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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")
translate(T tree)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      */
translate(List<T> trees)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      */
translateVarDefs(List<JCVariableDecl> trees)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      */
translateTypeParams(List<JCTypeParameter> trees)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      */
translateCases(List<JCCase> trees)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      */
translateCatchers(List<JCCatch> trees)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      */
translateAnnotations(List<JCAnnotation> trees)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 
visitTopLevel(JCCompilationUnit tree)118     public void visitTopLevel(JCCompilationUnit tree) {
119         tree.pid = translate(tree.pid);
120         tree.defs = translate(tree.defs);
121         result = tree;
122     }
123 
visitImport(JCImport tree)124     public void visitImport(JCImport tree) {
125         tree.qualid = translate(tree.qualid);
126         result = tree;
127     }
128 
visitClassDef(JCClassDecl tree)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 
visitMethodDef(JCMethodDecl tree)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.recvparam = translate(tree.recvparam);
143         tree.params = translateVarDefs(tree.params);
144         tree.thrown = translate(tree.thrown);
145         tree.body = translate(tree.body);
146         result = tree;
147     }
148 
visitVarDef(JCVariableDecl tree)149     public void visitVarDef(JCVariableDecl tree) {
150         tree.mods = translate(tree.mods);
151         tree.nameexpr = translate(tree.nameexpr);
152         tree.vartype = translate(tree.vartype);
153         tree.init = translate(tree.init);
154         result = tree;
155     }
156 
visitSkip(JCSkip tree)157     public void visitSkip(JCSkip tree) {
158         result = tree;
159     }
160 
visitBlock(JCBlock tree)161     public void visitBlock(JCBlock tree) {
162         tree.stats = translate(tree.stats);
163         result = tree;
164     }
165 
visitDoLoop(JCDoWhileLoop tree)166     public void visitDoLoop(JCDoWhileLoop tree) {
167         tree.body = translate(tree.body);
168         tree.cond = translate(tree.cond);
169         result = tree;
170     }
171 
visitWhileLoop(JCWhileLoop tree)172     public void visitWhileLoop(JCWhileLoop tree) {
173         tree.cond = translate(tree.cond);
174         tree.body = translate(tree.body);
175         result = tree;
176     }
177 
visitForLoop(JCForLoop tree)178     public void visitForLoop(JCForLoop tree) {
179         tree.init = translate(tree.init);
180         tree.cond = translate(tree.cond);
181         tree.step = translate(tree.step);
182         tree.body = translate(tree.body);
183         result = tree;
184     }
185 
visitForeachLoop(JCEnhancedForLoop tree)186     public void visitForeachLoop(JCEnhancedForLoop tree) {
187         tree.var = translate(tree.var);
188         tree.expr = translate(tree.expr);
189         tree.body = translate(tree.body);
190         result = tree;
191     }
192 
visitLabelled(JCLabeledStatement tree)193     public void visitLabelled(JCLabeledStatement tree) {
194         tree.body = translate(tree.body);
195         result = tree;
196     }
197 
visitSwitch(JCSwitch tree)198     public void visitSwitch(JCSwitch tree) {
199         tree.selector = translate(tree.selector);
200         tree.cases = translateCases(tree.cases);
201         result = tree;
202     }
203 
visitCase(JCCase tree)204     public void visitCase(JCCase tree) {
205         tree.pat = translate(tree.pat);
206         tree.stats = translate(tree.stats);
207         result = tree;
208     }
209 
visitSynchronized(JCSynchronized tree)210     public void visitSynchronized(JCSynchronized tree) {
211         tree.lock = translate(tree.lock);
212         tree.body = translate(tree.body);
213         result = tree;
214     }
215 
visitTry(JCTry tree)216     public void visitTry(JCTry tree) {
