| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| |
| package org.apache.xalan.xsltc.compiler; |
| |
| import org.apache.bcel.generic.BranchHandle; |
| import org.apache.bcel.generic.BranchInstruction; |
| import org.apache.bcel.generic.ConstantPoolGen; |
| import org.apache.bcel.generic.GOTO; |
| import org.apache.bcel.generic.IFEQ; |
| import org.apache.bcel.generic.IFNE; |
| import org.apache.bcel.generic.IF_ICMPEQ; |
| import org.apache.bcel.generic.IF_ICMPNE; |
| import org.apache.bcel.generic.INVOKESTATIC; |
| import org.apache.bcel.generic.INVOKEVIRTUAL; |
| import org.apache.bcel.generic.InstructionList; |
| import org.apache.bcel.generic.PUSH; |
| import org.apache.xalan.xsltc.compiler.util.BooleanType; |
| import org.apache.xalan.xsltc.compiler.util.ClassGenerator; |
| import org.apache.xalan.xsltc.compiler.util.IntType; |
| import org.apache.xalan.xsltc.compiler.util.MethodGenerator; |
| import org.apache.xalan.xsltc.compiler.util.NodeSetType; |
| import org.apache.xalan.xsltc.compiler.util.NodeType; |
| import org.apache.xalan.xsltc.compiler.util.NumberType; |
| import org.apache.xalan.xsltc.compiler.util.RealType; |
| import org.apache.xalan.xsltc.compiler.util.ReferenceType; |
| import org.apache.xalan.xsltc.compiler.util.ResultTreeType; |
| import org.apache.xalan.xsltc.compiler.util.StringType; |
| import org.apache.xalan.xsltc.compiler.util.Type; |
| import org.apache.xalan.xsltc.compiler.util.TypeCheckError; |
| import org.apache.xalan.xsltc.runtime.Operators; |
| |
| /** |
| * @author Jacek Ambroziak |
| * @author Santiago Pericas-Geertsen |
| * @author Morten Jorgensen |
| * @author Erwin Bolwidt <ejb@klomp.org> |
| */ |
| final class EqualityExpr extends Expression { |
| |
| private final int _op; |
| private Expression _left; |
| private Expression _right; |
| |
| public EqualityExpr(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); |
| } |
| |
| public String toString() { |
| return Operators.getOpNames(_op) + '(' + _left + ", " + _right + ')'; |
| } |
| |
| public Expression getLeft() { |
| return _left; |
| } |
| |
| public Expression getRight() { |
| return _right; |
| } |
| |
| public boolean getOp() { |
| return (_op != Operators.NE); |
| } |
| |
| /** |
| * 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 hasLastCall() { |
| if (_left.hasLastCall()) return true; |
| if (_right.hasLastCall()) return true; |
| return false; |
| } |
| |
| private void swapArguments() { |
| final Expression temp = _left; |
| _left = _right; |
| _right = temp; |
| } |
| |
| /** |
| * Typing rules: see XSLT Reference by M. Kay page 345. |
| */ |
| public Type typeCheck(SymbolTable stable) throws TypeCheckError { |
| final Type tleft = _left.typeCheck(stable); |
| final Type tright = _right.typeCheck(stable); |
| |
| if (tleft.isSimple() && tright.isSimple()) { |
| if (tleft != tright) { |
| if (tleft instanceof BooleanType) { |
| _right = new CastExpr(_right, Type.Boolean); |
| } |
| else if (tright instanceof BooleanType) { |
| _left = new CastExpr(_left, Type.Boolean); |
| } |
| else if (tleft instanceof NumberType || |
| tright instanceof NumberType) { |
| _left = new CastExpr(_left, Type.Real); |
| _right = new CastExpr(_right, Type.Real); |
| } |
| else { // both compared as strings |
| _left = new CastExpr(_left, Type.String); |
| _right = new CastExpr(_right, Type.String); |
| } |
| } |
| } |
