
1.62 + * }
1.63 + * {@literal @}Override
1.64 + * public Integer reduce(Integer r1, Integer r2) {
1.65 + * return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
1.66 + * }
1.67 + * }
1.68 + * </pre>
1.69 + *
1.70 + * @author Peter von der Ahé
1.71 + * @author Jonathan Gibbons
1.72 + * @since 1.6
1.73 + */
1.74 +@jdk.Exported
1.75 +public class TreeScanner<R,P> implements TreeVisitor<R,P> {
1.76 +
1.77 + /** Scan a single node.
1.78 + */
1.79 + public R scan(Tree node, P p) {
1.80 + return (node == null) ? null : node.accept(this, p);
1.81 + }
1.82 +
1.83 + private R scanAndReduce(Tree node, P p, R r) {
1.84 + return reduce(scan(node, p), r);
1.85 + }
1.86 +
1.87 + /** Scan a list of nodes.
1.88 + */
1.89 + public R scan(Iterable<? extends Tree> nodes, P p) {
1.90 + R r = null;
1.91 + if (nodes != null) {
1.92 + boolean first = true;
1.93 + for (Tree node : nodes) {
1.94 + r = (first ? scan(node, p) : scanAndReduce(node, p, r));
1.95 + first = false;
1.96 + }
1.97 + }
1.98 + return r;
1.99 + }
1.100 +
1.101 + private R scanAndReduce(Iterable<? extends Tree> nodes, P p, R r) {
1.102 + return reduce(scan(nodes, p), r);
1.103 + }
1.104 +
1.105 + /**
1.106 + * Reduces two results into a combined result.
1.107 + * The default implementation is to return the first parameter.
1.108 + * The general contract of the method is that it may take any action whatsoever.
1.109 + */
1.110 + public R reduce(R r1, R r2) {
1.111 + return r1;
1.112 + }
1.113 +
1.114 +
1.115 +/* ***************************************************************************
1.116 + * Visitor methods
1.117 + ****************************************************************************/
1.118 +
1.119 + public R visitCompilationUnit(CompilationUnitTree node, P p) {
1.120 + R r = scan(node.getPackageAnnotations(), p);
1.121 + r = scanAndReduce(node.getPackageName(), p, r);
1.122 + r = scanAndReduce(node.getImports(), p, r);
1.123 + r = scanAndReduce(node.getTypeDecls(), p, r);
1.124 + return r;
1.125 + }
1.126 +
1.127 + public R visitImport(ImportTree node, P p) {
1.128 + return scan(node.getQualifiedIdentifier(), p);
1.129 + }
1.130 +
1.131 + public R visitClass(ClassTree node, P p) {
1.132 + R r = scan(node.getModifiers(), p);
1.133 + r = scanAndReduce(node.getTypeParameters(), p, r);
1.134 + r = scanAndReduce(node.getExtendsClause(), p, r);
1.135 + r = scanAndReduce(node.getImplementsClause(), p, r);
1.136 + r = scanAndReduce(node.getMembers(), p, r);
1.137 + return r;
1.138 + }
1.139 +
1.140 + public R visitMethod(MethodTree node, P p) {
1.141 + R r = scan(node.getModifiers(), p);
1.142 + r = scanAndReduce(node.getReturnType(), p, r);
1.143 + r = scanAndReduce(node.getTypeParameters(), p, r);
1.144 + r = scanAndReduce(node.getParameters(), p, r);
1.145 + r = scanAndReduce(node.getReceiverParameter(), p, r);
1.146 + r = scanAndReduce(node.getThrows(), p, r);
1.147 + r = scanAndReduce(node.getBody(), p, r);
1.148 + r = scanAndReduce(node.getDefaultValue(), p, r);
1.149 + return r;
1.150 + }
1.151 +
1.152 + public R visitVariable(VariableTree node, P p) {
1.153 + R r = scan(node.getModifiers(), p);
1.154 + r = scanAndReduce(node.getType(), p, r);
1.155 + r = scanAndReduce(node.getNameExpression(), p, r);
1.156 + r = scanAndReduce(node.getInitializer(), p, r);
1.157 + return r;
1.158 + }
1.159 +
1.160 + public R visitEmptyStatement(EmptyStatementTree node, P p) {
1.161 + return null;
1.162 + }
1.163 +
1.164 + public R visitBlock(BlockTree node, P p) {
1.165 + return scan(node.getStatements(), p);
1.166 + }
1.167 +
1.168 + public R visitDoWhileLoop(DoWhileLoopTree node, P p) {
1.169 + R r = scan(node.getStatement(), p);
1.170 + r = scanAndReduce(node.getCondition(), p, r);
1.171 + return r;
1.172 + }
1.173 +
1.174 + public R visitWhileLoop(WhileLoopTree node, P p) {
1.175 + R r = scan(node.getCondition(), p);
1.176 + r = scanAndReduce(node.getStatement(), p, r);
1.177 + return r;
1.178 + }
1.179 +
1.180 + public R visitForLoop(ForLoopTree node, P p) {
