/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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: StringType.java 468649 2006-10-28 07:00:55Z minchau $
*/
package org.apache.xalan.xsltc.compiler.util;
import org.apache.bcel.generic.ALOAD;
import org.apache.bcel.generic.ASTORE;
import org.apache.bcel.generic.BranchHandle;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.GOTO;
import org.apache.bcel.generic.IFEQ;
import org.apache.bcel.generic.IFNONNULL;
import org.apache.bcel.generic.INVOKESTATIC;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.PUSH;
import org.apache.xalan.xsltc.compiler.Constants;
import org.apache.xalan.xsltc.compiler.FlowList;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
*/
public class StringType extends Type {
protected StringType() {}
public String toString() {
return "string";
}
public boolean identicalTo(Type other) {
return this == other;
}
public String toSignature() {
return "Ljava/lang/String;";
}
public boolean isSimple() {
return true;
}
public org.apache.bcel.generic.Type toJCType() {
return org.apache.bcel.generic.Type.STRING;
}
/**
* Translates a string into an object of internal type <code>type</code>.
* The translation to int is undefined since strings are always converted
* to reals in arithmetic expressions.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
*/
public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
Type type) {
if (type == Type.Boolean) {
translateTo(classGen, methodGen, (BooleanType) type);
}
else if (type == Type.Real) {
translateTo(classGen, methodGen, (RealType) type);
}
else if (type == Type.Reference) {
translateTo(classGen, methodGen, (ReferenceType) type);
}
else {
ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
toString(), type.toString());
classGen.getParser().reportError(Constants.FATAL, err);
}
}
/**
* Translates a string into a synthesized boolean.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
*/
public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
BooleanType type) {
final InstructionList il = methodGen.getInstructionList();
FlowList falsel = translateToDesynthesized(classGen, methodGen, type);
il.append(ICONST_1);
final BranchHandle truec = il.append(new GOTO(null));
falsel.backPatch(il.append(ICONST_0));
truec.setTarget(il.append(NOP));
}
/**
* Translates a string into a real by calling stringToReal() from the
* basis library.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
*/
public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
RealType type) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
il.append(new INVOKESTATIC(cpg.addMethodref(BASIS_LIBRARY_CLASS,
STRING_TO_REAL,
STRING_TO_REAL_SIG)));
}
/**
* Translates a string into a non-synthesized boolean. It does not push a
* 0 or a 1 but instead returns branchhandle list to be appended to the
* false list.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateToDesynthesized
*/
public FlowList translateToDesynthesized(ClassGenerator classGen,
MethodGenerator methodGen,
BooleanType type) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_CLASS,
"length", "()I")));
return new FlowList(il.append(new IFEQ(null)));
}
/**
* Expects a string on the stack and pushes a boxed string.
* Strings are already boxed so the translation is just a NOP.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateTo
*/
public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
ReferenceType type) {
methodGen.getInstructionList().append(NOP);
}
/**
* Translates a internal string into an external (Java) string.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateFrom
*/
public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
Class clazz)
{
// Is String <: clazz? I.e. clazz in { String, Object }
if (clazz.isAssignableFrom(java.lang.String.class)) {
methodGen.getInstructionList().append(NOP);
}
else {
ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
toString(), clazz.getName());
classGen.getParser().reportError(Constants.FATAL, err);
}
}
/**
* Translates an external (primitive) Java type into a string.
*
* @see org.apache.xalan.xsltc.compiler.util.Type#translateFrom
*/
public void translateFrom(ClassGenerator classGen,
MethodGenerator methodGen, Class clazz)
{
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
if (clazz.getName().equals("java.lang.String")) {
// same internal representation, convert null to ""
il.append(DUP);
final BranchHandle ifNonNull = il.append(new IFNONNULL(null));
il.append(POP);
il.append(new PUSH(cpg, ""));
ifNonNull.setTarget(il.append(NOP));
}
else {
ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
toString(), clazz.getName());
classGen.getParser().reportError(Constants.FATAL, err);
}
}
/**
* Translates an object of this type to its boxed representation.
*/
public void translateBox(ClassGenerator classGen,
MethodGenerator methodGen) {
translateTo(classGen, methodGen, Type.Reference);
}
/**
* Translates an object of this type to its unboxed representation.
*/
public void translateUnBox(ClassGenerator classGen,
MethodGenerator methodGen) {
methodGen.getInstructionList().append(NOP);
}
/**
* Returns the class name of an internal type's external representation.
*/
public String getClassName() {
return(STRING_CLASS);
}
public Instruction LOAD(int slot) {
return new ALOAD(slot);
}
public Instruction STORE(int slot) {
return new ASTORE(slot);
}
}