217         tree.resources = translate(tree.resources);
218         tree.body = translate(tree.body);
219         tree.catchers = translateCatchers(tree.catchers);
220         tree.finalizer = translate(tree.finalizer);
221         result = tree;
222     }
223 
visitCatch(JCCatch tree)224     public void visitCatch(JCCatch tree) {
225         tree.param = translate(tree.param);
226         tree.body = translate(tree.body);
227         result = tree;
228     }
229 
visitConditional(JCConditional tree)230     public void visitConditional(JCConditional tree) {
231         tree.cond = translate(tree.cond);
232         tree.truepart = translate(tree.truepart);
233         tree.falsepart = translate(tree.falsepart);
234         result = tree;
235     }
236 
visitIf(JCIf tree)237     public void visitIf(JCIf tree) {
238         tree.cond = translate(tree.cond);
239         tree.thenpart = translate(tree.thenpart);
240         tree.elsepart = translate(tree.elsepart);
241         result = tree;
242     }
243 
visitExec(JCExpressionStatement tree)244     public void visitExec(JCExpressionStatement tree) {
245         tree.expr = translate(tree.expr);
246         result = tree;
247     }
248 
visitBreak(JCBreak tree)249     public void visitBreak(JCBreak tree) {
250         result = tree;
251     }
252 
visitContinue(JCContinue tree)253     public void visitContinue(JCContinue tree) {
254         result = tree;
255     }
256 
visitReturn(JCReturn tree)257     public void visitReturn(JCReturn tree) {
258         tree.expr = translate(tree.expr);
259         result = tree;
260     }
261 
visitThrow(JCThrow tree)262     public void visitThrow(JCThrow tree) {
263         tree.expr = translate(tree.expr);
264         result = tree;
265     }
266 
visitAssert(JCAssert tree)267     public void visitAssert(JCAssert tree) {
268         tree.cond = translate(tree.cond);
269         tree.detail = translate(tree.detail);
270         result = tree;
271     }
272 
visitApply(JCMethodInvocation tree)273     public void visitApply(JCMethodInvocation tree) {
274         tree.meth = translate(tree.meth);
275         tree.args = translate(tree.args);
276         result = tree;
277     }
278 
visitNewClass(JCNewClass tree)279     public void visitNewClass(JCNewClass tree) {
280         tree.encl = translate(tree.encl);
281         tree.clazz = translate(tree.clazz);
282         tree.args = translate(tree.args);
283         tree.def = translate(tree.def);
284         result = tree;
285     }
286 
visitLambda(JCLambda tree)287     public void visitLambda(JCLambda tree) {
288         tree.params = translate(tree.params);
289         tree.body = translate(tree.body);
290         result = tree;
291     }
292 
visitNewArray(JCNewArray tree)293     public void visitNewArray(JCNewArray tree) {
294         tree.annotations = translate(tree.annotations);
295         List<List<JCAnnotation>> dimAnnos = List.nil();
296         for (List<JCAnnotation> origDimAnnos : tree.dimAnnotations)
297             dimAnnos = dimAnnos.append(translate(origDimAnnos));
298         tree.dimAnnotations = dimAnnos;
299         tree.elemtype = translate(tree.elemtype);
300         tree.dims = translate(tree.dims);
301         tree.elems = translate(tree.elems);
302         result = tree;
303     }
304 
visitParens(JCParens tree)305     public void visitParens(JCParens tree) {
306         tree.expr = translate(tree.expr);
307         result = tree;
308     }
309 
visitAssign(JCAssign tree)310     public void visitAssign(JCAssign tree) {
311         tree.lhs = translate(tree.lhs);
312         tree.rhs = translate(tree.rhs);
313         result = tree;
314     }
315 
visitAssignop(JCAssignOp tree)316     public void visitAssignop(JCAssignOp tree) {
317         tree.lhs = translate(tree.lhs);
318         tree.rhs = translate(tree.rhs);
319         result = tree;
320     }
321 
visitUnary(JCUnary tree)322     public void visitUnary(JCUnary tree) {
323         tree.arg = translate(tree.arg);
324         result = tree;
325     }
326 
visitBinary(JCBinary tree)327     public void visitBinary(JCBinary tree) {
328         tree.lhs = translate(tree.lhs);
