author | erikj |
Tue, 12 Sep 2017 19:03:39 +0200 | |
changeset 47216 | 71c04702a3d5 |
parent 44797 | jaxp/src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/compiler/Predicate.java@8b3b3b911b8a |
child 47359 | e1a6c0168741 |
permissions | -rw-r--r-- |
6 | 1 |
/* |
2 |
* reserved comment block |
|
3 |
* DO NOT REMOVE OR ALTER! |
|
4 |
*/ |
|
5 |
/* |
|
44797
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
6 |
* Licensed to the Apache Software Foundation (ASF) under one or more |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
7 |
* contributor license agreements. See the NOTICE file distributed with |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
8 |
* this work for additional information regarding copyright ownership. |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
9 |
* The ASF licenses this file to You under the Apache License, Version 2.0 |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
10 |
* (the "License"); you may not use this file except in compliance with |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
11 |
* the License. You may obtain a copy of the License at |
6 | 12 |
* |
44797
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
|
13 |
* http://www.apache.org/licenses/LICENSE-2.0 |
6 | 14 |
* |
15 |
* Unless required by applicable law or agreed to in writing, software |
|
16 |
* distributed under the License is distributed on an "AS IS" BASIS, |
|
17 |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
18 |
* See the License for the specific language governing permissions and |
|
19 |
* limitations under the License. |
|
20 |
*/ |
|
21 |
||
22 |
package com.sun.org.apache.xalan.internal.xsltc.compiler; |
|
23 |
||
24 |
import java.util.ArrayList; |
|
25 |
||
26 |
import com.sun.org.apache.bcel.internal.classfile.Field; |
|
27 |
import com.sun.org.apache.bcel.internal.generic.ASTORE; |
|
28 |
import com.sun.org.apache.bcel.internal.generic.CHECKCAST; |
|
29 |
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen; |
|
30 |
import com.sun.org.apache.bcel.internal.generic.GETFIELD; |
|
31 |
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL; |
|
32 |
import com.sun.org.apache.bcel.internal.generic.InstructionList; |
|
33 |
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; |
|
34 |
import com.sun.org.apache.bcel.internal.generic.NEW; |
|
35 |
import com.sun.org.apache.bcel.internal.generic.PUSH; |
|
36 |
import com.sun.org.apache.bcel.internal.generic.PUTFIELD; |
|
37 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType; |
|
38 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator; |
|
39 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.FilterGenerator; |
|
40 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.IntType; |
|
41 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator; |
|
42 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NumberType; |
|
43 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ReferenceType; |
|
44 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; |
|
45 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TestGenerator; |
|
46 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type; |
|
47 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError; |
|
48 |
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util; |
|
49 |
