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 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
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 * 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
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 * endorse or promote products derived from this software without specific prior written
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package com.oracle.truffle.llvm.parser.metadata;

public final class MDGlobalVariableExpression implements MDBaseNode {

    private static final int ARGINDEX_VARIABLE = 1;
    private static final int ARGINDEX_EXPRESSION = 2;

    private MDBaseNode globalVariable;
    private MDBaseNode expression;

    private MDGlobalVariableExpression() {
        this.globalVariable = MDVoidNode.INSTANCE;
        this.expression = MDVoidNode.INSTANCE;
    }

    public static MDGlobalVariableExpression create(long[] args, MetadataValueList md) {
        final MDGlobalVariableExpression expression = new MDGlobalVariableExpression();

        expression.globalVariable = md.getNullable(args[ARGINDEX_VARIABLE], expression);
        expression.expression = md.getNullable(args[ARGINDEX_EXPRESSION], expression);

        return expression;
    }

    public MDBaseNode getGlobalVariable() {
        return globalVariable;
    }

    public MDBaseNode getExpression() {
        return expression;
    }

    @Override
    public void replace(MDBaseNode oldValue, MDBaseNode newValue) {
        if (globalVariable == oldValue) {
            globalVariable = newValue;
        }
        if (expression == oldValue) {
            expression = newValue;
        }
    }

    @Override
    public void accept(MetadataVisitor visitor) {
        visitor.visit(this);
    }
}