329         tree.rhs = translate(tree.rhs);
330         result = tree;
331     }
332 
visitTypeCast(JCTypeCast tree)333     public void visitTypeCast(JCTypeCast tree) {
334         tree.clazz = translate(tree.clazz);
335         tree.expr = translate(tree.expr);
336         result = tree;
337     }
338 
visitTypeTest(JCInstanceOf tree)339     public void visitTypeTest(JCInstanceOf tree) {
340         tree.expr = translate(tree.expr);
341         tree.clazz = translate(tree.clazz);
342         result = tree;
343     }
344 
visitIndexed(JCArrayAccess tree)345     public void visitIndexed(JCArrayAccess tree) {
346         tree.indexed = translate(tree.indexed);
347         tree.index = translate(tree.index);
348         result = tree;
349     }
350 
visitSelect(JCFieldAccess tree)351     public void visitSelect(JCFieldAccess tree) {
352         tree.selected = translate(tree.selected);
353         result = tree;
354     }
355 
visitReference(JCMemberReference tree)356     public void visitReference(JCMemberReference tree) {
357         tree.expr = translate(tree.expr);
358         result = tree;
359     }
360 
visitIdent(JCIdent tree)361     public void visitIdent(JCIdent tree) {
362         result = tree;
363     }
364 
visitLiteral(JCLiteral tree)365     public void visitLiteral(JCLiteral tree) {
366         result = tree;
367     }
368 
visitTypeIdent(JCPrimitiveTypeTree tree)369     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
370         result = tree;
371     }
372 
visitTypeArray(JCArrayTypeTree tree)373     public void visitTypeArray(JCArrayTypeTree tree) {
374         tree.elemtype = translate(tree.elemtype);
375         result = tree;
376     }
377 
visitTypeApply(JCTypeApply tree)378     public void visitTypeApply(JCTypeApply tree) {
379         tree.clazz = translate(tree.clazz);
380         tree.arguments = translate(tree.arguments);
381         result = tree;
382     }
383 
visitTypeUnion(JCTypeUnion tree)384     public void visitTypeUnion(JCTypeUnion tree) {
385         tree.alternatives = translate(tree.alternatives);
386         result = tree;
387     }
388 
visitTypeIntersection(JCTypeIntersection tree)389     public void visitTypeIntersection(JCTypeIntersection tree) {
390         tree.bounds = translate(tree.bounds);
391         result = tree;
392     }
393 
visitTypeParameter(JCTypeParameter tree)394     public void visitTypeParameter(JCTypeParameter tree) {
395         tree.annotations = translate(tree.annotations);
396         tree.bounds = translate(tree.bounds);
397         result = tree;
398     }
399 
400     @Override
visitWildcard(JCWildcard tree)401     public void visitWildcard(JCWildcard tree) {
402         tree.kind = translate(tree.kind);
403         tree.inner = translate(tree.inner);
404         result = tree;
405     }
406 
407     @Override
visitTypeBoundKind(TypeBoundKind tree)408     public void visitTypeBoundKind(TypeBoundKind tree) {
409         result = tree;
410     }
411 
visitErroneous(JCErroneous tree)412     public void visitErroneous(JCErroneous tree) {
413         result = tree;
414     }
415 
visitLetExpr(LetExpr tree)416     public void visitLetExpr(LetExpr tree) {
417         tree.defs = translateVarDefs(tree.defs);
418         tree.expr = translate(tree.expr);
419         result = tree;
420     }
421 
visitModifiers(JCModifiers tree)422     public void visitModifiers(JCModifiers tree) {
423         tree.annotations = translateAnnotations(tree.annotations);
424         result = tree;
425     }
426 
visitAnnotation(JCAnnotation tree)427     public void visitAnnotation(JCAnnotation tree) {
428         tree.annotationType = translate(tree.annotationType);
429         tree.args = translate(tree.args);
430         result = tree;
431     }
432 
visitAnnotatedType(JCAnnotatedType tree)433     public void visitAnnotatedType(JCAnnotatedType tree) {
434         tree.annotations = translate(tree.annotations);
435         tree.underlyingType = translate(tree.underlyingType);
436         result = tree;
437     }
438 
visitTree(JCTree tree)439     public void visitTree(JCTree tree) {
440         throw new AssertionError(tree);
441     }
442 }
443