Ant example source code file (JavaCC.java)

This example Ant source code file (JavaCC.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

archive_locations, buildexception, buildexception, file, file, io, javacc, javacc, org_javacc_class, org_package_3_1, path, string, string, taskdef_type_javacc, taskdef_type_jjtree, util

The JavaCC.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.apache.tools.ant.taskdefs.optional.javacc;

import java.io.File;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Hashtable;

import org.apache.tools.ant.AntClassLoader;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.taskdefs.Execute;
import org.apache.tools.ant.types.Commandline;
import org.apache.tools.ant.types.CommandlineJava;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.util.JavaEnvUtils;

/**
 * JavaCC compiler compiler task.
 *
 */
public class JavaCC extends Task {

    // keys to optional attributes
    private static final String LOOKAHEAD              = "LOOKAHEAD";
    private static final String CHOICE_AMBIGUITY_CHECK = "CHOICE_AMBIGUITY_CHECK";
    private static final String OTHER_AMBIGUITY_CHECK  = "OTHER_AMBIGUITY_CHECK";

    private static final String STATIC                 = "STATIC";
    private static final String DEBUG_PARSER           = "DEBUG_PARSER";
    private static final String DEBUG_LOOKAHEAD        = "DEBUG_LOOKAHEAD";
    private static final String DEBUG_TOKEN_MANAGER    = "DEBUG_TOKEN_MANAGER";
    private static final String OPTIMIZE_TOKEN_MANAGER = "OPTIMIZE_TOKEN_MANAGER";
    private static final String ERROR_REPORTING        = "ERROR_REPORTING";
    private static final String JAVA_UNICODE_ESCAPE    = "JAVA_UNICODE_ESCAPE";
    private static final String UNICODE_INPUT          = "UNICODE_INPUT";
    private static final String IGNORE_CASE            = "IGNORE_CASE";
    private static final String COMMON_TOKEN_ACTION    = "COMMON_TOKEN_ACTION";
    private static final String USER_TOKEN_MANAGER     = "USER_TOKEN_MANAGER";
    private static final String USER_CHAR_STREAM       = "USER_CHAR_STREAM";
    private static final String BUILD_PARSER           = "BUILD_PARSER";
    private static final String BUILD_TOKEN_MANAGER    = "BUILD_TOKEN_MANAGER";
    private static final String SANITY_CHECK           = "SANITY_CHECK";
    private static final String FORCE_LA_CHECK         = "FORCE_LA_CHECK";
    private static final String CACHE_TOKENS           = "CACHE_TOKENS";
    private static final String KEEP_LINE_COLUMN       = "KEEP_LINE_COLUMN";
    private static final String JDK_VERSION            = "JDK_VERSION";

    private final Hashtable optionalAttrs = new Hashtable();

    // required attributes
    private File outputDirectory = null;
    private File targetFile      = null;
    private File javaccHome      = null;

    private CommandlineJava cmdl = new CommandlineJava();

    protected static final int TASKDEF_TYPE_JAVACC = 1;
    protected static final int TASKDEF_TYPE_JJTREE = 2;
    protected static final int TASKDEF_TYPE_JJDOC = 3;

    protected static final String[] ARCHIVE_LOCATIONS =
        new String[] {
            "JavaCC.zip",
            "bin/lib/JavaCC.zip",
            "bin/lib/javacc.jar",
            "javacc.jar", // used by jpackage for JavaCC 3.x
        };

    protected static final int[] ARCHIVE_LOCATIONS_VS_MAJOR_VERSION =
        new int[] {
            1,
            2,
            3,
            3,
        };

    protected static final String COM_PACKAGE = "COM.sun.labs.";
    protected static final String COM_JAVACC_CLASS = "javacc.Main";
    protected static final String COM_JJTREE_CLASS = "jjtree.Main";
    protected static final String COM_JJDOC_CLASS = "jjdoc.JJDocMain";

    protected static final String ORG_PACKAGE_3_0 = "org.netbeans.javacc.";
    protected static final String ORG_PACKAGE_3_1 = "org.javacc.";
    protected static final String ORG_JAVACC_CLASS = "parser.Main";
    protected static final String ORG_JJTREE_CLASS = COM_JJTREE_CLASS;
    protected static final String ORG_JJDOC_CLASS = COM_JJDOC_CLASS;

    /**
     * Sets the LOOKAHEAD grammar option.
     * @param lookahead an <code>int value.
     */
    public void setLookahead(int lookahead) {
        optionalAttrs.put(LOOKAHEAD, new Integer(lookahead));
    }

