com.tangosol.dev.compiler.java.ThisExpression Maven / Gradle / Ivy

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/*
 * Copyright (c) 2000, 2020, Oracle and/or its affiliates.
 *
 * Licensed under the Universal Permissive License v 1.0 as shown at
 * http://oss.oracle.com/licenses/upl.
 */


package com.tangosol.dev.compiler.java;


import com.tangosol.dev.assembler.CodeAttribute;

import com.tangosol.dev.compiler.CompilerException;
import com.tangosol.dev.compiler.Context;

import com.tangosol.dev.component.DataType;

import com.tangosol.util.ErrorList;

import java.util.Set;
import java.util.Map;


/**
* Implements the reserved name "this".
*
* @version 1.00, 01/25/99
* @author  Cameron Purdy
*/
public class ThisExpression extends Expression
    {
    // ----- construction ---------------------------------------------------

    /**
    * Construct a ThisExpression.  The passed "this" token may be
    * zero-length, which means that the "this" is implied, in which case
    * it means either "this" (for instance methods) or this-class (for
    * static methods).
    *
    * @param block    the containing block
    * @param tokThis  the "this" token
    */
    public ThisExpression(Block block, Token tokThis)
        {
        super(block, tokThis);
        }


    // ----- code generation ------------------------------------------------

    /**
    * Perform semantic checks, parse tree re-organization, name binding,
    * and optimizations.
    *
    * @param ctx        the compiler context
    * @param setUVars   the set of potentially unassigned variables
    * @param setFVars   the set of potentially assigned final variables
    * @param mapThrown  the set of potentially thrown checked exceptions
    * @param errlist    the error list
    *
    * @return the resulting language element (typically this)
    *
    * @exception CompilerException  thrown if an error occurs that should
    *            stop the compilation process
    */
    protected Element precompile(Context ctx, DualSet setUVars, DualSet setFVars, Map mapThrown, ErrorList errlist)
            throws CompilerException
        {
        Expression expr    = this;
        Block      block   = getBlock();
        Token      tokName = getStartToken();
        Variable   var     = block.getVariable(tokName.getText());
        if (var == null) // i.e. static method
            {
            // if the "this" was inserted by the compiler or pre-assembler,
            // then it will be zero-length (because it is an imaginary
            // token)
            if (tokName.getLength() != 0)
                {
                logError(ERROR, THIS_ILLEGAL, null, errlist);
                }

            // translate it into this-class
            DataType dt = ctx.getMethodInfo().getTypeInfo().getDataType();
            expr = new TypeExpression(block, tokName, dt);
            }
        else
            {
            expr = new VariableExpression(block, tokName);
            }

        return (Expression) expr.precompile(ctx, setUVars, setFVars, mapThrown, errlist);
        }

    /**
    * Perform final optimizations and code generation.
    *
    * @param ctx       the compiler context
    * @param code      the assembler code attribute to compile to
    * @param fReached  true if this language element is reached (JLS 14.19)
    * @param errlist   the error list to log errors to
    *
    * @return true if the element can complete normally (JLS 14.1)
    *
    * @exception CompilerException  thrown if an error occurs that should
    *            stop the compilation process
    */
    protected boolean compile(Context ctx, CodeAttribute code, boolean fReached, ErrorList errlist)
            throws CompilerException
        {
        throw new IllegalStateException();
        }


    // ----- data members ---------------------------------------------------

    /**
    * The class name.
    */
    private static final String CLASS = "ThisExpression";
    }