Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> This makes it challenging to wrap things like `define-minor-mode' into a new
>> macro, and autoload the resulting forms.  This small patch adds a new
>> variant of the autoload cookie:
>>
>> ;;;autoload-expand
>> (my-autoloadable-macro-to-expand ...)
>
> I suspect this will often fail to work because autoloads are often
> generated by a fresh new session where `my-autoloadable-macro-to-expand`
> will not yet be defined.

Good point.  That chicken-and-egg problem was definitely in the back of
my mind, and is why I didn't attempt to create an expandable list to
replace the list of hard-coded special macros.

> I've been wanting to add the feature you propose, but this "macro is not
> defined" has gotten in the way until now.  I think we need to add
> something like a file-local `autoload-requires-for-macros`.

How about this solution?  If the car of the following form is not a
macro (and not a function), attempt to load the file itself (temporarily
expanding `load-path' to include the file's containing directory).  If
that fails to define the macro, warn the user, and simply proceed
without expansion.