Anderson Lizardo’s Blog

Last night I tried enabling coverage in boomerang compilation. It seems it will not be as easy as I thought. Gcov is failing to find source files, although the .gcda and .gcno files are being generated and are on the correct location. Snippet from gcov error:

$ gcov c/ansi-c-parser.gcda -o c -b >/dev/null
ansi-c.y:cannot open source file
/usr/local/lib/bison.cc:cannot open source file
ansi-c-parser.cpp:cannot open source file


In this case the source file is in c/ansi-c-parser.cpp, but it insists on looking for it in the current directory. For this specific case, I figured out the errors are due to #line directives generated by bison++, but there are various errors like this. I’ll look into them at another time. Currently, I’m investigating unexpected errors reported by the functional testsuite (more on this later).

Last weekend I made my first code contribution to the Boomerang project: I fixed some tests from the testsuite that were segfaulting or failing due to changes in the debug output. After sending the patch to the mailing list, I was given write access to their CVS repository so I can now commit my fixes myself .

My plans for now are to:

1. do test coverage analysis on the current code using gcov/lcov
2. if coverage is not acceptable, add more tests to the testsuite
3. when coverage become acceptable (I still need to define the acceptance criterion), I can then starting making improvements or more complex changes to the code

Of course, before doing any big changes that would affect current functionality, I will submit a patch to the list, so other developers can comment on it. That’s the “Open Source way” of development IMHO.

I am about to graduate in Computer Science at Universidade Federal do Amazonas (UFAM), so I think I will now have more time to continue my personal research on some subjects I am interested in, but never found time to continue after I entered college.

One of these subjects is Reverse Engineering (RE). Before entering college, I played a little with RE and started a project on reverse engineering a driver for my scanner. It was quite challenging, and I liked it a lot, but never had time since then to either continue this project or start new ones.

Now it is time to change . During college I developed interest in Artificial Intelligence (IA) and ontologies. This (somehow ) led me to create interest in a research area known as “program comprehension” or “program understanding”. This is a research domain that, in my opinion, includes RE when it is applied to understanding how a system works. Therefore, my focus will be on applying RE techniques for program understanding.

As a first step, I started gathering some domain knowledge, but I would like to make something more pragmatic in parallel, so my studies could have a focus. I decided for now to work with the Boomerang decompiler and make some RE experiments with it. I chose it because It is, to my knowledge, the most advanced Open Source decompiler I am aware of, and decompilers can help understanding programs for which you don’t have sources. Of course, there are some other tools I would like to experiment with, such as Sparse.

I will probably make some kind of schedule so I don’t lose track during my research. More to follow!