Semantic patch inference

We propose a tool for inferring transformation specifications from a few examples of original and updated code. These transformation specifications may contain multiple code fragments from within a single function, all of which must be present for the transformation to apply. This makes the inferred transformations context sensitive. Our algorithm is based on depth-first search, with pruning. Because it is applied locally to a collection of functions that contain related changes, it is efficient in practice. We illustrate the approach on an example drawn from recent changes to the Linux kernel.