com.strumenta.antlrkotlin.gradleplugin.internal.AntlrExecuter Maven / Gradle / Ivy
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Kotlin multiplatform port of ANTLR
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/*
* Copyright 2014 the original author or authors.
*
* 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.strumenta.antlrkotlin.gradleplugin.internal;
import org.gradle.api.GradleException;
import org.gradle.internal.UncheckedException;
import org.gradle.internal.os.OperatingSystem;
import org.gradle.internal.reflect.JavaMethod;
import org.gradle.internal.reflect.NoSuchPropertyException;
import org.gradle.internal.reflect.PropertyMutator;
import org.gradle.process.internal.worker.RequestHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.List;
public class AntlrExecuter implements RequestHandler {
private static final Logger LOGGER = LoggerFactory.getLogger(AntlrExecuter.class);
@Override
public AntlrResult run(AntlrSpec spec) {
AntlrTool antlrTool = new Antlr4Tool();
if (antlrTool.available()) {
LOGGER.info("Processing with ANTLR 4");
return antlrTool.process(spec);
}
throw new IllegalStateException("No ANTLR 4 implementation available");
}
private abstract static class AntlrTool {
/**
* Utility method to create an instance of the Tool class.
*
* @throws ClassNotFoundException if class was not on the runtime classpath.
*/
static Object loadTool(String className, String[] args) throws ClassNotFoundException {
LOGGER.debug("Loading tool " + className);
try {
Class toolClass = Class.forName(className); // ok to use caller classloader
LOGGER.debug("Tool loaded " + className);
if (args == null) {
return toolClass.newInstance();
} else {
Constructor constructor = toolClass.getConstructor(String[].class);
return constructor.newInstance(new Object[]{args});
}
} catch (ClassNotFoundException cnf) {
LOGGER.error("Tool not loaded " + cnf.getMessage());
throw cnf;
} catch (InvocationTargetException e) {
LOGGER.error("Tool not loaded " + e.getMessage());
throw new GradleException("Failed to load ANTLR", e.getCause());
} catch (Exception e) {
LOGGER.error("Tool not loaded " + e.getMessage());
throw new GradleException("Failed to load ANTLR", e);
}
}
public final AntlrResult process(AntlrSpec spec) {
try {
return doProcess(spec);
} catch (ClassNotFoundException e) {
//this shouldn't happen if you call check availability with #available first
throw new GradleException("Cannot process antlr sources", e);
}
}
public static String relativePath(File from, File to) {
try {
return org.apache.tools.ant.util.FileUtils.getRelativePath(from, to);
} catch (Exception e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
/**
* process used for antlr3/4
*/
public AntlrResult doProcess(AntlrSpec spec) throws ClassNotFoundException {
int numErrors = 0;
if (spec.getInputDirectories().size() == 0) {
// we have not root source folder information for the grammar files,
// so we don't force relativeOutput as we can't calculate it.
// This results in flat generated sources in the output directory
numErrors += invoke(spec.asArgumentsWithFiles(), null);
} else {
boolean onWindows = OperatingSystem.current().isWindows();
for (File inputDirectory : spec.getInputDirectories()) {
final List arguments = spec.getArguments();
arguments.add("-Dlanguage=Kotlin");
arguments.add("-o");
arguments.add(spec.getOutputDirectory().getAbsolutePath());
for (File grammarFile : spec.getGrammarFiles()) {
String relativeGrammarFilePath = relativePath(inputDirectory, grammarFile);
if (onWindows) {
relativeGrammarFilePath = relativeGrammarFilePath.replace('/', File.separatorChar);
}
arguments.add(relativeGrammarFilePath);
}
numErrors += invoke(arguments, inputDirectory);
}
}
return new AntlrResult(numErrors);
}
abstract int invoke(List arguments, File inputDirectory) throws ClassNotFoundException;
public abstract boolean available();
protected static String[] toArray(List strings) {
return strings.toArray(new String[0]);
}
}
static class Antlr4Tool extends AntlrTool {
@Override
int invoke(List arguments, File inputDirectory) throws ClassNotFoundException {
final Object backedObject = loadTool("org.antlr.v4.Tool", toArray(arguments));
if (inputDirectory != null) {
writeableField(backedObject.getClass(), "inputDirectory").setValue(backedObject, inputDirectory);
}
JavaMethod.of(backedObject, Void.class, "processGrammarsOnCommandLine").invoke(backedObject);
return JavaMethod.of(backedObject, Integer.class, "getNumErrors").invoke(backedObject);
}
@Override
public boolean available() {
try {
loadTool("org.antlr.v4.Tool", null);
} catch (ClassNotFoundException cnf) {
return false;
}
return true;
}
}
/**
* Locates the field with the given name as a writable property. Searches only public properties.
*
* @throws org.gradle.internal.reflect.NoSuchPropertyException when the given property does not exist.
*/
private static PropertyMutator writeableField(Class target, String fieldName) throws NoSuchPropertyException {
Field field = findField(target, fieldName);
if (field != null) {
return new FieldBackedPropertyMutator(fieldName, field);
}
throw new NoSuchPropertyException(String.format("Could not find writeable field '%s' on class %s.", fieldName, target.getSimpleName()));
}
private static Field findField(Class target, String fieldName) {
Field[] fields = target.getFields();
for (Field field : fields) {
if (fieldName.equals(field.getName())) {
return field;
}
}
return null;
}
private static class FieldBackedPropertyMutator implements PropertyMutator {
private final String name;
private final Field field;
FieldBackedPropertyMutator(String name, Field field) {
this.name = name;
this.field = field;
}
@Override
public String toString() {
return "field " + field.getDeclaringClass().getSimpleName() + "." + name;
}
public String getName() {
return name;
}
public Class getType() {
return field.getType();
}
@Override
public void setValue(Object target, Object value) {
try {
field.set(target, value);
} catch (IllegalAccessException e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
}
}