1.181 + R r = scan(node.getInitializer(), p);
1.182 + r = scanAndReduce(node.getCondition(), p, r);
1.183 + r = scanAndReduce(node.getUpdate(), p, r);
1.184 + r = scanAndReduce(node.getStatement(), p, r);
1.185 + return r;
1.186 + }
1.187 +
1.188 + public R visitEnhancedForLoop(EnhancedForLoopTree node, P p) {
1.189 + R r = scan(node.getVariable(), p);
1.190 + r = scanAndReduce(node.getExpression(), p, r);
1.191 + r = scanAndReduce(node.getStatement(), p, r);
1.192 + return r;
1.193 + }
1.194 +
1.195 + public R visitLabeledStatement(LabeledStatementTree node, P p) {
1.196 + return scan(node.getStatement(), p);
1.197 + }
1.198 +
1.199 + public R visitSwitch(SwitchTree node, P p) {
1.200 + R r = scan(node.getExpression(), p);
1.201 + r = scanAndReduce(node.getCases(), p, r);
1.202 + return r;
1.203 + }
1.204 +
1.205 + public R visitCase(CaseTree node, P p) {
1.206 + R r = scan(node.getExpression(), p);
1.207 + r = scanAndReduce(node.getStatements(), p, r);
1.208 + return r;
1.209 + }
1.210 +
1.211 + public R visitSynchronized(SynchronizedTree node, P p) {
1.212 + R r = scan(node.getExpression(), p);
1.213 + r = scanAndReduce(node.getBlock(), p, r);
1.214 + return r;
1.215 + }
1.216 +
1.217 + public R visitTry(TryTree node, P p) {
1.218 + R r = scan(node.getResources(), p);
1.219 + r = scanAndReduce(node.getBlock(), p, r);
1.220 + r = scanAndReduce(node.getCatches(), p, r);
1.221 + r = scanAndReduce(node.getFinallyBlock(), p, r);
1.222 + return r;
1.223 + }
1.224 +
1.225 + public R visitCatch(CatchTree node, P p) {
1.226 + R r = scan(node.getParameter(), p);
1.227 + r = scanAndReduce(node.getBlock(), p, r);
1.228 + return r;
1.229 + }
1.230 +
1.231 + public R visitConditionalExpression(ConditionalExpressionTree node, P p) {
1.232 + R r = scan(node.getCondition(), p);
1.233 + r = scanAndReduce(node.getTrueExpression(), p, r);
1.234 + r = scanAndReduce(node.getFalseExpression(), p, r);
1.235 + return r;
1.236 + }
1.237 +
1.238 + public R visitIf(IfTree node, P p) {
1.239 + R r = scan(node.getCondition(), p);
1.240 + r = scanAndReduce(node.getThenStatement(), p, r);
1.241 + r = scanAndReduce(node.getElseStatement(), p, r);
1.242 + return r;
1.243 + }
1.244 +
1.245 + public R visitExpressionStatement(ExpressionStatementTree node, P p) {
1.246 + return scan(node.getExpression(), p);
1.247 + }
1.248 +
1.249 + public R visitBreak(BreakTree node, P p) {
1.250 + return null;
1.251 + }
1.252 +
1.253 + public R visitContinue(ContinueTree node, P p) {
1.254 + return null;
1.255 + }
1.256 +
1.257 + public R visitReturn(ReturnTree node, P p) {
1.258 + return scan(node.getExpression(), p);
1.259 + }
1.260 +
1.261 + public R visitThrow(ThrowTree node, P p) {
1.262 + return scan(node.getExpression(), p);
1.263 + }
1.264 +
1.265 + public R visitAssert(AssertTree node, P p) {
1.266 + R r = scan(node.getCondition(), p);
1.267 + r = scanAndReduce(node.getDetail(), p, r);
1.268 + return r;
1.269 + }
1.270 +
1.271 + public R visitMethodInvocation(MethodInvocationTree node, P p) {
1.272 + R r = scan(node.getTypeArguments(), p);
1.273 + r = scanAndReduce(node.getMethodSelect(), p, r);
1.274 + r = scanAndReduce(node.getArguments(), p, r);
1.275 + return r;
1.276 + }
1.277 +
1.278 + public R visitNewClass(NewClassTree node, P p) {
1.279 + R r = scan(node.getEnclosingExpression(), p);
1.280 + r = scanAndReduce(node.getIdentifier(), p, r);
1.281 + r = scanAndReduce(node.getTypeArguments(), p, r);
1.282 + r = scanAndReduce(node.getArguments(), p, r);
1.283 + r = scanAndReduce(node.getClassBody(), p, r);
1.284 + return r;
1.285 + }
1.286 +
1.287 + public R visitNewArray(NewArrayTree node, P p) {
1.288 + R r = scan(node.getType(), p);
1.289 + r = scanAndReduce(node.getDimensions(), p, r);
1.290 + r = scanAndReduce(node.getInitializers(), p, r);
1.291 + r = scanAndReduce(node.getAnnotations(), p, r);
1.292 + for (Iterable< ? extends Tree> dimAnno : node.getDimAnnotations()) {