| else if (tleft instanceof ReferenceType) { |
| _right = new CastExpr(_right, Type.Reference); |
| } |
| else if (tright instanceof ReferenceType) { |
| _left = new CastExpr(_left, Type.Reference); |
| } |
| // the following 2 cases optimize @attr|.|.. = 'string' |
| else if (tleft instanceof NodeType && tright == Type.String) { |
| _left = new CastExpr(_left, Type.String); |
| } |
| else if (tleft == Type.String && tright instanceof NodeType) { |
| _right = new CastExpr(_right, Type.String); |
| } |
| // optimize node/node |
| else if (tleft instanceof NodeType && tright instanceof NodeType) { |
| _left = new CastExpr(_left, Type.String); |
| _right = new CastExpr(_right, Type.String); |
| } |
| else if (tleft instanceof NodeType && tright instanceof NodeSetType) { |
| // compare(Node, NodeSet) will be invoked |
| } |
| else if (tleft instanceof NodeSetType && tright instanceof NodeType) { |
| swapArguments(); // for compare(Node, NodeSet) |
| } |
| else { |
| // At least one argument is of type node, node-set or result-tree |
| |
| // Promote an expression of type node to node-set |
| if (tleft instanceof NodeType) { |
| _left = new CastExpr(_left, Type.NodeSet); |
| } |
| if (tright instanceof NodeType) { |
| _right = new CastExpr(_right, Type.NodeSet); |
| } |
| |
| // If one arg is a node-set then make it the left one |
| if (tleft.isSimple() || |
| tleft instanceof ResultTreeType && |
| tright instanceof NodeSetType) { |
| swapArguments(); |
| } |
| |
| // Promote integers to doubles to have fewer compares |
| if (_right.getType() instanceof IntType) { |
| _right = new CastExpr(_right, Type.Real); |
| } |
| } |
| return _type = Type.Boolean; |
| } |
| |
| public void translateDesynthesized(ClassGenerator classGen, |
| MethodGenerator methodGen) { |
| final Type tleft = _left.getType(); |
| final InstructionList il = methodGen.getInstructionList(); |
| |
| if (tleft instanceof BooleanType) { |
| _left.translate(classGen, methodGen); |
| _right.translate(classGen, methodGen); |
| _falseList.add(il.append(_op == Operators.EQ ? |
| (BranchInstruction)new IF_ICMPNE(null) : |
| (BranchInstruction)new IF_ICMPEQ(null))); |
| } |
| else if (tleft instanceof NumberType) { |
| _left.translate(classGen, methodGen); |
| _right.translate(classGen, methodGen); |
| |
| if (tleft instanceof RealType) { |
| il.append(DCMPG); |
| _falseList.add(il.append(_op == Operators.EQ ? |
| (BranchInstruction)new IFNE(null) : |
| (BranchInstruction)new IFEQ(null))); |
| } |
| else { |
| _falseList.add(il.append(_op == Operators.EQ ? |
| (BranchInstruction)new IF_ICMPNE(null) : |
| (BranchInstruction)new IF_ICMPEQ(null))); |
| } |
| } |
| else { |
| translate(classGen, methodGen); |
| desynthesize(classGen, methodGen); |
| } |
| } |
| |
| public void translate(ClassGenerator classGen, MethodGenerator methodGen) { |
| final ConstantPoolGen cpg = classGen.getConstantPool(); |
| final InstructionList il = methodGen.getInstructionList(); |
| |
| final Type tleft = _left.getType(); |
| Type tright = _right.getType(); |
| |
| if (tleft instanceof BooleanType || tleft instanceof NumberType) { |
| translateDesynthesized(classGen, methodGen); |
| synthesize(classGen, methodGen); |
| return; |
| } |
| |
| if (tleft instanceof StringType) { |
| final int equals = cpg.addMethodref(STRING_CLASS, |
| "equals", |
| "(" + OBJECT_SIG +")Z"); |
| _left.translate(classGen, methodGen); |
