Mark put-clojure-indent safe for use in LocalVariables, .dir-locals.el, etc.

[rlbdv]

Add a put-clojure-indent form validator and attach it as a
safe-local-eval-function property so that safe invocations won't
trigger open-file prompts when used in local variables, or when added
to .dir-locals.el like this:

  ((clojure-mode
    (eval . (put-clojure-indent 'defrecord '(2 :form :form (1))))))

For now, only support specs specified as lists, not vectors.

---

This work assumes that we don't want to rely on any existing validation, and so attempts to perform thorough validation up front. Also happy to make further changes, but thought I'd post what I have, to see if I'm on a reasonable track.

[rlbdv]

I don't have access to circleci at the moment (wondering why their test results aren't public without a login), but since the test and test-checks targets work here, I wondered if it might be the test-bytecomp target. That one fails on the bare $ in the target rules, and if I do this:

--- a/Makefile
+++ b/Makefile
@@ -38,5 +38,5 @@ test-checks:
 test-bytecomp: $(SRCS:.el=.elc-test)

 %.elc-test: %.el elpa
-       $(CASK) exec $(EMACS) --no-site-file --no-site-lisp --batch \
-               -l test/clojure-mode-bytecomp-warnings.el $
+       $(CASK) exec $(EMACS) -L . --no-site-file --no-site-lisp --batch \
+               -l test/clojure-mode-bytecomp-warnings.el $<

It gets further, but fails like this:

In toplevel form:
clojure-mode.el:482:25:Error: reference to free variable `clojure--let-regexp'

After moving some functions around and removing the #s from (make-obsolete #'clojure-no-space-after-tag #'clojure-space-for-delimiter-p "5.12.0"), it gets further still, but then crashes because end-of-thing is undefined. I'm just guessing that might indicate a missing thingatpt dependency.

[rlbdv]

Not sure what's going on in CI with 25 and master, but I went ahead and fixed up everything that was causing trouble with Emacs 27 here.

[rlbdv]

i.e. I moved those declarations before their first use, and added the missing (require 'thingatpt), etc.

[bbatsov]

Your changes look good to me overall, but I won't be able to review them more carefully until next week. Sorry about the slow response.

[rlbdv]

No worries, and no rush -- if I get time, I might see what's up with emacs 25 and master later, either locally, or in a vm.

[rlbdv]

Fixed the issues. Emacs 25 doesn't have caddr (switched to nth which is likely more approachable anyway), and test-bytecomp wouldn't allow the existing clojure-align-separator docstring because it's longer than 80 characters.

[bbatsov]

Well done!