import com.sun.org.apache.xalan.internal.xsltc.runtime.Operators; |
|
50 |
||
51 |
/** |
|
52 |
* @author Jacek Ambroziak |
|
53 |
* @author Santiago Pericas-Geertsen |
|
54 |
* @author Morten Jorgensen |
|
55 |
*/ |
|
56 |
final class Predicate extends Expression implements Closure { |
|
57 |
||
58 |
/** |
|
59 |
* The predicate's expression. |
|
60 |
*/ |
|
61 |
private Expression _exp = null; |
|
62 |
||
63 |
/** |
|
64 |
* This flag indicates if optimizations are turned on. The |
|
65 |
* method <code>dontOptimize()</code> can be called to turn |
|
66 |
* optimizations off. |
|
67 |
*/ |
|
68 |
private boolean _canOptimize = true; |
|
69 |
||
70 |
/** |
|
71 |
* Flag indicatig if the nth position optimization is on. It |
|
72 |
* is set in <code>typeCheck()</code>. |
|
73 |
*/ |
|
74 |
private boolean _nthPositionFilter = false; |
|
75 |
||
76 |
/** |
|
77 |
* Flag indicatig if the nth position descendant is on. It |
|
78 |
* is set in <code>typeCheck()</code>. |
|
79 |
*/ |
|
80 |
private boolean _nthDescendant = false; |
|
81 |
||
82 |
/** |
|
83 |
* Cached node type of the expression that owns this predicate. |
|
84 |
*/ |
|
85 |
int _ptype = -1; |
|
86 |
||
87 |
/** |
|
88 |
* Name of the inner class. |
|
89 |
*/ |
|
90 |
private String _className = null; |
|
91 |
||
92 |
/** |
|
93 |
* List of variables in closure. |
|
94 |
*/ |
|
95 |
private ArrayList _closureVars = null; |
|
96 |
||
97 |
/** |
|
98 |
* Reference to parent closure. |
|
99 |
*/ |
|
100 |
private Closure _parentClosure = null; |
|
101 |
||
102 |
/** |
|
103 |
* Cached value of method <code>getCompareValue()</code>. |
|
104 |
*/ |
|
105 |
private Expression _value = null; |
|
106 |
||
107 |
/** |
|
108 |
* Cached value of method <code>getCompareValue()</code>. |
|
109 |
*/ |
|
110 |
private Step _step = null; |
|
111 |
||
112 |
/** |
|
113 |
* Initializes a predicate. |
|
114 |
*/ |
|
115 |
public Predicate(Expression exp) { |
|
116 |
_exp = exp; |
|
117 |
_exp.setParent(this); |
|
118 |
||
119 |
} |
|
120 |
||
121 |
/** |
|
122 |
* Set the parser for this expression. |
|
123 |
*/ |
|
124 |
public void setParser(Parser parser) { |
|
125 |
super.setParser(parser); |
|
126 |
_exp.setParser(parser); |
|
127 |
} |
|
128 |
||
129 |
/** |
|
130 |
* Returns a boolean value indicating if the nth position optimization |
|
131 |
* is on. Must be call after type checking! |
|
132 |
*/ |
|
133 |
public boolean isNthPositionFilter() { |
|
134 |
return _nthPositionFilter; |
|
135 |
} |
|
136 |
||
137 |
/** |
|
138 |
* Returns a boolean value indicating if the nth descendant optimization |
|
139 |
* is on. Must be call after type checking! |
|
140 |
*/ |
|
141 |
public boolean isNthDescendant() { |
|
142 |
return _nthDescendant; |
|
143 |
} |
|
144 |
||
145 |
/** |
|
146 |
* Turns off all optimizations for this predicate. |
|
147 |
*/ |
|
148 |
public void dontOptimize() { |
|
149 |
_canOptimize = false; |
|
150 |
} |
|
151 |
||
152 |
/** |
|
153 |
* Returns true if the expression in this predicate contains a call |
|
154 |
* to position(). |
|
155 |
*/ |
|
156 |
public boolean hasPositionCall() { |
|
157 |
return _exp.hasPositionCall(); |
|
158 |
} |
|
159 |
||
160 |
/** |
|
161 |
* Returns true if the expression in this predicate contains a call |
|
162 |
* to last(). |
|
163 |
*/ |
|
164 |