| _right.translate(classGen, methodGen); |
| il.append(new INVOKEVIRTUAL(equals)); |
| |
| if (_op == Operators.NE) { |
| il.append(ICONST_1); |
| il.append(IXOR); // not x <-> x xor 1 |
| } |
| return; |
| } |
| |
| BranchHandle truec, falsec; |
| |
| if (tleft instanceof ResultTreeType) { |
| if (tright instanceof BooleanType) { |
| _right.translate(classGen, methodGen); |
| if (_op == Operators.NE) { |
| il.append(ICONST_1); |
| il.append(IXOR); // not x <-> x xor 1 |
| } |
| return; |
| } |
| |
| if (tright instanceof RealType) { |
| _left.translate(classGen, methodGen); |
| tleft.translateTo(classGen, methodGen, Type.Real); |
| _right.translate(classGen, methodGen); |
| |
| il.append(DCMPG); |
| falsec = il.append(_op == Operators.EQ ? |
| (BranchInstruction) new IFNE(null) : |
| (BranchInstruction) new IFEQ(null)); |
| il.append(ICONST_1); |
| truec = il.append(new GOTO(null)); |
| falsec.setTarget(il.append(ICONST_0)); |
| truec.setTarget(il.append(NOP)); |
| return; |
| } |
| |
| // Next, result-tree/string and result-tree/result-tree comparisons |
| |
| _left.translate(classGen, methodGen); |
| tleft.translateTo(classGen, methodGen, Type.String); |
| _right.translate(classGen, methodGen); |
| |
| if (tright instanceof ResultTreeType) { |
| tright.translateTo(classGen, methodGen, Type.String); |
| } |
| |
| final int equals = cpg.addMethodref(STRING_CLASS, |
| "equals", |
| "(" +OBJECT_SIG+ ")Z"); |
| il.append(new INVOKEVIRTUAL(equals)); |
| |
| if (_op == Operators.NE) { |
| il.append(ICONST_1); |
| il.append(IXOR); // not x <-> x xor 1 |
| } |
| return; |
| } |
| |
| if (tleft instanceof NodeSetType && tright instanceof BooleanType) { |
| _left.translate(classGen, methodGen); |
| _left.startIterator(classGen, methodGen); |
| Type.NodeSet.translateTo(classGen, methodGen, Type.Boolean); |
| _right.translate(classGen, methodGen); |
| |
| il.append(IXOR); // x != y <-> x xor y |
| if (_op == Operators.EQ) { |
| il.append(ICONST_1); |
| il.append(IXOR); // not x <-> x xor 1 |
| } |
| return; |
| } |
| |
| if (tleft instanceof NodeSetType && tright instanceof StringType) { |
| _left.translate(classGen, methodGen); |
| _left.startIterator(classGen, methodGen); // needed ? |
| _right.translate(classGen, methodGen); |
| il.append(new PUSH(cpg, _op)); |
| il.append(methodGen.loadDOM()); |
| final int cmp = cpg.addMethodref(BASIS_LIBRARY_CLASS, |
| "compare", |
| "(" |
| + tleft.toSignature() |
| + tright.toSignature() |
| + "I" |
| + DOM_INTF_SIG |
| + ")Z"); |
| il.append(new INVOKESTATIC(cmp)); |
| return; |
| } |
| |
| // Next, node-set/t for t in {real, string, node-set, result-tree} |
| _left.translate(classGen, methodGen); |
| _left.startIterator(classGen, methodGen); |
| _right.translate(classGen, methodGen); |
| _right.startIterator(classGen, methodGen); |
| |
| // Cast a result tree to a string to use an existing compare |
| if (tright instanceof ResultTreeType) { |
| tright.translateTo(classGen, methodGen, Type.String); |
| tright = Type.String; |
| } |
| |
| // Call the appropriate compare() from the BasisLibrary |
| il.append(new PUSH(cpg, _op)); |
| il.append(methodGen.loadDOM()); |
| |
| final int compare = cpg.addMethodref(BASIS_LIBRARY_CLASS, |
| "compare", |
| "(" |
| + tleft.toSignature() |
| + tright.toSignature() |
| + "I" |
| + DOM_INTF_SIG |
| + ")Z"); |
| il.append(new INVOKESTATIC(compare)); |
| } |
| } |