1 /*
   2  * Copyright (c) 1999, 2014, Oracle and/or its affiliates. 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.javac.tree;
  27 
  28 import com.sun.tools.javac.util.*;
  29 import com.sun.tools.javac.tree.JCTree.*;
  30 
  31 /** A subclass of Tree.Visitor, this class defines
  32  *  a general tree translator pattern. Translation proceeds recursively in
  33  *  left-to-right order down a tree, constructing translated nodes by
  34  *  overwriting existing ones. There is one visitor method in this class
  35  *  for every possible kind of tree node.  To obtain a specific
  36  *  translator, it suffices to override those visitor methods which
  37  *  do some interesting work. The translator class itself takes care of all
  38  *  navigational aspects.
  39  *
  40  *  <p><b>This is NOT part of any supported API.
  41  *  If you write code that depends on this, you do so at your own risk.
  42  *  This code and its internal interfaces are subject to change or
  43  *  deletion without notice.</b>
  44  */
  45 public class TreeTranslator extends JCTree.Visitor {
  46 
  47     /** Visitor result field: a tree
  48      */
  49     protected JCTree result;
  50 
  51     /** Visitor method: Translate a single node.
  52      */
  53     @SuppressWarnings("unchecked")
  54     public <T extends JCTree> T translate(T tree) {
  55         if (tree == null) {
  56             return null;
  57         } else {
  58             tree.accept(this);
  59             JCTree tmpResult = this.result;
  60             this.result = null;
  61             return (T)tmpResult; // XXX cast
  62         }
  63     }
  64 
  65     /** Visitor method: translate a list of nodes.
  66      */
  67     public <T extends JCTree> List<T> translate(List<T> trees) {
  68         if (trees == null) return null;
  69         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
  70             l.head = translate(l.head);
  71         return trees;
  72     }
  73 
  74     /**  Visitor method: translate a list of variable definitions.
  75      */
  76     public List<JCVariableDecl> translateVarDefs(List<JCVariableDecl> trees) {
  77         for (List<JCVariableDecl> l = trees; l.nonEmpty(); l = l.tail)
  78             l.head = translate(l.head);
  79         return trees;
  80     }
  81 
  82     /**  Visitor method: translate a list of type parameters.
  83      */
  84     public List<JCTypeParameter> translateTypeParams(List<JCTypeParameter> trees) {
  85         for (List<JCTypeParameter> l = trees; l.nonEmpty(); l = l.tail)
  86             l.head = translate(l.head);
  87         return trees;
  88     }
  89 
  90     /**  Visitor method: translate a list of case parts of switch statements.
  91      */
  92     public List<JCCase> translateCases(List<JCCase> trees) {
  93         for (List<JCCase> l = trees; l.nonEmpty(); l = l.tail)
  94             l.head = translate(l.head);
  95         return trees;
  96     }
  97 
  98     /**  Visitor method: translate a list of catch clauses in try statements.
  99      */
 100     public List<JCCatch> translateCatchers(List<JCCatch> trees) {
 101         for (List<JCCatch> l = trees; l.nonEmpty(); l = l.tail)
 102             l.head = translate(l.head);
 103         return trees;
 104     }
 105 
 106     /**  Visitor method: translate a list of catch clauses in try statements.
 107      */
 108     public List<JCAnnotation> translateAnnotations(List<JCAnnotation> trees) {
 109         for (List<JCAnnotation> l = trees; l.nonEmpty(); l = l.tail)
 110             l.head = translate(l.head);
 111         return trees;
 112     }
 113 
 114 /* ***************************************************************************
 115  * Visitor methods
 116  ****************************************************************************/
 117 
 118     public void visitTopLevel(JCCompilationUnit tree) {
 119         tree.defs = translate(tree.defs);
 120         result = tree;
 121     }
 122 
 123     public void visitPackageDef(JCPackageDecl tree) {
 124         tree.annotations = translate(tree.annotations);
 125         tree.pid = translate(tree.pid);
 126         result = tree;
 127     }
 128 
 129     public void visitImport(JCImport tree) {
 130         tree.qualid = translate(tree.qualid);
 131         result = tree;
 132     }
 133 
 134     public void visitClassDef(JCClassDecl tree) {
 135         tree.mods = translate(tree.mods);
 136         tree.typarams = translateTypeParams(tree.typarams);
 137         tree.extending = translate(tree.extending);
 138         tree.implementing = translate(tree.implementing);
 139         tree.defs = translate(tree.defs);
 140         result = tree;
 141     }
 142 
 143     public void visitMethodDef(JCMethodDecl tree) {
 144         tree.mods = translate(tree.mods);
 145         tree.restype = translate(tree.restype);
 146         tree.typarams = translateTypeParams(tree.typarams);