    /**
     * Sets the CHOICE_AMBIGUITY_CHECK grammar option.
     * @param choiceAmbiguityCheck an <code>int value.
     */
    public void setChoiceambiguitycheck(int choiceAmbiguityCheck) {
        optionalAttrs.put(CHOICE_AMBIGUITY_CHECK, new Integer(choiceAmbiguityCheck));
    }

    /**
     * Sets the OTHER_AMBIGUITY_CHECK grammar option.
     * @param otherAmbiguityCheck an <code>int value.
     */
    public void setOtherambiguityCheck(int otherAmbiguityCheck) {
        optionalAttrs.put(OTHER_AMBIGUITY_CHECK, new Integer(otherAmbiguityCheck));
    }

    /**
     * Sets the STATIC grammar option.
     * @param staticParser a <code>boolean value.
     */
    public void setStatic(boolean staticParser) {
        optionalAttrs.put(STATIC, staticParser ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the DEBUG_PARSER grammar option.
     * @param debugParser a <code>boolean value.
     */
    public void setDebugparser(boolean debugParser) {
        optionalAttrs.put(DEBUG_PARSER, debugParser ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the DEBUG_LOOKAHEAD grammar option.
     * @param debugLookahead a <code>boolean value.
     */
    public void setDebuglookahead(boolean debugLookahead) {
        optionalAttrs.put(DEBUG_LOOKAHEAD, debugLookahead ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the DEBUG_TOKEN_MANAGER grammar option.
     * @param debugTokenManager a <code>boolean value.
     */
    public void setDebugtokenmanager(boolean debugTokenManager) {
        optionalAttrs.put(DEBUG_TOKEN_MANAGER, debugTokenManager ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the OPTIMIZE_TOKEN_MANAGER grammar option.
     * @param optimizeTokenManager a <code>boolean value.
     */
    public void setOptimizetokenmanager(boolean optimizeTokenManager) {
        optionalAttrs.put(OPTIMIZE_TOKEN_MANAGER,
                          optimizeTokenManager ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the ERROR_REPORTING grammar option.
     * @param errorReporting a <code>boolean value.
     */
    public void setErrorreporting(boolean errorReporting) {
        optionalAttrs.put(ERROR_REPORTING, errorReporting ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the JAVA_UNICODE_ESCAPE grammar option.
     * @param javaUnicodeEscape a <code>boolean value.
     */
    public void setJavaunicodeescape(boolean javaUnicodeEscape) {
        optionalAttrs.put(JAVA_UNICODE_ESCAPE, javaUnicodeEscape ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the UNICODE_INPUT grammar option.
     * @param unicodeInput a <code>boolean value.
     */
    public void setUnicodeinput(boolean unicodeInput) {
        optionalAttrs.put(UNICODE_INPUT, unicodeInput ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the IGNORE_CASE grammar option.
     * @param ignoreCase a <code>boolean value.
     */
    public void setIgnorecase(boolean ignoreCase) {
        optionalAttrs.put(IGNORE_CASE, ignoreCase ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the COMMON_TOKEN_ACTION grammar option.
     * @param commonTokenAction a <code>boolean value.
     */
    public void setCommontokenaction(boolean commonTokenAction) {
        optionalAttrs.put(COMMON_TOKEN_ACTION, commonTokenAction ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the USER_TOKEN_MANAGER grammar option.
     * @param userTokenManager a <code>boolean value.
     */
    public void setUsertokenmanager(boolean userTokenManager) {
        optionalAttrs.put(USER_TOKEN_MANAGER, userTokenManager ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the USER_CHAR_STREAM grammar option.
     * @param userCharStream a <code>boolean value.
     */
    public void setUsercharstream(boolean userCharStream) {
        optionalAttrs.put(USER_CHAR_STREAM, userCharStream ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the BUILD_PARSER grammar option.
     * @param buildParser a <code>boolean value.
     */
    public void setBuildparser(boolean buildParser) {
        optionalAttrs.put(BUILD_PARSER, buildParser ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the BUILD_TOKEN_MANAGER grammar option.
     * @param buildTokenManager a <code>boolean value.
     */
    public void setBuildtokenmanager(boolean buildTokenManager) {
        optionalAttrs.put(BUILD_TOKEN_MANAGER, buildTokenManager ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the SANITY_CHECK grammar option.
     * @param sanityCheck a <code>boolean value.
     */
    public void setSanitycheck(boolean sanityCheck) {
        optionalAttrs.put(SANITY_CHECK, sanityCheck ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the FORCE_LA_CHECK grammar option.
     * @param forceLACheck a <code>boolean value.
     */
    public void setForcelacheck(boolean forceLACheck) {
        optionalAttrs.put(FORCE_LA_CHECK, forceLACheck ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the CACHE_TOKENS grammar option.
     * @param cacheTokens a <code>boolean value.
     */
    public void setCachetokens(boolean cacheTokens) {
        optionalAttrs.put(CACHE_TOKENS, cacheTokens ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the KEEP_LINE_COLUMN grammar option.
     * @param keepLineColumn a <code>boolean value.
     */
    public void setKeeplinecolumn(boolean keepLineColumn) {
        optionalAttrs.put(KEEP_LINE_COLUMN, keepLineColumn ? Boolean.TRUE : Boolean.FALSE);
    }

