org.checkerframework.dataflow.analysis.TransferFunction Maven / Gradle / Ivy

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package org.checkerframework.dataflow.analysis;

/*>>>
import org.checkerframework.checker.nullness.qual.Nullable;
*/

import java.util.List;
import org.checkerframework.dataflow.cfg.UnderlyingAST;
import org.checkerframework.dataflow.cfg.node.LocalVariableNode;
import org.checkerframework.dataflow.cfg.node.Node;
import org.checkerframework.dataflow.cfg.node.NodeVisitor;

/**
 * Interface of a transfer function for the abstract interpretation used for the flow analysis.
 *
 * A transfer function consists of the following components:
 *
 * 

 *   A method {@code initialStore} that determines which initial store should be used in the
 *       org.checkerframework.dataflow analysis.
 *   
A function for every {@link Node} type that determines the behavior of the
 *       org.checkerframework.dataflow analysis in that case. This method takes a {@link Node} and
 *       an incoming store, and produces a {@link RegularTransferResult}.
 * 
 *
 * Important: The individual transfer functions ( {@code visit*}) are allowed to use
 * (and modify) the stores contained in the argument passed; the ownership is transfered from the
 * caller to that function.
 *
 * @author Stefan Heule
 * @param  the {@link Store} used to keep track of intermediate results
 */
public interface TransferFunction, S extends Store>
        extends NodeVisitor, TransferInput> {

    /**
     * @return the initial store to be used by the org.checkerframework.dataflow analysis. {@code
     *     parameters} is only set if the underlying AST is a method.
     */
    S initialStore(UnderlyingAST underlyingAST, /*@Nullable*/ List parameters);
}