Difficult: most C programs I know would convert to one single large "unsafe" block... One might argue that re-writing from scratch is the safer option; and a r

Difficult: most C programs I know would convert to one single large "unsafe" block... One might argue that re-writing from scratch is the safer option; and a re-write is also an opportunity to do things differently (read: improve the architecture by using what one has learned), despite the much-feared "second system" syndrome. But nothing wrong with spending some research dollars towards tooling for "assisted legacy rewrites". DARPA and her sister IARPA fund step innovation (high risk, high reward), and this is an area where good things can come potentially come from.