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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         result = tree;
262     }
263 
visitYield(JCYield tree)264     public void visitYield(JCYield tree) {
265         tree.value = translate(tree.value);
266         result = tree;
267     }
268 
visitContinue(JCContinue tree)269     public void visitContinue(JCContinue tree) {
270         result = tree;
271     }
272 
visitReturn(JCReturn tree)273     public void visitReturn(JCReturn tree) {
274         tree.expr = translate(tree.expr);
275         result = tree;
276     }
277 
visitThrow(JCThrow tree)278     public void visitThrow(JCThrow tree) {
279         tree.expr = translate(tree.expr);
280         result = tree;
281     }
282 
visitAssert(JCAssert tree)283     public void visitAssert(JCAssert tree) {
284         tree.cond = translate(tree.cond);
285         tree.detail = translate(tree.detail);
286         result = tree;
287     }
288 
visitApply(JCMethodInvocation tree)289     public void visitApply(JCMethodInvocation tree) {
290         tree.meth = translate(tree.meth);
291         tree.args = translate(tree.args);
292         result = tree;
293     }
294 
visitNewClass(JCNewClass tree)295     public void visitNewClass(JCNewClass tree) {
296         tree.encl = translate(tree.encl);
297         tree.clazz = translate(tree.clazz);
298         tree.args = translate(tree.args);
299         tree.def = translate(tree.def);
300         result = tree;
301     }
302 
visitLambda(JCLambda tree)303     public void visitLambda(JCLambda tree) {
304         tree.params = translate(tree.params);
305         tree.body = translate(tree.body);
306         result = tree;
307     }
308 
visitNewArray(JCNewArray tree)309     public void visitNewArray(JCNewArray tree) {
310         tree.annotations = translate(tree.annotations);
311         List<List<JCAnnotation>> dimAnnos = List.nil();
312         for (List<JCAnnotation> origDimAnnos : tree.dimAnnotations)
313             dimAnnos = dimAnnos.append(translate(origDimAnnos));
314         tree.dimAnnotations = dimAnnos;
315         tree.elemtype = translate(tree.elemtype);
316         tree.dims = translate(tree.dims);
317         tree.elems = translate(tree.elems);
318         result = tree;
319     }
320 
visitParens(JCParens tree)321     public void visitParens(JCParens tree) {
322         tree.expr = translate(tree.expr);
323         result = tree;
324     }
325 
visitAssign(JCAssign tree)326     public void visitAssign(JCAssign tree) {
327         tree.lhs = translate(tree.lhs);
328         tree.rhs = translate(tree.rhs);
329         result = tree;
330     }
331 
visitAssignop(JCAssignOp tree)332     public void visitAssignop(JCAssignOp tree) {
333         tree.lhs = translate(tree.lhs);
334         tree.rhs = translate(tree.rhs);
335         result = tree;
336     }
337 
visitUnary(JCUnary tree)338     public void visitUnary(JCUnary tree) {
339         tree.arg = translate(tree.arg);
340         result = tree;
341     }
342 
visitBinary(JCBinary tree)343     public void visitBinary(JCBinary tree) {
344         tree.lhs = translate(tree.lhs);
345         tree.rhs = translate(tree.rhs);
346         result = tree;
347     }
348 
visitTypeCast(JCTypeCast tree)349     public void visitTypeCast(JCTypeCast tree) {
350         tree.clazz = translate(tree.clazz);
351         tree.expr = translate(tree.expr);
352         result = tree;
353     }
354 
visitTypeTest(JCInstanceOf tree)355     public void visitTypeTest(JCInstanceOf tree) {
356         tree.expr = translate(tree.expr);
357         tree.pattern = translate(tree.pattern);
358         result = tree;
359     }
360 
visitBindingPattern(JCBindingPattern tree)361     public void visitBindingPattern(JCBindingPattern tree) {
362         tree.vartype = translate(tree.vartype);
363         result = tree;
364     }
365 
visitIndexed(JCArrayAccess tree)366     public void visitIndexed(JCArrayAccess tree) {
367         tree.indexed = translate(tree.indexed);
368         tree.index = translate(tree.index);
369         result = tree;
370     }
371 
visitSelect(JCFieldAccess tree)372     public void visitSelect(JCFieldAccess tree) {
373         tree.selected = translate(tree.selected);
374         result = tree;
375     }
376 
visitReference(JCMemberReference tree)377     public void visitReference(JCMemberReference tree) {
378         tree.expr = translate(tree.expr);
379         result = tree;
380     }
381 
visitIdent(JCIdent tree)382     public void visitIdent(JCIdent tree) {
383         result = tree;
384     }
385 
visitLiteral(JCLiteral tree)386     public void visitLiteral(JCLiteral tree) {
387         result = tree;
388     }
389 
visitTypeIdent(JCPrimitiveTypeTree tree)390     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
391         result = tree;
392     }
393 
visitTypeArray(JCArrayTypeTree tree)394     public void visitTypeArray(JCArrayTypeTree tree) {
395         tree.elemtype = translate(tree.elemtype);
396         result = tree;
397     }
398 
visitTypeApply(JCTypeApply tree)399     public void visitTypeApply(JCTypeApply tree) {
400         tree.clazz = translate(tree.clazz);
401         tree.arguments = translate(tree.arguments);
402         result = tree;
403     }
404 
visitTypeUnion(JCTypeUnion tree)405     public void visitTypeUnion(JCTypeUnion tree) {
406         tree.alternatives = translate(tree.alternatives);
407         result = tree;
408     }
409 
visitTypeIntersection(JCTypeIntersection tree)410     public void visitTypeIntersection(JCTypeIntersection tree) {
411         tree.bounds = translate(tree.bounds);
412         result = tree;
413     }
414 
visitTypeParameter(JCTypeParameter tree)415     public void visitTypeParameter(JCTypeParameter tree) {
416         tree.annotations = translate(tree.annotations);
417         tree.bounds = translate(tree.bounds);
418         result = tree;
419     }
420 
421     @Override
visitWildcard(JCWildcard tree)422     public void visitWildcard(JCWildcard tree) {
423         tree.kind = translate(tree.kind);
424         tree.inner = translate(tree.inner);
425         result = tree;
426     }
427 
428     @Override
visitTypeBoundKind(TypeBoundKind tree)429     public void visitTypeBoundKind(TypeBoundKind tree) {
430         result = tree;
431     }
432 
visitErroneous(JCErroneous tree)433     public void visitErroneous(JCErroneous tree) {
434         result = tree;
435     }
436 
visitLetExpr(LetExpr tree)437     public void visitLetExpr(LetExpr tree) {
438         tree.defs = translate(tree.defs);
439         tree.expr = translate(tree.expr);
440         result = tree;
441     }
442 
visitModifiers(JCModifiers tree)443     public void visitModifiers(JCModifiers tree) {
444         tree.annotations = translateAnnotations(tree.annotations);
445         result = tree;
446     }
447 
visitAnnotation(JCAnnotation tree)448     public void visitAnnotation(JCAnnotation tree) {
449         tree.annotationType = translate(tree.annotationType);
450         tree.args = translate(tree.args);
451         result = tree;
452     }
453 
visitAnnotatedType(JCAnnotatedType tree)454     public void visitAnnotatedType(JCAnnotatedType tree) {
455         tree.annotations = translate(tree.annotations);
456         tree.underlyingType = translate(tree.underlyingType);
457         result = tree;
458     }
459 
visitTree(JCTree tree)460     public void visitTree(JCTree tree) {
461         throw new AssertionError(tree);
462     }
463 }
464