1 /*
   2  * Copyright (c) 1999, 2006, 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 result = this.result;
  60             this.result = null;
  61             return (T)result; // 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.pid = translate(tree.pid);
 120         tree.defs = translate(tree.defs);
 121         result = tree;
 122     }
 123 
 124     public void visitImport(JCImport tree) {
 125         tree.qualid = translate(tree.qualid);
 126         result = tree;
 127     }
 128 
 129     public void visitClassDef(JCClassDecl tree) {
 130         tree.mods = translate(tree.mods);
 131         tree.typarams = translateTypeParams(tree.typarams);
 132         tree.extending = translate(tree.extending);
 133         tree.implementing = translate(tree.implementing);
 134         tree.defs = translate(tree.defs);
 135         result = tree;
 136     }
 137 
 138     public void visitMethodDef(JCMethodDecl tree) {
 139         tree.mods = translate(tree.mods);
 140         tree.restype = translate(tree.restype);
 141         tree.typarams = translateTypeParams(tree.typarams);
 142         tree.params = translateVarDefs(tree.params);
 143         tree.thrown = translate(tree.thrown);
 144         tree.body = translate(tree.body);
 145         result = tree;
 146     }
 147 
 148     public void visitVarDef(JCVariableDecl tree) {
 149         tree.mods = translate(tree.mods);
 150         tree.vartype = translate(tree.vartype);
 151         tree.init = translate(tree.init);
 152         result = tree;
 153     }
 154 
 155     public void visitSkip(JCSkip tree) {
 156         result = tree;
 157     }
 158 
 159     public void visitBlock(JCBlock tree) {
 160         tree.stats = translate(tree.stats);
 161         result = tree;
 162     }
 163 
 164     public void visitDoLoop(JCDoWhileLoop tree) {
 165         tree.body = translate(tree.body);
 166         tree.cond = translate(tree.cond);
 167         result = tree;
 168     }
 169 
 170     public void visitWhileLoop(JCWhileLoop tree) {
 171         tree.cond = translate(tree.cond);
 172         tree.body = translate(tree.body);
 173         result = tree;
 174     }
 175 
 176     public void visitForLoop(JCForLoop tree) {
 177         tree.init = translate(tree.init);
 178         tree.cond = translate(tree.cond);
 179         tree.step = translate(tree.step);
 180         tree.body = translate(tree.body);
 181         result = tree;
 182     }
 183 
 184     public void visitForeachLoop(JCEnhancedForLoop tree) {
 185         tree.var = translate(tree.var);
 186         tree.expr = translate(tree.expr);
 187         tree.body = translate(tree.body);
 188         result = tree;
 189     }
 190 
 191     public void visitLabelled(JCLabeledStatement tree) {
 192         tree.body = translate(tree.body);
 193         result = tree;
 194     }
 195 
 196     public void visitSwitch(JCSwitch tree) {
 197         tree.selector = translate(tree.selector);
 198         tree.cases = translateCases(tree.cases);
 199         result = tree;
 200     }
 201 
 202     public void visitCase(JCCase tree) {
 203         tree.pat = translate(tree.pat);
 204         tree.stats = translate(tree.stats);
 205         result = tree;
 206     }
 207 
 208     public void visitSynchronized(JCSynchronized tree) {
 209         tree.lock = translate(tree.lock);
 210         tree.body = translate(tree.body);
 211         result = tree;
 212     }
 213 
 214     public void visitTry(JCTry tree) {
 215         tree.body = translate(tree.body);
 216         tree.catchers = translateCatchers(tree.catchers);
 217         tree.finalizer = translate(tree.finalizer);
 218         tree.resources = translate(tree.resources);
 219         result = tree;
 220     }
 221 
 222     public void visitCatch(JCCatch tree) {
 223         tree.param = translate(tree.param);
 224         tree.body = translate(tree.body);
 225         result = tree;
 226     }
 227 
 228     public void visitConditional(JCConditional tree) {
 229         tree.cond = translate(tree.cond);
 230         tree.truepart = translate(tree.truepart);
 231         tree.falsepart = translate(tree.falsepart);
 232         result = tree;
 233     }
 234 
 235     public void visitIf(JCIf tree) {
 236         tree.cond = translate(tree.cond);
 237         tree.thenpart = translate(tree.thenpart);
 238         tree.elsepart = translate(tree.elsepart);
 239         result = tree;
 240     }
 241 
 242     public void visitExec(JCExpressionStatement tree) {
 243         tree.expr = translate(tree.expr);
 244         result = tree;
 245     }
 246 
 247     public void visitBreak(JCBreak tree) {
 248         result = tree;
 249     }
 250 
 251     public void visitContinue(JCContinue tree) {
 252         result = tree;
 253     }
 254 
 255     public void visitReturn(JCReturn tree) {
 256         tree.expr = translate(tree.expr);
 257         result = tree;
 258     }
 259 
 260     public void visitThrow(JCThrow tree) {
 261         tree.expr = translate(tree.expr);
 262         result = tree;
 263     }
 264 
 265     public void visitAssert(JCAssert tree) {
 266         tree.cond = translate(tree.cond);
