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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.defs = translate(tree.defs);
120         result = tree;
121     }
122 
visitPackageDef(JCPackageDecl tree)123     public void visitPackageDef(JCPackageDecl tree) {
124         tree.annotations = translate(tree.annotations);
125         tree.pid = translate(tree.pid);
126         result = tree;
127     }
128 
visitImport(JCImport tree)129     public void visitImport(JCImport tree) {
130         tree.qualid = translate(tree.qualid);
131         result = tree;
132     }
133 
visitClassDef(JCClassDecl tree)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 
visitMethodDef(JCMethodDecl tree)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 
visitVarDef(JCVariableDecl tree)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 
visitSkip(JCSkip tree)162     public void visitSkip(JCSkip tree) {
163         result = tree;
164     }
165 
visitBlock(JCBlock tree)166     public void visitBlock(JCBlock tree) {
167         tree.stats = translate(tree.stats);
168         result = tree;
169     }
170 
visitDoLoop(JCDoWhileLoop tree)171     public void visitDoLoop(JCDoWhileLoop tree) {
172         tree.body = translate(tree.body);
173         tree.cond = translate(tree.cond);
174         result = tree;
175     }
176 
visitWhileLoop(JCWhileLoop tree)177     public void visitWhileLoop(JCWhileLoop tree) {
178         tree.cond = translate(tree.cond);
179         tree.body = translate(tree.body);
180         result = tree;
181     }
182 
visitForLoop(JCForLoop tree)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 
visitForeachLoop(JCEnhancedForLoop tree)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 
visitLabelled(JCLabeledStatement tree)198     public void visitLabelled(JCLabeledStatement tree) {
199         tree.body = translate(tree.body);
200         result = tree;
201     }
202 
visitSwitch(JCSwitch tree)203     public void visitSwitch(JCSwitch tree) {
204         tree.selector = translate(tree.selector);
205         tree.cases = translateCases(tree.cases);
206         result = tree;
207     }
208 
visitCase(JCCase tree)209     public void visitCase(JCCase tree) {
210         tree.pats = translate(tree.pats);
211         tree.stats = translate(tree.stats);
212         result = tree;
213     }
214 
visitSwitchExpression(JCSwitchExpression tree)215     public void visitSwitchExpression(JCSwitchExpression tree) {
216         tree.selector = translate(tree.selector);
217         tree.cases = translateCases(tree.cases);
218         result = tree;
219     }
220 
visitSynchronized(JCSynchronized tree)221     public void visitSynchronized(JCSynchronized tree) {
222         tree.lock = translate(tree.lock);
223         tree.body = translate(tree.body);
224         result = tree;
225     }
226 
visitTry(JCTry tree)227     public void visitTry(JCTry tree) {
228         tree.resources = translate(tree.resources);
229         tree.body = translate(tree.body);
230         tree.catchers = translateCatchers(tree.catchers);
231         tree.finalizer = translate(tree.finalizer);
232         result = tree;
233     }
234 
visitCatch(JCCatch tree)235     public void visitCatch(JCCatch tree) {
236         tree.param = translate(tree.param);
237         tree.body = translate(tree.body);
238         result = tree;
239     }
240 
visitConditional(JCConditional tree)241     public void visitConditional(JCConditional tree) {
242         tree.cond = translate(tree.cond);
243         tree.truepart = translate(tree.truepart);
244         tree.falsepart = translate(tree.falsepart);
245         result = tree;
246     }
247 
visitIf(JCIf tree)248     public void visitIf(JCIf tree) {
249         tree.cond = translate(tree.cond);
250         tree.thenpart = translate(tree.thenpart);
251         tree.elsepart = translate(tree.elsepart);
252         result = tree;
253     }
254 
visitExec(JCExpressionStatement tree)255     public void visitExec(JCExpressionStatement tree) {
256         tree.expr = translate(tree.expr);
257         result = tree;
258     }
259 
visitBreak(JCBreak tree)260     public void visitBreak(JCBreak tree) {
261         if (tree.isValueBreak())
262             tree.value = translate(tree.value);
263         result = tree;
264     }
265 
visitContinue(JCContinue tree)266     public void visitContinue(JCContinue tree) {
267         result = tree;
268     }
269 
visitReturn(JCReturn tree)270     public void visitReturn(JCReturn tree) {
271         tree.expr = translate(tree.expr);
272         result = tree;
273     }
274 
visitThrow(JCThrow tree)275     public void visitThrow(JCThrow tree) {
276         tree.expr = translate(tree.expr);
277         result = tree;
278     }
279 
visitAssert(JCAssert tree)280     public void visitAssert(JCAssert tree) {
281         tree.cond = translate(tree.cond);
282         tree.detail = translate(tree.detail);
283         result = tree;
284     }
285 
visitApply(JCMethodInvocation tree)286     public void visitApply(JCMethodInvocation tree) {
287         tree.meth = translate(tree.meth);
288         tree.args = translate(tree.args);
289         result = tree;
290     }
291 
visitNewClass(JCNewClass tree)292     public void visitNewClass(JCNewClass tree) {
293         tree.encl = translate(tree.encl);
294         tree.clazz = translate(tree.clazz);
295         tree.args = translate(tree.args);
296         tree.def = translate(tree.def);
297         result = tree;
298     }
299 
visitLambda(JCLambda tree)300     public void visitLambda(JCLambda tree) {
301         tree.params = translate(tree.params);
302         tree.body = translate(tree.body);
