[jira] [Commented] (DRILL-5052) Option to debug generated Java code using an IDE

["Paul Rogers (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DRILL-5052?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15945835#comment-15945835 ] 

Paul Rogers commented on DRILL-5052:
------------------------------------

Development-only issue, no QA verification needed.

> Option to debug generated Java code using an IDE
> ------------------------------------------------
>
>                 Key: DRILL-5052
>                 URL: https://issues.apache.org/jira/browse/DRILL-5052
>             Project: Apache Drill
>          Issue Type: Improvement
>          Components: Execution - Codegen
>    Affects Versions: 1.8.0
>            Reporter: Paul Rogers
>            Assignee: Paul Rogers
>            Priority: Minor
>              Labels: ready-to-commit
>             Fix For: 1.10.0
>
>
> Drill makes extensive use of Java code generation to implement its operators. Drill uses sophisticated techniques to blend generated code with pre-compiled template code. An unfortunate side-effect of this behavior is that it is very difficult to visualize and debug the generated code.
> As it turns out, Drill's code-merge facility is, in essence, a do-it-yourself version of subclassing. The Drill "template" is the parent class, the generated code is the subclass. But, rather than using plain-old subclassing, Drill combines the code from the two classes into a single "artificial" packet of byte codes for which no source exists.
> Modify the code generation path to optionally allow "plain-old Java" compilation: the generated code is a subclass of the template. Compile the generated code as a plain-old Java class with no byte-code fix-up. Write the code to a known location that the IDE can search when looking for source files.
> With this change, developers can turn on the above feature, set a breakpoint in a template, then step directly into the generated Java code called from the template.
> This feature should be an option, enabled by developers when needed. The existing byte-code technique should be used for production code generation.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)