Wednesday, January 25, 2012

Return on Investment

About a year ago, a friend and I were discussing the evolution of learning new tools while working under time constraints. He claimed that, regardless of the pressure, it is almost always better to sacrifice the upfront time in learning a new tool than to stay in your comfort zone to construct the illusion of progress. By illusion he simply meant that early stage progress is shadowed by the long-term effect of having to maintain and update a homegrown solution.

He used the following illustration to convey his point:

The effect is that if you choose to develop your own tools you satisfy the immediate gratification of results but the final solution is more likely to end up as a house of cards.

I had forgotten about this conversation until recently. The program I am currently working on had me in line to provide relevant results in a shortened amount of time. I am working with the llvm compiler infrastructure and it's unique assembly language. Part of what I needed to do is understand, at a high level, the contents of an llvm assembly file. My natural reaction to this was to implement some minimal parser in Ruby to get to a working set of results quickly. Things went well until I wanted to make a decent tool for broader use within the team: I was starting to spend more time on developing the Ruby code than making headway on my tasks. Not only did I dig myself a grave in that respect but since I was quick to satisyfy the initial demand for results I set an expectation that the work was less complicated than it truly is (and will continue to be). I was building a house of cards.

I ended up scrapping the Ruby implementation and I'm now happily coming up to speed on how to manage llvm code with, well, llvm tools. This is not without effect from the leads of the program, of course. Live and learn, I suppose.

Monday, January 16, 2012

Just making sure

I was pouring over some code recently and came across one expression that really made me shake my head:
buff[strlen(buff)] = 0;
I pretty sure the intent was
buff[strlen(buff) - 1] = 0;
Either that, or they really wanted to make sure the string was null-terminated.