public boolean hasLastCall() { |
|
165 |
return _exp.hasLastCall(); |
|
166 |
} |
|
167 |
||
168 |
// -- Begin Closure interface -------------------- |
|
169 |
||
170 |
/** |
|
171 |
* Returns true if this closure is compiled in an inner class (i.e. |
|
172 |
* if this is a real closure). |
|
173 |
*/ |
|
174 |
public boolean inInnerClass() { |
|
175 |
return (_className != null); |
|
176 |
} |
|
177 |
||
178 |
/** |
|
179 |
* Returns a reference to its parent closure or null if outermost. |
|
180 |
*/ |
|
181 |
public Closure getParentClosure() { |
|
182 |
if (_parentClosure == null) { |
|
183 |
SyntaxTreeNode node = getParent(); |
|
184 |
do { |
|
185 |
if (node instanceof Closure) { |
|
186 |
_parentClosure = (Closure) node; |
|
187 |
break; |
|
188 |
} |
|
189 |
if (node instanceof TopLevelElement) { |
|
190 |
break; // way up in the tree |
|
191 |
} |
|
192 |
node = node.getParent(); |
|
193 |
} while (node != null); |
|
194 |
} |
|
195 |
return _parentClosure; |
|
196 |
} |
|
197 |
||
198 |
/** |
|
199 |
* Returns the name of the auxiliary class or null if this predicate |
|
200 |
* is compiled inside the Translet. |
|
201 |
*/ |
|
202 |
public String getInnerClassName() { |
|
203 |
return _className; |
|
204 |
} |
|
205 |
||
206 |
/** |
|
207 |
* Add new variable to the closure. |
|
208 |
*/ |
|
209 |
public void addVariable(VariableRefBase variableRef) { |
|
210 |
if (_closureVars == null) { |
|
211 |
_closureVars = new ArrayList(); |
|
212 |
} |
|
213 |
||
214 |
// Only one reference per variable |
|
215 |
if (!_closureVars.contains(variableRef)) { |
|
216 |
_closureVars.add(variableRef); |
|
217 |
||
218 |
// Add variable to parent closure as well |
|
219 |
Closure parentClosure = getParentClosure(); |
|
220 |
if (parentClosure != null) { |
|
221 |
parentClosure.addVariable(variableRef); |
|
222 |
} |
|
223 |
} |
|
224 |
} |
|
225 |
||
226 |
// -- End Closure interface ---------------------- |
|
227 |
||
228 |
/** |
|
229 |
* Returns the node type of the expression owning this predicate. The |
|
230 |
* return value is cached in <code>_ptype</code>. |
|
231 |
*/ |
|
232 |
public int getPosType() { |
|
233 |
if (_ptype == -1) { |
|
234 |
SyntaxTreeNode parent = getParent(); |
|
235 |
if (parent instanceof StepPattern) { |
|
236 |
_ptype = ((StepPattern)parent).getNodeType(); |
|
237 |
} |
|
238 |
else if (parent instanceof AbsoluteLocationPath) { |
|
239 |
AbsoluteLocationPath path = (AbsoluteLocationPath)parent; |
|
240 |
Expression exp = path.getPath(); |
|
241 |
if (exp instanceof Step) { |
|
242 |
_ptype = ((Step)exp).getNodeType(); |
|
243 |
} |
|
244 |
} |
|
245 |
else if (parent instanceof VariableRefBase) { |
|
246 |
final VariableRefBase ref = (VariableRefBase)parent; |
|
247 |
final VariableBase var = ref.getVariable(); |
|
248 |
final Expression exp = var.getExpression(); |
|
249 |
if (exp instanceof Step) { |
|
250 |
_ptype = ((Step)exp).getNodeType(); |
|
251 |
} |
|
252 |
} |
|
253 |
else if (parent instanceof Step) { |
|
254 |
_ptype = ((Step)parent).getNodeType(); |
|
255 |
} |
|
256 |
} |
|
257 |
return _ptype; |
|
258 |
} |
|
259 |
||
260 |
public boolean parentIsPattern() { |
|
261 |
return (getParent() instanceof Pattern); |
|
262 |
} |
|
263 |
||
264 |
public Expression getExpr() { |
|
265 |
return _exp; |
|
266 |
} |
|
267 |