1.293 + r = scanAndReduce(dimAnno, p, r);
1.294 + }
1.295 + return r;
1.296 + }
1.297 +
1.298 + public R visitLambdaExpression(LambdaExpressionTree node, P p) {
1.299 + R r = scan(node.getParameters(), p);
1.300 + r = scanAndReduce(node.getBody(), p, r);
1.301 + return r;
1.302 + }
1.303 +
1.304 + public R visitParenthesized(ParenthesizedTree node, P p) {
1.305 + return scan(node.getExpression(), p);
1.306 + }
1.307 +
1.308 + public R visitAssignment(AssignmentTree node, P p) {
1.309 + R r = scan(node.getVariable(), p);
1.310 + r = scanAndReduce(node.getExpression(), p, r);
1.311 + return r;
1.312 + }
1.313 +
1.314 + public R visitCompoundAssignment(CompoundAssignmentTree node, P p) {
1.315 + R r = scan(node.getVariable(), p);
1.316 + r = scanAndReduce(node.getExpression(), p, r);
1.317 + return r;
1.318 + }
1.319 +
1.320 + public R visitUnary(UnaryTree node, P p) {
1.321 + return scan(node.getExpression(), p);
1.322 + }
1.323 +
1.324 + public R visitBinary(BinaryTree node, P p) {
1.325 + R r = scan(node.getLeftOperand(), p);
1.326 + r = scanAndReduce(node.getRightOperand(), p, r);
1.327 + return r;
1.328 + }
1.329 +
1.330 + public R visitTypeCast(TypeCastTree node, P p) {
1.331 + R r = scan(node.getType(), p);
1.332 + r = scanAndReduce(node.getExpression(), p, r);
1.333 + return r;
1.334 + }
1.335 +
1.336 + public R visitInstanceOf(InstanceOfTree node, P p) {
1.337 + R r = scan(node.getExpression(), p);
1.338 + r = scanAndReduce(node.getType(), p, r);
1.339 + return r;
1.340 + }
1.341 +
1.342 + public R visitArrayAccess(ArrayAccessTree node, P p) {
1.343 + R r = scan(node.getExpression(), p);
1.344 + r = scanAndReduce(node.getIndex(), p, r);
1.345 + return r;
1.346 + }
1.347 +
1.348 + public R visitMemberSelect(MemberSelectTree node, P p) {
1.349 + return scan(node.getExpression(), p);
1.350 + }
1.351 +
1.352 + public R visitMemberReference(MemberReferenceTree node, P p) {
1.353 + R r = scan(node.getQualifierExpression(), p);
1.354 + r = scanAndReduce(node.getTypeArguments(), p, r);
1.355 + return r;
1.356 + }
1.357 +
1.358 + public R visitIdentifier(IdentifierTree node, P p) {
1.359 + return null;
1.360 + }
1.361 +
1.362 + public R visitLiteral(LiteralTree node, P p) {
1.363 + return null;
1.364 + }
1.365 +
1.366 + public R visitPrimitiveType(PrimitiveTypeTree node, P p) {
1.367 + return null;
1.368 + }
1.369 +
1.370 + public R visitArrayType(ArrayTypeTree node, P p) {
1.371 + return scan(node.getType(), p);
1.372 + }
1.373 +
1.374 + public R visitParameterizedType(ParameterizedTypeTree node, P p) {
1.375 + R r = scan(node.getType(), p);
1.376 + r = scanAndReduce(node.getTypeArguments(), p, r);
1.377 + return r;
1.378 + }
1.379 +
1.380 + public R visitUnionType(UnionTypeTree node, P p) {
1.381 + return scan(node.getTypeAlternatives(), p);
1.382 + }
1.383 +
1.384 + public R visitIntersectionType(IntersectionTypeTree node, P p) {
1.385 + return scan(node.getBounds(), p);
1.386 + }
1.387 +
1.388 + public R visitTypeParameter(TypeParameterTree node, P p) {
1.389 + R r = scan(node.getAnnotations(), p);
1.390 + r = scanAndReduce(node.getBounds(), p, r);
1.391 + return r;
1.392 + }
1.393 +
1.394 + public R visitWildcard(WildcardTree node, P p) {
1.395 + return scan(node.getBound(), p);
1.396 + }
1.397 +
1.398 + public R visitModifiers(ModifiersTree node, P p) {
1.399 + return scan(node.getAnnotations(), p);
1.400 + }
1.401 +
1.402 + public R visitAnnotation(AnnotationTree node, P p) {
1.403 + R r = scan(node.getAnnotationType(), p);
1.404 + r = scanAndReduce(node.getArguments(), p, r);
1.405 + return r;
1.406 + }
1.407 +
1.408 + public R visitAnnotatedType(AnnotatedTypeTree node, P p) {
1.409 + R r = scan(node.getAnnotations(), p);
1.410 + r = scanAndReduce(node.getUnderlyingType(), p, r);
1.411 + return r;
1.412 + }
1.413 +
1.414 + public R visitOther(Tree node, P p) {
1.415 + return null;
1.416 + }
1.417 +
1.418 + public R visitErroneous(ErroneousTree node, P p) {
1.419 + return null;
1.420 + }
1.421 +}
