As far as I'm concerned, as a Lisp programmer, code is data. :) Yes, and what exactly constitutes "dead code"? Tree shakers rely on heuristics that can fail in

As far as I'm concerned, as a Lisp programmer, code is data. :) Yes, and what exactly constitutes "dead code"? Tree shakers rely on heuristics that can fail in practice. There is provably no way to remove functions from a Lisp image and guarantee your application to work. LispWorks has a "tree shaker", but has umpteen options to tame it so your application doesn't inadvertently break. Fortunately, it is possible to remove these functions if you, an application developer, so please. Nothing stops you. It's not even difficult. But SBCL has not implemented these (potentially fallible) heuristics for you, because (and only because) an insignificant number of users would find shaving a little binary size off to be valuable at the expense of program correctness.