||
268 |
public String toString() { |
|
269 |
return "pred(" + _exp + ')'; |
|
270 |
} |
|
271 |
||
272 |
/** |
|
273 |
* Type check a predicate expression. If the type of the expression is |
|
274 |
* number convert it to boolean by adding a comparison with position(). |
|
275 |
* Note that if the expression is a parameter, we cannot distinguish |
|
276 |
* at compile time if its type is number or not. Hence, expressions of |
|
277 |
* reference type are always converted to booleans. |
|
278 |
* |
|
279 |
* This method may be called twice, before and after calling |
|
280 |
* <code>dontOptimize()</code>. If so, the second time it should honor |
|
281 |
* the new value of <code>_canOptimize</code>. |
|
282 |
*/ |
|
283 |
public Type typeCheck(SymbolTable stable) throws TypeCheckError { |
|
284 |
Type texp = _exp.typeCheck(stable); |
|
285 |
||
286 |
// We need explicit type information for reference types - no good! |
|
287 |
if (texp instanceof ReferenceType) { |
|
288 |
_exp = new CastExpr(_exp, texp = Type.Real); |
|
289 |
} |
|
290 |
||
291 |
// A result tree fragment should not be cast directly to a number type, |
|
292 |
// but rather to a boolean value, and then to a numer (0 or 1). |
|
293 |
// Ref. section 11.2 of the XSLT 1.0 spec |
|
294 |
if (texp instanceof ResultTreeType) { |
|
295 |
_exp = new CastExpr(_exp, Type.Boolean); |
|
296 |
_exp = new CastExpr(_exp, Type.Real); |
|
297 |
texp = _exp.typeCheck(stable); |
|
298 |
} |
|
299 |
||
300 |
// Numerical types will be converted to a position filter |
|
301 |
if (texp instanceof NumberType) { |
|
302 |
// Cast any numerical types to an integer |
|
303 |
if (texp instanceof IntType == false) { |
|
304 |
_exp = new CastExpr(_exp, Type.Int); |
|
305 |
} |
|
306 |
||
307 |
if (_canOptimize) { |
|
308 |
// Nth position optimization. Expression must not depend on context |
|
309 |
_nthPositionFilter = |
|
310 |
!_exp.hasLastCall() && !_exp.hasPositionCall(); |
|
311 |
||
312 |
// _nthDescendant optimization - only if _nthPositionFilter is on |
|
313 |
if (_nthPositionFilter) { |
|
314 |
SyntaxTreeNode parent = getParent(); |
|
315 |
_nthDescendant = (parent instanceof Step) && |
|
316 |
(parent.getParent() instanceof AbsoluteLocationPath); |
|
317 |
return _type = Type.NodeSet; |
|
318 |
} |
|
319 |
} |
|
320 |
||
321 |
// Reset optimization flags |
|
322 |
_nthPositionFilter = _nthDescendant = false; |
|
323 |
||
324 |
// Otherwise, expand [e] to [position() = e] |
|
325 |
final QName position = |
|
326 |
getParser().getQNameIgnoreDefaultNs("position"); |
|
327 |
final PositionCall positionCall = |
|
328 |
new PositionCall(position); |
|
329 |
positionCall.setParser(getParser()); |
|
330 |
positionCall.setParent(this); |
|
331 |
||
332 |
_exp = new EqualityExpr(Operators.EQ, positionCall, |
|
333 |
_exp); |
|
334 |
if (_exp.typeCheck(stable) != Type.Boolean) { |
|
335 |
_exp = new CastExpr(_exp, Type.Boolean); |
|
336 |
} |
|
337 |
return _type = Type.Boolean; |
|
338 |
} |
|
339 |
else { |
|
340 |
// All other types will be handled as boolean values |
|
341 |
if (texp instanceof BooleanType == false) { |
|
342 |
_exp = new CastExpr(_exp, Type.Boolean); |
|
343 |
} |
|
344 |
return _type = Type.Boolean; |
|
345 |
} |
|
346 |
} |
|
347 |
||
348 |
/** |
|
349 |
* Create a new "Filter" class implementing |
