Listed below are three statements. Based on my nearly thirty years in the embedded space I can confidently state that: One I have never heard stated. Another I have rarely heard stated, and the third I hear a lot. Here they are in order:
- I write crap code.
- You know so-and-so. (S)he writes really good code.
- This code is complete crap.
If your experience comports with mine, then it leads to what I have coined the ‘crap code conundrum’. In short, crap code is everywhere – but no one admits to or realizes they are writing it! So how can this be? Well I see several possibilities:
- In fact a lot of so called crap code is labeled as such because the author did things differently to the way the reader would have done it. I think it’s important to recognize this before summarily dismissing some code. Notwithstanding this, I all too often find myself saying ‘this code is complete crap’ – because it is!
- This is related to point 1, and essentially comes down to different people have different ideas about what constitutes good code. For example I think wrapping code in complex macros is an invitation for disaster. Others see it as a perfectly good way of simplifying things. (I’m right )
- The code started out being pretty good and has degenerated over time because the author hasn’t been allowed the time to perform the necessary refactoring. I think this does explain a lot of the bad code I see.
- The folks that write crap code are completely oblivious to the fact they are doing it. Indeed it’s only the self aware / self critical types that would even bother to ask themselves the question ‘is my code any good?’ Indeed, the first step to improving ones code is to ask oneself the question – how can I improve my code?
My gut feel is that point 4 is most likely the main cause. Now if you are so self-absorbed that you wouldn’t even dream to ask yourself the question ‘do I write crap code?’, then I seriously doubt whether you’d be reading this article. However if you have crossed this hurdle, then how can you determine if the code you are writing is any good? Well I took a stab at this a while back with this article . However some of the commenters pointed out that it’s quite easy to write code that has good metrics – yet is still complete crap. So clearly the code metrics approach is part of the story – but not the entire story.
So a couple of weeks ago I found myself in a bar in San Francisco having a beer with Michael Barr and a very smart guy Steve Loudon. The topic of crap code came up and I posed the question ‘how can you tell code is crap?’ After all I think that crap code is a bit like pornography – you know it when you see it. After a spirited debate, the most pithy statement we could come up with is this:
If it’s hard to maintain, it’s crap.
Clearly there are all sorts of exceptions and qualifications, but at the end of the day I think this statement pretty much says it all. Thus if you are wondering if you write crap code, just ask yourself the question – how hard is this code to maintain? If you don’t like the answer, then it’s time to make a change.