/**
* 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.drill.exec.compile;
import java.io.IOException;
import java.io.StringReader;
import org.apache.drill.exec.exception.ClassTransformationException;
import org.codehaus.commons.compiler.CompileException;
import org.codehaus.janino.ClassLoaderIClassLoader;
import org.codehaus.janino.IClassLoader;
import org.codehaus.janino.Java;
import org.codehaus.janino.Parser;
import org.codehaus.janino.Scanner;
import org.codehaus.janino.UnitCompiler;
import org.codehaus.janino.util.ClassFile;
public class JaninoClassCompiler implements ClassCompiler{
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(JaninoClassCompiler.class);
private IClassLoader compilationClassLoader;
private boolean debugLines = true;
private boolean debugVars = true;
private boolean debugSource = true;
public JaninoClassCompiler(ClassLoader parentClassLoader) {
this.compilationClassLoader = new ClassLoaderIClassLoader(parentClassLoader);
}
public byte[] getClassByteCode(final String className, final String code) throws CompileException, IOException, ClassNotFoundException, ClassTransformationException {
if(logger.isDebugEnabled()){
logger.debug("Compiling:\n {}", prefixLineNumbers(code));
}
StringReader reader = new StringReader(code);
Scanner scanner = new Scanner((String) null, reader);
Java.CompilationUnit compilationUnit = new Parser(scanner).parseCompilationUnit();
ClassFile[] classFiles = new UnitCompiler(compilationUnit, compilationClassLoader).compileUnit(this.debugSource,
this.debugLines, this.debugVars);
if (classFiles.length != 1)
throw new ClassTransformationException("Only one class file should have been generated from source code.");
return classFiles[0].toByteArray();
}
private String prefixLineNumbers(String code) {
if (!debugLines) return code;
StringBuilder out = new StringBuilder();
int i = 1;
for (String line : code.split("\n")) {
int start = out.length();
out.append(i++);
int numLength = out.length() - start;
out.append(":");
for (int spaces = 0; spaces < 7 - numLength; ++spaces){
out.append(" ");
}
out.append(line);
out.append('\n');
}
return out.toString();
}
public void setDebuggingInformation(boolean debugSource, boolean debugLines, boolean debugVars) {
this.debugSource = debugSource;
this.debugLines = debugLines;
this.debugVars = debugVars;
}
}