303         result = tree;
304     }
305 
visitNewArray(JCNewArray tree)306     public void visitNewArray(JCNewArray tree) {
307         tree.annotations = translate(tree.annotations);
308         List<List<JCAnnotation>> dimAnnos = List.nil();
309         for (List<JCAnnotation> origDimAnnos : tree.dimAnnotations)
310             dimAnnos = dimAnnos.append(translate(origDimAnnos));
311         tree.dimAnnotations = dimAnnos;
312         tree.elemtype = translate(tree.elemtype);
313         tree.dims = translate(tree.dims);
314         tree.elems = translate(tree.elems);
315         result = tree;
316     }
317 
visitParens(JCParens tree)318     public void visitParens(JCParens tree) {
319         tree.expr = translate(tree.expr);
320         result = tree;
321     }
322 
visitAssign(JCAssign tree)323     public void visitAssign(JCAssign tree) {
324         tree.lhs = translate(tree.lhs);
325         tree.rhs = translate(tree.rhs);
326         result = tree;
327     }
328 
visitAssignop(JCAssignOp tree)329     public void visitAssignop(JCAssignOp tree) {
330         tree.lhs = translate(tree.lhs);
331         tree.rhs = translate(tree.rhs);
332         result = tree;
333     }
334 
visitUnary(JCUnary tree)335     public void visitUnary(JCUnary tree) {
336         tree.arg = translate(tree.arg);
337         result = tree;
338     }
339 
visitBinary(JCBinary tree)340     public void visitBinary(JCBinary tree) {
341         tree.lhs = translate(tree.lhs);
342         tree.rhs = translate(tree.rhs);
343         result = tree;
344     }
345 
visitTypeCast(JCTypeCast tree)346     public void visitTypeCast(JCTypeCast tree) {
347         tree.clazz = translate(tree.clazz);
348         tree.expr = translate(tree.expr);
349         result = tree;
350     }
351 
visitTypeTest(JCInstanceOf tree)352     public void visitTypeTest(JCInstanceOf tree) {
353         tree.expr = translate(tree.expr);
354         tree.clazz = translate(tree.clazz);
355         result = tree;
356     }
357 
visitIndexed(JCArrayAccess tree)358     public void visitIndexed(JCArrayAccess tree) {
359         tree.indexed = translate(tree.indexed);
360         tree.index = translate(tree.index);
361         result = tree;
362     }
363 
visitSelect(JCFieldAccess tree)364     public void visitSelect(JCFieldAccess tree) {
365         tree.selected = translate(tree.selected);
366         result = tree;
367     }
368 
visitReference(JCMemberReference tree)369     public void visitReference(JCMemberReference tree) {
370         tree.expr = translate(tree.expr);
371         result = tree;
372     }
373 
visitIdent(JCIdent tree)374     public void visitIdent(JCIdent tree) {
375         result = tree;
376     }
377 
visitLiteral(JCLiteral tree)378     public void visitLiteral(JCLiteral tree) {
379         result = tree;
380     }
381 
visitTypeIdent(JCPrimitiveTypeTree tree)382     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
383         result = tree;
384     }
385 
visitTypeArray(JCArrayTypeTree tree)386     public void visitTypeArray(JCArrayTypeTree tree) {
387         tree.elemtype = translate(tree.elemtype);
388         result = tree;
389     }
390 
visitTypeApply(JCTypeApply tree)391     public void visitTypeApply(JCTypeApply tree) {
392         tree.clazz = translate(tree.clazz);
393         tree.arguments = translate(tree.arguments);
394         result = tree;
395     }
396 
visitTypeUnion(JCTypeUnion tree)397     public void visitTypeUnion(JCTypeUnion tree) {
398         tree.alternatives = translate(tree.alternatives);
399         result = tree;
400     }
401 
visitTypeIntersection(JCTypeIntersection tree)402     public void visitTypeIntersection(JCTypeIntersection tree) {
403         tree.bounds = translate(tree.bounds);
404         result = tree;
405     }
406 
visitTypeParameter(JCTypeParameter tree)407     public void visitTypeParameter(JCTypeParameter tree) {
408         tree.annotations = translate(tree.annotations);
409         tree.bounds = translate(tree.bounds);
410         result = tree;
411     }
412 
413     @Override
visitWildcard(JCWildcard tree)414     public void visitWildcard(JCWildcard tree) {
415         tree.kind = translate(tree.kind);
416         tree.inner = translate(tree.inner);
417         result = tree;
418     }
419 
420     @Override
visitTypeBoundKind(TypeBoundKind tree)421     public void visitTypeBoundKind(TypeBoundKind tree) {
422         result = tree;
423     }
424 
visitErroneous(JCErroneous tree)425     public void visitErroneous(JCErroneous tree) {
426         result = tree;
427     }
428 
visitLetExpr(LetExpr tree)429     public void visitLetExpr(LetExpr tree) {
430         tree.defs = translate(tree.defs);
431         tree.expr = translate(tree.expr);
432         result = tree;
433     }
434 
visitModifiers(JCModifiers tree)435     public void visitModifiers(JCModifiers tree) {
436         tree.annotations = translateAnnotations(tree.annotations);
437         result = tree;
438     }
439 
visitAnnotation(JCAnnotation tree)440     public void visitAnnotation(JCAnnotation tree) {
441         tree.annotationType = translate(tree.annotationType);
442         tree.args = translate(tree.args);
443         result = tree;
444     }
445 
visitAnnotatedType(JCAnnotatedType tree)446     public void visitAnnotatedType(JCAnnotatedType tree) {
447         tree.annotations = translate(tree.annotations);
448         tree.underlyingType = translate(tree.underlyingType);
449         result = tree;
450     }
451 
visitTree(JCTree tree)452     public void visitTree(JCTree tree) {
453         throw new AssertionError(tree);
454     }
455 }
456