drill-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From arina-ielchiieva <...@git.apache.org>
Subject [GitHub] drill pull request #660: DRILL-5052: Option to debug generated Java code usi...
Date Thu, 08 Dec 2016 15:27:01 GMT
Github user arina-ielchiieva commented on a diff in the pull request:

    https://github.com/apache/drill/pull/660#discussion_r91533256
  
    --- Diff: exec/java-exec/src/main/java/org/apache/drill/exec/compile/ClassBuilder.java
---
    @@ -0,0 +1,190 @@
    +/**
    + * 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.File;
    +import java.io.FileWriter;
    +import java.io.IOException;
    +import java.util.Map;
    +
    +import org.apache.drill.common.config.DrillConfig;
    +import org.apache.drill.exec.compile.ClassTransformer.ClassNames;
    +import org.apache.drill.exec.exception.ClassTransformationException;
    +import org.apache.drill.exec.expr.CodeGenerator;
    +import org.apache.drill.exec.server.options.OptionManager;
    +import org.codehaus.commons.compiler.CompileException;
    +
    +/**
    + * Implements the "plain-old Java" method of code generation and
    + * compilation. Given a {@link CodeGenerator}, obtains the generated
    + * source code, compiles it with the selected compiler, loads the
    + * byte-codes into a class loader and provides the resulting
    + * class. Compared with the {@link ClassTransformer} mechanism,
    + * this one requires the code generator to have generated a complete
    + * Java class that is capable of direct compilation and loading.
    + * This means the generated class must be a subclass of the template
    + * so that the JVM can use normal Java inheritance to associate the
    + * template and generated methods.
    + * <p>
    + * Here is how to use the plain-old Java technique to debug
    + * generated code:
    + * <ul>
    + * <li>Set the config option <var>drill.exec.compile.save_source</var>
    + * to <var>true</var>.</li>
    + * <li>Set the config option <var>drill.exec.compile.code_dir</var>
    + * to the location where you want to save the generated source
    + * code.</li>
    + * <li>Where you generate code (using a {@link CodeGenerator}),
    + * set the "plain-old Java" options:<pre>
    + * CodeGenerator&lt;Foo> cg = ...
    + * cg.plainOldJavaCapable(true); // Class supports plain-old Java
    + * cg.preferPlainOldJava(true); // Actually generate plain-old Java
    + * ...</pre></li>
    + * <li>In your favorite IDE, add to the code lookup path the
    + * code directory saved earlier. In Eclipse, for example, you do
    + * this in the debug configuration you will use to debug Drill.</li>
    + * <li>Set a breakpoint in template used for the generated code.</li>
    + * <li>Run Drill. The IDE will stop at your breakpoint.</li>
    + * <li>Step into the generated code. Examine class field and
    + * local variables. Have fun!</li>
    + * </ul>
    + * <p>
    + * Note: not all generated code is ready to be compiled as plain-old
    + * Java. Some classes omit from the template the proper <code>throws</code>
    + * declarations. Other minor problems may also crop up. All are easy
    + * to fix. Once you've done so, add the following to mark that you've
    + * done the clean-up:<pre>
    --- End diff --
    
    May be to create Jira to add this support?


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message