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

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Here is the source code for com.google.errorprone.refaster.RefasterRule.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.common.base.Preconditions.checkState;

import com.google.auto.value.AutoValue;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Ascii;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableClassToInstanceMap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.errorprone.CodeTransformer;
import com.google.errorprone.DescriptionListener;
import com.google.errorprone.SubContext;
import com.sun.source.util.TreePath;
import com.sun.tools.javac.code.Symbol.PackageSymbol;
import com.sun.tools.javac.file.JavacFileManager;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.util.Context;
import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.util.Collection;
import java.util.List;
import javax.annotation.Nullable;
import javax.tools.JavaFileManager;

/**
 * A representation of an entire Refaster rule, corresponding to a class with @BeforeTemplates
 * and @AfterTemplates.
 * 
 * @author lowasser@google.com (Louis Wasserman)
 * @param <M> The type of a match.
 * @param <T> The type of the template used to find matches and generate replacements.
 */
@AutoValue
public abstract class RefasterRule<M extends TemplateMatch, T extends Template<M>>
        implements CodeTransformer, Serializable {
    public static RefasterRule<?, ?> create(String qualifiedTemplateClass,
            Collection<? extends Template<?>> beforeTemplates, Collection<? extends Template<?>> afterTemplates) {
        return create(qualifiedTemplateClass, ImmutableList.<UTypeVar>of(), beforeTemplates, afterTemplates,
                ImmutableClassToInstanceMap.<Annotation>builder().build());
    }

    public static RefasterRule<?, ?> create(String qualifiedTemplateClass, Iterable<UTypeVar> typeVariables,
            Collection<? extends Template<?>> beforeTemplates, Collection<? extends Template<?>> afterTemplates,
            ImmutableClassToInstanceMap<Annotation> annotations) {

        checkState(!beforeTemplates.isEmpty(), "No @BeforeTemplate was found in the specified class: %s",
                qualifiedTemplateClass);
        Class<?> templateType = beforeTemplates.iterator().next().getClass();
        for (Template<?> beforeTemplate : beforeTemplates) {
            checkState(beforeTemplate.getClass().equals(templateType),
                    "Expected all templates to be of type %s but found template of type %s in %s", templateType,
                    beforeTemplate.getClass(), qualifiedTemplateClass);
        }
        for (Template<?> afterTemplate : afterTemplates) {
            checkState(afterTemplate.getClass().equals(templateType),
                    "Expected all templates to be of type %s but found template of type %s in %s", templateType,
                    afterTemplate.getClass(), qualifiedTemplateClass);
        }
        @SuppressWarnings({ "unchecked", "rawtypes" })
        RefasterRule<?, ?> result = new AutoValue_RefasterRule(qualifiedTemplateClass,
                ImmutableList.copyOf(typeVariables), ImmutableList.copyOf(beforeTemplates),
                ImmutableList.copyOf(afterTemplates), annotations);
        return result;
    }

    RefasterRule() {
    }

    abstract String qualifiedTemplateClass();

    abstract ImmutableList<UTypeVar> typeVariables();

    abstract ImmutableList<T> beforeTemplates();

    @Nullable
    abstract ImmutableList<T> afterTemplates();

    @Override
    public abstract ImmutableClassToInstanceMap<Annotation> annotations();

    @Override
    public void apply(TreePath path, Context context, DescriptionListener listener) {
        RefasterScanner.create(this, listener).scan(path,
                prepareContext(context, (JCCompilationUnit) path.getCompilationUnit()));
    }

    boolean rejectMatchesWithComments() {
        return true; // TODO(lowasser): worth making configurable?
    }

    static final Context.Key<ImmutableList<UTypeVar>> RULE_TYPE_VARS = new Context.Key<>();

    private Context prepareContext(Context baseContext, JCCompilationUnit compilationUnit) {
        Context context = new SubContext(baseContext);
        if (context.get(JavaFileManager.class) == null) {
            JavacFileManager.preRegister(context);
        }
        context.put(JCCompilationUnit.class, compilationUnit);
        context.put(PackageSymbol.class, compilationUnit.packge);
        context.put(RULE_TYPE_VARS, typeVariables());
        return context;
    }

    @VisibleForTesting
    static String fromSecondLevel(String qualifiedTemplateClass) {
        List<String> path = Splitter.on('.').splitToList(qualifiedTemplateClass);
        for (int topLevel = 0; topLevel < path.size() - 1; topLevel++) {
            if (Ascii.isUpperCase(path.get(topLevel).charAt(0))) {
                return Joiner.on('_').join(path.subList(topLevel + 1, path.size()));
            }
        }
        return Iterables.getLast(path);
    }

    @Override
    public String toString() {
        return fromSecondLevel(qualifiedTemplateClass());
    }
}