|
350 |
* <code>CurrentNodeListFilter</code>. Allocate registers for local |
|
351 |
* variables and local parameters passed in the closure to test(). |
|
352 |
* Notice that local variables need to be "unboxed". |
|
353 |
*/ |
|
354 |
private void compileFilter(ClassGenerator classGen, |
|
355 |
MethodGenerator methodGen) { |
|
356 |
TestGenerator testGen; |
|
357 |
LocalVariableGen local; |
|
358 |
FilterGenerator filterGen; |
|
359 |
||
360 |
_className = getXSLTC().getHelperClassName(); |
|
361 |
filterGen = new FilterGenerator(_className, |
|
362 |
"java.lang.Object", |
|
363 |
toString(), |
|
364 |
ACC_PUBLIC | ACC_SUPER, |
|
365 |
new String[] { |
|
366 |
CURRENT_NODE_LIST_FILTER |
|
367 |
}, |
|
368 |
classGen.getStylesheet()); |
|
369 |
||
370 |
final ConstantPoolGen cpg = filterGen.getConstantPool(); |
|
371 |
final int length = (_closureVars == null) ? 0 : _closureVars.size(); |
|
372 |
||
373 |
// Add a new instance variable for each var in closure |
|
374 |
for (int i = 0; i < length; i++) { |
|
375 |
VariableBase var = ((VariableRefBase) _closureVars.get(i)).getVariable(); |
|
376 |
||
377 |
filterGen.addField(new Field(ACC_PUBLIC, |
|
378 |
cpg.addUtf8(var.getEscapedName()), |
|
379 |
cpg.addUtf8(var.getType().toSignature()), |
|
380 |
null, cpg.getConstantPool())); |
|
381 |
} |
|
382 |
||
383 |
final InstructionList il = new InstructionList(); |
|
384 |
testGen = new TestGenerator(ACC_PUBLIC | ACC_FINAL, |
|
385 |
com.sun.org.apache.bcel.internal.generic.Type.BOOLEAN, |
|
386 |
new com.sun.org.apache.bcel.internal.generic.Type[] { |
|
387 |
com.sun.org.apache.bcel.internal.generic.Type.INT, |
|
388 |
com.sun.org.apache.bcel.internal.generic.Type.INT, |
|
389 |
com.sun.org.apache.bcel.internal.generic.Type.INT, |
|
390 |
com.sun.org.apache.bcel.internal.generic.Type.INT, |
|
391 |
Util.getJCRefType(TRANSLET_SIG), |
|
392 |
Util.getJCRefType(NODE_ITERATOR_SIG) |
|
393 |
}, |
|
394 |
new String[] { |
|
395 |
"node", |
|
396 |
"position", |
|
397 |
"last", |
|
398 |
"current", |
|
399 |
"translet", |
|
400 |
"iterator" |
|
401 |
}, |
|
402 |
"test", _className, il, cpg); |
|
403 |
||
404 |
// Store the dom in a local variable |
|
405 |
local = testGen.addLocalVariable("document", |
|
406 |
Util.getJCRefType(DOM_INTF_SIG), |
|
407 |
null, null); |
|
408 |
final String className = classGen.getClassName(); |
|
409 |
il.append(filterGen.loadTranslet()); |
|
410 |
il.append(new CHECKCAST(cpg.addClass(className))); |
|
411 |
il.append(new GETFIELD(cpg.addFieldref(className, |
|
412 |
DOM_FIELD, DOM_INTF_SIG))); |
|
12458 | 413 |
local.setStart(il.append(new ASTORE(local.getIndex()))); |
6 | 414 |
|
415 |
// Store the dom index in the test generator |
|
416 |
testGen.setDomIndex(local.getIndex()); |
|
417 |
||
418 |
_exp.translate(filterGen, testGen); |
|
419 |
il.append(IRETURN); |
|
420 |
||
421 |
filterGen.addEmptyConstructor(ACC_PUBLIC); |
|
12458 | 422 |
filterGen.addMethod(testGen); |
6 | 423 |
|
424 |
getXSLTC().dumpClass(filterGen.getJavaClass()); |
|
425 |
} |
|
426 |
||
427 |
/** |
|
428 |
* Returns true if the predicate is a test for the existance of an |
|
429 |
* element or attribute. All we have to do is to get the first node |
|
430 |
* from the step, check if it is there, and then return true/false. |
|
431 |
*/ |
|
432 |
