/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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: RealType.java,v 1.2.4.1 2005/09/05 11:28:45 pvedula Exp $

 */

package com.sun.org.apache.xalan.internal.xsltc.compiler.util;

import com.sun.org.apache.bcel.internal.generic.BranchHandle;

import com.sun.org.apache.bcel.internal.generic.CHECKCAST;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;

import com.sun.org.apache.bcel.internal.generic.DLOAD;

import com.sun.org.apache.bcel.internal.generic.DSTORE;

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.IFNE;

import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;

import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;

import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;

import com.sun.org.apache.bcel.internal.generic.Instruction;

import com.sun.org.apache.bcel.internal.generic.InstructionConstants;

import com.sun.org.apache.bcel.internal.generic.InstructionList;

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;

import com.sun.org.apache.bcel.internal.generic.NEW;

import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;

import com.sun.org.apache.xalan.internal.xsltc.compiler.FlowList;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 */

public final class RealType extends NumberType {

    protected RealType() {}

    public String toString() {

        return "real";

    }

    public boolean identicalTo(Type other) {

        return this == other;

    }

    public String toSignature() {

        return "D";

    }

    public com.sun.org.apache.bcel.internal.generic.Type toJCType() {

        return com.sun.org.apache.bcel.internal.generic.Type.DOUBLE;

    }

    /**

     * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#distanceTo

     */

    public int distanceTo(Type type) {

        if (type == this) {

            return 0;

        }

        else if (type == Type.Int) {

            return 1;

        }

        else {

            return Integer.MAX_VALUE;

        }

    }

    /**

     * Translates a real into an object of internal type <code>type</code>. The

     * translation to int is undefined since reals are never converted to ints.

     *

     * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo

     */

    public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,

                            Type type) {

        if (type == Type.String) {

            translateTo(classGen, methodGen, (StringType) type);

        }

        else if (type == Type.Boolean) {

            translateTo(classGen, methodGen, (BooleanType) type);

        }

        else if (type == Type.Reference) {

            translateTo(classGen, methodGen, (ReferenceType) type);

        }

        else if (type == Type.Int) {

            translateTo(classGen, methodGen, (IntType) type);

        }

        else {

            ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,

                                        toString(), type.toString());

            classGen.getParser().reportError(Constants.FATAL, err);

        }

    }

    /**

     * Expects a real on the stack and pushes its string value by calling

     * <code>Double.toString(double d)</code>.

     *

     * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo

     */

    public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,

                            StringType type) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        il.append(new INVOKESTATIC(cpg.addMethodref(BASIS_LIBRARY_CLASS,

                                                    "realToString",

                                                    "(D)" + STRING_SIG)));

    }

    /**

     * Expects a real on the stack and pushes a 0 if that number is 0.0 and

     * a 1 otherwise.

     *

     * @see     com.sun.org.apache.xalan.internal.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));

    }

    /**

     * Expects a real on the stack and pushes a truncated integer value

     *

     * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo

     */

    public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,

                            IntType type) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        il.append(new INVOKESTATIC(cpg.addMethodref(BASIS_LIBRARY_CLASS,

                                                    "realToInt","(D)I")));

    }

    /**

     * Translates a real 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. A NaN must be converted to "false".

     *

     * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateToDesynthesized

     */

    public FlowList translateToDesynthesized(ClassGenerator classGen,

                                             MethodGenerator methodGen,

                                             BooleanType type) {

        LocalVariableGen local;

        final FlowList flowlist = new FlowList();

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        // Store real into a local variable

        il.append(DUP2);

        local = methodGen.addLocalVariable("real_to_boolean_tmp",

                                           com.sun.org.apache.bcel.internal.generic.Type.DOUBLE,

        // Compare it to 0.0

        il.append(DCONST_0);

        il.append(DCMPG);

        flowlist.add(il.append(new IFEQ(null)));

        //!!! call isNaN

        // Compare it to itself to see if NaN

        il.append(new DLOAD(local.getIndex()));

        il.append(DCMPG);

        flowlist.add(il.append(new IFNE(null)));        // NaN != NaN

        return flowlist;

    }

    /**

     * Expects a double on the stack and pushes a boxed double. Boxed

     * double are represented by an instance of <code>java.lang.Double</code>.

     *

     * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo

     */

    public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,

                            ReferenceType type) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        il.append(new NEW(cpg.addClass(DOUBLE_CLASS)));

        il.append(DUP_X2);

        il.append(DUP_X2);

        il.append(POP);

        il.append(new INVOKESPECIAL(cpg.addMethodref(DOUBLE_CLASS,

                                                     "<init>", "(D)V")));

    }

    /**

     * Translates a real into the Java type denoted by <code>clazz</code>.

     * Expects a real on the stack and pushes a number of the appropriate

     * type after coercion.

     */

    public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,

                            final Class clazz) {

        final InstructionList il = methodGen.getInstructionList();

        if (clazz == Character.TYPE) {

            il.append(D2I);

            il.append(I2C);

        }

        else if (clazz == Byte.TYPE) {

            il.append(D2I);

            il.append(I2B);

        }

        else if (clazz == Short.TYPE) {

            il.append(D2I);

            il.append(I2S);

        }

        else if (clazz == Integer.TYPE) {

            il.append(D2I);

        }

        else if (clazz == Long.TYPE) {

            il.append(D2L);

        }

        else if (clazz == Float.TYPE) {

            il.append(D2F);

        }

        else if (clazz == Double.TYPE) {

            il.append(NOP);

        }

        // Is Double <: clazz? I.e. clazz in { Double, Number, Object }

        else if (clazz.isAssignableFrom(java.lang.Double.class)) {

            translateTo(classGen, methodGen, Type.Reference);

        }

        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 real. Expects a java

     * object on the stack and pushes a real (i.e., a double).

     */

    public void translateFrom(ClassGenerator classGen, MethodGenerator methodGen,

                              Class clazz) {

        InstructionList il = methodGen.getInstructionList();

        if (clazz == Character.TYPE || clazz == Byte.TYPE ||

            clazz == Short.TYPE || clazz == Integer.TYPE) {

            il.append(I2D);

        }

        else if (clazz == Long.TYPE) {

            il.append(L2D);

        }

        else if (clazz == Float.TYPE) {

            il.append(F2D);

        }

        else if (clazz == Double.TYPE) {

            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) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        il.append(new CHECKCAST(cpg.addClass(DOUBLE_CLASS)));

        il.append(new INVOKEVIRTUAL(cpg.addMethodref(DOUBLE_CLASS,

                                                     DOUBLE_VALUE,

                                                     DOUBLE_VALUE_SIG)));

    }

    public Instruction ADD() {

        return InstructionConstants.DADD;

    }

    public Instruction SUB() {

        return InstructionConstants.DSUB;

    }

    public Instruction MUL() {

        return InstructionConstants.DMUL;

    }

    public Instruction DIV() {

        return InstructionConstants.DDIV;

    }

    public Instruction REM() {

        return InstructionConstants.DREM;

    }

    public Instruction NEG() {

        return InstructionConstants.DNEG;

    }

    public Instruction LOAD(int slot) {

        return new DLOAD(slot);

    }

    public Instruction STORE(int slot) {

        return new DSTORE(slot);

    }

    public Instruction POP() {

        return POP2;

    }

    public Instruction CMP(boolean less) {

        return less ? InstructionConstants.DCMPG : InstructionConstants.DCMPL;

    }

    public Instruction DUP() {

        return DUP2;

    }

}