As an ArgoUML contributor I'm going to blog my activities here, so that they may draw interest by other developers or help other developers when doing tasks similar to what I've done. AND(!) the grand vision that makes an Argonaut what he is, TO THRIVE IN THE BIG DANGEROUS WORLD, TAKING THE Argo TO A GOOD SHORE ;-))

Wednesday, January 26, 2005

C++ reveng - Exploring and analyzing the possible solutions

"do not reinvent the wheel" – this is one of the strongest rules of Software Engineering! Following the rule, I must select the first option to move the work forward more effectively. The next step is to look at the already existing implementations and start from there.

These are:

  • The java programming language reverse engineering implementation, made in the context of the main Argo's project – argouml/src_new/org/argouml/uml/reveng/java.
  • The classfiles and JAR file import reverse engineering implementation, which exists as an Argo's module argouml/modules/java_rte.

Exploring and analyzing the possible solutions

The cookbook is very scarce about how to implement reverse engineering for ArgoUML. The only statement is that the reverse engineering is located in org.argouml.uml.reveng. From a simple analysis in the java reveng implementation (in, it seams you must implement the org.argouml.application.api.PluggableImport interface. ArgoUML reveng provides the FileImportSupport class to be used as a base for languages based on source code stored in files. For java the class is JavaImport. The parsing is done by ANTLR generated classes (JavaLexer, JavaTokenTypes and JavaRecognizer), being the model populated by the Modeller.

Class diagram of ArgoUML's class hierarchy for reverse engineering.

Picture 1 – Class diagram of ArgoUML's class hierarchy for reverse engineering.

After all argouml/modules/java_rte wasn't the other module where reveng was available [check my extended note on this]! The Classfile module (argouml/modules/classfile) was the one, with the class org.argouml.uml.reveng.classfile.ClassfileImport being an implementation of PluggableImport. Since the classfile import supports java reverse engineering also, the Modeller from java source files reveng is reused in this module.

One thing that I still don't know well about the rev eng modules is the generation of the parser classes from the ANTLR grammar. I must check how those classes are being generated, which files are used and if the ANTLR version contained in the ArgoUML CVS contains a grammar for C++.

The main Ant target for generating code is generateparser. It uses two sub-targets, that actually do the work, one – generateparser1 – for generating parser classes for rev eng and another – generateparser2 for generating parser classes for the generator. The actual Ant tasks are the execution of antlr.Tool class with the command line syntax:

java antlr.Tool -o <output_path> <grammar>

Java generator and reveng ANTLR parser classes generation from grammar

Picture 2 – Java generator and reveng ANTLR parser classes generation from grammar.

The ANTLR C++ grammar doesn't exist in the CVS source and the one that exists in the ANTLR site is for integration in C++ programs... I have to look deeper on this... Maybe I'll have to port the grammar to java.

ArgoUML shared models

Interesting... I'm working in a modeling tool, but, to make the analysis of the possible solution I started from the correct place, re-checking if the above shown implementations were really the only existing "official or open sourced" implementations of reverse engineering for the ArgoUML project. So I looked for the sources in Eclipse...

I already had sure that Java reveng is supported. It lives within the Argo project. Java classfile reveng I had sure, but, not about the java_rte module, that has only the package which isn't certainly for reveng, but, for something UI related. So I looked for alternative modules and the most obvious was classfile.

This analysis went from the top of the module's package to the implementation. I had to make several mouse clicks and only at the end – specific implementation package – I selected the correct class. If I had a proper modeling tool and a proper Argo's project model, I should have gone there and read the module description (which would be accessible from the modules diagram) instead of going to the Argo's project in my IDE. So, is there some Argo project model, kept uptodate as the cookbook so that interested contributors could look for software engineering information?

I looked for one and... Nothing in the cookbook, nothing in the developer's zone, and nothing in the developer's list. No shareable and reused model or group of models' of the ArgoUML modeling tool, officially maintained by the project members and existing in the CVS!!! This should be fix and ASAP! So I sent a proposal to the dev list.

(...) Some time went by and I didn't received any answer. I tried with 0.17.2 version, saving the file in text format, but, for a partial rev eng of Argo, the file was about 8 MB! Sure thing this isn't usable for sharing files in CVS... The only way is to have several models, based in the compressed format for each specific section. I'm going to take the lead by adding a development model for the C++ module in the argouml/modules/cpp/doc directory.

1 comment:

stev4n said...

I work in reverse engineering myself, and l like what you have to say.

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