Frama-C Just a quick update to provide context for the previous post. The previous post assumes the reader is familiar with the notion of undefined behavior and how C compilers have started to justify their more aggressive optimizations along the lines of “this program has always been undefined”. Long ago, a...
Read MoreThe restrict keyword in C99 C99 introduced a restrict keyword. The intention is to let the programmer specify the absence of alias between some inputs of a function ey is writing. Consider the function: int f1(int * restrict p int * restrict q) { *p = 1; *q = 2;...
Read MoreA contest and a self-pitying lament John Regehr was organizing a craziest undefined behavior contest and the results are in. I had an entry in the contest but I did not win. My entry apparently was too obviously dangerous. As John puts it “I would have expected a modern C...
Read MoreThis blog post is on the subject of “code smells” and what is wrong with them. I initially wanted to go with the title “Code smells are crap”. That made it clearer that the title was grammatically a sentence, with “code smells” a nominal group followed by a verb. But...
Read MoreMark Shroyer has discovered an interesting consequence of undefined behavior in the compiled version of a C program: a variable behaves as both true and false as a result of being uninitialized. The post is great and could not come at a better time. I needed for the talk I...
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