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
26package com.sun.tools.javac.tree;
27
28import com.sun.tools.javac.util.*;
29import 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 */
45public 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}
448