public boolean isBooleanTest() { |
|
433 |
return (_exp instanceof BooleanExpr); |
|
434 |
} |
|
435 |
||
436 |
/** |
|
437 |
* Method to see if we can optimise the predicate by using a specialised |
|
438 |
* iterator for expressions like '/foo/bar[@attr = $var]', which are |
|
439 |
* very common in many stylesheets |
|
440 |
*/ |
|
441 |
public boolean isNodeValueTest() { |
|
442 |
if (!_canOptimize) return false; |
|
443 |
return (getStep() != null && getCompareValue() != null); |
|
444 |
} |
|
445 |
||
446 |
/** |
|
447 |
* Returns the step in an expression of the form 'step = value'. |
|
448 |
* Null is returned if the expression is not of the right form. |
|
449 |
* Optimization if off if null is returned. |
|
450 |
*/ |
|
451 |
public Step getStep() { |
|
452 |
// Returned cached value if called more than once |
|
453 |
if (_step != null) { |
|
454 |
return _step; |
|
455 |
} |
|
456 |
||
457 |
// Nothing to do if _exp is null |
|
458 |
if (_exp == null) { |
|
459 |
return null; |
|
460 |
} |
|
461 |
||
462 |
// Ignore if not equality expression |
|
463 |
if (_exp instanceof EqualityExpr) { |
|
464 |
EqualityExpr exp = (EqualityExpr)_exp; |
|
465 |
Expression left = exp.getLeft(); |
|
466 |
Expression right = exp.getRight(); |
|
467 |
||
468 |
// Unwrap and set _step if appropriate |
|
469 |
if (left instanceof CastExpr) { |
|
470 |
left = ((CastExpr) left).getExpr(); |
|
471 |
} |
|
472 |
if (left instanceof Step) { |
|
473 |
_step = (Step) left; |
|
474 |
} |
|
475 |
||
476 |
// Unwrap and set _step if appropriate |
|
477 |
if (right instanceof CastExpr) { |
|
478 |
right = ((CastExpr)right).getExpr(); |
|
479 |
} |
|
480 |
if (right instanceof Step) { |
|
481 |
_step = (Step)right; |
|
482 |
} |
|
483 |
} |
|
484 |
return _step; |
|
485 |
} |
|
486 |
||
487 |
/** |
|
488 |
* Returns the value in an expression of the form 'step = value'. |
|
489 |
* A value may be either a literal string or a variable whose |
|
490 |
* type is string. Optimization if off if null is returned. |
|
491 |
*/ |
|
492 |
public Expression getCompareValue() { |
|
493 |
// Returned cached value if called more than once |
|
494 |
if (_value != null) { |
|
495 |
return _value; |
|
496 |
} |
|
497 |
||
498 |
// Nothing to to do if _exp is null |
|
499 |
if (_exp == null) { |
|
500 |
return null; |
|
501 |
} |
|
502 |
||
503 |
// Ignore if not an equality expression |
|
504 |
if (_exp instanceof EqualityExpr) { |
|
505 |
EqualityExpr exp = (EqualityExpr) _exp; |
|
506 |
Expression left = exp.getLeft(); |
|
507 |
Expression right = exp.getRight(); |
|
508 |
||
509 |
// Return if left is literal string |
|
510 |
if (left instanceof LiteralExpr) { |
|
511 |
_value = left; |
|
512 |
return _value; |
|
513 |
} |
|
514 |
// Return if left is a variable reference of type string |
|
515 |
if (left instanceof VariableRefBase && |
|
516 |
left.getType() == Type.String) |
|
517 |
{ |
|
518 |
_value = left; |
|
519 |
return _value; |
|
520 |
} |
|
521 |
||
522 |
// Return if right is literal string |
|
523 |
if (right instanceof LiteralExpr) { |
|
524 |
_value = right; |
|
525 |
return _value; |
|
526 |
} |
|
527 |
// Return if left is a variable reference whose type is string |
|
528 |
if (right instanceof VariableRefBase && |
|
529 |
right.getType() == Type.String) |
|
530 |
{ |
|
