com.fluxtion.agrona.generation.CompilerUtil Maven / Gradle / Ivy
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/*
* Copyright 2014-2024 Real Logic Limited.
*
* 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
*
* https://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.fluxtion.agrona.generation;
import com.fluxtion.agrona.LangUtil;
import com.fluxtion.agrona.SystemUtil;
import javax.tools.*;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
import static java.util.stream.Collectors.toList;
/**
* Utilities for compiling Java source files at runtime.
*/
public final class CompilerUtil
{
/**
* Temporary directory for files.
*/
private static final String TEMP_DIR_NAME = SystemUtil.tmpDirName();
private CompilerUtil()
{
}
/**
* Compile a {@link Map} of source files in-memory resulting in a {@link Class} which is named.
*
* @param className to return after compilation.
* @param sources to be compiled.
* @return the named class that is the result of the compilation.
* @throws ClassNotFoundException of the named class cannot be found.
*/
public static Class compileInMemory(final String className, final Map sources)
throws ClassNotFoundException
{
final JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (null == compiler)
{
throw new IllegalStateException("JDK required to run tests. JRE is not sufficient.");
}
final JavaFileManager fileManager = new ClassFileManager<>(
compiler.getStandardFileManager(null, null, null));
final DiagnosticCollector diagnostics = new DiagnosticCollector<>();
final JavaCompiler.CompilationTask task = compiler.getTask(
null, fileManager, diagnostics, null, null, wrap(sources));
return compileAndLoad(className, diagnostics, fileManager, task);
}
/**
* Compile a {@link Map} of source files on disk resulting in a {@link Class} which is named.
*
* @param className to return after compilation.
* @param sources to be compiled.
* @return the named class that is the result of the compilation.
* @throws ClassNotFoundException of the named class cannot be found.
* @throws IOException if an error occurs when writing to disk.
*/
public static Class compileOnDisk(final String className, final Map sources)
throws ClassNotFoundException, IOException
{
final JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (null == compiler)
{
throw new IllegalStateException("JDK required to run tests. JRE is not sufficient.");
}
final DiagnosticCollector diagnostics = new DiagnosticCollector<>();
try (StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null))
{
final ArrayList options = new ArrayList<>(Arrays.asList(
"-classpath", System.getProperty("java.class.path") + File.pathSeparator + TEMP_DIR_NAME));
final Collection files = persist(sources);
final Iterable compilationUnits = fileManager.getJavaFileObjectsFromFiles(files);
final JavaCompiler.CompilationTask task = compiler.getTask(
null, fileManager, diagnostics, options, null, compilationUnits);
return compileAndLoad(className, diagnostics, fileManager, task);
}
}
/**
* Compile and load a class.
*
* @param className name of the class to compile.
* @param diagnostics attached to the compilation task.
* @param fileManager to load compiled class from disk.
* @param task compilation task.
* @return {@link Class} for the compiled class or {@code null} if compilation fails.
* @throws ClassNotFoundException if compiled class was not loaded.
*/
public static Class compileAndLoad(
final String className,
final DiagnosticCollector diagnostics,
final JavaFileManager fileManager,
final JavaCompiler.CompilationTask task) throws ClassNotFoundException
{
if (!compile(diagnostics, task))
{
return null;
}
return fileManager.getClassLoader(null).loadClass(className);
}
/**
* Execute compilation task and report errors if it fails.
*
* @param diagnostics attached to the compilation task.
* @param task compilation to be executed.
* @return {@code true} if compilation succeeds.
*/
public static boolean compile(
final DiagnosticCollector diagnostics, final JavaCompiler.CompilationTask task)
{
final Boolean succeeded = task.call();
if (!succeeded)
{
for (final Diagnostic diagnostic : diagnostics.getDiagnostics())
{
System.err.println(diagnostic.getCode());
System.err.println(diagnostic.getKind());
final JavaFileObject source = diagnostic.getSource();
System.err.printf("Line = %d, Col = %d, File = %s",
diagnostic.getLineNumber(), diagnostic.getColumnNumber(), source);
System.err.println("Start: " + diagnostic.getStartPosition());
System.err.println("End: " + diagnostic.getEndPosition());
System.err.println("Pos: " + diagnostic.getPosition());
try
{
final String content = source.getCharContent(true).toString();
final int begin = content.lastIndexOf('\n', (int)diagnostic.getStartPosition());
final int end = content.indexOf('\n', (int)diagnostic.getEndPosition());
System.err.println(diagnostic.getMessage(null));
System.err.println(content.substring(Math.max(0, begin), end));
}
catch (final IOException ex)
{
LangUtil.rethrowUnchecked(ex);
}
}
}
return succeeded;
}
/**
* Persist source files to disc.
*
* @param sources to persist.
* @return a collection of {@link File} objects pointing to the persisted sources.
* @throws IOException in case of I/O errors.
*/
public static Collection persist(final Map sources) throws IOException
{
final Collection files = new ArrayList<>(sources.size());
for (final Map.Entry entry : sources.entrySet())
{
final String fqClassName = entry.getKey();
String className = fqClassName;
Path path = Paths.get(TEMP_DIR_NAME);
final int indexOfLastDot = fqClassName.lastIndexOf('.');
if (indexOfLastDot != -1)
{
className = fqClassName.substring(indexOfLastDot + 1);
path = Paths.get(
TEMP_DIR_NAME + fqClassName.substring(0, indexOfLastDot).replace('.', File.separatorChar));
Files.createDirectories(path);
}
final File file = new File(path.toString(), className + ".java");
files.add(file);
try (FileWriter out = new FileWriter(file))
{
out.append(entry.getValue());
out.flush();
}
}
return files;
}
private static Collection wrap(final Map sources)
{
return sources
.entrySet()
.stream()
.map((e) -> new CharSequenceJavaFileObject(e.getKey(), e.getValue()))
.collect(toList());
}
}
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