- /*
- * 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: Choose.java,v 1.9 2004/02/16 22:24:29 minchau Exp $
- */
-
- package com.sun.org.apache.xalan.internal.xsltc.compiler;
-
- import java.util.Enumeration;
- import java.util.Vector;
-
- import com.sun.org.apache.bcel.internal.generic.BranchHandle;
- import com.sun.org.apache.bcel.internal.generic.GOTO;
- import com.sun.org.apache.bcel.internal.generic.IFEQ;
- import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
- import com.sun.org.apache.bcel.internal.generic.InstructionList;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
- import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
- 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 Morten Jorgensen
- */
- final class Choose extends Instruction {
-
- /**
- * Display the element contents (a lot of when's and an otherwise)
- */
- public void display(int indent) {
- indent(indent);
- Util.println("Choose");
- indent(indent + IndentIncrement);
- displayContents(indent + IndentIncrement);
- }
-
- /**
- * Translate this Choose element. Generate a test-chain for the various
- * <xsl:when> elements and default to the <xsl:otherwise> if present.
- */
- public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
- final Vector whenElements = new Vector();
- Otherwise otherwise = null;
- Enumeration elements = elements();
-
- // These two are for reporting errors only
- ErrorMsg error = null;
- final int line = getLineNumber();
-
- // Traverse all child nodes - must be either When or Otherwise
- while (elements.hasMoreElements()) {
- Object element = elements.nextElement();
- // Add a When child element
- if (element instanceof When) {
- whenElements.addElement(element);
- }
- // Add an Otherwise child element
- else if (element instanceof Otherwise) {
- if (otherwise == null) {
- otherwise = (Otherwise)element;
- }
- else {
- error = new ErrorMsg(ErrorMsg.MULTIPLE_OTHERWISE_ERR, this);
- getParser().reportError(Constants.ERROR, error);
- }
- }
- else if (element instanceof Text) {
- ((Text)element).ignore();
- }
- // It is an error if we find some other element here
- else {
- error = new ErrorMsg(ErrorMsg.WHEN_ELEMENT_ERR, this);
- getParser().reportError(Constants.ERROR, error);
- }
- }
-
- // Make sure that there is at least one <xsl:when> element
- if (whenElements.size() == 0) {
- error = new ErrorMsg(ErrorMsg.MISSING_WHEN_ERR, this);
- getParser().reportError(Constants.ERROR, error);
- return;
- }
-
- InstructionList il = methodGen.getInstructionList();
-
- // next element will hold a handle to the beginning of next
- // When/Otherwise if test on current When fails
- BranchHandle nextElement = null;
- Vector exitHandles = new Vector();
- InstructionHandle exit = null;
-
- Enumeration whens = whenElements.elements();
- while (whens.hasMoreElements()) {
- final When when = (When)whens.nextElement();
- final Expression test = when.getTest();
-
- InstructionHandle truec = il.getEnd();
-
- if (nextElement != null)
- nextElement.setTarget(il.append(NOP));
- test.translateDesynthesized(classGen, methodGen);
-
- if (test instanceof FunctionCall) {
- FunctionCall call = (FunctionCall)test;
- try {
- Type type = call.typeCheck(getParser().getSymbolTable());
- if (type != Type.Boolean) {
- test._falseList.add(il.append(new IFEQ(null)));
- }
- }
- catch (TypeCheckError e) {
- // handled later!
- }
- }
- // remember end of condition
- truec = il.getEnd();
-
- // The When object should be ignored completely in case it tests
- // for the support of a non-available element
- if (!when.ignore()) when.translateContents(classGen, methodGen);
-
- // goto exit after executing the body of when
- exitHandles.addElement(il.append(new GOTO(null)));
- if (whens.hasMoreElements() || otherwise != null) {
- nextElement = il.append(new GOTO(null));
- test.backPatchFalseList(nextElement);
- }
- else
- test.backPatchFalseList(exit = il.append(NOP));
- test.backPatchTrueList(truec.getNext());
- }
-
- // Translate any <xsl:otherwise> element
- if (otherwise != null) {
- nextElement.setTarget(il.append(NOP));
- otherwise.translateContents(classGen, methodGen);
- exit = il.append(NOP);
- }
-
- // now that end is known set targets of exit gotos
- Enumeration exitGotos = exitHandles.elements();
- while (exitGotos.hasMoreElements()) {
- BranchHandle gotoExit = (BranchHandle)exitGotos.nextElement();
- gotoExit.setTarget(exit);
- }
- }
- }