 147         tree.recvparam = translate(tree.recvparam);
 148         tree.params = translateVarDefs(tree.params);
 149         tree.thrown = translate(tree.thrown);
 150         tree.body = translate(tree.body);
 151         result = tree;
 152     }
 153 
 154     public void visitVarDef(JCVariableDecl tree) {
 155         tree.mods = translate(tree.mods);
 156         tree.nameexpr = translate(tree.nameexpr);
 157         tree.vartype = translate(tree.vartype);
 158         tree.init = translate(tree.init);
 159         result = tree;
 160     }
 161 
 162     public void visitSkip(JCSkip tree) {
 163         result = tree;
 164     }
 165 
 166     public void visitBlock(JCBlock tree) {
 167         tree.stats = translate(tree.stats);
 168         result = tree;
 169     }
 170 
 171     public void visitDoLoop(JCDoWhileLoop tree) {
 172         tree.body = translate(tree.body);
 173         tree.cond = translate(tree.cond);
 174         result = tree;
 175     }
 176 
 177     public void visitWhileLoop(JCWhileLoop tree) {
 178         tree.cond = translate(tree.cond);
 179         tree.body = translate(tree.body);
 180         result = tree;
 181     }
 182 
 183     public void visitForLoop(JCForLoop tree) {
 184         tree.init = translate(tree.init);
 185         tree.cond = translate(tree.cond);
 186         tree.step = translate(tree.step);
 187         tree.body = translate(tree.body);
 188         result = tree;
 189     }
 190 
 191     public void visitForeachLoop(JCEnhancedForLoop tree) {
 192         tree.var = translate(tree.var);
 193         tree.expr = translate(tree.expr);
 194         tree.body = translate(tree.body);
 195         result = tree;
 196     }
 197 
 198     public void visitLabelled(JCLabeledStatement tree) {
 199         tree.body = translate(tree.body);
 200         result = tree;
 201     }
 202 
 203     public void visitSwitch(JCSwitch tree) {
 204         tree.selector = translate(tree.selector);
 205         tree.cases = translateCases(tree.cases);
 206         result = tree;
 207     }
 208 
 209     public void visitCase(JCCase tree) {
 210         tree.pat = translate(tree.pat);
 211         tree.stats = translate(tree.stats);
 212         result = tree;
 213     }
 214 
 215     public void visitSynchronized(JCSynchronized tree) {
 216         tree.lock = translate(tree.lock);
 217         tree.body = translate(tree.body);
 218         result = tree;
 219     }
 220 
 221     public void visitTry(JCTry tree) {
 222         tree.resources = translate(tree.resources);
 223         tree.body = translate(tree.body);
 224         tree.catchers = translateCatchers(tree.catchers);
 225         tree.finalizer = translate(tree.finalizer);
 226         result = tree;
 227     }
 228 
 229     public void visitCatch(JCCatch tree) {
 230         tree.param = translate(tree.param);
 231         tree.body = translate(tree.body);
 232         result = tree;
 233     }
 234 
 235     public void visitConditional(JCConditional tree) {
 236         tree.cond = translate(tree.cond);
 237         tree.truepart = translate(tree.truepart);
 238         tree.falsepart = translate(tree.falsepart);
 239         result = tree;
 240     }
 241 
 242     public void visitIf(JCIf tree) {
 243         tree.cond = translate(tree.cond);
 244         tree.thenpart = translate(tree.thenpart);
 245         tree.elsepart = translate(tree.elsepart);
 246         result = tree;
 247     }
 248 
 249     public void visitExec(JCExpressionStatement tree) {
 250         tree.expr = translate(tree.expr);
 251         result = tree;
 252     }
 253 
 254     public void visitBreak(JCBreak tree) {
 255         result = tree;
 256     }
 257 
 258     public void visitContinue(JCContinue tree) {
 259         result = tree;
 260     }
 261 
 262     public void visitReturn(JCReturn tree) {
 263         tree.expr = translate(tree.expr);
 264         result = tree;
 265     }
 266 
 267     public void visitThrow(JCThrow tree) {
 268         tree.expr = translate(tree.expr);
 269         result = tree;
 270     }
 271 
 272     public void visitAssert(JCAssert tree) {
 273         tree.cond = translate(tree.cond);
 274         tree.detail = translate(tree.detail);
 275         result = tree;
 276     }
 277 
 278     public void visitApply(JCMethodInvocation tree) {
 279         tree.meth = translate(tree.meth);
 280         tree.args = translate(tree.args);
 281         result = tree;
 282     }
 283 
 284     public void visitNewClass(JCNewClass tree) {
 285         tree.encl = translate(tree.encl);
 286         tree.clazz = translate(tree.clazz);
 287         tree.args = translate(tree.args);
 288         tree.def = translate(tree.def);
 289         result = tree;
 290     }
 291 
 292     public void visitLambda(JCLambda tree) {
 293         tree.params = translate(tree.params);
 294         tree.body = translate(tree.body);