    /**
     * Sets the JDK_VERSION option.
     * @param jdkVersion the version to use.
     * @since Ant1.7
     */
    public void setJDKversion(String jdkVersion) {
        optionalAttrs.put(JDK_VERSION, jdkVersion);
    }

    /**
     * The directory to write the generated files to.
     * If not set, the files are written to the directory
     * containing the grammar file.
     * @param outputDirectory the output directory.
     */
    public void setOutputdirectory(File outputDirectory) {
        this.outputDirectory = outputDirectory;
    }

    /**
     * The grammar file to process.
     * @param targetFile the grammar file.
     */
    public void setTarget(File targetFile) {
        this.targetFile = targetFile;
    }

    /**
     * The directory containing the JavaCC distribution.
     * @param javaccHome the directory.
     */
    public void setJavacchome(File javaccHome) {
        this.javaccHome = javaccHome;
    }

    /**
     * Constructor
     */
    public JavaCC() {
        cmdl.setVm(JavaEnvUtils.getJreExecutable("java"));
    }

    /**
     * Run the task.
     * @throws BuildException on error.
     */
    public void execute() throws BuildException {

        // load command line with optional attributes
        Enumeration iter = optionalAttrs.keys();
        while (iter.hasMoreElements()) {
            String name  = (String) iter.nextElement();
            Object value = optionalAttrs.get(name);
            cmdl.createArgument().setValue("-" + name + ":" + value.toString());
        }

        // check the target is a file
        if (targetFile == null || !targetFile.isFile()) {
            throw new BuildException("Invalid target: " + targetFile);
        }

        // use the directory containing the target as the output directory
        if (outputDirectory == null) {
            outputDirectory = new File(targetFile.getParent());
        } else if (!outputDirectory.isDirectory()) {
            throw new BuildException("Outputdir not a directory.");
        }
        cmdl.createArgument().setValue("-OUTPUT_DIRECTORY:"
                                       + outputDirectory.getAbsolutePath());

        // determine if the generated java file is up-to-date
        final File javaFile = getOutputJavaFile(outputDirectory, targetFile);
        if (javaFile.exists() && targetFile.lastModified() < javaFile.lastModified()) {
            log("Target is already built - skipping (" + targetFile + ")", Project.MSG_VERBOSE);
            return;
        }
        cmdl.createArgument().setValue(targetFile.getAbsolutePath());

        final Path classpath = cmdl.createClasspath(getProject());
        final File javaccJar = JavaCC.getArchiveFile(javaccHome);
        classpath.createPathElement().setPath(javaccJar.getAbsolutePath());
        classpath.addJavaRuntime();

        cmdl.setClassname(JavaCC.getMainClass(classpath,
                                              JavaCC.TASKDEF_TYPE_JAVACC));

        final Commandline.Argument arg = cmdl.createVmArgument();
        arg.setValue("-mx140M");
        arg.setValue("-Dinstall.root=" + javaccHome.getAbsolutePath());

        Execute.runCommand(this, cmdl.getCommandline());
    }

    /**
     * Helper method to retrieve the path used to store the JavaCC.zip
     * or javacc.jar which is different from versions.
     *
     * @param home the javacc home path directory.
     * @throws BuildException thrown if the home directory is invalid
     * or if the archive could not be found despite attempts to do so.
     * @return the file object pointing to the JavaCC archive.
     */
    protected static File getArchiveFile(File home) throws BuildException {
        return new File(home,
                        ARCHIVE_LOCATIONS[getArchiveLocationIndex(home)]);
    }

    /**
     * Helper method to retrieve main class which is different from versions.
     * @param home the javacc home path directory.
     * @param type the taskdef.
     * @throws BuildException thrown if the home directory is invalid
     * or if the archive could not be found despite attempts to do so.
     * @return the main class for the taskdef.
     */
    protected static String getMainClass(File home, int type)
        throws BuildException {