 267         tree.detail = translate(tree.detail);
 268         result = tree;
 269     }
 270 
 271     public void visitApply(JCMethodInvocation tree) {
 272         tree.meth = translate(tree.meth);
 273         tree.args = translate(tree.args);
 274         result = tree;
 275     }
 276 
 277     public void visitNewClass(JCNewClass tree) {
 278         tree.encl = translate(tree.encl);
 279         tree.clazz = translate(tree.clazz);
 280         tree.args = translate(tree.args);
 281         tree.def = translate(tree.def);
 282         result = tree;
 283     }
 284 
 285     public void visitNewArray(JCNewArray tree) {
 286         tree.annotations = translate(tree.annotations);
 287         List<List<JCTypeAnnotation>> dimAnnos = List.nil();
 288         for (List<JCTypeAnnotation> origDimAnnos : tree.dimAnnotations)
 289             dimAnnos = dimAnnos.append(translate(origDimAnnos));
 290         tree.dimAnnotations = dimAnnos;
 291         tree.elemtype = translate(tree.elemtype);
 292         tree.dims = translate(tree.dims);
 293         tree.elems = translate(tree.elems);
 294         result = tree;
 295     }
 296 
 297     public void visitParens(JCParens tree) {
 298         tree.expr = translate(tree.expr);
 299         result = tree;
 300     }
 301 
 302     public void visitAssign(JCAssign tree) {
 303         tree.lhs = translate(tree.lhs);
 304         tree.rhs = translate(tree.rhs);
 305         result = tree;
 306     }
 307 
 308     public void visitAssignop(JCAssignOp tree) {
 309         tree.lhs = translate(tree.lhs);
 310         tree.rhs = translate(tree.rhs);
 311         result = tree;
 312     }
 313 
 314     public void visitUnary(JCUnary tree) {
 315         tree.arg = translate(tree.arg);
 316         result = tree;
 317     }
 318 
 319     public void visitBinary(JCBinary tree) {
 320         tree.lhs = translate(tree.lhs);
 321         tree.rhs = translate(tree.rhs);
 322         result = tree;
 323     }
 324 
 325     public void visitTypeCast(JCTypeCast tree) {
 326         tree.clazz = translate(tree.clazz);
 327         tree.expr = translate(tree.expr);
 328         result = tree;
 329     }
 330 
 331     public void visitTypeTest(JCInstanceOf tree) {
 332         tree.expr = translate(tree.expr);
 333         tree.clazz = translate(tree.clazz);
 334         result = tree;
 335     }
 336 
 337     public void visitIndexed(JCArrayAccess tree) {
 338         tree.indexed = translate(tree.indexed);
 339         tree.index = translate(tree.index);
 340         result = tree;
 341     }
 342 
 343     public void visitSelect(JCFieldAccess tree) {
 344         tree.selected = translate(tree.selected);
 345         result = tree;
 346     }
 347 
 348     public void visitIdent(JCIdent tree) {
 349         result = tree;
 350     }
 351 
 352     public void visitLiteral(JCLiteral tree) {
 353         result = tree;
 354     }
 355 
 356     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
 357         result = tree;
 358     }
 359 
 360     public void visitTypeArray(JCArrayTypeTree tree) {
 361         tree.elemtype = translate(tree.elemtype);
 362         result = tree;
 363     }
 364 
 365     public void visitTypeApply(JCTypeApply tree) {
 366         tree.clazz = translate(tree.clazz);
 367         tree.arguments = translate(tree.arguments);
 368         result = tree;
 369     }
 370 
 371     public void visitTypeDisjoint(JCTypeDisjoint tree) {
 372         tree.components = translate(tree.components);
 373         result = tree;
 374     }
 375 
 376     public void visitTypeParameter(JCTypeParameter tree) {
 377         tree.annotations = translate(tree.annotations);
 378         tree.bounds = translate(tree.bounds);
 379         result = tree;
 380     }
 381 
 382     @Override
 383     public void visitWildcard(JCWildcard tree) {
 384         tree.kind = translate(tree.kind);
 385         tree.inner = translate(tree.inner);
 386         result = tree;
 387     }
 388 
 389     @Override
 390     public void visitTypeBoundKind(TypeBoundKind tree) {
 391         result = tree;
 392     }
 393 
 394     public void visitErroneous(JCErroneous tree) {
 395         result = tree;
 396     }
 397 
 398     public void visitLetExpr(LetExpr tree) {
 399         tree.defs = translateVarDefs(tree.defs);
 400         tree.expr = translate(tree.expr);
 401         result = tree;
 402     }
 403 
 404     public void visitModifiers(JCModifiers tree) {
 405         tree.annotations = translateAnnotations(tree.annotations);
 406         result = tree;
 407     }
 408 
 409     public void visitAnnotation(JCAnnotation tree) {
 410         tree.annotationType = translate(tree.annotationType);
 411         tree.args = translate(tree.args);
 412         result = tree;
 413     }
 414 
 415     public void visitAnnotatedType(JCAnnotatedType tree) {
 416         tree.annotations = translate(tree.annotations);
 417         tree.underlyingType = translate(tree.underlyingType);
 418         result = tree;
 419     }
 420 
 421     public void visitTree(JCTree tree) {
 422         throw new AssertionError(tree);
 423     }
 424 }