org.mutabilitydetector.checkers.CheckerRunner Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of MutabilityDetector Show documentation
Lightweight analysis tool for detecting mutability in Java classes.
There is a newer version: 0.10.6
package org.mutabilitydetector.checkers;

/*
 * #%L
 * MutabilityDetector
 * %%
 * Copyright (C) 2008 - 2014 Graham Allan
 * %%
 * 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.
 * #L%
 */



import static java.lang.String.format;
import static org.mutabilitydetector.checkers.CheckerRunner.ExceptionPolicy.FAIL_FAST;

import java.io.IOException;
import java.io.InputStream;

import org.mutabilitydetector.AnalysisErrorReporter;
import org.mutabilitydetector.AnalysisResult;
import org.mutabilitydetector.AnalysisErrorReporter.AnalysisError;
import org.mutabilitydetector.locations.Dotted;
import org.objectweb.asm.ClassReader;

import com.google.classpath.ClassPath;
import com.google.classpath.ClassPathFactory;

public final class CheckerRunner {

    private final ClassPath classpath;
    private final UnhandledExceptionBuilder unhandledExceptionBuilder;
    private final ExceptionPolicy exceptionPolicy;

    private CheckerRunner(ClassPath classpath, UnhandledExceptionBuilder unhandledExceptionBuilder, ExceptionPolicy exceptionPolicy) {
        this.classpath = classpath;
        this.unhandledExceptionBuilder = unhandledExceptionBuilder;
        this.exceptionPolicy = exceptionPolicy;
    }

    public static CheckerRunner createWithClasspath(ClassPath classpath, ExceptionPolicy exceptionPolicy) {
        return new CheckerRunner(classpath, new UnhandledExceptionBuilder(), exceptionPolicy);
    }

    public static CheckerRunner createWithCurrentClasspath(ExceptionPolicy exceptionPolicy) {
        return createWithClasspath(new ClassPathFactory().createFromJVM(), exceptionPolicy);
    }
    
    public static enum ExceptionPolicy {
        FAIL_FAST, CARRY_ON
    }

    public CheckerResult run(AsmMutabilityChecker checker, Dotted className, AnalysisErrorReporter errorReporter, Iterable resultsSoFar) {
        try {
            try {
                analyseFromStream(checker, className);
            } catch (Exception e) {
                analyseFromClassLoader(checker, className);
            }
        } catch (Throwable e) {
            attemptRecovery(checker, className, errorReporter, resultsSoFar, e);
        }
        return checker.checkerResult();
    }


    private void analyseFromStream(AsmMutabilityChecker checker, Dotted dottedClassPath) throws IOException {
        InputStream classStream = classpath.getResourceAsStream(asResourceName(dottedClassPath));
        analyse(checker, classStream);
    }

    private void analyseFromClassLoader(AsmMutabilityChecker checker, Dotted className) throws Exception {
        InputStream classStream = getClass().getClassLoader().getResourceAsStream(asResourceName(className));
        analyse(checker, classStream);
    }

    private void analyse(AsmMutabilityChecker checker, InputStream classStream) throws IOException {
        ClassReader cr = new ClassReader(classStream);
        cr.accept(checker, 0);
    }

    private String asResourceName(Dotted className) {
        return className.asString().replace(".", "/").concat(".class");
    }

    private void attemptRecovery(AsmMutabilityChecker checker,
                                 Dotted className,
                                 AnalysisErrorReporter errorReporter,
                                 Iterable resultsSoFar,
                                 Throwable e) {

        if (!isRecoverable(e) || exceptionPolicy == FAIL_FAST) {
            throw unhandledExceptionBuilder.unhandledException(e, resultsSoFar, checker, className);
        } else {
            handleException(errorReporter, checker, className.asString(), e);
        }
    }
    
    private boolean isRecoverable(Throwable e) {
        Throwable cause = underlyingCause(e);
        return (cause instanceof Exception) || (cause instanceof LinkageError);
    }

    private Throwable underlyingCause(Throwable e) {
        Throwable rootCause = e;
        while (rootCause.getCause() != null) {
            rootCause = rootCause.getCause();
        }
        return rootCause;
    }

    private void handleException(AnalysisErrorReporter errorReporter, AsmMutabilityChecker checker, String dottedClassPath, Throwable e) {
        String errorDescription = createErrorDescription(dottedClassPath);
        checker.visitAnalysisException(e);
        AnalysisError error = new AnalysisError(dottedClassPath, getNameOfChecker(checker), errorDescription);
        errorReporter.addAnalysisError(error);
    }

    public String createErrorDescription(String dottedClassPath) {
        return format("It is likely that the class %s has dependencies outwith the given class path.", dottedClassPath);
    }

    private String getNameOfChecker(AsmMutabilityChecker checker) {
        String checkerName = checker.getClass().getName();
        return checkerName.substring(checkerName.lastIndexOf(".") + 1);
    }
}