com.google.errorprone.refaster.UTry.java Source code

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Here is the source code for com.google.errorprone.refaster.UTry.java

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/*
 * Copyright 2014 Google Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.errorprone.refaster;

import static com.google.errorprone.refaster.Unifier.unifications;
import static com.google.errorprone.refaster.Unifier.unifyList;

import com.google.auto.value.AutoValue;
import com.google.common.collect.ImmutableList;
import com.sun.source.tree.TreeVisitor;
import com.sun.source.tree.TryTree;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.JCTree.JCBlock;
import com.sun.tools.javac.tree.JCTree.JCTry;
import java.util.List;
import javax.annotation.Nullable;

/**
 * {@code UTree} representation of a {@code TryTree}.
 *
 * @author lowasser@google.com (Louis Wasserman)
 */
@AutoValue
abstract class UTry extends USimpleStatement implements TryTree {
    static UTry create(Iterable<? extends UTree<?>> resources, UBlock block, Iterable<UCatch> catches,
            @Nullable UBlock finallyBlock) {
        return new AutoValue_UTry(ImmutableList.copyOf(resources), block, ImmutableList.copyOf(catches),
                finallyBlock);
    }

    @Override
    public abstract List<UTree<?>> getResources();

    @Override
    public abstract UBlock getBlock();

    @Override
    public abstract List<UCatch> getCatches();

    @Override
    @Nullable
    public abstract UBlock getFinallyBlock();

    @Override
    public Kind getKind() {
        return Kind.TRY;
    }

    @Override
    public <R, D> R accept(TreeVisitor<R, D> visitor, D data) {
        return visitor.visitTry(this, data);
    }

    @Override
    public JCTry inline(Inliner inliner) throws CouldNotResolveImportException {
        return inliner.maker().Try(inliner.<JCTree>inlineList(getResources()), getBlock().inline(inliner),
                inliner.inlineList(getCatches()), inlineFinallyBlock(inliner));
    }

    /**
     * Skips the finally block if the result would be empty.
     */
    @Nullable
    private JCBlock inlineFinallyBlock(Inliner inliner) throws CouldNotResolveImportException {
        if (getFinallyBlock() != null) {
            JCBlock block = getFinallyBlock().inline(inliner);
            if (!block.getStatements().isEmpty()) {
                return block;
            }
        }
        return null;
    }

    @Override
    @Nullable
    public Choice<Unifier> visitTry(TryTree node, @Nullable Unifier unifier) {
        return unifyList(unifier, getResources(), node.getResources())
                .thenChoose(unifications(getBlock(), node.getBlock()))
                .thenChoose(unifications(getCatches(), node.getCatches()))
                .thenChoose(unifications(getFinallyBlock(), node.getFinallyBlock()));
    }
}