Re: Recognizing obsolete external package versions

[Glenn Morris <rgm@gnu.org>]

Richard Stallman wrote:

> That code seems basically right except that I would rather it avoid
> calling eval. It should give the name of a variable, and the values
> that are bad.

I don't see the problem with eval, given that we write the code that
gets evalled, and this feature would not be for external use. If you
are worried about malicious code in the filed being loaded, well, it's
already been loaded at this point, so if it wanted to do anything
nasty it could have done so directly without needing to go through
this mechanism. No different to any other external package.

> I think it would be better to check at the beginning of loading the
> file rather than at the end. That is possible by searching for
> "(defvar VARIABLE", evaluating the sexp that comes next, and looking
> at its value.

Oof. This seems like overkill, as has been said.

> That would require detecting the file by its name rather than by
> a feature it provides.

eval-after-load can work with file names as well; so the mechanism I
proposed can already work with either features or filenames. But it is
_after_ load, of course.