531 |
_value = right; |
|
532 |
return _value; |
|
533 |
} |
|
534 |
} |
|
535 |
return null; |
|
536 |
} |
|
537 |
||
538 |
/** |
|
539 |
* Translate a predicate expression. This translation pushes |
|
540 |
* two references on the stack: a reference to a newly created |
|
541 |
* filter object and a reference to the predicate's closure. |
|
542 |
*/ |
|
543 |
public void translateFilter(ClassGenerator classGen, |
|
544 |
MethodGenerator methodGen) |
|
545 |
{ |
|
546 |
final ConstantPoolGen cpg = classGen.getConstantPool(); |
|
547 |
final InstructionList il = methodGen.getInstructionList(); |
|
548 |
||
549 |
// Compile auxiliary class for filter |
|
550 |
compileFilter(classGen, methodGen); |
|
551 |
||
552 |
// Create new instance of filter |
|
553 |
il.append(new NEW(cpg.addClass(_className))); |
|
554 |
il.append(DUP); |
|
555 |
il.append(new INVOKESPECIAL(cpg.addMethodref(_className, |
|
556 |
"<init>", "()V"))); |
|
557 |
||
558 |
// Initialize closure variables |
|
559 |
final int length = (_closureVars == null) ? 0 : _closureVars.size(); |
|
560 |
||
561 |
for (int i = 0; i < length; i++) { |
|
562 |
VariableRefBase varRef = (VariableRefBase) _closureVars.get(i); |
|
563 |
VariableBase var = varRef.getVariable(); |
|
564 |
Type varType = var.getType(); |
|
565 |
||
566 |
il.append(DUP); |
|
567 |
||
568 |
// Find nearest closure implemented as an inner class |
|
569 |
Closure variableClosure = _parentClosure; |
|
570 |
while (variableClosure != null) { |
|
571 |
if (variableClosure.inInnerClass()) break; |
|
572 |
variableClosure = variableClosure.getParentClosure(); |
|
573 |
} |
|
574 |
||
575 |
// Use getfield if in an inner class |
|
576 |
if (variableClosure != null) { |
|
577 |
il.append(ALOAD_0); |
|
578 |
il.append(new GETFIELD( |
|
579 |
cpg.addFieldref(variableClosure.getInnerClassName(), |
|
580 |
var.getEscapedName(), varType.toSignature()))); |
|
581 |
} |
|
582 |
else { |
|
583 |
// Use a load of instruction if in translet class |
|
584 |
il.append(var.loadInstruction()); |
|
585 |
} |
|
586 |
||
587 |
// Store variable in new closure |
|
588 |
il.append(new PUTFIELD( |
|
589 |
cpg.addFieldref(_className, var.getEscapedName(), |
|
590 |
varType.toSignature()))); |
|
591 |
} |
|
592 |
} |
|
593 |
||
594 |
/** |
|
595 |
* Translate a predicate expression. If non of the optimizations apply |
|
596 |
* then this translation pushes two references on the stack: a reference |
|
597 |
* to a newly created filter object and a reference to the predicate's |
|
598 |
* closure. See class <code>Step</code> for further details. |
|
599 |
*/ |
|
600 |
public void translate(ClassGenerator classGen, MethodGenerator methodGen) { |
|
601 |
||
602 |
final ConstantPoolGen cpg = classGen.getConstantPool(); |
|
603 |
final InstructionList il = methodGen.getInstructionList(); |
|
604 |
||
605 |
if (_nthPositionFilter || _nthDescendant) { |
|
606 |
_exp.translate(classGen, methodGen); |
|
607 |
} |
|
608 |
else if (isNodeValueTest() && (getParent() instanceof Step)) { |
|
609 |
_value.translate(classGen, methodGen); |
|
610 |
il.append(new CHECKCAST(cpg.addClass(STRING_CLASS))); |
|
611 |
il.append(new PUSH(cpg, ((EqualityExpr)_exp).getOp())); |
|
612 |
} |
|
613 |
else { |
|
614 |
translateFilter(classGen, methodGen); |
|
615 |
} |
|
616 |
} |
|
617 |
} |