package org.checkerframework.dataflow.analysis;
/*>>>
import org.checkerframework.checker.nullness.qual.Nullable;
*/
import java.util.Map;
import javax.lang.model.type.TypeMirror;
/**
* {@code TransferResult} is used as the result type of the individual transfer functions of a
* {@link TransferFunction}. It always belongs to the result of the individual transfer function for
* a particular {@link org.checkerframework.dataflow.cfg.node.Node}, even though that {@code
* org.checkerframework.dataflow.cfg.node.Node} is not explicitly store in {@code TransferResult}.
*
* <p>A {@code TransferResult} contains one or two stores (for 'then' and 'else'), and zero or more
* stores with a cause ({@link TypeMirror}).
*
* @author Stefan Heule
* @param <S> the {@link Store} used to keep track of intermediate results
*/
public abstract class TransferResult<A extends AbstractValue<A>, S extends Store<S>> {
/**
* The stores in case the basic block throws an exception (or {@code null} if the corresponding
* {@link org.checkerframework.dataflow.cfg.node.Node} does not throw any exceptions). Does not
* necessarily contain a store for every exception, in which case the in-store will be used.
*/
protected /*@Nullable*/ Map<TypeMirror, S> exceptionalStores;
/**
* The abstract value of the {@link org.checkerframework.dataflow.cfg.node.Node} associated with
* this {@link TransferResult}, or {@code null} if no value has been produced.
*/
protected /*@Nullable*/ A resultValue;
public TransferResult(/*@Nullable*/ A resultValue) {
this.resultValue = resultValue;
}
/** @return the abstract value produced by the transfer function */
public A getResultValue() {
return resultValue;
}
public void setResultValue(A resultValue) {
this.resultValue = resultValue;
}
/**
* @return the regular result store produced if no exception is thrown by the {@link
* org.checkerframework.dataflow.cfg.node.Node} corresponding to this transfer function
* result.
*/
public abstract S getRegularStore();
/**
* @return the result store produced if the {@link org.checkerframework.dataflow.cfg.node.Node}
* this result belongs to evaluates to {@code true}.
*/
public abstract S getThenStore();
/**
* @return the result store produced if the {@link org.checkerframework.dataflow.cfg.node.Node}
* this result belongs to evaluates to {@code false}.
*/
public abstract S getElseStore();
/**
* @return the store that flows along the outgoing exceptional edge labeled with {@code
* exception} (or {@code null} if no special handling is required for exceptional edges).
*/
public /*@Nullable*/ S getExceptionalStore(TypeMirror exception) {
if (exceptionalStores == null) {
return null;
}
return exceptionalStores.get(exception);
}
/**
* @return a Map of {@link TypeMirror} to {@link Store}
* @see TransferResult#getExceptionalStore(TypeMirror)
*/
public Map<TypeMirror, S> getExceptionalStores() {
return exceptionalStores;
}
/**
* @return {@code true} if and only if this transfer result contains two stores that are
* potentially not equal. Note that the result {@code true} does not imply that {@code
* getRegularStore} cannot be called (or vice versa for {@code false}). Rather, it indicates
* that {@code getThenStore} or {@code getElseStore} can be used to give more precise
* results. Otherwise, if the result is {@code false}, then all three methods {@code
* getRegularStore}, {@code getThenStore}, and {@code getElseStore} return equivalent
* stores.
*/
public abstract boolean containsTwoStores();
/**
* @return {@code true} if and only if the transfer function returning this transfer result
* changed the regularStore, elseStore, or thenStore.
*/
public abstract boolean storeChanged();
}