        Path p = new Path(null);
        p.createPathElement().setLocation(getArchiveFile(home));
        p.addJavaRuntime();
        return getMainClass(p, type);
    }

    /**
     * Helper method to retrieve main class which is different from versions.
     * @param path classpath to search in.
     * @param type the taskdef.
     * @throws BuildException thrown if the home directory is invalid
     * or if the archive could not be found despite attempts to do so.
     * @return the main class for the taskdef.
     * @since Ant 1.7
     */
    protected static String getMainClass(Path path, int type)
        throws BuildException {
        String packagePrefix = null;
        String mainClass = null;

        AntClassLoader l = new AntClassLoader();
        l.setClassPath(path.concatSystemClasspath("ignore"));
        String javaccClass = COM_PACKAGE + COM_JAVACC_CLASS;
        InputStream is = l.getResourceAsStream(javaccClass.replace('.', '/')
                                               + ".class");
        if (is != null) {
            packagePrefix = COM_PACKAGE;
            switch (type) {
            case TASKDEF_TYPE_JAVACC:
                mainClass = COM_JAVACC_CLASS;

                break;

            case TASKDEF_TYPE_JJTREE:
                mainClass = COM_JJTREE_CLASS;

                break;

            case TASKDEF_TYPE_JJDOC:
                mainClass = COM_JJDOC_CLASS;

                break;
            default:
                // Fall Through
            }
        } else {
            javaccClass = ORG_PACKAGE_3_1 + ORG_JAVACC_CLASS;
            is = l.getResourceAsStream(javaccClass.replace('.', '/')
                                       + ".class");
            if (is != null) {
                packagePrefix = ORG_PACKAGE_3_1;
            } else {
                javaccClass = ORG_PACKAGE_3_0 + ORG_JAVACC_CLASS;
                is = l.getResourceAsStream(javaccClass.replace('.', '/')
                                           + ".class");
                if (is != null) {
                    packagePrefix = ORG_PACKAGE_3_0;
                }
            }

            if (is != null) {
                switch (type) {
                case TASKDEF_TYPE_JAVACC:
                    mainClass = ORG_JAVACC_CLASS;

                break;

                case TASKDEF_TYPE_JJTREE:
                    mainClass = ORG_JJTREE_CLASS;

                    break;

                case TASKDEF_TYPE_JJDOC:
                    mainClass = ORG_JJDOC_CLASS;

                    break;
                default:
                    // Fall Through
                }
            }
        }

        if (packagePrefix == null) {
            throw new BuildException("failed to load JavaCC");
        }
        if (mainClass == null) {
            throw new BuildException("unknown task type " + type);
        }
        return packagePrefix + mainClass;
    }

    /**
     * Helper method to determine the archive location index.
     *
     * @param home the javacc home path directory.
     * @throws BuildException thrown if the home directory is invalid
     * or if the archive could not be found despite attempts to do so.
     * @return the archive location index
     */
    private static int getArchiveLocationIndex(File home)
        throws BuildException {

        if (home == null || !home.isDirectory()) {
            throw new BuildException("JavaCC home must be a valid directory.");
        }

        for (int i = 0; i < ARCHIVE_LOCATIONS.length; i++) {
            File f = new File(home, ARCHIVE_LOCATIONS[i]);

            if (f.exists()) {
                return i;
            }
        }

        throw new BuildException("Could not find a path to JavaCC.zip "
                                 + "or javacc.jar from '" + home + "'.");
    }

    /**
     * Helper method to determine the major version number of JavaCC.
     *
     * @param home the javacc home path directory.
     * @throws BuildException thrown if the home directory is invalid
     * or if the archive could not be found despite attempts to do so.
     * @return a the major version number
     */
    protected static int getMajorVersionNumber(File home)
        throws BuildException {

        return
            ARCHIVE_LOCATIONS_VS_MAJOR_VERSION[getArchiveLocationIndex(home)];
    }

    /**
     * Determines the output Java file to be generated by the given grammar
     * file.
     *
     */
    private File getOutputJavaFile(File outputdir, File srcfile) {
        String path = srcfile.getPath();

        // Extract file's base-name
        int startBasename = path.lastIndexOf(File.separator);
        if (startBasename != -1) {
            path = path.substring(startBasename + 1);
        }

        // Replace the file's extension with '.java'
        int startExtn = path.lastIndexOf('.');
        if (startExtn != -1) {
            path = path.substring(0, startExtn) + ".java";
        } else {
            path += ".java";
        }

        // Change the directory
        if (outputdir != null) {
            path = outputdir + File.separator + path;
        }

        return new File(path);
    }
}