JFlexTask.java
/*
* JFlex Anttask
* Copyright (C) 2001 Rafal Mantiuk <Rafal.Mantiuk@bellstream.pl>
* Copyright (C) 2003 changes by Gerwin Klein <lsf@jflex.de>
* SPDX-License-Identifier: BSD-3-Clause
*/
package jflex.anttask;
import java.io.File;
import java.io.IOException;
import java.io.LineNumberReader;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import jflex.core.OptionUtils;
import jflex.exceptions.GeneratorException;
import jflex.generator.LexGenerator;
import jflex.option.Options;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;
/**
* JFlex ant task.
*
* @author Rafal Mantiuk
* @version JFlex 1.10.0-SNAPSHOT
*/
public class JFlexTask extends Task {
private static final Pattern PACKAGE_PATTERN = Pattern.compile("package\\s+(\\S+)\\s*;");
private static final Pattern CLASS_PATTERN = Pattern.compile("%class\\s+(\\S+)");
private File inputFile;
// found out by looking into .flex file
private String className = null;
private String packageName = null;
/** for javac-like dest dir behaviour */
private File destinationDir;
/** the actual output directory (outputDir = destinationDir + package)) */
private File outputDir = null;
/** Constructor for JFlexTask. */
public JFlexTask() {
OptionUtils.setDefaultOptions();
// ant default is different from the rest of JFlex
setVerbose(false);
setUnusedWarning(true);
Options.progress = false;
}
/** Throws CloneNotSupportedException. */
@Override
public Object clone() throws CloneNotSupportedException {
// Super class implements Cloneable, so we should implement the method,
// but we don't make use of cloning, so we just throw.
throw new CloneNotSupportedException();
}
/**
* Executes the ant task.
*
* @throws BuildException if any.
*/
@Override
public void execute() {
try {
if (inputFile == null)
throw new BuildException("Input file needed. Use <jflex file=\"your_scanner.flex\"/>");
if (!inputFile.canRead()) throw new BuildException("Cannot read input file " + inputFile);
try {
findPackageAndClass();
normalizeOutdir();
File destFile = new File(outputDir, className + ".java");
if (inputFile.lastModified() > destFile.lastModified()) {
new LexGenerator(inputFile).generate();
if (!Options.verbose) System.out.println("Generated: " + destFile.getName());
}
} catch (IOException e1) {
throw new BuildException(e1);
}
} catch (GeneratorException e) {
throw new BuildException("JFlex generation failed", e);
}
}
/**
* Peek into .flex file to get package and class name
*
* @throws java.io.IOException if there is a problem reading the .flex file
*/
public void findPackageAndClass() throws IOException {
// find name of the package and class in jflex source file
packageName = null;
className = null;
Reader r = Files.newBufferedReader(inputFile.toPath(), StandardCharsets.UTF_8);
try (LineNumberReader reader = new LineNumberReader(r)) {
while (className == null || packageName == null) {
String line = reader.readLine();
if (line == null) {
break;
}
if (packageName == null) {
Matcher matcher = PACKAGE_PATTERN.matcher(line);
if (matcher.find()) {
packageName = matcher.group(1);
}
}
if (className == null) {
Matcher matcher = CLASS_PATTERN.matcher(line);
if (matcher.find()) {
className = matcher.group(1);
}
}
}
// package name may be null, but class name not
if (className == null) {
className = "Yylex";
}
}
}
/**
* Sets the actual output directory if not already set.
*
* <p>Uses javac logic to determine output dir = dest dir + package name If not destdir has been
* set, output dir = parent of input file
*
* <p>Assumes that package name is already set.
*/
public void normalizeOutdir() {
if (outputDir != null) return;
// find out what the destination directory is. Append packageName to dest
// dir.
File destDir;
// this is not the default the jflex logic, but javac-like
if (destinationDir != null) {
if (packageName == null) {
destDir = destinationDir;
} else {
String path = packageName.replace('.', File.separatorChar);
destDir = new File(destinationDir, path);
}
} else { // save parser to the same dir as .flex
destDir = new File(inputFile.getParent());
}
setOutdir(destDir);
}
/**
* getPackage.
*
* @return package name of input file
* @see #findPackageAndClass()
*/
public String getPackage() {
return packageName;
}
/**
* Getter for the field {@code className}.
*
* @return class name of input file
* @see #findPackageAndClass()
*/
public String getClassName() {
return className;
}
/**
* setDestdir.
*
* @param destinationDir a {@link java.io.File} object.
*/
public void setDestdir(File destinationDir) {
this.destinationDir = destinationDir;
}
/**
* setOutdir.
*
* @param outDir a {@link java.io.File} object.
*/
public void setOutdir(File outDir) {
this.outputDir = outDir;
OptionUtils.setDir(outputDir);
}
/**
* setFile.
*
* @param file a {@link java.io.File} object.
*/
public void setFile(File file) {
this.inputFile = file;
}
/**
* setGenerateDot.
*
* @param genDot a boolean.
*/
public void setGenerateDot(boolean genDot) {
setDot(genDot);
}
/**
* setTimeStatistics.
*
* @param displayTime a boolean.
*/
public void setTimeStatistics(boolean displayTime) {
Options.time = displayTime;
}
/**
* setTime.
*
* @param displayTime a boolean.
*/
public void setTime(boolean displayTime) {
setTimeStatistics(displayTime);
}
/**
* setVerbose.
*
* @param verbose a boolean.
*/
public final void setVerbose(boolean verbose) {
Options.verbose = verbose;
OptionUtils.set_unused_warning(verbose);
}
/**
* setUnusedWarning.
*
* @param warn a boolean.
*/
public final void setUnusedWarning(boolean warn) {
OptionUtils.set_unused_warning(warn);
}
/**
* setSkeleton.
*
* @param skeleton a {@link java.io.File} object.
*/
public void setSkeleton(File skeleton) {
OptionUtils.setSkeleton(skeleton);
}
/**
* setSkel.
*
* @param skeleton a {@link java.io.File} object.
*/
public void setSkel(File skeleton) {
setSkeleton(skeleton);
}
/**
* setSkipMinimization.
*
* @param skipMin a boolean.
*/
public void setSkipMinimization(boolean skipMin) {
setNomin(skipMin);
}
/**
* setNomin.
*
* @param b a boolean.
*/
public void setNomin(boolean b) {
Options.no_minimize = b;
}
/**
* setNobak.
*
* @param b a boolean.
*/
public void setNobak(boolean b) {
Options.no_backup = b;
}
/**
* setPack.
*
* @param b a boolean.
*/
public void setPack(boolean b) {
/* no-op - this is the only available generation method */
}
/**
* setDot.
*
* @param b a boolean.
*/
public void setDot(boolean b) {
Options.dot = b;
}
/**
* setDump.
*
* @param b a boolean.
*/
public void setDump(boolean b) {
Options.dump = b;
}
/**
* setJLex.
*
* @param b a boolean.
*/
public void setJLex(boolean b) {
Options.jlex = b;
}
/**
* setLegacyDot.
*
* @param b a boolean.
*/
public void setLegacyDot(boolean b) {
Options.legacy_dot = b;
}
/**
* Set the input encoding. If unset will use the JVM default.
*
* @param encodingName the name of the encoding to set (e.g. "utf-8").
*/
public void setEncoding(String encodingName) {
OptionUtils.setEncoding(encodingName);
}
}