 295         result = tree;
 296     }
 297 
 298     public void visitNewArray(JCNewArray tree) {
 299         tree.annotations = translate(tree.annotations);
 300         List<List<JCAnnotation>> dimAnnos = List.nil();
 301         for (List<JCAnnotation> origDimAnnos : tree.dimAnnotations)
 302             dimAnnos = dimAnnos.append(translate(origDimAnnos));
 303         tree.dimAnnotations = dimAnnos;
 304         tree.elemtype = translate(tree.elemtype);
 305         tree.dims = translate(tree.dims);
 306         tree.elems = translate(tree.elems);
 307         result = tree;
 308     }
 309 
 310     public void visitParens(JCParens tree) {
 311         tree.expr = translate(tree.expr);
 312         result = tree;
 313     }
 314 
 315     public void visitAssign(JCAssign tree) {
 316         tree.lhs = translate(tree.lhs);
 317         tree.rhs = translate(tree.rhs);
 318         result = tree;
 319     }
 320 
 321     public void visitAssignop(JCAssignOp tree) {
 322         tree.lhs = translate(tree.lhs);
 323         tree.rhs = translate(tree.rhs);
 324         result = tree;
 325     }
 326 
 327     public void visitUnary(JCUnary tree) {
 328         tree.arg = translate(tree.arg);
 329         result = tree;
 330     }
 331 
 332     public void visitBinary(JCBinary tree) {
 333         tree.lhs = translate(tree.lhs);
 334         tree.rhs = translate(tree.rhs);
 335         result = tree;
 336     }
 337 
 338     public void visitTypeCast(JCTypeCast tree) {
 339         tree.clazz = translate(tree.clazz);
 340         tree.expr = translate(tree.expr);
 341         result = tree;
 342     }
 343 
 344     public void visitTypeTest(JCInstanceOf tree) {
 345         tree.expr = translate(tree.expr);
 346         tree.clazz = translate(tree.clazz);
 347         result = tree;
 348     }
 349 
 350     public void visitIndexed(JCArrayAccess tree) {
 351         tree.indexed = translate(tree.indexed);
 352         tree.index = translate(tree.index);
 353         result = tree;
 354     }
 355 
 356     public void visitSelect(JCFieldAccess tree) {
 357         tree.selected = translate(tree.selected);
 358         result = tree;
 359     }
 360 
 361     public void visitReference(JCMemberReference tree) {
 362         tree.expr = translate(tree.expr);
 363         result = tree;
 364     }
 365 
 366     public void visitIdent(JCIdent tree) {
 367         result = tree;
 368     }
 369 
 370     public void visitLiteral(JCLiteral tree) {
 371         result = tree;
 372     }
 373 
 374     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
 375         result = tree;
 376     }
 377 
 378     public void visitTypeArray(JCArrayTypeTree tree) {
 379         tree.elemtype = translate(tree.elemtype);
 380         result = tree;
 381     }
 382 
 383     public void visitTypeApply(JCTypeApply tree) {
 384         tree.clazz = translate(tree.clazz);
 385         tree.arguments = translate(tree.arguments);
 386         result = tree;
 387     }
 388 
 389     public void visitTypeUnion(JCTypeUnion tree) {
 390         tree.alternatives = translate(tree.alternatives);
 391         result = tree;
 392     }
 393 
 394     public void visitTypeIntersection(JCTypeIntersection tree) {
 395         tree.bounds = translate(tree.bounds);
 396         result = tree;
 397     }
 398 
 399     public void visitTypeParameter(JCTypeParameter tree) {
 400         tree.annotations = translate(tree.annotations);
 401         tree.bounds = translate(tree.bounds);
 402         result = tree;
 403     }
 404 
 405     @Override
 406     public void visitWildcard(JCWildcard tree) {
 407         tree.kind = translate(tree.kind);
 408         tree.inner = translate(tree.inner);
 409         result = tree;
 410     }
 411 
 412     @Override
 413     public void visitTypeBoundKind(TypeBoundKind tree) {
 414         result = tree;
 415     }
 416 
 417     public void visitErroneous(JCErroneous tree) {
 418         result = tree;
 419     }
 420 
 421     public void visitLetExpr(LetExpr tree) {
 422         tree.defs = translateVarDefs(tree.defs);
 423         tree.expr = translate(tree.expr);
 424         result = tree;
 425     }
 426 
 427     public void visitModifiers(JCModifiers tree) {
 428         tree.annotations = translateAnnotations(tree.annotations);
 429         result = tree;
 430     }
 431 
 432     public void visitAnnotation(JCAnnotation tree) {
 433         tree.annotationType = translate(tree.annotationType);
 434         tree.args = translate(tree.args);
 435         result = tree;
 436     }
 437 
 438     public void visitAnnotatedType(JCAnnotatedType tree) {
 439         tree.annotations = translate(tree.annotations);
 440         tree.underlyingType = translate(tree.underlyingType);
 441         result = tree;
 442     }
 443 
 444     public void visitTree(JCTree tree) {
 445         throw new AssertionError(tree);
 446     }
 447 }