checker.src.org.checkerframework.checker.nullness.KeyForTransfer Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of checker Show documentation

The Checker Framework enhances Java’s type system to make it more powerful and useful. This lets software developers detect and prevent errors in their Java programs. The Checker Framework includes compiler plug-ins ("checkers") that find bugs or verify their absence. It also permits you to write your own compiler plug-ins.

There is a newer version: 3.42.0

Show newest version

package org.checkerframework.checker.nullness;


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

import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.type.TypeMirror;

import org.checkerframework.checker.nullness.qual.KeyFor;
import org.checkerframework.checker.nullness.qual.UnknownKeyFor;
import org.checkerframework.dataflow.analysis.ConditionalTransferResult;
import org.checkerframework.dataflow.analysis.TransferInput;
import org.checkerframework.dataflow.analysis.TransferResult;
import org.checkerframework.dataflow.analysis.FlowExpressions.Receiver;
import org.checkerframework.dataflow.cfg.node.MethodInvocationNode;
import org.checkerframework.framework.flow.CFAbstractTransfer;
import org.checkerframework.framework.flow.CFStore;
import org.checkerframework.framework.flow.CFValue;
import org.checkerframework.framework.util.FlowExpressionParseUtil;
import org.checkerframework.framework.util.FlowExpressionParseUtil.FlowExpressionContext;
import org.checkerframework.javacutil.AnnotationUtils;
import org.checkerframework.javacutil.TypesUtils;

/*
 * KeyForTransfer ensures that java.util.Map.put and containsKey
 * cause the appropriate @KeyFor annotation to be added to the key.
 */
public class KeyForTransfer extends
    CFAbstractTransfer {

    /** Type-specific version of super.analysis and super.checker. */
    protected KeyForAnalysis analysis;
    protected KeyForSubchecker checker;

    protected final AnnotationMirror UNKNOWNKEYFOR, KEYFOR;

    public KeyForTransfer(KeyForAnalysis analysis, KeyForSubchecker checker) {
        super(analysis);
        this.analysis = analysis;
        this.checker = checker;
        UNKNOWNKEYFOR = AnnotationUtils.fromClass(analysis.getTypeFactory()
                .getElementUtils(), UnknownKeyFor.class);
        KEYFOR = AnnotationUtils.fromClass(analysis.getTypeFactory()
                .getElementUtils(), KeyFor.class);
    }

    /*
         * Provided that m is of a type that implements interface java.util.Map:
         * -Given a call m.containsKey(k), ensures that k is @KeyFor("m") in the thenStore of the transfer result.
         * -Given a call m.put(k, ...), ensures that k is @KeyFor("m") in the thenStore and elseStore of the transfer result.
         */
    @Override
    public TransferResult visitMethodInvocation(MethodInvocationNode node,
            TransferInput in) {

        TransferResult result = super.visitMethodInvocation(node, in);

        String methodName = node.getTarget().getMethod().toString();

        // First verify if the method name is containsKey or put. This is an inexpensive check.

        boolean containsKey = methodName.startsWith("containsKey(");
        boolean put = methodName.startsWith("put(");

        if (containsKey || put) {
            // Now verify that the receiver of the method invocation is of a type
            // that extends that java.util.Map interface. This is a more expensive check.

            javax.lang.model.util.Types types = analysis.getTypes();

            TypeMirror mapInterfaceTypeMirror = types.erasure(TypesUtils.typeFromClass(types, analysis.getEnv().getElementUtils(), Map.class));

            TypeMirror receiverType = types.erasure(node.getTarget().getReceiver().getType());

            if (types.isSubtype(receiverType, mapInterfaceTypeMirror)) {

                FlowExpressionContext flowExprContext = FlowExpressionParseUtil
                        .buildFlowExprContextForUse(node, checker);

                String mapName = flowExprContext.receiver.toString();
                Receiver keyReceiver = flowExprContext.arguments.get(0);

                KeyForAnnotatedTypeFactory atypeFactory = (KeyForAnnotatedTypeFactory) analysis.getTypeFactory();

                LinkedHashSet keyForMaps = new LinkedHashSet<>();
                keyForMaps.add(mapName);

                final CFValue previousKeyValue = in.getValueOfSubNode(node.getArgument(0));
                if (previousKeyValue != null) {
                    final AnnotationMirror prevAm = previousKeyValue.getType().getAnnotationInHierarchy(KEYFOR);
                    if (prevAm != null && AnnotationUtils.areSameByClass(prevAm, KeyFor.class)) {
                        keyForMaps.addAll(getKeys(prevAm));
                    }
                }

                AnnotationMirror am = atypeFactory.createKeyForAnnotationMirrorWithValue(keyForMaps);


                if (containsKey) {
                    ConditionalTransferResult conditionalResult = (ConditionalTransferResult) result;
                    conditionalResult.getThenStore().insertValue(keyReceiver, am);
                } else if (put) {
                    result.getThenStore().insertValue(keyReceiver, am);
                    result.getElseStore().insertValue(keyReceiver, am);
                }
            }
        }

        return result;
    }

    /**
     * @return the String value of a KeyFor, this will throw an exception
     */
    private Set getKeys(final AnnotationMirror keyFor) {
        if (keyFor.getElementValues().size() == 0) {
            return new LinkedHashSet<>();
        }

        return new LinkedHashSet<>(AnnotationUtils.getElementValueArray(keyFor, "value", String.class, true));
    }
}