29
Jan 09

Semantic Rewriting of Code with Pork – A bitter recap

LWN published an article about a tool that does refactoring of C code. Guess what, it’s yet another tool on top of a crappy C-parser that will never grok C well or even hope to support C++. To my great disappointment the author was not aware of my work on Pork. Clearly I have failed in letting people know that complex C and C++ can be refactored with (somewhat raw, but powerful) open source tools.

In addition to Dehydra (which is even mentioned in the first comment, yay!), I also maintain Pork – a fork of oink that is well suited to large-scale refactoring of real-world C/C++ code.

So far pork has been used for “minor” things like renaming classes&functions, rotating outparameters and correcting prbool bugs. Additionally, Pork proved itself in an experiment which involved rewriting almost every function(ie generating a 3+MB patch) in Mozilla to use garbage collection instead of reference-counting.

So to summarize:

  • Refactoring C is hard, but C++ is much harder
  • For refactoring C++ there is no better toolchain to start with than Pork
  • Pork shares no code with Dehydra.
  • Pork is built on the Elsa parser which makes it well-suited for rewriting large amounts of code. Dehydra’s isn’t suitable for rewriting code due to GCC providing a very lossy AST and incomplete location information.
  • Pork is not as convenient for analysis needs as Dehydra

For any questions regarding Pork feel free to post on the mailing list or ping me on IRC.

Language Wars

I find it depressing that the comments to the LWN article ended up being about language wars rather than the refactoring topic. Pork is written in C++ which is much more widely known than OCaml. However, I seriously doubt it’s easier for anyone to hack on advanced compiler frontend pieces in a language as ill-suited for the task as C++.


27
Jan 09

GCC Plugins are a Go!

The nice folks at FSF allowed GCC have plugins. In a couple of GCC releases, Dehydra(4.5 if we are lucky) will work with distribution GCCs. Of course the API is yet to be decided on, but we have been coordinating with authors of other GCC plugin efforts to ensure that the final API meets reasonable needs.

In the future enabling static analysis checks will involve little more than specifying –with-static-checking in your Mozilla build!

JSHydra

The other breakthrough news is that Joshua Cranmer has been working on hooking up a *hydra style API to the Spidermonkey parser. This resulted in JSHydra. Ability to look into JavaScript has been sorely missing from our stack, so this is extremely exciting.


13
Jan 09

Seven Things You May Not Know About Me

I got tagged by Benjamin, so I better comply and get my blog memed.

Rules

  1. Link back to your original tagger and list the rules in your post.
  2. Share seven facts about yourself.
  3. Tag some (seven?) people by leaving names and links to their blogs.
  4. Let them know they’ve been tagged.

Seven Things

  1. In Soviet Ukraine, kindergarten failed me (luckily they don’t make you retake that). Apparently when I was six, my handwriting and reading skills were not up to the communist standards of time. I still fondly remember excepts of various communist hymns we got to sing along.
  2. Grade 1 coincided with the fall of communism and me getting the most kickass grades of my academic career.
  3. I have owned two cars, but I have since traded that lifestyle for a garage full of bikes. I never liked the effects that driving had on my health nor the effect that crappy German engineering had on my savings.
  4. I met my wife on my first midnight mystery ride. Riding at midnight is awesome because that’s the only time that traffic dies down enough that one sees nothing but fellow bikers and drunk pedestrians.
  5. To buy groceries I ride a comical contraption called an adult tricycle. We even worked the trike into our wedding.
  6. I never had a real job. For some reason all of the Burger Kings and Subways that I applied at never took an interest in me. Instead, in grade 8 my first source of income was teaching Java to someone 2.5x my age for $3 an hour. From then on I bounced around various part-time jobs and internships until I ended up at Mozilla, my first real job.

  7. For a something like six years I wore long hair to go along with my taste for Metal. I’m always looking for more awesome metal music, currently in heavy rotation are Testament, Winds of Plague, Dying Fetus and Opeth. If you think there is an awesome metal band I might be missing out on, let me know.

Tags

Damon Sicore – There are seven random things I need to know about my boss.

Joshua Cranmer – lets hear seven things about you without mentioning dem0rkification.

Chris Double – I hope to hear seven reasons for one to program in Reverse Polish Notation

Graydon Hoare –  because his blog hasn’t been memed. It’s also getting a bit dated