- /*
- * Copyright 2001-2004 The Apache Software Foundation.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- /*
- * $Id: AncestorPattern.java,v 1.10 2004/02/16 22:24:29 minchau Exp $
- */
-
- package com.sun.org.apache.xalan.internal.xsltc.compiler;
-
- import com.sun.org.apache.bcel.internal.generic.BranchHandle;
- import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
- import com.sun.org.apache.bcel.internal.generic.GOTO;
- import com.sun.org.apache.bcel.internal.generic.IFLT;
- import com.sun.org.apache.bcel.internal.generic.ILOAD;
- import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
- import com.sun.org.apache.bcel.internal.generic.ISTORE;
- import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
- import com.sun.org.apache.bcel.internal.generic.InstructionList;
- import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
-
- /**
- * @author Jacek Ambroziak
- * @author Santiago Pericas-Geertsen
- * @author Erwin Bolwidt <ejb@klomp.org>
- */
- final class AncestorPattern extends RelativePathPattern {
-
- private final Pattern _left; // may be null
- private final RelativePathPattern _right;
- private InstructionHandle _loop;
-
- public AncestorPattern(RelativePathPattern right) {
- this(null, right);
- }
-
- public AncestorPattern(Pattern left, RelativePathPattern right) {
- _left = left;
- (_right = right).setParent(this);
- if (left != null) {
- left.setParent(this);
- }
- }
-
- public InstructionHandle getLoopHandle() {
- return _loop;
- }
-
- public void setParser(Parser parser) {
- super.setParser(parser);
- if (_left != null) {
- _left.setParser(parser);
- }
- _right.setParser(parser);
- }
-
- public boolean isWildcard() {
- //!!! can be wildcard
- return false;
- }
-
- public StepPattern getKernelPattern() {
- return _right.getKernelPattern();
- }
-
- public void reduceKernelPattern() {
- _right.reduceKernelPattern();
- }
-
- public Type typeCheck(SymbolTable stable) throws TypeCheckError {
- if (_left != null) {
- _left.typeCheck(stable);
- }
- return _right.typeCheck(stable);
- }
-
- public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
- InstructionHandle parent;
- final ConstantPoolGen cpg = classGen.getConstantPool();
- final InstructionList il = methodGen.getInstructionList();
-
- /*
- * The scope of this local var must be the entire method since
- * a another pattern may decide to jump back into the loop
- */
- final LocalVariableGen local =
- methodGen.addLocalVariable2("app", Util.getJCRefType(NODE_SIG),
- il.getEnd());
-
- final com.sun.org.apache.bcel.internal.generic.Instruction loadLocal =
- new ILOAD(local.getIndex());
- final com.sun.org.apache.bcel.internal.generic.Instruction storeLocal =
- new ISTORE(local.getIndex());
-
- if (_right instanceof StepPattern) {
- il.append(DUP);
- il.append(storeLocal);
- _right.translate(classGen, methodGen);
- il.append(methodGen.loadDOM());
- il.append(loadLocal);
- }
- else {
- _right.translate(classGen, methodGen);
-
- if (_right instanceof AncestorPattern) {
- il.append(methodGen.loadDOM());
- il.append(SWAP);
- }
- }
-
- if (_left != null) {
- final int getParent = cpg.addInterfaceMethodref(DOM_INTF,
- GET_PARENT,
- GET_PARENT_SIG);
- parent = il.append(new INVOKEINTERFACE(getParent, 2));
-
- il.append(DUP);
- il.append(storeLocal);
- _falseList.add(il.append(new IFLT(null)));
- il.append(loadLocal);
-
- _left.translate(classGen, methodGen);
-
- final SyntaxTreeNode p = getParent();
- if (p == null || p instanceof Instruction ||
- p instanceof TopLevelElement)
- {
- // do nothing
- }
- else {
- il.append(loadLocal);
- }
-
- final BranchHandle exit = il.append(new GOTO(null));
- _loop = il.append(methodGen.loadDOM());
- il.append(loadLocal);
- local.setEnd(_loop);
- il.append(new GOTO(parent));
- exit.setTarget(il.append(NOP));
- _left.backPatchFalseList(_loop);
-
- _trueList.append(_left._trueList);
- }
- else {
- il.append(POP2);
- }
-
- /*
- * If _right is an ancestor pattern, backpatch this pattern's false
- * list to the loop that searches for more ancestors.
- */
- if (_right instanceof AncestorPattern) {
- final AncestorPattern ancestor = (AncestorPattern) _right;
- _falseList.backPatch(ancestor.getLoopHandle()); // clears list
- }
-
- _trueList.append(_right._trueList);
- _falseList.append(_right._falseList);
- }
-
- public String toString() {
- return "AncestorPattern(" + _left + ", " + _right + ')';
- }
- }