/*
* @(#)$Id: RelationalExpr.java,v 1.12 2002/02/01 20:07:08 tmiller Exp $
*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 2001, Sun
* Microsystems., http://www.sun.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
*
*/
package org.apache.xalan.xsltc.compiler;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.ReferenceType;
import org.apache.xalan.xsltc.runtime.Operators;
import org.apache.bcel.generic.*;
import org.apache.xalan.xsltc.compiler.util.*;
final class RelationalExpr extends Expression implements Operators {
private int _op;
private Expression _left, _right;
public RelationalExpr(int op, Expression left, Expression right) {
_op = op;
(_left = left).setParent(this);
(_right = right).setParent(this);
}
public void setParser(Parser parser) {
super.setParser(parser);
_left.setParser(parser);
_right.setParser(parser);
}
/**
* Returns true if this expressions contains a call to position(). This is
* needed for context changes in node steps containing multiple predicates.
*/
public boolean hasPositionCall() {
if (_left.hasPositionCall()) return true;
if (_right.hasPositionCall()) return true;
return false;
}
public boolean hasReferenceArgs() {
return _left.getType() instanceof ReferenceType ||
_right.getType() instanceof ReferenceType;
}
public boolean hasNodeArgs() {
return _left.getType() instanceof NodeType ||
_right.getType() instanceof NodeType;
}
public boolean hasNodeSetArgs() {
return _left.getType() instanceof NodeSetType ||
_right.getType() instanceof NodeSetType;
}
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
Type tleft = _left.typeCheck(stable);
Type tright = _right.typeCheck(stable);
//bug fix # 2838, cast to reals if both are result tree fragments
if (tleft instanceof ResultTreeType &&
tright instanceof ResultTreeType )
{
_right = new CastExpr(_right, Type.Real);
_left = new CastExpr(_left, Type.Real);
return _type = Type.Boolean;
}
// If one is of reference type, then convert the other too
if (hasReferenceArgs()) {
Type type = null;
Type typeL = null;
Type typeR = null;
if (tleft instanceof ReferenceType) {
if (_left instanceof VariableRefBase) {
VariableRefBase ref = (VariableRefBase)_left;
VariableBase var = ref.getVariable();
typeL = var.getType();
}
}
if (tright instanceof ReferenceType) {
if (_right instanceof VariableRefBase) {
VariableRefBase ref = (VariableRefBase)_right;
VariableBase var = ref.getVariable();
typeR = var.getType();
}
}
// bug fix # 2838
if (typeL == null)
type = typeR;
else if (typeR == null)
type = typeL;
else {
type = Type.Real;
}
if (type == null) type = Type.Real;
_right = new CastExpr(_right, type);
_left = new CastExpr(_left, type);
return _type = Type.Boolean;
}
if (hasNodeSetArgs()) {
// Ensure that the node-set is the left argument
if (tright instanceof NodeSetType) {
final Expression temp = _right; _right = _left; _left = temp;
_op = (_op == Operators.GT) ? Operators.LT :
(_op == Operators.LT) ? Operators.GT :
(_op == Operators.GE) ? Operators.LE : Operators.GE;
tright = _right.getType();
}
// Promote nodes to node sets
if (tright instanceof NodeType) {
_right = new CastExpr(_right, Type.NodeSet);
}
// Promote integer to doubles to have fewer compares
if (tright instanceof IntType) {
_right = new CastExpr(_right, Type.Real);
}
return _type = Type.Boolean;
}
// In the node-boolean case, convert node to boolean first
if (hasNodeArgs()) {
if (tleft instanceof BooleanType) {
_right = new CastExpr(_right, Type.Boolean);
tright = Type.Boolean;
}
if (tright instanceof BooleanType) {
_left = new CastExpr(_left, Type.Boolean);
tleft = Type.Boolean;
}
}
// Lookup the table of primops to find the best match
MethodType ptype = lookupPrimop(stable, Operators.names[_op],
new MethodType(Type.Void,
tleft, tright));
if (ptype != null) {
Type arg1 = (Type) ptype.argsType().elementAt(0);
if (!arg1.identicalTo(tleft)) {
_left = new CastExpr(_left, arg1);
}
Type arg2 = (Type) ptype.argsType().elementAt(1);
if (!arg2.identicalTo(tright)) {
_right = new CastExpr(_right, arg1);
}
return _type = ptype.resultType();
}
throw new TypeCheckError(this);
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
if (hasNodeSetArgs() || hasReferenceArgs()) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
// Call compare() from the BasisLibrary
_left.translate(classGen, methodGen);
_left.startResetIterator(classGen, methodGen);
_right.translate(classGen, methodGen);
_right.startResetIterator(classGen, methodGen);
il.append(new PUSH(cpg, _op));
il.append(methodGen.loadContextNode());
il.append(methodGen.loadDOM());
int index = cpg.addMethodref(BASIS_LIBRARY_CLASS, "compare",
"("
+ _left.getType().toSignature()
+ _right.getType().toSignature()
+ "I"
+ NODE_SIG
+ DOM_INTF_SIG
+ ")Z");
il.append(new INVOKESTATIC(index));
}
else {
translateDesynthesized(classGen, methodGen);
synthesize(classGen, methodGen);
}
}
public void translateDesynthesized(ClassGenerator classGen,
MethodGenerator methodGen) {
if (hasNodeSetArgs() || hasReferenceArgs()) {
translate(classGen, methodGen);
desynthesize(classGen, methodGen);
}
else {
BranchInstruction bi = null;
final InstructionList il = methodGen.getInstructionList();
_left.translate(classGen, methodGen);
_right.translate(classGen, methodGen);
// TODO: optimize if one of the args is 0
boolean tozero = false;
Type tleft = _left.getType();
if (tleft instanceof RealType) {
il.append(tleft.CMP(_op == LT || _op == LE));
tleft = Type.Int;
tozero = true;
}
switch (_op) {
case LT:
bi = tleft.GE(tozero);
break;
case GT:
bi = tleft.LE(tozero);
break;
case LE:
bi = tleft.GT(tozero);
break;
case GE:
bi = tleft.LT(tozero);
break;
default:
ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_RELAT_OP_ERR,this);
getParser().reportError(Constants.FATAL, msg);
}
_falseList.add(il.append(bi)); // must be backpatched
}
}
public String toString() {
return Operators.names[_op] + '(' + _left + ", " + _right + ')';
}
}