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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.pat = translate(tree.pat);
211         tree.stats = translate(tree.stats);
212         result = tree;
213     }
214 
visitSynchronized(JCSynchronized tree)215     public void visitSynchronized(JCSynchronized tree) {
216         tree.lock = translate(tree.lock);
217         tree.body = translate(tree.body);
218         result = tree;
219     }
220 
visitTry(JCTry tree)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 
visitCatch(JCCatch tree)229     public void visitCatch(JCCatch tree) {
230         tree.param = translate(tree.param);
231         tree.body = translate(tree.body);
232         result = tree;
233     }
234 
visitConditional(JCConditional tree)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 
visitIf(JCIf tree)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 
visitExec(JCExpressionStatement tree)249     public void visitExec(JCExpressionStatement tree) {
250         tree.expr = translate(tree.expr);
251         result = tree;
252     }
253 
visitBreak(JCBreak tree)254     public void visitBreak(JCBreak tree) {
255         result = tree;
256     }
257 
visitContinue(JCContinue tree)258     public void visitContinue(JCContinue tree) {
259         result = tree;
260     }
261 
visitReturn(JCReturn tree)262     public void visitReturn(JCReturn tree) {
263         tree.expr = translate(tree.expr);
264         result = tree;
265     }
266 
visitThrow(JCThrow tree)267     public void visitThrow(JCThrow tree) {
268         tree.expr = translate(tree.expr);
269         result = tree;
270     }
271 
visitAssert(JCAssert tree)272     public void visitAssert(JCAssert tree) {
273         tree.cond = translate(tree.cond);
274         tree.detail = translate(tree.detail);
275         result = tree;
276     }
277 
visitApply(JCMethodInvocation tree)278     public void visitApply(JCMethodInvocation tree) {
279         tree.meth = translate(tree.meth);
280         tree.args = translate(tree.args);
281         result = tree;
282     }
283 
visitNewClass(JCNewClass tree)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 
visitLambda(JCLambda tree)292     public void visitLambda(JCLambda tree) {
293         tree.params = translate(tree.params);
294         tree.body = translate(tree.body);
295         result = tree;
296     }
297 
visitNewArray(JCNewArray tree)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 
visitParens(JCParens tree)310     public void visitParens(JCParens tree) {
311         tree.expr = translate(tree.expr);
312         result = tree;
313     }
314 
visitAssign(JCAssign tree)315     public void visitAssign(JCAssign tree) {
316         tree.lhs = translate(tree.lhs);
317         tree.rhs = translate(tree.rhs);
318         result = tree;
319     }
320 
visitAssignop(JCAssignOp tree)321     public void visitAssignop(JCAssignOp tree) {
322         tree.lhs = translate(tree.lhs);
323         tree.rhs = translate(tree.rhs);
324         result = tree;
325     }
326 
visitUnary(JCUnary tree)327     public void visitUnary(JCUnary tree) {
328         tree.arg = translate(tree.arg);
329         result = tree;
330     }
331 
visitBinary(JCBinary tree)332     public void visitBinary(JCBinary tree) {
333         tree.lhs = translate(tree.lhs);
334         tree.rhs = translate(tree.rhs);
335         result = tree;
336     }
337 
visitTypeCast(JCTypeCast tree)338     public void visitTypeCast(JCTypeCast tree) {
339         tree.clazz = translate(tree.clazz);
340         tree.expr = translate(tree.expr);
341         result = tree;
342     }
343 
visitTypeTest(JCInstanceOf tree)344     public void visitTypeTest(JCInstanceOf tree) {
345         tree.expr = translate(tree.expr);
346         tree.clazz = translate(tree.clazz);
347         result = tree;
348     }
349 
visitIndexed(JCArrayAccess tree)350     public void visitIndexed(JCArrayAccess tree) {
351         tree.indexed = translate(tree.indexed);
352         tree.index = translate(tree.index);
353         result = tree;
354     }
355 
visitSelect(JCFieldAccess tree)356     public void visitSelect(JCFieldAccess tree) {
357         tree.selected = translate(tree.selected);
358         result = tree;
359     }
360 
visitReference(JCMemberReference tree)361     public void visitReference(JCMemberReference tree) {
362         tree.expr = translate(tree.expr);
363         result = tree;
364     }
365 
visitIdent(JCIdent tree)366     public void visitIdent(JCIdent tree) {
367         result = tree;
368     }
369 
visitLiteral(JCLiteral tree)370     public void visitLiteral(JCLiteral tree) {
371         result = tree;
372     }
373 
visitTypeIdent(JCPrimitiveTypeTree tree)374     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
375         result = tree;
376     }
377 
visitTypeArray(JCArrayTypeTree tree)378     public void visitTypeArray(JCArrayTypeTree tree) {
379         tree.elemtype = translate(tree.elemtype);
380         result = tree;
381     }
382 
visitTypeApply(JCTypeApply tree)383     public void visitTypeApply(JCTypeApply tree) {
384         tree.clazz = translate(tree.clazz);
385         tree.arguments = translate(tree.arguments);
386         result = tree;
387     }
388 
visitTypeUnion(JCTypeUnion tree)389     public void visitTypeUnion(JCTypeUnion tree) {
390         tree.alternatives = translate(tree.alternatives);
391         result = tree;
392     }
393 
visitTypeIntersection(JCTypeIntersection tree)394     public void visitTypeIntersection(JCTypeIntersection tree) {
395         tree.bounds = translate(tree.bounds);
396         result = tree;
397     }
398 
visitTypeParameter(JCTypeParameter tree)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
visitWildcard(JCWildcard tree)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
visitTypeBoundKind(TypeBoundKind tree)413     public void visitTypeBoundKind(TypeBoundKind tree) {
414         result = tree;
415     }
416 
visitErroneous(JCErroneous tree)417     public void visitErroneous(JCErroneous tree) {
418         result = tree;
419     }
420 
visitLetExpr(LetExpr tree)421     public void visitLetExpr(LetExpr tree) {
422         tree.defs = translateVarDefs(tree.defs);
423         tree.expr = translate(tree.expr);
424         result = tree;
425     }
426 
visitModifiers(JCModifiers tree)427     public void visitModifiers(JCModifiers tree) {
428         tree.annotations = translateAnnotations(tree.annotations);
429         result = tree;
430     }
431 
visitAnnotation(JCAnnotation tree)432     public void visitAnnotation(JCAnnotation tree) {
433         tree.annotationType = translate(tree.annotationType);
434         tree.args = translate(tree.args);
435         result = tree;
436     }
437 
visitAnnotatedType(JCAnnotatedType tree)438     public void visitAnnotatedType(JCAnnotatedType tree) {
439         tree.annotations = translate(tree.annotations);
440         tree.underlyingType = translate(tree.underlyingType);
441         result = tree;
442     }
443 
visitTree(JCTree tree)444     public void visitTree(JCTree tree) {
445         throw new AssertionError(tree);
446     }
447 }
448