Teaching Python Informally to Kids

For the last few months I’ve been running a “coding club” for my son’s sixth-grade class. Once a week, the interested students (about 2/3 of the class) stick around for an hour after school and I help them learn to program. The structure is basically like the lab part of a programming class, without the …

A Tourist’s Guide to the LLVM Source Code

In my Advanced Compilers course last fall we spent some time poking around in the LLVM source tree. A million lines of C++ is pretty daunting but I found this to be an interesting exercise and at least some of the students agreed, so I thought I’d try to write up something similar. We’ll be …

Undefined Behavior: Not Just for Programming Languages

This is an oldie but goodie. Start with this premise: a = b Multiply both sides by a: a2 = ab Subtract b2 from both sides: a2 – b2 = ab – b2 Factor the left side: (a + b)(a – b) = ab – b2 Factor the right side: (a + b)(a – b) …

Vigorous Public Debates in Academic Computer Science

The other day a non-CS friend remarked to me that since computer science is a quantitative, technical discipline, most issues probably have an obvious objective truth. Of course this is not at all the case, and it is not uncommon to find major disagreements even when all parties are apparently reasonable and acting in good …

Advanced Compilers Weeks 3-5

This continues a previous post. We went through the lattice theory and introduction to dataflow analysis parts of SPA. I consider this extremely good and important material, but I’m afraid that the students looked pretty bored. It may be the case that this material is best approached by first looking at practical aspects and only …

Too Much Milk: The Secret Origin Story

When I first taught operating systems 12 years ago, I based my teaching materials on a set of slides inherited from John Carter, the previous instructor at Utah. I was generally happy with these slides, and I’ve continued to evolve them since then, but one thing I was always curious about was the “too much …

Heartbleed and Static Analysis

Today in my Writing Solid Code class we went through some of the 151 defects that Coverity Scan reports for OpenSSL. I can’t link to these results but take my word for it that they are a pleasure to read — the interface clearly explains each flaw and the reasoning that leads up to it, …